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ENGINEERING (1248 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 8)
3D Research     Hybrid Journal   (Followers: 20)
AAPG Bulletin     Hybrid Journal   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 14)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 275)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 3)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 7)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 5)
Advanced Science Letters     Full-text available via subscription   (Followers: 10)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 13)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 29)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 44)
Advances in Science and Research (ASR)     Open Access   (Followers: 5)
Aerobiologia     Hybrid Journal   (Followers: 3)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 6)
AIChE Journal     Hybrid Journal   (Followers: 35)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access   (Followers: 1)
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 26)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 10)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 4)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Antarctic Science     Hybrid Journal   (Followers: 1)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 18)
Applied Clay Science     Hybrid Journal   (Followers: 6)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 11)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 3)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 5)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 6)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 26)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Motor Trade Survey     Full-text available via subscription  
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Beyond : Undergraduate Research Journal     Open Access  
Bhakti Persada : Jurnal Aplikasi IPTEKS     Open Access  
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 10)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 21)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 37)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 13)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 14)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 31)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 42)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Thermal Engineering     Open Access   (Followers: 5)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal  
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 3)
CienciaUAT     Open Access   (Followers: 1)
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 13)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 1)
Clinical Science     Full-text available via subscription   (Followers: 9)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 6)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 2)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 28)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Composite Structures     Hybrid Journal   (Followers: 276)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 212)
Composites Part B : Engineering     Hybrid Journal   (Followers: 247)
Composites Science and Technology     Hybrid Journal   (Followers: 187)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computers & Geosciences     Hybrid Journal   (Followers: 31)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 8)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 5)
Computers and Geotechnics     Hybrid Journal   (Followers: 11)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 33)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 9)
Control Engineering Practice     Hybrid Journal   (Followers: 43)

        1 2 3 4 5 6 7 | Last

Journal Cover Applied Sciences
  [SJR: 0.178]   [H-I: 9]   [3 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Online) 2076-3417
   Published by MDPI Homepage  [202 journals]
  • Applied Sciences, Vol. 8, Pages 654: Deep Neural Networks for Document
           Processing of Music Score Images

    • Authors: Jorge Calvo-Zaragoza, Francisco J. Castellanos, Gabriel Vigliensoni, Ichiro Fujinaga
      First page: 654
      Abstract: There is an increasing interest in the automatic digitization of medieval music documents. Despite efforts in this field, the detection of the different layers of information on these documents still poses difficulties. The use of Deep Neural Networks techniques has reported outstanding results in many areas related to computer vision. Consequently, in this paper, we study the so-called Convolutional Neural Networks (CNN) for performing the automatic document processing of music score images. This process is focused on layering the image into its constituent parts (namely, background, staff lines, music notes, and text) by training a classifier with examples of these parts. A comprehensive experimentation in terms of the configuration of the networks was carried out, which illustrates interesting results as regards to both the efficiency and effectiveness of these models. In addition, a cross-manuscript adaptation experiment was presented in which the networks are evaluated on a different manuscript from the one they were trained. The results suggest that the CNN is capable of adapting its knowledge, and so starting from a pre-trained CNN reduces (or eliminates) the need for new labeled data.
      Citation: Applied Sciences
      PubDate: 2018-04-24
      DOI: 10.3390/app8050654
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 655: Photovoltaic Cell and Module I-V
           Characteristic Approximation Using Bézier Curves

    • Authors: Roland Szabo, Aurel Gontean
      First page: 655
      Abstract: The aim of this work was to introduce new ways to model the I-V characteristic of a photovoltaic (PV) cell or PV module using straight lines and Bézier curves. This is a complete novel approach, Bézier curves being previously used mainly for computer graphics. The I-V characteristic is divided into three sections, modeled with lines and a quadratic Bézier curve in the first case and with three cubic Bézier curves in the second case. The result proves to be accurate and relies on the fundamental points usually present in the PV cell datasheets: V o c (the open circuit voltage), I s c (the short circuit current), V m p (the maximum power corresponding voltage) and I m p (the maximum power corresponding current), and the parasitic resistances R s h 0 (shunt resistance at I s c ) and R s 0 (series resistance at V o c ). The proposed algorithm completely defines all the implied control points and the error is analyzed. The temperature and irradiance influence is also analyzed. The model is also compared using the least squares fitting method. The final validation shows how to use Bézier cubic curves to accurately represent the I-V curves of an extensive range of PV cells and arrays.
      Citation: Applied Sciences
      PubDate: 2018-04-24
      DOI: 10.3390/app8050655
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 656: Analytical Point-Cloud Based
           Geometric Modeling for Additive Manufacturing and Its Application to
           Cultural Heritage Preservation

    • Authors: Tashi, AMM Sharif Ullah, Michiko Watanabe, Akihiko Kubo
      First page: 656
      Abstract: Point-cloud is a valuable piece of information for geometric modeling and additive manufacturing of different types of objects. In most cases, a point-cloud is obtained by using the 3D scanners or by using image processing. Alternatively, one can rely on an analytical approach for creating the required point-cloud. In this study, we develop an analytical method that uses both equation and algorithm-based approaches for creating a point-cloud for modeling a given object (or shape). The analytically created point-cloud can then be processed by using a commercially available CAD package to create a virtual model (or solid CAD model) of the object. Finally, the virtual model can be used to create a physical model (or replica) of the underlying object using a commercially available additive manufacturing device (e.g., a 3D printer). The abovementioned procedure of analytical point-cloud based geometric modeling for additive manufacturing can be applied to preserve artifacts having cultural significance. In particular, we consider the Ainu motifs that represent the cultural heritage of Ainus living in the northern part of Japan (Hokkaido). We first classify the motifs and then model them in the form of a point-clouds using both equations and a recursive process (algorithm) proposed in this study. Finally, we create the CAD model and physical models of the artifacts having Ainu motifs on them. This way, we show the effectiveness of the analytical point-cloud based geometric modeling for additive manufacturing.
      Citation: Applied Sciences
      PubDate: 2018-04-24
      DOI: 10.3390/app8050656
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 657: One Layer Nonlinear Economic
           Closed-Loop Generalized Predictive Control for a Wastewater Treatment

    • Authors: Hicham El bahja, Pastora Vega, Silvana Revollar, Mario Francisco
      First page: 657
      Abstract: The main scope of this paper is the proposal of a new single layer Nonlinear Economic Closed-Loop Generalized Predictive Control (NECLGPC) as an efficient advanced control technique for improving economics in the operation of nonlinear plants. Instead of the classic dual-mode MPC (model predictive controller) schemes, where the terminal control law defined in the terminal region is obtained offline solving a linear quadratic regulator problem, here the terminal control law in the NECLGPC is determined online by an unconstrained Nonlinear Generalized Predictive Control (NGPC). In order to make the optimization problem more tractable two considerations have been made in the present work. Firstly, the prediction model consisting of a nonlinear phenomenological model of the plant is expressed with linear structure and state dependent matrices. Secondly, instead of including the nonlinear economic cost in the objective function, an approximation of the reduced gradient of the economic function is used. These assumptions allow us to design an economic unconstrained nonlinear GPC analytically and to state the NECLGPC allow for the design of an economic problem as a QP (Quadratic Programing) problem each sampling time. Four controllers based on GPC that differ in designs and structures are compared with the proposed control technique in terms of process performance and energy costs. Particularly, the methodology is implemented in the N-Removal process of a Wastewater Treatment Plant (WWTP) and the results prove the efficiency of the method and that it can be used profitably in practical cases.
      Citation: Applied Sciences
      PubDate: 2018-04-24
      DOI: 10.3390/app8050657
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 658: Investigation into the Effects of the
           Variable Displacement Mechanism on Swash Plate Oscillation in High-Speed
           Piston Pumps

    • Authors: Xu Fang, Xiaoping Ouyang, Huayong Yang
      First page: 658
      Abstract: High-speed, pressure-compensated variable displacement piston pumps are widely used in aircraft hydraulic systems for their high power density. The swash plate is controlled by the pressure-compensated valve, which uses pressure feedback so that the instantaneous output flow of the pump is exactly enough to maintain a presetting pressure. The oscillation of the swash plate is one of the major excitation sources in the high-speed piston pump, which may cause lower efficiency, shorter service life, and even serious damage. This paper presents an improved model to investigate the influence of the variable displacement mechanism on the swash plate oscillation and introduces some feasible ways to reduce oscillation of the swash plate. Most of the variable structural parameters of the variable displacement mechanism are taken into consideration, and their influences on swash plate oscillation are discussed in detail. The influence of the load pipe on the oscillation of the swash plate is considered in the improved model. A test rig is built and similarities between the experiments and simulated results prove that the simulation model can effectively predict the variable displacement mechanism state. The simulation results show that increasing the volume of the outlet chamber, the spring stiffness of the control valve, the action area of the actuator piston, and offset distance of the actuator piston can significantly reduce the oscillation amplitude of the swash plate. Furthermore, reducing the diameter of the control valve spool and the dead volume of the actuator piston chamber can also have a positive effect on oscillation amplitude reduction.
      Citation: Applied Sciences
      PubDate: 2018-04-24
      DOI: 10.3390/app8050658
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 659: Overview of Lithium-Ion Battery
           Modeling Methods for State-of-Charge Estimation in Electrical Vehicles

    • Authors: Jinhao Meng, Guangzhao Luo, Mattia Ricco, Maciej Swierczynski, Daniel-Ioan Stroe, Remus Teodorescu
      First page: 659
      Abstract: As a critical indictor in the Battery Management System (BMS), State of Charge (SOC) is closely related to the reliable and safe operation of lithium-ion (Li-ion) batteries. Model-based methods are an effective solution for accurate and robust SOC estimation, the performance of which heavily relies on the battery model. This paper mainly focuses on battery modeling methods, which have the potential to be used in a model-based SOC estimation structure. Battery modeling methods are classified into four categories on the basis of their theoretical foundations, and their expressions and features are detailed. Furthermore, the four battery modeling methods are compared in terms of their pros and cons. Future research directions are also presented. In addition, after optimizing the parameters of the battery models by a Genetic Algorithm (GA), four typical battery models including a combined model, two RC Equivalent Circuit Model (ECM), a Single Particle Model (SPM), and a Support Vector Machine (SVM) battery model are compared in terms of their accuracy and execution time.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050659
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 660: Quantitative Analysis of Patellar
           Tendon Abnormality in Asymptomatic Professional “Pallapugno” Players:
           A Texture-Based Ultrasound Approach

    • Authors: Kristen M. Meiburger, Massimo Salvi, Maurizio Giacchino, U. Rajendra Acharya, Marco A. Minetto, Cristina Caresio, Filippo Molinari
      First page: 660
      Abstract: Abnormalities in B-mode ultrasound images of the patellar tendon often take place in asymptomatic athletes but it is still not clear if these modifications forego or can predict the development of tendinopathy. Subclinical tendinopathy can be arbitrarily defined as either (1) the presence of light structural changes in B-mode ultrasound images in association with mild neovascularization (determined with Power Doppler images) or (2) the presence of moderate/severe structural changes with or without neovascularization. Up to now, the structural changes and neovascularization of the tendon are evaluated qualitatively by visual inspection of ultrasound images. The aim of this study is to investigate the capability of a quantitative texture-based approach to determine tendon abnormality of “pallapugno” players. B-mode ultrasound images of the patellar tendon were acquired in 14 players and quantitative texture parameters were calculated within a Region of Interest (ROI) of both the non-dominant and the dominant tendon. A total of 90 features were calculated for each ROI, including 6 first-order descriptors, 24 Haralick features, and 60 higher-order spectra and entropy features. These features on the dominant and non-dominant side were used to perform a multivariate linear regression analysis (MANOVA) and our results show that the descriptors can be effectively used to determine tendon abnormality and, more importantly, the occurrence of subclinical tendinopathy.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050660
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 661: Feasibility of LED-Assisted CMOS
           Camera: Contrast Estimation for Laser Tattoo Treatment

    • Authors: Ngot Thi Pham, Woosub Song, Hyejin Kim, Jae Hyun Jung, Suhyun Park, Hyun Wook Kang
      First page: 661
      Abstract: Understanding the residual tattoo ink in skin after laser treatment is often critical for achieving good clinical outcomes. The current study aims to investigate the feasibility of a light-emitting diode (LED)-assisted CMOS camera to estimate the relative variations in tattoo contrast after the laser treatment. Asian mice were tattooed using two color inks (black and red). The LED illumination was a separate process from the laser tattoo treatment. Images of the ink tattoos in skin were acquired under the irradiation of three different LED colors (red, green, and blue) for pre- and post-treatment. The degree of contrast variation due to the treatment was calculated and compared with the residual tattoo distribution in the skin. The black tattoo demonstrated that the contrast consistently decreased after the laser treatment for all LED colors. However, the red tattoo showed that the red LED yielded an insignificant contrast whereas the green and blue LEDs induced a 30% (p < 0.001) and 26% (p < 0.01) contrast reduction between the treatment conditions, respectively. The proposed LED-assisted CMOS camera can estimate the relative variations in the image contrast before and after the laser tattoo treatment.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050661
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 662: Iterative 2D Tissue Motion Tracking
           in Ultrafast Ultrasound Imaging

    • Authors: John Albinsson, Hideyuki Hasegawa, Hiroki Takahashi, Enrico Boni, Alessandro Ramalli, Åsa Rydén Ahlgren, Magnus Cinthio
      First page: 662
      Abstract: In order to study longitudinal movement and intramural shearing of the arterial wall with a Lagrangian viewpoint using ultrafast ultrasound imaging, a new tracking scheme is required. We propose the use of an iterative tracking scheme based on temporary down-sampling of the frame-rate, anteroposterior tracking, and unbiased block-matching using two kernels per position estimate. The tracking scheme was evaluated on phantom B-mode cine loops and considered both velocity and displacement for a range of down-sampling factors (k = 1–128) at the start of the iterations. The cine loops had a frame rate of 1300–1500 Hz and were beamformed using delay-and-sum. The evaluation on phantom showed that both the mean estimation errors and the standard deviations decreased with an increasing initial down-sampling factor, while they increased with an increased velocity or larger pitch. A limited in vivo study shows that the major pattern of movement corresponds well with state-of-the-art low frame rate motion estimates, indicating that the proposed tracking scheme could enable the study of longitudinal movement of the intima–media complex using ultrafast ultrasound imaging, and is one step towards estimating the propagation velocity of the longitudinal movement of the arterial wall.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050662
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 663: Investigation on a Sensitive
           Chemiluminescence System Based on Ni(IV) Complex to Determine Two
           β2-Agonist Drugs in Urine and Swine Feed and Their Mechanism

    • Authors: Xiao Dong, Yajie Diao, Xinghua Li, Tingting Dai, Hongmei Shi, Shan Li
      First page: 663
      Abstract: Veterinary drug residues, particularly traces of β2-agonists, can cause various kinds of harmful impact to the environment and public health. Here, a sensitive chemiluminescence (CL) method incorporated with a flow injection analysis is developed for the determination of two β2-agonists [i.e., salbutamol (SAL) and terbutaline (TEB)]. The system is based on the CL reaction of Ni(IV) complex with luminol in alkaline solutions, whereas SAL and TEB can significantly enhance CL intensities. Under optimum conditions, CL intensities are proportional to the SAL and TEB concentration in the range of 1.0 × 10−9 M to 5.0 × 10−7 M and 1.0 × 10−9 M to 1.0 × 10−7 M, respectively. The limits of detection (3σ) are 1.0 × 10−11 M for TEB, and 1.3 × 10−11 for SAL respectively. Relative standard deviations (n = 11) are less than 2% for 5.0 × 10−8 M SAL and TEB. Possible reaction mechanisms for the CL system are suggested based on the CL system spectra, Ni(IV) complex oxidation characteristics, and electron spin resonance (ESR) techniques. The proposed method has been applied to the analysis of urine and swine feed samples with satisfactory results.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050663
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 664: DF Relayed Subcarrier FSO Links over
           Malaga Turbulence Channels with Phase Noise and Non-Zero Boresight
           Pointing Errors

    • Authors: George K. Varotsos, Hector E. Nistazakis, Wilfried Gappmair, Harilaos G. Sandalidis, George S. Tombras
      First page: 664
      Abstract: Subcarrier free-space optical (FSO) systems using coherent recovery techniques at the receiver have acquired growing research interest in recent times. However, their optimal performance is diminished by the non-perfect synchronization of carrier frequency and phase, which is mainly due to phase noise problems. Moreover, turbulence and pointing error effects further deteriorate the overall performance. However, relay transmission schemes can extend the coverage distance and offer substantial improvements over fading conditions. In this respect, we consider a serially relayed network using decode-and-forward relays, and investigate its performance by means of average symbol error probability and mean outage duration. Turbulence is modeled by the recently unified M(alaga) distribution, which constitutes a very general statistical model that accurately describes the irradiance fluctuations from weak-to-strong turbulence conditions. Additionally, the presence of non-zero boresight pointing errors due to misalignment between the transmitter–receiver pair is considered, while the effect of phase noise is specified by a Tikhonov distribution. A comparison between single line-of-sight and serially relayed FSO configurations is provided as well. Novel approximated mathematical expressions are deduced, which are proved to be accurate enough over a wide range of turbulence strengths and signal-to-noise values. Finally, proper numerical results are presented and validated by Monte Carlo simulations.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050664
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 665: Propagation Characteristics of
           High-Power Vortex Laguerre-Gaussian Laser Beams in Plasma

    • Authors: Zhili Lin, Xudong Chen, Weibin Qiu, Jixiong Pu
      First page: 665
      Abstract: The propagation characteristics of high-power laser beams in plasma is an important research topic and has many potential applications in fields such as laser machining, laser-driven accelerators and laser-driven inertial confined fusion. The dynamic evolution of high-power Laguerre-Gaussian (LG) beams in plasma is numerically investigated by using the finite-difference time-domain (FDTD) method based on the nonlinear Drude model, with both plasma frequency and collision frequency modulated by the light intensity of laser beam. The numerical algorithms and implementation techniques of FDTD method are presented for numerically simulating the nonlinear permittivity model of plasma and generating the LG beams with predefined parameters. The simulation results show that the plasma has different field modulation effects on the two exemplified LG beams with different cross-sectional patterns. The self-focusing and stochastic absorption phenomena of high-power laser beam in plasma are also demonstrated. This research also provides a new means for the field modulation of laser beams by plasma.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050665
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 666: Optimization of Two-Level
           Disassembly/Remanufacturing/Assembly System with an Integrated Maintenance

    • Authors: Zouhour Guiras, Sadok Turki, Nidhal Rezg, Alexandre Dolgui
      First page: 666
      Abstract: With an increase of environmental pressure on economic activities, reverse flow is increasingly important. It seeks to save resources, eliminate waste, and improve productivity. This paper investigates the optimization of the disassembly, remanufacturing and assembly system, taking into account assembly-disassembly system degradation. An analytical model is developed to consider disassembly, remanufacturing of used/end-of-life product and assembly of the finished product. The finished product is composed of remanufactured and new components. A maintenance policy is sequentially integrated to reduce the system unavailability. The aim of this study is to help decision-makers, under certain conditions, choose the most cost-effective process for them to satisfy the customer as well as to adapt to the potential risk that can perturb the disassembly-assembly system. A heuristic is developed to determine the optimal ordered date of the used end-of-life product as well as the optimum release dates of new external components. The results reveal that considering some remanufacturing and purchase components costs, the proposed model is more economical in comparison with a model without remanufactured parts. Numerical results are provided to illustrate the impact of the variation of the ordering cost and quality of the used end-of-life product on the system profitability. Finally, the risk due to system repair periods is discussed, which has an impact on managerial decision-making.
      Citation: Applied Sciences
      PubDate: 2018-04-25
      DOI: 10.3390/app8050666
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 667: Application of Mastic Asphalt
           Waterproofing Layer in High-Speed Railway Track in Cold Regions

    • Authors: Song Liu, Jun Yang, Xianhua Chen, Guotao Yang, Degou Cai
      First page: 667
      Abstract: Freeze-thaw damage is a typical distress incurred in road and railway engineering in cold regions. Concrete waterproofing layer is commonly used in high-speed railway tracks to prevent the penetration of surface water, however, it cracks easily under thermal stress, especially in cold regions. Recently solutions have been proposed to increase the waterproofing layer’s cracking resistance by using asphalt layers. Nonetheless, the use of emulsified asphalt as well as dense-graded asphalt mixture were not effective enough. To improve the effectiveness, in this study, mastic asphalt was designed for application as the waterproofing layer on the subgrade surface of high-speed railway tracks in cold regions. The overall performance of mastic asphalt was preliminarily evaluated by laboratory tests, then a 200-m test section was constructed for field validation in northeastern China as part of a new high-speed railway line, and water content sensors were placed inside the subgrade to monitor the performance of the mastic asphalt waterproofing layer (MAWL). The subsequent field investigation and monitoring data during the two years operation showed that MAWL dramatically outperformed the conventional concrete waterproofing layer in terms of waterproof performance. Plenty of serious cracks were found in the conventional concrete waterproofing layer, but only a limited number of local cracks were observed in MAWL. As a result, MAWL keeps the water content of subgrade at a stable level. In addition, MAWL showed relatively high stability during the two years investigation period, and no obvious deterioration was observed in the test section.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050667
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 668: Nature Inspired Plasmonic Structures:
           Influence of Structural Characteristics on Sensing Capability

    • Authors: Gerardo Perozziello, Patrizio Candeloro, Maria Laura Coluccio, Godind Das, Loredana Rocca, Salvatore Andrea Pullano, Antonino Secondo Fiorillo, Mario De Stefano, Enzo Di Fabrizio
      First page: 668
      Abstract: Surface enhanced Raman scattering (SERS) is a powerful analytical technique that allows the enhancement of a Raman signal in a molecule or molecular assemblies placed in the proximity of nanostructured metallic surfaces, due to plasmonic effects. However, laboratory methods to obtain of these prototypes are time-consuming, expensive and they do not always lead to the desired result. In this work, we analyse structures existing in nature that show, on a nanoscale, characteristic conformations of photonic crystals. We demonstrate that these structures, if covered with gold, change into plasmonic nanostructures and are able to sustain the SERS effect. We study three different structures with this property: opal, a hydrated amorphous form of silica (SiO2·nH2O); diatoms, a kind of unicellular alga; and peacock tail feather. Rhodamine 6G (down to 10−12 M) is used to evaluate their capability to increase the Raman signal. These results allow us to define an alternative way to obtain a high sensitivity in Raman spectroscopy, currently achieved by a long and expensive technique, and to fabricate inexpensive nanoplasmonic structures which could be integrated into optical sensors.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050668
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 669: Experimental Study on Dynamic Effects
           of a Long-span Railway Continuous Beam Bridge

    • Authors: Hongye Gou, Wen Zhou, Yi Bao, Xiaobin Li, Qianhui Pu
      First page: 669
      Abstract: Studies on impact effects of trains on the railway bridge are important for ensuring the reliability of bridge and the safety of train operation. This paper presents an experimental study on the dynamic effects of moving trains on a long-span railway continuous beam bridge. The dynamic responses of the bridge under the moving trains were measured through in-situ testing and finite element analysis. The influences of the moving trains and track irregularity are considered. The investigated influencing factors include the weight and speed of the train and the irregularity of the track on the bridge. The results indicate that the train’s speed does not have obvious influence on the impact factor, while train’s weight and track irregularity have notable effects on the impact factor. But from the overall development law, with the increase of train speed, the impact factor increases. The impact factors obtained in this study are larger than the values provided by the China bridge design codes, which indicates that the bridge code underestimates the impact effect of the train on the bridge. The design value of the impact factor should be properly improved in the bridge design.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050669
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 670: Strained Silicon Single Nanowire
           Gate-All-Around TFETs with Optimized Tunneling Junctions

    • Authors: Keyvan Narimani, Stefan Trellenkamp, Andreas Tiedemann, Siegfried Mantl, Qing-Tai Zhao
      First page: 670
      Abstract: In this work, we demonstrate a strained Si single nanowire tunnel field effect transistor (TFET) with gate-all-around (GAA) structure yielding Ion-current of 15 μA/μm at the supply voltage of Vdd = 0.5V with linear onset at low drain voltages. The subthreshold swing (SS) at room temperature shows an average of 76 mV/dec over 4 orders of drain current Id from 5 × 10−6 to 5 × 10−2 µA/µm. Optimized devices also show excellent current saturation, an important feature for analog performance.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050670
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 671: Synthesis, Characterization, and
           Self-Assembly of a Tetrathiafulvalene (TTF)–Triglycyl Derivative

    • Authors: Sónia Pérez-Rentero, Ramon Eritja, Marleen Häring, César Saldías, David Díaz Díaz
      First page: 671
      Abstract: In this work, we describe the synthesis, characterization, and self-assembly properties of a new tetrathiafulvalene (TTF)–triglycyl low-molecular-weight (LMW) gelator. Supramolecular organogels were obtained in various solvents via a heating–cooling cycle. Critical gelation concentrations (CGC) (range ≈ 5–50 g/L) and thermal gel-to-sol transition temperatures (Tgel) (range ≈ 36–51 °C) were determined for each gel. Fourier transform infrared (FT-IR) spectroscopy suggested that the gelator is also aggregated in its solid state via a similar hydrogen-bonding pattern. The fibrillar microstructure and viscoelastic properties of selected gels were demonstrated by means of field-emission electron microscopy (FE-SEM) and rheological measurements. As expected, exposure of a model xerogel to I2 vapor caused the oxidation of the TTF unit as confirmed by UV-vis-NIR analysis. However, FT-IR spectroscopy showed that the oxidation was accompanied with concurrent alteration of the hydrogen-bonded network.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050671
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 672: Noise Attenuation Based on Wave
           Vector Characteristics

    • Authors: Jun Lu, Yun Wang, Jingyi Chen
      First page: 672
      Abstract: Polarization filtering has been widely used to enhance signal-to-noise ratios for multicomponent seismic data. Polarization filters routinely depend on the ellipticity and directionality of spatial particle motions. However, factors such as noise and formation heterogeneity often make the polarization characteristics of body waves hard to distinguish. Here, we introduce a technique in the time domain for the separation of valid body waves and noise based on wave vector characteristics. First, we characterise the ground-roll polarization by the median wave vectors derived in large-scale moving time windows. For the suppression of ground roll, we fit the particle trajectory of ground roll by the least square method using all components simultaneously. Second, we apply three-stage smoothing to the ground-roll-removed multicomponent records. In each stage, we use mean or median vectors derived in small-scale moving-time or moving-trace windows to attenuate random noise and other non-ground-roll related coherent noise. The filter in the proposed method is not devised according to ellipticity and directionality. Instead, we use the wave vector decomposition to distinguish between noise and valid signals. Synthetic data and field data examples confirm that the proposed method can effectively suppress noise without damaging the high and low frequencies of a valid signal.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050672
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 673: Silver Nanowires: Synthesis,
           Antibacterial Activity and Biomedical Applications

    • Authors: Richard S. Jones, Roger R. Draheim, Marta Roldo
      First page: 673
      Abstract: Silver is well known for its antibacterial properties and low toxicity, and it is currently widely used both in the form of ions and of nanoparticles in many diverse products. One-dimensional silver nanowires (AgNWs) have the potential to further enhance the properties of nanosilver-containing products, since they appear to have higher antimicrobial efficacy and lower cytotoxicity. While they are widely used in optics and electronics, more studies are required in order to better understand their behavior in the biological environment and to be able to advance their application in uses such as wound healing, surface coating and drug delivery.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050673
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 674: Microstructure and Mechanical
           Properties of the Dactylopodites of the Chinese Mitten Crab (Eriocheir

    • Authors: Ying Wang, Xiujuan Li, Jianqiao Li, Feng Qiu
      First page: 674
      Abstract: The dactylopodites of the Chinese mitten crab (Eriocheir sinensis) have evolved extraordinary resistance to wear and impact loading after direct contact with rough surfaces or clashing with hard materials. In this study, the microstructure, components, and mechanical properties of the dactylopodites of the Chinese mitten crab were investigated. Images from a scanning electron microscope show that the dactylopodites’ exoskeleton was multilayered, with an epicuticle, exocuticle, and endocuticle. Cross sections and longitudinal sections of the endocuticle revealed a Bouligand structure, which contributes to the dactylopodites’ mechanical properties. The main organic constituents of the exoskeleton were chitin and protein, and the major inorganic compound was CaCO3, crystallized as calcite. Dry and wet dactylopodites were brittle and ductile, respectively, characteristics that are closely related to their mechanical structure and composition. The findings of this study can be a reference for the bionic design of strong and durable structural materials.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050674
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 675: In Situ Experimental Study of the
           Friction of Sea Ice and Steel on Sea Ice

    • Authors: Qingkai Wang, Zhijun Li, Peng Lu, Xiaowei Cao, Matti Leppäranta
      First page: 675
      Abstract: The kinetic coefficient of friction μk was measured for sea ice, stainless steel, and coated steel sliding on a natural sea ice cover. The effects of normal stress (3.10–8.11 kPa), ice columnar grain orientation (vertical and parallel to the sliding direction), sliding velocity (0.02–2.97 m·s–1), and contact material were investigated. Air temperature was higher than −5.0 °C for the test duration. The results showed a decline of μk with increasing normal stress with μk independent of ice grain orientation. The μk of different materials varied, partly due to distinct surface roughnesses, but all cases showed a similar increasing trend with increasing velocity because of the viscous resistance of melt-water film. The velocity dependence of μk was quantified using the rate- and state- dependent model, and μk was found to increase logarithmically with increasing velocity. In addition, μk obtained at higher air temperatures was greater than at lower temperatures. The stick-slip phenomenon was observed at a relatively high velocity compared with previous studies, which was partly due to the low-stiffness device used in the field. Based on the experimental data, the calculation of physical models can be compared.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050675
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 676: Improved Deep Belief Networks (IDBN)
           Dynamic Model-Based Detection and Mitigation for Targeted Attacks on
           Heavy-Duty Robots

    • Authors: Lianpeng Li, Lun Xie, Weize Li, Zhenzong Liu, Zhiliang Wang
      First page: 676
      Abstract: In recent years, the robots, especially heavy-duty robots, have become the hardest-hit areas for targeted attacks. These attacks come from both the cyber-domain and the physical-domain. In order to improve the security of heavy-duty robots, this paper proposes a detection and mitigation mechanism which based on improved deep belief networks (IDBN) and dynamic model. The detection mechanism consists of two parts: (1) IDBN security checks, which can detect targeted attacks from the cyber-domain; (2) Dynamic model and security detection, used to detect the targeted attacks which can possibly lead to a physical-domain damage. The mitigation mechanism was established on the base of the detection mechanism and could mitigate transient and discontinuous attacks. Moreover, a test platform was established to carry out the performance evaluation test for the proposed mechanism. The results show that, the detection accuracy for the attack of the cyber-domain of IDBN reaches 96.2%, and the detection accuracy for the attack of physical-domain control commands reaches 94%. The performance evaluation test has verified the reliability and high efficiency of the proposed detection and mitigation mechanism for heavy-duty robots.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050676
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 677: Capability of the Direct Dimethyl
           Ether Synthesis Process for the Conversion of Carbon Dioxide

    • Authors: Ainara Ateka, Javier Ereña, Miguel Sánchez-Contador, Paula Perez-Uriarte, Javier Bilbao, Andrés T. Aguayo
      First page: 677
      Abstract: The direct synthesis of dimethyl ether (DME) is an ideal process to achieve the environmental objective of CO2 conversion together with the economic objective of DME production. The effect of the reaction conditions (temperature, pressure, space time) and feed composition (ternary mixtures of H2 + CO + CO2 with different CO2/CO and H2/COx molar ratios) on the reaction indices (COx conversion, product yield and selectivity, CO2 conversion) has been studied by means of experiments carried out in a fixed-bed reactor, with a CuO-ZnO-MnO/SAPO-18 catalyst, in order to establish suitable ranges of operating conditions for enhancing the individual objectives of CO2 conversion and DME yield. The optimums of these two objectives are achieved in opposite conditions, and for striking a good balance between both objectives, the following conditions are suitable: 275–300 °C; 20–30 bar; 2.5–5 gcat h (molC)−1 and a H2/COx molar ratio in the feed of 3. CO2/CO molar ratio in the feed is of great importance. Ratios below 1/3 are suitable for enhancing DME production, whereas CO2/CO ratios above 1 improve the conversion of CO2. This conversion of CO2 in the overall process of DME synthesis is favored by the reverse water gas shift equation, since CO is more active than CO2 in the methanol synthesis reaction.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050677
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 678: Forecasting of Energy Consumption in
           China Based on Ensemble Empirical Mode Decomposition and Least Squares
           Support Vector Machine Optimized by Improved Shuffled Frog Leaping

    • Authors: Shuyu Dai, Dongxiao Niu, Yan Li
      First page: 678
      Abstract: For social development, energy is a crucial material whose consumption affects the stable and sustained development of the natural environment and economy. Currently, China has become the largest energy consumer in the world. Therefore, establishing an appropriate energy consumption prediction model and accurately forecasting energy consumption in China have practical significance, and can provide a scientific basis for China to formulate a reasonable energy production plan and energy-saving and emissions-reduction-related policies to boost sustainable development. For forecasting the energy consumption in China accurately, considering the main driving factors of energy consumption, a novel model, EEMD-ISFLA-LSSVM (Ensemble Empirical Mode Decomposition and Least Squares Support Vector Machine Optimized by Improved Shuffled Frog Leaping Algorithm), is proposed in this article. The prediction accuracy of energy consumption is influenced by various factors. In this article, first considering population, GDP (Gross Domestic Product), industrial structure (the proportion of the second industry added value), energy consumption structure, energy intensity, carbon emissions intensity, total imports and exports and other influencing factors of energy consumption, the main driving factors of energy consumption are screened as the model input according to the sorting of grey relational degrees to realize feature dimension reduction. Then, the original energy consumption sequence of China is decomposed into multiple subsequences by Ensemble Empirical Mode Decomposition for de-noising. Next, the ISFLA-LSSVM (Least Squares Support Vector Machine Optimized by Improved Shuffled Frog Leaping Algorithm) model is adopted to forecast each subsequence, and the prediction sequences are reconstructed to obtain the forecasting result. After that, the data from 1990 to 2009 are taken as the training set, and the data from 2010 to 2016 are taken as the test set to make an empirical analysis for energy consumption prediction. Four models, ISFLA-LSSVM, SFLA-LSSVM (Least Squares Support Vector Machine Optimized by Shuffled Frog Leaping Algorithm), LSSVM (Least Squares Support Vector Machine), and BP(Back Propagation) neural network (Back Propagation neural network), are selected to compare with the EEMD-ISFLA-LSSVM model based on the evaluation indicators of mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute error (MAE), which fully prove the practicability of the EEMD-ISFLA-LSSVM model for energy consumption forecasting in China. Finally, the EEMD-ISFLA-LSSVM model is adopted to forecast the energy consumption in China from 2018 to 2022, and, according to the forecasting results, it can be seen that China’s energy consumption from 2018 to 2022 will have a trend of significant growth.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050678
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 679: Experimental Study of Ground
           Subsidence Mechanism Caused by Sewer Pipe Cracks

    • Authors: Tarek Karoui, Seong-Yun Jeong, Yeong-Hoon Jeong, Dong-Soo Kim
      First page: 679
      Abstract: Simultaneous leakage of soil particles and groundwater into underground vacant spaces caused by sewer pipe defects and cracks can cause underground cavities and even ground collapse on the surface. Numerical studies of this problem are limited, and the mechanism of ground subsidence caused by leakage of soil and groundwater into construction sites has yet to be verified. In this study, the factors affecting the mechanism of ground subsidence are verified via physical modelling of a sewer pipe defect. Through visual inspection and particle image velocimetry analysis, it has been found that the groundwater flow direction, hydraulic gradient around the leakage point, and strength of the ground to support itself are the main factors that dominate the mechanism of ground subsidence. These factors can affect ground deformation and cavity expansion direction, ground subsidence development and collapse speed, and occurrence of sudden ground collapse, respectively. It was also found that pore pressure fluctuates when cavity cavern collapse and cavity expansion occur.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050679
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 680: An Effective Directional Residual
           Interpolation Algorithm for Color Image Demosaicking

    • Authors: Ke Yu, Chengyou Wang, Sen Yang, Zhiwei Lu, Dan Zhao
      First page: 680
      Abstract: In this paper, we propose an effective directional Bayer color filter array (CFA) demosaicking algorithm based on residual interpolation (RI). The proposed directional interpolation algorithm aims to reduce computational complexity and get more accurate interpolated pixel values in the complex edge areas. We use the horizontal and vertical weights to combine and smooth color difference estimations. Compared with four directional weights in minimized Laplacian residual interpolation, the proposed algorithm not only guarantees the quality of color images but also reduces the computational complexity. Generally, the directional estimations may be inaccurately calculated because of the false edge information in irregular edges. We alleviate it by using a new method to calculate the directional color difference estimations. Experimental results show that the proposed algorithm provides outstanding performance compared with some previous algorithms, especially in the complex edge areas. In addition, it has lower computational complexity and better visual effect.
      Citation: Applied Sciences
      PubDate: 2018-04-26
      DOI: 10.3390/app8050680
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 681: Experimental and Simulation
           Identification of Xanthohumol as an Inhibitor and Substrate of ABCB1

    • Authors: Fangming Liu, Hannah Hoag, Chun Wu, Haizhou Liu, Hua Yin, Jianjun Dong, Zhonghua Qian, Feng Miao, Ming Liu, Jinlai Miao
      First page: 681
      Abstract: Xanthohumol (XN) is a well-known prenylated flavonoid found in Humulus lupulus L. It is involved in several pharmacological activities, including the sensitization of doxorubicin-resistant breast cancer (MCF-7/ADR) cells to doxorubicin (DOX) through a reduction in cell viability and stemness. In the present study, we revealed another mechanism to further explain the reverse of the drug resistance of XN. In the MCF-7/ADR cell line, we found that XN inhibited the efflux functions of ATP-binding cassette subfamily B member 1 (ABCB1). We also observed that XN was a substrate of ABCB1 and stimulated its ATPase activity. Moreover, our results revealed that XN showed a synergic effect with the ABCB1 substrate colchicine (COL) in the MCF-7/ADR cell line. Further, we showed that XN bound to the central transmembrane domain (TMD) site, overlapping with the DOX binding site. This mechanism was supported by molecular modeling and simulation data, which revealed that XN bound to the ABCB1 transmembrane domain, where doxorubicin also binds, and its binding affinity was stronger than that of doxorubicin, resulting in less protein and ligand position fluctuation. These results support the XN-induced reversal of drug resistance via the inhibition of ABCB1-mediated transport of doxorubicin, stimulating ABCB1 ATPase activity and acting as a substrate of ABCB1.
      Citation: Applied Sciences
      PubDate: 2018-04-27
      DOI: 10.3390/app8050681
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 682: Performance Evaluation of a Chinese
           Lean Iron Ore as the Oxygen Carrier in Multi and Short-Time Redox Cycles

    • Authors: Xudong Wang, Xiaojia Wang, Xiaoyu Hu, Yali Shao, Zhaoyang Jin, Baosheng Jin
      First page: 682
      Abstract: The performance of a Chinese lean iron ore as the oxygen carrier in chemical looping combustion was investigated in a fixed bed reactor. Considering the short contact time between the fuel gas and oxygen carrier in the sub-pilot experimental setup, the short injection time of CO was employed in the reactor to simulate this event. The injection time of CO was set to 60 s, 50 s and 40 s respectively, to investigate its effects on the reactivity of the oxygen carrier. A total of 100 cyclic reactions under each condition were carried out to test the reactivity stability of the oxygen carrier. The oxygen carriers prior and after reactions were characterized using SEM, XRD and BET. Results showed that there was an activation process of the reactivity during initial cycles. The extension of the reaction time was beneficial to the diffusion of CO into the oxygen carrier and could improve the conversion of CO. Also, it could form larger pore volumes for gas diffusion in the oxygen carrier. However, it led to the formation of the Fe2SiO4 and severe sintering on the surface, which was harmful to the stability of the oxygen carrier’s reactivity.
      Citation: Applied Sciences
      PubDate: 2018-04-27
      DOI: 10.3390/app8050682
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 683: Experimental Analysis on Pre-Stress
           Friction Loss of Crushed Limestone Sand Concrete Beams

    • Authors: Yunfeng Xiao, Yaoting Zhang, Jiezhi Lu, Yong Liu, Wenjie Cheng
      First page: 683
      Abstract: This paper presents an experimental research work that evaluates the pre-stress loss caused by friction in crushed limestone sand (CLS) concrete members with post-tensioning. A total of 26 full-scale pre-stressed concrete beams were constructed and tested for the friction loss experiment. The considered variables mainly included the duct-forming materials, wires of tendons and arrangement of ducts. The tensile forces at both active and passive ends of specimen were recorded by steps, and then the pre-stress friction loss for each case was calculated. The result shows that the proportion of pre-stress friction loss in specimen with multi-wire tendons is in the range of 10–40%, with the trend first increasing before decreasing. The pre-stress friction loss in specimen with curve duct accounts for 10–30%. The pressure on the curved part definitely increases the friction when compared with the straight duct. The pre-stress friction loss in specimen with rubber hose reaches nearly 40%, which is larger than the metal bellow and plastic bellow. The suggested values for each case are proposed for a deviation coefficient κ of 0.0017–0.007 and a friction coefficient μ of 0.108–0.858. This can provide reliable theoretical support for the design and construction.
      Citation: Applied Sciences
      PubDate: 2018-04-27
      DOI: 10.3390/app8050683
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 684: CFD Simulation of Vortex Induced
           Vibration for FRP Composite Riser with Different Modeling Methods

    • Authors: Chunguang Wang, Mingyu Sun, Krishnakumar Shankar, Shibo Xing, Lu Zhang
      First page: 684
      Abstract: Steel risers are widely used in offshore oil and gas industry. However, the production capacity and depths are limited due to their extreme weight and poor fatigue and corrosion resistance. Nowadays, it is confirmed that fiber reinforced polymer (FRP) composite risers have apparent advantages over steel risers. However, the study of vortex induced vibration (VIV) for composite risers is rarely involved. Three different risers (one steel riser and two composite risers) were compared for their VIV characteristics. The effects of 2D and 3D models and fluid–structure interaction (FSI) were considered. The models of composite risers are established by effective modulus method (EMM) and layered-structure method (LSM). It is found that 2D model are only suitable for ideal condition, while, for real situation, 3D model with FSI has to be considered. The results show that the displacements of the FRP composite risers are significantly larger than those of the steel riser, while the stresses are reversed. In addition, the distributions of the displacements and stresses depend on the geometries, material properties, top-tension force, constraints, etc. In addition, it is obvious that EMM are suitable to study the global working condition while LSM can be utilized to obtain the results in every single composite layer.
      Citation: Applied Sciences
      PubDate: 2018-04-27
      DOI: 10.3390/app8050684
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 685: Displays Based on Dynamic Phase-Only

    • Authors: Jamieson Christmas, Neil Collings
      First page: 685
      Abstract: Static holographic displays of high quality are works of art. We are creating commercial displays using dynamic phase-only spatial light modulators (SLMs). The main advantages of this approach are light efficiency and fault tolerance. When polarized lasers are used as the illumination source, there is no requirement for polarizers in the light engine. Moreover, the illumination beam can be directed towards bright points of the image and away from dark regions. Due to the many-to-one correspondence between the pixels in the SLM and the points in the image, faults in high complexity SLMs will be annealed in the image. Compared with normal displays where etendue is of overriding importance for light efficiency, holographic displays favor small pixel devices. Smaller pixel devices generate a larger reconstruction which improves the etendue for a second stage imaging system.
      Citation: Applied Sciences
      PubDate: 2018-04-27
      DOI: 10.3390/app8050685
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 686: Active Noise Control Using Modified
           FsLMS and Hybrid PSOFF Algorithm

    • Authors: Ranjan Walia, Smarajit Ghosh
      First page: 686
      Abstract: Active noise control is an efficient technique for noise cancellation of the system, which has been defined in this paper with the aid of Modified Filtered-s Least Mean Square (MFsLMS) algorithm. The Hybrid Particle Swarm Optimization and Firefly (HPSOFF) algorithm are used to identify the stability factor of the MFsLMS algorithm. The computational difficulty of the modified algorithm is reduced when compared with the original Filtered-s Least Mean Square (FsLMS) algorithm. The noise sources are removed from the signal and it is compared with the existing FsLMS algorithm. The performance of the system is established with the normalized mean square error for two different types of noises. The proposed method has also been compared with the existing algorithms for the same purposes.
      Citation: Applied Sciences
      PubDate: 2018-04-27
      DOI: 10.3390/app8050686
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 687: Dynamic Multiple Junction Selection
           Based Routing Protocol for VANETs in City Environment

    • Authors: Irshad Ahmed Abbasi, Adnan Shahid Khan, Shahzad Ali
      First page: 687
      Abstract: VANET (Vehicular Ad-hoc Network) is an emerging offshoot of MANETs (Mobile Ad-hoc Networks) with highly mobile nodes. It is envisioned to play a vital role in providing safety communications and commercial applications to the on-road public. Establishing an optimal route for vehicles to send packets to their respective destinations in VANETs is challenging because of quick speed of vehicles, dynamic nature of the network, and intermittent connectivity among nodes. This paper presents a novel position based routing technique called Dynamic Multiple Junction Selection based Routing (DMJSR) for the city environment. The novelty of DMJSR as compared to existing approaches comes from its novel dynamic multiple junction selection mechanism and an improved greedy forwarding mechanism based on one-hop neighbors between the junctions. To the best of our knowledge, it is the first ever attempt to study the impact of multiple junction selection mechanism on routing in VANETs. We present a detailed depiction of our protocol and the improvements it brings as compared to existing routing strategies. The simulation study exhibits that our proposed protocol outperforms the existing protocols like Geographic Source Routing Protocol (GSR), Enhanced Greedy Traffic Aware Routing Protocol (E-GyTAR) and Traffic Flow Oriented Routing Protocol (TFOR) in terms of packet delivery ratio, end-to-end delay, and routing overhead.
      Citation: Applied Sciences
      PubDate: 2018-04-28
      DOI: 10.3390/app8050687
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 688: Development of Semantic Web-Enabled
           BDI Multi-Agent Systems Using SEA_ML: An Electronic Bartering Case Study

    • Authors: Moharram Challenger, Baris Tekin Tezel, Omer Faruk Alaca, Bedir Tekinerdogan, Geylani Kardas
      First page: 688
      Abstract: In agent-oriented software engineering (AOSE), the application of model-driven development (MDD) and the use of domain-specific modeling languages (DSMLs) for Multi-Agent System (MAS) development are quite popular since the implementation of MAS is naturally complex, error-prone, and costly due to the autonomous and proactive properties of the agents. The internal agent behavior and the interaction within the agent organizations become even more complex and hard to implement when the requirements and interactions for the other agent environments such as the Semantic Web are considered. Hence, in this study, we propose a model-driven MAS development methodology which is based on a domain-specific modeling language (called SEA_ML) and covers the whole process of analysis, modeling, code generation and implementation of a MAS working in the Semantic Web according to the well-known Belief-Desire-Intention (BDI) agent principles. The use of new SEA_ML-based MAS development methodology is exemplified with the development of a semantic web-enabled MAS for electronic bartering (E-barter). Achieved results validated the generation and the development-time performance of applying this new MAS development methodology. More than half of the all agents and artifacts needed for fully implementing the E-barter MAS were automatically obtained by just using the generation features of the proposed methodology.
      Citation: Applied Sciences
      PubDate: 2018-04-28
      DOI: 10.3390/app8050688
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 689: A Short-Term Photovoltaic Power
           Prediction Model Based on the Gradient Boost Decision Tree

    • Authors: Jidong Wang, Peng Li, Ran Ran, Yanbo Che, Yue Zhou
      First page: 689
      Abstract: Due to the development of photovoltaic (PV) technology and the support from governments across the world, the conversion efficiency of solar energy has been improved. However, the PV power output is influenced by environment factors, resulting in features of randomness and intermittency. These features may have a negative influence on power systems. As a result, accurate and timely power prediction data is necessary for power grids to absorb solar energy. In this paper, we propose a new PV power prediction model based on the Gradient Boost Decision Tree (GBDT), which ensembles several binary trees by the gradient boosting ensemble method. The Gradient Boost method builds a strong learner by combining weak learners through iterative methods and the Decision Tree is a basic classification and regression method. As an ensemble machine learning algorithm, the Gradient Boost Decision Tree algorithm can offer higher forecast accuracy than one single learning algorithm. So GBDT is of value in both theoretical research and actual practice in the field of photovoltaic power prediction. The prediction model based on GBDT uses historical weather data and PV power output data to iteratively train the model, which is used to predict the future PV power output based on weather forecast data. Simulation results show that the proposed model based on GBDT has advantages of strong model interpretation, high accuracy, and stable error performance, and thus is of great significance for supporting the secure, stable and economic operation of power systems.
      Citation: Applied Sciences
      PubDate: 2018-04-28
      DOI: 10.3390/app8050689
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 690: Optimal Power Allocation with Hybrid
           Relaying Based on the Channel Condition

    • Authors: Junpyo Jeon, Yeonggyu Shim, Hyuncheol Park
      First page: 690
      Abstract: This paper considers a hybrid relay network consisting of the source, the amplify-and-forward (AF) relay, the decode-and-forward (DF) relay, and the destination. In hybrid three-hop relay systems, the transmitted signal from source can be received at the destination after processing the signals through two relays. If the first relay amplifies and forwards the received signal, and the second relay decodes and forwards the received signal, the system model is considered to be an AF-DF relay system. The reverse case is considered for the DF-AF relay system. The AF-DF and DF-AF relay systems have different error rates and achievable throughput with respect to the channel conditions between two nodes. We propose optimal power allocation schemes for two different relays in order to maximize the achievable rate under a sum relay power constraint for given channel gains and transmit power from the source. By solving the optimization problem to maximize the achievable rate for each relay network, the transmit power values in closed form are derived. When the channel gains are the same, the optimal power allocation scheme for the AF-DF relay network proves that greater power should be allocated at the first relay to maximize the achievable rate. In the case of the DF-AF relay network, we derive an optimal power allocation scheme for the four possible cases. Under the same signal-to-noise ratio (SNR) condition, at the first hop we show that the achievable rate of the AF-DF relay network is greater than that of the DF-AF relay network when the channel gain between two relays is greater than that between the second relay and destination. Simulation results show that the proposed power allocation schemes provide a higher achievable rate than the equal power allocation scheme and the grid search schemes.
      Citation: Applied Sciences
      PubDate: 2018-04-29
      DOI: 10.3390/app8050690
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 691: Fatigue Equation of Cement-Treated
           Aggregate Base Materials under a True Stress Ratio

    • Authors: Songtao Lv, Chaochao Liu, Jingting Lan, Hongwei Zhang, Jianlong Zheng, Zhanping You
      First page: 691
      Abstract: The objective of this article is to establish a fatigue equation based on the true stress ratio for cement-treated aggregate base materials. The true stress ratio herein means the ratio of the stress and the true strength of the cement-treated aggregate base materials related to loading rates and curing times. The unconfined compressive strength tests and compressive resilience modulus tests were carried out under various loading rates and curing times of 3, 7, 14, 28, 60, 90 days, respectively. According to the test results, the relationship between the unconfined compressive strength (a mix design parameter in China) and the compressive resilience modulus (a structural design parameter and the construction quality control parameter in China) of the cement-treated aggregate base material with different curing times was established. However, it was found that the strengths varied with the loading rates, which is not reflected in the existing fatigue equations. Therefore, it is questionable to obtain the stress ratio of fatigue tests with a fixed strength value obtained from the standard strength test where the loading rate is fixed (in China, the fixed loading rate is 1 mm/min for cement-treated aggregate base materials). Thus, in this paper, the four-point bending strength (i.e., flexural strength) test was carried out at different loading rates to resolve such deficiencies. Based on the strength test results at different loading rates, the true stress ratio of the fatigue test corresponding to the fatigue loading rate can be calculated. Then the four-point bending fatigue test was conducted to establish an improved fatigue equation characterized by the true stress ratio. The results show that the patterns of variation for unconfined compressive strength increasing with the curing time were similar to that of the compressive resilience modulus. The fatigue equation curve based on the true stress ratio can be extended to the strength failure point of (1, 1), where both the true stress ratio and the fatigue life value are one. The internal relationship between the strength failure and the fatigue failure was unified. This article provides a theoretical method and basis for unifying the mix design parameters and the construction quality control parameters.
      Citation: Applied Sciences
      PubDate: 2018-04-29
      DOI: 10.3390/app8050691
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 692: An Ultrasonic Through-Metal-Wall
           Power Transfer System with Regulated DC Output

    • Authors: Hengxu Yang, Ming Wu, Ziying Yu, Jun Yang
      First page: 692
      Abstract: This paper presents a novel and efficient system capable of transmitting medium-power electric energy through a solid metal wall and generating a regulated direct current (DC) output. The electric power is transmitted using radio frequency (RF) ultrasound without physical penetration. An RF alternating current to direct current converter with input impedance matching is used to convert the transmitted RF signal to a DC output, which is directly suitable as a power supply for electronic devices. The system is constructed from commercial off-the-shelf components, and a computer-controlled measurement method is designed to test the effectiveness of the full system. The measurement results show that the system is able to transfer power through a 40-mm-thick stainless steel plate and generate 5-V, 15.7-W regulated DC output power with an overall power transfer efficiency of 27.7%. In addition, the effectiveness of the system is successfully demonstrated by powering ARM® evaluation boards with liquid-crystal display panels. A discussion of potential enhancements that could be made to improve the transfer capability and efficiency of the system is also presented. This system could be applied to improve safety and preserve structural integrity in many industrial and military applications, such as submarines, space crafts, planes, nuclear storage facilities, etc.
      Citation: Applied Sciences
      PubDate: 2018-04-29
      DOI: 10.3390/app8050692
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 693: Mechanical Construction and
           Propulsion Analysis of a Rescue Underwater Robot in the case of Drowning

    • Authors: Angelo Bonfitto, Nicola Amati
      First page: 693
      Abstract: This paper presents the design of an unmanned and tele-operated robotized life-saving system aimed to work as a recovery tool in case of water-related disasters. The device is designed to save people in distress in the water, either conscious or unconscious, without exposing the rescuer’s life to risk. The data of in water accidents show that the greatest number of casualties occurs because of dangerous predicaments conducted by people who want to save other lives. All present solutions are based on aerial, surface or submarine systems needing a crew and able to save only conscious people. This paper intends to fill this gap in the literature by analyzing the main critical issues in the design of a marine autonomous rescue vehicle in terms of performance, capabilities of maneuver in rough sea conditions and the costs. The proposed robot is fully electric and tele-manipulated, from the shore in case of accidents near dry land, or directly from boats or helicopters if drowning is occurring in the open sea. The paper demonstrates the feasibility of a system and its readiness for prototyping phases while presenting a trade-off and cost analysis between six different configurations as well as illustrating in detail the design of the selected layout. The motivations behind the choice of diving strategy to tackle rough sea conditions are described along with the design and the numerical validations of the hydroplane and propulsion systems.
      Citation: Applied Sciences
      PubDate: 2018-04-30
      DOI: 10.3390/app8050693
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 694: Surface State Dynamics of Topological
           Insulators Investigated by Femtosecond Time- and Angle-Resolved
           Photoemission Spectroscopy

    • Authors: Hamoon Hedayat, Davide Bugini, Hemian Yi, Chaoyu Chen, Xingjiang Zhou, Giulio Cerullo, Claudia Dallera, Ettore Carpene
      First page: 694
      Abstract: Topological insulators (TI) are known for striking quantum phenomena associated with their spin-polarized topological surface state (TSS). The latter in particular forms a Dirac cone that bridges the energy gap between valence and conduction bands, providing a unique opportunity for prospective device applications. In TI of the BixSb2−xTeySe3−y (BSTS) family, stoichiometry determines the morphology and position of the Dirac cone with respect to the Fermi level. In order to engineer specific transport properties, a careful tuning of the TSS is highly desired. Therefore, we have systematically explored BSTS samples with different stoichiometries by time- and angle-resolved photoemission spectroscopy (TARPES). This technique provides snapshots of the electronic structure and discloses the carrier dynamics in surface and bulk states, providing crucial information for the design of electro-spin current devices. Our results reveal the central role of doping level on the Dirac cone structure and its femtosecond dynamics. In particular, an extraordinarily long TSS lifetime is observed when the the vertex of the Dirac cone lies at the Fermi level.
      Citation: Applied Sciences
      PubDate: 2018-04-30
      DOI: 10.3390/app8050694
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 695: Special Issue on Wastewater Treatment
           and Reuse Technologies

    • Authors: Faisal I. Hai, Kazuo Yamamoto, Jega Veeriah Jegatheesan
      First page: 695
      Abstract: Wastewater treatment allows for the safe disposal of municipal and industrial wastewater to protect public health and the ecosystem[...]
      Citation: Applied Sciences
      PubDate: 2018-05-01
      DOI: 10.3390/app8050695
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 696: Fault Detection in a Multistage
           Gearbox Based on a Hybrid Demodulation Method Using Modulation Intensity
           Distribution and Variational Mode Decomposition

    • Authors: Chaofan Hu, Yanxue Wang, Jianwei Yang, Suofeng Zhang
      First page: 696
      Abstract: It is critical to detect hidden, periodically impulsive signatures caused by tooth defects in a gearbox. A hybrid demodulation method for detecting tooth defects has been developed in this work based on the variational mode decomposition algorithm combined with modulation intensity distribution. An original multi-component signal is first non-recursively decomposed into a number of band-limited mono-components with specific sparsity properties in the spectral domain using variational mode decomposition. The hidden meaningful cyclostationary features can be clearly identified in the bi-frequency domain via the modulation intensity distribution (MID) technique. Moreover, the reduced frequency aliasing effect of variational mode decomposition is evaluated as well, which is very useful for separating noise and harmonic components in the original signal. The influences of the spectral coherence density and the spectral correlation density of the modulation intensity distribution on the demodulation were also investigated. The effectiveness and noise robustness of the proposed method have been well-verified using a simulated signal compared with the empirical mode decomposition algorithm associated with modulation intensity distribution. The proposed technique is then applied to detect four different defects in a multi-stage gearbox. The results demonstrated that the demodulated numerical information and pigmentation directly illustrated in the bi-frequency plot of the modulation intensity distribution can be successfully used to quantitatively differentiate the four gear defects.
      Citation: Applied Sciences
      PubDate: 2018-05-01
      DOI: 10.3390/app8050696
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 697: Multi-Class Sleep Stage Analysis and
           Adaptive Pattern Recognition

    • Authors: Aleš Procházka, Jiří Kuchyňka, Oldřich Vyšata, Pavel Cejnar, Martin Vališ, Vladimír Mařík
      First page: 697
      Abstract: Multimodal signal analysis based on sophisticated sensors, efficient communication systems and fast parallel processing methods has a rapidly increasing range of multidisciplinary applications. The present paper is devoted to pattern recognition, machine learning, and the analysis of sleep stages in the detection of sleep disorders using polysomnography (PSG) data, including electroencephalography (EEG), breathing (Flow), and electro-oculogram (EOG) signals. The proposed method is based on the classification of selected features by a neural network system with sigmoidal and softmax transfer functions using Bayesian methods for the evaluation of the probabilities of the separate classes. The application is devoted to the analysis of the sleep stages of 184 individuals with different diagnoses, using EEG and further PSG signals. Data analysis points to an average increase of the length of the Wake stage by 2.7% per 10 years and a decrease of the length of the Rapid Eye Movement (REM) stages by 0.8% per 10 years. The mean classification accuracy for given sets of records and single EEG and multimodal features is 88.7% ( standard deviation, STD: 2.1) and 89.6% (STD:1.9), respectively. The proposed methods enable the use of adaptive learning processes for the detection and classification of health disorders based on prior specialist experience and man–machine interaction.
      Citation: Applied Sciences
      PubDate: 2018-05-01
      DOI: 10.3390/app8050697
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 698: Predicting the Failure of Dental
           Implants Using Supervised Learning Techniques

    • Authors: Chia-Hui Liu, Cheng-Jyun Lin, Ya-Han Hu, Zi-Hung You
      First page: 698
      Abstract: Prosthodontic treatment has been a crucial part of dental treatment for patients with full mouth rehabilitation. Dental implant surgeries that replace conventional dentures using titanium fixtures have become the top choice. However, because of the wide-ranging scope of implant surgeries, patients’ body conditions, surgeons’ experience, and the choice of implant system should be considered during treatment. The higher price charged by dental implant treatments compared to conventional dentures has led to a rush among medical staff; therefore, the future impact of surgeries has not been analyzed in detail, resulting in medial disputes. Previous literature on the success factors of dental implants is mainly focused on single factors such as patients’ systemic diseases, operation methods, or prosthesis types for statistical correlation significance analysis. This study developed a prediction model for providing an early warning mechanism to reduce the chances of dental implant failure. We collected the clinical data of patients who received artificial dental implants at the case hospital for a total of 8 categories and 20 variables. Supervised learning techniques such as decision tree (DT), support vector machines, logistic regressions, and classifier ensembles (i.e., Bagging and AdaBoost) were used to analyze the prediction of the failure of dental implants. The results show that DT with both Bagging and Adaboost techniques possesses the highest prediction performance for the failure of dental implant (area under the receiver operating characteristic curve, AUC: 0.741); the analysis also revealed that the implant systems affect dental implant failure. The model can help clinical surgeons to reduce medical failures by choosing the optimal implant system and prosthodontics treatments for their patients.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050698
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 699: Vacuum Ultraviolet Single-Photon
           Postionization of Amino Acids

    • Authors: Hsu Chen Hsu, Chi-Kung Ni
      First page: 699
      Abstract: In this study, ultraviolet (UV) laser desorption and vacuum UV single-photon (VUV SP) postionization were performed to ionize and successfully analyze 20 common amino acids. The analytical merit and efficiency of the ionization was compared with those of conventional UV matrix-assisted laser desorption ionization (UV-MALDI). A VUV light source (118 nm) was generated from the ninth harmonic of a Q-switched Nd:YAG laser, and the photon number was determined to be larger than 1012 for each laser pulse in the ionization region. In general, the detection sensitivity of VUV-SP-postionization was 10–100 times higher than that of conventional UV-MALDI. In particular, the ion signal from VUV-SP-postionization was considerably larger than that from UV-MALDI for analytes with low proton affinity such as glycine. However, some fragmentation of intact ions was observed in VUV-SP-postionization. Quantitative analysis performed using a glycine/histidine mixture and tryptophan/phenylalanine mixture revealed that the dynamic range of VUV-SP-postionization was one order of magnitude larger than that of UV-MALDI, indicating that VUV-SP-postionization is suitable for the quantitative analysis of amino acids.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050699
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 700: Time Dependence of Wetting Behavior
           Upon Applying Hierarchic Nano-Micro Periodic Surface Structures on Brass
           Using Ultra Short Laser Pulses

    • Authors: Stefan Rung, Simon Schwarz, Babette Götzendorfer, Cemal Esen, Ralf Hellmann
      First page: 700
      Abstract: We present a comprehensive experimental study on laser-induced hierarchic nano-micro periodic surface structures on brass that influences wetting behavior. Using ultra short laser pulses with a wavelength of 1030 nm, large scaled areas completely covered by laser-induced periodic surface structures (LIPSS) are generated with these areas being superimposed by ablation trenches and u-ripples. The influence of the incident laser fluence and pulse overlap on the apparent contact angle for coverage of the surface with distilled water with a surface tension of 74 mN/m are examined with its temporal evolution being observed over a period of two weeks. Our results show an initial drop in the apparent contact angle below the angle of an unstructured surface. Using atomic force microscopy, the roughness factor described by the Wenzel model is determined and compared to the roughness factor given by the apparent contact angle measurement. The ascertained difference in roughness cannot be entirely attributed to the topography of the laser-structured surface. We suggest that changes in the surface chemistry additionally alter the wetting behavior as confirmed by X-ray photoelectron spectroscopy (XPS) measurements. On a time scale of days after laser irradiation, the apparent contact angle increases into the hydrophobic range. Both the absolute apparent contact angle and this temporal change reveal a pronounced dependence on the applied laser fluence and pulse overlap. In particular, increasing both, the fluence and the pulse overlap leads to smaller apparent contact angles directly after the irradiation and to higher apparent contact angles after an observation period of two weeks.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050700
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 701: Rapid and Quantitative Determination
           of Soil Water-Soluble Nitrogen Based on Surface-Enhanced Raman
           Spectroscopy Analysis

    • Authors: Tao Dong, Shupei Xiao, Yong He, Yu Tang, Pengcheng Nie, Lei Lin, Fangfang Qu, Shaoming Luo
      First page: 701
      Abstract: An accurate and rapid determination of soil water-soluble nitrogen is conducive to scientific fertilization in precision agriculture. Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive fingerprint with the advantages of simple operation and high detection efficiency. In this paper, partial least squares (PLS), principal components analysis (PCA), and least squares supports vector machine (LS-SVM) were applied to analyze the relationship between soil water-soluble nitrogen concentration and SERS. The results showed that the SERS-enhancing effect based on Opto Trace Raman 202 (OTR 202) was better than that of silver nanosubstrate and gold nanosubstrate. In addition, the prediction accuracy of soil water-soluble nitrogen in PLS was the highest ( R p 2 = 0.91 ,   RMSE p = 8.76   mg / L , R P D = 3.00 ) when the original spectra were preprocessed with first-derivative. Moreover, 1028, 1370, 1436, and 1636 cm−1 could be determined as characteristic peaks of soil water-soluble nitrogen, the association between soil water-soluble nitrogen concentration and a SERS intensity of 1370 cm−1 was the highest   ( R p 2 = 0.94 ) , and the regression equation was y = 93.491x + 1771.5. Beyond that, the prediction accuracy of distinguishing between a low soil water-soluble nitrogen concentration (22.7–63.7 mg/L) and a high soil water-soluble nitrogen concentration (70.5–118.3 mg/L) based on PCA and LS-LVM was 86.67%. In conclusion, soil water-soluble nitrogen could be detected rapidly and quantitatively using SERS, which was beneficial to provide a rapid, accurate, and reliable scheme for scientific and precise fertilization.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050701
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 702: Virtual Diagnostic Sensors Design for
           an Automated Guided Vehicle

    • Authors: Ralf Stetter, Marcin Witczak, Marcin Pazera
      First page: 702
      Abstract: In recent years, Automated Guided Vehicles (AGVs) have been playing an increasingly important role in producing industry and infrastructure and will soon arrive to other areas of human life such as the transportation of goods and people. However, several challenges still aggravate the operation of AGVs, which limit the amount of implementation. One major challenge is the realization of reliable sensors that can capture the different aspects of the state of an AGV as well as its surroundings. One promising approach towards more reliable sensors is the supplementary application of virtual sensors, which are able to generate virtual measurements by using other sources of information such as actuator states and already existing sensors together with appropriate mathematical models. The focus of the research described in this paper is the design of virtual sensors determining forces and torques acting on an AGV. The proposed novel approach is using a quadratic boundedness approach, which makes it possible to include bounded disturbances acting on the AGV. One major advantage of the presented approach is that the use of complex tire models can be avoided. Information from acceleration and yaw rate sensors is processed in order to realize reliable virtual force and torque sensors. The resulting force and torque information can be used for several diagnostic purposes such as fault detection or fault prevention. The presented approach is explained and verified on the basis of an innovative design of an AGV. This innovative design addresses another major challenge for AGVs, which is the limited maneuvering possibilities of many AGV designs. The innovative design allows nearly unlimited maneuvering possibilities but requires reliable sensor data. The application of the approach in the AGV resulted in the insight that the generated estimates are consistent with the longitudinal forces and torques obtained by a proven reference model.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050702
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 703: Vibrometry Assessment of the External
           Thermal Composite Insulation Systems Influence on the Façade Airborne
           Sound Insulation

    • Authors: Daniel Urbán, N.B. Roozen, Herbert Muellner, Peter Zaťko, Alexander Niemczanowski, Monika Rychtáriková, Christ Glorieux
      First page: 703
      Abstract: This paper verifies the impact of the use of an external thermal composite system (ETICS) on air-borne sound insulation. For optimum accuracy over a wide frequency range, classical microphone based transmission measurements are combined with accelerometer based vibrometry measurements. Consistency is found between structural resonance frequencies and bending wave velocity dispersion curves determined by vibrometry on the one hand and spectral features of the sound reduction index, the ETICS mass-spring-mass resonance induced dip in the acoustic insulation spectrum, and the coincidence induced dip on the other hand. Scanning vibrometry proves to be an effective tool for structural assessment in the design phase of ETICS systems. The measured spectra are obtained with high resolution in wide frequency range, and yield sound insulation values are not affected by the room acoustic features of the laboratory transmission rooms. The complementarity between the microphone and accelerometer based results allows assessing the effect of ETICS on the sound insulation spectrum in an extended frequency range from 20 Hz to 10 kHz. The modified engineering ΔR prediction model for frequency range up to coincidence frequency of external plaster layer is recommended. Values for the sound reduction index obtained by a modified prediction method are consistent with the measured data.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050703
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 704: User-In-The-Loop Content Delivery in
           Cellular Communication Networks with Heterogeneous User Behaviors

    • Authors: Weicheng Zhang, Yaodong Li, Hai Lu, Xuemin Hong, Jianghong Shi
      First page: 704
      Abstract: User-in-the-loop (UiL) content delivery is a recently proposed scheme for personalized content retrieval over mobile communication networks. It is a promising scheme that can better manage the overall user quality-of-experience (QoE) throughout the entire content retrieval process. The performance of the scheme, however, has only been investigated in a simplified system model that assumed synchronized user behavior, inflexible delay constraint, and identical quality-of-service (QoS) requirement among users. This paper studies the performance of UiL content delivery scheme in a generalized and realistic system model with asynchronous user behavior, flexible outage delay constraint, and customized user QoS. Heuristic algorithms and theoretical bounds are investigated for the UiL content delivery problem. The proposed system is shown to be effective in managing the user QoE in generalized practical scenarios.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050704
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 705: Numerical Simulation of Temperature
           Fields in a Three-Dimensional SiC Crystal Growth Furnace with Axisymmetric
           and Spiral Coils

    • Authors: Chunzhen Yang, Guangxia Liu, Chengmin Chen, Yanjin Hou, Min Xu, Yongxian Zhang
      First page: 705
      Abstract: Three-dimensional numerical simulation platform for silicon carbide crystal growth furnace was established using C programing language, where a physical model of the furnace was built based on cylindrical coordinates; governing equations for electromagnetic and temperature fields were discretized by finite volume method; radiation characteristics were studied with the help of S2S model (surface to surface radiation model); and the least distance method was proposed to check radiation faces visibility efficiently. LU decomposition algorithm based on graphic processing unit (GPU) technology was developed to accelerate the solving process of surface to surface radiation. Then the radiation heat transfer in silicon carbide crystal (SiC) growth chamber and temperature field of silicon carbide growth furnace were studied quantificationally at I = 1250 A and F = 16 kHz. The effects of coil structures (axisymmetric and spiral) on temperature field and its gradient distributions were investigated by standard deviation method. The simulation results demonstrate that spiral electromagnetic coil generates non-axisymmetric temperature field easily; the radiation heat flux is 102~103 times more than conduction heat flux, radiation heat transfer is helpful to increase temperature evenness; the spiral temperature field on the SiC crystal cross-section reduces the poor homogeneity of temperature gradient, which will cause crystal to generate large defects.
      Citation: Applied Sciences
      PubDate: 2018-05-02
      DOI: 10.3390/app8050705
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 706: Calibrated Phase-Shifting Digital
           Holographic Microscope Using a Sampling Moiré Technique

    • Authors: Peng Xia, Qinghua Wang, Shien Ri, Hiroshi Tsuda
      First page: 706
      Abstract: A calibrated phase-shifting digital holographic microscope system capable of improving the quality of reconstructed images is proposed. Phase-shifting errors are introduced in phase-shifted holograms for numerous reasons, such as the non-linearity of piezoelectric transducers (PZTs), wavelength fluctuations in lasers, and environmental disturbances, leading to poor-quality reconstructions. In our system, in addition to the camera used to record object information, an extra camera is used to record interferograms, which are used to analyze phase-shifting errors using a sampling Moiré technique. The quality of the reconstructed object images can be improved by the phase-shifting error compensation algorithm. Both the numerical simulation and experiment demonstrate the effectiveness of the proposed system.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050706
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 707: A Review of Mid-Infrared
           Supercontinuum Generation in Chalcogenide Glass Fibers

    • Authors: Shixun Dai, Yingying Wang, Xuefeng Peng, Peiqing Zhang, Xunsi Wang, Yinsheng Xu
      First page: 707
      Abstract: Chalcogenide glasses have the advantages of a wide transparency window (over 20 μm) and high optical nonlinearity (up to a thousand times greater than that of silica glasses), making them good candidates for mid-infrared supercontinuum generation. In this review, we describe both the history and recent developments in mid-infrared supercontinuum generation from chalcogenide fibers according to three kinds of fiber structures: step-index, microstructured and tapered fibers. We also review the coherence properties of mid-infrared supercontinuum generation and all-fiber supercontinuum sources based on chalcogenide fibers.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050707
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 708: Real-Time Estimation for Cutting Tool
           Wear Based on Modal Analysis of Monitored Signals

    • Authors: Yongjiao Chi, Wei Dai, Zhiyuan Lu, Meiqing Wang, Yu Zhao
      First page: 708
      Abstract: There is a growing body of literature that recognizes the importance of product safety and the quality problems during processing. The working status of cutting tools may lead to project delay and cost overrun if broken down accidentally, and tool wear is crucial to processing precision in mechanical manufacturing, therefore, this study contributes to this growing area of research by monitoring condition and estimating wear. In this research, an effective method for tool wear estimation was constructed, in which, the signal features of machining process were extracted by ensemble empirical mode decomposition (EEMD) and were used to estimate the tool wear. Based on signal analysis, vibration signals that had better linear relationship with tool wearing process were decomposed, then the intrinsic mode functions (IMFs), frequency spectrums of IMFs and the features relating to amplitude changes of frequency spectrum were obtained. The trend that tool wear changes with the features was fitted by Gaussian fitting function to estimate the tool wear. Experimental investigation was used to verify the effectiveness of this method and the results illustrated the correlation between tool wear and the modal features of monitored signals.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050708
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 709: Optic Disc Detection from Fundus
           Photography via Best-Buddies Similarity

    • Authors: Kangning Hou, Naiwen Liu, Weikuan Jia, Yunlong He, Jian Lian, Yuanjie Zheng
      First page: 709
      Abstract: Robust and effective optic disc (OD) detection is a necessary processing step in the research work of the automatic analysis of fundus images. In this paper, we propose a novel and robust method for the automated detection of ODs from fundus photographs. It is essentially carried out by performing template matching using the Best-Buddies Similarity (BBS) measure between the hand-marked OD region and the small parts of target images. For well characterizing the local spatial information of fundus images, a gradient constraint term was introduced for computing the BBS measurement. The performance of the proposed method is validated with Digital Retinal Images for Vessel Extraction (DRIVE) and Standard Diabetic Retinopathy Database Calibration Level 1 (DIARETDB1) databases, and quantitative results were obtained. Success rates/error distances of 100%/10.4 pixel and of 97.7%/12.9 pixel, respectively, were achieved. The algorithm has been tested and compared with other commonly used methods, and the results show that the proposed method shows superior performance.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050709
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 710: Development of a Combined
           Trifluoroacetic Acid Hydrolysis and HPLC-ELSD Method to Identify and
           Quantify Inulin Recovered from Jerusalem artichoke Assisted by Ultrasound

    • Authors: Shuyi Li, Qian Wu, Fangfang Yin, Zhenzhou Zhu, Jingren He, Francisco J. Barba
      First page: 710
      Abstract: Over the last years, inulin, a fructan mixture consisting of oligosaccharides and polysaccharides, has attracted more and more attention from both food industry and researchers, due to its unique functional properties as a natural resource. Therefore, there is an increased interest in the extraction and quantification of inulin for its valorization from inulin rich plants, wastes and by-products. In this work, ultrasonic treatment was applied for inulin extraction, observing a great impact of extraction temperature and ultrasonic power on the inulin content in the obtained extracts. A combined process including trifluoroacetic acid (TFA)-assisted hydrolysis and analysis with high performance liquid chromatography equipped with evaporative light scattering detector (HPLC-ELSD) was developed to quantify inulin content. The effect of hydrolysis parameters was investigated, obtaining the optimal conditions after using TFA at a concentration of 1 mg/mL, hydrolysis temperature of 90 °C, and hydrolysis duration of 60 min. The good linearity (>0.995), precision, recovery (100.27%), and stability obtained during the validation process showed that this developed method allows the quantification of total inulin content in the samples analyzed. This combined method may also contribute to the investigation of the functional properties of inulin (e.g., as prebiotic).
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050710
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 711: Comparison of Heuristic Algorithms in
           Discrete Search and Surveillance Tasks Using Aerial Swarms

    • Authors: Pablo Garcia-Aunon, Antonio Barrientos Cruz
      First page: 711
      Abstract: The search of a given area is one of the most studied tasks in swarm robotics. Different heuristic methods have been studied in the past taking into account the peculiarities of these systems (number of robots, limited communications and sensing and computational capacities). In this work, we introduce a behavioral network made up of different well-known behaviors that act together to achieve a good performance, while adapting to different scenarios. The algorithm is compared with six strategies based on movement patterns in terms of three performance models. For the comparison, four scenario types are considered: plain, with obstacles, with the target location probability distribution and a combination of obstacles and the target location probability distribution. For each scenario type, different variations are considered, such as the number of agents and area size. Results show that although simplistic solutions may be convenient for the simplest scenario type, for the more complex ones, the proposed algorithm achieves better results.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050711
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 712: A Design Method for Multijoint
           Explosive-Proof Manipulators by Two Motors

    • Authors: Jingchao Zhao, Junyao Gao, Fangzhou Zhao, Zhe Xu, Yi Liu
      First page: 712
      Abstract: With the increase of accidents and disasters occurring in the explosive environment, search-and-rescue activities are more and more essential. At present, explosive-proof robots can be designed for detection in the explosive environment. However, most robots only detect parameters of disaster scenes, and cannot go forward when they are blocked by obstacles. So, manipulators are needed in order for robots to finish search-and-rescue missions. However, few robots can meet these requirements, because it is difficult to design an explosive-proof manipulator. This paper introduces a method used for designing manipulators which can work in the explosive environment. The manipulator adopted in this design method can drive more than three joints, and only uses two motors. One motor is used to supply power for driving joints and the other is used for switching the power among joints. Both of them can be separated with a manipulator and mounted on a robot chassis with an explosive-proof box. In this way, the load capacity and explosion-proof security of manipulators can be improved. The development of this design method can provide a reference for designers to develop future search-and-rescue robots in explosive environments.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050712
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 713: Using Neural Networks in Modeling
           Customer Loyalty in Passenger Cars Maintenance and Repair Services

    • Authors: Aleksander Lotko, Paweł Albert Korneta, Małgorzata Anna Lotko, Rafał Longwic
      First page: 713
      Abstract: Background: In the study, we researched if it is possible to identify the segments of customers of auto repair shops with the use of neural networks' The study attempts to contribute to literature by way of classifying customers of the auto repair shops, accordingly to their loyalty, with the use of advanced statistical methods. Methods: The paper covers classification trees, neural networks, and cluster analyses that were applied in order to classify customers according to their loyalty. Results: It has been proved that three groups of factors influence loyalty: (1) social and demographic factors concerning customer characteristics; (2) technical factors concerning the vehicle and the manner of its use; and (3) factors defining the evaluation of the service quality provided by the auto repair shops. Four segments of customers which vary in terms of formal characteristics and assessment of the quality of services were obtained. Conclusions: (1) identification of factors shaping customers’ loyalty; (2) possibility of checking which changes of the quality of services may influence the loyalty of the customers; and (3) identification of the segments of the customers in the case of which the marketing strategies applied to increase the loyalty, must be treated with the utmost priority.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050713
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 714: Optimal Release Time and Sensitivity
           Analysis Using a New NHPP Software Reliability Model with Probability of
           Fault Removal Subject to Operating Environments

    • Authors: Kwang Yoon Song, In Hong Chang, Hoang Pham
      First page: 714
      Abstract: With the latest technological developments, the software industry is at the center of the fourth industrial revolution. In today’s complex and rapidly changing environment, where software applications must be developed quickly and easily, software must be focused on rapidly changing information technology. The basic goal of software engineering is to produce high-quality software at low cost. However, because of the complexity of software systems, software development can be time consuming and expensive. Software reliability models (SRMs) are used to estimate and predict the reliability, number of remaining faults, failure intensity, total and development cost, etc., of software. Additionally, it is very important to decide when, how, and at what cost to release the software to users. In this study, we propose a new nonhomogeneous Poisson process (NHPP) SRM with a fault detection rate function affected by the probability of fault removal on failure subject to operating environments and discuss the optimal release time and software reliability with the new NHPP SRM. The example results show a good fit to the proposed model, and we propose an optimal release time for a given change in the proposed model.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050714
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 715: Application of Semiconductor Optical
           Amplifier (SOA) in Managing Chirp of Optical Code Division Multiple Access
           (OCDMA) Code Carriers in Temperature Affected Fibre Link

    • Authors: Md Shakil Ahmed, Ivan Glesk
      First page: 715
      Abstract: Chromatic and temperature induced dispersion can both severely affect incoherent high data rate communications in optical fibre. This is certainly also true for incoherent optical code division multiple access (OCDMA) systems with multi-wavelength picosecond code carriers. Here, even a relatively small deviation from a fully dispersion compensated transmission link can strongly impact the overall system performance, the number of simultaneous users, and the system cardinality due to the recovered OCDMA auto-correlation being strongly distorted, time-skewed, and having its full width at half maximum (FWHM) value changed. It is therefore imperative to have a simple tunable means for controlling fibre chromatic or temperature induced dispersion with high sub-picosecond accuracy. To help address this issue, we have investigated experimentally and by simulations the use of a semiconductor optical amplifier (SOA) for its ability to control the chirp of the passing optical signal (OCDMA codes) and to exploit the SOA ability for dispersion management of a fibre link in an incoherent OCDMA system. Our investigation is done using a 19.5 km long fibre transmission link that is exposed to different temperatures (20 °C and 50 °C) using an environmental chamber. By placing the SOA on a transmission site and using it to manipulate the code carrier’s chirp via SOA bias adjustments, we have shown that this approach can successfully control the overall fibre link dispersion, and it can also mitigate the impact on the received OCDMA auto-correlation and its FWHM. The experimental data obtained are in a very good agreement with our simulation results.
      Citation: Applied Sciences
      PubDate: 2018-05-03
      DOI: 10.3390/app8050715
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 716: Applying Acoustical and Musicological
           Analysis to Detect Brain Responses to Realistic Music: A Case Study

    • Authors: Niels Trusbak Haumann, Marina Kliuchko, Peter Vuust, Elvira Brattico
      First page: 716
      Abstract: Music information retrieval (MIR) methods offer interesting possibilities for automatically identifying time points in music recordings that relate to specific brain responses. However, how the acoustical features and the novelty of the music structure affect the brain response is not yet clear. In the present study, we tested a new method for automatically identifying time points of brain responses based on MIR analysis. We utilized an existing database including brain recordings of 48 healthy listeners measured with electroencephalography (EEG) and magnetoencephalography (MEG). While we succeeded in capturing brain responses related to acoustical changes in the modern tango piece Adios Nonino, we obtained less reliable brain responses with a metal rock piece and a modern symphony orchestra musical composition. However, brain responses might also relate to the novelty of the music structure. Hence, we added a manual musicological analysis of novelty in the musical structure to the computational acoustic analysis, obtaining strong brain responses even to the rock and modern pieces. Although no standardized method yet exists, these preliminary results suggest that analysis of novelty in music is an important aid to MIR analysis for investigating brain responses to realistic music.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050716
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 717: Nickel Complexes Immobilized in
           Modified Ionic Liquids Anchored in Structured Materials for Ethylene

    • Authors: Camila A. Busatta, Marcelo L. Mignoni, Roberto F. de Souza, Katia Bernardo-Gusmão
      First page: 717
      Abstract: This work describes the study of ethylene oligomerization reactions catalyzed by nickel-β-diimine complexes immobilized on β-zeolite, [Si]-MCM-41 (Mobil Composition of Matter 41) and [Si,Al]-MCM-41 modified with an ionic liquid. XRD and N2 adsorption and desorption analyses were used to characterize the modified supports—namely, IL-Zeoβ, IL-MCM-41 and IL-Al-MCM-41—and the data showed that material organization remained intact even after incorporation of ionic liquid. N2 adsorption and desorption analyses suggested that ionic liquid can be confined in pores of support materials. Catalytic properties of synthesized materials were tested under different conditions. The following parameters were varied: Al/Ni molar ratio, temperature, pressure and catalyst loading. The homogeneous catalysts were more active but less selective in ethylene oligomerization, relative to heterogeneous ones, which can be attributed to the effect of confinement suffered by catalyst within channels of the support materials. NiIL-Zeoβ complexes were active, with activities greater than 23 s−1 and selectivities higher than 80% for butenes, including more than 85% of 1-butene. On the other hand, the NiIL-MCM-41 system was less active than NiIL-Zeoβ complexes, with activities above 1 s−1 with 100% selectivity for butenes (96% in 1-butene). NiIL-Al-MCM-41 system was more active than NiIL-MCM-41 system and showed an activity of 2.3 s−1 with 90% selectivity in 1-butenes.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050717
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 718: Frequency Comb-Based WDM Transmission
           Systems Enabling Joint Signal Processing

    • Authors: Lars Lundberg, Magnus Karlsson, Abel Lorences-Riesgo, Mikael Mazur, Victor Torres-Company, Jochen Schröder, Peter A. Andrekson
      First page: 718
      Abstract: We review the use of optical frequency combs in wavelength-division multiplexed (WDM) fiber optic communication systems. In particular, we focus on the unique possibilities that are opened up by the stability of the comb-line spacing and the phase coherence between the lines. We give an overview of different techniques for the generation of optical frequency combs and review their use in WDM systems. We discuss the benefits of the stable line spacing of frequency combs for creating densely-packed optical superchannels with high spectral efficiency. Additionally, we discuss practical considerations when implementing frequency-comb-based transmitters. Furthermore, we describe several techniques for comb-based superchannel receivers that enables the phase coherence between the lines to be used to simplify or increase the performance of the digital carrier recovery. The first set of receiver techniques is based on comb-regeneration from optical pilot tones, enabling low-overhead self-homodyne detection. The second set of techniques takes advantage of the phase coherence by sharing phase information between the channels through joint digital signal processing (DSP) schemes. This enables a lower DSP complexity or a higher phase-noise tolerance.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050718
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 719: Multiwavelength Absolute Phase
           Retrieval from Noisy Diffractive Patterns: Wavelength Multiplexing

    • Authors: Vladimir Katkovnik, Igor Shevkunov, Nikolay V. Petrov, Karen Eguiazarian
      First page: 719
      Abstract: We study the problem of multiwavelength absolute phase retrieval from noisy diffraction patterns. The system is lensless with multiwavelength coherent input light beams and random phase masks applied for wavefront modulation. The light beams are formed by light sources radiating all wavelengths simultaneously. A sensor equipped by a Color Filter Array (CFA) is used for spectral measurement registration. The developed algorithm targeted on optimal phase retrieval from noisy observations is based on maximum likelihood technique. The algorithm is specified for Poissonian and Gaussian noise distributions. One of the key elements of the algorithm is an original sparse modeling of the multiwavelength complex-valued wavefronts based on the complex-domain block-matching 3D filtering. Presented numerical experiments are restricted to noisy Poissonian observations. They demonstrate that the developed algorithm leads to effective solutions explicitly using the sparsity for noise suppression and enabling accurate reconstruction of absolute phase of high-dynamic range.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050719
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 720: Improvement of the Torque-Speed
           Performance and Drive Efficiency in an SRM Using an Optimal Torque Sharing

    • Authors: Wei Ye, Qishuang Ma, Poming Zhang
      First page: 720
      Abstract: In this paper, by evaluating the extreme value of the qth-power current, a torque sharing function (TSF) family for reducing the torque ripples in the switched reluctance motor (SRM) is proposed. The optimization criteria of the TSF has two secondary objectives, including the maximization of the torque-speed range and the minimization of copper loss. The evaluation indices in terms of the peak phase current, the rms (root mean square) phase current, and the torque ripple factor are compared between the proposed TSF family and four conventional TSFs including linear, sinusoidal, exponential, and cubic TSFs. An optimization objective function that combines the maximum absolute value of the rate-of-change of the flux linkage (MAV-RCFL) and the qth-power of current is proposed and a weighting factor is used to balance the influence of the two optimization objectives. An optimal TSF can be easily obtained by solving the optimization problem from the TSF family. The proposed TSF is validated by using simulations and experiments with a three-phase 6/4 SRM with 7.5 kW, 3000 rpm, and 270 V DC-link voltage. The dynamic simulation model is implemented in Matlab/Simulink. The results demonstrate the validity and superiority of the proposed control method; the optimal TSF provides better torque-speed performance, and a better reduction in copper loss and torque ripples at high speed, as compared to conventional TSFs.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050720
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 721: Deep Embedment (DE) FRP Shear
           Strengthening of Concrete Bridge Slabs under Loads Close to Supports

    • Authors: Lipeng Xia, Yu Zheng
      First page: 721
      Abstract: Shear forces are the most common governing failure mechanism of reinforced concrete bridge deck slabs subjected to loads close to their supports. This paper reveals a comprehensive study of the behaviour of concrete slabs shear-strengthened with a deep embedment fibre reinforced polymer (FRP) technique. In the experimental investigation, a series of eight full scale concrete slabs were created and tested up to failure. Several structural variables were changed to assess the effectiveness of this shear strengthening technique. The behaviour of test slabs is discussed and the influence of this strategy was evaluated by comparing the test results. It was shown that brittle shear failures could be avoided by using this strengthening strategy. The ultimate capacity and deflection at the failure were both enhanced by using the deep embedment strengthening method. Additionally, a nonlinear finite element analysis (NLFEA) was proposed to develop further investigation. This NLFEA model gave excellent predictions for the structural behaviour of the test concrete slabs. Finally, a two-way theoretical model was proposed to predict the loading-carrying capacity of concrete slabs strengthened with deep embedment FRP bars. The ultimate strength predicted by this theoretical method showed good agreement with that from the test results.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050721
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 722: Learning Frameworks for Cooperative
           Spectrum Sensing and Energy-Efficient Data Protection in Cognitive Radio

    • Authors: Vinh Quang Do, Insoo Koo
      First page: 722
      Abstract: This paper studies learning frameworks for energy-efficient data communications in an energy-harvesting cognitive radio network in which secondary users (SUs) harvest energy from solar power while opportunistically accessing a licensed channel for data transmission. The SUs perform spectrum sensing individually, and send local decisions about the presence of the primary user (PU) on the channel to a fusion center (FC). We first design a new cooperative spectrum-sensing technique based on a convolutional neural network in which the FC uses historical sensing data to train the network for classification problem. The system is assumed to operate in a time-slotted manner. At the beginning of each time slot, the FC uses the current local decisions as input for the trained network to decide whether the PU is active or not in that time slot. In addition, legitimate transmissions can be vulnerable to a hidden eavesdropper, which always passively listens to the communication. Therefore, we further propose a transfer learning actor–critic algorithm for an SU to decide its operation mode to increase the security level under the constraint of limited energy. In this approach, the SU directly interacts with the environment to learn its dynamics (i.e., an arrival of harvested energy); then, the SU can either stay idle to save energy or transmit to the FC secured data that are encrypted using a suitable private-key encryption method to maximize the long-term effective security level of the network. We finally present numerical simulation results under various configurations to evaluate our proposed schemes.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050722
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 723: A Novel Robust Audio Watermarking
           Algorithm by Modifying the Average Amplitude in Transform Domain

    • Authors: Qiuling Wu, Meng Wu
      First page: 723
      Abstract: In order to improve the robustness and imperceptibility in practical application, a novel audio watermarking algorithm with strong robustness is proposed by exploring the multi-resolution characteristic of discrete wavelet transform (DWT) and the energy compaction capability of discrete cosine transform (DCT). The human auditory system is insensitive to the minor changes in the frequency components of the audio signal, so the watermarks can be embedded by slightly modifying the frequency components of the audio signal. The audio fragments segmented from the cover audio signal are decomposed by DWT to obtain several groups of wavelet coefficients with different frequency bands, and then the fourth level detail coefficient is selected to be divided into the former packet and the latter packet, which are executed for DCT to get two sets of transform domain coefficients (TDC) respectively. Finally, the average amplitudes of the two sets of TDC are modified to embed the binary image watermark according to the special embedding rule. The watermark extraction is blind without the carrier audio signal. Experimental results confirm that the proposed algorithm has good imperceptibility, large payload capacity and strong robustness when resisting against various attacks such as MP3 compression, low-pass filtering, re-sampling, re-quantization, amplitude scaling, echo addition and noise corruption.
      Citation: Applied Sciences
      PubDate: 2018-05-04
      DOI: 10.3390/app8050723
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 724: Accurate and Detailed Transversal
           Road Section Characteristics Extraction Using Laser Scanner

    • Authors: Felipe Jiménez, Miguel Clavijo, Fernando Castellanos, Carlos Álvarez
      First page: 724
      Abstract: Road vehicle lateral positioning is a key aspect of many assistance applications and autonomous driving. However, conventional GNSS-based positioning systems and fusion with inertial systems are not able to achieve these levels of accuracy under real traffic conditions. Onboard perception systems provide knowledge of the surroundings of the vehicle, and some algorithms have been proposed to detect road boundaries and lane lines. This information could be used to locate the vehicle in the lane. However, most proposed algorithms are quite partial and do not take advantage of a complete knowledge of the road section. This paper proposes an integrated approach to the two tasks that provides a higher level of robustness of results: road boundaries detection and lane lines detection. Furthermore, the algorithm is not restricted to certain scenarios such as the detection of curbs; it could be also used in off-road tracks. The functions have been tested in real environments and their capabilities for autonomous driving have been verified. The algorithm is ready to be merged with digital map information; this development would improve results accuracy.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050724
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 725: Influence of Synthesis Parameters in
           Obtaining KIT-6 Mesoporous Material

    • Authors: Fernando R. D. Fernandes, Francisco G. H. S. Pinto, Ewelanny L. F. Lima, Luiz D. Souza, Vinícius P. S. Caldeira, Anne G. D. Santos
      First page: 725
      Abstract: In the present work, modifications were made in the typical synthesis of KIT-6 mesoporous material. The molar ratio of P123 and its dissolution time, the type of alcohol, the aging time, and the heat treatment time were varied. The materials obtained were characterized by X-ray diffraction (XRD), thermogravimetry and differential thermogravimetry (TG/DTG), Fourier-transform infrared spectroscopy (FTIR), adsorption and desorption of N2 and transmission electron microscopy (TEM). It was observed that the modifications interfered directly in the ordered structure of materials, displaying materials with cubic structures Ia3d (KIT-6 mesoporous material) and hexagonal structures P6mm, (SBA-15 mesoporous material). The type of alcohol probably acts on generation of the micelle, influencing the formation of the porous system and ordered structure. The results obtained indicate that the cubic structure of KIT-6 can be formed with a reduction of 30% in the P123 concentration, and decreases of 2, 6 and 12 h in times of P123 dissolution, aging and heat treatment, respectively. The modifications carried out in the synthesis procedure have resulted in ir being possible to employ materials with different characteristics, such as mesoscopic ordering and textural properties, in applications in the areas of catalysis and adsorption.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050725
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 726: Contact Pressure Algorithm of
           Multi-Layer Interference Fit Considering Centrifugal Force and Temperature

    • Authors: Zebing Bai, Jianmei Wang, Ke Ning, Dingbang Hou
      First page: 726
      Abstract: In order to optimize the algorithm on contact pressure and interference magnitude of multi-layer interference cylinders, the effects of centrifugal force and temperature gradient on the performance of multi-layer interference cylinders are considered. The mathematical matrix model of contact pressure and interference magnitude of multi-layer interference cylinder is constructed under centrifugal force and temperature gradient. Four kinds of interference cylinder models are established, and the numerical solutions using finite element methods are compared with the analytical solutions. The results show that the contact pressure of each contact surface of multi-layer interference cylinder decreases with speed increase; the slip rate of contact pressure increases with speed increase; the maximum radial displacement of an interference cylinder under centrifugal force occurs at the outermost layer. The contact pressure of a multi-layer interference cylinder decreases linearly with the increase of temperature gradient. The analytical solution is basically consistent with the numerical solution, and the maximum relative error of midpoint is 11.62% and −7.69% under two factors. It means that the algorithm can provide a theoretical guide for the design of a multi-layer interference cylinder considering centrifugal force and temperature gradient.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050726
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 727: A Hybrid Ultrasonic Guided Wave-Fiber
           Optic System for Flaw Detection in Pipe

    • Authors: Joseph L. Rose, Jason Philtron, Guigen Liu, Yupeng Zhu, Ming Han
      First page: 727
      Abstract: The work presented in this paper shows that Fiber Bragg Grating (FBG) optical fiber sensors can potentially be used as receivers in a long-range guided wave torsional-mode pipe inspection system. Benefits over the conventional pulse-echo method arise due to reduced total travel distance of the ultrasonic guided wave reflections, since reflections from defects and structural features do not need to propagate a full round trip back to the transmitting collar. This is especially important in pipe configurations with high attenuation, such as coated and buried pipelines. The use of FBGs as receivers instead of conventional piezoelectric or magnetostrictive elements also significantly reduces cabling, since multiple FBG receivers can be placed along a single optical fiber which has a diameter on the order of only around 100 μm. The basic approach and sample results are presented in the paper. Additionally, a brief overview of some topics in ultrasonic guided waves is presented as a background to understand the inspection problem presented here.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050727
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 728: Theoretical Study: High Harmonic
           Generation by Light Transients

    • Authors: Maximilian Wendl, Maximilian Högner, Hanieh Fattahi
      First page: 728
      Abstract: The dynamic of electron densities in matter upon the interaction with an intense, few-cycle electric field of light causes variety of nonlinear phenomena. Capturing the spatiotemporal dynamics of electrons calls for isolated attosecond pulses in the X-ray regime, with sufficient flux to allow for: (i) attosecond pump–attosecond probe spectroscopy; or (ii) four-dimensional imaging. Light field synthesizers generate arbitrary sub-cycle, non-sinusoidal waveforms. They have a great potential to overcome the limitations of current laser sources and to extend attosecond pulses towards the X-ray regime. In this paper, we show theoretically how the achievable high-energy, high-power waveforms from current light field synthesizers can be optimized to enhance the harmonic yield at high photon energies and can serve as a promising source for scaling the photon energies of attosecond pulses. We demonstrate that the simulated optimized, non-sinusoidal waveform in this work can increase the photon flux of keV, attosecond pulses by five orders of magnitude compared to the achievable flux from longer wavelength sources and at similar photon energies.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050728
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 729: Exploration of Swarm Dynamics
           Emerging from Asymmetry

    • Authors: Naoki Nishikawa, Reiji Suzuki, Takaya Arita
      First page: 729
      Abstract: A swarm might exhibit interesting motions or structures when it includes different types of agents. On a swarm model named Swarm Chemistry, some interesting patterns can appear if the parameters are well-tuned. However, there is a hurdle for us to get capable of tuning the parameters by automatic searching methods like a genetic algorithm, particularly because defining interestingness itself is a challenging issue. This paper aims to investigate how interesting patterns can be detected, comparing seven measures from an aspect of system asymmetries. Based on numerical experiments, the effects of changing kinetic parameters are discussed, finding that: (1) segregating patterns, which are frequently observed but uninteresting, tend to appear when the perception range is small and normal (ideal) speed is large or when cohesive force is weak and separating force is strong; (2) asymmetry of information transfer represented by topological connectivity is an effective way to characterize the interestingness; (3) pulsation-like patterns can be captured well by using time-derivative of state variables like network-degrees; (4) it helps capture a gradual structural deformation when fitness function adopts the mean over min-max differences of state variables. The findings will help the efficient search of already-discovered or undiscovered interesting swarm dynamics.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050729
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 730: Evaluation of Fe-Based Shape Memory
           Alloy (Fe-SMA) as Strengthening Material for Reinforced Concrete

    • Authors: Kinam Hong, Sugyu Lee, Sanghoon Han, Yeongmo Yeon
      First page: 730
      Abstract: This paper aims to evaluate potential of an Fe-based shape memory alloy (Fe-SMA) for strengthening civil structures. Mechanical properties of the Fe-SMA were investigated with a direct tensile test, which showed the stress-induced transformation, stress at fracture of the Fe-SMA, and modulus of elasticity. Heating temperature ranging from 110 ℃ to 220 ℃ and pre-straining level ranging from 2% to 8% of the Fe-SMA were considered as variables to provoke a shape memory effect (SME), which generates a recovery stress. The recovery stresses ranged from 207.59 MPa to 438.61 MPa, which plays a role in introducing a pre-stressing force to concrete members. Bonding behavior of the Fe-SMA embedded into a groove with a cement-based mortar filler was investigated to determine the required bonding length to fully develop the pre-stressing force of the Fe-SMA with a near-surface mounted (NSM) strengthening technique. All the tested specimens showed slippage failure and suggested a minimum bonding length of 600 mm. The pre-stressing force applied on the concrete can be calculated with the recovery stress of the Fe-SMA. Based on those test results, the Fe-SMA shows sufficient potential to be used as strengthening material for civil structures.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050730
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 731: Non-Linear Bending of Functionally
           Graded Thin Plates with Different Moduli in Tension and Compression and
           Its General Perturbation Solution

    • Authors: He, Li, Liu, Yang, Sun
      First page: 731
      Abstract: In this study, a set of Föppl–von Kármán equations for a bimodular functionally graded thin plate subjected to a uniformly distributed load is established, and its general perturbation solution in axisymmetric case is also obtained under different boundary conditions. First, the equation of equilibrium of the plate is established on the existence of the neutral layer when considering different properties in tension and compression. During the derivation of the consistency equation, the tensile effect in the thin plate with bimodular effect is fully taken into account. The perturbation method is used to solve the set of governing equations under different edge constraints, in which the central deflection and the load of the plate are taken as a perturbation parameter, respectively. The results indicate that the two selections for perturbation parameters are valid and consistent, and the two solutions are convenient for engineering application. This study also shows that the bimodular effect will modify the relation of load versus central deflection of the plate to some extent, and under the same edge constraint, the capacities resisting deformation in different cases of moduli depend on the relative magnitudes among the tensile modulus, the neutral layer modulus, and the compressive modulus.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050731
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 732: Analysis and Modelling of Shrinkage
           and Creep of Reactive Powder Concrete

    • Authors: Pang Chen, Wenzhong Zheng, Ying Wang, Wei Chang
      First page: 732
      Abstract: The objective of this study was to examine the shrinkage and creep of reactive power concrete (RPC) with different steel fibre contents (0%, 1% and 2% by volume). A total of 37 RPC specimens were prepared and tested for compression strength, elastic modulus, shrinkage, and creep. In addition, different axial stress ratios (0.2, 0.3 and 0.4) were used in the creep tests. Furthermore, the accuracy of the ACI 209-82 model, CEB-FIP 90 model, B3 model, and GL 2000 model for predicting the shrinkage and creep of RPC was evaluated and new numerical shrinkage and creep models were developed. The experimental results revealed that the compressive strength and elastic modulus increase with increasing steel fibre content. The shrinkage and creep decreased with increasing addition of steel fibre from 0% to 2%. A good linear relationship was found between the axial stress ratios and creep strain. All four existing models were unable to accurately predict the shrinkage and creep of RPC. A good agreement between the experimental results and proposed shrinkage and creep numerical models was observed. Therefore, it is suggested that the proposed shrinkage and creep models can be used to calculate the shrinkage and creep of RPC.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050732
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 733: A Gas-Kinetic BGK Scheme for Natural
           Convection in a Rotating Annulus

    • Authors: Zhou, Lu, Guo
      First page: 733
      Abstract: In this paper, a gas-kinetic Bhatnagar–Gross–Krook (BGK) scheme is developed for simulating natural convection in a rotating annulus, which arises in many scientific and engineering fields. Different from most existing methods for the solution of the incompressible Navier–Stokes (N–S) equations with the Boussinesq approximation, compressible full N–S equations with allowable density variation are concerned. An appropriate BGK model is constructed for the macroscopic equations defined in a rotating frame of reference. In particular, in order to account for the source (non-inertial) effects in the BGK model, a microscopic source term is introduced into the modified Boltzmann equation. By using the finite volume method and assuming the flow is smooth, the time-dependent distribution function is simply obtained, from which the fluxes at the cell interface can be evaluated. For validation, a closed rotating annulus with differentially heated cylindrical walls is studied. A conventional N–S solver with the preconditioner is used for comparison. The numerical results show that the present method can accurately predict the variation of the Nusselt number with the Rayleigh number, but no preconditioning is required due to its delicate dissipation property. The computed instantaneous streamlines and temperature contours are also investigated, and it is verified that the Rayleigh–Bénard convection in a rotating annulus is very similar to that in a classical stationary horizontal enclosure.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050733
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 734: Adaptive Noise Cancellation Based on
           Time Delay Estimation for Low Frequency Communication

    • Authors: Peng Wang, Xiaotong Zhang, Liyuan Xu, Zhiyang Liu, Yadong Wan
      First page: 734
      Abstract: Low frequency communication, taking advantage of the features of low frequency electromagnetic signals in near field, is widely used in through-the-earth (TTE) wireless applications. However, the low frequency non-Gaussian noise severely limits the communication performance. In this paper, an adaptive noise cancellation algorithm based on time delay estimation (ANC-TDE) and maximum correntropy criterion (MCC) is proposed. The explicit time delay estimation algorithm based on MCC (MCC-ETDE) is used to estimate the time-varying delay and the noise correlationship between the primary input and reference inputs. With a reference noise selected and time delay compensated, the non-Gaussian noise is canceled by adaptive filter based on MCC. The proposed algorithm is implemented on field programmable gate array (FPGA) and the performance is evaluated by simulation and experiment. As shown in the results, the ANC-TDE algorithm can reduce the complexity of ANC filter and adaptively compensate the varied time delay between the primary input and reference input. With the time delay compensated, the ANC-TDE algorithm has better performance in non-Gaussian noise environment and is more suitable for real-time systems.
      Citation: Applied Sciences
      PubDate: 2018-05-05
      DOI: 10.3390/app8050734
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 735: Control of Carrier Concentration by
           Ag Doping in N-Type Bi2Te3 Based Compounds

    • Authors: Jae Lee, Ji Son, Yong-Il Kim, Byungki Ryu, Byung Cho, Sookyung Kim, Su-Dong Park, Min-Wook Oh
      First page: 735
      Abstract: Many elements have been used as dopants to enhance the thermoelectric performance of Bi2Te3-related materials. Among them, Ag’s effect on thermoelectric properties, where Ag acts as a donor or acceptor, remains unclear. To elucidate the role of Ag in n-type Bi2Te3 based compounds, Ag was added to n-type (Bi0.9Sb0.1)2(Te0.85Se0.15)3. As the amount of Ag was increased, the electron concentration decreased, which means Ag acted as an acceptor. The added Ag atoms were found to occupy interstitial sites in the hexagonal lattices, as confirmed by X-ray analysis and first principles calculations. The reduction in electron concentration was attributed to the interaction between the interstitial Ag and intrinsic defects.
      Citation: Applied Sciences
      PubDate: 2018-05-06
      DOI: 10.3390/app8050735
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 736: MHD Steady/Unsteady Porous Boundary
           Layer of Cu–Water Nanofluid with Micropolar Effect over a Permeable

    • Authors: Kamal Raslan, Selim Mohamadain, Mohamed Abdel-wahed, Elsayed M. Abedel-aal
      First page: 736
      Abstract: This work provides a mathematical model for the cooling process of a moving surface, in the presence of a uniform external magnetic field and thermal radiation, through a porous medium by using a weak concentration micropolar nanofluid. The model—based on the conservation equations of the unsteady case in the momentum and thermal boundary layer—takes into consideration the effect of the suction process. The conservation equations were transformed into ordinary differential equations using similar transformation techniques. The equations were solved numerically for the general case and analytically for the steady case. The rate of heat transfer, couple shear stress, and surface shear stress are deduced. We discuss the impact of these physical characteristics on the mechanical properties of the surface that will be cooled.
      Citation: Applied Sciences
      PubDate: 2018-05-07
      DOI: 10.3390/app8050736
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 737: A Shack-Hartmann Sensor for
           Single-Shot Multi-Contrast Imaging with Hard X-rays

    • Authors: Tomy dos Santos Rolo, Stefan Reich, Dmitry Karpov, Sergey Gasilov, Danays Kunka, Edwin Fohtung, Tilo Baumbach, Anton Plech
      First page: 737
      Abstract: An array of compound refractive X-ray lenses (CRL) with 20 × 20 lenslets, a focal distance of 20cm and a visibility of 0.93 is presented. It can be used as a Shack-Hartmann sensor for hard X-rays (SHARX) for wavefront sensing and permits for true single-shot multi-contrast imaging the dynamics of materials with a spatial resolution in the micrometer range, sensitivity on nanosized structures and temporal resolution on the microsecond scale. The object’s absorption and its induced wavefront shift can be assessed simultaneously together with information from diffraction channels. In contrast to the established Hartmann sensors the SHARX has an increased flux efficiency through focusing of the beam rather than blocking parts of it. We investigated the spatiotemporal behavior of a cavitation bubble induced by laser pulses. Furthermore, we validated the SHARX by measuring refraction angles of a single diamond CRL, where we obtained an angular resolution better than 4 μ rad.
      Citation: Applied Sciences
      PubDate: 2018-05-07
      DOI: 10.3390/app8050737
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 738: Algorithm for Virtual Aggregates’
           Reconstitution Based on Image Processing and Discrete-Element Modeling

    • Authors: Danhua Wang, Xunhao Ding, Tao Ma, Weiguang Zhang, Deyu Zhang
      First page: 738
      Abstract: Based on the Aggregate Imaging Measurement System (AIMS) and the Particle Flow Code in Two Dimensions (PFC2D), an algorithm for modeling two-dimensional virtual aggregates was proposed in this study. To develop the virtual particles precisely, the realistic shapes of the aggregates were captured by the AIMS firstly. The shape images were then processed, and the morphological characteristics of aggregates were quantified by the angularity index. By dividing the particle irregular shape into many triangle areas and adjusting the positions of the generated balls via coordinate systems’ conversion within PFC2D, the virtual particles could be reconstructed accurately. By calculating the mapping area, the gradations in two-dimensions could be determined. Controlled by two variables (μ_1 and μ_2), which were drawn from the uniform distribution (0, 1), the virtual particles forming the specimens could be developed with random sizes and angular shapes. In the end, the rebuilt model of the SMA-13 aggregate skeleton was verified by the virtual penetration tests. The results indicated that the proposed algorithm can not only model the realistic particle shape and gradations precisely, but also predict its mechanical behavior well.
      Citation: Applied Sciences
      PubDate: 2018-05-07
      DOI: 10.3390/app8050738
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 739: Captioning Transformer with Stacked
           Attention Modules

    • Authors: Xinxin Zhu, Lixiang Li, Jing Liu, Haipeng Peng, Xinxin Niu
      First page: 739
      Abstract: Image captioning is a challenging task. Meanwhile, it is important for the machine to understand the meaning of an image better. In recent years, the image captioning usually use the long-short-term-memory (LSTM) as the decoder to generate the sentence, and these models show excellent performance. Although the LSTM can memorize dependencies, the LSTM structure has complicated and inherently sequential across time problems. To address these issues, recent works have shown benefits of the Transformer for machine translation. Inspired by their success, we develop a Captioning Transformer (CT) model with stacked attention modules. We attempt to introduce the Transformer to the image captioning task. The CT model contains only attention modules without the dependencies of the time. It not only can memorize dependencies between the sequence but also can be trained in parallel. Moreover, we propose the multi-level supervision to make the Transformer achieve better performance. Extensive experiments are carried out on the challenging MSCOCO dataset and the proposed Captioning Transformer achieves competitive performance compared with some state-of-the-art methods.
      Citation: Applied Sciences
      PubDate: 2018-05-07
      DOI: 10.3390/app8050739
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 740: A Hydraulic Semi-Active Suspension
           Based on Road Statistical Properties and Its Road Identification

    • Authors: Leilei Zhao, Yuewei Yu, Changcheng Zhou, Shufeng Wang, Fuxing Yang, Song Wang
      First page: 740
      Abstract: The existing semi-active suspensions are very expensive and difficult to be popularized. Therefore, the search for the low-cost semi-active suspension has become a hotspot. To reduce the product cost of semi-active suspensions, this study proposed a new hydraulic semi-active suspension system based on road statistical properties and creates an identification method of road conditions. Firstly, the working process of the proposed semi-active suspension was given. Then, the formula for calculating the mean square value of the body acceleration under the running road condition was derived. Based on the formula, the road identification method was created. Finally, the road test was carried out using a test vehicle. The identified road PSD (power spectral density) values are all consistent with the real values. The test results show that the road identification method can effectively perceive the actual road grades. The identification interval with 20 s can meet the requirements of practical applications. The slight fluctuation of the running speed v has little effect on the identification results because of the statistical characteristics of road conditions.
      Citation: Applied Sciences
      PubDate: 2018-05-08
      DOI: 10.3390/app8050740
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 741: Failure Pattern Transition of Shape
           Memory NiTi Foam Subjected to Compression: From Quasi-Static to Dynamic

    • Authors: Xiaojuan Wang, Hongyuan Zhou
      First page: 741
      Abstract: Shape memory alloy can recover its original configuration, while lightweight foam can absorb a considerable amount of energy. It is desirable to test whether shape memory foam has merits in terms of both shape memory effect and exceptional energy absorption capacity. In the present study, shape memory NiTi foam is compressed quasi-statically and dynamically in order to investigate its response and failure pattern transition with an increasing loading rate. A universal testing machine is used in a quasi-static test, while the split Hopkinson pressure bar is employed in the dynamic test. It is observed that the NiTi foam fails differently: under a quasi-static load, small foam parts of various sizes fall off from the specimen fringe; meanwhile, under dynamic load, the foam fractures in the specimen center to split it into multiple pieces. The underlying failure mechanisms accounting for the shape memory foam behavior under different loading rates are discussed.
      Citation: Applied Sciences
      PubDate: 2018-05-08
      DOI: 10.3390/app8050741
      Issue No: Vol. 8, No. 5 (2018)
  • Applied Sciences, Vol. 8, Pages 642: Stability Analysis of
           Stagnation-Point Flow in a Nanofluid over a Stretching/Shrinking Sheet
           with Second-Order Slip, Soret and Dufour Effects: A Revised Model

    • Authors: Najwa Najib, Norfifah Bachok, Norihan Md Arifin, Fadzilah Md Ali
      First page: 642
      Abstract: The mathematical model of the two-dimensional steady stagnation-point flow over a stretching or shrinking sheet of nanofluid in the presence of the Soret and Dufour effects and of second-order slip at the boundary was considered in this paper. The partial differential equations were transformed into the ordinary differential equations by applying a suitable similarity transformation. The numerical results were obtained by using bvp4c codes in Matlab. The skin friction coefficient, heat transfer coefficient, mass transfer coefficient, as well as the velocity, temperature, and concentration profiles were presented graphically for different values of slip parameters, Soret effect, Dufour effect, Brownian motion parameter, and thermophoresis parameter. A dual solution was obtained in this present paper. The presence of the slip parameters (first- and second-order slip parameters) was found to expand the range of solutions. However, the presence of the slip parameters led to a decrease in the skin friction coefficient, whereas the heat transfer coefficient increased. Besides that, a larger Soret effect (smallest Dufour effect) led to the decrement of the heat transfer coefficient. The effects of the Brownian motion and thermophoresis parameters on the heat transfer coefficient were also studied in this paper. A stability analysis was performed in this paper to verify the stability of the solutions obtained.
      Citation: Applied Sciences
      PubDate: 2018-04-20
      DOI: 10.3390/app8040642
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 643: Carbon Nanotube Mode-Locked Fiber
           Laser Generating Cylindrical Vector Beams with a Two-Mode Fiber Bragg

    • Authors: Yu Cai, Jiaojiao Zhang, Changle Wang, Lin Zhang, Zuxing Zhang
      First page: 643
      Abstract: We propose and demonstrate a compact all-fiber laser generating cylindrical vector beam (CVB) using carbon nanotubes as the saturable absorber for mode-locking and a two-mode fiber Bragg grating (TM-FBG) as the mode discriminator. Both radially and azimuthally polarized beams with a polarization purity of 90% were obtained by simply adjusting the polarization controllers. The CVB mode-locked fiber laser operates at 1552.9 nm with a 3-dB line width of less than 0.02 nm, generating ns CVB pulses. The all-fiber CVB laser may have potential applications from fundamental research to practical applications, such as particle capture, high-resolution measurement and material processing.
      Citation: Applied Sciences
      PubDate: 2018-04-20
      DOI: 10.3390/app8040643
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 644: Camera Calibration with
           Phase-Shifting Wedge Grating Array

    • Authors: Jiayuan Tao, Yuwei Wang, Bolin Cai, Keyi Wang
      First page: 644
      Abstract: Planar targets with known features have been widely used for camera calibration in various vision systems. This paper utilizes phase-shifting wedge grating (PWG) arrays as an active calibration target. Features points are encoded into the carrier phase, which can be accurately calculated using the phase-shifting algorithm. The 2π-phase points are roughly extracted with edge detection and then optimized by windowed bicubic fitting with sub-pixel accuracy. Two 2π-phase lines for each PWG are obtained using linear fitting method. The PWG centers that are used as feature points are detected through computing the intersections of 2π-phase lines. Experiment results indicate that the proposed method is accurate and reliable.
      Citation: Applied Sciences
      PubDate: 2018-04-20
      DOI: 10.3390/app8040644
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 645: A Review of MEMS Scale Piezoelectric
           Energy Harvester

    • Authors: Wenchao Tian, Zongyu Ling, Wenbo Yu, Jing Shi
      First page: 645
      Abstract: Piezoelectric energy harvester (PEH) is emerging as a novel device which can convert mechanical energy into electrical energy. It is mainly used to collect ambient vibration energy to power sensors, chips and some other small applications. This paper first introduces the working principle of PEH. Then, the paper elaborates the research progress of PEH from three aspects: piezoelectric materials, piezoelectric modes and energy harvester structures. Piezoelectric material is the core of the PEH. The piezoelectric and mechanical properties of piezoelectric material determine its application in energy harvesting. There are three piezoelectric modes, d31, d33 and d15, the choice of which influences the maximum output voltage and power. Matching the external excitation frequency maximizes the conversion efficiency of the energy harvester. There are three approaches proposed in this paper to optimize the PEH’s structure and match the external excitation frequency, i.e., adjusting the resonant frequency, frequency up-converting and broadening the frequency bandwidth. In addition, harvesting maximum output power from the PEH requires impedance matching. Finally, this paper analyzes the above content and predicts PEH’s future development direction.
      Citation: Applied Sciences
      PubDate: 2018-04-20
      DOI: 10.3390/app8040645
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 646: Proposing Enhanced Feature
           Engineering and a Selection Model for Machine Learning Processes

    • Authors: Muhammad Fahim Uddin, Jeongkyu Lee, Syed Rizvi, Samir Hamada
      First page: 646
      Abstract: Machine Learning (ML) requires a certain number of features (i.e., attributes) to train the model. One of the main challenges is to determine the right number and the type of such features out of the given dataset’s attributes. It is not uncommon for the ML process to use dataset of available features without computing the predictive value of each. Such an approach makes the process vulnerable to overfit, predictive errors, bias, and poor generalization. Each feature in the dataset has either a unique predictive value, redundant, or irrelevant value. However, the key to better accuracy and fitting for ML is to identify the optimum set (i.e., grouping) of the right feature set with the finest matching of the feature’s value. This paper proposes a novel approach to enhance the Feature Engineering and Selection (eFES) Optimization process in ML. eFES is built using a unique scheme to regulate error bounds and parallelize the addition and removal of a feature during training. eFES also invents local gain (LG) and global gain (GG) functions using 3D visualizing techniques to assist the feature grouping function (FGF). FGF scores and optimizes the participating feature, so the ML process can evolve into deciding which features to accept or reject for improved generalization of the model. To support the proposed model, this paper presents mathematical models, illustrations, algorithms, and experimental results. Miscellaneous datasets are used to validate the model building process in Python, C#, and R languages. Results show the promising state of eFES as compared to the traditional feature selection process.
      Citation: Applied Sciences
      PubDate: 2018-04-20
      DOI: 10.3390/app8040646
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 647: Novel Guidance CPS Based on the
           FatBeacon Protocol

    • Authors: Moisés Lodeiro-Santiago, Iván Santos-González, Cándido Caballero-Gil, Pino Caballero-Gil, Félix Herrera-Priano
      First page: 647
      Abstract: Throughout this work, the use of a new technology is proposed to give an innovative solution to the problem of indoor and outdoor positioning and a guidance system in areas where there is no coverage of Internet or global positioning systems. This novel solution is based on the Bluetooth protocol called FatBeacon, created by Google, which can be used in places such as subway stations located below ground, outdoor areas where even 2G coverage is unreachable or simply as an alternative to current technologies that may require an additional cost, such as the Internet in some countries. In particular, this work describes a new solution for supporting tourism called Smart Tourism for which an interactive and non-intrusive guidance application based on the FatBeacon protocol is presented. The developed application informs the users about the way to reach their destination without getting lost and can be used to obtain user data tracking anonymously. In this way, the cooperation between the different systems and components of the scheme creates a distributed ecosystem that is independent of an Internet connection. Since no FatBeacon implementations can be found yet, an experimental implementation was developed to test the proposal, and the obtained results are promising.
      Citation: Applied Sciences
      PubDate: 2018-04-20
      DOI: 10.3390/app8040647
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 648: Energy Management Scheme for an EV
           Smart Charger V2G/G2V Application with an EV Power Allocation Technique
           and Voltage Regulation

    • Authors: Saad Ullah Khan, Khawaja Khalid Mehmood, Zunaib Maqsood Haider, Syed Basit Ali Bukhari, Soon-Jeong Lee, Muhammad Kashif Rafique, Chul-Hwan Kim
      First page: 648
      Abstract: The increasing penetration of electric vehicles (EVs) in the distribution grid has established them as a prospective resource for ancillary services. These services require adequate control strategies for prompt and efficient operation. In this study, an energy management scheme (EMS) has been proposed to employ an off-board EV smart charger to support the grid during short-term variance of renewables and reactive load onset. The scheme operates by calculating power references for the charger instantaneously. The EMS incorporates a proportional power division methodology, proposed to allocate power references to the individual EVs connected to the charger DC-bus. This methodology considers the state-of-charge and battery sizes of the EVs, and it can aggregate energy from various types of EVs. The proposed scheme is compared with another power allocation method, and the entire EMS is tested under the scenarios of power mismatch and voltage sag/swell events. The results show that the proposed scheme achieves the goal of the aggregation of EVs at the charger level to support the grid. The EMS also fulfills the objectives of voltage regulation and four-quadrant operation of the smart charger.
      Citation: Applied Sciences
      PubDate: 2018-04-21
      DOI: 10.3390/app8040648
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 649: Lyapunov Equivalent Representation
           Form of Forced, Damped, Nonlinear, Two Degree-of-Freedom Systems

    • Authors: Alex Elías-Zúñiga, Luis M. Palacios-Pineda, Daniel Olvera-Trejo, Oscar Martínez-Romero
      First page: 649
      Abstract: The aim of this paper focuses on finding equivalent representation forms of forced, damped, two degree-of-freedom, nonlinear systems in the sense of Lyapunov by using a nonlinear transformation approach that provides decoupled, forced, damped, nonlinear equations of the Duffing type, under the assumption that the driving frequency and the external forces are equal in both systems. The values of Lyapunov characteristic exponents (LCEs), Lyapunov largest exponents (LLE), and time-amplitude and frequency-amplitude curves computed from numerical integration solutions, indicate that the decoupled Duffing-type equations are equivalent, in the sense of Lyapunov, to the original dynamic system, since both set of motion equations tend to have the same qualitative and quantitative behaviors.
      Citation: Applied Sciences
      PubDate: 2018-04-21
      DOI: 10.3390/app8040649
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 650: Dynamic Response of a Long-Span
           Concrete-Filled Steel Tube Tied Arch Bridge and the Riding Comfort of
           Monorail Trains

    • Authors: Hongye Gou, Wen Zhou, Changwei Yang, Yi Bao, Qianhui Pu
      First page: 650
      Abstract: In this study, a dynamic response analysis procedure is proposed and applied to investigate the dynamic responses of a straddle-type concrete-filled steel tube tied arch bridge under train and truck loadings. A numerical model of the coupled monorail train–bridge system is established to investigate the dynamic behaviors of the bridge under moving trains. A refined three-dimensional finite element model is built for the bridge and a 15 degrees-of-freedom vehicle model is presented for the train. The numerical model is validated using in-situ test results and then used to analyze the dynamic displacement and acceleration of the bridge and the trains on the bridge. Based on the simulation results, the impact factor of the bridge is investigated and the riding comfort of the trains is evaluated. The investigation results show that the impact factor of vehicle loads reaches the maximum value when the resonance of the bridge is induced by the moving vehicles. The effect of train braking predominates the longitudinal vibration of the bridge but is negligible in the transverse and vertical directions. The vehicle speed is the dominating factor for the riding comfort of the train.
      Citation: Applied Sciences
      PubDate: 2018-04-23
      DOI: 10.3390/app8040650
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 651: On the Statistical Characterization
           of Lightning-Induced Voltages

    • Authors: Amedeo Andreotti, Fabio Mottola, Antonio Pierno, Daniela Proto
      First page: 651
      Abstract: Protection against lightning-induced voltages is a particularly critical issue, especially for smart grids, due to the presence of electronic-based equipment, as well as control and monitoring devices. Analysis of the severity of the induced voltages is then imperative; on the other hand, the random nature of the lightning phenomenon cannot be disregarded. In this paper, the severity of lightning-induced voltage is analyzed by means of a probabilistic approach which, starting from closed-form solutions, uses a Monte Carlo procedure. Parametric distributions that best fit the distributions of the induced voltages are investigated as well. The results show that the lognormal and the generalized extreme value distributions are the best candidates.
      Citation: Applied Sciences
      PubDate: 2018-04-23
      DOI: 10.3390/app8040651
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 652: Rapid High-Resolution Wavenumber
           Extraction from Ultrasonic Guided Waves Using Adaptive Array Signal

    • Authors: Shigeaki Okumura, Vu-Hieu Nguyen, Hirofumi Taki, Guillaume Haïat, Salah Naili, Toru Sato
      First page: 652
      Abstract: Quantitative ultrasound techniques for assessment of bone quality have been attracting significant research attention. The axial transmission technique, which involves analysis of ultrasonic guided waves propagating along cortical bone, has been proposed for assessment of cortical bone quality. Because the frequency-dependent wavenumbers reflect the elastic parameters of the medium, high-resolution estimation of the wavenumbers is required at each frequency with low computational cost. We use an adaptive array signal processing method and propose a technique that can be used to estimate the numbers of propagation modes that exist at each frequency without the need for time-consuming calculations. An experimental study of 4-mm-thick copper and bone-mimicking plates showed that the proposed method estimated the wavenumbers accurately with estimation errors of less than 4% and a calculation time of less than 0.5 s when using a laptop computer.
      Citation: Applied Sciences
      PubDate: 2018-04-23
      DOI: 10.3390/app8040652
      Issue No: Vol. 8, No. 4 (2018)
  • Applied Sciences, Vol. 8, Pages 653: External Field Response and
           Applications of Metal Coated Hemispherical Janus Particles

    • Authors: So Aizawa, Keisuke Seto, Eiji Tokunaga
      First page: 653
      Abstract: Hemispherical Janus particles that were coated with silver or nickel on the equatorial plane of hemispherical polymer microparticles were prepared and dispersed in water and the responses to AC electric and stationary magnetic fields applied were investigated. Both of the particles are so oriented that the equatorial plane is parallel to the AC electric field, owing to electric-field induced dipole orientation, which is the response proportional to the quadratic electric field. The nickel coated particles are self-assembled to make a chain-like structure aligned in the direction of the stationary magnetic field. In addition, when both AC electric and stationary magnetic fields are applied, the orientation of a nickel-coated hemispherical particle is uniquely determined in such a way that the equatorial plane is parallel to both electric and magnetic fields. Because the particle is magnetized on the plane, its direction is reversed when the magnetic field is reversed, which is the response that is proportional to the magnetic field. Utilizing these features, mirrors are fabricated that can switch the transmittance and reflectance with electric and magnetic fields. Such features of the Janus particles as to be controlled by an electric and magnetic fields will find wide applications in the fields of microoptics and microfluidics.
      Citation: Applied Sciences
      PubDate: 2018-04-23
      DOI: 10.3390/app8040653
      Issue No: Vol. 8, No. 4 (2018)
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