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  Subjects -> COMPUTER SCIENCE (Total: 1996 journals)
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    - COMPUTER SCIENCE (1162 journals)
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COMPUTER SCIENCE (1162 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 13)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 23)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 9)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 12)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 14)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 5)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 21)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 8)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 9)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 25)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 16)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 14)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 51)
Advances in Engineering Software     Hybrid Journal   (Followers: 26)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
Advances in Human-Computer Interaction     Open Access   (Followers: 20)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 39)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 3)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 8)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 9)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 5)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 11)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 7)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 1)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 13)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 33)
Applied Medical Informatics     Open Access   (Followers: 11)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 134)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 7)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access   (Followers: 1)
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 4)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 11)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Biodiversity Information Science and Standards     Open Access  
Bioinformatics     Hybrid Journal   (Followers: 272)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 14)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 33)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 45)
British Journal of Educational Technology     Hybrid Journal   (Followers: 128)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Capturing Intelligence     Full-text available via subscription  
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal   (Followers: 1)
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access  
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 12)
Circuits and Systems     Open Access   (Followers: 16)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 12)
Communication Theory     Hybrid Journal   (Followers: 20)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 54)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 9)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 30)
Computer     Full-text available via subscription   (Followers: 87)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 7)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 8)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 21)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 16)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 12)
Computer Science Education     Hybrid Journal   (Followers: 13)
Computer Science Journal     Open Access   (Followers: 20)

        1 2 3 4 5 6 | Last

Journal Cover Algorithms
  [SJR: 0.357]   [H-I: 17]   [11 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Print) 1999-4893
   Published by MDPI Homepage  [156 journals]
  • Algorithms, Vol. 10, Pages 109: Properties of Vector Embeddings in Social

    • Authors: Fatemeh Salehi Rizi, Michael Granitzer, Konstantin Ziegler
      First page: 109
      Abstract: Embedding social network data into a low-dimensional vector space has shown promising performance for many real-world applications, such as node classification, node clustering, link prediction and network visualization. However, the information contained in these vector embeddings remains abstract and hard to interpret. Methods for inspecting embeddings usually rely on visualization methods, which do not work on a larger scale and do not give concrete interpretations of vector embeddings in terms of preserved network properties (e.g., centrality or betweenness measures). In this paper, we study and investigate network properties preserved by recent random walk-based embedding procedures like node2vec, DeepWalk or LINE. We propose a method that applies learning to rank in order to relate embeddings to network centralities. We evaluate our approach with extensive experiments on real-world and artificial social networks. Experiments show that each embedding method learns different network properties. In addition, we show that our graph embeddings in combination with neural networks provide a computationally efficient way to approximate the Closeness Centrality measure in social networks.
      Citation: Algorithms
      PubDate: 2017-09-27
      DOI: 10.3390/a10040109
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 110: DDC Control Techniques for Three-Phase
           BLDC Motor Position Control

    • Authors: Rana Masood, Dao Wang, Zain Ali, Babar Khan
      First page: 110
      Abstract: In this article, a novel hybrid control scheme is proposed for controlling the position of a three-phase brushless direct current (BLDC) motor. The hybrid controller consists of discrete time sliding mode control (SMC) with model free adaptive control (MFAC) to make a new data-driven control (DDC) strategy that is able to reduce the simulation time and complexity of a nonlinear system. The proposed hybrid algorithm is also suitable for controlling the speed variations of a BLDC motor, and is also applicable for the real time simulation of platforms such as a gimbal platform. The DDC method does not require any system model because it depends on data collected by the system about its Inputs/Outputs (IOS). However, the model-based control (MBC) method is difficult to apply from a practical point of view and is time-consuming because we need to linearize the system model. The above proposed method is verified by multiple simulations using MATLAB Simulink. It shows that the proposed controller has better performance, more precise tracking, and greater robustness compared with the classical proportional integral derivative (PID) controller, MFAC, and model free learning adaptive control (MFLAC).
      Citation: Algorithms
      PubDate: 2017-09-25
      DOI: 10.3390/a10040110
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 111: Game Theory-Inspired Evolutionary
           Algorithm for Global Optimization

    • Authors: Guanci Yang
      First page: 111
      Abstract: Many approaches that model specific intelligent behaviors perform excellently in solving complex optimization problems. Game theory is widely recognized as an important tool in many fields. This paper introduces a game theory-inspired evolutionary algorithm for global optimization (GameEA). A formulation to estimate payoff expectations is provided, which is a mechanism to make a player become a rational decision-maker. GameEA has one population (i.e., set of players) and generates new offspring only through an imitation operator and a belief-learning operator. An imitation operator adopts learning strategies and actions from other players to improve its competitiveness and applies these strategies to future games where one player updates its chromosome by strategically copying segments of gene sequences from a competitor. Belief learning refers to models in which a player adjusts his/her strategies, behavior or chromosomes by analyzing the current history information to improve solution quality. Experimental results on various classes of problems show that GameEA outperforms the other four algorithms on stability, robustness, and accuracy.
      Citation: Algorithms
      PubDate: 2017-09-30
      DOI: 10.3390/a10040111
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 112: Mapping Higher-Order Network Flows in
           Memory and Multilayer Networks with Infomap

    • Authors: Daniel Edler, Ludvig Bohlin, and Rosvall
      First page: 112
      Abstract: Comprehending complex systems by simplifying and highlighting important dynamical patterns requires modeling and mapping higher-order network flows. However, complex systems come in many forms and demand a range of representations, including memory and multilayer networks, which in turn call for versatile community-detection algorithms to reveal important modular regularities in the flows. Here we show that various forms of higher-order network flows can be represented in a unified way with networks that distinguish physical nodes for representing a complex system’s objects from state nodes for describing flows between the objects. Moreover, these so-called sparse memory networks allow the information-theoretic community detection method known as the map equation to identify overlapping and nested flow modules in data from a range of different higher-order interactions such as multistep, multi-source, and temporal data. We derive the map equation applied to sparse memory networks and describe its search algorithm Infomap, which can exploit the flexibility of sparse memory networks. Together they provide a general solution to reveal overlapping modular patterns in higher-order flows through complex systems.
      Citation: Algorithms
      PubDate: 2017-09-30
      DOI: 10.3390/a10040112
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 113: Scale Reduction Techniques for Computing
           Maximum Induced Bicliques

    • Authors: Shahram Shahinpour, Shirin Shirvani, Zeynep Ertem, Sergiy Butenko
      First page: 113
      Abstract: Given a simple, undirected graph G, a biclique is a subset of vertices inducing a complete bipartite subgraph in G. In this paper, we consider two associated optimization problems, the maximum biclique problem, which asks for a biclique of the maximum cardinality in the graph, and the maximum edge biclique problem, aiming to find a biclique with the maximum number of edges in the graph. These NP-hard problems find applications in biclustering-type tasks arising in complex network analysis. Real-life instances of these problems often involve massive, but sparse networks. We develop exact approaches for detecting optimal bicliques in large-scale graphs that combine effective scale reduction techniques with integer programming methodology. Results of computational experiments with numerous real-life network instances demonstrate the performance of the proposed approach.
      Citation: Algorithms
      PubDate: 2017-10-04
      DOI: 10.3390/a10040113
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 114: Variable Selection in Time Series
           Forecasting Using Random Forests

    • Authors: Hristos Tyralis, Georgia Papacharalampous
      First page: 114
      Abstract: Time series forecasting using machine learning algorithms has gained popularity recently. Random forest is a machine learning algorithm implemented in time series forecasting; however, most of its forecasting properties have remained unexplored. Here we focus on assessing the performance of random forests in one-step forecasting using two large datasets of short time series with the aim to suggest an optimal set of predictor variables. Furthermore, we compare its performance to benchmarking methods. The first dataset is composed by 16,000 simulated time series from a variety of Autoregressive Fractionally Integrated Moving Average (ARFIMA) models. The second dataset consists of 135 mean annual temperature time series. The highest predictive performance of RF is observed when using a low number of recent lagged predictor variables. This outcome could be useful in relevant future applications, with the prospect to achieve higher predictive accuracy.
      Citation: Algorithms
      PubDate: 2017-10-04
      DOI: 10.3390/a10040114
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 115: A Multi-Threading Algorithm to Detect and
           Remove Cycles in Vertex- and Arc-Weighted Digraph

    • Authors: Huanqing Cui, Jian Niu, Chuanai Zhou, Minglei Shu
      First page: 115
      Abstract: A graph is a very important structure to describe many applications in the real world. In many applications, such as dependency graphs and debt graphs, it is an important problem to find and remove cycles to make these graphs be cycle-free. The common algorithm often leads to an out-of-memory exception in commodity personal computer, and it cannot leverage the advantage of multicore computers. This paper introduces a new problem, cycle detection and removal with vertex priority. It proposes a multithreading iterative algorithm to solve this problem for large-scale graphs on personal computers. The algorithm includes three main steps: simplification to decrease the scale of graph, calculation of strongly connected components, and cycle detection and removal according to a pre-defined priority in parallel. This algorithm avoids the out-of-memory exception by simplification and iteration, and it leverages the advantage of multicore computers by multithreading parallelism. Five different versions of the proposed algorithm are compared by experiments, and the results show that the parallel iterative algorithm outperforms the others, and simplification can effectively improve the algorithm's performance.
      Citation: Algorithms
      PubDate: 2017-10-10
      DOI: 10.3390/a10040115
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 116: Remote Sensing Image Enhancement Based on
           Non-Local Means Filter in NSCT Domain

    • Authors: Liangliang Li, Yujuan Si, Zhenhong Jia
      First page: 116
      Abstract: In this paper, a novel remote sensing image enhancement technique based on a non-local means filter in a nonsubsampled contourlet transform (NSCT) domain is proposed. The overall flow of the approach can be divided into the following steps: Firstly, the image is decomposed into one low-frequency sub-band and several high-frequency sub-bands with NSCT. Secondly, contrast stretching is adopted to deal with the low-frequency sub-band coefficients, and the non-local means filter is applied to suppress the noise contained in the first high-frequency sub-band coefficients. Thirdly, the processed coefficients are reconstructed with the inverse NSCT transform. Finally, the unsharp filter is used to enhance the details of the image. The simulation results show that the proposed algorithm has better performance in remote sensing image enhancement than the existing approaches.
      Citation: Algorithms
      PubDate: 2017-10-11
      DOI: 10.3390/a10040116
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 117: Fabric Weave Pattern and Yarn Color
           Recognition and Classification Using a Deep ELM Network

    • Authors: Babar Khan, Zhijie Wang, Fang Han, Ather Iqbal, Rana Masood
      First page: 117
      Abstract: Usually, a fabric weave pattern is recognized using methods which identify the warp floats and weft floats. Although these methods perform well for uniform or repetitive weave patterns, in the case of complex weave patterns, these methods become computationally complex and the classification error rates are comparatively higher. Furthermore, the fault-tolerance (invariance) and stability (selectivity) of the existing methods are still to be enhanced. We present a novel biologically-inspired method to invariantly recognize the fabric weave pattern (fabric texture) and yarn color from the color image input. We proposed a model in which the fabric weave pattern descriptor is based on the HMAX model for computer vision inspired by the hierarchy in the visual cortex, the color descriptor is based on the opponent color channel inspired by the classical opponent color theory of human vision, and the classification stage is composed of a multi-layer (deep) extreme learning machine. Since the weave pattern descriptor, yarn color descriptor, and the classification stage are all biologically inspired, we propose a method which is completely biologically plausible. The classification performance of the proposed algorithm indicates that the biologically-inspired computer-aided-vision models might provide accurate, fast, reliable and cost-effective solution to industrial automation.
      Citation: Algorithms
      PubDate: 2017-10-13
      DOI: 10.3390/a10040117
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 118: Iterative Parameter Estimation Algorithms
           for Dual-Frequency Signal Models

    • Authors: Siyu Liu, Ling Xu, Feng Ding
      First page: 118
      Abstract: This paper focuses on the iterative parameter estimation algorithms for dual-frequency signal models that are disturbed by stochastic noise. The key of the work is to overcome the difficulty that the signal model is a highly nonlinear function with respect to frequencies. A gradient-based iterative (GI) algorithm is presented based on the gradient search. In order to improve the estimation accuracy of the GI algorithm, a Newton iterative algorithm and a moving data window gradient-based iterative algorithm are proposed based on the moving data window technique. Comparative simulation results are provided to illustrate the effectiveness of the proposed approaches for estimating the parameters of signal models.
      Citation: Algorithms
      PubDate: 2017-10-14
      DOI: 10.3390/a10040118
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 119: An Optimization Algorithm Inspired by the
           Phase Transition Phenomenon for Global Optimization Problems with
           Continuous Variables

    • Authors: Zijian Cao, Lei Wang
      First page: 119
      Abstract: In this paper, we propose a novel nature-inspired meta-heuristic algorithm for continuous global optimization, named the phase transition-based optimization algorithm (PTBO). It mimics three completely different kinds of motion characteristics of elements in three different phases, which are the unstable phase, the meta-stable phase, and the stable phase. Three corresponding operators, which are the stochastic operator of the unstable phase, the shrinkage operator in the meta-stable phase, and the vibration operator of the stable phase, are designed in the proposed algorithm. In PTBO, the three different phases of elements dynamically execute different search tasks according to their phase in each generation. It makes it such that PTBO not only has a wide range of exploration capabilities, but also has the ability to quickly exploit them. Numerical experiments are carried out on twenty-eight functions of the CEC 2013 benchmark suite. The simulation results demonstrate its better performance compared with that of other state-of-the-art optimization algorithms.
      Citation: Algorithms
      PubDate: 2017-10-20
      DOI: 10.3390/a10040119
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 120: A Comparative Study on Recently-Introduced
           Nature-Based Global Optimization Methods in Complex Mechanical System

    • Authors: Abdulbaset Saad, Zuomin Dong, Meysam Karimi
      First page: 120
      Abstract: Advanced global optimization algorithms have been continuously introduced and improved to solve various complex design optimization problems for which the objective and constraint functions can only be evaluated through computation intensive numerical analyses or simulations with a large number of design variables. The often implicit, multimodal, and ill-shaped objective and constraint functions in high-dimensional and “black-box” forms demand the search to be carried out using low number of function evaluations with high search efficiency and good robustness. This work investigates the performance of six recently introduced, nature-inspired global optimization methods: Artificial Bee Colony (ABC), Firefly Algorithm (FFA), Cuckoo Search (CS), Bat Algorithm (BA), Flower Pollination Algorithm (FPA) and Grey Wolf Optimizer (GWO). These approaches are compared in terms of search efficiency and robustness in solving a set of representative benchmark problems in smooth-unimodal, non-smooth unimodal, smooth multimodal, and non-smooth multimodal function forms. In addition, four classic engineering optimization examples and a real-life complex mechanical system design optimization problem, floating offshore wind turbines design optimization, are used as additional test cases representing computationally-expensive black-box global optimization problems. Results from this comparative study show that the ability of these global optimization methods to obtain a good solution diminishes as the dimension of the problem, or number of design variables increases. Although none of these methods is universally capable, the study finds that GWO and ABC are more efficient on average than the other four in obtaining high quality solutions efficiently and consistently, solving 86% and 80% of the tested benchmark problems, respectively. The research contributes to future improvements of global optimization methods.
      Citation: Algorithms
      PubDate: 2017-10-17
      DOI: 10.3390/a10040120
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 121: Evolutionary Hybrid Particle Swarm
           Optimization Algorithm for Solving NP-Hard No-Wait Flow Shop Scheduling

    • Authors: Laxmi Bewoor, V. Chandra Prakash, Sagar Sapkal
      First page: 121
      Abstract: The no-wait flow shop is a flowshop in which the scheduling of jobs is continuous and simultaneous through all machines without waiting for any consecutive machines. The scheduling of a no-wait flow shop requires finding an appropriate sequence of jobs for scheduling, which in turn reduces total processing time. The classical brute force method for finding the probabilities of scheduling for improving the utilization of resources may become trapped in local optima, and this problem can hence be observed as a typical NP-hard combinatorial optimization problem that requires finding a near optimal solution with heuristic and metaheuristic techniques. This paper proposes an effective hybrid Particle Swarm Optimization (PSO) metaheuristic algorithm for solving no-wait flow shop scheduling problems with the objective of minimizing the total flow time of jobs. This Proposed Hybrid Particle Swarm Optimization (PHPSO) algorithm presents a solution by the random key representation rule for converting the continuous position information values of particles to a discrete job permutation. The proposed algorithm initializes population efficiently with the Nawaz-Enscore-Ham (NEH) heuristic technique and uses an evolutionary search guided by the mechanism of PSO, as well as simulated annealing based on a local neighborhood search to avoid getting stuck in local optima and to provide the appropriate balance of global exploration and local exploitation. Extensive computational experiments are carried out based on Taillard’s benchmark suite. Computational results and comparisons with existing metaheuristics show that the PHPSO algorithm outperforms the existing methods in terms of quality search and robustness for the problem considered. The improvement in solution quality is confirmed by statistical tests of significance.
      Citation: Algorithms
      PubDate: 2017-10-28
      DOI: 10.3390/a10040121
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 122: Scheduling Non-Preemptible Jobs to
           Minimize Peak Demand

    • Authors: Sean Yaw, Brendan Mumey
      First page: 122
      Abstract: This paper examines an important problem in smart grid energy scheduling; peaks in power demand are proportionally more expensive to generate and provision for. The issue is exacerbated in local microgrids that do not benefit from the aggregate smoothing experienced by large grids. Demand-side scheduling can reduce these peaks by taking advantage of the fact that there is often flexibility in job start times. We focus attention on the case where the jobs are non-preemptible, meaning once started, they run to completion. The associated optimization problem is called the peak demand minimization problem, and has been previously shown to be NP-hard. Our results include an optimal fixed-parameter tractable algorithm, a polynomial-time approximation algorithm, as well as an effective heuristic that can also be used in an online setting of the problem. Simulation results show that these methods can reduce peak demand by up to 50% versus on-demand scheduling for household power jobs.
      Citation: Algorithms
      PubDate: 2017-10-28
      DOI: 10.3390/a10040122
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 123: A Selection Process for Genetic Algorithm
           Using Clustering Analysis

    • Authors: Adam Chehouri, Rafic Younes, Jihan Khoder, Jean Perron, Adrian Ilinca
      First page: 123
      Abstract: This article presents a newly proposed selection process for genetic algorithms on a class of unconstrained optimization problems. The k-means genetic algorithm selection process (KGA) is composed of four essential stages: clustering, membership phase, fitness scaling and selection. Inspired from the hypothesis that clustering the population helps to preserve a selection pressure throughout the evolution of the population, a membership probability index is assigned to each individual following the clustering phase. Fitness scaling converts the membership scores in a range suitable for the selection function which selects the parents of the next generation. Two versions of the KGA process are presented: using a fixed number of clusters K (KGAf) and via an optimal partitioning Kopt (KGAo) determined by two different internal validity indices. The performance of each method is tested on seven benchmark problems.
      Citation: Algorithms
      PubDate: 2017-11-02
      DOI: 10.3390/a10040123
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 124: Improvement of ID3 Algorithm Based on
           Simplified Information Entropy and Coordination Degree

    • Authors: Yingying Wang, Yibin Li, Yong Song, Xuewen Rong, Shuaishuai Zhang
      First page: 124
      Abstract: The decision tree algorithm is a core technology in data classification mining, and ID3 (Iterative Dichotomiser 3) algorithm is a famous one, which has achieved good results in the field of classification mining. Nevertheless, there exist some disadvantages of ID3 such as attributes biasing multi-values, high complexity, large scales, etc. In this paper, an improved ID3 algorithm is proposed that combines the simplified information entropy based on different weights with coordination degree in rough set theory. The traditional ID3 algorithm and the proposed one are fairly compared by using three common data samples as well as the decision tree classifiers. It is shown that the proposed algorithm has a better performance in the running time and tree structure, but not in accuracy than the ID3 algorithm, for the first two sample sets, which are small. For the third sample set that is large, the proposed algorithm improves the ID3 algorithm for all of the running time, tree structure and accuracy. The experimental results show that the proposed algorithm is effective and viable.
      Citation: Algorithms
      PubDate: 2017-11-06
      DOI: 10.3390/a10040124
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 125: Simulation Optimization of Search and
           Rescue in Disaster Relief Based on Distributed Auction Mechanism

    • Authors: Jian Tang, Kejun Zhu, Haixiang Guo, Can Liao, Shuwen Zhang
      First page: 125
      Abstract: In this paper, we optimize the search and rescue (SAR) in disaster relief through agent-based simulation. We simulate rescue teams’ search behaviors with the improved Truncated Lévy walks. Then we propose a cooperative rescue plan based on a distributed auction mechanism, and illustrate it with the case of landslide disaster relief. The simulation is conducted in three scenarios, including “fatal”, “serious” and “normal”. Compared with the non-cooperative rescue plan, the proposed rescue plan in this paper would increase victims’ relative survival probability by 7–15%, increase the ratio of survivors getting rescued by 5.3–12.9%, and decrease the average elapsed time for one site getting rescued by 16.6–21.6%. The robustness analysis shows that search radius can affect the rescue efficiency significantly, while the scope of cooperation cannot. The sensitivity analysis shows that the two parameters, the time limit for completing rescue operations in one buried site and the maximum turning angle for next step, both have a great influence on rescue efficiency, and there exists optimal value for both of them in view of rescue efficiency.
      Citation: Algorithms
      PubDate: 2017-11-15
      DOI: 10.3390/a10040125
      Issue No: Vol. 10, No. 4 (2017)
  • Algorithms, Vol. 10, Pages 72: Hierarchical Gradient Similarity Based
           Video Quality Assessment Metric

    • Authors: Jie Yang, Jian Xiong, Guan Gui, Rongfang Song, Wang Luo, Xianzhong Long
      First page: 72
      Abstract: Video quality assessment (VQA) plays an important role in video applications for quality evaluation and resource allocation. It aims to evaluate video quality in a way that is consistent with human perception. In this letter, a hierarchical gradient similarity based VQA metric is proposed inspired by the structure of the primate visual cortex, in which visual information is processed through sequential visual areas. These areas are modeled with the corresponding measures to evaluate the overall perceptual quality. Experimental results on the LIVE database show that the proposed VQA metric significantly outperforms most of the state-of-the-art VQA metrics.
      PubDate: 2017-06-23
      DOI: 10.3390/a10030072
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 73: Variable Selection Using Adaptive Band
           Clustering and Physarum Network

    • Authors: Huanyu Chen, Tong Chen, Zhihao Zhang, Guangyuan Liu
      First page: 73
      Abstract: Variable selection is a key step for eliminating redundant information in spectroscopy. Among various variable selection methods, the physarum network (PN) is a newly-introduced and efficient one. However, the whole spectrum has to be equally divided into sub-spectral bands in PN. These division criteria limit the selecting ability and prediction performance. In this paper, we transform the spectrum division problem into a clustering problem and solve the problem by using an affinity propagation (AP) algorithm, an adaptive clustering method, to find the optimized number of sub-spectral bands and the number of wavelengths in each sub-spectral band. Experimental results show that combining AP and PN together can achieve similar prediction accuracy with much less wavelength than what PN alone can achieve.
      PubDate: 2017-06-27
      DOI: 10.3390/a10030073
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 74: The Isomorphic Version of Brualdi’s and
           Sanderson’s Nestedness

    • Authors: Annabell Berger, Berit Schreck
      First page: 74
      Abstract: The discrepancy BR for an m × n 0, 1-matrix from Brualdi and Sanderson in 1998 is defined as the minimum number of 1 s that need to be shifted in each row to the left to achieve its Ferrers matrix, i.e., each row consists of consecutive 1 s followed by consecutive 0 s. For ecological bipartite networks, BR describes a nested set of relationships. Since two different labelled networks can be isomorphic, but possess different discrepancies due to different adjacency matrices, we define a metric determining the minimum discrepancy in an isomorphic class. We give a reduction to k ≤ n minimum weighted perfect matching problems. We show on 289 ecological matrices (given as a benchmark by Atmar and Patterson in 1995) that classical discrepancy can underestimate the nestedness by up to 30%.
      PubDate: 2017-06-27
      DOI: 10.3390/a10030074
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 75: Thresholds of the Inner Steps in Multi-Step
           Newton Method

    • Authors: Stefan Maruster
      First page: 75
      Abstract: We investigate the efficiency of multi-step Newton method (the classical Newton method in which the first derivative is re-evaluated periodically after m steps) for solving nonlinear equations, F ( x ) = 0 , F : D ⊆ R n → R n . We highlight the following property of multi-step Newton method with respect to some other Newton-type method: for a given n, there exist thresholds of m, that is an interval ( m i , m s ) , such that for m inside of this interval, the efficiency index of multi-step Newton method is better than that of other Newton-type method. We also search for optimal values of m.
      PubDate: 2017-06-27
      DOI: 10.3390/a10030075
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 76: A Genetic Algorithm Using Triplet
           Nucleotide Encoding and DNA Reproduction Operations for Unconstrained
           Optimization Problems

    • Authors: Wenke Zang, Weining Zhang, Wenqian Zhang, Xiyu Liu
      First page: 76
      Abstract: As one of the evolutionary heuristics methods, genetic algorithms (GAs) have shown a promising ability to solve complex optimization problems. However, existing GAs still have difficulties in finding the global optimum and avoiding premature convergence. To further improve the search efficiency and convergence rate of evolution algorithms, inspired by the mechanism of biological DNA genetic information and evolution, we present a new genetic algorithm, called GA-TNE+DRO, which uses a novel triplet nucleotide coding scheme to encode potential solutions and a set of new genetic operators to search for globally optimal solutions. The coding scheme represents potential solutions as a sequence of triplet nucleotides and the DNA reproduction operations mimic the DNA reproduction process more vividly than existing DNA-GAs. We compared our algorithm with several existing GA and DNA-based GA algorithms using a benchmark of eight unconstrained optimization functions. Our experimental results show that the proposed algorithm can converge to solutions much closer to the global optimal solutions in a much lower number of iterations than the existing algorithms. A complexity analysis also shows that our algorithm is computationally more efficient than the existing algorithms.
      PubDate: 2017-06-30
      DOI: 10.3390/a10030076
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 77: New Methodology to Approximate

    • Authors: Emanuel Ontiveros-Robles, Patricia Melin, Oscar Castillo
      First page: 77
      Abstract: Interval Type-2 fuzzy systems allow the possibility of considering uncertainty in models based on fuzzy systems, and enable an increase of robustness in solutions to applications, but also increase the complexity of the fuzzy system design. Several attempts have been previously proposed to reduce the computational cost of the type-reduction stage, as this process requires a lot of computing time because it is basically a numerical approximation based on sampling, and the computational cost is proportional to the number of samples, but also the error is inversely proportional to the number of samples. Several works have focused on reducing the computational cost of type-reduction by developing strategies to reduce the number of operations. The first type-reduction method was proposed by Karnik and Mendel (KM), and then was followed by its enhanced version called EKM. Then continuous versions were called CKM and CEKM, and there were variations of this and also other types of variations that eliminate the type-reduction process reducing the computational cost to a Type-1 defuzzification, such as the Nie-Tan versions and similar enhancements. In this work we analyzed and proposed a variant of CEKM by viewing this process as solving a root-finding problem, in this way taking advantage of existing numerical methods to solve the type-reduction problem, the main objective being eliminating the type-reduction process and also providing a continuous solution of the defuzzification.
      Citation: Algorithms
      PubDate: 2017-07-05
      DOI: 10.3390/a10030077
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 78: An Efficient Algorithm for the Separable
           Nonlinear Least Squares Problem

    • Authors: Yunqiu Shen, Tjalling Ypma
      First page: 78
      Abstract: The nonlinear least squares problem m i n y , z ∥ A ( y ) z + b ( y ) ∥ , where A ( y ) is a full-rank ( N + ℓ ) × N matrix, y ∈ R n , z ∈ R N and b ( y ) ∈ R N + ℓ with ℓ ≥ n , can be solved by first solving a reduced problem m i n y ∥ f ( y ) ∥ to find the optimal value y * of y, and then solving the resulting linear least squares problem m i n z ∥ A ( y * ) z + b ( y * ) ∥ to find the optimal value z * of z. We have previously justified the use of the reduced function f ( y ) = C T ( y ) b ( y ) , where C ( y ) is a matrix whose columns form an orthonormal basis for the nullspace of A T ( y ) , and presented a quadratically convergent Gauss–Newton type method for solving m i n y ∥ C T ( y ) b ( y ) ∥ based on the use of QR factorization. In this note, we show how LU factorization can replace the QR factorization in those computations, halving the associated computational cost while also providing opportunities to exploit sparsity and thus further enhance computational efficiency.
      Citation: Algorithms
      PubDate: 2017-07-10
      DOI: 10.3390/a10030078
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 79: Design of an Optimized Fuzzy Classifier for
           the Diagnosis of Blood Pressure with a New Computational Method for Expert
           Rule Optimization

    • Authors: Juan Carlos Guzman, Patricia Melin, German Prado-Arechiga
      First page: 79
      Abstract: A neuro fuzzy hybrid model (NFHM) is proposed as a new artificial intelligence method to classify blood pressure (BP). The NFHM uses techniques such as neural networks, fuzzy logic and evolutionary computation, and in the last case genetic algorithms (GAs) are used. The main goal is to model the behavior of blood pressure based on monitoring data of 24 h per patient and based on this to obtain the trend, which is classified using a fuzzy system based on rules provided by an expert, and these rules are optimized by a genetic algorithm to obtain the best possible number of rules for the classifier with the lowest classification error. Simulation results are presented to show the advantage of the proposed model.
      Citation: Algorithms
      PubDate: 2017-07-14
      DOI: 10.3390/a10030079
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 80: A Hybrid Algorithm for Optimal Wireless
           Sensor Network Deployment with the Minimum Number of Sensor Nodes

    • Authors: Yasser El Khamlichi, Abderrahim Tahiri, Anouar Abtoy, Inmaculada Medina-Bulo, Francisco Palomo-Lozano
      First page: 80
      Abstract: Wireless sensor network (WSN) applications are rapidly growing and are widely used in various disciplines. Deployment is one of the key issues to be solved in WSNs, since the sensor nodes’ positioning affects highly the system performance. An optimal WSN deployment should maximize the collection of the desired interest phenomena, guarantee the required coverage and connectivity, extend the network lifetime, and minimize the network cost in terms of energy consumption. Most of the research effort in this area aims to solve the deployment issue, without minimizing the network cost by reducing unnecessary working nodes in the network. In this paper, we propose a deployment approach based on the gradient method and the Simulated Annealing algorithm to solve the sensor deployment problem with the minimum number of sensor nodes. The proposed algorithm is able to heuristically optimize the number of sensors and their positions in order to achieve the desired application requirements.
      Citation: Algorithms
      PubDate: 2017-07-18
      DOI: 10.3390/a10030080
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 81: Low-Resource Cross-Domain Product Review
           Sentiment Classification Based on a CNN with an Auxiliary Large-Scale

    • Authors: Xiaocong Wei, Hongfei Lin, Yuhai Yu, Liang Yang
      First page: 81
      Abstract: The literature [-5]contains several reports evaluating the abilities of deep neural networks in text transfer learning. To our knowledge, however, there have been few efforts to fully realize the potential of deep neural networks in cross-domain product review sentiment classification. In this paper, we propose a two-layer convolutional neural network (CNN) for cross-domain product review sentiment classification (LM-CNN-LB). Transfer learning research into product review sentiment classification based on deep neural networks has been limited by the lack of a large-scale corpus; we sought to remedy this problem using a large-scale auxiliary cross-domain dataset collected from Amazon product reviews. Our proposed framework exhibits the dramatic transferability of deep neural networks for cross-domain product review sentiment classification and achieves state-of-the-art performance. The framework also outperforms complex engineered features used with a non-deep neural network method. The experiments demonstrate that introducing large-scale data from similar domains is an effective way to resolve the lack of training data. The LM-CNN-LB trained on the multi-source related domain dataset outperformed the one trained on a single similar domain.
      Citation: Algorithms
      PubDate: 2017-07-19
      DOI: 10.3390/a10030081
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 82: Optimization of Intelligent Controllers
           Using a Type-1 and Interval Type-2 Fuzzy Harmony Search Algorithm

    • Authors: Cinthia Peraza, Fevrier Valdez, Patricia Melin
      First page: 82
      Abstract: This article focuses on the dynamic parameter adaptation in the harmony search algorithm using Type-1 and interval Type-2 fuzzy logic. In particular, this work focuses on the adaptation of the parameters of the original harmony search algorithm. At present there are several types of algorithms that can solve complex real-world problems with uncertainty management. In this case the proposed method is in charge of optimizing the membership functions of three benchmark control problems (water tank, shower, and mobile robot). The main goal is to find the best parameters for the membership functions in the controller to follow a desired trajectory. Noise experiments are performed to test the efficacy of the method.
      Citation: Algorithms
      PubDate: 2017-07-20
      DOI: 10.3390/a10030082
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 83: Fuzzy Fireworks Algorithm Based on a Sparks
           Dispersion Measure

    • Authors: Juan Barraza, Patricia Melin, Fevrier Valdez, Claudia Gonzalez
      First page: 83
      Abstract: The main goal of this paper is to improve the performance of the Fireworks Algorithm (FWA). To improve the performance of the FWA we propose three modifications: the first modification is to change the stopping criteria, this is to say, previously, the number of function evaluations was utilized as a stopping criteria, and we decided to change this to specify a particular number of iterations; the second and third modifications consist on introducing a dispersion metric (dispersion percent), and both modifications were made with the goal of achieving dynamic adaptation of the two parameters in the algorithm. The parameters that were controlled are the explosion amplitude and the number of sparks, and it is worth mentioning that the control of these parameters is based on a fuzzy logic approach. To measure the impact of these modifications, we perform experiments with 14 benchmark functions and a comparative study shows the advantage of the proposed approach. We decided to call the proposed algorithms Iterative Fireworks Algorithm (IFWA) and two variants of the Dispersion Percent Iterative Fuzzy Fireworks Algorithm (DPIFWA-I and DPIFWA-II, respectively).
      Citation: Algorithms
      PubDate: 2017-07-21
      DOI: 10.3390/a10030083
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 84: Auxiliary Model Based Multi-Innovation
           Stochastic Gradient Identification Algorithm for Periodically
           Non-Uniformly Sampled-Data Hammerstein Systems

    • Authors: Li Xie, Huizhong Yang
      First page: 84
      Abstract: Due to the lack of powerful model description methods, the identification of Hammerstein systems based on the non-uniform input-output dataset remains a challenging problem. This paper introduces a time-varying backward shift operator to describe periodically non-uniformly sampled-data Hammerstein systems, which can simplify the structure of the lifted models using the traditional lifting technique. Furthermore, an auxiliary model-based multi-innovation stochastic gradient algorithm is presented to estimate the parameters involved in the linear and nonlinear blocks. The simulation results confirm that the proposed algorithm is effective and can achieve a high estimation performance.
      Citation: Algorithms
      PubDate: 2017-07-31
      DOI: 10.3390/a10030084
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 85: A New Meta-Heuristics of Optimization with
           Dynamic Adaptation of Parameters Using Type-2 Fuzzy Logic for Trajectory
           Control of a Mobile Robot

    • Authors: Camilo Caraveo, Fevrier Valdez, Oscar Castillo
      First page: 85
      Abstract: Fuzzy logic is a soft computing technique that has been very successful in recent years when it is used as a complement to improve meta-heuristic optimization. In this paper, we present a new variant of the bio-inspired optimization algorithm based on the self-defense mechanisms of plants in the nature. The optimization algorithm proposed in this work is based on the predator-prey model originally presented by Lotka and Volterra, where two populations interact with each other and the objective is to maintain a balance. The system of predator-prey equations use four variables (α, β, λ, δ) and the values of these variables are very important since they are in charge of maintaining a balance between the pair of equations. In this work, we propose the use of Type-2 fuzzy logic for the dynamic adaptation of the variables of the system. This time a fuzzy controller is in charge of finding the optimal values for the model variables, the use of this technique will allow the algorithm to have a higher performance and accuracy in the exploration of the values.
      Citation: Algorithms
      PubDate: 2017-07-26
      DOI: 10.3390/a10030085
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 86: An Improved MOEA/D with Optimal DE Schemes
           for Many-Objective Optimization Problems

    • Authors: Wei Zheng, Yanyan Tan, Xiaonan Fang, Shengtao Li
      First page: 86
      Abstract: MOEA/D is a promising multi-objective evolutionary algorithm based on decomposition, and it has been used to solve many multi-objective optimization problems very well. However, there is a class of multi-objective problems, called many-objective optimization problems, but the original MOEA/D cannot solve them well. In this paper, an improved MOEA/D with optimal differential evolution (oDE) schemes is proposed, called MOEA/D-oDE, aiming to solve many-objective optimization problems. Compared with MOEA/D, MOEA/D-oDE has two distinguishing points. On the one hand, MOEA/D-oDE adopts a newly-introduced decomposition approach to decompose the many-objective optimization problems, which combines the advantages of the weighted sum approach and the Tchebycheff approach. On the other hand, a kind of combination mechanism for DE operators is designed for finding the best child solution so as to do the a posteriori computing. In our experimental study, six continuous test instances with 4–6 objectives comparing NSGA-II (nondominated sorting genetic algorithm II) and MOEA/D as accompanying experiments are applied. Additionally, the final results indicate that MOEA/D-oDE outperforms NSGA-II and MOEA/D in almost all cases, particularly in those problems that have complicated Pareto shapes and higher dimensional objectives, where its advantages are more obvious.
      Citation: Algorithms
      PubDate: 2017-07-26
      DOI: 10.3390/a10030086
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 87: Evolutionary Optimization for Robust
           Epipolar-Geometry Estimation and Outlier Detection

    • Authors: Mozhdeh Shahbazi, Gunho Sohn, Jérôme Théau
      First page: 87
      Abstract: In this paper, a robust technique [-5]based on a genetic algorithm is proposed for estimating two-view epipolar-geometry of uncalibrated perspective stereo images from putative correspondences containing a high percentage of outliers. The advantages of this technique are three-fold: (i) replacing random search with evolutionary search applying new strategies of encoding and guided sampling; (ii) robust and fast estimation of the epipolar geometry via detecting a more-than-enough set of inliers without making any assumptions about the probability distribution of the residuals; (iii) determining the inlier-outlier threshold based on the uncertainty of the estimated model. The proposed method was evaluated both on synthetic data and real images. The results were compared with the most popular techniques from the state-of-the-art, including RANSAC (random sample consensus), MSAC, MLESAC, Cov-RANSAC, LO-RANSAC, StaRSAC, Multi-GS RANSAC and least median of squares (LMedS). Experimental results showed that the proposed approach performed better than other methods regarding the accuracy of inlier detection and epipolar-geometry estimation, as well as the computational efficiency for datasets majorly contaminated by outliers and noise.
      Citation: Algorithms
      PubDate: 2017-07-27
      DOI: 10.3390/a10030087
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 88: On the Lagged Diffusivity Method for the
           Solution of Nonlinear Finite Difference Systems

    • Authors: Francesco Mezzadri, Emanuele Galligani
      First page: 88
      Abstract: In this paper, we extend the analysis of the Lagged Diffusivity Method for nonlinear, non-steady reaction-convection-diffusion equations. In particular, we describe how the method can be used to solve the systems arising from different discretization schemes, recalling some results on the convergence of the method itself. Moreover, we also analyze the behavior of the method in case of problems presenting boundary layers or blow-up solutions.
      Citation: Algorithms
      PubDate: 2017-08-02
      DOI: 10.3390/a10030088
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 89: On the Existence of Solutions of Nonlinear
           Fredholm Integral Equations from Kantorovich’s Technique

    • Authors: José Ezquerro, Miguel Hernández-Verón
      First page: 89
      Abstract: The well-known Kantorovich technique based on majorizing sequences is used to analyse the convergence of Newton’s method when it is used to solve nonlinear Fredholm integral equations. In addition, we obtain information about the domains of existence and uniqueness of a solution for these equations. Finally, we illustrate the above with two particular Fredholm integral equations.
      Citation: Algorithms
      PubDate: 2017-08-02
      DOI: 10.3390/a10030089
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 90: Local Community Detection Based on Small

    • Authors: Michael Hamann, Eike Röhrs, Dorothea Wagner
      First page: 90
      Abstract: Community detection aims to find dense subgraphs in a network. We consider the problem of finding a community locally around a seed node both in unweighted and weighted networks. This is a faster alternative to algorithms that detect communities that cover the whole network when actually only a single community is required. Further, many overlapping community detection algorithms use local community detection algorithms as basic building block. We provide a broad comparison of different existing strategies of expanding a seed node greedily into a community. For this, we conduct an extensive experimental evaluation both on synthetic benchmark graphs as well as real world networks. We show that results both on synthetic as well as real-world networks can be significantly improved by starting from the largest clique in the neighborhood of the seed node. Further, our experiments indicate that algorithms using scores based on triangles outperform other algorithms in most cases. We provide theoretical descriptions as well as open source implementations of all algorithms used.
      Citation: Algorithms
      PubDate: 2017-08-11
      DOI: 10.3390/a10030090
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 91: Transformation-Based Fuzzy Rule
           Interpolation Using Interval Type-2 Fuzzy Sets

    • Authors: Chengyuan Chen, Qiang Shen
      First page: 91
      Abstract: In support of reasoning with sparse rule bases, fuzzy rule interpolation (FRI) offers a helpful inference mechanism for deriving an approximate conclusion when a given observation has no overlap with any rule in the existing rule base. One of the recent and popular FRI approaches is the scale and move transformation-based rule interpolation, known as T-FRI in the literature. It supports both interpolation and extrapolation with multiple multi-antecedent rules. However, the difficult problem of defining the precise-valued membership functions required in the representation of fuzzy rules, or of the observations, restricts its applications. Fortunately, this problem can be alleviated through the use of type-2 fuzzy sets, owing to the fact that the membership functions of such fuzzy sets are themselves fuzzy, providing a more flexible means of modelling. This paper therefore, extends the existing T-FRI approach using interval type-2 fuzzy sets, which covers the original T-FRI as its specific instance. The effectiveness of this extension is demonstrated by experimental investigations and, also, by a practical application in comparison to the state-of-the-art alternative approach developed using rough-fuzzy sets.
      Citation: Algorithms
      PubDate: 2017-08-15
      DOI: 10.3390/a10030091
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 92: Automatic Modulation Recognition Using
           Compressive Cyclic Features

    • Authors: Lijin Xie, Qun Wan
      First page: 92
      Abstract: Higher-order cyclic cumulants (CCs) have been widely adopted for automatic modulation recognition (AMR) in cognitive radio. However, the CC-based AMR suffers greatly from the requirement of high-rate sampling. To overcome this limit, we resort to the theory of compressive sensing (CS). By exploiting the sparsity of CCs, recognition features can be extracted from a small amount of compressive measurements via a rough CS reconstruction algorithm. Accordingly, a CS-based AMR scheme is formulated. Simulation results demonstrate the availability and robustness of the proposed approach.
      Citation: Algorithms
      PubDate: 2017-08-18
      DOI: 10.3390/a10030092
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 93: Post-Processing Partitions to Identify
           Domains of Modularity Optimization

    • Authors: William Weir, Scott Emmons, Ryan Gibson, Dane Taylor, Peter Mucha
      First page: 93
      Abstract: We introduce the Convex Hull of Admissible Modularity Partitions (CHAMP) algorithm to prune and prioritize different network community structures identified across multiple runs of possibly various computational heuristics. Given a set of partitions, CHAMP identifies the domain of modularity optimization for each partition—i.e., the parameter-space domain where it has the largest modularity relative to the input set—discarding partitions with empty domains to obtain the subset of partitions that are “admissible” candidate community structures that remain potentially optimal over indicated parameter domains. Importantly, CHAMP can be used for multi-dimensional parameter spaces, such as those for multilayer networks where one includes a resolution parameter and interlayer coupling. Using the results from CHAMP, a user can more appropriately select robust community structures by observing the sizes of domains of optimization and the pairwise comparisons between partitions in the admissible subset. We demonstrate the utility of CHAMP with several example networks. In these examples, CHAMP focuses attention onto pruned subsets of admissible partitions that are 20-to-1785 times smaller than the sets of unique partitions obtained by community detection heuristics that were input into CHAMP.
      Citation: Algorithms
      PubDate: 2017-08-19
      DOI: 10.3390/a10030093
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 94: NBTI and Power Reduction Using an Input
           Vector Control and Supply Voltage Assignment Method

    • Authors: Peng Sun, Zhiming Yang, Yang Yu, Junbao Li, Xiyuan Peng
      First page: 94
      Abstract: As technology scales, negative bias temperature instability (NBTI) becomes one of the primary failure mechanisms for Very Large Scale Integration (VLSI) circuits. Meanwhile, the leakage power increases dramatically as the supply/threshold voltage continues to scale down. These two issues pose severe reliability problems for complementary metal oxide semiconductor (CMOS) devices. Because both the NBTI and leakage are dependent on the input vector of the circuit, we present an input vector control (IVC) method based on a linear programming algorithm, which can co-optimize circuit aging and power dissipation simultaneously. In addition, our proposed IVC method is combined with the supply voltage assignment technique to further reduce delay degradation and leakage power. Experimental results on various circuits show the effectiveness of the proposed combination method.
      Citation: Algorithms
      PubDate: 2017-08-19
      DOI: 10.3390/a10030094
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 95: A Parallel Two-Stage Iteration Method for
           Solving Continuous Sylvester Equations

    • Authors: Manyu Xiao, Quanyi Lv, Zhuo Xing, Yingchun Zhang
      First page: 95
      Abstract: In this paper we propose a parallel two-stage iteration algorithm for solving large-scale continuous Sylvester equations. By splitting the coefficient matrices, the original linear system is transformed into a symmetric linear system which is then solved by using the SYMMLQ algorithm. In order to improve the relative parallel efficiency, an adjusting strategy is explored during the iteration calculation of the SYMMLQ algorithm to decrease the degree of the reduce-operator from two to one communications at each step. Moreover, the convergence of the iteration scheme is discussed, and finally numerical results are reported showing that the proposed method is an efficient and robust algorithm for this class of continuous Sylvester equations on a parallel machine.
      Citation: Algorithms
      PubDate: 2017-08-21
      DOI: 10.3390/a10030095
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 96: Double-Threshold Cooperative Spectrum
           Sensing Algorithm Based on Sevcik Fractal Dimension

    • Authors: Xueying Diao, Qianhui Dong, Zijian Yang, Yibing Li
      First page: 96
      Abstract: Spectrum sensing is of great importance in the cognitive radio (CR) networks. Compared with individual spectrum sensing, cooperative spectrum sensing (CSS) has been shown to greatly improve the accuracy of the detection. However, the existing CSS algorithms are sensitive to noise uncertainty and are inaccurate in low signal-to-noise ratio (SNR) detection. To address this, we propose a double-threshold CSS algorithm based on Sevcik fractal dimension (SFD) in this paper. The main idea of the presented scheme is to sense the presence of primary users in the local spectrum sensing by analyzing different characteristics of the SFD between signals and noise. Considering the stochastic fluctuation characteristic of the noise SFD in a certain range, we adopt the double-threshold method in the multi-cognitive user CSS so as to improve the detection accuracy, where thresholds are set according to the maximum and minimum values of the noise SFD. After obtaining the detection results, the cognitive user sends local detection results to the fusion center for reliability fusion. Simulation results demonstrate that the proposed method is insensitive to noise uncertainty. Simulations also show that the algorithm presented in this paper can achieve high detection performance at the low SNR region.
      Citation: Algorithms
      PubDate: 2017-08-21
      DOI: 10.3390/a10030096
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 97: A Simplified Matrix Formulation for
           Sensitivity Analysis of Hidden Markov Models

    • Authors: Seifemichael B. Amsalu,  Abdollah Homaifar, Albert Esterline
      First page: 97
      Abstract: In this paper, a new algorithm for sensitivity analysis of discrete hidden Markov models (HMMs) is proposed. Sensitivity analysis is a general technique for investigating the robustness of the output of a system model. Sensitivity analysis of probabilistic networks has recently been studied extensively. This has resulted in the development of mathematical relations between a parameter and an output probability of interest and also methods for establishing the effects of parameter variations on decisions. Sensitivity analysis in HMMs has usually been performed by taking small perturbations in parameter values and re-computing the output probability of interest. As recent studies show, the sensitivity analysis of an HMM can be performed using a functional relationship that describes how an output probability varies as the network’s parameters of interest change. To derive this sensitivity function, existing Bayesian network algorithms have been employed for HMMs. These algorithms are computationally inefficient as the length of the observation sequence and the number of parameters increases. In this study, a simplified efficient matrix-based algorithm for computing the coefficients of the sensitivity function for all hidden states and all time steps is proposed and an example is presented.
      Citation: Algorithms
      PubDate: 2017-08-22
      DOI: 10.3390/a10030097
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 98: Adaptive Virtual RSU Scheduling for
           Scalable Coverage under Bidirectional Vehicle Traffic Flow

    • Authors: Fei Chen, Xiaohong Bi, Ruimin Lyu, Zhongwei Hua, Yuan Liu, Xiaoting Zhang
      First page: 98
      Abstract: Over the past decades, vehicular ad hoc networks (VANETs) have been a core networking technology to provide drivers and passengers with safety and convenience. As a new emerging technology, the vehicular cloud computing (VCC) can provide cloud services for various data-intensive applications in VANETs, such as multimedia streaming. However, the vehicle mobility and intermittent connectivity present challenges to the large-scale data dissemination with underlying computing and networking architecture. In this paper, we will explore the service scheduling of virtual RSUs for diverse request demands in the dynamic traffic flow in vehicular cloud environment. Specifically, we formulate the RSU allocation problem as maximum service capacity with multiple-source and multiple-destination, and propose a bidirectional RSU allocation strategy. In addition, we formulate the content replication in distributed RSUs as the minimum replication set coverage problem in a two-layer mapping model, and analyze the solutions in different scenarios. Numerical results further prove the superiority of our proposed solution, as well as the scalability to various traffic condition variations.
      Citation: Algorithms
      PubDate: 2017-08-24
      DOI: 10.3390/a10030098
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 99: Hybrid Learning for General Type-2 TSK
           Fuzzy Logic Systems

    • Authors: Mauricio Sanchez, Juan Castro, Violeta Ocegueda-Miramontes, Leticia Cervantes
      First page: 99
      Abstract: This work is focused on creating fuzzy granular classification models based on general type-2 fuzzy logic systems when consequents are represented by interval type-2 TSK linear functions. Due to the complexity of general type-2 TSK fuzzy logic systems, a hybrid learning approach is proposed, where the principle of justifiable granularity is heuristically used to define an amount of uncertainty in the system, which in turn is used to define the parameters in the interval type-2 TSK linear functions via a dual LSE algorithm. Multiple classification benchmark datasets were tested in order to assess the quality of the formed granular models; its performance is also compared against other common classification algorithms. Shown results conclude that classification performance in general is better than results obtained by other techniques, and in general, all achieved results, when averaged, have a better performance rate than compared techniques, demonstrating the stability of the proposed hybrid learning technique.
      Citation: Algorithms
      PubDate: 2017-08-25
      DOI: 10.3390/a10030099
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 100: Biogeography-Based Optimization of the
           Portfolio Optimization Problem with Second Order Stochastic Dominance

    • Authors: Tao Ye, Ziqiang Yang, Siling Feng
      First page: 100
      Abstract: The portfolio optimization problem is the central problem of modern economics and decision theory; there is the Mean-Variance Model and Stochastic Dominance Model for solving this problem. In this paper, based on the second order stochastic dominance constraints, we propose the improved biogeography-based optimization algorithm to optimize the portfolio, which we called ε BBO. In order to test the computing power of ε BBO, we carry out two numerical experiments in several kinds of constraints. In experiment 1, comparing the Stochastic Approximation (SA) method with the Level Function (LF) algorithm and Genetic Algorithm (GA), we get a similar optimal solution by ε BBO in [ 0 , 0 . 6 ] and [ 0 , 1 ] constraints with the return of 1.174% and 1.178%. In [ - 1 , 2 ] constraint, we get the optimal return of 1.3043% by ε BBO, while the return of SA and LF is 1.23% and 1.26%. In experiment 2, we get the optimal return of 0.1325% and 0.3197% by ε BBO in [ 0 , 0 . 1 ] and [ - 0 . 05 , 0 . 15 ] constraints. As a comparison, the return of FTSE100 Index portfolio is 0.0937%. The results prove that ε BBO algorithm has great potential in the field of financial decision-making, it also shows that ε BBO algorithm has a better performance in optimization problem.
      Citation: Algorithms
      PubDate: 2017-08-25
      DOI: 10.3390/a10030100
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 101: Comparative Study of Type-2 Fuzzy Particle

    • Authors: Frumen Olivas, Leticia Amador-Angulo, Jonathan Perez, Camilo Caraveo, Fevrier Valdez, Oscar Castillo
      First page: 101
      Abstract: In this paper, a comparison among Particle swarm optimization (PSO), Bee Colony Optimization (BCO) and the Bat Algorithm (BA) is presented. In addition, a modification to the main parameters of each algorithm through an interval type-2 fuzzy logic system is presented. The main aim of using interval type-2 fuzzy systems is providing dynamic parameter adaptation to the algorithms. These algorithms (original and modified versions) are compared with the design of fuzzy systems used for controlling the trajectory of an autonomous mobile robot. Simulation results reveal that PSO algorithm outperforms the results of the BCO and BA algorithms.
      Citation: Algorithms
      PubDate: 2017-08-28
      DOI: 10.3390/a10030101
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 102: Local Community Detection in Dynamic
           Graphs Using Personalized Centrality

    • Authors: Eisha Nathan, Anita Zakrzewska, Jason Riedy, David Bader
      First page: 102
      Abstract: Analyzing massive graphs poses challenges due to the vast amount of data available. Extracting smaller relevant subgraphs allows for further visualization and analysis that would otherwise be too computationally intensive. Furthermore, many real data sets are constantly changing, and require algorithms to update as the graph evolves. This work addresses the topic of local community detection, or seed set expansion, using personalized centrality measures, specifically PageRank and Katz centrality. We present a method to efficiently update local communities in dynamic graphs. By updating the personalized ranking vectors, we can incrementally update the corresponding local community. Applying our methods to real-world graphs, we are able to obtain speedups of up to 60× compared to static recomputation while maintaining an average recall of 0.94 of the highly ranked vertices returned. Next, we investigate how approximations of a centrality vector affect the resulting local community. Specifically, our method guarantees that the vertices returned in the community are the highly ranked vertices from a personalized centrality metric.
      Citation: Algorithms
      PubDate: 2017-08-29
      DOI: 10.3390/a10030102
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 103: An Enhanced Dynamic Spectrum Allocation
           Algorithm Based on Cournot Game in Maritime Cognitive Radio Communication

    • Authors: Jingbo Zhang, Henan Yu, Shufang Zhang
      First page: 103
      Abstract: The recent development of maritime transport has resulted in the demand for a wider communication bandwidth being more intense. Cognitive radios can dynamically manage resources in a spectrum. Thus, building a new type of maritime cognitive radio communication system (MCRCS) is an effective solution. In this paper, the enhanced dynamic spectrum allocation algorithm (EDSAA) is proposed, which is based on the Cournot game model. In EDSAA, the decision-making center (DC) sets the weights according to the detection capability of the secondary user (SU), before adding these weighting coefficients in the price function. Furthermore, the willingness of the SU will reduce after meeting their basic communication needs when it continues to increase the leasable spectrum by adding the elastic model in the SU’s revenue function. On this basis, the profit function is established. The simulation results show that the EDSAA has Nash equilibrium and conforms to the actual situation. It shows that the results of spectrum allocation are fair, efficient and reasonable.
      Citation: Algorithms
      PubDate: 2017-09-03
      DOI: 10.3390/a10030103
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 104: Contract-Based Incentive Mechanism for
           Mobile Crowdsourcing Networks

    • Authors: Nan Zhao, Menglin Fan, Chao Tian, Pengfei Fan
      First page: 104
      Abstract: Mobile crowdsourcing networks (MCNs) are a promising method of data collecting and processing by leveraging the mobile devices’ sensing and computing capabilities. However, because of the selfish characteristics of the service provider (SP) and mobile users (MUs), crowdsourcing participants only aim to maximize their own benefits. This paper investigates the incentive mechanism between the above two parties to create mutual benefits. By modeling MCNs as a labor market, a contract-based crowdsourcing model with moral hazard is proposed under the asymmetric information scenario. In order to incentivize the potential MUs to participate in crowdsourcing tasks, the optimization problem is formulated to maximize the SP’s utility by jointly examining the crowdsourcing participants’ risk preferences. The impact of crowdsourcing participants’ attitudes of risks on the incentive mechanism has been studied analytically and experimentally. Numerical simulation results demonstrate the effectiveness of the proposed contract design scheme for the crowdsourcing incentive.
      Citation: Algorithms
      PubDate: 2017-09-04
      DOI: 10.3390/a10030104
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 105: Comparison of Internal Clustering
           Validation Indices for Prototype-Based Clustering

    • Authors: Joonas Hämäläinen, Susanne Jauhiainen, Tommi Kärkkäinen
      First page: 105
      Abstract: Clustering is an unsupervised machine learning and pattern recognition method. In general, in addition to revealing hidden groups of similar observations and clusters, their number needs to be determined. Internal clustering validation indices estimate this number without any external information. The purpose of this article is to evaluate, empirically, characteristics of a representative set of internal clustering validation indices with many datasets. The prototype-based clustering framework includes multiple, classical and robust, statistical estimates of cluster location so that the overall setting of the paper is novel. General observations on the quality of validation indices and on the behavior of different variants of clustering algorithms will be given.
      Citation: Algorithms
      PubDate: 2017-09-06
      DOI: 10.3390/a10030105
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 106: Type-1 Fuzzy Sets and Intuitionistic Fuzzy

    • Authors: Krassimir Atanassov
      First page: 106
      Abstract: A comparison between type-1 fuzzy sets (T1FSs) and intuitionistic fuzzy sets (IFSs) is made. The operators defined over IFSs that do not have analogues in T1FSs are shown, and such analogues are introduced whenever possible.
      Citation: Algorithms
      PubDate: 2017-09-13
      DOI: 10.3390/a10030106
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 107: A Monarch Butterfly Optimization for the
           Dynamic Vehicle Routing Problem

    • Authors: Shifeng Chen, Rong Chen, Jian Gao
      First page: 107
      Abstract: The dynamic vehicle routing problem (DVRP) is a variant of the Vehicle Routing Problem (VRP) in which customers appear dynamically. The objective is to determine a set of routes that minimizes the total travel distance. In this paper, we propose a monarch butterfly optimization (MBO) algorithm to solve DVRPs, utilizing a greedy strategy. Both migration operation and the butterfly adjusting operator only accept the offspring of butterfly individuals that have better fitness than their parents. To improve performance, a later perturbation procedure is implemented, to maintain a balance between global diversification and local intensification. The computational results indicate that the proposed technique outperforms the existing approaches in the literature for average performance by at least 9.38%. In addition, 12 new best solutions were found. This shows that this proposed technique consistently produces high-quality solutions and outperforms other published heuristics for the DVRP.
      Citation: Algorithms
      PubDate: 2017-09-12
      DOI: 10.3390/a10030107
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 108: Performance Analysis of Four
           Decomposition-Ensemble Models for One-Day-Ahead Agricultural Commodity
           Futures Price Forecasting

    • Authors: Deyun Wang, Chenqiang Yue, Shuai Wei, Jun Lv
      First page: 108
      Abstract: Agricultural commodity futures prices play a significant role in the change tendency of these spot prices and the supply–demand relationship of global agricultural product markets. Due to the nonlinear and nonstationary nature of this kind of time series data, it is inevitable for price forecasting research to take this nature into consideration. Therefore, we aim to enrich the existing research literature and offer a new way of thinking about forecasting agricultural commodity futures prices, so that four hybrid models are proposed based on the back propagation neural network (BPNN) optimized by the particle swarm optimization (PSO) algorithm and four decomposition methods: empirical mode decomposition (EMD), wavelet packet transform (WPT), intrinsic time-scale decomposition (ITD) and variational mode decomposition (VMD). In order to verify the applicability and validity of these hybrid models, we select three futures prices of wheat, corn and soybean to conduct the experiment. The experimental results show that (1) all the hybrid models combined with decomposition technique have a better performance than the single PSO–BPNN model; (2) VMD contributes the most in improving the forecasting ability of the PSO–BPNN model, while WPT ranks second; (3) ITD performs better than EMD in both cases of corn and soybean; and (4) the proposed models perform well in the forecasting of agricultural commodity futures prices.
      Citation: Algorithms
      PubDate: 2017-09-12
      DOI: 10.3390/a10030108
      Issue No: Vol. 10, No. 3 (2017)
  • Algorithms, Vol. 10, Pages 36: DNA Paired Fragment Assembly Using Graph

    • Authors: J. Quiroz-Ibarra, Guillermo Mallén-Fullerton, Guillermo Fernández-Anaya
      First page: 36
      Abstract: DNA fragment assembly requirements have generated an important computational problem created by their structure and the volume of data. Therefore, it is important to develop algorithms able to produce high-quality information that use computer resources efficiently. Such an algorithm, using graph theory, is introduced in the present article. We first determine the overlaps between DNA fragments, obtaining the edges of a directed graph; with this information, the next step is to construct an adjacency list with some particularities. Using the adjacency list, it is possible to obtain the DNA contigs (group of assembled fragments building a contiguous element) using graph theory. We performed a set of experiments on real DNA data and compared our results to those obtained with common assemblers (Edena and Velvet). Finally, we searched the contigs in the original genome, in our results and in those of Edena and Velvet.
      PubDate: 2017-03-24
      DOI: 10.3390/a10020036
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 37: A Spatial-Temporal-Semantic Neural Network
           Algorithm for Location Prediction on Moving Objects

    • Authors: Fan Wu, Kun Fu, Yang Wang, Zhibin Xiao, Xingyu Fu
      First page: 37
      Abstract: Location prediction has attracted much attention due to its important role in many location-based services, such as food delivery, taxi-service, real-time bus system, and advertisement posting. Traditional prediction methods often cluster track points into regions and mine movement patterns within the regions. Such methods lose information of points along the road and cannot meet the demand of specific services. Moreover, traditional methods utilizing classic models may not perform well with long location sequences. In this paper, a spatial-temporal-semantic neural network algorithm (STS-LSTM) has been proposed, which includes two steps. First, the spatial-temporal-semantic feature extraction algorithm (STS) is used to convert the trajectory to location sequences with fixed and discrete points in the road networks. The method can take advantage of points along the road and can transform trajectory into model-friendly sequences. Then, a long short-term memory (LSTM)-based model is constructed to make further predictions, which can better deal with long location sequences. Experimental results on two real-world datasets show that STS-LSTM has stable and higher prediction accuracy over traditional feature extraction and model building methods, and the application scenarios of the algorithm are illustrated.
      PubDate: 2017-03-24
      DOI: 10.3390/a10020037
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 38: An Asynchronous Message-Passing Distributed
           Algorithm for the Generalized Local Critical Section Problem

    • Authors: Sayaka Kamei, Hirotsugu Kakugawa
      First page: 38
      Abstract: This paper discusses the generalized local version of critical section problems including mutual exclusion, mutual inclusion, k-mutual exclusion and l-mutual inclusion. When a pair of numbers (li, ki) is given for each process Pi, it is the problem of controlling the system in such a way that the number of processes that can execute their critical sections at a time is at least li and at most ki among its neighboring processes and Pi itself. We propose the first solution for the generalized local (li, Ni + 1)-critical section problem (i.e., the generalized local li-mutual inclusion problem). Additionally, we show the relationship between the generalized local (li, ki)-critical section problem and the generalized local ( Ni + 1 − ki, Ni + 1 − li)-critical section problem. Finally, we propose the first solution for the generalized local (li, ki)-critical section problem for arbitrary (li, ki), where 0 ≤ li < ki + Ni + 1 for each process Pi.
      PubDate: 2017-03-24
      DOI: 10.3390/a10020038
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 39: From Intrusion Detection to an Intrusion
           Response System: Fundamentals, Requirements, and Future Directions

    • Authors: Shahid Anwar, Jasni Mohamad Zain, Mohamad Fadli Zolkipli, Zakira Inayat, Suleman Khan, Bokolo Anthony, Victor Chang
      First page: 39
      Abstract: In the past few decades, the rise in attacks on communication devices in networks has resulted in a reduction of network functionality, throughput, and performance. To detect and mitigate these network attacks, researchers, academicians, and practitioners developed Intrusion Detection Systems (IDSs) with automatic response systems. The response system is considered an important component of IDS, since without a timely response IDSs may not function properly in countering various attacks, especially on a real-time basis. To respond appropriately, IDSs should select the optimal response option according to the type of network attack. This research study provides a complete survey of IDSs and Intrusion Response Systems (IRSs) on the basis of our in-depth understanding of the response option for different types of network attacks. Knowledge of the path from IDS to IRS can assist network administrators and network staffs in understanding how to tackle different attacks with state-of-the-art technologies.
      PubDate: 2017-03-27
      DOI: 10.3390/a10020039
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 40: Fuzzy Random Walkers with Second Order
           Bounds: An Asymmetric Analysis

    • Authors: Georgios Drakopoulos, Andreas Kanavos, Konstantinos Tsakalidis
      First page: 40
      Abstract: Edge-fuzzy graphs constitute an essential modeling paradigm across a broad spectrum of domains ranging from artificial intelligence to computational neuroscience and social network analysis. Under this model, fundamental graph properties such as edge length and graph diameter become stochastic and as such they are consequently expressed in probabilistic terms. Thus, algorithms for fuzzy graph analysis must rely on non-deterministic design principles. One such principle is Random Walker, which is based on a virtual entity and selects either edges or, like in this case, vertices of a fuzzy graph to visit. This allows the estimation of global graph properties through a long sequence of local decisions, making it a viable strategy candidate for graph processing software relying on native graph databases such as Neo4j. As a concrete example, Chebyshev Walktrap, a heuristic fuzzy community discovery algorithm relying on second order statistics and on the teleportation of the Random Walker, is proposed and its performance, expressed in terms of community coherence and number of vertex visits, is compared to the previously proposed algorithms of Markov Walktrap, Fuzzy Walktrap, and Fuzzy Newman–Girvan. In order to facilitate this comparison, a metric based on the asymmetric metrics of Tversky index and Kullback–Leibler divergence is used.
      PubDate: 2017-03-30
      DOI: 10.3390/a10020040
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 41: RST Resilient Watermarking Scheme Based on
           DWT-SVD and Scale-Invariant Feature Transform

    • Authors: Yunpeng Zhang, Chengyou Wang, Xiao Zhou
      First page: 41
      Abstract: Currently, most digital image watermarking schemes are affected by geometric attacks like rotation, scaling, and translation (RST). In the watermark embedding process, a robust watermarking scheme is proposed against RST attacks. In this paper, three-level discrete wavelet transform (DWT) is applied to the original image. The three-level low frequency sub-band is decomposed by the singular value decomposition (SVD), and its singular values matrix is extracted for watermarking embedding. Before the watermarking extraction, the keypoints are selected by scale-invariant feature transform (SIFT) in the original image and attacked image. By matching the keypoints in two images, the RST attacks can be precisely corrected and the better performance can be obtained. The experimental results show that the proposed scheme achieves good performance of imperceptibility and robustness to common image processing and malicious attacks, especially geometric attacks.
      PubDate: 2017-03-30
      DOI: 10.3390/a10020041
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 42: RGloVe: An Improved Approach of Global
           Vectors for Distributional Entity Relation Representation

    • Authors: Ziyan Chen, Yu Huang, Yuexian Liang, Yang Wang, Xingyu Fu, Kun Fu
      First page: 42
      Abstract: Most of the previous works on relation extraction between named entities are often limited to extracting the pre-defined types; which are inefficient for massive unlabeled text data. Recently; with the appearance of various distributional word representations; unsupervised methods for many natural language processing (NLP) tasks have been widely researched. In this paper; we focus on a new finding of unsupervised relation extraction; which is called distributional relation representation. Without requiring the pre-defined types; distributional relation representation aims to automatically learn entity vectors and further estimate semantic similarity between these entities. We choose global vectors (GloVe) as our original model to train entity vectors because of its excellent balance between local context and global statistics in the whole corpus. In order to train model more efficiently; we improve the traditional GloVe model by using cosine similarity between entity vectors to approximate the entity occurrences instead of dot product. Because cosine similarity can convert vector to unit vector; it is intuitively more reasonable and more easily converge to a local optimum. We call the improved model RGloVe. Experimental results on a massive corpus of Sina News show that our proposed model outperforms the traditional global vectors. Finally; a graph database of Neo4j is introduced to store these relationships between named entities. The most competitive advantage of Neo4j is that it provides a highly accessible way to query the direct and indirect relationships between entities.
      PubDate: 2017-04-17
      DOI: 10.3390/a10020042
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 43: Reliable Portfolio Selection Problem in
           Fuzzy Environment: An mλ Measure Based Approach

    • Authors: Yuan Feng, Li Wang, Xinhong Liu
      First page: 43
      Abstract: This paper investigates a fuzzy portfolio selection problem with guaranteed reliability, in which the fuzzy variables are used to capture the uncertain returns of different securities. To effectively handle the fuzziness in a mathematical way, a new expected value operator and variance of fuzzy variables are defined based on the m λ measure that is a linear combination of the possibility measure and necessity measure to balance the pessimism and optimism in the decision-making process. To formulate the reliable portfolio selection problem, we particularly adopt the expected total return and standard variance of the total return to evaluate the reliability of the investment strategies, producing three risk-guaranteed reliable portfolio selection models. To solve the proposed models, an effective genetic algorithm is designed to generate the approximate optimal solution to the considered problem. Finally, the numerical examples are given to show the performance of the proposed models and algorithm.
      PubDate: 2017-04-18
      DOI: 10.3390/a10020043
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 44: Revised Gravitational Search Algorithms
           Based on Evolutionary-Fuzzy Systems

    • Authors: Danilo Pelusi, Raffaele Mascella, Luca Tallini
      First page: 44
      Abstract: The choice of the best optimization algorithm is a hard issue, and it sometime depends on specific problem. The Gravitational Search Algorithm (GSA) is a search algorithm based on the law of gravity, which states that each particle attracts every other particle with a force called gravitational force. Some revised versions of GSA have been proposed by using intelligent techniques. This work proposes some GSA versions based on fuzzy techniques powered by evolutionary methods, such as Genetic Algorithms (GA), Particle Swarm Optimization (PSO) and Differential Evolution (DE), to improve GSA. The designed algorithms tune a suitable parameter of GSA through a fuzzy controller whose membership functions are optimized by GA, PSO and DE. The results show that Fuzzy Gravitational Search Algorithm (FGSA) optimized by DE is optimal for unimodal functions, whereas FGSA optimized through GA is good for multimodal functions.
      PubDate: 2017-04-21
      DOI: 10.3390/a10020044
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 45: An Efficient Sixth-Order Newton-Type Method
           for Solving Nonlinear Systems

    • Authors: Xiaofeng Wang, Yang Li
      First page: 45
      Abstract: In this paper, we present a new sixth-order iterative method for solving nonlinear systems and prove a local convergence result. The new method requires solving five linear systems per iteration. An important feature of the new method is that the LU (lower upper, also called LU factorization) decomposition of the Jacobian matrix is computed only once in each iteration. The computational efficiency index of the new method is compared to that of some known methods. Numerical results are given to show that the convergence behavior of the new method is similar to the existing methods. The new method can be applied to small- and medium-sized nonlinear systems.
      PubDate: 2017-04-25
      DOI: 10.3390/a10020045
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 46: An Improved Multiobjective Particle Swarm
           Optimization Based on Culture Algorithms

    • Authors: Chunhua Jia, Hong Zhu
      First page: 46
      Abstract: In this paper, we propose a new approach to raise the performance of multiobjective particle swam optimization. The personal guide and global guide are updated using three kinds of knowledge extracted from the population based on cultural algorithms. An epsilon domination criterion has been employed to enhance the convergence and diversity of the approximate Pareto front. Moreover, a simple polynomial mutation operator has been applied to both the population and the non-dominated archive. Experiments on two series of bench test suites have shown the effectiveness of the proposed approach. A comparison with several other algorithms that are considered good representatives of particle swarm optimization solutions has also been conducted, in order to verify the competitive performance of the proposed algorithm in solve multiobjective optimization problems.
      PubDate: 2017-04-25
      DOI: 10.3390/a10020046
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 47: Trust in the Balance: Data Protection Laws
           as Tools for Privacy and Security in the Cloud

    • Authors: Darra Hofman, Luciana Duranti, Elissa How
      First page: 47
      Abstract: A popular bumper sticker states: “There is no cloud. It’s just someone else’s computer.” Despite the loss of control that comes with its use, critical records are increasingly being entrusted to the cloud, generating ever-growing concern about the privacy and security of those records. Ultimately, privacy and security constitute an attempt to balance competing needs: privacy balances the need to use information against the need to protect personal data, while security balances the need to provide access to records against the need to stop unauthorized access. The importance of these issues has led to a multitude of legal and regulatory efforts to find a balance and, ultimately, to ensure trust in both digital records and their storage in the cloud. Adding a particular challenge is the fact that distinct jurisdictions approach privacy differently and an in-depth understanding of what a jurisdiction’s laws may be, or even under what jurisdiction particular data might be, requires a Herculean effort. And yet, in order to protect privacy and enhance security, this effort is required. This article examines two legal tools for ensuring the privacy and security of records in the cloud, data protection laws, and data localization laws, through the framework of “trust” as understood in archival science. This framework of trust provides new directions for algorithmic research, identifying those areas of digital record creation and preservation most in need of novel solutions.
      PubDate: 2017-04-27
      DOI: 10.3390/a10020047
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 48: Adaptive Mutation Dynamic Search Fireworks

    • Authors: Xi-Guang Li, Shou-Fei Han, Liang Zhao, Chang-Qing Gong, Xiao-Jing Liu
      First page: 48
      Abstract: The Dynamic Search Fireworks Algorithm (dynFWA) is an effective algorithm for solving optimization problems. However, dynFWA easily falls into local optimal solutions prematurely and it also has a slow convergence rate. In order to improve these problems, an adaptive mutation dynamic search fireworks algorithm (AMdynFWA) is introduced in this paper. The proposed algorithm applies the Gaussian mutation or the Levy mutation for the core firework (CF) with mutation probability. Our simulation compares the proposed algorithm with the FWA-Based algorithms and other swarm intelligence algorithms. The results show that the proposed algorithm achieves better overall performance on the standard test functions.
      PubDate: 2017-04-28
      DOI: 10.3390/a10020048
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 49: Multivariate Statistical Process Control
           Using Enhanced Bottleneck Neural Network

    • Authors: Khaled Bouzenad, Messaoud Ramdani
      First page: 49
      Abstract: Monitoring process upsets and malfunctions as early as possible and then finding and removing the factors causing the respective events is of great importance for safe operation and improved productivity. Conventional process monitoring using principal component analysis (PCA) often supposes that process data follow a Gaussian distribution. However, this kind of constraint cannot be satisfied in practice because many industrial processes frequently span multiple operating states. To overcome this difficulty, PCA can be combined with nonparametric control charts for which there is no assumption need on the distribution. However, this approach still uses a constant confidence limit where a relatively high rate of false alarms are generated. Although nonlinear PCA (NLPCA) using autoassociative bottle-neck neural networks plays an important role in the monitoring of industrial processes, it is difficult to design correct monitoring statistics and confidence limits that check new performance. In this work, a new monitoring strategy using an enhanced bottleneck neural network (EBNN) with an adaptive confidence limit for non Gaussian data is proposed. The basic idea behind it is to extract internally homogeneous segments from the historical normal data sets by filling a Gaussian mixture model (GMM). Based on the assumption that process data follow a Gaussian distribution within an operating mode, a local confidence limit can be established. The EBNN is used to reconstruct input data and estimate probabilities of belonging to the various local operating regimes, as modelled by GMM. An abnormal event for an input measurement vector is detected if the squared prediction error (SPE) is too large, or above a certain threshold which is made adaptive. Moreover, the sensor validity index (SVI) is employed successfully to identify the detected faulty variable. The results demonstrate that, compared with NLPCA, the proposed approach can effectively reduce the number of false alarms, and is hence expected to better monitor many practical processes.
      PubDate: 2017-04-29
      DOI: 10.3390/a10020049
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 50: Hierarchical Parallel Evaluation of a
           Hamming Code

    • Authors: Shmuel Klein, Dana Shapira
      First page: 50
      Abstract: The Hamming code is a well-known error correction code and can correct a single error in an input vector of size n bits by adding logn parity checks. A new parallel implementation of the code is presented, using a hierarchical structure of n processors in logn layers. All the processors perform similar simple tasks, and need only a few bytes of internal memory.
      PubDate: 2017-04-30
      DOI: 10.3390/a10020050
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 51: Adaptive Vector Quantization for Lossy
           Compression of Image Sequences

    • Authors: Raffaele Pizzolante, Bruno Carpentieri, Sergio De Agostino
      First page: 51
      Abstract: In this work, we present a scheme for the lossy compression of image sequences, based on the Adaptive Vector Quantization (AVQ) algorithm. The AVQ algorithm is a lossy compression algorithm for grayscale images, which processes the input data in a single-pass, by using the properties of the vector quantization to approximate data. First, we review the key aspects of the AVQ algorithm and, subsequently, we outline the basic concepts and the design choices behind the proposed scheme. Finally, we report the experimental results, which highlight an improvement in compression performances when our scheme is compared with the AVQ algorithm.
      PubDate: 2017-05-09
      DOI: 10.3390/a10020051
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 52: Searchable Data Vault: Encrypted Queries in
           Secure Distributed Cloud Storage

    • Authors: Geong Poh, Vishnu Baskaran, Ji-Jian Chin, Moesfa Mohamad, Kay Win Lee, Dharmadharshni Maniam, Muhammad Z’aba
      First page: 52
      Abstract: Cloud storage services allow users to efficiently outsource their documents anytime and anywhere. Such convenience, however, leads to privacy concerns. While storage providers may not read users’ documents, attackers may possibly gain access by exploiting vulnerabilities in the storage system. Documents may also be leaked by curious administrators. A simple solution is for the user to encrypt all documents before submitting them. This method, however, makes it impossible to efficiently search for documents as they are all encrypted. To resolve this problem, we propose a multi-server searchable symmetric encryption (SSE) scheme and construct a system called the searchable data vault (SDV). A unique feature of the scheme is that it allows an encrypted document to be divided into blocks and distributed to different storage servers so that no single storage provider has a complete document. By incorporating the scheme, the SDV protects the privacy of documents while allowing for efficient private queries. It utilizes a web interface and a controller that manages user credentials, query indexes and submission of encrypted documents to cloud storage services. It is also the first system that enables a user to simultaneously outsource and privately query documents from a few cloud storage services. Our preliminary performance evaluation shows that this feature introduces acceptable computation overheads when compared to submitting documents directly to a cloud storage service.
      PubDate: 2017-05-09
      DOI: 10.3390/a10020052
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 53: Application of Gradient Descent Continuous
           Actor-Critic Algorithm for Bilateral Spot Electricity Market Modeling
           Considering Renewable Power Penetration

    • Authors: Huiru Zhao, Yuwei Wang, Mingrui Zhao, Chuyu Sun, Qingkun Tan
      First page: 53
      Abstract: The bilateral spot electricity market is very complicated because all generation units and demands must strategically bid in this market. Considering renewable resource penetration, the high variability and the non-dispatchable nature of these intermittent resources make it more difficult to model and simulate the dynamic bidding process and the equilibrium in the bilateral spot electricity market, which makes developing fast and reliable market modeling approaches a matter of urgency nowadays. In this paper, a Gradient Descent Continuous Actor-Critic algorithm is proposed for hour-ahead bilateral electricity market modeling in the presence of renewable resources because this algorithm can solve electricity market modeling problems with continuous state and action spaces without causing the “curse of dimensionality” and has low time complexity. In our simulation, the proposed approach is implemented on an IEEE 30-bus test system. The adequate performance of our proposed approach—such as reaching Nash Equilibrium results after enough iterations of training are tested and verified, and some conclusions about the relationship between increasing the renewable power output and participants’ bidding strategy, locational marginal prices, and social welfare—is also evaluated. Moreover, the comparison of our proposed approach with the fuzzy Q-learning-based electricity market approach implemented in this paper confirms the superiority of our proposed approach in terms of participants’ profits, social welfare, average locational marginal prices, etc.
      PubDate: 2017-05-10
      DOI: 10.3390/a10020053
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 54: Extending the Applicability of the MMN-HSS
           Method for Solving Systems of Nonlinear Equations under Generalized

    • Authors: Ioannis Argyros, Janak Sharma, Deepak Kumar
      First page: 54
      Abstract: We present the semilocal convergence of a multi-step modified Newton-Hermitian and Skew-Hermitian Splitting method (MMN-HSS method) to approximate a solution of a nonlinear equation. Earlier studies show convergence under only Lipschitz conditions limiting the applicability of this method. The convergence in this study is shown under generalized Lipschitz-type conditions and restricted convergence domains. Hence, the applicability of the method is extended. Moreover, numerical examples are also provided to show that our results can be applied to solve equations in cases where earlier study cannot be applied. Furthermore, in the cases where both old and new results are applicable, the latter provides a larger domain of convergence and tighter error bounds on the distances involved.
      PubDate: 2017-05-12
      DOI: 10.3390/a10020054
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 55: Erratum: Ahmad, F., et al. A Preconditioned
           Iterative Method for Solving Systems of Nonlinear Equations Having Unknown
           Multiplicity. Algorithms 2017, 10, 17

    • Authors: Fayyaz Ahmad, Toseef Bhutta, Umar Shoaib, Malik Ullah, Ali Alshomrani, Shamshad Ahmad, Shahid Ahmad
      First page: 55
      Abstract: n/a
      PubDate: 2017-05-12
      DOI: 10.3390/a10020055
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 56: Clustering Using an Improved Krill Herd

    • Authors: Qin Li, Bo Liu
      First page: 56
      Abstract: In recent years, metaheuristic algorithms have been widely used in solving clustering problems because of their good performance and application effects. krill herd algorithm (KHA) is a new effective algorithm to solve optimization problems based on the imitation of krill individual behavior, and it is proven to perform better than other swarm intelligence algorithms. However, there are some weaknesses yet. In this paper, an improved krill herd algorithm (IKHA) is studied. Modified mutation operators and updated mechanisms are applied to improve global optimization, and the proposed IKHA can overcome the weakness of KHA and performs better than KHA in optimization problems. Then, KHA and IKHA are introduced into the clustering problem. In our proposed clustering algorithm, KHA and IKHA are used to find appropriate cluster centers. Experiments were conducted on University of California Irvine (UCI) standard datasets, and the results showed that the IKHA clustering algorithm is the most effective.
      PubDate: 2017-05-17
      DOI: 10.3390/a10020056
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 57: A Prediction of Precipitation Data Based on
           Support Vector Machine and Particle Swarm Optimization (PSO-SVM)

    • Authors: Jinglin Du, Yayun Liu, Yanan Yu, Weilan Yan
      First page: 57
      Abstract: Precipitation is a very important topic in weather forecasts. Weather forecasts, especially precipitation prediction, poses complex tasks because they depend on various parameters to predict the dependent variables like temperature, humidity, wind speed and direction, which are changing from time to time and weather calculation varies with the geographical location along with its atmospheric variables. To improve the prediction accuracy of precipitation, this context proposes a prediction model for rainfall forecast based on Support Vector Machine with Particle Swarm Optimization (PSO-SVM) to replace the linear threshold used in traditional precipitation. Parameter selection has a critical impact on the predictive accuracy of SVM, and PSO is proposed to find the optimal parameters for SVM. The PSO-SVM algorithm was used for the training of a model by using the historical data for precipitation prediction, which can be useful information and used by people of all walks of life in making wise and intelligent decisions. The simulations demonstrate that prediction models indicate that the performance of the proposed algorithm has much better accuracy than the direct prediction model based on a set of experimental data if other things are equal. On the other hand, simulation results demonstrate the effectiveness and advantages of the SVM-PSO model used in machine learning and further promises the scope for improvement as more and more relevant attributes can be used in predicting the dependent variables.
      PubDate: 2017-05-17
      DOI: 10.3390/a10020057
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 58: A Flexible Pattern-Matching Algorithm for
           Network Intrusion Detection Systems Using Multi-Core Processors

    • Authors: Chun-Liang Lee, Tzu-Hao Yang
      First page: 58
      Abstract: As part of network security processes, network intrusion detection systems (NIDSs) determine whether incoming packets contain malicious patterns. Pattern matching, the key NIDS component, consumes large amounts of execution time. One of several trends involving general-purpose processors (GPPs) is their use in software-based NIDSs. In this paper, we describe our proposal for an efficient and flexible pattern-matching algorithm for inspecting packet payloads using a head-body finite automaton (HBFA). The proposed algorithm takes advantage of multi-core GPP parallelism and single-instruction multiple-data operations to achieve higher throughput compared to that resulting from traditional deterministic finite automata (DFA) using the Aho-Corasick algorithm. Whereas the head-body matching (HBM) algorithm is based on pre-defined DFA depth value, our HBFA algorithm is based on head size. Experimental results using Snort and ClamAV pattern sets indicate that the proposed algorithm achieves up to 58% higher throughput compared to its HBM counterpart.
      PubDate: 2017-05-24
      DOI: 10.3390/a10020058
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 59: Contradiction Detection with
           Contradiction-Specific Word Embedding

    • Authors: Luyang Li, Bing Qin, Ting Liu
      First page: 59
      Abstract: Contradiction detection is a task to recognize contradiction relations between a pair of sentences. Despite the effectiveness of traditional context-based word embedding learning algorithms in many natural language processing tasks, such algorithms are not powerful enough for contradiction detection. Contrasting words such as “overfull” and “empty” are mostly mapped into close vectors in such embedding space. To solve this problem, we develop a tailored neural network to learn contradiction-specific word embedding (CWE). The method can separate antonyms in the opposite ends of a spectrum. CWE is learned from a training corpus which is automatically generated from the paraphrase database, and is naturally applied as features to carry out contradiction detection in SemEval 2014 benchmark dataset. Experimental results show that CWE outperforms traditional context-based word embedding in contradiction detection. The proposed model for contradiction detection performs comparably with the top-performing system in accuracy of three-category classification and enhances the accuracy from 75.97% to 82.08% in the contradiction category.
      PubDate: 2017-05-24
      DOI: 10.3390/a10020059
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 60: Correction: A No Reference Image Quality
           Assessment Metric Based on Visual Perception. Algorithms 2016, 9, 87

    • Authors: Yan Fu, Shengchun Wang
      First page: 60
      Abstract: We would like to make the following change to our article [1]. [...]
      PubDate: 2017-05-26
      DOI: 10.3390/a10020060
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 61: Design and Implementation of a Multi-Modal
           Biometric System for Company Access Control

    • Authors: Elisabetta Stefani, Carlo Ferrari
      First page: 61
      Abstract: This paper is about the design, implementation, and deployment of a multi-modal biometric system to grant access to a company structure and to internal zones in the company itself. Face and iris have been chosen as biometric traits. Face is feasible for non-intrusive checking with a minimum cooperation from the subject, while iris supports very accurate recognition procedure at a higher grade of invasivity. The recognition of the face trait is based on the Local Binary Patterns histograms, and the Daughman’s method is implemented for the analysis of the iris data. The recognition process may require either the acquisition of the user’s face only or the serial acquisition of both the user’s face and iris, depending on the confidence level of the decision with respect to the set of security levels and requirements, stated in a formal way in the Service Level Agreement at a negotiation phase. The quality of the decision depends on the setting of proper different thresholds in the decision modules for the two biometric traits. Any time the quality of the decision is not good enough, the system activates proper rules, which ask for new acquisitions (and decisions), possibly with different threshold values, resulting in a system not with a fixed and predefined behaviour, but one which complies with the actual acquisition context. Rules are formalized as deduction rules and grouped together to represent “response behaviors” according to the previous analysis. Therefore, there are different possible working flows, since the actual response of the recognition process depends on the output of the decision making modules that compose the system. Finally, the deployment phase is described, together with the results from the testing, based on the AT&T Face Database and the UBIRIS database.
      PubDate: 2017-05-27
      DOI: 10.3390/a10020061
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 62: Influence Factors Analysis on the Modal
           Characteristics of Irregularly-Shaped Bridges Based on a Free-Interface
           Mode Synthesis Algorithm

    • Authors: Hanbing Liu, Mengsu Zhang, Xianqiang Wang, Shuai Tian, Yubo Jiao
      First page: 62
      Abstract: In order to relieve traffic congestion, irregularly-shaped bridges have been widely used in urban overpasses. However, the analysis on modal characteristics of irregularly-shaped bridges is not exhaustive, and the effect of design parameters on modal characteristics will be deeply investigated in future studies. In this paper, a novel strategy based on a free-interface mode synthesis algorithm is proposed to evaluate the parameters’ effect on the modal characteristics of irregularly-shaped bridges. First, a complicated, irregularly-shaped bridge is divided into several substructures based on its properties. Then, the modal characteristics of the overall structure can be obtained, only by a few low-order modal parameters of each substructure, using a free-interface mode synthesis method. A numerical model of a typical irregularly-shaped bridge is employed to verify the effectiveness of the proposed strategy. Simulation results reveal that the free-interface mode synthesis method possesses favorable calculation accuracy for analyzing the modal characteristics of irregularly-shaped bridges. The effect of design parameters such as ramp curve radius, diaphragm beam stiffness, cross-section feature, and bearing conditions on the modal characteristics of an irregularly-shaped bridge is evaluated in detail. Analysis results can provide references for further research into and the design of irregularly-shaped bridges.
      PubDate: 2017-05-28
      DOI: 10.3390/a10020062
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 63: Development of Filtered Bispectrum for EEG
           Signal Feature Extraction in Automatic Emotion Recognition Using
           Artificial Neural Networks

    • Authors: Prima Purnamasari, Anak Ratna, Benyamin Kusumoputro
      First page: 63
      Abstract: The development of automatic emotion detection systems has recently gained significant attention due to the growing possibility of their implementation in several applications, including affective computing and various fields within biomedical engineering. Use of the electroencephalograph (EEG) signal is preferred over facial expression, as people cannot control the EEG signal generated by their brain; the EEG ensures a stronger reliability in the psychological signal. However, because of its uniqueness between individuals and its vulnerability to noise, use of EEG signals can be rather complicated. In this paper, we propose a methodology to conduct EEG-based emotion recognition by using a filtered bispectrum as the feature extraction subsystem and an artificial neural network (ANN) as the classifier. The bispectrum is theoretically superior to the power spectrum because it can identify phase coupling between the nonlinear process components of the EEG signal. In the feature extraction process, to extract the information contained in the bispectrum matrices, a 3D pyramid filter is used for sampling and quantifying the bispectrum value. Experiment results show that the mean percentage of the bispectrum value from 5 × 5 non-overlapped 3D pyramid filters produces the highest recognition rate. We found that reducing the number of EEG channels down to only eight in the frontal area of the brain does not significantly affect the recognition rate, and the number of data samples used in the training process is then increased to improve the recognition rate of the system. We have also utilized a probabilistic neural network (PNN) as another classifier and compared its recognition rate with that of the back-propagation neural network (BPNN), and the results show that the PNN produces a comparable recognition rate and lower computational costs. Our research shows that the extracted bispectrum values of an EEG signal using 3D filtering as a feature extraction method is suitable for use in an EEG-based emotion recognition system.
      PubDate: 2017-05-30
      DOI: 10.3390/a10020063
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 64: Expanding the Applicability of Some High
           Order Househölder-Like Methods

    • Authors: Sergio Amat, Ioannis Argyros, Miguel Hernández-Verón, Natalia Romero
      First page: 64
      Abstract: This paper is devoted to the semilocal convergence of a Househölder-like method for nonlinear equations. The method includes many of the studied third order iterative methods. In the present study, we use our new idea of restricted convergence domains leading to smaller γ -parameters, which in turn lead to the following advantages over earlier works (and under the same computational cost): larger convergence domain; tighter error bounds on the distances involved, and at least as precise information on the location of the solution.
      PubDate: 2017-05-31
      DOI: 10.3390/a10020064
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 65: Seismic Signal Compression Using
           Nonparametric Bayesian Dictionary Learning via Clustering

    • Authors: Xin Tian, Song Li
      First page: 65
      Abstract: We introduce a seismic signal compression method based on nonparametric Bayesian dictionary learning method via clustering. The seismic data is compressed patch by patch, and the dictionary is learned online. Clustering is introduced for dictionary learning. A set of dictionaries could be generated, and each dictionary is used for one cluster’s sparse coding. In this way, the signals in one cluster could be well represented by their corresponding dictionaries. A nonparametric Bayesian dictionary learning method is used to learn the dictionaries, which naturally infers an appropriate dictionary size for each cluster. A uniform quantizer and an adaptive arithmetic coding algorithm are adopted to code the sparse coefficients. With comparisons to other state-of-the art approaches, the effectiveness of the proposed method could be validated in the experiments.
      PubDate: 2017-06-07
      DOI: 10.3390/a10020065
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 66: A New Approach to Image-Based Estimation of
           Food Volume

    • Authors: Hamid Hassannejad, Guido Matrella, Paolo Ciampolini, Ilaria Munari, Monica Mordonini, Stefano Cagnoni
      First page: 66
      Abstract: A balanced diet is the key to a healthy lifestyle and is crucial for preventing or dealing with many chronic diseases such as diabetes and obesity. Therefore, monitoring diet can be an effective way of improving people’s health. However, manual reporting of food intake has been shown to be inaccurate and often impractical. This paper presents a new approach to food intake quantity estimation using image-based modeling. The modeling method consists of three steps: firstly, a short video of the food is taken by the user’s smartphone. From such a video, six frames are selected based on the pictures’ viewpoints as determined by the smartphone’s orientation sensors. Secondly, the user marks one of the frames to seed an interactive segmentation algorithm. Segmentation is based on a Gaussian Mixture Model alongside the graph-cut algorithm. Finally, a customized image-based modeling algorithm generates a point-cloud to model the food. At the same time, a stochastic object-detection method locates a checkerboard used as size/ground reference. The modeling algorithm is optimized such that the use of six input images still results in an acceptable computation cost. In our evaluation procedure, we achieved an average accuracy of 92 % on a test set that includes images of different kinds of pasta and bread, with an average processing time of about 23 s.
      PubDate: 2017-06-10
      DOI: 10.3390/a10020066
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 67: Research on Misalignment Fault Isolation of
           Wind Turbines Based on the Mixed-Domain Features

    • Authors: Yancai Xiao, Yujia Wang, Huan Mu, Na Kang
      First page: 67
      Abstract: The misalignment of the drive system of the DFIG (Doubly Fed Induction Generator) wind turbine is one of the important factors that cause damage to the gears, bearings of the high-speed gearbox and the generator bearings. How to use the limited information to accurately determine the type of failure has become a difficult study for the scholars. In this paper, the time-domain indexes and frequency-domain indexes are extracted by using the vibration signals of various misaligned simulation conditions of the wind turbine drive system, and the time-frequency domain features—energy entropy are also extracted by the IEMD (Improved Empirical Mode Decomposition). A mixed-domain feature set is constructed by them. Then, SVM (Support Vector Machine) is used as the classifier, the mixed-domain features are used as the inputs of SVM, and PSO (Particle Swarm Optimization) is used to optimize the parameters of SVM. The fault types of misalignment are classified successfully. Compared with other methods, the accuracy of the given fault isolation model is improved.
      PubDate: 2017-06-10
      DOI: 10.3390/a10020067
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 68: An Easily Understandable Grey Wolf
           Optimizer and Its Application to Fuzzy Controller Tuning

    • Authors: Radu-Emil Precup, Radu-Codrut David, Alexandra-Iulia Szedlak-Stinean, Emil M. Petriu, Florin Dragan
      First page: 68
      Abstract: This paper proposes an easily understandable Grey Wolf Optimizer (GWO) applied to the optimal tuning of the parameters of Takagi-Sugeno proportional-integral fuzzy controllers (T-S PI-FCs). GWO is employed for solving optimization problems focused on the minimization of discrete-time objective functions defined as the weighted sum of the absolute value of the control error and of the squared output sensitivity function, and the vector variable consists of the tuning parameters of the T-S PI-FCs. Since the sensitivity functions are introduced with respect to the parametric variations of the process, solving these optimization problems is important as it leads to fuzzy control systems with a reduced process parametric sensitivity obtained by a GWO-based fuzzy controller tuning approach. GWO algorithms applied with this regard are formulated in easily understandable terms for both vector and scalar operations, and discussions on stability, convergence, and parameter settings are offered. The controlled processes referred to in the course of this paper belong to a family of nonlinear servo systems, which are modeled by second order dynamics plus a saturation and dead zone static nonlinearity. Experimental results concerning the angular position control of a laboratory servo system are included for validating the proposed method.
      PubDate: 2017-06-10
      DOI: 10.3390/a10020068
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 69: Cross-Language Plagiarism Detection System
           Using Latent Semantic Analysis and Learning Vector Quantization

    • Authors: Anak Agung Putri Ratna, Prima Dewi Purnamasari, Boma Anantasatya Adhi, F. Astha Ekadiyanto, Muhammad Salman, Mardiyah Mardiyah, Darien Jonathan Winata
      First page: 69
      Abstract: Computerized cross-language plagiarism detection has recently become essential. With the scarcity of scientific publications in Bahasa Indonesia, many Indonesian authors frequently consult publications in English in order to boost the quantity of scientific publications in Bahasa Indonesia (which is currently rising). Due to the syntax disparity between Bahasa Indonesia and English, most of the existing methods for automated cross-language plagiarism detection do not provide satisfactory results. This paper analyses the probability of developing Latent Semantic Analysis (LSA) for a computerized cross-language plagiarism detector for two languages with different syntax. To improve performance, various alterations in LSA are suggested. By using a linear vector quantization (LVQ) classifier in the LSA and taking into account the Frobenius norm, output has reached up to 65.98% in accuracy. The results of the experiments showed that the best accuracy achieved is 87% with a document size of 6 words, and the document definition size must be kept below 10 words in order to maintain high accuracy. Additionally, based on experimental results, this paper suggests utilizing the frequency occurrence method as opposed to the binary method for the term–document matrix construction.
      PubDate: 2017-06-13
      DOI: 10.3390/a10020069
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 70: An Improved Brain-Inspired Emotional
           Learning Algorithm for Fast Classification

    • Authors: Ying Mei, Guanzheng Tan, Zhentao Liu
      First page: 70
      Abstract: Classification is an important task of machine intelligence in the field of information. The artificial neural network (ANN) is widely used for classification. However, the traditional ANN shows slow training speed, and it is hard to meet the real-time requirement for large-scale applications. In this paper, an improved brain-inspired emotional learning (BEL) algorithm is proposed for fast classification. The BEL algorithm was put forward to mimic the high speed of the emotional learning mechanism in mammalian brain, which has the superior features of fast learning and low computational complexity. To improve the accuracy of BEL in classification, the genetic algorithm (GA) is adopted for optimally tuning the weights and biases of amygdala and orbitofrontal cortex in the BEL neural network. The combinational algorithm named as GA-BEL has been tested on eight University of California at Irvine (UCI) datasets and two well-known databases (Japanese Female Facial Expression, Cohn–Kanade). The comparisons of experiments indicate that the proposed GA-BEL is more accurate than the original BEL algorithm, and it is much faster than the traditional algorithm.
      PubDate: 2017-06-14
      DOI: 10.3390/a10020070
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 71: Bayesian and Classical Estimation of
           Stress-Strength Reliability for Inverse Weibull Lifetime Models

    • Authors: Qixuan Bi, Wenhao Gui
      First page: 71
      Abstract: In this paper, we consider the problem of estimating stress-strength reliability for inverse Weibull lifetime models having the same shape parameters but different scale parameters. We obtain the maximum likelihood estimator and its asymptotic distribution. Since the classical estimator doesn’t hold explicit forms, we propose an approximate maximum likelihood estimator. The asymptotic confidence interval and two bootstrap intervals are obtained. Using the Gibbs sampling technique, Bayesian estimator and the corresponding credible interval are obtained. The Metropolis-Hastings algorithm is used to generate random variates. Monte Carlo simulations are conducted to compare the proposed methods. Analysis of a real dataset is performed.
      PubDate: 2017-06-21
      DOI: 10.3390/a10020071
      Issue No: Vol. 10, No. 2 (2017)
  • Algorithms, Vol. 10, Pages 26: Analysis and Improvement of Fireworks

    • Authors: Xi-Guang Li, Shou-Fei Han, Chang-Qing Gong
      First page: 26
      Abstract: The Fireworks Algorithm is a recently developed swarm intelligence algorithm to simulate the explosion process of fireworks. Based on the analysis of each operator of Fireworks Algorithm (FWA), this paper improves the FWA and proves that the improved algorithm converges to the global optimal solution with probability 1. The proposed algorithm improves the goal of further boosting performance and achieving global optimization where mainly include the following strategies. Firstly using the opposition-based learning initialization population. Secondly a new explosion amplitude mechanism for the optimal firework is proposed. In addition, the adaptive t-distribution mutation for non-optimal individuals and elite opposition-based learning for the optimal individual are used. Finally, a new selection strategy, namely Disruptive Selection, is proposed to reduce the running time of the algorithm compared with FWA. In our simulation, we apply the CEC2013 standard functions and compare the proposed algorithm (IFWA) with SPSO2011, FWA, EFWA and dynFWA. The results show that the proposed algorithm has better overall performance on the test functions.
      PubDate: 2017-02-17
      DOI: 10.3390/a10010026
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 27: Fragile Watermarking for Image
           Authentication Using the Characteristic of SVD

    • Authors: Heng Zhang, Chengyou Wang, Xiao Zhou
      First page: 27
      Abstract: Digital image authentication has become a hot topic in the last few years. In this paper, a pixel-based fragile watermarking method is presented for image tamper identification and localization. By analyzing the left and right singular matrices of SVD, it is found that the matrix product between the first column of the left singular matrix and the transposition of the first column in the right singular matrix is closely related to the image texture features. Based on this characteristic, a binary watermark consisting of image texture information is generated and inserted into the least significant bit (LSB) of the original host image. To improve the security of the presented algorithm, the Arnold transform is applied twice in the watermark embedding process. Experimental results indicate that the proposed watermarking algorithm has high security and perceptual invisibility. Moreover, it can detect and locate the tampered region effectively for various malicious attacks.
      PubDate: 2017-02-17
      DOI: 10.3390/a10010027
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 28: Mining Domain-Specific Design Patterns: A
           Case Study †

    • Authors: Vassiliki Gkantouna, Giannis Tzimas
      First page: 28
      Abstract: Domain-specific design patterns provide developers with proven solutions to common design problems that arise, particularly in a target application domain, facilitating them to produce quality designs in the domain contexts. However, research in this area is not mature and there are no techniques to support their detection. Towards this end, we propose a methodology which, when applied on a collection of websites in a specific domain, facilitates the automated identification of domain-specific design patterns. The methodology automatically extracts the conceptual models of the websites, which are subsequently analyzed in terms of all of the reusable design fragments used in them for supporting common domain functionalities. At the conceptual level, we consider these fragments as recurrent patterns consisting of a configuration of front-end interface components that interrelate each other and interact with end-users to support certain functionality. By performing a pattern-based analysis of the models, we locate the occurrences of all the recurrent patterns in the various website designs which are then evaluated towards their consistent use. The detected patterns can be used as building blocks in future designs, assisting developers to produce consistent and quality designs in the target domain. To support our case, we present a case study for the educational domain.
      PubDate: 2017-02-21
      DOI: 10.3390/a10010028
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 29: Stable Analysis of Compressive Principal
           Component Pursuit

    • Authors: Qingshan You, Qun Wan
      First page: 29
      Abstract: Compressive principal component pursuit (CPCP) recovers a target matrix that is a superposition of low-complexity structures from a small set of linear measurements. Pervious works mainly focus on the analysis of the existence and uniqueness. In this paper, we address its stability. We prove that the solution to the related convex programming of CPCP gives an estimate that is stable to small entry-wise noise. We also provide numerical simulation results to support our result. Numerical results show that the solution to the related convex program is stable to small entry-wise noise under board condition.
      PubDate: 2017-02-21
      DOI: 10.3390/a10010029
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 30: Towards Efficient Positional Inverted Index

    • Authors: Petr Procházka, Jan Holub
      First page: 30
      Abstract: We address the problem of positional indexing in the natural language domain. The positional inverted index contains the information of the word positions. Thus, it is able to recover the original text file, which implies that it is not necessary to store the original file. Our Positional Inverted Self-Index (PISI) stores the word position gaps encoded by variable byte code. Inverted lists of single terms are combined into one inverted list that represents the backbone of the text file since it stores the sequence of the indexed words of the original file. The inverted list is synchronized with a presentation layer that stores separators, stop words, as well as variants of the indexed words. The Huffman coding is used to encode the presentation layer. The space complexity of the PISI inverted list is O ( ( N − n ) ⌈ log 2 b N ⌉ + ( ⌊ N − n α ⌋ + n ) × ( ⌈ log 2 b n ⌉ + 1 ) ) where N is a number of stems, n is a number of unique stems, α is a step/period of the back pointers in the inverted list and b is the size of the word of computer memory given in bits. The space complexity of the presentation layer is O ( − ∑ i = 1 N ⌈ log 2 p i n ( i ) ⌉ − ∑ j = 1 N ′ ⌈ log 2 p j ′ ⌉ + N ) with respect to p i n ( i ) as a probability of a stem variant at position i, p j ′ as the probability of separator or stop word at position j and N ′ as the number of separators and stop words.
      PubDate: 2017-02-22
      DOI: 10.3390/a10010030
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 31: Optimization-Based Approaches to Control of
           Probabilistic Boolean Networks

    • Authors: Koichi Kobayashi, Kunihiko Hiraishi
      First page: 31
      Abstract: Control of gene regulatory networks is one of the fundamental topics in systems biology. In the last decade, control theory of Boolean networks (BNs), which is well known as a model of gene regulatory networks, has been widely studied. In this review paper, our previously proposed methods on optimal control of probabilistic Boolean networks (PBNs) are introduced. First, the outline of PBNs is explained. Next, an optimal control method using polynomial optimization is explained. The finite-time optimal control problem is reduced to a polynomial optimization problem. Furthermore, another finite-time optimal control problem, which can be reduced to an integer programming problem, is also explained.
      PubDate: 2017-02-22
      DOI: 10.3390/a10010031
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 32: A New Quintic Spline Method for Integro
           Interpolation and Its Error Analysis

    • Authors: Feng-Gong Lang
      First page: 32
      Abstract: In this paper, to overcome the innate drawbacks of some old methods, we present a new quintic spline method for integro interpolation. The method is free of any exact end conditions, and it can reconstruct a function and its first order to fifth order derivatives with high accuracy by only using the given integral values of the original function. The approximation properties of the obtained integro quintic spline are well studied and examined. The theoretical analysis and the numerical tests show that the new method is very effective for integro interpolation.
      PubDate: 2017-03-03
      DOI: 10.3390/a10010032
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 33: Large Scale Implementations for Twitter
           Sentiment Classification

    • Authors: Andreas Kanavos, Nikolaos Nodarakis, Spyros Sioutas, Athanasios Tsakalidis, Dimitrios Tsolis, Giannis Tzimas
      First page: 33
      Abstract: Sentiment Analysis on Twitter Data is indeed a challenging problem due to the nature, diversity and volume of the data. People tend to express their feelings freely, which makes Twitter an ideal source for accumulating a vast amount of opinions towards a wide spectrum of topics. This amount of information offers huge potential and can be harnessed to receive the sentiment tendency towards these topics. However, since no one can invest an infinite amount of time to read through these tweets, an automated decision making approach is necessary. Nevertheless, most existing solutions are limited in centralized environments only. Thus, they can only process at most a few thousand tweets. Such a sample is not representative in order to define the sentiment polarity towards a topic due to the massive number of tweets published daily. In this work, we develop two systems: the first in the MapReduce and the second in the Apache Spark framework for programming with Big Data. The algorithm exploits all hashtags and emoticons inside a tweet, as sentiment labels, and proceeds to a classification method of diverse sentiment types in a parallel and distributed manner. Moreover, the sentiment analysis tool is based on Machine Learning methodologies alongside Natural Language Processing techniques and utilizes Apache Spark’s Machine learning library, MLlib. In order to address the nature of Big Data, we introduce some pre-processing steps for achieving better results in Sentiment Analysis as well as Bloom filters to compact the storage size of intermediate data and boost the performance of our algorithm. Finally, the proposed system was trained and validated with real data crawled by Twitter, and, through an extensive experimental evaluation, we prove that our solution is efficient, robust and scalable while confirming the quality of our sentiment identification.
      PubDate: 2017-03-04
      DOI: 10.3390/a10010033
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 34: A Novel, Gradient Boosting Framework for
           Sentiment Analysis in Languages where NLP Resources Are Not Plentiful: A
           Case Study for Modern Greek

    • Authors: Vasileios Athanasiou, Manolis Maragoudakis
      First page: 34
      Abstract: Sentiment analysis has played a primary role in text classification. It is an undoubted fact that some years ago, textual information was spreading in manageable rates; however, nowadays, such information has overcome even the most ambiguous expectations and constantly grows within seconds. It is therefore quite complex to cope with the vast amount of textual data particularly if we also take the incremental production speed into account. Social media, e-commerce, news articles, comments and opinions are broadcasted on a daily basis. A rational solution, in order to handle the abundance of data, would be to build automated information processing systems, for analyzing and extracting meaningful patterns from text. The present paper focuses on sentiment analysis applied in Greek texts. Thus far, there is no wide availability of natural language processing tools for Modern Greek. Hence, a thorough analysis of Greek, from the lexical to the syntactical level, is difficult to perform. This paper attempts a different approach, based on the proven capabilities of gradient boosting, a well-known technique for dealing with high-dimensional data. The main rationale is that since English has dominated the area of preprocessing tools and there are also quite reliable translation services, we could exploit them to transform Greek tokens into English, thus assuring the precision of the translation, since the translation of large texts is not always reliable and meaningful. The new feature set of English tokens is augmented with the original set of Greek, consequently producing a high dimensional dataset that poses certain difficulties for any traditional classifier. Accordingly, we apply gradient boosting machines, an ensemble algorithm that can learn with different loss functions providing the ability to work efficiently with high dimensional data. Moreover, for the task at hand, we deal with a class imbalance issues since the distribution of sentiments in real-world applications often displays issues of inequality. For example, in political forums or electronic discussions about immigration or religion, negative comments overwhelm the positive ones. The class imbalance problem was confronted using a hybrid technique that performs a variation of under-sampling the majority class and over-sampling the minority class, respectively. Experimental results, considering different settings, such as translation of tokens against translation of sentences, consideration of limited Greek text preprocessing and omission of the translation phase, demonstrated that the proposed gradient boosting framework can effectively cope with both high-dimensional and imbalanced datasets and performs significantly better than a plethora of traditional machine learning classification approaches in terms of precision and recall measures.
      PubDate: 2017-03-06
      DOI: 10.3390/a10010034
      Issue No: Vol. 10, No. 1 (2017)
  • Algorithms, Vol. 10, Pages 35: A Geo-Clustering Approach for the Detection
           of Areas-of-Interest and Their Underlying Semantics

    • Authors: Evaggelos Spyrou, Michalis Korakakis, Vasileios Charalampidis, Apostolos Psallas, Phivos Mylonas
      First page: 35
      Abstract: Living in the “era of social networking”, we are experiencing a data revolution, generating an astonishing amount of digital information every single day. Due to this proliferation of data volume, there has been an explosion of new application domains for information mined from social networks. In this paper, we leverage this “socially-generated knowledge” (i.e., user-generated content derived from social networks) towards the detection of areas-of-interest within an urban region. These large and homogeneous areas contain multiple points-of-interest which are of special interest to particular groups of people (e.g., tourists and/or consumers). In order to identify them, we exploit two types of metadata, namely location-based information included within geo-tagged photos that we collect from Flickr, along with plain simple textual information from user-generated tags. We propose an algorithm that divides a predefined geographical area (i.e., the center of Athens, Greece) into “tile”-shaped sub-regions and based on an iterative merging procedure, it aims to detect larger, cohesive areas. We examine the performance of the algorithm both in a qualitative and quantitative manner. Our experiments demonstrate that the proposed geo-clustering algorithm is able to correctly detect regions that contain popular tourist attractions within them with very promising results.
      PubDate: 2017-03-18
      DOI: 10.3390/a10010035
      Issue No: Vol. 10, No. 1 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
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