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  Subjects -> COMPUTER SCIENCE (Total: 2011 journals)
    - ANIMATION AND SIMULATION (30 journals)
    - ARTIFICIAL INTELLIGENCE (98 journals)
    - AUTOMATION AND ROBOTICS (98 journals)
    - CLOUD COMPUTING AND NETWORKS (61 journals)
    - COMPUTER ARCHITECTURE (9 journals)
    - COMPUTER ENGINEERING (9 journals)
    - COMPUTER GAMES (16 journals)
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    - COMPUTER SCIENCE (1172 journals)
    - COMPUTER SECURITY (46 journals)
    - DATA BASE MANAGEMENT (13 journals)
    - DATA MINING (32 journals)
    - E-BUSINESS (22 journals)
    - E-LEARNING (29 journals)
    - ELECTRONIC DATA PROCESSING (21 journals)
    - IMAGE AND VIDEO PROCESSING (39 journals)
    - INFORMATION SYSTEMS (108 journals)
    - INTERNET (92 journals)
    - SOCIAL WEB (50 journals)
    - SOFTWARE (34 journals)
    - THEORY OF COMPUTING (8 journals)

COMPUTER SCIENCE (1172 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: 15)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 24)
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: 4)
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: 3)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 15)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 6)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 2)
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: 4)
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: 10)
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: 7)
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: 6)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 18)
Advances in Computer Science : an International Journal     Open Access   (Followers: 15)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 52)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 11)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 27)
Advances in Human-Computer Interaction     Open Access   (Followers: 21)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 40)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 4)
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: 5)
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: 12)
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: 2)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 33)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 15)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
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: 135)
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: 9)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Biodiversity Information Science and Standards     Open Access  
Bioinformatics     Hybrid Journal   (Followers: 285)
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: 18)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 34)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 47)
British Journal of Educational Technology     Hybrid Journal   (Followers: 136)
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: 2)
Cell Communication and Signaling     Open Access   (Followers: 2)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access   (Followers: 1)
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: 11)
Circuits and Systems     Open Access   (Followers: 15)
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: 14)
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: 55)
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   (Followers: 1)
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: 22)
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: 14)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 30)
Computer     Full-text available via subscription   (Followers: 91)
Computer Aided Surgery     Hybrid Journal   (Followers: 5)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 9)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 12)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 2)
Computer Music Journal     Hybrid Journal   (Followers: 18)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computer Science and Information Technology     Open Access   (Followers: 13)
Computer Science Education     Hybrid Journal   (Followers: 14)
Computer Science Journal     Open Access   (Followers: 22)

        1 2 3 4 5 6 | Last

Journal Cover Automation in Construction
  [SJR: 1.571]   [H-I: 65]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0926-5805
   Published by Elsevier Homepage  [3123 journals]
  • A tri-objective ant colony optimization based model for planning safe
           construction site layout
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Xin Ning, Jingyan Qi, Chunlin Wu, Wenjuan Wang
      Realizing safety improvements in construction site layout planning (CSLP) is vitally important to construction project safety management. Unlike previous studies in which the safety objective is built without detailed risk factors analysis, this study transforms CSLP into a multi-objective optimization (MOO) problem with designing two safety objective functions due to facility safety relationships (potential risks arising from interaction flows) and geographic safety relationship (potential risks arising from hazardous sources) from the holistic interpretation of interaction relationship connecting temporary facilities. Besides, a supplementary cost reduction objective function was also derived as cost is a critical barrier against safety improvement. Subsequently, a tri-objective ant colony optimization based model was developed to solve MOO problem. Finally, a case study is used to verify the proposed model. The study enriches safety implications by considering onsite safety issues from interaction relationship and enhances site safety of CSLP in the pre-construction stage.

      PubDate: 2018-02-04T21:21:45Z
       
  • Perspectives on a BIM-integrated software platform for robotic
           construction through Contour Crafting
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Omid Davtalab, Ali Kazemian, Behrokh Khoshnevis
      Robotic construction through concrete 3D printing is an in-progress revolution in construction industry. While significant progress is made on hardware related challenges, software and information related issues of such innovative system are less discussed. In this paper, a software platform is proposed for data retrieval and analysis from BIM models and utilizing it efficiently during various stages of the process. While the general idea of using BIM for automated construction has been mentioned before, the implementation details (the focus of this paper) were not previously discussed. To this aim, a framework is proposed to integrate BIM into an automated construction system. A Planning and Operations Control Software for Automated Construction (POCSAC) is developed as a major enabler for a seamless integration of BIM and Contour Crafting. The interoperation between different components of the construction system and BIM platform are designed to maximize the realized benefits through synergy of the two technologies.

      PubDate: 2018-02-04T21:21:45Z
       
  • An integrated visualization framework to support whole-process management
           of water pipeline safety
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Donghai Liu, Junjie Chen, Shuai Li, Wei Cui
      Timely assessment of structural conditions of water diversion pipelines and taking necessary precautions are essential to ensure the operational safety of large water diversion structures. This paper presents an integrated visualization framework to support the safety management of water diversion pipelines. This holistic framework streamlines data collection, data analysis, warning issuance, and decision-making support in an integrated platform, which improves the automation level of safety management and the efficiency of emergency response. A system prototype was developed based on the proposed framework and implemented in a water supply project in Tianjin, China. The system prototype can automatically assess the structural condition of water diversion pipelines and issue corresponding warnings to relevant professionals, and provide visual cues and a set of useful functions to support decision-making. This system prototype and its implementation validate the applicability and efficacy of the proposed framework.

      PubDate: 2018-02-04T21:21:45Z
       
  • SLAM-driven robotic mapping and registration of 3D point clouds
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Pileun Kim, Jingdao Chen, Yong K. Cho
      With the rapid advancement of laser scanning and photogrammetry technologies, frequent geometric data collection at construction sites by contractors has been increased for the purpose of improving constructability, productivity, and onsite safety. However, the conventional static laser scanning method suffers from operational limitations due to the presence of many occlusions commonly found in a typical construction site. Obtaining a complete scan of a construction site without information loss requires that laser scans are obtained from multiple scanning locations around the site, which also necessitates extra work for registering each scanned point cloud. As an alternate solution to this problem, this paper introduces an autonomous mobile robot which navigates a scan site based on a continuously updated point cloud map. This mobile robot system utilizes the 2D Hector Simultaneous Localization and Mapping (SLAM) technique to estimate real-time positions and orientations of the robot in the x-y plane. Then, the 2D localization information is used to create 3D point clouds of unknown environments in real time to determine its navigation paths as a pre-scanning process. The advantage of this framework is the ability to determine the optimal scan position and scan angle to reduce the scanning time and effort for gathering high resolution point cloud data in real-time. The mobile robot system is able to capture survey-quality RGB-mapped point cloud data, and automatically register the scans for geometric reconstruction of the site. The performance of the overall system was tested in an indoor environment and validated with promising results.

      PubDate: 2018-02-04T21:21:45Z
       
  • Assessment of the feasibility of detecting concrete cracks in images
           acquired by unmanned aerial vehicles
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Xingu Zhong, Xiong Peng, Shengkun Yan, Mingyan Shen, Yinyin Zhai
      An 8-rotor unmanned aerial vehicle is used as a working platform. Its motion characteristics in a hovering state are obtained using a non-contact measurement instrument, which, along with the modulation transfer function of its airborne images, indicates the reliability of the airborne images of unmanned aerial vehicles in a hovering state. By installing a laser range finder on the cradle synchronized with the camera shutter to measure the object distance, the pixel resolution of the object distance is obtained. The airborne images are then processed using the MATLAB image processing toolbox, from which the pixels of concrete cracks are extracted. Compared to a static image and direct manual measurements, the airborne image of the unmanned aerial vehicle has higher precision, indicating its wide potential applications as an alternative of the conventional inspection methods of bridge-inspection vehicle and working platforms.

      PubDate: 2018-02-04T21:21:45Z
       
  • An empirical validation of the performance of project control tolerance
           limits
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Annelies Martens, Mario Vanhoucke
      The goal of project control is monitoring the project progress during project execution to detect potential problems and taking corrective actions when necessary. Tolerance limits are a tool to assess whether the project progress is acceptable or not, and generate warnings signals that act as triggers for corrective action to the project manager. In this paper, three distinct types of tolerance limits that have been proposed in literature are validated on a large and diverse set of real-life projects mainly situated in the construction sector. Moreover, a novel approach to construct tolerance limits that integrate the project risk information into the monitoring process is introduced. The results of the empirical experiment have shown that integrating project-specific information into the construction of the tolerance limits results in a higher efficiency of the monitoring process. More specifically, while including cost information increases the efficiency only marginally, incorporating the available resource information substantially improves the efficiency of the monitoring process. Furthermore, when projects are not restricted by scarce resources, the efficiency can be enhanced by integrating the available project risk information.

      PubDate: 2018-02-04T21:21:45Z
       
  • Process, productivity, and economic analyses of BIM–based multi-trade
           prefabrication—A case study
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Sejun Jang, Ghang Lee
      Previous studies yielded contradicting results regarding the benefits of multi-trade prefabrication (MTP) based on building information modeling (BIM). This study investigates the causes of the contradicting results by analyzing the process, productivity, and economic benefits of BIM-based MTP through a case study. The process analysis results indicate that coordinating mechanical, electrical, and plumbing (MEP) systems took longer in MTP than in the conventional method because of the newly added offsite coordination activities. Nevertheless, the overall project duration was reduced because of the parallel execution of MTP and concrete work. The productivity analysis shows that the newly added MTP activities also increased person-hours. However, as the assembly process was repeated, the required person-hours decreased by 40% from that of the initial stage because of the learning effect. The case study revealed that the management of coordination activities and the selection of projects were critical for the successful implementation of BIM-based MTP.

      PubDate: 2018-02-04T21:21:45Z
       
  • Automated defect detection tool for closed circuit television (cctv)
           inspected sewer pipelines
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Alaa Hawari, Mazen Alamin, Firas Alkadour, Mohamed Elmasry, Tarek Zayed
      In sewer networks, the economic effects and costs that result from a pipeline failure are rising sharply. As a result, there is huge demand for inspection and rehabilitation of sewer pipelines. In addition to being inaccurate, current practices of sewer pipelines inspection are time consuming and may not keep up with the deterioration rates of the pipelines. This papers presents the development of an automated tool to detect some defects such as: cracks, deformation, settled deposits and joint displacement in sewer pipelines. The automated approach is dependent upon using image-processing techniques and several mathematical formulas to analyze output data from Closed Circuit Television (CCTV) camera images. The automated tool was able to detect cracks, displaced joints, ovality and settled deposits in pipelines using CCTV camera inspection output footage using two different datasets. To examine the performance of the proposed detection methodology, confusion matrices were constructed, in which true positives for crack, settled deposits and displaced joints were 74%, 53% and 65%. As for the ovality, all defects in the images were detected successfully. Although these values could indicate low performance, however the proposed methodology could be improved if additional images were used. Given that one inspection session can result in hundreds of CCTV camera footage, introducing an automated tool would help yield faster results. Additionally, given the subjective nature of evaluating the severity of defects, it would result in more systematic outputs since the current method rely heavily on the operator's experience.

      PubDate: 2018-02-04T21:21:45Z
       
  • Applications of additive manufacturing in the construction industry
           – A forward-looking review
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Daniel Delgado Camacho, Patricia Clayton, William J. O'Brien, Carolyn Seepersad, Maria Juenger, Raissa Ferron, Salvatore Salamone
      Additive manufacturing (AM), also known as 3D printing, fabricates components in a layerwise fashion directly from a digital file. Many of the early applications of AM technologies have been in the aerospace, automotive, and healthcare industries. Building on the advances in AM in these industries, there are several experimental applications of AM in the construction sector. Early investigations suggest that use of AM technologies for construction have the potential to decrease labor costs, reduce material waste, and create customized complex geometries that are difficult to achieve using conventional construction techniques. However, these initial investigations do not cover the full range of potential applications for construction or exploit the rapidly maturing AM technologies for a variety of material types. This paper provides an up-to-date review of AM as it relates to the construction industry, identifies the trend of AM processes and materials being used, and discusses related methods of implementing AM and potential advancements in applications of AM. Examples of potential advancements include use of multi-materials (e.g., use of high-performance materials only in areas where they are needed), in-situ repair in locations that are difficult or dangerous for humans to access, disaster relief construction in areas with limited construction workforce and material resources, structural and non-structural elements with optimized topologies, and customized parts of high value. AM's future in the construction industry is promising, but interdisciplinary research is still needed to provide new materials, new processes, faster printing, quality assurance, and data on mechanical properties before AM can realize its full potential in infrastructure construction.

      PubDate: 2018-02-04T21:21:45Z
       
  • 4-Plane congruent sets for automatic registration of as-is 3D point clouds
           with 3D BIM models
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Martín Bueno, Frédéric Bosché, Higinio González-Jorge, Joaquín Martínez-Sánchez, Pedro Arias
      Construction quality and progress control are demanding, yet critical construction activities. Building Information Models and as-built scanned data can be used in Scan-vs-BIM processes to effectively and comprehensively support these activities. This however requires accurate registration of scanned point clouds with 3D (BIM) models. Automating such registration remains a challenge in the context of the built environment, because as-built can be incomplete and/or contain data from non-model objects, and construction buildings and other structures often present symmetries and self-similarities that are very challenging to registration. In this paper, we present a novel automatic coarse registration method that is an adaptation of the ‘4 Points Congruent Set’ algorithm to the use of planes; we call it the ‘4-Plane Congruent Set’ (4-PlCS) algorithm. The approach is further integrated in a software system that delivers not one but a ranked list of the most likely transformations, so to allow the user to quickly select the correct transformation, if need be. Two variants of the method are also considered, in particular one in the case when the vertical axis is known a priori; we call that method the 4.5-PlCS method. The proposed algorithm is tested using five different datasets, including three simulated and two real-life ones. The results show the effectiveness of the proposed method, where the correct transformation always ranks very high (in our experiments, first or second), and is extremely close to the ground-truth transformation. Experimental comparison of the proposed approach with a standard, more intuitive approach based on finding 3-plane congruent sets shows the discriminatory power of 4-plane bases over 3-plane bases, albeit at no clear benefits in terms of computational time. The experimental results for the 4.5-PlCS method show that it delivers a non-negligible reduction in computational time (approx. 20%), but at no additional benefit in terms of effectiveness in finding the correct transformation.

      PubDate: 2018-02-04T21:21:45Z
       
  • Integrated condition rating and forecasting method for bridge decks using
           Visual Inspection and Ground Penetrating Radar
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Mohammed Alsharqawi, Tarek Zayed, Saleh Abu Dabous
      The growing problem of bridge deterioration globally has imposed prominent challenges on transportation agencies, mainly in terms of ensuring safety and serviceability of the bridge infrastructure. The large number of bridges built during the 20th century has aged and produced a complex decision-making problem that departments of transportation need to deal with. Bridge management, as a particular domain of infrastructure asset management, has focused on developing methods for condition rating and deterioration modeling. The current research reviews bridge inspection practices and identifies the main defects and deterioration signs of concrete bridge decks that are typically captured by Visual Inspection (VI) and Non-Destructive Evaluation (NDE) techniques. The research introduces the Quality Function Deployment (QFD) theory and Weibull Distribution Function (WDF) as an integrated novel method to the area of bridge condition assessment and deterioration modeling. The proposed QFD condition assessment model is developed based on integrating VI and Ground Penetrating Radar (GPR) evaluation results to provide consistent condition ratings and performance predictions. The QFD model is demonstrated with a real case study and compared to other condition assessment models. Moreover, the QFD method is validated with data extracted from twenty bridge inspection reports completed by bridge inspectors and assessed by bridge experts. The developed deterioration curves using the reliability function for the Weibull distribution show absolute matching in these results through predicting the structure future performance and defining its useful service life. Accordingly, these models can enhance bridge Maintenance, Repair and Replacement (MRR) decisions since they produce reliable condition ratings and predictions that can link to proper rehabilitation action, and eventually assist in the decision making and planning for the selected MRR action. All these processes are integrated within one framework.

      PubDate: 2018-02-04T21:21:45Z
       
  • An Internet of Things-enabled BIM platform for on-site assembly services
           in prefabricated construction
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Clyde Zhengdao Li, Fan Xue, Xiao Li, Jingke Hong, Geoffrey Qiping Shen
      Building Information Modelling (BIM) serves as a useful tool in facilitating the on-site assembly services (OAS) of prefabricated construction for its benefits of powerful management of physical and functional digital presentations. However, the benefits of using BIM in the OAS of prefabricated construction cannot be cultivated with an incomplete, inaccurate, and untimely data exchange and lack of real-time visibility and traceability. To deal with these challenges, an Internet of Things (IoT)-enabled platform is designed by integrating IoT and BIM for prefabricated public housing projects in Hong Kong. The demands of the stakeholders were analysed; then smart construction objects (SCOs) and smart gateway are defined and designed to collect real-time data throughout the working processes of on-site assembly of prefabricated construction using the radio frequency identification (RFID) technology. The captured data is uploaded to cloud in real-time to process and analyse for decision support purposes for the involved site managers and workers. Visibility and traceability functions are developed with BIM and virtual reality (VR) technologies, through which managers can supervise the construction progress and approximate cost information in a real-time manner. The IoT-enabled platform can provide various decision support tools and services to different stakeholders, for improving the efficiency and effectiveness of daily operations, decision making, collaboration, and supervision throughout on-site assembly processes of prefabricated construction.

      PubDate: 2018-02-04T21:21:45Z
       
  • Geostatistical analysis of intelligent compaction measurements for asphalt
           pavement compaction
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Wei Hu, Xiang Shu, Xiaoyang Jia, Baoshan Huang
      Although unable to address the issue of spatial uniformity, univariate statistics are commonly used to evaluate the compaction uniformity of asphalt layers nowadays. Intelligent compaction (IC) technology can provide the spatial IC measurement values (ICMV) with 100% coverage during compaction and offers an opportunity to perform the geostatistical analysis on the compacted asphalt layers. In this study, the construction quality of two typical asphalt pavement projects, including one new pavement construction project and one resurfacing construction project, were evaluated by performing geostatistical analysis for ICMV. Some critical issues regarding the use of geostatistical method for the evaluation of construction quality were also addressed by the case studies. The results from the geostatistical analyses show that IC technology can offer detailed information about spatial compaction uniformity. Upon comparison of the spatial uniformity between different layers, the semivariogram after the normal score transformation was suggested due to the measuring depths of the IC roller. The spatial statistics of ICMV could be adopted to monitor the changes in spatial uniformity during compaction. The factors affecting ICMV and geostatistical analysis were further discussed.

      PubDate: 2018-02-04T21:21:45Z
       
  • A mobile android tool for simplified GPR data processing in construction
           applications
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Francisco Javier Prego, Luis Nieto, Mercedes Solla, Iván Puente
      This work presents a new GPR signal processing tool for mobile devices, which uses the free Android platform in smartphones and tablets. The developed application is able to display and process radargrams without using the most common commercial software applied for GPR signal processing. These existing applications have usually been developed for advanced signal processing, which results in complex processes and requires large computational resources. Therefore, the aim of this work was to develop a simplified and intuitive tool, which allows speeding up the GPR signal processing. For such purpose, the application implements basic filters to optimize the GPR images analysis and to facilitate data interpretation. Different tools have also been implemented to obtain interesting geometric measurements, such as thicknesses and diameters in rebar or piping. Thus, any non-expert user on the GPR technique could generate preliminary in-situ results using conventional smartphone or tablet devices.

      PubDate: 2018-02-04T21:21:45Z
       
  • Optimization of crane setup location and servicing schedule for urgent
           material requests with non-homogeneous and non-fixed material supply
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Chun Huang, C.K. Wong
      Reducing hook movement distances could decrease crane operation times to deliver heavyweight materials in construction sites. Conventional scheduling methods include first-in-first-serve (FIFS), shortest-job-first (SJF), nearest-neighbor-first (NNF), and Traveling salesman problem (TSP). A new optimization model to optimize crane setup location, hook movement sequences and servicing schedules serving all supply and demand locations is proposed. Proposed model is able to model homogeneous and non-homogeneous material supply. Initial hook location can be given as input for optimization. Fixed material supply and demand location pairs are relaxed as model variables. Maximum crane lifting capacity is considered and multiple hook movement trips between material supply and demand locations are modeled if requested material weights exceed this maximum crane lifting capacity. Users may place “urgent” material demand requests and the proposed optimization model can optimize a servicing sequence to prioritize all urgent requests. The problem is formulated as a Binary-Mixed-Integer-Linear-Program (BMILP) which is solved by standard branch-and-bound techniques. Significant reduction in total operation time is achieved while comparing to other conventional scheduling strategies.

      PubDate: 2018-02-04T21:21:45Z
       
  • Teleyes: A telepresence system based on stereoscopic vision and head
           motion tracking
    • Abstract: Publication date: May 2018
      Source:Automation in Construction, Volume 89
      Author(s): Ming-Chang Wen, Cheng-Hsuan Yang, Meng-Han Tsai, Shih-Chung Kang
      This study develops a telepresence system, Teleyes, to reduce visual distortion in remote environments. The primary objective of this research is to take advantage of state-of-art three-dimensional (3D) input/outputs technologies and to develop an avatar-like mechanism to synchronize the physical behavior of an operator with a remote system. Two 3D input/output methods are used in this research: stereoscopic vision and motion tracking. The system is designed to work under closed-loop control involving human feedback. Two cameras that are optimized according to the human eye angle-of-view to accommodate for the perspective of human eyes are used as stereoscopic vision inputs on the unmanned vehicle. At the operator end, a head mounted display is used to display the stereoscopic image and to track the operator's head movement with embedded sensors. The head-movement tracking data are interpreted into control signals and returned to the unmanned vehicle to control a three-axis gimbal mechanism, on which the two cameras are installed. The Teleyes system has been validated using a designed experimental application scenario and compared with current methods using five different operators. On average, the proposed system reduced the distance error of operators by 45.1% and the time usage by 18.2%. The results show that the system has significantly improved the visual experience and operating efficiency, thus having the potential to save resources and expand the application of unmanned vehicle systems (UVSs). The developed system provides the operator with a realistic first-person view of a UVS and a visual experience similar to being onboard.

      PubDate: 2018-02-04T21:21:45Z
       
  • Design for Manufacture and Assembly-oriented parametric design of
           prefabricated buildings
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Zhenmin Yuan, Chengshuang Sun, Yaowu Wang
      Many design systems are developed in the context of non-prefabricated buildings, and cannot be well suitable for prefabricated buildings which are being popular at present. In order to solve the problem, this paper introduces Design for Manufacture and Assembly (DFMA) into prefabricated building design, and combines it with parametric design of Building Information Modeling (BIM) to develop the concept and process of DFMA-oriented parametric design. For making DFMA-oriented parametric design implemented better, DFMA-oriented architectural design team, precast component creation process based on family template and DFMA, DFMA-oriented BIM re-development process, and optimization process of DFMA-oriented prefabricated building information model are also explored and developed. In the end, some principles of DFMA-oriented parametric design are partially reflected by several examples, and DFMA-oriented parametric design needs to be constantly improved according to its subsequent actual use.

      PubDate: 2018-02-04T21:21:45Z
       
  • 3D reconstruction of a concrete mixer truck for training object detectors
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Hongjo Kim, Hyoungkwan Kim
      Vision-based monitoring methods have been actively studied in the construction industry because they can be used to automatically generate information related to progress, productivity, and safety. Object detection is essentially used in such monitoring methods to infer jobsite context. However, as many classes of construction entities exist in a job site, large amounts of image data are required to train a detection algorithm to detect each class object in images. Although image data augmentation methods using 3D models were proposed, publicly available 3D models are limited to some construction object classes. Therefore, this study proposes a three-dimensional reconstruction method to generate the image data required for training object detectors. To use the generated synthetic images as training data, a histogram of oriented gradient (HOG) descriptor of a target object is obtained from these images. The descriptor is refined by a support vector machine to increase sensitivity to the target object in test images. The performance of the HOG-based object detector is evaluated using real images from ImageNet. The result shows that the proposed method can generate training data more effectively than existing manual data collection practices.
      Graphical abstract image

      PubDate: 2018-02-04T21:21:45Z
       
  • Enhancing the safety of construction crew by accounting for brain resource
           requirements of activities in job assignment
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Alireza Ahmadian Fard Fini, Ali Akbarnezhad, Taha H. Rashidi, S. Travis Waller
      Safety management is regarded traditionally as an aggregate attribute for Human Resources (HR) in which the focus is placed on safety of construction crew by assuming same behaviour, capabilities and thus level of exposure to risk for all workers in the crew. In line with this, a team-based approach is generally adopted for task assignment to workers in construction operations. However, this approach tends to disregard the differences between skill level, experience, capabilities, learning rates and fatigue rates of different individual workers forming the team. In particular, due to differences in visual, auditory, cognitive and psychomotor capabilities of different workers and brain resource demands of different activities, the traditional approach may result in inconsistent workloads and uneven fatigue rates within a crew, affecting the workers' and crew's safety negatively. This paper proposes a novel framework for task assignment to construction workers in which safety of individual workers and thus the crew is ensured through optimizing workload distributions within a crew. The framework computes visual, auditory, cognitive, and psychomotor requirements of the jobs assigned to a worker and minimizes the identified workload imbalances through collaborative execution of shared tasks. The application of the proposed framework is examined on a pipe spool fabrication operation of a refinery project in a simulation environment.

      PubDate: 2018-02-04T21:21:45Z
       
  • 6D DBSCAN-based segmentation of building point clouds for planar object
           classification
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): T. Czerniawski, B. Sankaran, M. Nahangi, C. Haas, F. Leite
      Due to constraints in manufacturing and construction, buildings and many of the manmade objects within them are often rectangular and composed of planar parts. Detection and analysis of planes is, therefore, central to processing point clouds captured in these spaces. This paper presents a study of the semantic information stored in the planar objects of noisy building point clouds. The dataset considered is the Scene Meshes Dataset with aNNotations (SceneNN), a collection of over 100 indoor scenes captured by consumer-grade depth cameras. All planar objects within the dataset are detected using a new point cloud segmentation method that applies Density Based Spatial Clustering of Applications with Noise (DBSCAN) in a six dimensional clustering space. With all planes isolated, an extensive list of features describing the planes is extracted and studied using feature selection. Then dimensionality reduction and unsupervised learning are used to explore the discriminative ability of the final feature set as well as emergent class groupings. Finally, we train a bagged decision tree classifier that achieves 71.2% accuracy in predicting the object class from which individual planes originate.

      PubDate: 2018-02-04T21:21:45Z
       
  • Minimizing duration and crew work interruptions of repetitive construction
           projects
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Ayman Altuwaim, Khaled El-Rayes
      This paper presents the development of a novel scheduling model for minimizing the duration and crew work interruptions of repetitive construction projects. The main contributions of the developed model are its ability to (1) generate early and late start schedules that minimize the duration of repetitive construction projects while keeping the total work interruptions of their utilized crews to a minimum; (2) calculate novel types of crew work-continuity floats that consider the impact of delaying the early start of repetitive activities on crew work continuity; (3) develop a wide range of intermediate schedules between the early and late start schedules that maintain the least project duration and minimum total crew work interruptions; and (4) compare shortest duration schedules with and without interruptions to identify the best schedule that fits the specific project needs. The model performance was evaluated using an application example of a repetitive construction project.

      PubDate: 2018-02-04T21:21:45Z
       
  • An IoT-based autonomous system for workers' safety in construction sites
           with real-time alarming, monitoring, and positioning strategies
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Riad Kanan, Obaidallah Elhassan, Rofaida Bensalem
      Civil construction sites are considered as one of the riskiest environments where many potential hazards may occur. To protect construction workers and prevent accidents in such sites, this paper proposes a novel design for an autonomous system that monitors, localizes, and warns site laborers who avail within danger zones. The proposed system is user-friendly, and its architecture is based on Internet of Things (IoT). The heterogeneous components of this architecture are seamlessly integrated into a middleware backend online server. To accurately detect and identify construction workers, the proposed system employs three combined techniques. They are 1) the 868MHz radio frequency, 2) directional antennas, and 3) the 40kHz ultrasound waves. Vehicle's rear is secured by a sensing unit that ensures good coverage along with a wearable device for workers. The design of the wearable device includes a set of components which are a radio transceiver (transmitter/receiver), a wake-up sensor, an alarm actuator, and a GPRS module. The wearable device has a power saving scheme with a current consumption as low as 0.5μA at 3V supply; thanks to our RF wake-up sensor. Via proximity, this wearable device becomes hybrid (active/passive) in which it remains in deep sleep mode until the presence of a radio frequency (RF) field. Consequently, the rechargeable battery's life gets increased by up to 2days of autonomy before recharging. Furthermore, the paper presents an implementation of wireless nodes that are powered by light energy using photovoltaic cells. These nodes adopt energy management and storage schemes for continuous operation for indoor and outdoor environments.

      PubDate: 2018-02-04T21:21:45Z
       
  • Analysing real world data streams with spatio-temporal correlations:
           Entropy vs. Pearson correlation
    • Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Maria Bermudez-Edo, Payam Barnaghi, Klaus Moessner
      Smart Cities use different Internet of Things (IoT) data sources and rely on big data analytics to obtain information or extract actionable knowledge crucial for urban planners for efficiently use and plan the construction infrastructures. Big data analytics algorithms often consider the correlation of different patterns and various data types. However, the use of different techniques to measure the correlation with smart cities data and the exploitation of correlations to infer new knowledge are still open questions. This paper proposes a methodology to analyse data streams, based on spatio-temporal correlations using different correlation algorithms and provides a discussion on co-occurrence vs. causation. The proposed method is evaluated using traffic data collected from the road sensors in the city of Aarhus in Denmark.

      PubDate: 2018-02-04T21:21:45Z
       
  • Civil Integrated Management: Empirical study of digital practices in
           highway project delivery and asset management
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Bharathwaj Sankaran, Guillermo Nevett, William J. O'Brien, Paul M. Goodrum, Joshua Johnson
      Principal technologies and practices contributing to the workflow of highway infrastructure projects are undergoing significant changes due to Civil Integrated Management (CIM). CIM encapsulates key digital technologies that provide managers with opportunities to use accurate data and information throughout the life cycle of a transportation asset. Despite the potential of CIM tools, the extent to which State Transportation Agencies (STAs) across the U.S. make use of CIM and the factors enhancing the utilization of CIM have not been studied sufficiently. This paper presents the principal findings of a national survey of forty-two STAs on CIM usage. Results show that while thirty-two STAs use the CIM tool of 3D design for terrain modeling, only sixteen reported using it for structures and advanced visualization. The research also analyzed the influence of key agency policies such as contract specifications, project delivery methods, and STA budget on the use of CIM. While the budget does not have a statistically significant effect on increased CIM usage, results indicate contract specifications and various procedural guidelines for CIM do affect CIM usage. STAs also appear to use CIM more when they have alternative delivery methods available, with a statistically significant positive impact being shown by the Public-Private Partnerships model. This study provides both a benchmark of current practices as well as suggestions that may expedite beneficial implementation and future research in this area.

      PubDate: 2018-02-04T21:21:45Z
       
  • e-BIM: a BIM-centric design and analysis software for Building Integrated
           Photovoltaics
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Gui Ning, He Kan, Qiu Zhifeng, Gui Weihua, Deconinck Geert
      Building Integrated Photovoltaics (BIPV) has gained large popularity in recent years. However, its effective design remains challenging. Different but often related design concerns regarding BIPV are normally treated, in the current practice, in multiple but separated design phases with different models and tools. The complexities in maintaining the consistency between those models employed in separated phases make seamless PV and building integration, one of the major concerns of BIPV design, far from satisfying. To this end, this paper proposes a uniform BIPV design platform: e-BIM, which is a BIM (Building Information Modelling) - centric BIPV design and analysis software platform, to address the related design concerns via one uniform data model. The concept of domain-specific models is introduced to allow the external PV-related models to be integrated into the uniform model. To simplify model synchronization problem, the domain-specific views corresponding to specific domains are provided to designers and meanwhile a synchronization engine is developed to automate data consistency among views and the uniform model. The current prototype is developed based on Autodesk® Revit and tested in a practical BIPV application. The results show that this platform achieves seamless BIPV design for architects, PV system designers and electricity professionals. Moreover, compared to the initial BIPV design, the photovoltaic system cost is reduced by 11.7% and the transmission losses by 2.95%.

      PubDate: 2018-02-04T21:21:45Z
       
  • Conflict resolution-motivated strategy towards integrated construction
           
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Xiaoling Song, Jiuping Xu, Charles Shen, Feniosky Peña-Mora
      Efficiency of construction site layout planning (CSLP) and construction material logistics planning (CMLP) is of great significance for a successful project control. Despite considerable research undertaken to separately optimize the site layout plan or material logistics plan, the interdependencies and decision conflicts of the layout planner and the logistics planner are neglected in the construction planning and design phase. The ignorance of the decision conflicts and interdependencies can lead to an overrun cost, a delayed project or a worse quality. This research proposes a decentralized methodology based on a bi-level model and a Bi-PSO algorithm, enabling the layout planner and the logistics planner to optimize the CSLP and the CMLP in an integrated model. Fuzzy random parameters are utilized to deal with uncertainty in the data collection process. By utilizing the methodology, the stakeholders are capable of adjusting the respective decisions based on the changes of others. By iteratively adjusting the CSLP and CMLP solutions, the CSLP-CMLP decision conflicts are dealt with, accordingly, the bi-stakeholder conflict resolution-motivated CSLP-CMLP strategy is planned. To demonstrate the applicability of the proposed methodology, a real case study is conducted to optimize CSLP and CMLP simultaneously. The significance of optimizing an integrated CSLP-CMLP for the layout planner, the logistics planner and the general contractor is also justified. The contributions of this research include the capability of modeling the decision conflicts in a bi-level model, the ability of generating an integrated CSLP-CMLP solution and the practicality of guiding academic researchers and practitioners to optimize construction management from a global viewpoint. The research can be extended to other fields to explore the effects of decentralized decision making on other bi-stakeholder conflict resolution cases.

      PubDate: 2018-02-04T21:21:45Z
       
  • Performance analysis of simulation-based optimization of construction
           projects using High Performance Computing
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Shide Salimi, Mohammed Mawlana, Amin Hammad
      The complexity and uncertain nature of bridge construction projects require simulation for analyzing and planning these projects. On the other hand, optimization can be used to address the inverse relationship between the cost and time of a project and to find a proper trade-off between these two key elements. In addition, the large number of resources required in large-scale bridge construction projects results in a very large search space. Therefore, there is a need for using parallel computing to reduce the computational time of the simulation-based optimization problem. Another problem in this area is that most of the construction simulation tools need an integration platform to be combined with optimization techniques. To alleviate these limitations, an integrated simulation-based optimization framework is developed within one High Performance Computing (HPC) platform, and its performance is analyzed by carrying out a case study. A master-slave (or global) parallel Genetic Algorithm (GA) is used to decrease the computation time and to efficiently use the full capacity of the computer. In addition, sensitivity analysis is applied to identify the promising configuration for GA and the best number of cores used in parallel and to analyze the impact of GA parameters on the overall performance of the simulation-based optimization model. Using NSGA-ΙΙ as the optimization algorithm resulted in better near-optimal solutions compared to those of fast-messy GA. Moreover, performing the proposed framework on multiple nodes using the cluster system led to 31% saving in the computation time on average. Furthermore, the GA was tuned using sensitivity analyses, which resulted in the selection of the best parameters of the GA.

      PubDate: 2018-02-04T21:21:45Z
       
  • Integration of ifc objects and facility management work information using
           Semantic Web
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Karam Kim, Hyunjoo Kim, Wooyoung Kim, Changduk Kim, Jaeyo Kim, Jungho Yu
      The management of information throughout a building's lifecycle is becoming increasingly important, and building information modeling (BIM) is often used to ensure the interoperability of data. However, BIM-based facility information from the construction phase is difficult to access and use during the operation and maintenance phase. This occurs because the BIM information is not utilized well in facility management (FM). In this research, we propose an approach to effectively manage BIM-based FM information by linking the BIM-based building elements and FM work information in an FM system database. We present a Semantic Web-based FM information system that semantically links BIM data to relevant historical work records. The proposed ontology was evaluated using a sample dataset of the architectural maintenance work records of an office building. Using the proposed approach, facility managers will be able to increase their efficiency in searching related work records that consider shared BIM objects by enhancing the interoperability and accessibility of FM data via the Semantic Web.

      PubDate: 2018-02-04T21:21:45Z
       
  • An integrated decision support model for selecting the most feasible crane
           at heavy construction sites
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): SangHyeok Han, Shafiul Hasan, Ahmed Bouferguene, Mohamed Al-Hussein, Joe Kosa
      Heavy industrial projects, especially oil refinery facilities, consist of numerous components such as modules and vessels, which are large, heavy, and long objects. The successful completion of these projects requires precise planning and selection of safe and efficient single- and/or tandem crane lifts, which are strongly influenced by the crane types and models used. Thus, selecting not only the best crane type and model, but also the most efficient crane operation among alternatives, can result in productivity and safety improvements. In this respect, this paper proposes an integrated decision support model which designs, simulates, and evaluates potential crane operations in accordance with feasible crane types and models based on equipment, cost, site, and environmental aspects of the project. The proposed methodology consists of two components: (1) 3D-based crane selection simulation, which enhances the process of crane selection by not only accurately verifying and identifying engineering factors, but also analyzing feasibility (procedures) of tandem and single-crane operations, from crane installation to lift completion and disassembly of the crane configuration, in a 3D environment; and (2) a crane selection matrix which calculates the crane evaluation scores by measuring various factors of each feasible crane against the project criteria and constraints. The methodology is tested in a case study in order to illustrate its effectiveness.

      PubDate: 2018-02-04T21:21:45Z
       
  • Environmental monitoring system based on an Open Source Platform and the
           Internet of Things for a building energy retrofit
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): A. Martín-Garín, J.A. Millán-García, A. Baïri, J. Millán-Medel, J.M. Sala-Lizarraga
      This paper deals with the design and development of a low cost building environmental monitoring system, and it is based on Open Source Platforms and on the Internet of Things. To achieve this aim, a wireless microcontroller with attached sensors has been used to collect the environmental data. The information obtained from the sensors is collected and stored in a flash memory card, and simultaneously is sent via WiFi to the cloud. This data is stored in an online spreadsheet, which permits us to access the information in real time. On the other hand, a comparative analysis of the results obtained from sensors has been carried out, thanks to which several guidance guidelines have been developed for the selection of the most appropriate environmental sensor for each project. Finally, an additional evaluation of the device has been carried out through the analysis of its energy performance and providing information related to the data storage and its cost of development. The current research shows a clear ability to develop monitoring systems for the building sector, which can also be extended to multiple applications of Smart Environments. The development of projects through these platforms will allow future research to tackle the existing barriers in monitoring campaigns.

      PubDate: 2018-02-04T21:21:45Z
       
  • The structure and knowledge flow of building information modeling based on
           patent citation network analysis
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Yoo-Na Park, Yoon-Sun Lee, Jae-Jun Kim, Tai Sik Lee
      Building information modeling (BIM) creates new business value and innovation in the construction engineering industry. This study identifies BIM technology structure and the characteristics of knowledge flow through a patent citation network. A technology patent database was collected with backward and forward citation patents currently registered in the US Patents and Trademark Office and identified by the Cooperative Patent Classification. Technology citation networks interact and follow the power law distribution. The analysis of individual patent characteristics and intermediaries revealed digital data processing and telemetry systems as core technology fields stimulating innovative BIM technology. This study overcomes the limitations of previous methods of technology forecasting that have depended on expert opinion or peer review by performing a patent big data analysis to ascertain the domain of the BIM industry. This approach could soon be applied to R&D strategy planning and competition in business and the development of cutting-edge technology.
      Graphical abstract image

      PubDate: 2018-02-04T21:21:45Z
       
  • Application of dynamic time warping to the recognition of mixed equipment
           activities in cycle time measurement
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Hyunsoo Kim, Changbum R. Ahn, David Engelhaupt, SangHyun Lee
      Analyzing and measuring construction equipment operation are key tasks for managing construction projects. In monitoring construction equipment operation, the cycle-time provides fundamental information. Traditional cycle-time measurement methods have been limited by requiring significant efforts such as additional observers, time, and cost. Thus, this study investigates the feasibility of measuring cycle times by using inertial measurement units (IMUs) embedded in a smartphone. Because the mixed activities of construction equipment involve simultaneous actions of multiple parts, they cause low accuracy in equipment activity classification and cycle-time measurement. To enhance the recognition of these mixed activities and translate the results into reliable cycle time measurements, a dynamic time warping (DTW) algorithm was applied and the DTW distances of IMU signals were used as additional features in activity classification. To test its feasibility, data was collected on-site and the excavator's operation was recorded via IMUs embedded in a smartphone attached to a cabin. Using DTW, the suggested method achieved 91.83% accuracy for cycle-time measurement. This result demonstrates an opportunity to use operators' prevalent mobile devices to measure and report their equipment's cycle times in a cost-effective and continuous manner.

      PubDate: 2018-02-04T21:21:45Z
       
  • Critical evaluation of off-site construction research: A Scientometric
           analysis
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): M. Reza Hosseini, Igor Martek, Edmundas Kazimieras Zavadskas, Ajibade A. Aibinu, Mehrdad Arashpour, Nicholas Chileshe
      Practical interest in ‘off-site construction’ has risen remarkably over the last decade, and with it there has been a burgeoning of academic research in the field. Complementing this research, a number of literature reviews have been conducted. None, however, are systematic. This study addresses this lack, offering the first bibliometric study to explore the state of off-site construction research (OCR). A quantitative approach using ‘science mapping’ techniques is employed to examine 501 top-ranked construction journal articles. Longitudinal trends in publishing are identified, as are dominant research sub-fields, their connectedness with other areas of study, as well as citation patterns, publication journal areas of focus, key research institutions, key research persons, along with the extent to which these interact with each other in research networks. The findings are instructive in identifying the deficiencies in current research. Among these is a bias towards product research over operations and management, and a sharp compartmentalization of sub-fields, with little or no cross-fertilization between researcher areas, the researchers themselves, nor the research institutions. Clearly, this awareness will inform industry, journal editors and researchers of the need for a deeper exchange of ideas in any future research efforts.
      Graphical abstract image

      PubDate: 2018-02-04T21:21:45Z
       
  • Mapping and localization module in a mobile robot for insulating building
           crawl spaces
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Sergio Cebollada, Luis Payá, Miguel Juliá, Mathew Holloway, Oscar Reinoso
      This paper presents a novel robotic system that applies spray foam insulation in underfloor voids in order to improve the energy efficiency of buildings. The work focuses on solving the mapping and localization problems in such environments, since they are a key factor in the autonomy of the robot. Solving these tasks in underfloor voids is especially challenging because the terrain is extremely uneven due to the presence of stones, bricks and sand. Within these environments, the robot should be able to localize itself and apply the insulation foam to the underside of the floor. The robot is equipped with a 2D laser sensor which permits building point clouds from several positions of the underfloor environment. The localization process is solved by estimating the position of the robot with respect to previously known positions. For this purpose, the alignment between point clouds is calculated. This paper describes two algorithms to robustly obtain the alignment between two positions. The proposed algorithms are tested with a set of point clouds captured with a laser scan in several environments under real working conditions. The results show that the localization problem can be solved in such challenging underfloor voids by using depth information.

      PubDate: 2018-02-04T21:21:45Z
       
  • Resource leveling using normalized entropy and relative entropy
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Jianfeng Qiao, Yu Li
      The resource leveling problem (RLP) involves the development of a project schedule that specifies the starting time of each activity constrained by the project deadline and precedence, aimed at the minimizing the variation of the resource utilization. To shorten project duration and to find more effective and flexible object functions, normalized entropy and relative entropy are proposed. The former considers shortening the project duration, improved based on the entropy model; the latter measures the similarity of two distributions, that is the actual versus the theoretical resource allocation based on the resource assignments per activity, and which covers not only entropy itself, but also cross entropy. Finally, discrete particle swarm optimization (DPSO) is encoded to investigate the performance of the proposed normalized entropy and relative entropy with other objective functions.

      PubDate: 2018-02-04T21:21:45Z
       
  • Automated system for form layout to increase the proportion of standard
           forms and improve work efficiency
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Chijoo Lee, Sungil Ham
      This paper proposes an automated form layout system that: 1) arranges standard and nonstandard slab-forms automatically to improve work efficiency, and 2) maximizes the proportion of standard forms to reduce manufacturing cost. To accomplish this, the proposed system considers factors such as building shape, connected areas, beams and shores, form size, boundary lines, and layout direction. When applied to six previous construction cases, the proposed layout system is shown to produce a higher proportion of standard to nonstandard form (a maximum of about 23%) than existing methods, which rely on a combination of automated and manual approaches. Furthermore, no more than 31min are required to determine the layout using the proposed automated system. The proposed system can improve the operational efficiency of form layout, reduce form manufacturing cost, and improve the efficiency of form installation work by increasing the proportion of standard forms used.

      PubDate: 2018-02-04T21:21:45Z
       
  • A decision support framework for estimating project duration under the
           impact of weather
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Foad Marzoughi, Tiru Arthanari, Davood Askarany
      This paper proposes a decision support (DS) framework that incorporates weather-related factors for the purpose of estimating the duration of projects. Inclement weather can have a serious effect on construction projects, particularly with regard to duration and costs. The weather has an impact on human resource productivity, supplier effectiveness and material damage which can, in turn, affect the duration of a construction project. The proposed five-module framework integrates weather variables, project performance variables and duration of project activities. This framework uses expert knowledge about the importance of weather variables, pairwise comparisons of weather variables with respect to different performance criteria, and similarly, pairwise comparisons of performance variables with respect to project activities. A model based on this framework, using multivariate statistical techniques and an analytical network process (ANP), is developed to estimate the duration of project activities, taking into account the impact of weather. The proposed model is illustrated with data from a construction project from Iran. Validation of the model is provided by comparing the actual duration of an activity with the estimated duration, using the proposed framework.

      PubDate: 2018-02-04T21:21:45Z
       
  • Interaction analysis for vision-based activity identification of
           earthmoving excavators and dump trucks
    • Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Jinwoo Kim, Seokho Chi, Jongwon Seo
      Activity identification is an essential step to measure and monitor the performance of earthmoving operations. Many vision-based methods that automatically capture and explain activity information from image data have been developed with economic advantages and analysis efficiency. However, the previous methods failed to consider the interactive operations among equipment, and thus limited the applicability to the operation time estimation for productivity analysis. To address the drawback, this research developed a vision-based activity identification framework that incorporates interactive aspects of earthmoving equipment's operation. This framework included four main processes: equipment tracking, action recognition of individual equipment, interaction analysis, and post-processing. The interactions between excavators and dump trucks were examined due to its significant impacts on earthmoving operations. TLD (Tracking-Learning-Detection) was adapted to track the heavy equipment. Spatio-temporal reasoning and image differencing techniques were then implemented to categorize individual actions. Third, interactions were interpreted based on a knowledge-based system that evaluates equipment actions and proximity between operating equipment. Lastly, outliers or noisy results were filtered out considering work continuity. To validate the proposed framework, two experiments were performed: one with the interaction analysis and the other without the analysis. 11,513 image frames from actual earthmoving sites in total were tested. The consequent average precision of activity analysis was enhanced from 75.68% to 91.27% after the interaction analysis was applied. In conclusion, this research contributes to identifying critical elements that explain interactive operations, characterize the vision-based activity identification framework, and improve the applicability of the vision-based method for the automated equipment operations analysis.

      PubDate: 2018-02-04T21:21:45Z
       
  • Integration of parametric design into modular coordination: A construction
           waste reduction workflow
    • Authors: Saeed Banihashemi; Amir Tabadkani; M. Reza Hosseini
      Pages: 1 - 12
      Abstract: Publication date: April 2018
      Source:Automation in Construction, Volume 88
      Author(s): Saeed Banihashemi, Amir Tabadkani, M. Reza Hosseini
      The construction industry is under pressure as to reduce the sizable quantities of construction waste generated during construction operations. Modular coordination (MC) and parametric design both have great potentials in reducing waste at the design stage. And anecdotal evidence suggests that great volumes of waste can be reduced through integration of parametric design into MC. The issue of proposing workflows in this context, however, is under-researched, and practical applications, if any, are at the rhetorical stage. To accomplish this, an integration attempt is made in this study to provide the details of a developed-and-experimented workflow for this purpose; a generative algorithm is developed through the Rhinoceros 3D–Grasshopper platform, subject to MC rules. Two sets of horizontal and vertical modules are obtained from a prototype model, while an evolutionary solver function is applied in reducing the generated construction waste volume. According to a pre-defined standard specification, different modular design variants that fully conform to the design constraints in modules array are developed, providing an operational workflow in construction waste reduction at the design stage. Introducing this workflow, and how the proposed workflow reduces the volume of post-optimization paneling waste by 2% at its minimum are the major findings here. The insights derived from this study, would promote the interest of both the construction practitioners and researchers; the practicality of integrating parametric design into MC is proven.

      PubDate: 2017-12-26T18:22:06Z
      DOI: 10.1016/j.autcon.2017.12.026
      Issue No: Vol. 88 (2017)
       
  • A GBMO-based PIλDμ controller for vibration mitigation of
           seismic-excited structures
    • Authors: Sadegh Etedali; Abbas-Ali Zamani; Saeed Tavakoli
      Pages: 1 - 12
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Sadegh Etedali, Abbas-Ali Zamani, Saeed Tavakoli
      The advantages of fractional-order proportional–integral–derivative (FOPID) controllers in terms of flexibility, robustness against model uncertainties and good disturbance rejection, are good motivations to use them for vibration mitigation of seismic-excited structures. The application of the FOPID controller for adjusting the control force of an active tuned mass damper (ATMD) for seismic control a building is studied in this paper. Gases Brownian motion optimization (GBMO) algorithm is employed for optimal tuning of parameters of the FOPID and PID controllers. Evaluation of the frequency responses of the structure for uncontrolled and controlled cases shows that PID and FOPID controllers are very effective for the seismic control of structures. For further investigation, the performance of the FOPID controller in the reduction of seismic responses of the building in four well-known earthquake excitations is compared with those provided by the PID, linear–quadratic regulator (LQR) and fuzzy logic control (FLC). Simulation results show that the PID and LQR controllers provide the same performance in reducing the maximum top floor displacement of the structure. Moreover, the FLC and FOPID controllers demonstrate a superior performance in seismic control of the structure. The FLC is able to reduce the maximum displacements of all stories for all studied earthquakes. However, the proposed FOPID controller is able to provide a better performance in comparison with the FLC. In average, the FOPID controller mitigates the seismic responses of the structure as much as 29%, 27% and 15% better than the LQR, PID controller and FLC.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.005
      Issue No: Vol. 87 (2017)
       
  • Design-by-analogy: A characteristic tree method for geotechnical
           engineering
    • Authors: ZhiJia You; HouLi Fu; Jian Shi
      Pages: 13 - 21
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): ZhiJia You, HouLi Fu, Jian Shi
      Geotechnical engineers frequently use design-by-analogy methods to promote innovative design solutions, or reuse existing design schemes. However, this approach has not yet provided a means for comparing various potential project solutions quantitatively. Moreover, while geotechnical engineering has accumulated data in large quantities, the value of this historical data has not been exploited fully for the identification of useful analogies. To address these challenges, we proposed the characteristic tree analogy method and a key algorithm for calculating the similarity index between objects. On this basis, we developed a decision support system that makes comprehensive use of geotechnical engineering historical data. We applied the system successfully to the roadway support design for Liangjia coal mine. The results verified the applicability of the characteristic tree analogy method for realizing geotechnical engineering designs, making maximum use of historical data. This approach can be extended to other areas of geotechnical engineering that have large quantities historical data.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.008
      Issue No: Vol. 87 (2017)
       
  • Planning and developing facility management-enabled building information
           model (FM-enabled BIM)
    • Authors: Pardis Pishdad-Bozorgi; Xinghua Gao; Charles Eastman; Alonzo Patrick Self
      Pages: 22 - 38
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Pardis Pishdad-Bozorgi, Xinghua Gao, Charles Eastman, Alonzo Patrick Self
      Successful implementation of FM-enabled BIM can be achieved with 1) a clear definition of what FM-enabled BIM constitutes, 2) a seamless and practical process of collecting the FM-enabled BIM data throughout project development phases, and 3) a well-executed interoperability plan for exchanging data between BIM tools and facility management systems, such as Computerized Maintenance Management System (CMMS). This research contributes to the body of knowledge by first defining, and examining one of the first few pilots implementation of FM-enabled BIM, and discussing the challenges encountered and the lessons learned, and then by proposing a research framework for future researchers to systematically and strategically build the knowledge foundation on BIM for FM field. The implementation process described and the lessons learned captured in this pilot project provide valuable insights into the successful implementation of FM-enabled BIM.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.004
      Issue No: Vol. 87 (2017)
       
  • A simple method for combining fire and structural models and its
           application to fire safety evaluation
    • Authors: Shicai Chen; Yong Zhang; Aizhu Ren
      Pages: 39 - 48
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Shicai Chen, Yong Zhang, Aizhu Ren
      To consider the actual fire characteristics in the fire response analysis of building structures and to simplify the complex relationship between the fire analysis model and the structural finite element analysis model, a spatio-temporal model of the fire temperature and heat flux boundary for heat conduction analysis is developed. The proposed model adopts a two-way orthogonal polynomial approach for fitting the discrete data from the fire simulation and obtains continuous spatial polynomial equations. It is shown to be accurate for capturing the distributions of temperature and heat flux that are required for a heat conduction analysis and a thermal mechanical coupling analysis. Finally, the model is implemented through user-subroutines UTEMP and DFLUX in ABAQUS, and it is applied to a new archive in Beijing. The results show that this method may be used to combine fire simulation and structural analysis for the safety evaluation of structures under fire.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.015
      Issue No: Vol. 87 (2017)
       
  • Development and application of a wireless MEMS-based borehole inclinometer
           for automated measurement of ground movement
    • Authors: Dae Woong Ha; Jong Moon Kim; Yousok Kim; Hyo Seon Park
      Pages: 49 - 59
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Dae Woong Ha, Jong Moon Kim, Yousok Kim, Hyo Seon Park
      Generally, the excavation work performed to lay the foundation and create the underground space of structures causes deformation of the surrounding ground. Such deformations could threaten the lives of residents and the safety of structures. Consequently, borehole inclinometers have been used to monitor these deformations. The typically used underground inclinometers have the disadvantages of lack of durability, difficulties in measuring local inclination because of a relatively long inclinometer, loss of data due to long connecting cables, and electromagnetic interference. To overcome these disadvantages, in the present study, a wireless MEMS-based borehole inclinometer system composed of a tilt sensor module, processor module, and slave and master nodes was developed. The developed borehole inclinometer system was configured by a two tier sensor to minimize its diameter. Its field applicability was improved by minimizing the cables between the sensor and the server through the application of a long range wireless module between the computer server and master node and a short range wireless communication between the master node and sensor node. A field test was conducted to verify the applicability and data reliability of the developed wireless MEMS-based borehole inclinometer. The reliability of the proposed system has been proved by the analysis of data collected for two months at two different construction sites.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.011
      Issue No: Vol. 87 (2017)
       
  • Optimal cut-fill pairing and sequencing method in earthwork operation
    • Authors: Han-Seong Gwak; Jongwon Seo; Dong-Eun Lee
      Pages: 60 - 73
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Han-Seong Gwak, Jongwon Seo, Dong-Eun Lee
      Earthwork operations consist of repeated cycles of excavating, moving, and backfilling processes, in which rock-earth block is excavated from its cut pit, moved to a fill pit, and then backfilled into its corresponding fill prism. An efficient earth allocation plan reduces the total earthwork cost. This paper presents a computational method called Optimal cut-fill Pairing and Sequencing (OPS) which identifies the most economical EAP. It identifies the optimal cut-fill pairs and their sequence which minimizes the total earthwork cost by hybridizing the mixed integer linear programming (MILP) and evolutionary algorithm (i.e., harmony search). The proposed method is of value to earthwork managers because it identifies the most favorable EAP by accounting for the rock-earth type of each and every prism, the series of prisms occupying each and every cut and fill pits, and the moving directions (i.e., the order of cut-fill prism pairs), expeditiously. This study is also of relevance to researchers because it provides a white box which defines the mathematical formula and computational procedures to identify the global solution in detail. Two test cases confirm the usability and validity of the computational method.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.010
      Issue No: Vol. 87 (2017)
       
  • A direct load control strategy of centralized air-conditioning systems for
           building fast demand response to urgent requests of smart grids
    • Authors: Rui Tang; Shengwei Wang; Chengchu Yan
      Pages: 74 - 83
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Rui Tang, Shengwei Wang, Chengchu Yan
      When receiving an urgent request from a smart grid, shutting down part of operating chillers directly in the air-conditioning system in a building can achieve immediate power reduction. However, no study has addressed how to determine the number of chillers/pumps to be shut down and how to regulate the load of retained equipment systematically during DR events. This paper presents a new approach to address these issues based on three schemes. A power demand optimization scheme predicts the building cooling demand and the power limiting threshold in response to a received DR request. A system sequence control resetting scheme determines the number of operating chillers/pumps to be retained. An online control/regulation scheme ensures the system power following the expected profile by regulating the total chilled water flow delivered to the building and therefore the chiller load. It also employs a cooling distributor to distribute chilled water to individual zones concerning different sensitivities/sacrifices to temperature increases. Case studies are conducted on a simulated dynamic building air-conditioning system. Results show that, during DR events, the proposed strategy can achieve the expected power reduction (i.e., about 23%) and also maintain acceptable zone temperature even though uncertainties exist in the prediction process.

      PubDate: 2017-12-13T09:37:25Z
      DOI: 10.1016/j.autcon.2017.12.012
      Issue No: Vol. 87 (2017)
       
  • Stochastic Petri net-based modelling of the durability of renderings
    • Authors: C. Ferreira; L. Canhoto Neves; A. Silva; J. de Brito
      Pages: 96 - 105
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): C. Ferreira, L. Canhoto Neves, A. Silva, J. de Brito
      In this study, a methodology to model and predict the life-cycle performance of building façades based on Stochastic Petri Nets is proposed. The proposed model evaluates the performance of rendered façades over time, evaluating the uncertainty of the future performance of these coatings. The performance of rendered façades is evaluated based on a discrete qualitative scale composed of five condition levels, established according to the physical and visual degradation of these elements. In this study, the deterioration is modelled considering that the transition times between these condition states can be modelled as a random variable with different distributions. For that purpose, a Stochastic Petri Nets model is used, as a formal framework to describe this problem. The model's validation is based on probabilistic indicators of performance, computed using Monte-Carlo simulation and the probability distribution parameters leading to better fit are defined as those maximizing the likelihood, computed using Genetic Algorithm. In this study, a sample of 99 rendered façades, located in Portugal, is analysed, and the degradation condition of each case study is evaluated through in-situ visual inspections. The model proposed allows evaluating: i) the transition rate between degradation conditions; ii) the probability of belonging to a given degradation condition over time; and iii) the mean time of permanence in each degradation condition. The use of Petri Nets shows to be more accurate than a more traditional approach based on Markov Chains, but also allows developing future research to consider different environmental conditions, maintenance actions or inspections, amongst other aspects of life-cycle analysis of existing assets.

      PubDate: 2017-12-26T18:22:06Z
      DOI: 10.1016/j.autcon.2017.12.007
      Issue No: Vol. 87 (2017)
       
  • An approach to combining related notifications in large-scale building
           management systems with a rehabilitation facility case study
    • Authors: Yulia Evchina; Jose Luis Martinez Lastra
      Pages: 106 - 116
      Abstract: Publication date: March 2018
      Source:Automation in Construction, Volume 87
      Author(s): Yulia Evchina, Jose Luis Martinez Lastra
      ICT advances have enabled the incorporation of multiple devices that monitor various aspects of the environment into building management (BM) systems. The data from these devices is used to detect multiple abnormal situations, which require the awareness of system users and/or timely response. However, the number of abnormal situations is usually large, and delivering all of the associated notifications is overwhelming for users, rather than helping them to interpret the ongoing status of the environment. This work proposes a novel approach for combining ongoing notifications in the monitoring systems by their types, priorities, locations, and receivers. The approach is based on formal classification of possible alarms and runtime analysis of ongoing notifications with the aim of reducing repeating information pieces delivered as part of multiple notifications. The paper provides details of combination principles of notifications and applies them to real data from a rehabilitation facility. The results show a reduction in the users' information load of approximately 42% of the peak number of ongoing notifications. It is expected that the proposed approach will improve situation awareness in the managed facilities – enabling better and faster decisions on the ongoing status of the environment.

      PubDate: 2017-12-26T18:22:06Z
      DOI: 10.1016/j.autcon.2017.12.020
      Issue No: Vol. 87 (2017)
       
 
 
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