The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Dominique Ginhac - One of the best experts on this subject based on the ideXlab platform.
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Semantic enrichment of spatio-temporal trajectories for worker safety on construction sites
Personal and Ubiquitous Computing, 2019Co-Authors: Muhammad Arslan, Christophe Cruz, Dominique GinhacAbstract:Thousands of fatalities are reported from the construction industry every year and a high percentage of them are due to the unsafe worker movements which resulted in falling from heights, transportation accidents, exposure to harmful environments, and striking against or being struck by the moving equipment. To reduce such fatalities, a system is proposed to monitor worker movements on a construction site by collecting their raw spatio-temporal Trajectory data and enriching it with the relevant semantic information. To acquire the trajectories, the use of an indoor positioning system (IPS) is considered. Bluetooth beacons are used for collecting spatio-temporal information of the building users. By means of an Android-based mobile application, neighboring beacons’ signals are selected, and a geo-localization technique is performed to get the unique pairs of users’ location coordinates. After pre-processing this collected data, three semantic enrichment techniques are used to construct semantically enriched trajectories which are as follows: (1) enrichment with the semantic points which maps site location identification to the Trajectory points; (2) enrichment with the semantic lines which relies on the speed-based segmentation approach to infer user modes of transportation; (3) enrichment with the semantic region for mapping a Complete Trajectory on an actual building or a construction site zone. The proposed system will help in extracting multifaceted Trajectory characteristics and generates semantic trajectories to enable the desired semantic insights for better understanding of the underlying meaningful worker movements using the contextual data related to the building environment. Generated semantic trajectories will help health and safety (H&S) managers in making improved decisions for monitoring and controlling site activities by visualizing site-zones’ density to avoid congestion, proximity analysis to prevent workers collisions, identifying unauthorized access to hazardous areas, and monitoring movements of workers and machinery to reduce transportation accidents.
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Semantic Enrichment of Spatio-temporal Trajectories for Worker Safety on Construction Sites
Procedia Computer Science, 2018Co-Authors: Muhammad Arslan, Christophe Cruz, Dominique GinhacAbstract:Existing literature reveals that major reasons of fatalities on construction sites are linked to mobility related issues such as unsafe human behaviors, difficult site conditions and workers striking against or being struck by the moving objects. In an attempt to reduce such fatalities, a system is proposed to enrich spatio-temporal trajectories of construction workers. Three semantic enrichment techniques are used to construct semantically enriched trajectories which are: (1) enrichment with semantic points that maps site location identification to Trajectory points; (2) enrichment with semantic lines that relies on the speed based segmentation approach infers modes of transportation used in Trajectory‘s episodes; and (3) enrichment with semantic region for mapping a Complete Trajectory on an actual construction site zone. Constructed semantic trajectories will help Health and Safety (H&S) managers in making improved decisions for monitoring and controlling site activities by understanding workers behaviors that ultimately attempts to contribute in reducing fatal accidents occurring on construction sites each year.
Vijay Kumar - One of the best experts on this subject based on the ideXlab platform.
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safe and Complete Trajectory generation for robot teams with higher order dynamics
Intelligent Robots and Systems, 2016Co-Authors: Sarah Tang, Vijay KumarAbstract:In this work, we consider the labeled multi-robot planning problem. In this paradigm, a team of robots at fixed start positions must navigate to pre-specified and noninterchangable goal positions. While many algorithms have been proposed for finding optimal solutions to this problem, most methods assume that the robots are kinematic agents, whereas in reality, robots often have high-order dynamics that must be respected by their trajectories. Here, we propose a centralized method for generating trajectories for teams of robots with general nth-order dynamics navigating to labeled goals. Our algorithm is safe and Complete and additionally allows for decoupled optimization of each robot's Trajectory as a Quadratic Program with linear constraints. We present simulation results for teams of up to 20 robots.
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IROS - Safe and Complete Trajectory generation for robot teams with higher-order dynamics
2016 IEEE RSJ International Conference on Intelligent Robots and Systems (IROS), 2016Co-Authors: Sarah Tang, Vijay KumarAbstract:In this work, we consider the labeled multi-robot planning problem. In this paradigm, a team of robots at fixed start positions must navigate to pre-specified and noninterchangable goal positions. While many algorithms have been proposed for finding optimal solutions to this problem, most methods assume that the robots are kinematic agents, whereas in reality, robots often have high-order dynamics that must be respected by their trajectories. Here, we propose a centralized method for generating trajectories for teams of robots with general nth-order dynamics navigating to labeled goals. Our algorithm is safe and Complete and additionally allows for decoupled optimization of each robot's Trajectory as a Quadratic Program with linear constraints. We present simulation results for teams of up to 20 robots.
Muhammad Arslan - One of the best experts on this subject based on the ideXlab platform.
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Semantic enrichment of spatio-temporal trajectories for worker safety on construction sites
Personal and Ubiquitous Computing, 2019Co-Authors: Muhammad Arslan, Christophe Cruz, Dominique GinhacAbstract:Thousands of fatalities are reported from the construction industry every year and a high percentage of them are due to the unsafe worker movements which resulted in falling from heights, transportation accidents, exposure to harmful environments, and striking against or being struck by the moving equipment. To reduce such fatalities, a system is proposed to monitor worker movements on a construction site by collecting their raw spatio-temporal Trajectory data and enriching it with the relevant semantic information. To acquire the trajectories, the use of an indoor positioning system (IPS) is considered. Bluetooth beacons are used for collecting spatio-temporal information of the building users. By means of an Android-based mobile application, neighboring beacons’ signals are selected, and a geo-localization technique is performed to get the unique pairs of users’ location coordinates. After pre-processing this collected data, three semantic enrichment techniques are used to construct semantically enriched trajectories which are as follows: (1) enrichment with the semantic points which maps site location identification to the Trajectory points; (2) enrichment with the semantic lines which relies on the speed-based segmentation approach to infer user modes of transportation; (3) enrichment with the semantic region for mapping a Complete Trajectory on an actual building or a construction site zone. The proposed system will help in extracting multifaceted Trajectory characteristics and generates semantic trajectories to enable the desired semantic insights for better understanding of the underlying meaningful worker movements using the contextual data related to the building environment. Generated semantic trajectories will help health and safety (H&S) managers in making improved decisions for monitoring and controlling site activities by visualizing site-zones’ density to avoid congestion, proximity analysis to prevent workers collisions, identifying unauthorized access to hazardous areas, and monitoring movements of workers and machinery to reduce transportation accidents.
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Semantic Enrichment of Spatio-temporal Trajectories for Worker Safety on Construction Sites
Procedia Computer Science, 2018Co-Authors: Muhammad Arslan, Christophe Cruz, Dominique GinhacAbstract:Existing literature reveals that major reasons of fatalities on construction sites are linked to mobility related issues such as unsafe human behaviors, difficult site conditions and workers striking against or being struck by the moving objects. In an attempt to reduce such fatalities, a system is proposed to enrich spatio-temporal trajectories of construction workers. Three semantic enrichment techniques are used to construct semantically enriched trajectories which are: (1) enrichment with semantic points that maps site location identification to Trajectory points; (2) enrichment with semantic lines that relies on the speed based segmentation approach infers modes of transportation used in Trajectory‘s episodes; and (3) enrichment with semantic region for mapping a Complete Trajectory on an actual construction site zone. Constructed semantic trajectories will help Health and Safety (H&S) managers in making improved decisions for monitoring and controlling site activities by understanding workers behaviors that ultimately attempts to contribute in reducing fatal accidents occurring on construction sites each year.
Meng Zhan - One of the best experts on this subject based on the ideXlab platform.
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Complete synchronization in coupled limit-cycle systems
Europhysics Letters (EPL), 2007Co-Authors: Wei Zou, Meng ZhanAbstract:Most of the previous studies on the synchronization of coupled limit-cycle systems focused on synchronization in the context of phase or frequency locking. In this letter, we study Complete synchronization in coupled limit-cycle systems in terms of Complete Trajectory locking, by generalizing the master stability function method, which is originally developed in the study of synchronization in coupled chaotic systems. Four typical types of transverse Lyapunov exponent of standard mode, which lead to different synchronization-desynchronization patterns, are classified. In many respects, the behaviors in such coupled systems are distinct from those in coupled chaotic systems, such as the size effect and the desynchronous behavior.
Christine Buisson - One of the best experts on this subject based on the ideXlab platform.
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New Filtering Method for Trajectory Measurement Errors and Its Comparison with Existing Methods
Transportation Research Record, 2012Co-Authors: Florian Marczak, Christine BuissonAbstract:Dynamic traffic simulation tools are increasingly being used to help traffic managers and urban planners to make decisions. Therefore, simulation tool users require a validated methodology guaranteeing that simulation results can be trusted. This study contributes to the identification and correction of a possible deficiency in detailed calibration and validation of car-following models: the data errors of individual Trajectory data. Some studies addressed the problem of filtering Trajectory data. A new filtering technique to reduce the measurement errors on trajectories, speed profiles, and acceleration profiles is proposed here. This technique is based on some piecewise polynomials termed "splines." The proposed technique is compared with a set of filtering techniques found in the literature. A Complete Trajectory data set available within the NGSIM program is used. As a quality indicator of the various filtering techniques, velocity distribution, acceleration distribution, and jerk analysis are used fo...
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New Filtering Method for Trajectory Measurement Errors and Its Comparison with Existing Methods
Transportation Research Record, 2012Co-Authors: Florian Marczak, Christine BuissonAbstract:Dynamic traffic simulation tools are more and more used to help traffic managers and urban planners to make decisions. Therefore, simulation tools users now ask to research a validated methodology guaranteeing that simulation results are trustable. This paper contributes to identify and correct one of the possible lacks of detailed calibration and validation process of car-following models, the data errors of individual Trajectory data. Some studies addressed the problem of filtering Trajectory data. We propose in this paper a new filtering technique to reduce the measurement errors on trajectories, speed profiles and acceleration profiles. This technique is based on I-splines; some piecewise polynomials. Then we compare our proposal with a set of filtering technique found in the literature. We use a Complete Trajectory dataset available within the NGSIM program. As a quality indicator of the various filtering techniques we use velocity distribution, acceleration distribution and jerk analysis for the whole dataset. We also suggest analyzing acceleration standard deviation for each Trajectory of the dataset. The main findings are as follows: (1) among the methods compared within this work, the I-splines methods with the action points reduces the most the spikes in the velocity distribution; (2) moreover the I-splines method reduces also the most the percentage of jerk values higher than 15 m/s3 and the percentage of one-second window with more than one sign inversion of the jerk; (3) but in some cases, this method increases the acceleration variability of smoothed trajectories.