Visual Surveillance of Human Activities via Gradient-Based Coverage Control on Matrix Manifolds

2020 ◽  
Vol 28 (6) ◽  
pp. 2220-2234 ◽  
Author(s):  
Takeshi Hatanaka ◽  
Riku Funada ◽  
Masayuki Fujita
Author(s):  
Christopher G. Valicka ◽  
Richard A. Rekoske ◽  
Dušan M. Stipanovic ◽  
Ali E. Abbas

AbstractThis paper presents theoretical and experimental results related to the control and coordination of multirobot systems interested in dynamically covering a compact domain while remaining proximal, so as to promote robust inter-robot communications, and while remaining collision free with respect to each other and static obstacles. A design for a novel, gradient-based controller using nonnegative definite objective functions and an overapproximation to the maximum function is presented. By using a multiattribute utility copula to scalarize the multiobjective control problem, a control law is presented that allows for flexible tuning of the tradeofs between objectives. This procedure mitigates the controller’s dependence on objective function parameters and allows for the straightforward integration of a novel global coverage objective. Simulation and experiments demonstrate the controller’s efectiveness in promoting scenarios with collision free trajectories, robust communications, and satisfactory coverage of the entire coverage domain concurrently for a group of differential drive robots.


2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Ting-quan Deng ◽  
Jia-shu Dai ◽  
Tian-zhen Dong ◽  
Ke-jia Yi

In the visual tracking scenarios, if there are multiple objects, due to the interference of similar objects, tracking may fail in the progress of occlusion to separation. To address this problem, this paper proposed a visual tracking algorithm with discrimination through multimanifold learning. Color-gradient-based feature tensor was used to describe object appearance for accommodation of partial occlusion. A prior multimanifold tensor dataset is established through the template matching tracking algorithm. For the purpose of discrimination, tensor distance was defined to determine the intramanifold and intermanifold neighborhood relationship in multimanifold space. Then multimanifold discriminate analysis was employed to construct multilinear projection matrices of submanifolds. Finally, object states were obtained by combining with sequence inference. Meanwhile, the multimanifold dataset and manifold learning embedded projection should be updated online. Experiments were conducted on two real visual surveillance sequences to evaluate the proposed algorithm with three state-of-the-art tracking methods qualitatively and quantitatively. Experimental results show that the proposed algorithm can achieve effective and robust effect in multi-similar-object mutual occlusion scenarios.


2018 ◽  
Vol 188 ◽  
pp. 05010
Author(s):  
Sotiris Papatheodorou ◽  
Anthony Tzes

The fault tolerance characteristics of a distributed multi-agent coverage algorithm are examined. A team of sensor-equipped mobile agents is tasked with covering a planar region of interest. A distributed, gradient-based control scheme is utilized for this purpose. The agents are assumed to consist of three subsystems, each one of which may fail. The subsystems under examination are the actuation, sensing and the communication subsystem. Partial and catastrophic faults are examined. Several simulation studies are conducted highlighting the robustness of the distributed nature of the control scheme to these classes of faults, even when several of them happen at the same time.


Author(s):  
Jay Prakash Gupta ◽  
Nishant Singh ◽  
Pushkar Dixit ◽  
Vijay Bhaskar Semwal ◽  
Shiv Ram Dubey

Vision-based human activity recognition is the process of labelling image sequences with action labels. Accurate systems for this problem are applied in areas such as visual surveillance, human computer interaction and video retrieval. The challenges are due to variations in motion, recording settings and gait differences. Here the authors propose an approach to recognize the human activities through gait. Activity recognition through Gait is the process of identifying an activity by the manner in which they walk. The identification of human activities in a video, such as a person is walking, running, jumping, jogging etc are important activities in video surveillance. The authors contribute the use of Model based approach for activity recognition with the help of movement of legs only. Experimental results suggest that their method are able to recognize the human activities with a good accuracy rate and robust to shadows present in the videos.


2012 ◽  
Author(s):  
Lyndsey K. Lanagan-Leitzel ◽  
Emily Skow ◽  
Cathleen M. Moore

2007 ◽  
Vol 51 (1-2) ◽  
pp. 43
Author(s):  
Balázs Polgár ◽  
Endre Selényi
Keyword(s):  

“We regard the recent science –based consensual reports that climate change is, to a large extend, caused by human activities that emit green houses as tenable, Such activities range from air traffic, with a global reach over industrial belts and urban conglomerations to local small, scale energy use for heating homes and mowing lawns. This means that effective climate strategies inevitably also require action all the way from global to local levels. Since the majority of those activities originate at the local level and involve individual action, however, climate strategies must literally begin at home to hit home.”


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