Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525875
J. Colgate, Michael C. Stanley, J. M. Brown
Our group is interested in using haptic display for training tool use. Applications include training doctors to use tools during surgery, and training astronauts to use tools during EVA. This paper describes some of the challenges of creating realistic haptic perceptions of tool use. Many of these challenges stem from the importance of unilateral constraints during tool use. Unilateral constraints occur whenever rigid bodies collide, resisting the interpenetration of the bodies, but not holding the bodies together. To identify unilateral constraints, a tool/environment simulation must perform collision detection. To respond properly to a collision, the simulation must estimate the forces that ensue, and integrate the equations of motion. All of these computations must occur in real time, and the simulation as a whole must be stable (to ensure the user's safety). Approaches to these problems are described.
{"title":"Issues in the haptic display of tool use","authors":"J. Colgate, Michael C. Stanley, J. M. Brown","doi":"10.1109/IROS.1995.525875","DOIUrl":"https://doi.org/10.1109/IROS.1995.525875","url":null,"abstract":"Our group is interested in using haptic display for training tool use. Applications include training doctors to use tools during surgery, and training astronauts to use tools during EVA. This paper describes some of the challenges of creating realistic haptic perceptions of tool use. Many of these challenges stem from the importance of unilateral constraints during tool use. Unilateral constraints occur whenever rigid bodies collide, resisting the interpenetration of the bodies, but not holding the bodies together. To identify unilateral constraints, a tool/environment simulation must perform collision detection. To respond properly to a collision, the simulation must estimate the forces that ensue, and integrate the equations of motion. All of these computations must occur in real time, and the simulation as a whole must be stable (to ensure the user's safety). Approaches to these problems are described.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121155339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525826
John B. Morrell, J. Salisbury
Current force control capabilities are limited by actuator performance. Brush friction and actuator saturation lead to limit cycles and instability in many force control systems. The authors propose that actuators with the proper passive characteristics provide the best potential for fast, accurate force control. The authors report on a new actuator concept which combines two actuators to create a micro-macro actuator which has improved force resolution and bandwidth. Unlike previous micro-macro robots which used actuators coupled in series, the actuators in this system are coupled in parallel using a compliant transmission. Three specifications for force control performance are defined and a model is presented. A control law for the combined actuator is presented and a general analysis of the design is formulated. Finally, measurements of performance in a prototype device are presented. This system has achieved force resolution of 0.25% and force control bandwidth of 60 Hz.
{"title":"Parallel coupled actuators for high performance force control: a micro-macro concept","authors":"John B. Morrell, J. Salisbury","doi":"10.1109/IROS.1995.525826","DOIUrl":"https://doi.org/10.1109/IROS.1995.525826","url":null,"abstract":"Current force control capabilities are limited by actuator performance. Brush friction and actuator saturation lead to limit cycles and instability in many force control systems. The authors propose that actuators with the proper passive characteristics provide the best potential for fast, accurate force control. The authors report on a new actuator concept which combines two actuators to create a micro-macro actuator which has improved force resolution and bandwidth. Unlike previous micro-macro robots which used actuators coupled in series, the actuators in this system are coupled in parallel using a compliant transmission. Three specifications for force control performance are defined and a model is presented. A control law for the combined actuator is presented and a general analysis of the design is formulated. Finally, measurements of performance in a prototype device are presented. This system has achieved force resolution of 0.25% and force control bandwidth of 60 Hz.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121240835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525797
J. Adams, R. Bajcsy, J. Kosecka, Vijay R. Kumar, R. Mandelbaum, M. Mintz, R. Paul, Curtis Wang, Y. Yamamoto, X. Yun
Presents a collaborative effort to design and implement a cooperative material handling system by a small team of human and robotic agents in an unstructured indoor environment. The authors' approach makes fundamental use of the human agents' expertise for aspects of task planning, task monitoring, and error recovery. The authors' system is neither fully autonomous nor fully teleoperated. It is designed to make effective use of the human's abilities within the present state of the art of autonomous systems. The authors' robotic agents refer to systems which are each equipped with at least one sensing modality and which possess some capability for self-orientation and/or mobility. The authors' robotic agents are not required to be homogeneous with respect to either capabilities or function. The authors' research stresses both paradigms and testbed experimentation. Theory issues include the requisite coordination principles and techniques which are fundamental to a cooperative multiagent system's basic functioning. The authors have constructed an experimental distributed multiagent-architecture testbed facility. The required modular components of this testbed are currently operational and have been tested individually. The authors' current research focuses on the agents' integration in a scenario for cooperative material handling.
{"title":"Cooperative material handling by human and robotic agents: module development and system synthesis","authors":"J. Adams, R. Bajcsy, J. Kosecka, Vijay R. Kumar, R. Mandelbaum, M. Mintz, R. Paul, Curtis Wang, Y. Yamamoto, X. Yun","doi":"10.1109/IROS.1995.525797","DOIUrl":"https://doi.org/10.1109/IROS.1995.525797","url":null,"abstract":"Presents a collaborative effort to design and implement a cooperative material handling system by a small team of human and robotic agents in an unstructured indoor environment. The authors' approach makes fundamental use of the human agents' expertise for aspects of task planning, task monitoring, and error recovery. The authors' system is neither fully autonomous nor fully teleoperated. It is designed to make effective use of the human's abilities within the present state of the art of autonomous systems. The authors' robotic agents refer to systems which are each equipped with at least one sensing modality and which possess some capability for self-orientation and/or mobility. The authors' robotic agents are not required to be homogeneous with respect to either capabilities or function. The authors' research stresses both paradigms and testbed experimentation. Theory issues include the requisite coordination principles and techniques which are fundamental to a cooperative multiagent system's basic functioning. The authors have constructed an experimental distributed multiagent-architecture testbed facility. The required modular components of this testbed are currently operational and have been tested individually. The authors' current research focuses on the agents' integration in a scenario for cooperative material handling.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123688734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525825
G. Mennitto, M. Buehler
Introduces new compliance models for LADD (linear to angular displacement device) transmissions which reduce, by an order of magnitude, inelastic model errors of up to 18% full scale over force and position operating ranges. Elastic models introduced so far were all based on fiber elasticity, which show an increase an LADD length from the inelastic length with force. The authors show that in experiments the opposite is true. The LADD is always shorter than predicted from the inelastic model. As the load force increases, the LADD length approaches the inelastic length. The authors found the cause for this fundamentally different elastic behavior to be fiber bending. The authors also employ one of the new models to improve the prediction of the kinematics of a CLADD, which consists of two concentric LADD devices. The new LADD models are essential for the design of LADD based systems, the online estimation of LADD forces, and accurate control.
{"title":"Experimental validation of compliance models for LADD transmission kinematics","authors":"G. Mennitto, M. Buehler","doi":"10.1109/IROS.1995.525825","DOIUrl":"https://doi.org/10.1109/IROS.1995.525825","url":null,"abstract":"Introduces new compliance models for LADD (linear to angular displacement device) transmissions which reduce, by an order of magnitude, inelastic model errors of up to 18% full scale over force and position operating ranges. Elastic models introduced so far were all based on fiber elasticity, which show an increase an LADD length from the inelastic length with force. The authors show that in experiments the opposite is true. The LADD is always shorter than predicted from the inelastic model. As the load force increases, the LADD length approaches the inelastic length. The authors found the cause for this fundamentally different elastic behavior to be fiber bending. The authors also employ one of the new models to improve the prediction of the kinematics of a CLADD, which consists of two concentric LADD devices. The new LADD models are essential for the design of LADD based systems, the online estimation of LADD forces, and accurate control.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123555634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525853
T. Tarn, N. Xi, Chuanfan Guo, A. Bejczy
A new function-based control sharing scheme for robotic systems has been developed based on the event-based planning and control theory. It provides a unified model to integrate a human operator control command with action planning and control of autonomous operation. As a result, the robotic systems can perform tasks which cannot be done by either human operator or autonomous planner/controller alone. This scheme lays down a foundation for planning and control of a general robotic system involving human operators, and provides a natural and efficient way to fuse the human intelligence with the machine intelligence. The scheme is implemented and tested on a PUMA 560 dual-arm system. The experimental results of obstacle avoidance, hybrid force/position control with a commanded force as well as dual-arm coordinated teleoperation are presented.
{"title":"Function-based control sharing for robotic systems","authors":"T. Tarn, N. Xi, Chuanfan Guo, A. Bejczy","doi":"10.1109/IROS.1995.525853","DOIUrl":"https://doi.org/10.1109/IROS.1995.525853","url":null,"abstract":"A new function-based control sharing scheme for robotic systems has been developed based on the event-based planning and control theory. It provides a unified model to integrate a human operator control command with action planning and control of autonomous operation. As a result, the robotic systems can perform tasks which cannot be done by either human operator or autonomous planner/controller alone. This scheme lays down a foundation for planning and control of a general robotic system involving human operators, and provides a natural and efficient way to fuse the human intelligence with the machine intelligence. The scheme is implemented and tested on a PUMA 560 dual-arm system. The experimental results of obstacle avoidance, hybrid force/position control with a commanded force as well as dual-arm coordinated teleoperation are presented.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128567928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525862
A. Farahat, B. S. Graves, J. Trinkle
The efficiency of the automatic execution of complex assembly tasks can be enhanced by the identification of the contact state. In this paper we derive a new method for testing a hypothesized contact state using force sensing in the presence of sensing and control uncertainty. The hypothesized contact state is represented as a collection of elementary contacts. The feasibility of the elementary contacts is tested by solving a linear program. No knowledge of the contact pressure distribution or of the contact forces is required, so our method can be used even when the contact forces are statically indeterminate. We give a geometric interpretation of the contact identification problem using the theory of polyhedral convex cones. If more than one contact state is feasible, we use the geometric interpretation to determine the likelihood of each feasible contact formation.
{"title":"Identifying contact formations in the presence of uncertainty","authors":"A. Farahat, B. S. Graves, J. Trinkle","doi":"10.1109/IROS.1995.525862","DOIUrl":"https://doi.org/10.1109/IROS.1995.525862","url":null,"abstract":"The efficiency of the automatic execution of complex assembly tasks can be enhanced by the identification of the contact state. In this paper we derive a new method for testing a hypothesized contact state using force sensing in the presence of sensing and control uncertainty. The hypothesized contact state is represented as a collection of elementary contacts. The feasibility of the elementary contacts is tested by solving a linear program. No knowledge of the contact pressure distribution or of the contact forces is required, so our method can be used even when the contact forces are statically indeterminate. We give a geometric interpretation of the contact identification problem using the theory of polyhedral convex cones. If more than one contact state is feasible, we use the geometric interpretation to determine the likelihood of each feasible contact formation.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128601217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525833
R. Simmons, E. Krotkov, L. Chrisman, Fabio Gagliardi Cozman, R. Goodwin, M. Hebert, Lalitesh K. Katragadda, Sven Koenig, G. Krishnaswamy, Y. Shinoda, W. Whittaker, P. Klarer
Reliable navigation is critical for a lunar rover, both for autonomous traverses and safeguarded remote teleoperation. This paper describes an implemented system that has autonomously driven a prototype wheeled lunar rover over a kilometer in natural, outdoor terrain. The navigation system uses stereo terrain maps to perform local obstacle avoidance, and arbitrates steering recommendations from both the user and the rover. The paper describes the system architecture, each of the major components, and the experimental results to date.
{"title":"Experience with rover navigation for lunar-like terrains","authors":"R. Simmons, E. Krotkov, L. Chrisman, Fabio Gagliardi Cozman, R. Goodwin, M. Hebert, Lalitesh K. Katragadda, Sven Koenig, G. Krishnaswamy, Y. Shinoda, W. Whittaker, P. Klarer","doi":"10.1109/IROS.1995.525833","DOIUrl":"https://doi.org/10.1109/IROS.1995.525833","url":null,"abstract":"Reliable navigation is critical for a lunar rover, both for autonomous traverses and safeguarded remote teleoperation. This paper describes an implemented system that has autonomously driven a prototype wheeled lunar rover over a kilometer in natural, outdoor terrain. The navigation system uses stereo terrain maps to perform local obstacle avoidance, and arbitrates steering recommendations from both the user and the rover. The paper describes the system architecture, each of the major components, and the experimental results to date.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130711503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.526174
D. Kurabayashi, J. Ota, T. Arai, E. Yoshida
Proposes an algorithm of dividing a work area into small pieces in order to make multiple mobile robots cooperate efficiently. Searching of a whole work area is the most fundamental and the most essential task of mobile robots. The authors expect that the cost of searching is shared by cooperation of multiple robots. In the proposed algorithm, searching motions of robots are represented by paths. Both edges of the configuration space and the Voronoi diagram are introduced so as to compute paths in the whole area. The authors generate a tour of the paths to traverse all the paths using the algorithm of the Chinese postman problem. The cost is estimated as the total length of the paths. By means of the cost evaluation, the appropriate paths are assigned to each robot. The efficiency of the proposed algorithm is verified by simulations.
{"title":"An algorithm of dividing a work area to multiple mobile robots","authors":"D. Kurabayashi, J. Ota, T. Arai, E. Yoshida","doi":"10.1109/IROS.1995.526174","DOIUrl":"https://doi.org/10.1109/IROS.1995.526174","url":null,"abstract":"Proposes an algorithm of dividing a work area into small pieces in order to make multiple mobile robots cooperate efficiently. Searching of a whole work area is the most fundamental and the most essential task of mobile robots. The authors expect that the cost of searching is shared by cooperation of multiple robots. In the proposed algorithm, searching motions of robots are represented by paths. Both edges of the configuration space and the Voronoi diagram are introduced so as to compute paths in the whole area. The authors generate a tour of the paths to traverse all the paths using the algorithm of the Chinese postman problem. The cost is estimated as the total length of the paths. By means of the cost evaluation, the appropriate paths are assigned to each robot. The efficiency of the proposed algorithm is verified by simulations.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129274567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.525851
M. Hamerlain
This paper introduces a new actuator which is able to confer to the robot arm. The arm actuated by pneumatic artificial antagonistic muscles resembles the movements of the human arm. In this work the problem of the control of this actuator is considered via a variable structure algorithm, and a comparison with a classical PID control given. High robustness performances with respect to model errors, parameter variations, and quick responses are obtained. The paper presents an experimental study of the variable structure control applied to the actuator considered. The control performances considered include step response and tracking trajectory modes.
{"title":"An anthropomorphic robot arm driven by artificial muscles using a variable structure control","authors":"M. Hamerlain","doi":"10.1109/IROS.1995.525851","DOIUrl":"https://doi.org/10.1109/IROS.1995.525851","url":null,"abstract":"This paper introduces a new actuator which is able to confer to the robot arm. The arm actuated by pneumatic artificial antagonistic muscles resembles the movements of the human arm. In this work the problem of the control of this actuator is considered via a variable structure algorithm, and a comparison with a classical PID control given. High robustness performances with respect to model errors, parameter variations, and quick responses are obtained. The paper presents an experimental study of the variable structure control applied to the actuator considered. The control performances considered include step response and tracking trajectory modes.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126012604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-08-05DOI: 10.1109/IROS.1995.526267
Y. Kuwana, I. Shimoyama, H. Miura
A male silk moth (Bombyx mori) pursues a female by following a pheromone, called Bombycol. This action is caused by only a few molecules of pheromone which arrive at the antenna of a male silk moth. The antenna has very sharp sensitivity and specificity. In this paper, the use of a biological sensor is discussed as a new type of sensor, in other words "living sensors". The electrical activity of a silk moth antenna, called the electroantennogram (EAG) was obtained using self-made electrodes and amplifier. Two pheromone sensors were attached to a simple mobile robot to determine the direction of a pheromone trace. From this information, we were able to control the direction of the robot. The robot followed the pheromone trace just like a real male silk moth.
{"title":"Steering control of a mobile robot using insect antennae","authors":"Y. Kuwana, I. Shimoyama, H. Miura","doi":"10.1109/IROS.1995.526267","DOIUrl":"https://doi.org/10.1109/IROS.1995.526267","url":null,"abstract":"A male silk moth (Bombyx mori) pursues a female by following a pheromone, called Bombycol. This action is caused by only a few molecules of pheromone which arrive at the antenna of a male silk moth. The antenna has very sharp sensitivity and specificity. In this paper, the use of a biological sensor is discussed as a new type of sensor, in other words \"living sensors\". The electrical activity of a silk moth antenna, called the electroantennogram (EAG) was obtained using self-made electrodes and amplifier. Two pheromone sensors were attached to a simple mobile robot to determine the direction of a pheromone trace. From this information, we were able to control the direction of the robot. The robot followed the pheromone trace just like a real male silk moth.","PeriodicalId":124483,"journal":{"name":"Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126376856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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