Pub Date : 2013-10-17DOI: 10.1109/ICRA.2013.6631078
Hesuan Hu, Mengchu Zhou, Zhiwu Li
In the framework of automated manufacturing systems (AMS), Petri nets are widely used to model, analyze, and control them. Resolving deadlocks is of paramount significance because their emergence reduces the system throughput to zero. Supervisory control technique is the most widely adopted method to resolve them. A control policy can be converted into satisfying a set of inequalities, each of which corresponds to a siphon in a Petri net structure. The number of siphons can be exponential in the worst case, so does the number of inequalities. Taking into account the independent and dependent inequalities, this paper proposes a method to remove all the dependent inequalities while preserving only the independent ones. This method can significantly reduce the size of a supervisory controller. Examples are presented to illustrate the effectiveness and efficiency of this method.
{"title":"A novel method to simplify supervisor for AMS based on Petri nets and inequality analysis","authors":"Hesuan Hu, Mengchu Zhou, Zhiwu Li","doi":"10.1109/ICRA.2013.6631078","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6631078","url":null,"abstract":"In the framework of automated manufacturing systems (AMS), Petri nets are widely used to model, analyze, and control them. Resolving deadlocks is of paramount significance because their emergence reduces the system throughput to zero. Supervisory control technique is the most widely adopted method to resolve them. A control policy can be converted into satisfying a set of inequalities, each of which corresponds to a siphon in a Petri net structure. The number of siphons can be exponential in the worst case, so does the number of inequalities. Taking into account the independent and dependent inequalities, this paper proposes a method to remove all the dependent inequalities while preserving only the independent ones. This method can significantly reduce the size of a supervisory controller. Examples are presented to illustrate the effectiveness and efficiency of this method.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131478058","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 : 2013-10-17DOI: 10.1109/ICRA.2013.6631192
P. Donner, A. Mortl, S. Hirche, M. Buss
This paper investigates goal-directed cooperative object swinging as a novel physical human-robot interaction scenario. We develop an energy-based control concept, which enables a robot to cooperate with a human in a goal-directed swing-up task. The robot can be assigned to be a leader or an actively contributing follower. We conduct a virtual reality experiment to compare effort sharing and performance of mixed human-human and human-robot dyads. The leader and the follower controllers yield similar results compared to their human standard.
{"title":"Human-robot cooperative object swinging","authors":"P. Donner, A. Mortl, S. Hirche, M. Buss","doi":"10.1109/ICRA.2013.6631192","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6631192","url":null,"abstract":"This paper investigates goal-directed cooperative object swinging as a novel physical human-robot interaction scenario. We develop an energy-based control concept, which enables a robot to cooperate with a human in a goal-directed swing-up task. The robot can be assigned to be a leader or an actively contributing follower. We conduct a virtual reality experiment to compare effort sharing and performance of mixed human-human and human-robot dyads. The leader and the follower controllers yield similar results compared to their human standard.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"159 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132016926","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 : 2013-10-17DOI: 10.1109/ICRA.2013.6631286
Emmanouil Spyrakos-Papastavridis, G. Medrano-Cerda, N. Tsagarakis, J. Dai, D. Caldwell
This paper presents a sufficient condition to establish the existence of unique equilibrium points for three types of gravity compensation controller when applied to over-actuated systems. As compared to the existing work, this paper extends the current theory by introducing feedback gain matrices that are not constrained to being diagonal and positive definite. The inherently COmpliant huMANoid (COMAN) served as a platform for the validation of the designed gravity compensation controller that employed reference link positions. The displayed experimental results provide evidence of successful link tracking of sinusoidal references on a humanoid system composed of series elastic actuators.
{"title":"Gravity compensation control of compliant joint systems with multiple drives","authors":"Emmanouil Spyrakos-Papastavridis, G. Medrano-Cerda, N. Tsagarakis, J. Dai, D. Caldwell","doi":"10.1109/ICRA.2013.6631286","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6631286","url":null,"abstract":"This paper presents a sufficient condition to establish the existence of unique equilibrium points for three types of gravity compensation controller when applied to over-actuated systems. As compared to the existing work, this paper extends the current theory by introducing feedback gain matrices that are not constrained to being diagonal and positive definite. The inherently COmpliant huMANoid (COMAN) served as a platform for the validation of the designed gravity compensation controller that employed reference link positions. The displayed experimental results provide evidence of successful link tracking of sinusoidal references on a humanoid system composed of series elastic actuators.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132116733","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 : 2013-10-17DOI: 10.1109/ICRA.2013.6630767
X. Hou, R. Mahony, F. Schill
This paper considers the question of providing effective feedback of vehicle dynamic forces to a pilot in haptic teleoperation of aerial robots. We claim that the usual state-of-the-art haptic interface, based on research motivated by robotic manipulator slaves and virtual haptic environments, does a poor job of reflecting dynamic forces of a mobile robotic vehicle to the user. This leads us to propose a novel force feedback user interface for mobile robotic vehicles with dynamics. An analysis of the closed-loop force-displacement transfer functions experienced by the master joystick for the classical and the new approach clearly indicate the advantages of the proposed formulation. Both the classical and the proposed approach have been implemented in the teleoperation of a quadrotor vehicle and we present quantitative and cognitive performance data from a user study that corroborates the expected performance advantages.
{"title":"Representation of vehicle dynamics in haptic teleoperation of aerial robots","authors":"X. Hou, R. Mahony, F. Schill","doi":"10.1109/ICRA.2013.6630767","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6630767","url":null,"abstract":"This paper considers the question of providing effective feedback of vehicle dynamic forces to a pilot in haptic teleoperation of aerial robots. We claim that the usual state-of-the-art haptic interface, based on research motivated by robotic manipulator slaves and virtual haptic environments, does a poor job of reflecting dynamic forces of a mobile robotic vehicle to the user. This leads us to propose a novel force feedback user interface for mobile robotic vehicles with dynamics. An analysis of the closed-loop force-displacement transfer functions experienced by the master joystick for the classical and the new approach clearly indicate the advantages of the proposed formulation. Both the classical and the proposed approach have been implemented in the teleoperation of a quadrotor vehicle and we present quantitative and cognitive performance data from a user study that corroborates the expected performance advantages.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123144900","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 : 2013-10-17DOI: 10.1109/ICRA.2013.6631254
Tianyu Yang, Baopu Li, Chao Hu, M. Meng
This paper introduces a novel tracking framework for robots that can adapt various appearance changes of object and also owns the ability of reacquisition after drift. Two classifiers, LaRank and Online Random Ferns, are adopted to realize this tracking algorithm. The former one maintains the adaptive tracking using a Condensation-based method with an online support vector machine (SVM) as observation model, which also provides the reliable image patch samples to detector for updating. The other one is in charge of the task of detection in order to redetect the object when the target drifts. We also present a refinement strategy to improve the tracker's performance by discarding the support vector corresponding to possible wrong updates by a matching template after re-initialization. The experiments on benchmark dataset compare our tracking method with several other state-of-the-art algorithms, demonstrating a promising performance of the proposed framework.
{"title":"Adaptive visual tracking with reacquisition ability for arbitrary objects","authors":"Tianyu Yang, Baopu Li, Chao Hu, M. Meng","doi":"10.1109/ICRA.2013.6631254","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6631254","url":null,"abstract":"This paper introduces a novel tracking framework for robots that can adapt various appearance changes of object and also owns the ability of reacquisition after drift. Two classifiers, LaRank and Online Random Ferns, are adopted to realize this tracking algorithm. The former one maintains the adaptive tracking using a Condensation-based method with an online support vector machine (SVM) as observation model, which also provides the reliable image patch samples to detector for updating. The other one is in charge of the task of detection in order to redetect the object when the target drifts. We also present a refinement strategy to improve the tracker's performance by discarding the support vector corresponding to possible wrong updates by a matching template after re-initialization. The experiments on benchmark dataset compare our tracking method with several other state-of-the-art algorithms, demonstrating a promising performance of the proposed framework.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126979238","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 : 2013-10-09DOI: 10.1109/ICRA.2013.6630956
M. Ciocarlie, F. Hicks, S. Stanford
We design, optimize and demonstrate the behavior of a tendon-driven robotic gripper performing fingertip and enveloping grasps. The gripper consists of two fingers, each with two links, and is actuated using a single active tendon. During unobstructed closing, the distal links remain parallel, creating exact fingertip grasps. Conversely, if the proximal links are stopped by contact with an object, the distal links start flexing, creating a stable enveloping grasp. We optimize the route of the active tendon and the parameters of the springs providing passive extension forces in order to achieve this behavior. We show how an additional passive tendon can be used as a constraint preventing the gripper from entering undesirable parts of the joint workspace. Finally, we introduce a method for optimizing the dimensions of the links in order to achieve enveloping grasps of a large range of objects, and apply it to a set of common household objects.
{"title":"Kinetic and dimensional optimization for a tendon-driven gripper","authors":"M. Ciocarlie, F. Hicks, S. Stanford","doi":"10.1109/ICRA.2013.6630956","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6630956","url":null,"abstract":"We design, optimize and demonstrate the behavior of a tendon-driven robotic gripper performing fingertip and enveloping grasps. The gripper consists of two fingers, each with two links, and is actuated using a single active tendon. During unobstructed closing, the distal links remain parallel, creating exact fingertip grasps. Conversely, if the proximal links are stopped by contact with an object, the distal links start flexing, creating a stable enveloping grasp. We optimize the route of the active tendon and the parameters of the springs providing passive extension forces in order to achieve this behavior. We show how an additional passive tendon can be used as a constraint preventing the gripper from entering undesirable parts of the joint workspace. Finally, we introduce a method for optimizing the dimensions of the links in order to achieve enveloping grasps of a large range of objects, and apply it to a set of common household objects.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127953019","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 : 2013-05-06DOI: 10.1109/ICRA.2013.6630748
Takahiro Matsuno, A. Kakogawa, Shugen Ma
This paper presents a new suction cup with a disc spring for exiting adsorption mechanisms (for example, wall-climbing robots). The center of the suction cup can be pulled up manually through the use of buckling of the disc spring. When deformation of the disc spring reaches a certain balance point, it can sufficiently generate adsorption force. However, with time, the adsorption force will gradually decrease because of air inflow into the suction cup. Then, the spring can be automatically pulled up again to next balance point according to the air inflow. Repeating this process enables the adsorption for a long duration. By pushing back the disc spring to the original position manually, the suction cup is easily detached from the wall. This proposed suction cup can achieve long adsorption, easy attachment and detachment, and energy saving. In this paper, analysis of the adsorption force, design of the suction cup, and experiment of the prototype are conducted.
{"title":"Development of a suction cup with a disc spring","authors":"Takahiro Matsuno, A. Kakogawa, Shugen Ma","doi":"10.1109/ICRA.2013.6630748","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6630748","url":null,"abstract":"This paper presents a new suction cup with a disc spring for exiting adsorption mechanisms (for example, wall-climbing robots). The center of the suction cup can be pulled up manually through the use of buckling of the disc spring. When deformation of the disc spring reaches a certain balance point, it can sufficiently generate adsorption force. However, with time, the adsorption force will gradually decrease because of air inflow into the suction cup. Then, the spring can be automatically pulled up again to next balance point according to the air inflow. Repeating this process enables the adsorption for a long duration. By pushing back the disc spring to the original position manually, the suction cup is easily detached from the wall. This proposed suction cup can achieve long adsorption, easy attachment and detachment, and energy saving. In this paper, analysis of the adsorption force, design of the suction cup, and experiment of the prototype are conducted.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115710877","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 : 2013-05-06DOI: 10.1109/ICRA.2013.6630886
J. Delmerico, D. Baran, P. David, J. Ryde, Jason J. Corso
Localization and modeling of stairways by mobile robots can enable multi-floor exploration for those platforms capable of stair traversal. Existing approaches focus on either stairway detection or traversal, but do not address these problems in the context of path planning for the autonomous exploration of multi-floor buildings. We propose a system for detecting and modeling ascending stairways while performing simultaneous localization and mapping, such that the traversability of each stairway can be assessed by estimating its physical properties. The long-term objective of our approach is to enable exploration of multiple floors of a building by allowing stairways to be considered during path planning as traversable portals to new frontiers. We design a generative model of a stairway as a single object. We localize these models with respect to the map, and estimate the dimensions of the stairway as a whole, as well as its steps. With these estimates, a robot can determine if the stairway is traversable based on its climbing capabilities. Our system consists of two parts: a computationally efficient detector that leverages geometric cues from dense depth imagery to detect sets of ascending stairs, and a stairway modeler that uses multiple detections to infer the location and parameters of a stairway that is discovered during exploration. We demonstrate the performance of this system when deployed on several mobile platforms using a Microsoft Kinect sensor.
{"title":"Ascending stairway modeling from dense depth imagery for traversability analysis","authors":"J. Delmerico, D. Baran, P. David, J. Ryde, Jason J. Corso","doi":"10.1109/ICRA.2013.6630886","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6630886","url":null,"abstract":"Localization and modeling of stairways by mobile robots can enable multi-floor exploration for those platforms capable of stair traversal. Existing approaches focus on either stairway detection or traversal, but do not address these problems in the context of path planning for the autonomous exploration of multi-floor buildings. We propose a system for detecting and modeling ascending stairways while performing simultaneous localization and mapping, such that the traversability of each stairway can be assessed by estimating its physical properties. The long-term objective of our approach is to enable exploration of multiple floors of a building by allowing stairways to be considered during path planning as traversable portals to new frontiers. We design a generative model of a stairway as a single object. We localize these models with respect to the map, and estimate the dimensions of the stairway as a whole, as well as its steps. With these estimates, a robot can determine if the stairway is traversable based on its climbing capabilities. Our system consists of two parts: a computationally efficient detector that leverages geometric cues from dense depth imagery to detect sets of ascending stairs, and a stairway modeler that uses multiple detections to infer the location and parameters of a stairway that is discovered during exploration. We demonstrate the performance of this system when deployed on several mobile platforms using a Microsoft Kinect sensor.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124462418","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 : 2013-05-06DOI: 10.1109/ICRA.2013.6630627
Moises Pacheco, M. Moghadam, A. Magnusson, B. Silverman, H. Lund, D. Christensen
We are developing the Fable modular robotic system as a playware platform that will enable non-expert users to develop robots ranging from advanced robotic toys to robotic solutions to problems encountered in their daily lives. This paper presents the mechanical design of Fable: a chain-based system composed of reconfigurable heterogeneous modules with a reliable and scalable connector. Furthermore, this paper describes tests where the connector design is tested with children, and presents examples of a moving snake and a quadruped robot, as well as an interactive upper humanoid torso.
{"title":"Fable: Design of a modular robotic playware platform","authors":"Moises Pacheco, M. Moghadam, A. Magnusson, B. Silverman, H. Lund, D. Christensen","doi":"10.1109/ICRA.2013.6630627","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6630627","url":null,"abstract":"We are developing the Fable modular robotic system as a playware platform that will enable non-expert users to develop robots ranging from advanced robotic toys to robotic solutions to problems encountered in their daily lives. This paper presents the mechanical design of Fable: a chain-based system composed of reconfigurable heterogeneous modules with a reliable and scalable connector. Furthermore, this paper describes tests where the connector design is tested with children, and presents examples of a moving snake and a quadruped robot, as well as an interactive upper humanoid torso.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123167488","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 : 2013-05-06DOI: 10.1109/ICRA.2013.6630747
J. D. Dickson, Jigar L. Patel, Jonathan E. Clark
Dynamic climbing robots have shown vertical speeds that approach those of the fastest climbing animals, but to date, no work has been conducted on directional control or maneuverability while climbing for these platforms. Directional control in animals during high-speed terrestrial running utilizes altered leg kinematics and leg specialization, however, little work has been done to classify biological strategies for maneuverability in the scansorial regime. To gain insight on how alterations of leg kinematics effect maneuverability during high-speed climbing, we propose three methods for directional control and implement them on a high-speed, dynamic climbing robotic platform. These methods alter the leg kinematics of the platform through asymmetrically changing the foot placement, center of mass, and leg length. We show that heading angles of up to 37° off of vertical are possible while only decreasing the vertical ascension rate by 20%.
{"title":"Towards maneuverability in plane with a dynamic climbing platform","authors":"J. D. Dickson, Jigar L. Patel, Jonathan E. Clark","doi":"10.1109/ICRA.2013.6630747","DOIUrl":"https://doi.org/10.1109/ICRA.2013.6630747","url":null,"abstract":"Dynamic climbing robots have shown vertical speeds that approach those of the fastest climbing animals, but to date, no work has been conducted on directional control or maneuverability while climbing for these platforms. Directional control in animals during high-speed terrestrial running utilizes altered leg kinematics and leg specialization, however, little work has been done to classify biological strategies for maneuverability in the scansorial regime. To gain insight on how alterations of leg kinematics effect maneuverability during high-speed climbing, we propose three methods for directional control and implement them on a high-speed, dynamic climbing robotic platform. These methods alter the leg kinematics of the platform through asymmetrically changing the foot placement, center of mass, and leg length. We show that heading angles of up to 37° off of vertical are possible while only decreasing the vertical ascension rate by 20%.","PeriodicalId":259746,"journal":{"name":"2013 IEEE International Conference on Robotics and Automation","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116954027","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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