Pub Date : 1994-09-12DOI: 10.1109/IROS.1994.407401
H. Terasaki, T. Hasegawa
Humans have numerous manipulation skills which they can intelligently combine to execute tasks. The authors have developed motion planning systems for intelligent manipulations using parallel two-fingered grippers. They propose a new method to integrate these motion planning systems. The basic idea of this method is the state-space approach which is described in states and operators and solves problems by searching state-space from initial state to goal state. The operators correspond to the primitive manipulation skills and transform a state into another state. This method was applied to a manipulator equipped with a parallel two-fingered gripper. The key idea behind this application is to augment the handling ability of a parallel two-fingered gripper, instead of developing a difficult and complicated control method that uses a sophisticated but weak multifingered gripper. To actually implement this idea, we have developed a new, small and simple mechanism attached to a parallel two-fingered gripper.<>
{"title":"Motion planning for intelligent manipulations by sliding and rotating operations with parallel two-fingered grippers","authors":"H. Terasaki, T. Hasegawa","doi":"10.1109/IROS.1994.407401","DOIUrl":"https://doi.org/10.1109/IROS.1994.407401","url":null,"abstract":"Humans have numerous manipulation skills which they can intelligently combine to execute tasks. The authors have developed motion planning systems for intelligent manipulations using parallel two-fingered grippers. They propose a new method to integrate these motion planning systems. The basic idea of this method is the state-space approach which is described in states and operators and solves problems by searching state-space from initial state to goal state. The operators correspond to the primitive manipulation skills and transform a state into another state. This method was applied to a manipulator equipped with a parallel two-fingered gripper. The key idea behind this application is to augment the handling ability of a parallel two-fingered gripper, instead of developing a difficult and complicated control method that uses a sophisticated but weak multifingered gripper. To actually implement this idea, we have developed a new, small and simple mechanism attached to a parallel two-fingered gripper.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131374598","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 : 1994-09-12DOI: 10.1109/IROS.1994.407395
Gregory Hager, G. Grunwald, G. Hirzinger
Advances in visual servoing theory and practice now make it possible to accurately and robustly position a robot manipulator relative to a target. Both the vision and control algorithms are extremely simple, however they must be initialized on task-relevant features in order to be applied. Consequently, they are particularly well-suited to telerobotics systems where an operator can initialize the system but round-trip delay prohibits direct operator feedback during motion. This paper describes the basic theory behind feature-based visual servoing, and discusses the issues involved in integrating visual servoing into the ROTEX space teleoperation system.<>
{"title":"Feature-based visual servoing and its application to telerobotics","authors":"Gregory Hager, G. Grunwald, G. Hirzinger","doi":"10.1109/IROS.1994.407395","DOIUrl":"https://doi.org/10.1109/IROS.1994.407395","url":null,"abstract":"Advances in visual servoing theory and practice now make it possible to accurately and robustly position a robot manipulator relative to a target. Both the vision and control algorithms are extremely simple, however they must be initialized on task-relevant features in order to be applied. Consequently, they are particularly well-suited to telerobotics systems where an operator can initialize the system but round-trip delay prohibits direct operator feedback during motion. This paper describes the basic theory behind feature-based visual servoing, and discusses the issues involved in integrating visual servoing into the ROTEX space teleoperation system.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131877954","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 : 1994-09-12DOI: 10.1109/IROS.1994.407505
F. Cheng, Rong-Jing Sheu, Tsing-Hua Chen
The compact QP method is an effective and efficient algorithm for resolving the manipulator redundancy under inequality constraints. In this paper, a more computationally efficient scheme which will improve the efficiency of the compact QP method-the improved compact QP method -is developed. With the technique of workspace decomposition, the redundant inverse kinematics problem can be decomposed into two subproblems. Thus, the size of the redundancy problem can be reduced. For an n degree-of-freedom spatial redundant manipulator, instead of a 6/spl times/n matrix, only a 3/spl times/(n-3) matrix is needed to be manipulated by Gaussian elimination with partial pivoting for selecting the free variables. The simulation results on the CESAR manipulator indicate that the speedup of the compact QP method as compared with the original QP method is about 4.3. Furthermore, the speedup of the improved compact QP method is about 5.6. Therefore, it is believed that the improved compact QP method is one of the most efficient and effective optimization algorithm for resolving the manipulator redundancy under inequality constraints.<>
{"title":"The improved compact QP method for resolving manipulator redundancy","authors":"F. Cheng, Rong-Jing Sheu, Tsing-Hua Chen","doi":"10.1109/IROS.1994.407505","DOIUrl":"https://doi.org/10.1109/IROS.1994.407505","url":null,"abstract":"The compact QP method is an effective and efficient algorithm for resolving the manipulator redundancy under inequality constraints. In this paper, a more computationally efficient scheme which will improve the efficiency of the compact QP method-the improved compact QP method -is developed. With the technique of workspace decomposition, the redundant inverse kinematics problem can be decomposed into two subproblems. Thus, the size of the redundancy problem can be reduced. For an n degree-of-freedom spatial redundant manipulator, instead of a 6/spl times/n matrix, only a 3/spl times/(n-3) matrix is needed to be manipulated by Gaussian elimination with partial pivoting for selecting the free variables. The simulation results on the CESAR manipulator indicate that the speedup of the compact QP method as compared with the original QP method is about 4.3. Furthermore, the speedup of the improved compact QP method is about 5.6. Therefore, it is believed that the improved compact QP method is one of the most efficient and effective optimization algorithm for resolving the manipulator redundancy under inequality constraints.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133733759","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 : 1994-09-12DOI: 10.1109/IROS.1994.407509
E. Prassler, E. Milios
An approach to motion planning amongst arbitrarily moving unknown objects is presented. As opposed to other approaches to motion planning we avoid the assumption that the motion parameters and the shape of moving objects are known a priori or can be predicted over longer time intervals. By giving up this assumption, traditional methods such as space-time representation and search in space-time no longer apply. Our approach is based on a massively parallel network of simple processing elements. A relaxation process, which is driven by the simultaneous execution of a simple formula in these processing elements, creates a two-dimensional distribution of real numbers, denoted as potentials, which encodes information about collision-free trajectories. Our approach is different from classical algorithmic motion planning in that we do not employ an analytical planning or search algorithm. Instead, desired behaviors, such as the avoidance of moving objects, are achieved through adroit manipulation of the two-dimensional potential distribution.<>
{"title":"Motion planning amongst arbitrarily moving unknown objects","authors":"E. Prassler, E. Milios","doi":"10.1109/IROS.1994.407509","DOIUrl":"https://doi.org/10.1109/IROS.1994.407509","url":null,"abstract":"An approach to motion planning amongst arbitrarily moving unknown objects is presented. As opposed to other approaches to motion planning we avoid the assumption that the motion parameters and the shape of moving objects are known a priori or can be predicted over longer time intervals. By giving up this assumption, traditional methods such as space-time representation and search in space-time no longer apply. Our approach is based on a massively parallel network of simple processing elements. A relaxation process, which is driven by the simultaneous execution of a simple formula in these processing elements, creates a two-dimensional distribution of real numbers, denoted as potentials, which encodes information about collision-free trajectories. Our approach is different from classical algorithmic motion planning in that we do not employ an analytical planning or search algorithm. Instead, desired behaviors, such as the avoidance of moving objects, are achieved through adroit manipulation of the two-dimensional potential distribution.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130602851","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 : 1994-09-12DOI: 10.1109/IROS.1994.407655
M. Rude
Crossings represent a classical example for the conflict regions of mobile robot systems. Two robots in a crossing situation are considered where the priorities and sequences of passing have been determined beforehand. Communication and sensing are regarded as an ideal combination of data sources for the collision avoidance control process. Nevertheless, in this case, temporal uncertainties have to be considered in parallel to the spatial uncertainty of sensing and localisation. The event transformation into the local space-time coordinate frame of a robot is introduced as a major element of the iterative process to reduce the sources of uncertainty. This transform is the basic part of the collision avoidance control procedure.<>
{"title":"Cooperation of mobile robots by event transforms into local space-time","authors":"M. Rude","doi":"10.1109/IROS.1994.407655","DOIUrl":"https://doi.org/10.1109/IROS.1994.407655","url":null,"abstract":"Crossings represent a classical example for the conflict regions of mobile robot systems. Two robots in a crossing situation are considered where the priorities and sequences of passing have been determined beforehand. Communication and sensing are regarded as an ideal combination of data sources for the collision avoidance control process. Nevertheless, in this case, temporal uncertainties have to be considered in parallel to the spatial uncertainty of sensing and localisation. The event transformation into the local space-time coordinate frame of a robot is introduced as a major element of the iterative process to reduce the sources of uncertainty. This transform is the basic part of the collision avoidance control procedure.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"453 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115619823","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 : 1994-09-12DOI: 10.1109/IROS.1994.407548
H. Osumi, T. Arai
This paper proposes a strategy for handling a single object by cooperation of multiple robots controlled by PID position controllers. Since such a cooperative system has mechanical closed loops, installation of free joints or flexibility among robots is necessary to avoid excessive inner forces caused by the positioning error of each robot. First, the essential kinematic conditions to achieve the cooperation among position-controlled robots are shown. Second, the relationship between the positioning error of the handling object and that of each robot is analyzed. Finally, a mechanism for the cooperation of three mobile robots is proposed and its kinematic characteristics and statics are analyzed. The strategy proposed here is very effective and practical for cooperation of not only conventional industrial robots but also distributed autonomous mobile robot systems with non-holonomic constraints.<>
{"title":"Design of mechanisms for cooperation among multiple position-controlled robots","authors":"H. Osumi, T. Arai","doi":"10.1109/IROS.1994.407548","DOIUrl":"https://doi.org/10.1109/IROS.1994.407548","url":null,"abstract":"This paper proposes a strategy for handling a single object by cooperation of multiple robots controlled by PID position controllers. Since such a cooperative system has mechanical closed loops, installation of free joints or flexibility among robots is necessary to avoid excessive inner forces caused by the positioning error of each robot. First, the essential kinematic conditions to achieve the cooperation among position-controlled robots are shown. Second, the relationship between the positioning error of the handling object and that of each robot is analyzed. Finally, a mechanism for the cooperation of three mobile robots is proposed and its kinematic characteristics and statics are analyzed. The strategy proposed here is very effective and practical for cooperation of not only conventional industrial robots but also distributed autonomous mobile robot systems with non-holonomic constraints.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115878759","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 : 1994-09-12DOI: 10.1109/IROS.1994.407362
I. Suh, K. Eom, H. Yeo, B. Kang, Sang-Rok Oh, B. Lee
In this paper, a fuzzy force control algorithm is suggested for commercialized industrial robots equipped with the position servo drives, where control rules of the proposed fuzzy controller are changed according to the magnitude of environmental stiffness in such a way that good force response is maintained regardless of changes of environmental stiffness. Specifically, some fuzzy control rules are designed for several representative environmental stiffness values, and then a control action for a given arbitrary environmental stiffness value is decided by a fuzzy interpolation method. To show the validity of the proposed fuzzy controller, several experimental results are illustrated, where a 5-axis articulated robot manipulator equipped with the wrist force/torque sensor system and our prototype dual robot controller are employed.<>
{"title":"Explicit fuzzy force control of industrial manipulators with position servo drives","authors":"I. Suh, K. Eom, H. Yeo, B. Kang, Sang-Rok Oh, B. Lee","doi":"10.1109/IROS.1994.407362","DOIUrl":"https://doi.org/10.1109/IROS.1994.407362","url":null,"abstract":"In this paper, a fuzzy force control algorithm is suggested for commercialized industrial robots equipped with the position servo drives, where control rules of the proposed fuzzy controller are changed according to the magnitude of environmental stiffness in such a way that good force response is maintained regardless of changes of environmental stiffness. Specifically, some fuzzy control rules are designed for several representative environmental stiffness values, and then a control action for a given arbitrary environmental stiffness value is decided by a fuzzy interpolation method. To show the validity of the proposed fuzzy controller, several experimental results are illustrated, where a 5-axis articulated robot manipulator equipped with the wrist force/torque sensor system and our prototype dual robot controller are employed.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124159030","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 : 1994-09-12DOI: 10.1109/IROS.1994.407379
M. Knick, C. Schlegel
In the autonomous mobile systems project (AMOS), the FAW uses a mobile robot to study questions related to the deep integration of sub-symbolic and symbolic information processing. AMOS aims at methods for autonomously acquiring new concepts via induction from its interaction with its environment. This paper presents an architecture which integrates both symbolic planning as well as nonsymbolic reactive mechanisms, thus providing a basic autonomy, so that the robot can freely maneuver around without any detailed model of itself and its complex real-world environment . Substantial differences between expectation and observation are used as hints-generated via the robot's interaction with the environment-to situations which are of relevance for the robot. In particular, the concepts of plan breakdown and region of interest play a fundamental role. Autonomously, based on the robot's decision, images are taken and clustered without supervision into groups which are expected to correspond to semantically similar situations. These hypotheses shall be used in further work as a necessary pre-requisite in order to autonomously generate a new concept relating the recognition of such perception classes to appropriate actions.<>
{"title":"AMOS; active perception of an autonomous system","authors":"M. Knick, C. Schlegel","doi":"10.1109/IROS.1994.407379","DOIUrl":"https://doi.org/10.1109/IROS.1994.407379","url":null,"abstract":"In the autonomous mobile systems project (AMOS), the FAW uses a mobile robot to study questions related to the deep integration of sub-symbolic and symbolic information processing. AMOS aims at methods for autonomously acquiring new concepts via induction from its interaction with its environment. This paper presents an architecture which integrates both symbolic planning as well as nonsymbolic reactive mechanisms, thus providing a basic autonomy, so that the robot can freely maneuver around without any detailed model of itself and its complex real-world environment . Substantial differences between expectation and observation are used as hints-generated via the robot's interaction with the environment-to situations which are of relevance for the robot. In particular, the concepts of plan breakdown and region of interest play a fundamental role. Autonomously, based on the robot's decision, images are taken and clustered without supervision into groups which are expected to correspond to semantically similar situations. These hypotheses shall be used in further work as a necessary pre-requisite in order to autonomously generate a new concept relating the recognition of such perception classes to appropriate actions.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124278269","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 : 1994-09-12DOI: 10.1109/IROS.1994.407425
M. Stein, C. Sayers, R. Paul
The teleprogramming system employs a supervisory control approach where operator interaction with a virtual environment directs the actions of a remote manipulator operating semi-autonomously. We focus on the detection, diagnosis, and recovery from unexpected situations frequently arising during normal operation. The teleprogramming system employs a single thread approach to error recovery that is inherent in the system design. We perform two experimental tasks, each highlighting a different role for the operator, using the teleprogramming system with a simulated communication time delay of 10 seconds. In the first task of inserting and extracting bolts, the operator assumes the role of "task level reasoning" or task planning and sequencing, task state reasoning, and diagnostic procedure generation. In the second task, puncturing and slicing duct tape, the operator performs "action level reasoning" or diagnosing and correcting unexpected situations and determining success of actions. Our experimental results indicate that complex tasks can be accomplished when the operator is provided multiple and overlapping forms of feedback.<>
{"title":"The recovery from task execution errors during time delayed teleoperation","authors":"M. Stein, C. Sayers, R. Paul","doi":"10.1109/IROS.1994.407425","DOIUrl":"https://doi.org/10.1109/IROS.1994.407425","url":null,"abstract":"The teleprogramming system employs a supervisory control approach where operator interaction with a virtual environment directs the actions of a remote manipulator operating semi-autonomously. We focus on the detection, diagnosis, and recovery from unexpected situations frequently arising during normal operation. The teleprogramming system employs a single thread approach to error recovery that is inherent in the system design. We perform two experimental tasks, each highlighting a different role for the operator, using the teleprogramming system with a simulated communication time delay of 10 seconds. In the first task of inserting and extracting bolts, the operator assumes the role of \"task level reasoning\" or task planning and sequencing, task state reasoning, and diagnostic procedure generation. In the second task, puncturing and slicing duct tape, the operator performs \"action level reasoning\" or diagnosing and correcting unexpected situations and determining success of actions. Our experimental results indicate that complex tasks can be accomplished when the operator is provided multiple and overlapping forms of feedback.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"1 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124295054","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 : 1994-09-12DOI: 10.1109/IROS.1994.407650
R. Hui
In previous works on modeling of space manipulators, the satellite base or spacecraft is assumed to be at one end of the chain and the robot end-effector at the other. In this paper, a general model allowing any link on a floating kinematic chain to be either the spacecraft or the end-effector is developed and characterized. Properties discovered in the past about space manipulators are generalized to these systems with "non-specific" reference links.<>
{"title":"Analysis of space manipulators with non-specific reference links","authors":"R. Hui","doi":"10.1109/IROS.1994.407650","DOIUrl":"https://doi.org/10.1109/IROS.1994.407650","url":null,"abstract":"In previous works on modeling of space manipulators, the satellite base or spacecraft is assumed to be at one end of the chain and the robot end-effector at the other. In this paper, a general model allowing any link on a floating kinematic chain to be either the spacecraft or the end-effector is developed and characterized. Properties discovered in the past about space manipulators are generalized to these systems with \"non-specific\" reference links.<<ETX>>","PeriodicalId":437805,"journal":{"name":"Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'94)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114884316","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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