Mulin Luo, Qingsong He, Xue-li Han, Yongxu Li, Hui Jin
In this paper, a new type of variable stiffness joint is proposed, which uses spring as elastic element, gear rack and special-shaped shell as stiffness adjusting mechanism, and is applied to industrial robot. The stiffness adjustment characteristics of variable stiffness joints are studied. The dynamic model of the joint system is established. The correctness of the dynamic model is verified by MATLAB/Simulink simulation experiment. The relationship between the stiffness of the variable stiffness joint and the rotation angle of the mechanism, the relationship between the stiffness of the joint and the angular velocity, the input response of the joint system in different states, and the torque state of the joint output are studied, which provides a theoretical basis for the research of the variable stiffness joint in the future.
{"title":"Dynamic characteristics analysis of a new variable stiffness robot joint","authors":"Mulin Luo, Qingsong He, Xue-li Han, Yongxu Li, Hui Jin","doi":"10.1145/3483845.3483853","DOIUrl":"https://doi.org/10.1145/3483845.3483853","url":null,"abstract":"In this paper, a new type of variable stiffness joint is proposed, which uses spring as elastic element, gear rack and special-shaped shell as stiffness adjusting mechanism, and is applied to industrial robot. The stiffness adjustment characteristics of variable stiffness joints are studied. The dynamic model of the joint system is established. The correctness of the dynamic model is verified by MATLAB/Simulink simulation experiment. The relationship between the stiffness of the variable stiffness joint and the rotation angle of the mechanism, the relationship between the stiffness of the joint and the angular velocity, the input response of the joint system in different states, and the torque state of the joint output are studied, which provides a theoretical basis for the research of the variable stiffness joint in the future.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"673 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113994393","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}
It is necessary for humanoid robots to have the capability of human-like social environment perception, which could enable robots to interact with people intelligently. In order to improve the interaction capability of humanoid robots in complex and changeable social environments, an interactive intention prediction model(IIPM) is proposed, which can quantitatively predict the intensity of interactive intention by the visual features of face orientation, social distance and facial expression in the actual social environment. Based on this model, humanoid robots can make autonomous decisions and select interactive person to carry out interactive tasks reasonably. Finally, the prediction accuracy of the IIPM is proved by single-person and multi-person experiments, which provides an effective and accurate solution for natural human-robot interaction (HRI).
{"title":"Interactive Intention Prediction Model for Humanoid Robot Based on Visual Features","authors":"Jian Bi, Miao He, Mingnan Luo, Fangchao Hu","doi":"10.1145/3483845.3483852","DOIUrl":"https://doi.org/10.1145/3483845.3483852","url":null,"abstract":"It is necessary for humanoid robots to have the capability of human-like social environment perception, which could enable robots to interact with people intelligently. In order to improve the interaction capability of humanoid robots in complex and changeable social environments, an interactive intention prediction model(IIPM) is proposed, which can quantitatively predict the intensity of interactive intention by the visual features of face orientation, social distance and facial expression in the actual social environment. Based on this model, humanoid robots can make autonomous decisions and select interactive person to carry out interactive tasks reasonably. Finally, the prediction accuracy of the IIPM is proved by single-person and multi-person experiments, which provides an effective and accurate solution for natural human-robot interaction (HRI).","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114317844","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}
Based on how to predict the core functions of the antecedent and the afterword belongs to the adjacency pairs according to different speaker's turn in the process of dialogue, So as to achieve overall control of the dialogue process, The core function prediction model based on BERT-BIGRU-CRF is put forward. The inputs of the model are the different turns of the conversationalist, Firstly, the model used BERT get sentence of vectorization, then it is input into BIGRU to make the two directional encoding, Finally, CRF is used to form the mark of its core function and the output of core function by S, R, Q, A and DO adjacent is completed. Experiments show that this prediction method has better performance than the previous sequential labeling model and its accuracy and F1 score are significantly improved.
{"title":"Research on Core Function of Adjacency Pairs Prediction Based on BERT-BIGRU-CRF∗","authors":"Xin Chen, Zhanzhi Qiu","doi":"10.1145/3483845.3483866","DOIUrl":"https://doi.org/10.1145/3483845.3483866","url":null,"abstract":"Based on how to predict the core functions of the antecedent and the afterword belongs to the adjacency pairs according to different speaker's turn in the process of dialogue, So as to achieve overall control of the dialogue process, The core function prediction model based on BERT-BIGRU-CRF is put forward. The inputs of the model are the different turns of the conversationalist, Firstly, the model used BERT get sentence of vectorization, then it is input into BIGRU to make the two directional encoding, Finally, CRF is used to form the mark of its core function and the output of core function by S, R, Q, A and DO adjacent is completed. Experiments show that this prediction method has better performance than the previous sequential labeling model and its accuracy and F1 score are significantly improved.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122543362","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}
Chang Yuan, S. Bi, Lin Chen, Chang Liu, Jun Cheng, Yueri Cai
∗In view of the great danger of manual emergency repair of oil and gas pipeline, we utilized an unmanned equipment (namely a robot) to replace manual operation. While the robot doing the pipeline repair work at the accident site, the staff operates the robot remotely outside the dangerous zone. In the work described in this paper, a 3D environment perception system is developed, a 2D LiDAR is assembled on a rotating unit driven by a stepper motor. While the 2D LiDAR is rotated, it collects data continuously. The 3D point clouds are calculated by combining the return data of the 2D LiDAR and the rotation angle of the rotating unit. This costumed 3D laser scanner is mounted on the robot to sense the 3D outline of the environment of the accident site. Two sets of upper computer software are developed to transmit the 3D point cloud data from the robot to the control terminal which is in the safe zone, and analyze the 3D point cloud to obtain useful information, such as the diameter, position, and posture of the pipeline, which is helpful for the remote control of the robot. The experimental results verified the accuracy of the 3D environment perception system.
{"title":"Development of a 3D environment perception system for unmanned emergency repair robots for oil and gas pipelines","authors":"Chang Yuan, S. Bi, Lin Chen, Chang Liu, Jun Cheng, Yueri Cai","doi":"10.1145/3483845.3483849","DOIUrl":"https://doi.org/10.1145/3483845.3483849","url":null,"abstract":"∗In view of the great danger of manual emergency repair of oil and gas pipeline, we utilized an unmanned equipment (namely a robot) to replace manual operation. While the robot doing the pipeline repair work at the accident site, the staff operates the robot remotely outside the dangerous zone. In the work described in this paper, a 3D environment perception system is developed, a 2D LiDAR is assembled on a rotating unit driven by a stepper motor. While the 2D LiDAR is rotated, it collects data continuously. The 3D point clouds are calculated by combining the return data of the 2D LiDAR and the rotation angle of the rotating unit. This costumed 3D laser scanner is mounted on the robot to sense the 3D outline of the environment of the accident site. Two sets of upper computer software are developed to transmit the 3D point cloud data from the robot to the control terminal which is in the safe zone, and analyze the 3D point cloud to obtain useful information, such as the diameter, position, and posture of the pipeline, which is helpful for the remote control of the robot. The experimental results verified the accuracy of the 3D environment perception system.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129792043","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}
Continuous deformation of elastic rods/sheets makes flexible-link parallel mechanisms be able to generate dexterous motion and passive compliance, but simultaneously produces difficulties toward their structure design. Based on the principal axis decomposition of a compliance matrix, a kinematic equivalence method from rigid to elastic chains is proposed for structure synthesis of such mechanisms. Then, a validating model using minimum elastic potential energy as its objective is established to identify the existence of the equivalent elastic chains. Finally, cases of equivalence for a RPC chain and its application in the structure design of the corresponding low-DoF flexible-link parallel mechanism are studied through numerical kineto-statics analysis. The kinematics results demonstrate the feasibility and effectiveness of the design approach in this paper.
{"title":"A Design Approach for Flexible-Link Parallel Mechanisms using Kinematic Equivalence between Rigid and Elastic Chains","authors":"H. Pan, Genliang Chen, Hao Wang","doi":"10.1145/3483845.3483860","DOIUrl":"https://doi.org/10.1145/3483845.3483860","url":null,"abstract":"Continuous deformation of elastic rods/sheets makes flexible-link parallel mechanisms be able to generate dexterous motion and passive compliance, but simultaneously produces difficulties toward their structure design. Based on the principal axis decomposition of a compliance matrix, a kinematic equivalence method from rigid to elastic chains is proposed for structure synthesis of such mechanisms. Then, a validating model using minimum elastic potential energy as its objective is established to identify the existence of the equivalent elastic chains. Finally, cases of equivalence for a RPC chain and its application in the structure design of the corresponding low-DoF flexible-link parallel mechanism are studied through numerical kineto-statics analysis. The kinematics results demonstrate the feasibility and effectiveness of the design approach in this paper.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122478670","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}
Tracking moving objects is an important research direction in the field of robot vision. Tracking failure is still a challenging problem when the object tracking system is disturbed by the outside world or itself. In this paper, based on the theory of vestibulo-ocular reflex and its adaptive characteristics, fuzzy control is introduced to compensate the control parameters of the system, which leads to reduction of the external interference to the system and improvement of the tracking control system of the object. By imitating and learning the mechanism of human visual system, the performance of object tracking can be improved. In this paper, a "head-eye" structure is built. By experimenting with different interferences on the system, the sight is fixed on the target, which verifies the effectiveness of the algorithm.
{"title":"Research on Active Visual Tracking Based on Vestibulo-Ocular Reflex","authors":"Nianqiang Cui, Liying Su, Lilei Zhao, Ying Dai","doi":"10.1145/3483845.3483882","DOIUrl":"https://doi.org/10.1145/3483845.3483882","url":null,"abstract":"Tracking moving objects is an important research direction in the field of robot vision. Tracking failure is still a challenging problem when the object tracking system is disturbed by the outside world or itself. In this paper, based on the theory of vestibulo-ocular reflex and its adaptive characteristics, fuzzy control is introduced to compensate the control parameters of the system, which leads to reduction of the external interference to the system and improvement of the tracking control system of the object. By imitating and learning the mechanism of human visual system, the performance of object tracking can be improved. In this paper, a \"head-eye\" structure is built. By experimenting with different interferences on the system, the sight is fixed on the target, which verifies the effectiveness of the algorithm.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133800910","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}
Because complex software usually faces high concurrency and complex permission control scenarios, and there are problems with low code reuse rate and chaotic function module structure in the development process of its access control module, so providing software design methodology for such scenarios is helpful to improve software productivity and software quality play an important role. This paper proposes a hierarchical software design methodology for the development of complex software under high concurrency and fine-grained permission control scenarios. The software design methodology divides the hierarchical structure according to the characteristics of the access control process, and provides support for fine-grained control and multi-level control of permissions. For high concurrency scenarios, a cache management layer is added to improve the efficiency of the access control process. According to the actual needs of software development, the specific levels in the software design methodology are divided. By decoupling the user status detection, user status verification and permission authentication in the access control process, the support of this software design methodology in different framework environments is guaranteed and the security risks caused by the high coupling between frameworks are reduced. Through a series of 0-500K concurrent test experiments, the performance data of different frameworks in the same scenario is obtained, which provides users with a reference when implementing the software design methodology proposed in this article, enable it to choose a framework for better performance depending on the scenario it faces.
{"title":"Hierarchical Software Design Methodology for High Concurrency and Fine-Grained Permission Control Scenarios","authors":"Y. Han, Qingqing Song, Xin-Hao Huang, Jie Yin","doi":"10.1145/3483845.3483867","DOIUrl":"https://doi.org/10.1145/3483845.3483867","url":null,"abstract":"Because complex software usually faces high concurrency and complex permission control scenarios, and there are problems with low code reuse rate and chaotic function module structure in the development process of its access control module, so providing software design methodology for such scenarios is helpful to improve software productivity and software quality play an important role. This paper proposes a hierarchical software design methodology for the development of complex software under high concurrency and fine-grained permission control scenarios. The software design methodology divides the hierarchical structure according to the characteristics of the access control process, and provides support for fine-grained control and multi-level control of permissions. For high concurrency scenarios, a cache management layer is added to improve the efficiency of the access control process. According to the actual needs of software development, the specific levels in the software design methodology are divided. By decoupling the user status detection, user status verification and permission authentication in the access control process, the support of this software design methodology in different framework environments is guaranteed and the security risks caused by the high coupling between frameworks are reduced. Through a series of 0-500K concurrent test experiments, the performance data of different frameworks in the same scenario is obtained, which provides users with a reference when implementing the software design methodology proposed in this article, enable it to choose a framework for better performance depending on the scenario it faces.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116792247","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}
With the development of tennis, tennis ball picking robots have received more and more attention. Aiming at the characteristics that the existing tennis ball picking robot is expensive, complicated in design, and relies heavily on various sensors for control, a tennis ball picking robot with simple structure and Bluetooth control is designed. It is mainly composed of STC89C51 microcontroller, L298N drive motor, Bluetooth chip and mobile phone software. Focusing on Bluetooth control, the application of the robot's system architecture and hardware model under Bluetooth control is described. Finally, the tennis ball picking robot was tested on the ground by Bluetooth control and ball picking. The experimental results show that the tennis ball picking robot can perform corresponding operations according to the information sent by the mobile phone software, and can complete the task of picking the ball.
{"title":"Tennis Ball Picking Robot Based on Bluetooth Control","authors":"Min Xiao, Qingfeng Wen, Lili Ji, Wen Wang","doi":"10.1145/3483845.3483848","DOIUrl":"https://doi.org/10.1145/3483845.3483848","url":null,"abstract":"With the development of tennis, tennis ball picking robots have received more and more attention. Aiming at the characteristics that the existing tennis ball picking robot is expensive, complicated in design, and relies heavily on various sensors for control, a tennis ball picking robot with simple structure and Bluetooth control is designed. It is mainly composed of STC89C51 microcontroller, L298N drive motor, Bluetooth chip and mobile phone software. Focusing on Bluetooth control, the application of the robot's system architecture and hardware model under Bluetooth control is described. Finally, the tennis ball picking robot was tested on the ground by Bluetooth control and ball picking. The experimental results show that the tennis ball picking robot can perform corresponding operations according to the information sent by the mobile phone software, and can complete the task of picking the ball.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132507472","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}
As a powerful tool, machine learning has promoted the development of natural science in many fields and it also has helped engineers make many remarkable achievements in industry. Recently, using machine learning has already emerge in control of heavy ion accelerators. By studying synchronization of heavy ion accelerators, a method based on reinforcement learning is proposed. It’s a method that can make automatic synchronization correction. The action of power supply is simulated to interact with agent. As a precondition of synchronization correction processing, a novel approach is proposed to identify the slower power supply. Experimental results have show that our method can automatically identify the slower power between power supplies and it can make power supply complete synchronization through interaction. Compared with the past method, our algorithm not only saves manpower but also increaing the accuracy of synchronization.
{"title":"Application of reinforcement learning in synchrotron power supply synchronization correction","authors":"Yanlin Li, S. An, Wei Zhang","doi":"10.1145/3483845.3483864","DOIUrl":"https://doi.org/10.1145/3483845.3483864","url":null,"abstract":"As a powerful tool, machine learning has promoted the development of natural science in many fields and it also has helped engineers make many remarkable achievements in industry. Recently, using machine learning has already emerge in control of heavy ion accelerators. By studying synchronization of heavy ion accelerators, a method based on reinforcement learning is proposed. It’s a method that can make automatic synchronization correction. The action of power supply is simulated to interact with agent. As a precondition of synchronization correction processing, a novel approach is proposed to identify the slower power supply. Experimental results have show that our method can automatically identify the slower power between power supplies and it can make power supply complete synchronization through interaction. Compared with the past method, our algorithm not only saves manpower but also increaing the accuracy of synchronization.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125076934","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}
Aiming at the problem of manual operations and low accuracy in current hand-eye calibration process for a robotic manipulator, this paper proposes a novel method of Automatic Pose Generation and Calibration (APGC). First, a series of initial robot poses are automatically generated in Cartesian space. Then, RANSAC and K-means clustering algorithms are introduced to perform a two-step pre-screening process to select the optimal initial poses, so as to acquire robot poses that contribute to improving the calibration accuracy. Finally, the existing dual quaternion and convex relaxation global optimization theory are employed to solve the calibration matrix equation. The simulation results show that position and orientation errors of the APGC are more stable than those of two state of the arts to camera focal length noise. The experimental results show that the average position error is 0.516mm, the average orientation error is 0.048°. Compared with two state of the arts, the position and orientation errors are smaller, and the calibration accuracy is higher.
{"title":"A novel method of automatic hand-eye calibration for robotic manipulator","authors":"Kung-Ting Wei, Yaojun Chu, Haiyun Gan","doi":"10.1145/3483845.3483887","DOIUrl":"https://doi.org/10.1145/3483845.3483887","url":null,"abstract":"Aiming at the problem of manual operations and low accuracy in current hand-eye calibration process for a robotic manipulator, this paper proposes a novel method of Automatic Pose Generation and Calibration (APGC). First, a series of initial robot poses are automatically generated in Cartesian space. Then, RANSAC and K-means clustering algorithms are introduced to perform a two-step pre-screening process to select the optimal initial poses, so as to acquire robot poses that contribute to improving the calibration accuracy. Finally, the existing dual quaternion and convex relaxation global optimization theory are employed to solve the calibration matrix equation. The simulation results show that position and orientation errors of the APGC are more stable than those of two state of the arts to camera focal length noise. The experimental results show that the average position error is 0.516mm, the average orientation error is 0.048°. Compared with two state of the arts, the position and orientation errors are smaller, and the calibration accuracy is higher.","PeriodicalId":134636,"journal":{"name":"Proceedings of the 2021 2nd International Conference on Control, Robotics and Intelligent System","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125115860","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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