Pub Date : 2020-07-01DOI: 10.23919/CCC50068.2020.9188775
Mengjie Lu, Xiaoyuan Zhu, Tianzhen Wang
Fault estimation plays an important role in health monitoring as well as fault tolerant control, which can help ensure the reliability and safety of helicopter system. As the helicopter is a typical nonlinear, strong coupling and unstable system, its fault estimation design is challenging. Besides, it is also of great risk and cost to conduct experimental validation of different fault estimation schemes for real helicopter system. Thus, this paper is intended to conduct comparative research of fault estimation for helicopter system with table-mount experimental platform. Based on helicopter’s dynamic model, four observer-based fault estimation approaches are presented, in which Luenberger observer, Kalman filter, unknown input observer, and modified proportional-integral-derivative observer design are adopted separately. For the modified proportional-integral-derivative observer based fault estimation design, measurement noise is specifically considered. Based on Quanser’s 3-DOF helicopter system, both simulation and experimental tests are carried out to show the performance differences of these fault estimation approaches.
{"title":"Comparative study of fault estimation for 3-DOF helicopter","authors":"Mengjie Lu, Xiaoyuan Zhu, Tianzhen Wang","doi":"10.23919/CCC50068.2020.9188775","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9188775","url":null,"abstract":"Fault estimation plays an important role in health monitoring as well as fault tolerant control, which can help ensure the reliability and safety of helicopter system. As the helicopter is a typical nonlinear, strong coupling and unstable system, its fault estimation design is challenging. Besides, it is also of great risk and cost to conduct experimental validation of different fault estimation schemes for real helicopter system. Thus, this paper is intended to conduct comparative research of fault estimation for helicopter system with table-mount experimental platform. Based on helicopter’s dynamic model, four observer-based fault estimation approaches are presented, in which Luenberger observer, Kalman filter, unknown input observer, and modified proportional-integral-derivative observer design are adopted separately. For the modified proportional-integral-derivative observer based fault estimation design, measurement noise is specifically considered. Based on Quanser’s 3-DOF helicopter system, both simulation and experimental tests are carried out to show the performance differences of these fault estimation approaches.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116330941","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 : 2020-07-01DOI: 10.23919/CCC50068.2020.9189032
Zongyang Li, Yiheng Wei, Jiachang Wang, Ang Li, Jianli Wang, Yong Wang
This study discusses the control of parallel fractional order systems (FOSs) by the fractional-order active disturbance rejection control (FOADRC) technique. The FOADRC framework for linear FOSs and the necessary conditions for the existence of a stable controller of the system are given. The fractional-order tracking differentiator (FOTD) and the fractional-order extended state observer (FOESO) are introduced. Then, the FOADRC scheme for parallel FOSs is proposed. The effectiveness of the proposed scheme in this study paper is verified by a simulation example.
{"title":"Fractional-order ADRC framework for fractional-order parallel systems","authors":"Zongyang Li, Yiheng Wei, Jiachang Wang, Ang Li, Jianli Wang, Yong Wang","doi":"10.23919/CCC50068.2020.9189032","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9189032","url":null,"abstract":"This study discusses the control of parallel fractional order systems (FOSs) by the fractional-order active disturbance rejection control (FOADRC) technique. The FOADRC framework for linear FOSs and the necessary conditions for the existence of a stable controller of the system are given. The fractional-order tracking differentiator (FOTD) and the fractional-order extended state observer (FOESO) are introduced. Then, the FOADRC scheme for parallel FOSs is proposed. The effectiveness of the proposed scheme in this study paper is verified by a simulation example.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"100 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113982896","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 : 2020-07-01DOI: 10.23919/CCC50068.2020.9188564
Qiyuan Xu, Z. Chen, Baochuan Fu, Xue-Jun Shao
Considering that the existing trajectory data protection methods will result in low data availability, this paper considers the characteristics of trajectory data. It proposes a trajectory data protection method that satisfies differential privacy. It not only protects the privacy of the user’s trajectory but also has certain data analyzability. First, with the introduction of the weighted-multi-point judgment method, the infection points in the trajectory are found by setting the threshold of the infection angle. Second, the density of each trajectory point is calculated so as to determine the initial clustering center point. In addition, the privacy protection of the trajectory data is processed with the use of an improved differential privacy k − means method, which improves the availability of the trajectory data on the premise of satisfying the differential privacy. Finally, some numerical experiments are carried out to verify the effectiveness of the method.
{"title":"Trajectory Data Protection based on Differential Privacy k-means","authors":"Qiyuan Xu, Z. Chen, Baochuan Fu, Xue-Jun Shao","doi":"10.23919/CCC50068.2020.9188564","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9188564","url":null,"abstract":"Considering that the existing trajectory data protection methods will result in low data availability, this paper considers the characteristics of trajectory data. It proposes a trajectory data protection method that satisfies differential privacy. It not only protects the privacy of the user’s trajectory but also has certain data analyzability. First, with the introduction of the weighted-multi-point judgment method, the infection points in the trajectory are found by setting the threshold of the infection angle. Second, the density of each trajectory point is calculated so as to determine the initial clustering center point. In addition, the privacy protection of the trajectory data is processed with the use of an improved differential privacy k − means method, which improves the availability of the trajectory data on the premise of satisfying the differential privacy. Finally, some numerical experiments are carried out to verify the effectiveness of the method.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124352015","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}
In this paper, finite-time time-varying formation tracking problems are investigated for second-order multi-agent systems (MAS) over directed topology, where the MAS consist of a leader with fully unknown input and several followers. The followers are required to realize the desired time-varying formation and to track the expected trajectory generated by the leader in finite time simultaneously. The method for solving the finite-time formation tracking problems involves the following steps. First, finite-time observers are designed for each follower, to get the estimated states of the leader. Then, a finite-time formation tracking algorithm is proposed by using the neighboring information. Furthermore, it is proved that the given formation tracking can be accomplished by the MAS in finite time by using the Lyapunov theory. Finally, a numerical example is given to verify the effectiveness of the theoretical results.
{"title":"Finite-time time-varying formation tracking for second-order multi-agent systems with a leader of fully unknown input","authors":"Ruiwen Liao, Liang Han, Xiwang Dong, Fei Liu, Qingdong Li, Z. Ren","doi":"10.23919/CCC50068.2020.9189241","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9189241","url":null,"abstract":"In this paper, finite-time time-varying formation tracking problems are investigated for second-order multi-agent systems (MAS) over directed topology, where the MAS consist of a leader with fully unknown input and several followers. The followers are required to realize the desired time-varying formation and to track the expected trajectory generated by the leader in finite time simultaneously. The method for solving the finite-time formation tracking problems involves the following steps. First, finite-time observers are designed for each follower, to get the estimated states of the leader. Then, a finite-time formation tracking algorithm is proposed by using the neighboring information. Furthermore, it is proved that the given formation tracking can be accomplished by the MAS in finite time by using the Lyapunov theory. Finally, a numerical example is given to verify the effectiveness of the theoretical results.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124073315","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}
Considering the communication interference and occlusion for close following, this paper proposes an intelligent vehicle following method based on Ultra-Wideband (UWB). Based on the characteristics of UWB ranging, we proposed four ranging schemes by combining different base station placement methods and positioning algorithms. We obtained the best method by collecting a large number of distance data from vehicle to beacon and angle data away from the front of the vehicle. Taking the characteristics of vehicle following into account, the deviation between the distance from the vehicle to the beacon and the safety distance is used to control the linear velocity, the angle away from the front of the vehicle is used to control the angular velocity. Finally, in order to test the following method, we carried out tracking experiment, and it is verified that it has good tracing effect under linear, V-shaped and S-shaped tracks.
{"title":"Research on Intelligent Vehicle Following Technology Based on UWB","authors":"Jing-run Pan, Yi-geng Dou, Xu-dong Huang, Jianhua Xu, Jia-Bin Chen, Ling Xie","doi":"10.23919/CCC50068.2020.9189543","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9189543","url":null,"abstract":"Considering the communication interference and occlusion for close following, this paper proposes an intelligent vehicle following method based on Ultra-Wideband (UWB). Based on the characteristics of UWB ranging, we proposed four ranging schemes by combining different base station placement methods and positioning algorithms. We obtained the best method by collecting a large number of distance data from vehicle to beacon and angle data away from the front of the vehicle. Taking the characteristics of vehicle following into account, the deviation between the distance from the vehicle to the beacon and the safety distance is used to control the linear velocity, the angle away from the front of the vehicle is used to control the angular velocity. Finally, in order to test the following method, we carried out tracking experiment, and it is verified that it has good tracing effect under linear, V-shaped and S-shaped tracks.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127735225","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 : 2020-07-01DOI: 10.23919/CCC50068.2020.9189013
Xuan Xiao, Jiaxin Liu, Chao Xu, Chen Wang
In this paper, an improved optimal fusion algorithm based on independent fusion of states is proposed for federal filter, which can mainly solve the problem that the state with poor estimation accuracy pollutes other states during fusion, which causes the estimation accuracy of the federated filter system to decrease and the convergence rate to slow down. This improves the stability of the federated filter, thereby improving the robustness of the federal filter. Meanwhile, for the problem of complex fusion weighting matrix, large amount of calculation and poor stability in the fusion algorithm proposed by Carlson, the improved fusion algorithm, the improved fusion algorithm can reduce the complexity of fusion, reduce the operation time of the filtering system, and improve the stability of the filtering system.
{"title":"An Improved State-Independent Fusion Algorithm Based on the Federated Kalman Filters","authors":"Xuan Xiao, Jiaxin Liu, Chao Xu, Chen Wang","doi":"10.23919/CCC50068.2020.9189013","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9189013","url":null,"abstract":"In this paper, an improved optimal fusion algorithm based on independent fusion of states is proposed for federal filter, which can mainly solve the problem that the state with poor estimation accuracy pollutes other states during fusion, which causes the estimation accuracy of the federated filter system to decrease and the convergence rate to slow down. This improves the stability of the federated filter, thereby improving the robustness of the federal filter. Meanwhile, for the problem of complex fusion weighting matrix, large amount of calculation and poor stability in the fusion algorithm proposed by Carlson, the improved fusion algorithm, the improved fusion algorithm can reduce the complexity of fusion, reduce the operation time of the filtering system, and improve the stability of the filtering system.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126358950","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 : 2020-07-01DOI: 10.23919/CCC50068.2020.9188802
Huiming Li, Hao Chen, Shaowu Yang, Xiangke Wang
This paper investigates the standard formation generation and keeping problem for multiple fixed-wing unmanned aerial vehicles (UAVs), where a standard formation is defined as the basic shape of UAVs when executing tasks. Firstly, a control law based on the gradient of potential functions is proposed to drive multiple UAVs to form and keep the standard formation, with theoretical analysis showing that the desired collective behaviors can be obtained. The control law is then extended to achieve obstacle avoidance by taking the virtual repulsion strategy into account. Numerical simulations are finally provided, verifying the effectiveness of the proposed strategy.
{"title":"Standard Formation Generation and Keeping of Unmanned Aerial Vehicles Through a Potential Functional Approach","authors":"Huiming Li, Hao Chen, Shaowu Yang, Xiangke Wang","doi":"10.23919/CCC50068.2020.9188802","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9188802","url":null,"abstract":"This paper investigates the standard formation generation and keeping problem for multiple fixed-wing unmanned aerial vehicles (UAVs), where a standard formation is defined as the basic shape of UAVs when executing tasks. Firstly, a control law based on the gradient of potential functions is proposed to drive multiple UAVs to form and keep the standard formation, with theoretical analysis showing that the desired collective behaviors can be obtained. The control law is then extended to achieve obstacle avoidance by taking the virtual repulsion strategy into account. Numerical simulations are finally provided, verifying the effectiveness of the proposed strategy.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126502839","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 : 2020-07-01DOI: 10.23919/CCC50068.2020.9188982
Jia Ren, Xiaochuan Liu, Jianbo Yang
Drop test of the mine protected seat is the process of simulating the explosion shock waveform by drop test platform. And it plays an important role in the stage of seat development, design optimization, stereotype and mass production. So, the waveform simulated method for the mine protected seat drop test is proposed in this article to simulating the detonation wave, and the identification method of designing and debugging the waveform generator elastic material is established here. In this article, waveform design principle and modeling method are given based on the specific test process, and the debugging and correction method of waveform are given based on the actual test data. The methods are used in multiple tests. At last, combined with the specific test, the process of design and debugging frequently problems in actual test are given. The results are shown that the technology of explosion shock waveform modeling and simulation shown in this article is effective and useful.
{"title":"Modeling and Simulation of Detonation Wave Based on Mine Protected Seat Test","authors":"Jia Ren, Xiaochuan Liu, Jianbo Yang","doi":"10.23919/CCC50068.2020.9188982","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9188982","url":null,"abstract":"Drop test of the mine protected seat is the process of simulating the explosion shock waveform by drop test platform. And it plays an important role in the stage of seat development, design optimization, stereotype and mass production. So, the waveform simulated method for the mine protected seat drop test is proposed in this article to simulating the detonation wave, and the identification method of designing and debugging the waveform generator elastic material is established here. In this article, waveform design principle and modeling method are given based on the specific test process, and the debugging and correction method of waveform are given based on the actual test data. The methods are used in multiple tests. At last, combined with the specific test, the process of design and debugging frequently problems in actual test are given. The results are shown that the technology of explosion shock waveform modeling and simulation shown in this article is effective and useful.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126522839","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 : 2020-07-01DOI: 10.23919/CCC50068.2020.9188556
Yan Zhou, Yonghui Sun, Sen Wang, Dognchen Hou, Linchuang Zhang
Efficient and accurate power prediction of wind farm cluster is an effective method to improve the safety and reliability of power system for large-scale wind power. In this paper, the probabilistic prediction model of regional wind power is studied. The nonparametric method based on least absolute shrinkage and selection operator (LASSO) is used for the ultra-short-term probabilistic prediction. In this paper, the prediction model of nonlinear quantile regression (NQR) model based on quantile regression (QR) and extreme learning machine (ELM) is studied. Then, LASSO is utilized to shrink the output weights for the sparsity. The penalty of LASSO can prevent the overfitting and improve the performance of prediction intervals (PIs), without the reduction of computational efficiency. With the actual dataset of the wind farms in northeast China, the PIs performance is verified, compared with other well-established benchmarks.
{"title":"Ultra-short-term Interval Prediction of Wind Farm Cluster Power Based on LASSO","authors":"Yan Zhou, Yonghui Sun, Sen Wang, Dognchen Hou, Linchuang Zhang","doi":"10.23919/CCC50068.2020.9188556","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9188556","url":null,"abstract":"Efficient and accurate power prediction of wind farm cluster is an effective method to improve the safety and reliability of power system for large-scale wind power. In this paper, the probabilistic prediction model of regional wind power is studied. The nonparametric method based on least absolute shrinkage and selection operator (LASSO) is used for the ultra-short-term probabilistic prediction. In this paper, the prediction model of nonlinear quantile regression (NQR) model based on quantile regression (QR) and extreme learning machine (ELM) is studied. Then, LASSO is utilized to shrink the output weights for the sparsity. The penalty of LASSO can prevent the overfitting and improve the performance of prediction intervals (PIs), without the reduction of computational efficiency. With the actual dataset of the wind farms in northeast China, the PIs performance is verified, compared with other well-established benchmarks.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128072434","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}
This paper studies the decentralized event-triggered ${{mathcal{H}}_infty }$ control for networked switched systems subject to stochastic cyber attacks and actuator failures. First, since the system state is divided into multiple communication channels, decentralized states are sampled and triggered, respectively. A set of decentralized event-triggering mechanisms (DETMs) is introduced to determine whether the sampled data is released. Subsequently, a data buffer merges the released data from decentralized triggering mechanisms. Stochastic cyber attacks and actuator failures are taken into account for a more practical situation. By using a delay system analysis approach, a time-delay closed-loop switched system is derived. Then, sufficient conditions are provided to guarantee ${{mathcal{H}}_infty }$ performance of switched system by utilizing piecewise Lyapunov functional method and average dwell time technique. Moreover, sufficient conditions for designing event-triggered state feedback controllers and event-triggering parameters are given. Finally, a numerical simulation is shown to verify the effectiveness of the proposed method.
{"title":"Decentralized Event-Triggered Control for Switched Systems Under Stochastic Cyber Attacks and Actuator Failures","authors":"Xiujuan Zhao, Yiwen Qi, Shuo Yuan, Xindi Xu, Yiwen Tang","doi":"10.23919/CCC50068.2020.9189023","DOIUrl":"https://doi.org/10.23919/CCC50068.2020.9189023","url":null,"abstract":"This paper studies the decentralized event-triggered ${{mathcal{H}}_infty }$ control for networked switched systems subject to stochastic cyber attacks and actuator failures. First, since the system state is divided into multiple communication channels, decentralized states are sampled and triggered, respectively. A set of decentralized event-triggering mechanisms (DETMs) is introduced to determine whether the sampled data is released. Subsequently, a data buffer merges the released data from decentralized triggering mechanisms. Stochastic cyber attacks and actuator failures are taken into account for a more practical situation. By using a delay system analysis approach, a time-delay closed-loop switched system is derived. Then, sufficient conditions are provided to guarantee ${{mathcal{H}}_infty }$ performance of switched system by utilizing piecewise Lyapunov functional method and average dwell time technique. Moreover, sufficient conditions for designing event-triggered state feedback controllers and event-triggering parameters are given. Finally, a numerical simulation is shown to verify the effectiveness of the proposed method.","PeriodicalId":255872,"journal":{"name":"2020 39th Chinese Control Conference (CCC)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125492186","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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