Pub Date : 2021-12-14DOI: 10.1109/CDC45484.2021.9683775
Rodrigo A. González, C. Rojas, Siqi Pan, J. Welsh
Continuous-time system identification has primarily dealt with sampled input and output data for constructing continuous-time models. However, sampled signals can lead to inaccurate models if their intersample behavior is not addressed appropriately. In this paper, this effect is explored in detail with respect to the SRIVC and CLSRIVC estimators, which are some of the most popular methods for open and closed-loop continuous-time system identification respectively. Based on our consistency analysis, we propose an algorithm that alleviates the asymptotic bias of these methods for arbitrary input excitations and provide an alternative procedure to achieve consistent estimates for band-limited signals. Simulation examples show the effectiveness of our approach.
{"title":"The SRIVC algorithm for continuous-time system identification with arbitrary input excitation in open and closed loop","authors":"Rodrigo A. González, C. Rojas, Siqi Pan, J. Welsh","doi":"10.1109/CDC45484.2021.9683775","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683775","url":null,"abstract":"Continuous-time system identification has primarily dealt with sampled input and output data for constructing continuous-time models. However, sampled signals can lead to inaccurate models if their intersample behavior is not addressed appropriately. In this paper, this effect is explored in detail with respect to the SRIVC and CLSRIVC estimators, which are some of the most popular methods for open and closed-loop continuous-time system identification respectively. Based on our consistency analysis, we propose an algorithm that alleviates the asymptotic bias of these methods for arbitrary input excitations and provide an alternative procedure to achieve consistent estimates for band-limited signals. Simulation examples show the effectiveness of our approach.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"482 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116518405","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683434
Xu Jin, Shi‐Lu Dai, Jia-hong Liang, Dejun Guo
Constrained operations for autonomous vehicles have been extensively studied in the literature over recent years. However, to the best of the authors’ knowledge, all of the existing works address only constant or time-varying constraint functions. In this work, we study path-dependent constraint requirements, which explicitly depend on the path parameter, instead of depending on the time variable directly. This formulation of constraints is more practical in reality, where the constraint requirements are often shaped by the environment boundaries. From the system users’ perspectives, it is also much easier to define constraint functions based on the path parameter. A modified version of the universal barrier function is used in the analysis of path-dependent constraint requirements. Furthermore, system unknowns and uncertainties are taken into considerations when designing the adaptive control algorithm. A simulation study further demonstrates the efficacy of the proposed scheme.
{"title":"Adaptive Path-Following Control of An Autonomous Vehicle with Path-Dependent Constraint Requirements","authors":"Xu Jin, Shi‐Lu Dai, Jia-hong Liang, Dejun Guo","doi":"10.1109/CDC45484.2021.9683434","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683434","url":null,"abstract":"Constrained operations for autonomous vehicles have been extensively studied in the literature over recent years. However, to the best of the authors’ knowledge, all of the existing works address only constant or time-varying constraint functions. In this work, we study path-dependent constraint requirements, which explicitly depend on the path parameter, instead of depending on the time variable directly. This formulation of constraints is more practical in reality, where the constraint requirements are often shaped by the environment boundaries. From the system users’ perspectives, it is also much easier to define constraint functions based on the path parameter. A modified version of the universal barrier function is used in the analysis of path-dependent constraint requirements. Furthermore, system unknowns and uncertainties are taken into considerations when designing the adaptive control algorithm. A simulation study further demonstrates the efficacy of the proposed scheme.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122292031","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683707
Federico Celi, Giacomo Baggio, F. Pasqualetti
While classic controller design methods rely on a model of the underlying dynamics, data-driven methods allow to compute controllers leveraging solely a set of previously recorded input-output trajectories, with relatively mild assumptions. Assuming knowledge of the dynamics is especially unrealistic in decentralized systems, since information is typically localized by design. In this paper we investigate a decentralized data-driven approach to learn quadraticallyoptimal controls for interconnected linear systems. Our main result is a distributed algorithm that computes a control input to reach a desired target configuration with provable, and tunable, suboptimality guarantees. Our distributed procedure converges after a finite number of iterations and the suboptimality gap can be characterized analytically in terms of the data properties. Our algorithm relies on a new set of closed-form data-driven expressions of quadratically-optimal controls, which complement the existing literature on data-driven linear-quadratic control. We complement and validate our theoretical analysis by means of numerical simulations with different interconnected systems.
{"title":"Distributed Learning of Optimal Controls for Linear Systems","authors":"Federico Celi, Giacomo Baggio, F. Pasqualetti","doi":"10.1109/CDC45484.2021.9683707","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683707","url":null,"abstract":"While classic controller design methods rely on a model of the underlying dynamics, data-driven methods allow to compute controllers leveraging solely a set of previously recorded input-output trajectories, with relatively mild assumptions. Assuming knowledge of the dynamics is especially unrealistic in decentralized systems, since information is typically localized by design. In this paper we investigate a decentralized data-driven approach to learn quadraticallyoptimal controls for interconnected linear systems. Our main result is a distributed algorithm that computes a control input to reach a desired target configuration with provable, and tunable, suboptimality guarantees. Our distributed procedure converges after a finite number of iterations and the suboptimality gap can be characterized analytically in terms of the data properties. Our algorithm relies on a new set of closed-form data-driven expressions of quadratically-optimal controls, which complement the existing literature on data-driven linear-quadratic control. We complement and validate our theoretical analysis by means of numerical simulations with different interconnected systems.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122407778","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683203
A. Kundu
This paper deals with the design of scheduling logics for Networked Control Systems (NCSs) whose shared communication networks have limited capacity. We assume that among N plants, only M < (N) plants can communicate with their controllers at any time instant. We present an algorithm to allocate the network to the plants periodically such that stability of each plant is preserved. The main apparatus for our analysis is a switched systems representation of the individual plants in an NCS. We rely on multiple Lyapunov-like functions and graph-theoretic arguments to design our scheduling logics. The set of results presented in this paper is a continuous-time counterpart of the results proposed in [12]. We present a set of numerical experiments to demonstrate the performance of our techniques.
{"title":"Scheduling networked control systems under limited communication capacity","authors":"A. Kundu","doi":"10.1109/CDC45484.2021.9683203","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683203","url":null,"abstract":"This paper deals with the design of scheduling logics for Networked Control Systems (NCSs) whose shared communication networks have limited capacity. We assume that among N plants, only M < (N) plants can communicate with their controllers at any time instant. We present an algorithm to allocate the network to the plants periodically such that stability of each plant is preserved. The main apparatus for our analysis is a switched systems representation of the individual plants in an NCS. We rely on multiple Lyapunov-like functions and graph-theoretic arguments to design our scheduling logics. The set of results presented in this paper is a continuous-time counterpart of the results proposed in [12]. We present a set of numerical experiments to demonstrate the performance of our techniques.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114184329","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9682824
Cesar Santoyo, Gustav Nilsson, S. Coogan
In this paper, we consider an electric vehicle charging facility that offers various levels of service, i.e., charging rates, for varying prices such that rational users choose a level of service based on their value of time, also called impatience. In particular, we characterize the sensitivity of the expected number of users, i.e., occupancy, at the facility to the probability distribution of users’ impatience. We first provide an upper bound for the difference between the expected occupancy under any two different distributions on users’ impatience. Next, we consider the case when the users’ impatience are discrete random variables, and we study the sensitivity of the expected occupancy to the probability masses and attained values of the random variables. We show that the expected occupancy varies linearly with respect to the probability masses and is piecewise constant with respect to the attained values. These results suggest how the facility operator might design prices such that the expected occupancy does not vary much under small changes in the distribution of users’ impatience, which is generally difficult to characterize accurately from data. We demonstrate this idea via examples.
{"title":"Sensitivity of Electric Vehicle Charging Facility Occupancy to Users’ Impatience","authors":"Cesar Santoyo, Gustav Nilsson, S. Coogan","doi":"10.1109/CDC45484.2021.9682824","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9682824","url":null,"abstract":"In this paper, we consider an electric vehicle charging facility that offers various levels of service, i.e., charging rates, for varying prices such that rational users choose a level of service based on their value of time, also called impatience. In particular, we characterize the sensitivity of the expected number of users, i.e., occupancy, at the facility to the probability distribution of users’ impatience. We first provide an upper bound for the difference between the expected occupancy under any two different distributions on users’ impatience. Next, we consider the case when the users’ impatience are discrete random variables, and we study the sensitivity of the expected occupancy to the probability masses and attained values of the random variables. We show that the expected occupancy varies linearly with respect to the probability masses and is piecewise constant with respect to the attained values. These results suggest how the facility operator might design prices such that the expected occupancy does not vary much under small changes in the distribution of users’ impatience, which is generally difficult to characterize accurately from data. We demonstrate this idea via examples.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122230712","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683626
Mohammad Khajenejad, Fatima Shoaib, Sze Zheng Yong
This paper proposes novel set-theoretic approaches for recursive state estimation in bounded-error discrete-time nonlinear systems subject to nonlinear observations/constraints. By transforming the polytopes that are characterized as zonotope bundles (ZB) and/or constrained zonotopes (CZ), from the state space to the space of the generators of ZB/CZ, we leverage a recent result on remainder-form mixed-monotone decomposition functions to compute the propagated set, i.e., a ZB/CZ that is guaranteed to enclose the set of the state trajectories of the considered system. Further, by applying the remainder-form decomposition functions to the nonlinear observation function, we derive the updated set, i.e., an enclosing ZB/CZ of the intersection of the propagated set and the set of states that are compatible/consistent with the observations/constraints. In addition, we show that the mean value extension result in [1] for computing propagated sets can also be extended to compute the updated set when the observation function is nonlinear.
{"title":"Guaranteed State Estimation via Indirect Polytopic Set Computation for Nonlinear Discrete-Time Systems","authors":"Mohammad Khajenejad, Fatima Shoaib, Sze Zheng Yong","doi":"10.1109/CDC45484.2021.9683626","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683626","url":null,"abstract":"This paper proposes novel set-theoretic approaches for recursive state estimation in bounded-error discrete-time nonlinear systems subject to nonlinear observations/constraints. By transforming the polytopes that are characterized as zonotope bundles (ZB) and/or constrained zonotopes (CZ), from the state space to the space of the generators of ZB/CZ, we leverage a recent result on remainder-form mixed-monotone decomposition functions to compute the propagated set, i.e., a ZB/CZ that is guaranteed to enclose the set of the state trajectories of the considered system. Further, by applying the remainder-form decomposition functions to the nonlinear observation function, we derive the updated set, i.e., an enclosing ZB/CZ of the intersection of the propagated set and the set of states that are compatible/consistent with the observations/constraints. In addition, we show that the mean value extension result in [1] for computing propagated sets can also be extended to compute the updated set when the observation function is nonlinear.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116725512","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683185
Ferran Arqu'e, César A. Uribe, C. Ocampo‐Martinez
This paper presents a Wasserstein attraction approach for solving dynamic mass transport problems over networks. In the transport problem over networks, we start with a distribution over the set of nodes that needs to be "transported" to a target distribution accounting for the network topology. We exploit the specific structure of the problem, characterized by the computation of implicit gradient steps, and formulate an approach based on discretized flows. As a result, our proposed algorithm relies on the iterative computation of constrained Wasserstein barycenters. We show how the proposed method finds approximate solutions to the network transport problem, taking into account the topology of the network, the capacity of the communication channels, and the capacity of the individual nodes.
{"title":"Application of Wasserstein Attraction Flows for Optimal Transport in Network Systems","authors":"Ferran Arqu'e, César A. Uribe, C. Ocampo‐Martinez","doi":"10.1109/CDC45484.2021.9683185","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683185","url":null,"abstract":"This paper presents a Wasserstein attraction approach for solving dynamic mass transport problems over networks. In the transport problem over networks, we start with a distribution over the set of nodes that needs to be \"transported\" to a target distribution accounting for the network topology. We exploit the specific structure of the problem, characterized by the computation of implicit gradient steps, and formulate an approach based on discretized flows. As a result, our proposed algorithm relies on the iterative computation of constrained Wasserstein barycenters. We show how the proposed method finds approximate solutions to the network transport problem, taking into account the topology of the network, the capacity of the communication channels, and the capacity of the individual nodes.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129757062","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683139
R. Benyoucef, H. Hadj-Abdelkader, L. Nehaoua, Hichem Arioui
In this paper, a 3D point feature depth and camera focal length estimation is proposed, using a partially calibrated low cost monocular camera. The camera intrinsic parameters are known, except for the focal length, which may vary across different views. The camera perspective projection model is augmented using dynamic extension approach, then decomposed into two interconnected subsystems. The subsystems are described as quasi-Linear Parameter Varying (qLPV) systems with unmeasured premise variables for which an interconnected fuzzy observer is designed. Necessary and sufficient conditions to ensure the observer existence are presented. The error convergence analysis is performed based on Lyapunov theory associated with Lipchitz condition. Gains that guarantee the asymptotic stability of the estimation error are computed in terms of Linear Matrix Inequalities (LMI) with eigenvalues clustering in LMI region to improve the estimation performance.
{"title":"Structure from Motion with variable focal length: Interconnected fuzzy observer","authors":"R. Benyoucef, H. Hadj-Abdelkader, L. Nehaoua, Hichem Arioui","doi":"10.1109/CDC45484.2021.9683139","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683139","url":null,"abstract":"In this paper, a 3D point feature depth and camera focal length estimation is proposed, using a partially calibrated low cost monocular camera. The camera intrinsic parameters are known, except for the focal length, which may vary across different views. The camera perspective projection model is augmented using dynamic extension approach, then decomposed into two interconnected subsystems. The subsystems are described as quasi-Linear Parameter Varying (qLPV) systems with unmeasured premise variables for which an interconnected fuzzy observer is designed. Necessary and sufficient conditions to ensure the observer existence are presented. The error convergence analysis is performed based on Lyapunov theory associated with Lipchitz condition. Gains that guarantee the asymptotic stability of the estimation error are computed in terms of Linear Matrix Inequalities (LMI) with eigenvalues clustering in LMI region to improve the estimation performance.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129052576","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9683480
Jie Yao, M. Xin
In this paper, a suboptimal controller is designed by the θ −D technique for a differential wheeled mobile robot with holonomic and nonholonomic constraints. The challenge of wheel actuators not being exerted into the coordinate of the robot base is addressed by a proper transformation, leading to controllability of the mobile robot system. This transformation lowers the complexity of control design since it yields reduced-order state-space equations. The θ − D algorithm provides an approximate closed-form suboptimal controller that is easy to implement onboard. It is compared favorably with the similar state-dependent Riccati equation technique in terms of computation efficiency and control effort. The simulation experiments verify that the proposed technique is an effective and efficient tool for designing the controller of the differential wheeled mobile robots.
{"title":"Suboptimal Control Design for Differential Wheeled Mobile Robots with θ − D Technique","authors":"Jie Yao, M. Xin","doi":"10.1109/CDC45484.2021.9683480","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9683480","url":null,"abstract":"In this paper, a suboptimal controller is designed by the θ −D technique for a differential wheeled mobile robot with holonomic and nonholonomic constraints. The challenge of wheel actuators not being exerted into the coordinate of the robot base is addressed by a proper transformation, leading to controllability of the mobile robot system. This transformation lowers the complexity of control design since it yields reduced-order state-space equations. The θ − D algorithm provides an approximate closed-form suboptimal controller that is easy to implement onboard. It is compared favorably with the similar state-dependent Riccati equation technique in terms of computation efficiency and control effort. The simulation experiments verify that the proposed technique is an effective and efficient tool for designing the controller of the differential wheeled mobile robots.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129276151","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 : 2021-12-14DOI: 10.1109/CDC45484.2021.9682966
B. Taner, K. Subbarao
This paper studies distributed edge weight synthesis of a cooperative system for a fixed topology to improve H∞ performance, considering that disturbances are injected at interconnection channels. This problem is cast into a linear matrix inequality problem by replacing original cooperative system with an equivalent ideal cooperative system. Derivations of the method relies on dissipative system framework. Proposed method provides an upper bound for the induced ℒ2 norm of the original lumped cooperative system while reducing the computation time. A comparison for computation time illustrates the advantage of the proposed method against the lumped counterpart.
{"title":"Distributed H∞ Edge Weight Synthesis for Cooperative Systems","authors":"B. Taner, K. Subbarao","doi":"10.1109/CDC45484.2021.9682966","DOIUrl":"https://doi.org/10.1109/CDC45484.2021.9682966","url":null,"abstract":"This paper studies distributed edge weight synthesis of a cooperative system for a fixed topology to improve H∞ performance, considering that disturbances are injected at interconnection channels. This problem is cast into a linear matrix inequality problem by replacing original cooperative system with an equivalent ideal cooperative system. Derivations of the method relies on dissipative system framework. Proposed method provides an upper bound for the induced ℒ2 norm of the original lumped cooperative system while reducing the computation time. A comparison for computation time illustrates the advantage of the proposed method against the lumped counterpart.","PeriodicalId":229089,"journal":{"name":"2021 60th IEEE Conference on Decision and Control (CDC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130303113","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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