Motivated by the provably-correct execution of complex reactive tasks for robots with nonlinear, under-actuated dynamics, our focus is on the synthesis of a library of low-level controllers that implements the behaviors of a high-level controller. The synthesized controllers should allow the robot to react to its environment whenever dynamically feasible given the geometry of the workspace. For any behaviors that cannot guarantee the task given the dynamics, such behaviors should be transformed into dynamically-informative revisions to the high-level task. We therefore propose a framework for synthesizing such low-level controllers and, moreover, offer an approach for re-partitioning and abstracting the system based on the synthesized controller library. We accomplish these goals by introducing a synthesis approach that we call conforming funnels, in which controllers are synthesized with respect to the given high-level behaviors, the geometrical constraints of the workspace, and a robot dynamics model. Our approach computes controllers using a verification approach that optimizes over a wide range of possible controllers to guarantee the geometrical constraints are satisfied. We also devise an algorithm that uses the controllers to re-partition the workspace and automatically adapt the high-level specification with a new discrete abstraction generated on these new partitions. We demonstrate the controllers generated by our synthesis framework in an experimental setting with a KUKA youBot executing a box transportation task.
{"title":"Nonlinear Controller Synthesis and Automatic Workspace Partitioning for Reactive High-Level Behaviors","authors":"Jonathan A. DeCastro, H. Kress-Gazit","doi":"10.1145/2883817.2883832","DOIUrl":"https://doi.org/10.1145/2883817.2883832","url":null,"abstract":"Motivated by the provably-correct execution of complex reactive tasks for robots with nonlinear, under-actuated dynamics, our focus is on the synthesis of a library of low-level controllers that implements the behaviors of a high-level controller. The synthesized controllers should allow the robot to react to its environment whenever dynamically feasible given the geometry of the workspace. For any behaviors that cannot guarantee the task given the dynamics, such behaviors should be transformed into dynamically-informative revisions to the high-level task. We therefore propose a framework for synthesizing such low-level controllers and, moreover, offer an approach for re-partitioning and abstracting the system based on the synthesized controller library. We accomplish these goals by introducing a synthesis approach that we call conforming funnels, in which controllers are synthesized with respect to the given high-level behaviors, the geometrical constraints of the workspace, and a robot dynamics model. Our approach computes controllers using a verification approach that optimizes over a wide range of possible controllers to guarantee the geometrical constraints are satisfied. We also devise an algorithm that uses the controllers to re-partition the workspace and automatically adapt the high-level specification with a new discrete abstraction generated on these new partitions. We demonstrate the controllers generated by our synthesis framework in an experimental setting with a KUKA youBot executing a box transportation task.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122186320","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}
Aditya Zutshi, S. Sankaranarayanan, Jyotirmoy V. Deshmukh, Xiaoqing Jin
We study the problem of falsifying reachability properties of real-time control software acting in a closed-loop with a given model of the plant dynamics. Our approach employs numerical techniques to simulate a plant model, which may be highly nonlinear and hybrid, in combination with symbolic simulation of the controller software. The state-space and input-space of the plant are systematically searched using a plant abstraction that is implicitly defined by ``quantization'' of the plant state, but never explicitly constructed. Simultaneously, the controller behaviors are explored using a symbolic execution of the control software. On-the-fly exploration of the overall closed-loop abstraction results in abstract counterexamples, which are used to refine the plant abstraction iteratively until a concrete violation is found. Empirical evaluation of our approach shows its promise in treating controller software that has precise, formal semantics, using an exact method such as symbolic execution, while using numerical simulations to produce abstractions of the underlying plant model that is often an approximation of the actual plant. We also discuss a preliminary comparison of our approach with techniques that are primarily simulation-based.
{"title":"Symbolic-Numeric Reachability Analysis of Closed-Loop Control Software","authors":"Aditya Zutshi, S. Sankaranarayanan, Jyotirmoy V. Deshmukh, Xiaoqing Jin","doi":"10.1145/2883817.2883819","DOIUrl":"https://doi.org/10.1145/2883817.2883819","url":null,"abstract":"We study the problem of falsifying reachability properties of real-time control software acting in a closed-loop with a given model of the plant dynamics. Our approach employs numerical techniques to simulate a plant model, which may be highly nonlinear and hybrid, in combination with symbolic simulation of the controller software. The state-space and input-space of the plant are systematically searched using a plant abstraction that is implicitly defined by ``quantization'' of the plant state, but never explicitly constructed. Simultaneously, the controller behaviors are explored using a symbolic execution of the control software. On-the-fly exploration of the overall closed-loop abstraction results in abstract counterexamples, which are used to refine the plant abstraction iteratively until a concrete violation is found. Empirical evaluation of our approach shows its promise in treating controller software that has precise, formal semantics, using an exact method such as symbolic execution, while using numerical simulations to produce abstractions of the underlying plant model that is often an approximation of the actual plant. We also discuss a preliminary comparison of our approach with techniques that are primarily simulation-based.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126429951","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}
Alexandar Kozarev, John F. Quindlen, J. How, U. Topcu
We interpret several dynamical system verification questions, e.g., region of attraction and reachability analyses, as data classification problems. We discuss some of the tradeoffs between conventional optimization-based certificate constructions with certainty in the outcomes and this new date-driven approach with quantified confidence in the outcomes. The new methodology is aligned with emerging computing paradigms and has the potential to extend systematic verification to systems that do not necessarily admit closed-form models from certain specialized families. We demonstrate its effectiveness on a collection of both conventional and unconventional case studies including model reference adaptive control systems, nonlinear aircraft models, and reinforcement learning problems.
{"title":"Case Studies in Data-Driven Verification of Dynamical Systems","authors":"Alexandar Kozarev, John F. Quindlen, J. How, U. Topcu","doi":"10.1145/2883817.2883846","DOIUrl":"https://doi.org/10.1145/2883817.2883846","url":null,"abstract":"We interpret several dynamical system verification questions, e.g., region of attraction and reachability analyses, as data classification problems. We discuss some of the tradeoffs between conventional optimization-based certificate constructions with certainty in the outcomes and this new date-driven approach with quantified confidence in the outcomes. The new methodology is aligned with emerging computing paradigms and has the potential to extend systematic verification to systems that do not necessarily admit closed-form models from certain specialized families. We demonstrate its effectiveness on a collection of both conventional and unconventional case studies including model reference adaptive control systems, nonlinear aircraft models, and reinforcement learning problems.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115527083","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}
Giuseppe Bombara, C. Vasile, Francisco Penedo, Hirotoshi Yasuoka, C. Belta
This paper introduces a framework for inference of timed temporal logic properties from data. The dataset is given as a finite set of pairs of finite-time system traces and labels, where the labels indicate whether the traces exhibit some desired behavior (e.g., a ship traveling along a safe route). We propose a decision-tree based approach for learning signal temporal logic classifiers. The method produces binary decision trees that represent the inferred formulae. Each node of the tree contains a test associated with the satisfaction of a simple formula, optimally tuned from a predefined finite set of primitives. Optimality is assessed using heuristic impurity measures, which capture how well the current primitive splits the data with respect to the traces' labels. We propose extensions of the usual impurity measures from machine learning literature to handle classification of system traces by leveraging upon the robustness degree concept. The proposed incremental construction procedure greatly improves the execution time and the accuracy compared to existing algorithms. We present two case studies that illustrate the usefulness and the computational advantages of the algorithms. The first is an anomaly detection problem in a maritime environment. The second is a fault detection problem in an automotive powertrain system.
{"title":"A Decision Tree Approach to Data Classification using Signal Temporal Logic","authors":"Giuseppe Bombara, C. Vasile, Francisco Penedo, Hirotoshi Yasuoka, C. Belta","doi":"10.1145/2883817.2883843","DOIUrl":"https://doi.org/10.1145/2883817.2883843","url":null,"abstract":"This paper introduces a framework for inference of timed temporal logic properties from data. The dataset is given as a finite set of pairs of finite-time system traces and labels, where the labels indicate whether the traces exhibit some desired behavior (e.g., a ship traveling along a safe route). We propose a decision-tree based approach for learning signal temporal logic classifiers. The method produces binary decision trees that represent the inferred formulae. Each node of the tree contains a test associated with the satisfaction of a simple formula, optimally tuned from a predefined finite set of primitives. Optimality is assessed using heuristic impurity measures, which capture how well the current primitive splits the data with respect to the traces' labels. We propose extensions of the usual impurity measures from machine learning literature to handle classification of system traces by leveraging upon the robustness degree concept. The proposed incremental construction procedure greatly improves the execution time and the accuracy compared to existing algorithms. We present two case studies that illustrate the usefulness and the computational advantages of the algorithms. The first is an anomaly detection problem in a maritime environment. The second is a fault detection problem in an automotive powertrain system.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129418785","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}
Houssam Abbas, Kuk Jin Jang, Zhihao Jiang, R. Mangharam
Ventricular Fibrillation is a disorganized electrical excitation of the heart that results in inadequate blood flow to the body. It usually ends in death within a minute. A common way to treat the symptoms of fibrillation is to implant a medical device, known as an Implantable Cardioverter Defibrillator (ICD), in the patient's body. Model-based verification can supply rigorous proofs of safety and efficacy. In this paper, we build a hybrid system model of the human heart+ICD closed loop, and show it to be a STORMED system, a class of o-minimal hybrid systems that admit finite bisimulations. In general, it may not be possible to compute the bisimulation. We show that approximate reachability can yield a finite simulation for STORMED systems, and that certain compositions respect the STORMED property. The results of this paper are theoretical and motivate the creation of concrete model checking procedures for STORMED systems.
{"title":"Towards Model Checking of Implantable Cardioverter Defibrillators","authors":"Houssam Abbas, Kuk Jin Jang, Zhihao Jiang, R. Mangharam","doi":"10.1145/2883817.2883841","DOIUrl":"https://doi.org/10.1145/2883817.2883841","url":null,"abstract":"Ventricular Fibrillation is a disorganized electrical excitation of the heart that results in inadequate blood flow to the body. It usually ends in death within a minute. A common way to treat the symptoms of fibrillation is to implant a medical device, known as an Implantable Cardioverter Defibrillator (ICD), in the patient's body. Model-based verification can supply rigorous proofs of safety and efficacy. In this paper, we build a hybrid system model of the human heart+ICD closed loop, and show it to be a STORMED system, a class of o-minimal hybrid systems that admit finite bisimulations. In general, it may not be possible to compute the bisimulation. We show that approximate reachability can yield a finite simulation for STORMED systems, and that certain compositions respect the STORMED property. The results of this paper are theoretical and motivate the creation of concrete model checking procedures for STORMED systems.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129840143","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}
We revisit the problem of finding controlled invariants sets (viability), for a class of differential inclusions, using topological methods based on Wazewski property. In many ways, this generalizes the Viability Theorem approach, which is itself a generalization of the Lyapunov function approach for systems described by ordinary differential equations. We give a computable criterion based on SoS methods for a class of differential inclusions to have a non-empty viability kernel within some given region. We use this method to prove the existence of (controlled) invariant sets of switched systems inside a region described by a polynomial template, both with time-dependent switching and with state-based switching through a finite set of hypersurfaces. A Matlab implementation allows us to demonstrate its use.
{"title":"A Topological Method for Finding Invariant Sets of Switched Systems","authors":"L. Fribourg, É. Goubault, S. Putot, Sameh Mohamed","doi":"10.1145/2883817.2883822","DOIUrl":"https://doi.org/10.1145/2883817.2883822","url":null,"abstract":"We revisit the problem of finding controlled invariants sets (viability), for a class of differential inclusions, using topological methods based on Wazewski property. In many ways, this generalizes the Viability Theorem approach, which is itself a generalization of the Lyapunov function approach for systems described by ordinary differential equations. We give a computable criterion based on SoS methods for a class of differential inclusions to have a non-empty viability kernel within some given region. We use this method to prove the existence of (controlled) invariant sets of switched systems inside a region described by a polynomial template, both with time-dependent switching and with state-based switching through a finite set of hypersurfaces. A Matlab implementation allows us to demonstrate its use.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121600973","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}
Mikhail Vilgelm, M. Mamduhi, W. Kellerer, S. Hirche
Control over shared communication networks is a key challenge in design and analysis of cyber-physical systems. The quality of control in such systems might be degraded due to the congestion while accessing the scarce communication resources. In this paper, we consider a multiple-loop networked control system (NCS), where all control loops share a communication network. Medium Access Control (MAC) is performed in contention-based fashion using a multi-channel slotted ALOHA protocol, where each control loop decides locally whether to attempt a transmission based on some error thresholds. We further introduce a local event-based resource-aware scheduling design with an adaptive choice of the error thresholds for a transmission. This leads to a hybrid channel access mechanism where the control loops are deterministically categorized into two sets of eligible and ineligible sub-systems for transmission in an event-based fashion, before a random process to select the available channels. In addition, employing the introduced policy, we show the stability of the resulting NCS in terms of Lyapunov stability in probability. We illustrate numerically the efficiency of our proposed approach in terms of reducing the average networked-induced error variance, and show the superiority of the adaptive event-based scheduler compared to the scheduling design with non-adaptive thresholds.
{"title":"Adaptive Decentralized MAC for Event-Triggered Networked Control Systems","authors":"Mikhail Vilgelm, M. Mamduhi, W. Kellerer, S. Hirche","doi":"10.1145/2883817.2883829","DOIUrl":"https://doi.org/10.1145/2883817.2883829","url":null,"abstract":"Control over shared communication networks is a key challenge in design and analysis of cyber-physical systems. The quality of control in such systems might be degraded due to the congestion while accessing the scarce communication resources. In this paper, we consider a multiple-loop networked control system (NCS), where all control loops share a communication network. Medium Access Control (MAC) is performed in contention-based fashion using a multi-channel slotted ALOHA protocol, where each control loop decides locally whether to attempt a transmission based on some error thresholds. We further introduce a local event-based resource-aware scheduling design with an adaptive choice of the error thresholds for a transmission. This leads to a hybrid channel access mechanism where the control loops are deterministically categorized into two sets of eligible and ineligible sub-systems for transmission in an event-based fashion, before a random process to select the available channels. In addition, employing the introduced policy, we show the stability of the resulting NCS in terms of Lyapunov stability in probability. We illustrate numerically the efficiency of our proposed approach in terms of reducing the average networked-induced error variance, and show the superiority of the adaptive event-based scheduler compared to the scheduling design with non-adaptive thresholds.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130682545","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}
Reactive synthesis with the ambitious goal of automatically synthesizing correct-by-construction controllers from high-level specifications, has recently attracted significant attention in system design and control. In practice, complex systems are often not constructed from scratch but from a set of existing building blocks. For example in robot motion planning, a robot usually has a number of predefined motion primitives that can be selected and composed to enforce a high-level objective. In this paper, we propose a novel framework for synthesis from a library of parametric and reactive controllers. Parameters allow us to take advantage of the symmetry in many synthesis problems. Reactivity of the controllers takes into account that the environment may be dynamic and potentially adversarial. We first show how these controllers can be automatically constructed from parametric objectives specified by the user to form a library of parametric and reactive controllers. We then give a synthesis algorithm that selects and instantiates controllers from the library in order to satisfy a given linear temporal logic objective. We implement our algorithms symbolically and illustrate the potential of our method by applying it to an autonomous vehicle case study.
{"title":"Compositional Synthesis with Parametric Reactive Controllers","authors":"R. Alur, Salar Moarref, U. Topcu","doi":"10.1145/2883817.2883842","DOIUrl":"https://doi.org/10.1145/2883817.2883842","url":null,"abstract":"Reactive synthesis with the ambitious goal of automatically synthesizing correct-by-construction controllers from high-level specifications, has recently attracted significant attention in system design and control. In practice, complex systems are often not constructed from scratch but from a set of existing building blocks. For example in robot motion planning, a robot usually has a number of predefined motion primitives that can be selected and composed to enforce a high-level objective. In this paper, we propose a novel framework for synthesis from a library of parametric and reactive controllers. Parameters allow us to take advantage of the symmetry in many synthesis problems. Reactivity of the controllers takes into account that the environment may be dynamic and potentially adversarial. We first show how these controllers can be automatically constructed from parametric objectives specified by the user to form a library of parametric and reactive controllers. We then give a synthesis algorithm that selects and instantiates controllers from the library in order to satisfy a given linear temporal logic objective. We implement our algorithms symbolically and illustrate the potential of our method by applying it to an autonomous vehicle case study.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133891033","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 work we present parallelotope bundles, i.e., sets of parallelotopes for a symbolic representation of polytopes. We define a compact representation of these objects and show that any polytope can be canonically expressed by a bundle. We propose efficient algorithms for the manipulation of bundles. Among these, we define techniques for computing tight over-approximations of polynomial transformations. We apply our framework, in combination with the Bernstein technique, to the reachability problem for polynomial dynamical systems. The accuracy and scalability of our approach are validated on a number of case studies.
{"title":"Parallelotope Bundles for Polynomial Reachability","authors":"T. Dreossi, T. Dang, C. Piazza","doi":"10.1145/2883817.2883838","DOIUrl":"https://doi.org/10.1145/2883817.2883838","url":null,"abstract":"In this work we present parallelotope bundles, i.e., sets of parallelotopes for a symbolic representation of polytopes. We define a compact representation of these objects and show that any polytope can be canonically expressed by a bundle. We propose efficient algorithms for the manipulation of bundles. Among these, we define techniques for computing tight over-approximations of polynomial transformations. We apply our framework, in combination with the Bernstein technique, to the reachability problem for polynomial dynamical systems. The accuracy and scalability of our approach are validated on a number of case studies.","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"516 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116223465","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}
{"title":"Session details: Case Studies and Tool Papers","authors":"A. Rajhans","doi":"10.1145/3261110","DOIUrl":"https://doi.org/10.1145/3261110","url":null,"abstract":"","PeriodicalId":337926,"journal":{"name":"Proceedings of the 19th International Conference on Hybrid Systems: Computation and Control","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124943120","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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