Pub Date : 2019-12-01DOI: 10.1109/ICC47138.2019.9123152
Arvind Ravi, N. Kaisare
An integrated architecture comprising of a state estimator, dynamic optimizer and model predictive control (MPC) is designed in this work for an output feedback multi-objective control of a process system involving multiple units. The output feedback control uses a multi-rate extended Kalman Filter (EKF) for state estimation. Measurement delays in the arrival of the measurements of the infrequently sampled primary process variable are fused using a computationally efficient sampled-state augmentation approach. Certainty equivalence is assumed, and the state estimates are used by a dynamic multi-objective optimizer (D-MOO) followed by the coordinator MPC to implement feasible inputs to the plant. The trade-off between multiple objectives are handled by the D-MOO using the augmented -constraint method (AUGMECON) to generate the Pareto optimal solutions. This method computes efficient solution by incorporating slack variable in the optimization. The best solution among the Pareto optimal points is chosen close to the Utopian point. The significance of this algorithm in comparison with the conventional weight-based multi-objective control is discussed. The proposed algorithm is implemented on case study of a multi-unit system involving a series of two reactors followed by a separator.
{"title":"Integrated multi-objective predictive control for multi-unit system","authors":"Arvind Ravi, N. Kaisare","doi":"10.1109/ICC47138.2019.9123152","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123152","url":null,"abstract":"An integrated architecture comprising of a state estimator, dynamic optimizer and model predictive control (MPC) is designed in this work for an output feedback multi-objective control of a process system involving multiple units. The output feedback control uses a multi-rate extended Kalman Filter (EKF) for state estimation. Measurement delays in the arrival of the measurements of the infrequently sampled primary process variable are fused using a computationally efficient sampled-state augmentation approach. Certainty equivalence is assumed, and the state estimates are used by a dynamic multi-objective optimizer (D-MOO) followed by the coordinator MPC to implement feasible inputs to the plant. The trade-off between multiple objectives are handled by the D-MOO using the augmented -constraint method (AUGMECON) to generate the Pareto optimal solutions. This method computes efficient solution by incorporating slack variable in the optimization. The best solution among the Pareto optimal points is chosen close to the Utopian point. The significance of this algorithm in comparison with the conventional weight-based multi-objective control is discussed. The proposed algorithm is implemented on case study of a multi-unit system involving a series of two reactors followed by a separator.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"218 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131683782","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123243
J. Myala, V. Patel, G. K. Singh
Fault Detection and Diagnosis system (FDD) is used to isolate the aircraft fault which provides information to reconfiguration mechanism to recover its operation during the fault occurrence. Using FDD, only anticipated faults can be tackled by design. Inaccurate information from the FDD and if interpreted incorrectly by the reconfiguration mechanism, can lead to a complete loss of system stability. Robust fault identification methods need to be explored especially for the unanticipated fault scenarios. In this paper, single control surface damage fault scenario arising due to either bird strike or battle damage is considered. A typical mathematical model of the aircraft is simulated with single control surface damage which captures the dynamics of high performance aircraft. The real-time parameter estimation of augmented aircraft is essential for reconfigurable flight control. Fault detection and identification is solved with extended Kalman filter considering only state and observation equations for lateral and directional axis.
{"title":"Reliable Fault Identification for Aircraft Control Surface Damage","authors":"J. Myala, V. Patel, G. K. Singh","doi":"10.1109/ICC47138.2019.9123243","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123243","url":null,"abstract":"Fault Detection and Diagnosis system (FDD) is used to isolate the aircraft fault which provides information to reconfiguration mechanism to recover its operation during the fault occurrence. Using FDD, only anticipated faults can be tackled by design. Inaccurate information from the FDD and if interpreted incorrectly by the reconfiguration mechanism, can lead to a complete loss of system stability. Robust fault identification methods need to be explored especially for the unanticipated fault scenarios. In this paper, single control surface damage fault scenario arising due to either bird strike or battle damage is considered. A typical mathematical model of the aircraft is simulated with single control surface damage which captures the dynamics of high performance aircraft. The real-time parameter estimation of augmented aircraft is essential for reconfigurable flight control. Fault detection and identification is solved with extended Kalman filter considering only state and observation equations for lateral and directional axis.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129132970","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123167
Chayan Bhawal, Debasattam Pal, M. Belur
In this paper we deal with a special class of Lyapunov equations which we call circulant Lyapunov equations. These are Lyapunov equations arising from system matrices that are circulant. Here we bring out new theoretical insights into such Lyapunov operators. We show that, under a suitable projection map, two-variable polynomials are related to circulant Lyapunov operators. We also give necessary and sufficient conditions for the solvability of a circulant Lyapunov equation using two dimensional Fourier transform operation (2D-DFT) performed on a specially constructed matrix. Using these links among circulant Lyapunov operators, two-variable polynomials and 2D-DFT, an algorithm to solve circulant Lyapunov equations using 2D-DFT is developed in this paper.
{"title":"On circulant Lyapunov operators, two-variable polynomials, and DFT","authors":"Chayan Bhawal, Debasattam Pal, M. Belur","doi":"10.1109/ICC47138.2019.9123167","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123167","url":null,"abstract":"In this paper we deal with a special class of Lyapunov equations which we call circulant Lyapunov equations. These are Lyapunov equations arising from system matrices that are circulant. Here we bring out new theoretical insights into such Lyapunov operators. We show that, under a suitable projection map, two-variable polynomials are related to circulant Lyapunov operators. We also give necessary and sufficient conditions for the solvability of a circulant Lyapunov equation using two dimensional Fourier transform operation (2D-DFT) performed on a specially constructed matrix. Using these links among circulant Lyapunov operators, two-variable polynomials and 2D-DFT, an algorithm to solve circulant Lyapunov equations using 2D-DFT is developed in this paper.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127444317","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123177
Satyanarayana Neeli, Pooja Sharma
A new discretization technique for the linear continuous-time systems having a delay in the state is proposed. The proposed method employs linear interpolation and zero-order hold (ZOH) for approximating the state and control input variables between two sampling instants respectively. A numerical example is considered to demonstrate and validate the proposed method.
{"title":"Discretization of Linear Continuous-time Systems with State Delay","authors":"Satyanarayana Neeli, Pooja Sharma","doi":"10.1109/ICC47138.2019.9123177","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123177","url":null,"abstract":"A new discretization technique for the linear continuous-time systems having a delay in the state is proposed. The proposed method employs linear interpolation and zero-order hold (ZOH) for approximating the state and control input variables between two sampling instants respectively. A numerical example is considered to demonstrate and validate the proposed method.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128815957","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123171
G. Gurumurthy, D. Das
In the present paper, a Proportional-Integral (PI) controller design methodology is proposed for liquid level control in decoupled Two Input Two Output (TITO)-coupled tank system. First Order Plus Dead Time (FOPDT) model of TITOcoupled tank system is identified by using the least square estimation method. An inverted decoupler is designed to decouple the TITO-coupled tank process into two separate Single Input Single Output (SISO) processes. A model reduction method is used to reduce the order of decoupled systems. The designed PI controller is implemented in both simulation and real-time. Simulation and real-time results show that the proposed PI controller gives better tracking performance such as 18.28% lower setting time, 185.24% lower MP (%) than the reported work in the literature. In control action performance aspect, the proposed PI controller gives 13.40% lower 2-norm when compare to reported work in the literature.
{"title":"A Proportional-Integral (PI) Controller Design and Implementation for Decoupled Two-Input Two-Output-Coupled Tank System with Dead-time","authors":"G. Gurumurthy, D. Das","doi":"10.1109/ICC47138.2019.9123171","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123171","url":null,"abstract":"In the present paper, a Proportional-Integral (PI) controller design methodology is proposed for liquid level control in decoupled Two Input Two Output (TITO)-coupled tank system. First Order Plus Dead Time (FOPDT) model of TITOcoupled tank system is identified by using the least square estimation method. An inverted decoupler is designed to decouple the TITO-coupled tank process into two separate Single Input Single Output (SISO) processes. A model reduction method is used to reduce the order of decoupled systems. The designed PI controller is implemented in both simulation and real-time. Simulation and real-time results show that the proposed PI controller gives better tracking performance such as 18.28% lower setting time, 185.24% lower MP (%) than the reported work in the literature. In control action performance aspect, the proposed PI controller gives 13.40% lower 2-norm when compare to reported work in the literature.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128854308","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123212
Sanjana Vijayshankar, Maziar S. Hemati, Andrew G. Lamperski, S. Dhople
This paper discusses methods for model reduction of power system dynamics. Dynamical models for realistic power-systems can very easily contain several thousands of states. The dimensionality increases further when considering the dynamics of distributed energy resources; these systems are typically smaller in power rating, so many more are installed at the grid edge to scale capacity. Computationally efficient models that capture the dominant modes of the system are important for all aspects of power-system operation, control, and analysis. In this paper, we analyze two data-driven methods for model reduction of power systems: i) proper orthogonal decomposition, which is based on singular value decomposition, and ii) a constrained convex-optimization framework with stability guarantees. Advantages and disadvantages of both of these methods are discussed. Exhaustive numerical simulations for a low-inertia system with mixed synchronous generator and wind energy conversion system resources are provided to verify the accuracy of the model-reduction methods.
{"title":"Model Reduction of Power System Dynamics using a Constrained Convex-optimization Method","authors":"Sanjana Vijayshankar, Maziar S. Hemati, Andrew G. Lamperski, S. Dhople","doi":"10.1109/ICC47138.2019.9123212","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123212","url":null,"abstract":"This paper discusses methods for model reduction of power system dynamics. Dynamical models for realistic power-systems can very easily contain several thousands of states. The dimensionality increases further when considering the dynamics of distributed energy resources; these systems are typically smaller in power rating, so many more are installed at the grid edge to scale capacity. Computationally efficient models that capture the dominant modes of the system are important for all aspects of power-system operation, control, and analysis. In this paper, we analyze two data-driven methods for model reduction of power systems: i) proper orthogonal decomposition, which is based on singular value decomposition, and ii) a constrained convex-optimization framework with stability guarantees. Advantages and disadvantages of both of these methods are discussed. Exhaustive numerical simulations for a low-inertia system with mixed synchronous generator and wind energy conversion system resources are provided to verify the accuracy of the model-reduction methods.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129718284","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123242
Dieter Verbeke, J. Schoukens, R. Relan
Non-parametric estimates play an important role in frequency domain identification of higher-order dynamical systems. Accurate measurements of the frequency response can be used as an intermediate step towards a parametric transfer function model, or provide an effective mechanism for model validation. This paper concerns several aspects of nonparametric frequency domain identification. We review developments in frequency response estimation for a class of linear or weakly nonlinear systems. We examine some properties of the associated confidence bounds. We describe an approach to localize resonant behavior without estimating a parametric model first, and demonstrate its use on experimental data of a steel beam. As models become more complex and diverse in response to the challenges of modern control strategies there will be an increasing need for a greater range of model validation procedures. We draw attention to the appearance of multiple testing problems in system identification, propose one method and contrast with another approach found in the statistics literature.
{"title":"Frequency Response Functions, Uncertainty Estimates, Localization of Resonances, and Model Validation","authors":"Dieter Verbeke, J. Schoukens, R. Relan","doi":"10.1109/ICC47138.2019.9123242","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123242","url":null,"abstract":"Non-parametric estimates play an important role in frequency domain identification of higher-order dynamical systems. Accurate measurements of the frequency response can be used as an intermediate step towards a parametric transfer function model, or provide an effective mechanism for model validation. This paper concerns several aspects of nonparametric frequency domain identification. We review developments in frequency response estimation for a class of linear or weakly nonlinear systems. We examine some properties of the associated confidence bounds. We describe an approach to localize resonant behavior without estimating a parametric model first, and demonstrate its use on experimental data of a steel beam. As models become more complex and diverse in response to the challenges of modern control strategies there will be an increasing need for a greater range of model validation procedures. We draw attention to the appearance of multiple testing problems in system identification, propose one method and contrast with another approach found in the statistics literature.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127431545","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 : 2019-12-01DOI: 10.1109/ICC47138.2019.9123221
Benjamin S. Cooper, Raghvendra V. Cowlagi
We address path-planning for a mobile vehicle, called the actor, to minimize exposure to an unknown spatiotemporally varying scalar threat field. Multiple sensor agents commanded by the actor take pointwise measurements and estimate the threat field using a consensus filter. The actor and sensors communicate over a network with fixed distance-based topology. We introduce a novel interactive planning and sensing algorithm, where sensor agents are iteratively reconfigured to minimize the actor’s cost. Two sensor reconfiguration policies are proposed: one that enforces all sensors to remain within the actor’s communication network, and the other that allows sensors to be deployed farther away. Through numerical simulation results we demonstrate that the proposed algorithm achieves near-optimal performance for the actor.
{"title":"Decentralized Interactive Planning and Sensing in an Unknown Spatiotemporal Threat Field","authors":"Benjamin S. Cooper, Raghvendra V. Cowlagi","doi":"10.1109/ICC47138.2019.9123221","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123221","url":null,"abstract":"We address path-planning for a mobile vehicle, called the actor, to minimize exposure to an unknown spatiotemporally varying scalar threat field. Multiple sensor agents commanded by the actor take pointwise measurements and estimate the threat field using a consensus filter. The actor and sensors communicate over a network with fixed distance-based topology. We introduce a novel interactive planning and sensing algorithm, where sensor agents are iteratively reconfigured to minimize the actor’s cost. Two sensor reconfiguration policies are proposed: one that enforces all sensors to remain within the actor’s communication network, and the other that allows sensors to be deployed farther away. Through numerical simulation results we demonstrate that the proposed algorithm achieves near-optimal performance for the actor.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121783749","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 : 2019-10-06DOI: 10.1109/ICC47138.2019.9123166
Anant A. Joshi, Maulik Bhatt, A. Sinha
This paper addresses the problem of exploring a region using Hilbert’s space-filling curve in the presence of obstacles. No prior knowledge of the region being explored is assumed. An online algorithm is proposed which can implement evasive strategies to avoid up to two obstacles placed side by side and successfully explore the entire region. The strategies are specified changing the waypoint array followed by the robot, locally at the hole. The fractal nature of Hilbert’s space-filling curve has been exploited in proving the validity of the solution. Extension of algorithm for bigger obstacles is briefly shown.
{"title":"Modification of Hilbert’s Space-Filling Curve to Avoid Obstacles: A Robotic Path-Planning Strategy","authors":"Anant A. Joshi, Maulik Bhatt, A. Sinha","doi":"10.1109/ICC47138.2019.9123166","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123166","url":null,"abstract":"This paper addresses the problem of exploring a region using Hilbert’s space-filling curve in the presence of obstacles. No prior knowledge of the region being explored is assumed. An online algorithm is proposed which can implement evasive strategies to avoid up to two obstacles placed side by side and successfully explore the entire region. The strategies are specified changing the waypoint array followed by the robot, locally at the hole. The fractal nature of Hilbert’s space-filling curve has been exploited in proving the validity of the solution. Extension of algorithm for bigger obstacles is briefly shown.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133323829","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 : 2019-05-23DOI: 10.1109/ICC47138.2019.9123209
Jianyu Wang, Anit Kumar Sahu, Zhouyi Yang, Gauri Joshi, S. Kar
Decentralized stochastic gradient descent (SGD) is a promising approach to learn a machine learning model over a network of workers connected in an arbitrary topology. Although a densely-connected network topology can ensure faster convergence in terms of iterations, it incurs more communication time/delay per iteration, resulting in longer training time. In this paper, we propose a novel algorithm MATCHA to achieve a win-win in this error-runtime trade-off. MATCHA uses matching decomposition sampling of the base topology to parallelize inter-worker information exchange so as to significantly reduce communication delay. At the same time, the algorithm communicates more frequently over critical links such that it can maintain the same convergence rate as vanilla decentralized SGD. Experiments on a suite of datasets and deep neural networks validate the theoretical analysis and demonstrate the effectiveness of the proposed scheme as far as reducing communication delays is concerned.
{"title":"MATCHA: Speeding Up Decentralized SGD via Matching Decomposition Sampling","authors":"Jianyu Wang, Anit Kumar Sahu, Zhouyi Yang, Gauri Joshi, S. Kar","doi":"10.1109/ICC47138.2019.9123209","DOIUrl":"https://doi.org/10.1109/ICC47138.2019.9123209","url":null,"abstract":"Decentralized stochastic gradient descent (SGD) is a promising approach to learn a machine learning model over a network of workers connected in an arbitrary topology. Although a densely-connected network topology can ensure faster convergence in terms of iterations, it incurs more communication time/delay per iteration, resulting in longer training time. In this paper, we propose a novel algorithm MATCHA to achieve a win-win in this error-runtime trade-off. MATCHA uses matching decomposition sampling of the base topology to parallelize inter-worker information exchange so as to significantly reduce communication delay. At the same time, the algorithm communicates more frequently over critical links such that it can maintain the same convergence rate as vanilla decentralized SGD. Experiments on a suite of datasets and deep neural networks validate the theoretical analysis and demonstrate the effectiveness of the proposed scheme as far as reducing communication delays is concerned.","PeriodicalId":231050,"journal":{"name":"2019 Sixth Indian Control Conference (ICC)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128515324","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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