Pub Date : 2012-10-01DOI: 10.1109/CCA.2012.6402731
A. Kotsopoulos, T. Antonakopoulos
Accurate nanopositioning is of significant importance in modern Atomic Force Microscopy (AFM) applications that demand high-speed and ultra-precise probe operation. In such applications, position sensors are mostly used in order to provide the control mechanism with feedback regarding probe movement. It has been shown experimentally that the measurement noise introduced by the positioning sensors significantly impairs the overall system performance. In this work, the use of symbol timing recovery for providing medium-derived velocity feedback in nanopositioning tracking controllers for probe-based storage devices is investigated. Although dedicated storage areas with predefined data sequences are used to provide real-time estimates of the system velocity, the proposed approach can also be applied to systems using non-data aided symbol timing recovery. A complete controller enhanced with timing synchronization feedback was designed and its performance was evaluated. It is shown that this medium-derived velocity estimation can be used as an alternative to the sensor-derived position or velocity readings with similar and in some cases superior performance results for a given motion controller. The superiority of the proposed scheme is even more profound when controllers of high-speed nanopositioning are considered, due to the elimination of the position sensor measurement noise, which would corrupt the usually used high-bandwidth closed loop system.
{"title":"Investigating the use of symbol timing recovery for medium-derived feedback in nanopositioning controllers","authors":"A. Kotsopoulos, T. Antonakopoulos","doi":"10.1109/CCA.2012.6402731","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402731","url":null,"abstract":"Accurate nanopositioning is of significant importance in modern Atomic Force Microscopy (AFM) applications that demand high-speed and ultra-precise probe operation. In such applications, position sensors are mostly used in order to provide the control mechanism with feedback regarding probe movement. It has been shown experimentally that the measurement noise introduced by the positioning sensors significantly impairs the overall system performance. In this work, the use of symbol timing recovery for providing medium-derived velocity feedback in nanopositioning tracking controllers for probe-based storage devices is investigated. Although dedicated storage areas with predefined data sequences are used to provide real-time estimates of the system velocity, the proposed approach can also be applied to systems using non-data aided symbol timing recovery. A complete controller enhanced with timing synchronization feedback was designed and its performance was evaluated. It is shown that this medium-derived velocity estimation can be used as an alternative to the sensor-derived position or velocity readings with similar and in some cases superior performance results for a given motion controller. The superiority of the proposed scheme is even more profound when controllers of high-speed nanopositioning are considered, due to the elimination of the position sensor measurement noise, which would corrupt the usually used high-bandwidth closed loop system.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133366036","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402725
X. Gong, Qifang Liu, Yunfeng Hu, Hong Chen
In this paper, an idle speed controller is designed in the framework of active disturbance rejection control (ADRC) for spark ignition (SI) engine. The SI engine model based on the mean value model is proposed. As the system can be considered as a cascade system, the developed controller incorporates a nonlinear state error feedback law (NLSEF) which handles the speed tracking and an ADRC controller based on the Extended State Observer (ESO) to deal with the unknown dynamics and disturbance of the engine system.The robustness stability of the controller is analyzed. Simulation results are provided to demonstrate the advantage and effectiveness of the controller.
{"title":"Idle speed controller design for SI engine based on ADRC","authors":"X. Gong, Qifang Liu, Yunfeng Hu, Hong Chen","doi":"10.1109/CCA.2012.6402725","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402725","url":null,"abstract":"In this paper, an idle speed controller is designed in the framework of active disturbance rejection control (ADRC) for spark ignition (SI) engine. The SI engine model based on the mean value model is proposed. As the system can be considered as a cascade system, the developed controller incorporates a nonlinear state error feedback law (NLSEF) which handles the speed tracking and an ADRC controller based on the Extended State Observer (ESO) to deal with the unknown dynamics and disturbance of the engine system.The robustness stability of the controller is analyzed. Simulation results are provided to demonstrate the advantage and effectiveness of the controller.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133589300","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402677
S. Tabatabaeipour, T. Bak
In this paper we consider the problem of fault estimation and accommodation for discrete time piecewise linear systems. A robust fault estimator is designed to estimate the fault such that the estimation error converges to zero and H∞ performance of the fault estimation is minimized. Then, the estimate of fault is used to compensate for the effect of the fault. Hence, using the estimate of fault, a fault tolerant controller using a piecewise linear static output feedback is designed such that it stabilizes the system and provides an upper bound on the H∞ performance of the faulty system. Sufficient conditions for the existence of robust fault estimator and fault tolerant controller are derived in terms of linear matrix inequalities. Upper bounds on the H∞ performance can be minimized by solving convex optimization problems with linear matrix inequality constraints. The efficiency of the method is demonstrated by means of a numerical example.
{"title":"H∞ integrated fault estimation and fault tolerant control of discrete-time piecewise linear systems","authors":"S. Tabatabaeipour, T. Bak","doi":"10.1109/CCA.2012.6402677","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402677","url":null,"abstract":"In this paper we consider the problem of fault estimation and accommodation for discrete time piecewise linear systems. A robust fault estimator is designed to estimate the fault such that the estimation error converges to zero and H∞ performance of the fault estimation is minimized. Then, the estimate of fault is used to compensate for the effect of the fault. Hence, using the estimate of fault, a fault tolerant controller using a piecewise linear static output feedback is designed such that it stabilizes the system and provides an upper bound on the H∞ performance of the faulty system. Sufficient conditions for the existence of robust fault estimator and fault tolerant controller are derived in terms of linear matrix inequalities. Upper bounds on the H∞ performance can be minimized by solving convex optimization problems with linear matrix inequality constraints. The efficiency of the method is demonstrated by means of a numerical example.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121968879","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402650
H. Nasir, Abubakr Muhammad
In this paper, we investigate methods for automated localization of leaks and dumps in an open channel flow. We propose a framework under which we solve this important system health monitoring problem by using a network of level sensors and estimation algorithms. We first discuss numerical techniques for simulating a channel with leaks or dumps. We then give results of a multiple-model estimation technique and study its performance against model uncertainty and noise. We find the method to be both robust and accurate. We also find that the sensing accuracy increases at least quadratically by addition of sensors. This is achieved by using a search algorithm on the errors generated by multiple PDE models.
{"title":"Locating leaks & dumps in open channels with minimal sensing","authors":"H. Nasir, Abubakr Muhammad","doi":"10.1109/CCA.2012.6402650","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402650","url":null,"abstract":"In this paper, we investigate methods for automated localization of leaks and dumps in an open channel flow. We propose a framework under which we solve this important system health monitoring problem by using a network of level sensors and estimation algorithms. We first discuss numerical techniques for simulating a channel with leaks or dumps. We then give results of a multiple-model estimation technique and study its performance against model uncertainty and noise. We find the method to be both robust and accurate. We also find that the sensing accuracy increases at least quadratically by addition of sensors. This is achieved by using a search algorithm on the errors generated by multiple PDE models.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117293623","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402706
V. Spinu, M. Lazar
This paper investigates the integration of control theory and real-time implementation specifications within a single tractable controller synthesis method. It is proposed to guarantee real-time feasibility through specific low-complexity partitions of the piecewise affine (PWA) control law. The control-theory specification, i.e., stability under state and input constraints, are integrated through conic partitions induced by a polyhedral control Lyapunov function (CLF). The combination of the controller and conic partitions yields the hybrid polytopic partition, which is the cornerstone of the developed synthesis method. Based on the HPP, the controller synthesis is pursued by low complexity linear programming. The effectiveness of the approach is demonstrated in a case-study on real-time control of a buck power converter.
{"title":"Integration of real-time and stability constraints via hybrid polytopic partitions","authors":"V. Spinu, M. Lazar","doi":"10.1109/CCA.2012.6402706","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402706","url":null,"abstract":"This paper investigates the integration of control theory and real-time implementation specifications within a single tractable controller synthesis method. It is proposed to guarantee real-time feasibility through specific low-complexity partitions of the piecewise affine (PWA) control law. The control-theory specification, i.e., stability under state and input constraints, are integrated through conic partitions induced by a polyhedral control Lyapunov function (CLF). The combination of the controller and conic partitions yields the hybrid polytopic partition, which is the cornerstone of the developed synthesis method. Based on the HPP, the controller synthesis is pursued by low complexity linear programming. The effectiveness of the approach is demonstrated in a case-study on real-time control of a buck power converter.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121106168","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402432
M. Tabatabaei
In this paper the characteristic ratio assignment (CRA) method is employed to control transient response of a class of non-minimum phase fractional order systems. Since fractional order all-pass filter could not be realized, the fractional unstable zeros are converted to integer unstable zeros by multiplying complementary polynomials to numerator and denominator polynomials of system's transfer function. Doing so, the closed loop system would be an integer order all-pass filter multiple an all-pole fractional transfer function determined from CRA method. Computer simulation results are presented to illustrate the performance of the proposed method.
{"title":"CRA based Control of non-minimum phase fractional order systems","authors":"M. Tabatabaei","doi":"10.1109/CCA.2012.6402432","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402432","url":null,"abstract":"In this paper the characteristic ratio assignment (CRA) method is employed to control transient response of a class of non-minimum phase fractional order systems. Since fractional order all-pass filter could not be realized, the fractional unstable zeros are converted to integer unstable zeros by multiplying complementary polynomials to numerator and denominator polynomials of system's transfer function. Doing so, the closed loop system would be an integer order all-pass filter multiple an all-pole fractional transfer function determined from CRA method. Computer simulation results are presented to illustrate the performance of the proposed method.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116631983","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402686
Zhen Sun, Zhenyu Yang
The Time-Varying First Order Plus Dead Time (TV-FOPDT) model is an extension of the conventional FOPDT by allowing the system parameters, which are primarily defined on the transfer function description, i.e., the DC-gain, time constant and time delay, to be time dependent. The TV-FOPDT identification problem turns to estimate these time-varying parameters based on measured control input and system output. This work considers a TV-FOPDT identification problem in the presence of an unknown disturbance input. By regarding the unknown input as one extra system parameter, the considered identification problem is formulated as a Stochastic Mixed Integral Programming (SMIP) problem after discretizing the original problem. The sliding window technique with forgetting factor is employed to cope with time resolution issue, and the Least Mean Square (LMS) method is used to obtain the optimal solution of each individual optimization problem based on different time delay assumptions. The proposed method is firstly tested through a number of numerical examples, and then it is applied to estimate a TV-FOPDT model of the superheat dynamic of a supermarket refrigeration system.
{"title":"Time-Varying FOPDT system identification with unknown disturbance input","authors":"Zhen Sun, Zhenyu Yang","doi":"10.1109/CCA.2012.6402686","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402686","url":null,"abstract":"The Time-Varying First Order Plus Dead Time (TV-FOPDT) model is an extension of the conventional FOPDT by allowing the system parameters, which are primarily defined on the transfer function description, i.e., the DC-gain, time constant and time delay, to be time dependent. The TV-FOPDT identification problem turns to estimate these time-varying parameters based on measured control input and system output. This work considers a TV-FOPDT identification problem in the presence of an unknown disturbance input. By regarding the unknown input as one extra system parameter, the considered identification problem is formulated as a Stochastic Mixed Integral Programming (SMIP) problem after discretizing the original problem. The sliding window technique with forgetting factor is employed to cope with time resolution issue, and the Least Mean Square (LMS) method is used to obtain the optimal solution of each individual optimization problem based on different time delay assumptions. The proposed method is firstly tested through a number of numerical examples, and then it is applied to estimate a TV-FOPDT model of the superheat dynamic of a supermarket refrigeration system.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116130207","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402434
Yao Li, W. Levine
In earlier work, an optimal control model of human posture regulation that replicated significant features of experimental observations of humans' response to perturbations was presented. In that work the muscles were modeled as ideal torque generators and the performance measure was quartic in the states and quadratic in the controls. Here, a much more realistic model of muscles is utilized and performance criteria up to eighth order in the states are considered. The resulting closed-loop systems use less muscle force, less neural control signal, and responds faster to initial condition errors than the corresponding linear quadratic optimal control.
{"title":"Nonlinear optimal muscular control of human posture","authors":"Yao Li, W. Levine","doi":"10.1109/CCA.2012.6402434","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402434","url":null,"abstract":"In earlier work, an optimal control model of human posture regulation that replicated significant features of experimental observations of humans' response to perturbations was presented. In that work the muscles were modeled as ideal torque generators and the performance measure was quartic in the states and quadratic in the controls. Here, a much more realistic model of muscles is utilized and performance criteria up to eighth order in the states are considered. The resulting closed-loop systems use less muscle force, less neural control signal, and responds faster to initial condition errors than the corresponding linear quadratic optimal control.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116420852","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402448
P. Bonhomme, Anouch Hovsepian
In this paper a novel schedulability analysis technique of real-time systems is presented. The developed approach is based on the consideration of the reachability graph of the (untimed) underlying Petri net of the studied model. The schedulability analysis is then conducted in two steps. Once a feasible firing sequence (called occurrence sequence) is highlighted, this sequence is then described under an algebraic form of type Ax ≤ b. The particular features of matrix A lead to a bimonotone linear inequality system. A bimonotone linear inequality is a linear inequality with at most two nonzero coefficients that are of opposite signs (if both different from zero). Thus, deciding whether a firing sequence is schedulable or not takes the form of the solution of a single-source shortest path problem which can be polynomially solved via the Bellman-Ford algorithm.
{"title":"Towards a new schedulability technique of real-time systems based on difference of constraints system","authors":"P. Bonhomme, Anouch Hovsepian","doi":"10.1109/CCA.2012.6402448","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402448","url":null,"abstract":"In this paper a novel schedulability analysis technique of real-time systems is presented. The developed approach is based on the consideration of the reachability graph of the (untimed) underlying Petri net of the studied model. The schedulability analysis is then conducted in two steps. Once a feasible firing sequence (called occurrence sequence) is highlighted, this sequence is then described under an algebraic form of type Ax ≤ b. The particular features of matrix A lead to a bimonotone linear inequality system. A bimonotone linear inequality is a linear inequality with at most two nonzero coefficients that are of opposite signs (if both different from zero). Thus, deciding whether a firing sequence is schedulable or not takes the form of the solution of a single-source shortest path problem which can be polynomially solved via the Bellman-Ford algorithm.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116891371","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 : 2012-10-01DOI: 10.1109/CCA.2012.6402366
Jonqlan Lin, Youmin Ding, Julian Chang
Using a combination of the cart-seesaw and the inverted pendulum system, this paper presents a novel laboratory apparatus called the cart-pendulum-seesaw (CPS) system. The proposed pneumatic CPS is a classic example of a super articulated mechanical system (SAMS). The resulting system has two inputs: a force applied to the cart and another force applied to the loading cart which tries to balance the seesaw test-bed. With two inputs and four available for the measurement outputs, the unstable multi-input-multi-output (MIMO) system offers an interesting control challenge. This study decomposes the system into several tasks, one for pendulum swinging up and the other for seesaw balancing. The pendulum is first swung up; then, balancing the pendulum at the upright position with a fuzzy controller, the seesaw is balanced by another fuzzy controller. This study incorporates a fuzzy coordinator into the seesaw system to take control action in extreme situations. The experimental device is used to evaluate the efficiency of the proposed methodology. Unlike other model-based methods, the proposed fuzzy control methodology does not need an accurate measurement of all state parameters; moreover, it is robust for parameter changes and other disturbances in the system.
{"title":"Dynamics modeling and hybrid fuzzy control for pneumatic cart-pendulum-seesaw system","authors":"Jonqlan Lin, Youmin Ding, Julian Chang","doi":"10.1109/CCA.2012.6402366","DOIUrl":"https://doi.org/10.1109/CCA.2012.6402366","url":null,"abstract":"Using a combination of the cart-seesaw and the inverted pendulum system, this paper presents a novel laboratory apparatus called the cart-pendulum-seesaw (CPS) system. The proposed pneumatic CPS is a classic example of a super articulated mechanical system (SAMS). The resulting system has two inputs: a force applied to the cart and another force applied to the loading cart which tries to balance the seesaw test-bed. With two inputs and four available for the measurement outputs, the unstable multi-input-multi-output (MIMO) system offers an interesting control challenge. This study decomposes the system into several tasks, one for pendulum swinging up and the other for seesaw balancing. The pendulum is first swung up; then, balancing the pendulum at the upright position with a fuzzy controller, the seesaw is balanced by another fuzzy controller. This study incorporates a fuzzy coordinator into the seesaw system to take control action in extreme situations. The experimental device is used to evaluate the efficiency of the proposed methodology. Unlike other model-based methods, the proposed fuzzy control methodology does not need an accurate measurement of all state parameters; moreover, it is robust for parameter changes and other disturbances in the system.","PeriodicalId":284064,"journal":{"name":"2012 IEEE International Conference on Control Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121179019","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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