Pub Date : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465263
J. Quiroz, I. Soto, Esteban Toledo-Mercado, H. Chávez, Raul Zamorano-Illanes, Jonathan Pereira-Mendoza
This work proposes a model for inertia identification of an electrical power system. A non-linear regression is used from a mathematical model that relates power and frequency variation, obtained from a synchrophasor network. Fitting of the non-linear regressions processed with Big Data, from the PMU and the different real generation contingencies, obtained from the national system operator, are presented.
{"title":"A non-linear regression model for inertia identification using synchrophasors and Big Data","authors":"J. Quiroz, I. Soto, Esteban Toledo-Mercado, H. Chávez, Raul Zamorano-Illanes, Jonathan Pereira-Mendoza","doi":"10.1109/ICAACCA51523.2021.9465263","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465263","url":null,"abstract":"This work proposes a model for inertia identification of an electrical power system. A non-linear regression is used from a mathematical model that relates power and frequency variation, obtained from a synchrophasor network. Fitting of the non-linear regressions processed with Big Data, from the PMU and the different real generation contingencies, obtained from the national system operator, are presented.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"2000 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116680191","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465319
N. Silva, A. Cervantes, F. Gomes, Reinel Aguedo
This article presents a supervision and automatic control system of the pilot plant present in the Laboratory of Instrumentation, Automation and Control (LIAC) at UACSAUFRPE, aiming to cover the first three levels of the automation pyramid: field devices, control and supervision. The system architecture consists of two reservoirs, a programmable logic controller S7-1200, sensors, actuators, and the Elipse SCADA and Matlab software. The methodology for modeling using experimental identification for the level system is presented applying an input step to the plant, with the data being accessed from the supervisory system by the network through the OPC protocol. With the model obtained, simulation and experimentation results are presented using the Proportional- Integral (PI) control strategy for changes in the reference. Finally, a plant supervision and control system and a human-user interface are developed, allowing supervision of the four process variables: level, temperature, pressure and flow, and the level control in the upper reservoir. In addition, it is possible to manage alarms, historical records and reports, for decision making in failure prevision, maintenance and troubleshooting.
{"title":"Supervision and control system of a didactic plant in the teaching of industrial automation and control","authors":"N. Silva, A. Cervantes, F. Gomes, Reinel Aguedo","doi":"10.1109/ICAACCA51523.2021.9465319","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465319","url":null,"abstract":"This article presents a supervision and automatic control system of the pilot plant present in the Laboratory of Instrumentation, Automation and Control (LIAC) at UACSAUFRPE, aiming to cover the first three levels of the automation pyramid: field devices, control and supervision. The system architecture consists of two reservoirs, a programmable logic controller S7-1200, sensors, actuators, and the Elipse SCADA and Matlab software. The methodology for modeling using experimental identification for the level system is presented applying an input step to the plant, with the data being accessed from the supervisory system by the network through the OPC protocol. With the model obtained, simulation and experimentation results are presented using the Proportional- Integral (PI) control strategy for changes in the reference. Finally, a plant supervision and control system and a human-user interface are developed, allowing supervision of the four process variables: level, temperature, pressure and flow, and the level control in the upper reservoir. In addition, it is possible to manage alarms, historical records and reports, for decision making in failure prevision, maintenance and troubleshooting.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130341453","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465192
Elmer Calle, Jose Oliden
Model Predictive Control (MPC) is an excellent control strategy that has high performance and a great ability to deal with multivariate process interactions; constraints on both system inputs and states; and real-time optimization requirements. However, some control problem drawbacks such as process non-linearity, or the non-convexity of the resulting optimization problem generate a higher computational cost for real-time MPC implementation, requiring embedded devices with a higher memory and processing capacity. Consequently, MPC is mostly used in processes with large time constants and/or where devices with high computational performance are available. In this article a controller based on a Neural Network trained from the data generated by a suitable MPC is presented. The proposed controller uses a Recurrent Neural Network to accurately predict the control input based on the previous training data, and once trained the RNN replaces the MPC completely. This reduces the computational cost by not requiring to solve the optimization problem online. The effectiveness of the proposed approach is demonstrated through simulations on a multivariate four coupled-tanks system.
{"title":"Recurrent Neural Network Based Predictive Control Applied to 4 Coupled-tank System","authors":"Elmer Calle, Jose Oliden","doi":"10.1109/ICAACCA51523.2021.9465192","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465192","url":null,"abstract":"Model Predictive Control (MPC) is an excellent control strategy that has high performance and a great ability to deal with multivariate process interactions; constraints on both system inputs and states; and real-time optimization requirements. However, some control problem drawbacks such as process non-linearity, or the non-convexity of the resulting optimization problem generate a higher computational cost for real-time MPC implementation, requiring embedded devices with a higher memory and processing capacity. Consequently, MPC is mostly used in processes with large time constants and/or where devices with high computational performance are available. In this article a controller based on a Neural Network trained from the data generated by a suitable MPC is presented. The proposed controller uses a Recurrent Neural Network to accurately predict the control input based on the previous training data, and once trained the RNN replaces the MPC completely. This reduces the computational cost by not requiring to solve the optimization problem online. The effectiveness of the proposed approach is demonstrated through simulations on a multivariate four coupled-tanks system.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134325477","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465293
Jean C. Campos, Jose Manrique-Silupu, W. Ipanaqué
This paper presents a nonlinear predictive controller based on state space model applied to a dynamic model with partial equations of refrigeration for mango preservation. Refrigeration systems are widely used in the food industry and are essentially important for the Perú's agro-export sector, the main products in this sector are mango, banana, and grape. Advanced control strategies offer the potential to increase the energy efficiency of refrigeration processes while ensuring the quality required for agro-export products. This paper proposes a NMPC designed from a dynamic model based on the fundamentals of thermodynamics and heat transfer of all the elements involved in this system, implemented in a simulated plant from a mathematical model with a switching mode of operation in the evaporator that was previously validated to ensure a similar behavior to a real plant and has been compared with a PID controller to check the control efficiency.
{"title":"Design and Simulation of NMPC based on state space model applied to refrigeration system for mango exportation","authors":"Jean C. Campos, Jose Manrique-Silupu, W. Ipanaqué","doi":"10.1109/ICAACCA51523.2021.9465293","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465293","url":null,"abstract":"This paper presents a nonlinear predictive controller based on state space model applied to a dynamic model with partial equations of refrigeration for mango preservation. Refrigeration systems are widely used in the food industry and are essentially important for the Perú's agro-export sector, the main products in this sector are mango, banana, and grape. Advanced control strategies offer the potential to increase the energy efficiency of refrigeration processes while ensuring the quality required for agro-export products. This paper proposes a NMPC designed from a dynamic model based on the fundamentals of thermodynamics and heat transfer of all the elements involved in this system, implemented in a simulated plant from a mathematical model with a switching mode of operation in the evaporator that was previously validated to ensure a similar behavior to a real plant and has been compared with a PID controller to check the control efficiency.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133672574","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}
The advancement of Internet of Things produces a massive increase in the use of low-power devices, which can contain sensitive information. Most of these devices do not have the necessary security to protect their information. Therefore, the work aims is analyze and compare countermeasures for SCA in low-power devices with 128-AES encryption. In this scenario, we analyze existing countermeasures and conclude that algorithm-based countermeasures are more suitable for low-power devices. Subsequently, we run a set of tests to understand the scope of CPA attacks and thus establish a countermeasure that is tailored to these devices. Finally, we propose a countermeasure based on byte logic, comparing it with traditional countermeasures of the same type.
{"title":"Side Channel Attack Countermeasure for Low Power Devices with AES Encryption","authors":"Nicolás Ruminot-Ahumada, Claudio Valencia-Cordero, Rodrigo Abarzúa-Ortiz","doi":"10.1109/ICAACCA51523.2021.9465337","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465337","url":null,"abstract":"The advancement of Internet of Things produces a massive increase in the use of low-power devices, which can contain sensitive information. Most of these devices do not have the necessary security to protect their information. Therefore, the work aims is analyze and compare countermeasures for SCA in low-power devices with 128-AES encryption. In this scenario, we analyze existing countermeasures and conclude that algorithm-based countermeasures are more suitable for low-power devices. Subsequently, we run a set of tests to understand the scope of CPA attacks and thus establish a countermeasure that is tailored to these devices. Finally, we propose a countermeasure based on byte logic, comparing it with traditional countermeasures of the same type.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116203889","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465229
M. Mineo, Márcia Roberto Covacic, R. Gaino
In this manuscript, a variable structure control strategy is proposed for a simplified linear model which represents a wheelchair commanded by blowing and suction. This model has a proportional and a proportional-integral controller, which were previously included to guarantee stability on the wheelchair. In the simplified model, variations on the parameters of the motors are assumed as polytopic uncertainties, which are considered for the description of the system in state space. Firstly, for a plant ${A(alpha), B(alpha), C}$ an output feedback matrix $G$ and a constant output tandem matrix $F$ were obtained such that the system ${A((x)-B(alpha)GC, B((x), FC}$ is strictly positive real. Then, the variable structure control law is designed for the system. The simulation results show the fast convergence of the state variables, even considering the uncertainties.
{"title":"Variable Structure Control for a Simplified Linear Model of a Wheelchair","authors":"M. Mineo, Márcia Roberto Covacic, R. Gaino","doi":"10.1109/ICAACCA51523.2021.9465229","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465229","url":null,"abstract":"In this manuscript, a variable structure control strategy is proposed for a simplified linear model which represents a wheelchair commanded by blowing and suction. This model has a proportional and a proportional-integral controller, which were previously included to guarantee stability on the wheelchair. In the simplified model, variations on the parameters of the motors are assumed as polytopic uncertainties, which are considered for the description of the system in state space. Firstly, for a plant ${A(alpha), B(alpha), C}$ an output feedback matrix $G$ and a constant output tandem matrix $F$ were obtained such that the system ${A((x)-B(alpha)GC, B((x), FC}$ is strictly positive real. Then, the variable structure control law is designed for the system. The simulation results show the fast convergence of the state variables, even considering the uncertainties.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123414632","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465322
R. Galindo, Y. O. Unufio
A wide variety of methods are used to solve control problems and find optimal control laws that improve the behavior of systems. In this article, a control law is designed for fully actuated dynamic Lagrange systems, that is, systems that have the characteristic that their control input dimension is the same as the dimension of the generalized position vector, beside their parameters are known and their states are known or can be estimated. Canceling part of the dynamics of the system and using the Pontryagin Theorem, a control law is determined that allows the proposed quadratic criterion to be minimized and that ensures the asymptotic stability of the feedback system in the Lyapunov sense. This control law is implemented for optimal regulation, in one of the known problems of optimization of the carriage with the pendulum.
{"title":"Optimal Nonlinear Regulation of Euler-Lagrange Dynamic Systems","authors":"R. Galindo, Y. O. Unufio","doi":"10.1109/ICAACCA51523.2021.9465322","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465322","url":null,"abstract":"A wide variety of methods are used to solve control problems and find optimal control laws that improve the behavior of systems. In this article, a control law is designed for fully actuated dynamic Lagrange systems, that is, systems that have the characteristic that their control input dimension is the same as the dimension of the generalized position vector, beside their parameters are known and their states are known or can be estimated. Canceling part of the dynamics of the system and using the Pontryagin Theorem, a control law is determined that allows the proposed quadratic criterion to be minimized and that ensures the asymptotic stability of the feedback system in the Lyapunov sense. This control law is implemented for optimal regulation, in one of the known problems of optimization of the carriage with the pendulum.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"222 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123237124","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465181
Melannie Sepúlveda, E. Baeza, M. Carrillo, Nathalie Risso, J. Rohten
Severe climate change effects along with the increasing need for countries to become independent from fossil fuels are leading countries to seek more sustainable energy sources. This is not an easy task, as many renewables lack the portability and reduced variability which is required to properly satisfy energy demands. In this context, hydrogen technologies are a promising alternative to work towards this goal. This work presents a brief summary on hydrogen technology properties, focusing in particular on the description of hydrogen cells, their characteristics and main applications. Finally, the operation of a PEM cell is simulated using a computer model, in order to illustrate how these tools can be used to further characterize PEM cell performance when designing hydrogen-based solutions.
{"title":"Hydrogen technologies and PEM fuel cells: A sustainable alternative for Chile","authors":"Melannie Sepúlveda, E. Baeza, M. Carrillo, Nathalie Risso, J. Rohten","doi":"10.1109/ICAACCA51523.2021.9465181","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465181","url":null,"abstract":"Severe climate change effects along with the increasing need for countries to become independent from fossil fuels are leading countries to seek more sustainable energy sources. This is not an easy task, as many renewables lack the portability and reduced variability which is required to properly satisfy energy demands. In this context, hydrogen technologies are a promising alternative to work towards this goal. This work presents a brief summary on hydrogen technology properties, focusing in particular on the description of hydrogen cells, their characteristics and main applications. Finally, the operation of a PEM cell is simulated using a computer model, in order to illustrate how these tools can be used to further characterize PEM cell performance when designing hydrogen-based solutions.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123592971","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465201
Diego Verdugo, F. Rojas, J. Pereda, M. Díaz, G. Gatica
Multi-cell converters increase their current rating by adding more cells in parallel, if also the cells are interleaved the output THDi and input ripple get lower reducing the filter requirements. However interleaving causes circulating currents that need to be mitigated. This work proposes a model and control strategy that decouple the circulating currents from the output current under discontinuous modulation of a multi-cell converter based on Input-Parallel Output-Parallel (IPOP) bridge-cell. The discontinuous modulation eliminates the circulating current between one leg of the bridge cells. The proposed model and control are verified by simulations in Plecs.
{"title":"Modelling and control of a multi-cell converter based on Input-Parallel Output-Parallel bridge-cells with discontinuous interleaved modulation","authors":"Diego Verdugo, F. Rojas, J. Pereda, M. Díaz, G. Gatica","doi":"10.1109/ICAACCA51523.2021.9465201","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465201","url":null,"abstract":"Multi-cell converters increase their current rating by adding more cells in parallel, if also the cells are interleaved the output THDi and input ripple get lower reducing the filter requirements. However interleaving causes circulating currents that need to be mitigated. This work proposes a model and control strategy that decouple the circulating currents from the output current under discontinuous modulation of a multi-cell converter based on Input-Parallel Output-Parallel (IPOP) bridge-cell. The discontinuous modulation eliminates the circulating current between one leg of the bridge cells. The proposed model and control are verified by simulations in Plecs.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130381894","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 : 2021-03-22DOI: 10.1109/ICAACCA51523.2021.9465307
A. Eid, S. Kamel
In this work, the newly metaheuristic Levy Flight Distribution (LFD) optimization technique is implemented for optimal allocation of distributed generations (DG) in radial distribution systems (RDS). The integration of DGs elevates the performance of the distribution systems. The system performance improvement appears in reducing the power losses and voltage deviation and maximizing the system stability. Different numbers of DGs operating at unity power factor (UPF) and optimal lagging power factor (OLPF) are used to achieve the various objectives. The IEEE 33-bus RDS is used as the test system. The obtained results verify the value of the LFD algorithm for solving the DG allocation problem.
{"title":"Optimal Allocation of Multiple Distributed Generations in Radial Distribution Systems Using Levy Flight Distribution Algorithm","authors":"A. Eid, S. Kamel","doi":"10.1109/ICAACCA51523.2021.9465307","DOIUrl":"https://doi.org/10.1109/ICAACCA51523.2021.9465307","url":null,"abstract":"In this work, the newly metaheuristic Levy Flight Distribution (LFD) optimization technique is implemented for optimal allocation of distributed generations (DG) in radial distribution systems (RDS). The integration of DGs elevates the performance of the distribution systems. The system performance improvement appears in reducing the power losses and voltage deviation and maximizing the system stability. Different numbers of DGs operating at unity power factor (UPF) and optimal lagging power factor (OLPF) are used to achieve the various objectives. The IEEE 33-bus RDS is used as the test system. The obtained results verify the value of the LFD algorithm for solving the DG allocation problem.","PeriodicalId":328922,"journal":{"name":"2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129436031","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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