Pub Date : 2012-11-01DOI: 10.1109/INDUSCON.2012.6451380
E. J. Lima, E. C. Sousa, S. F. de Paula Silva, A. Silveira, A. C. Delaiba
This paper aims to present a new point of view about the active power measurement, for billing purposes, measured at the Point of Common Coupling (PCC) between the utility and the consumer when harmonic distortions are involved. Depending on the origin of it, the active power can result in higher or lower values in comparison to the fundamental component. The consequences are higher costs for the consumer or losses for the utility. Using computational simulations and theoretical analysis, these aspects are evaluated and compared.
{"title":"Energy billing under nonsinusoidal conditions","authors":"E. J. Lima, E. C. Sousa, S. F. de Paula Silva, A. Silveira, A. C. Delaiba","doi":"10.1109/INDUSCON.2012.6451380","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6451380","url":null,"abstract":"This paper aims to present a new point of view about the active power measurement, for billing purposes, measured at the Point of Common Coupling (PCC) between the utility and the consumer when harmonic distortions are involved. Depending on the origin of it, the active power can result in higher or lower values in comparison to the fundamental component. The consequences are higher costs for the consumer or losses for the utility. Using computational simulations and theoretical analysis, these aspects are evaluated and compared.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114502494","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6452525
R. C. Viero, F. D. dos Reis
As is well known the Zeta converter is a fourth-order system. Therefore, the selection of the type of feedback controllers and its design, it is not an easy task. Usually many restrictions must be met in closed-loop control systems. For instance, it is necessary ensure system stability, as well as, guarantee that transient and steady-state responses are under preset limits. In order to design a controller (P, I, PD, PI, PID, Lead, Lag, Lead-Lag), is usually necessary to know the system plant. However, unfortunately, the system plant is not always available and even when it is accessible, designers must have good knowledge of control systems theory in order to design properly the controllers. Aiming to make the compensators design a simpler task to everyone this paper presents a computational model of the dynamic behavior of the Zeta converter working in discontinuous conduction mode, as well as, two design examples of feedback controllers. Two compensators were designed using MATLAB® and SIMULINK® specifically by means of the design optimization library, which could be used thanks to the computational model of the Zeta converter. It was performed a set of simulations using the PSIM® software, in order to validate the proposed computational model. The obtained results confirm that the computational model of the dynamic behavior of the Zeta converter in DCM is useful to design feedback controllers and also to reduce the development time of the compensators.
众所周知，Zeta变换器是一个四阶系统。因此，反馈控制器类型的选择及其设计，并不是一件容易的事情。在闭环控制系统中，通常必须满足许多限制条件。例如，既要保证系统的稳定性，又要保证系统的暂态和稳态响应在预设的范围内。为了设计一个控制器(P, I, PD, PI, PID, Lead, Lag, Lead-Lag)，通常需要知道系统的工厂。然而，不幸的是，系统工厂并不总是可用的，即使当它是可访问的，设计人员必须有良好的控制系统理论知识，以便设计适当的控制器。为了使补偿器的设计更简单，本文给出了不连续导通模式下Zeta变换器动态行为的计算模型，以及两个反馈控制器的设计实例。利用Zeta变换器的计算模型，利用设计优化库，分别利用MATLAB®和SIMULINK®设计了两个补偿器。使用PSIM®软件进行了一组模拟，以验证所提出的计算模型。计算结果表明，该模型对DCM中Zeta变换器的动态特性设计和补偿器的研制具有指导意义。
{"title":"Designing closed-loop controllers using a MatlabP® dynamic model of the Zeta converter in DCM","authors":"R. C. Viero, F. D. dos Reis","doi":"10.1109/INDUSCON.2012.6452525","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6452525","url":null,"abstract":"As is well known the Zeta converter is a fourth-order system. Therefore, the selection of the type of feedback controllers and its design, it is not an easy task. Usually many restrictions must be met in closed-loop control systems. For instance, it is necessary ensure system stability, as well as, guarantee that transient and steady-state responses are under preset limits. In order to design a controller (P, I, PD, PI, PID, Lead, Lag, Lead-Lag), is usually necessary to know the system plant. However, unfortunately, the system plant is not always available and even when it is accessible, designers must have good knowledge of control systems theory in order to design properly the controllers. Aiming to make the compensators design a simpler task to everyone this paper presents a computational model of the dynamic behavior of the Zeta converter working in discontinuous conduction mode, as well as, two design examples of feedback controllers. Two compensators were designed using MATLAB® and SIMULINK® specifically by means of the design optimization library, which could be used thanks to the computational model of the Zeta converter. It was performed a set of simulations using the PSIM® software, in order to validate the proposed computational model. The obtained results confirm that the computational model of the dynamic behavior of the Zeta converter in DCM is useful to design feedback controllers and also to reduce the development time of the compensators.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129257606","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6451436
R. C. Annunziato, R. Gules, E. Romaneli
This paper presents a complete paralleling control method to be used for the parallel inverters connection. The algorithm performs a phase/frequency droop, and presents a new method for the voltage control that operates with or without data communication among the inverters. When communication is operating, a new algorithm is used inserting a variable virtual resistance in the inverter output control, along with active power sharing control, obtaining a low THD value and very good power sharing. Without communication a constant virtual resistance is inserted, increasing the output THD with non-linear load, but still allowing a good active power sharing. The advantage is to obtain a good performance operation with communication, but, in case of communication failure, the system still works providing more reliability. The experimental results are obtained with the parallel connection of two inverters with 8.4 kW and 5.6 kW of nominal output power. The control algorithm allows the correct operation with the communication connection or disconnection, as well with the insertion or removal of the parallel inverters during the system operation.
{"title":"Development of parallel operation of UPS with variable virtual resistance and flexible communication","authors":"R. C. Annunziato, R. Gules, E. Romaneli","doi":"10.1109/INDUSCON.2012.6451436","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6451436","url":null,"abstract":"This paper presents a complete paralleling control method to be used for the parallel inverters connection. The algorithm performs a phase/frequency droop, and presents a new method for the voltage control that operates with or without data communication among the inverters. When communication is operating, a new algorithm is used inserting a variable virtual resistance in the inverter output control, along with active power sharing control, obtaining a low THD value and very good power sharing. Without communication a constant virtual resistance is inserted, increasing the output THD with non-linear load, but still allowing a good active power sharing. The advantage is to obtain a good performance operation with communication, but, in case of communication failure, the system still works providing more reliability. The experimental results are obtained with the parallel connection of two inverters with 8.4 kW and 5.6 kW of nominal output power. The control algorithm allows the correct operation with the communication connection or disconnection, as well with the insertion or removal of the parallel inverters during the system operation.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129900901","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6451434
A. Lopes, F. Favarim, E. Carati
This paper presents a parallel implementation approach of selective harmonic compensator for active power filters. This approach uses field programmable gate array (FPGAs) in order to reduce the compensator computational time. To compensate for even a small number of harmonics digital filters require multiple calculation instructions involving multiplications and additions. Thus, to improve the performance of the computer system it is proposed the digital compensator implementation using parallel structures in FPGA devices. Experimental results are presented to compare the speedup of the proposed parallel approach with the DSP sequential execution time conventionally used in active power filters applications.
{"title":"Active power filters compensator implementation using parallel structures in FPGA devices","authors":"A. Lopes, F. Favarim, E. Carati","doi":"10.1109/INDUSCON.2012.6451434","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6451434","url":null,"abstract":"This paper presents a parallel implementation approach of selective harmonic compensator for active power filters. This approach uses field programmable gate array (FPGAs) in order to reduce the compensator computational time. To compensate for even a small number of harmonics digital filters require multiple calculation instructions involving multiplications and additions. Thus, to improve the performance of the computer system it is proposed the digital compensator implementation using parallel structures in FPGA devices. Experimental results are presented to compare the speedup of the proposed parallel approach with the DSP sequential execution time conventionally used in active power filters applications.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126578195","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6452393
L. M. Cúnico, Y. D. de Novaes, A. Nied, S. Oliveira
This paper presents the modular multilevel converter as medium voltage motor driver. An investigation of the capacitor requirements is performed and a novel control method, based in the inner current control, is proposed. This method can ensure the capacitor balancing as well minimizes the harmonic current in the converter phases. The control method is evaluated by computational simulations of a three-phase driver of a 350 kW, 2.3 kV induction motor. The simulated results have proven the effectiveness of the control structure in the startup procedure and steady state operation.
{"title":"Inner current control method for modular multilevel converter applied in motor drive","authors":"L. M. Cúnico, Y. D. de Novaes, A. Nied, S. Oliveira","doi":"10.1109/INDUSCON.2012.6452393","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6452393","url":null,"abstract":"This paper presents the modular multilevel converter as medium voltage motor driver. An investigation of the capacitor requirements is performed and a novel control method, based in the inner current control, is proposed. This method can ensure the capacitor balancing as well minimizes the harmonic current in the converter phases. The control method is evaluated by computational simulations of a three-phase driver of a 350 kW, 2.3 kV induction motor. The simulated results have proven the effectiveness of the control structure in the startup procedure and steady state operation.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132865855","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6453575
W. Correia, B. C. Torrico
Electromagnetic brakes are commonly applied as variable loads for motor's certification purposes. Otherwise, depending upon its constructive characteristics a proper control strategy may be required. In this work the application of control strategies to control the current applied to an electromagnetic brake as variable load coupled to a 3-phase Induction Motor is investigated. This arrangement composes the motor's certification bench of Lamotriz (Laboratório de Estudos de Eficientizaç ão Enegética em Forças Motizes) at UFC (Universidade Federal do Ceará) which was designed and built [1] for this purpose. A GPC controller is compared to the LMI-MPC control technique.
电磁制动器通常用于电机认证目的的可变负载。否则，根据其构造特性，可能需要适当的控制策略。本文研究了作为变负载耦合到三相感应电动机上的电磁制动器的电流控制策略的应用。这种安排构成了UFC (Universidade Federal do earar )的Lamotriz (Laboratório de Estudos de Eficientizaç o enegtica em foras Motizes)电机认证平台，该平台是为此目的而设计和建造的[1]。将GPC控制器与LMI-MPC控制技术进行了比较。
{"title":"Electromagnetic brake control strategy: A LMI-MPC/GPC comparison subject to time delay","authors":"W. Correia, B. C. Torrico","doi":"10.1109/INDUSCON.2012.6453575","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6453575","url":null,"abstract":"Electromagnetic brakes are commonly applied as variable loads for motor's certification purposes. Otherwise, depending upon its constructive characteristics a proper control strategy may be required. In this work the application of control strategies to control the current applied to an electromagnetic brake as variable load coupled to a 3-phase Induction Motor is investigated. This arrangement composes the motor's certification bench of Lamotriz (Laboratório de Estudos de Eficientizaç ão Enegética em Forças Motizes) at UFC (Universidade Federal do Ceará) which was designed and built [1] for this purpose. A GPC controller is compared to the LMI-MPC control technique.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133138458","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6452633
Antonio Barbosa de Souza Júnior, Francisco G. Sena, B. C. Torrico, Luiz H. S. C. Barreto, S. V. Dias, V. P. Pinto
This work showing a control strategy of position the axis of a three-phase induction motor. Using indirect vector control, was implemented in the block control of position the generalized predictive control, in order to obtain low oscillations in stead state and follow up the set point. The simulation and experimental results validated the proposed strategy.
{"title":"Generalized predictive control applied to the position control of a induction motor","authors":"Antonio Barbosa de Souza Júnior, Francisco G. Sena, B. C. Torrico, Luiz H. S. C. Barreto, S. V. Dias, V. P. Pinto","doi":"10.1109/INDUSCON.2012.6452633","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6452633","url":null,"abstract":"This work showing a control strategy of position the axis of a three-phase induction motor. Using indirect vector control, was implemented in the block control of position the generalized predictive control, in order to obtain low oscillations in stead state and follow up the set point. The simulation and experimental results validated the proposed strategy.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133198776","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6453835
H. Filho, D. Oliveira, C.E.A. Silva
This paper presents the analysis, design, simulation, and experimental results for a three-stage static power converter for battery charging feasible to small wind energy conversion systems (SWECS). The system employs a boost converter cascaded with a Graetz bridge, what allows the implementation of a Maximum Power Point Tracker (MPPT) and the reduction of the mechanical speed under overvoltage conditions across the batteries. Besides, a buck converter is connected in series with the boost stage to ensure a constant voltage bus between the aforementioned topologies. Thus, it is possible to extract the maximum power over the entire wind speed range, and battery charging can be realized through conventional techniques. The complete design of the proposed battery charger including power, control, and supervisory circuits are presented and developed, considering a 300 W system, with the possibility of charging battery banks rated at 12 V or 24 V. Simulation results are presented to prove the existence of maximum power points in the wind generator. Finally, the experimental results of the developed prototype required to validate the functionality of the proposed study are presented and discussed.
{"title":"Three-stage static power converter for battery charging feasible to small wind energy conversion systems","authors":"H. Filho, D. Oliveira, C.E.A. Silva","doi":"10.1109/INDUSCON.2012.6453835","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6453835","url":null,"abstract":"This paper presents the analysis, design, simulation, and experimental results for a three-stage static power converter for battery charging feasible to small wind energy conversion systems (SWECS). The system employs a boost converter cascaded with a Graetz bridge, what allows the implementation of a Maximum Power Point Tracker (MPPT) and the reduction of the mechanical speed under overvoltage conditions across the batteries. Besides, a buck converter is connected in series with the boost stage to ensure a constant voltage bus between the aforementioned topologies. Thus, it is possible to extract the maximum power over the entire wind speed range, and battery charging can be realized through conventional techniques. The complete design of the proposed battery charger including power, control, and supervisory circuits are presented and developed, considering a 300 W system, with the possibility of charging battery banks rated at 12 V or 24 V. Simulation results are presented to prove the existence of maximum power points in the wind generator. Finally, the experimental results of the developed prototype required to validate the functionality of the proposed study are presented and discussed.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131724121","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6453673
L. Costa, S. A. Mussa, I. Barbi
This paper presents a nonisolated multilevel step-down dc-dc converter suitable for high voltage application. The main features of this topology are: low voltage across the semiconductors; low switching losses and reduced volume of output filter. This paper focuses on the five-level structure of the proposed converter, in which the theoretical analysis is carried out and discussed. The five-level proposed dc-dc converter has four capacitors and their voltages should be balanced for its correct operation. Therefore, a capacitor voltage balancing active control is presented and analyzed in detail herein. In order to demonstrate the performance of this converter, experimental results for a prototype of the 700-V input voltage to 450-V output voltage, 5-kW rated power and switching frequency of 20 kHz are reported herein.
{"title":"Multilevel buck dc-dc converter for high voltage application","authors":"L. Costa, S. A. Mussa, I. Barbi","doi":"10.1109/INDUSCON.2012.6453673","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6453673","url":null,"abstract":"This paper presents a nonisolated multilevel step-down dc-dc converter suitable for high voltage application. The main features of this topology are: low voltage across the semiconductors; low switching losses and reduced volume of output filter. This paper focuses on the five-level structure of the proposed converter, in which the theoretical analysis is carried out and discussed. The five-level proposed dc-dc converter has four capacitors and their voltages should be balanced for its correct operation. Therefore, a capacitor voltage balancing active control is presented and analyzed in detail herein. In order to demonstrate the performance of this converter, experimental results for a prototype of the 700-V input voltage to 450-V output voltage, 5-kW rated power and switching frequency of 20 kHz are reported herein.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126731705","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 : 2012-11-01DOI: 10.1109/INDUSCON.2012.6452971
J. Dreher, F. Marangoni, J. Ortiz, C. Rech, M. L. da S. Martins, H. T. Camara, L. D. Flora
This paper presents a new methodology to generate high step-up voltage gain converters based on the combination of two standard DC/DC converters. The converters are combined so that their Input sections are integrated reducing the converter component count. Their Output sections are associated to derive three basic configurations, the series, the parallel and the cascade outputs. The paper presents as an example, the integration of the boost and flyback converters with experimental results.
{"title":"Integrated flyback topologies for high step-up voltage conversion","authors":"J. Dreher, F. Marangoni, J. Ortiz, C. Rech, M. L. da S. Martins, H. T. Camara, L. D. Flora","doi":"10.1109/INDUSCON.2012.6452971","DOIUrl":"https://doi.org/10.1109/INDUSCON.2012.6452971","url":null,"abstract":"This paper presents a new methodology to generate high step-up voltage gain converters based on the combination of two standard DC/DC converters. The converters are combined so that their Input sections are integrated reducing the converter component count. Their Output sections are associated to derive three basic configurations, the series, the parallel and the cascade outputs. The paper presents as an example, the integration of the boost and flyback converters with experimental results.","PeriodicalId":442317,"journal":{"name":"2012 10th IEEE/IAS International Conference on Industry Applications","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120895151","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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