Pub Date : 2012-10-01DOI: 10.1109/VPPC.2012.6422763
C. Mayet, M. Mejri, A. Bouscayrol, J. Pouget, Y. Riffonneau
The EMR (Energetic Macroscopic Representation) of the traction system of a hybrid locomotive is presented. Different models are studied in order to be use for energy management of the entire system including energy storage subsystems. The simulation model is validated by comparison with experimental results.
{"title":"Energetic Macroscopic Representation and inversion-based control of the traction system of a hybrid locomotive","authors":"C. Mayet, M. Mejri, A. Bouscayrol, J. Pouget, Y. Riffonneau","doi":"10.1109/VPPC.2012.6422763","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422763","url":null,"abstract":"The EMR (Energetic Macroscopic Representation) of the traction system of a hybrid locomotive is presented. Different models are studied in order to be use for energy management of the entire system including energy storage subsystems. The simulation model is validated by comparison with experimental results.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"61 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114102890","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/VPPC.2012.6422611
Yun-Sung Kim, D. Jung, Byoung-Kuk Lee
This paper reports the development of power recycle type test bed for aging test applied to Hyundai Motor's LPI AVANTE HEV in mass production. In the general aging test of LDC, the external input power is required and output power is burned by heat through the load device. Accordingly, solutions to reduce input power installation cost and get rid of load heat consumption during aging test are required. Therefore, this study introduces the way to reuse input of LDC by recycling output power of LDC. The developed power recycle type test bed is designed as 1.5kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500W after power recycle. This paper reports the theoretical design analysis and operational characteristics analysis results of test bed and verifies the practicality and reliability of it through the test result. The finally developed test bed was able to confirm high energy recycle performance in entire output load section of LDC.
{"title":"Development of a high efficient LDC test bed in HEVs using power recycle technique","authors":"Yun-Sung Kim, D. Jung, Byoung-Kuk Lee","doi":"10.1109/VPPC.2012.6422611","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422611","url":null,"abstract":"This paper reports the development of power recycle type test bed for aging test applied to Hyundai Motor's LPI AVANTE HEV in mass production. In the general aging test of LDC, the external input power is required and output power is burned by heat through the load device. Accordingly, solutions to reduce input power installation cost and get rid of load heat consumption during aging test are required. Therefore, this study introduces the way to reuse input of LDC by recycling output power of LDC. The developed power recycle type test bed is designed as 1.5kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500W after power recycle. This paper reports the theoretical design analysis and operational characteristics analysis results of test bed and verifies the practicality and reliability of it through the test result. The finally developed test bed was able to confirm high energy recycle performance in entire output load section of LDC.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"48 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":"127606169","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/VPPC.2012.6422715
Soon-Jeong Lee, H. Seo, Chul-Hwan Kim
Recently, by increasing of devices which are sensitive to power quality, the deterioration of power quality has been accelerated. For this reason, the social and economic losses are increased also. So not only correct measurement and evaluation, but also countermeasure for improvement of power quality is surely necessary for both electric power supplier and customer. In this paper, the classification of events and variations occurred in distribution systems using S-transform is proposed. Firstly, we review for events and variations occurred in distribution system. Next, IEEE 13 Node Test is modeled for simulation of events and variations on various conditions using ElectroMagnetic Transient Program - Restructured Version (EMTP-RV). Finally, simulation results are analyzed by using S-transform.
{"title":"Classification of event and variation occurred in distribution system using S-transform","authors":"Soon-Jeong Lee, H. Seo, Chul-Hwan Kim","doi":"10.1109/VPPC.2012.6422715","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422715","url":null,"abstract":"Recently, by increasing of devices which are sensitive to power quality, the deterioration of power quality has been accelerated. For this reason, the social and economic losses are increased also. So not only correct measurement and evaluation, but also countermeasure for improvement of power quality is surely necessary for both electric power supplier and customer. In this paper, the classification of events and variations occurred in distribution systems using S-transform is proposed. Firstly, we review for events and variations occurred in distribution system. Next, IEEE 13 Node Test is modeled for simulation of events and variations on various conditions using ElectroMagnetic Transient Program - Restructured Version (EMTP-RV). Finally, simulation results are analyzed by using S-transform.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"30 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":"132001215","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/VPPC.2012.6422758
Tae‑Hun Kim, Ju-Han Lee, Gyeong-Hun Kim, Minwon Park, I. Yu
The works on the distributed generation systems, such as photovoltaic (PV) power generation system connected to the power grid, has increased in the last decades due to need of supplying the rising worldwide demand for electric power. The utility is created an adverse effect through variety loads. So, this paper presents a three phase grid-connected PV power generation system with active filter (AF) and static synchronous compensator (STATCOM). This system contains an AF function for harmonic currents compensation and a STATCOM function for reactive power compensation without extra devices. The operational characteristics of a grid connected PV system were verified by a fabricated system. Simulation and experimental results are presented to validate the proposed methodology for grid connected PV generation power system.
{"title":"Operation characteristic analysis of Three-phase grid connected PV system with AF and STATCOM","authors":"Tae‑Hun Kim, Ju-Han Lee, Gyeong-Hun Kim, Minwon Park, I. Yu","doi":"10.1109/VPPC.2012.6422758","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422758","url":null,"abstract":"The works on the distributed generation systems, such as photovoltaic (PV) power generation system connected to the power grid, has increased in the last decades due to need of supplying the rising worldwide demand for electric power. The utility is created an adverse effect through variety loads. So, this paper presents a three phase grid-connected PV power generation system with active filter (AF) and static synchronous compensator (STATCOM). This system contains an AF function for harmonic currents compensation and a STATCOM function for reactive power compensation without extra devices. The operational characteristics of a grid connected PV system were verified by a fabricated system. Simulation and experimental results are presented to validate the proposed methodology for grid connected PV generation power system.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"25 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":"132229215","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/VPPC.2012.6422729
Guojing Gao, Fuyuan Yang, Lin Chen, Yuping Yang, M. Ouyang
The use of low-temperature premixed combustion can significantly reduce NOx and soot emission of diesel engines. However, due to application of high EGR rate, the combustion process is sensitive to the variation of the intake fresh air amount. In engine transient operating conditions, the reduction of oxygen concentration of the fuel-air mixture will lead to deterioration of soot emission and the thermal efficiency. Limiting the transient air-fuel ratio by reducing the fuel injection amount is a feasible solution to eliminate the soot emission peak. However it will result in insufficient power output of the engine. In order to solve this problem, an ISG motor, which has the advantage of fast torque response, is integrated on the diesel engine. An in-cylinder pressure based engine torque on-board estimation method is designed and verified. Through calculating the difference between the desired engine torque and the actual engine output torque, a strategy using ISG motor dynamic torque compensation to improve transient power performance is designed. Experiments with different transient control strategies are carried out. The result shows that, by using air-fuel ratio limitation and ISG motor dynamic torque compensation in transient operation conditions of low-temperature premixed combustion, the soot emission can be reduced substantially, while the engine keeps good power performance.
{"title":"Transient control of low-temperature premixed combustion using ISG motor dynamic torque compensation","authors":"Guojing Gao, Fuyuan Yang, Lin Chen, Yuping Yang, M. Ouyang","doi":"10.1109/VPPC.2012.6422729","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422729","url":null,"abstract":"The use of low-temperature premixed combustion can significantly reduce NOx and soot emission of diesel engines. However, due to application of high EGR rate, the combustion process is sensitive to the variation of the intake fresh air amount. In engine transient operating conditions, the reduction of oxygen concentration of the fuel-air mixture will lead to deterioration of soot emission and the thermal efficiency. Limiting the transient air-fuel ratio by reducing the fuel injection amount is a feasible solution to eliminate the soot emission peak. However it will result in insufficient power output of the engine. In order to solve this problem, an ISG motor, which has the advantage of fast torque response, is integrated on the diesel engine. An in-cylinder pressure based engine torque on-board estimation method is designed and verified. Through calculating the difference between the desired engine torque and the actual engine output torque, a strategy using ISG motor dynamic torque compensation to improve transient power performance is designed. Experiments with different transient control strategies are carried out. The result shows that, by using air-fuel ratio limitation and ISG motor dynamic torque compensation in transient operation conditions of low-temperature premixed combustion, the soot emission can be reduced substantially, while the engine keeps good power performance.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","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":"129986117","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/VPPC.2012.6422502
Jung-Hyo Lee, C. Won, Byoung-Kuk Lee, Hyun-Bae Kim, J. Baek, Kyu-Bum Han, U. Chung
This paper proposes a PMSM torque control method considering DC-link voltage variations and friction torque. For EV/HEV applications, a two-dimensional look-up table (2D-LUT) is used for a current reference generation due to its stable and robust torque control performance. Conventionally, this 2D-LUT is established by a flux-torque table to overcome DC-link voltage variations. However, the flux table establishment is more complex than the speed table establishment. Moreover, one flux data reflects several speed conditions in variable DC-link voltage, friction torque cannot be considered by using the flux table. In this paper, a speed-torque 2D-LUT is used for a current reference generation. With this table, PMSM torque control is well achieved regardless of DC-link voltage variations by the proposed control method. Also, friction torque is compensated by a novel compensation block described on this paper.
{"title":"IPMSM torque control method considering DC-link voltage variation and friction torque for EV/HEV applications","authors":"Jung-Hyo Lee, C. Won, Byoung-Kuk Lee, Hyun-Bae Kim, J. Baek, Kyu-Bum Han, U. Chung","doi":"10.1109/VPPC.2012.6422502","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422502","url":null,"abstract":"This paper proposes a PMSM torque control method considering DC-link voltage variations and friction torque. For EV/HEV applications, a two-dimensional look-up table (2D-LUT) is used for a current reference generation due to its stable and robust torque control performance. Conventionally, this 2D-LUT is established by a flux-torque table to overcome DC-link voltage variations. However, the flux table establishment is more complex than the speed table establishment. Moreover, one flux data reflects several speed conditions in variable DC-link voltage, friction torque cannot be considered by using the flux table. In this paper, a speed-torque 2D-LUT is used for a current reference generation. With this table, PMSM torque control is well achieved regardless of DC-link voltage variations by the proposed control method. Also, friction torque is compensated by a novel compensation block described on this paper.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","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":"130261947","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/VPPC.2012.6422650
Il-Ho Lee, Jun-Gu Kim, Taek-Gi Lee, Yong-Chae Jung, C. Won
In this paper, a novel bidirectional DC-DC converter using improved ZVT method is proposed to overcome the drawbacks of the conventional bidirectional DC-DC converter using general PWM methods and resonance. In order to achieve ZVT operation, auxiliary circuit is added to the conventional topology. The added auxiliary circuit consists of one inductor and two capacitors, two switches for bidirectional operation and resonant circuit. In fact, the structure of the ZVT, the auxiliary switch is turned off hard switching. But, because the main switch is turn-on and turn-off with ZVS that decrease losses. Also, Main diode is a big advantage without reverse recovery phenomenon. In this paper, the operational characteristic of the topology is analyzed, and simulation and experiment are performed to verify the validity of the topology.
{"title":"A new bidirectional DC-DC converter with ZVT switching","authors":"Il-Ho Lee, Jun-Gu Kim, Taek-Gi Lee, Yong-Chae Jung, C. Won","doi":"10.1109/VPPC.2012.6422650","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422650","url":null,"abstract":"In this paper, a novel bidirectional DC-DC converter using improved ZVT method is proposed to overcome the drawbacks of the conventional bidirectional DC-DC converter using general PWM methods and resonance. In order to achieve ZVT operation, auxiliary circuit is added to the conventional topology. The added auxiliary circuit consists of one inductor and two capacitors, two switches for bidirectional operation and resonant circuit. In fact, the structure of the ZVT, the auxiliary switch is turned off hard switching. But, because the main switch is turn-on and turn-off with ZVS that decrease losses. Also, Main diode is a big advantage without reverse recovery phenomenon. In this paper, the operational characteristic of the topology is analyzed, and simulation and experiment are performed to verify the validity of the topology.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"16 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":"134186560","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/VPPC.2012.6422774
F. Mensing, R. Trigui, E. Bideaux
Hybrid vehicles are found to be one solution to reduce fuel consumption in the transportation sector. Eco-driving is a concept that is immediately applicable by drivers to improve the efficiency of their vehicle. In this work the potential of eco-driving for hybrid drive train vehicles is discussed. The operation of hybrid vehicles is strongly dependent on their energy management and therefore on battery state-of-charge. Here, the velocity trajectory will be optimized taking into account battery state-of-charge. The vehicle and its control strategy will be modeled to simulate its operation. Given constraints on distance, velocity and time the optimal velocity trajectory is computed using the dynamic programming method in a non-standard approach. The optimal operation of the vehicle is compared to standard driving with respect to fuel consumption and battery state-of-charge. The algorithm is applicable to any hybrid vehicle architecture and will be illustrated on the Toyota Prius II vehicle.
{"title":"Vehicle trajectory optimization for hybrid vehicles taking into account battery state-of-charge","authors":"F. Mensing, R. Trigui, E. Bideaux","doi":"10.1109/VPPC.2012.6422774","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422774","url":null,"abstract":"Hybrid vehicles are found to be one solution to reduce fuel consumption in the transportation sector. Eco-driving is a concept that is immediately applicable by drivers to improve the efficiency of their vehicle. In this work the potential of eco-driving for hybrid drive train vehicles is discussed. The operation of hybrid vehicles is strongly dependent on their energy management and therefore on battery state-of-charge. Here, the velocity trajectory will be optimized taking into account battery state-of-charge. The vehicle and its control strategy will be modeled to simulate its operation. Given constraints on distance, velocity and time the optimal velocity trajectory is computed using the dynamic programming method in a non-standard approach. The optimal operation of the vehicle is compared to standard driving with respect to fuel consumption and battery state-of-charge. The algorithm is applicable to any hybrid vehicle architecture and will be illustrated on the Toyota Prius II vehicle.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"124 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":"134310625","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/VPPC.2012.6422506
T. Yamazaki, Y. Namekawa, S. Yamaguchi, Y. Takahashi
We are developing a single person operated small fuel cell vehicle with a 1kW fuel cell, which we named the micro FCV. A dual drive train system using a small motor and a reduction system has also been designed for the micro FCV. The dual drive train is installed on the left and right sides of the vehicle. By replacing the differential gear, we intend to reduce the overall cost of the mechanism by using a smaller motor. Running experimental results revealed that the micro FCV performed as desired using the dual drive train system. This paper will present the designs of the micro FCV, the motor, the reduction system, the rear drive system, the vehicle state monitoring system, and the experimental results.
{"title":"Dual drive train for single operator fuel cell vehicle","authors":"T. Yamazaki, Y. Namekawa, S. Yamaguchi, Y. Takahashi","doi":"10.1109/VPPC.2012.6422506","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422506","url":null,"abstract":"We are developing a single person operated small fuel cell vehicle with a 1kW fuel cell, which we named the micro FCV. A dual drive train system using a small motor and a reduction system has also been designed for the micro FCV. The dual drive train is installed on the left and right sides of the vehicle. By replacing the differential gear, we intend to reduce the overall cost of the mechanism by using a smaller motor. Running experimental results revealed that the micro FCV performed as desired using the dual drive train system. This paper will present the designs of the micro FCV, the motor, the reduction system, the rear drive system, the vehicle state monitoring system, and the experimental results.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","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":"131251530","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/VPPC.2012.6422770
Yao Guo, Ren-gui Lu, Guoliang Wu, Chunbo Zhu
Equalization for battery pack to enhance its usage life and performance is important for xEVs. In this paper, an isolated bidirectional equalizer based on full-bridge for Lithium-ion battery string is proposed. If a battery charge is excessive, the equalizer transfer charge from this cell to battery string; if a battery charge is insufficient, the equalizer will charge this cell from battery string. Closed-loop control keeps the equalization current constant, allowing precise control of the transferred charge. On the basis of considering OCV hysteresis, we proposed an equalization strategy based on SOC estimation for the equalizer. The equalizer features small size, high efficiency, and high accuracy. Experimental results confirm the applicability of the equalization scheme.
{"title":"A high efficiency isolated bidirectional equalizer for Lithium-ion battery string","authors":"Yao Guo, Ren-gui Lu, Guoliang Wu, Chunbo Zhu","doi":"10.1109/VPPC.2012.6422770","DOIUrl":"https://doi.org/10.1109/VPPC.2012.6422770","url":null,"abstract":"Equalization for battery pack to enhance its usage life and performance is important for xEVs. In this paper, an isolated bidirectional equalizer based on full-bridge for Lithium-ion battery string is proposed. If a battery charge is excessive, the equalizer transfer charge from this cell to battery string; if a battery charge is insufficient, the equalizer will charge this cell from battery string. Closed-loop control keeps the equalization current constant, allowing precise control of the transferred charge. On the basis of considering OCV hysteresis, we proposed an equalization strategy based on SOC estimation for the equalizer. The equalizer features small size, high efficiency, and high accuracy. Experimental results confirm the applicability of the equalization scheme.","PeriodicalId":341659,"journal":{"name":"2012 IEEE Vehicle Power and Propulsion Conference","volume":"51 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":"130740629","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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