Pub Date : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521757
Mohammed Kh. Al-Nussairi, R. Bayindir
In this paper, the fuzzy logic control (FLC) is presented to address the instability effects of constant power load, and how to regulate the output voltage of a DC-DC Boost converter. The constant power load has negative incremental resistance, which makes the system unstable under a small disturbance on the load. To evaluate the performance, the proposed method is simulated by a MATLAB-SIMULINK model. Furthermore, the proposed concept is validated experimentally using a field programmable gate Array FPGA-Based Hardware-in-the-Loop Simulation by hardware description language.
{"title":"DC-DC Boost Converter Stability with Constant Power Load","authors":"Mohammed Kh. Al-Nussairi, R. Bayindir","doi":"10.1109/EPEPEMC.2018.8521757","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521757","url":null,"abstract":"In this paper, the fuzzy logic control (FLC) is presented to address the instability effects of constant power load, and how to regulate the output voltage of a DC-DC Boost converter. The constant power load has negative incremental resistance, which makes the system unstable under a small disturbance on the load. To evaluate the performance, the proposed method is simulated by a MATLAB-SIMULINK model. Furthermore, the proposed concept is validated experimentally using a field programmable gate Array FPGA-Based Hardware-in-the-Loop Simulation by hardware description language.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124275257","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521860
R. Marinescu, P. Nicolae, I. Nicolae, Cristina-Diana Marinescu, M. Popescu
This paper deals with specific aspects related to the PWM supplying of a load that consists of a uncontrolled rectifier, filtering elements (a coil and capacitor), a chopper with MOSFET and a DC motor. An original experimental setup was conceived. It allows the study of the influence exercised by a simple PWM technique's operational parameter (namely the duty cycle) along with the LC filter over the harmonic distortions of the waveforms acquired from the load terminals. Various operational contexts were addressed. The MATLAB/Simulink package was employed in order to design, simulate and implement the algorithm used in the control side. An interface relying on ControlDesk was conceived. Afterward, the algorithm was implemented in a real time setup by using the dSPACE controller board. An analysis of certain power quality indices (power factor, THD and distorting power factor) was made and conclusions were drawn.
{"title":"Experimental Setup for the Evaluation of the Duty Cycle Influence over the Distorting Regime","authors":"R. Marinescu, P. Nicolae, I. Nicolae, Cristina-Diana Marinescu, M. Popescu","doi":"10.1109/EPEPEMC.2018.8521860","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521860","url":null,"abstract":"This paper deals with specific aspects related to the PWM supplying of a load that consists of a uncontrolled rectifier, filtering elements (a coil and capacitor), a chopper with MOSFET and a DC motor. An original experimental setup was conceived. It allows the study of the influence exercised by a simple PWM technique's operational parameter (namely the duty cycle) along with the LC filter over the harmonic distortions of the waveforms acquired from the load terminals. Various operational contexts were addressed. The MATLAB/Simulink package was employed in order to design, simulate and implement the algorithm used in the control side. An interface relying on ControlDesk was conceived. Afterward, the algorithm was implemented in a real time setup by using the dSPACE controller board. An analysis of certain power quality indices (power factor, THD and distorting power factor) was made and conclusions were drawn.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"312 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120847844","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521999
L. Mandache, A. Marinescu, I. Dumbravă
Wireless charging of electric vehicle batteries is a modern technology of real interest to replace the classical solutions with plugged-in chargers with their mechanical and electrical hazards related to cables and power connectors. Although the technical solution of near-field contactless power transfer is well known, and several achievements are described in the technical literature, the issues of charging time, power transfer efficiency, system stability in real-world conditions and EMC-related problems remain of wider interest. In such a context, this paper presents a novel design approach of wireless power transfer systems with tight coupling for electric vehicles to get a reasonable transferred power with high efficiency and with less sensibility to parameter deviations as in real practice. It also does not require a supplying inverter with variable output frequency. The study is focused on design optimization of magnetically coupled resonators in series-derivation topology. Our theoretical analysis is proven by relevant experimental results.
{"title":"Novel Design Approach of Wireless Chargers for Electric Vehicles","authors":"L. Mandache, A. Marinescu, I. Dumbravă","doi":"10.1109/EPEPEMC.2018.8521999","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521999","url":null,"abstract":"Wireless charging of electric vehicle batteries is a modern technology of real interest to replace the classical solutions with plugged-in chargers with their mechanical and electrical hazards related to cables and power connectors. Although the technical solution of near-field contactless power transfer is well known, and several achievements are described in the technical literature, the issues of charging time, power transfer efficiency, system stability in real-world conditions and EMC-related problems remain of wider interest. In such a context, this paper presents a novel design approach of wireless power transfer systems with tight coupling for electric vehicles to get a reasonable transferred power with high efficiency and with less sensibility to parameter deviations as in real practice. It also does not require a supplying inverter with variable output frequency. The study is focused on design optimization of magnetically coupled resonators in series-derivation topology. Our theoretical analysis is proven by relevant experimental results.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124478627","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521976
P. Pichlík
Torsional vibrations that occur between masses in mechanical systems are undesirable and should be limited. The torsional vibrations are limited in many industrial applications by a control of a dynamic electric drive. However, the torsional vibrations which occur in locomotives axles are different because the vibrations emergence mainly depends on an adhesion conditions change or external sources that are present on the track. The paper presents a method for the torsional vibrations detection and suppression. The detection method is based on an unscented Kalman filter that is simultaneously used as a part of the slip controller that can limit the torsional vibrations besides wheels slip control that is the primary purpose of the slip controller. The method verification is made on the simulations.
{"title":"Method for Torsional Vibrations Detection of Locomotive Wheelset Based on Unscented Kalman Filter","authors":"P. Pichlík","doi":"10.1109/EPEPEMC.2018.8521976","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521976","url":null,"abstract":"Torsional vibrations that occur between masses in mechanical systems are undesirable and should be limited. The torsional vibrations are limited in many industrial applications by a control of a dynamic electric drive. However, the torsional vibrations which occur in locomotives axles are different because the vibrations emergence mainly depends on an adhesion conditions change or external sources that are present on the track. The paper presents a method for the torsional vibrations detection and suppression. The detection method is based on an unscented Kalman filter that is simultaneously used as a part of the slip controller that can limit the torsional vibrations besides wheels slip control that is the primary purpose of the slip controller. The method verification is made on the simulations.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125062177","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521862
A. Isfanuti, M. Paicu, L. Tutelea, T. Staudt, I. Boldea
In this paper, two sensorless control strategies for the spoke-PM rotor synchronous motor drive in a wide speed range are studied: the V/F control with two stabilizing loops and the sensorless field-oriented control (FOC). The FOC was implemented for comparison, only. To improve drive dynamics and responses during transients, the standard V/f control has been enhanced with two stabilizing loops, which provide corrections for both voltage vector amplitude and voltage vector position angle. The main advantages of the V/f control with stabilizing loops are the simplicity, low computation time and lower calibration effort, which makes it desirable for home appliances such pumps and refrigerator compressors. The novelty consists of a new and more simpler formulae for the voltage vector amplitude correction than the ones already existent. The motion sensorless control of the spoke-PM rotor synchronous motor drive is obtained via model-based stator flux estimation using the “active flux” concept. Experimental results between 200 rpm and 2000 rpm validate the two control systems. Finally, a comparison between the experimental results employing both control systems has been done.
{"title":"V/f with stabilizing loops versus FOC of Spoke-PM rotor SM drive: control with experiments","authors":"A. Isfanuti, M. Paicu, L. Tutelea, T. Staudt, I. Boldea","doi":"10.1109/EPEPEMC.2018.8521862","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521862","url":null,"abstract":"In this paper, two sensorless control strategies for the spoke-PM rotor synchronous motor drive in a wide speed range are studied: the V/F control with two stabilizing loops and the sensorless field-oriented control (FOC). The FOC was implemented for comparison, only. To improve drive dynamics and responses during transients, the standard V/f control has been enhanced with two stabilizing loops, which provide corrections for both voltage vector amplitude and voltage vector position angle. The main advantages of the V/f control with stabilizing loops are the simplicity, low computation time and lower calibration effort, which makes it desirable for home appliances such pumps and refrigerator compressors. The novelty consists of a new and more simpler formulae for the voltage vector amplitude correction than the ones already existent. The motion sensorless control of the spoke-PM rotor synchronous motor drive is obtained via model-based stator flux estimation using the “active flux” concept. Experimental results between 200 rpm and 2000 rpm validate the two control systems. Finally, a comparison between the experimental results employing both control systems has been done.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130598995","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521985
Chang-Hua Lin, Chien-Ming Wang, Guan-Jung Chen
A programmable MCU-based battery tester encompasses low-cost and compact configuration is proposed. The proposed battery tester is composed of a MCU, a signal capturing circuit, a HMI (human machine interface) and a programmable sinusoidal load. In order to validate the dynamic characteristics of the lithium-ion battery in practical applications, the programmable sinusoidal load is implemented and used to test. Furthermore, the extracted energy from the lithium-ion battery during diagnostic process can be recycled. Moreover, the loading current can be preset and programmed by the HMI. All the implemented functions and experimental results are fully consistence with the theoretical predictions.
{"title":"A Programmable Battery Tester with Energy Recycling Technique for Lithium-ion Battery","authors":"Chang-Hua Lin, Chien-Ming Wang, Guan-Jung Chen","doi":"10.1109/EPEPEMC.2018.8521985","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521985","url":null,"abstract":"A programmable MCU-based battery tester encompasses low-cost and compact configuration is proposed. The proposed battery tester is composed of a MCU, a signal capturing circuit, a HMI (human machine interface) and a programmable sinusoidal load. In order to validate the dynamic characteristics of the lithium-ion battery in practical applications, the programmable sinusoidal load is implemented and used to test. Furthermore, the extracted energy from the lithium-ion battery during diagnostic process can be recycled. Moreover, the loading current can be preset and programmed by the HMI. All the implemented functions and experimental results are fully consistence with the theoretical predictions.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132467500","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521897
W. Peng, J. Gyselinck, Jin-Woo Ahn, Dong-Hee Lee
This paper focuses on the selection of current sensors and the two-current separation during the commutation region for Switched Reluctance Machines (SRMs) taking into account possible faults. In order to reduce the number of the used current sensors, the proposed current sensor location is presented in consideration of the phase current measurement and fault detection. A 1.5 kW 8/6 SRM is considered; both simulation and experimental results show the effectiveness of the proposed approach under the healthy and faulty conditions.
{"title":"Optimal Current Sensor Position for Switched Reluctance Motor Drives in View of Fault Detection","authors":"W. Peng, J. Gyselinck, Jin-Woo Ahn, Dong-Hee Lee","doi":"10.1109/EPEPEMC.2018.8521897","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521897","url":null,"abstract":"This paper focuses on the selection of current sensors and the two-current separation during the commutation region for Switched Reluctance Machines (SRMs) taking into account possible faults. In order to reduce the number of the used current sensors, the proposed current sensor location is presented in consideration of the phase current measurement and fault detection. A 1.5 kW 8/6 SRM is considered; both simulation and experimental results show the effectiveness of the proposed approach under the healthy and faulty conditions.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126791424","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521991
R. Polichshuk, Nurzhan Zhuldassov, A. Ruderman, B. Reznikov
Cascade H-bridge inverter with Phase-Shifted Pulse Width Modulation (PS-PWM) is an attractive choice for integration of DC sources of different nature. Non-equal DC sources compromise current Total Harmonic Distortion (THD) by introducing undesirable low frequency subharmonics. This paper suggests that, for more than 3 H-bridges, there are two unique current Total Harmonic Distortion (THD) extreme DC source switching sequences on a PWM period-the best that minimizes undesirable low frequency current harmonic content (minimal THD) and the worst that delivers maximal current THD. These extreme sequences depend solely on DC source voltage inequality relationships.
{"title":"On Current THD Extreme Switching Sequences for a Single-Phase Cascade H-Bridge Inverter with Phase-Shifted PWM and Non-Equal DC Sources","authors":"R. Polichshuk, Nurzhan Zhuldassov, A. Ruderman, B. Reznikov","doi":"10.1109/EPEPEMC.2018.8521991","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521991","url":null,"abstract":"Cascade H-bridge inverter with Phase-Shifted Pulse Width Modulation (PS-PWM) is an attractive choice for integration of DC sources of different nature. Non-equal DC sources compromise current Total Harmonic Distortion (THD) by introducing undesirable low frequency subharmonics. This paper suggests that, for more than 3 H-bridges, there are two unique current Total Harmonic Distortion (THD) extreme DC source switching sequences on a PWM period-the best that minimizes undesirable low frequency current harmonic content (minimal THD) and the worst that delivers maximal current THD. These extreme sequences depend solely on DC source voltage inequality relationships.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126813677","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521886
S. Karimi, F. Tahami
Nowadays high efficiency and power density are desired for designing a power electronic converter. Technology advances in power semiconductor devices, makes it possible to design converters for operation in higher frequencies to reduce size of the converters. As the frequency is increased, switching losses and temperature is also increased, so designing a converter for high frequency operation needs some tradeoffs. In this paper a multi-objective design optimization procedure with regard to efficiency and volume has been carried out for an LLC resonant converter used in telecom applications. This optimization algorithm results in the best set of operating frequency, dead time and suitable choice of wide bandgap switches for the primary bridge and the synchronous rectifier in the secondary side. Finally, a 400V to 48V, lKW LLC resonant converter is designed by the proposed algorithm and a full load efficiency of 96% at 775kHz is obtained.
{"title":"Design Optimization of High-Frequency WBG-Based LLC Resonant Converter for Telecom Applications","authors":"S. Karimi, F. Tahami","doi":"10.1109/EPEPEMC.2018.8521886","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521886","url":null,"abstract":"Nowadays high efficiency and power density are desired for designing a power electronic converter. Technology advances in power semiconductor devices, makes it possible to design converters for operation in higher frequencies to reduce size of the converters. As the frequency is increased, switching losses and temperature is also increased, so designing a converter for high frequency operation needs some tradeoffs. In this paper a multi-objective design optimization procedure with regard to efficiency and volume has been carried out for an LLC resonant converter used in telecom applications. This optimization algorithm results in the best set of operating frequency, dead time and suitable choice of wide bandgap switches for the primary bridge and the synchronous rectifier in the secondary side. Finally, a 400V to 48V, lKW LLC resonant converter is designed by the proposed algorithm and a full load efficiency of 96% at 775kHz is obtained.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126850048","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 : 2018-08-01DOI: 10.1109/EPEPEMC.2018.8521753
Yota Saito, Masaya Yamamoto, M. Uno, S. Urabe
A novel voltage equalizer utilizing diffusion capacitance of photovoltaic (PV) cells has been proposed to increase the energy yield from partially-shaded PV modules. The losses of the proposed equalizer are significantly influenced by partial shading conditions because the proposed equalizer processes the unique amount of charge depending on partial shading conditions and duty cycle. This paper investigates loss tendencies of the equalizer under various partial shading conditions. The prototype for twelve cells was built. Equalization tests under one-cell and two-cell shading conditions were performed. Although extractable maximum powers were improved by the proposed equalization under any shading conditions, losses as well as module utilization factors were significantly dependent on duty cycle. The results suggest that, to maximize the energy yield, the duty cycle of the equalizer should be properly adjusted depending on shading conditions.
{"title":"Loss Analysis and Field Testing Under Various Partial Shading Conditions for Switched Capacitor-Based Cell-Level Power Balancing Utilizing Diffusion Capacitance of Photovoltaic Cells","authors":"Yota Saito, Masaya Yamamoto, M. Uno, S. Urabe","doi":"10.1109/EPEPEMC.2018.8521753","DOIUrl":"https://doi.org/10.1109/EPEPEMC.2018.8521753","url":null,"abstract":"A novel voltage equalizer utilizing diffusion capacitance of photovoltaic (PV) cells has been proposed to increase the energy yield from partially-shaded PV modules. The losses of the proposed equalizer are significantly influenced by partial shading conditions because the proposed equalizer processes the unique amount of charge depending on partial shading conditions and duty cycle. This paper investigates loss tendencies of the equalizer under various partial shading conditions. The prototype for twelve cells was built. Equalization tests under one-cell and two-cell shading conditions were performed. Although extractable maximum powers were improved by the proposed equalization under any shading conditions, losses as well as module utilization factors were significantly dependent on duty cycle. The results suggest that, to maximize the energy yield, the duty cycle of the equalizer should be properly adjusted depending on shading conditions.","PeriodicalId":251046,"journal":{"name":"2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC)","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121289128","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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