Pub Date : 2000-08-01DOI: 10.1109/IECON.1999.819365
P. Pillay, Yaguang Liu, O. G. Durham
Due to its magnetic nonlinearities, SRM drive control is complicated and normally requires a microprocessor or a DSP. This paper presents a simple and reliable SRM drive using an innovative encoder based on optical graphical programming technology. There is no microprocessor in the drive, no A/D or D/A circuitry, with a drive system that matches the simplicity of the motor construction. It features a simple and effective control capability. Current waveform optimization for the encoder is carried out offline, for high efficiency and programmed directly into the encoder. Experimental results validate the concept.
{"title":"A novel switched reluctance motor drive with optical graphical programming technology","authors":"P. Pillay, Yaguang Liu, O. G. Durham","doi":"10.1109/IECON.1999.819365","DOIUrl":"https://doi.org/10.1109/IECON.1999.819365","url":null,"abstract":"Due to its magnetic nonlinearities, SRM drive control is complicated and normally requires a microprocessor or a DSP. This paper presents a simple and reliable SRM drive using an innovative encoder based on optical graphical programming technology. There is no microprocessor in the drive, no A/D or D/A circuitry, with a drive system that matches the simplicity of the motor construction. It features a simple and effective control capability. Current waveform optimization for the encoder is carried out offline, for high efficiency and programmed directly into the encoder. Experimental results validate the concept.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115195175","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 : 2000-04-01DOI: 10.1109/IECON.1999.816425
西村 欣剛
Mechanical ventilation systems are designed to maintain a comfortable indoor environment by supplying a precise amount of processed air to the air-conditioned space. It is one of the major energy consumers in the building sector, especially for tropical countries like Singapore where air-conditioning operates on a 12-months basis. A well-balanced ventilation system improves the thermal comfort and indoor air quality, as well as can reduce the energy consumption of the building. It is estimated that air balancing technologies can bring up to 40% energy saving compared with an imbalanced ventilation system. As a result, the air balancing technologies are very important to realize energy saving for green buildings. However, the existing air balancing method lacks systematic theory, which are based on a ‘trial and error’ way. Unfortunately, the human experiences cannot guarantee satisfied air balancing requirement, resulting in more labour cost, lead to worse indoor air quality and more energy waste.
{"title":"The 25th Annual Conference Of The IEEE Industrial Electronics Society","authors":"西村 欣剛","doi":"10.1109/IECON.1999.816425","DOIUrl":"https://doi.org/10.1109/IECON.1999.816425","url":null,"abstract":"Mechanical ventilation systems are designed to maintain a comfortable indoor environment by supplying a precise amount of processed air to the air-conditioned space. It is one of the major energy consumers in the building sector, especially for tropical countries like Singapore where air-conditioning operates on a 12-months basis. A well-balanced ventilation system improves the thermal comfort and indoor air quality, as well as can reduce the energy consumption of the building. It is estimated that air balancing technologies can bring up to 40% energy saving compared with an imbalanced ventilation system. As a result, the air balancing technologies are very important to realize energy saving for green buildings. However, the existing air balancing method lacks systematic theory, which are based on a ‘trial and error’ way. Unfortunately, the human experiences cannot guarantee satisfied air balancing requirement, resulting in more labour cost, lead to worse indoor air quality and more energy waste.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115096482","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 : 1999-11-29DOI: 10.1109/IECON.1999.816537
Y. Kwon, D. W. Jin
Speed and torque control of an induction motor is usually attained by application of a speed or position sensor. However, speed and position sensors require the additional mounting space, reduce the reliability in harsh environments and increase the cost of the motor. Various control algorithms have been proposed for the elimination of speed and position sensors. This paper investigates a novel speed sensorless control of an induction motor. The proposed control strategy is based on MRAS (model reference adaptive system) using state observer model with current error feedback and rotor current model as two models for flux estimation. The rotor speed is estimated so that the difference between the outputs of state observer model and rotor current model may be zero. This algorithm may overcome several shortages of conventional MRAS: integrator problems, small EMF at low speed, and relatively large sensitivity to resistance variation. The proposed algorithm is verified through simulation and experiment.
{"title":"A novel MRAS based speed sensorless control of induction motor","authors":"Y. Kwon, D. W. Jin","doi":"10.1109/IECON.1999.816537","DOIUrl":"https://doi.org/10.1109/IECON.1999.816537","url":null,"abstract":"Speed and torque control of an induction motor is usually attained by application of a speed or position sensor. However, speed and position sensors require the additional mounting space, reduce the reliability in harsh environments and increase the cost of the motor. Various control algorithms have been proposed for the elimination of speed and position sensors. This paper investigates a novel speed sensorless control of an induction motor. The proposed control strategy is based on MRAS (model reference adaptive system) using state observer model with current error feedback and rotor current model as two models for flux estimation. The rotor speed is estimated so that the difference between the outputs of state observer model and rotor current model may be zero. This algorithm may overcome several shortages of conventional MRAS: integrator problems, small EMF at low speed, and relatively large sensitivity to resistance variation. The proposed algorithm is verified through simulation and experiment.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116982366","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 : 1999-11-29DOI: 10.1109/IECON.1999.822189
Chao-Cheng Wu, C. Young
A new PWM control strategy for the buck converters is presented. The proposed control strategy is based on the switching converter large signal average model linearization and use modern control theory to achieve the control laws for the expected response. Therefore, a new nonlinear PWM controller is made to implement the control law. The new nonlinear PWM controller development is based on the error between the switched variable and the control reference of expected system response to zero each cycle. As a result, the system transfer functions are derived as a function of the desired closed loop poles. Simplifying the design procedure and bringing forward all the important characteristics of the closed loop system. From a conventional control point of view: first, the proposed PWM control strategy such uses an observer approach both to reconstruct an inductor current state and to control the converter based on a current mode technique. Second, this technique also a method of indirectly implementing the sliding-mode control law. The proposed control strategy has significant advantages over conventional current mode control techniques in noise susceptibility, dynamic response and without inductor current sensing. Finally, the simulation results confirm the theory.
{"title":"A new PWM control strategy for the buck converter","authors":"Chao-Cheng Wu, C. Young","doi":"10.1109/IECON.1999.822189","DOIUrl":"https://doi.org/10.1109/IECON.1999.822189","url":null,"abstract":"A new PWM control strategy for the buck converters is presented. The proposed control strategy is based on the switching converter large signal average model linearization and use modern control theory to achieve the control laws for the expected response. Therefore, a new nonlinear PWM controller is made to implement the control law. The new nonlinear PWM controller development is based on the error between the switched variable and the control reference of expected system response to zero each cycle. As a result, the system transfer functions are derived as a function of the desired closed loop poles. Simplifying the design procedure and bringing forward all the important characteristics of the closed loop system. From a conventional control point of view: first, the proposed PWM control strategy such uses an observer approach both to reconstruct an inductor current state and to control the converter based on a current mode technique. Second, this technique also a method of indirectly implementing the sliding-mode control law. The proposed control strategy has significant advantages over conventional current mode control techniques in noise susceptibility, dynamic response and without inductor current sensing. Finally, the simulation results confirm the theory.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116985508","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 : 1999-11-29DOI: 10.1109/IECON.1999.819430
Hoang Le-Fleuy
This paper presents a study on the design and simulation of a direct torque control (DTC) induction motor drive using PSPICE behavioral modeling. The direct torque control principle of induction motors fed by PWM inverters is explained using system equations established in the stationary reference frame. Modeling of a DTC induction motor drive using a behavioral approach is considered and a complete diagram using PSpice analog behavioral models is described. Simulation results including steady-state and transient waveforms illustrating the operation of an DTC induction motor drive are presented.
{"title":"Behavioral modeling and simulation of a direct-torque-control induction motor drive using PSPICE","authors":"Hoang Le-Fleuy","doi":"10.1109/IECON.1999.819430","DOIUrl":"https://doi.org/10.1109/IECON.1999.819430","url":null,"abstract":"This paper presents a study on the design and simulation of a direct torque control (DTC) induction motor drive using PSPICE behavioral modeling. The direct torque control principle of induction motors fed by PWM inverters is explained using system equations established in the stationary reference frame. Modeling of a DTC induction motor drive using a behavioral approach is considered and a complete diagram using PSpice analog behavioral models is described. Simulation results including steady-state and transient waveforms illustrating the operation of an DTC induction motor drive are presented.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121131326","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 : 1999-11-29DOI: 10.1109/IECON.1999.822196
G. Greco, A. Raciti, G. Belverde, A. Galluzzo, M. Melito, S. Musumeci
In the field of power electronics the use of series connected insulated gate devices, such as IGBTs or power MOSFETs, is interesting in order to obtain fast and efficient power switches in medium range power converters. In this kind of application, the control of the voltage sharing across the series strings of devices is an important aspect worth considering. The proposed technique allows safe commutations of the switches to be obtained by a simple and effective control circuit acting on the gate side of the power devices. In particular, the gate drive units are arranged in order to ensure good performances during the switching transients, while preventing overvoltage peaks on the devices. Both the design criteria and analysis of the control circuit are developed. Several experimental tests are reported in order to demonstrate the validity and correctness of the proposed approach.
{"title":"Control of the switching transients of IGBTs series strings by high-performance drive units","authors":"G. Greco, A. Raciti, G. Belverde, A. Galluzzo, M. Melito, S. Musumeci","doi":"10.1109/IECON.1999.822196","DOIUrl":"https://doi.org/10.1109/IECON.1999.822196","url":null,"abstract":"In the field of power electronics the use of series connected insulated gate devices, such as IGBTs or power MOSFETs, is interesting in order to obtain fast and efficient power switches in medium range power converters. In this kind of application, the control of the voltage sharing across the series strings of devices is an important aspect worth considering. The proposed technique allows safe commutations of the switches to be obtained by a simple and effective control circuit acting on the gate side of the power devices. In particular, the gate drive units are arranged in order to ensure good performances during the switching transients, while preventing overvoltage peaks on the devices. Both the design criteria and analysis of the control circuit are developed. Several experimental tests are reported in order to demonstrate the validity and correctness of the proposed approach.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127103453","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 : 1999-11-29DOI: 10.1109/IECON.1999.816519
Jinjun Liu, Jun Yang, Zhaoan Wang
In this paper, a new approach for single-phase harmonic current detection is presented. The approach was obtained through extending ideas of three-phase instantaneous reactive power theory and constructing a two-phase system from the existing single-phase circuit. By theoretical and simulation analysis, it is shown to be a precise approach, which can be easily realized and has the merits of better steady state and dynamic performance than conventional approaches that could be used in single-phase circuits. The approach was applied into a hybrid active power filter, which combines a series active filter and a shunt passive filter together and aims at solving the harmonics problem originated by high-power single-phase nonlinear load. Following the system configuration and basic principles of the hybrid active power filter, the overall detection and control algorithm, the PWM generating technique and the DC voltage stabilizing method are introduced in detail. The detection and control algorithm were then realized by a digital control circuit with DSP processor, and successfully employed in a prototype hybrid active power filter. Experimental results on the prototype verified the effectiveness of the new detecting approach, the performance of the control circuit and the filtering characteristics of the hybrid active power filter.
{"title":"A new approach for single-phase harmonic current detecting and its application in a hybrid active power filter","authors":"Jinjun Liu, Jun Yang, Zhaoan Wang","doi":"10.1109/IECON.1999.816519","DOIUrl":"https://doi.org/10.1109/IECON.1999.816519","url":null,"abstract":"In this paper, a new approach for single-phase harmonic current detection is presented. The approach was obtained through extending ideas of three-phase instantaneous reactive power theory and constructing a two-phase system from the existing single-phase circuit. By theoretical and simulation analysis, it is shown to be a precise approach, which can be easily realized and has the merits of better steady state and dynamic performance than conventional approaches that could be used in single-phase circuits. The approach was applied into a hybrid active power filter, which combines a series active filter and a shunt passive filter together and aims at solving the harmonics problem originated by high-power single-phase nonlinear load. Following the system configuration and basic principles of the hybrid active power filter, the overall detection and control algorithm, the PWM generating technique and the DC voltage stabilizing method are introduced in detail. The detection and control algorithm were then realized by a digital control circuit with DSP processor, and successfully employed in a prototype hybrid active power filter. Experimental results on the prototype verified the effectiveness of the new detecting approach, the performance of the control circuit and the filtering characteristics of the hybrid active power filter.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127492430","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 : 1999-11-29DOI: 10.1109/IECON.1999.822238
Wenrui Dai, M. Kampker
In order to meet the demands of small and medium sized enterprises (SME) for high effective robot offline programming in the welding business, a graphical robot simulation and offline programming system (called PIN-PC-based interactive programming system for industry robots) has been developed. Its specially tailored design enables fast, easy and economical programming assisted by user-oriented functions. Running on a PC, PIN offers features which previously could only be performed by workstations and powerful graphical tools. One of the key programming functions includes macro programming techniques which are based on the idea of combining often repeated actions (for example sequences of torch motion, TCP measurement, sensor-based calibration and search operations, program initialisation, etc.) in task-oriented macro modules. The use of macros will lead to reduced programming times and increased flexibility in program generation. Combined with an icon-oriented man-machine interface, PIN enables robot programming without knowledge of robot language syntax. An integrated simulation module will improve the system performance by visualisation of the robot motion and path validation. A Win32 communication interface takes responsibility for up- and download operations between robot controller and PIN-system as well as for controller functions' execution.
{"title":"PIN-a PC-based robot simulation and offline programming system using macro programming techniques","authors":"Wenrui Dai, M. Kampker","doi":"10.1109/IECON.1999.822238","DOIUrl":"https://doi.org/10.1109/IECON.1999.822238","url":null,"abstract":"In order to meet the demands of small and medium sized enterprises (SME) for high effective robot offline programming in the welding business, a graphical robot simulation and offline programming system (called PIN-PC-based interactive programming system for industry robots) has been developed. Its specially tailored design enables fast, easy and economical programming assisted by user-oriented functions. Running on a PC, PIN offers features which previously could only be performed by workstations and powerful graphical tools. One of the key programming functions includes macro programming techniques which are based on the idea of combining often repeated actions (for example sequences of torch motion, TCP measurement, sensor-based calibration and search operations, program initialisation, etc.) in task-oriented macro modules. The use of macros will lead to reduced programming times and increased flexibility in program generation. Combined with an icon-oriented man-machine interface, PIN enables robot programming without knowledge of robot language syntax. An integrated simulation module will improve the system performance by visualisation of the robot motion and path validation. A Win32 communication interface takes responsibility for up- and download operations between robot controller and PIN-system as well as for controller functions' execution.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125864138","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 : 1999-11-29DOI: 10.1109/IECON.1999.822200
E. Trabach, P.F.S. Amaral, D. Simonetti, J.L.F. Vieira
A stabilized single-phase electronic step-down autotransformer with improved switching characteristics is presented in this paper. It employs bi-directional switches in a four step PWM switching strategy for commutating inductive load currents. A low cost microcontroller is employed simplifying the control circuitry, giving robustness and reliability. A 600 VA-220 V/110 V prototype operating at 18 kHz has been built, and experimental results are presented validating the AC controller operation.
{"title":"A stabilized single phase electronic autotransformer","authors":"E. Trabach, P.F.S. Amaral, D. Simonetti, J.L.F. Vieira","doi":"10.1109/IECON.1999.822200","DOIUrl":"https://doi.org/10.1109/IECON.1999.822200","url":null,"abstract":"A stabilized single-phase electronic step-down autotransformer with improved switching characteristics is presented in this paper. It employs bi-directional switches in a four step PWM switching strategy for commutating inductive load currents. A low cost microcontroller is employed simplifying the control circuitry, giving robustness and reliability. A 600 VA-220 V/110 V prototype operating at 18 kHz has been built, and experimental results are presented validating the AC controller operation.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125397936","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 : 1999-11-29DOI: 10.1109/IECON.1999.819396
R. Bharadwaj, A. Parlos, H. Toliyat
Effective sensorless speed estimation is desirable for both online condition monitoring of induction motors and sensorless adjustable speed AC drive applications. In this paper, the authors present a neural network-based sensorless adaptive speed filter for induction motors. In addition to nameplate information required for the initial set-up, the proposed neural network-based speed filter uses only actual motor currents and voltages. The initial training of the filter helps in obtaining quite acceptable transient speed response from the estimation algorithm. The paper demonstrates the feasibility of adaptive speed filtering for induction motor which could be used for both diagnosis and control purposes.
{"title":"Adaptive neural network-based state filter for induction motor speed estimation","authors":"R. Bharadwaj, A. Parlos, H. Toliyat","doi":"10.1109/IECON.1999.819396","DOIUrl":"https://doi.org/10.1109/IECON.1999.819396","url":null,"abstract":"Effective sensorless speed estimation is desirable for both online condition monitoring of induction motors and sensorless adjustable speed AC drive applications. In this paper, the authors present a neural network-based sensorless adaptive speed filter for induction motors. In addition to nameplate information required for the initial set-up, the proposed neural network-based speed filter uses only actual motor currents and voltages. The initial training of the filter helps in obtaining quite acceptable transient speed response from the estimation algorithm. The paper demonstrates the feasibility of adaptive speed filtering for induction motor which could be used for both diagnosis and control purposes.","PeriodicalId":378710,"journal":{"name":"IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126946645","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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