Pub Date : 2011-11-10DOI: 10.1109/IAS.2011.6074471
S. Saleh, R. Ahshan, M. Rahman, M. A. Khaizaran, B. Alsayed
This paper introduces an implementation procedure and performance testings of a wavelet packet transform (WPT)-based digital protection for micro-grid systems. This digital protection is structured for detecting and classifying faults based on the values of the WPT coefficients of the high frequency sub-bands present in the d − q-axis current components. The WPT coefficients are determined using the Daubechies db4 wavelet basis functions, which are found optimal for analyzing transient disturbances likely to occur in power systems and electric machines. The proposed digital protection is implemented for experimental performance testing on a test micro-grid system that is constructed as a laboratory scale of an actual micro-grid system located in Fermeuse, Newfoundland, Canada. Several transient disturbances occurring in different parts of the test micro-grid system are experimentally investigated. Performance results demonstrate significant capabilities of the d − q WPT-based digital protection for accurate and reliable detection and classification of fault conditions, along with fast response to classified faults.
{"title":"Implementing and testing d − q WPT-based digital protection for micro-grid systems","authors":"S. Saleh, R. Ahshan, M. Rahman, M. A. Khaizaran, B. Alsayed","doi":"10.1109/IAS.2011.6074471","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074471","url":null,"abstract":"This paper introduces an implementation procedure and performance testings of a wavelet packet transform (WPT)-based digital protection for micro-grid systems. This digital protection is structured for detecting and classifying faults based on the values of the WPT coefficients of the high frequency sub-bands present in the d − q-axis current components. The WPT coefficients are determined using the Daubechies db4 wavelet basis functions, which are found optimal for analyzing transient disturbances likely to occur in power systems and electric machines. The proposed digital protection is implemented for experimental performance testing on a test micro-grid system that is constructed as a laboratory scale of an actual micro-grid system located in Fermeuse, Newfoundland, Canada. Several transient disturbances occurring in different parts of the test micro-grid system are experimentally investigated. Performance results demonstrate significant capabilities of the d − q WPT-based digital protection for accurate and reliable detection and classification of fault conditions, along with fast response to classified faults.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124534268","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074279
M. Plopeanu, L. Dascalescu, B. Yahiaoui, A. Antoniu, M. Hulea, P. Notingher
Electric charging of non-woven materials employed as filter media improves their particle collection efficiency by the electrostatic particle capture mechanism that enhances the conventional mechanical filtration without causing an increase of the pressure drop. The aim of this paper is to provide a better understanding of the corona-charging process of such materials, by analyzing some of the factors that affect the distribution of the electric potential at the surface of the respective media. The experiments were carried out on two types of polypropylene samples: non-woven fabrics and films. The experimental results show that the area occupied by the charge increases with both the voltage applied to the corona electrode and the duration charging process. The same area increases also with the time elapsed from the end of the charging, which points out the charge redistribution at the surface of the media by a lateral conduction mechanism.
{"title":"Distribution of electric potential at the surface of corona-charged non-woven fabrics","authors":"M. Plopeanu, L. Dascalescu, B. Yahiaoui, A. Antoniu, M. Hulea, P. Notingher","doi":"10.1109/IAS.2011.6074279","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074279","url":null,"abstract":"Electric charging of non-woven materials employed as filter media improves their particle collection efficiency by the electrostatic particle capture mechanism that enhances the conventional mechanical filtration without causing an increase of the pressure drop. The aim of this paper is to provide a better understanding of the corona-charging process of such materials, by analyzing some of the factors that affect the distribution of the electric potential at the surface of the respective media. The experiments were carried out on two types of polypropylene samples: non-woven fabrics and films. The experimental results show that the area occupied by the charge increases with both the voltage applied to the corona electrode and the duration charging process. The same area increases also with the time elapsed from the end of the charging, which points out the charge redistribution at the surface of the media by a lateral conduction mechanism.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114209817","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074309
E. A. Mahmoud, Hussien F. Soliman, M. Elbuluk
This paper presents a novel least mean square (LMS) estimator for a sensor-less drive of a three phase induction motor. Also, the proposed system includes the use of the matrix converter instead of the two-level inverter to improve the estimator performance. The system studied consists of a three phase induction motor driven by a matrix converter, a hysteris current controller, and an indirect field oriented controller. Also, a proportional plus integral speed controller and the proposed speed estimator are used. The LMS estimator includes a step size factor (SSF). The value of the SSF affects the dynamic performance of the speed estimator. Different simulation results of the overall system are conducted to depict the dynamic performance of the induction motor including the effect of the SSF, used in the LMS estimator. The simulation results show that the low value of the SSF gives high estimation accuracy when the actual speed is nearly constant. Meanwhile, the estimated motor speed follows the actual value with a higher time lag during the speed change. On the other hand, the high step size value reduces the time lag during the speed change but reduces the estimation accuracy during the steady state. A variable LMS SSF is introduced to achieve both advantages of the low and high SSF. The simulation results show improvement in the dynamic performance of the estimator regarding the low time lag during the speed change and the high estimation accuracy during the steady state. The simulation results show excellent of the proposed estimator using LMS with matrix converter driven by variable SSF in reference speed tracking. The main advantage of this proposed estimator is reducing the mathematical calculation time while maintaining high estimation accuracy. This leads to using a slower processor and smaller memory which reduces the drive cost.
{"title":"A sensorless induction motor drive using a least mean square speed estimator and the matrix converter","authors":"E. A. Mahmoud, Hussien F. Soliman, M. Elbuluk","doi":"10.1109/IAS.2011.6074309","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074309","url":null,"abstract":"This paper presents a novel least mean square (LMS) estimator for a sensor-less drive of a three phase induction motor. Also, the proposed system includes the use of the matrix converter instead of the two-level inverter to improve the estimator performance. The system studied consists of a three phase induction motor driven by a matrix converter, a hysteris current controller, and an indirect field oriented controller. Also, a proportional plus integral speed controller and the proposed speed estimator are used. The LMS estimator includes a step size factor (SSF). The value of the SSF affects the dynamic performance of the speed estimator. Different simulation results of the overall system are conducted to depict the dynamic performance of the induction motor including the effect of the SSF, used in the LMS estimator. The simulation results show that the low value of the SSF gives high estimation accuracy when the actual speed is nearly constant. Meanwhile, the estimated motor speed follows the actual value with a higher time lag during the speed change. On the other hand, the high step size value reduces the time lag during the speed change but reduces the estimation accuracy during the steady state. A variable LMS SSF is introduced to achieve both advantages of the low and high SSF. The simulation results show improvement in the dynamic performance of the estimator regarding the low time lag during the speed change and the high estimation accuracy during the steady state. The simulation results show excellent of the proposed estimator using LMS with matrix converter driven by variable SSF in reference speed tracking. The main advantage of this proposed estimator is reducing the mathematical calculation time while maintaining high estimation accuracy. This leads to using a slower processor and smaller memory which reduces the drive cost.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114297669","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074312
Toru Inoue, S. Ito, K. Azegami, Y. Nakajima, K. Matsuse
The purpose of this paper is to present multiple motors connected in parallel are driven with stability. The parameters of each motor, namely stator current, rotor flux, and speed were estimated using adaptive rotor flux observers to achieve sensorless control. The validity and effective of the proposed method was demonstrated through simulations.
{"title":"Dynamic performance of sensorless vector controlled multiple induction motor drive connected in parallel fed by single inverter","authors":"Toru Inoue, S. Ito, K. Azegami, Y. Nakajima, K. Matsuse","doi":"10.1109/IAS.2011.6074312","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074312","url":null,"abstract":"The purpose of this paper is to present multiple motors connected in parallel are driven with stability. The parameters of each motor, namely stator current, rotor flux, and speed were estimated using adaptive rotor flux observers to achieve sensorless control. The validity and effective of the proposed method was demonstrated through simulations.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116748314","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074423
M. Lang, K. Jones
Recent testing with various electrode configurations and insulating barriers suggests that 250V equipment omitted from arc flash hazard analyses has the potential for burn injury. Research into the sustainability of arcs at these voltages shows assumptions about the magnitude of these hazards need to be revised. This research enhanced the work of previous efforts by focusing on the sustainability of arcs with fault currents lower than 10kA. Gap lengths between electrodes, electrode shape, electrode material and voltage variations were studied for their effects on arc sustainability. A modified barrier design, representative of the space around panelboard bus bars was also studied.
{"title":"Investigation of factors affecting the sustainability of arcs below 250V","authors":"M. Lang, K. Jones","doi":"10.1109/IAS.2011.6074423","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074423","url":null,"abstract":"Recent testing with various electrode configurations and insulating barriers suggests that 250V equipment omitted from arc flash hazard analyses has the potential for burn injury. Research into the sustainability of arcs at these voltages shows assumptions about the magnitude of these hazards need to be revised. This research enhanced the work of previous efforts by focusing on the sustainability of arcs with fault currents lower than 10kA. Gap lengths between electrodes, electrode shape, electrode material and voltage variations were studied for their effects on arc sustainability. A modified barrier design, representative of the space around panelboard bus bars was also studied.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116757339","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074343
M. Chy, B. Boulet
This paper presents an improved mathematical model to represent a more accurate relationship among inputs and outputs of the heating phase of the thermoforming process. The proposed state-space model of the heating phase of thermoforming process can present and explain some incidents which are impossible to explain using the existing model. The main purpose of the paper is to improve the quality of predictions of the system's output and state through more accurate evaluation of the inputs and system properties. First, the modeling is developed based on the heat transfer method and system's behaviour. Then, a series of specialized experimental data were compared with the simulation data obtained from the developed model to validate it. All three kind of heat transfer methods (conduction, convection and radiation) are considered in the development of the model of a thermoforming machine. The proposed state space model is simulated using a Simulink model to compare with real time results. The input output relationship of the proposed model almost accurately follows the real time relationship of the inputs and outputs at different operating conditions. The proposed model gives the improved results compared to the existing model with the real time experimental data even there was some discrepancy of the existed model result with the real time data. The accuracy of the proposed model is evidenced by the results.
{"title":"Development of an improved mathematical model of the heating phase of thermoforming process","authors":"M. Chy, B. Boulet","doi":"10.1109/IAS.2011.6074343","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074343","url":null,"abstract":"This paper presents an improved mathematical model to represent a more accurate relationship among inputs and outputs of the heating phase of the thermoforming process. The proposed state-space model of the heating phase of thermoforming process can present and explain some incidents which are impossible to explain using the existing model. The main purpose of the paper is to improve the quality of predictions of the system's output and state through more accurate evaluation of the inputs and system properties. First, the modeling is developed based on the heat transfer method and system's behaviour. Then, a series of specialized experimental data were compared with the simulation data obtained from the developed model to validate it. All three kind of heat transfer methods (conduction, convection and radiation) are considered in the development of the model of a thermoforming machine. The proposed state space model is simulated using a Simulink model to compare with real time results. The input output relationship of the proposed model almost accurately follows the real time relationship of the inputs and outputs at different operating conditions. The proposed model gives the improved results compared to the existing model with the real time experimental data even there was some discrepancy of the existed model result with the real time data. The accuracy of the proposed model is evidenced by the results.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126352208","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074401
Chin-Chu Tsai, Weijen Lee, Shun-Hsien Huang, John Adams
This paper proposes a new identification process for solving generator parameter identification problem for industrial plants with co-generation facilities by using data from Phasor Measurement Unit (PMU). First of all, a seamless hybrid dynamic method is proposed to implement in commercially available software to realize the equivalent of an external-system outside the buses of PMU boundary. Then, the trajectory sensitivity is adopted to screen out the key parameters. Finally, a high dimension optimization algorithm, Simultaneous Perturbation Stochastic Approximation (SPSA) is used to compute a set of model parameters that provide a best fit between measurements and simulation response. This approach is based on ISO's view that only PMU measurement data is known, models are unchangeable and condition of system during disturbance is uncertain. The effectiveness and feasibility of the proposed process were demonstrated by processing data from newly installed generator unit in ERCOT system. The experiment showed encouraging results, verifying that the proposed approach was capable of identify parameters with better accuracy.
{"title":"Parameter identification for an industrial plant with in-house generators","authors":"Chin-Chu Tsai, Weijen Lee, Shun-Hsien Huang, John Adams","doi":"10.1109/IAS.2011.6074401","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074401","url":null,"abstract":"This paper proposes a new identification process for solving generator parameter identification problem for industrial plants with co-generation facilities by using data from Phasor Measurement Unit (PMU). First of all, a seamless hybrid dynamic method is proposed to implement in commercially available software to realize the equivalent of an external-system outside the buses of PMU boundary. Then, the trajectory sensitivity is adopted to screen out the key parameters. Finally, a high dimension optimization algorithm, Simultaneous Perturbation Stochastic Approximation (SPSA) is used to compute a set of model parameters that provide a best fit between measurements and simulation response. This approach is based on ISO's view that only PMU measurement data is known, models are unchangeable and condition of system during disturbance is uncertain. The effectiveness and feasibility of the proposed process were demonstrated by processing data from newly installed generator unit in ERCOT system. The experiment showed encouraging results, verifying that the proposed approach was capable of identify parameters with better accuracy.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116577977","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074301
Fei Gao, D. Chrenko, B. Blunier, D. Bouquain, A. Miraoui
This paper presents, a multi-physical fuel cell stack model. The stack model is divided into 3 sub-models describing the different physical domains: electrical, fluidic and thermal. The stacking method has been used to model the fuel cell stack from a single cell model. The proposed model has been validated against a 1.2 kW commercial fuel cell stack with excellent agreement between simulation and experimentation. Based on the simulation results, a novel model reduction method is proposed. The reduced model is suitable for real-time simulation purpose. Moreover, a real-time model based fuel cell emulator is introduced. The emulator has 3 real-time computation cores with different rates. The 3 computation cores are interconnected with a digital communication bus. A DC/DC buck converter is designed, in order to receive the model predicted stack power conditions and emulate the real fuel cell stack power output. The experimental test results show that such an emulator is suitable for fuel cell system Hardware-in-the-loop (HIL) applications.
{"title":"Multi-rates fuel cell emulation with spatial reduced real-time fuel cell modelling","authors":"Fei Gao, D. Chrenko, B. Blunier, D. Bouquain, A. Miraoui","doi":"10.1109/IAS.2011.6074301","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074301","url":null,"abstract":"This paper presents, a multi-physical fuel cell stack model. The stack model is divided into 3 sub-models describing the different physical domains: electrical, fluidic and thermal. The stacking method has been used to model the fuel cell stack from a single cell model. The proposed model has been validated against a 1.2 kW commercial fuel cell stack with excellent agreement between simulation and experimentation. Based on the simulation results, a novel model reduction method is proposed. The reduced model is suitable for real-time simulation purpose. Moreover, a real-time model based fuel cell emulator is introduced. The emulator has 3 real-time computation cores with different rates. The 3 computation cores are interconnected with a digital communication bus. A DC/DC buck converter is designed, in order to receive the model predicted stack power conditions and emulate the real fuel cell stack power output. The experimental test results show that such an emulator is suitable for fuel cell system Hardware-in-the-loop (HIL) applications.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113949025","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074477
A. Fidigatti, P. Baroncelli, M. Carminati, E. Ragaini
Topic of this paper is the selection of low voltage circuit breakers and contactors in wind power applications. General requirements for components which need to be installed in the nacelle are first examined. Then, the three most common design structures of wind generators are briefly described. For each of them, the choice and sizing of switching devices are discussed, based on the number and kind of required operations.
{"title":"Selection of low voltage switching and protection devices in wind power generators","authors":"A. Fidigatti, P. Baroncelli, M. Carminati, E. Ragaini","doi":"10.1109/IAS.2011.6074477","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074477","url":null,"abstract":"Topic of this paper is the selection of low voltage circuit breakers and contactors in wind power applications. General requirements for components which need to be installed in the nacelle are first examined. Then, the three most common design structures of wind generators are briefly described. For each of them, the choice and sizing of switching devices are discussed, based on the number and kind of required operations.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133240052","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 : 2011-11-10DOI: 10.1109/IAS.2011.6074384
F. Bulnes, R. Usamentiaga, D. García, J. Molleda, J. Rendueles
This document presents a technique to detect a particularly serious problem: periodical defects. Periodical defects can cause serious damage to steel strips, and so should be corrected as quickly as possible. The technique proposed, which is based on information provided by an artificial vision system, reports on periodical defects detected in one strip before starting to roll the next.
{"title":"Vision-based technique for periodical defect detection in hot steel strips","authors":"F. Bulnes, R. Usamentiaga, D. García, J. Molleda, J. Rendueles","doi":"10.1109/IAS.2011.6074384","DOIUrl":"https://doi.org/10.1109/IAS.2011.6074384","url":null,"abstract":"This document presents a technique to detect a particularly serious problem: periodical defects. Periodical defects can cause serious damage to steel strips, and so should be corrected as quickly as possible. The technique proposed, which is based on information provided by an artificial vision system, reports on periodical defects detected in one strip before starting to roll the next.","PeriodicalId":268988,"journal":{"name":"2011 IEEE Industry Applications Society Annual Meeting","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128792856","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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