Pub Date : 2014-05-22DOI: 10.1109/OPTIM.2014.6851007
C. Ciontea, D. Sera, F. Iov
One of the main issues concerning large penetration of the renewable energy based generators on the distribution network is related to the voltage variations due to intermittent character of the solar irradiance and wind. The actual power quality standards provide only general information regarding the evaluation procedure of the voltage fluctuations and no directions regarding the sampling frequency of the data used. As a consequence, most of the studies neglect effect of the solar irradiance and wind speed in fast changing conditions on the utility grid. This work proposes a methodology to evaluate the voltage fluctuations into the low voltage distribution network caused by variable generation and reveals the influence of data resolution on the final results. A short review regarding the assessment of the voltage variations is presented in advance and an appropriate model of the power system is build, including the generating units that are capable to operate with high resolution input data. Real parameters for the components of the simulated system are used in order to obtain realistic results.
{"title":"Influence of resolution of the input data on distributed generation integration studies","authors":"C. Ciontea, D. Sera, F. Iov","doi":"10.1109/OPTIM.2014.6851007","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6851007","url":null,"abstract":"One of the main issues concerning large penetration of the renewable energy based generators on the distribution network is related to the voltage variations due to intermittent character of the solar irradiance and wind. The actual power quality standards provide only general information regarding the evaluation procedure of the voltage fluctuations and no directions regarding the sampling frequency of the data used. As a consequence, most of the studies neglect effect of the solar irradiance and wind speed in fast changing conditions on the utility grid. This work proposes a methodology to evaluate the voltage fluctuations into the low voltage distribution network caused by variable generation and reveals the influence of data resolution on the final results. A short review regarding the assessment of the voltage variations is presented in advance and an appropriate model of the power system is build, including the generating units that are capable to operate with high resolution input data. Real parameters for the components of the simulated system are used in order to obtain realistic results.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"199 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122752931","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850965
S. Nechifor, A. Petrescu, D. Damian, D. Puiu, B. Târnauca
Reducing the amount of lost and damaged perishable goods (food and medicines) during transportation and storage represents a substantial global challenge, which imply the implementation of cold chain monitoring at all levels of the supply chains. The main objective of this work is to develop an IoT enabled infrastructure, which supports the development of smart transportation specific applications. The proposed infrastructure contains an emulator, which can be used for emulating the conditions inside a truck during the transportation process and some CEP based tools for processing the data generated by the sensors.
{"title":"Predictive analytics based on CEP for logistic of sensitive goods","authors":"S. Nechifor, A. Petrescu, D. Damian, D. Puiu, B. Târnauca","doi":"10.1109/OPTIM.2014.6850965","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850965","url":null,"abstract":"Reducing the amount of lost and damaged perishable goods (food and medicines) during transportation and storage represents a substantial global challenge, which imply the implementation of cold chain monitoring at all levels of the supply chains. The main objective of this work is to develop an IoT enabled infrastructure, which supports the development of smart transportation specific applications. The proposed infrastructure contains an emulator, which can be used for emulating the conditions inside a truck during the transportation process and some CEP based tools for processing the data generated by the sensors.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128721432","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850885
A. Câmpeanu, I. Vlad, S. Enache, M. Enache
The dynamic properties of back-to-back single supply high power salient poles synchronous machine are analyzed by modeling and simulation. The considered mathematical model is convenient for high power salient poles synchronous machines. The dynamic electromagnetic torques and windings currents where particularly considered. Of a special concern is also the steady state operation. This issue is of theoretical and practical interest in the field of electrical machines, especially high power, and there are no detailed references in literature. Simulations and experiments confirm the possibility of synchronous operation. The recoverable character of operation is fundamental. The proposed test method at rated load is experimentally validated. It is quite appropriate for high power machines, comparing with other methods.
{"title":"Simulation and back-to-back testing of synchronous machine","authors":"A. Câmpeanu, I. Vlad, S. Enache, M. Enache","doi":"10.1109/OPTIM.2014.6850885","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850885","url":null,"abstract":"The dynamic properties of back-to-back single supply high power salient poles synchronous machine are analyzed by modeling and simulation. The considered mathematical model is convenient for high power salient poles synchronous machines. The dynamic electromagnetic torques and windings currents where particularly considered. Of a special concern is also the steady state operation. This issue is of theoretical and practical interest in the field of electrical machines, especially high power, and there are no detailed references in literature. Simulations and experiments confirm the possibility of synchronous operation. The recoverable character of operation is fundamental. The proposed test method at rated load is experimentally validated. It is quite appropriate for high power machines, comparing with other methods.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123990895","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6851035
B. Moaşa, E. Helerea, M. Ignat, G. Ţelipan
Man-made fibers have the propensity to generate static electricity which becomes dangerous for electronics and individuals. There are many efforts to diminish the accumulation of the electrostatic charges through using the dissipative structures. In this paper an analysis of the dissipative properties of various types of textiles is done. The experimental determinations have been made on the various samples of double-layer textile structure consisting of cotton fibers and fibers with trilobal shape conducting core surrounded by a sheath of polyester. The apparent surface and volume resistivities are obtained of order 1012, showing the dissipative properties of this class of textile It was determined surface and volume resistivities and electrical charge dissipation capacity has put in evidence through protection coefficient and charge decay time of electrical charge. Test method used to characterize the electrical charge dissipation capacity was electrical induction charging method. Assessing the charge dissipation capacity has been characterized by the obtained coefficient of protection, within the limits 0.78-0.92. The charge decay time of the samples is of order 50-150 ms, proving the capacity to dissipate electric charges.
{"title":"Experimental research on dissipative textile structures","authors":"B. Moaşa, E. Helerea, M. Ignat, G. Ţelipan","doi":"10.1109/OPTIM.2014.6851035","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6851035","url":null,"abstract":"Man-made fibers have the propensity to generate static electricity which becomes dangerous for electronics and individuals. There are many efforts to diminish the accumulation of the electrostatic charges through using the dissipative structures. In this paper an analysis of the dissipative properties of various types of textiles is done. The experimental determinations have been made on the various samples of double-layer textile structure consisting of cotton fibers and fibers with trilobal shape conducting core surrounded by a sheath of polyester. The apparent surface and volume resistivities are obtained of order 1012, showing the dissipative properties of this class of textile It was determined surface and volume resistivities and electrical charge dissipation capacity has put in evidence through protection coefficient and charge decay time of electrical charge. Test method used to characterize the electrical charge dissipation capacity was electrical induction charging method. Assessing the charge dissipation capacity has been characterized by the obtained coefficient of protection, within the limits 0.78-0.92. The charge decay time of the samples is of order 50-150 ms, proving the capacity to dissipate electric charges.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121483914","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6851028
C. Ion, C. Marinescu
This paper presents the experimental testing of a control strategy for the parallel operation of two micro hydro power plants (MHPPs) on an islanded micro-grid (MG). The two MHPPs are equipped with constant-speed turbines that drive induction generators (IG). The proposed control system is a combination between a voltage source inverter (VSI) and a dump load (DL). The VSI operates at constant frequency, thus stabilizing the MG frequency. The voltage regulation is accomplished by the DL, by dissipating the exceeding active power. Experimental tests are performed to highlight the control system response to significant transitory regimes such as the connection of the second generator to the MG or a large load being suddenly switched on and off.
{"title":"Experimental testing of an isolated micro-grid supplied by two micro hydro power plants","authors":"C. Ion, C. Marinescu","doi":"10.1109/OPTIM.2014.6851028","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6851028","url":null,"abstract":"This paper presents the experimental testing of a control strategy for the parallel operation of two micro hydro power plants (MHPPs) on an islanded micro-grid (MG). The two MHPPs are equipped with constant-speed turbines that drive induction generators (IG). The proposed control system is a combination between a voltage source inverter (VSI) and a dump load (DL). The VSI operates at constant frequency, thus stabilizing the MG frequency. The voltage regulation is accomplished by the DL, by dissipating the exceeding active power. Experimental tests are performed to highlight the control system response to significant transitory regimes such as the connection of the second generator to the MG or a large load being suddenly switched on and off.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115056851","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850888
O. Pelan, O. Cornea, N. Muntean, F. Blaabjerg
This paper presents and discusses design considerations and efficiency investigation of a conventional step-down and a hybrid switched-capacitor DC-DC converter. Three MOSFETs with low on-resistance have been tested for each converter in order to find the most adequate switch for this application. The experimental results and comparative efficiency graphs were obtained with a 1kW laboratory prototype dedicated for a 42/14V dual voltage automotive system.
{"title":"Comparative efficiency evaluation of buck and hybrid buck DC-DC converters for automotive applications","authors":"O. Pelan, O. Cornea, N. Muntean, F. Blaabjerg","doi":"10.1109/OPTIM.2014.6850888","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850888","url":null,"abstract":"This paper presents and discusses design considerations and efficiency investigation of a conventional step-down and a hybrid switched-capacitor DC-DC converter. Three MOSFETs with low on-resistance have been tested for each converter in order to find the most adequate switch for this application. The experimental results and comparative efficiency graphs were obtained with a 1kW laboratory prototype dedicated for a 42/14V dual voltage automotive system.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122450117","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850910
D. Neacşu, B. Lehman
This paper investigates for the first time the use of a very large SD Card flash memory to the design of a three-phase Pulse Width Modulation (PWM) generator and describes the hardware and software used for implementation. The new digital architecture differs from conventional counter-based implementation and it follows a pre-programmed optimal PWM pattern that is read from memory with magnitude and phase as coordinates. This architecture allows the inclusion of multiple optimization criteria within the PWM pattern. Experimental results are shown with a PICDEM PIC18 Explorer Board and a SD Card Reader PICtail Daughter Board, both from Microchip. The optimal PWM pattern is defined in MATLAB and the entire design process is described in this paper.
{"title":"A technology demonstrator with a SD Card flash memory for implementation of three-phase multi-optimal PWM generator","authors":"D. Neacşu, B. Lehman","doi":"10.1109/OPTIM.2014.6850910","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850910","url":null,"abstract":"This paper investigates for the first time the use of a very large SD Card flash memory to the design of a three-phase Pulse Width Modulation (PWM) generator and describes the hardware and software used for implementation. The new digital architecture differs from conventional counter-based implementation and it follows a pre-programmed optimal PWM pattern that is read from memory with magnitude and phase as coordinates. This architecture allows the inclusion of multiple optimization criteria within the PWM pattern. Experimental results are shown with a PICDEM PIC18 Explorer Board and a SD Card Reader PICtail Daughter Board, both from Microchip. The optimal PWM pattern is defined in MATLAB and the entire design process is described in this paper.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122828886","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850929
C. Nistor, G. Scutaru, I. Peter, O. Plesa
The aim of this paper is to analyze the magnetic noise produced by an three phase induction motor power of 7.5kW, 1000 rpm simple layer windings produced by the company Electroprecizia Sacele located in Brasov Romania. It was chosen this engine knowing that from 2015 it will be adopted the standard IEC 60034-30 IE3 category which provides noise limits for these induction motors. A second reason for choosing this type of motor 7.5kW-1000rpm is connected to the fact that its functioning in normal regime is very silent, the total noise produced has low values, the higher value of noise is given by the electromagnetic noise. In this paper we have considered the direct network feed because these are the only conditions in which this motor function. This category of induction motors are used most frequently, almost every time, without inverter. The simulation was performed considering supply voltage 400 V (nominal voltage) and fixed frequency 50Hz. Engine speed is fixed and induction motor is directly connected from the grid without inverter (at no load). For the simulation was used a finite element program Flux 2D, and experimental measurements were performed in a semi-anechoic chamber located in the research laboratory of the company which making the induction motor.
{"title":"Determination of magnetic noise for a 7.5 kW three-phase induction motor fed directly from the grid","authors":"C. Nistor, G. Scutaru, I. Peter, O. Plesa","doi":"10.1109/OPTIM.2014.6850929","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850929","url":null,"abstract":"The aim of this paper is to analyze the magnetic noise produced by an three phase induction motor power of 7.5kW, 1000 rpm simple layer windings produced by the company Electroprecizia Sacele located in Brasov Romania. It was chosen this engine knowing that from 2015 it will be adopted the standard IEC 60034-30 IE3 category which provides noise limits for these induction motors. A second reason for choosing this type of motor 7.5kW-1000rpm is connected to the fact that its functioning in normal regime is very silent, the total noise produced has low values, the higher value of noise is given by the electromagnetic noise. In this paper we have considered the direct network feed because these are the only conditions in which this motor function. This category of induction motors are used most frequently, almost every time, without inverter. The simulation was performed considering supply voltage 400 V (nominal voltage) and fixed frequency 50Hz. Engine speed is fixed and induction motor is directly connected from the grid without inverter (at no load). For the simulation was used a finite element program Flux 2D, and experimental measurements were performed in a semi-anechoic chamber located in the research laboratory of the company which making the induction motor.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122921425","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850904
C. Stancu, P. Notingher, D. Panaitescu, V. Marinescu
Polymer/metal composite materials have good rheological properties due to the polymer matrix and superior electrical or magnetic properties through the conductive or magnetic filler. For this reason, they can be used in a number of industrial applications as electromagnetic shields or permanent magnets. This paper deals with the results of an experimental study regarding the manufacturing and characterization of composite materials containing low density polyethylene (LDPE) as matrix and neodymium (Nd) as filler, obtained by melt processing. The structure of composites, the loss factor measured in harmonic fields at frequencies between 1 mHz and 1 MHz and temperature between 30 and 80 oC and the relative and specific losses are presented and discussed in this paper. Both loss factor and specific losses vary with the frequency of the electric field, temperature and filler content. For certain values of the frequency, the loss factor and relative losses show maximum values which increase of the temperature and filler content. The specific losses decrease with temperature but increase with the filler content and frequency of the electric field. For frequency values close to 1 MHz the specific losses overlap the ones in copper conductors.
{"title":"Dielectric losses in polyethylene/neodymium composites","authors":"C. Stancu, P. Notingher, D. Panaitescu, V. Marinescu","doi":"10.1109/OPTIM.2014.6850904","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850904","url":null,"abstract":"Polymer/metal composite materials have good rheological properties due to the polymer matrix and superior electrical or magnetic properties through the conductive or magnetic filler. For this reason, they can be used in a number of industrial applications as electromagnetic shields or permanent magnets. This paper deals with the results of an experimental study regarding the manufacturing and characterization of composite materials containing low density polyethylene (LDPE) as matrix and neodymium (Nd) as filler, obtained by melt processing. The structure of composites, the loss factor measured in harmonic fields at frequencies between 1 mHz and 1 MHz and temperature between 30 and 80 oC and the relative and specific losses are presented and discussed in this paper. Both loss factor and specific losses vary with the frequency of the electric field, temperature and filler content. For certain values of the frequency, the loss factor and relative losses show maximum values which increase of the temperature and filler content. The specific losses decrease with temperature but increase with the filler content and frequency of the electric field. For frequency values close to 1 MHz the specific losses overlap the ones in copper conductors.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129637747","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 : 2014-05-22DOI: 10.1109/OPTIM.2014.6850966
J. Vittek, P. Bris, P. Butko, T. Fedor
Design and verification of a new energy saving position control algorithm for PMSM drives loaded with combined constant, linear and quadratic friction torques is the main contribution of this paper. For minimization of energy losses a symmetrical trapezoidal speed-time profile based on prescribed maneuver time is computed to achieve prescribed dynamics to achieve the demanded reference position. Overall control system exploits principles of vector control and forced dynamics control. A zero dynamic lag pre-compensator is included for precise tracking of prescribed state variables. The simulation results confirmed possibility to achieve energy savings with prescribed constant acceleration, trapezoidal speed and position profiles for pre-planned rest to rest maneuver.
{"title":"Energy saving position control of PMSM drives with constant, linear and quadratic frictions","authors":"J. Vittek, P. Bris, P. Butko, T. Fedor","doi":"10.1109/OPTIM.2014.6850966","DOIUrl":"https://doi.org/10.1109/OPTIM.2014.6850966","url":null,"abstract":"Design and verification of a new energy saving position control algorithm for PMSM drives loaded with combined constant, linear and quadratic friction torques is the main contribution of this paper. For minimization of energy losses a symmetrical trapezoidal speed-time profile based on prescribed maneuver time is computed to achieve prescribed dynamics to achieve the demanded reference position. Overall control system exploits principles of vector control and forced dynamics control. A zero dynamic lag pre-compensator is included for precise tracking of prescribed state variables. The simulation results confirmed possibility to achieve energy savings with prescribed constant acceleration, trapezoidal speed and position profiles for pre-planned rest to rest maneuver.","PeriodicalId":298237,"journal":{"name":"2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129130179","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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