Pub Date : 2019-08-01DOI: 10.1109/ICCSSE.2019.00017
Yunfeng Zhang, Xiangshun Li, Chuyue Lou, Jin Jiang
In this paper, fault detection methods based on principal component analysis (PCA) have been investigated. The methods have been evaluated using the data acquired from a practical nuclear power plant simulation platform. PCA, dynamic principal component analysis (DPCA), kernel principal component analysis (KPCA), two-step principal component analysis (TS-PCA) have been considered. The performance of these methods in fault detection has been compared.
{"title":"Principal Component Analysis Methods for Fault Detection Evaluated on a Nuclear Power Plant Simulation Platform","authors":"Yunfeng Zhang, Xiangshun Li, Chuyue Lou, Jin Jiang","doi":"10.1109/ICCSSE.2019.00017","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00017","url":null,"abstract":"In this paper, fault detection methods based on principal component analysis (PCA) have been investigated. The methods have been evaluated using the data acquired from a practical nuclear power plant simulation platform. PCA, dynamic principal component analysis (DPCA), kernel principal component analysis (KPCA), two-step principal component analysis (TS-PCA) have been considered. The performance of these methods in fault detection has been compared.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"300 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116218249","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00029
Jiaran Zhang, Taizhi Sun
Nowadays variable-frequency air-condition with some obvious characteristics such as energy conservation, comfortable will gradually occupy the entire market of air-condition. Aiming at the changes of the electromagnetic parameters of running PMSM in air-condition compressor drive system, recursive least squares with forgetting factor method is used to identify the resistance and inductance of the motor online. In order to overcome disadvantages of high-complexity and length-counting period in the traditional simulation language, the paper enhances simulation efficiency by calling S-function to compile the least squares algorithm in Matlab. The rationality of the algorithm is verified by comparing between the estimated parameters and real parameters in the simulation system of double closed loop control system and identification model. Simulation results show that the method can accurately identify the motor parameters and have considerable practical value.
{"title":"Parameters Identification of Air-Condition Compressor Driven by Motor Using the Least Squares Method","authors":"Jiaran Zhang, Taizhi Sun","doi":"10.1109/ICCSSE.2019.00029","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00029","url":null,"abstract":"Nowadays variable-frequency air-condition with some obvious characteristics such as energy conservation, comfortable will gradually occupy the entire market of air-condition. Aiming at the changes of the electromagnetic parameters of running PMSM in air-condition compressor drive system, recursive least squares with forgetting factor method is used to identify the resistance and inductance of the motor online. In order to overcome disadvantages of high-complexity and length-counting period in the traditional simulation language, the paper enhances simulation efficiency by calling S-function to compile the least squares algorithm in Matlab. The rationality of the algorithm is verified by comparing between the estimated parameters and real parameters in the simulation system of double closed loop control system and identification model. Simulation results show that the method can accurately identify the motor parameters and have considerable practical value.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128009560","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00038
Weiwei Sun, Min Huang, Yiqian He
Aiming at the problems of inaccurate monitoring and untimely fault detection in online tool condition monitoring system of CNC machine tools, an automatic feature extraction method based on multiple sensors is proposed. Firstly, different sensors are selected to collect vibration signal, three-phase current signal and acoustic emission signal during tool processing. Then the signals collected by all sensors are analyzed in time domain, frequency domain and wavelet domain respectively. After analyzing the signal, different features are extracted from it. For each feature, the least square method is used to obtain the fitting line. Finally, according to the comparison of the slope and square error of the fitting line, the characteristics that are highly correlated with tool wear are selected. These features are composed into an eigenvector to reflect the tool wear state. This method can monitor tool wear more accurately and timely.
{"title":"An Automatic Feature Extraction Method Based on Multiple Sensors","authors":"Weiwei Sun, Min Huang, Yiqian He","doi":"10.1109/ICCSSE.2019.00038","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00038","url":null,"abstract":"Aiming at the problems of inaccurate monitoring and untimely fault detection in online tool condition monitoring system of CNC machine tools, an automatic feature extraction method based on multiple sensors is proposed. Firstly, different sensors are selected to collect vibration signal, three-phase current signal and acoustic emission signal during tool processing. Then the signals collected by all sensors are analyzed in time domain, frequency domain and wavelet domain respectively. After analyzing the signal, different features are extracted from it. For each feature, the least square method is used to obtain the fitting line. Finally, according to the comparison of the slope and square error of the fitting line, the characteristics that are highly correlated with tool wear are selected. These features are composed into an eigenvector to reflect the tool wear state. This method can monitor tool wear more accurately and timely.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124359176","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00009
B. Ren, Min Liu, L. Cui, Haoran Chen, F. Wang
Based on the highest density domain analysis, a new algorithm is proposed to perform prediction of the aviation safety in an uncertain framework. In order to perform the prediction of the aviation safety, highest density domain (HDR) is combined with uncertainty description technique to obtain the aviation safety interval and the corresponding interval probability level in the proposed method. Firstly, the kernel density estimator is further utilized with to produce the probability distribution. Secondly, highest density regions based on the estimated probability density function have been considered, to further investigate the underlying information. Then the aviation safety interval and the corresponding interval probability level are given to complete the aviation safety prediction. Compared with the methods of traditional aviation safety causal prediction and aviation safety time series prediction, this paper considers the uncertainty properties of aviation safety more thoroughly. Discussions with the flight accident hourly rate of the US Air Force from 1991 to 1999 have evidenced the applicability and adaptability of the proposed method.
{"title":"A New Method for Aviation Safety Prediction Based on the Highest Density Domain in Uncertainty Environment","authors":"B. Ren, Min Liu, L. Cui, Haoran Chen, F. Wang","doi":"10.1109/ICCSSE.2019.00009","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00009","url":null,"abstract":"Based on the highest density domain analysis, a new algorithm is proposed to perform prediction of the aviation safety in an uncertain framework. In order to perform the prediction of the aviation safety, highest density domain (HDR) is combined with uncertainty description technique to obtain the aviation safety interval and the corresponding interval probability level in the proposed method. Firstly, the kernel density estimator is further utilized with to produce the probability distribution. Secondly, highest density regions based on the estimated probability density function have been considered, to further investigate the underlying information. Then the aviation safety interval and the corresponding interval probability level are given to complete the aviation safety prediction. Compared with the methods of traditional aviation safety causal prediction and aviation safety time series prediction, this paper considers the uncertainty properties of aviation safety more thoroughly. Discussions with the flight accident hourly rate of the US Air Force from 1991 to 1999 have evidenced the applicability and adaptability of the proposed method.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125835645","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}
In order to suppress the periodic error in the control of the gimbal, an error prediction compensation model is established based on the error compensation theory in predictive control. The error feature extraction and matching of the servo gimbal system is completed based on the error time domain and frequency domain analysis results. Based on the analysis of the error energy spectral density characteristics, according to the energy distribution of different frequency bands, combined with the design of the gimbal control system, the influencing factors such as position sensor error, motor drive error and system structure error are obtained. At the same time, determine the impact domain of each factor. Based on this, through the optimal parameter estimation, the design of the error prediction compensation controller is completed, and finally a new optimal control strategy for error prediction compensation gimbal is obtained. Test verification in a high-precision gimbal shows that the control strategy can significantly improve the speed stability of the gimbal system by about 78%.
{"title":"Optimal Gimbal System Control Strategy for Error Prediction Compensation","authors":"Yongqing Yang, Wei Hao, Tianye Yu, Mei-lin Xie, Yanbing Liang, Peng Liu","doi":"10.1109/ICCSSE.2019.00022","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00022","url":null,"abstract":"In order to suppress the periodic error in the control of the gimbal, an error prediction compensation model is established based on the error compensation theory in predictive control. The error feature extraction and matching of the servo gimbal system is completed based on the error time domain and frequency domain analysis results. Based on the analysis of the error energy spectral density characteristics, according to the energy distribution of different frequency bands, combined with the design of the gimbal control system, the influencing factors such as position sensor error, motor drive error and system structure error are obtained. At the same time, determine the impact domain of each factor. Based on this, through the optimal parameter estimation, the design of the error prediction compensation controller is completed, and finally a new optimal control strategy for error prediction compensation gimbal is obtained. Test verification in a high-precision gimbal shows that the control strategy can significantly improve the speed stability of the gimbal system by about 78%.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126294947","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00047
Qifan Yang, Xiu-Juan Li, Chuntao Li
This paper analyzes the force state in landing process of carrier UAV after arresting cable, and deduces the model of arresting resistance after arresting cable. Then, the hydraulic system model is built through the working mechanism of the arresting hydraulic device and combined with the arresting system model, the movement and dynamics model of the arresting process are obtained. The simulation results show that the model produces acceleration, unilateral arresting force and other parameters, which accord with the physical characteristics of shipborne UAV arresting process. By adjusting the parameters of the carrier UAV arresting model, it can meet the requirements of dynamic simulation of carrier aircraft arresting under different speed and mass conditions.
{"title":"Modeling and Analysis of Landing Block of Carrier Aircraft","authors":"Qifan Yang, Xiu-Juan Li, Chuntao Li","doi":"10.1109/ICCSSE.2019.00047","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00047","url":null,"abstract":"This paper analyzes the force state in landing process of carrier UAV after arresting cable, and deduces the model of arresting resistance after arresting cable. Then, the hydraulic system model is built through the working mechanism of the arresting hydraulic device and combined with the arresting system model, the movement and dynamics model of the arresting process are obtained. The simulation results show that the model produces acceleration, unilateral arresting force and other parameters, which accord with the physical characteristics of shipborne UAV arresting process. By adjusting the parameters of the carrier UAV arresting model, it can meet the requirements of dynamic simulation of carrier aircraft arresting under different speed and mass conditions.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121567042","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00045
Yu Zhilong, Liu Yinghui, Dong Zehong, Xu Wenfeng
Aiming at the problem that icing leads to poor aerodynamic characteristics and affects the safe flight of aircraft . To study how the nonlinear factors contribute to the safety flight ,this paper use NASA’s generic transport model(GTM) as an example, this paper establish 4-dimension longitudinal dynamics model and icing effects model, and use the bifurcation theory to analyze the stability of aircraft under different degree of icing, and the maneuverable range of aircraft under corresponding conditions is obtained . It is shown that with the increase of icing degree, the control range of elevator deflection is narrowed, and the possibility of aircraft stall is increasing which brings hidden trouble for flight safety. The evaluation results are consistent with the actual situation, which can provide some reference for the pilot control.
{"title":"Icing Aircraft Safety Analysis Based on the Bifurcation Method","authors":"Yu Zhilong, Liu Yinghui, Dong Zehong, Xu Wenfeng","doi":"10.1109/ICCSSE.2019.00045","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00045","url":null,"abstract":"Aiming at the problem that icing leads to poor aerodynamic characteristics and affects the safe flight of aircraft . To study how the nonlinear factors contribute to the safety flight ,this paper use NASA’s generic transport model(GTM) as an example, this paper establish 4-dimension longitudinal dynamics model and icing effects model, and use the bifurcation theory to analyze the stability of aircraft under different degree of icing, and the maneuverable range of aircraft under corresponding conditions is obtained . It is shown that with the increase of icing degree, the control range of elevator deflection is narrowed, and the possibility of aircraft stall is increasing which brings hidden trouble for flight safety. The evaluation results are consistent with the actual situation, which can provide some reference for the pilot control.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114335978","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00028
Yong Zhang, Wen-qing Liu
In the next generation train control system based on vehicle-vehicle communication, resource autonomous management pattern is proposed, replacing traditional ground interlocking system to manage ground line resources. Firstly, the composition, function and information interaction of the train control system and resource management modules are analyzed. Secondly, the traditional interlocking system and resource autonomous management pattern are compared and analyzed, and the resource using process is proposed. Then, the typical scenario of resource management is described by UML, and the key properties of the system, such as boundedness and reachability, are validated by modeling with colored Petri nets (CPN). In this paper, formal modeling and validation analysis of typical resource management scenarios in the system are carried out to ensure that the system meets the security, functionality and performance requirements, thereby reducing system design defects, which is of great significance for system design and system security.
{"title":"Typical Resource Management Scenario Modeling and Analysis of Train Control System Based on Vehicle-Vehicle Communication","authors":"Yong Zhang, Wen-qing Liu","doi":"10.1109/ICCSSE.2019.00028","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00028","url":null,"abstract":"In the next generation train control system based on vehicle-vehicle communication, resource autonomous management pattern is proposed, replacing traditional ground interlocking system to manage ground line resources. Firstly, the composition, function and information interaction of the train control system and resource management modules are analyzed. Secondly, the traditional interlocking system and resource autonomous management pattern are compared and analyzed, and the resource using process is proposed. Then, the typical scenario of resource management is described by UML, and the key properties of the system, such as boundedness and reachability, are validated by modeling with colored Petri nets (CPN). In this paper, formal modeling and validation analysis of typical resource management scenarios in the system are carried out to ensure that the system meets the security, functionality and performance requirements, thereby reducing system design defects, which is of great significance for system design and system security.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"409 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123537490","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00019
Jun Wang, Yuanfeng Zhang
Aimed at actuator failures, the design problem of the passive robust H_∞ fault-tolerant controller for the uncertain island AC micro-grid inverter system is studied, which has good suppression ability to the external limited energy disturbance. Firstly, the fault model of the uncertain island AC micro-grid inverter system is established; then the robust H_∞ fault-tolerant controller is designed offline. Finally, the MATLAB simulation is given to illustrate the feasibility of the control law, which make the system progressively stable when the system actuator fails.
{"title":"Reliable Control of AC Micro-Grid Inverter System in Island Mode","authors":"Jun Wang, Yuanfeng Zhang","doi":"10.1109/ICCSSE.2019.00019","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00019","url":null,"abstract":"Aimed at actuator failures, the design problem of the passive robust H_∞ fault-tolerant controller for the uncertain island AC micro-grid inverter system is studied, which has good suppression ability to the external limited energy disturbance. Firstly, the fault model of the uncertain island AC micro-grid inverter system is established; then the robust H_∞ fault-tolerant controller is designed offline. Finally, the MATLAB simulation is given to illustrate the feasibility of the control law, which make the system progressively stable when the system actuator fails.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127624990","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 : 2019-08-01DOI: 10.1109/ICCSSE.2019.00021
Dongze Lv, Yanting Che, C. Li
In this paper, a new frequency spot jamming is proposed to solve the problem that the conventional repeater jamming cannot generate advance jamming signal and the coherence between the jamming signal and the radar signal is poor. Based on the kay algorithm, a new frequency spot jamming against Frequency modulated interrupted continuous wave radar (FMICW) is designed. First of all, the kay algorithm is used for estimating the instant frequency of each pulse. Secondly, the Least Squares (LS) fitting is used for estimating the chirp rate of pulses. Thirdly, the frequency spot Continuous Wave (CW) signal is generated based on the estimates of instant frequency and chirp rate. And then, the frequency spot CW jamming is modulated by both pulse modulation and frequency modulation. Finally, the parameter controllable pulse frequency spot jamming which can be modulated to advance jamming is generated and transmitted. The simulation results show that the jamming pattern can effectively achieve both advance and delay jamming in the time domain, and it is also possible to mask the peak of the real radar echo spectrum in the frequency domain.
{"title":"Frequency Spot Jamming Against FMICW","authors":"Dongze Lv, Yanting Che, C. Li","doi":"10.1109/ICCSSE.2019.00021","DOIUrl":"https://doi.org/10.1109/ICCSSE.2019.00021","url":null,"abstract":"In this paper, a new frequency spot jamming is proposed to solve the problem that the conventional repeater jamming cannot generate advance jamming signal and the coherence between the jamming signal and the radar signal is poor. Based on the kay algorithm, a new frequency spot jamming against Frequency modulated interrupted continuous wave radar (FMICW) is designed. First of all, the kay algorithm is used for estimating the instant frequency of each pulse. Secondly, the Least Squares (LS) fitting is used for estimating the chirp rate of pulses. Thirdly, the frequency spot Continuous Wave (CW) signal is generated based on the estimates of instant frequency and chirp rate. And then, the frequency spot CW jamming is modulated by both pulse modulation and frequency modulation. Finally, the parameter controllable pulse frequency spot jamming which can be modulated to advance jamming is generated and transmitted. The simulation results show that the jamming pattern can effectively achieve both advance and delay jamming in the time domain, and it is also possible to mask the peak of the real radar echo spectrum in the frequency domain.","PeriodicalId":443482,"journal":{"name":"2019 5th International Conference on Control Science and Systems Engineering (ICCSSE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130640610","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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