Pub Date : 2019-06-19DOI: 10.1109/ICIEA.2019.8834171
Kui Xu, Zhexian Shen, Ming Zhang, Dongmei Zhang, Wei Xie, Nan Sha
In this paper, we consider the channel tracking and energy hybrid beamforming for the wireless power transfer (WPT) enabled Internet of Things (IoT) system, where the mobile base station (MBS) serves a set of half-duplex (HD) sensors that are uniformly distributed within its coverage area. A linear Kalman filter based multipath channel tracking and hybrid energy beamforming scheme is proposed by investigating the temporal and spatial properties of channel. Firstly, the Doppler frequency offset (DFO) is compensated through beam alignment and capturing the precise angular information from signals. Then, the multipath channel is tracked during the angle of arrival time (AOAT). Finally, the hybrid beamforming is applied to realize downlink WPT and uplink data transmission. The superiority of the proposed scheme is evaluated through simulations.
{"title":"Channel Tracking and Hybrid Energy Beamforming for WPT Enabled IoT System with Mobile mMIMO BS","authors":"Kui Xu, Zhexian Shen, Ming Zhang, Dongmei Zhang, Wei Xie, Nan Sha","doi":"10.1109/ICIEA.2019.8834171","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8834171","url":null,"abstract":"In this paper, we consider the channel tracking and energy hybrid beamforming for the wireless power transfer (WPT) enabled Internet of Things (IoT) system, where the mobile base station (MBS) serves a set of half-duplex (HD) sensors that are uniformly distributed within its coverage area. A linear Kalman filter based multipath channel tracking and hybrid energy beamforming scheme is proposed by investigating the temporal and spatial properties of channel. Firstly, the Doppler frequency offset (DFO) is compensated through beam alignment and capturing the precise angular information from signals. Then, the multipath channel is tracked during the angle of arrival time (AOAT). Finally, the hybrid beamforming is applied to realize downlink WPT and uplink data transmission. The superiority of the proposed scheme is evaluated through simulations.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131475192","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8833935
Tariku Sinshaw Tamir, G. Xiong, Yanfu Tian, G. Xiong
This study is about passivity based control, as one of the tools available to design robust controllers, is introduced for trajectory tracking of the Stewart platform. PD+ controller is designed based on passivation principle so that the closed loop system becomes globally uniform and asymptotically stable. In the study, the mathematical model of the Stewart platform, derived from Euler Lagrange equations of motion, is Simulated on MATLAB/Simulink. So as to get the desired leg-length trajectory, the inverse kinematics formulation is investigated. The mathematical model is verified using automatic dynamic analysis of mechanical systems (ADAMS) software. More realistic results are observed from ADAMS simulation results.
{"title":"Passivity Based Control Of Stewart Platform For Trajectory Tracking","authors":"Tariku Sinshaw Tamir, G. Xiong, Yanfu Tian, G. Xiong","doi":"10.1109/ICIEA.2019.8833935","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8833935","url":null,"abstract":"This study is about passivity based control, as one of the tools available to design robust controllers, is introduced for trajectory tracking of the Stewart platform. PD+ controller is designed based on passivation principle so that the closed loop system becomes globally uniform and asymptotically stable. In the study, the mathematical model of the Stewart platform, derived from Euler Lagrange equations of motion, is Simulated on MATLAB/Simulink. So as to get the desired leg-length trajectory, the inverse kinematics formulation is investigated. The mathematical model is verified using automatic dynamic analysis of mechanical systems (ADAMS) software. More realistic results are observed from ADAMS simulation results.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124061512","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8834209
U. Datta, Akhtar Kalam, Juan Shi, Jiangrong Li
The contribution of electric vehicles (EV) in a microgrid with high intermittent renewable energy penetration could strengthen power system security and reliability. This paper investigates the contribution of EV in regulating and improving primary frequency response of the power system. EV is designed to halt charging and inject power to the grid during an under-frequency event and to consume surplus energy following an over-frequency event when EV state-of-charge (SOC) is available. The minimum SOC threshold is kept to a higher value to ensure EV is available to be driven at any given time. Simulation results demonstrate that EV enhances primary frequency response of the system and also better frequency regulation is observed as the levels of EV penetration increases. In addition, high EV power output during a short period of time indicates its low impact on EV SOC and the need of high power EV charger to reduce the number of EV participation.
{"title":"Electric Vehicle Charging Station for Providing Primary Frequency Control in Microgrid","authors":"U. Datta, Akhtar Kalam, Juan Shi, Jiangrong Li","doi":"10.1109/ICIEA.2019.8834209","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8834209","url":null,"abstract":"The contribution of electric vehicles (EV) in a microgrid with high intermittent renewable energy penetration could strengthen power system security and reliability. This paper investigates the contribution of EV in regulating and improving primary frequency response of the power system. EV is designed to halt charging and inject power to the grid during an under-frequency event and to consume surplus energy following an over-frequency event when EV state-of-charge (SOC) is available. The minimum SOC threshold is kept to a higher value to ensure EV is available to be driven at any given time. Simulation results demonstrate that EV enhances primary frequency response of the system and also better frequency regulation is observed as the levels of EV penetration increases. In addition, high EV power output during a short period of time indicates its low impact on EV SOC and the need of high power EV charger to reduce the number of EV participation.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123532946","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8833842
Jiao Shang-Bin, Liu Jing-wei, Zhang You-min, Zhang Xiao-liang, Xie Guo
Firstly, the parameter analysis of the double-cylinder permanent-magnet eddy current coupler is carried out by using Maxwell finite element analysis software. Considering the theoretical and practical situation, the relationship between the main structural parameters and the transfer torque is determined. Then, in order to reduce the calculation cost of the subsequent optimization, BP neural network and support vector machine are used to establish the nonlinear model between the main structural parameters and the transfer torque. Comparing the two methods, it is found that the SVM method is superior to the BP method in predicting performance and running time. Finally, a test system is built to verify the accuracy of the SVM nonlinear model.
{"title":"Nonlinear Modeling of Double-barrel Eddy Current Coupler","authors":"Jiao Shang-Bin, Liu Jing-wei, Zhang You-min, Zhang Xiao-liang, Xie Guo","doi":"10.1109/ICIEA.2019.8833842","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8833842","url":null,"abstract":"Firstly, the parameter analysis of the double-cylinder permanent-magnet eddy current coupler is carried out by using Maxwell finite element analysis software. Considering the theoretical and practical situation, the relationship between the main structural parameters and the transfer torque is determined. Then, in order to reduce the calculation cost of the subsequent optimization, BP neural network and support vector machine are used to establish the nonlinear model between the main structural parameters and the transfer torque. Comparing the two methods, it is found that the SVM method is superior to the BP method in predicting performance and running time. Finally, a test system is built to verify the accuracy of the SVM nonlinear model.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122586050","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8833667
Xuan Hou, Jun Wang, Peng Wang, Tao Wang
With the continuous development of smart grid technology, the implementation of smart home energy management system (HEMS) has become possible, where HEMS can potentially change electricity consumption habits of users by reducing costs. In this paper, the HEMS model based on mixed integer linear programming (MILP) is designed to reduce dissatisfaction and cost of consumers. In the meantime, the model includes renewable energy, energy storage system (ESS), plug-in electric vehicle (PEV) and domestic appliances. Moreover, an energy optimization method with the ESS and PEV mixed charging and discharging strategy is exploited to calculate the above model. Then, simulation experiment will verify the effectiveness of the method.
{"title":"Smart Home Energy Management Optimization Method Considering ESS and PEV","authors":"Xuan Hou, Jun Wang, Peng Wang, Tao Wang","doi":"10.1109/ICIEA.2019.8833667","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8833667","url":null,"abstract":"With the continuous development of smart grid technology, the implementation of smart home energy management system (HEMS) has become possible, where HEMS can potentially change electricity consumption habits of users by reducing costs. In this paper, the HEMS model based on mixed integer linear programming (MILP) is designed to reduce dissatisfaction and cost of consumers. In the meantime, the model includes renewable energy, energy storage system (ESS), plug-in electric vehicle (PEV) and domestic appliances. Moreover, an energy optimization method with the ESS and PEV mixed charging and discharging strategy is exploited to calculate the above model. Then, simulation experiment will verify the effectiveness of the method.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116783252","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8834060
Nico Zengeler, M. Grimm, C. Borgmann, M. Jansen, S. Eimler, U. Handmann
In this paper we evaluate different machine learning models for human body detection in heavy industry environments. Contributing a framework to asses the reliability of a detection system in industrial environments, we compare techniques of feature extraction for support vector machines to artificial neural networks. To accommodate for common environmental challenges in heavy industry, such as dust, difficult light conditions and partially covered persons, we apply programmatic changes to our test image set and evaluate the accuracy of person detection, foot point estimation and the tendency of erroneous detections.
{"title":"An Evaluation of Human Detection Methods on Camera Images in Heavy Industry Environments","authors":"Nico Zengeler, M. Grimm, C. Borgmann, M. Jansen, S. Eimler, U. Handmann","doi":"10.1109/ICIEA.2019.8834060","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8834060","url":null,"abstract":"In this paper we evaluate different machine learning models for human body detection in heavy industry environments. Contributing a framework to asses the reliability of a detection system in industrial environments, we compare techniques of feature extraction for support vector machines to artificial neural networks. To accommodate for common environmental challenges in heavy industry, such as dust, difficult light conditions and partially covered persons, we apply programmatic changes to our test image set and evaluate the accuracy of person detection, foot point estimation and the tendency of erroneous detections.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124086707","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8833831
Yan Yang, Yue Li, Ze Cheng, Tian Gao
High frequency is the development trend of switching power supplies to achieve miniaturization density of switching power supplies. However, the increase in frequency makes the leakage inductance parameter of the transformer in the switching power supply more and more important to the performance of the circuit. In this paper, the leakage inductance and winding loss of high frequency transformer in LLC resonant converter are analyzed in detail. An optimized design scheme of high frequency transformer based on winding structure is introduced, which can effectively reduce the leakage inductance and winding losses of high frequency transformer, and improve stability and efficiency of the transformer resonant converter. Finite-element analysis simulation validate the design scheme.
{"title":"Optimal Design of Transformer Windings for Full-Bridge LLC Resonant Converters","authors":"Yan Yang, Yue Li, Ze Cheng, Tian Gao","doi":"10.1109/ICIEA.2019.8833831","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8833831","url":null,"abstract":"High frequency is the development trend of switching power supplies to achieve miniaturization density of switching power supplies. However, the increase in frequency makes the leakage inductance parameter of the transformer in the switching power supply more and more important to the performance of the circuit. In this paper, the leakage inductance and winding loss of high frequency transformer in LLC resonant converter are analyzed in detail. An optimized design scheme of high frequency transformer based on winding structure is introduced, which can effectively reduce the leakage inductance and winding losses of high frequency transformer, and improve stability and efficiency of the transformer resonant converter. Finite-element analysis simulation validate the design scheme.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126594006","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8833928
Hongyu Pan, Wei Hu, Qi Yang, Kai Zhang
Nowadays, almost all applications store data on servers, and servers provide a wide variety of services. Due to differences in the development environment during development, testing, and production, traditionally building services directly on the server may lead to application deployment failures. In such cases, it is particularly important for the server to have a private service management system. Aiming at a series of problems in current environment construction including server deployment, this paper proposes a method of using Docker to manage the server, and designs and implements a Docker-based server management system. The implementation tests show that this system can provide efficient services as its design.
{"title":"Design and Implementation of Server Management System Based on Docker","authors":"Hongyu Pan, Wei Hu, Qi Yang, Kai Zhang","doi":"10.1109/ICIEA.2019.8833928","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8833928","url":null,"abstract":"Nowadays, almost all applications store data on servers, and servers provide a wide variety of services. Due to differences in the development environment during development, testing, and production, traditionally building services directly on the server may lead to application deployment failures. In such cases, it is particularly important for the server to have a private service management system. Aiming at a series of problems in current environment construction including server deployment, this paper proposes a method of using Docker to manage the server, and designs and implements a Docker-based server management system. The implementation tests show that this system can provide efficient services as its design.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132261238","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8834070
Lei Yang, Ben Zhang, Minna Ju
As widely used mobile devices and the electric vehicles, the wireless charging system has been developed quickly. However, when it comes to the underwater wireless charging system, there are few research papers and the industrial applications. For the Autonomous Underwater Vehicles, they always use the battery swapping and physical power cable (conductive charging). These methods are not convenient. Another method is the AUVs docking station. This system should adapt the accurate navigation system with the expensive price. In order to deal with these challenges, the underwater wireless power transfer system (UWPT) is provided. For the marine environments, the key challenge of the UWPT is the regulation for the load battery in the dynamical operation. This article describes a new design method to deal with the misalignment and the changeable distance between the transmitter side and receiver side of the UWPT system to get the stable load regulation. In this paper, the authors adapt the switched capacitor (SC) converter acting as the boost DC-DC converter. The SC converter is controlled by the nonlinear verified one-cycle control (VOCC) method to reject the disturbance occurred when the misalignment happens and the distance changes between the transmitter side and receiver side. The load voltage of the UWPT could be regulated robustly with the fast-dynamical response speed to reject the external disturbance.
{"title":"A Fast Dynamic Response Regulation Method for Undersea Wireless Power Transfer System","authors":"Lei Yang, Ben Zhang, Minna Ju","doi":"10.1109/ICIEA.2019.8834070","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8834070","url":null,"abstract":"As widely used mobile devices and the electric vehicles, the wireless charging system has been developed quickly. However, when it comes to the underwater wireless charging system, there are few research papers and the industrial applications. For the Autonomous Underwater Vehicles, they always use the battery swapping and physical power cable (conductive charging). These methods are not convenient. Another method is the AUVs docking station. This system should adapt the accurate navigation system with the expensive price. In order to deal with these challenges, the underwater wireless power transfer system (UWPT) is provided. For the marine environments, the key challenge of the UWPT is the regulation for the load battery in the dynamical operation. This article describes a new design method to deal with the misalignment and the changeable distance between the transmitter side and receiver side of the UWPT system to get the stable load regulation. In this paper, the authors adapt the switched capacitor (SC) converter acting as the boost DC-DC converter. The SC converter is controlled by the nonlinear verified one-cycle control (VOCC) method to reject the disturbance occurred when the misalignment happens and the distance changes between the transmitter side and receiver side. The load voltage of the UWPT could be regulated robustly with the fast-dynamical response speed to reject the external disturbance.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129218317","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 : 2019-06-19DOI: 10.1109/ICIEA.2019.8834044
Swati Tandon, A. Rathore
A novel soft switched grid connected single phase inverter topology is proposed and analyzed in this paper. Single phase single stage inverter consist of a full bridge converter (FBC) and a center taped rectifier interfaced with a high frequency transformer. To achieve Zero Voltage switching of the DC side Mosfets and reduced harmonics at the output side LCL-T resonant tank is introduced at the primary side of the high frequency transformer. Phase shift modulation of DC side full bridge is implemented for power flow control from DC to AC side. AC side converter is line frequency switched resulting in reduced switching losses. The performance of the proposed inverter topology is analyzed under different operating conditions for 200W prototype. Detailed analysis of converter and effect of secondary leakage inductance on the overall performance of the converter has also been analyzed.
{"title":"LCL Resonant Soft-switching Single Stage single-phase Grid Connected Inverter","authors":"Swati Tandon, A. Rathore","doi":"10.1109/ICIEA.2019.8834044","DOIUrl":"https://doi.org/10.1109/ICIEA.2019.8834044","url":null,"abstract":"A novel soft switched grid connected single phase inverter topology is proposed and analyzed in this paper. Single phase single stage inverter consist of a full bridge converter (FBC) and a center taped rectifier interfaced with a high frequency transformer. To achieve Zero Voltage switching of the DC side Mosfets and reduced harmonics at the output side LCL-T resonant tank is introduced at the primary side of the high frequency transformer. Phase shift modulation of DC side full bridge is implemented for power flow control from DC to AC side. AC side converter is line frequency switched resulting in reduced switching losses. The performance of the proposed inverter topology is analyzed under different operating conditions for 200W prototype. Detailed analysis of converter and effect of secondary leakage inductance on the overall performance of the converter has also been analyzed.","PeriodicalId":311302,"journal":{"name":"2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122540831","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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