Pub Date : 2018-11-01DOI: 10.1109/RTUCON.2018.8659866
E. Mele, Charalambos Elias, A. Ktena
Short-Term Load Forecasting (STLF) is nowadays a crucial and integral part of the energy production procedure to the emerging technologies for demand side management. The numerous approaches and algorithms proposed take advantage of the advances in information, metering and control technologies to address the challenges of distributed generation and intermittent energy sources on the one hand and the electricity markets on the other. This paper describes a flexible and easily customized, modular toolbox, called Divinus, for electricity use profiling and forecasting in microgrids. Divinus supports algorithms for forecasting and profiling that can be used independently or combined and its architecture consists of several interconnected well-defined components where each one interacts directly with the other. In this work, we have implemented Self-Organizing Maps for profiling and k-Neighbors for forecasting. In order to test the functionalities of the platform, we used electricity consumption data of the TEISTE campus in Evia, Greece from January 2010 till March 2018. From the tests that have been carried out so far, we have observed that the proposed approach yields high accuracy and acceptable mean errors.
{"title":"Electricity use profiling and forecasting at microgrid level","authors":"E. Mele, Charalambos Elias, A. Ktena","doi":"10.1109/RTUCON.2018.8659866","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659866","url":null,"abstract":"Short-Term Load Forecasting (STLF) is nowadays a crucial and integral part of the energy production procedure to the emerging technologies for demand side management. The numerous approaches and algorithms proposed take advantage of the advances in information, metering and control technologies to address the challenges of distributed generation and intermittent energy sources on the one hand and the electricity markets on the other. This paper describes a flexible and easily customized, modular toolbox, called Divinus, for electricity use profiling and forecasting in microgrids. Divinus supports algorithms for forecasting and profiling that can be used independently or combined and its architecture consists of several interconnected well-defined components where each one interacts directly with the other. In this work, we have implemented Self-Organizing Maps for profiling and k-Neighbors for forecasting. In order to test the functionalities of the platform, we used electricity consumption data of the TEISTE campus in Evia, Greece from January 2010 till March 2018. From the tests that have been carried out so far, we have observed that the proposed approach yields high accuracy and acceptable mean errors.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127126586","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659880
Ģ. Staņa, V. Brazis
Fast trolleybus acceleration causes high power peaks in the overhead network. For this reason, smoothing of power peaks has been a topical issue in the field of electric public transport. In part, this can be achieved through energy storage systems capable of storing braking energy that can be reused during the next acceleration. This paper compares the possibilities to apply mobile energy storage systems for two trolleybus types of standard Škoda 24Tr and articulated Škoda 27Tr. Idealized motion simulations were made in Matlab/Simullnk environment.
{"title":"Comparative Modeling of Mobile Energy Storage System Application for Trolleybuses","authors":"Ģ. Staņa, V. Brazis","doi":"10.1109/RTUCON.2018.8659880","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659880","url":null,"abstract":"Fast trolleybus acceleration causes high power peaks in the overhead network. For this reason, smoothing of power peaks has been a topical issue in the field of electric public transport. In part, this can be achieved through energy storage systems capable of storing braking energy that can be reused during the next acceleration. This paper compares the possibilities to apply mobile energy storage systems for two trolleybus types of standard Škoda 24Tr and articulated Škoda 27Tr. Idealized motion simulations were made in Matlab/Simullnk environment.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125518263","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 : 2018-11-01DOI: 10.1109/rtucon.2018.8659910
J. Survilo
By grid optimization, the determination of the size of the fed zone, when per unit cost of electricity delivery - the cost referred to transmitted energy - is minimum, is understood. Per unit cost is a function of substation cost and of fed zone grid indexes: length of the power lines and the amount of their material, losses of energy and of voltages which, in turn, are functions of the fed zone size. The indexes are different for various fed zone shapes. When outlines of a fed zone are not defined topographically, the most profitable shape of the zone is hexagon. However, the square or some other fed zone shape sometimes can be more acceptable due to the location of consumers. These indexes are defined in the paper. Besides, it turns out that, when minimizing the per unit cost of electricity delivery, a binomial of a fed zone main size is insufficient to represent the said per unit cost; it is shown here that a trinomial or even four-term polynomial is necessary to represent the per unit cost of electricity delivery.
{"title":"Features of Distribution Grid Optimization","authors":"J. Survilo","doi":"10.1109/rtucon.2018.8659910","DOIUrl":"https://doi.org/10.1109/rtucon.2018.8659910","url":null,"abstract":"By grid optimization, the determination of the size of the fed zone, when per unit cost of electricity delivery - the cost referred to transmitted energy - is minimum, is understood. Per unit cost is a function of substation cost and of fed zone grid indexes: length of the power lines and the amount of their material, losses of energy and of voltages which, in turn, are functions of the fed zone size. The indexes are different for various fed zone shapes. When outlines of a fed zone are not defined topographically, the most profitable shape of the zone is hexagon. However, the square or some other fed zone shape sometimes can be more acceptable due to the location of consumers. These indexes are defined in the paper. Besides, it turns out that, when minimizing the per unit cost of electricity delivery, a binomial of a fed zone main size is insufficient to represent the said per unit cost; it is shown here that a trinomial or even four-term polynomial is necessary to represent the per unit cost of electricity delivery.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123350853","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659872
Nezha El Hichami, A. Abbou, S. Rhaili, Abdellah Ziouh, Saloua Marhraoui
This paper concentrated on the modeling and simulation of grid-connected photovoltaic systems. This work presents a maximum power point tracking approach based on a fuzzy logic control to improve the efficacy and hardiness of photovoltaic solar power generation and establishes a model dynamic of PV system connected to the network by the environment Matlab/ Simulink that reflects the features of the system accurately. The grid-connected photovoltaic system comprises a photovoltaic generator, a converter DC-DC, a fuzzy logic control MPPT, an inverter, a distribution network, and sinusoidal PWM technique is presented for the inverter control system as well as the synchronization condition of the network. The simulation results presented here validate the selected component models and control schemes.
{"title":"Grid Connected Photovoltaic System using a Fuzzy Logic Control Approach","authors":"Nezha El Hichami, A. Abbou, S. Rhaili, Abdellah Ziouh, Saloua Marhraoui","doi":"10.1109/RTUCON.2018.8659872","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659872","url":null,"abstract":"This paper concentrated on the modeling and simulation of grid-connected photovoltaic systems. This work presents a maximum power point tracking approach based on a fuzzy logic control to improve the efficacy and hardiness of photovoltaic solar power generation and establishes a model dynamic of PV system connected to the network by the environment Matlab/ Simulink that reflects the features of the system accurately. The grid-connected photovoltaic system comprises a photovoltaic generator, a converter DC-DC, a fuzzy logic control MPPT, an inverter, a distribution network, and sinusoidal PWM technique is presented for the inverter control system as well as the synchronization condition of the network. The simulation results presented here validate the selected component models and control schemes.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"230 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121541227","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659839
Mahmoud Aref, Amir Abdelmeneam, V. Oboskalov, A. Mahņitko, A. Gavrilov
Due to the increasing penetration level of microgrids (MGs), it becomes a critical issue for MGs to help sustaining power system stability. Therefore, this paper is aimed at investigating comparison between transient analysis AC and DC Microgrid connected to the grid in case of using Superconducting Fault current limiter (SFCL) at the connection point of Microgrid and grid. When the three-phase-to-ground fault is applied at connection point of Microgrid and grid, the SFCL minimized the oscillating currents and the active and reactive power of AC and DC microgrid to range 20-30%. The transient analysis of AC microgrid is better than DC microgrid except the values currents and the active and reactive power are very high during the fault. The time required to recover pre-fault values of AC microgrid (0.1 sec) is less than those time of DC microgrid (3 sec).
{"title":"Transient Analysis of AC and DC Microgrid with Effective of SFCL","authors":"Mahmoud Aref, Amir Abdelmeneam, V. Oboskalov, A. Mahņitko, A. Gavrilov","doi":"10.1109/RTUCON.2018.8659839","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659839","url":null,"abstract":"Due to the increasing penetration level of microgrids (MGs), it becomes a critical issue for MGs to help sustaining power system stability. Therefore, this paper is aimed at investigating comparison between transient analysis AC and DC Microgrid connected to the grid in case of using Superconducting Fault current limiter (SFCL) at the connection point of Microgrid and grid. When the three-phase-to-ground fault is applied at connection point of Microgrid and grid, the SFCL minimized the oscillating currents and the active and reactive power of AC and DC microgrid to range 20-30%. The transient analysis of AC microgrid is better than DC microgrid except the values currents and the active and reactive power are very high during the fault. The time required to recover pre-fault values of AC microgrid (0.1 sec) is less than those time of DC microgrid (3 sec).","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"54 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120887404","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659877
Rahims Geidarovs, Andrejs Podgornovs, I. Galkin
The purpose of this paper is to introduce readers with a proposal of a new approach of permanent magnet synchronous motor with arc shaped stator for wheelchair application. The arc shaped stator allows user to vary motor power and in the same time it’s torque by removing or adding arc shaped modules of the stator. It is an excellent opportunity allowing to adjust motor power according to users weight. In the same time it allows to save money when comparing with the same type of motor with a whole stator.
{"title":"Simulation and Initial Evaluation of Modular Motor-Generator for Cost-Effective Power-Assist Wheelchair","authors":"Rahims Geidarovs, Andrejs Podgornovs, I. Galkin","doi":"10.1109/RTUCON.2018.8659877","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659877","url":null,"abstract":"The purpose of this paper is to introduce readers with a proposal of a new approach of permanent magnet synchronous motor with arc shaped stator for wheelchair application. The arc shaped stator allows user to vary motor power and in the same time it’s torque by removing or adding arc shaped modules of the stator. It is an excellent opportunity allowing to adjust motor power according to users weight. In the same time it allows to save money when comparing with the same type of motor with a whole stator.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120968474","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659842
B. Asad, T. Vaimann, A. Kallaste, A. Belahcen
In this paper, the frequency spectrum of a three- phase induction motor’s stator current on a linear scale is investigated. The broken rotor bar, spatial and grid fed harmonics are taken into consideration. Since the fundamental component of the power supply is always the most powerful component, it makes the spectrum less legible, increases the spectral leakage and makes the logarithmic scale inevitable. In this paper, a Chebyshev filter is used for attenuation of the fundamental component, because of its good transition band and no passband ripples. The current signals are taken from both simulation and laboratory environment and harmonics due to above-mentioned causes are segregated.
{"title":"Harmonic Spectrum Analysis of Induction Motor With Broken Rotor Bar Fault","authors":"B. Asad, T. Vaimann, A. Kallaste, A. Belahcen","doi":"10.1109/RTUCON.2018.8659842","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659842","url":null,"abstract":"In this paper, the frequency spectrum of a three- phase induction motor’s stator current on a linear scale is investigated. The broken rotor bar, spatial and grid fed harmonics are taken into consideration. Since the fundamental component of the power supply is always the most powerful component, it makes the spectrum less legible, increases the spectral leakage and makes the logarithmic scale inevitable. In this paper, a Chebyshev filter is used for attenuation of the fundamental component, because of its good transition band and no passband ripples. The current signals are taken from both simulation and laboratory environment and harmonics due to above-mentioned causes are segregated.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122840635","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659814
M. Kosmecki, R. Rink
A new method for on-line grid impedance estimation is presented in the paper. It is based on an algorithm that requires no measurements from other buses. What is more, in normal operation it does not need to inject any current to the grid at the point of common coupling as it common in active methods for impedance estimation. The paper includes a mathematical derivation of the key equations, simulation results for a simple test system as well as performance evaluation. Laboratory tests are ongoing.
{"title":"Hybrid Method for Grid Impedance Estimation Based on Local Measurements","authors":"M. Kosmecki, R. Rink","doi":"10.1109/RTUCON.2018.8659814","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659814","url":null,"abstract":"A new method for on-line grid impedance estimation is presented in the paper. It is based on an algorithm that requires no measurements from other buses. What is more, in normal operation it does not need to inject any current to the grid at the point of common coupling as it common in active methods for impedance estimation. The paper includes a mathematical derivation of the key equations, simulation results for a simple test system as well as performance evaluation. Laboratory tests are ongoing.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"242 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133033214","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659816
K. Sejejs, E. Kamoliņš, K. Gulbis
Due to their comparatively higher efficiency and power density, permanent magnet synchronous machines (PMSM) is the most popular type of the electric machines used for the traction systems in electric vehicles (EV). Considering the increasing cost of rare earth materials and other disadvantages of PMSMs, it is necessary to develop reluctance machines needed for the usage in the EVs. In order to increase the competitiveness of the reluctance machines, it is important to develop solutions that would increase their torque density, overall efficiency, and eliminate disadvantages such as torque ripple, which is very undesirable in the field of EVs. One of the solutions is in the development of the longitudinal cross-section of the electric machine tooth zone - the proposed use of the Shark concept. In this paper, several Shark profiles (air gap shapes) are examined. Results of experiments conducted of three-dimensional (3D) magnetic field calculations using finite element analysis (FEA) have been discussed and the efficiency and behaviour of different Shark profiles have been compared. The results of experiments show that the Shark concept can be a perspective solution for the improvement of the reluctance machines, thus making them more competitive in the field of the traction systems of EVs.
{"title":"Research of Shark Concept Using 3D Finite Element Analysis","authors":"K. Sejejs, E. Kamoliņš, K. Gulbis","doi":"10.1109/RTUCON.2018.8659816","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659816","url":null,"abstract":"Due to their comparatively higher efficiency and power density, permanent magnet synchronous machines (PMSM) is the most popular type of the electric machines used for the traction systems in electric vehicles (EV). Considering the increasing cost of rare earth materials and other disadvantages of PMSMs, it is necessary to develop reluctance machines needed for the usage in the EVs. In order to increase the competitiveness of the reluctance machines, it is important to develop solutions that would increase their torque density, overall efficiency, and eliminate disadvantages such as torque ripple, which is very undesirable in the field of EVs. One of the solutions is in the development of the longitudinal cross-section of the electric machine tooth zone - the proposed use of the Shark concept. In this paper, several Shark profiles (air gap shapes) are examined. Results of experiments conducted of three-dimensional (3D) magnetic field calculations using finite element analysis (FEA) have been discussed and the efficiency and behaviour of different Shark profiles have been compared. The results of experiments show that the Shark concept can be a perspective solution for the improvement of the reluctance machines, thus making them more competitive in the field of the traction systems of EVs.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114496310","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 : 2018-11-01DOI: 10.1109/RTUCON.2018.8659815
A. Patlins
the phenomenon of motivation has been researched in current paper. It outlines the significance of motivation towards to science, through effective teaching, learning, research and scientific writing as the approach for electrical and power engineering education. This paper examines how to solve the problem of de-motivation of students, researchers and administrative stuff of the university. The aim of this study is to collect, analyze and obtain the information about motivation to stimulate effective teaching, learning, research and scientific writing to increase the level of electrical and power engineering education. Research will be based on worlds literature, scientific publications, own experience, experience obtained by Kaunas University of Technology and experience of international experts. Author has performed this research also to initiate debates in scientific world and society about significance of motivation for sustainable development of scientific institutes, universities and all the education system.
{"title":"Research the phenomenon of motivation, towards to science, through effective teaching, learning, research and scientific writing as the approach for improvement of electrical and power engineering education","authors":"A. Patlins","doi":"10.1109/RTUCON.2018.8659815","DOIUrl":"https://doi.org/10.1109/RTUCON.2018.8659815","url":null,"abstract":"the phenomenon of motivation has been researched in current paper. It outlines the significance of motivation towards to science, through effective teaching, learning, research and scientific writing as the approach for electrical and power engineering education. This paper examines how to solve the problem of de-motivation of students, researchers and administrative stuff of the university. The aim of this study is to collect, analyze and obtain the information about motivation to stimulate effective teaching, learning, research and scientific writing to increase the level of electrical and power engineering education. Research will be based on worlds literature, scientific publications, own experience, experience obtained by Kaunas University of Technology and experience of international experts. Author has performed this research also to initiate debates in scientific world and society about significance of motivation for sustainable development of scientific institutes, universities and all the education system.","PeriodicalId":192943,"journal":{"name":"2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133690057","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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