Pub Date : 2018-05-13DOI: 10.1109/ICHQP.2018.8378818
Mateus M. de Oliveira, L. Silva, C. Duque, L. M. de Andrade Filho, P. Ribeiro
The storage of voltage and current signals over a period of time generates a large memory expense. Therefore, signal compression techniques became important in this context. This paper presents an implementation in Field Gate Programmable Array (FPGA) of an algorithm of sparse representation using redundant dictionaries, applied to the compression of electrical signals, from power systems. The representation will be based on a dictionary constituted by elements of the Fourier and Wavelet basis, that are capable to represent the stationary and transient components of the electrical signals. The results will be analyzed due to two parameters: the quality of the compressed signal, in terms of its correlation coefficient related to the original signal; and the number of elements in te representation, that is related with the compression ratio. The feasibility of the implementation in real time will be evaluated in terms of the consumed FPGA resources and the necessary frequency of operation.
{"title":"Implementation of an electrical signal compression system using sparce representation","authors":"Mateus M. de Oliveira, L. Silva, C. Duque, L. M. de Andrade Filho, P. Ribeiro","doi":"10.1109/ICHQP.2018.8378818","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378818","url":null,"abstract":"The storage of voltage and current signals over a period of time generates a large memory expense. Therefore, signal compression techniques became important in this context. This paper presents an implementation in Field Gate Programmable Array (FPGA) of an algorithm of sparse representation using redundant dictionaries, applied to the compression of electrical signals, from power systems. The representation will be based on a dictionary constituted by elements of the Fourier and Wavelet basis, that are capable to represent the stationary and transient components of the electrical signals. The results will be analyzed due to two parameters: the quality of the compressed signal, in terms of its correlation coefficient related to the original signal; and the number of elements in te representation, that is related with the compression ratio. The feasibility of the implementation in real time will be evaluated in terms of the consumed FPGA resources and the necessary frequency of operation.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"159 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76481975","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378925
Stefano Lodetti, I. Azcarate, J. Gutiérrez, K. Redondo, Purificatión Sáiz, J. J. Melero, J. Bruna
Rapid Voltage Changes (RVCs) are one of the Power Quality disturbances that are recently receiving a lot of attention from the point of view of international standards. However, although they can cause or contribute to flicker, IEC 61000-4-15 only addresses periodic amplitude fluctuations and more effort is needed to regulate the occurrence of RVCs, according to their effect on flicker perceptibility. Alongside, flicker perception is challenged by the integration of modern lighting technology, whose response is different from the traditional incandescent lamp. This paper studies the connection between the increasing importance of RVCs and the evolution of illumination technologies. Sensitivity of modern lighting technologies to RVCs is studied by measuring flicker with a high precision light flickermeter. A large set of modern lamps is tested and the relationship between RVCs parameters and flicker perceptibility is analyzed.
{"title":"Sensitivity of modern lighting technologies to rapid voltage changes","authors":"Stefano Lodetti, I. Azcarate, J. Gutiérrez, K. Redondo, Purificatión Sáiz, J. J. Melero, J. Bruna","doi":"10.1109/ICHQP.2018.8378925","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378925","url":null,"abstract":"Rapid Voltage Changes (RVCs) are one of the Power Quality disturbances that are recently receiving a lot of attention from the point of view of international standards. However, although they can cause or contribute to flicker, IEC 61000-4-15 only addresses periodic amplitude fluctuations and more effort is needed to regulate the occurrence of RVCs, according to their effect on flicker perceptibility. Alongside, flicker perception is challenged by the integration of modern lighting technology, whose response is different from the traditional incandescent lamp. This paper studies the connection between the increasing importance of RVCs and the evolution of illumination technologies. Sensitivity of modern lighting technologies to RVCs is studied by measuring flicker with a high precision light flickermeter. A large set of modern lamps is tested and the relationship between RVCs parameters and flicker perceptibility is analyzed.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"54 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76606700","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378813
Victor P. Brasil, A. de Leles Ferreira Filho, J. Ishihara
Nowadays, reactive power and power factor in unbalanced circuits and/or with the presence of harmonics are still being investigated by several researchers. In this context, quaternions, whose use has recently been intensified in the electrical engineering field, is presented as an alternative tool to analyze electrical quantities in single and three-phase circuits. However, studies solving three-phase circuits by quaternions are not yet in literature, nor a complete electrical description with this tool. This article, therefore, presents single and balanced three-phase quantities expressed as quaternions. Results of an analysis of a series RLC single and balanced three-phase circuits are presented. It is important to notice that this tool can also be employed to represent three-phase power under unbalanced situations and with the presence of harmonics.
{"title":"Electrical three phase circuit analysis using quaternions","authors":"Victor P. Brasil, A. de Leles Ferreira Filho, J. Ishihara","doi":"10.1109/ICHQP.2018.8378813","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378813","url":null,"abstract":"Nowadays, reactive power and power factor in unbalanced circuits and/or with the presence of harmonics are still being investigated by several researchers. In this context, quaternions, whose use has recently been intensified in the electrical engineering field, is presented as an alternative tool to analyze electrical quantities in single and three-phase circuits. However, studies solving three-phase circuits by quaternions are not yet in literature, nor a complete electrical description with this tool. This article, therefore, presents single and balanced three-phase quantities expressed as quaternions. Results of an analysis of a series RLC single and balanced three-phase circuits are presented. It is important to notice that this tool can also be employed to represent three-phase power under unbalanced situations and with the presence of harmonics.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"6 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75251574","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378852
A. Pessoa, M. Oleskovicz, P. E. T. Martins
In the context of smart grids and microgrids, fault location is an important point that can be explored with all the possibilities of this new paradigm. This study presents a multi-stage methodology that involves decision trees as well as artificial neural networks for fault location purposes. Another aspect to be considered is the use of an allocation of smart meters in the distribution system for the tests. The IEEE 34-bus distribution system was used to validate the methodology. This system was chosen due to its considerable number of monophasic branches and its extension. The focus of this paper is the multiple estimation problem, in which, for a same distance of the fault, there is more than one possibility to locate it. Confusion matrices were used to explore the results and show the performance of the proposed algorithm.
{"title":"A multi-stage methodology for fault location in radial distribution systems","authors":"A. Pessoa, M. Oleskovicz, P. E. T. Martins","doi":"10.1109/ICHQP.2018.8378852","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378852","url":null,"abstract":"In the context of smart grids and microgrids, fault location is an important point that can be explored with all the possibilities of this new paradigm. This study presents a multi-stage methodology that involves decision trees as well as artificial neural networks for fault location purposes. Another aspect to be considered is the use of an allocation of smart meters in the distribution system for the tests. The IEEE 34-bus distribution system was used to validate the methodology. This system was chosen due to its considerable number of monophasic branches and its extension. The focus of this paper is the multiple estimation problem, in which, for a same distance of the fault, there is more than one possibility to locate it. Confusion matrices were used to explore the results and show the performance of the proposed algorithm.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"145 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80473219","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378935
Álvaro Ortega, F. Milano
Accurate and fast-responding Phase-Locked Loops (PLLs) are crucial for the implementation of primary frequency controllers of non-synchronous generation and energy storage devices that are connected to the grid through power electronic converters. PLLs are primarily designed to synchronize a converter to the grid and their ability to estimate frequency deviations is a design-dependent, not necessarily optimized byproduct. The goal of the paper is to establish which design better filters noise and reduces numerical spikes after sudden variations of the voltage at the terminal ac bus of the converter. To this aim, the paper compares five well-assessed PLL implementations through a standard IEEE benchmark system considering both contingencies and noise.
{"title":"Comparison of different PLL implementations for frequency estimation and control","authors":"Álvaro Ortega, F. Milano","doi":"10.1109/ICHQP.2018.8378935","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378935","url":null,"abstract":"Accurate and fast-responding Phase-Locked Loops (PLLs) are crucial for the implementation of primary frequency controllers of non-synchronous generation and energy storage devices that are connected to the grid through power electronic converters. PLLs are primarily designed to synchronize a converter to the grid and their ability to estimate frequency deviations is a design-dependent, not necessarily optimized byproduct. The goal of the paper is to establish which design better filters noise and reduces numerical spikes after sudden variations of the voltage at the terminal ac bus of the converter. To this aim, the paper compares five well-assessed PLL implementations through a standard IEEE benchmark system considering both contingencies and noise.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"411 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79900999","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378882
C. H. Beuter, M. Oleskovicz, C. I. Golfieri, Guilherme Spavieri, R. Fernandes
This work proposes a method for the selection of the optimized window of analysis for the Generalized S- Transform (GST), through an adaptation in the Particle Swarm Optimization (PSO) algorithm. The new version of the algorithm, called Adaptive Individual Inertia Weight Based on Best, Worst and Individual (AIW-PSO), uses an inertia weight, where the performance of the best and the worst particle are employed in the adaptive process. The GST is applied to the signal by using AIW-PSO, whose objective function to be minimized is the concentration of energy that will provide the proposed window selection. To evaluate the efficacy of the proposed method, two synthetic signals were analysed by the GST, based on parameters r, m, p and k, and compared with the standard version and an optimized version of the S-Transform (ST) available in the literature. It was found that the GST, optimized via the AIW-PSO algorithm, provided a better response in the Time-Frequency Representation (TFR) when compared to the standard non-ideal ST window, as well as an additional gain in energy concentration relative to the optimized version approach.
{"title":"Selection of the optimized window for the generalized s-transform using the AIW-PSO algorithm","authors":"C. H. Beuter, M. Oleskovicz, C. I. Golfieri, Guilherme Spavieri, R. Fernandes","doi":"10.1109/ICHQP.2018.8378882","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378882","url":null,"abstract":"This work proposes a method for the selection of the optimized window of analysis for the Generalized S- Transform (GST), through an adaptation in the Particle Swarm Optimization (PSO) algorithm. The new version of the algorithm, called Adaptive Individual Inertia Weight Based on Best, Worst and Individual (AIW-PSO), uses an inertia weight, where the performance of the best and the worst particle are employed in the adaptive process. The GST is applied to the signal by using AIW-PSO, whose objective function to be minimized is the concentration of energy that will provide the proposed window selection. To evaluate the efficacy of the proposed method, two synthetic signals were analysed by the GST, based on parameters r, m, p and k, and compared with the standard version and an optimized version of the S-Transform (ST) available in the literature. It was found that the GST, optimized via the AIW-PSO algorithm, provided a better response in the Time-Frequency Representation (TFR) when compared to the standard non-ideal ST window, as well as an additional gain in energy concentration relative to the optimized version approach.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"613 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80428694","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378864
N. Tang, G. Chang
In this paper, a stochastic approach is applied to determine the photovoltaic (PV) hosting capacity in a distribution feeder. The hosting capacity is determined accounting for the four voltage quality criteria: overvoltage, voltage deviation, dynamic voltage drop, and voltage unbalance. By applying the stochastic approach, a large number of potential PV deployment scenarios are simulated in a benchmark distribution feeder. While considering the unpredictability of future PV deployments, both sizes and locations are regarded as randomly generated factors. Simulations for assessments of voltage quality impacts are quantified and PV hosting capacities are statistically determined. In addition, smart inverter functions are included to improve voltage quality and enhance PV hosting capacity.
{"title":"A stochastic approach for determining PV hosting capacity of a distribution feeder considering voltage quality constraints","authors":"N. Tang, G. Chang","doi":"10.1109/ICHQP.2018.8378864","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378864","url":null,"abstract":"In this paper, a stochastic approach is applied to determine the photovoltaic (PV) hosting capacity in a distribution feeder. The hosting capacity is determined accounting for the four voltage quality criteria: overvoltage, voltage deviation, dynamic voltage drop, and voltage unbalance. By applying the stochastic approach, a large number of potential PV deployment scenarios are simulated in a benchmark distribution feeder. While considering the unpredictability of future PV deployments, both sizes and locations are regarded as randomly generated factors. Simulations for assessments of voltage quality impacts are quantified and PV hosting capacities are statistically determined. In addition, smart inverter functions are included to improve voltage quality and enhance PV hosting capacity.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"49 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79375359","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378857
J. Drapela, R. Langella, A. Testa, A. Collin, Xiao Xu, S. Djokic
The paper reports on the experimental evaluation and classification of LED lamps for light flicker sensitivity. After the description of the experimental setup designed for tests, a classification based on the driving circuits is proposed. For each class, the circuit description and the Gain Factor (GF) curves versus interharmonic frequencies are reported. Finally, a comparison of the different GF curves is presented to show the Light Flicker sensitivity of the tested LED lamps.
{"title":"Experimental evaluation and classification of LED lamps for light flicker sensitivity","authors":"J. Drapela, R. Langella, A. Testa, A. Collin, Xiao Xu, S. Djokic","doi":"10.1109/ICHQP.2018.8378857","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378857","url":null,"abstract":"The paper reports on the experimental evaluation and classification of LED lamps for light flicker sensitivity. After the description of the experimental setup designed for tests, a classification based on the driving circuits is proposed. For each class, the circuit description and the Gain Factor (GF) curves versus interharmonic frequencies are reported. Finally, a comparison of the different GF curves is presented to show the Light Flicker sensitivity of the tested LED lamps.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"16 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78302355","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378863
R. H. Furlan, C. H. Beuter, Rodrigo P. Bataglioli, Iago de M. Faria, M. Oleskovicz
This paper presents the impact caused by the Distributed Generators (DGs) on the Overcurrent Relays (ORs) performance for Distribution Systems (DSs) protection, as well as an analysis of the resulting disturbances associated to power quality. A real-time digital simulator was used to model the base test system and to perform the analysis. The base test system is composed by a DG, based on a solar farm, connected to a typical DS substation. The simulations consist of several fault scenarios, in order to show the OR misoperation. The voltage unbalances observed with the tests were used to improve the overcurrent function. Closed loop simulation was performed with a commercial relay to validate the proposed protection function.
{"title":"Improvement of overcurrent protection considering distribution systems with distributed generation","authors":"R. H. Furlan, C. H. Beuter, Rodrigo P. Bataglioli, Iago de M. Faria, M. Oleskovicz","doi":"10.1109/ICHQP.2018.8378863","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378863","url":null,"abstract":"This paper presents the impact caused by the Distributed Generators (DGs) on the Overcurrent Relays (ORs) performance for Distribution Systems (DSs) protection, as well as an analysis of the resulting disturbances associated to power quality. A real-time digital simulator was used to model the base test system and to perform the analysis. The base test system is composed by a DG, based on a solar farm, connected to a typical DS substation. The simulations consist of several fault scenarios, in order to show the OR misoperation. The voltage unbalances observed with the tests were used to improve the overcurrent function. Closed loop simulation was performed with a commercial relay to validate the proposed protection function.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"9 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90449074","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 : 2018-05-13DOI: 10.1109/ICHQP.2018.8378907
G. Celli, F. Pilo, G. Pisano, G. G. Soma
Energy storage systems are valuable components of the future Smart Distribution Systems, thanks to their ability to increase the flexibility of the overall system and to provide a wide range of services. Unfortunately, their costs are still high and their profitable implementation has to be carefully justified. Voltage dips are the most common power quality disturbance in distribution networks. Their mitigation can be obtained by reinforcing the networks, i.e. by substituting overhead lines, with high fault rates, with buried cables, or, more easily, by installing custom power devices, as Dynamic Voltage Restorers (DVR) able to supply the needed energy to the protected customers during the dip. Among other services, energy storage systems can perform the same task of DVRs against the voltage dips and this benefit can contribute to make cost-effective their investment. The paper proposes an approach to estimate the benefit derived by the use of storages as DVR for reducing the expected number of voltage dips suffered by the customers. The obtained revenue can be added to the total benefit ascribable to the storage.
{"title":"Including voltage dips mitigation in cost-benefit analysis of storages","authors":"G. Celli, F. Pilo, G. Pisano, G. G. Soma","doi":"10.1109/ICHQP.2018.8378907","DOIUrl":"https://doi.org/10.1109/ICHQP.2018.8378907","url":null,"abstract":"Energy storage systems are valuable components of the future Smart Distribution Systems, thanks to their ability to increase the flexibility of the overall system and to provide a wide range of services. Unfortunately, their costs are still high and their profitable implementation has to be carefully justified. Voltage dips are the most common power quality disturbance in distribution networks. Their mitigation can be obtained by reinforcing the networks, i.e. by substituting overhead lines, with high fault rates, with buried cables, or, more easily, by installing custom power devices, as Dynamic Voltage Restorers (DVR) able to supply the needed energy to the protected customers during the dip. Among other services, energy storage systems can perform the same task of DVRs against the voltage dips and this benefit can contribute to make cost-effective their investment. The paper proposes an approach to estimate the benefit derived by the use of storages as DVR for reducing the expected number of voltage dips suffered by the customers. The obtained revenue can be added to the total benefit ascribable to the storage.","PeriodicalId":6506,"journal":{"name":"2018 18th International Conference on Harmonics and Quality of Power (ICHQP)","volume":"22 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83227569","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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