Pub Date : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241143
E. Carlini, Albert C Pesce, Mirko Piazza, Alessio Salmaso, A. Berizzi, D. Falabretti, Corrado Mattevi
The paper describes the events that led, in November 2019, to a local blackout in Trentino-Alto Adige (Northern Italy). The events were caused by a heavy snowstorm that resulted in about 7000 faults on the electric system for short-circuits, trees falling on electrical lines etc. In consequence, a 132 kV portion of the grid, and the underlying MV/LV distribution grid, remained isolated from the national transmission grid a part of the 132 kV power system. Overall, approximately 25 thousand customers were involved in a local blackout for more than 24 hours. However, the blackout has been mitigated by the attempts of operating the local system as an electric island, exploiting the black start capability of hydro power plants with enough power capacity to supply the island resulting from the disconnection. The paper describes the main features of the island operation, the main problems encountered until the final restoration, the lessons learned and provides a set of suggestions in order to mitigate the effects of such heavy weather phenomena in the future.
{"title":"Islanding Operation During the 2019 Alto Adige Snowstorm Emergency","authors":"E. Carlini, Albert C Pesce, Mirko Piazza, Alessio Salmaso, A. Berizzi, D. Falabretti, Corrado Mattevi","doi":"10.23919/AEIT50178.2020.9241143","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241143","url":null,"abstract":"The paper describes the events that led, in November 2019, to a local blackout in Trentino-Alto Adige (Northern Italy). The events were caused by a heavy snowstorm that resulted in about 7000 faults on the electric system for short-circuits, trees falling on electrical lines etc. In consequence, a 132 kV portion of the grid, and the underlying MV/LV distribution grid, remained isolated from the national transmission grid a part of the 132 kV power system. Overall, approximately 25 thousand customers were involved in a local blackout for more than 24 hours. However, the blackout has been mitigated by the attempts of operating the local system as an electric island, exploiting the black start capability of hydro power plants with enough power capacity to supply the island resulting from the disconnection. The paper describes the main features of the island operation, the main problems encountered until the final restoration, the lessons learned and provides a set of suggestions in order to mitigate the effects of such heavy weather phenomena in the future.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"56 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77198522","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241127
M. Caliano, A. Buonanno, G. Graditi, A. Pontecorvo, Gianluca Sforza, M. Valenti
Electricity load forecasting plays an important role in planning and a vital role in the operational management of an electric power system based on smart grids. In this work, several data-driven approaches are used to forecast the individual electricity demand for the subsequent hour of three Italian households in a nanogrid context. For each user, the tested prediction models exploit only the historic series of total electricity consumption. The results show similar performances in all models implemented. Despite a widespread delay, the predictions follow the measurement trend well, while also highlighting the particular difficulty of predicting peak values.
{"title":"Consumption based-only load forecasting for individual households in nanogrids: a case study","authors":"M. Caliano, A. Buonanno, G. Graditi, A. Pontecorvo, Gianluca Sforza, M. Valenti","doi":"10.23919/AEIT50178.2020.9241127","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241127","url":null,"abstract":"Electricity load forecasting plays an important role in planning and a vital role in the operational management of an electric power system based on smart grids. In this work, several data-driven approaches are used to forecast the individual electricity demand for the subsequent hour of three Italian households in a nanogrid context. For each user, the tested prediction models exploit only the historic series of total electricity consumption. The results show similar performances in all models implemented. Despite a widespread delay, the predictions follow the measurement trend well, while also highlighting the particular difficulty of predicting peak values.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"48 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74721674","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241126
R. Lamedica, A. Ruvio, G. G. Buffarini, N. Carones, C. Cianfarani
The paper focuses on evaluation of stray current distribution and rail potential for “Albate-Chiasso” DC railway line, that connects Italy and Switzerland. A model has been developed to calculate stray current and rail potential taking into account the European Standard, in order to avoid electrolytic corrosion and electrical safety problems. A real case study has been presented and simulated using Simulink software. A measurement campaign has been used to validate the model proposed.
{"title":"Analysis of the electrolytic corrosion in the railway line Albate-Chiasso","authors":"R. Lamedica, A. Ruvio, G. G. Buffarini, N. Carones, C. Cianfarani","doi":"10.23919/AEIT50178.2020.9241126","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241126","url":null,"abstract":"The paper focuses on evaluation of stray current distribution and rail potential for “Albate-Chiasso” DC railway line, that connects Italy and Switzerland. A model has been developed to calculate stray current and rail potential taking into account the European Standard, in order to avoid electrolytic corrosion and electrical safety problems. A real case study has been presented and simulated using Simulink software. A measurement campaign has been used to validate the model proposed.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"46 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79230700","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241207
Massimo Battaglioni, M. Baldi, G. Cancellieri
We focus on regular and irregular quasi-cyclic low-density parity-check codes and analyze their codewords. We show that any codeword can be decomposed into component codewords with smaller weight belonging to some component codes. Component codewords can be associated to cycles in the Tanner graph of the code. We transfer these theoretical results into the code design, finding that the removal of some specific classes of cycles yields benefits in terms of minimum distance and error rate performance.
{"title":"Improving the minimum distance of QC-LDPC codes by removing cycles","authors":"Massimo Battaglioni, M. Baldi, G. Cancellieri","doi":"10.23919/AEIT50178.2020.9241207","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241207","url":null,"abstract":"We focus on regular and irregular quasi-cyclic low-density parity-check codes and analyze their codewords. We show that any codeword can be decomposed into component codewords with smaller weight belonging to some component codes. Component codewords can be associated to cycles in the Tanner graph of the code. We transfer these theoretical results into the code design, finding that the removal of some specific classes of cycles yields benefits in terms of minimum distance and error rate performance.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"53 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83174429","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241128
Alessandro Bosisio, A. Berizzi, A. Morotti, B. Greco, G. Iannarelli
The paper proposes a reliability evaluation for meshed distribution networks based on minimal cut sets method. Distribution networks with meshed layout but radially operated have been commonly used in urban environments since they give some advantages in terms of lines thermal limit and voltage drop. The evaluation procedure is divided into three steps: firstly, it determines the minimal cut sets from each source node to each load nodes of the DN; secondly, it calculates the failure rate and the outage time for each minimal cut sets identified; lastly, it calculates the system average interruption frequency index and the system average interruption duration index. A sensitivity analysis of two specific system layouts, which we refer to as 1-step ladder and 2-steps ladder, has been carried out varying the maximum power flow allowed during normal operation. The method shows that, to improve reliability, as more as the distribution network is loaded as more as it should be meshed.
{"title":"Reliability evaluation for meshed distribution networks based on minimal cut sets method","authors":"Alessandro Bosisio, A. Berizzi, A. Morotti, B. Greco, G. Iannarelli","doi":"10.23919/AEIT50178.2020.9241128","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241128","url":null,"abstract":"The paper proposes a reliability evaluation for meshed distribution networks based on minimal cut sets method. Distribution networks with meshed layout but radially operated have been commonly used in urban environments since they give some advantages in terms of lines thermal limit and voltage drop. The evaluation procedure is divided into three steps: firstly, it determines the minimal cut sets from each source node to each load nodes of the DN; secondly, it calculates the failure rate and the outage time for each minimal cut sets identified; lastly, it calculates the system average interruption frequency index and the system average interruption duration index. A sensitivity analysis of two specific system layouts, which we refer to as 1-step ladder and 2-steps ladder, has been carried out varying the maximum power flow allowed during normal operation. The method shows that, to improve reliability, as more as the distribution network is loaded as more as it should be meshed.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"7 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88227388","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241152
Emilio Giovannini
Open-cast mines and quarries often use high power electrical machinery to extract materials from the site they are located. Due to the power of machinery, these activities require a MV electricity supply. They are very often located in sites where the soil has high resistivity, and it couldn’t be easy to guarantee the protection against indirect contacts according to EN 50522:2010-11 provisions. This is particularly true along the excavation front. The electrical properties of the soil on which the machinery are installed may change quickly and so changes the distribution of the potentials during MV earth faults. Risk control based on touch voltages measurements could not be a reliable technique; better to search structural solutions to guarantee the worker’s protection. The requirements of the EN 50522:2010-11 standard are evaluated not only under the electrical point of view, but keeping in mind the particular context. A metal mesh laid along the operating locations and connected to the metal chassis of the machinery is a simple and reliable solution. Measures executed in Italian quarries confirm this.
{"title":"Risk assessment and control in protection against indirect contacts for Medium Voltage earth faults in open-cast mines and quarries","authors":"Emilio Giovannini","doi":"10.23919/AEIT50178.2020.9241152","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241152","url":null,"abstract":"Open-cast mines and quarries often use high power electrical machinery to extract materials from the site they are located. Due to the power of machinery, these activities require a MV electricity supply. They are very often located in sites where the soil has high resistivity, and it couldn’t be easy to guarantee the protection against indirect contacts according to EN 50522:2010-11 provisions. This is particularly true along the excavation front. The electrical properties of the soil on which the machinery are installed may change quickly and so changes the distribution of the potentials during MV earth faults. Risk control based on touch voltages measurements could not be a reliable technique; better to search structural solutions to guarantee the worker’s protection. The requirements of the EN 50522:2010-11 standard are evaluated not only under the electrical point of view, but keeping in mind the particular context. A metal mesh laid along the operating locations and connected to the metal chassis of the machinery is a simple and reliable solution. Measures executed in Italian quarries confirm this.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"10 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88734796","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241184
Baheej Alghamdi, Katharina Wieninger, C. Cañizares
This paper presents a distributed, droop-free voltage control of a dc microgrid in grid-connected and isolated mode. The proposed control technique, based on a distributed consensus approach, addresses reliability issues of centralized controllers that are prone to single point failure, while sharing the loads among Distributed Energy Resources (DERs) more effectively than conventional decentralized droop controllers. The distributed control scheme is implemented, demonstrated, and compared with conventional droop control using time-domain simulations for a model of an actual dc microgrid in Xiamen University, China, based on various realistic scenarios.
{"title":"Distributed Voltage Control of DC Microgrids","authors":"Baheej Alghamdi, Katharina Wieninger, C. Cañizares","doi":"10.23919/AEIT50178.2020.9241184","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241184","url":null,"abstract":"This paper presents a distributed, droop-free voltage control of a dc microgrid in grid-connected and isolated mode. The proposed control technique, based on a distributed consensus approach, addresses reliability issues of centralized controllers that are prone to single point failure, while sharing the loads among Distributed Energy Resources (DERs) more effectively than conventional decentralized droop controllers. The distributed control scheme is implemented, demonstrated, and compared with conventional droop control using time-domain simulations for a model of an actual dc microgrid in Xiamen University, China, based on various realistic scenarios.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"15 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87316846","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241144
S. De Vito, E. Esposito, G. D’Elia, Antonio Del Giudice, G. Fattoruso, S. Ferlito, P. D’Auria, F. Intini, G. Di Francia, E. Terzini
COVID19 Pandemic impacts have been associated with Air Quality (AQ) with its mortality index being significantly affected by high pollution levels. Significant mobility limitations have contributed to slow down the pandemic in Italy having as a side effect a definite decrease of pollution levels. Phase 2 while easing those limits still see a significant reduction of commuting and schools related car traffic emissions. High resolution AQ monitoring can now allow to obtain a picture of AQ if smart cities will be capable to reach long sought emissions goals. Furthermore, it could support the identification and forecasting of possible future local SARS-COV-2 outbursts. In this work, we present the outcomes of a high resolution AQ monitoring opportunistic campaign. These have been achieved through the deployment of field data driven calibration trough machine learning and a smartphone centered IoT infrastructure, capable to store, visualize and give exposome feedback to monitoring volunteers.
{"title":"High Resolution Air Quality Monitoring with IoT Intelligent Multisensor devices during COVID-19 Pandemic Phase 2 in Italy","authors":"S. De Vito, E. Esposito, G. D’Elia, Antonio Del Giudice, G. Fattoruso, S. Ferlito, P. D’Auria, F. Intini, G. Di Francia, E. Terzini","doi":"10.23919/AEIT50178.2020.9241144","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241144","url":null,"abstract":"COVID19 Pandemic impacts have been associated with Air Quality (AQ) with its mortality index being significantly affected by high pollution levels. Significant mobility limitations have contributed to slow down the pandemic in Italy having as a side effect a definite decrease of pollution levels. Phase 2 while easing those limits still see a significant reduction of commuting and schools related car traffic emissions. High resolution AQ monitoring can now allow to obtain a picture of AQ if smart cities will be capable to reach long sought emissions goals. Furthermore, it could support the identification and forecasting of possible future local SARS-COV-2 outbursts. In this work, we present the outcomes of a high resolution AQ monitoring opportunistic campaign. These have been achieved through the deployment of field data driven calibration trough machine learning and a smartphone centered IoT infrastructure, capable to store, visualize and give exposome feedback to monitoring volunteers.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"518 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77170670","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241172
R. Musca, Lazar Bizumic
The paper presents a study of primary frequency control within the power system of Continental Europe (CE) including the dynamics of the high voltage direct current (HVDC) link between France and Great Britain (GB). The large-scale dynamic model of the CE system originally provided by ENTSO-E is extended with a more detailed representation of the whole HVDC interconnection. The dynamics of the GB synchronous area is also considered in the analysis, implementing a system equivalent suitable for primary frequency control studies. The opportunity of frequency containment reserve exchange between the two areas through the link is also investigated, considering supplementary frequency controls within the HVDC control system, namely synthetic inertia and fast frequency response. The overall system is then simulated in two different scenarios: a base case of all synchronous generation, and a reduced inertia scenario with the introduction of a given amount of non-synchronous generation share. The reference incident for the CE system of 3 GW loss is considered for the analysis. The specific effects on the frequency dynamics of the system in the different operating conditions are illustrated and discussed.
{"title":"Primary Frequency Control in the Power System of Continental Europe including the Dynamics of the HVDC Link France-Great Britain","authors":"R. Musca, Lazar Bizumic","doi":"10.23919/AEIT50178.2020.9241172","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241172","url":null,"abstract":"The paper presents a study of primary frequency control within the power system of Continental Europe (CE) including the dynamics of the high voltage direct current (HVDC) link between France and Great Britain (GB). The large-scale dynamic model of the CE system originally provided by ENTSO-E is extended with a more detailed representation of the whole HVDC interconnection. The dynamics of the GB synchronous area is also considered in the analysis, implementing a system equivalent suitable for primary frequency control studies. The opportunity of frequency containment reserve exchange between the two areas through the link is also investigated, considering supplementary frequency controls within the HVDC control system, namely synthetic inertia and fast frequency response. The overall system is then simulated in two different scenarios: a base case of all synchronous generation, and a reduced inertia scenario with the introduction of a given amount of non-synchronous generation share. The reference incident for the CE system of 3 GW loss is considered for the analysis. The specific effects on the frequency dynamics of the system in the different operating conditions are illustrated and discussed.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"19 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74915268","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 : 2020-09-23DOI: 10.23919/AEIT50178.2020.9241168
A. Fedele, Gabriella Di Benedettto, A. Pascucci, G. Pecoraro, F. Allella, E. Carlini
The Electricity Balancing Regulation defines rules for a European Electricity Balancing Market (EEBM) aimed at the exchange of manual frequency restoration reserves among the transmission system operators (TSOs). The implementation of the EEBM will enhance the national balancing markets and their traded products by introducing a common market platform and a standard balancing product with 15 minutes of energy delivery. Terna in their role will change a part of its balancing mechanism in order to fulfil the market requirements and ensure an activation of balancing bids compatible with grid security. This paper finally shows the challenges related to the Italian participation in the EEBM. In this framework, a possible dispatching methodology to ensure activations of balancing bids fulfilling grid security is evaluated from a theoretical perspective.
{"title":"European Electricity Market Integration: the exchange of manual frequency restoration reserves among Terna and the other TSOs","authors":"A. Fedele, Gabriella Di Benedettto, A. Pascucci, G. Pecoraro, F. Allella, E. Carlini","doi":"10.23919/AEIT50178.2020.9241168","DOIUrl":"https://doi.org/10.23919/AEIT50178.2020.9241168","url":null,"abstract":"The Electricity Balancing Regulation defines rules for a European Electricity Balancing Market (EEBM) aimed at the exchange of manual frequency restoration reserves among the transmission system operators (TSOs). The implementation of the EEBM will enhance the national balancing markets and their traded products by introducing a common market platform and a standard balancing product with 15 minutes of energy delivery. Terna in their role will change a part of its balancing mechanism in order to fulfil the market requirements and ensure an activation of balancing bids compatible with grid security. This paper finally shows the challenges related to the Italian participation in the EEBM. In this framework, a possible dispatching methodology to ensure activations of balancing bids fulfilling grid security is evaluated from a theoretical perspective.","PeriodicalId":6689,"journal":{"name":"2020 AEIT International Annual Conference (AEIT)","volume":"38 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90507672","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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