Pub Date : 2016-07-17DOI: 10.1109/PESGM.2016.7741835
Yanling Lin, Tao Ding, Z. Bie, Gengfeng Li
As photovoltaic (PV) integration increases in distribution systems, an effective way of assessing the maximum allowable PV integration capacity is urgently needed. In this paper, a new method is proposed to evaluate the maximum PV integration capacity with AC power flow limits, and the effect of topology reconfiguration on PV integration is also considered. In addition, the single commodity flow constraint is put forward to guarantee topology radiality. Usually, this problem requires mix integer non-convex optimization, which is a great challenge to solve. To address this problem, second order cones are employed to relax the non-convex constraints so that the model can be efficiently solved. Furthermore, the IEEE 33-bus test system with four PV integration cases for maximum integration capacity is studied. The test result shows the effectiveness of reconfiguration in increasing maximum PV integration capacity.
{"title":"A new method to evaluate maximum capacity of photovoltaic integration considering network topology reconfiguration","authors":"Yanling Lin, Tao Ding, Z. Bie, Gengfeng Li","doi":"10.1109/PESGM.2016.7741835","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741835","url":null,"abstract":"As photovoltaic (PV) integration increases in distribution systems, an effective way of assessing the maximum allowable PV integration capacity is urgently needed. In this paper, a new method is proposed to evaluate the maximum PV integration capacity with AC power flow limits, and the effect of topology reconfiguration on PV integration is also considered. In addition, the single commodity flow constraint is put forward to guarantee topology radiality. Usually, this problem requires mix integer non-convex optimization, which is a great challenge to solve. To address this problem, second order cones are employed to relax the non-convex constraints so that the model can be efficiently solved. Furthermore, the IEEE 33-bus test system with four PV integration cases for maximum integration capacity is studied. The test result shows the effectiveness of reconfiguration in increasing maximum PV integration capacity.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"19 3‐4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132340723","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741801
Jin-quan Zhao, X. Liu, Changnian Lin, Wenhui Wei
Extensive penetration of single phase distributed generators (DGs) such as photovoltaic generations may cause serious phase unbalance problems in distribution networks. The phase unbalance condition will make voltage/VAR optimization problem difficult to be solved by using traditional model and methods for balanced distribution networks. A three-phase unbalanced voltage/VAR optimization model for active distribution networks is proposed in this paper. The OLTC transformers and distributed reactive power resources such as static VAR compensators, embedded generators and capacitors banks are considered as control devices to minimize the negative sequence system voltages and network losses. The voltage/VAR optimization problem is formulated as a mixed-integer quadratic constrains quadratic programming (MIQCQP) problem in rectangular coordinates. The optimal solution is obtained by solving the MIQCQP problem using the branch-bound and primal-dual interior point method. Simulation results of the modified IEEE 33-bus test system demonstrate that the proposed model and method are effective.
{"title":"Three-phase unbalanced voltage/VAR optimization for active distribution networks","authors":"Jin-quan Zhao, X. Liu, Changnian Lin, Wenhui Wei","doi":"10.1109/PESGM.2016.7741801","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741801","url":null,"abstract":"Extensive penetration of single phase distributed generators (DGs) such as photovoltaic generations may cause serious phase unbalance problems in distribution networks. The phase unbalance condition will make voltage/VAR optimization problem difficult to be solved by using traditional model and methods for balanced distribution networks. A three-phase unbalanced voltage/VAR optimization model for active distribution networks is proposed in this paper. The OLTC transformers and distributed reactive power resources such as static VAR compensators, embedded generators and capacitors banks are considered as control devices to minimize the negative sequence system voltages and network losses. The voltage/VAR optimization problem is formulated as a mixed-integer quadratic constrains quadratic programming (MIQCQP) problem in rectangular coordinates. The optimal solution is obtained by solving the MIQCQP problem using the branch-bound and primal-dual interior point method. Simulation results of the modified IEEE 33-bus test system demonstrate that the proposed model and method are effective.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132457270","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741272
Yannan Sun, Z. Hou, Da Meng, N. Samaan, Y. Makarov, Zhenyu Huang
In this study, we represent and reduce the uncertainties in short-term load forecasting by integrating time series analysis tools including ARIMA modeling, sequential Gaussian simulation, and principal component analysis. The approaches are mainly focusing on maintaining the interdependency between multiple geographically related areas. These approaches are applied onto cross-correlated load time series as well as their forecast errors. Multiple short-term prediction realizations are then generated from the reduced uncertainty ranges, which are useful for power system risk analyses1.
{"title":"Quantifying and reducing uncertainty in correlated multi-area short-term load forecasting","authors":"Yannan Sun, Z. Hou, Da Meng, N. Samaan, Y. Makarov, Zhenyu Huang","doi":"10.1109/PESGM.2016.7741272","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741272","url":null,"abstract":"In this study, we represent and reduce the uncertainties in short-term load forecasting by integrating time series analysis tools including ARIMA modeling, sequential Gaussian simulation, and principal component analysis. The approaches are mainly focusing on maintaining the interdependency between multiple geographically related areas. These approaches are applied onto cross-correlated load time series as well as their forecast errors. Multiple short-term prediction realizations are then generated from the reduced uncertainty ranges, which are useful for power system risk analyses1.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130007244","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741839
A. Moraco, Marley F. Tavares, E. Geraldi, R. Ramos
In this paper, an approach to evaluate the occurrence of flicker induced by electromechanical oscillations is proposed. This approach employs the extended participation factors (EPF) to statistically quantify the presence of electromechanical modes in the dynamics of the terminal voltage of a distributed synchronous generator. Once the results obtained by the EPF indicate a high probability for the manifestation of the electromechanical mode in the terminal voltage of the distributed generator, an estimate for the probability of occurrence of flicker can be obtained.
{"title":"An approach to evaluate the occurrence of flicker induced by electromechanical oscillations","authors":"A. Moraco, Marley F. Tavares, E. Geraldi, R. Ramos","doi":"10.1109/PESGM.2016.7741839","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741839","url":null,"abstract":"In this paper, an approach to evaluate the occurrence of flicker induced by electromechanical oscillations is proposed. This approach employs the extended participation factors (EPF) to statistically quantify the presence of electromechanical modes in the dynamics of the terminal voltage of a distributed synchronous generator. Once the results obtained by the EPF indicate a high probability for the manifestation of the electromechanical mode in the terminal voltage of the distributed generator, an estimate for the probability of occurrence of flicker can be obtained.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131644584","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741188
C. Lashway, A. Elsayed, O. Mohammed
As the electric vehicle (EV) gains traction in the modern automotive market, a focus has been placed on the development of efficient and long-lasting methods to store energy. In order to exploit the advantages of a hybrid energy storage system (HESS), new management schemes are needed which understand the mechanics of each energy storage device. Many EVs have introduced regenerative braking as a method to recharge the battery bank while in operation. Unfortunately, the combination of long duration discharge drive currents and short, high powered charging currents from regenerative breaking place batteries under enormous stress resulting in shorter lifetimes. Moreover, when the battery bank is at a high state of charge, electrochemical constraints will limit current injection during regenerative braking thus some energy is left to waste. In this work, a parallel-connected lithium ion battery bank and supercapacitor HESS demonstrates a new multi-state EV control and management scheme. Unnecessary cycling of the lithium ion battery array is reduced while the efficiency of a regenerative braking pulse is increased. The scheme is demonstrated experimentally using the DOE Hybrid Pulsed Power Characterization test profile procedure.
{"title":"Management scheme for parallel connected hybrid energy storage in electric vehicles","authors":"C. Lashway, A. Elsayed, O. Mohammed","doi":"10.1109/PESGM.2016.7741188","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741188","url":null,"abstract":"As the electric vehicle (EV) gains traction in the modern automotive market, a focus has been placed on the development of efficient and long-lasting methods to store energy. In order to exploit the advantages of a hybrid energy storage system (HESS), new management schemes are needed which understand the mechanics of each energy storage device. Many EVs have introduced regenerative braking as a method to recharge the battery bank while in operation. Unfortunately, the combination of long duration discharge drive currents and short, high powered charging currents from regenerative breaking place batteries under enormous stress resulting in shorter lifetimes. Moreover, when the battery bank is at a high state of charge, electrochemical constraints will limit current injection during regenerative braking thus some energy is left to waste. In this work, a parallel-connected lithium ion battery bank and supercapacitor HESS demonstrates a new multi-state EV control and management scheme. Unnecessary cycling of the lithium ion battery array is reduced while the efficiency of a regenerative braking pulse is increased. The scheme is demonstrated experimentally using the DOE Hybrid Pulsed Power Characterization test profile procedure.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132974986","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741520
M. Lecouvez, R. Falgout, C. Woodward, P. Top
This paper presents a fully multilevel approach to parallel in time solution of transient power system simulations. The method employs a multigrid reduction algorithm in time parallelized using the MPI distributed memory programming model. The method is demonstrated on a simple Single Machine Infinite Bus differential-algebraic equation model problem, for which speedup is obtained for as few as 8 processing cores on a problem with 10,000 time steps. Speedup of a factor of 13 is observed for a 100,000 step version of this simple problem. Based on these results, we expect significantly better speedup on larger problems where more work is available to each processor allowing greater amortization of the parallel communication.
{"title":"A parallel multigrid reduction in time method for power systems","authors":"M. Lecouvez, R. Falgout, C. Woodward, P. Top","doi":"10.1109/PESGM.2016.7741520","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741520","url":null,"abstract":"This paper presents a fully multilevel approach to parallel in time solution of transient power system simulations. The method employs a multigrid reduction algorithm in time parallelized using the MPI distributed memory programming model. The method is demonstrated on a simple Single Machine Infinite Bus differential-algebraic equation model problem, for which speedup is obtained for as few as 8 processing cores on a problem with 10,000 time steps. Speedup of a factor of 13 is observed for a 100,000 step version of this simple problem. Based on these results, we expect significantly better speedup on larger problems where more work is available to each processor allowing greater amortization of the parallel communication.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127574254","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741071
Zhao Wang, Hongbo Sun, D. Nikovski
A distributed secondary voltage controller is designed for droop-controlled microgrids in power distribution networks to improve power quality. Microgrids are typically managed by the droop control mechanism that ensures stability but does not guarantee power quality of voltage magnitude. To solve this power quality problem, the proposed distributed secondary voltage controller maintains a constant voltage at a microgrid's point of common coupling (PCC) using only local measurements. With the voltage regulation capability, a microgrid can be used to improve power quality so that greatly promote the microgrid's value to power system daily operations. The improved voltage regulation in a power network is demonstrated through simulation tests of a modified IEEE 37-node test feeder. Furthermore, this secondary voltage controller is compatible with existing voltage control devices, such as tap-changing transformers that automatically regulate voltage.
{"title":"Distributed secondary voltage controller for droop-controlled microgrids to improve power quality in power distribution networks","authors":"Zhao Wang, Hongbo Sun, D. Nikovski","doi":"10.1109/PESGM.2016.7741071","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741071","url":null,"abstract":"A distributed secondary voltage controller is designed for droop-controlled microgrids in power distribution networks to improve power quality. Microgrids are typically managed by the droop control mechanism that ensures stability but does not guarantee power quality of voltage magnitude. To solve this power quality problem, the proposed distributed secondary voltage controller maintains a constant voltage at a microgrid's point of common coupling (PCC) using only local measurements. With the voltage regulation capability, a microgrid can be used to improve power quality so that greatly promote the microgrid's value to power system daily operations. The improved voltage regulation in a power network is demonstrated through simulation tests of a modified IEEE 37-node test feeder. Furthermore, this secondary voltage controller is compatible with existing voltage control devices, such as tap-changing transformers that automatically regulate voltage.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131043586","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741443
R. Quint, D. Kosterev, J. Undrill, J. Eto, R. Bravo, J. Wen
End-use load composition is rapidly changing, particularly towards electronically-coupled or inverter-based load. In particularly, the proliferation of electric vehicles (EV) is expected to continue as consumer prices decrease and charging capability expands. The electric power grid has experienced disruptive technologies since its inception, and it is imperative to study potential future impacts in order to prepare for them if they do occur. This paper highlights fundamental load response of EV chargers, and proposes a set of requirements that are deemed “grid-friendly” to the overall stability and control of the bulk power system at the interconnection-level. Loads exhibiting at least constant current characteristic (constant impedance are very much desirable if possible) with ride-through and reconnection capability will ensure long-term reliability of the grid. The goal is to outline these grid-level requirements in an effort to collaborate with the manufacturing community for sustained grid support from the end-use loads.
{"title":"Power quality requirements for electric vehicle chargers: Bulk power system perspective","authors":"R. Quint, D. Kosterev, J. Undrill, J. Eto, R. Bravo, J. Wen","doi":"10.1109/PESGM.2016.7741443","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741443","url":null,"abstract":"End-use load composition is rapidly changing, particularly towards electronically-coupled or inverter-based load. In particularly, the proliferation of electric vehicles (EV) is expected to continue as consumer prices decrease and charging capability expands. The electric power grid has experienced disruptive technologies since its inception, and it is imperative to study potential future impacts in order to prepare for them if they do occur. This paper highlights fundamental load response of EV chargers, and proposes a set of requirements that are deemed “grid-friendly” to the overall stability and control of the bulk power system at the interconnection-level. Loads exhibiting at least constant current characteristic (constant impedance are very much desirable if possible) with ride-through and reconnection capability will ensure long-term reliability of the grid. The goal is to outline these grid-level requirements in an effort to collaborate with the manufacturing community for sustained grid support from the end-use loads.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133352039","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741178
M. Ortega-Vazquez
This paper presents an assessment of the security-constrained optimal power flow (SCOPF) solutions, under probabilistic generation and transmission contingencies. The proposed SCOPF approach schedules the optimal level of system security by balancing the security cost (i.e. out-of-merit dispatch cost) against the cost of corrective actions and expected cost of energy interruptions due to contingencies. This approach can accommodate any set of N-k generation and transmission contingencies, and the probabilities of the contingencies are sensitive to common mode failures and adverse weather conditions. The results show that common mode failures and adverse weather conditions have a significant impact on the probabilities of the contingencies, and thus on the scheduled levels of security.
{"title":"Assessment of N-k contingencies in a probabilistic security-constrained optimal power flow","authors":"M. Ortega-Vazquez","doi":"10.1109/PESGM.2016.7741178","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741178","url":null,"abstract":"This paper presents an assessment of the security-constrained optimal power flow (SCOPF) solutions, under probabilistic generation and transmission contingencies. The proposed SCOPF approach schedules the optimal level of system security by balancing the security cost (i.e. out-of-merit dispatch cost) against the cost of corrective actions and expected cost of energy interruptions due to contingencies. This approach can accommodate any set of N-k generation and transmission contingencies, and the probabilities of the contingencies are sensitive to common mode failures and adverse weather conditions. The results show that common mode failures and adverse weather conditions have a significant impact on the probabilities of the contingencies, and thus on the scheduled levels of security.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132187549","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}
Inter-area oscillation in a large power systems draws much attention because it might severely influence system security and reduce transmission capability. The recent large-scale deployment of phasor measurement units (PMUs) enables online measurement-based monitoring and analysis on inter-area oscillatory modes. However, the nonstationary characteristics of measurements become obstacles for oscillation analysis. This work proposes multivariate empirical mode decomposition (MEMD), a multi-channel time frequency analysis method, for ring-down oscillation mode identification. The capability of the MEMD in oscillation mode identification is verified based on a test system. In addition, MEMD is compared with classical Empirical Mode Decomposition (EMD) and Fast Fourier Transform (FFT) for evaluation. The result shows that MEMD can improve oscillation identification through separating different oscillation modes while persevering their phase and amplitude information.
{"title":"Ring-down oscillation mode identification using multivariate Empirical Mode Decomposition","authors":"Shutang You, Jiahui Guo, Wenxuan Yao, Siqi Wang, Yong Liu, Yilu Liu","doi":"10.1109/PESGM.2016.7742032","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7742032","url":null,"abstract":"Inter-area oscillation in a large power systems draws much attention because it might severely influence system security and reduce transmission capability. The recent large-scale deployment of phasor measurement units (PMUs) enables online measurement-based monitoring and analysis on inter-area oscillatory modes. However, the nonstationary characteristics of measurements become obstacles for oscillation analysis. This work proposes multivariate empirical mode decomposition (MEMD), a multi-channel time frequency analysis method, for ring-down oscillation mode identification. The capability of the MEMD in oscillation mode identification is verified based on a test system. In addition, MEMD is compared with classical Empirical Mode Decomposition (EMD) and Fast Fourier Transform (FFT) for evaluation. The result shows that MEMD can improve oscillation identification through separating different oscillation modes while persevering their phase and amplitude information.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133103957","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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