Pub Date : 2001-07-15DOI: 10.1109/PESS.2001.970092
S. Rahman
Fuel cells can convert a remarkably high proportion of the chemical energy in a fuel to electricity. With the efficiencies approaching 60%, even without cogeneration, fuel cell power plants are nearly twice as efficient as conventional power plants. Fuel cells contribute significantly to the cleaner environment; they produce dramatically fewer emissions, and their byproducts are primarily hot water and carbon dioxide in small amounts. And because of their modular nature, fuel cells can be placed at or near load centers resulting in savings of transmission network expansion. Industry has slowly begun to appreciate the commercial value of fuel cells. In addition to stationary power generation applications, there is now a strong push to develop fuel cells for automotive use. Even though fuel cells provide high performance characteristics, reliability, durability and environmental benefits, a very high investment cost still is the major barrier against large-scale deployment.
{"title":"Fuel cell as a distributed generation technology","authors":"S. Rahman","doi":"10.1109/PESS.2001.970092","DOIUrl":"https://doi.org/10.1109/PESS.2001.970092","url":null,"abstract":"Fuel cells can convert a remarkably high proportion of the chemical energy in a fuel to electricity. With the efficiencies approaching 60%, even without cogeneration, fuel cell power plants are nearly twice as efficient as conventional power plants. Fuel cells contribute significantly to the cleaner environment; they produce dramatically fewer emissions, and their byproducts are primarily hot water and carbon dioxide in small amounts. And because of their modular nature, fuel cells can be placed at or near load centers resulting in savings of transmission network expansion. Industry has slowly begun to appreciate the commercial value of fuel cells. In addition to stationary power generation applications, there is now a strong push to develop fuel cells for automotive use. Even though fuel cells provide high performance characteristics, reliability, durability and environmental benefits, a very high investment cost still is the major barrier against large-scale deployment.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124666184","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 : 2001-07-15DOI: 10.1109/PESS.2001.970254
A.A. Abido
In this paper, a new multiobjective evolutionary algorithm for environmental/economic power dispatch (EED) optimization problem is presented. The EED problem is formulated as a nonlinear constrained multiobjective optimization problem with both equality and inequality constraints. A new nondominated sorting genetic algorithm (NSGA) based approach is proposed to handle the problem as a true multiobjective optimization problem with competing and noncommensurable objectives. The proposed approach employs a diversity-preserving technique to overcome the premature convergence and search bias problems and produce a well-distributed Pareto-optimal set of nondominated solutions. A hierarchical clustering technique is also imposed to provide the decision maker with a representative and manageable Pareto-optimal set. Several optimization runs of the proposed approach are carried out on a standard IEEE test system. The results demonstrate the capabilities of the proposed NSGA based approach to generate the true Pareto-optimal set of nondominated solutions of the multiobjective EED problem in one single run. Simulation results with the proposed approach have been compared to those reported in the literature. The comparison shows the superiority of the proposed NSGA based approach and confirms its potential to solve the multiobjective EED problem.
{"title":"A new multiobjective evolutionary algorithm for environmental/economic power dispatch","authors":"A.A. Abido","doi":"10.1109/PESS.2001.970254","DOIUrl":"https://doi.org/10.1109/PESS.2001.970254","url":null,"abstract":"In this paper, a new multiobjective evolutionary algorithm for environmental/economic power dispatch (EED) optimization problem is presented. The EED problem is formulated as a nonlinear constrained multiobjective optimization problem with both equality and inequality constraints. A new nondominated sorting genetic algorithm (NSGA) based approach is proposed to handle the problem as a true multiobjective optimization problem with competing and noncommensurable objectives. The proposed approach employs a diversity-preserving technique to overcome the premature convergence and search bias problems and produce a well-distributed Pareto-optimal set of nondominated solutions. A hierarchical clustering technique is also imposed to provide the decision maker with a representative and manageable Pareto-optimal set. Several optimization runs of the proposed approach are carried out on a standard IEEE test system. The results demonstrate the capabilities of the proposed NSGA based approach to generate the true Pareto-optimal set of nondominated solutions of the multiobjective EED problem in one single run. Simulation results with the proposed approach have been compared to those reported in the literature. The comparison shows the superiority of the proposed NSGA based approach and confirms its potential to solve the multiobjective EED problem.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123446661","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 : 2001-07-15DOI: 10.1109/PESS.2001.970184
K. Sedraoui, K. Al-haddad, G. Olivier
This paper presents a new approach for the dynamic control of FACTS apparatus, such as the UPFC and the STATCOM. With the new control strategy, the capabilities of the UPFC can be exploited not only for steady state power flow control but also to improve damping and transient stability assuring a good behavior during contingencies and the protection of the equipment. To achieve optimal UPFC behavior during the dynamic phenomena, the controllable system parameters are determined on-line based on the local instantaneous voltage and current measurements. The strategy is based on the theory of instantaneous powers defined in the positive, negative and zero sequence with real and imaginary components. The power flow calculation should not involve any conventional definitions of power. The Fortescus transformation will be used to conform the relation of the instantaneous active and reactive power (p, q) with the conventional active and reactive power (P/sub 3/spl phi//, Q/sub 3/spl phi//). A complete model of the UPFC and the transmission system has been implemented in a digital simulator to demonstrate the versatility of the new control strategy. Interesting results have been obtained, which are presented in this paper.
{"title":"A new approach for the dynamic control of unified power flow controller (UPFC)","authors":"K. Sedraoui, K. Al-haddad, G. Olivier","doi":"10.1109/PESS.2001.970184","DOIUrl":"https://doi.org/10.1109/PESS.2001.970184","url":null,"abstract":"This paper presents a new approach for the dynamic control of FACTS apparatus, such as the UPFC and the STATCOM. With the new control strategy, the capabilities of the UPFC can be exploited not only for steady state power flow control but also to improve damping and transient stability assuring a good behavior during contingencies and the protection of the equipment. To achieve optimal UPFC behavior during the dynamic phenomena, the controllable system parameters are determined on-line based on the local instantaneous voltage and current measurements. The strategy is based on the theory of instantaneous powers defined in the positive, negative and zero sequence with real and imaginary components. The power flow calculation should not involve any conventional definitions of power. The Fortescus transformation will be used to conform the relation of the instantaneous active and reactive power (p, q) with the conventional active and reactive power (P/sub 3/spl phi//, Q/sub 3/spl phi//). A complete model of the UPFC and the transmission system has been implemented in a digital simulator to demonstrate the versatility of the new control strategy. Interesting results have been obtained, which are presented in this paper.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129384058","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 : 2001-07-15DOI: 10.1109/PESS.2001.970070
R. Smeets, A. Lathouwers
Partly due to economic considerations, dc time constants of short circuit currents have increased in recent years. This has consequences for circuit breakers, that should interrupt these currents. As a result, the asymmetrical peak value and the arcing time are increased. An analysis is given of arcing time and arcing energy as a function of circuit- and circuit breaker parameters, and the impact on testing. Another factor that can increase the asymmetrical peak factor drastically is the scatter that the three poles (either naturally, either deliberately) have in their instant of closing. It is demonstrated that switchgear, intended for synchronized ('soft') switching of ungrounded capacitor banks can produce unexpectcdly large asymmetrical current when closing into a short circuit. Finally, the use of local (co-)generation may cause extended periods in which no natural current zero occurs. In this respect (among others) circuit breakers have to meet special requirements, that usually go beyond standard circuit breaker requirements.
{"title":"Economy motivated increase of DC time constants in power systems and consequences for fault current interruption","authors":"R. Smeets, A. Lathouwers","doi":"10.1109/PESS.2001.970070","DOIUrl":"https://doi.org/10.1109/PESS.2001.970070","url":null,"abstract":"Partly due to economic considerations, dc time constants of short circuit currents have increased in recent years. This has consequences for circuit breakers, that should interrupt these currents. As a result, the asymmetrical peak value and the arcing time are increased. An analysis is given of arcing time and arcing energy as a function of circuit- and circuit breaker parameters, and the impact on testing. Another factor that can increase the asymmetrical peak factor drastically is the scatter that the three poles (either naturally, either deliberately) have in their instant of closing. It is demonstrated that switchgear, intended for synchronized ('soft') switching of ungrounded capacitor banks can produce unexpectcdly large asymmetrical current when closing into a short circuit. Finally, the use of local (co-)generation may cause extended periods in which no natural current zero occurs. In this respect (among others) circuit breakers have to meet special requirements, that usually go beyond standard circuit breaker requirements.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131076189","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 : 2001-07-15DOI: 10.1109/PESS.2001.970300
J. Teng, R. Lee, Yi-Hwa Liu, R. Leou
An Internet- and virtual-instrument-based Supervisory Control And Data Acquisition (SCADA) system for industrial applications is developed in this paper. In this paper, general purpose virtual instruments (VIs), which is used to communicate with RS232, acquire measurements, transmit data to the Internet and receive data from Internet etc., are developed first. Then, using these Vis as building blocks, the proposed Internet-based SCADA system can be developed efficiently In order to study the performance of the Internet and the test results, two network performance VIs are also presented in this paper. Test results show that the proposed method is useful for industrial automation.
{"title":"Integration of Internet and virtual instruments to develop an industrial SCADA","authors":"J. Teng, R. Lee, Yi-Hwa Liu, R. Leou","doi":"10.1109/PESS.2001.970300","DOIUrl":"https://doi.org/10.1109/PESS.2001.970300","url":null,"abstract":"An Internet- and virtual-instrument-based Supervisory Control And Data Acquisition (SCADA) system for industrial applications is developed in this paper. In this paper, general purpose virtual instruments (VIs), which is used to communicate with RS232, acquire measurements, transmit data to the Internet and receive data from Internet etc., are developed first. Then, using these Vis as building blocks, the proposed Internet-based SCADA system can be developed efficiently In order to study the performance of the Internet and the test results, two network performance VIs are also presented in this paper. Test results show that the proposed method is useful for industrial automation.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130496876","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 : 2001-07-15DOI: 10.1109/PESS.2001.970273
S. Gim
The authors considered the possibility of the conversion of ordinary temperature thermal energy into mechanical form. This conversion system makes the environment free from thermal, chemical and radioactive pollution problems. Although thermal energy conversion efficiency is less than several times that of conventional steam turbines the fuel itself will be obtained virtually free and unlimited.
{"title":"Proposal on the conversion of room temperature thermal energy into useful form","authors":"S. Gim","doi":"10.1109/PESS.2001.970273","DOIUrl":"https://doi.org/10.1109/PESS.2001.970273","url":null,"abstract":"The authors considered the possibility of the conversion of ordinary temperature thermal energy into mechanical form. This conversion system makes the environment free from thermal, chemical and radioactive pollution problems. Although thermal energy conversion efficiency is less than several times that of conventional steam turbines the fuel itself will be obtained virtually free and unlimited.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122158323","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 : 2001-07-15DOI: 10.1109/PESS.2001.970360
R. A. Shaffer
Summary form only given. Elements of Power Systems is a senior level course in the electrical engineering program at Embry-Riddle Aeronautical University (ERAU). The subject matter of the course is an introduction to the subject of power electronics. The purpose of ERAU is to prepare students to support the needs of the aviation and aerospace industries. The vast majority of students are hired by government administrations and private sector companies that are involved in aviation, aerospace, national defense, and related areas. The introductory power course Elements of Power Systems was designed to support the mission of the university. Thus, the course presents to the student the type of power systems used on aircraft and spacecraft. The course has an accompanying laboratory. The main elements of the course are outlined.
{"title":"Summary of Elements of Power Systems at Embry-Riddle Aeronautical University","authors":"R. A. Shaffer","doi":"10.1109/PESS.2001.970360","DOIUrl":"https://doi.org/10.1109/PESS.2001.970360","url":null,"abstract":"Summary form only given. Elements of Power Systems is a senior level course in the electrical engineering program at Embry-Riddle Aeronautical University (ERAU). The subject matter of the course is an introduction to the subject of power electronics. The purpose of ERAU is to prepare students to support the needs of the aviation and aerospace industries. The vast majority of students are hired by government administrations and private sector companies that are involved in aviation, aerospace, national defense, and related areas. The introductory power course Elements of Power Systems was designed to support the mission of the university. Thus, the course presents to the student the type of power systems used on aircraft and spacecraft. The course has an accompanying laboratory. The main elements of the course are outlined.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"124 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126062074","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 : 2001-07-15DOI: 10.1109/PESS.2001.970255
I. D. da Silva, L. Nepomuceno
A neural approach to solve the problem defined by the economic load dispatch in power systems is presented in this paper. Systems based on artificial neural networks have high computational rates due to the use of a massive number of simple processing elements and the high degree of connectivity between these elements The ability of neural networks to realize some complex nonlinear function makes them attractive for system optimization The neural networks applied in economic load dispatch reported in literature sometimes fail to converge towards feasible equilibrium points The internal parameters of the modified Hopfield network developed here are computed using the valid-subspace technique These parameters guarantee the network convergence to feasible equilibrium points. A solution for the economic load dispatch problem corresponds to an equilibrium point of the network. Simulation results and comparative analysis in relation to other neural approaches are presented to illustrate efficiency of the proposed approach.
{"title":"An efficient neural approach to economic load dispatch in power systems","authors":"I. D. da Silva, L. Nepomuceno","doi":"10.1109/PESS.2001.970255","DOIUrl":"https://doi.org/10.1109/PESS.2001.970255","url":null,"abstract":"A neural approach to solve the problem defined by the economic load dispatch in power systems is presented in this paper. Systems based on artificial neural networks have high computational rates due to the use of a massive number of simple processing elements and the high degree of connectivity between these elements The ability of neural networks to realize some complex nonlinear function makes them attractive for system optimization The neural networks applied in economic load dispatch reported in literature sometimes fail to converge towards feasible equilibrium points The internal parameters of the modified Hopfield network developed here are computed using the valid-subspace technique These parameters guarantee the network convergence to feasible equilibrium points. A solution for the economic load dispatch problem corresponds to an equilibrium point of the network. Simulation results and comparative analysis in relation to other neural approaches are presented to illustrate efficiency of the proposed approach.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126954648","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 : 2001-07-15DOI: 10.1109/PESS.2001.970171
H. Takada, Y. Kato, S. Iwamoto
Power systems have become larger and more complicated. Deregulation of electric power industries has begun in some countries and power system operation is becoming more difficult. But the stability of the power supply is a most important consideration for customers. Therefore power system operators consider not only economic load dispatch but also the on-line stability aspect. In this paper, we pay attention to one of the most important transient stability indices, critical clearing time (CCT), and propose a new transient stability preventive control method using generation rescheduling to satisfy predefined target CCTs. At first, contingency screening is carried out to select severe contingencies that have smaller CCTs than the target CCT. Rescheduled generator outputs are determined using the linear relationship between the generator output at the faulted bus and CCT and generation margins that indicate the surplus generation capabilities of generators. The proposed method is demonstrated using a 9 machine 20 bus system.
{"title":"Transient stability preventive control using CCT and generation margin","authors":"H. Takada, Y. Kato, S. Iwamoto","doi":"10.1109/PESS.2001.970171","DOIUrl":"https://doi.org/10.1109/PESS.2001.970171","url":null,"abstract":"Power systems have become larger and more complicated. Deregulation of electric power industries has begun in some countries and power system operation is becoming more difficult. But the stability of the power supply is a most important consideration for customers. Therefore power system operators consider not only economic load dispatch but also the on-line stability aspect. In this paper, we pay attention to one of the most important transient stability indices, critical clearing time (CCT), and propose a new transient stability preventive control method using generation rescheduling to satisfy predefined target CCTs. At first, contingency screening is carried out to select severe contingencies that have smaller CCTs than the target CCT. Rescheduled generator outputs are determined using the linear relationship between the generator output at the faulted bus and CCT and generation margins that indicate the surplus generation capabilities of generators. The proposed method is demonstrated using a 9 machine 20 bus system.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127058211","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 : 2001-07-15DOI: 10.1109/PESS.2001.970288
A. Monti, E. Santi, R. Dougal, F. Ponci, M. Riva
This paper presents a methodology for automatically extracting an equivalent circuit model starting from a set of equations. Once the device models are built, they can be easily handled and interconnected. This method therefore proves to be particularly suitable for large system studies using an object oriented implementation. The proposed methodology involves the following steps. The equations are mapped in an equivalent circuit with symbolic parameters and then the resistive companion method (RCM) is applied to build a discrete time equivalent of the system. The procedure is based on the Matlab Symbolic Toolbox and it is able to generate a model according to the specifications of the Virtual Test Bed (VTB) environment. A custom SPICE-like language bias been defined to create the circuit description of the system. The methodology description is enriched with a set of examples.
{"title":"Symbolic analysis for automatic model generation","authors":"A. Monti, E. Santi, R. Dougal, F. Ponci, M. Riva","doi":"10.1109/PESS.2001.970288","DOIUrl":"https://doi.org/10.1109/PESS.2001.970288","url":null,"abstract":"This paper presents a methodology for automatically extracting an equivalent circuit model starting from a set of equations. Once the device models are built, they can be easily handled and interconnected. This method therefore proves to be particularly suitable for large system studies using an object oriented implementation. The proposed methodology involves the following steps. The equations are mapped in an equivalent circuit with symbolic parameters and then the resistive companion method (RCM) is applied to build a discrete time equivalent of the system. The procedure is based on the Matlab Symbolic Toolbox and it is able to generate a model according to the specifications of the Virtual Test Bed (VTB) environment. A custom SPICE-like language bias been defined to create the circuit description of the system. The methodology description is enriched with a set of examples.","PeriodicalId":273578,"journal":{"name":"2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125913650","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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