Pub Date : 2010-11-09DOI: 10.1109/ICHQP.2010.5625411
S. Ronnberg, M. Bollen, M. Wahlberg
This paper presents an investigation after the impact on a number of power-quality parameters due to the change from incandescent lamps to energy saving lamps like CFL and LED. The measurements were conducted in a full-scale laboratory model with ordinary household equipment connected, thus simulating an ordinary domestic customer. Incandescent lamps have been replaced in stages by CFL and LED lamps. The CFL's and LED lamps will contribute to an increase in current distortion but the amplitude of the harmonics is quite low so the change of lighting will only have a minor effect on the total current harmonic distortion. It is also shown that the (total) power factor is not a good indicator to compare the impact of different loads on the system.
{"title":"Harmonic emission before and after changing to LED and CFL — Part I: Laboratory measurements for a domestic customer","authors":"S. Ronnberg, M. Bollen, M. Wahlberg","doi":"10.1109/ICHQP.2010.5625411","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625411","url":null,"abstract":"This paper presents an investigation after the impact on a number of power-quality parameters due to the change from incandescent lamps to energy saving lamps like CFL and LED. The measurements were conducted in a full-scale laboratory model with ordinary household equipment connected, thus simulating an ordinary domestic customer. Incandescent lamps have been replaced in stages by CFL and LED lamps. The CFL's and LED lamps will contribute to an increase in current distortion but the amplitude of the harmonics is quite low so the change of lighting will only have a minor effect on the total current harmonic distortion. It is also shown that the (total) power factor is not a good indicator to compare the impact of different loads on the system.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133940424","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625405
I. Ziari, A. Jalilian
This paper introduces a modified particle swarm optimization (MPSO) algorithm which gets benefit from all remarkable advantages of conventional PSO (CPSO) in addition to lower possibility of catching in premature convergence and higher accuracy. In this paper, influence of CPSO parameters changes on the output accuracy is firstly represented and studied; then, a modified PSO called MPSO is studied to calculate these parameters optimally and improve the premature convergence problem along with the accuracy. In the proposed approach, CPSO parameters are determined using another CPSO algorithm in which parameters are selected typically. To evaluate the proposed MPSO, a 6-bus power system is considered in which two nonlinear loads are located as harmonics generators. A Comparison between the results of MPSO and those of CPSO and genetic algorithm (GA) is used to demonstrate the applicability and effectiveness of the MPSO-based algorithm and its superiority over other techniques.
{"title":"A PSO-based approach to adjust CPSO parameters","authors":"I. Ziari, A. Jalilian","doi":"10.1109/ICHQP.2010.5625405","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625405","url":null,"abstract":"This paper introduces a modified particle swarm optimization (MPSO) algorithm which gets benefit from all remarkable advantages of conventional PSO (CPSO) in addition to lower possibility of catching in premature convergence and higher accuracy. In this paper, influence of CPSO parameters changes on the output accuracy is firstly represented and studied; then, a modified PSO called MPSO is studied to calculate these parameters optimally and improve the premature convergence problem along with the accuracy. In the proposed approach, CPSO parameters are determined using another CPSO algorithm in which parameters are selected typically. To evaluate the proposed MPSO, a 6-bus power system is considered in which two nonlinear loads are located as harmonics generators. A Comparison between the results of MPSO and those of CPSO and genetic algorithm (GA) is used to demonstrate the applicability and effectiveness of the MPSO-based algorithm and its superiority over other techniques.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122378757","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625407
A. H. Jahanikia, M. Abbaspour
This paper studies the effects of using compact fluorescent lamps (CFLs) on the power distribution system elements on both the generation and the consumption sides. Previously, we presented a comprehensive analysis of how the harmonic distortion is generated in the CFLs and how it affects the distribution system wave shape. Here we study the technical and practical issues of mass utilization of CFLs in power systems with focus on different devices that and how the CFL harmonics affect the equipment on both feeding and consuming sides. Although there are some research works that study this effect on individual system elements, such studies do not integrate the analysis of different devices. Different classes of equipments are introduced and analyzed using their mathematical model.
{"title":"Studying the effects of using compact fluorescent lamps in power systems","authors":"A. H. Jahanikia, M. Abbaspour","doi":"10.1109/ICHQP.2010.5625407","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625407","url":null,"abstract":"This paper studies the effects of using compact fluorescent lamps (CFLs) on the power distribution system elements on both the generation and the consumption sides. Previously, we presented a comprehensive analysis of how the harmonic distortion is generated in the CFLs and how it affects the distribution system wave shape. Here we study the technical and practical issues of mass utilization of CFLs in power systems with focus on different devices that and how the CFL harmonics affect the equipment on both feeding and consuming sides. Although there are some research works that study this effect on individual system elements, such studies do not integrate the analysis of different devices. Different classes of equipments are introduced and analyzed using their mathematical model.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122430930","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625422
A. Collin, C. Cresswell, S. Djokic
Switch-mode power supplies (SMPS) are one of the most common category of loads, typically found in large numbers in modern power supply systems. These devices usually draw non-linear current and are, therefore, significant sources of harmonics. Although it is well known that the presence of harmonics will result in negative effects (e.g. higher thermal stresses and overloading, or increased neutral conductor currents), the assessment of the actual harmonic levels is not a simple task.
{"title":"Harmonic cancellation of modern switch-mode power supply load","authors":"A. Collin, C. Cresswell, S. Djokic","doi":"10.1109/ICHQP.2010.5625422","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625422","url":null,"abstract":"Switch-mode power supplies (SMPS) are one of the most common category of loads, typically found in large numbers in modern power supply systems. These devices usually draw non-linear current and are, therefore, significant sources of harmonics. Although it is well known that the presence of harmonics will result in negative effects (e.g. higher thermal stresses and overloading, or increased neutral conductor currents), the assessment of the actual harmonic levels is not a simple task.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129346272","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625484
M. Klatt, J. Meyer, M. Elst, P. Schegner
Voltage quality plays an important role in modern distribution networks. One voltage quality parameter is harmonic distortion. Voltage harmonics in MV-networks are measured in most cases by using installed inductive voltage transformers (IVT). The accuracy of these transformers for frequencies above nominal frequency (50Hz or 60Hz) is usually not known. The paper presents a systematic analysis of the frequency-dependent accuracy of these IVT's for harmonic measurements in the frequency range up to 10 kHz and it's dependency from different factors and operating conditions. After an overview of possible factors that influence the frequency response, the used measurement equipment and methodology is described. The frequency responses of more than 85 IVT's with rated primary voltages between 10 kV and 35 kV were measured and analysed. The significance of each influencing factor to the frequency response is discussed and finally a frequency-dependent measurement uncertainty range for 20 kV IVT's is proposed.
{"title":"Frequency Responses of MV voltage transformers in the range of 50 Hz to 10 kHz","authors":"M. Klatt, J. Meyer, M. Elst, P. Schegner","doi":"10.1109/ICHQP.2010.5625484","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625484","url":null,"abstract":"Voltage quality plays an important role in modern distribution networks. One voltage quality parameter is harmonic distortion. Voltage harmonics in MV-networks are measured in most cases by using installed inductive voltage transformers (IVT). The accuracy of these transformers for frequencies above nominal frequency (50Hz or 60Hz) is usually not known. The paper presents a systematic analysis of the frequency-dependent accuracy of these IVT's for harmonic measurements in the frequency range up to 10 kHz and it's dependency from different factors and operating conditions. After an overview of possible factors that influence the frequency response, the used measurement equipment and methodology is described. The frequency responses of more than 85 IVT's with rated primary voltages between 10 kV and 35 kV were measured and analysed. The significance of each influencing factor to the frequency response is discussed and finally a frequency-dependent measurement uncertainty range for 20 kV IVT's is proposed.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128855378","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625505
P. Janik, Z. Waclawek
Matching various types of disturbances helps to accurately assess the stress imposed on load and electrical network itself. Electrical equipment susceptibility to disturbances varies significantly from type to type. Additionally, not only one physical phenomenon (e.g. harmonics) can cause equipment malfunctioning or damage, but more likely a superposition of some different disturbances. On the contrary, certain disturbance levels, even higher than prescribed in standards - if not superimposed with others disturbances - can be harmless to some types of equipment. Logical and functional coupling between disturbances sources and sinks is needed. The authors consider a neuro-fuzzy architecture appropriate for power quality characterization, establishing a promising link between distortions levels and equipment susceptibility. Neuro-fuzzy system performance has been compared with radial basis function neural networks.
{"title":"Merging of various indicators and levels of disturbances for optimized power quality characterization","authors":"P. Janik, Z. Waclawek","doi":"10.1109/ICHQP.2010.5625505","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625505","url":null,"abstract":"Matching various types of disturbances helps to accurately assess the stress imposed on load and electrical network itself. Electrical equipment susceptibility to disturbances varies significantly from type to type. Additionally, not only one physical phenomenon (e.g. harmonics) can cause equipment malfunctioning or damage, but more likely a superposition of some different disturbances. On the contrary, certain disturbance levels, even higher than prescribed in standards - if not superimposed with others disturbances - can be harmless to some types of equipment. Logical and functional coupling between disturbances sources and sinks is needed. The authors consider a neuro-fuzzy architecture appropriate for power quality characterization, establishing a promising link between distortions levels and equipment susceptibility. Neuro-fuzzy system performance has been compared with radial basis function neural networks.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128584141","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625387
A. Pana, A. Baloi, F. Molnar-Matei
The paper presents the results of few numerical applications for sustaining the idea of unbalancing transversal capacitive compensation like a method for balancing the load of the electrical distribution networks and consequently to increase the voltage quality and the efficiency. The load balancing, analytical described by the annulment of negative component of the currents on the load phases, is possible by using a three-phase shunt compensator in delta connection, which contains only capacitive susceptances and/or inductive susceptances. The authors sustain in this paper the advantages of using simplified compensators, which contains only capacitive susceptances, and which, in the most of practical situations allows the total or almost total balancing of the load. The structures of this compensators will conduce to low costs, even when this are used for an on-line compensation, the capacitive susceptances control is individually depending on the nature and the dimension of the load unbalancing. The paper contains numerical examples regarding a three-phase low voltage network.
{"title":"Load balancing by unbalanced capacitive shunt compensation — A numerical approach","authors":"A. Pana, A. Baloi, F. Molnar-Matei","doi":"10.1109/ICHQP.2010.5625387","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625387","url":null,"abstract":"The paper presents the results of few numerical applications for sustaining the idea of unbalancing transversal capacitive compensation like a method for balancing the load of the electrical distribution networks and consequently to increase the voltage quality and the efficiency. The load balancing, analytical described by the annulment of negative component of the currents on the load phases, is possible by using a three-phase shunt compensator in delta connection, which contains only capacitive susceptances and/or inductive susceptances. The authors sustain in this paper the advantages of using simplified compensators, which contains only capacitive susceptances, and which, in the most of practical situations allows the total or almost total balancing of the load. The structures of this compensators will conduce to low costs, even when this are used for an on-line compensation, the capacitive susceptances control is individually depending on the nature and the dimension of the load unbalancing. The paper contains numerical examples regarding a three-phase low voltage network.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116804819","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625452
R. Zheng, M. Bollen, J. Zhong
This paper studies the impact of a grid-connected wind farm on the harmonic resonances. The basic theory on the harmonic resonances is introduced as well as its consequences. The models of wind farm for resonance analysis are presented for both calculations and simulations. The resonance orders and amplifications of voltage distortion with different capacity of capacitor banks are studied under different operation modes. Several case studies with a 200 MW wind farm have been carried out to illustrate the methods for harmonic resonance analysis.
{"title":"Harmonic resonances due to a grid-connected wind farm","authors":"R. Zheng, M. Bollen, J. Zhong","doi":"10.1109/ICHQP.2010.5625452","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625452","url":null,"abstract":"This paper studies the impact of a grid-connected wind farm on the harmonic resonances. The basic theory on the harmonic resonances is introduced as well as its consequences. The models of wind farm for resonance analysis are presented for both calculations and simulations. The resonance orders and amplifications of voltage distortion with different capacity of capacitor banks are studied under different operation modes. Several case studies with a 200 MW wind farm have been carried out to illustrate the methods for harmonic resonance analysis.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115670370","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625417
L. Kovernikova
The paper studies the problems on centralized normalization of harmonic voltages in the network with distributed nonlinear loads by the passive filters. The nonlinear loads are connected to the extended HV network at practically equal distances. Each nonlinear load is of sufficiently high power. The harmonic voltage values at the nodes of nonlinear loads connection to the supply network exceed the limits established by the standard. The paper addresses the problems of choosing the passive filters: determination of a desired value of harmonic voltages after filter installation, choice of the node for filter installation, calculation of filter parameters and evaluation of the efficiency of chosen filters for centralized normalization of harmonic voltages at the network nodes. An example of choosing the third-order filters for the real 220 kV network supplying power to traction loads is given.
{"title":"The problems of centralized decrease of harmonic voltages in the HV networks with distributed nonlinear loads","authors":"L. Kovernikova","doi":"10.1109/ICHQP.2010.5625417","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625417","url":null,"abstract":"The paper studies the problems on centralized normalization of harmonic voltages in the network with distributed nonlinear loads by the passive filters. The nonlinear loads are connected to the extended HV network at practically equal distances. Each nonlinear load is of sufficiently high power. The harmonic voltage values at the nodes of nonlinear loads connection to the supply network exceed the limits established by the standard. The paper addresses the problems of choosing the passive filters: determination of a desired value of harmonic voltages after filter installation, choice of the node for filter installation, calculation of filter parameters and evaluation of the efficiency of chosen filters for centralized normalization of harmonic voltages at the network nodes. An example of choosing the third-order filters for the real 220 kV network supplying power to traction loads is given.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114535143","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 : 2010-11-09DOI: 10.1109/ICHQP.2010.5625485
A. Damnjanovic, A. Islam, A. Domijan
Power system devices such as transformers, generators, and reactors have nonlinear characteristics because of the magnetic material used for their construction. Hence, understanding how the harmonics affect the power system requires explorations of the harmonic characteristics of each nonlinear component including the transformers. Thus, particular models need to be developed for the power system and machines design, and harmonic power flow analysis. Regarding the modeling of transformer nonlinearity, including hysteresis, there are many numerical methods that have been applied and many models have been developed. The nonlinearity of these devices cannot be correctly represented unless the hysteresis is included. Although the developed model can be used for other devices such as reactors, generators and motors, we are primarily focused on modeling of the transformers. There are many models developed for nonlinear transformer characteristics from various aspects, but none address the influences of the actual mechanical stresses on the magnetic materials. Mechanical stress modifies the nonlinear characteristics of the transformer and consequentially influences the operation of the transformers generating higher level of harmonics, increasing both losses and transformer noise. Our goal was to develop an accurate model and expressive formulas that can be used for practical engineering applications in transformer design and power system analysis based on minimal measured data requirements. The excitation characteristics of the transformer are presented with two piecewise approximated functions. The Harmonic Balance Method - Describing Function is used to obtain the harmonic magnitude and phase angles of the excitation current. The proposed model has been verified with experimentally obtained results for the transformer excitation current.
{"title":"Harmonic domain modeling of transformer nonlinear characteristic with piece-wise approximation","authors":"A. Damnjanovic, A. Islam, A. Domijan","doi":"10.1109/ICHQP.2010.5625485","DOIUrl":"https://doi.org/10.1109/ICHQP.2010.5625485","url":null,"abstract":"Power system devices such as transformers, generators, and reactors have nonlinear characteristics because of the magnetic material used for their construction. Hence, understanding how the harmonics affect the power system requires explorations of the harmonic characteristics of each nonlinear component including the transformers. Thus, particular models need to be developed for the power system and machines design, and harmonic power flow analysis. Regarding the modeling of transformer nonlinearity, including hysteresis, there are many numerical methods that have been applied and many models have been developed. The nonlinearity of these devices cannot be correctly represented unless the hysteresis is included. Although the developed model can be used for other devices such as reactors, generators and motors, we are primarily focused on modeling of the transformers. There are many models developed for nonlinear transformer characteristics from various aspects, but none address the influences of the actual mechanical stresses on the magnetic materials. Mechanical stress modifies the nonlinear characteristics of the transformer and consequentially influences the operation of the transformers generating higher level of harmonics, increasing both losses and transformer noise. Our goal was to develop an accurate model and expressive formulas that can be used for practical engineering applications in transformer design and power system analysis based on minimal measured data requirements. The excitation characteristics of the transformer are presented with two piecewise approximated functions. The Harmonic Balance Method - Describing Function is used to obtain the harmonic magnitude and phase angles of the excitation current. The proposed model has been verified with experimentally obtained results for the transformer excitation current.","PeriodicalId":180078,"journal":{"name":"Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114244101","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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