The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Robert G. Moyle - One of the best experts on this subject based on the ideXlab platform.
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relationships of morphological groups in the northern Flicker superspecies complex colaptes auratus c chrysoides
Systematics and Biodiversity, 2017Co-Authors: Joseph D. Manthey, Mark Geiger, Robert G. MoyleAbstract:Many species complexes have diversified rapidly and recently, resulting in morphologically diverse populations; however, the rapid pace of diversification often prevents identification of clear phylogeographic structure. Recently, the use of large genomic and reduced-representation genomic datasets has improved resolution of the evolutionary histories in such species and allowed identification of lineages on distinct evolutionary trajectories. The northern Flicker (Colaptes auratus) and gilded Flicker (Colaptes chrysoides) form a polytypic superspecies group with a complex taxonomic history. The superspecies group includes up to 13 described subspecies, which represent slight geographic variation among five main morphological groups: red-shafted Flickers of western North America (cafer group), yellow-shafted Flickers of eastern North America (auratus group), Cuban Flickers of the Caribbean (chrysocaulosus group), gilded Flickers of the U.S. south-west and Mexican north-west (chrysoides group), and Guatema...
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Relationships of morphological groups in the northern Flicker superspecies complex (Colaptes auratus & C. chrysoides)
Systematics and Biodiversity, 2016Co-Authors: Joseph D. Manthey, Mark Geiger, Robert G. MoyleAbstract:Many species complexes have diversified rapidly and recently, resulting in morphologically diverse populations; however, the rapid pace of diversification often prevents identification of clear phylogeographic structure. Recently, the use of large genomic and reduced-representation genomic datasets has improved resolution of the evolutionary histories in such species and allowed identification of lineages on distinct evolutionary trajectories. The northern Flicker (Colaptes auratus) and gilded Flicker (Colaptes chrysoides) form a polytypic superspecies group with a complex taxonomic history. The superspecies group includes up to 13 described subspecies, which represent slight geographic variation among five main morphological groups: red-shafted Flickers of western North America (cafer group), yellow-shafted Flickers of eastern North America (auratus group), Cuban Flickers of the Caribbean (chrysocaulosus group), gilded Flickers of the U.S. south-west and Mexican north-west (chrysoides group), and Guatema...
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Relationships of morphological groups in the northern Flicker superspecies complex (Colaptes auratus & C. chrysoides)
2016Co-Authors: Joseph D. Manthey, Mark Geiger, Robert G. MoyleAbstract:Many species complexes have diversified rapidly and recently, resulting in morphologically diverse populations; however, the rapid pace of diversification often prevents identification of clear phylogeographic structure. Recently, the use of large genomic and reduced-representation genomic datasets has improved resolution of the evolutionary histories in such species and allowed identification of lineages on distinct evolutionary trajectories. The northern Flicker (Colaptes auratus) and gilded Flicker (Colaptes chrysoides) form a polytypic superspecies group with a complex taxonomic history. The superspecies group includes up to 13 described subspecies, which represent slight geographic variation among five main morphological groups: red-shafted Flickers of western North America (cafer group), yellow-shafted Flickers of eastern North America (auratus group), Cuban Flickers of the Caribbean (chrysocaulosus group), gilded Flickers of the U.S. south-west and Mexican north-west (chrysoides group), and Guatemalan Flickers of Central America (mexicanoides group). These groups are largely differentiable by variation in feather shaft colour, malar colour, throat colour, crown colour, and back barring. Here, using mitochondrial DNA (mtDNA) and hundreds of single nucleotide polymorphisms (SNPs), we characterized the genetic relationships and genomic distinctiveness of the five morphological groups. We found the mexicanoides group to be the most genetically distinct in both mtDNA (∼1.4% sequence divergence) and large SNP panels. The chrysocaulosus group is differentiated by a single basepair mutation in a small mtDNA fragment. In both mtDNA and SNP panels, there is little genetic distinctiveness between auratus, cafer, and chrysoides morphological groups, with evidence of admixture and a lack of fixed differences.
Zhe Chen - One of the best experts on this subject based on the ideXlab platform.
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Flicker mitigation by active power control of variable speed wind turbines with full scale back to back power converters
IEEE Transactions on Energy Conversion, 2009Co-Authors: Zhe Chen, Yue Wang, Zhaoan WangAbstract:Grid-connected wind turbines are fluctuating power sources that may produce Flicker during continuous operation. This paper presents a simulation model of a megawatt-level variable-speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of PSCAD/EMTDC. Flicker emission of this system is investigated. Reactive power compensation is mostly adopted for Flicker mitigation. However, the Flicker mitigation technique shows its limits, when the grid impedance angle is low in some distribution networks. A new method of Flicker mitigation by controlling active power is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the dc-link voltage of the full-scale converter. Simulation results show that damping the 3p active power oscillation by using the Flicker mitigation controller is an effective means for Flicker mitigation of variable-speed wind turbines with full-scale back-to-back power converters during continuous operation.
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Flicker study on variable speed wind turbines with doubly fed induction generators
IEEE Transactions on Energy Conversion, 2005Co-Authors: Tao Sun, Zhe Chen, Frede BlaabjergAbstract:Grid connected wind turbines may produce Flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a doubly fed induction generator developed in the simulation tool of PSCAD/EMTDC. Flicker emission of variable speed wind turbines with doubly fed induction generators is investigated during continuous operation, and the dependence of Flicker emission on mean wind speed, wind turbulence intensity, short circuit capacity of grid and grid impedance angle are analyzed. A comparison is done with the fixed speed wind turbine, which leads to a conclusion that the factors mentioned above have different influences on Flicker emission compared with that in the case of the fixed speed wind turbine. Flicker mitigation is realized by output reactive power control of the variable speed wind turbine with doubly fed induction generator. Simulation results show the wind turbine output reactive power control provides an effective means for Flicker mitigation regardless of mean wind speed, turbulence intensity and short circuit capacity ratio.
Frede Blaabjerg - One of the best experts on this subject based on the ideXlab platform.
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Flicker study on variable speed wind turbines with doubly fed induction generators
IEEE Transactions on Energy Conversion, 2005Co-Authors: Tao Sun, Zhe Chen, Frede BlaabjergAbstract:Grid connected wind turbines may produce Flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a doubly fed induction generator developed in the simulation tool of PSCAD/EMTDC. Flicker emission of variable speed wind turbines with doubly fed induction generators is investigated during continuous operation, and the dependence of Flicker emission on mean wind speed, wind turbulence intensity, short circuit capacity of grid and grid impedance angle are analyzed. A comparison is done with the fixed speed wind turbine, which leads to a conclusion that the factors mentioned above have different influences on Flicker emission compared with that in the case of the fixed speed wind turbine. Flicker mitigation is realized by output reactive power control of the variable speed wind turbine with doubly fed induction generator. Simulation results show the wind turbine output reactive power control provides an effective means for Flicker mitigation regardless of mean wind speed, turbulence intensity and short circuit capacity ratio.
Joseph D. Manthey - One of the best experts on this subject based on the ideXlab platform.
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relationships of morphological groups in the northern Flicker superspecies complex colaptes auratus c chrysoides
Systematics and Biodiversity, 2017Co-Authors: Joseph D. Manthey, Mark Geiger, Robert G. MoyleAbstract:Many species complexes have diversified rapidly and recently, resulting in morphologically diverse populations; however, the rapid pace of diversification often prevents identification of clear phylogeographic structure. Recently, the use of large genomic and reduced-representation genomic datasets has improved resolution of the evolutionary histories in such species and allowed identification of lineages on distinct evolutionary trajectories. The northern Flicker (Colaptes auratus) and gilded Flicker (Colaptes chrysoides) form a polytypic superspecies group with a complex taxonomic history. The superspecies group includes up to 13 described subspecies, which represent slight geographic variation among five main morphological groups: red-shafted Flickers of western North America (cafer group), yellow-shafted Flickers of eastern North America (auratus group), Cuban Flickers of the Caribbean (chrysocaulosus group), gilded Flickers of the U.S. south-west and Mexican north-west (chrysoides group), and Guatema...
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Relationships of morphological groups in the northern Flicker superspecies complex (Colaptes auratus & C. chrysoides)
Systematics and Biodiversity, 2016Co-Authors: Joseph D. Manthey, Mark Geiger, Robert G. MoyleAbstract:Many species complexes have diversified rapidly and recently, resulting in morphologically diverse populations; however, the rapid pace of diversification often prevents identification of clear phylogeographic structure. Recently, the use of large genomic and reduced-representation genomic datasets has improved resolution of the evolutionary histories in such species and allowed identification of lineages on distinct evolutionary trajectories. The northern Flicker (Colaptes auratus) and gilded Flicker (Colaptes chrysoides) form a polytypic superspecies group with a complex taxonomic history. The superspecies group includes up to 13 described subspecies, which represent slight geographic variation among five main morphological groups: red-shafted Flickers of western North America (cafer group), yellow-shafted Flickers of eastern North America (auratus group), Cuban Flickers of the Caribbean (chrysocaulosus group), gilded Flickers of the U.S. south-west and Mexican north-west (chrysoides group), and Guatema...
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Relationships of morphological groups in the northern Flicker superspecies complex (Colaptes auratus & C. chrysoides)
2016Co-Authors: Joseph D. Manthey, Mark Geiger, Robert G. MoyleAbstract:Many species complexes have diversified rapidly and recently, resulting in morphologically diverse populations; however, the rapid pace of diversification often prevents identification of clear phylogeographic structure. Recently, the use of large genomic and reduced-representation genomic datasets has improved resolution of the evolutionary histories in such species and allowed identification of lineages on distinct evolutionary trajectories. The northern Flicker (Colaptes auratus) and gilded Flicker (Colaptes chrysoides) form a polytypic superspecies group with a complex taxonomic history. The superspecies group includes up to 13 described subspecies, which represent slight geographic variation among five main morphological groups: red-shafted Flickers of western North America (cafer group), yellow-shafted Flickers of eastern North America (auratus group), Cuban Flickers of the Caribbean (chrysocaulosus group), gilded Flickers of the U.S. south-west and Mexican north-west (chrysoides group), and Guatemalan Flickers of Central America (mexicanoides group). These groups are largely differentiable by variation in feather shaft colour, malar colour, throat colour, crown colour, and back barring. Here, using mitochondrial DNA (mtDNA) and hundreds of single nucleotide polymorphisms (SNPs), we characterized the genetic relationships and genomic distinctiveness of the five morphological groups. We found the mexicanoides group to be the most genetically distinct in both mtDNA (∼1.4% sequence divergence) and large SNP panels. The chrysocaulosus group is differentiated by a single basepair mutation in a small mtDNA fragment. In both mtDNA and SNP panels, there is little genetic distinctiveness between auratus, cafer, and chrysoides morphological groups, with evidence of admixture and a lack of fixed differences.
Zhaoan Wang - One of the best experts on this subject based on the ideXlab platform.
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Flicker mitigation by active power control of variable speed wind turbines with full scale back to back power converters
IEEE Transactions on Energy Conversion, 2009Co-Authors: Zhe Chen, Yue Wang, Zhaoan WangAbstract:Grid-connected wind turbines are fluctuating power sources that may produce Flicker during continuous operation. This paper presents a simulation model of a megawatt-level variable-speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of PSCAD/EMTDC. Flicker emission of this system is investigated. Reactive power compensation is mostly adopted for Flicker mitigation. However, the Flicker mitigation technique shows its limits, when the grid impedance angle is low in some distribution networks. A new method of Flicker mitigation by controlling active power is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the dc-link voltage of the full-scale converter. Simulation results show that damping the 3p active power oscillation by using the Flicker mitigation controller is an effective means for Flicker mitigation of variable-speed wind turbines with full-scale back-to-back power converters during continuous operation.
