The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
William Amos - One of the best experts on this subject based on the ideXlab platform.
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Group Structure, mating system and extra‐Group paternity in the co‐operatively breeding White‐breasted Thrasher Ramphocinclus brachyurus
Ibis, 2009Co-Authors: H.j. Temple, Joseph I. Hoffman, William AmosAbstract:Avian co-operative breeders show a diverse range of social and reproductive systems. Here we combined microsatellite genotyping with field observations over three consecutive breeding seasons to investigate the social Structure and mating system of the White-breasted Thrasher Ramphocinclus brachyurus . Co-operative breeding was facultative in this species, with approximately one-third of nests having helpers. Breeding Groups comprised a pair of breeding adults and up to three helpers of either sex. Within co-operative Groups, age was associated with parentage in both sexes. Helpers were retained offspring and either rarely or never achieved parentage in current broods. There was no evidence of egg dumping and a relatively small percentage of chicks (7.5%, n = 67) were fathered by males from outside the co-operative Group. The White-breasted Thrasher is a globally Endangered species with a very small and declining population. A captive breeding programme for this species is not recommended at present, but may become necessary in the future, and any such programme should take account of our findings regarding breeding behaviour and Group Structure.
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Group Structure mating system and extra Group paternity in the co operatively breeding white breasted thrasher ramphocinclus brachyurus
Ibis, 2009Co-Authors: H.j. Temple, Joseph I. Hoffman, William AmosAbstract:Avian co-operative breeders show a diverse range of social and reproductive systems. Here we combined microsatellite genotyping with field observations over three consecutive breeding seasons to investigate the social Structure and mating system of the White-breasted Thrasher Ramphocinclus brachyurus . Co-operative breeding was facultative in this species, with approximately one-third of nests having helpers. Breeding Groups comprised a pair of breeding adults and up to three helpers of either sex. Within co-operative Groups, age was associated with parentage in both sexes. Helpers were retained offspring and either rarely or never achieved parentage in current broods. There was no evidence of egg dumping and a relatively small percentage of chicks (7.5%, n = 67) were fathered by males from outside the co-operative Group. The White-breasted Thrasher is a globally Endangered species with a very small and declining population. A captive breeding programme for this species is not recommended at present, but may become necessary in the future, and any such programme should take account of our findings regarding breeding behaviour and Group Structure.
H.j. Temple - One of the best experts on this subject based on the ideXlab platform.
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Group Structure, mating system and extra‐Group paternity in the co‐operatively breeding White‐breasted Thrasher Ramphocinclus brachyurus
Ibis, 2009Co-Authors: H.j. Temple, Joseph I. Hoffman, William AmosAbstract:Avian co-operative breeders show a diverse range of social and reproductive systems. Here we combined microsatellite genotyping with field observations over three consecutive breeding seasons to investigate the social Structure and mating system of the White-breasted Thrasher Ramphocinclus brachyurus . Co-operative breeding was facultative in this species, with approximately one-third of nests having helpers. Breeding Groups comprised a pair of breeding adults and up to three helpers of either sex. Within co-operative Groups, age was associated with parentage in both sexes. Helpers were retained offspring and either rarely or never achieved parentage in current broods. There was no evidence of egg dumping and a relatively small percentage of chicks (7.5%, n = 67) were fathered by males from outside the co-operative Group. The White-breasted Thrasher is a globally Endangered species with a very small and declining population. A captive breeding programme for this species is not recommended at present, but may become necessary in the future, and any such programme should take account of our findings regarding breeding behaviour and Group Structure.
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Group Structure mating system and extra Group paternity in the co operatively breeding white breasted thrasher ramphocinclus brachyurus
Ibis, 2009Co-Authors: H.j. Temple, Joseph I. Hoffman, William AmosAbstract:Avian co-operative breeders show a diverse range of social and reproductive systems. Here we combined microsatellite genotyping with field observations over three consecutive breeding seasons to investigate the social Structure and mating system of the White-breasted Thrasher Ramphocinclus brachyurus . Co-operative breeding was facultative in this species, with approximately one-third of nests having helpers. Breeding Groups comprised a pair of breeding adults and up to three helpers of either sex. Within co-operative Groups, age was associated with parentage in both sexes. Helpers were retained offspring and either rarely or never achieved parentage in current broods. There was no evidence of egg dumping and a relatively small percentage of chicks (7.5%, n = 67) were fathered by males from outside the co-operative Group. The White-breasted Thrasher is a globally Endangered species with a very small and declining population. A captive breeding programme for this species is not recommended at present, but may become necessary in the future, and any such programme should take account of our findings regarding breeding behaviour and Group Structure.
Joseph I. Hoffman - One of the best experts on this subject based on the ideXlab platform.
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Group Structure, mating system and extra‐Group paternity in the co‐operatively breeding White‐breasted Thrasher Ramphocinclus brachyurus
Ibis, 2009Co-Authors: H.j. Temple, Joseph I. Hoffman, William AmosAbstract:Avian co-operative breeders show a diverse range of social and reproductive systems. Here we combined microsatellite genotyping with field observations over three consecutive breeding seasons to investigate the social Structure and mating system of the White-breasted Thrasher Ramphocinclus brachyurus . Co-operative breeding was facultative in this species, with approximately one-third of nests having helpers. Breeding Groups comprised a pair of breeding adults and up to three helpers of either sex. Within co-operative Groups, age was associated with parentage in both sexes. Helpers were retained offspring and either rarely or never achieved parentage in current broods. There was no evidence of egg dumping and a relatively small percentage of chicks (7.5%, n = 67) were fathered by males from outside the co-operative Group. The White-breasted Thrasher is a globally Endangered species with a very small and declining population. A captive breeding programme for this species is not recommended at present, but may become necessary in the future, and any such programme should take account of our findings regarding breeding behaviour and Group Structure.
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Group Structure mating system and extra Group paternity in the co operatively breeding white breasted thrasher ramphocinclus brachyurus
Ibis, 2009Co-Authors: H.j. Temple, Joseph I. Hoffman, William AmosAbstract:Avian co-operative breeders show a diverse range of social and reproductive systems. Here we combined microsatellite genotyping with field observations over three consecutive breeding seasons to investigate the social Structure and mating system of the White-breasted Thrasher Ramphocinclus brachyurus . Co-operative breeding was facultative in this species, with approximately one-third of nests having helpers. Breeding Groups comprised a pair of breeding adults and up to three helpers of either sex. Within co-operative Groups, age was associated with parentage in both sexes. Helpers were retained offspring and either rarely or never achieved parentage in current broods. There was no evidence of egg dumping and a relatively small percentage of chicks (7.5%, n = 67) were fathered by males from outside the co-operative Group. The White-breasted Thrasher is a globally Endangered species with a very small and declining population. A captive breeding programme for this species is not recommended at present, but may become necessary in the future, and any such programme should take account of our findings regarding breeding behaviour and Group Structure.
Barry Ruback - One of the best experts on this subject based on the ideXlab platform.
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automatically detecting the small Group Structure of a crowd
Workshop on Applications of Computer Vision, 2009Co-Authors: Robert T Collins, Barry RubackAbstract:Recent work on computer vision analysis of crowds tends to focus on robustly tracking individuals through the crowd or on analyzing the overall pattern of flow. Our work seeks a deeper analysis of social behavior by identifying the small Group Structure of crowds, forming the basis for mid-level activity analysis at the granularity of human social Groups. Building upon state-of-the-art algorithms for pedestrian detection and multi-object tracking, and inspired by social science models of human collective behavior, we automatically detect small Groups of individuals who are traveling together. These Groups are discovered using a bottom-up hierarchical clustering approach that compares sets of individuals based on a generalized, symmetric Hausdorff distance defined with respect to pairwise proximity and velocity. We validate our results quantitatively and qualitatively on videos of real-world pedestrian scenes. Where human-coded ground truth is available, we find substantial statistical agreement between our results and the human-perceived small Group Structure of the crowd.
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WACV - Automatically detecting the small Group Structure of a crowd
2009 Workshop on Applications of Computer Vision (WACV), 2009Co-Authors: Robert T Collins, Barry RubackAbstract:Recent work on computer vision analysis of crowds tends to focus on robustly tracking individuals through the crowd or on analyzing the overall pattern of flow. Our work seeks a deeper analysis of social behavior by identifying the small Group Structure of crowds, forming the basis for mid-level activity analysis at the granularity of human social Groups. Building upon state-of-the-art algorithms for pedestrian detection and multi-object tracking, and inspired by social science models of human collective behavior, we automatically detect small Groups of individuals who are traveling together. These Groups are discovered using a bottom-up hierarchical clustering approach that compares sets of individuals based on a generalized, symmetric Hausdorff distance defined with respect to pairwise proximity and velocity. We validate our results quantitatively and qualitatively on videos of real-world pedestrian scenes. Where human-coded ground truth is available, we find substantial statistical agreement between our results and the human-perceived small Group Structure of the crowd.
Zhongqiu Zhao - One of the best experts on this subject based on the ideXlab platform.
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online feature selection with Group Structure analysis
arXiv: Computer Vision and Pattern Recognition, 2016Co-Authors: Jing Wang, Meng Wang, Luoqi Liu, Zhongqiu ZhaoAbstract:Online selection of dynamic features has attracted intensive interest in recent years. However, existing online feature selection methods evaluate features individually and ignore the underlying Structure of feature stream. For instance, in image analysis, features are generated in Groups which represent color, texture and other visual information. Simply breaking the Group Structure in feature selection may degrade performance. Motivated by this fact, we formulate the problem as an online Group feature selection. The problem assumes that features are generated individually but there are Group Structure in the feature stream. To the best of our knowledge, this is the first time that the correlation among feature stream has been considered in the online feature selection process. To solve this problem, we develop a novel online Group feature selection method named OGFS. Our proposed approach consists of two stages: online intra-Group selection and online inter-Group selection. In the intra-Group selection, we design a criterion based on spectral analysis to select discriminative features in each Group. In the inter-Group selection, we utilize a linear regression model to select an optimal subset. This two-stage procedure continues until there are no more features arriving or some predefined stopping conditions are met. %Our method has been applied Finally, we apply our method to multiple tasks including image classification %, face verification and face verification. Extensive empirical studies performed on real-world and benchmark data sets demonstrate that our method outperforms other state-of-the-art online feature selection %method methods.
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online feature selection with Group Structure analysis
IEEE Transactions on Knowledge and Data Engineering, 2015Co-Authors: Jing Wang, Meng Wang, Luoqi Liu, Zhongqiu ZhaoAbstract:Online selection of dynamic features has attracted intensive interest in recent years. However, existing online feature selection methods evaluate features individually and ignore the underlying Structure of a feature stream. For instance, in image analysis, features are generated in Groups which represent color, texture, and other visual information. Simply breaking the Group Structure in feature selection may degrade performance. Motivated by this observation, we formulate the problem as an online Group feature selection. The problem assumes that features are generated individually but there are Group Structures in the feature stream. To the best of our knowledge, this is the first time that the correlation among streaming features has been considered in the online feature selection process. To solve this problem, we develop a novel online Group feature selection method named OGFS. Our proposed approach consists of two stages: online intra-Group selection and online inter-Group selection. In the intra-Group selection, we design a criterion based on spectral analysis to select discriminative features in each Group. In the inter-Group selection, we utilize a linear regression model to select an optimal subset. This two-stage procedure continues until there are no more features arriving or some predefined stopping conditions are met. Finally, we apply our method to multiple tasks including image classification and face verification. Extensive empirical studies performed on real-world and benchmark data sets demonstrate that our method outperforms other state-of-the-art online feature selection methods.
