The Experts below are selected from a list of 35910 Experts worldwide ranked by ideXlab platform
Martin Kenney - One of the best experts on this subject based on the ideXlab platform.
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the chinese platform business group an alternative to the silicon valley model
Journal of Chinese Governance, 2021Co-Authors: Kai Jia, Martin KenneyAbstract:The current understanding of platform expansion is based upon the experience of US West Coast firms. China, with its largely protected but enormous internal market, provides an Ideal ‘Experiment’ f...
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the chinese platform business group an alternative to the silicon valley model
Social Science Research Network, 2021Co-Authors: Kai Jia, Martin KenneyAbstract:The current understanding of platform expansion is based upon the experience of US West Coast firms. China, with its largely protected but enormous internal market, provides an Ideal “Experiment” for examining how platform business models might develop different evolutionary trajectories in different environments. Based upon a study of the two largest platform firms, Tencent and Alibaba, and the far smaller but dominant Chinese online travel agency platform, Trip.com, we demonstrate that a different business model has emerged. In contrast to the West Coast model—in which the expansion occurs through internal development and introduction, acquisition, and venture capital investment—Chinese firms have employed two other strategies. The first is listing some of their existing operations separately on the stock market (what we term “selling off”) but not giving up control. The second strategy is interfirm cross investments. The use of these two strategies has led to the formation of an organizational form, that we term the “platform business group (PBG)”, which extends and transforms the existing Chinese business group model. We discuss the environmental conditions that enable PBGs to pursue business strategies in a different manner than their Western counterparts and to identify the key conditions that allowed the PBG model to develop. Our extension of platform studies to China enriches and extends theoretical and practical understanding of Chinese platforms. Finally, we discuss the difficulties that PBG firms face in employing their business model internationally.
Kai Jia - One of the best experts on this subject based on the ideXlab platform.
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the chinese platform business group an alternative to the silicon valley model
Journal of Chinese Governance, 2021Co-Authors: Kai Jia, Martin KenneyAbstract:The current understanding of platform expansion is based upon the experience of US West Coast firms. China, with its largely protected but enormous internal market, provides an Ideal ‘Experiment’ f...
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the chinese platform business group an alternative to the silicon valley model
Social Science Research Network, 2021Co-Authors: Kai Jia, Martin KenneyAbstract:The current understanding of platform expansion is based upon the experience of US West Coast firms. China, with its largely protected but enormous internal market, provides an Ideal “Experiment” for examining how platform business models might develop different evolutionary trajectories in different environments. Based upon a study of the two largest platform firms, Tencent and Alibaba, and the far smaller but dominant Chinese online travel agency platform, Trip.com, we demonstrate that a different business model has emerged. In contrast to the West Coast model—in which the expansion occurs through internal development and introduction, acquisition, and venture capital investment—Chinese firms have employed two other strategies. The first is listing some of their existing operations separately on the stock market (what we term “selling off”) but not giving up control. The second strategy is interfirm cross investments. The use of these two strategies has led to the formation of an organizational form, that we term the “platform business group (PBG)”, which extends and transforms the existing Chinese business group model. We discuss the environmental conditions that enable PBGs to pursue business strategies in a different manner than their Western counterparts and to identify the key conditions that allowed the PBG model to develop. Our extension of platform studies to China enriches and extends theoretical and practical understanding of Chinese platforms. Finally, we discuss the difficulties that PBG firms face in employing their business model internationally.
Brian Keating - One of the best experts on this subject based on the ideXlab platform.
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cmb temperature polarization correlation and primordial gravitational waves
Monthly Notices of the Royal Astronomical Society, 2008Co-Authors: Alexander G Polnarev, Nathan Miller, Brian KeatingAbstract:We examine the use of the TE cross-correlation power spectrum of the cosmic microwave background (CMB) as a complementary test to detect primordial gravitational waves (PGWs). The first method used is based on the determination of the lowest multipole, l 0 , where the TE power spectrum, C TE l , first changes sign. The second method uses Wiener filtering on the CMB TE data to remove the density perturbations contribution to the TE power spectrum. In principle this leaves only the contribution of PGWs. We examine two toy Experiments (one Ideal and another more realistic) to see their ability to constrain PGWs using the TE power spectrum alone. We found that an Ideal Experiment, one limited only by cosmic variance, can detect PGWs with a ratio of tensor to scalar metric perturbation power spectra r = 0.3 at 99.9 per cent confidence level using only the TE correlation. This value is comparable with current constraints obtained by the Wilkinson Microwave Anisotropy Probe based on the 2σ upper limits to the B-mode amplitude. We demonstrate that to measure PGWs by their contribution to the TE cross-correlation power spectrum in a realistic ground-based Experiment when real instrumental noise is taken into account, the tensor-to-scalar ratio, r, should be approximately three times larger.
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cmb temperature polarization correlation and primordial gravitational waves
arXiv: Astrophysics, 2007Co-Authors: Alexander G Polnarev, Nathan Miller, Brian KeatingAbstract:We examine the use of the CMB's TE cross correlation power spectrum as a complementary test to detect primordial gravitational waves (PGWs). The first method used is based on the determination of the lowest multipole, $\ell_0$, where the TE power spectrum, $C_{\ell}^{TE}$, first changes sign. The second method uses Wiener filtering on the CMB TE data to remove the density perturbations contribution to the TE power spectrum. In principle this leaves only the contribution of PGWs. We examine two toy Experiments (one Ideal and another more realistic) to see their ability to constrain PGWs using the TE power spectrum alone. We found that an Ideal Experiment, one limited only by cosmic variance, can detect PGWs with a ratio of tensor to scalar metric perturbation power spectra $r=0.3$ at 99.9% confidence level using only the TE correlation. This value is comparable with current constraints obtained by WMAP based on the $2\sigma$ upper limits to the B-mode amplitude. We demonstrate that to measure PGWs by their contribution to the TE cross correlation power spectrum in a realistic ground based Experiment when real instrumental noise is taken into account, the tensor-to-scalar ratio, $r$, should be approximately three times larger.
Alexander G Polnarev - One of the best experts on this subject based on the ideXlab platform.
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cmb temperature polarization correlation and primordial gravitational waves
Monthly Notices of the Royal Astronomical Society, 2008Co-Authors: Alexander G Polnarev, Nathan Miller, Brian KeatingAbstract:We examine the use of the TE cross-correlation power spectrum of the cosmic microwave background (CMB) as a complementary test to detect primordial gravitational waves (PGWs). The first method used is based on the determination of the lowest multipole, l 0 , where the TE power spectrum, C TE l , first changes sign. The second method uses Wiener filtering on the CMB TE data to remove the density perturbations contribution to the TE power spectrum. In principle this leaves only the contribution of PGWs. We examine two toy Experiments (one Ideal and another more realistic) to see their ability to constrain PGWs using the TE power spectrum alone. We found that an Ideal Experiment, one limited only by cosmic variance, can detect PGWs with a ratio of tensor to scalar metric perturbation power spectra r = 0.3 at 99.9 per cent confidence level using only the TE correlation. This value is comparable with current constraints obtained by the Wilkinson Microwave Anisotropy Probe based on the 2σ upper limits to the B-mode amplitude. We demonstrate that to measure PGWs by their contribution to the TE cross-correlation power spectrum in a realistic ground-based Experiment when real instrumental noise is taken into account, the tensor-to-scalar ratio, r, should be approximately three times larger.
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cmb temperature polarization correlation and primordial gravitational waves
arXiv: Astrophysics, 2007Co-Authors: Alexander G Polnarev, Nathan Miller, Brian KeatingAbstract:We examine the use of the CMB's TE cross correlation power spectrum as a complementary test to detect primordial gravitational waves (PGWs). The first method used is based on the determination of the lowest multipole, $\ell_0$, where the TE power spectrum, $C_{\ell}^{TE}$, first changes sign. The second method uses Wiener filtering on the CMB TE data to remove the density perturbations contribution to the TE power spectrum. In principle this leaves only the contribution of PGWs. We examine two toy Experiments (one Ideal and another more realistic) to see their ability to constrain PGWs using the TE power spectrum alone. We found that an Ideal Experiment, one limited only by cosmic variance, can detect PGWs with a ratio of tensor to scalar metric perturbation power spectra $r=0.3$ at 99.9% confidence level using only the TE correlation. This value is comparable with current constraints obtained by WMAP based on the $2\sigma$ upper limits to the B-mode amplitude. We demonstrate that to measure PGWs by their contribution to the TE cross correlation power spectrum in a realistic ground based Experiment when real instrumental noise is taken into account, the tensor-to-scalar ratio, $r$, should be approximately three times larger.
Nathan Miller - One of the best experts on this subject based on the ideXlab platform.
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cmb temperature polarization correlation and primordial gravitational waves
Monthly Notices of the Royal Astronomical Society, 2008Co-Authors: Alexander G Polnarev, Nathan Miller, Brian KeatingAbstract:We examine the use of the TE cross-correlation power spectrum of the cosmic microwave background (CMB) as a complementary test to detect primordial gravitational waves (PGWs). The first method used is based on the determination of the lowest multipole, l 0 , where the TE power spectrum, C TE l , first changes sign. The second method uses Wiener filtering on the CMB TE data to remove the density perturbations contribution to the TE power spectrum. In principle this leaves only the contribution of PGWs. We examine two toy Experiments (one Ideal and another more realistic) to see their ability to constrain PGWs using the TE power spectrum alone. We found that an Ideal Experiment, one limited only by cosmic variance, can detect PGWs with a ratio of tensor to scalar metric perturbation power spectra r = 0.3 at 99.9 per cent confidence level using only the TE correlation. This value is comparable with current constraints obtained by the Wilkinson Microwave Anisotropy Probe based on the 2σ upper limits to the B-mode amplitude. We demonstrate that to measure PGWs by their contribution to the TE cross-correlation power spectrum in a realistic ground-based Experiment when real instrumental noise is taken into account, the tensor-to-scalar ratio, r, should be approximately three times larger.
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cmb temperature polarization correlation and primordial gravitational waves
arXiv: Astrophysics, 2007Co-Authors: Alexander G Polnarev, Nathan Miller, Brian KeatingAbstract:We examine the use of the CMB's TE cross correlation power spectrum as a complementary test to detect primordial gravitational waves (PGWs). The first method used is based on the determination of the lowest multipole, $\ell_0$, where the TE power spectrum, $C_{\ell}^{TE}$, first changes sign. The second method uses Wiener filtering on the CMB TE data to remove the density perturbations contribution to the TE power spectrum. In principle this leaves only the contribution of PGWs. We examine two toy Experiments (one Ideal and another more realistic) to see their ability to constrain PGWs using the TE power spectrum alone. We found that an Ideal Experiment, one limited only by cosmic variance, can detect PGWs with a ratio of tensor to scalar metric perturbation power spectra $r=0.3$ at 99.9% confidence level using only the TE correlation. This value is comparable with current constraints obtained by WMAP based on the $2\sigma$ upper limits to the B-mode amplitude. We demonstrate that to measure PGWs by their contribution to the TE cross correlation power spectrum in a realistic ground based Experiment when real instrumental noise is taken into account, the tensor-to-scalar ratio, $r$, should be approximately three times larger.
