The Experts below are selected from a list of 15597 Experts worldwide ranked by ideXlab platform
Lie Wang - One of the best experts on this subject based on the ideXlab platform.
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stable recovery of sparse signals and an oracle inequality
IEEE Transactions on Information Theory, 2010Co-Authors: Tony T Cai, Lie WangAbstract:This article considers sparse signal recovery in the presence of noise. A mutual Incoherence condition which was previously used for exact recovery in the noiseless case is shown to be sufficient for stable recovery in the noisy case. Furthermore, the condition is proved to be sharp. A specific counterexample is given. In addition, an oracle inequality is derived under the mutual Incoherence condition in the case of Gaussian noise.
Xiongjun Zhang - One of the best experts on this subject based on the ideXlab platform.
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on o max n_1 n_2 log max n_1 n_2 n_3 sample entries for n_1 times n_2 times n_3 tensor completion via unitary transformation
arXiv: Machine Learning, 2020Co-Authors: Guangjing Song, Xiongjun ZhangAbstract:One of the key problems in tensor completion is the number of uniformly random sample entries required for recovery guarantee. The main aim of this paper is to study $n_1 \times n_2 \times n_3$ third-order tensor completion and investigate into Incoherence conditions of $n_3$ low-rank $n_1$-by-$n_2$ matrix slices under the transformed tensor singular value decomposition where the unitary transformation is applied along $n_3$-dimension. We show that such low-rank tensors can be recovered exactly with high probability when the number of randomly observed entries is of order $O( r\max \{n_1, n_2 \} \log ( \max \{ n_1, n_2 \} n_3))$, where $r$ is the sum of the ranks of these $n_3$ matrix slices in the transformed tensor. By utilizing synthetic data and imaging data sets, we demonstrate that the theoretical result can be obtained under valid Incoherence conditions, and the tensor completion performance of the proposed method is also better than that of existing methods in terms of sample sizes requirement.
Oleh E Omelchenko - One of the best experts on this subject based on the ideXlab platform.
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coherence Incoherence patterns in a ring of non locally coupled phase oscillators
Nonlinearity, 2013Co-Authors: Oleh E OmelchenkoAbstract:We consider a paradigmatic spatially extended model of non-locally coupled phase oscillators which are uniformly distributed within a one-dimensional interval and interact depending on the distance between their sites' modulo periodic boundary conditions. This model can display peculiar spatio-temporal patterns consisting of alternating patches with synchronized (coherent) or irregular (incoherent) oscillator dynamics, hence the name coherence–Incoherence pattern, or chimera state. For such patterns we formulate a general bifurcation analysis scheme based on a hierarchy of continuum limit equations. This provides the possibility of classifying known coherence–Incoherence patterns and of suggesting directions for the search for new ones.
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chimera states the natural link between coherence and Incoherence
Physical Review Letters, 2008Co-Authors: Yuri Maistrenko, Oleh E Omelchenko, Peter A TassAbstract:Chimera states are remarkable spatiotemporal patterns in which coherence coexists with Incoherence. As yet, chimera states have been considered as nongeneric, since they emerge only for particular initial conditions. In contrast, we show here that in a network of globally coupled oscillators delayed feedback stimulation with realistic (i.e., spatially decaying) stimulation profile generically induces chimera states. Intriguingly, a bifurcation analysis reveals that these chimera states are the natural link between the coherent and the incoherent states.
Andrea Lenschow - One of the best experts on this subject based on the ideXlab platform.
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energy policy coherence from an intra institutional perspective energy security and environmental policy coordination within the european commission
2015Co-Authors: Iulii Selianko, Andrea LenschowAbstract:Utilising the theoretical framework of discursive institutionalism, this article investigates the problem of policy Incoherence. We suggest focusing on the micro-level of policy-shaping processes through the lenses of discursive institutionalism as it is the most suitable approach to study the combination of institutional factors and actor-interaction. Empirically we focus on the field of energy policy, where despite the introduction of specific coordinative mechanisms, high levels of policy Incoherence prevail. We further zoom in at the preparatory stage of policy-making, where policy coherence can be assumed to be highest, in the intra-institutional politics in the Commission. In this setting we study the implications of intra-institutional coordinative discourse and ask under what conditions it affects policy coherence. In this quest, the process of energy policy-making inside the European Commission is further exemplified by a detailed case study about the Energy Efficiency Directive. Evidence suggests that even in an institutional context that is formally favourable to policy coordination, policy coherence may fail in highly politicized contexts and within an unproductive mode of coordinative discourse that undermines the moderation of sharply differing ideas between DGs.
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energy policy coherence from an intra institutional perspective energy security and environmental policy coordination within the european commission
European Integration online Papers (EIoP), 2015Co-Authors: Iulii Selianko, Andrea LenschowAbstract:Utilising the theoretical framework of discursive institutionalism, this article investigates the problem of policy Incoherence. We suggest focusing on the micro-level of policy-shaping processes through the lenses of discursive institutionalism as it is the most suitable approach to study the combination of institutional factors and actor-interaction. Empirically we focus on the field of energy policy, where despite the introduction of specific coordinative mechanisms, high levels of policy Incoherence prevail. We further zoom in at the preparatory stage of policy-making, where policy coherence can be assumed to be highest, in the intra-institutional politics in the Commission. In this setting we study the implications of intra- institutional coordinative discourse and ask under what conditions it affects policy coherence. In this quest, the process of energy policy-making inside the European Commission is further exemplified by a detailed case study about the Energy Efficiency Directive. Evidence suggests
Tony T Cai - One of the best experts on this subject based on the ideXlab platform.
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stable recovery of sparse signals and an oracle inequality
IEEE Transactions on Information Theory, 2010Co-Authors: Tony T Cai, Lie WangAbstract:This article considers sparse signal recovery in the presence of noise. A mutual Incoherence condition which was previously used for exact recovery in the noiseless case is shown to be sufficient for stable recovery in the noisy case. Furthermore, the condition is proved to be sharp. A specific counterexample is given. In addition, an oracle inequality is derived under the mutual Incoherence condition in the case of Gaussian noise.
