229 research outputs found

    Antiferromagnetic ordering induced by paramagnetic depairing in unconventional superconductors

    Full text link
    Antiferromagnetic (AFM) (or spin-density wave) quantum critical fluctuation enhanced just below H_c2(0) have been often observed in d-wave superconductors with a strong Pauli paramagnetic depairing (PD) including CeCoIn_5. It is shown here that such a tendency of field-induced AFM ordering is a consequence of strong PD and should appear particularly in superconductors with a gap node along the AFM modulation. Two phenomena seen in CeCoIn_5, the anomalous vortex lattice form factor and the AFM order in the Fulde-Ferrell-Larkin-Ovchinnikov state, are explained based on this peculiar PD effect.Comment: 4 pages, 3 figures Title and text were changed. References are added. Resubmitted versio

    Equal-Spin Pairing State of Superfluid 3^3He in Aerogel

    Full text link
    The equal-spin pairing (ESP) state, the so-called A-like phase, of superfluid 3^3He in aerogels is studied theoretically in the Ginzburg-Landau (GL) region by examining thermodynamics, and the resulting equilibrium phase diagram is mapped out. We find that, among the ABM, planar, and robust pairing states, the ABM state with presumably quasi long-ranged superfluid order is the best candidate of the A-like phase with a strange lowering of the polycritical point (PCP) observed experimentally.Comment: 4 pages, 1 figure, one reference added, accepted for publication in Phys. Rev.

    Bayesian Nonparametric Learning of Cloth Models for Real-time State Estimation

    Get PDF
    Robotic solutions to clothing assistance can significantly improve quality of life for the elderly and disabled. Real-time estimation of the human-cloth relationship is crucial for efficient learning of motor skills for robotic clothing assistance. The major challenge involved is cloth-state estimation due to inherent nonrigidity and occlusion. In this study, we present a novel framework for real-time estimation of the cloth state using a low-cost depth sensor, making it suitable for a feasible social implementation. The framework relies on the hypothesis that clothing articles are constrained to a low-dimensional latent manifold during clothing tasks. We propose the use of manifold relevance determination (MRD) to learn an offline cloth model that can be used to perform informed cloth-state estimation in real time. The cloth model is trained using observations from a motion capture system and depth sensor. MRD provides a principled probabilistic framework for inferring the accurate motion-capture state when only the noisy depth sensor feature state is available in real time. The experimental results demonstrate that our framework is capable of learning consistent task-specific latent features using few data samples and has the ability to generalize to unseen environmental settings. We further present several factors that affect the predictive performance of the learned cloth-state model

    Complete Cross-triplet Loss in Label Space for Audio-visual Cross-modal Retrieval

    Full text link
    The heterogeneity gap problem is the main challenge in cross-modal retrieval. Because cross-modal data (e.g. audiovisual) have different distributions and representations that cannot be directly compared. To bridge the gap between audiovisual modalities, we learn a common subspace for them by utilizing the intrinsic correlation in the natural synchronization of audio-visual data with the aid of annotated labels. TNN-CCCA is the best audio-visual cross-modal retrieval (AV-CMR) model so far, but the model training is sensitive to hard negative samples when learning common subspace by applying triplet loss to predict the relative distance between inputs. In this paper, to reduce the interference of hard negative samples in representation learning, we propose a new AV-CMR model to optimize semantic features by directly predicting labels and then measuring the intrinsic correlation between audio-visual data using complete cross-triple loss. In particular, our model projects audio-visual features into label space by minimizing the distance between predicted label features after feature projection and ground label representations. Moreover, we adopt complete cross-triplet loss to optimize the predicted label features by leveraging the relationship between all possible similarity and dissimilarity semantic information across modalities. The extensive experimental results on two audio-visual double-checked datasets have shown an improvement of approximately 2.1% in terms of average MAP over the current state-of-the-art method TNN-CCCA for the AV-CMR task, which indicates the effectiveness of our proposed model.Comment: 9 pages, 5 figures, 3 tables, accepted by IEEE ISM 202

    ネット イケン カツヨウ ノ タメ ノ カイセキ オヨビ ブンルイ ギジュツ 二 カンスル ケンキュウ

    Full text link
    this is the author’s version of a work that was accepted for publication in Knowledge-Based Systems. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in PUBLICATION, [VOL51, ( October 2013)] DOI:10.1016/j.knosys.2013.06.02

    Fluctuation and Order of Antiferromagnetism induced by Paramagnetic Pair-Breaking in Superconducting Vortex Lattice

    Full text link
    Effects of the strong Pauli-paramagnetic pair-breaking (PPB) on the vortex lattice in d-wave superconductors are theoretically studied by putting emphasis on consequences of the PPB-induced antiferromagnetic (AFM) ordering in the spatial modulation in the vortex lattice. It is shown that the PPB-induced AFM fluctuation in the superconducting state leads to an enhancement of the vortex lattice form factor which is a measure of spatial variations of the internal magnetic field and that the enhancement becomes more remarkable as an AFM instability is approached. It is also demonstrated that the PPB-induced AFM ordering is assisted by the vortex-lattice modulation, and thus, that the resulting AFM order is spatially modulated, while it is not localized in the vortex cores but coexistent with the nonvanishing superconducting order parameter. These results are discussed in connection with two phenomena observed in CeCoIn5, the anomalous field dependence of the vortex lattice form factor and the AFM order appearing inside the high-field and low-temperature superconducting phase.Comment: 26 pages, 13 figure
    corecore