712 research outputs found

    Shipping Conferences: Their Future in the Face of Political and Technological Changes

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    Shipping conferences developed more than a century ago because a means was required to regulate the intense competition in the international shipping industry. This competition, which is natural, was intensified because of technological innovation, high capital investment, and overtonnage. This study is undertaken to show, through a discussion of the development of conferences, tools available for their use, and current political and technological environment in which they operate, that similar conditions still exist, and although the nature of the shipping industry has been experiencing major changes in technology and operations, the conference system still offers a viable forum for negotiating, compromising, and regulating in an important transportation industry

    Abundant stable gauge field hair for black holes in anti-de sitter space

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    We present new hairy black hole solutions of SU(N) Einstein-Yang-Mills (EYM) theory in asymptotically anti–de Sitter (AdS) space. These black holes are described by N+1 independent parameters and have N-1 independent gauge field degrees of freedom. Solutions in which all gauge field functions have no zeros exist for all N, and for a sufficiently large (and negative) cosmological constant. At least some of these solutions are shown to be stable under classical, linear, spherically symmetric perturbations. Therefore there is no upper bound on the amount of stable gauge field hair with which a black hole in AdS can be endowed

    Soliton and black hole solutions of su(N) Einstein-Yang-Mills theory in anti-de Sitter space

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    We present new soliton and hairy black hole solutions of su(N) Einstein-Yang-Mills theory in asymptotically anti-de Sitter space. These solutions are described by N+1 independent parameters, and have N-1 gauge field degrees of freedom. We examine the space of solutions in detail for su(3) and su(4) solitons and black holes. If the magnitude of the cosmological constant is sufficiently large, we find solutions where all the gauge field functions have no zeros. These solutions are of particular interest because we anticipate that at least some of them will be linearly stable.Comment: 15 pages, 20 figures, minor changes, accepted for publication in Physical Review

    Manifold Contrastive Learning with Variational Lie Group Operators

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    Self-supervised learning of deep neural networks has become a prevalent paradigm for learning representations that transfer to a variety of downstream tasks. Similar to proposed models of the ventral stream of biological vision, it is observed that these networks lead to a separation of category manifolds in the representations of the penultimate layer. Although this observation matches the manifold hypothesis of representation learning, current self-supervised approaches are limited in their ability to explicitly model this manifold. Indeed, current approaches often only apply augmentations from a pre-specified set of "positive pairs" during learning. In this work, we propose a contrastive learning approach that directly models the latent manifold using Lie group operators parameterized by coefficients with a sparsity-promoting prior. A variational distribution over these coefficients provides a generative model of the manifold, with samples which provide feature augmentations applicable both during contrastive training and downstream tasks. Additionally, learned coefficient distributions provide a quantification of which transformations are most likely at each point on the manifold while preserving identity. We demonstrate benefits in self-supervised benchmarks for image datasets, as well as a downstream semi-supervised task. In the former case, we demonstrate that the proposed methods can effectively apply manifold feature augmentations and improve learning both with and without a projection head. In the latter case, we demonstrate that feature augmentations sampled from learned Lie group operators can improve classification performance when using few labels

    Intuitive eating is associated with weight and glucose control during pregnancy and in the early postpartum period in women with gestational diabetes mellitus (GDM): A clinical cohort study.

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    High pre-pregnancy weight and body mass index (BMI) increase the risk of gestational diabetes mellitus (GDM) and diabetes after pregnancy. To tackle weight and metabolic health problems, there is a need to investigate novel lifestyle approaches. Outside of pregnancy, higher adherence to intuitive eating (IE) is associated with lower BMI and improved glycemic control. This study investigated the association between IE and metabolic health during pregnancy and in the early postpartum period among women with GDM. Two-hundred and fourteen consecutive women aged ≥18, diagnosed with GDM between 2015 and 2017 and completed the "Eating for Physical rather than Emotional Reasons (EPR)" and "Reliance on Hunger and Satiety cues (RHSC) subscales" of the French Intuitive Eating Scale-2 (IES-2) questionnaire at the first GDM clinic visit were included in this study. Participants' mean age was 33.32 ± 5.20 years. Their weight and BMI before pregnancy were 68.18 ± 14.83 kg and 25.30 ± 5.19 kg/m <sup>2</sup> respectively. After adjusting for confounding variables, the cross-sectional analyses showed that the two subscales of IES-2 at the first GDM visit were associated with lower weight and BMI before pregnancy, and lower weight at the first GDM visit (β = -0.181 to -0.215, all p ≤ 0.008). In addition, the EPR subscale was associated with HbA1c and fasting plasma glucose at the first GDM visit (β = -0.170 and to -0.196; all p ≤ 0.016). In the longitudinal analyses, both subscales of IES-2 at first GDM visit were associated with lower weight at the end of pregnancy, BMI and fasting plasma glucose at 6-8 weeks postpartum (β = -0.143 to -0.218, all p ≤ 0.040) after adjusting for confounders. Increase adherence to IE could represent a novel approach to weight and glucose control during and after pregnancy in women with GDM

    Scaling down an insect-size microrobot, HAMR-VI into HAMR-Jr

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    Here we present HAMR-Jr, a \SI{22.5}{\milli\meter}, \SI{320}{\milli\gram} quadrupedal microrobot. With eight independently actuated degrees of freedom, HAMR-Jr is, to our knowledge, the most mechanically dexterous legged robot at its scale and is capable of high-speed locomotion (\SI{13.91}{bodylengths~\second^{-1}}) at a variety of stride frequencies (\SI{1}{}-\SI{200}{\hertz}) using multiple gaits. We achieved this using a design and fabrication process that is flexible, allowing scaling with minimum changes to our workflow. We further characterized HAMR-Jr's open-loop locomotion and compared it with the larger scale HAMR-VI microrobot to demonstrate the effectiveness of scaling laws in predicting running performance.Comment: IEEE International Conference on Robotics and Automation 2020 (accepted

    Impairment in predictive processes during auditory mismatch negativity in ScZ: evidence from event-related fields

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    Patients with schizophrenia (ScZ) show pronounced dysfunctions in auditory perception but the underlying mechanisms as well as the localization of the deficit remain unclear. To examine these questions, the current study examined whether alterations in the neuromagnetic mismatch negativity (MMNm) in ScZ-patients could involve an impairment in sensory predictions in local sensory and higher auditory areas. Using a whole-head MEG-approach, we investigated the MMNm as well as P300m and N100m amplitudes during a hierarchical auditory novelty paradigm in 16 medicated ScZ-patients and 16 controls. In addition, responses to omitted sounds were investigated, allowing for a critical test of the predictive coding hypothesis. Source-localization was performed to identify the generators of the MMNm, omission responses as well as the P300m. Clinical symptoms were examined with the positive and negative syndrome scale. Event-related fields (ERFs) to standard sounds were intact in ScZ-patients. However, the ScZ-group showed a reduction in the amplitude of the MMNm during both local (within trials) and global (across trials) conditions as well as an absent P300m at the global level. Importantly, responses to sound omissions were reduced in ScZ-patients which overlapped both in latency and generators with the MMNm sources. Thus, our data suggest that auditory dysfunctions in ScZ involve impaired predictive processes that involve deficits in both automatic and conscious detection of auditory regularities

    Bibliography of environmental research: ecosystems department, 1952--1975

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    A bibliography of environmental research is presented which consists of items published between 1952 and mid-1975 by past and present staff members of the Ecosystems Dept., Battelle Pacific Northwest Laboratories. The material is arranged by alphabetical listing of author. Under each author, publications are listed chronologically by publication date in the categories of: journal articles, books, reports, and patents. No indexes are included. (LCL
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