226 research outputs found

    Effect of dust size and structure on scattered light images of protoplanetary discs

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    We study scattered light properties of protoplanetary discs at near-infrared wavelengths for various dust size and structure by performing radiative transfer simulations. We show that different dust structures might be probed by measuring disk polarisation fraction as long as the dust radius is larger than the wavelength. When the radius is larger than the wavelength, disc scattered light will be highly polarised for highly porous dust aggregates, whereas more compact dust structure tends to show low polarisation fraction. Next, roles of monomer radius and fractal dimension for scattered light colours are studied. We find that, outside the Rayleigh regime, as fractal dimension or monomer radius increases, colours of the effective albedo at near-infrared wavelengths vary from blue to red. Our results imply that discs showing grey or slightly blue colours and high polarisation fraction in near-infrared wavelengths might be explained by the presence of large porous aggregates containing sub-microns sized monomers.Comment: Accepted for publication in MNRAS, 18 pages, 19 figure

    Traffic Incident Database with Multiple Labels Including Various Perspective Environmental Information

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    A large dataset of annotated traffic accidents is necessary to improve the accuracy of traffic accident recognition using deep learning models. Conventional traffic accident datasets provide annotations on traffic accidents and other teacher labels, improving traffic accident recognition performance. However, the labels annotated in conventional datasets need to be more comprehensive to describe traffic accidents in detail. Therefore, we propose V-TIDB, a large-scale traffic accident recognition dataset annotated with various environmental information as multi-labels. Our proposed dataset aims to improve the performance of traffic accident recognition by annotating ten types of environmental information as teacher labels in addition to the presence or absence of traffic accidents. V-TIDB is constructed by collecting many videos from the Internet and annotating them with appropriate environmental information. In our experiments, we compare the performance of traffic accident recognition when only labels related to the presence or absence of traffic accidents are trained and when environmental information is added as a multi-label. In the second experiment, we compare the performance of the training with only contact level, which represents the severity of the traffic accident, and the performance with environmental information added as a multi-label. The results showed that 6 out of 10 environmental information labels improved the performance of recognizing the presence or absence of traffic accidents. In the experiment on the degree of recognition of traffic accidents, the performance of recognition of car wrecks and contacts was improved for all environmental information. These experiments show that V-TIDB can be used to learn traffic accident recognition models that take environmental information into account in detail and can be used for appropriate traffic accident analysis.Comment: Conference paper accepted to IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2023 Reason for revision: Corrected due to a missing space between sentences in the preview's abstract, which led to an unintended URL interpretatio

    Cardiovascular and Muscular Response to NO LOAD Exercise with Blood Flow Restriction

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    International Journal of Exercise Science 13(2): 1807-1818, 2020. Changes in muscle thickness (MT), isometric torque, and arterial occlusion pressure (AOP) were examined following four sets of twenty unilateral elbow flexion exercise. Participants performed four sets of maximal voluntary contractions with no external load throughout a full range of motion of a bicep curl with and without the application of blood flow restriction (BFR). For torque there was an interaction (p = 0.012). The BFR condition had lower torque following exercise (56.07 ± 17.78 Nm) compared to the control condition (58.67 ± 19.06 Nm). For MT, there was a main effect for time (p \u3c 0.001). MT increased from pre (3.52 ± .78cm) to post (3.68 ± 81cm) exercise and remained increased above baseline 15 min post-exercise. For AOP, there was an interaction (p = 0.027). The change in AOP was greater in the BFR condition (16.6 ± 13.42mmHg) compared to the control (11.1 ± 11.84 mmHg). NO LOAD exercise with BFR let to greater reductions in torque and an exaggerated cardiovascular response compared to exercise alone. There were no differences in swelling. These results suggest that the application of BFR to NO LOAD exercise may result in greater fatigue

    Mohawk promotes the maintenance and regeneration of the outer annulus fibrosus of intervertebral discs.

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    The main pathogenesis of intervertebral disc (IVD) herniation involves disruption of the annulus fibrosus (AF) caused by ageing or excessive mechanical stress and the resulting prolapse of the nucleus pulposus. Owing to the avascular nature of the IVD and lack of understanding the mechanisms that maintain the IVD, current therapies do not lead to tissue regeneration. Here we show that homeobox protein Mohawk (Mkx) is a key transcription factor that regulates AF development, maintenance and regeneration. Mkx is mainly expressed in the outer AF (OAF) of humans and mice. In Mkx(-/-) mice, the OAF displays a deficiency of multiple tendon/ligament-related genes, a smaller OAF collagen fibril diameter and a more rapid progression of IVD degeneration compared with the wild type. Mesenchymal stem cells overexpressing Mkx promote functional AF regeneration in a mouse AF defect model, with abundant collagen fibril formation. Our results indicate a therapeutic strategy for AF regeneration

    Reducer-integrated motor using simultaneous engagement of gear pairs with small and no differences in teeth number

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    The motors for industrial robots and transporting robots require high-precision positioning, large torque output, and downsizing. However, conventional motors have difficulties in downsizing or supporting large torque. In this research, we propose a novel reducer-integrated motor to solve the problems of existing motors. The proposed reducer-integrated motor has a differential gear mechanism using the simultaneous engagement of two kinds of external and internal gear pairs: one with a small difference in teeth number and the other with no difference in teeth number. Inside the reducer, linear actuators are installed. Two gear pairs with no difference in teeth number are fixed on the base and the gear pair with a small difference in teeth number is set between them. When the linear actuators revolve the external gear, the two kinds of the gear pairs engage simultaneously and the internal gear of the gear pair with a small difference in teeth number outputs the rotation. It is thought that the structure of the proposed motor can realize downsizing of the entire motor system, high load-supporting capacity, and high stiffness. In this paper, the structure and movement of the proposed motor are explained. The geometrical conditions for simultaneous engagement of the two gear pairs with small and no differences in teeth number are clarified. Through the discussion on the solution satisfying the conditions and the relation with the bending strength, a design method for the reducer of this motor is proposed. An experiment conducted on a prototype verifies that the proposed motor works as expected
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