Chiral corrections to the axial charges of the octet baryons from quenched QCD

We calculate one-loop correction to the axial charges of the octet baryons using quenched chiral perturbation theory, in order to understand chiral behavior of the axial charges in quenched approximation to quantum chromodynamics (QCD). In contrast to regular behavior of the full QCD chiral perturbation theory result, $c_0+c_{l2}m_\pi^2\,\ln{m_\pi^2}+\cdots$, we find that the quenched chiral perturbation theory result, $c_0^Q+(c_{l0}^Q+c_{l2}^Qm_\pi^2)\ln{m_\pi^2}+c_2^Q m_\pi^2+\cdots$, is singular in the chiral limit.Comment: standard LaTeX, 16 pages, 4 epsf figure

Abnormal Electromagnetic Noise of Motors depending on Fixing Methods of Permanent Magnets

Abnormal electromagnetic noise of traction motor in hybrid electric vehicle (HEV) occurred after the endurance test is experimentally investigated. Theoretical model explains that the abnormal components, which are ±1 orders of the number of slots, can be sourced from an unbalanced rotor. Experimental approach confirms that the abnormal noise is mainly from the rotor. Since there are no variations in the strength of the magnet flux, the vibration of the magnets is strongly believed as the main reason of the abnormal noise. Finally, the magnetic fixing method is changed from bond to mold, and the improvement of the noise is demonstrated

On-Line Detection and Segmentation of Sports Motions Using a Wearable Sensor

In sports motion analysis, observation is a prerequisite for understanding the quality of motions. This paper introduces a novel approach to detect and segment sports motions using a wearable sensor for supporting systematic observation. The main goal is, for convenient analysis, to automatically provide motion data, which are temporally classified according to the phase definition. For explicit segmentation, a motion model is defined as a sequence of sub-motions with boundary states. A sequence classifier based on deep neural networks is designed to detect sports motions from continuous sensor inputs. The evaluation on two types of motions (soccer kicking and two-handed ball throwing) verifies that the proposed method is successful for the accurate detection and segmentation of sports motions. By developing a sports motion analysis system using the motion model and the sequence classifier, we show that the proposed method is useful for observation of sports motions by automatically providing relevant motion data for analysis

Optical and Acoustic Sensor-Based 3D Ball Motion Estimation for Ball Sport Simulators †

Estimation of the motion of ball-shaped objects is essential for the operation of ball sport simulators. In this paper, we propose an estimation system for 3D ball motion, including speed and angle of projection, by using acoustic vector and infrared (IR) scanning sensors. Our system is comprised of three steps to estimate a ball motion: sound-based ball firing detection, sound source localization, and IR scanning for motion analysis. First, an impulsive sound classification based on the mel-frequency cepstrum and feed-forward neural network is introduced to detect the ball launch sound. An impulsive sound source localization using a 2D microelectromechanical system (MEMS) microphones and delay-and-sum beamforming is presented to estimate the firing position. The time and position of a ball in 3D space is determined from a high-speed infrared scanning method. Our experimental results demonstrate that the estimation of ball motion based on sound allows a wider activity area than similar camera-based methods. Thus, it can be practically applied to various simulations in sports such as soccer and baseball

Ferrite-Decorated Ultrathin and Lightweight Carbon Nanotube Film for Electromagnetic Interference Shielding

High-performance electromagnetic interference (EMI) shielding is urgently needed for next-generation electronic devices that are becoming more sensitive and minimized. The current EMI-shielding materials and metals have adaptation issues because of their high density and corrosion. Therefore, several alternatives have been investigated to overcome these obstacles. Although some of these materials satisfy commercial shielding efficiency (SE) requirements, their capability for commercial mass production is doubtful. In this work, a freestanding carbon nanotube (CNT) film is synthesized via direct spinning and decorated with ferrite nanoparticles (FCNTs) to achieve good magnetic permeability without using any binder. According to the overall research, the size of ferrite nanoparticles greatly impacts magnetic properties, and the FCNT composite exhibits a superparamagnetic property due to the nanosized ferrite particles. Therefore, FCNT shows good magnetic permeability and high electrical conductivity, two main factors affecting SE improvement. As a result, FCNT exhibits 10 times higher specific SE than a copper foil, even though it is nearly 2 times thinner. Also, the FCNT composite film with 25 μm thickness exhibits an SE of 91.4 dB, which exceeds the commercial SE threshold and the SE of copper foil of the same thickness. The results show that the FCNT composite film has great potential for utilization as an ultrathin freestanding EMI-shielding material

Protective effect of uridine on cornea in a rabbit dry eye model

PURPOSE: To investigate the effect of uridine on cultured human corneal epithelial cells and keratocytes in vitro and to evaluate whether the application of uridine-containing eye drops could improve ocular surface health in an in vivo dry eye model. METHODS: Uridine was added to cultured epithelial cells (3 x 10(4) cells/well) and keratocytes (1 x 10(4) cells/well) at various concentrations (0.5-50 microM). Cytotoxicity was tested with the use of MTT assay, and the cells were assessed for apoptosis with the use of flow cytometry. Expressions of hyaluronic acid (HA), glycosaminoglycan (GAG), nitric oxide (NO), and matrix metalloproteinase (MMP)-9 were measured. In vivo, the degree of reepithelialization was assessed after topical application of uridine (100 microM) in a rabbit corneal wound model. Changes in tear production and conjunctival goblet cell counts were investigated after instillation of various concentrations of uridine-containing eye drops in a rabbit dry eye model. RESULTS: In vitro, uridine showed no cellular toxicity. It increased the biosynthesis of HA and GAG and reduced MMP-9 levels in cultured corneal epithelial cells and keratocytes. In vivo, uridine enhanced corneal wound healing and significantly increased the number of conjunctival goblet cells in rabbits. CONCLUSIONS: Uridine can restore the health of the ocular surface in a rabbit corneal wound and dry eye model