Ritsumeikan UniversityShiga

College of Science and, Japan

Ritsumeikan UniversityShiga

College of Science and, Japan
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Kim J.,Kyoto University | Yamasue E.,Ritsumeikan UniversityShiga | Ichitsubo T.,Kyoto University | Okumura H.,Kyoto University | Ishihara K.N.,Kyoto University
Journal of Electroanalytical Chemistry | Year: 2017

Hexagonal boron nitride (h-BN) has been explored for lithium intercalation due to its similar crystal structure to graphite, a well-known anode material for Li-ion secondary batteries. Lithium h-BN intercalation compounds (Li-BNICs) have been successfully synthesized through heat treatment. In this study, potential physical properties related to electrical conductivity were investigated using pristine and milled h-BN, which is further mixed/combined with milled graphite. The electrochemical properties were characterized by cyclic voltammetry (CV) and galvanostatic cycling with potential limitation (GCPL). The chemical potential of h-BN was estimated about 1.0 V versus Li/Li+ and a two-phase reaction was suggested. Accordingly, Li-BNIC is more stable than Li-GICs (lithium graphite intercalation compounds) in terms of thermal stability. © 2017 Elsevier B.V.

Yamashita D.,Japan Institute of Sports SciencesTokyo | Fujii K.,Nagoya UniversityAichi | Fujii K.,Japan Society for the Promotion of Science | Yoshioka S.,University of Science and Arts of Iran | And 2 more authors.
Journal of Biomechanics | Year: 2017

Sideways movement at a wide variety of speeds is required in daily life and sports. The purpose of this study was to identify the characteristics of asymmetry in power output between lower limbs during sideways gait patterns. Seven healthy men performed steady-state sideways locomotion at various speeds. The mechanical external power of each limb was calculated and decomposed to the lateral and vertical components by the center of mass velocity and ground reaction force. We acquired data from 126 steps of sideways walking at 0.44–1.21 m/s, and from 41 steps of sideways galloping at 1.04–3.00 m/s. The results showed asymmetric power production between the limbs during sideways locomotion. During sideways walking, the trailing limb predominantly produced positive external power and the leading limb produced predominantly negative external power, and these amplitudes increased with step speed. In contrast, during sideways galloping, negative and subsequent positive power production was observed in both limbs. These differences in asymmetric interlimb role-sharing were mainly due to the vertical component. During sideways galloping, the trailing limb absorbs vertical power produced by the leading limb due to the longer flight time. This characteristic of vertical power production in the trailing limb may explain the presence of a double-support phase, which is not observed during forward running, even at high speeds. Our results will help to elucidate the asymmetric movements of the limbs in lateral directions at various speeds. © 2017 Elsevier Ltd

Tanizaki T.,Hiroshima University | Shimmura T.,Ritsumeikan UniversityShiga | Fujii N.,Kobe UniversityHyogo
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

In this paper, shift scheduling method to improve customer satisfaction (CS), employee satisfaction (ES) and management satisfaction (MS) in service workplace where employees and robots collaborated is proposed. In service industry, it is important to introduce the labor force created as a result of operations efficiency improvement to the other business that creates added value. For this purpose, in recent years, it has been researched to introduce robots to service workplace. In restaurant business, it is necessary to improve CS, ES and MS together, because of increasing customers’ repeat and improving profitability. Therefore we started to research mentioned at the beginning. Since there are a trade-off relationship among CS, ES and MS, it is required to make a balanced plan. Therefore shift scheduling problem is modeled as multi-objective optimization problem so as to improve CS, MS, ES and formulated as a set cover problem. Finally, relationship of CS, ES, MS and method to create shift schedule to improve them are discussed based on numerical experiments. © Springer International Publishing AG 2017.

Hoang H.,Ritsumeikan UniversityShiga | Hoang H.,ATR Neural Information Analysis Laboratories | Yamashita O.,ATR Neural Information Analysis Laboratories | Yamashita O.,Brain Functional Imaging Technologies Group | And 4 more authors.
Frontiers in Computational Neuroscience | Year: 2015

The inverse problem for estimating model parameters from brain spike data is an ill-posed problem because of a huge mismatch in the system complexity between the model and the brain as well as its non-stationary dynamics, and needs a stochastic approach that finds the most likely solution among many possible solutions. In the present study, we developed a segmental Bayesian method to estimate the two parameters of interest, the gap-junctional (gc) and inhibitory conductance (gi) from inferior olive spike data. Feature vectors were estimated for the spike data in a segment-wise fashion to compensate for the non-stationary firing dynamics. Hierarchical Bayesian estimation was conducted to estimate the gc and gi for every spike segment using a forward model constructed in the principal component analysis (PCA) space of the feature vectors, and to merge the segmental estimates into single estimates for every neuron. The segmental Bayesian estimation gave smaller fitting errors than the conventional Bayesian inference, which finds the estimates once across the entire spike data, or the minimum error method, which directly finds the closest match in the PCA space. The segmental Bayesian inference has the potential to overcome the problem of non-stationary dynamics and resolve the ill-posedness of the inverse problem because of the mismatch between the model and the brain under the constraints based, and it is a useful tool to evaluate parameters of interest for neuroscience from experimental spike train data. © 2015 Hoang, Yamashita, Tokuda, Sato, Kawato and Toyama.

Satoh Y.,University of TsukubaIbaraki | Sugawara Y.,Ritsumeikan UniversityShiga | Wada T.,Ritsumeikan UniversityShiga
Journal of High Energy Physics | Year: 2016

We study type II string vacua defined by torus compactifications accompanied by T-duality twists. We realize the string vacua, specifically, by means of the asymmetric orbifolding associated to the chiral reflections combined with a shift, which are interpreted asdescribing the compactification on ‘T-folds’. We discuss possible consistent actions of the chiral reflection on the Ramond-sector of the world-sheet fermions, and explicitly construct non-supersymmetric as well as supersymmetric vacua. Above all, we demonstrate a simple realization of non-supersymmetric vacua with vanishing cosmological constant at one loop. Our orbifold group is generated only by a single element, which results in simpler models than those with such property known previously. © The Authors.

Dau V.T.,Sumitomo Chemical | Dinh T.X.,Ritsumeikan UniversityShiga | Bui T.T.,Vietnam National University, Hanoi | Terebessy T.,Atrium Innovation Ltd.
Flow Measurement and Instrumentation | Year: 2016

In this paper, we present a study on a jet flow, assisted by low net charge ion wind from bipolar corona discharge setup. The ion wind is simultaneously generated from both positive and negative electrodes placed in parallel, adding momentum to the bulk flow directed alongside the electrodes and focused in the middle of interelectrode space. The electrodes are connected to a single battery-operated power source in a symmetrical arrangement, where the electrode creating charged ions of one polarity also serves as the reference electrode to establish the electric field required for ion creation by the opposite electrode, and vice versa. Multiphysics numerical simulation is carried out with programmable open source OpenFOAM, where the measured current-voltage is applied as a boundary condition to simulate the electrohydrodynamics flow. The jet flow inside the device is verified by hotwire anemometry using hotwires embedded within the device, with the measured values in good agreement with simulation. The corona discharge helped to focus the jet and increased the flow peak velocity from 1.41 m/s to 2.42 m/s with only 27.1 mW of consumed discharge power. The device is robust, ready-to-use and minimal in cost. In addition, as the oppositely charged corona flows are self-neutralized, the generated air flow remains neutral and therefore does not attach to a particular target, which expands the application range. These are important features, which can contribute to the development of multi-axis fluidic inertial sensors, fluidic amplifiers, micro blowers, gas mixing, coupling and analysis with space constraints and/or where neutralized discharge process is required, such as circulatory flow heat transfer or the formation of low charged aerosol for inhalation and charged particle deposition. © 2016 Elsevier Ltd

Imai T.,Kyoto University | Kurihara T.,Kyoto University | Esaki N.,Kyoto University | Mihara H.M.,Ritsumeikan UniversityShiga
Bioscience, Biotechnology and Biochemistry | Year: 2014

Selenite is a selenium source for selenoprotein biosynthesis in mammalian cells. Although previous studies have suggested the involvement of glutathione (GSH) and/or thioredoxin reductase in selenite metabolism, intracellular selenite metabolism remains largely unknown. Here, we report that GSH depletion did not affect the amount of selenoprotein in Hepa 1-6 cells, suggesting that GSH does not play a central role in the reduction of selenite in selenoprotein biosynthesis. On the other hand, we found that GSH is involved in the efflux of lowmolecular-weight selenium compounds from cells, presumably via the formation of selenodiglutathione. Moreover, selenite inhibited the efflux of a fluorescent bimane-GS conjugate that is mediated by ATPdependent multidrug-resistant proteins, implying the existence of an active transporter for selenodiglutathione. This is the first report demonstrating that GSH plays a role in selenium excretion from cells by forming a GSH-conjugate, which may contribute to the distribution, detoxification, and homeostasis of selenium in the body. © 2014 Japan Society for Bioscience, Biotechnology, and Agrochemistry.

Fujii R.,Ritsumeikan UniversityShiga | Tateyama T.,Ritsumeikan UniversityShiga | Kitrungrotsakul T.,Ritsumeikan UniversityShiga | Tanaka S.,Ritsumeikan UniversityShiga | Chen Y.-W.,Zhejiang University
Smart Innovation, Systems and Technologies | Year: 2016

The purpose of this study is to construct a system for surgical assistance by touchless interactions. In the clinical site, surgeons usually need to use some contacting devices to display or visualize medical images and check the anatomic information of the patient. However, after operating the visualization device, re-sterilization is necessary in order to maintain hygiene. Though some touchless surgery support systems using Kinect have been developed, their functions are not enough for surgical support. In this paper, we develop a new system, which can visualize 3D medical image by simple touchless single-handed interactions. © Springer International Publishing Switzerland 2016.

Dau V.T.,Sumitomo Chemical | Bui T.T.,Japan National Institute of Advanced Industrial Science and Technology | Dinh T.X.,Ritsumeikan UniversityShiga | Terebessy T.,Atrium Innovation Ltd.
Sensors and Actuators, A: Physical | Year: 2016

We present a pressure sensing unit based on a unique corona discharge setup using symmetrical electrode arrangement with simultaneous positive and negative corona generation. The device generates stable corona discharge and enables reliable air pressure measurement in the range of 80-105 kPa, tested with five prototypes. The current-voltage characteristics of bipolar discharge system is analyzed in general form and three governing parameters, namely electrode geometry, electrode distance and discharge current, are studied in relation with absolute pressure. The sensors are driven with constant discharge current as low as 1 μA. The measured sensitivity is in good agreement with theoretical prediction and the sensor stability has been confirmed with 20-h continuous test without sensitivity deterioration. The sensitivity does not depend on the tested temperature range and its variation between devices is small, approximately ±3.0%. The advantage of the proposed system compared with similar corona-based constructions is its stable operation at low current with low power consumption and minimum electrode deterioration, which provides a cost effective and reliable solution. & copy;2015 Elsevier B.V. All rights reserved.

Fujie S.,Ritsumeikan UniversityShiga | Hasegawa N.,Ritsumeikan UniversityShiga | Sato K.,Ritsumeikan UniversityShiga | Fujita S.,Ritsumeikan UniversityShiga | And 3 more authors.
American Journal of Physiology - Heart and Circulatory Physiology | Year: 2015

Aging-induced arterial stiffening is reduced by aerobic exercise training, and elevated production of nitric oxide (NO) participates in this effect. Adropin is a regulator of endothelial NO synthase and NO release, and circulating adropin level decreases with age. However, the effect of habitual aerobic exercise on circulating adropin levels in healthy middleaged and older adults remains unclear. We sought to determine whether serum adropin level is associated with exercise training-induced changes in arterial stiffness. First, in a cross-sectional study, we investigated the association between serum adropin level and both arterial stiffness and cardiorespiratory fitness in 80 healthy middle-aged and older subjects (65.6_0.9 yr). Second, in an intervention study, we examined the effects of 8-wk aerobic exercise training on serum adropin level and arterial stiffness in 40 healthy middle-aged and older subjects (67.3 ± 1.0 yr) divided into two groups: aerobic exercise training and sedentary controls. In the cross-sectional study, serum adropin level was negatively correlated with carotid _-stiffness (r = –0.437, P < 0.001) and positively correlated with plasma NOx level (r = 0.493, P < 0.001) and cardiorespiratory fitness (r = 0.457, P < 0.001). Serum adropin levels were elevated after the 8-wk aerobic exercise training intervention, and training-induced changes in serum adropin level were correlated with traininginduced changes in carotid β-stiffness (r = –0.399, P < 0.05) and plasma NOx level (r = 0.623, P < 0.001). Thus the increase in adropin may participate in the exercise-induced reduction of arterial stiffness. © 2015 the American Physiological Society.

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