A depth averaged model of open channel flows with a horseshoe vortex

River engineeringNumerical modelling in river engineerin

Realization of three-dimensional walking of a cheetah-modeled bio-inspired quadruped robot

Adaptability of quadruped animals is not solely reached by brain control, but by the interaction between its body, environment, and control. Especially, morphology of the body is supposed to contribute largely to the adaptability. We have tried to understand quadrupedal locomotion by building a bio-inspired quadruped robot named ”Pneupard”, which has a feline-like muscular-skeletal structure. In our previous study, we successfully realized alternative gait of hindlimbs by reflex control based on the sole touch information, which is called an unloading rule, and that of forelimbs as well. In this paper, we finally connect forelimbs and hindlimbs by a rigid spine, and conduct 3D walking experiments only with the simple unloading rule. Through several preliminary experiments, we realize that the touch information on the sole is the most critical for stable 3D walking.This work was partially supported by Grant-in-Aid for Scientific Research on 23220004, 25540117 of Japan.This is the accepted manuscript. The final version is available at http://dx.doi.org/10.1109/ROBIO.2014.7090426

Quadrupedal locomotion based on a muscular activation pattern with stretch-reflex

Cyclical locomotion, such as walking, hopping and running, is known to be generated at the spinal cord, guiding human and animal strides over different gaits. Over the last years, many researchers concentrated their study on the origin of such signals, replicating them by either controlling joint angles or torques. In this work, we use a quadruped pneumatic robot to reproduce stable walking on a treadmill through a muscular activation pattern. Unlike previous studies, neither angles or torques are taken into consideration. Similarly to biological morphology, with variating moment arms, muscles contract rhythmically and their inherent compliance adapts to the floor. Proportional feedback upon touching the floor (stretch-reflex) is also tested, and its effects are explained. In the future, this methodology can be used to produce adaptive gait and improve current robotic by exploring interaction between control and soft bodies.This work was aided by KAKENHI Kiban(S) 23220004 and 25540117.This is the accepted manuscript. The final version is available at http://dx.doi.org/10.1109/ROBIO.2014.7090425

Analysis of the phenomenon of speculative trading in one of its basic manifestations: postage stamp bubbles

We document and analyze the empirical facts concerning one of the clearest evidence of speculation in financial trading as observed in the postage collection stamp market. We unravel some of the mechanisms of speculative behavior which emphasize the role of fancy and collective behavior. In our conclusion, we propose a classification of speculative markets based on two parameters, namely the amplitude of the price peak and a second parameter that measures its ``sharpness''. This study is offered to anchor modeling efforts to realistic market constraints and observations.Comment: 9 pages, 5 figures and 2 tables, in press in Int. J. Mod. Phys.

Anomalous phonon behavior in the high temperature shape memory alloy: TiPd:Cr

Ti50 Pd50-xCrx is a high temperature shape memory alloy with a martensitic transformation temperature strongly dependent on the Cr composition. Prior to the transformation a premartensitic phase is present with an incommensurate modulated cubic lattice with wave vector of q0=(0.22, 0.22, 0). The temperature dependence of the diffuse scattering in the cubic phase is measured as a function temperature for x=6.5, 8.5, and 10 at. %. The lattice dynamics has been studied and reveals anomalous temperature and q-dependence of the [110]-TA2 transverse phonon branch. The phonon linewidth is broad over the entire Brillouin zone and increases with decreasing temperature, contrary to the behavior expected for anharmonicity. No anomaly is observed at q0. The results are compared with first principles calculation of the phonon structure.Comment: 26 pages, 11 figure

Effects of monthly feedback of VFA measured by dual BIA method in Japanese patients with obesity: a randomized controlled study

Objective: To investigate the effects of monthly feedback of changes in visceral fat area (VFA) as measured by dual bioelectrical impedance analysis method and the importance of VFA in individuals with obesity. Methods: Thirty‐eight Japanese patients with obesity underwent VFA measurements. The feedback group was given feedback on VFA measurements each month for 4 months. The control group underwent VFA measurements at the beginning and end of the study but was not informed of the results. All the study participants completed eating behaviour and weight efficacy lifestyle questionnaires. Results: Mean age was 53.9 (14.3) years; mean body mass index was 30.6 (4.3) kg m⁻². At the 4‐month follow‐up, there was no significant difference in VFA reduction between the control and feedback groups (−4.4% vs. −3.0%; 95% CI, −3.8 to 5.5). In post‐hoc analysis using the overall group irrespective of allocation, changes of eating style were significantly associated with a reduction in VFA at 4 months (p = 0.034). Conclusions: Monthly feedback on changes in VFA does not reduce VFA. More frequent feedback may be required. In post‐hoc analysis, changes of eating style were associated with a reduction in VFA

A unified theory of the dynamics of closed-loop supply chains

We investigate the dynamics of a closed-loop supply chain with first-order auto-regressive (AR(1)) demand and return processes. We assume these two processes are cross-correlated. The remanufacturing process is subject to a random triage yield. Remanufactured products are considered as-goodas- new and used to partially satisfy market demand; newly manufactured products make up the remainder. We derive the optimal linear policy in our closed-loop supply chain setting to minimise the manufacturer’s inventory costs. We show that the lead-time paradox can emerge in many cases. In particular, the auto- and cross-correlation parameters and variances of the error terms in the demand and the returns, as well as the remanufacturing lead time, all influence the existence of the lead-time paradox. Finally, we propose managerial recommendations for manufacturers