Waseda Research Institute for Science and Engineering

Science and, Japan

Waseda Research Institute for Science and Engineering

Science and, Japan
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Kasai R.,International University of Health and Welfare | Takeda S.,Waseda Research Institute for Science and Engineering
Journal of Physical Therapy Science | Year: 2016

[Purpose] The Hybrid Assistive Limb® (HAL®) robot suit is a powered exoskeleton that can assist a user’s lower limb movement. The purpose of this study was to assess the effectiveness of HAL® in stroke rehabilitation, focusing on the change of the sit-to-stand (STS) movement pattern and standing posture. [Subjects and Methods] Five stroke patients participated in this study. Single leg HAL® was attached to each subject’s paretic lower limb. The subjects performed STS three times both with and without HAL® use. A tri-axial accelerometer was used to assess the STS movement pattern. Forward-tilt angle (FTA) and the time required for STS were measured with and without HAL® use. Surface electromyography (EMG) of STS and standing were recorded to assess the vastus medialis muscle activities of the paretic limb. [Results] The average FTA without HAL® use was 35° and it improved to 43° with HAL® use. The time required for STS was longer for all subjects with HAL® use (without HAL® use: 3.42 s, with HAL® use: 5.11 s). The integrated EMGs of HAL®use compared to those without HAL®, were 83.6% and 66.3% for STS and standing, respectively. [Conclusion] HAL® may be effective in improving STS and standing patterns of stroke patients. © 2016 The Society of Physical Therapy Science.


Zhang Z.,Waseda University | Morishima S.,Waseda Research Institute for Science and Engineering
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

In this paper, we present a novel approach that utilizes the geometry shader to dynamically voxelize 3D models in real-time. In the geometry shader, the primitives are split by their Z-order, and then rendered to tiles which compose a single 2D texture. This method is completely based on graphic pipeline, rather than computational methods like CUDA/OpenCL implementation. So it can be easily integrated into a rendering or simulation system. Another advantage of our algorithm is that while doing voxelization, it can simultaneously record the additional mesh information like normal, material properties and even speed of vertex displacement. Our method achieves conservative voxelization by only two passes of rendering without any preprocessing and it fully runs on GPU. As a result, our algorithm is very useful for dynamic application. © 2014 Springer International Publishing.


Terada A.,Tokyo University of Agriculture and Technology | Terada A.,Waseda Research Institute for Science and Engineering | Okuyama K.,Tokyo University of Agriculture and Technology | Nishikawa M.,Tokyo University of Agriculture and Technology | And 2 more authors.
Biotechnology and Bioengineering | Year: 2012

Polyethylene (PE) sheets were modified by radiation-induced graft polymerization (RIGP) of an epoxy-group containing monomer glycidyl methacrylate (GMA). The epoxy group of GMA was opened by introducing sodium sulfite (SS) and diethylamine (DEA) as representatives of negatively and positively charged functional groups, respectively. These modified surfaces by RIGP, termed GMA, SS, and DEA sheets, were investigated to elucidate their effects on initial adhesion and subsequent biofilm formation of Escherichia coli. Initial adhesion test revealed that E. coli density and viability were governed by sheet surface electrostatic property: E. coli cell density on the DEA sheet was 23 times higher than that on the SS sheet after 8h incubation. The viability of E. coli cells dramatically decreased after contact with the DEA sheet, but remained high on the SS sheet. E. coli biofilm structure on the DEA sheet was dense, homogeneous, and uniform, with biomass higher than that of the GMA and SS sheets by factors of 14.0 and 37.5, respectively. On the contrary, biofilm structure on the SS sheet was sparse, heterogeneous, and mushroom-shaped. More than 40% of E. coli biofilm on the DEA sheet was retained under a high liquid shear force condition (5,000s -1), whereas 97% and 100% of biofilms on the GMA and SS sheets were sloughed, indicating that E. coli biofilm robustness depends on surface charge property of the substratum. This suggests that substratum surface fabrication by RIGP may enhance or suppress biofilm formation, a finding with potentially important practical implications. © 2012 Wiley Periodicals, Inc.


Hirai T.,Waseda University | Morishima S.,Waseda Research Institute for Science and Engineering | Morishima S.,Japan Science and Technology Agency
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

This paper describes a method for freely changing the length of a video clip, leaving its content almost unchanged, by removing video frames considering both audio and video transitions. In a video clip that contains many video frames, there are less important frames that only extend the length of the clip. Taking the continuity of audio and video frames into account, the method enables changing the length of a video clip by removing or inserting frames that do not significantly affect the content. Our method can be used to change the length of a clip without changing the playback speed. Subjective experimental results demonstrate the effectiveness of our method in preserving the clip content. © Springer International Publishing Switzerland 2016.


Kawai M.,Waseda University | Morishima S.,Waseda Research Institute for Science and Engineering
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

Facial image synthesis creates blurred facial images almost without high-frequency components, resulting in flat edges. Moreover, the synthesis process results in inconsistent facial images, such as the conditions where the white part of the eye is tinged with the color of the iris and the nasal cavity is tinged with the skin color. Therefore, we propose a method that can deblur an inconsistent synthesized facial image, including strong blurs created by common image morphing methods, and synthesize photographic quality facial images as clear as an image captured by a camera. Our system uses two original algorithms: patch color transfer and patch-optimized visio-lization. Patch color transfer can normalize facial luminance values with high precision, and patch-optimized visio-lization can synthesize a deblurred, photographic quality facial image. The advantages of our method are that it enables the reconstruction of the high-frequency components (concavo-convex) of human skin and removes strong blurs by employing only the input images used for original image morphing. © Springer International Publishing Switzerland 2015.


Nozawa M.,Waseda University | Maeda K.-I.,Waseda University | Maeda K.-I.,Waseda Research Institute for Science and Engineering
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

In recent series of papers, we found an arbitrary dimensional, time-evolving, and spatially inhomogeneous solution in Einstein-Maxwell-dilaton gravity with particular couplings. Similar to the supersymmetric case, the solution can be arbitrarily superposed in spite of nontrivial time-dependence, since the metric is specified by a set of harmonic functions. When each harmonic has a single point source at the center, the solution describes a spherically symmetric black hole with regular Killing horizons and the spacetime approaches asymptotically to the Friedmann-Lemaître-Robertson-Walker (FLRW) cosmology. We discuss in this paper that in 5 dimensions, this equilibrium condition traces back to the first-order "Killing spinor" equation in "fake supergravity" coupled to arbitrary U(1) gauge fields and scalars. We present a five-dimensional, asymptotically FLRW, rotating black-hole solution admitting a nontrivial "Killing spinor," which is a spinning generalization of our previous solution. We argue that the solution admits nondegenerate and rotating Killing horizons in contrast with the supersymmetric solutions. It is shown that the present pseudo-supersymmetric solution admits closed timelike curves around the central singularities. When only one harmonic is time-dependent, the solution oxidizes to 11 dimensions and realizes the dynamically intersecting M2/M2/M2-branes in a rotating Kasner universe. The Kaluza-Klein-type black holes are also discussed. © 2011 The American Physical Society.


Maeda K.-I.,Waseda University | Maeda K.-I.,Waseda Research Institute for Science and Engineering | Nozawa M.,Waseda University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We present a time-dependent and spatially inhomogeneous solution that interpolates the extremal Reissner-Nordström (RN) black hole and the Friedmann-Lemaître-Robertson-Walker (FLRW) universe with arbitrary power-law expansion. It is an exact solution of the D-dimensional Einstein-Maxwell-dilaton system, where two Abelian gauge fields couple to the dilaton with different coupling constants, and the dilaton field has a Liouville-type exponential potential. It is shown that the system satisfies the weak energy condition. The solution involves two harmonic functions on a (D-1)-dimensional Ricci-flat base space. In the case where the harmonics have a single-point source on the Euclidean space, we find that the spacetime describes a spherically symmetric charged black hole in the FLRW universe, which is characterized by three parameters: the steepness parameter of the dilaton potential nT, the U(1) charge Q, and the nonextremality τ. In contrast with the extremal RN solution, the spacetime admits a nondegenerate Killing horizon unless these parameters are finely tuned. The global spacetime structures are discussed in detail. © 2010 The American Physical Society.


Maeda K.-I.,Waseda University | Maeda K.-I.,Waseda Research Institute for Science and Engineering | Ohta N.,Kinki University | Tanabe M.,Waseda Research Institute for Science and Engineering | Wakebe R.,Waseda University
Journal of High Energy Physics | Year: 2010

We construct a general family of supersymmetric solutions in time- and spacedependent wave backgrounds in general supergravity theories describing single and intersecting p-branes embedded into time-dependent dilaton-gravity plane waves of an arbitrary (isotropic) profile, with the brane world-volume aligned parallel to the propagation direction of the wave. We discuss how many degrees of freedom we have in the solutions. We also propose that these solutions can be used to describe higher-dimensional time-dependent "black holes", and discuss their property briefly. © SISSA 2010.


Maeda K.-I.,Waseda University | Maeda K.-I.,Waseda Research Institute for Science and Engineering | Nozawa M.,Waseda University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We study physical properties and global structures of a time-dependent, spherically symmetric solution obtained via the dimensional reduction of intersecting M-branes. We find that the spacetime describes a maximally charged black hole which asymptotically tends to the Friedmann-Lemaître-Robertson- Walker universe filled by a stiff matter. The metric solves the field equations of the Einstein-Maxwell-dilaton system, in which four Abelian gauge fields couple to the dilation with different coupling constants. The spacetime satisfies the dominant energy condition and is characterized by two parameters, Q and τ, related to the Maxwell charge and the relative ratio of black-hole horizon radii, respectively. In spite of the nontrivial time dependence of the metric, it turns out that the black-hole event horizon is a Killing horizon. This unexpected symmetry may be ascribed to the fact that the 11-dimensional brane configurations are supersymmetric in the static limit. Finally, combining with laws of the trapping horizon, we discuss the thermodynamic properties of the black hole. It is shown that the horizon possesses a nonvanishing temperature, contrary to the extremal Reissner-Nordström solution. © 2010 The American Physical Society.


Fujisaki M.,Waseda University | Morishima S.,Waseda Research Institute for Science and Engineering
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In this paper, we propose a novel facial fattening and slimming deformation method in 2D images that preserves the individuality of the input face by estimating the skull structure from a frontal face image and prevents unnatural deformation (e.g. penetration into the skull). Our method is composed of skull estimation, optimizing fattening and slimming rules appropriate to the estimated skull, mesh deformation to generate fattening and slimming face, and generation background image adapted to the generated face contour. Finally, we verify our method by comparison with other rules, precision of skull estimation, subjective experiment, and execution time. © Springer International Publishing Switzerland 2015.

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