University of Electro-Communications

About: University of Electro-Communications is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Laser & Robot. The organization has 8041 authors who have published 16950 publications receiving 235832 citations. The organization is also known as: UEC & Denki-Tsūshin Daigaku.

d x 2 − y 2 - versus d xy - like pairings in organic superconductors κ − ( BEDT − TTF ) 2 X

Abstract: Pairing symmetry in $\ensuremath{\kappa}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}X$ is reexamined by applying the fluctuation exchange method to the Hubbard model on the original four-band lattice. Our study is motivated by the discrepancy between recent thermal conductivity/tunneling spectroscopy experiments and the previous theories based on the effective single or two-band model. In contrast to the previous theories, we find that ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-like pairing dominates over ${d}_{\mathrm{xy}}$ in agreement with recent experiments. Our study provides a general lesson that even if the Fermi surface seems to be reproduced by an effective model, the pairing symmetry can be different from that of the original system.

Development of intelligent robot hand using proximity, contact and slip sensing

Abstract: To achieve the skillful task like the human, many researchers have been working on robot hand. An interaction with vision and tactile information are indispensable for realization of skillful tasks. In the existing research, the method using a camera to get the vision information is often found. But, in the boundary area of a non-contact phase and a contact phase, there are problem that lack of sensor information because the influence of occlusion comes up to surface. We devise to introduce the proximity sensor in this area. And we call the robot hand which is equipped with proximity, tactile and slip sensor “intelligent robot hand”. In this research, we show the constitution example of the intelligent robot hand and propose the method to realize Pick&Place as concrete task.

Concentration profile of endemic equilibrium of a reaction–diffusion–advection SIS epidemic model

Abstract: Cui and Lou (J Differ Equ 261:3305–3343, 2016) proposed a reaction–diffusion–advection SIS epidemic model in heterogeneous environments, and derived interesting results on the stability of the DFE (disease-free equilibrium) and the existence of EE (endemic equilibrium) under various conditions. In this paper, we are interested in the asymptotic profile of the EE (when it exists) in the three cases: (i) large advection; (ii) small diffusion of the susceptible population; (iii) small diffusion of the infected population. We prove that in case (i), the density of both the susceptible and infected populations concentrates only at the downstream behaving like a delta function; in case (ii), the density of the susceptible concentrates only at the downstream behaving like a delta function and the density of the infected vanishes on the entire habitat, and in case (iii), the density of the susceptible is positive while the density of the infected vanishes on the entire habitat. Our results show that in case (ii) and case (iii), the asymptotic profile is essentially different from that in the situation where no advection is present. As a consequence, we can conclude that the impact of advection on the spatial distribution of population densities is significant.

Development of Iodine Cells for the Subaru HDS and the Okayama HIDES: I. Instrumentation and Performance of the Spectrographs

Abstract: We have developed iodine (I2) cells for the High Dispersion Spectrograph (HDS) on the Subaru telescope and for the HIgh Dispersion Echelle Spectrograph (HIDES) on the Okayama 1.88m reflector. The cell is put into a compact vacuum vessel, which fits into a small space behind the entrance slit of the HDS. The cell assembly is designed to minimize heat losses from the cell, which is heated during observations, to keep I2 vapor from condensation. The amount of I2 in the cell is determined to be best suited for radial-velocity measurements of solar-type stars. We also report on some performances of the HDS and HIDES as well as their instrumental profiles based on tests of our I2 cells. Lastly, we discuss future improvements of our instruments and data-analysis softwares for I2 observations, and also describe the scientific goals of our project.

Kriging-Based Interference Power Constraint: Integrated Design of the Radio Environment Map and Transmission Power

Abstract: This paper proposes a probabilistic interference constraint method with a radio environment map (REM) for spatial spectrum sharing. The REM stores the spatial distribution of the average received signal power. We can optimize the accuracy of the measurement-based REM using the Kriging interpolation. Although several researchers have maintained a continuous interest in improving the accuracy of the REM, sufficient study has not been done to actually explore the interference constraint considering the estimation error. The proposed method uses ordinary Kriging interpolation for the spectrum cartography. According to the predicted distribution of the estimation error, the allowable interference power to the primary user is approximately formulated. Numerical results show that the proposed method can achieve the probabilistic interference constraint asymptotically. Additionally, we compare the performance of the proposed technique with three methods: the perfect estimation, the path loss-based method, and the Kriging-based method without the error prediction. The comparison results show that the proposed method has a higher spectrum sharing opportunity than the path loss-based method, even if only a small amount of measurement data is available. It is also shown that the proposed method dramatically improves the outage probability of the interference power compared to the conventional Kriging-based method.