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.

A rate-distortion problem for a communication system with a secondary decoder to be hindered

Abstract: A rate-distortion problem is considered for a communication system (f, phi /sub 1/) with a secondary decoder phi /sub 2/ to be hindered which uses a different distortion measure from the primary system. The least achievable distortion of the secondary decoder is evaluated for the most secure primary system. Source coding for sources with additional outputs to be kept secret from the receiver or wiretappers is also discussed. Security is evaluated by distortion measures instead of the equivocation function used by H. Tamamoto (1983). >

Relativistic Electron Microbursts as High-Energy Tail of Pulsating Aurora Electrons

Abstract: In this study, by simulating the wave-particle interactions, we show that sub-relativistic/relativistic electron microbursts form the high-energy tail of pulsating aurora (PsA). Whistler-mode choru...

Characterization of Ce@C82 and its anion.

Abstract: Ce@C82 is isolated by high-performance liquid chromatography (HPLC) and the cage symmetry is determined as C2v by measuring the 13C NMR spectra of its anion. The 13C NMR peaks of [Ce@C82]- show temperature-dependent shifts ascribed to the f electron remaining on the Ce atom. Both Ce@C82 and [Ce@C82]- are silent in electron spin resonance spectroscopy (ESR) because of the highly anisotropic g matrix as well as of the fast relaxation process originating from the orbital angular momentum of the f electron. This is the complementary relationship to the observation of the paramagnetic shift in 13C NMR. [Ce@C82]- has lower stability in air than [La@C82]-.

DS-CUDA: A Middleware to Use Many GPUs in the Cloud Environment

Abstract: GPGPU (General-purpose computing on graphics processing units) has several difficulties when used in cloud environment, such as narrow bandwidth, higher cost, and lower security, compared with computation using only CPUs. Most high performance computing applications require huge communication between nodes, and do not fit a cloud environment, since network topology and its bandwidth are not fixed and they affect the performance of the application program. However, there are some applications for which little communication is needed, such as molecular dynamics (MD) simulation with the replica exchange method (REM). For such applications, we propose DS-CUDA (Distributed-shared compute unified device architecture), a middleware to use many GPUs in a cloud environment with lower cost and higher security. It virtualizes GPUs in a cloud such that they appear to be locally installed GPUs in a client machine. Its redundant mechanism ensures reliable calculation with consumer GPUs, which reduce the cost greatly. It also enhances the security level since no data except command and data for GPUs are stored in the cloud side. REM-MD simulation with 64 GPUs showed 58 and 36 times more speed than a locally-installed GPU via InfiniBand and the Internet, respectively.

Formation of Water Layers on Graphene Surfaces

Abstract: Although graphitic materials were thought to be hydrophobic, recent experimental results based on contact angle measurements show that the hydrophobicity of graphitic surfaces stems from airborne contamination of hydrocarbons This leads us to question whether a pristine graphitic surface is indeed hydrophobic To investigate the water wettability of graphitic surfaces, we use molecular dynamics simulations of water molecules on the surface of a single graphene layer at room temperature The results indicate that a water droplet spreads over the entire surface and that a double-layer structure of water molecules forms on the surface, which means that wetting of graphitic surfaces is possible, but only by two layers of water molecules No further water layers can cohere to the double-layer structure, but the formation of three-dimensional clusters of liquid water is confirmed The surface of the double-layer structure acts as a hydrophobic surface Such peculiar behavior of water molecules can be reasonabl