Yoichiro Watanabe

Learn More
In December 2011 a long-range acoustic communication experiment was conducted in deep water, west of Izu-Ogasawara Islands, Japan. The experiment involved a stationary source (450-550 Hz) and an 18-element vertical array (102-m aperture), both deployed at around the sound channel axis. Initial analysis of data demonstrates that a data rate of 400 bits/s can(More)
Under-recognition of depression is common in many countries. Education of medical staff, focusing on their attitudes towards depression, may be necessary to change their behavior and enhance recognition of depression. Several studies have previously reported on attitudes toward depression among general physicians. However, little is known about attitudes of(More)
— The necessary and sufficient condition of the channel capacity is rigorously formulated for the N-user discrete memoryless multiple-access channel (MAC). The essence of the formulation is to invoke an elementary MAC where sizes of input alphabets are not greater than the size of output alphabet. The main objective is to demonstrate that the channel(More)
— Adaptive beamforming with Hamiltonian algorithm is proposed for ESPAR antenna. Hamilton's equations describing the motion of particles are used to solve optimization problems. In an application of Hamiltonian algorithm to ESPAR antenna, the cost function for beamforming is considered as the potential energy. Although the kinetic energy, acted by(More)
SUMMARY Coding scheme for a noisy multiple-access adder channel is proposed. When a T-user δ-decodable affine code C is given ÔÖÖÓÖÖ, a qT-user λδ-decodable affine code C * is produced by using a q × q matrix B satisfying BA = λI q×q , e.g., a Hadamard matrix or a conference matrix. In particular, the case of δ = 1 is considered for the practical purposes.(More)