Kazuhiro Motegi

A Lockout Avoidance Algorithm without Using Time-Stamps for the k-Exclusion Problem

We propose a lockout avoidance algorithm for the k-exclusion problem on the asynchronous multi-writer/reader shared memory model. This algorithm is the extension of an accelerated version of the n-process algorithm to the k-exclusion problem. The running time by the algorithm for the trying region of any faultless process is bounded by (n - k)c + O(n(n - k)2)l if the number of stopping process failures is less than k, where n is the number of processes, l is an upper bound on the time between two successive atomic steps for any faultless process, and c is an upper bound on the time that any user spends in the criticalregion.

On-line measurement system for internal resistance in lead acid battery

An on-line measurement system for internal resistance of battery is developed as an IoT (Internet of Things) device in order to evaluate the effect of pulse generation which is expected to prolong the life of lead acid battery. This system consists of a pulse control sub-system and a monitoring and recording sub-system. The pulse control sub-system generates a controlling pulse with its specified width and cycle. The monitoring and recording sub-system has an SD card drive recording the measurement data for the backup as well as an Ethernet interface transmitting them when measured. The proposed on-line measurement system is implemented by the combination of one-board microcomputer and some peripheral circuits. In the experiments, the internal resistances and the voltages of the battery, temperature and humidity of the air and measured-times are actually measured once every hour for three weeks. The measurement data are successfully recorded in the SD card and are transmitted to the server at the same time. Moreover, the operating status can be checked at any time by way of web browser.

Fast and Dependable Communication in Hyper-rings

A graph G = (V,E) is called a hyper-ring with N nodes (N-HR for short) if V = {0, ...,N - 1} and E = {{u, v}|v - u modulo N is a power of 2}. The following results are shown. We prove that the node-connectivity ? of an N-HR is equal to its degree, say ?, by presenting an algorithm for the explicit construction of ? node-disjoint paths connecting nodes s and t. The length of these paths is bounded by ?logD? + 3, where D is the positional distance between s and t. Finally, we show a node-to-node communication scheme for HRs that requires only ?logD? + 3 rounds, even in the presence of up to ?-1 node failures.

Secret Key Exchange Using Random Deals of Cards on Hierarchical Structures

We propose the problem of how to transmit an information-theoretically secure bit using random deals of cards among players in hierarchical groups and a computationally unlimited eavesdropper. A player in the highest group wants to send players in lower groups a secret bit which is secure from the eavesdropper and some other players. We formalize this problem and design protocols for constructing secret key exchange spanning trees on hierarchical groups. For each protocol we give sufficient conditions to successfully construct a secret key exchange spanning tree for the hand sizes of the players and the eavesdropper.

Pressure transfer function for aorta model in cardiovascular simulator: Feasibility study of wearable central blood-pressure gauge

A noninvasive estimation of central blood-pressure is required by the researchers or the medical practitioners in the cardiovascular field. Up to now, a simulation based approach has been pursued by many researchers and the practical results are obtained. As the progresses in the electrical engineering, the possibility that a wearable central blood-pressure gauge can be realized is increased. This study shows that the aorta model in the cardiovascular simulator can be equivalently transformed to the pressure transfer function and gives the feasibility of wearable central blood-pressure gauge.

Simulation based defect estimation of metal pole by analyzing hammering sounds

This paper proposes a new measurement metric for estimating the defects in a metal pole by analyzing its hammering sounds. The validity of this measurement metric is supported by the simulation which is based on the Stress Harmonic Analysis. Moreover, the simulator is constructed by applying Model Based Approach and this makes it possible to extend the simulator to be applicable to some variations of metal poles. The configuration of the defect estimation system, the proposed measurement metric and the details of Stress Harmonic Analysis are described. As a result, the possibility of applying the proposed new measurement metric is increased in the actual defect estimation of metal poles.

A hybrid particle swarm optimization for component placement in 3D IC design

This paper deals with a component placement algorithm for 3D IC design. The Particle Swarm Optimization (PSO) is a general purpose stochastic algorithm mimicking the behaviors of particles self-organizing a system. The size of solution space is very large in the 3D component placement problem and it is afraid that the objective function value will be degraded. The Clustering Algorithm (CA) is an efficient initial placement algorithm and this algorithm is used for partitioning the placement problem into clusters with the total pseudo wire-length minimization. PSO is applied to each of the clusters for determining the detailed placement of components with the acceleration as well as the objective function optimization. This hybrid PSO (CA-PSO) is experimentally evaluated against a component placement problem of actual printed wiring board consisting of 217 components and 462 nets and the results show its feasibility.