Hideaki Okazaki

A transmitting and receiving method for CDMA communications over indoor electrical power lines

Transmitting and receiving methods for CDMA communications through 2-wire or 3-wire power line cord over indoor power lines are proposed. The key idea for transmitting method is to use a fundamental model of a coupling transformer-less transmitting circuit including the influence of the distribution transformer and to find out the combinations of model parameters giving the acceptable distortion of the transmitted waveforms for CDMA communications. The receiving method is to use a filtering method that separates arbitrary waveforms of transmitted data signal from the superposition waveforms of the sinusoidal high power signal and transmitted data signal without distorting arbitrary waveforms of transmitting signal at all. These methods are experimentally confirmed to be effective.

Chaotic and bifurcation behaviour in an autonomous flip-flop circuit using piecewise linear tunnel diodes

A circuit realization of an autonomous flip-flop circuit using piecewise linear tunnel diodes, producing chaotic and bifurcation behaviour, is proposed. The proposed circuit is made of four linear passive element (2 capacitors, 1 inductor, 1 resistor), one active element (1 DC battery) and two piecewise linear characteristic nonlinear resistors realized by using an operational amplifier. Typical global behaviour in the circuit is illustrated. By using an analysis of the one-dimensional Poincare map constructed from experimental data, chaotic behaviour is examined, and the Liapunov exponents are estimated. The experimental observations are compared with the digital computer simulations.

Brayton - Moser's equations of transmission line circuits and their complete stability

How to define an integral type mixed potential for a transmission line circuit with one-port elements at the line ends was exhibited to derive Brayton - Mosers equations of the transmission line circuits. Moreover complete stability (global asymptotic stability) conditions of the transmission line circuits were established by using the integral type mixed potential and Brayton - Mosers equations of them.

A one dimensional mapping method for time series data

The problem of constructing one dimensional map model based on time series data, especially the one dimensional map exactly reproducing the time series data is considered. A new method that employs a piecewise linear canonical representing function and implements the one dimensional map as MATLAB vectrized M-files, is proposed. The application of this method is illustrated by examples of time series data such as a Nikkei Stock Average, an exchange rate, and an EEG.

A piecewise polynomial canonical representing function and its application to image edge processing

The purpose of this paper is to present an explicit analytical representation for piecewise polynomial functions and to illustrate the application of this representation in cognitive processing in computer vision.

Simulink based model realization for CDMA communication over power lines

This paper discusses a Simulink based model realization for many-to-one and one-to-many access CDMA communication over power lines through a 2-wire power line cord with neutral line cord (2WN). In addition, a hardware prototype with TCP/IP data link layer (IEEE802.3) that can send and receive video images at a speed of 1 Mbps through 2WN is introduced.

Canards in a slow-fast continuous piecewise linear vector field

Canards are phenomena which occur in slow-fast systems when the parameter, /spl epsiv/, is appropriately small. An RLC circuit with a five-segment piecewise linear resistor, namely a two-dimensional five region continuous piecewise linear (CPWL) vector field, is considered. The paper discusses rigorously the canard in the four region CPWL vector field, in the case of /spl epsiv//spl rarr/0, and verification of the boundary canard without head and canard with head in the four region.

Rigorous Verification of Poincaré Map Generated by a Continuous Piece-Wise Linear Vector Field and Its Application

This paper provides algorithms in order to solve an interval implicit function of the Poincare map generated by a continuous piecewise linear (CPWL) vector field, with the use of interval arithmetic. The algorithms are implemented with the use of MATLAB and INTLAB. We present an application to verification of canards in two-dimensional CPWL vector field appearing in nonlinear piecewise linear circuits frequently, and confirm that the algorithms are effective.

A bivariate fractal interpolation surface with an individual vertical scaling factor

In this paper, a lemma, and two theorems for a bivariate fractal interpolation surface (BFIS) generated by an iterated function system (IFS) with an individual vertical scaling factor, are provided. Further, as a demonstration for the effect of the individual vertical scaling factor which characterizes the BFIS, the examples of higher resolution reconstructions from low resolution images are illustrated.

Modeling and simulation of motion of a quadcopter in a light wind

The complete dynamics for controlling a quad-copter are complex. Therefore, although simplified models of a quadcopter requiring a minimum number of states and inputs have been considered, unified methods to describe the dynamic state equations of quadcopters have yet to be established. This paper presents how system dynamics and system control equations for a quadcopter in a light wind were reliably derived using an Arnold-type operator together with moving and stationary inertia coordinate systems. The relationship between the Euler angles, the stationary inertia coordinate system and the moving coordinate system is clarified. The Lagrangian Method is also discussed and the simulation results are illustrated.