ANALYSIS OF SYNCHRONIZATION PHENOMENA IN PARALLELED BUCK CONVERTERS

This paper studies bifurcation phenomena in a paralleled system of two dc-dc buck converters. A simple current mode threshold switching rule is used for the paralleled connection and the system exhibits synchronization phenomena of periodic orbits. The synchronization phenomena are suitable for current sharing for ripple reduction and fault tolerance. As parameters vary, the synchronization phenomena are changed into various complicated phenomena including chaos. In order to simplify the analysis, we introduce simple piecewise linear model. Using the mapping procedure, we analyze bifurcation from synchronization phenomena to chaos. Presenting a simple test circuit, the typical phenomena are confirmed experimentally

WTAスイッチングを有する並列化昇圧コンバータの安定性解析

This paper studies stability analysis of paralleled boost converters with WTA switching. We analyze basic dynamics of paralleled boost converters coupled by N boost converters through witch N pieces of input voltage sources are applied to a load. We use Winner-Take-All(WTA) switching rule for switching of paralleled boost converters. So N converters are coupled. If some converter is broken, the other converters can preserve the operation. Simplifying the system into a piecewise linear model. Using piecewise linear model, we analyze stability of N phase synchronization and ripple characteristics exactly.Key Words : Boost converter, WTA switching, Stability, Rippl

STABILITY AND RIPPLE CHARACTERISTICS OF PARALLELED BOOST CONVERTERS

This paper studies basic dynamics of a coupled system of boost converters. The converters are coupled by current-threshold and Winner-Take-All(WTA) switching rules. This WTA switching rule can realize multi-phase synchronization automatically. The WTA switching rule is effective to reinforce the fault tolerance. It is suitable for current sharing and ripple reduction. Simplifying the system into a piecewise linear model, stability of the synchronization phenomena and fault tolerance can be analyzed precisely

Analysis of various steady states and transient phenomena in digital maps : foundation for theory construction and engineering applications

研究成果の概要 (和文) : デジタルマップ(Dmap)の解析と実装に関して以下のような成果を得た。まず、周期軌道の豊富さと安定性に関する特徴量を用いた解析法を考案し、典型例を解析し、現象の基本的な分類を行った。次に、簡素な進化計算によって所望のDmapを合成するアルゴリズムを考案した。アルゴリズムの個体はDmapに対応し、個体数は柔軟に変化する。典型的な例題によってアルゴリズムの妥当性を確認した。さらに、Dmapをデジタルスパイキングニューロン(DSN)によって実現する方法を構築した。DSNは2つのシフトレジスタと配線回路で構成され、様々なスパイク列を生成する。FPGAによる簡素な試作回路を構成し、動作を確認した。研究成果の概要 (英文) : We have studied analysis and implementation of digital maps (Dmaps). The major results are as the following. First, we have developed an analysis method based on two feature quantities. The first quantity characterizes plentifulness of periodic orbits and the second quantity characterizes stability of the periodic orbits. Applying the method, typical Dmap examples are analyzed and basic phenomena are classified. Second, we have developed a simple evolutionary algorithm to realize a desired Dmap. The algorithm uses individuals each of which corresponds to one Dmap and the number of individuals can vary flexibly. Using typical example problems, the algorithm efficiency is confirmed. Third, we have developed a realization method of Dmaps by means of digital spiking neurons (DSNs). The DSN consists of two shift registers connected by a wiring circuit and can generate various periodic spike-trains. Presenting a FPGA based simple test circuit, the DSN dynamics is confirmed

The drivers of Corporate Social Responsibility in the supply chain. A case study.

Purpose: The paper studies the way in which a SME integrates CSR into its corporate strategy, the practices it puts in place and how its CSR strategies reflect on its suppliers and customers relations. Methodology/Research limitations: A qualitative case study methodology is used. The use of a single case study limits the generalizing capacity of these findings. Findings: The entrepreneur’s ethical beliefs and value system play a fundamental role in shaping sustainable corporate strategy. Furthermore, the type of competitive strategy selected based on innovation, quality and responsibility clearly emerges both in terms of well defined management procedures and supply chain relations as a whole aimed at involving partners in the process of sustainable innovation. Originality/value: The paper presents a SME that has devised an original innovative business model. The study pivots on the issues of innovation and eco-sustainability in a context of drivers for CRS and business ethics. These values are considered fundamental at International level; the United Nations has declared 2011 the “International Year of Forestry”

The Music Sound

A guide for music: compositions, events, forms, genres, groups, history, industry, instruments, language, live music, musicians, songs, musicology, techniques, terminology , theory, music video. Music is a human activity which involves structured and audible sounds, which is used for artistic or aesthetic, entertainment, or ceremonial purposes. The traditional or classical European aspects of music often listed are those elements given primacy in European-influenced classical music: melody, harmony, rhythm, tone color/timbre, and form. A more comprehensive list is given by stating the aspects of sound: pitch, timbre, loudness, and duration. Common terms used to discuss particular pieces include melody, which is a succession of notes heard as some sort of unit; chord, which is a simultaneity of notes heard as some sort of unit; chord progression, which is a succession of chords (simultaneity succession); harmony, which is the relationship between two or more pitches; counterpoint, which is the simultaneity and organization of different melodies; and rhythm, which is the organization of the durational aspects of music