• 한국유변학회:학술대회논문집
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• 한국유변학회 2006년도 춘계 학술발표회 논문집
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• pp.143-147
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• 2006

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.111-112
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• 2008

In this study, an image processing algorithm with Lab VIEW IMAQ Module is presented and discussed for the development of a microscopic gap measuring system using CCD sensor. LabVIEW IMAQ development application that is developed by National Instrument Co. Inc. has a graphical interface and many image processing functions, so that it provides an easier environment for the development of a measurement algorithm using the image data. Actual microscopic gap measuring experiment was executed using the algorithm developed in this study and it showed a promising result. Also, we could obtain the convenience of Lab VIEW IMAQ in developing the algorithm.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.100-108
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• 2006

Time-resolved current and voltage measurements for an inductive automotive spark system were made. Also presented are measurements of the total energy delivered to the spark gap. The measurements were made in air for a range of pressures from 1-18atm, at ambient temperatures. The measured voltage and current characteristics were found to be a function of many ignition parameters; some of these include: spark gap distance, internal resistance of the spark plug and high tension wire, and pressure. The voltages presented were measured either at the top of the spark plug or at the spark gap. The measurements were made at different time resolutions to more accurately resolve the voltage and current behavior throughout the discharge process. This was necessary because the breakdown event occurs on a time scale much shorter than the arc and glow phases. The breakdown, are, and glow voltages were found to be functions of spark plug resistance, gas density, and spark plug gap as expected from the literature. Spark duration was found to decrease as either pressure or gap was increased. The transition from the arc to glow phase is usually distinguished by a sudden rise in the voltage across the gap. At pressures above about 7atm this transition was not observed suggesting that a glow phase was not present. Energy delivered to the gap increased with increasing pressure. The effective resistance of the spark gap during discharge was about twice as large for the glow phase as the arc phase.

• 한국강구조학회 논문집
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• 제19권4호
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• pp.345-355
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• 2007

장대레일은 동절기에 기온하강으로 인한 인장력을 발생하는데 중위온도 이하로 떨어져 파단이 발생되면 인장파단과 레일 간에 틈이 발생되며 이를 개구부라 한다. 이 개구부를 차륜이 통과하면 충격하중이 발생하며, 큰 손실이 발생할 수 있는 열차탈선이 발생할 수 있다. 본 연구에서는 동적해석을 위해 개구부를 가진 궤도와 차량의 상호작용을 고려한 동적해석모델을 제안하였다. 궤도와 차량의 선형시스템은 비선형 헤르찌안 접촉 스프링에 의해 연성되었으며 전체 궤도-차량 시스템 운동방정식을 정식화하였다. 그리고 개구부에서의 상호작용 현상을 고려하여 궤도 불균일부의 함수를 정의하고 개구부에서의 전후방 레일 사이의 개구량을 고려하였다. 비선형 방정식을 풀기위해 동적해석은 수정된 Newton-Raphson 방법에 근거한 Newmark - $\beta$ 방법에 의해 수행되었다. 그리고 차량속도, 개구량, 레일지지강성에 따른 매개변수를 조건으로 수치해석을 수행하였다.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2006년도 춘계 학술발표회 논문집
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• pp.119-122
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• 2006

• 대한토목학회논문집
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• 제28권6D호
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• pp.895-904
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• 2008

장대레일은 동절기에 중위온도 이하로 떨어져 레일의 인장파단에 의해 개구부가 발생할 수 있다. 레일 파단을 미리 감지 못하는 경우에 개구부에서 동적하중에 의해서 차륜과 레일의 파손이 발생할 수 있으며, 열차주행 안전성이 감소될 수 있다. 본 연구에서는 개구부에서의 궤도와 차량의 동적거동 분석을 위해 레일 파단시 개구부에서의 궤도와 차량의 상호작용을 고려한 동적해석모델을 제안하였다. 궤도와 차량의 선형시스템은 비선형 헤르찌안 접촉 스프링에 의해 연성되었으며 전체 궤도-차량 시스템 운동방정식을 정식화하였다. 그리고 개구부에서의 상호작용 현상을 고려하여 궤도 불균일부의 함수를 정의하고 개구부에서의 전후방 레일 사이의 개구량을 고려하였다. 비선형 방정식을 풀기위해 동적해석은 $Newmark-{\beta}$ 방법에 의해 수행되었다. 그리고 차량속도, 개구량, 레일지지강성에 따른 매개변수에 대한 궤도-차량의 동적상호작용해석을 수행하였고 변수에 대한 영향을 분석하였다.

• 대한기계학회논문집A
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• 제27권10호
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• pp.1800-1808
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• 2003

This work deals with the electrical conductivity of dielectric on output parameters such as metal removal rate and surface roughness value of a carbon steel(SM25C) and sintered carbides cut by wire-electrical discharge machining(W-EDM). Dielectric has several functions like insulation, ionization, cooling, the removal of waste metal particles. The presence of minute particles(gap debris) in spark gap contaminates and lowers the breakdown strength of dielectric. And it is considered that too much debris in spark gap is generally believed to be the cause of arcing. Experimental results show that increases of cobalt amount in carbides affects the metal removal rate and worsens the surface quality as a greater quantity of solidified metal deposits on the eroded surface. Lower electrical conductivity of the dielectric results in a lower metal removal rate because the gap between wire electrode and workpiece reduced. Especially, the surface characteristics of rough-cut workpiece and wire electrode were analyzed too. Debris were analyzed also through scanning electron microscopy(SEM) and surface roughness tester. Micro cracks and some of electrode material are found on the workpiece surface by energy dispersive spectrometer(EDS).

• 수산경영론집
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• 제39권3호
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• pp.25-47
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• 2008

The Fishing Communities (so-called Uchongae) in Korea was legally established in 1962. It has been gradually expanded by quantity, and we have total 1,969 communities in 2006. The major establishment purpose of Uchongae was put 2 functions. The first function is to make up the double industry structure in coastal region, and second function is to make economical condition for Uchongae. Nevertheless the Fishing Communities System in Korea was not successfully developed after first beginning. The Income gap have become heavily between fishing area and non - fishing area, including agricultural area. The income gap has been due to rapid industrialization and urbanization in Korea. And the income gap even have become heavily among Uchongaes. In this paper, It have been researched the degree of Income inequality among Uchongaes in Korea during 1986-2006. The income inequality degree was analyzed by Gini coefficient and Mean Log Deviation (MLD) using Lorenz Curve. According to analysis result, the Gini coefficient of Uchongaes in Korea has been about 2-times high from 0.0847 to 0.1770 during 20 years. And the MLD has been 5.4 times from 0.0125 to 0.0679 during same periods. This means to more wide the general Income Inequality among the Uchongaes in Korea. Especially, It means to more wide the gap of high ranking Uchongaes and low ranking Uchongaes that MLD index multiplier has been more high.

• 대한토목학회논문집
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• 제29권2D호
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• pp.199-207
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• 2009

본 연구에서는 운전자들이 현재 이용하는 교통정보 서비스 품질 차이 모형(GAP)과 구조방정식을 통한 분석을 통하여, 첨단교통정보시스템의 일환으로 도입을 추진 중인 UTIS 활성화에 대한 방향을 제시하고자 하였다. 본 연구의 결과를 정리하면 다음과 같다. 첫째. 교통정보 서비스의 항목별 서비스 품질 차이 모형 구축을 통하여, 현재 운전자들의 이용률을 높일 수 있는 서비스의 개선사항 및 우선순위를 파악할 수 있었다. 둘째. 교통정보 이용 만족도, 전체 교통정보 만족도를 관측변수로 사용하여 구조방정식 모형을 구축할 수 있었다. 교통정보의 전체 만족도는 교통정보 시스템의 확장성, 편리성, 정확성, 경제성 요인 순으로 영향을 미쳤으며, 각 요인별 서비스 기능의 우선순위를 파악하여, 향후 UTIS 서비스의 활성화를 위한 서비스 시행 순위를 결정할 수 있는 근거를 마련한 것도 본 연구의 성과라 할 수 있다. 셋째. 최근 사회적 경제적인 환경 변화로 인하여, 경제적인 요인보다 운행 중 여가 및 취미 생활을 즐길 수 있는 멀티미디어의 기능, 운행 보조적 기능, 운행 이외의 상황에서도 개인의 편리성을 위한 다양한 기능을 지속적으로 사용할 수 있도록 희망함을 객관적 수치로 확인할 수 있었다.

• Asia pacific journal of information systems
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• 제4권2호
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• pp.131-164
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• 1994

A contingency model of outsourcing is developed from the information systems (IS) literature and strategic management literature in order to assess the following question: What factors influence change in the extent to which an organization outsources IS functions? Based on the literature, this study identifies four IS factors-gaps in information quality, IS support quality, IS staff quality, and IS cost effectiveness-and three organizational factors-the gap in financial performance, strategic orientation, and the role of information technology in an organization-that influence the change in degree of outsourcing. These factors are hypothesized to influence the change in the extent of an organization's outsourcing of IS functions. From a mail survey of 188 top IS executives in U.S. companies, the results of analysis of covariance and bivariate correlational and multivariate regression analyses provide the following major findings: (a) This study found support for the proposed research model. (b) The change in the degree of IS outsourcing is determined by gaps in information quality, IS support quality, IS cost effectiveness, and financial performance and by the role of IT among IS and organizational factors.