• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1017_1018
• /
• 2009

LLC 하프브리지 공진형 컨버터는 일반적으로 게이트 구동드라이버, 구형파 발생부, 공진회로 및 정류회로로 구성되어 있다. 구형 파발생기는 두 개의 스위치 소자가 각각 50%의 주기와 약간의 데드타임을 가지고 반복하여 동작함으로써 구형파 전압을 발생하며, 공진회로에 구형파 전압이 인가되어도 높은 차수의 고주파 전류를 필터링하여 기본적으로 정현파 전류만 흐르도록 한다. 본 연구에서는 LLC 컨버터를 이용하여 LED를 구동을 하였고 시뮬레이션 결과를 실제 실험을 통해서 비교하였다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2005년도 추계학술발표회 요지
• /
• pp.130-131
• /
• 2005

• 한국대기환경학회지
• /
• 제18권2호
• /
• pp.85-94
• /
• 2002

In this study, a 3-dimensional numerical model, has been developed applied for the investigation of combustion characteristics, and used to optimize operating conditions in MSW incinerator, in Gwangju. The model developed in this study has been verified by exacting both the predicted and the measured temperature in combustion chamber which has been operated to provide a reference condition. By predictive results, the Sangmoo incinerator has a good characteristics of combustion and low emission however after burning zone produced incomplete products, also probably because the supply of primary air was not enough. Parametric screening studies have been conducted to study optimal operating conditions. For the optimal combustion characteristics, operating conditions should be adjusted with the waste properties.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 2008년도 추계학술대회 및 정기총회
• /
• pp.415-419
• /
• 2008

In this study, an empirical research based on survey has been performed to study the influence of user expectation to user satisfaction of commercial and open source DBMSs. According to the survey results, word-of-mouth and past experiences influence significantly to user expectation, and price influences to user expectation only for commercial DBMS users. The results show that the expectancy disconfirmation influences significantly to user satisfaction. Expectation and satisfaction levels of commercial DBMS users are higher significantly than those of open source DBMS users. However, expectancy disconfirmation of open source DBMS users is higher than that of commercial DBMS users.

• 한국기술사회:학술대회논문집
• /
• 한국기술사회 1995년도 제25회 한일기술사 합동 심포지엄 한국편 자료(2차)
• /
• pp.65-79
• /
• 1995

As the economy has picked up in recent years, so have the changes in the food industry. Due to trends in the family structure, two income households are becoming more common, including the in-crease of the female working population. Leisure activities and time continue to increase and to cause changes in the food industry which makes many kinds of food available to everyone, compared to previous times when people ate simply to live. This trend can be easily seen by considering the year to year increase of expenses for eating out. As life as become more and more complicated and full of variety, the trend towards a consumer oriented food industry has accelerated and is becoming a major element of Korean life. In the past, quantity of food was the most important aspect of the food preparation. Today, the dining experience includes social and cultural meanings which emphasizes customar oriented menus and services. In the restaurant business, successful management must consider the interests of both employees and custmers and must be run efficiently and probide good service.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
• /
• pp.760-763
• /
• 2002

Nanoparticle size of Titanium dioxide thin films was prepared by novel method. Particle size and surface structure of $TiO_2$ thin films were investigated by atomic force microscopy(AFM), scanning electron microscopy(SEM). All thin films process were prepared at room temperature. Particle size was reduced from 100 to 30nm with increasing amount of $Ti[OCH(CH_3)_2]_4$ observed by AFM images. All thin films were irradiated for 5 minutes by white light. Increasing the annealing temperature, particles size was increased. In the $TiO_2$(40%) thin films was annealed at $300^{\circ}C$ for 30minutes, the particle size was about 10nm.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
• /
• pp.756-759
• /
• 2002

Nanoparticles of titanium dioxide$(TiO_2)$ were prepared by photochemical synthesis. Surface structure, morphology and particle size of $TiO_2$ thin films were investigated by UV-VIS spectrophotometer, scanning electron microscopy(SEM) and transmission electron microscopy(TEM). All process was prepared at room temperature. The absorption peak of the films was showed at 360nm and $TiO_2$ nanopaticle size was observed at about 20~30nm. Electron diffraction ring patterns of $TiO_2$ nanoparticles and crystallographic spacing were observed by TEM. As a result, crystallographic spacing was about 3.6A in HR-TEM micrographs.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 2004년도 하계종합학술발표회논문초록집
• /
• pp.168-168
• /
• 2004

• 한국기계가공학회지
• /
• 제6권4호
• /
• pp.71-75
• /
• 2007

Geometrical error of ultra-precision machining due to spherical tool alignment error is analyzed. Deviation of spherical edge, ranged several ten micrometers, generates vertical and horizontal error of tool path and affects profile accuracy of machined surface. Simulation of machined error shows effect of tool alignment error and enables to estimate alignment error. This work provides technical insights into the minimizing of geometrical error of ultra-precision machining.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 춘계학술대회 논문집
• /
• pp.574-580
• /
• 1996

The objective of the research is to automate the process of making screen for textile printing. Conventional process give rise to the trouble of high cost, long development period, pollution and etc. The automatized system using laser would give the competitive power for the textile industry by reducing the production cost and period.