• 한국레이저가공학회지
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• 제4권2호
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• pp.47-57
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• 2001

This study deals with the laser cutting of stencil for the PCB. The most important aim of this study is to determine optimal conditions which make good-qualify stencil in Nd:YAG laser cutting. We made an experiment according to various variables (power. type of mask. gas pressure, cutting speed, and pulse width) and analyzed the cutting characteristics (surface roughness, kerf width. dross) . Each variable has optimal value for good-qualify cut edge under fixed condition. And neural network after learning experimental data with a million time iteration could predict surface roughness of cut edge under arbitrary condition approximately.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.342-352
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• 2003

Idle NVH characteristics are one of the most important aspects among the vehicle performances. Vehicle developers are devoted to improve vehicle interior noise and steering wheel and seat vibrations. In order to improve the idle quality, noise and vibration transfer path should be carefully evaluated. Also, effects of various components related to the idle performance should be confirmed. A general procedure for improving the idle qualify is described in detail. The relationship among cylinder pressure characteristics, crankshaft rotational speed variation, and vehicle vibrations is also investigated. Influences of drive shaft, torque converter, air conditioning system, vehicle structure including engine mount system, and idle control parameters on the vehicle idle quality are studied. Weak points of typical vehicles on the idle qualify are identified. Some of improvement measures are proposed and verified.

• 한국음향학회지
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• 제25권3호
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• pp.129-136
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• 2006

소음에 대한 인간의 심리적 인지는 소음의 여러 가지 물리적 요인에 의하여 영향을 받는다. 그러나 현재의 환경소음 평가는 A 가중치 등가 소음 수준을 기준으로 평가되고 있으며 인간의 다양한 감성적 요인을 반영하지 못하고 있다. 따라서 본 연구에서는 환경소음 평가를 위하여 환경소음원 43개에 대하여 주관평가와 통계적 분석방법을 사용하여 인간의 감성에 영향을 주는 음질인자 (Sound quality factor)를 분석하였다. 분석방법은 먼저 다양한 환경소음원에 대한 음질물리량 (Sound quality metrics)을 분석하여 음원을 분류하였으며 분류된 음원의 주된 음질 물리량을 고찰하였다. 그리고 쌍대비교법 (Paired comparisons method)과 어의분별척도법 (Semantic differential method)을 사용하여 주관 평가를 실시하고 음질의 요인을 분석하였으며 물리량과의 관계를 규명하였다. 마지막으로 요인에 대한 물리량의 기여도를 분석함으로써 환경소음의 감성적 인지에 대한 기초 물리량을 설정하였다.

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2007년도 정기총회 및 학술논문발표회
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• pp.219-222
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• 2007

• 한국철도학회논문집
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• 제2권2호
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• pp.6-12
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• 1999

In this study, the most important suspension characteristics of railway vehicle, such as primary and secondary stiffness, are optimized to maximize ride qualify. Critical speed, secondary suspension stroke oil tangent track and derailment coefficient on the maximum curvature, are selected as the performance constraints. Piecewise linear curving model is used to evaluate derailment coefficient where it is assumed that wheel/rail contacts occurs at tread or at idealized flange. The combined design procedure is used to optimize above design variables at the same time.

• 한국컴퓨터정보학회논문지
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• 제1권1호
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• pp.65-82
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• 1996

소프트웨어의 개발과 관련하여 품질보증의 문제는 그 특성상 다른 제품의 품질문제와 달리 매우 복잡하다. 소프트웨어의 품질시스템 구축을 위해서는 객관적 개밭표준 혹을 지침의 활용과 사용자 요구사항과의 일치의 확인 등이 중요시 된다 또한 품질표준의 올바른 이해와 품질감사에 대비한 점검사항의 계속적인 활용이 요구 된다 ISO 9000 시리즈는 품질보증을 위한 국제적 표준으로서 탄생되었다. 이 가운데 ISO 9000-3은 소프트웨어 품질경영 및 보증 표준으로 소프트웨어의 설계. 개발，공급. 설치 및 유지보수를 위한 지침이다. 최근 개정된 ISO/CD 9000-3:1995는 일반 제품의 품질표준인 ISO 9001의 늘 속에서 내용상 많은 강화된 변경사항들을 담고 있다 본 연구에서는 새로이 개정된 ISO 9000-3을 ISO 9001과 비교하여 내용을 분석하였고. 품질감사의 중요 점검사항을 도출하여 향후 품질감사에 대비하고 활용할 수 있도록 하였다.

• 한국컴퓨터정보학회논문지
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• 제11권4호
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• pp.197-206
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• 2006

정지 영상 압축 표준인 JPEG2000의 가장 큰 특징 중의 하나는 관심영역(ROI) 코딩이다. JPEG2000은 다양한 ROI 기법과 ROI 파리미터를 제공하는데, 이것을 특정 응용 프로그램에 적용하기 위해서는 적절한 값을 선택해야 한다. 본 논문에서는 JPEG2000 성능에 영향을 미치는 ROI 코딩 기법과 ROI 파라미터가 ROI 품질과 전체 영상 품질에 어떤 영향을 미치는지를 평가한다. 평가에 사용된 ROI 기법은 Maxshift 방법과 Implicit 방법이며 평가된 파라미터는 타일 크기와 ROI 크기, 코드블록의 크기, DWT 분해 레벨의 수, ROI 중요도가 사용된다. 타일 크기가 크면 품질은 좋아지며, ROI가 크면 품질은 떨어지며, 코드블록은 Maxshit와 Implicit 모두에서 $32{\times}32$가 최고의 품질을 보이며, ROI 중요도가 커지면 품질은 떨어지고, 분해 레벨의 수가 증가할수록 품질은 떨어진다.

• 산업경영시스템학회지
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• 제14권24호
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• pp.133-139
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• 1991

If the specifications of product. in general. art determined too wide. the precision of product becomes diminished. Otherwise it costs dearly to keep the precision. Therefore, It is realistic to consider various factors in determining specification of qualify characteristics TAGUCH Idefines quality of an object as "Quality is the loss that a product causes to society after being shipped. other than any losses caused by its intrinsic function". Particularly, to improve the performances of product TAGUCHI focuses his attention on the product design and process design which enable the functional characteristics of product to he robust to noises. In this paper, by the TAGUCHI's loss function, the characteristics which affect the variation of a product performance are classified into the scrappable characteristics and the reworkable characteristics when the target values of functional characteristics have been determined. And we will determine the tolerance of each characteristic which minimize the quality cost by the cost function which considers the economic factors and probability features of each characteristic.cteristic.

• Journal of Advanced Marine Engineering and Technology
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• 제29권1호
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• pp.49-59
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• 2005

The evaporation heat transfer experiments are conducted with the shell and plate heat exchanger (S&PHE) without oil in the refrigerant loop using R-410A. An experimental refrigerant loop has been established to measure the evaporation heat transfer coefficient h. of R-410A in a vertical S&PHE. Two vertical counter flow channels were formed in the S&PHE by three plates haying a corrugated trapezoid shape of a $45^{\circ}C$ chevron angle. UP flow of the boiling R-410A in one channel receives heat from the hot down flow of water in the other channel The effects of the refrigerant mass flux. average heat flux. refrigerant saturation temperature and vapor qualify are explored in detail. Similar to the case of a plate heat exchanger. even at a very low Reynolds number, the flow in the S&PHE remains turbulent. The Present data shows that the evaporation heat transfer coefficients of R-410A increased with the vapor qualify. The results indicate a rise in the refrigerant mass flux caused an increase in the h.. Raising the imposed wall heat flux is found to slightly improve h., while h, is found to be lower at a higher refrigerant saturation temperature. Based on the present data. empirical correlation of the evaporation heat transfer coefficient is proposed.

• 지역사회간호학회지
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• 제17권3호
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• pp.364-375
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• 2006

Purpose: The purpose of the study was to investigate burden and the qualify of life in caregivers who are taking care of home-based rare and incurable disease patients. Methods: The subjects of this study were 300 caregivers of rare and incurable disease patients registered at five health centers in Seoul. A survey was conducted by mail and visit in person during the period from the 25th of March to the 12th of May 2005. Collected data were analyzed through t-test, ANOVA, Pearson's correlation coefficient. Result: The mean burden of caregivers was 3.42, and the mean qualify of life of caregivers was 2.71. Burden and QoL showed significant differences according to caregivers' characteristics such as sender, age, relation to the patient, academic qualification, religion, occupation, monthly household income and perceived health condition. Caregivers' burden was in an inverse correlation with their quality of life. Conclusions: According to the results of this study, rare and incurable disease caregivers' burden and their quality of life were in a significant correlation with each other. In order to improve caregivers' quality of life by reducing their burden, we need to reestablish comprehensive policies for rare and incurable disease management including nursing intervention strategies for caregivers.