• 대한기계학회논문집B
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• 제24권4호
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• pp.543-554
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• 2000

The engineering equations, which have been used in many engineering companies, were employed for the dynamic modelling part in order to develop the naturally circulated boiler simulator. The fuzzy algorithm, which is similar to the algorithm of making decision by the human being, was developed for the boiler simulator controller and its simulated variables were compared with those of classical PID simulations to verify the stability and the effectiveness of fuzzy controller. The simulator is for the naturally circulated boiler and the main components are the furnace, the drum, the super heater, and the economizer. The combustion and thermal radiation dominant equations were used within the furnace and the mass conservation and the energy rate balance equations were employed for the drum part. The heat transfer rates were calculated using the logarithmic mean temperature differences both for the super heater and for the economizer. The simulations are very useful to understand the boiler operations and the engineering design of the main components. The main program was developed under the PC window condition by linking the fuzzy controller to the main boiler program using the Visual C++ language. The various operational conditions such as the abrupt changes of load, the changes of water supply pipes and the diameter of drum were simulated.

• 지구물리와물리탐사
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• 제8권2호
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• pp.163-169
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• 2005

속도중합을 역산을 이용하면 탄성파 자료처리에서 있어서 다양한 처리가 가능하므로, 이 분야는 최근에 들어 매우 유용한 영역으로 주목을 받고 있다. 이러한 다양한 처리에 속도중합 역산을 응용하기 위해서는 사용하는 역산이 잡음에 강하면서도 고해상도의 속도중합 결과를 얻을 수 있어야 한다. 이러한 성질을 갖는 역산 방법들 중에서 가장 성공적인 방법 중의 하나라고 볼 수 있는 반복적 가중의 최소자승법(Iteratively Reweighted Least-Squares: IRLS)의 이론적 배경과 구현 방법을 소개하고, 기존 기술 특성과 한계성을 살펴보았다.

• 지질공학
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• 제17권2호
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• pp.271-277
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• 2007

천매암 및 편암으로 구성된 기지의 절개사면에서 제시된 이상대는 사면 하단부에 설정된 전류원과 상단부의 전위전극으로 하는 단극-쌍극자 배열을 이용한 전기비저항 토모그래피 방식으로 파악되었다. 해석 방법은 각 측선에서 얻어진 측정 자료를 가지고 3차원 전기비저항 역산 방법으로 하였다. 각 측선에 따른 영상들을 볼 때, 사면의 중앙부에 위치한 단층은 사면에 거의 수직인 방향으로 연장된 영상들로 제시되었다. 수치모델링 결과에서 이상대의 영상들은 절개사면에서 제시된 위치에 매우 정확한 결과들로 보여 주었으며, 단층은 절개사면으로부터 거리가 멀어질수록 지표로부터 그 심도가 깊어지는 경향으로 나타났다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.263-269
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• 2012

Condition-based maintenance (CBM) has been used as a useful concept for optimizing maintenance plan and decreasing maintenance cost in several kinds of plant sites. This study introduced an example that developed an integrated management system for maintenance parameters and hydraulic turbine of hydro-power plant in order to improve its maintenance system as applying CBM techinique. The integrated management system consists of three parts. One is a hardware part including PDA inspection system and several kind of precision measuring instruments. Another is a vibration monitoring system on hydraulic turbine. The other is a software part that takes charge of making hierarchy tree of maintenance parameters and their inspection route, managing accumulated database, assessing health condition of components, and supporting interface with other enterprise management system. The system has been installed at Chuncheon Hydro-power plant for test and demonstration. It is expected that the system can contribute database construction for diagnostics and prognostics on facility health condition and systematic accumulation of know-how on operation and maintenance of plant.

• 한국해양공학회지
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• 제23권1호
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• pp.81-88
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• 2009

An evaluation of the structural integrity of an oceanographic buoy subjected to extreme loads was carried out in this study. Load components, such as the current, waves, and wind load, which were required for the sea's environmental conditions, were calculated precisely. A non linear finite element analysis was conducted to elucidate the structural response of the buoy under extreme environmental conditions. Based on the surface drift velocity scheme, a dynamic impact analysis was also carried out for the case of collision accidents. The proposed numerical technique would be a useful and cost effective tool for design scheme evaluation in the field of oceanographic buoys.

• 한국게임학회 논문지
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• 제18권4호
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• pp.65-74
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• 2018

상용 게임 엔진이 개인에게 공개되면서, 게임 엔진을 범용 연구에 사용하려는 시도가 계속되고 있다. 본 연구는 의료 시뮬레이션 개발에 게임 엔진을 이용하려 한다. 구체적 방법으로, 인체의 주요한 부분을 사용자가 선택하면, 선택한 부분의 가시화 파라미터를 두드러지게 변경하는 초점 배경 가시화를 볼륨 데이터에 적용하려 한다. 그 과정에서 본 연구는 누적 기반 초점 배경 볼륨 가시화 방법을 제안하며, 배경 부분은 초점 부분과 자연스럽게 투명해져 융합된다. 또한 제안 방법은 기존 볼륨 가시화 방법과 잘 결합되기 때문에 절개와 같은 가상 수술 기능이 원활하게 수행된다. 충돌처리 및 사용자 입력 기능을 가진 게임 엔진은 범용 연구를 효율적으로 개발하는 데 도움이 된다.

• 대한기계학회논문집A
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• 제26권1호
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• pp.48-54
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• 2002

A part definition must not only provide shape information of a nominal part but also contain non-shape information such as tolerances, surface roughness and material specifications. Although machining features are useful for suitable shape information fur process reasoning in CAPP, they need to be integrated with tolerance information for effective process planning. We develop a tolerance modeler that efficiently integrates the machining features with the tolerance information fur feature-based CAPP. It is based on the association of machining features, tolerance features, and tolerances. The tolerance features in this study, where tolerances are assigned, are classified into two types; one type is a face that is a topological entity on a solid model and the other type is a functional geometry that is not referenced to topological entities. The (unctional geometry is represented by using machining features. All the data fur representing the tolerance information are stored completely and unambiguously in an independent tolerance data structure. The developed tolerance modeler is implemented as a module of a comprehensive feature-based CAPP system.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.23-28
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• 2014

This study investigates fluid flow and thermal stress at automotive exhaust manifolds as model 1 and 2. The maximum displacements happen at joint part connected with 4 pipes and upper middle of both parts in cases of model 1 and 2 respectively. At inner surface of the part connected with engine, maximum equivalent stresses of 991.85 and 698.96 MPa are shown in cases of model 1 and 2 respectively. As maximum velocities at the outlet at model 1 are shown at 19.46 and 14.61 m/s in cases of model 1 and 2 respectively, model 1 has more pressure drop than model 2. As result, model 2 has less pressure drop than 1. Model 2 has less deformation and stress than model 1. Model 2 has also less pressure drop than model 1. Therefore model 2 has more strength durability than model 1. This study result is applied with the design of safe automotive manifold and it can be useful to improve the durability by predicting prevention against the deformation due to exhaust gas.

• 패션비즈니스
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• 제17권6호
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• pp.141-157
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• 2013

In this study, we analyzed the figure type and lower-body size of Shanghai and Hong Kong adult women in their early twenties using the data obtained from 3D whole body scanners. We also provided concrete information related to women's lower bodies, in terms of crotch width, crotch length, inseam, outseam, slope of waist, etc., among women in Shanghai and Hong Kong. The result may be useful to the Chinese apparel industry when designing trouser pants for adult women. According to the results of the factor analysis for categorizing the body shape of the lower half, 5 factors were obtained: obesity of the lower half factor, height of the lower half factor, length from waist to the crotch factor, factor related to legs, and shape of the abdomen factor. After performing a cluster analysis according to the factor analysis, three clusters were set: Cluster 1 was represented as the lower half growth type, which has a high value in height of the lower half factor and grows in the abdomen part. Cluster 2 was represented as thin legs type, which has a low value in most part compared to the length of leg bones and factors about legs that have high value. Cluster 3 was represented as the obesity type having a high value in the obesity of the lower half factor. Overall, thin legs type achieved a high rate in Shanghai adult women and obesity type received a high rate in adult women living in Hong Kong.

• 한국의류학회지
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• 제43권6호
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• pp.930-940
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• 2019

This study analyzes the facial data required for sheet design in order to pursue the facial compatibility of disposable sheets used in facial mask products that are increasing in popularity as self-care methods. The subjects of the study were 23 facial measurements of 1,001 women in their 20s to 60s from Size Korea's 6th 3D data. Through factor analysis, sheet-related facial measurements were collected into six factors included in the vertical length of each part of the face: length of face surface from the ear to each part of the face, width of eyes, nose, lips, length of nose, vertical length of lower face, width of the head and width of chin. Three sheet face types were classified using six factor scores as variables, and the characteristics of each type differed according to age group. As a result of the discriminant analysis to identify the dimension items that classify the three cluster types, 12 contributing items were extracted out of 23 items. This study provides useful information and data for further studies of products requiring facial fitness.