• 대한기계학회논문집A
• /
• 제20권11호
• /
• pp.3538-3548
• /
• 1996

In this study, as a part of basic study for developing the simulation program for the assemssment of reliability of electronic EMC packaging which covers from EMC mixing step to thermal analysis, comparison between a measured and predicted values of material properties of EMC and finitde element analysis of thermal stress are performed. For the experimental testing specimens of fifty, sixty hive and eighty percent filler($13\mu m$, spherical silica) weight fraction are fabricated using tranfer molding. Coefficient of thermal expansion, elastic modulus and thermla conductivity are measured using these specimens and then these measured values are compared with the predicted values by various equations ( such as dilute suspension method. self consistent method, generalized self consistent method, Hashin-Shtrikman's bounds. Shapery's bounds, Nielsen's method and others). Measured values are distributed within the upper and lower bounds of equations. Measured elastic modulus and coefficient of thermal expansion approaches closely the perdicted values with self consisten mehtod and upper bound of Shaperys equation respectively. However small differences of thermal conductivity between the different filler volume fraction are obserbed. FEM analysis indicates that firstly stress is concentrated at the corner section of EMC and secondly EMC with eighty percent filler weight fraction shows less thermal stress when package is cooling down and relatively high thermal stress when package is heating up.

• 암석학회지
• /
• 제2권2호
• /
• pp.130-138
• /
• 1993

주로 연대측정이 어려운 변성최적암류로 이루어진 선캠브리아의 경기육괴에 대해 정량적 연대측정 방법을 개발하기 위하여 대리암에 대한 연대측정법의 적용 가능성에 대해 연구하였다. 이 지역의 대리암은 대부분 규산염 광물을 함유하고 있으므로 염산을 사용한 선별용해 실험을 하였다. 미량원소 분석결과 Zr과 Rb은 거의 대부분 잔류물에 함유되어 있으며 U도 염산용해 부분보다는 잔류물에 많이 포함되어 있음을 알 수 있었다. 또한 Pb, Sr, Sm, Nd은 양쪽에 비슷하게 포함되며 Th은 다소 복잡한 양상을 보인다. 선별용해에 의한 Sr 동위원소 분석시에는 Sr 동위원소비가 높은 규산염 광물의 영향을 쉽게 영향을 받기 때문에 많은 주의와 연구가 요구된다. 탄산염 광물로만 구성된 순수한 대리암 시료를 골라 여러 조각으로 나눈 후 각각에 대해 분석된 Pb 동위원소비로부터 연대를 구하는 방법이 Sr 동위원소 분석에 의한 연대측정보다 성공 가능성이 높은 연대측정법으로 판단된다.

• Elastomers and Composites
• /
• 제47권3호
• /
• pp.188-193
• /
• 2012

고무부품의 신뢰성을 확보하기 위해서는 피로수명예측 및 평가기술 개발이 중요하다 하겠다. 최근에 고무부품에 대한 고 성능, 고 신뢰성을 위해 설계, 해석 및 평가기술이 요구되고 있으나, 지금까지는 경험과 시행착오적인 방법으로 개발되고 있는 실정이다. 따라서, 본 연구에서는 고무소재에 대해 배합조건, 기계적 특성, 열화 및 피로수명 등을 포함하는 고무소재 물성 데이터베이스를 구축하고, 고무부품의 특성해석 결과를 데이터베이스와 연계하여 고무부품의 피로해석 모델을 개발하였으며, 실제 피로시험 결과를 통하여 개발된 모델의 타당성을 검증하였다.

• 복식문화연구
• /
• 제31권2호
• /
• pp.228-247
• /
• 2023

In this study, an empirical analysis was conducted on the use of Korean design elements in the Hanbokwave project in 2022 in order to identify the expressed fashion characteristics and define Korean style. A case study was conducted on 98 items of clothing representing 10 Hanbok designer brands, and an analysis card was developed and used that classifies the silhouette of each item in detail. The analysis showed that in addition to the traditional skirt and Jeogori, the four stages of simulakr's image were prevalent in various fashion items such as shirts, blouses, jackets, crop tops, vests, dresses, and pants. In the composition of sleeves, many western clothing methods such as set-in-sleeve use and adjustment, hardcover buttons, and zippers were used to fuse the three-dimensional structure of western clothing and elements of traditional Hanbok to redefine it as postmodernism. It was recognized as a modern fashion, such as the trend of mixing and matching tops and bottoms, not a skirt and Jeogori set, by layering traditional clothes without hesitation or using them as a dress. As for the silhouette of the bottoms, the A-line showed a high frequency, and the prominent shape was identified as a traditional element widely used in modern Hanboks along with the element of wrinkles. This study is thought to be used as practical data for design development for the globalization of K-fashion in the future.

• 한국자동차공학회논문집
• /
• 제18권5호
• /
• pp.68-75
• /
• 2010

The one of the major problems in the development of PEMFC was regarding to the assurance of sealing on stack. The failure on the sealing creates the problems of fuel leakage, mixing, internal combustion, damage on parts and can be a direct reason for the degrading the efficiency of fuel cell. This paper studies on the analytical approach for improving the contacting pressure distribution on the gasket at the evaluation on the sealing of fuel cell stack. So, the assembly analysis on multi layered fuel cell stack was performed. The research on the simplification of finite element model was performed for three dimensional analysis at the multi layered state. The improved contact pressure distribution was obtained through the case studies on gasket for better sealing. In addition, the number of the cell was determined for the effective analysis and the structural characteristics were evaluated based on this research.

• 한국정밀공학회지
• /
• 제30권5호
• /
• pp.544-551
• /
• 2013

Recently high speed mixer, which is mixing, grinding, dispersion for liquid-liquid material, has been widely used several industries such as food, cosmetics, pharmaceuticals, fine chemicals, electronic material. This high speed mixer has a core element part called particle separation device. Particle separation device, which makes mixed liquid and liquid material using shear forces from a rotor and a stator, is a decisive factor in the distributed parts. In this study, we examined the velocity distribution of the two models of particle separation device using computation fluid dynamics, so that we were able to see the difference of the velocity distribution according to the shape. Also, by experiment, we observed that the use of rotor-screen type is deemed more suitable in case of accurately considering the effect of improving of the dispersibility through the circulation of the future.

• 한국실내디자인학회논문집
• /
• 제20권2호
• /
• pp.147-155
• /
• 2011

The purpose of this study is to grope for plan methods through analyzing preferences on expression methods of materials for visual differentiation in hosing space. The results are as follows : First, we could know that finish material is the important element to make differential design in housing space. It is a effective method to use the color and material of finish materials. Second, we could find they preferred woods in materials and Y color, N9.5, bright and light in colors through grasping preference about types in material elements. The preferred texture is soft and the preferred patterns are solid and geometry. Third, it is a good method to mix materials which give us different season feeling, and to mix colors which are different tones to lead the differential design by materials in housing space. In case texture and patterns, what we mix similar things is the effective method. Fourth, preference of the expression method is manifested differently depending on the selected elements. so when we plan the housing, we have to consider that. lastly, I think this study will be a basic data on a study to differentiate the design of the residential space.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
• /
• pp.853-858
• /
• 2001

The PSC bridge being built by ILM may have greater bending moment during its construction rather than after completion. When it occurs, Engineer should suggest to reduce stress-resultants than to make bigger cross-section with considering stability ,economics, and proper span-to-depth ratio. The used method is to install extruded nose at the end of girder. It substitutes the weighted segment for the light. From the reference, the stiffness of extruded nose, is 1/10 of the main girder, and the length is 60 to 70% of the length of the span, with little justification. In this study, the proper length and stiffness of the nose element is determined by the parametric study and idealizing procedure. The results about the extruded nose through the mixing of the parameter of its stiffness and length, the proper length of extruded nose is 80% of the longest span and the proper stiffenss is 13% of the bending stiffness of the superstructure and the proper length of extruded nose is 70% of the longest span and the proper stiffness is 9.5% of the bending stiffness of the superstructure.

• 한국멀티미디어학회논문지
• /
• 제12권6호
• /
• pp.856-866
• /
• 2009

Recent development in game technologies has offered various game environments, but the existing games have not provided realistically felt game environments because the element of the game is virtually generated in most of the games. Therefore, we propose a mixed game environment based on spatial augmented reality by using a creature that really exists. In the proposed game environment, tracking based on camera images created in real-time enables the provision of information about the real creature that is both still and moving. The game environment is presented with virtual object by using the coordinate of a real creature. Then, spatial augmented reality technology is applied for mixing a real creature and virtual game elements. Thus, the game scene is displayed by the spatial augmented reality technique based on the real-time coordinate of real creatures. Moreover, by providing the realistic game environment based on the spatial augmented reality, our system can be applied to various game contents that are actually felt as real. Most importantly, our system arouses the players' interest in a new kind of game environment.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2005년도 추계 학술대회논문집
• /
• pp.11-19
• /
• 2005

First, methods of numerical analysis of gas-particle flows is classified into micro, meso and macro scale approaches based on the concept of multi-scale mechanics. Next, the explanation moves on to discrete particle simulation where motion of individual particles is calculated numerically using the Newtonian equations of motion. The author focuses on the cases where particle-to-particle interaction has significant effects on the phenomena. Concerning the particle-to-particle interaction, two cases are considered: the one is collision-dominated flows and the other is the contact-dominated flows. To treat this interaction mathematically, techniques named DEM(Distinct Element Method) or DSMC (Direct Simulation Monte Carlo) have been developed DEM, which has been developed in the field of soil mechanics, is useful for the contact -dominated flows and DSMC method, developed in molecular gas flows, is for the collision-dominated flows. Combining DEM or DSMC with CFD (computer fluid dynamics), the discrete particle simulation becomes a more practical tool for industrial flows because not only the particle-particle interaction but particle-fluid interaction can be handled. As examples of simulations, various results are shown, such as hopper flows, particle segregation phenomena, particle mixing in a rotating drum, dense phase pneumatic conveying, spouted bed, dense phase fluidized bed, fast circulating fluidized bed and so on.