• 한국정밀공학회지
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• 제21권6호
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• pp.52-59
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• 2004

Recently the high speed end-milling processing is demanded the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. The working factors of high speed end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to analyze the working factors to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on distance of cut, feed rate, revolution of spindle and depth of cut. By design of experiment, it is effectively represented shape characteristics of surface roughness in high speed end-milling. And determination($R^2$) coefficient of regression equation had a satisfactory reliability of 76.3% and regression equation of surface roughness is made by regression analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.247-250
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• 2005

Underwater acoustic transducers are widely used for SONAR application, whose important design parameters are shapes, materials, dimensions and supporting structures. Practical design method of transducers consists of manufacturing, experiments and modifications so that It requires much time and expenses. In this study, an analytical method was developed for the Tonpilz type transducers using the commercial finite element analysis code ATILA which can solve the electro-mechanical coupling Problems. A finite element model was established including the transducer elements such as ceramic stack, head mass, tall mass, tensile bolt, and molding layers. The proposed model was verified and modified by comparing the in-air and in-water test results of prototypes. The developed analysis method will be effectively used for the sensitivity analysis of design parameters in transducer design process.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2001년도 추계산학기술 심포지엄 및 학술대회 발표논문집
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• pp.144-146
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• 2001

본 연구는 사출성형공정상에서 발생할 수 있는 문제점을 설계시에 미리 예측하여 좋은 설계를 얻기 위한 시도이다. 사출성형 관련 설계는 사출금형설계전문가의 축적된 지식과 경험을 활용하여 수행되어 왔으며, 설계에 필요한 설계자의 경험이 전무한 경우 많은 시행오치를 유발하고 있는 실정이다. 본 연구에서는 백라이트 패널을 설계함에 있어 설계초기에 성형시 발생할 수 있는 성형성, 기계적 강도 등의 문제를 수치해석을 통하여 시뮬레이션 함으로써 시행오차를 최소화하고 성형성을 고려한 설계를 구현하고자 시도하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.916-921
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• 2004

The penalty method has been widely applied to analyses of incompressible fluid flow. However, we have not yet found any prior studies that employed penalty method to analyze compressible fluid flow. In this study, with an eye on the apparent similarity between the slight compressible formulation and the penalty formulation, we have proposed a new approximate approach that can analyze compressible packing process using the penalty parameter l. Based on the assumption of the isothermal flow, a set of reference solutions was obtained to verify the validity of the proposed scheme. Furthermore, we have applied the proposed scheme to the analysis of the packing process of different cases.

• 한국가구학회지
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• 제22권1호
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• pp.34-41
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• 2011

Surrealism is 20th century avant-garde art movement that gave the greatest impact. Surrealism art as Visual us consciousness that exists or is worth checking out. 1920 around the concept of the surreal appears on the Visual language is fine art molding, including design, fashion, advertising, etc, all of the art field. In addition, their artistic concept is limited to pure art without the commercialization and product as the transition you want to find a way to be. As a result, the concept of the surreal fine art as well as the design sector in particular, furniture design, but many more impact art trends. Therefore, this study examines the concept of the surrealism, appeared in the furniture design based on surrealism representation of research aims. And how these representations are modern furniture design in any affected for research. Representation and features about the analysis is largely four separated by the survey, and classified representation of research and analysis features.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.281-285
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• 2001

The design of injection molded polymeric parts has been done empirically, since it requires profound knowledge about the moldability and causal effects on the properties of the part, which are not available to designers through current CAD systems. An interactive computer-based design system is developed in order to realize the concept of rational design for the productivity and quality of mold making. The knowledge-based CAD system is constructed by adding the knowledge-base module for mold feature synthesis and appropriate CAE programs for mold design analysis in order to provide designers, at the initial design stage, with comprehensive process knowledge for feature synthesis performance analysis and feature-based geometric modeling. A knowledge-based CAD system is a new tool which enables the concurrent design with integrated and balanced design decisions at the initial design stage of injection molding.

• Nuclear Engineering and Technology
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• 제38권5호
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• pp.423-426
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• 2006

A developed neutron activation analysis(NAA) and gamma-spectrometry were applied to improve the analytical sensitivity and precision of impurities in electronic-circuit raw materials. It is well known that soft errors in high precision electronic circuits can be induced by alpha particles emitted from naturally occurring radioactive impurities such as U and Th. As electronic circuits have recently become smaller in dimension and higher in density, these alpha-particle emitting radioactive impurities must be strictly controlled. Therefore, new NAA methods have been established using a HTS(Hydraulic Transfer System) irradiation facility and a background reduction method. For eliminating or stabilizing fluctuated background caused by Rn-222 and its progeny nuclides in air, a nitrogen purging system is used. Using the developed NAA and gamma-spectrometry, ultra trace amounts of U(0.1ng/g) and Th(0.01ng/g) in an alumina ball and high purity silica used for an epoxy molding compound (EMC) could be determined.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.933-937
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• 1995

The design of injection molded prlymeric parts has been done empirically, since it requires profound knowledge about the moldability and causal effects on the properties of the parts. This study shows CAE approach for the design of the seat frame of fiber-reinforced composite material in order to realize the concept os rationsl design for the productivity and quality of mold making. The knowledge-based CAE system is constructed by adding the knowledge-basw module for the design evaluation and appropriate CAE programs for mold design analysis in order to provied designers, at the initial design stage, with comprehensive process knowledge for the performance analysis and the design evaluation. A knowledge-based CAE system is a new tool which enables the concurrent design with integrated and balanced design decisions at the initial design stage of injection molding.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
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• pp.43-46
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• 2001

The DC dielectric breakdown of epoxy composites used for transformer was experimented and then its data were simulated by Weibull distribution equation in this study. The more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical, and the breakdown strength of specimens with filler was lower than it of non-filler specimens because it was believed that the adding filler formed interface, charges were accumulated in it, the molecular mobility was raised, the electric field was concentrated, electrons were accelerated and then electron avalanche was early accomplished. From the analysis of Wei bull distribution equation, it was confirmed that as the allowed breakdown probability was· given by 0.1[%], the value of 'applied field was needed to be under 17.20[kV/mm].

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.28-33
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• 2001

Screw conveyors are used extensively in industrial for conveying and elevating materials. Despite their apparent simplicity, the mechanics of the conveying action is very complex. so many engineers depend on experiential data. Capacities of screw are pumping, steady flow of polymer melts, steady volumetric throughput etc. they are affected by geometry of screw, heat flux, pressure on inside barrel, rotating velocity, friction coefficient at screw surface etc. by computation volumetric efficiency increases as rotating velocity increases and decreases as friction coefficient increases. also it decreases with short pitch length. and double flight screw is more effective than single flight screw. The temperature of polymer melts by heating pad and injection pressure play a very important role in the injection molding machine. so in this paper we analyze thermal distortion and stress of screw includes pressure and temperature distributions by finite element analysis to understand what design factors influence on volumetric throughput efficiency of the screw and thermo-mechanical characteristics of screw.