• 열처리공학회지
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• 제22권1호
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• pp.16-22
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• 2009

The rolling process is an efficient and economical approach for the manufacturing of plate metals. In the rolling process, the temperature variation is very critical for plate thickness accuracy. The main cause of thickness variation in hot plate mills is the non-uniform temperature distribution along the length of the slab. Also the exit plate thickness is mainly affected by the rolling conditions such as mill modulus, plate thickness and plate width. Hence the thickness variation in top-end is also dependent on these factors. Therefore this study has concentrated on determining the correct amounts of thickness variation due to top-end temperature drop and process parameters.

• 한국컴퓨터정보학회논문지
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• 제14권3호
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• pp.217-226
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• 2009

본 연구는 한국우정의 우편물류통합정보시스템(PostNet)의 구축 사례를 통하여 정보시스템 통합의 단계별 추진과정과 성공적인 실행동인을 살펴보고자 하는데 그 목적이 있다. PostNet은 조직상의 통합(조직구조 개편), 전략적 통합(업무처리절차 재설계), 기술적 통합(데이터통합, 어플리케이션통합, 통합플렛폼 구축)을 상황적으로 고려하여 정보시스템 통합을 수행하였다. 또한 통합과정에서 세 가지 측면의 통합을 목적에 맞게 연계되도록 구현하였다. PostNet은 기존에 물리적 통합 및 하드웨어 통합의 단계에 머물러 있던 정보시스템 통합의 수준을 경영 목표, 운영 목표와 일치시키도록 진일보시켰다는데 큰 의의가 있다. 한국우정은 물류산업 내에서 최대의 물류망, 조직 서비스를 보유하고 있다 따라서 본 논문의 결과는 향후 정보시스템 통합의 이론적 근거의 틀을 제시할 뿐 아니라 특히 물류시스템 통합에 대한 가이드라인으로 활용될 수 있을 것이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.320-323
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• 2002

This paper discusses process design of cold forging for inner tooth part, drum clutch. In respect to high productivity, low material consumption and low piece production costs, Metal forming has more merits than machining process. Net shape forming is huh technology which satisfies merits of metal forming and achieves high accuracy. Recently, net shape forming method widely applied because of high productivity, low material consumption and low piece production costs using press. In this study, the method which accuracy of drum clutch, automatic transmission pin, can be improved is discussed. First, process variables for process design of drum clutch are selected, and then process design is accomplished using forming analysis method. from forming analysis, forming load, stress, unfiling part is obtained. and comparing these results, optimal process design can be determined.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.71-74
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• 2008

In order to resolve the problems which appear after the clean large ingot production process, the impurities which are involved in the steel smelting process should be removed by developing cleaner materials. Through the rationalization of cogging process that is the first forging process of large ingot the quality is to be improved. For the sake of the optimization of an open die forging process and the improvement of the subject matter frequency ratio, a hazard precise die forging process must be developed and a Near Net Shape Forming accomplished. As a result, energy can be reduced by minimizing an after control process. In order to produce large axes and other forming parts, processing techniques are to be developed. In this context, this paper is a study about a reduction ratio, dies width ratio and rotary angles, the amount of overlap, and intends to analysis cogging processes, utilizing Deform-3D cogging module

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.190-194
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• 2001

The integration of rapid prototyping and tooling has the potential for the rapid net shape manufacturing of three-dimensional parts with geometrical complexity. In this study, a new rapid prototyping process, transfer type of Variable Lamination Manufacturing (VLM-ST), was proposed to manufacture net shape of 3-D prototypes. In order to examine the efficiency and applicability of the proposed process, various 3-D parts, such as a world-cup logo, and extruded cross and a knob shape, were fabricated on the apparatus. In addition, the new rapid tooling process, which is a triple reverse process, was proposed to manufacture of 3-D functional part using VLM-ST prototypes and the plastic part of the knob shape was produced by the new rapid tooling process.

• 한국기계가공학회지
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• 제15권3호
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• pp.28-35
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• 2016

Forging operations are non-stationary processes occurring because of indirect pressure, generally, under conditions of three-dimensional stress and deformation. Furthermore, due to friction and the constraints of die geometry, deformation is not homogeneous. Material flow and deformation are largely determined by the shape of the tools. It is well known that net-shape forging can improve the mechanical strength of the final product as well as reduce material waste. Oxygen-free copper that is used for electrical and electronic components has excellent electrical and thermal conductivity. Oxygen-free copper parts have a low productivity in cutting process. Thus, the forging process is performed in order to improve the low productivity in cutting process. The forging of oxygen-free copper for electrode body parts was modeled using finite element simulation and forging experiments that were conducted for producing electrode body parts at room temperature. In order to reduce the cost of cutting products, the forging was performed in a closed cavity to obtain near-net or net-shape parts.

• 수산해양기술연구
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• 제15권2호
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• pp.95-100
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• 1979

권현망에서는 어획물을 손상시키지 않도록 양망해야 하는데, 재래식에서는 순전히 인력으로서 양망하므로 30-34명이나 되는 인원이 필요하다. 이것을 성력화하기 위하여, 자루그물의 옆판쪽에 속으로 반달코가 있는 힘줄을 6가닥씩 넣고, 배에는 선미에 데릭부움을 설치하여, 거기에 장치된 블록줄끝의 훅을 반달코에 걸어서 사이드 드럼으로 감아 재래식처럼 자루그물을 까뒤집으면서 양망한 바, (1) 어획물이 손상되지 않고, (2) 사이드 드럼의 권양장력은 30명의 선원의 그것보다 크며, (3) 본래식의 반이하인 14명의 선원으로서 조업이 가능하고, (4) 자루그물의 양망 소요시간은 어획량이 많을수록 재래식보다 적게 소요된다는 사실이 규명되었다.

• 대한기계학회논문집A
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• 제34권11호
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• pp.1779-1784
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• 2010

어업 분야에서 그물세척 작업은 엄청난 노동력과 작업시간을 요구하며 심한 환경 오염을 발생시킨다. 본 연구에서는 그물 양망 기능과 세척 기능, 그물펴짐 기능을 동시에 갖춘 그물세척용 양망기를 개발하였다. 양망회전체의 구조를 개선하여 구조물의 안정성을 높이고 대형 그물의 양망 중에 발생할 수 있는 그물 슬립 문제를 해결하였다. 양망기에 세척 기능을 부가하여 그물자동세척기를 이용한 최종 세척 전 단계에서 1 차 세척을 수행하거나 중소형 그물의 주 세척 작업에 세척용 양망기를 사용할 수 있도록 하였다. 대형 그물 세척을 위한 그물자동세척기의 세척 효율을 높이기 위하여 양망기 하단에 그물펴짐보조대를 설치함으로써 양망기로부터 접힌 채내려오는 그물을 펴는 작업이 용이하도록 양망기를 설계하였다. 시작품을 제작하여 그물 세척 실험을 수행한 결과, 양망 중에 그물슬립을 완벽히 방지할 수 있었고 양망기의 1 차 세척 기능에 의하여 그물 펴는 작업의 수월함을 확보함으로써 작업 효율과 세척 효율을 대폭 향상시킬 수 있었다.

• 대한기계학회논문집
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• 제18권9호
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• pp.2234-2244
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• 1994

A process sequence of multi-operation cold forging for actual application in industry is designed with the rigid-plastic finite element method to form a constant velocity joint housing(CVJ housing). The material flow during the CVJ housing forming is axisymmetric until the final forging process for forming of ball grooves. This study treats the deformation as an axisymmetric case. The main objective of the process sequence design is to obtain preforms which satisfy the design criteria of near-net-shape product requiring less machining after forming. The process sequence design also investigates velocity distributions, effective strain distributions and forging loads, which are useful information in the real process design.

• 한국환경과학회지
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• 제14권9호
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• pp.835-842
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• 2005

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0 -0.50 mg/m2/day. The net decomposition rate of COD was 0 -0.04 mg/m2/day in middle level(3 -6m) and 0.05 -0.1 5 mg/m2/day in bottom level(6m -bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.