• 한국시뮬레이션학회논문지
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• 제17권2호
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• pp.63-74
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• 2008

공정 개선의 문제는 원가 절감, 수익구조 개선을 목표로 하는 생산 전략부서, 생산 계획에 의해 제시된 제품의 목적 생산량을 달성할 수 있는 공정 설계하고자 하는(설계 공정 능력, Tact time) 공정 설계 부서의 공통 요구사항이다. 목표하는 생산량을 달성하기 위해 작게는 라인밸런싱(Line-Balancing), 병목공정 제거를 수행하고 있으며, 크게는 설비 증설, 작업자 증원 등의 공정 개선을 시도한다. 문제는 대부분의 경우, 공정 개선 프로세스가 정적 예측 기반의 수리적인 방식에 기인하고 있다는 점이며, 특히 라인 생산 기반의 컨베이어 공정의 경우, 컨베이어의 이송 능력에 따른 대기시간 부분이 배제되고 있다는 것이다. 공정 대기시간은 설비의 정미시간과는 별개의 문제로 설비의 싸이클 타임(Cycle Time)의 수치에 따라 변동하는 변수로서 중요하다. 이에 본 논문에서는 H 사의 컨베이어 라인 공정을 대상으로 이산 사건 기반의 시뮬레이션을 수행하여 일련의 공정 개선 프로세스를 밟아가며, 컨베이어에 의해 발생하는 공정 대기시간의 공정 개선에의 기여도를 측정하여 공정 개선의 주요 변수로서 제시하고자 한다.

• 한국정밀공학회지
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• 제18권10호
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• pp.101-108
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• 2001

In this study, the static and dynamic characteristics of endmilling process were modelled and the analytic realization of chatter mechanism was discussed. In this reward, We have discussed on the comparative assessment of recursive time series modeling algorithms that cal represent time machining process and detect the abnormal machining behaviors in precision endmilling operation. In this study, simulation and experimental works were performed to show the malfunctional behaviors. For this purpose, new recursive algorithm(RLSM) was adopted for the oil-line system identification and monitoring of a machining process, we can apply these new algorithms in real process for detection of abnormal chatter. Also, The stability lobe of chatter was analysed by varying parameter of cutting dynamics in regenerative chatter mechanics.

• 한국국방경영분석학회지
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• 제35권1호
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• pp.33-49
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• 2009

현재 국방 선진국들은 장기적 차원에서 미래전투체계의 개발에 박차를 가하고 있다. 이에 우리 육군도 국방개혁의 연장선에서 미래전에 대비한 전투체계 개발에 역점을 두어야 한다. 먼저, 본 연구는 육군의 미래전투체계 구축에 대한 당위성을 제기하고 둘째, 미래전투체계를 구성하는 개별 전투체계에 대한 우선순위를 계층화 분석기법을 적용하여 분석함으로써 앞으로 있을 육군 FCS 관련사업의 구체적인 마스터플랜 작성에 활용될 수 있는 방안을 제시하고자 한다.

• 대한토목학회논문집
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• 제35권3호
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• pp.639-645
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• 2015

최근 지상역 승강장에서 승객의 안전 확보, 지상역 조건과 열차 차종 자동 인식에 따른 상하 개폐 기능이 탑재된 Rope 스크린도어의 실용화 기술에 대한 연구개발이 수행되고 있다. 현재 대구도시철도 2호선 문양역에 2013년 3월부터 시범설치 운영 중에 있으나, 앞으로 개선된 RPSD에 대하여 고속철도 역사를 대상으로 각 철도운영기관의 니즈에 부합하고, 철도 승강장 안전시설로써 역사에 적합한 시범사업 대상지를 선정할 필요성이 있다. 따라서 본 연구에서는 AHP를 이용하여 각 KTX역의 위험도 분석과 시설관리 및 운영기관의 사업추진의지 등 정책적 분석기준에 따라 RPSD 설치 대상지 우선순위를 분석하였다. 또한 AHP를 적용함에 있어 사례 분석할 KTX역과 같이 평가대상이 많을 경우 쌍대비교에 의한 우선순위 평가가 불가능하기 때문에, 상위 평가항목에 대해서는 상대평가에 의해 가중치를 구하고, 각각의 하위 목적요소에는 평점에 의한 절대평가법을 조합하여 우선순위를 산정하였다.

• Journal of Korea Trade
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• 제23권7호
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• pp.34-44
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• 2019

Purpose - The purpose of this study is to present what the port of Pyeongtaek, the hub of Korean trade with China, should improve in the current situation, wherein the e-commerce trade volume between Korea and China is increasing due to the development of online technology. Design/methodology - In this study, through prior research and expert interviews on e-commerce and port activation between borders, we derived the main improvement factors for 1) Administration and Systems, 2) Facilities, 3) Transport, and 4) Manpower, and selected 12 detailed variables for the major improvement factors. To identify the relative importance of the major improvement factors, the Analytic Hierarchy Process (AHP) method was applied, and a survey was conducted among 15 related experts. Findings - As a result, among the 12 detailed variables, Composition of Association (0.267) was the first factor to be improved, followed by Incentive Support (0.143) and E-Commerce Cluster (0.131). Based on these analyses, the main implications of this study are, first, in the current situation where the cross-border e-commerce market is growing, Pyeongtaek Port needs to form a consultative body among the government, local governments, and related businesses in connection with cross-border e-commerce and develop various support policies for the e-commerce market. Second, it will have to be able to provide differentiated services from competing ports by establishing e-commerce market-oriented clusters. Originality/value - In existing related studies, various improvements were presented to revitalize trade in line with the growth of the cross-border e-commerce market. However, with regard to most cross-border e-commerce businesses, one-dimensional improvement measures, such as improvement of payment systems, improvement of customs clearance services, and promotion of human resources, are presented in a piecemeal manner. In other words, none of the studies have proposed the importance and priority of each measure in terms of both the forward-looking and efficient allocation of resources, which is the purpose of this study. Therefore, this study contributed politically, practically, and academically by presenting countermeasures for ports to revitalize cross-border e-commerce and presenting strategic priorities using quantitative analysis methods.

• 한국소음진동공학회논문집
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• 제20권12호
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• pp.1216-1222
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• 2010

Based on the MacDonald's analytic model for the diffracted sound field of a semi-infinite noise barrier, computer simulations were performed for various positions of error microphones for an active noise barrier system. The simulation process also included the effects of floor reflections on both sides of the barrier. The results were also compared with Niu's simulation results and showed a straight line arrangement of sensors and actuators, in the order of primary source, secondary source and error microphone is better than over the top arrangement of the error microphones.

• Journal of Mechanical Science and Technology
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• 제14권10호
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• pp.1104-1113
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• 2000

This paper proposes an efficient reverse engineering technique for compound surfaces using a boundary detection method. This approach consists in extracting geometric edge information using a vision system, which can be used in order to drastically reduce geometric errors in the vicinity of compound surface boundaries. Through the image-processing technique and the interpolation process, boundaries are reconstructed by either analytic curves (e. g. circle, ellipse, line) or parametric curves (B-spline curve). In other regions, except boundaries, geometric data are acquired on CMM as points inspected using a touch type probe, and then they are interpolated on several surfaces using a B-spline skinning method. Finally, the boundary edge and the skinned surfaces are combined to reconstruct the final compound surface. Through simulations and experimental works, the effectiveness of the proposed method is confirmed.

• 산업경영시스템학회지
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• 제21권48호
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• pp.241-251
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• 1998

The purpose of this study is to evaluate the relative importance of seven JIT operational techniques in Domestic industries. These techniques are used to improve manufacturing effectiveness and efficiency such as : Setup time reduction, Kanban, Multi-functional worker, U type layout, Andon(line stop), Atonomation, and Smoothing production. The new analytic hierarchy process(AHP) model is used in order to evaluate the relative importance of the seven JIT operational techniques which are used to increase the manufacturing effectiveness and efficiency. To aggregate the multi-divisions priorities, in this paper, we suggest a way which decision maker can exclude outlier matrix from group by using the concept of the compatibility in AHP.

• 한국산학기술학회논문지
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• 제9권2호
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• pp.544-549
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• 2008

교육행정정보시스템(NEIS)은 인터넷을 통하여 학교와 그 상위기관간의 행정 업무를 연계하기 위하여 정부에 의해 주도된 교육 분야의 혁신적 프로젝트이다. NEIS는 교육행정업무에 대한 재설계와 정보화 전략에 따라 행정서식을 표준화하여 교원의 업무를 경감시켜 보다 나은 품질의 교육을 제공하고 온라인을 통해 관련된 교육 문제를 해결하기 위해 도입되었다. 본 논문은 NEIS의 효과적인 활용에 영향을 미치는 요인들을 도출하여 이를 계층화하고, 다중 의사결정기법을 이용하여 핵심요인간의 상대적인 중요도 평가를 통해 NEIS의 효과적인 활용방안을 모색하고자 한다. 분석결과는 NEIS의 사용자들의 만족도 제고와 향후 NEIS의 개선 전략을 개발하는데 유용하게 사용될 수 있다.

• 한국해양공학회지
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• 제16권2호
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• pp.38-43
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• 2002

Die-less forming is a cold forming process which is to bend thick flat plates into compound curved plates using two asymmetric rollers. This forming method has several advantages compared with line heating which is widely used to fabricate compound curved pieces in shipyards. The die-less forming, however, has scarcely been studied. Even the deformation mechanism in this forming process has not been understood clearly. So, in this paper, the deformation characteristics of die-less forming is investigated analytically and numerically. for the analytic investigation, slab method based on equilibrium equation is applied. And the mechanism of curvature generation is derived for the asymmetry in roller applied. And three dimensional numerical analyses are performed with realistic modeling of interactions between the rollers and work-piece using finite element program, ABAQUS. It is shown that curvature generation is mainly due to the difference of normal positive strain distribution between the top and bottom surface of the work-piece. And a convex-type curved plate is formed if the center region of the work-piece is rolled with asymmetric rollers of which the lower is larger than the upper in diameter.