• 대한안전경영과학회지
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• 제9권4호
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• pp.121-127
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• 2007

CSP(Concurrent Spare Parts) is supplied with the procurement of new equipment or weapon system and is used to sustain the equipment without resupply during the initial coverage period. This study is concerned with a problem of determining the near optimal inventory level of the spare parts, especially Concurrent Spare Parts. For this, we utilize the mixed periodic and continuous review polices considering the CSP and (r,Q) Policies concurrently in a two-echelon distribution system. We propose the mathematical model to minimize the total cost which is composed with ordering cost, purchasing cost, holding cost, and stickout cost. If the mixed policy is compared to other policies(CSP, (r,Q)), the proposed methodology performs well and is best policy in the equipment maintenance expenses.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.896-900
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• 1992

This paper presents a comprehensive methodology of automatic feature recognition for rotational parts. The parts of interest are rotational without deviation. In stage one, IGES formatted daa of 2D engineering drawings are transformed into three independent graphs through upperhalf profile. In stage two, recursive evaluations are made to recognize features and relevant information is acquired. Finally,an example is evaluated to demonstrate the recognition power of the developed algorithm for rotational features.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.56-59
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• 1997

Vision system is mainly consist of three parts of perception, action. One of these parts, perception system detects visual target in surrounding environment. Block-based motion estimation with compensation is one of the popular approaches without accuracy. The hierarchical method the optical flow with gradient is used to improve optical flow time delay.

• 디지털융복합연구
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• 제11권7호
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• pp.185-192
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• 2013

본 연구는 산업현장에서 작업자의 숙련도에 맞추어 학습이 가능한 3D 가시화기술과 이를 바탕으로 하여 자동차 엔진을 구성하고 있는 각각의 부품들 사이의 관계를 설정하고 태스크 온톨로지를 이용하여 자동차 부품을 추천하는 방법을 제안한다. 복합지식을 네트워크 형태의 의미화된 링크와 노드로 구조화하고 3차원 형태로 보여줄 수 있도록 SOM을 이용한 가시화방법을 제안하였다. 또한, is-a Relationship 기반 hierarchical Taxonomy를 이용하여 자동차 엔진을 구성하고 있는 각각의 부품들 사이의 관계를 설정하고, 가중치를 이용한 추천이 이루어 질 수 있도록 하였다. 3D 공간상에 복합지식을 배치하고 사용자에게 제공함으로써 보다 실감적이고 직관적인 네비게이션의 기회를 제공하고, 임의의 자동차 부품을 선택했을 때 해당 부품과 밀접한 관계를 가진 부품을 추천하여 특별한 전문 지식 없이도 손쉽게 자동차 부품의 조립 및 쓰임새와 중요성을 알 수 있게 해준다.

• 한국의류산업학회지
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• 제6권1호
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• pp.109-113
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• 2004

The present study attempted to consider the effects of cutting lines in the knee parts of slacks on the clothing pressure and comfort. The study compared and analyzed the pressure imposed to the body in a stooping position and the consequent sensations felt by the wearer according to the slack shapes. The conclusion was drawn as follows: The pressure imposed by the slacks to the body is greater on the two points slightly upper and lower from the knee point than on the knee point itself, regardless of the slack shapes. Clothing pressure was lower in the slacks with 10 cm-wide and 14 cm-wide cutting lines in the knee parts than those with 18 cm-wide cutting lines. Subjective sensations felt in the knee parts were analyzed according to slacks shapes. As a result, it was found that slacks without cutting lines on the knee parts or with sewing lines far from the knee points were more comfortable. In slacks construction, the use of cutting lines in the knee parts can decrease pressure imposed to the knee area or improve the comfort of the slacks. When designing slacks, however, overall appearance should be considered and the weakness of cutting line that makes legs look shorter should also be complemented.

• 한국CDE학회논문집
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• 제2권2호
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• pp.103-110
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• 1997

In the development of large complex assembly, most design changes are from the following reasons.: 1) insufficient consideration of assembling sequence of downstream process. 2) interference and fit-up of related parts. 3) initial design changes which are not completely resolved. In order to reduce the first reason of above, the assembly-centric modeling methodology was proposed in the part (1) of the thesis. In this part (2), a Digital Mock-Up system, which is a tool to build a virtual mock-up in design stage, has been developed in order to prevent the other two reasons. The system can build a virtual assembly in various ways as followings.: 1) assembling parts which are located in user defined envelope. 2) assembling parts with the specified disciplines. 3) assembling parts that are selected in the part list. It can also make an assembly by the combination of above methods. In addition to that, it has the functions to read/write the virtual assembly and to explode parts of the assembly in desired direction. With the virtual assembly, engineers can design interference free parts without making physical mock-up. The system has been implemented with Oracle database management system in CATIA environment.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 춘계학술대회논문집
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• pp.106-111
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• 2000

The residual stresses in molded plastic parts can be divided into the flow induced residual stresses produced in flowing stages and the thermally induced residual stresses produced in cooling state. Reducing residual stresses in the final parts is one of the goals in recent study. The present study focused on comparing the predicted values for thermal residual stresses in freely and constrained quenched plastic plates with and without free volume theory. As a result the final residual stresses showed the opposite pattern in thickness direction. furthermore by applying free volume theory the predicted residual stress at the center showed about 50% of the values without free volume theory for constrained quenched case.

• 한국정밀공학회지
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• 제30권5호
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• pp.474-479
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• 2013

Mass reduction of the machine tool movable parts is a tool for achieving lower energy demands of the machine tool operation. The realization of lightweight design in machine tool can be achieved by structural lightweight design and material lightweight design. In this study, topology optimization strategy was applied to design optimized structures of movable parts of 5 axis machining center. The weight of ram which has most significant influence on the stiffness of whole machine tool was reduced without stiffness deterioration. The redesigned optimized ram has 24.2% less weight while maintaining the same displacement caused by cutting force.

• Journal of Advanced Marine Engineering and Technology
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• 제23권6호
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• pp.806-813
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• 1999

The effect of Post-Weld Heat Treatment(PWHT) of SS400 Steel was investigated with parameters such as micro vickers hardness corrosion potential polarization behaviors galvanic current Al anode generating current Al anode weight loss etc. Hardness of each parts(HAZ, BM, WM)by PWHT is lower than that of each parts by Non Post-Weld Heat Treatment(NPWHT) However hardness of WM of HAZ part was the highest among those three parts and HAZ area were also acted as cathode without any case of heat treatment. Potential difference between each three parts by PWHT was also smaller compared to NPWHT. Therefore it is suggested that Corrosion resistance property is increased by PWHT. However both Al anode generating current and anode weight loss was also decreased by PWHT compared to NPWHT when SS400 steel is cathodically protected by Al anode.

• 한국소음진동공학회논문집
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• 제26권5호
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• pp.594-601
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• 2016

Mass estimation analysis of loose-parts in pressure vessel is necessary for the structural integrity assessment of pressure boundary in nuclear power plants. Mass of loose-parts can be generally estimated from the peak values and the center frequency of impact signals. Magnitude of impact signals is, however, inevitably attenuated according to the traveling distance of the signals and depending on the frequencies. Attenuation rate must be therefore carefully compensated for the precise estimation of loose-part mass. This paper proposes a new compensation method for the attenuation rate based on Bessel function instead of Hankel function in conventional method which has a limitation of usage in near the impact location. It was verified that the suggested compensating equation based on the Bessel function can be applied to the attenuation rate calculation without any limitation.