• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.291-295
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• 2022

본 논문은 시민들의 Life Style 변화에 대응하고 송산그린시티의 미래상을 달성하기 위해 기술과 주거, 산업, 관광레저 등 기능이 상호 효율적으로 융합된 환경친화적 첨단도시를 건설하기 위하여 스마트도시에 적용한 u-상수도 관로파손감지시스템 구축기술에 대하여 기술하기로 한다. 관로파손감지시스템은 송산그린시티 동측지구내 상수도관 상부에 설치되는 스마트예방시트, 관로파손감지기, 관파손감지 소프트웨어, 서버 등으로 구성되며 중앙제어부(관파손감지소프트웨어, 서버)는 화성시 맑은물사업소내에 설치되어 SKT의 WCDMA방식의 무선통신망을 통하여 현장에서 화성시로 데이터를 전송하고 있다. 본 시스템은 굴착공사중 시설물 파손을 예방하고 관로 손상여부를 실시간으로 감지하여 이벤트 발생위치를 관리자에게 알려주여 누수손실을 예방하여 시설물의 수명연장을 도모한다.

• 한국산업융합학회 논문집
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• 제26권5호
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• pp.855-866
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• 2023

With the rapid advancement and sophistication of defense weapon systems, the government, military, and the defense industry have conducted various innovative attempts to improve the efficiency of post-logistics support(PLS). The Ministry of Defense has mandated RAM-C(Reliability, Availability, and Maintainability-Cost) analysis as a requirement according to revised Total Life Cycle System Management Code of Practice in May 2022. Especially, for the project budget forecast of new PBL(Performance Based Logistics) business contacts, RAM-C is recognized as an obligatory factor. However, relevant entities have not officially provided guidelines or manuals for RAM-C analysis, and each defense contractor conducts RAM-C analysis with different standards and methods to win PBL-related business contract. Hence, this study aims to contribute to the generalization of the analysis procedure by presenting a cost analysis case based on RAM-C for the supply of military depot maintenance PBL project. This study presents formulas and procedures to determine requirements of military depot maintenance PBL project for repair parts supply. Moreover, a sensitivity analysis was conducted to find the optimal cost/utilization ratio. During the process, a correlation was found between supply delay and total cost of ownership as well as between cost variability and utilization rate. The analysis results are expected to provide an important basis for the conceptualization of the cost analysis for the supply of military depot maintenance PBL project and are capable of proposing the optimal utilization rate in relation to cost.

• 경영과학
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• 제28권3호
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• pp.1-13
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• 2011

Hub-and-spoke transportation network is a powerful and useful network structure that takes full advantage of economies of scale on routes between hubs. In recent studies, the network structure is extended to hybrid hub-andspoke that allows direct transportation between spokes. In this study, we considered more extended network structure which is called hybrid multiple hub-and-spoke that has multiple hubs and allows direct transportation between spokes. We developed a mathematical optimization model for automotive service parts transportation planning under hybrid multiple hub-and-spoke network structure. The model suggests a long-term transportation route planning and a short-term vehicle assignment planning. The model is verified by simulation and validated in real world application to Hyundai Mobis automotive service parts transportation planning. From the simulation result, the model reduced the transportation cost about 24.7%, the total distance about 6.8% and the CO2 emissions about 8.8%. In real world application for 6 months from July to December 2010, the model reduced the transportation cost about 9.1% by changing the long-term transportation route without daily vehicle assignment planning.

• 한국환경복원기술학회지
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• 제9권3호
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• pp.39-50
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• 2006

In this study, the water quality investigated during 2002s to 2004s for Anyang river and its affluent that was based on biological and chemical methods as well as ecological index of each streams. The improving of water quality and the multiplicity of specious in the most streams except for Anyang, which was due to the improving of water quality and water resource. The seasonal dry states are completely disappeared, but water quality of Anyang main stream was classified as fifth grades water with BIP 8.51~10.00 and BOD 8.16~14.4mg/l in Anyang stream overall. And alpha-mesosaprobic in upper, mid parts and polysaprobic in down parts of Anyang main stream are appeared according to Saprobien system, respectively. The water supply of treated sewage is appeared that upgrading effects of water quality in Anyang main stream and affluents of Anyang city area, but the practical effects of "Saving Anyang River" could not gained because the water quality of other branches in upstream parts than upstream measuring point of Anyang main stream, Wanggok stream Sanbon stream in Gunpo and Eeiwang cities, was not improved.

• 복식
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• 제45권
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• pp.41-54
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• 1999

The purpose of this thesis is to trace the development of cotton Early Chosun Period by examining the historical literary sources : such as production of cotton various uses of cotton trade with other countries The developement process of cotton fabrics during this period can be divided into three stages. The first stage which can be discribed as a settling period lasted 27 years from A.D. 1392 to 1418. In this stage cotton fabrics were just about to be used as fabrics for popular clothing. The second stage which can be discribed as a developmental period lasted 50 years from A. D.1418 to 1468. In this stage cotton fabrics were mainly produced in the southern parts of the country which are Kyungasng-Do, Choongcheng-Do and Jeunla-Do. And cotton fabrics were used not only by the common people but also by the royal family. The third stage, that is the last one was an extensive period and lasted from A.D.1469 to 1592. In this stage as the demand for cotton fabrics greatly increased the production from southern parts of the country fell in short of the supply needed. Therefore the production was extended to the northwestern parts. In addition cotton fabrics finally came to be used as money to value the goods.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.448-466
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• 2019

오늘날 기업들은 비용절감과 효율적인 운영을 위한 수단으로서 SCM(공급사슬관리)에 관심이 더욱 집중되고 있다. 글로벌 환경의 불확실성과 미래 경쟁력에 있어서 기업은 지속적인 경쟁우위를 차지하고 이를 지속적으로 유지할 수 있는가 하는 것이 기업의 궁극적인 최대 목표인 것이다. 이러한 점에서, 중소부품제조업체의 경영전략, 협업프로세스 및 SCM통합이 기업성과에 미치는 영향력을 밝히는데 목적을 갖고 실증분석을 하였으며 그 결과를 종합하면 다음과 같다. 국내 중소부품제조업체에서의 경영전략, 협업프로세스 및 SCM통합이 기업성과에 긍정적인 영향을 미쳐 가설은 모두 채택되었다. 이는 중소부품제조업으로서의 경영전략을 위한 품질, 원가, 유연성, 납기와 협업을 위한 전략적 목표인지, 지원정책, 문제해결방안, 지식정보공유가 SCM통합의 품질신뢰성, 비용절감, 납기준수능력, 정보시스템운영을 향상시켜 종국적으로 기업의 정량적, 정성적 성과를 높여주는 기제임을 확인시켜준 것으로 평가할 수 있다.

• Tribology and Lubricants
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• 제37권5호
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• pp.172-178
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• 2021

An injector is a mechanical device present inside the engine. Its main function is to supply an appropriate volume of fuel into the combustion chamber, which is directly related to the overall engine efficiency of a car. During the operation of an injector, a magnetic force lifts the parts of the injector from closed position to open position which generates a horizontal force on the needle. The horizontal force acts on a different position from that of the center of mass of the needle. Therefore, this causes eccentricity in the needle and the generation of a tilting motion during the lifting operation which can result in wear. However, appropriate selection of clearances for these parts can prevent wear. In this study, lubrication analysis is conducted to determine the optimum clearance of parts with sliding motion inside the injector. The height functions are derived considering the dynamic behavior and relative velocity of the parts. Using the derived height function, the pressure profiles are calculated for the lubricated surfaces from the Reynolds' equation. Subsequently, the fluid reaction forces are calculated. The equations of motions are applied to the fluid reaction forces and external forces are solved to calculate the minimum film thickness between each part with variation in the clearances. Finally, the optimum clearances are determined. The effect of the clearances on the behavior of the moving parts is presented and discussed.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.183-186
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• 2003

Reaction injection molding (RIM) is a widely used process for producing various kinds of complex parts including automobiles, furniture, appliances, and housings. In RIM, products are made from two or more chemical components through mixing, chemical reaction, and molding [1]. Liquid reactants from two supply tanks flow at high pressure into a mix head, where they impinge at high velocity. (omitted)

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 추계학술대회
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• pp.269-278
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• 2012

The purpose of VE (Value Engineering) activities is to come to an achievement of building necessary functions at the lowest possible cost. This study unfolds the co-VE activities which occurred between Gas Range and its partner company in the supply of Grill Body. The co-VE activity has accomplished the cost reduction of about 57 million through performing the function deployment of 12 parts and by devising the alternatives.

• 경영과학
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• 제5권2호
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• pp.57-70
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• 1988

This paper examines both MRP and JIT for reducing WIP(Work In Process). The MRP/JIT system is suitable for multi-model, small-production manufacturing comparies in Korea because of the short delivery distance and low risk of accident during delivery. The objective of this paper is to manage vendors effectively by informing supply points and quantity of parts of vendors with MRP and JIT.