• 산업공학
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• 제13권3호
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• pp.348-357
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• 2000

SCM(Supply Chain Management) is a new approach to satisfy customers via an integrated management for the whole business processes of the manufacturing from the raw material procurement to the product or service delivery to customers. Typically the semiconductor industry is the one whose supply chain network is distributed all over the world, and its manufacturing process has the particular characteristics which has to be considered in the modeling of supply chain. In this paper we suggest the push and pull type supply chain models based on the manufacturing characteristics and their mathematical formulation for the semiconductor industry. Push supply chain model pursuits the high throughput and the balance of the WIP flow, and pull supply chain model does to minimize the total cost of order-based manufacturing, distribution and transportation process in order to meet customer's request appropriately.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.193-198
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• 2005

According to the ISO 14040(1997), Life Cycle Assessment is not the tool only focusing on the emissions from the manufacturing processes of a product, but the tool also expressing environmental adverse impact quantitatively through products entire life cycle (i.e. raw material acquisition, manufacturing, transportation, use, and end-of-life stage). Because the LCA for EMUs(Electrical Multiple Units), however, requires astronomical time and cost for collecting big amount of data. it is inevitable to bring in the simplified LCA methodology, In this study, we introduced standardized methodology of LCA in the world, and found appropriate S-LCA methodology for EMUs. Furthermore, we recommended how to evaluate the environmental impact of EMUs in detail and precisely, using the S-LCA.

• 수산경영론집
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• 제18권2호
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• pp.53-67
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• 1987

In the fish industry, the perishabiliy of raw material, saeasonality of catch and diatance between production and consumption combine to cause physical distribution to be a difficult decision problem. In fishery physical distribution, the choice of appropriate landing port is a major problem. This paper deals with transshipment model to determine landing port as intermediate transfer point and the market to which fish should be sent. Transshipment model is useful to determine intermediate transfer point and can be reformulated as LP model. So this study developes transshipment model for korea large trawler ana analized the model output. It can be expended to a realistic problem in order to provide information to port planner and decision maker on the trade-offs between the cost and efficiency of fishery transportation.

• 산업경영시스템학회지
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• 제38권2호
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• pp.145-151
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• 2015

As order quantity is increased, the ordering cost per item will be cheaper due to saving of transportation and material handling costs. In this paper, two realistic assumptions such as quantity discount and budget limit are considered. Quantity discount means that all units in the order will be discounted according to the predetermined order levels. Budget limit represents that the costs for inventory investments are bounded. This paper develops a Lagrangian relaxation approach for a continuous review inventory model with a budget constraint and quantity discounts. Computational results indicate that the proposed approach provides a good solution. Sensitivity analysis is done to get some insights on budget limit and quantity discount. As budget limit or the amount of discount according to order quantity is increased, order quantity is increased, whereas reorder point is not always increased.

• 보건행정학회지
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• 제20권4호
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• pp.139-169
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• 2010

The purpose of this study is to compare accreditation criteria of environmentally-friendly hospitals in the USA, UK and Australia and find out the implications for Korean hospitals. The comparison was made in terms of 11 categories : sustainable site, water efficiency, energy & atmosphere, transportation, indoor environmental quality, health, material & resources, management, waste, innovation, and regional priority. Literature review of the study revealed that most of the environmentally-friendly hospitals have experienced such positive effects as cost saving, health promotion of patients & employees and good reputation etc. The study result implies that the following factors are so critical to settle environmentally-friendly hospitals in Korea: 1) CEO's interest & support, 2) education for employees, 3) efficient renovation of existing facility and 4) data accumulation on the effectiveness of environmentally- friendly hospitals by scientific methods.

• 융복합기술연구소 논문집
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• 제6권1호
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• pp.31-35
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• 2016

In this paper, the present status of shale gas development was briefly introduced and intended the growing importance and shale gas as a source of chemicals. The large amounts of shale are expected to be produced thereby, a wealth of methane and ethane will be provided as a raw material of ethylene. This manuscript also focus on the influence of potential volumes of shale gas on petrochemical industry, especially domestic one based on naphtha cracking because ethane cracking can offer cost effective ways to convert methane to higher value chemicals.

• 전기화학회지
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• 제15권2호
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• pp.95-100
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• 2012

올리빈 구조를 가지는 $LiFePO_4$ 양극활물질은 낮은 가격과 안정성으로 인해 리튬 이차전지 시장에서 큰 관심을 받고 있다. 그러나 낮은 이온 전도도와 작동전압 때문에 상업적으로 이용되기엔 사용분야의 응용에 제한이 있다. 이러한 문제를 해결하기 위해서 철 양이온을 망간 양이온과 같은 전이금속으로 치환함으로써 작동전압을 높이는 연구가 시행되고 있다. 또한 미세구조의 나노화를 통해 리튬 이온의 확산거리를 짧게 만들어 줌으로써 이온 전도도를 높여주는 연구도 진행 중이다. 그래서 이번 연구에서는 이온의 확산거리를 짧게 만들어 주기 위해 표면적을 넓힐 수 있는 전기방사를 이용해 물질을 합성하였고, 이를 확인하기 위하여 시차주사현미경 관측을 통해 균일한 나노 섬유의 형성을 확인하였다. 또한 결정구조를 관찰하기 위해 X-선 회절 분석을 하였는데, 다른 상의 관찰 없이 단일상의 결정구조를 얻음을 확인하였다. 전기화학적 성능 확인방법으로는 충방전 테스트기를 이용하여 초기 충방전 곡선을 분석하였고, 계면저항 및 리튬 양이온의 확산을 알아보기 위해 임피던스 측정을 실행하였다.

• 한국전자통신학회논문지
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• 제8권8호
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• pp.1241-1246
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• 2013

현재 일반적인 반송 장치에서는 전기자를 반송 경로 전장에 배치하는 지상 1차측 시스템이 적용되고 있다. 하지만 이러한 시스템을 장거리 반송 장치에 적용하면 초기 설치비용과 제작시간이 상승하는 문제점이 발생한다. 이러한 문제점을 해결하기 위해 전기자를 분산시켜 배치하는 방식이 제시되고 있다. 하지만 전기자 분산배치 방식은 전기자가 존재하지 않는 구간에서 외란 발생 시 가동자가 정지할 수 있으며 이 때 전기자에 의한 제어가 불가능하게 되어 가동자를 이동 시킬 수 없는 문제점을 내재하고 있다. 따라서 이러한 문제점을 해결하기 위한 전기자 간격 결정이 매우 중요하다. 또한 전기자를 분산배치 할 경우 단부가 발생하게 된다. 이는 가동자가 전기자에 진입 또는 반출 시에 코깅력을 크게 발생시켜 추력 맥동의 원인이 되며, 소음과 진동을 발생시키므로 저감하여야 한다. 따라서 본 논문에서는 전기자를 분산 배치함에 따라 존재하는 단부 코깅력을 유한요소법을 이용한 2-D 수치해석을 통해 파악하고 이를 최소화하기 위한 전기자 간격을 도출하고자 한다.

• 한국안전학회지
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• 제31권2호
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• pp.83-89
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• 2016

As the world's industrial development quickens, the highways and regional expressways have been expanding to serve the logistics and transportation needs of people. The burgeoning road construction has led to a growing interest in roadside installations. These must have reliable performance over long periods, reduced maintenance and high durability. Steel roadside barriers are prone to corrosion and other compromises to their functionality. Therefore, using high anti-corrosion steel material is now seen as a viable solution to this problem. Thus, the objective of this paper is to expand the scope of applications for high anti-corrosion steel material for roadside barriers. This paper assesses the impact safety such as structural performance, occupant protection performance and post-impact vehicular response performance by a simulation review on roadside barriers built with high strength anti-corrosion steel materials named as hot-dip zinc-aluminium-magnesium alloy-coated steel. The simulation test results for the roadside barriers built with high strength anti-corrosion steels with reduced sectional thickness meet the safety evaluation criteria, hence the proposed roadside barrier made by high strength and high anti-corrosion hot-dip zinc-aluminium-magnesium alloy-coated steel will be a good solution to serve safe impact performance as well as save maintenance cost.

• 한국분말재료학회지
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• 제30권3호
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• pp.223-232
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• 2023

Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.