• 한국경영과학회지
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• 제18권3호
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• pp.151-157
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• 1993

In this paper, we investigate the effects of yield randomness for lot-sizing in a multi-stage production system. The practical importance of incorporating yield randomness into production models has been emphasized by many researchers. Yield randomness, especially in semiconductor manufacturing, poses a mojor challenge for production planning and control. The task becomes even more difficult if the demand for final product is uncertain. An attempt to meet the demand with a higher level of confidence forces one to release more input in the fabrication line. This leads to excessive work-in-process (WIP) inventories which cause jobs to spend unpredictably longer time waiting for the machines. The result is that it is more difficult to meet demand with exceptionally long cycle time and puts further pressure to increase the safety stocks. Due to this spiral effect, it is common to find that the capital tied in inventory is the msot significant factor undermining profitability. We propose a policy to determine the quantity to be processed at each stage of a multi-stage production system in which the yield at each stage may be random and may need rework.

• Asian Journal of Business Environment
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• 제2권2호
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• pp.35-39
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• 2012

Purpose - Today's world is rapidly changing due to swift changes in organization's infrastructures and supply chain is becoming an important factor which affects the organization's global competitiveness. Research design / data / methodology - Researchers indicated that environment uncertainty is considered an external driving force to establish a unique supply chain. Market competition, reducing the gap of performance and quality between the products are compelling the practitioners and researcher to change the paradigm of managing the business processes effectively and efficiently. Results - In old times, supply chain of any organization was measured on the basis of inventory turns, defect rats, lead times, stock buffering and service level. But, Lee H.L. in 2004, published an article in Harvard Business Review who proposed three A (Adaptable, Agile and Aligned) termed as "Triple-A" of successful supply chain. Conclusions - He claimed that organizations can compete through the creation of Triple-A supply chain. Hence, the basic aim of this review paper is to develop basic insights regarding what is Triple-A of supply chain, its importance and functioning in today's competitive world.

• Nuclear Engineering and Technology
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• 제30권1호
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• pp.58-74
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• 1998

A PC window-based computer code, CONPAS (CONtainment Performance Analysis System), has been developed to integrate the numerical, graphical, and results-operation aspects of Level 2 probabilistic safety assessments (PSA) for nuclear power plants automatically. As a main logic for accident progression analysis, it employs a concept of the small containment phenomenological event tree (CPET) helpful to trace out visually individual accident progressions and of the detailed supporting event tree (DSET) for its detailed quantification. For the integrated analysis of Level 2 PSA, the code utilizes five distinct, but closely related modules. Its computational feasibility to real PSAs has been assessed through an application to the UCN 3&4 full scope Level 2 PSA. Compared with other existing computer codes for Level 2 PSA, the CONPAS code provides several advanced features: (1) systematic uncertainty analysis / importance analysis / sensitivity analysis, (2) table / graphical display & print, (3) employment of the recent Level 2 PSA technologies, and (4) highly effective user interface. The main purpose of this paper is to introduce the key features of CONPAS code and results of its feasibility study.

• 통상정보연구
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• 제9권1호
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• pp.355-379
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• 2007

With the effectuation of United Nations Framework Convention on Climate Change(UNFCCC) and Kyoto Protocol in 2005, ever growing concern on the importance of overseas forestation is diffusing worldwide. However, fierce international competition to secure overseas forestation sites, inherent uncertainty in UNFCCC or overseas forestation projects, and imbalances among policies on overseas natural resources development make it difficult to realize Korean long-term overseas forestation objective to secure 1 million ha by 2050. In view of necessity of overseas forestation projects for sustainable forest management and securing sinks of carbon to mitigate climate change, various efforts to reform current Korean overseas forestation systems are required. This study suggests several alternatives to improve current Korean overseas forestation systems including expanding financial support for overseas forestation projects, cultivating overseas forestation experts, establishing official organization for overseas forestation, constructing effective support system for overseas forestation projects, fostering international cooperation in the field of forest resources, and so on. Many theoretical, empirical or policy-oriented studies on the influences of UNFCCC and countermeasures on it in various Korean industries should follow this study.

• 전기학회논문지
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• 제58권12호
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• pp.2322-2327
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• 2009

Uncertainty of power system operation increases due to complexity and facilities diversification in the power system. Therefore the importance of SCADA(Supervisory Control and Data Acquisition) system which obtain and manage the actual data in real-time is very important. Accordingly in the studies of power system analysis, the efforts to include real-time power system analysis in simulation and applications are made in many ways. The real-time communication characteristics of SCADA system is considered so as to develop the power system analysis program that matches actual system conditions. The observation and management of SCADA system is realized by Intouch which is mainly used for factory automation and PSS/E(Power System Simulator for Engineers) provides real time system data. SQL DB and Python language is used for real-time communication between the softwares. It is very comfortable to use the various functions in Intouch WindowMaker.

• 대한간호학회지
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• 제29권4호
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• pp.755-765
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• 1999

Most people experience fatigue at some point in their lives, and they say the word ‘fatigue’ in their ordinary conversational speech. The ordinary word is used as a military or engineering term and has been studied in various different disciplines, such as ergonomics, physiology, psychology, medicine, and nursing. In spite of its widespread uses, however, fatigue has not been well defined. The term of fatigue Is thus often used with different meanings and is applied in diverse contexts that had led to a confusion of ideas. In people with cancer, fatigue is reported as a major distress. Despite the importance of fatigue in cancer patients, the phenomena of fatigue is poorly understood. Therefore, the purpose of the present study is to analyze the concept of fatigue in people with cancer. The process for the concept analysis was guided by Walker and Avant's conceptual analysis methodology. The identified attributes of fatigue in the present study were subjective feeling, lack of energy, sustenance, and multidimensions. The antecedents were cancer treatment and economic status. The consequences were decreased daily, vocational, leisure, and social activities, uncertainty, and difficulties in adjustment. Symptoms (pain, anorexia, and insomnia) and emotional disturbance were not clear whether they are antecedents or consequences. However, they are related with cancer related fatigue. Even though still in the beginning stage, instruments measuring cancer related fatigue have been developed by some nursing investigators.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.7-10
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• 2008

As the land price in the downtown area increases, buildings are becoming bigger, deeper and higher. Consequently, the importance of underground construction has increased. Although construction engineers make every effort to complete underground construction without any problem, construction failures like landslides and the collapse of a retaining wall occur because of the uncertainty of the soil conditions as well as the unexpected risks of excavation work. In order to prevent potential excavation accidents, it is essential to understand the causes and impacts of such accidents. However, there are only a few examples of construction failures, which show the economic impact on accidents during excavation because of the sensibility of the information. This paper presents two cases of excavation accidents, which were investigated by construction insurance company. The compensation for the accidents paid by the insurance company was compared with the estimated costs calculated based on the estimation method for excavation accidents proposed by our previous study. The comparison results showed that the estimate calculated by our method was much less than the actual compensation because the estimate solely focused on the construction costs whereas the compensation included other external factors.

• 기술혁신연구
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• 제6권2호
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• pp.122-158
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• 1998

This study empirically examined different patterns of collaborative R&D project with their key success factors(KSFs), using data from 82 projects in the Korean electronic parts industry. The patterns of R&D collaboration were categorized into 4 types by two criteria development motive(technology Push/market pull) and Project initiator (focal firm/partner). The bivariate relationships revealed that project characteristics (technological complexity, market uncertainty), management characteristics (participation in project formulation), problem solving characteristics(problem solving performance of the focal firm, users active role in problem solving, active role of university or research institute in problem solving) and success rates appear to be different among four types of collaboration. Each type of collaborative R&D projects also had different KSFs. The KSFs of type 1 (technology Push and focal firm initiation), for instance, include the strategic importance of the project, focal firms share of cost, active role of university or research institute in problem solving, while those of type 4(market pull and customer initiation) cover reliability of partner relationship, a time at partners involvement, information sharing. The findings suggest that the different contingencies brought different patterns and KSFs of collaborative R&D project, since different information, resources, and partners roles were needed to successfully implement the projects according to development motive and project initiator Finally, managerial, policy, and theoretical implications for the collaborative R&D activities in the Korean electronics parts industry were discussed, based on empirical results of this study.

• 한국지반공학회논문집
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• 제19권2호
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• pp.123-133
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• 2003

사면안정 신뢰성 해석을 통해 다양한 불확실성을 체계적으로 모델링할 수 있는 실용적 인 확률통계 기법을 제시한다. 새로운 제안식은, 지반성질의 확률적 특성화를 위해 공간적 변화와 공간평균으로 인한 분산감소뿐만 아니라 통계 및 측정오차까지도 고려하였다. 지진하중의 불확실성은 인공지진파를 대량으로 생성하고 이를 응답해석에 이용함으로써 반영하였다. 예제 해석결과, 한반도와 같이 지진이 활발하지 않은 지역(중약진 지진대)에서는 일반적 수준의지반성질 변화특성화가 지진위험도 특성화만큼이나 사면 파괴 위험도와 과도한 사면변형 계산값에 영향을 준다는 결론에 도달하였다.

• 산업공학
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• 제13권4호
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• pp.564-571
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• 2000

Manufacturing companies are implementing a so-called customer-centered supply chain management to have a competitive advantage. In these efforts, collaboration not only within a company but also with suppliers, partners and customers is emphasized. The fast delivery, reducing the total lead-time from development to delivery, is pursued more than ever, though the quality and cost are still importantly regarded. Die manufacturing companies are not exception from these trends, because a die is a necessary tool for almost manufacturing industries. The planning and scheduling system plays an important role in supply chain management. In this study, we address a scheduling problem of a die manufacturing company. The problem is very complex due to many reasons including the uncertainty in environment and the complexity of constraints. Considering the importance of due-date satisfaction and human planners' roles, we designed the solution algorithm and the user interface respectively. In the implementation phase, modeling constructs and basic solution algorithms of ILOG solver and ILOG scheduler are used. In the paper, the problem and the algorithm are described with ILOG constructs, and the experience of use is also addressed.