• International Journal of Reliability and Applications
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• 제18권1호
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• pp.9-20
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• 2017

In this paper, we consider a renewable repair-replacement warranty strategy with age-dependent minimal repair service and propose an optimal maintenance model during post-warranty period. Such model implements the repair time limit under warranty and follows with a certain form of system maintenance strategy when the warranty expires. The expected cost rate is investigated per unit time during the life period of the system as for the standard for optimality. Based on the cost design defined for each failure of the system, the expected cost rate is derived during the life period of the system, considering that a renewable minimal repair-replacement warranty strategy with the repair time limit is provided to the customer under warranty. When the warranty is finished, the maintenance of the system is the customer's responsibility. The life period of the system is defined and the expected cost rate is developed from the viewpoint of the customer's perspective. We obtain the optimal maintenance strategy during the maintenance period by minimizing such a cost rate after a warranty expires. Numerical examples using field data are shown to exemplify the application of the methodologies proposed in this paper.

• 대한전기학회논문지:전력기술부문A
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• 제51권12호
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• pp.597-602
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• 2002

The restructuring of power industry is still going on all over the world for last several decades. Many kinds of restructuring model have been studied, proposed, and applied. Among those models, power pool is more popular than other. This paper assumes the power pool market structure having competitive generation sector, and a new method is presented to build a bidding strategy in that market. The utilities participating in the market have the perfect information of their cost and price functions, but they don't know which strategy to be chosen by others. To define one's strategy as a vector, we make utility's cost/price functions into discrete step functions. An utility knows only his own strategy, so he estimates the other's cost/price functions into discrete step functions. An utility knows only his own strategy, so he estimates the other's strategy using Nash equilibrium or stochastic methods. And he also has to forecast the system demand. According to this forecasting result, his payoffs can be changed. Considering these all conditions, we formulate a bidding game problem and apply noncooperative game theory to that problem for the optimal strategy or solution. Some restrictive assumption are added for simplification of solving process. A numerical example is given in Case Study to show essential features and concrete results of this approach.

• 아태비즈니스연구
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• 제14권2호
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• pp.101-118
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• 2023

Purpose - The purpose of this study is to find out how a company can do reasonable cost calculations in a simple way and establish profitability improvement strategies based on the results. Design/methodology/approach - In this study, a case that compounding company K applied TDABC was studied. A case study was conducted on the process of company K reviewing and applying TDABC and the process of implementing the cost calculation for each product by applying TDABC, and establishing a profitability improvement strategy for each product based on the results. Findings - Company K rearranged the production standard information of the compounding industry such as productivity and batch size of each product to apply TDABC. Cost calculation was performed for each product according to the revised production standard information. After the cost calculation for each product was carried out, Company K established a strategy to improve profitability of each product. The profitability improvement strategy was implemented in two ways: a cost reduction strategy and a product price increase strategy. As a result of the final strategy execution, the profitability of each product was improved. Research implications or Originality - This study found a reasonable costing standard in consideration of the specificity of the research target company, and applied it to cost calculation cost for each product. It contains the process of establishing production and sales strategies for each product based on the cost calculation results. It is expected that this case study will serve as a good reference material for establishing cost calculation and profitability improvement strategies in similar businesses.

• 품질경영학회지
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• 제44권2호
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• pp.309-320
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• 2016

Purpose: The purpose of this study was to investigate if companies' efforts of environmental management practices have positive effect on the companies' performance in the first stage of study. In the second stage, we tried to confirm whether the degree of companies' making efforts on cost leadership strategy and quality leadership strategy function as moderate variable on relationship between environmental management practices and performance. Methods: The collected data through survey were analysed using multiple regression model in the first stage of the study and moderate regression model in the second. Results: The results of this study are as follows; environmental management practices have positive effect on corporate performance. Moreover, much effort on quality leadership strategy has limited significant moderate effect on relationship between environmental management practices and performance, while much effort by companies on cost leadership strategy does not have significant moderate effect on the relationship between the two variables. Conclusion: Manufacturing and services companies in Korea need to make effort for environmental management practices to improve corporate performance. Moreover, if that efforts are combined with quality leadership strategy, they can expect synergy effect with environmental management practices for performance improvement.

• 한국항공운항학회지
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• 제14권2호
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• pp.45-55
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• 2006

Air transportation industry becomes more competitive because that the restrictions on new access to market were eased and related enough for each airline to choose the freight rate and the route without rein. New competitors are pursuing convergence strategy which focuses on low freight rate as a niche strategy for increasing market share by stimulating low cost demand. This strategy is now spreading all over the world such places as Europe, Asia, Oceania and etc. As of December 1, 2004, hundreds of low cost carriers are participating actively in the market and finding their level as a new strategic group in the air transportation industry with expanding their market. In case of USA, however, many airlines, which had newly entered to the market, went into bankruptcy in the mid-1980s. People Express in USA established in 1980 is one of the examples of failure. In case of Japan, Hokkaido International Airline, a typical low cost carrier which established in 1997, filed for bankruptcy. This study is for examining the strategic implication closely through the study on management strategy and cases of failure of low cost carriers.

• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.248-256
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• 2015

With the dramatic increase in mobile traffic in recent years, some of the limitations of mobility management frameworks have magnified. The current centralized mobility management (CMM) strategy has various problems, such as a suboptimal routing path, low scalability, signaling overhead, and a single point of failure. To overcome these weaknesses in the CMM strategy, the Internet Engineering Task Force has been discussing distributed mobility management (DMM) strategies. The fundamental concept of a DMM strategy is to distribute the mobility anchors closer to the users. While the distribution of mobility anchors results in low-cost traffic delivery, it increases the signaling cost. To reduce this higher signaling cost, we propose a new DMM strategy applying the pointer forwarding technique. The proposed strategy keeps the existing tunnels and extends the traffic path as much as possible. In this paper, we analyze the performance of the pointer forwarding-DMM strategy and discuss its pros and cons.

• 한국멀티미디어학회논문지
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• 제8권7호
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• pp.953-960
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• 2005

모바일 컴퓨팅 환경은 네트워크가 손상되기 쉬우며 모바일 호스트(Mobile Host: MH)를 지원하는 모바일 서포트 스테이션(Mobile Support Station: MSS)이 안정적이지 못하다. 따라서 오류가 발생했을 경우, 저장된 정보를 복구하기 위해서는 많은 양의 네트워크 비용이 요구된다. 안정적인 복구를 위해서는 이미 보내진 메시지를 어떤 방식으로 저장할 것인가 하는 것과 어떤 핸드오프 기법을 사용해서 복구해 낼 것인가 하는 점을 고려해야 한다. 본 논문에서는 모바일 호스트의 이동성에 따라 복구 기법을 달리하는 ST(Switching Trickle) 기법을 제안한다 제안된 기법의 성능평가를 위해 이동성에 따라 점차 증가하는 누적비용을 시뮬레이션 한다. 실험 결과를 통해 기존에 구현된 기법들과 비교하여 제안된 기법에서 전체적인 비용이 감소된 것을 확인할 수 있다. 뿐만 아니라 제안된 기법은 MH의 이동성이 크지 않을 경우. 체크포인트(checkpoint)와 메시지 로그 정보를 안정적으로 저장할 수 있다.

• 한국구조물진단유지관리공학회 논문집
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• 제11권6호
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• pp.131-142
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• 2007

생애주기비용을 고려한 교량의 설계 및 유지관리에 있어서, 점검진단, 보수보강 등에 소요되는 직접적인 비용뿐만 아니라 간접적인 비용인 도로이용자비용은 중요한 비용항목으로 고려되고 있다. 직접비용과 비교하여 상대적으로 추정이 곤란한 도로이용자비용의 추정을 위하여 우회도로의 효과를 고려한 이용자지연비용과 차량운행비용의 정식화를 수행하고, 시간지체에 따른 도로이용자비용의 추정을 위한 회귀모델 개발을 위하여 교통해석과 회귀분석을 수행하였다. 개발된 회귀모델을 생애주기 비용 및 성능 기반 유지관리 전략 수립에 적용하여 도로이용자비용이 생애주기분석에 미치는 영향을 분석하고, 개발된 모델의 적용성에 대해서 고찰하였다. 도로이용자비용은 생애주기분석에 기초한 유지관리전략수립에 큰 영향을 미치며, 개발된 회귀모델은 교량의 도로이용자비용의 추정에 실용적으로 활용될 수 있을 것으로 판단된다.

• 설비공학논문집
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• 제12권2호
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• pp.140-149
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• 2000

A comparative analysis was peformed on the operation cost at partial loads between ice storage systems with the two conventional control strategies, i.e., storage priority and chiller priority. The storage priority control is shown to be more economic for small cooling loads, while the chiller priority control is superior when the cooling load is as large as the design value. Based on this finding, a new control strategy is devised for an ice-storage system to minimize the operation cost at any cooling load. The new control strategy is found to be comparable to the chiller priority for large cooling loads, while it is more economic for small loads compared to the conventional control strategies. The practicality of the new control strategy is also confirmed through a performance test applying the new control strategy to an existing ice-storage system.

• 아태비즈니스연구
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• 제12권2호
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• pp.61-79
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• 2021

Purpose - The purpose of this study was to analyze the impact of a company's competitive strategy on corporate performance in the highly competitive Chinese automotive industry. Design/methodology/approach - This study collected 14 survey data from automotive companies in China which be listed more than one year. We chosen the exploratory study with deriving research assignments, and the final research results are presented as propositions to proceed with the study. Findings - First, in the Chinese automobile industry, a company's competition strategy has a positive impact on corporate performance. and also the Differentiation strategy and the Low-cost strategy both have a positive impact on corporate performance. In addition, a company pursuing the Differentiation strategy that it would achieve better corporate performance than a company pursuing the Low-cost strategy. Second, it has been shown that the hybrid strategy rather than the pure strategy in the Chinese automobile industry can achieve higher corporate performance. Research implications or Originality - First, the type of competitive strategy in Chinese automotive industry were identified through the original strategies presented by Porter and Murray, and the impact of the Low-cost and the Differentiation strategies on corporate performance was analyzed. Second, contributing to the study of pure and hybrid strategies that are still under discussion now. Third, it also suggested practical implications that companies in China's automotive industry should pursue cost or differentiation advantages to secure competitive advantage.