• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.261-267
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• 2009

The purposes of this article is to analyse how market competition of credit card company affect price(interest rate) and survival length of card users. This paper uses individual account data from a large Korean credit card company during the periods from 2002 to 2006. The findings of our study are as follows. First, market competition of credit card company have a negative effect with interest rate of credit card. Second, market competition of credit card company have a affirmative effect with survival length. Finally, The effect of Increasing delinquency rate due to price increase is smaller than decreasing delinquency rate due to extending survival length.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.3
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• pp.81-96
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• 2006

We consider a rental company that dynamically manages Its capacity level through capacity addition and return While serving customer with its own capacity, the company expands its capacity by renting items from an outside source so that it can avoid lost opportunities of rental which occur when stock is not sufficient. If stock becomes sufficiently large enough to cope with demands, the company returns expanded capacity to the outside source. Formulating the model into a Markov decision problem, we identify an optimal capacity management Policy which states when the company should expand its capacity and when it should return expanded capacity after capacity addition. Since it is intractable to analytically find the optimal capacity management policy and the optimal size of capacity expansion, we present a numerical procedure that finds these optimal values based on the value iteration method. Numerical analysis is implemented and we observe monotonic properties of the optimal performance measures by system parameters, which are meaningful in developing effective heuristic policies.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.3
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• pp.197-204
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• 2004

This paper deals with a supply chain with a company and its contractor that produces products by the OEM contract with the company. The supply chain of interest has two distinct features. First, the company is the supplier of raw material required in the production at the contractor. Second, the company and its contractor make a delivery shipment arrangement that the replenishment lead time is determined depending on demand process. We show that the optimal inventory policy is monotonically changed as either the replenishment setup cost or inventory holding cost becomes increased or decreased. We also present asymptotic properties of the optimal inventory policy when either the number of outstanding customer orders or the inventory level becomes very large.

• Journal of Information Processing Systems
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• v.18 no.1
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• pp.48-58
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• 2022

Blind restoration for motion-blurred images is always the research hotspot, and the key for the blind restoration is the accurate blur kernel (BK) estimation. Therefore, to achieve high-quality blind image restoration, this thesis presents a novel windowed-total-variation method. The proposed method is based on the spatial scale of edges but not amplitude, and the proposed method thus can extract useful image edges for accurate BK estimation, and then recover high-quality clear images. A large number of experiments prove the superiority.

• Journal of Technology Innovation
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• v.8 no.2
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• pp.97-117
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• 2000

TOEM strategy is widely used in Japan and Korea because of the diverse advantages such as cost sharing, technology transfer, equipment lease and base technology acquisition between parent company and OEM supplier. There are, however, some disadvantages that (1)OEM suppliers are likely to be reactive to environmental changes and (2) may have difficulty in building competitive position and long-term growth. When the parent company relocates its plant to foreign countries to achieve lower labor cost or to enhance value added this change will affect directly the OEM supplier's outcome. The parent company's divestiture from existing businesses will also affect the OEM supplier. For the OEM supplier to survive in face of these strategic changes it must enter the new countries with the parent company. Alternatively, the OEM supplier must actively diversify its technologies based on its core capabilities of existing product and process technologies and seek new business arenas. The strategy of aligning its businesses with the parent company's new business strategy allows the OEM supplier to share the new market while it requires the OEM supplier to develop core capabilities. In Korea many small and medium sized OEM suppliers are dependent on a few large companies. For the industry structure in Korea where industry concentration is extremely high OEM suppliers should move away from the past strategy, where they are dependent on the parent company's low profitability businesses. They should actively enter new businesses for which parent companies enter to achieve long-term growth.

• Current Photovoltaic Research
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• v.10 no.4
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• pp.121-132
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• 2022

The need for floating photovoltaic is being emphasized to expand renewable energy but low residents' acceptance is a major obstacle to the deployment of floating photovoltaic. Using the discrete choice experiment, this study analyzed the preferences for community-based floating photovoltaic projects and proposed a method to increase the residents' acceptance of floating photovoltaic projects. The estimates of the marginal willingness to accept (MWTA) of the distance, the coverage ratio, the landscape, the project owner (public institution), and the project owner (large company) are -0.69%p/km, 0.13%p/%p, -0.57%p, -2.95%p, -1.73%p, respectively. According to the result of simulation analysis, the residents' acceptance is significantly higher when the project is operated by a public institution, with a choice probability of 58%, than when the project is operated by a private company, with a choice probability of 29%, 12% for a large and small company, respectively. In addition, as a result of the analysis of the expected returns, the results show that the closer the distance from the residence to the power plant, the higher the expected return.

• Korean Journal of Mathematics
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• v.16 no.2
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• pp.145-156
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• 2008

When we consider a life insurance company that sells a large number of continuous T-year term life insurance policies, it is important to find an optimal strategy which maximizes the surplus of the insurance company at time T. The purpose of this paper is to give an explicit expression for the optimal reinsurance and investment strategy which maximizes the expected exponential utility of the final value of the surplus at the end of T-th year. To do this we solve the corresponding Hamilton-Jacobi-Bellman equation.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.139-142
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• 1987

It is important to evaluate the voltage characteristics of diesel generator as an emergency power supply in nuclear power plant. On loss of offsite power sources, emergency safeguard loads required to safely shutdown the reactor should be supplied by diesel generator. This paper presents the dynamic stability program to evaluate diesel generator performance as an emergency power system. The results Indicate the diesel generator ability to start the motors successfully seems to life in its impedances and inertias.

• Journal of the Korea Safety Management & Science
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• v.2 no.1
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• pp.117-127
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• 2000

It is said that a large part of losses caused by company is attributet to the loss manpower material resources by industrial accident. To alleviate industrial accident, machine-oriented safety supervision is superior to that of manpower-oriented in spite of diversified efforts, in many aspects. It will not secured a sense of safety if people can not utilize machines correctly despite excellent machines. As a part of preventing industrial accident, industrial safety education is aimed to improvement of productivity of company through exact research of actual condition of industrial safety education.

• Journal of Labour Economics
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• v.36 no.2
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• pp.37-65
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• 2013

This study compares the return to seniority and experience among different groups of workers. Skilled workers in large company appear to enjoy the biggest seniority premium, while non-regular workers and small company workers hardly have any. Trade union did not have significant effect. Return to experience increased especially in large firms. Nonparametric model specification test shows that the biases for returns to seniority and experience of 30 years to be between -25~29%, and -42%~6%, respectively.