• Journal of the Korean Society for Railway
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• v.7 no.2
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• pp.93-98
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• 2004

For the reduction and efficient management of railway noise, first of all prediction of railway noise is necessarily requisted. At home and abroad many studies for prediction of railway nearby noise have been accomplished. But it is impossible to predict exactly for the Korean Railway, because the acoustic powers for each rolling stock used in Korea have not been built yet. So in this study, acoustic powers for each Korean rolling stock such as Samaeul, Mugungwha were builded acceding to the speed and rail support systems. Predicted results using the acoustic powers suggested in this study are compared with measured results and it is known that these acoustic powers can be used for precise prediction of railway noise.

• The Korean Journal of Financial Management
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• v.1 no.1
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• pp.133-149
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• 1985

The theory of option pricing has undergone rapid advances in recent years. Simultaneously, organized option markets have developed in the United States and Europe. The closed form solution for pricing options has only recently been developed, but its potential for application to problems in finance is tremendous. Almost all financial assets are really contingent claims. Especially, Black and Scholes(1973) suggest that the equity in a levered firm can be thought of as a call option. When shareholders issue bonds, it is equivalent to selling the assets of the firm to the bond holders in return for cash (the proceeds of the bond issues) and a call option. This paper takes the insight provided by Black and Scholes and shows how it may be applied to many of the traditional issues in corporate finance such as dividend policy, acquisitions and divestitures and capital structure. In this paper a combined capital asset pricing model (CAPM) and option pricing model (OPM) is considered and then applied to the derivation of equity value and its systematic risk. Essentially, this paper is an attempt to gain a clearer focus theoretically on the question of corporate stock risk and how the OPM adds to its understanding.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.552-552
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• 2000

In recent years, a number of successful nesting approaches have been developed by using the various heuristic algorithms, and due to their application potential several commercial CAD/CAM packages include a nesting module for solving the layout problem. Since a large portion of the complexity of the part nesting problem results from the overlapping computation, the geometric representation is one of the most important factors to reduce the complexity of the problem. The proposed part representation method can easily handle parts and raw materials with widely varying geometrical shape by using the redesigning modules. This considerably reduces the amount of processed data and consequently the run time of the computer. The aim of this research is to develop parametric macro for two-dimensional cutting stock on the Auto-CAD system. Therefore, this research can be called "pre-nesting"

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1655-1660
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• 2009

At the Rolling-stock, most important thing is thorough maintenance for safety as a mass transit. Recently, many studies of cost down method and acquisition of high reliability have being progressed with considering of safety. Maintenance cost is closely relative to the preventive maintenance. But generally the preventive maintenance is decided in compliance with an experience. So the study of cost down method at the preventive maintenance is difficult. In this study, many results of effectiveness and optimization for the preventive maintenance are checked. Then., it is possible that efficiency preventive maintenance method will be able to suggest.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.668-673
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• 2004

The Friction Stir Weld (FSW) has been prevailing in the rolling stock manufacturers now a day especially in Europe and Japan, that will be an inevitable welding method in Korean domestic railway industry in the near future. The Welding Institute (TWI) in United Kingdom (UK), who has the right of international patents, invented FSW. To meet the recommendation of Cullen's Report for Ladbroke Grove Rail Inquiry (LGRI) in UK, the FSW is considering for the only alternative welding method to improve the aluminium welding quality, i.e. for improve unzipping defect and crashworthiness on car body in Europe Railways within Railway Safety Research Program.

• Management & Information Systems Review
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• v.7
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• pp.381-400
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• 2001

Our country has been encountered with severe economic depression since IMF loan(1997). Korean economic system should be reformed according to the globalization and the world industrial trends based on adavanced technologies and skills. Todays the venture business should be considered to be the alternative of recovering Korean economy and increasing highly estimated values. Generally speaking, the venture business is defined as a new business with high risk-high return with new technical entrepreneurship. This treatise suggests the activating alternatives of the venture business in Korea. These alternatives are suggested as follows. First, several measures to incruit excellent technicians are suggested. These measures includes incruitment of parttime technicians, application of cooperative program of education training unemployees, the stock option system, a stock-sharing plan for the employees, etc. Second, in the financial aspect, activation of the foundation investment company, activation of the COSDAQ market, strengthening of technology security are suggested. Third, in the technical development aspect, amplification of inauguration assistant center, construction of technology accumulative network, etc. These measures will contribute to the development of Korean economy and the welfare of Korean people.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.50-53
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• 2001

In this paper, we applied the Utility Interactive Photovoltaic-Wind Hybrid Generation System for stock raising waste disposal system. For the power consumption reduction of proposed system, we used the electromotive control system. So as to verify the propriety of proposed system, we made a Pilot Plant and examined the system.

• International Journal of Railway
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• v.2 no.4
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• pp.175-179
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• 2009

The welding deformation and its prediction method at the HAZ (Heat-Affected Zone) are presented in this paper. The inherent strain method is well known as analytical method to predict welding deformation of large scale welded structure. Depend on the size of welding deformation in welding joints, the fatigue life, the stress concentration factor and the manufacturing quality of welded structure are decided. Many welded joints and its manufacturing control techniques are also required to railway rolling stock and its structural parts such as railway carbody and bogie frame. Proposed methods in this paper focus on the two different the inherent strain area at HAZ. This is main idea of proposed method and it makes more reliable result of welding deformation analysis at the HAZ.

• The Journal of Fisheries Business Administration
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• v.33 no.1
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• pp.1-18
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• 2002

The observer program is being utilized In various fishing areas and fisheries internationally and nationally due to the its expected effectiveness in fisheries management and the collection of bioeconomic data necessary in fisheries management policy. The timely gathered data by observers play substantially a major role in decision-making fisheries policy such as the change in management measures, the application of season closure and area closure and etc. The expected effectiveness of the observer program In fisheries management, generally mentioned, is that it would lead to the increase in stock size from which the level of harvest would consequently increases. This study is aimed to analyze this tentatively expected effectiveness of the observer program in fisheries management. The changes in stock size and the level of harvest over time are analyzed under the observer program assuming the fishermen bear the cost of the observer program by investigating the change in fisherman's fishing activity under the observer program and by combining this changed activity with the biological model. The level of fishing efforts of fishermen was decreased from the results of the increase in fishing cost caused by the observer cost and the decrease in catchable stock size restricted by observers. This reduced level of fishing efforts enables stock size to increase over time and therefore, the expected level of harvest increases as time goes on. Another benefit under the observer program is to reduce management costs from the fact that fishermen are responsible for the cost of the observer program and the avoidance cost of fisherman responding to the fisheries regulation could be eliminated from the surveillance of observer. Therefore, it may possible to accomplish the cost-efficient fisheries management policy.

• Journal of the Korean Operations Research and Management Science Society
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• v.1 no.1
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• pp.151-170
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• 1976

There are many cases of production processes which intermittently produce several different kinds of products for stock through one set of physical facility. In this case, an important question is what size of production run should be prduced once we do set-up for a product in order to minimize the total cost, that is, the sum of the set-up, carrying, and stock-out costs. This problem is used to be called scheduling of multiple products through a single facility in the production management field. Despite the very common occurrence of this type of production process, no one has yet devised a method for determining the optimal production schedule. The purpose of this study is to develop quantitative analytical models which can be used practically and give us rational production schedules. The study is to show improved models with application to a can-manufacturing plant. In this thesis the economic production quantity (EPQ) model was used as a basic model to develop quantitative analytical models for this scheduling problem and two cases, one with stock-out cost, the other without stock-out cost, were taken into consideration. The first analytical model was developed for the scheduling of products through a single facility. In this model we calculate No, the optimal number of production runs per year, minimizing the total annual cost above all. Next we calculate No$_{i}$ is significantly different from No, some manipulation of the schedule can be made by trial and error in order to try to fit the product into the basic (No schedule either more or less frequently as dictated by) No$_{i}$, But this trial and error schedule is thought of inefficient. The second analytical model was developed by reinterpretation by reinterpretation of the calculating process of the economic production quantity model. In this model we obtained two relationships, one of which is the relationship between optimal number of set-ups for the ith item and optimal total number of set-ups, the other is the relationship between optimal average inventory investment for the ith item and optimal total average inventory investment. From these relationships we can determine how much average inventory investment per year would be required if a rational policy based on m No set-ups per year for m products were followed and, alternatively, how many set-ups per year would be required if a rational policy were followed which required an established total average inventory inventory investment. We also learned the relationship between the number of set-ups and the average inventory investment takes the form of a hyperbola. But, there is no reason to say that the first analytical model is superior to the second analytical model. It can be said that the first model is useful for a basic production schedule. On the other hand, the second model is efficient to get an improved production schedule, in a sense of reducing the total cost. Another merit of the second model is that, unlike the first model where we have to know all the inventory costs for each product, we can obtain an improved production schedule with unknown inventory costs. The application of these quantitative analytical models to PoHang can-manufacturing plants shows this point.int.