• 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.

• International Journal of Quality Innovation
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• v.9 no.2
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• pp.129-147
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• 2008

This research is to investigate the effect of the improvement of investment environments with investment incentive on Korean national economy by looking into the foreign investment support system in Korea. To this end, first research model was set up based on our literary study and case study was conducted on 150 foreign companies that were located in industrial complex for foreign companies, received the tax benefit and government subsidization. And it was found that even though the foreign companies were contributing to the national economy in general such as in the area of production, export, employment, development of technology, there was no significant contributory difference between the investment incentive beneficiary and non-beneficiary foreign companies. Therefore it deemed reasonable to reconsider the way Korean government supports foreign companies in Korea and to reinforce foreign companies' relevance to national policy agenda with additional incentives to foreign companies located in comparatively less developed areas. As a way to promote foreign investment, promotion of investment infra such as improvement of follow-up services, openness to foreign investment, industrial deregulations in capital area, revitalization of free economic zone, efficient system to promote foreign investment and the reinforcement of public relations were considered necessary, especially the upgrading of economic structure and the integrated management of domestic and foreign investors deemed necessary for the optimal distribution of the industries.

• Environmental and Resource Economics Review
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• v.27 no.4
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• pp.639-666
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• 2018

This paper analyses the investment options of groundwater development project under water price uncertainty. The optimal investment threshold price which trigger the investment are calibrated base on monopolistic real options model. Stochastic dynamic model is set to reflect the uncertainty of water price which follows the GBM (Geometric Brownian Motion) process. Our finding from non-cooperative investment decision model is that uncertainty of water price could deter the groundwater investment by considering the existence of option values. For policy markers, it is easy to manage 'charges for utilization of groundwater' rather than 'performance guarantee ratio' when managing groundwater investment with pricing policy. And it is necessary to make comprehensive and well-designed policies considering the characteristics of regional groundwater reservoir and groundwater developers.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.171-184
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• 2023

Purpose: First, this paper suggests an alternative approach to find optimal portfolio (stocks, bonds and ESG stocks) under the maximizing utility of investors. Second, we include ESG stocks in our optimal portfolio, and compare improvement of welfares in the case with and without ESG stocks in portfolio. Methods: Our main method of analysis follows Brennan et al(2002), designed under the continuous time framework. We assume that the dynamics of stock price follow the Geometric Brownian Motion (GBM) while the short rate have the Vasicek model. For the utility function of investors, we use the Power Utility Function, which commonly used in financial studies. The optimal portfolio and welfares are derived in the partial equilibrium. The parameters are estimated by using Kalman filter and ordinary least square method. Results: During the overall analysis period, the portfolio including ESG, did not show clear welfare improvement. In 2017, it has slightly exceeded this benchmark 1, showing the possibility of improvement, but the ESG stocks we selected have not strongly shown statistically significant welfare improvement results. This paper showed that the factors affecting optimal asset allocation and welfare improvement were different each other. We also found that the proportion of optimal asset allocation was affected by factors such as asset return, volatility, and inverse correlation between stocks and bonds, similar to traditional financial theory. Conclusion: The portfolio with ESG investment did not show significant results in welfare improvement is due to that 1) the KRX ESG Leaders 150 selected in our study is an index based on ESG integrated scores, which are designed to affect stability rather than profitability. And 2) Korea has a short history of ESG investment. During the limited analysis period, the performance of stock-related assets was inferior to bond assets at the time of the interest rate drop.

• Journal of Korean Institute of Industrial Engineers
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• v.8 no.1
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• pp.61-67
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• 1982

This paper is concerned with the optimal control of dynamic expansion and operation of a single capacity under deterministic demand. Three cases of financing mode are considered : unlimited borrowing, debt aversion, and self financing. Using the net revenue as the objective function, the optimal paths of production and investment are analytically derived.

• East Asian mathematical journal
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• v.33 no.1
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• pp.23-36
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• 2017

We study an optimization problem for HARA utility function under a multi-scale Heston's stochastic volatility model. We investigate a practical strategy that do not depend on the incorporated factor which is unobservable in the market.

• The Korean Journal of Financial Studies
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• v.3 no.2
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• pp.235-256
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• 1996

This paper studies evaluation of illiquid assets by using a consumption and investment model. In particular, the paper defines the marginal values of illiquid assets and shows how optimal consumption and investment policies are related to the marginal values. The general results are illustrated by two concrete examples.

• East Asian Economic Review
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• v.16 no.1
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• pp.25-66
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• 2012

The paper analyzes the effect of expected future demand on the investment decisions of multinational enterprises. In particular, I explore the issue of the timing of switching between exporting and FDI in the host developing country and explicitly incorporate the firm's attitude toward risk in the model. The model demonstrates that the optimal time for switching to FDI depends on the expected future demand and the degree of its uncertainty.

• Journal of the Chungcheong Mathematical Society
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• v.32 no.2
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• pp.215-224
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• 2019

We investigate the optimal consumption and investment decision problem of an agent whose time preference is time-inconsistent. Specifically, for a time-separable utility function, the agent's subjective discount factor is supposed to be changed randomly in the future. We provide closed-form solutions in the presence of income process. The method can be extended into the case with a stochastic income process.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.428-433
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• 2010

According as economy grows, demand for power increases and satisfaction of customer about electricity quality is rising. There is in trend that investment expense by continuously increased supply of electric power equipment is on the increase continuously, but management efficiency improvement through curtailment of supply of electric power equipment investment expense through efficient operation is required rather than to increase investment. In this study, reconsidered about 6 divisions 3 ties that is distribution line basis configuration of Daejeon Geumsan area and analyzed division and tie present condition of truthful distribution System. Examined problem analyzing average division number, tie number and tie switch number, searched about most suitable division that consider load. Hereafter, I wish to take advantage of analysis result in most suitable division and tie of truthful distribution system for power failure section reduction and investment expense curtailment.