• Industrial Engineering and Management Systems
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• v.15 no.4
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• pp.354-363
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• 2016

Due to uncertain environment, various parameters such as price, queuing length, warranty, and so on influence on inventory models. In this paper, an inventory-queuing-pricing problem with continuous review inventory control policy and batch arrival queuing approach, is presented. To best of our knowledge, (I) demand function is stochastic and price dependent; (II) due to the uncertainty in real-world situations, a fuzzy programming approach is applied. Therefore, the presented model with goal of maximizing total profit of system analyzes the price and order quantity decision variables. Since the proposed model belongs to NP-hard problems, Pareto-based approaches based on non-dominated ranking and sorting genetic algorithm are proposed and justified to solve the model. Several numerical illustrations are generated to demonstrate the model validity and algorithms performance. The results showed the applicability and robustness of the proposed soft-computing-based approaches to analyze the problem.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.6
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• pp.21-32
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• 1982

The Ministry of the Energy and Resources is planning to invest a great deal of public funds in the energy conservation measures in order to conserve the energy. This study aims at applying the project scheduling model, especially to the energy conservation measures. In the study, we develop the project scheduling model, which is based on the modified Rorie-Savage problem. And the model is applied to the X-enterprise, which is one of the leading metal industry in the nation. The result shows that the model enables the top management to choose the set of projects which promises the largest profit among the entire projects. It appears that the proposed policy of the study is more profitable than the existing policy which is namely based on the qualitative consideration.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.4
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• pp.466-475
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• 1999

A backward Dynamic Programming(DP) model for the optimal facility replacement decision problem during a finite planning horizon is presented. Multiple alternative challengers to a current defender are considered. All facilities are assumed to have finite service lives. The objective of the DP model is to maximize the profit over a finite planning horizon. As for the cost elements, purchasing cost, maintenance costs and repair costs as well as salvage value are considered. The time to failure is assumed to follow a weibull distribution and the maximum likelihood estimation of Weibull parameters is used to evaluate the expected cost of repair. To evaluate the revenue, the rate of operation during a specified period is employed. The cash flow component of each challenger can vary independently according to the time of occurrence and the item can be extended easily. The effects of inflation and the time value of money are considered. The algorithm is illustrated with a numerical example. A MATLAB implementation of the model is used to identify the optimal sequence and timing of the replacement.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.52-59
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• 2021

In this paper, we propose a system that allows small business owners focusing on the restaurant business to easily understand the management situation, and to manage the operation and management centering on the cost of food materials and profits and losses. In general, the metadata structure is different depending on the POS system, so it is necessary to first develop a standardized metadata model for a food material cost management system for small business owners in various industries. For that reason, the system proposed in this paper was applied to the cost management app by referring to the development of a data model using the metadata standard. In addition, in order to implement a cost profit/loss management system for small business owners in the restaurant industry, it was designed to support standardized metadata models from various types of POS systems, and is a hybrid app that can support a smart environment. Interface) was configured.

• Educational Technology International
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• v.10 no.2
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• pp.63-83
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• 2009

The purpose of this study was to investigate the cognitive mechanism of e-Learning contents development projects on the basis of the Shared Mental Model theory perspective. To pursue the purpose, a theoretical model and several hypotheses were developed based on relevant literature. Thirty five (35) e-Learning contents development teams composed of 202 instructional designers from for-profit professional e-Learning companies in Korea were participated in this study. For the analyses of the fit of the Model and parameter estimations, Structural Equation Modeling (SEM) method was employed. As hypothesized, e-Learning contents development team members' interaction leads to higher SMMs which in turn facilitate member satisfaction within the team. Meanwhile, the frequency of interaction among team members decreases as projects progress.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.19-24
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• 2002

The result of management profits create to manufacturing activity. The gross sale profits must be maximum thraw spend of economic value. The profit maximum have to management based key value driver of manufacturing activity. The important factors of the study model are manufacturing value driver(MVD) and manufacturing value added(MVA). We show necessity of management based value by means of a case study.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.2
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• pp.45-56
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• 1994

This paper the profit maximizing order quantity model to the symmetric oligopoly consisting of sellers of a homogeneous product who compete with each other for the same potential buyers. Buyers are classified by type, each selecting an optimal purchase quantity in response to the nonlinear quantity discount pricing schedule given by the sellers. Symmetric equilibrium and the economic quantities that sellers must determine are analysed in a Cournot framework, which explicitly depend on the number of sellers. Economic implications are obtianed from the optimality conditions based on themarket share paraments which are used to characterize the competitior's marketing strategy.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.182-185
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• 1996

This paper analyzes how the international callback services affect on the international telecommunications market. We present a simple game-theoretic model to compare the equilibrium outcomes before and after the arrival of callback operator. We find that the callback service arises from the inefficiencies in the national telecommunications market and the accounting rate system between international telecommunications carriers. Also, we identify the conflicting interests among the governments and carriers, by examining how the callback service affects the collection rate, quantities demanded, carrier's profit and social welfare of each country.

• Journal of Korean Society for Quality Management
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• v.19 no.1
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• pp.95-102
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• 1991

This paper is concerned with the production-distribution problem with multiple conflicting objectives. In reality business firms should take account not only of the profit maximization but of various environmental criteria, namely customer services, in order to improve the business logistics. A production-distribution model of goal porgramming type considering the lead time and distribution cost by products is constructed, the solution algorithm is developed, which is based on the Ignizio's method. A numerical example is given to demonstrate the applicability of goal programming for production-distribution problem.

• Korean System Dynamics Review
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• v.2 no.1
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• pp.113-129
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• 2001

본 논문을 통하여 인터넷 환경의 B2B 마켓플레이스에서 경쟁 기업들 간에 왜 그리고 어떻게 협력(Collaboration)이 가능한지 살펴본다. 시스템 다이나믹스 시뮬레이션을 활용하여 잠정적으로 도달한 결론은 경쟁 기업들의 그러한 협력이 시장 수요의 증가를 가져오고 이를 통해 증대된 이윤을 실현할 수 있을 때 그와 같은 관계가 가능하다는 것이다. 즉, 경쟁기업간 협력이 지속가능하기 위해서는 기업간 협력이 시장 수요를 확대하고 그 결과로 개별 기업이(비록 시장 점유율이 하락하는 경우가 있을지라도) 더 많은 절대적인 이윤을 얻을 수 있어야 한다. 경우에 따라서는 파이를 분배하기 전에 파이의 절대적인 크기를 키우는 것이 좋다는 것과 유사한 논리이다.