• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.579-588
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• 2009

Enterprises and governments currently utilize COTS (Commercial off-the-Shelf) based information systems which are a kind of component based systems. Especially, COTS are widely utilized as components of information security systems and information systems. This paper suggests an appropriate adaptation level and a cost effective priority to replace security functional components in security environment. To make a cost effective decision on adapting security functional components, this paper develops a hierarchical model of information security technologies and analyzes findings through multiple decision-making criteria.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.129-140
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• 2007

The planning procedure of a transit operation consists of design, operation, and evaluation according to the research characteristics. There are some review studies on the operation and evaluation procedure, but the research on the design procedure has not yet been organized systematically. In this study, the research on transit system design was reviewed and the model structure and its solution method were arranged. The decision variables of the design procedure are network structure, line spacing or position, stop spacing, dispatching headway, and fleet size. In the analytical research on design procedure, system total cost is generally used as the objective function. System total cost is comprised of user cost, which is the sum of user access, waiting, and travel cost, and operating cost. Total cost of the transit system, used as the objective function, has the unique minimum because it is differentiable. There is a certain decision variable that makes the derivative of the objective function equal to zero and the second derivative of the objective function is positive. Therefore the decision variable that makes the first derivative of the objective function zero is the optimum that minimizes the objective function, and each of the cost components of the objective function become the same. This study is expected to help understanding about the research on the design procedure of transit operation planning and to help be a catalyst for relevant research.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.207-211
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• 2008

The importance of cost management in early stage has been increasing due to market change and competition severence in construction industry. Because the adjustable budget is only 20% after finishing design stage, the critical decision is made in the early stage. However, in the early stage, the design information is not enough to make crucial decision. Therefore, this research suggests the predicting method on the purpose of accurate cost estimation. The parametric estimation is appropriate for the early stage, especially it has the strength of rapidity in cost estimation. This research analyzes 84 actual data of public apartment on the scale of $11{\sim}15$ stories, and then performs the correlation analysis between cost and influence factors. After eliminating the parameters which causes the problem of multicollinearity, this research derived the formula through the multi-regression analysis.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.183-190
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• 2011

The paper is to analyze multi-attributes for expanding new renewable energy in agricultural sectors which have environmental, technical, economic, and social factors consisting of 15 attributes which have both positive and negative impacts. We applied the analytic hierarchy process (AHP) to data from opinion polls. As a result of the AHP survey, the overall results indicate that the respondents more weight on economical factor than environmental, technical, and social factors for expanding new renewable energy. At the lowest level, a comparison of individual 15 attributes within three factors shows that fixed cost highest in multi-attributes, followed by operating cost, technical superiority. To achieve the public acceptance about expanding new renewable energy in agricultural sectors, the policy-makers should take all relevant factors into account through the decision-making process by the public opinions.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.3
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• pp.345-356
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• 1995

The aim of this paper is to analyze the batch service queueing model M/M(a, b ; ${\mu}_k/1$) under general bulk service rule with mean service rate ${\mu}_k$ for a batch of k units, where $a{\leq}k{\leq}b$. This queueing model consists of the two-dimensional state space so that it is characterized by two-dimensional state Markov process. The steady-state solution and performane measure of this process are derived by using Matrix Geometric method. Meanwhile, a new approach is suggested to calculate the two-dimensional traffic density R which is used to obtain the steady-state solution. In addition, to determine the optimal service initiation threshold a, a decision model of this queueing system is developed evaluating cost of service per batch and cost of waiting per customer. In a job order production system, the decision-making procedure presented in this paper can be applicable to determining when production should be started.

• Journal of the Korean Operations Research and Management Science Society
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• v.25 no.3
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• pp.41-48
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• 2000

We consider the question of warranties for repairable items. During the warranty period, each time an item fails the manufacturer has the obligation to restore the item to operational condition either by repairing the item or by replacing it by a new item. In this paper, we consider a warranty policy for making this decision based on the condition of the failed item. For products with phase-type lifetime distributions where the phases represent the condition of the item, we develop algorithms to determine the expected cost of servicing a warranty and use it in making the repair/replacement decision. illustrative numerical examples are presented.

• Journal of the military operations research society of Korea
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• v.17 no.1
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• pp.84-104
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• 1991

Up to the present, the evaluation measures in the production and inventory management have been studied under the pre-condition that the costs for major factors(e.g,. cost of carrying inventory, cost of demand shortage) are given easily, although in practice, it is difficult. The case in which multiple participants have a different viewpoints in production and inventory management has not been studied, in spite of its frequent occurrence. This study suggests a production and inventory model with multiple objectives corresponding to major factors and the related interactive algorithm based on the preference structures of participants. The problem can be solved through a weighting vector generated by an interaction with participants. The concept of equity is also used in order to guarantee the reasonable distribution of group utility in determining the individual relative weights of participants. This study includes the reality of the model and the decision process in the production and inventory management.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.14-20
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• 2003

Supply chain is the link that moves products between suppliers, manufactures, wholesalers, distribution, retailers and ended consumers. Supply chain management(SCM) is a way to supervise the flow of products, materials and information as they move along the supply chain. In the recent years, Most of the companies are in a hurry the introduction of SCM to obtain international competitiveness. The goal of SCM is to optimize the supply chain, which can not only reduce inventories, but may also create a higher profit margin for finished goods by giving customers exactly what they want. There are four major decision areas (location, production, inventory, transportation) in supply chain management, and there are both strategic and operational elements in each of these decision areas. This paper is concerned with the integrated production planning problem including not only the production cost but also the transportation cost in supply chains, and an efficient algorithm using genetic algorithm and quickest path method is presented to solve the problem.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.3
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• pp.289-295
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• 2008

The shared-route decision algorithms in multicasting communications networks to provide the internet-based services such as IPTV, remote education/health, and internet broadcasting are presented. The three main measures of maximum delay, average delay and estimated delay between each node and member are adopted. Under the Mesh network with the uniform random cost between each node, the algorithm's performance is compared to the optimal solution with the minimum cost by all enumeration. The simulation results show that the algorithm using the estimated delay outperforms the other two methods.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.209-210
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• 1999

In the case of paper plant engineering company, one of the most important critical problems is to accurately estimate the cost and the delivery time of the project. This is necessary for the company to win a bidding and to have some room for negotiation. Moreover, the company needs to have time to process all the relevant informations to make timely response to, and deal with the changing conditions of the bidding environments as quickly as possible. One of the popular methodology dealing with this kind of situation is an effective "decision support system," and may researches are currently been done on this subject. In this article, and effective decision support system is developed which can provide automatic delivery time and cost estimates from which plant engineering company may be benefited.