• Journal of Environmental Science International
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• v.25 no.12
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• pp.1661-1671
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• 2016

Water quality in Nakdong river was analyzed using 699 monitoring data sets including flow rates and water quality concentrations collected at 195 tributary monitoring stations (the priority management areas: 35 stations, the non-priority management areas: 160 stations) in 2015. The highest average concentrations of all data for BOD, COD, T-N, T-P, SS, and TOC were 30~600 times higher than the lowest concentrations while the highest average loading rates were 800,000~2,700,000 times higher than the lowest loading rates. Because of the very large differences in the concentrations and loading rates, the variation of the concentrations and loading rates in a priority management monitoring station for BOD, T-P, and TOC was analyzed using the coefficient of variation, the ratio of the standard deviation value to the mean value. For BOD, T-P, and TOC, the coefficients of variation for concentration were mostly less than 100%, whereas the coefficients of variation for loading rate ranged from 31.1% to 232.2%. The very big difference in the loading rates was due to the large variation in flow rates. As a result of this, the estimation of water quality at each monitoring station using the average values of the concentrations and loading rates might be not rational in terms of their representativeness. In this study, new water quality analysis methods using all collected monitoring data were suggested and applied according to the water quality standard in medium-sized management areas.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.71-80
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• 2014

This study is performed to determine the priorites of the evaluation factors for the improvement of fire emergency medical service by increasing it's efficiency to protect the people's lives effectively, and by recognizing it's mid-long term development. Based on the output of the analysis, the critical evaluation factors of the fire emergency medical services to be improved shall be identified, and shall be intended to use strategically for increasing the efficiency of all the activity in the EMT service, and also for providing the basic date to product and manage the good quality services. To calculate the priority of the evaluation factor for each level as shown on this study, AHP(anaysis hierarchy process) with pairwise comparison method is applied. According to the priority analysis for the evaluation factors in main category (evaluation zone), 'medical service professional aspect' is recognized as highest one, and 'service infrastructure aspect', 'service management aspect' are indicated in order. According to the priority analysis for the evaluation factors in evaluation index, 'professional personal arrangement' in the service infrastructure aspect, 'appropriateness and timeliness of emergency medical care' in the medical service professional aspect, and 'clinical training' in the service management aspect are respectively recognized as most important factors.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.147-155
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• 2004

The goal of this paper is to offer a quantitative decision model using Quality Function Deployment(QFD). We consider the factors outsourcing that affect the benefits of the organization and the fifth alternatives that were selected to be considered for outsourcing as customer requirements and technical attributes in QFD. For selecting the outsourcing system, we compute the priority considering interdependencies among alternatives. Thus this paper propose a decision model, which uses the quality function deployment to help practitioners set priority and users in structuring the outsourcing problems.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.3
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• pp.41-51
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• 1994

The Analytic Hierarchy Process (AHP) is widely used for evaluation of large projects. If a group of experts with different expertise are involved in a AHP decision, they need some way to aggregate their opinions. In this paper, we suggest a way to aggregate the experts' priorities in a given hierarchy using the concept of the Bayesian decision analysis. A criterion that can be used for screening out unreliable data is introduced, and it is used for priority aggregation. Some numerical results are shown to illustrate the procedure.

• Korean Management Science Review
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• v.20 no.2
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• pp.151-163
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• 2003

Although there has been growing interests in outsourcing the logistics sectors in the industry, not much research was undertaken to provide the processes and standards in choosing the right 3PL for the company. In this research, we attempt to provide the 3PL selection criteria and its priority orders. We surveyed and interviewed the various industry experts and analyzed results using Analytic Hierarchy Process(AHP). The study reveals that manufactures and logistics companies have different understanding of the selection criteria and priorities in outsourcing the 3PL.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1104-1110
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• 2006

In this paper we present a simple approach to the joint queue length distribution in the nonpreemptive priority M/G/1 queue. Without using the supplementary variable technique, we derive the joint probability generating function of the stationary queue length at arbitrary time.

• Journal of the Korean Operations Research and Management Science Society
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• v.15 no.1
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• pp.117-133
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• 1990

This paper is concerned with determining a minisum location with jockeying for a server on a probabilistic network in which each customer type enters the network system permitting with jockeying through a specified node and a nonpreemptive service policy is in effect. An algorithm to locate a single Fixed Priority Queue Median with Jockeying (FPQMJ) on acyclic networks is developed by using the Generalized Benders' Decomposition technique. The results are then extended to a general network.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.3
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• pp.45-59
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• 2011

OFDMA systems have been expected to be widely used to provide multimedia services over wireless channels. To evaluate performance of the OFDMA system, power should be considered as system resource as well as subcarriers. This study propose a queueing traffic model incorporating two kinds of resources (power and subcarriers), and an extended model giving a priority to handoff calls over new calls. Some extensive experiments are conducted to illustrate the usefulness of the proposed traffic model.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.577-582
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• 1998

In nuclear power plant, it has been the important object to reduce the occupational radiation exposure (ORE). Recently, the optimization concept of management science has been studied to reduce the ORE in nuclear power plant. In optimization of the worker allocation, the collective dose, working time, individual dose, an total number of worker must be considered and their priority orders must be thought because the main constraint is necessary for determining the constraints variable of the radiological worker allocation problem. The ultimate object of this study s to look into the change of the optimal allocation of the radiological worker as priority order changes. In this study, the priority order is the characteristic of goal programming that is a kind of multi-objective linear programming. From a result of study using goal programming, the total number of worker and collective dose of worker have changed as the priority order has changed and the collective dose limit have played an important role in reducing the ORE.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.3
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• pp.417-423
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• 2024

This study compared and analyzed the importance of command priority between railway traffic controllers through pairwise comparison of AHP analysis. 27 railway traffic controllers working on metropolitan railway control center, urban railway control center, and unmanned driving control center responded. As a result of the analysis, all the railway traffic controllers generally recognized the train driving control and train signal control as the most important priorities. For the controller in the manned driving system, a train driving control was the highest at 0.375. On the other hand, the controller based on unmanned driving recognized train signal control as the highest priority at 0.469. In the result of the AHP analysis considering all the variables, the braking system was the highest priority at 0.19 based on manned train driving. On the other hand, the controller based on unmanned train driving recognized wired and wireless network systems and SCADA as the highest priority at 0.267.