• Journal of the Korean Mathematical Society
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• v.35 no.3
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• pp.691-712
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• 1998

We consider an M$_1$, M$_2$/G/1/ K retrial queueing system with a finite priority queue for type I calls and infinite retrial group for type II calls where blocked type I calls may join the retrial group. These models, for example, can be applied to cellular mobile communication system where handoff calls have higher priority than originating calls. In this paper we apply the supplementary variable method where supplementary variable is the elapsed service time of the call in service. We find the joint generating function of the numbers of calls in the priority queue and the retrial group in closed form and give some performance measures of the system.

• Korean Management Science Review
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• v.19 no.2
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• pp.139-153
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• 2002

The Analytic Hierarchy Process (AHP) is known as a very useful decision-making model developed for obtaining the relative weights of alternatives through pairwise comparison in the context of hierarchical structure. In this paper, we propose a method to reflect the reliability of evaluators in the process of pairwise comparison. This method is applied to the evaluation of aerospace technology alternatives. We have conducted a questionnaire survey for S company that is one of the representative aerospace companies in Korea. A questionnaire was designed for obtaining both the priority with considering the reliability of evaluators' importance weights (the modified AHP priority) and the priority with assuming equally reliable evaluators' importance weights (the AHP priority) in order to compare the priority derived by each of two methods. The result shows that there exists the difference hard to neglect between the final priorities gained by two methods.

• Journal of the Korean Chemical Society
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• v.38 no.6
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• pp.418-426
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• 1994

This study was aimed at the detection of 40 semi-volatile organic base/neutral compounds from soil among 129 priority pollutants listed by EPA. Two extraction procedures, sonication extraction and Soxhlet extraction, were studied as a extraction and concentration method for priority pollutants in soil. Extracts were analyted by GC/MS-SIM(selected ion monitoring). The analytical methods were tested by standard compounds spiked into blank soil. Accuracy and precision of the methods were measured by calculation of mean recovery and mean relative standard deviation. And the method detection limits were estimated.

• Korean Management Science Review
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• v.23 no.2
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• pp.93-107
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• 2006

This paper attempts to improve the typical DEA model that is often used as a performance evaluation method for service firms. The after-sales service system in a Korean electronic company is chosen as a sample case. The performance evaluation method currently practiced in the firm was reviewed and some critical issues of the current method were discussed. DEA model would be considered a solution for solving those Issues. However, typical DEA models has various drawbacks in determining the weights over evaluation criteria. Proposed is the priority-constrained DEA model that accommodates the strategic Importance of each evaluation criterion. The results of the proposed model are compared with those of typical DEA models. It is shown that the priority-constrained DEA model is superior to the others in terms of evaluation quality.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.195-209
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• 2016

This research determined priority of quality improvement of public institution's education service by using ASC for importance and applying Topsis, a multi-standard decision-making method simplifying various attributes and scales of evaluation items and deciding the comparative priority for satisfaction and discussed the differences so as to measure the quality of public institution's educational service and examine the priority of education service' quality improvement. This research classified the characteristics of quality improvement. As a result, it's significant to suggest positive direction and method to improve satisfaction and education service's quality from an angle of demander by analyzing educational satisfaction of education service quality of public education institution and effects on the following improvement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.5
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• pp.218-228
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• 1985

The input messages in communication network are processed according to their priority. If the messages which are had different types of priority are excessively entered to communication network in such prioruty process, and if high priority messages are continuously entered, the messages which are had law priority are experinenced delay beyond their priority. In this case, we proposed average delay compensation method to compensate contonuous delay in low priority messages.

• Analytical Science and Technology
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• v.10 no.6
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• pp.395-402
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• 1997

The comparison study between EPA method 3050 and the test method offered by Ministry of Environment in Korea was performed to investigate a matrix effect on extraction. In this study, 12 inorganic priority pollutants(Cd, Cr, Cu, Pb, Ni, Zn, As, Sb, Se, Hg, Be, Tl) were spiked to the sludges and estuary sediment samples. The extracts were analyzed by AAS, HG-AAS, and ICP/MS. Results were discussed in terms of recoveries, relative standard deviations, and the method detection limits. Mean recovery of the elements except As, Sb, and Se was 93% when the procedure of EPA method was applied. The Korean extraction method, however. showed a significant matrix effect to give very poor recoveries.

• Journal of Korean Society for Quality Management
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• v.43 no.2
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• pp.127-140
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• 2015

Purpose: To obtain the area for improvement, the Importance-Performance analysis(IPA) uses relatively simple questions, that is, satisfaction and importance at attribute level. However, no attempt has been made to consider the gap between own company's performance and those of competitors in IPA, in the field of quality management. This study is aimed to suggest a new prioritizing method for improvement and to test for validity of the proposed technique. Methods: This study used data collected from Song and Lim(2015), which is satisfaction of employees, customers and competitors as well as importance data for 7 quality attributes of K animal hospital. A correlation comparison with other priority methods such as Bacon(2003)'s model and Matzler and Hinterhuber(1998)'s QI index is conducted. Results: The priority results by the proposed method shows better in correlation coefficient with customer perceived priority for improvement than other methods. Conclusion: From the result of the current study, it can be concluded that the result of the proposed method is valid, while it is relatively easy to understand and analyze, and therefore no additional survey is necessary for improvement priority.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.263-272
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• 2012

In an attempt to analyze the policy priority on civil servant's education training policy as human resource management in this study, a positive analysis with the experts using AHP method was conducted. Summarizing the outcome of the study; First, in terms of relative priority of the evaluation elements by sector, the education training operation system, among education training program, education training evaluation, and education infrastructure, was analyzed as the most important element. Second, as a result of analyzing the priority of detail sectors of civil servant's education training, Action learning education program was proved to be the top priority project education training program aspect and education training operation system was also evaluated as the top priority project in education training agency budget expansion aspect, education training and personnel administration link was evaluated as the top priority project education training evaluation, and trainer secure was proved to be the top priority education infrastructure. Such outcome of the project is expected to make commitment for evaluating the civil servant's education training policy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1884-1892
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• 1993

In push out scheme, high priority cell which arrives when the buffer is full pushs low priority cell. The PBS scheme provides priority by variable threshold in buffer.In this paper, for Controlling congestion in ATM network we propose buffer processing method in which the PBS scheme has variable threshold. And we analysis The performance of this scheme. As a result of simulation, the proposed push out scheme with variable threshold reduces the loss of low priority cell compared with existing push out scheme. This proposed method not only reduces the loss of high priority cell like existing push out scheme but also reduces the loss of low priority cell by variable threshold.