• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3C
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• pp.224-232
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• 2012

Priority MAC is an important issue in every communication system when we consider differentiated service applications. In this paper, we propose a mechanism to support priority MAC based on multi-parameters for IEEE 802.15.7 visible light communication (VLC). By using three parameters such as number of backoff times (NB), backoff exponent (BE) and contention window (CW), we provide priority for multi-level differentiated service applications. We consider beacon-enabled VLC personal area network (VPAN) mode with slotted version for random access algorithm in this paper. Based on a discrete-time Markov chain, we analyze the performance of proposed mechanism under non-saturation environments. By building a Markov chain model for multi-parameters, this paper presents the throughput and transmission delay time for VLC system. Numerical results show that we can apply three parameters to control the priority for VLC MAC protocol.

• Industrial Engineering and Management Systems
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• v.3 no.1
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• pp.12-21
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• 2004

This paper investigates the design of a priority rule in a multi-product disassembly environment. Specifically, it is concerned with product scheduling by which the inventory control of disassembled parts can be incorporated into a priority rule to reduce part lead times. The part lead time consists of two components: flow time and supply delay. The primary focus of the paper is on the development of a disassembly priority rule that aims to reduce the supply delay. We propose a priority rule, called Minimum Distance (MD) rule, to improve the supply delay performance. Finally, we provide a comparative analysis on the performance of traditional rules and the new rule proposed in this paper via a simulation model.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.41-55
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• 2010

The aims of this study were to develop the suitable "system software" in chemical ranking and scoring (CRS) for the food hazardous chemicals associated with environmental emission and to suggest the priority lists of food contamination by environmental-origined pollutants. Study materials were selected with reference to the priority pollutants list for environment and food management from domestic and foreign research and the number of study materials is 103 pollutants (18 heavy metals, 10 PBTs, 10 EDs, and 65 organic compounds). The Food-CRS-Korea system consisted of the environmental fate model via multimedia, transfer environment to food model, and health risk assessment by contaminated food intake. We have established that health risks of excess cancer risks, hazard quotients (HQs) by chronic toxicity and HQs by reproductive toxicity convert to score, respectively. The creditable scoring system was designed to consider uncertainty of quantitative risk assessment based on VOI (Value-Of-Information). The predictability of the Food-CRS-Korea model was evaluated by comparing the presumable values and the measured ones of the environmental media and foodstuffs. The priority lists based on emissions with background-level-correction are 15 pollutants such as arsenic, cadmium, and etc. The priority lists based on environmental monitoring date are 17 pollutants including DEHP, TCDD, and so on. Consequently, we suggested the priority lists of 13 pollutants by considering the several emission and exposure scenarios. According to the Food-CRS-Korea system, arsenics, cadmium, chromes, DEHP, leads, and nickels have high health risk rates and reliable grades.

• 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 Korean Institute of Industrial Engineers
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• v.26 no.3
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• pp.213-219
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• 2000

Combination of AHP priorities is essential in combining opinions of multiple experts. There are two ways to get combined priorities: one is to combine the pairwise matrices and obtain the priority from it and another is to combine the individual priorities. In this paper, we use a Dirichlet probability model to combine the priorities from multiple experts. The resulting combined priority is an expected value of the model, which is a function of some measure of the homogeneity and credibility of the group of experts. We give some interpretations of this measure and illustrate them by numerical example.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.122-125
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• 2000

The Analytic Hierarchy Process (AHP), a decision making model, which is more applicable than other methods to R&D project selection, particularly when it is applied to intangibles. The objective of this paper is to develop an extended model of the AHP which Is linked to Cross Impact Analysis to assist in the ranking of a large number of technological alternatives. In this study, we developed a priority setting algorithm which considers the cross-impact of the future technology alternatives and thus developed an integrated cross-impact hierarchical decision-making model, which sets the priority by considering technological forecasting and technology dependency

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.2014-2027
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• 1994

A queueing model with two input streams of different service priorities is studied. Specifically, IBP+BP/D/1 with head-of-line priority is analyzed. IBP and BP stand for Interrupted Bernoulli Process and Bernoulli Process respectively. The BP-stream customers have the higher service priority over the IBP-stream customers. An exact analysis of this priority queue is presented to derive the distributions of the state of the system at steady state, the waiting time distributions for each class of customers, and the interdeparture time distributions. The numerical results of the analysis are presented to show how the various parameters of the low and high priority arrival processes affect the performance of the system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1084-1090
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• 2012

The objectives of this study were to investigate needs and determine the priority of needs of women immigrants on life-long education. The subjects of the study were 121 women immigrants who participated in life-long education programs before. Borich priority determination formula and Locus for Focus Model were used for the determination of the priority of needs. The result indicated that the priority of needs were in order of education for employment, education for child rearing, and education for pregnancy, delivery and health life. The suggestions for program development of women immigrants are discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.4
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• pp.21-29
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• 2007

We derive priority decision making on healthcare service technology standardization in the home network through the decision support process with industry professionals. We configured a research group with 4 industrial areas including Industry, Academic, Research Institution and Medical Institution. And we also applied AHP methodology for the priority decision making. The research group decides an evaluation criteria which are consisted of marketability, technology, ripple effect, strategy for national policies in order to make a priority for healthcare service on a home network. And it is also decided 7 fields and 24 sub-fields, technically. In order to make a priority for the standardization, we use an AHP methodology, that is more objective and feasible, as a decision tool. After two-phase survey that consists of paper survey and face to face meeting, we get a conclusion that home healthcare content is at the top and then wireless home network follows it.

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.189-208
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• 2017

This study is for figuring out major components of construction quality infrastructure and suggesting improvement plan by benchmarking global best practice model and analyzing gap between the model and sample practice. Based on improvement plan, researcher could derive major characters and components of construction quality infrastructure, and also about the priority among core competency components of construction quality experts. The result showed that the 'human resource' was ranked the best priority followed by 'method' 'environment', 'equipment' among major characters and components of construction quality infrastructure. Also, for core competency components of construction quality experts, 'number of years in work places' was the best priority, and the 'professional knowledge on engineering' was another priority ranked. Far from general perception on competency components, 'academic education' ranked the last. It may allude that the current education system in this country is not effective in developing competency of quality engineers. In summary, this study shows professionalism of quality engineer is the most important thing in all the components.