• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.54-68
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• 1995

In this paper, we develop detailed algorithms for implementing the so-called Limited Column Generation procedure for Local Access Telecommunication Network (LATN) Design problem. We formulate the problem into a tree-partitioning problem with an exponential number of variables. Its linear programming relaxation has all integral vertices, and can be solved by the Limited Column. Generation procedure in just n pivots, where n is the number of nodes in the network. Prior to each pivot, an entering variable is selected by detecting the Locally Most Violated (LMV) reduced cost, which can be obtained by solving a subproblem in pseudo-polynomial time. A critical step in the Limited Column Generation is to find all the LMV reduced costs. As dual variables are updated at each pivot, the reduced costs have to be computed in an on-line fashion. An efficient implementation is developed to execute such a task so that the LATN Design problem can be solved in O(n$^{2}$H), where H is the maximum concentrator capacity. Our computational experiments indicate that our algorithm delivers an outstanding performance. For instance, the LATN Design problem with n = 150 and H = 1000 can be solved in approximately 67 seconds on a SUN SPARC 1000 workstation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.1128-1135
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• 2003

e-Transformation of an enterprise requires the collaboration of business processes to be suited to the business participants' purpose. To realize this collaboration, business processes should be implemented as components and the system developers could be able to reuse the components for their specific purpose. The first step of this collaboration is the discovery of exact components for business processes. A dilemma, however, is the fact that there are thousands or even millions of business processes which vary from one enterprise to another. Moreover, business processes could be decomposed into multiple levels of semantics and classified into several process areas. In general, discovery of exact business processes requires understanding of widely adopted classification schemes such as CBPC, OAGIS, or SCOR. To cope with this obstacle, business process metadata should be defined and managed regardless of specific classification schemes to support effective discovery and reuse of business processes components. In this paper, a methodology to discover business process components published in different semantic levels is proposed. The proposed methodology represents the metadata of business process components as topic maps stored in a registry and utilizes the powerful features of topic maps for process discovery. TM4J, an open-source topic map engine, is modified to support concept matching and navigation. With the implemented tool, application system developers can discover and publish the business process components effectively.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.1
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• pp.161-176
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• 2005

In a situation that ordinal preferences on multiattribute weights are captured, we present two solution approaches: an exact approach and an approximate method. The former, an exact solution approach via interaction with a decision-maker, pursues the progressive reduction of a set of non-dominated alternatives by narrowing down the feasible attribute weights region. Subsequent interactive questions and responses, however, sometimes may not guarantee the best alternative or a complete rank order of a set of alternatives that the decision-maker desires to have. Approximate solution approaches, on the other hand, can be divided into three categories including surrogate weights methods, dominance value-based decision rules, and three classical decision rules. Their efficacies are evaluated in terms of choice accuracy via a simulation analysis. The simulation results indicate that a proposed hybrid approach, intended to combine an exact solution approach through interaction and a dominance value-based approach, is recommendable for aiding a decision making in a case that a final choice is seldom made at single step under attribute weights that are imprecisely specified beyond ordinal descriptions.

• Journal of the Korean Society of Food Culture
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• v.15 no.2
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• pp.123-137
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• 2000

Korea market of food service industry has been increased greatly since early 90's with the emergence of professional catering business and the expansion of school food service. Because of the characteristics of food service establishment, feeding many people at a time, there is always a high potential of foodborne outbreak which requires special sanitary management to prevent. Currently, many catering businesses are interested in HACCP(Hazard Analysis Critical Control Points), a new sanitary management system, and are trying to develop HACCP Plans for their food service establishment. Microbiological hazard analysis, a most important step for developing HACCP Plan, provides also basic information for evaluating sanitary aspect of prepared foods and their materials. There are not extensive data of microbiological hazard analysis for food service operations, especially for prepared foods and raw materials, which are helpful for developing a HACCP Plan. The extensive microbiological hazard analyses for 65 prepared foods and 51 raw materials selected from a couple of food service establishment were performed in this research. These results will provide useful information to determine hazards for developing a HACCP plan, and also to understand sanitary status for prepared foods and raw materials in food service establishment.

• Journal of the Korean Society of Food Culture
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• v.20 no.6
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• pp.638-643
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• 2005

As Korea has approached the aging society, older Koreans have become an important force in restaurant sales today. To succeed with this silver market, it is important for restaurant managers to know who they are and what factors influence older Koreans' eating-out decision making process. The purpose of this study was to investigate the effect of the silver consumers' education level on eating-out decision making process. Data were collected from 178 older consumers above 55 years old and analyzed using the descriptive statistic analysis, MANOVA, and one-way ANOVA. The results showed that the elderly consumers' education level significantly influenced the decision making process in determining where to eat out. Significant differences were found in the Problem Recognition Step(Wilks' Lambda=0.817, F=2.991), Information Search Step(Wilks' Lambda=0828, F=2.218), Alternative Evaluation Step II(Wilks' Lambda=0.741, F=3.596), Purchase Decision Step(Wilks' Lambda=0.859, F=2.223), and the Post-Purchase Behavior(Wilks' Lambda=0.885, F=1.780). The higher education level was, the more directly involved in the eating out decision process. The elderly consumers with university education were likely to 'propose to eat out by themselves'(F=9.346), to obtain restaurant information from the 'printed materials'(F=7.452), to go to 'family restaurant'(F=9.057), 'Japanese restaurant'(F=8.7891) and 'fine dining restaurants'(F=3.936), and to directly express their emotion when they had complaints about restaurant service(F=3.206). In conclusion, older Koreans will become more healthy and wealthy which means the dining out activity will be an important part of their life to socialize with people. Therefore, food service operations should consider the elderly consumers' needs and expectation of restaurant services and actively position themselves for this new market segment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.319-322
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• 2019

There are many techniques for locating users in an indoor spot. Among them, WiFi fingerprinting technique which is widely used is phased into a data collection step and a positioning step. In the data collection step, all surrounding Wi-Fi signals are collected and managed as a list. The more data collected, the better the accuracy of the indoor position based on Wi-Fi fingerprint. Existing high-quality data collection and management methods are time consuming and costly, and many operations are required to extract and generate data necessary for machine learning. Therefore, we research how to collect and manage large amount of data in limited resources. This paper presents efficient data collection methods and data generation for learning.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.909-916
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• 2021

The purpose of the research to analyze SMEs' technological innovation performance in the Special Region of Yogyakarta based on green supply chains. This study's technology innovation performance is influenced by environmental management practices, green supply chain integration, and supply chain knowledge-sharing. This research is important because many SMEs are underdeveloped in terms of technology innovation performance. Technology innovation performance shows that innovation has a multi-dimensional ecological performance in organizations. Therefore, SMEs' sustainable supply chain could be achieved by managing operations, support, and information by focusing on environmental and social issues to maximize the entire chain. This study used primary data. The number of respondents in this study was 200 SMEs that have implemented green supply chain management practices. The data collection method used was a questionnaire. The data analysis technique tool used is a two-step approach to SEM-AMOS. The results of this study indicate that SMEs are willing to implement a green supply chain to increase their performance. The technological innovation performance model of this study is acceptable. The findings of this research suggest that companies must be encouraged to maintain and increase the implementation of green supply chain integration and better supply chain knowledge-sharing with improved technological innovation performance enhancements.

• Korean Management Science Review
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• v.15 no.2
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• pp.143-152
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• 1998

This paper focuses on the determining the optimal replacement interval and the corresponding minimum cost of replacement for the renewal T-53 engine. It is assumed that sample failure data of T-53 engine are drawn from the mixed population, and then parameters of the failure distributions are estimated. On the basis of the above situation, the Multi-step Weibull distributions are estimated and then the optimal replacement time of T-53 engine is determined. This paper shows that if the replacement time is reduced to 2000 hours, the 2,217won of the replacement cost per unit time is only saved but also reliability of the T-53 engine is increased.

• Korean Management Science Review
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• v.15 no.2
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• pp.125-142
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• 1998

The aggregation on linear large-scale dynamic systems is examined in this paper and a "two-step" approach is proposed. In this procedure, the aggregated system consists of two subsystems. The first subsystem represents aggregation through the retainment of dominant eigenvalues of the original system, leading to a first approximation of the desired output of the original system. The purpose of augmenting it with a second subsystem is to provide an estimation of the error on the first approximation, thus permitting a second correction to the output approximation and resulting in an output approximation of greater accuracy. Optimization techniques are discussed for the determination of unknown parameters in the aggregated system. These techniques use minimization principles of certain suitable performance indices and are developed for both single input-single output and multiple input-multiple output system. Numerical examples illustrating these procedures are given and the results are compared with those obtained using existing methods. Finally, a pharmacokinetics problem is studied from the aggregation point of view.

• Korean Management Science Review
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• v.11 no.3
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• pp.13-26
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• 1994

In this paper we studied an integration scheme of some simplex algorithms and some efficient techniques to get the stable solution in linear programming code. And we developed a linear programming package (LPAK) by introducing this scheme and techniques. In LPAK three different algorithms were integrated, which were two primal simplex algorithms using Two phase method and big-M method respectively, and the dual simplex algorithm. LPAK introduces several heuristic techniques in each step of simplex method in order to enhance the stability and efficiency. They were new heuristic methods in structuring initial basis, choosing entering variable, choosing dropping variable and performing reinversion. The experimental results on the NETLIB problems showed that LPAK provided the stable solutions.