• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.198-206
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• 2005

The single sourcing policy, in which an automobile manufacturer purchases identical or similar parts from one supplier, has an advantage of scale economy. Meanwhile, multiple sourcing policy, which allows procuring similar parts from multiple suppliers, has benefits of dispersing risks and promoting competition among suppliers. This paper analyzes the procurement policies by presenting a model of the Japanese automobile parts trade. It concludes that maturity of technology involved should be taken into account besides above-mentioned factors which have traditionally been recognized. For parts produced using evolving technologies, the single sourcing enhances purchaser’s benefits because of the scale economy in learning process. In the meantime, multiple sourcing is more beneficial to the purchaser if the parts are based on mature technologies. In either policy, if the technology involved is evolving, motivating suppliers by returning a great part of cost reduction as a reward to them may eventually increase profit for the purchaser. The conclusion supports the situation where the number of suppliers is being cut down as the trend of modularization and system deliveries of parts progresses in the auto parts industry, and suggests that returning part of benefits to parts suppliers may be encouraged from the viewpoint of auto manufacturers’ own interest.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.153-162
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• 1997

M/G/1 queueing system is one of the most widely used one to model the real system. When operating a real systems, since it often takes cost, some control policies that change the operation scheme are adopted. In particular, the N-policy is the most popular among many control policies. Almost all researches on queueing system are based on the assumption that the arrival rates of customers into the queueing system is constant, In this paper, we consider the M/G/1 queueing system whose arrival rate varies according to the servers status : idle, set-up and busy states. For this study, we construct the steady state equations of queue lengths by means of the supplementary variable method, and derive the PGF(probability generating function) of them. The L-S-T(Laplace Stieltjes transform) of waiting time and average waiting time are also presented. We also develop an algorithm to find the optimal N-value from which the server starts his set-up. An analysis on the performance measures to minimize total operation cost of queueing system is included. We finally investigate the behavior of system operation cost as the optimal N and arrival rate change by a numerical study.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.2
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• pp.62-72
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• 1999

We consider a Direct Input Output Manufacturing System(DIOMS) which has a munber of machine centers placed along a built-in Automated Storage/Retrieval System(AS/RS). The Storage/Retrieval(S/R) machine handles parts placed on pallets for the machine centers located at either one or both sides of the AS/RS. This paper deals with the operational aspect of DIOMS and determines the optimal operating policy by combining computer simulation and genetic algorithm. The operational problem includes: input sequencing control, dispatching rule of the S/R machine, machine center-based part type selection rule and storage assignment policy. For each operating policy, several different policies are considered based on the known research results. In this paper, using the computer simulation and genetic algorithm we suggest a method which gives the optimal configuration of operating policies within reasonable computation time.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.165-183
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• 2003

The effect of red tide on the marine ecological system is so severe that many researches on the diverse subjects related to it have been conducted. Notwithstanding the enormous efforts and inputs the results of the past researches show no clear ways to deal with the HAB problems. As many researches are being conducted, the efficient and appropriate research project management systems as one of the critical factors for successful research are also needed as well as the fund and the capabilities of the researchers. It is assumed that the development of the evaluation and management systems for red tide research projects is so important and critical to enhance the researches and to utilize efficiently the physical and human resources for research. In this respect this study aims to present the evaluation and management scheme for the red tide researches that can not only decide the priority of the research subjects and tell the desirable research directions, but also support to develop the useful managerial policies and guidelines for the policy maker. The main subjects dealt with in this study are as follows : the characteristics of the HAB researches, the basic attributes and criterion of the research evaluation systems, the structure and design of the evaluation systems, and the development of the managerial policies by the type of the evaluation system. The conceptual scheme developed in this study is expected to be applied to the related areas and can suggest to the policy makers so many implications for identifying and setting the proper policy objects and management techniques. This study has a couple of weak points. It suggests only the conceptual scheme but not the applications so that the researches focusing on the applications in practical perspectives are needed to follow.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.1
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• pp.97-108
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• 2001

Design and evaluation of AGV-based material handling systems are very complicated due to the randomness and the large number of variables involved Vehicle travel time is a key parameter for designing and evaluating AGV systems. Although loaded travel time is relatively easy to estimate, determination of empty vehicle travel time is difficult due to the inherent randomness of material handling systems. Most previous studies assume that the empty vehicle travel time is the same as the loaded travel time or assume very specific environments. This paper presents new vehicle travel time models for AGV-based material transport systems. The research effort is focused on the estimation of empty vehicle travel time under various vehicle dispatching policies. Simulation experiments are used to verify the proposed travel time models.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.768-776
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• 1995

In a distributed computer system with star topology, the processing power of central node may be greater than that of peripheral nodes and the job arrival rate of each node may be different. The performance of load balancing may be very different according to the selection of sender criteria and receiver criteria for job transfer. But the optimal decision of sender and receiver criteria is very difficult in heterogeneous distributed computer systems. In this paper we propose effective destination decision policies using dynamic criteria such as mean job response time of a node and estimated response time of a job, instead of fixed threshold for dynamic load balancing.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.4
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• pp.143-152
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• 2009

This paper deals with a case which is focused on the policy development connected with IT, and verify its validity to enhance R&D capability for Korean steel industry. Korean steel industry, which is at a turning point from technological catch-up to technological frontier, should go ahead with open R&D system to be able to connect with other steel companies, universities and laboratories for its capability buildup. To meet such a challenge, IT should act a critical part in R&D capability enhancement. In this study we discuss not only IT-related support policies and validity of proposed policies through priority analysis, but also the role of government, company and academia within the framework of Triple Helix.

• Korean Journal of Childcare and Education
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• v.9 no.5
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• pp.513-538
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• 2013

As a childcare program of TaeHwa Christian Women's Institution in 1921, the childcare system in Korea was incepted. Since then, the political foothold of childcare system has steadily been advancing to provide high quality services to young children. In almost a hundred-year-history of public childcare in Korea, depending on the changes enforced on the related laws and regulations and varying perspectives over time, the administration office accountable for childcare policies has been authorized to the Ministries of Health, Social Affairs, Education, Labor, Home Affairs, Rural Development Administration, and/or others. But as of 1991, under the enactment of Infant and Child Care Act, it was changed to be administered by the unified authority of the Health and Social Welfare Ministry. Then, in 2004 and 2007, its statutory authority, respectively, transferred to the Ministry of Gender Equality and Family and back to the Ministry of Health and Social Welfare. Staring of the Infant and Child Care Act in 1991, Korean childcare policies have been managed by the dual systems of the Education Ministry and the Health and Social Welfare Ministry each holding jurisdiction over kindergartens and childcare centers, respectively. Faced with the recent marked decline of birth rate, diverse childcare policies are currently implemented in the pursuit of finding means to enhance the quality of childcare and to develop policies for the restoration of the low birth rate. This study presented distinct features of current childcare policies and discussed about future directions and challenges of these policies.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.120-128
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• 2018

OLED Display fabrication system is one of the most complicated discrete processing systems in the world. As the glass size grows from $550{\times}650mm$ to $1,500{\times}1,850mm$ in recent years, the efficiency of Automated Material Handling System (AMHS) has become very important and OLED glass manufacturers are trying to improve the overall efficiency of AMHS. Aiming to meet the demand for high efficiency of transportation, various kind of approaches have been applied for improving dispatching rules and facility layout, while simultaneously considering the system parameters such as glass cassettes due date, waiting time, and stocker buffer status. However, these works did not suggest the operational policy and conditions of distribution systems, especially for handling unnecessary material flows such as detour. Based on this motivation, in this paper, we proposed an efficient algorithm for improving detour transportation in OLED FAB. Specifically, we considered an OLED FAB simplifying OLED production environment in a Korean company, where four stockers are constructed for the delivery of Lot in a bay and linked to processing equipments. We developed a simulation model using Automod and performed a numerical experiment using real operational data to test the performance of three operation policies under considerations. We showed that a competitive policy for assigning alternative stocker in case of detour was superior to the current dedicated policy using a specified stocker and other considered policies.

• Journal of Distribution Science
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• v.11 no.1
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• pp.55-63
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• 2013

Purpose - As the members of the baby boomer generation have retired in earnest, the start-up market has received more attention than ever before. According to recent statistical data, an increasing number of entrepreneurs are in their fifties. There has been a continuous increase in promotional materials on small business issues published by start-ups. This means that senior start-ups have increased in number. A number of support systems have been established for youth start-ups, but there are few government support policies in place for the senior start-up market. Thus, this study suggests a number of constructive alternatives from the perspective of government policy and marketing strategy for entrepreneurs, in order to generate competitiveness in the start-up process, through examining the current state of the senior start-up and by diagnosing extant problems. Research design, data, methodology - This study gives a number of options regarding the government's support policies and the securing of competitiveness in order to vitalize senior business start-ups. As for the government's support policies, funding support policy, publicizing business start-up policies, and operating systematic mentoring policies before retirement have all been covered. In particular, in order for senior business start-ups to become competitive, development through mutual relations with diverse policies is urgently needed. The aging population is becoming an issue in Korea, so businesses for the aged, and the creation of jobs for these people, will become a social issue. Senior business start-ups are playing an important role in expanding enterprise productivity, in addition to enhancing national competitiveness. Expanding senior business start-ups is important, because they also serve to expand the national infrastructure. Productivity increase through continuous expansion is thus recommended. Results - In order to expand the competitiveness of business start-ups, marketing-related observations and learning in regard to customers are necessary for the baby boomer generation, and competitiveness for seniors is urgently needed. Conclusions - Studies on the business start-up policies for the domestic baby boomer generation are almost non-existent, and systematic studies on small businesses are necessary. Only the government is providing statistical studies for small businesses, and such research remains at a general level for entrepreneurs. Therefore, a support system that can actually assist entrepreneurs is essential. Continuous business start-up studies with respect to the baby boomers should be vitalized, to invigorate studies on competition. In order to supplement and strengthen foundational support, senior business start-ups must develop various competitive capabilities with a focus on the customer. The government and the various stakeholder agencies and organizations involved with start-up businesses must find ways to offer support to founders. Such support should include access to knowledge and legal and consultancy services in order to incubate the rapid increase in start-ups founded by seniors. Government support projects should be expanded to meet this end.