• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.61-69
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• 2020

Systems such as database and socal network systems have been broadly used, and their unexpected failure, with great losses and sometimes a social confusion, has received attention in recent years. Therefore, it is an important issue to find optimal maintenance plans for such kind of systems from the points of system reliability and maintaining cost. However, it is difficult to maintain a system during its working cycle, since stopping works might incur users some troubles. From the above viewpoint, this paper discusses minimal repair maintenance policy with periodic replacement, while considering the random working cycles. The random working cycle and periodic replacement policies with minimal repair has been discussed in traditional literatures by usually analyzing cases for the nonstopping works. However, maintenance can be more conveniently done at discrete time and even during the working cycle in real applications. So, we propose that periodic replacement is planned at discrete times while considering the random working cycle, and moreover provide a model in which system, with a minimal repair at failures between replacements, is replaced at the minimum of discrete times KT and random cycles Y. The average cost rate model is used to determine the optimal number of periodic replacement.

• Korean Business Review
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• v.11
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• pp.149-171
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• 1998

The most important thing in the Tourist Market Segmentation is to find descriptive variables which can describe the changes of tourist demand properly. There are many descriptive variables. Among them, vital statistical variables were proved to be effective. The strongest variable but which was studied much less is the Family Life Cycle. This study will focus on the relation between Family Life Cycle and Travel Behavior of Destination Choice. In this study, I will verify the validity of Family Life Cycle as a descriptive variable of Tourist Market Segmentation, and try to find the meaningful variable at each steps. Therefore, The purpose of this study is to explain the relation between Family Life Cycle and Travel Behavior of Destination Choice, to verify the validity of Family Life Cycle as descriptive variable and to find the strategy to respond to the increase in quantity and diversity of quality of Tourist Market. The studies on the Family Life Cycle should be updated continuously according to the change of family structure and it should be understood as standard for Tourist Market Segmentation in the public and private sphere.

• Journal of Korean Society for Quality Management
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• v.38 no.4
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• pp.540-548
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• 2010

We consider the problem of selecting the most profitable initial process mean and length of production cycle for manufacturing processes subject to a constant linear trend during the same cycle that varies after resetting the processes. Assuming that the quality characteristic of interest is normally distributed, the optimum initial process mean and the length of production cycle are jointly obtained by minimizing the expected loss per unit time. We assume that the quality loss function due to the deviation from the target value is quadratic and resetting loss is constant. We consider both cases of symmetric and asymmetric quality loss function. An illustrative example is given and sensitivity analysis performed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.1-9
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• 2010

To protect information resources, many organizations including private corporate and government employ integrated information security systems which provide the functions of intrusion detection, firewall, and virus vaccine. So, in order to develop a reliable integrated information security system during the development life cycle, the managers in charge of the development of the system must effectively distribute the development resources to the quality factors of an integrated information security system. This study suggests a distribution methodology that minimizes the total cost with satisfying the minimum quality level of an integrated information security system by appropriately assigning development resources to quality factors considered. To achieve this goal, we identify quality factors of an integrated information system and then measure the relative weights among the quality factors using analytic hierarchy process (AHP). The suggested distribution methodology makes it possible to search an optimal solution which minimizes the total cost with satisfying the required quality levels of processes by assigning development resources to quality factors during the development life cycle.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.68
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• pp.85-94
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• 2001

Most of customers want to know how to develop the computer system they want to get to use according to the their requirements. This study presents a Computer Integration management System for Quality (CISQ) model for system-integration organizations, which need to demonstrate their capability to consistently provide computer integrated system that meets customer satisfaction and applicable regulatory requirements. The Plan.Do.Check.Act(PDCA) cycle called by Doming wheel expresses the basic concept of continuous improvement action in order to emphasize on achieving business goal. It is useful for providing full competence of a system-integration organization to integrate management systems based on the international management system, and to take an advantage in its market. This study specifies International Certification Network Business Excellence Concept(IBEC) approach to ensure a harmonized integration of the variety of management systems and thereby produce synergy effect. The end part of this study specifies a Assessment Model including an assessment concept adding to the compliance audit according to the CISQ for the continuous improvement. A simple application on Failure Modes and Effects Analysis(FMEA) in testing phase in project life cycle has been done.

• Proceedings of the CALSEC Conference
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• 1999.07b
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• pp.501-508
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• 1999

In this paper, we discuss about the implementation of CITIS(Contractor Integrated Technical Information Service) which is information infrastructure for CALS. CALS concept is introduced by DoD(Department of Defense, US) to exchange technical data of product's life cycle electronically. This CALS concept is accepted by commercial industrial area and considered as a part of global concept of Electronic Commerce. CITIS- a service defined by MIL-STD-974- is about to be implemented by commercial industrial society, too. But, until now there is a few sites implementing CITIS and especially in Korea. In this paper, we discuss characteristics of some CALS/CITIS implementation and solutions, and introduce ETRI-CITIS.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.2
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• pp.35-48
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• 2011

In this paper, we have studied the impact of adopting XBRL (eXtensible Business Reporting Language) on information asymmetry in capital markets with the additional research on the usefulness of XBRL data how to improve the quality of accounting information. From the Kosdaq XBRL service, the samples are selected including 38 adopted companies and the 30 non-adopted companies for the paired analysis. The daily stock return volatility (VOLA) as independent variable and other several controlling variables have been added for the regression analysis to measure the impact on information asymmetry in capital markets. he analytical result indicated that the asymmetry hypotheses that XBRL data will give a significant impact on the capital market and will reduce the volatility, which are expected in the hypotheses. This is the first analytical research on the capital market and its impacts to the capital market from adopting XBRL based accounting information. Additionally, the analysis showed the impacts on the reporting cycle of accounting information and its usefulness of accounting data itself.

• World Technopolis Review
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• v.1 no.3
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• pp.186-191
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• 2012

To understand South Korea's economic success several contending paradigms have emerged, ranging from a neo-classical explanation to a statist perspective, and Schumpeterian structuralism. The Korean miracle can be seen as a product of multiple factors involving the strategic choice of export-led growth, timely and active human-capital investment, business activism, and individual innovative ideas. However, South Korea needs more complex and innovative ideas to continue its both economic growth and S&T Development. The ideas of Schumpeterian structuralist needs to be more emphasized. Changing state-society relations and subsequent policy choice are greatly influenced by the industrial life cycle. The industrial life cycle is closely related to the historical sequencing and diffusion of technology. The complex mixture of statist-market-Schumpeterian structuralist perspectives could lead more technologically advanced society in South Korea.

• Journal of Environmental Science International
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• v.22 no.3
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• pp.269-279
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• 2013

In this paper, an environmental assessment was carried out on the whole process of industrial business activities to establish a basic plan for climate change mitigation and energy independency. The whole process was divided into each discharge process in terms of water, air, solid waste, green house gases and refractory organic compounds. The flowcharts and basic unit of process were analysed for three years (2008-2010), being utilized as basic information for the life cycle assessment. It was found that the unit loading for the whole process significantly depends on changes in the operation rate change and highly concentrated wastewater inflow. About 35% of solid waste production was reduced by improving the incineration method with co-combustion in coal boiler, generating about 57% of electricity used for the whole process, and consequently reducing the energy costs. As the eco-efficiency index was found to be more than 1, compared to the previous years, it can be said that improvement in general has taken place.

• IE interfaces
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• v.25 no.2
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• pp.241-254
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• 2012

This paper studies the relationship between SCM(Supply Chain Management) metrics and corporate value (Tobin's Q) for manufacturing and wholesale/retail firms in Korea. Specifically, the multiple regression analysis is used to investigate the relationships 1) between inventory level, inventory turns, and days of inventory and Tobin's Q and 2) between cash-to-cash (C2C) cycle time including its components such as days of inventory, days sales outstanding, and days payable outstanding and Tobin's Q. The results indicate that there exist statistically significant negative relationships between inventory levels and days of inventory (DOI) and Tobin's Q. Also, we found that there exist commonly known negative correlations between days of raw materials inventory and days of work in process (WIP) inventory and Tobin's Q. For the C2C cycle time, we found that there -exists a statistically significant negative relationship between the C2C cycle time and Tobin's Q. Also, we found that there exist commonly known correlations between the two components of C2C cycle time and Tobin's Q such as the negative for DOI and days sales outstanding. This study clearly shows the negative relationship in general between inventory levels and corporate value and between C2C time and corporate value, and this kind of result has not been found by previous studies in Korea.