• Korean Management Science Review
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• v.18 no.1
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• pp.29-39
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• 2001

Traditionally, companies have been concerned with making an investment decision either to go now or never to go forever. However, owing to the development of the theory of options pricing in a financial investment field and its introduction to the appraisal of real investments in these days, we are now partially allowed to derive the value of a managerial flexibility of real investment projects. In this paper, we derived a general mathematical model to price the option value of real investment projects assuming that they have only one-period of time under which uncertainty exists. This mathematical model was developed based on the opportunity cost concept. We will show a simple numerical example to illustrate how the mathematical model works comparing it with the existing models.

• Journal of Korean Society for Quality Management
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• v.23 no.2
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• pp.10-27
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• 1995

This paper illustrates a method of developing a function of quality costs in manufacturing systems. It begins with a discussion of the problem statement of this research. A review of existing literatures related to quality costs and economic design of quality inspection methods are discussed. Next mathematical models that quantify the production cycle time and quality costs are formulated. This paper ends with an example that demonstrates the usefulness of the model and highlights the importance of using a system approach. The main contribution of this work is the more realistic considerations of the four types of quality costs (prevention cost, appraisal cost, internal failure cost, external failure cost) in manufacturing systems.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.2993-3002
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• 2018

This case study introduces the process of developing the technology rating evaluation model for investment. The technology evaluation rating model for investment is a project that the Financial Services Commission and the Ministry of Commerce, Industry and Energy collaborated to expand the scope of technology finance from loan to investment. The technology evaluation model for investment was developed with the aim of predicting high growth companies. The model consists of a statistical model and an expert model. Here, statistical models were modeled by using logistic regression analysis. Expert models gathered opinions of experts and identified the weight of each evaluation item and set the model. The rating system of the model is composed of 10 grades. The distribution of the model was consistent with KTRS grade distribution. Interestingly, the emphasis is on technology and marketability. In the technology valuation grade model for the goddess, there is a considerable difference from the emphasis on managerial competence or business performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.1
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• pp.7-16
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• 2003

At present, company has to produce a product that consumer like with a competitive price, a good quality, and a fitting time to supply. Process control and quality control are very important to supply with a product uniformly and inexpensively. Process control is given much weight in the quality control in manufacturing system. Statistical process controls(SPC) that are used in process generally have major impact on manufacturing, product design activities, and process development potentially. Control charts in statistical process control method can be interpreted the data from quality characteristics in production process and discriminated between chance variation and assignable variation in process. In addition, control chart can be used to monitor the process output and detect when changes in the inputs are required to bring the process back to an in-control state. The models that relate the influential inputs to process outputs help determine the nature and magnitude of the adjustments required. In this paper, the characteristic of product quality is monitored by control chart during the machining process and construction of quality control cycle is considered to divide into two types in this case that different assignable causes lead to shifts having different magnitudes. Then we are intended to find a process shift magnitude which has economical quality cost policy and are considered to quality cost functions to find a process shift magnitude. Those costs are categorized into the well-known categories of prevention, appraisal, and internal failure and external failure. This paper ends with numerical examples that demonstrate the usefulness of the model.

• Educational Technology International
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• v.6 no.2
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• pp.43-58
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• 2005

The purpose of this study was to investigate the impact of organizational learning culture on job satisfaction and organizational commitment. Two streams of scholarly work have provided the theoretical foundations for this study. The first stream comes from the literature on learning organization. The second stream of the theoretical foundation comes from an extensive literature on attitude-intention-behavior relationships. In addition, this study was tested three alternative models. Alternative model 1 employed job satisfaction as the mediating commitments variable between learning culture and organizational commitment. Alternative model 2 used organizational commitment as the mediating variable between learning culture and job satisfaction. Finally, alternative model 3 specified a direct impact of learning culture on both job satisfaction and organizational commitment, and reciprocal linkages between these two variables. The results of this study support the hypothesized relations among an organization's learning culture, job satisfaction, and organizational commitment. The findings of this study are various congruent with a widely accepted hypothesis that job satisfaction serves as an appraisal function in evaluating various work environments and determining emotional responses such as organizational commitment. Organizational learning culture is one of the important factors that organizations cannot overlook. Therefore, the findings of this study provide a new direction for researchers seeking to explain the complex relations among these central organizational variables.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.667-674
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• 1998

Numerical models simulating the process of NAPL from contaminated soil or groundwater through steam injection can be a useful tool for designing and evaluating the cleanup strategy under various field conditions. One and two dimensional numerical analyses were conducted based on the governing equations describing the NAPL removal as a non-isothermal, multi-phase and multi component process. Relatively good agreements were obtained between the numerical results and the observations from one-dimensional laboratory experiment, except some discrepancy due to experimental difficulties. Simulation effectively identified the steam displacement process of xylene floating on the water table and TCE sinking on the aquifer bottom in a two-dimensional analysis. Overall, simulation models have a high potential in the design/appraisal of a system for field application of the technique as well as in the examination of complex processes such as vaporization which is hard to identify experimentally.

• Journal of the Korean Geographical Society
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• v.39 no.2
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• pp.212-228
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• 2004

This paper is concerned with an important aspect of regional income convergence, ${\beta}$-convergence, which refers to the negative relationship between initial income levels and income growth rates of regions over a period of time. The common research framework on ${\beta}$-convergence which is based on OLS regression models has two drawbacks. First, it ignores spatially autocorrelated residuals. Second, it does not provide any way of exploring spatial heterogeneity across regions in terms of ${\beta}$-convergence. Given that empirical studies on ${\beta}$-convergence need to be edified by spatial data analysis, this paper aims to: (1) provide a critical review of empirical studies on ${\beta}$-convergence from a spatial perspective; (2) investigate spatio-temporal income dynamics across the U.S. labor market areas for the last 30 years (1969-1999) by fitting spatial regression models and applying bivariate ESDA techniques. The major findings are as follows. First, the hypothesis of ${\beta}$-convergence was only partially evidenced, and the trend substantively varied across sub-periods. Second, a SAR model indicated that ${\beta}$-coefficient for the entire period was not significant at the 99％ confidence level, which may lead to a conclusion that there is no statistical evidence of regional income convergence in the US over the last three decades. Third, the results from bivariate ESDA techniques and a GWR model report that there was a substantive level of spatial heterogeneity in the catch-up process, and suggested possible spatial regimes. It was also observed that the sub-periods showed a substantial level of spatio-temporal heterogeneity in ${\beta}$-convergence: the catch-up scenario in a spatial sense was least pronounced during the 1980s.

• Journal of Preventive Medicine and Public Health
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• v.44 no.3
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• pp.118-124
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• 2011

Objectives: Although cigarette smoking is known to be related to the exacerbation of asthma symptoms, several studies have indicated that the prevalence of cigarette smoking among asthmatic adolescents is similar to or even higher than that among non-asthmatic adolescents. The aim of this study was to evaluate the relationship between asthma and cigarette use behaviors and whether or not the presence of suicidal ideation modifies this relationship among Korean adolescents. Methods: We analyzed data from the 2008 Korea Youth Risk Behavior Web-based Survey, which included a nationally representative sample of middle and high school students. Multiple logistic regression models were used to calculate odd ratios and 95% confidence intervals of cigarette use behaviors among current asthmatics, former asthmatics, and nonasthmatics, after adjusting for gender, grade, school records, socioeconomic status, current alcohol use, and suicidal ideation. Results: Of 75 238 study participants, 3.5% were current asthmatics and 4.5% were former asthmatics. Compared with non-asthmatics, asthmatics were more likely to report current cigarette use, frequent and heavy cigarette use, and cigarette use before 13 years of age. There were statistically significant interactions between asthma and suicidal ideation in cigarette use behaviors. Conclusions: This study demonstrated that asthmatic adolescents are more likely than non-asthmatic adolescents to engage in cigarette use behaviors and the presence of suicidal ideation is an effect modifier of the relationship between asthma and cigarette use behaviors. Particular attention should be paid to the awareness of health risks of cigarette smoking and mental health problems among asthmatic adolescents.

• Journal of Korean Society of Archives and Records Management
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• v.2 no.1
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• pp.97-117
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• 2002

In the fast growing digital environment, assuring continued authenticity is an essential and intransigent preservation consideration for digital data and records. Several key issues need to be addressed, including: What are electronic records and data?; Which intellectual and technical elements of data and records are essential for assuring authenticity in electronic format?; How should these be maintained and preserved over time?; How are authentic data and records used in various systems of practice?; and What are the best strategies of preserving authentic electronic records and data?. There have been many research projects to answer these questions to date. This paper discusses the characteristics of electronic records in light of preservation consideration and reports the activities and findings of some of the research projects in brief. This paper focuses on explaining the InterPARES (International Research on Permanent Authentic Records in Electronic Systems) Project, which is defining requirements for authenticity that can help develop strategies for long-term preservation in electronic records. To identify those requirements, more than thirty case studies have been conducted with government agencies, academic institutions, and various organizations in America, Canada, Europe, Asia and Australia and models developed for appraisal, preservation, and strategies in relation to the management of electronic records. The paper also suggests research questions and implications for preserving authentic electronic records as well as the encouragement for Korean research on digital preservation.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.7-16
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• 2009

This paper proposes a plan which can raise the accuracy of economic benefit estimation in road construction projects. The point of existing economic appraisals may be that the speeds forecasted by models are different from the field speeds because only volumes are calibrated in the road network. The result of such a calibration has an influence on estimating wrong economic benefits in terms of vehicle operating cost savings, travel time savings, and air pollution savings. Then this study performs a calibration when volumes are at the same amount but the calibration between the field speeds and model speeds is different from each other with two different volume-delay functions; the differences of benefits are confirmed according to two different speed calibrations. Three improvement schemes, including the development of a new volume-delay function, are proposed in this study in order to solve the problem of current benefit calculations. The outcome of this study will help practitioners perform more accurate benefit calculations and reasonable economic appraisals.