• Journal of the Korean Data and Information Science Society
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• v.16 no.3
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• pp.567-580
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• 2005

It is usually assumed that asset returns in the stock market are normally distributed. However, analyses of real data show that the distribution tends to be skewed and to have heavier tails than those of the normal distribution. In this paper, we investigate the method of estimating the value at risk(VaR) of stock returns. The VaR is computed by using the transformation and back-transformation method. The analysis of KOSPI and KOSDAQ data shows that the proposed estimation outperformed that under the normal assumption.

• Journal of Distribution Research
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• v.3 no.1
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• pp.99-121
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• 1998

This study is to develop and test the types of choice strategy of alliance choice modes of the marketing channel. Previous studies have tended to emphasize such factors as opportunism, asset specificity, frequency as the determinants of the choice strategy. Therefore, this study is to construct a new framework which emphasizes the factors affecting the choice strategy. The purpose of this study is to derive factors affecting in choice of alliance modes. For this study, the data obtained from domestic manufacturing companies was analyzed by use of the discriminant analysis. The results analyzed are that transaction environmental variables affect on the choice strategy to determine the types of strategic alliance modes in marketing channels. And the performance of each mode revealed differently.

• Journal of the Korean Data and Information Science Society
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• v.22 no.5
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• pp.1007-1016
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• 2011

This article deals with the problem of testing for the correlation coefficient in the bivariate normal distribution. We propose Bayesian hypothesis testing procedures for the bivariate normal correlation coefficient under the noninformative prior. The noninformative priors are usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. A simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.935-944
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• 2010

In this paper, we develop the noninformative priors for the reliability in a stress-strength model where a strength X and a stress Y have independent exponential distributions with different scale parameters and a common location parameter. We derive the reference priors and prove the propriety of joint posterior distribution under the general prior including the reference priors. Through the simulation study, we show that the proposed reference priors match the target coverage probabilities in a frequentist sense.

• Communications for Statistical Applications and Methods
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• v.20 no.5
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• pp.387-394
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• 2013

In this paper, we develop the noninformative priors for the ratio of the scale parameters in the inverted exponential distributions. The first and second order matching priors, the reference prior and Jeffreys prior are developed. It turns out that the second order matching prior matches the alternative coverage probabilities, is a cumulative distribution function matching prior and is a highest posterior density matching prior. In addition, the reference prior and Jeffreys' prior are the second order matching prior. We show that the proposed reference prior matches the target coverage probabilities in a frequentist sense through a simulation study as well as provide an example based on real data is given.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.121-122
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• 2007

Recently, there are two big paradigm shifts in the global electric power industry. First, the maintenance practice is gradually moved from time-based activities to reliability-centered activities. On the other hand, asset management is emerging as a new framework to maximize the efficiency of investments. The two paradigms are mutually exclusive in natural. Thus the power utilities usually chose the investment alternative on the basis of reliability in the past. But today's changed business environment - competition -requires the power utilities to compromise the trade-off of reliability effects and economics of investments. This paper shows what and how to interpret the reliability effects of distribution system investments into financial indicators beneficial for power utilities's managers to make decision on the perspective of corporate value.

• Journal of Distribution Science
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• v.17 no.4
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• pp.59-68
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• 2019

Purpose - The purpose of this study is to examine the differential mediating effects of three dimensions of buyer trust in the influence of supplier characteristics on the relationship performance. In this study, transaction characteristics were classified into competences and assets. The corporate reputation is considered as intangible assets, the customer-linking capability is considered among the competencies and transaction specific asset is selected from tangible assets. This study is also to examine the moderating effect of technical environment uncertainty in the effects of integrity and benevolence on the intention to continue trading. This study aims to provide a guide on which dimension suppliers should manage and how to improve their trust in order to maintain business with companies in technical environment uncertainty. Research design, data, and methodology - The data for the empirical analysis of this study were obtained by interviewing the 274 purchasing managers of Daegu - Gyeongbuk small and medium enterprises. The items used in this survey were partially modified to fit the characteristics of the B2B industry. The reliability and validity of the variables were analyzed using SPSS 18.0 and AMOS 18.0 programs and hypotheses were verified through the structural equation modeling. Results - In this study, reliability was examined by Cronbach 'α test. Composite Reliability and Average Mean Variance extracted value exceeded the baseline values. As a result of hypotheses testing, the hypothesis that the transaction specific asset will improve the benevolence and that benevolence will improve the intention to continue the transaction were rejected and all the other 9 hypotheses were adopted include 2 moderating hypothesis. Conclusions - This study shows which dimension of trust suppliers should appeal to the buyer according to the uncertainty of the technology environment in order to maintain the transaction with the buyer. competence and integrity are important when technology environment uncertainty is low, and competence and benevolence are important when technical environment uncertainty is high. In order to improve competence, corporate reputation and transaction-specific asset are important. To improve integrity, corporate reputation and customer-linking capability are important. In order to improve benevolence, customer-linking capability is important. And various implications were discussed.

• International Commerce and Information Review
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• v.14 no.2
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• pp.3-27
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• 2012

As Chinese political and economical status gets higher, a lot of multinational firms have tried to find some chances from the Chinese market successfully. Though geographically Korea is located closely to China, a lot of firms entering into Chinese market have turned out failed. Thus, this study researched Korean manufacturing firms in China, surveyed their localization degree of distribution, and tried to find out factors which influence these localization from a far-reaching literature. As a result of analyzing 146 questionnaires, the length of channel, among Chinese environmental factors, has a positive influence on the distribution localization degree. In addition, the factor of distribution relation assets has a positive effect on the distribution localization degree. Considering this study, the Chinese market, especially distribution field, has recently grown up to the world-class level. Therefore a firm intending to enter into China needs to be careful not to underestimate China.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.1
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• pp.1-5
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• 2020

In this study, the objective is to improve the criteria used for statistical comparison of the VLF tanδ (TD) database and failure rate according to water-tree degradation in underground distribution power cables. The aging condition of the KEPCO criteria is divided into 6 levels using the Weibull distribution, and the "failure imminent" condition is quantified by using the statistical end-point of the lifetime parameter of the VLF big-data group obtained from KEPCO. Moreover, new criteria with a 2-dimensional combination of TD, DTD, and a statistical normalized factor are suggested. These criteria exhibit high reproducibility for the detection of cables in an imminent failure state. Consequently, it is expected that the adoption of the extended VLF-2019 criteria will reduce the asset management cost of cable replacement compared to the VLF-2012 criteria of KEPCO.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.147-158
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• 2021

Due to COVID-19, the risk of price volatility in commodity and equity markets increases. The research and application of hedging is the most effective way to reduce the market risk. Hedging is a risk management strategy employed to offset losses in investments by taking an opposite position in a related asset. We use K-means and hierarchical clustering methods to cluster companies and futures products respectively, and analyze the relationship between the number of hedging firms, regional distribution, nature of firms, capital distribution, company size, profitability, number of local Futures Commission Merchants (FCMs), regional location, and listing time. The study shows that listed companies with large scale and good profitability invest more money in hedging, while state-owned enterprises' participation in hedging is more likely to be affected by the company size and the number of local futures commission merchants, and private enterprises are more likely to be affected by the company profitability and the regional location. Listed companies are more willing to choose long-listed and mature futures products for hedging. We also provide policy advice based on our conclusion. So far, there is no study on the characteristics of hedging. This paper fills the gap. The results provide a basis and guidance for people's investment and risk management. Using clustering analysis in hedging study is another innovation of this paper.