• Communications for Statistical Applications and Methods
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• 제30권3호
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• pp.259-272
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• 2023

In this paper, we suggest a new method for the prediction of sharp changes in particulate matter (PM₁₀) using quantile mapping. To predict the current PM₁₀ density in Seoul, we consider PM₁₀ and precipitation in Baengnyeong and Ganghwa monitoring stations observed a few hours before. For the PM₁₀ distribution estimation, we use the extreme value mixture model, which is a combination of conventional probability distributions and the generalized Pareto distribution. Furthermore, we also consider a quantile generalized additive model (QGAM) for the relationship modeling between precipitation and PM₁₀. To prove the validity of our proposed model, we conducted a simulation study and showed that the proposed method gives lower mean absolute differences. Real data analysis shows that the proposed method could give a more accurate prediction when there are sharp changes in PM₁₀ in Seoul.

• 유통과학연구
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• 제15권8호
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• pp.5-14
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• 2017

Purpose - This study empirically analyses the sale changes in large retail stores directly resulting from increased controls on those stores. More specifically, we discuss the economic impacts on Korean regulations that restrict trading hours and mandate statutory store closure 'holidays' twice per month. Research design, data and methodology - we attempt to empirically analyse the economic effects of trading hours regulations through quantitative analysis of the sales revenue data of large retail stores. We introduce the data and methods of empirical analysis used to analyse the economic effects of trading-hour regulations on large retail stores. We use a panel regression to analyse the sales losses of large retail stores caused by the new constraints on business hours. Results - The results of this study show that the sales of large retail stores fell by the average of 3.4% per month during the regulation periods. However, regulations affecting large retail stores have various economic impacts, including variations in sales, changes in consumption patterns, and influences on consumer welfare and national economy. Conclusions - Such changes may also be captured by other metrics: accordingly, further researches are needed to measure the impact of regulations on economic indicators such as employment and GDP.

• Journal of Nutrition and Health
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• 제4권1호
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• pp.21-28
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• 1971

1. The effects of chloroform to the tissue lactic dehydrogenase (LDH) activities and its isozymes and to the tissue glutamic dehydrogenase (GDH) activities and its isoaymes are studied using the experimental albino male adult rats in this paper. The tissues studies are liver, kidney, heart, and brain. Besides the control group, two experimental groups are studied providing succeedingly 4 days interpariental administrations of chloroform, 0.0025ml and 0.025ml per day respectively. The changes of body weights, weights of organs, activities of GDH and LDH and their isozymes of each tissues, are analysed. 2. The body weights of rats are decreased due to the chloroform administration. 3. There are no significant differences of weights of organs due to the chloroform administration. 4. The significant decreases of tissue GDH activities and the significant changes in percent distribution of the GDH isozymes are found due to the chloroform administration. This weight be interpretated that chloroform effects to the protein and amino acid metabolism of rats. 5. Due to the chloroform administration, the significant changes in tissue LDH activities and in percent distribution of tissue LDH isozymes indicating the decreases of $LDH_1$ which is the aerobic heart type and the increase of $LDH_5$ which is the anaerobic muscle type, are observed. This could be estimated that chloroform effects to the carbohydrate metabolism, particularly to the anaerobic glycolysis of rats.

• 유통과학연구
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• 제13권10호
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• pp.23-34
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• 2015

Purpose - Currently, the foreign trade environment in China has shifted to a very different system. Korean enterprises have been forced to compete with Chinese enterprises in today's world market owing to the economic growth and technical improvement in China. Research design, data, and methodology - The author visited Korean export enterprises in Shanghai from January 5 to 12, 2014 to implement a questionnaire survey and conduct in-depth interviews with the local enterprises. The author investigated the Shenyang area using e-mail communication. For the questionnaire, one copy of the questionnaire was given to each business and to a staff member for each of the products when a company sold multiple products. Results - Selling cost advantage, efficiency of economic scale, and product differentiation had the most influence on Korean enterprises' export strategy to China. Additionally, entry barrier, product differentiation, and concentration all had an influence on Korean enterprise export strategy to China as well. Conclusion - Korean enterprises developed strategies for price priority, economies of scale, and product differentiation based on changes in the competitive structure in the Chinese market.

• 유통과학연구
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• 제13권5호
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• pp.23-31
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• 2015

Purpose - This study investigated competitive counteractions necessary for continuous growth in a rapidly changing logistics environment in Northeast Asia. Research Design, Data, and Methodology - Using a time series analysis, the study first investigated Northeast Asian trade scale and volume by examining online and offline material from the Ministry of Ocean and Fisheries, Busan Port Authority, and other government agencies. A literature survey was done to investigate the state and prospect of the logistics environment in Northeast Asia including changes in freight volume at major ports in the three Northeast Asian countries. Result - The results of the study suggest using the Trans-Korean Railroad (TKR), as well as promoting the North Pole and South Pole routes, to compete against changes in trade volume and the logistics environment in Northeast Asia. A SWOT analysis was done to examine the effectiveness of these strategies. Conclusions - The findings indicate that the TKR impact, using the Busan Port connecting the Trans-China Railway (TCR), the Trans-Siberian (TSR), and the North Pole Route, may be uncertain in practice considering the uncertainty in international politics.

• 산경연구논집
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• 제12권7호
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• pp.7-14
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• 2021

Purpose: The coronavirus (COVID-19) has become a worldwide pandemic and significantly influences the global economy. Therefore, this paper aims to determine the impact of COVID-19 on the accounting profession in Bangladesh. Research design, data, and methodology: The research has focused on its primary question. How much does COVID- 19 affect the accounting profession in Bangladesh? A formal questionnaire has been developed to address it. Questionnaire was spread via Facebook and email. Sample was determined by using random sampling method. The collection comprises 190 from Bangladesh. The Likert scale of five points was used. Descriptive and inferential statistical analysis (Wilcoxon signed-rank test) were used for analysis. Results: the study found a great impact of COVID-19 on the accounting profession in Bangladesh. Many changes are faced due to pandemics. Most accountants are working remotely during pandemic rather than before pandemic. They have adapted to new technology. Meetings and trainings are held virtually. They are also facing cybersecurity problems because of less data security. Job insecurity has increased. Conclusions Therefore, the global pandemic COVID-19 dramatically affects the accounting profession in Bangladesh. The changes that happened due to pandemics will advance the accounting profession. These revolutionary changes will become the world's new normal.

• 산경연구논집
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• 제14권3호
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• pp.27-43
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• 2023

Purpose: Changes in the employment environment in the era of the 4th Industrial Revolution are influencing various factors by the emergence of new jobs and the change in perception of job stability due to globalization of information technology and industry This study attempted to present implications by verifying the structural relationship of beauty workers' sustainable organizational commitment and the method necessary for conflict management in the industrial field due to the recent changes in the employment environment of the beauty industry in the 4th Industrial Revolution. Research design, data and methodology: This study sampled 604 beauty industry employees Frequency analysis, validity and reliability analysis, factor analysis, and path analysis were performed using SPSS WIN23.0. Results: It was found that the change in the employment environment caused by the 4th industrial revolution had a significant negative (-) effect on the job satisfaction and organizational commitment of beauty industry workers. Conclusion: This study is that changes in the employment environment negatively affect job satisfaction and organizational commitment of beauty workers. We hope to contribute to the development and growth of the beauty industry by providing basic data for the beauty tech service industry in the 4th industrial era.

• 한국농공학회논문집
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• 제48권2호
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• pp.45-55
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• 2006

This study analyze the hydrologic conditions and the effects of selected runoff characteristics as an attempt to estimate the optimal dredge amount for Asan Lake in Korea. The runoff feature was calculated by utilizing the water balance simulation from DIROM (Daily Irrigation Reservoir Operation Model), which allowed changes in landuse to be quantified using remote sensing for 14 years. The distribution of prospective sediment deposits was been tallied based on the changes in landuse, and quantity of incoming sediment estimated. From these findings, we were then able to simulate the fluctuation of water level, gauging the pumping days not already in use, to determine the frequency of the distribution for around the. requirement annual water storage and the changing water level. The optimal dredge amount was calculated on the basis of the distribution of frequency, taking into account the design criteria for agricultural water with the 10-year frequency of resistant capacity.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E3호
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• pp.95-105
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• 2005

The concentrations of sulfur dioxide ($SO_{2}$) were measured from seven major cities and nine provinces in Korea for the period covering 1998 to 2003. Its concentration data were analyzed to explore the possible influences of spatial and temporal factors on the $SO_{2}$ distribution characteristics. Examination of spatial trends of $SO_{2}$ distribution and behavior indicated several interesting features. Although its annual trends appeared to be affected by the changes in the surrounding environmental conditions (e.g., regulation on the use of S-containing fuels), the seasonal trends indicated a cyclic and systematic pattern that may be characterized as: a gradual decrease in concentrations across winter, spring, fall, and summer. The results showed the generally enhanced mean concentrations of $SO_{2}$ from Ulsan, Busan, and Daegu with 12.8, 10.1, and 8.80 ppb, respectively. On the other hand, notably reduced $SO_{2}$ concentrations were seen from Gwangju and Jeju sites with its mean values of 5.43 and 3.88 ppb, respectively. The overall results of our study indicate that a decrease in $SO_{2}$ concentration levels continued through time, while its spatial distribution appears to be affected most sensitively by such factor as city scale and industrial activities.

• Nuclear Engineering and Technology
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• 제33권3호
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• pp.270-282
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• 2001

A simple measure of uncertainty importance based on normalized metric distance to quantify the entire change of cumulative distribution functions (CDFs) has been developed for use in probability safety assessments (PSAs). The metric distance measure developed in this study reflects the relative impact of distributional changes of inputs on the change of an output distribution, white most of the existing uncertainty importance measures reflect the magnitude of relative contribution of input uncertainties to the output uncertainty. Normalization is made to make the metric distance measure a dimensionless quantity. The present measure has been evaluated analytically for various analytical distributions to examine its characteristics. To illustrate the applicability and strength of the present measure, two examples are provided. The first example is an application of the present measure to a typical problem of a system fault tree analysis and the second one is for a hypothetical non-linear model. Comparisons of the present result with those obtained by existing uncertainty importance measures show that the metric distance measure is a useful tool to express the measure of uncertainty importance in terms of the relative impact of distributional changes of inputs on the change of an output distribution.