• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.363-370
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• 2004

This Paper presents the response force distribution factor(RDF) and its application to recalculation of member forces in case of partial changes of structures. Using RDF, the mutuality of response forces between members can be estimated. The reanalysis technique recalculates directly any displacement or member force under consideration in real time without a full reanalysis in spite of local changes in member stiffness or connectivity using RDF. It is expected that RDF and the reanalysis technique can be used to develop efficient analysis techniques for tall buildings.

• Journal of Distribution Science
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• v.14 no.9
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• pp.31-45
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• 2016

Purpose - This study develops a simulation model that looks at the dynamics between social capital and business performance in strategic networks to understand their behaviors in relation to each other, and to suggest dynamic relationship strategies. Research design, data, and methodology - Based on existing literature, this study identifies the complex causal loop diagram on social capital and business performance in strategic networks, and converts them into a simulation model for observing how the changes in business environment and relationship dependency affect social capital and business performance. Results - The simulation results showed that, first, the formation in social capital and business performance of networks with low relationship dependency was less affected by the changes in business environment. Second, the formation in social capital and business performance of networks with high relationship dependency was negatively impacted by the changes in business environment. In other words, higher relationship dependency strengthened the impact of changes in business environment on business performance. Conclusions - Thus, this study confirmed that in strategic networks, the changes in business environment and the degree of relationship dependency dynamically affect business performance, and that relationship dependency mediates the degree in which changes in the business environment affect business performance. The results of the simulations were further verified through actual business cases.

• The Journal of Industrial Distribution & Business
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• v.14 no.6
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• pp.27-35
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• 2023

Purpose: Convergence and social ripple effects caused by the Fourth Industrial Revolution, which encompasses new technologies in various fields, will have a great impact on the beauty industry structure and market economy. This review reviewed the literature on the changes in the employment environment of the Korean beauty industry due to the 4th industrial revolution and the countermeasures of the beauty industry accordingly. Research design, data and methodology: Using the October 2022 PRISMA flowchart, it is a review of changes in the employment environment of the beauty industry, the need for human resource management of beauty workers, and the employment environment to be applied to the beauty industry in the future. Results: Changes in the employment environment in the era of the 4th Industrial Revolution, the current state of the beauty industry, and reviews on beauty industry workers were collected, and a direction for training beauty industry workers was presented. Conclusions: This study presented the direction of the beauty industry in preparation for changes in the employment environment of the 4th industrial revolution and suggested that research is needed to actively establish human resource management (HRM) to overcome the problem of fostering talent in the beauty industry.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.326-333
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• 2003

In the measurement using DMA and CPC in series, there is some time delay for particles classified in DMA to detect in CPC. During this time, the DMA time-response changes due to the velocity profile of sampling tube and the diffusion of particles in the volume that exists between the DMA exit and the detector of ultra-fine CPC. This is called mixing effect. In the accelerated measurement methods like the TSI -SMPS, the size distribution is obtained from the correlation between the time-varying electrical potential of the DMA and the corresponding particle concentrations sampled in DMA. If the DMA time -response changes during this delay time, this can cause the error of a size distribution measured by this accelerated technique. The kernel function considering this mixing effect using the residence time distribution is proposed by Russell et al. In this study, we obtained a size distribution using this kernel to compare to the result obtained by the commercial accelerated measurement system, TSI -SMPS for verification and considered the errors that result from the mixing effect with the geometric mean diameters of originally sampled particles, using virtually calculated responses obtained with this kernel as input data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.465-470
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• 2011

Recently fault currents are increasing in a network. It is caused by increase in electric demand and high penetration of distributed generation with renewable energy sources. Moreover, distribution network has become more and more complex as mesh network to improve the distribution system reliability and increase the flexibility and agility of network operation. Accordingly, the fault current will exceed capacity of circuit breakers soon and all the various rational solutions to solve this problem are taken into account. Under these circumstances, superconducting fault current limiter(SFCL) is a new alternative in the viewpoint of technical and economic aspects. This study presents operation processes for a resistive-type of SFCL, and it proposes reliability model for the SFCL. When a SFCL is installed into a network, the contribution of decreased fault currents to failure for distribution equipments can be quantified. As a result, it is expected that a SFCL makes the reliability of adjacent equipments on existing network improve and these changes are analyzed. We propose a methodology to evaluate the reliability in the distribution network where a SFCL is installed considering a reliability model for resistive-type of SFCL and reliability changes for adjacent equipments which are proposed in this paper.

• Journal of Distribution Science
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• v.21 no.3
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• pp.93-100
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• 2023

Purpose: The purpose of this paper is to confirm whether stocks belonging to the distribution industry in Korea have reversals, following large daily stock price changes accompanied by large trading volumes. Research design, data, and methodology: We examined whether there were reversals after the event date when large-scale stock price changes appeared for the entire sample of distribution-related companies listed on the Korea Composite Stock Price Index from January 2004 to July 2022. In addition, we reviewed whether the reversals differed depending on abnormal trading volume on the event date. Using multiple regression analysis, we tested whether high trading volume had a significant effect on the cumulative rate of return after the event date. Results: Reversals were confirmed after the stock price shock in the Korean distribution industry and the return after the event date varied depending on the size of the trading volume on the event day. In addition, even after considering both company-specific and event-specific factors, the trading volume on the event day was found to have significant explanatory power on the cumulative rate of return after the event date. Conclusions: Reversals identified in this paper can be used as a useful tool for establishing a trading strategy.

• Journal of the Korean Data and Information Science Society
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• v.15 no.2
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• pp.387-394
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• 2004

Zero-Inflated Poisson distribution is Poisson distribution with excess zeros. Recently defects of product hardley happen in the manufacturing process. In this case it is desirable to apply to the Zero-Inflated Poisson distribution rather than Poisson. Our target of this paper is to study the tests for changes of rate of defects after the unknown change-point. We are going to compare the powers of the two proposed tests with likelihood tests by the simulations.

• Journal of Distribution Science
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• v.14 no.10
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• pp.137-146
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• 2016

Purpose - Korean agriculture is facing internal and external environmental changes and the need for secure stable outlets. Active participation and mutually beneficial cooperation between enterprises and agricultural is necessary for a win-win situation. This study investigates the case for distribution cooperation and a cooperative system. To respond to the diverse needs of consumers and market reclamation, there is a need to analyze and categorize distribution cooperation. Research design, data, and methodology - A literature study, relevant interviews with enterprises, and meetings with local government practices were conducted. A survey frame was derived through the participation of agricultural enterprises and distribution cooperation models were categorized identifying win-win cooperation and best practices. It was organized on the basis of six best practice examples of distribution cooperation between industry and agricultural sectors, divided into three types: opening distribution channels, exporting cooperation, and developing new products. Results - An innovation management system that can adapt to environmental changes and problems of agriculture is necessary. A company has to supply high-quality agricultural products reliably to meet the preferences of consumers by introducing products that promote domestic market differentiation. In addition, consumers are choosing a variety of products that may include not only high quality products but also local products and safe products. The main areas of cooperation are the direct provision of agrifood raw materials to consumers. Next, would be to help agricultural sectors distribute and pioneer international markets. The ideal step for distribution cooperation is the joint investment in new products by business and agriculture. Conclusions - Agriculture and win-win cooperation with enterprises is in an early stage of social contribution. To implement a distribution cooperation model between business and agricultural sectors, it is crucial to establish a structured support system including joint councils. Additional requirements include strengthening agricultural capacities, creating a legal basis for provision, and producing a win-win cooperation environment. The promotion of win-win cooperation and agricultural enterprises needs to exist in various forms in order to establish a different type of incentive system.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.45-54
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• 2008

Our study indicates the zooplankton abundance with characteristics of water column and the vertical distribution in Lake Jinyang, South Korea. Seasonal changes of zooplankton community are determined by environmental parameters like water temperature, pH, dissolved oxygen, suspended solids and chlorophyll a. In lake Jinyang, this study showed that the zooplankton abundance in transition zone(St.1, St.2) was higher density than in lacustrine zone(St.3). Rotifers were dominant zooplankton and among them, Polyarthra spp., Keratella spp. and Nauplli(Copepoda) were common. But Cladoceran showed the low density. During survey period, zooplankton abundance with vertical distribution in surface layer(epilimnion) was higher than in bottom layer(hypolimninon). Zooplankton densities in Surface and middle layer showed positive relationship with water temperature and the densities in bottom layer(hypolimnion) showed positive relationship with chlorophyll a. Our assumption in spite of the short term study are supported by the facts that increase of temperature driven by climate change more maintains the thermocline duration by the summer temperature stratification. Thus the results suggest that the climate changes are an important source of changing zooplankton community feeding phytoplankton. So the zooplankton should be monitoring by the ecological management of Lake Jinyang to cope with climate changes like flood plain or drought.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.987-998
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• 2013

This paper considers the statistical characteristics on the air quality (PM10) of Korea collected hourly in 2011. PM10 in Korea exhibits very strong correlations even for higher lags, namely, long range dependence. It is power-law tailed in marginal distribution, and generalized Pareto distribution successfully captures the thicker tail than log-normal distribution. However, slowly decaying autocorrelations may confuse practitioners since a non-stationary model (such as changes in mean) can produce spurious long term correlations for finite samples. We conduct a statistical testing procedure to distinguish two models and argue that the high persistency can be explained by non-stationary changes in mean model rather than long range dependent time series models.