• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.395-406
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• 2015

This research carried out an analysis on input cost and leakage reduction effect by leakage reduction method, focusing on the project for establishing an optimal water pipe network management system in the Taebaek region, which has been executed annually since 2009. Based on the result, optimal cost-benefit analysis models for water distribution network rehabilitation project were developed using DEA(data envelopment analysis) and multiple regression analysis, which have been widely utilized for efficiency analysis in public and other projects. DEA and multiple regression analysis were carried out by applying 4 analytical methods involving different ratios and costs. The result showed that the models involving the analytical methods 2 and 4 were of low significance (which therefore were excluded), and only the models involving the analytical methods 1 and 3 were suitable. From the result it was judged that the leakage management method to be executed with the highest priority for the improvement of revenue water ratio was installation of pressure reduction valve, followed by replacement of water distribution pipe, replacement of water supply pipe, and then leakage detection and repair; and that the execution of leakage management methods in this order would be most economical. In addition, replacement of water meter was also shown to be necessary in case there were a large number of defective water meters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.301-302
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• 2021

After the Korona 19, "social distancing" was implemented, existing "pop culture" or entertainment programs were unable to communicate in both directions and declined. Since then, "Untact content" has shown its potential to grow due to untouch performances such as BTS' "Bangbangcon" and the rapid growth of Netflix, a global OTT (online video service). In addition, most of the global and Untact content is online and digital, which means a huge amount of big data will be poured out. Therefore, analyzing the big data poured out during the distribution of untact content will help us identify consumers' needs, and the growth expectations will also be high. Therefore, we would like to explore the research cases that have been conducted in existing studies regarding the subject of the study and analyze how big data can affect the distribution of content in the Untact era.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.141-156
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• 1995

This research is executed to find out the boundary of use by the conscious of local residents and to get the basic materials for the distribution of outdoor leisure-facilities. The map of use distribution of the outdoor leisure-facilities in a neighbourhood unit is made by applying a concept of the probabilistic contour line based on the choice model of outdoer leisure-facilities in the city of Seoul, Taegu an\ulcorner Kwangju. The results are listed as follows. 1) The use of outdoor leisure-facilities is influenced on the accessibility by the physical obstacles of streets and hills, etc. 2) The limitation of uses applying the model of choice probability are different according to the accessibility, the percentage of utilities and the arriving range based on the questionnaires which are surveyed the choice of outdoor leisure facilities of the residents of Seoul, Taegu and Kwangju. 3) The distribution of outdoor leisure facilities is decided by the limitation of use with the conscious of local residents.

• Journal of Korea Water Resources Association
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• v.51 no.7
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• pp.599-606
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• 2018

Most hydrological analysis such as probability rainfall and rainfall time distributions have typically carried out based on hourly rainfall and rainfall - runoff analysis have carried out by applying different periods of rainfall time distribution and probability rainfall. In this study, to quantify the change of design flood due to the data type (hourly and minutely rainfall data) and the probability rainfall and application of different data period to the rainfall time distribution, probability rainfall is calculated by point frequency analysis according to data type and period and rainfall time distribution was calculated by Huff's quartile distributions. In addition, the change analysis of design flood was carried out by rainfall - runoff analysis applying different data periods of design rainfall time distribution. and probability rainfall. As a result, rainfall analysis using minute rainfall data was more accurate and effective than using hourly rainfall data. And the design flood calculated by applying different data period of rainfall time distribution and probability rainfall made a large difference than by applying different data type. It is expected that this will contribute to the hydrological analysis using minutely rainfall.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.2953-2964
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• 1996

Heat Transfer with periodic fluctuation of fluid temperature caused by oscillatory flow or compression expansion can be out of phase with balk fluid-wall temperature difference. Newton's law of convection is inadequate to describe this phenomenon. In order to solve this problem the concept of the complex Nusselt number has been introduced by severla researchers. The complex Nusselt number expresses out of phase excellently while the first harmonic is dominant in the variations of both fluid-wall temperature difference and heat flux. However, in the case of oscillatory flow with non-linear wall temperature distribution, the complex Nusselt number is not appropriate to predict the heat transfer phenomena since the higher order harmonic components appear in periodic temperature variation. Analytic solutions to the heat transfer with an sinusoidal well temperature distribution were obtained to investagate the effect of non-linear wall temperature distribution. A new formula considering the thermal boundary layer was suggested based on the solutions. A comparison was also made with the complex Nusselt number. It was verified that the new formula describes well the heat transfer of oscillating flow even if the first harmonic component is not dominant in the fluid-wall temperature difference.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.4
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• pp.11-22
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• 1999

In this study, the validity of the currently used seismic regulations for seismic isolated building structures is investigated, and a new formula for vertical distribution of seismic load is proposed. The distribution formula in UBC-91 did not provide sufficient safety, and thus revised in 1994. However it is pointed out that the revised formula overestimates the seismic load because of its similarity to that of the fixed-base structure. Therefore, in the proposed approach, it is intended to satisfy safety, economy, and applicability by combining the mode shapes of the seismic isolated structure idealized as two degrees of freedom system and those of fixed-base structure. For verification of the proposed formula, both a moment resisting frame and a shear wall system are analyzed. The results obtained from the proposed method turn out to be close to the results from a dynamic analysis.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.281-284
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• 2008

Due to the remarkable development of the GIS and spatial information technology, the information on the national land and scientific management are disseminated. According to the result of research for an efficient analysis of forest site, it presents distinguishing of satellite image and methodology of TPI (Topographic Position Index). The prediction of forest site distribution through this research, specified Gyeongju-si area, gives an effect to distinguishing honor system through Quickbird image with the resolution 0.6m. Furthermore it was carried out through TPI grid that is abstracted by DEM, slope of study area and type of topography, as well as it put its operation on analysis and verification of relativity between the result of prediction on forest site distribution and the field survey report. It distinguishes distribution of country rock that importantly effects to producing of soil, using 1: 5000 forest maps and grasping distribution type of soil using satellite image and TPI, it is supposed to provide a foundation of the result on prediction of forest site. With the GIS techniques of analysis, inclination of discussion, altitude, etc, and using high resolution satellite image and TPI, it is considered to be capable to provide more exact basis information of forest resources, management of forest management both in rational and efficient.

• Journal of KIISE:Software and Applications
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• v.37 no.8
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• pp.591-598
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• 2010

In this study, we propose a new method for generating candidate solutions based on the Cauchy probability distribution in order to complement the shortcoming of the solutions generated by the normal distribution. The Cauchy probability distribution has infinite mean and variance, and it has rather large probability in the tail region relative to the normal distribution. Thus, the Cauchy distribution can yield higher probabilities of generating candidate solutions of large-varied variables, which in turn has an advantage of searching wider area of variable space. In order to compare and analyze the performance of the proposed method against the conventional method, we carried out an experiment using benchmarking problems of real valued function. From the result of the experiment, we found that the proposed method based on the Cauchy distribution outperformed the conventional one for all benchmarking problems, and verified its superiority by the statistical hypothesis test.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.4
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• pp.117-129
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• 2015

This study is to find out the changes and features of male consumers' life style and purchase tendency according to the change of Korean fashion market, and based on which to suggest the design for the 20s men as well as a proper distribution channel for it. Documentary research and investigation were done together for the study. By reviewing documents focused on previous studies and declaring the change of men's fashion shopping tendencies and the following changes and features of their fashion sense and styles a conceptional frame for a design suggestion was presented. Ways to investigate were men's wear collection research, Q-technique. First of all, they tend to boldly reduce unnecessary purchases and do not hesitate to focus on the wanted item, expanding the trend of 'value purchase.' Secondly, men's wear use various design elements with feminine images, while the materials, colors and design expressive techniques that have been exclusively used for women's wear, began to be applied to men's one, turning them into gentle styles with womanhood is stressed. Thirdly, Korean distribution channel is rapidly diversified from departments to new-concept ones such as multi-brand stores. Especially, displaying and selling various optional products, multi-brand stores lead such diversification of fashion distribution channel. Fourthly, features of the drapery types favored by the 20s men are that they like no-chromed dark or blackish colors with fixed structure and partially-applied drapery on the clothes. Fifthly, it turns out that men in their 20s set a premium on design and price while they buy clothes. In addition to that, they buy clothes mainly during discount period and displayed much bigger satisfaction for the purchase on discounted price that those on normal price.

• Fashion & Textile Research Journal
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• v.26 no.1
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• pp.44-54
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• 2024

In this study, the sizing systems of 40 unisex sweatshirt brands were analyzed to collect the size information needed to produce unisex clothing. Each size specification was compared with the body size distribution and percentiles of men and women aged 18 to 29. Depending on the brand, unisex sweatshirt sizes ranged from 1 to 8. Despite being unisex apparel, three brands offered only one or two sizes. Out of the brands surveyed, 50% were found to offer four or five sizes. Out of the 40 brands, 25 used letters such as "S," "M," and "L" to indicate the size designation. More than 92.5% of the brands included M and L, and the sizing system tended to focus on larger sizes such as XL and 2XL rather than smaller sizes such as XS and S. The size specifications of shoulder width, chest circumference, sleeve length, and total length were compared with the body size distribution and percentiles of men and women aged 18 to 29. The distribution of each size specification mostly appeared in a section larger than the men's body size. The size specifications of unisex sweatshirts were set close to or larger than men's sizes and hardly represented women's sizes. To increase consumer satisfaction with unisex clothing, establishing a size standard that could accurately reflect the body size distribution of men and women was found to be imperative. Such a size standard could also help each brand specify or diversify its target and differentiate itself with other brands.