• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.356-365
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• 2018

While social networks have become very popular and powerful way of connecting people and sharing new information, they also effectively spread wrong or biased information to the public. We examine the so-called "Shandong peninsular rumor" that claims Chinese government is responsible for the increased air pollution in South Korea and Japan, by moving pollution-causing industries near Beijing to the Shandong peninsular which is close to South Korea. We demonstrate that the amounts of $NO_x$ and $SO_2$ emissions inferred by space-borne monitoring and regional air quality models show clear declining trends in past several years. We do not have any evidences to support the relation of Shandong peninsular emissions change to South Korean air quality.

• STI Policy Review
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• v.6 no.2
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• pp.1-23
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• 2015

This study aims to contribute to the debate over the age-productivity relationships in scientific and technological research. For this purpose, we conducted an empirical experiment employing a time-series cross-section dataset derived from the KRI of the NRF containing data on individual researchers of fifty major universities in Korea covering the period of 2008-2013. This study has found that: (1) there exists an inverse U-shaped age-productivity relationship at the level of individual researchers; (2) the impact of the average age of a research group on the productivity of individual researchers varies across fields; (3) male and female researchers move along different age-productivity curves; and (4) the inverse U-shaped age-productivity relationship also holds at the level of organizations. The results suggest that the aging of researchers in Korea will soon reach the stage where serious losses in research productivity become a reality. Yet, it is not so clear whether the observed decline in the performance of older researchers is due to declining cognitive capability, which is an unavoidable result of aging, or to declining motivation, which results from an institutional system that discourages older researchers' research activities (such as reduced access to research opportunities or mandatory retirement). What is clear is that it is inevitable for the Korean science system to change the current seniority- and age-based organizational system into one of higher adaptability.

• Korean Journal of Rural Living Science
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• v.8 no.2
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• pp.93-110
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• 1997

The customs of women s riding horse was prevalent in thriving period. The face toilet was mainly used by Gau Chang pattern. Wha Jun (chinen; Hwa-Qun(화전), make-up on forehead), was influenced nearly by Gua Chang and distantly by India. Penciling eyebrows with blue was transmitted from persia. Chinese cosmetics was most influenced during Tang Dynasty for it's colorful make-up and facial decorations such as Aek-Whang(액황), Wha-Jung(화전), Jang-Yob(장엽), Swa-Hong(사홍) and those made many Dynasty, since those kinds of styles were the result of mixture between traditional chinese and western styles, it became so unique and diverse. The Declining period of the Tang Dynasty has begun from the turning point, resulting from Rebellion of An Ru Sha'. Rebellion of An Ru Sha' made the chinese people have a sense of precaution, and an antipathy against babarian. Furthermore, the power of Tang Dynasty onto the countries bordering on western china unfortunately was declining due to the defeat at 99 the Talas war in 751. As the fashion of ‘Ho’ disappeared the costume pattern was restored to the traditional Chinese style of large sleeve and broad width. However, the Tibetan mode was appeared in women's hair style and face toilet since Yuan Ha (801-812). In Song Dynasty, women's make-up and adorment were originated from Dang Dynasty, but those were more simple than in Dang Dynasty.

• Hwankyungkyoyuk
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• v.19 no.1 s.29
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• pp.104-115
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• 2006

This study was conducted to investigate whether attitudes and recognitions of middle and high school students regarding environmental concerns were improved after anuran call monitoring. It was a step toward monitoring local environmental changes with anuran calls. Three-striped pond frogs (Rana nigromaculata), Bullfrogs (R. catesbeiana), and Narrow-mouthed toads (Kaloula borealis) were surveyed to determine local abundance and distribution of them in 12 study sites using their advertising calls. A published booklet, which contains morphological, physiological, ecological, and acoustic information on amphibian species and methods of monitoring anuran calls were provided to monitoring students for identifying the three species. Pretest-posttest were conducted before and after monitoring from 10 April to 28 August in 2005 to determine how the monitoring students changed their attitudes on environmental issues, increased knowledges on amphibians, and improved the understanding on the cause and effect of declining amphibian populations. The amphibian monitoring program was effective to improve the students' attitudes towards conserving environments as well as the students' knowledge on general behavior and ecology of various amphibian species although their understanding about various environmental problems was not. In addition, the program increased the students' understanding on the problems of declining amphibian populations.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.1
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• pp.119-131
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• 2014

The phenomenon of cavitation is an unsteady flow, which is nearly inevitable in pump. It would degrade the pump performance, produce vibration and noise and even damage the pump. Hence, to improve accuracy of the numerical prediction of the pump cavitation performance is much desirable. In the present work, a homogenous model, the Zwart-Gerber-Belamri cavitation model, is considered to investigate the influence of the empirical coefficients on predicting the pump cavitation performance, concerning a centrifugal pump. Three coefficients are analyzed, namely the nucleation site radius, evaporation and condensation coefficients. Also, the experiments are carried out to validate the numerical simulations. The results indicate that, to get a precise prediction, the approaches of declining the initial bubble radius, the condensation coefficient or increasing the evaporation coefficient are all feasible, especially for declining the condensation coefficient, which is the most effective way.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.3
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• pp.1-7
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• 2021

The number of new students at many domestic universities is declining. In particular, private universities, which are highly dependent on tuition, are experiencing a crisis of existence. Amid the declining school-age population, universities are striving to fill new students by improving the quality of education and increasing the student employment rate. Recently, there is an increasing number of cases of using the accumulated big data of universities to prepare measures to fill new students. A representative example of this is the analysis of factors that affect student employment. Existing employment-influencing factor analysis studies have applied quantitative models such as regression analysis to university big data. However, since the factors affecting employment differ by major, it is necessary to reflect this. In this paper, the factors affecting employment by major are analyzed using the data of University C and the decision tree model. In addition, based on the analysis results, a roadmap for student employment by major is recommended. As a result of the experiment, four decision tree models were constructed for each major, and factors affecting employment by major and roadmap were derived.

• International Journal of Industrial Entomology and Biomaterials
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• v.38 no.1
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• pp.1-5
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• 2019

Bee's population is declining and disappearing at alarming rate. There are many factors responsible for declining the population of bees including diseases, natural enemies, environmental conditions and pesticides. Insecticides play its role dramatically for their population decline and neonicotinoid insecticides are critically important due to their wide application for pest control. Keeping in view of above problem, effect of neonicotinoid insecticides on olfactory learning behavior in Apis mellifera was observed using Proboscis Extension Reflex (PER) method. In this method, bees were harnessed in centrifuges tubes and feed on insecticides mixed sugar solution after three hours hunger. Bees were checked by feeding on non-treated sugar solution to observe PER response. Minimum proboscis extension was observed for acetamiprid and imidacloprid with 26% and 20% respectively at their recommend field doses while it was maximum for dinotefuran and thiamethoxam with 73% and 60% respectively. Only 40% bees showed response when exposed at 1/10 concentration of field dose for imidacloprid and the least at 1/100 of field dose. At control (Sugar solution) about 90% bees showed PER response. Among these neonicotinoid insecticides tested, imidacloprid and acetamiprid were the most damaging which impaired the olfactory learning performance in Apis mellifera.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.33 no.12
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• pp.73-83
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• 2017

Due to the changes in the contemporary society, small-scale traditional markets have declined and lost their functions as the center of neighborhood commercial and cultural affairs. While most traditional markets are deteriorating, there exist rare cases of neighborhood small-scale traditional markets that continuously maintain their vitality and popularity. This paper examines urban spatial characteristics of those markets. As for the cases, this paper inventoried eighteen such markets in Gwanak-gu, Seoul. The research methods include literature reviews, on-site investigation of total 18 such markets, and participant observations. The findings of this paper are as follows: There are distinctive differences in the urban-spatial characteristics of physical environmental factors between the revitalized markets and declining markets. In terms of neighborhood and commercial environment, the franchised super-markets are not necessarily in competition with small-scale traditional markets. The former often has symbiotic relationship the latter, if the small scale traditional markets are strategically located in between residential areas and subway stations, providing active pedestrian networks. There are many outdoor display stands in the revitalized markets, while the declining markets rarely have them. The market improvement projects such as transforming the open space into arcade space, hardly have effects on revitalization of the small-scale traditional markets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.570-576
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• 2020

This study uses beacons and smartphone Global Positioning System (GPS) receivers to establish a location-based disaster/hazard prediction system. Beacons are usually installed indoors to locate users using triangulation in the room, but this study is differentiated from previous studies because the system is used outdoors to collect information on registration location and temperature and humidity in hazardous areas. In addition, since it is installed outdoors, waterproof, dehumidifying, and dustproof functions in the beacons themselves are required, and in case of heat and humidity, the sensor must be exposed to the outside, so the waterproof function is supplemented with a separate container. Based on these functions, information on declining and vulnerable areas is identified in real time, and temperature/humidity information is collected. We also propose a system that provides weather and fine-dust information for the area concerned. User location data are acquired through beacons and smartphone GPS receivers, and when users transmit from declining or vulnerable areas, they can establish the data to identify dangerous areas. In addition, temperature/humidity data in a microspace can be collected and utilized to build data to cope with climate change. Data can be used to identify specific areas of decline in a microspace, and various analyses can be made through the accumulated data.

• Journal of Distribution Science
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• v.13 no.5
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• pp.71-82
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• 2015

Purpose - The purpose of this study is to investigate risk price implied from the pricing kernel of Korean stock distribution market. Recently, it is considered that the quantitative easing programs of major developed countries are contributing to a reduction in global uncertainty caused by the 2007~2009 financial crisis. If true, the risk premium as compensation for global systemic risk or economic uncertainty should show a decrease. We examine whether the risk price in the Korean stock distribution market has declined in recent years, and attempt to provide practical implications for investors to manage their portfolios more efficiently, as well as academic implications. Research design, data and methodology - To estimate the risk price, we adopt a non-parametric method; the minimum norm pricing kernel method under the LOP (Law of One Price) constraint. For the estimation, we use 17 industry sorted portfolios provided by the KRX (Korea Exchange). Additionally, the monthly returns of the 17 industry sorted portfolios, from July 2000 to June 2014, are utilized as data samples. We set 120 months (10 years) as the estimation window, and estimate the risk prices from July 2010 to June 2014 by month. Moreover, we analyze correlation between any of the two industry portfolios within the 17 industry portfolios to suggest further economic implications of the risk price we estimate. Results - According to our results, the risk price in the Korean stock distribution market shows a decline over the period of July 2010 to June 2014 with statistical significance. During the period of the declining risk price, the average correlation level between any of the two industry portfolios also shows a decrease, whereas the standard deviation of the average correlation shows an increase. The results imply that the amount of systematic risk in the Korea stock distribution market has decreased, whereas the amount of industry-specific risk has increased. It is one of the well known empirical results that correlation and uncertainty are positively correlated, therefore, the declining correlation may be the result of decreased global economic uncertainty. Meanwhile, less asset correlation enables investors to build portfolios with less systematic risk, therefore the investors require lower risk premiums for the efficient portfolio, resulting in the declining risk price. Conclusions - Our results may provide evidence of reduction in global systemic risk or economic uncertainty in the Korean stock distribution market. However, to defend the argument, further analysis should be done. For instance, the change of global uncertainty could be measured with funding costs in the global money market; subsequently, the relation between global uncertainty and the price of risk might be directly observable. In addition, as time goes by, observations of the risk price could be extended, enabling us to confirm the relation between the global uncertainty and the effect of quantitative easing. These topics are beyond our scope here, therefore we reserve them for future research.