• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.25-32
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• 2020

The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.

• Journal of the Korea Concrete Institute
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• v.20 no.4
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• pp.415-421
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• 2008

Reinforced concrete starts to corrode when the chloride ion concentration which is the sum of included in concrete and penetrated from environments exceeds a certain level of critical chloride concentration. Therefore each country regulates the upper bounds of chloride amount in concrete and the regulations are different for each country due to its circumstances. In this study, the critical threshold chloride content according to unit cement amount is empirically calculated to propose a reasonable regulation method on the chloride amount. As a result, the critical threshold chloride content increases considerably according to cement content and it agrees with the established theories. The present regulations on total chloride amount 0.3 or 0.6 kg chloride ions per $1\;m^3$ of concrete does not reflect the influences of mix design, environmental conditions and etc. So it can be said that it is more reasonable to regulate the critical threshold chloride content by the ratio of chloride amount per unit cement content than by the total chloride content in $1\;m^3$ of concrete.

• Journal of the Korean Institute of Gas
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• v.2 no.2
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• pp.26-33
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• 1998

The thickness of buried gas pipeline is determined mainly with internal pressure and location factor according to the requirements of ANSI B3l.8. But the stress of buried gas pipeline is determined by not only internal stress but also external loads. The change of burying and environmental conditions, therefore, may result in increasing stress of pipeline. In order to avoid the decrease of safety degree resulting from change of environmental condition, the evaluation of stress level shall be necessary. The reliable equations have been developed for calculating stress of buried pipeline from internal pressure, earth load, vehicle load, ground subsidence. But they are very difficult to understand and use for non-specialist. For easy calculation of non-specialist, the new computer program to calculate stress of buried natural gas pipeline have been developed. The program can calculate maximum stress resulted from earth load, vehicle load, thermal load, four type ground subsidence. The stress is calculated by the equations and extrapolation of the graph resulted from FEM. In this paper, as the series of paper I, the operating method and the functions of the program is explained.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.462-462
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• 2018

국내 신규댐 건설에 있어, 침수토양의 용출에 의한 호내 수질영향에 대해서는 현재까지 정량화된 사례는 찾기 어려우며, 댐 담수 초기에 증가되는 오염원에 대한 정확한 조사자료의 부족으로 담수이후의 수질변화에 대한 정확한 예측이 어려운 실정이다. 따라서 외부 오염부하의 강우시 유입과 퇴적물로부터의 영양염용출 등의 내부 오염부하가 함께 고려된 수질예측기법의 적용이 필요하다. 수몰지 토양 및 호내로부터의 내부부하에 있어서는 퇴적물 내의 다량 존재하는 오염물이 재용출 되거나 퇴적물 내의 화학적 생물학적 반응이 하천 수질에 악영향을 미치게 된다. 대부분 수몰지토양에서 수층으로 용출되는 유기물의 양은 수층에서 퇴적물로 흡수 또는 침강 되는 것보다 많은 경우도 있으며, 오염된 수계에서는 내부 부하량이 과다할 경우 수질 개선을 어렵게 하는 요인이 되고 있다. 따라서 본 연구에서는 2016년 시험담수 예정지인 신규댐 수몰지를 대상으로 토양에 포함된 유기물이 자연상태에서 수체로 용출되는 특성을 분석하여 수질에 미치는 영향을 검토하고자 한다. 댐 수몰지의 토양 시료는 시험담수전 2016년 7월, 토지이용 유형별로 5개지점(논, 밭, 대지, 임야, 하천)에서 시료를 채집하여 총 36일간 용출실험을 실시하였으며, 수층내 용존산소 조건을 호기성 조건과 혐기성 조건으로 나누어 실험하였다. 수질분석은 COD, T-N, T-P, $PO_4-P$등 9개 항목에 대해 실험기간 중 13회 실시하였다. 토양별 점유면적 대비 일 용출량은(kg/day) COD 63 kg/day, T-N 93.6 kg/day, T-P 5.8 kg/day, $PO_4-P$ 4.6 kg/day 였으며, 수몰지 내 토지이용현황별 오염원 기여율은 임야, 밭, 하천, 논, 대지 순 이었다. 본 실험은 수몰지토양의 순수용출량만을 담수개시~36일간 측정한 결과로서 실제 저수지환경에서는 실험값보다 낮을 것으로 판단되며, 수중 수질환경 변화 및 퇴적물의 퇴적 등으로 인하여 원토양으로부터의 용출로 인한 수질에의 영향은 시간의 경과와 함께 변화 또는 감소될 것으로 예상된다. 따라서 본 실험결과는 담수초기의 영향으로 국한하여 해석하는 것이 바람직하며, 보다 장기적인 영향파악을 위해서는 담수 후의 퇴적물의 거동(퇴적현황) 파악 및 담수 후 퇴적물의 장기용출실험을 통한 용출량 검토가 필요하다.

• Journal of Conservation Science
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• v.37 no.5
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• pp.440-450
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• 2021

Temperature and humidity data collection using real-time sensors and data loggers was conducted for integrated pest management in the collection storage and exhibition space of the Jeongnimsaji Museum, Buyeo. The real-time temperature and humidity monitoring system collected measurement data every 30 minutes and enabled real-time confirmation of the data through a linked application. If the temperature and humidity data measured in the real-time temperature and humidity monitoring system exceeds the set range, a push notification was sent to the mobile phone of the person in charge to provide status information to establish a continuous management system. Through this, it was possible to immediately recognize and take action when the temperature range exceeded the recommended relic temperature in August. We performed data visualization on the concentration of airborne fungus in the storage area and the inflow path and density of insects. Based on the recommended criteria presented by the National Institute of Cultural Heritage, The data on the spatial and temporal concentration of airborne fungus inside the collection storage were found to be maintained at a value below the standard recommended by the National Institute of Cultural Heritage (80 CFU/m³). Also, as a result of the insect inflow survey, no insects were captured inside the storage area, and in the case of the exhibition space, insects such as Scutigera coleoptrata, Loxoblemmus arietulus, Diestrammena asynamora, Koreoniscus racovitzai were captured. Based on this, as a result of visualization according to the individual density of captured insects by area, it was confirmed that the main inflow paths of insects were the external entrance and the toilet area.

• Land and Housing Review
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• v.13 no.4
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• pp.73-89
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• 2022

With the spread of COVID-19, the role of parks has been emphasized. Under the quarantine guidelines, including social distancing, people are visiting parks as a safe place. In line with these changes, parks need to be studied as pandemic adaptation measures according to their physical and location characteristics. This study aims to explore the potential of linear parks with accessibility and pass way functions based on the characteristics of surrounding land uses. The case study area was selected from Yeonnam-dong to Yeomni-dong of the Gyeongui Line Forest Park, and the area was divided into 4 sections based on the administrative boundary and surrounding land uses. Multiple regression models were adopted in each section using the total number of de facto population as a dependent variable and factors affecting external activities including COVID-19 as independent variables. The results show that first, the more diverse the interaction between commercial facilities and linear parks, the greater the impact of the pandemic. Second, where various commercial facilities are concentrated people respond more sensitively to short-term weather changes than seasonal ones. This study indicates that there are differences in the use of linear parks according to the surrounding land uses. In addition, it suggests that the linear park has potential as a means to overcome the Pandemic crisis of the city and to increase equity in access to green areas.

• Analyses & Alternatives
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• v.7 no.2
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• pp.179-207
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• 2023

Carbon neutrality, the international community's practical challenge in response to climate change, is becoming a key industrial strategy for the future development of nations. Despite concerns that China, as an economic powerhouse in the G2, may face challenges leading global climate change efforts due to its high-carbon-emitting industrial structure, it is leveraging carbon neutrality to enhance its industrial competitiveness. The Chinese government has formulated national policies for achieving carbon neutrality and detailed sector-specific plans to implement them. In particular, it aims to leverage carbon neutrality industrial strategies as a lever for adjusting the domestic industrial structure and fostering new industries, at the same time responding to international climate norms and external pressures. However, the effectiveness of carbon-neutral industrial strategies is expected to vary based on regional conditions such as economic and industrial levels. This article analyzes the regional conditions for implementing carbon neutrality in China, as well as the contents and characteristics of major industrial policies. Due to differing levels of economic development and industrial structures, significant variations in carbon emissions, size, emission sources, and efficiency are inevitable across regions. These disparities introduce diverse initial conditions and endogenous factors in pursuing carbon-neutral goals, limiting the direction and implementation of carbon-neutral industrial strategies favoring certain regions. In particular, the extent of policy autonomy granted to local governments regarding carbon neutrality implementation will influence the regional dynamics of central-local environmental governance. Consequently, it is crucial to emphasize regional monitoring alongside comprehensive national research to accurately navigate the path towards carbon neutrality in China. In summary, the article underscores the importance of understanding regional variations in economic development, industrial structure, and policy autonomy for successful carbon neutrality implementation in China. It highlights the need for regional monitoring and comprehensive national research to determine a more precise direction for achieving carbon neutrality.

• The Korean Journal of Franchise Management
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• v.2 no.2
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• pp.95-110
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• 2011

As global economic conditions are getting uneasy and polarization of our economy is intensified, the economic sentiment of small businesses is still low and unstable. The collapse of worldwide banking systems due to sub prime crisis in 2007 became the catalyst that shakes financial industries in each country in the world; the most sentiment people, small businesspersons, also have hard time facing survival way out, facing a great crisis. All organizing powers including manufactures, wholesales and retails are being gradually greater in mutual relations and dependence, and unstable factors about risks are also increasing. For exterior environmental and physical risk factors which cannot make small businesses survive themselves by developing ways out are eventually increasing, those who cannot cope with these factors face a great crisis. Although the government tries hard to overcome this situation conducting many ways, the effect does not continue. It is the real state that independent business markets including overall employment and establishing business have vicious cycle that they cannot be improved, due to increase of employment centered on short-term labors which lack durability in creation of employment and decline of household income. Recently, growth shows indication of slowdown because of multinational risk factors including financial crisis in each country in Europe, the death of Kim Jung-il, relationship with North Korea, and unstability of war situation in the Middle East Asia. Experts expect that growth rate will be about 4%, and independent business that ordinary people feel is still gloomy. It's reality that there is no adequate alternative for lack of jobs, unstable employment and a means of living after retirement. Also, the fact that large companies enter the market which is narrow and in the excessive competition should be an environmental factor that makes the situation worse. The business concept, a franchise, is the part we should think about whether it is the institutional solution that can guarantee independent businessmen stable life. Major companies are frightfully entering the market today, breaking the barrier to entry and shouting of a win-win with independent businesses. It's the small businesspersons who go through painful domestic recession, cannot predict the future and manage confusing and unstable independent business. It's very important to restore the domestic economy through wisely boosting consumption as soon as possible. It's also important to lead the situation by gathering powers of the government and related organizations, agonizing, suggesting solutions, and establishing accurate directions. The purpose of this study, therefore, is to suggest ways to strengthen competitiveness of small businesspersons by examining small business support policies which are currently implemented.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.934-947
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• 2011

The purpose of this study is to analyze products for good taste and convenience, which become an engine to constantly create customers. In addition, this study is aimed at investigating the relationship between the selective attributes of Home Meal Replacement, the perceived utilitarian value, and the repurchase intention, and drawing new suggestions on the Home Meal Replacement market from a new marketing perspective. Based on a total of 215 samples, this study reviewed the reliability and fitness of the research model and verified a total of 5 hypothesized using the Amos program. The result of study modeling was GFI=0.905, AGFI=0.849, NFI=0.889, CFI=0.945, and RMR=0.0.092 at the level of $x^2$=230.22 (df=126, p<0.001). First, the food quality (${\beta}$=0.221), convenience (${\beta}$=0.334), packing (${\beta}$=0.278), and employee service (${\beta}$=0.204) of home meal replacement consideration attributes had a positive (+) influence on perceived utilitarian value. Second, perceived utilitarian value (${\beta}$=0.584) had a positive (+) influence on repurchase intention. The factors to differentiate one company from other competitors in terms of the utilitarian value are the quality of food, convenience, wrapping, and services by employees. This study has illustrated the need to focus on the development of a premium menu to compete with other companies and to continue to research and develop nutritious foods that are easy to cook. Moreover, the key factors to have a distinct and constant competitive edge over other companies are the alleviation of consumer anxiety over wrapping container materials, the development of more designs, and the accumulation of service know-how. Therefore, it is necessary for a company to strongly develop the key factors based on its resources as a core capability.

• Sleep Medicine and Psychophysiology
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• v.7 no.2
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• pp.88-95
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• 2000

Objectives: The object of this experiment was to evaluate the effect of sleep deprivation on mood states of normal adults using a subjective scale and an objective scale, minimizing the effect of other factors other than that of sleep deprivation. Methods: Seventy volunteers were first participated in this sleep deprivation schedule, and 36 of them completed this experiment. The subjects and the control group members were all in their early 20's (mean $age=20.8{\pm}1.35$ vs $20.6{\pm}1.10$) and in good health. A log was checked by these subjects from a week before the laboratory study started. Drugs, alcohol and beverages containing any caffeine had been prohibited for a week before and during sleep deprivation periods. The study was performed only in summer to control other factors like sunlight, temperature and moisture. Before this experiment, the subjects had slept adequately for a week at least. On day 1 of the experiment the subjects got up at 6 a.m. and stayed in a sleep laboratory without sunlight or external noises. They could only go about their daily routines. They were forbidden to have a nap and be drowsy. GVA (Global Vigor and Affect) and MADRS (Montgomery-Asberg Depression Rating Scale) were checked 11 times. The data was analysed focusing on the changing mood states. Results: The mood during sleep deprivation became worse as the sleep deprivation time progressed. Especially 20 hours ($GA=59.25{\pm}8.06$, $MADRS=3.43{\pm}1.25$) and 40 hours ($GA=38.83{\pm}9.22$, $MADRS=6.08{\pm}1.46$) after sleep deprivation, there were significant changes compared to the control group ($MADRS=6.08{\pm}1.46$ vs $1.07{\pm}1.18$, p<0.001). Conclusions: While controlling factors other than sleep deprivation might have had some influence on mood changes, significant mood changes during sleep deprivation were observed. The mood states became worse as the sleep deprivation progressed.