• Tunnel and Underground Space
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• v.31 no.3
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• pp.167-183
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• 2021

It is essential to understand the complex thermo-hydro-mechanical-chemical (THMC) coupled behavior in the engineered barrier system and natural barrier system to secure the high-level radioactive waste repository's long-term safety. The heat from the high-level radioactive waste induces thermal pressurization and vaporization of groundwater in the repository system. Groundwater inflow affects the saturation variation in the engineered barrier system, and the saturation change influences the heat transfer and multi-phase flow characteristics in the buffer. Due to the complexity of the coupled behavior, a numerical simulation is a valuable tool to predict and evaluate the THMC interaction effect on the disposal system and safety assessment. To enhance the knowledge of THMC coupled interaction and validate modeling techniques in geological systems. DECOVALEX, an international cooperation project, was initiated in 1992, and KAERI has participated in the projects since 2008 in Korea. In this study, we introduced the main contents of all tasks in the DECOVALEX-2023, the current DECOVALEX phase, to the rock mechanics and geotechnical researchers in Korea.

• Maritime Security
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• v.2 no.1
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• pp.43-70
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• 2021

This study started from questioning our general view that the Japan Maritime Self-Defense Force (JMSDF) is a natural result of Japan being a prosperous and island country. Japan's naval power collapsed after World War II. The initial power of the JMSDF, founded in 1954, was very small and not different from the Republic of Korea Navy (ROKN), mostly consisting of ships given by or borrowed from the US. Although growing into the world's second-largest economy and the geographical characteristics of an island nation acted as an opportunity to increase naval forces, there were also difficulties in the early stage, such as a temporary severance with the Japanese Navy, strategic thinking centered on land forces, and an economic crisis caused by the oil crisis. As a result, the JMSDF has become a world-class naval power and is developing into a four helicopter carrier operating system, which may change the basic concept of exclusive defense. There are various factors behind the growth of Japan's naval power, but this study explores how to develop Korean naval forces by analyzing how Japan developed their escort fleet, the core of the JMSDF, focusing on the eight (艦)-eight (機) fleet system, which was the basic logic behind building the JMSDF.

• Journal of Life Science
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• v.30 no.12
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• pp.1128-1139
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• 2020

Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.

• Journal of Life Science
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• v.31 no.2
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• pp.164-174
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• 2021

This study confirmed the potential of Punica granatum L. extract for functional activity verification and cosmetic development. The electron-donating ability of Punica granatum L. extract was shown 60.6% at a 1,000 ㎍/ml concentration. Its ABTS+ radical scavenging ability was shown 93.9% at a 1,000 ㎍/ml concentration. Additionally, the inhibitive effects of elastase and collagenase inhibition effects were measured as 30% and 47.2%, respectively, at a 1,000 ㎍/ml concentration. To determine the effect of Punica granatum L. extract on the proliferation of fibroblasts (CCD-986sk), cell viability was measured using a 3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyl-tetrazoliumbromide (MTT) assay. As a result, survival rates of 130% or higher at a 500 ㎍/ml concentration or less were confirmed. According to the results of Western blot with Punica granatum L. extract, the expression inhibition rates of matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-3 (MMP-3) were decreased by 23.2%, 81.9%, and 69.2%, respectively, at a 100 ㎍/ml concentration. Based on the results above, O/W liquid crystal cream with 0.1% Punica granatum L. extract was prepared. The stabilities were tested at 4, 25, 45, and 50℃. By checking the pH, change over time, and stability by temperature, it was confirmed that all were stable for one month. Thus, Punica granatum L. extract shows potential as a natural material for cosmetics.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.79-90
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• 2021

Landscape composition and structure are important factors determining biological diversity including pests and natural enemires in agricultural ecosystem. This study was conducted to indentify effect of landscape composition on occurrence of lepidopteran pest population in Geochang, Gyoungdnam. For this, orchard characteristics and management practices were surveyed in 80 conventional apple orchards in Geochang, Korea, along with the monitoring of pest population densities. The landscape features of each surveyed orchard also obtained by extracting information from the public-service map. Grapholita molesta was the most dominat and damaging pest followed by Phyllonorycter ringoniella and Carposina sasakii in trap catches. Adoxophyes paraorana occurrences were low. Farmers spray insecticides and fungicides ap. 12.4 times per year respectively while acaricides were sprayed 2.4 times. Major landscape features such as surrounding apple orchard or paddy field did not influence the pest populations but presence of plum, peach, wild peach, graph, and even abandoned orchards significantly resulted in higher pest population mostly on G. molesta. C. sasakii population was higher in orchards with grape, peach, and P. ringoniella with peach, grape, abandoned orchards and jujube. Results highlight the need of landscape management not only for the rural amenity but also for increasing functional diversity of agroecosystem as well as reducing pest population.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.213-223
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• 2022

This study was conducted to establish a Habitat Suitability index (HSI) based on literature research and field surveys on ecology and habitat of 'Hynobius leechii'. And this study will be used as basic data for qualitative evaluation of habitat environment. The survey sites were divided into natural habitats close to the prototype habitat and artificial restoration areas where Hynobius leechii was monitored. So the types of habitats were diversified. Hynobius leechii is a vulnerable species to climate change because it is affected by the microhabitat and has low mobility. HSI variables of Hynobius leechii were extracted through domestic and overseas literature, and standards were extracted from literature research and field survey. The standards were presented as a value of the physical allowable category in consideration of realization. To verify the study, an in-depth consultation was conducted by amphibians experts. HSI variables of Hynobius leechii were included 9 variables such as Overstory canopy cover(%), Understory cover(%), Water-pH, Soil-pH, Soil relative humidity(%), Leaf litter depth(cm), Rock substrates (%), Type of Coarse woody, Distance from Street or Pollutant(m).

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.264-274
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• 2020

Background: Climate change has altered the various ecosystem processes including forest ecosystem in Himalayan region. Although the high mountain natural forests including treelines in the Himalayan region are mainly reported to be temperature sensitive, the temperature-related water stress in an important growth-limiting factor for middle elevation mountains. And there are very few evidences on growth performance of planted forest in changing climate in the Himalayan region. A dendrochronological study was carried out to verify and record the impact of warming temperature tree growth by using the tree cores of Pinus roxburghii from Batase village of Dhulikhel in Central Nepal with sub-tropical climatic zone. For this total, 29 tree cores from 25 trees of P. roxburghii were measured and analyzed. Result: A 44-year long tree ring width chronology was constructed from the cores. The result showed that the radial growth of P. roxburghii was positively correlated with pre-monsoon (April) rainfall, although the correlation was not significant and negatively correlated with summer rainfall. The strongest negative correlation was found between radial growth and rainfall of June followed by the rainfall of January. Also, the radial growth showed significant positive correlation with that previous year August mean temperature and maximum temperature, and significant negative correlation between radial growth and maximum temperature (Tmax) of May and of spring season (March-May), indicating moisture as the key factor for radial growth. Despite the overall positive trend in the basal area increment (BAI), we have found the abrupt decline between 1995 and 2005 AD. Conclusion: The results indicated that chir pine planted population was moisture sensitive, and the negative impact of higher temperature during early growth season (March-May) was clearly seen on the radial growth. We emphasize that the forest would experience further moisture stress if the trend of warming temperatures continues. The unusual decreasing BAI trend might be associated with forest management processes including resin collection and other disturbances. Our results showed that the planted pine forest stand is sub-healthy due to major human intervention at times. Further exploration of growth climate response from different climatic zones and management regimes is important to improve our understanding on the growth performance of mid-hill pine forests in Nepal.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.708-714
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• 2011

Wood store carbon that the forest absorbed until burned or decomposed over a long period. Such materials are most used in houses except in paper and pulp, and the use of wood in houses play an important role in reducing green-house gases. Therefore, we estimated the amount of carbon stocks in Korean houses, and analyzed how much contribution such stocks offers to green-house gas reduction. As the result, the carbon stocks amount of the wood products in Korean houses was 28.4 million $tCO_2$, which is 4.6% of the total annual green-house gas emission in Korea (620 million $tCO_2$ e), and 77.4% of forest sinks (LULUCF). Even though few wooden houses which use most wood in housing exist in Korea, the carbon stocks of wood products in houses in 2010 increased to 4.1 times that in 1975 (21.4 million $tCO_2$) because the carbon stocks increased due to apartment construction, which hit its stride from the last 1980's.

• (The)Study of the Eastern Classic
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• no.36
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• pp.403-432
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• 2009

In this paper, I examined two things. First explore the of the reality(眞) in poems written on paintings and discussion on paintings in men of letters of Pre-chosun dynasty, furthemore, it analyzes the meaning and thought. To explain it, I would like to analyse the discourse surrounding the reality(眞) in poems written on paintings and discussion on paintings, and concept of the borrowing(假) and the unreal(幻). First of all, I examine the ways that the view of nature of Confucians is pertinent to the abiding in reverence and the investigation of principles of confucians, also painting is necessarry condition for their moral and spiritual self-cultivation. In the discourse surrounding the reality, it is to suggest from 'natural reality (天眞)' to escape from the reality(眞), and proceeds to examine the transformation of reality(眞) in mind(人心). Furthermore I examine the meaning of transform and delicate difference between borrowing(假) and the unreal(幻). In this process, concept of the borrowing(假) and the unreal(幻) is divided into the two meaning. False(假) is to become the Borrowing and painting, the unreal(幻) is change into the act of recognition. In conclusion, I examined the significant transformation of the reality(眞) and the unreal(幻). The reality(眞) has been recognized as a important concept, it is diverged into the Nature, outer things and painting mind, and the object of ultimate value in appreciation and painting of Pre-chosun dynasty.

• Resources Recycling
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• v.30 no.3
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• pp.3-17
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• 2021

Currently, there is a drain of natural resources, environmental contamination, generation of waste, and problems of the earth's climate by CO₂ emissions according to mass production and overconsumption of mankind. It is effectuated by a linear economy that involves manufacturing products, use, and waste repeatedly; there is no guarantee in the lives of humans and the future of the globe if we do not find alternative proposals. For a sustainable developing society and to overcome the present global problems, we must successively change to a circular economy from a linear economy. The circular economy has the concept of an extended value chain in recovery, reuse, remanufacturing, and recycling, instead of discarding after the use of manufactured goods. New business models of circular economy have been realized to save the earth ecology and sustainable developing society in serious recognition of the linear economy system. New business models are established by creating a vision and developing a program, and by renovating technology, law, and financial support through a worldwide government policy.