• 대한수학회보
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• 제34권1호
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• pp.43-49
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• 1997

In this paper, we study an error of vanishing viscosity method for the first-order Hamilton-Jacobi equations.

• Environmental Engineering Research
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• 제15권2호
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• pp.85-91
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• 2010

Romania aims to adopt and implement the European Union's legislation, also including that for the field of water management. Like other countries, groundwater in Romania is locally polluted from point sources, such as leaking landfills, as well as from diffuse pollution sources, include fertilizers, pesticides and leakages from sewers, in urbanized areas. Diffuse pollution can also occur indirectly, by over-exploitation of groundwater wells, resulting in salt water intrusion, as well as from mining and exploitation of mineral aggregates. Romania has quite an intensive monitoring scheme to measure groundwater quality in phreatic and confined aquifers. The purpose of the work resumed in this paper was to derive natural background levels (NBL) for groundwater in order to distinguish the natural elevated concentrations of some substances (natural phenomena) from point and diffuse pollution (anthropogenic phenomena). Based on these NBLs, threshold values (TV) for groundwater will be set according to the requirements of the European Water Framework Directive and the related Groundwater Directive. This paper describes the results of a study for the derivation of NBL and TV in a pilot Groundwater Body. Also, the process and draft results for extrapolating this work for all Romanian groundwater bodies is explained, as well as points for future consideration with respect to monitoring and management.

• Animal cells and systems
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• 제1권4호
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• pp.583-587
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• 1997

Incubation of an NADPH-dependent succinic semialdehyde reductase from bovine brain with N-bromosuccinimide (NBS) resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo-first-order kinetics with the second-order rate constant of $6.8\times{10}^3$ $M^-1$ $min^{-1}$. The inactivation was prevented by preincubation of the enzyme with substrate succinic semialdehyde, but not with coenzyme NADPH. There was a linear relation-ship between oxindole formation and the loss of enzyme activity. Spectro-photometric studies indicated that about one oxindole group per molecule of the enzyme was formed following complete loss of enzymatic activity. It is suggested that the catalytic function of succinic semialdehyde reductase is modulated by binding of NBS to a specific tryptophan residue at or near the substrate binding site of the enzyme.

• 한국조경학회지
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• 제31권6호
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• pp.1-14
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• 2004

As urbanization becomes widely spread, environmental benefits of natural landscapes have been highly appreciated. The social demands to conserve such landscapes are becoming stronger in modem society. In order to effectively manage natural landscapes, one should know what natural landscapes are. The characteristics of natural landscapes revealed by foreign research include wilderness, absence of human intrusion, and presence of diverse natural element (plants, trees, waters). The purpose of this paper is to investigate the characteristics of diverse natural landscapes with different levels of naturalness. The methods adopted here consist of three phases. First, 368 landscapes were photographed to include different levels of naturalness. Second, two professional landscape groups assessed the degree of naturalness of the collected landscapes, in which the characteristics of five degrees of naturalness were examined. Lastly, undergraduate students, as laypersons, assessed the 33 landscapes that were selected as representative of the five degrees of naturalness. The results show that there is no difference between professionals and laypersons on the assessment of naturalness of landscape. The characteristics of natural landscape that participants perceive include no human intrusion, preservation of original state, traditional quality such as Korean-style architecture, dominance of natural elements, and minimum facilities that harmonize with natural surroundings, Many characteristics are similar to the results of foreign research, However, the results reveal that Koreans do not perceive man-made nature as natural, while they perceive traditional elements as natural. Based on the results, some suggestions for landscape management are presented in the conclusion section.

• 한국의류학회지
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• 제38권5호
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• pp.611-626
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• 2014

Reading and foreseeing fashion trends is crucial and difficult in the fashion industry due to accelerated and diversified changes in fashion trends. We use network analysis to investigate fashion trends from 2004 to 2013 in order to find the inter-relevance among fashion trends. We extracted words from fashion trend info for women's wear provided by Samsung Design Net, created a 2-mode network of seasons and trend languages, and visualized this network using NodeXl program. Fashion trends repeated a unique pattern during the period. In the first half (2004-2008), retro modern, feminine modern, and ecological modern were dominant trends in consecutive order. The years 2009-2013 witnessed distinctive fashion trends in S/S seasons and in F/W seasons. 11F/W, 12F/W and 13F/W seasons were characterized by artistic creative style. From 2010, natural style dominated S/S seasons. 10S/S and 12S/S seasons were distinguished as a calm natural style that reflected a peaceful and simple life. In 11S/S and 13S/S seasons, soft natural style emerged as a sign of increased importance of inner spirit and natural energy. A seasonal reappearance of trends was observed every two years in S/S seasons that enabled the prediction that 14S/S will see another version of natural style. A macroscopic trend for the last 10 years was represented by the keywords 'modern' and 'natural'. 'Modern' involved the past styles such as 60's, Baroque and the origin of human life. 'Natural' was connected with design elements such as material, silhouette and color. Managerial implications and future study directions are discussed based on the results.

• 한국환경과학회지
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• 제28권11호
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• pp.959-969
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• 2019

This study sought to contribute to the revitalization of local economy by developing a natural recreation forest, which is the base of ecotourism recreation, through utilizing forest resources and the natural environment of Gwangju-si. The study conducted a feasibility assessment through on-site surveys such as the suitability of the candidate sites, location analysis, and possibility of damage to the forest, before developing recreation forest sites in Gwangju-si and, based on the result, selected appropriate subject sites. The candidates for this study were 5 forest sites such as one site in the Mokheon-dong area, two in the Docheok-myeon area, and one in the Toechon-myeon area. For this study, the current status of the natural recreation forest was surveyed, its feasibility index and assessment process were investigated, and the local status and related regulations of Gyeonggi-do and Gwangju-si were reviewed. The final subject sites were selected after feasibility assessment utilizing assessment index in order to evaluate the candidate sites. The feasibility assessment was conducted after three separate on-site surveys for each candidate site between October 2018 and January 2019 utilizing "The Feasibility Assessment Criteria for Natural Recreation Forest (Notification 2018-71)" of the Korean Forest Service. The items instrumental to the feasibility assessment were classified into landscape, location, water system, induction of recreation, and development condition; the assessment was made after redefining each item into detailed items. Through this process, the Usan-ri area was selected as the final site for developing natural recreation forest, having obtained more than 100 points according to "The Feasibility Assessment Criteria for Natural Recreation Forest" of the Korean Forest Service. In order to develop natural recreation forest in the Usan-ri area in the future, further discussion is necessary with the relevant departments in consideration of the degree of ecological zoning map.

• International Journal of Costume and Fashion
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• 제10권1호
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• pp.29-45
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• 2010

In order to provide more systematic approach to analyze fabric trends and to develop fabrics accordingly, ecology fabric trend from 1986 to 2005 was analyzed related with fabric trend themes and fabric attributes. The result shows that in the 1980s, natural theme appeared, followed by primitive theme and imitated natural theme until the mid 1990s. From the late 1990s to the early 2000s, new natural theme appeared, followed by eco-friendly theme, and then recycling theme. In the natural theme, 'clean' was the most important fabric attribute and 'textured' and 'worn' were important fabric attributes in the primitive theme. In the imitated natural theme, 'wet' fabric attribute was preferred. In the new natural theme, 'lightweight' were preferred. The results of this study empirically demonstrated that abstract and ambiguous trend terms can be interpreted with a physical, substantial, and feasible attributes that fabric practitioners can easily understand.

• 한국수학사학회지
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• 제32권3호
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• pp.109-134
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• 2019

In order to improve the educational situation in which the natural number e and the natural logarithm are dealt with somewhat perfunctorily, this study explores the genetic process in which the natural logarithm and its base e occurred, and has an educational discussion based on that analysed process. Specifically, the study inquires into how the natural logarithm happened in relation to the quadrature of the hyperbolic curves through analysis and thought experimentation in mathematics history. Particularly, it sheds light on the role of e and the naturalness of the natural logarithm in terms of the introduction of the real number exponent. Also, this study discusses what the findings suggest educationally.

• 대한원격탐사학회지
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• 제35권1호
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• pp.163-177
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• 2019

As inter-Korean relations progress, the issue of natural disasters which could directly affect the lives of the people in both Koreas, has not yet been discussed. Considering the current status of inter-Korean relations and the ongoing disaster-related damage in North Korea, it is imperative to establish a technical plan at the pan-governmental level to reduce the damage from natural disasters. The purpose of this study is to secure the Korea Peninsula against natural disasters by organizing South Korea's science and technologies related to natural disasters in order to reduce the damage, and to evaluate the applicability of said technologies. The situation of natural disasters in North Korea for 17 years has been summarized and reclassified based on eight types of natural disasters. Technologies related to natural disasters in South Korea were also investigated and reclassified. Based on the data, a priority evaluation was performed and the prioritization of technology application for each natural disaster type in North Korea was calculated through a quadrant analysis. As a result, the three major categories of high-priority technologies were classified as natural disaster monitoring with remote sensing and spatial information technology, construction of research basis and database based on geographic information system (GIS) and integrated management of complex natural disasters.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제21권3호
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• pp.289-307
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• 2018

자연수의 혼합 계산은 초등학교에서 자연수의 사칙 계산을 완성하는 측면에서 중요한 내용임에도 불구하고, 그 지도 방안에 대한 연구가 많지 않다. 본 연구는 자연수의 혼합 계산과 관련하여 국내의 5차부터 2009 개정 수학 교과서와 국외(일본, 싱가포르) 교과서를 크게 괄호와 연산 순서에 초점을 두어 분석하였다. 분석 결과, 괄호를 명시적으로 제시한 횟수와 괄호 도입 시기 및 표현 방법에서 교육과정별로 교과서의 제시 방식에 차이가 있었다. 연산 순서와 관련하여 국내 교과서는 대체로 실생활 맥락을 활용하고 있었고 연산 순서를 도식화하여 표현하는 경우와 그렇지 않은 경우가 있었다. 반면, 싱가포르 교과서는 연산 순서를 직접적으로 제시하고 계산기 활용을 강조하는 측면이 있었으며, 일본은 실생활 맥락을 활용하면서 동시에 연산의 위계 지도를 제시하고 있었다. 이러한 분석 결과를 바탕으로 자연수의 혼합 계산에 대한 지도 방안 및 후속 교과서 개발에 대한 시사점을 논의하였다.