• The Journal of Engineering Geology
• /
• v.20 no.3
• /
• pp.281-295
• /
• 2010

A new, automated apparatus is proposed for calculating the Soil-Water Characteristic Curve (SWCC), representing a simple and easily applied testing device for continuous measurements of the volumetric water content and suction of unsaturated soils. The use of this apparatus helps to avoid the errors that arise when performing experiments. Consequently, the apparatus provides greater accuracy in calculating the SWCC of unsaturated soils. The apparatus is composed of a pressure panel, flow cell, water reservoir, air bubble trap, balance, sample-preparation accessories, and measurement system, among other components. The air pressure can attain 300 kPa, and a general test can be completed in a short time. The apparatus can simply control the drying process and wetting process. The changes in volumetric water content that occur during the drying and wetting processes are shown directly in the SWRC program, in real time. As a case study, we performed an SWCC test of Joomunjin sand (75% relative density) to measure matric suction and volumetric water content during both the drying and wetting processes. The test revealed hysteresis behavior, whereby the water content on the wetting curve is always lower than that on the drying curve for a specific matric suction, during the wetting and drying processes. Based on the test results, SWCCs were estimated using the Brooks and Corey, van Genuchten, and Fredlund and Xing models. The van Genuchten model performed best for the given soil conditions, as it yielded the highest coefficient of determination.

• 한국방재학회:학술대회논문집
• /
• 2011.02a
• /
• pp.193-193
• /
• 2011

본 연구에서는 산불발생인자들에 대한 정보를 각각의 요인별로 집적화하고 체계화시킴으로써 산불예방활동의 기초자료로 활용할 뿐만 아니라 산불발생 시, 산불의 거동을 예측하기 위한 자료로 활용하고자 하였다. 발생인자는 크게 연료 및 기상조건 관련 인자와 열적특성 관련 인자로 분류하고 연료 및 기상조건 관련 인자는 수종별, 부위별, 지역별, 고도별, 월별 산림연료들의 구성 요인들에 대해서 분석하였다. 수종별로는 생강나무, 초피나무, 조록싸리, 산초, 개암, 청미래, 고추나무, 철쭉, 조릿대, 털진달래 등 관목류 10개 수종과 김의털, 방아풀, 주름조개풀, 칡, 엉겅퀴 등 초본류 5개 수종 그리고 소나무, 잣나무, 리기다소나무, 해송, 구상나무, 주목 등 6개의 침엽수 및 굴참나무, 떡갈나무, 신갈나무, 갈참나무, 졸참나무, 상수리, 산개벚나무, 고채목, 개서어나무, 굴거리나무, 서어나무, 산벚나무, 때죽나무, 당단풍나무, 단풍나무 등 15개의 활엽수로 구성된 교목류를 대상으로 분석하였다. 부위별로는 생엽, 낙엽, 가지, 수피, 솔방울 등으로 구분하여 분석을 수행했으며, 지역별 구성은 강원(삼척/태백산), 경북(응봉산), 경기(용문산), 충북(월악산), 충남(계룡산), 전북(덕유산), 전남(월출산), 부산(금정산), 제주(한라산) 등 9개 지역을 대상으로 선정하였다. 고도별로는 강원도에 소재하고 있는 태백산을 중심으로 소나무와 신갈나무 생엽을 대상으로 900m, 1000m, 1100m, 1200m, 1300m, 1400m, 1500m 고도를 선정하여 분석을 수행하였다. 월별 분석데이터는 소나무 생엽의 경우, 2008년 6월부터 2010년 11월까지 매월 분석을 수행하였으며, 굴참나무 생엽의 경우에는 2008년부터 2010년까지 매년 6월부터 10월까지 생엽을 채취할 수 있는 기간 동안 분석을 수행하였다. 또한, 열적특성 관련 인자로는 착화특성(무염착화온도, 발염착화시간, 소염시간, 화염지속시간), 발열특성(총열방출량, 평균열방출률), 발연특성(총연기방출량, 최대연기밀도, 최대밀도시간) 등을 고찰하였다. 이와 같은 결과들은 산불발생인자 DB구축으로 부터 산불발생 위험도 및 동태예측의 기본 자료로 활용할 수 있을 뿐만 아니라 지역별 연료별 산림연료의 열적특성 DB로 부터 산불발생시 산불 위험도에 대한 기술정립과 응용성을 향상시킬 수 있을 것으로 사료된다. 이외에도 산림연료 종류별 열적특성을 결과를 토대로 문화재보존지역과 같이 문화적 가치가 높은 시설이나 주유소, 가스 충전소 등의 위험 시설에 대한 효과적인 보호를 위한 대처 방안을 사전에 준비할 수 있어 산불 피해에 대한 국민의 불안감을 줄일 수 있을 것으로 생각된다.

• The Korean Journal of Pesticide Science
• /
• v.18 no.4
• /
• pp.376-382
• /
• 2014

The soluble loess-sulfur mixture allowed standing to remove insoluble component materials for five weeks after manufacturing. We decreased the pH level of soluble loess-sulfur mixture at pH 1.0 modified with decreasing 25% sodium hydroxide than original content. The pH ranges of soluble loess-sulfur mixture solutions were adjusted to pH 5.0-pH 11.0 (pH 1 unit) with brown rice vinegar (pH 2.8). The pH of original loess-sulfur mixture was about pH 13 and damaged the foliar parts and young leaves of tomato after twice application. These stock solutions can be diluted 500:1 with tap water to make a 0.05% working solution and were sprayed two times with 7 days interval to the leaf and stem of tomato, which were spontaneously infected with E. cichoracearum. Control efficacy of powdery mildew ranged from 85% to 90% at 7 days after first application. After second application, each loess-sulfur mixture solutions adjusted pH level significantly suppressed the powdery mildew disease in tomato. Consequently, loess-sulfur complex adjusted pH level with brown rice vinegar was suggested to be low in acute toxicity at all different pH values and suggested to use an agent for control of tomato powdery mildew in organic farming.

• Applied Chemistry for Engineering
• /
• v.9 no.7
• /
• pp.1043-1046
• /
• 1998

Aluminium based inorganic flocculants are extensively used in this country in the removal of fine particles present in the raw water for the production of drinking water. These inorganic flocculants, however, have potential hazard of high residual aluminium ions in the treated waters, which is known to be one of the reasons of alzheimer's disease. Inorganic flocculants alone are sometimes incapable of treating water when there are excessive turbidity in the raw water sources due to flooding. A polyamine type polymeric flocculant has long been used to treat raw water in the drinking water production in the European countries and United State of America. The optimum reaction conditions such as mole ratio of epichlorohydrin(EPI) to dimethylamine(DMA), reaction temperature and time for each stage for the pilot scale preparation of polyamine from EPI-DMA was studied in this work. The variation of intrinsic viscosity and flocculating efficiency in the water treatment of the synthesized polyamines were evaluated. The residual materials after polymerization reaction were analyzed by gas chromatography to study the effect of variation of reaction conditions.

• Environmental and Resource Economics Review
• /
• v.23 no.3
• /
• pp.515-551
• /
• 2014

Recently, there has been a debate as to whether bioethanol should replace some portion of gasoline for fuels in South Korea, as energy security as well as climate change issues are rising as a significant national agenda. However, a considerable amount of subsidy will be required to compensate for the higher price of bioethanol-blended gasoline. In this context, government subsidy will obtain justification only when the positive social gains from consuming bioethanol for fuels can exceed the negative social costs. Through a nation-wide choice experimental survey, we examine if South Koreans have a positive value as well as non-linear preferences on substituting bioethanol for gasoline. The results reveal that the willingness to pay for purely domestic bioethanol-blended gasoline within 10% is about 52 KRW; Koreans have concave preferences on the blending ratio of bioethanol to gasoline. The turning point of the blending ratio of bioethanol was 6.5%. Also, we found inverse U-shaped curve between income and bioethanol choice probability and the turning point of the income was calculated as 250~299million KRW. Politically conservative propensity advocates uses of bioethanol blended gasoline, but awareness on bioethanol or more weights on environmental conservation have significantly negative effects on the choice of bioethanol. However, the design of the survey questionnaire is incompatible with the RFS of Korea and assumes orthogonality among the following four interrelated attributes: (i) domestic or offshore procurement of feedstocks in the case of domestic production, (ii) domestic production or import of bioethanol, (iii) the blending ratios, and (iv) the retail price increases. In addition, the results of model estimation and of model selection test are not definite. Hence, the results in this study should not be directly applied to the design of the specifics of the Korean RFS. Hence, the results in this study require cautions in applying to the design of the Korean RFS policy.

• Proceedings of the KSAR Conference
• /
• 2001.03a
• /
• pp.58-58
• /
• 2001

본 연구는 섬유소 분해효소 유전자 Cel D(Cellulase Digestion)가 도입된 형질전환 돼지 생산을 통하여 섬유소 함유 사료의 이용 효율을 증대시키고, 나아가 장기이식동물 및 고가의 의료용 단백질 생산가축을 개발하기 위한 원천기술 확보에 있다. 섬유소분해 유전자의 크로닝 및 조직 특이적 발현벡터를 개발하기 위하여, 우선 소의 위중 제4위 내의 미생물로부터 전체 유전자를 분리하였고, 이렇게 작성된 DNA library에서 섬유소분해 관련 유전자인 약 2.0 kb의 Cel D유전자를 크로닝하였으며, 췌장 특이적 발현 프로모터(rat elastase I: 약 200bp)를 크로닝한 후, 미세주입용 형질전환 재조합 벡터를 구축하기 위하여 rElastase I 프로모터 하류에 섬유소 분해 유전자(Cel D)를 연결하여 약 3.0 kb 크기의 재조합 벡터를 준비하였으며, 재조합 유전자를 1세포기 수정란 전핵내에 미세주입 하기 위해 Sal I과 BglII를 이용 유전자 단편을 만들었다. 구축된 유전자를 미세주입하기 위한 수정란을 회수하기위해 총68두의 돼지를 4-5두씩 분리사육하면서 발정동기화 및 과배란 유기를 위해 PG600, Altrenogest, FSH, hCG를 투여하였으며 hCG투여후 약54시간에 외과적 방법에 의해 총 1,359개의 수정란을 회수하였고, 이중 미세주입가능한 1세포기 수정란은 1,296개로 두당 평균 15.9개 였다. 1,296개의 1세포기 수정란 중에서 재조합 유전자(rE I-CelD)가 미세주입된 660개의 수정란을 32두의 수란돈에 외과적 방법에 의해 이식하였으며, 이식되어진 모돈 13두가 분만하여 40.6%의 임신율을 나타내었다. 이렇게 분만된 13두에서 총 65두(암:33두, 수:32두)의 자돈이 생산되었으며, 형질전환 여부를 판명하기 위해 자돈의 꼬리조직으로 부터 genomic DNA를 추출하고 PCR 검정을 실시하였다. PCR 검정 결과, 섬유소 분해 유전자가 도입된 자돈은 5두 이었으며, 그 결과를 Table에 나타내었다.(Table Omitted) Table 1 에서와 같이 섬유소 분해효소유전자가 형질전환된 자돈은 65마리 중 5마리로 7.69%의 형질전환율을 나타내었으며, 5마리의 자돈중 2두(암:1두, 수:1두)는 분만 후 즉시 폐사되었으며 2두(암:1두, 수:1두)는 86일령 그리고 14일령에 폐사하여 현재 1두(암)가 생존하여 섬유소 분해 사양 실험 중에 있다.

• The Journal of the Korea Contents Association
• /
• v.5 no.1
• /
• pp.27-35
• /
• 2005

Recently, despite of the rapid progress of information technology in the medical and health fields, the development and management of problem sets about medical and education contents related with radiological technologist has been still achieved by manual and offline method using document editor. In this study, the unique web-based problem management system is designed and implemented. That system can efficiently manage and present various kind of problem set about integrated education and personal license without time and space limitations in order to improve the efficiency of supplementary training and to obtain the professional license for CT radiological technologist. The proposed system is composed of administration module and user module. The former supports several functions such as problem creation, problem categorization, user management, and adjustment of leveled assessment. On the other hand, the latter functions examination applying , problem retrieval, personal score retrieval, and interpretation viewing, and so on. In addition, our system is expected as a useful and practical system which provides problem interpretation and analysis of score results after applying for the examination. It can elevate ability of learning and information interchange among them preparing for CT professional radiological technologist licensing examination

• The Journal of the Korea Contents Association
• /
• v.17 no.8
• /
• pp.121-129
• /
• 2017

The evolution of biotechnology is no longer strange to the hypothetical scenario of cloning human genes to make cloned human beings. The characters of are cloned humans made in the laboratory by the 100-year-old life planning. They are cohabited in a school called Hailsham, where they are secretly reared. The purpose of this project is to provide healthy organs to real human patients with incurable diseases. The main characters Cathy, Tommy, and Ruth experience the growth of body and consciousness here during adolescence, and they also know the secret of identity as a clone. As adults, they move to a second residence, Cottage and are ready to begin organ donation. The second stage is also part of a program to provide more genuine-like organs to real patients. Even though they know all the plans that humans have built, they do not resist them and fatefully accept their situation. However, their non-responsiveness is not a declaration of renunciation of life, but a self-sacrificing life extension for another future that is the extension of life through their organ donation. The film emphasizes the fraternity and sacrificial attitudes of the cloned human beings and shows that it is necessary to continue the discussions on cloned human beings from a bio-ethical point of view supported by philosophical reasons.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.489-498
• /
• 2018

The purpose of this study is to examine whether there is a difference in the awareness of death based on happiness (since attitude or way of life differs among the general public, depending on the perception of death), and to investigate whether there is a difference in the interest in hospices between a group with a high happiness index and a group with a low happiness index. A survey was conducted on 200 men and women aged over 20 who participated in a walking event held in a metropolitan city on April 22, 2017. The survey consisted of eight demographic items: gender, age, education, occupation, marital status, family cohabitation, religion, and health status. It included 29 questions regarding happiness and nine questions regarding the perception of death. For the statistical tests, a chi-square test, an independent sample t-test, correlation analysis, and canonical correlation analysis were performed on the items of the survey based on a happiness index. The results of the study showed that, for a suitable place for death, medical institutions was the highest score (46.3%) for the group with a low happiness index, and own house was highest (59.4%) for the group with a high happiness index. This was a significant difference. It is thought that management systems should be supplemented by professional manpower, educating people so as to increase the utilization rates of home-based hospice as a way for patients to die in a comfortable and familiar place because, for Korea, death is much more common in hospitals. It is also necessary to increase the awareness of death and to make effective use of hospices through individual and various other approaches, considering the demographics of the subjects.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.1
• /
• pp.92-97
• /
• 2018

Recently, the safety issue of high-rise concrete buildings damaged by fire, helicopter collisions, earthquakes, and faulty construction has attracted a great deal of interest. It is essential to know the strength of the concrete in order to accurately evaluate its safety for the reinforcement of these buildings. The core drilling method is considered to be the most effective method of assessing the compressive strength of concrete. However, it is very difficult to retrieve the core without the reinforcing bars, because buildings made with high-strength concrete are overcrowded with reinforcing bars. These reinforcing bars are often present in the core specimens, but there are few research studies and no regulations concerning the assessment of the strength of the concrete for high-strength core specimens within reinforcing bars. The purpose of this study is to investigate the effects of the reinforcement arrangement on the strength of the concrete and to present the quantitative values. To complete this research, the compressive strengths of different types of concrete with two different strengths (40 MPa and 60 MPa), two reinforcing bar diameters (10 mm and 12 mm), and 15 types of specimens with or without reinforcement arrangements were prepared and tested. As a result, the strength of the cylinders whose volume is less than or equal to the reinforcement volume of $53.1cm^3$ (about 4 - 13 mm) was predicted to have a low value of up to 60% of the strength of the cylinders without reinforcement.