• 제목/요약/키워드: Nature Environment

검색결과 2,229건 처리시간 0.028초

시계열 지표변위 관측기법(TCPInSAR와 SBAS)을 이용한 미국 알라스카 어거스틴 화산활동 감시 (Monitoring of Volcanic Activity of Augustine Volcano, Alaska Using TCPInSAR and SBAS Time-series Techniques for Measuring Surface Deformation)

  • 조민지;장레이;이창욱
    • 대한원격탐사학회지
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    • 제29권1호
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    • pp.21-34
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    • 2013
  • Permanent Scatterer InSAR (PSInSAR) 기법은 단일 주영상을 가지는 간섭도를 사용하여, 안정적인 신호를 보내는 고정산란체를 추출하고 시간에 따른 지표변위를 계산한다. 그러나 산악지역과 같이 고정산란체를 추출하기 어려운 지역에서는 적용되기 어렵다. 또 다른 다중시기 간섭기법인 Small BAseline Subset (SBAS)은 기선거리가 짧은 다중시기 주영상을 가지는 간섭도를 이용하기 때문에 산악지역에도 효과적으로 적용될 수 있으나, 사용되는 간섭도의 절대 위상 복원이 적절히 수행되지 못했을 경우 정확한 지표변위 계산이 어렵다. 본 연구에서는 앞서 언급된 다중시기 간섭기법들의 단점을 극복한 Temporarily Coherence Point InSAR (TCPInSAR) 기법을 소개한다. 이 기법은 간섭도의 절대 위상 복원이 필요 없고, 기선거리가 짧은 다중시기 주영상을 적용한다. 기존의 두 다중시기 간섭기법에 비해 산악지역에서도 충분한 고정산란체를 추출하여 공간적인 지표변위 양상을 관측하기에 충분하고, 절대 위상 복원으로 인한 오차가 없는 시계열 변위를 얻을 수 있다. 본 연구를 위해 미국 알라스카 어거스틴 화산의 ERS-1과 ERS-2 SAR 자료를 수집하여, SBAS와 TCPInSAR 기법을 통해 1992년부터 2005년까지 발생된 지표변위를 관측하고 시계열 지표변위 결과를 비교하였다.

항균성 Ag-30CaO·70SiO2 Gel의 MC3T3 세포적합성에 관한 연구 (Evaluate the Suitability of MC3T3 Cells to Antibacterial Ag-30CaO·70SiO2 Gel)

  • 윤금재;류재경;안응모;김윤종;김택남;노인섭;조성백
    • 한국재료학회지
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    • 제24권12호
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    • pp.671-676
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    • 2014
  • It is known that bones get damaged by accidents and aging. Since the discovery of Bioglass, various kinds of ceramics have been also found to bond to living bone; some of these ceramics are already being clinically used as bone-repairing materials. In the present study, antibacterial calcium silicate gel ($Ag-30CaO{\cdot}70SiO_2$ gel) was prepared by sol-gel method in order to control the microstructure, which is related to the dissolution rate and induction period of apatite formation in body environment. In addition, biological $Ag-30CaO{\cdot}70SiO_2$ is tested. This was done to impart antimicrobial activity to the $30CaO{\cdot}70SiO_2$. Ag ion was added during sol-gel synthesis to replace the $H_2O$ added during the making of the $30CaO{\cdot}70SiO_2$ gel, which has silver solutions of various concentration. After the sol-gel process, 1N-$HNO_3$ solution was used to wash the gel when synthesizing the gel, in order to maintain the porous structure and remove PEG, water soluble polymers. Then, the apatite forming ability of the sol-gel derived CaO-$SiO_2$ gels was investigated using simulated body fluid (SBF), which had almost the same ion concentration as that of human blood plasma. The gels were analyzed by FT-IR spectroscopy, SEM observation, XRD, and fluorescent microscopy. The apatite was successfully created even after washing the gel; apatite is present in an amorphous state, and was found to affect the concentration of the Ag ion in cells in MC3T3 live & dead assay results. From these results, it is suggested that a good material that can be used to repair defects of nature bone is $Ag-30CaO{\cdot}70SiO_2$ gel.

친수성에 의존하는 소수성 액체의 거동을 위한 분율 유동 접근 방식을 이용한 다상 유동 수치 모델링 개발 (Development of Multiphase Flow Simulator Using the Fractional Flow Based Approach for Wettability Dependent NAPL Migration)

  • 석희준;여인욱;이강근
    • 자원환경지질
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    • 제44권2호
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    • pp.161-170
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    • 2011
  • 석유공학분야에서 보고된 분율 흐름 접근 방식을 이용하여 물리적 또는 화학적으로 불균질한 매질에서 완전한 삼상유체를 고려할 수 있는 다상 흐름 수치 모의 프로그램인 CHMPS가 개발되었다. 이 프로그램은 석희준과 G.T. Yeh (2008)에 의해 개발된 MPS을 확장하였는데, 친수성이 NAPL 거동에 미치는 영향을 모의하기 위하여 개발되었다. 대부분 존재하는 모델들은 물리적으로 불균질한 매질을 고려하고 이상흐름과 특정한 경계조건에 국한되어 있다. 게다가 대부분의 모델들은 주로 water-wet 매질에만 국한되어 있다. 그러나 실제 존재하는 시스템에서는 water-wet과 oil-wet 매질 사이의 친수성의 변화는 종종 일어난다 더군다나 기름에 의한 다공성 매질의 젖음은 균등하기 보다는 불균질 또는 부분적일 수 있다. 왜냐하면 친수성에 영향을 미치는 요소들과 지하 매질이 불균질하기 때문이다. 따라서, 이번 연구에서는 물리적으로 불균질한 매질 뿐만 아니라 친수성 변에서 화학적으로 불균질한 매질을 CHEMPS을 활용하여 수치모의 하였다. 그 외에도 개개의 상에 대해서 유량 경계조건 및 고정경계조건의 두 가지 형식의 결합으로 표현되는 일반경계조건이 고려되었다.

유유기백서서(乳幼期白鼠)의 단백질부족(蛋白質不足)에 관(關)한 영양학적(營養學的) 연구(硏究) (Studies on Early Protein Undernutrition of Rats)

  • 유정열
    • Journal of Nutrition and Health
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    • 제2권4호
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    • pp.113-125
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    • 1969
  • These experiments were designed to study the influence of early protein undernutrition on growth, behaviors toward food, general attitude toward a new environment, brain size and body composition of the experimental rats. The following experimental groups were studied. Lactation period (3 weeks) (Diets of mother rats) 25% Casein diet 12% Casein diet 25% Casein diet 25% Casein diet 12% Casein diet 12% Casein diet After-weaning protein deprivation period None deprivation (25% Casein diet) None deprivation (25% Casein diet) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) After a long period of rehabilitation with 25% casein diet the following results were obtained. 1. Growth rate during lactation period is closely related with the protein levels of the diet for mother rats. The average body weight of offsprings of the mother rat fed 25% casein diet is 46.0 grams at 21 days old. However, that of the mother rat fed 12% casein diet is only 25.0 grams. 2. The group of protein undernutrition during lactation (S weeks) (offsprings of mother rat fed low protein diet, 12% casein diet) could never catch up with the normal group in its growth even after twenty-four (24) weeks of rehabilitation. 3. However, the groups of protein undernutrition during either four (4) or even eight (8) weeks after weaning could catch up with the normal group in their growth after long period of rehabilitation. 4. The absolute amounts of carcass protein and fat of the normal group are larger than those of the protein deficient groups. In terms of percent carcass, however, the normal group showed higher body fat and lower body protein than the early deficient groups. However, there is no difference between preweaning (3 weeks) and postweaning (8 weeks) deficient groups. It is assumed, from these differences in body composition, that there might be any differences in physiological and metabolic functions among these various groups, and also that the basic formation of various metabolic regulators (protein-nature) might be fixed mostly during lactation and postweaning period. 5. The groups of protein undernutrition during either three (3) weeks lactation or four (4) weeks after weaning are not so remarkably different from the normal group in their amounts of food intake and spillage. However, the groups of undernutrition during either eight (8) weeks postweaning or eleven (11) weeks (3 weeks lactation period plus 8 weeks postweaning period) showed higher amounts of food intake and spillage. In these respects, it seems that desire for food is closely related with the degree of early hunger in protein and also seems that the longer be deficient in early life the more food spillage is found. 6. Both preweaning and postweaning deficient groups showed generally nervous and restless. The normal group is staid and showed less mobilities. 7. The average size of the brains of the group subjected to protein deficiency during three (3) weeks lactation period is smaller than that of the group of the eight (8) weeks postweaning deficiency. This means that the development of the brain is made mostly during lactation period. The group of the eleven (11) weeks postnatal deficiency is significantly different from the normal group in its brain development. It is assumed, in connection with the results of various maze tests reported, that the brain size is closely related with the intellectual ability.

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강북 대형공원 기본계획 (Landscape Design Proposal for Gangbuk Large Park)

  • 김도경;최원만;홍형순
    • 한국조경학회지
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    • 제36권4호
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    • pp.1-14
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    • 2008
  • 드림랜드 부지는 산으로 둘러싸인 강북지 역의 유일한 평지화 된 놀이공원이었으나, 현재는 시설 노후화와 방치로 인해 지역 거점공원으로서의 기능이 상실되었다. 부지 주변은 기존의 밀집주거와 새로 조성될 뉴타운 등이 혼재할 것이며, 특히 지역 여건상 강북지역의 도시환경 개선을 위한 대형공원이 필요하다는 측면에서 강북 대형공원 조성사업이 대두되었다. 본 연구는 강북 대형공원 조성사업 국제 현상공모에서 우수작으로 선정된 작품의 설계전략과 내용을 서술하고자 한다. 계획안의 주안점은 다음과 같다. 첫째, 산지형 공원의 새로운 가능성을 찾고자 하였다. 지극히 일상적인 생활공간으로서 산책과 등산, 체력단련시설 등 제한적으로 이용되는 산지형 공원을 선조들이 산을 즐겼던 그 정취를 재현해 보고자 하였다. 둘째, 사회성 강한 자립공원을 만들고자 하였다. 도시 속에 섬으로 존재하는 녹색 숲으로서의 공원이 아닌 자체적인 변화의 에너지를 발산하면서 도시와 적극적으로 소통할 수 있는 공원이 되도록 하였다. 셋째, 다랑이 논은 자연과 더불어 사는 우리의 삶의 방식과 이념을 표현한 실체적 공간이었으며, 우리의 대표적인 향토적 경관이기도 하다. 이런 다랑이 논은 세 개의 낮은 산으로 둘러싸인 대상지를 아우를 수 있는 디자인 모티브였으며, 산에서부터 자연스럽게 흘러내리는 정겨운 풍경은 도시속의 명소로서 사람들의 이야기를 담아낼 수 있도록 계획하였다.

Population structure and regeneration of Himalayan endemic Larix species in three high-altitude valleys in Nepal Himalaya

  • Dhamala, Man Kumar;Aryal, Prakash Chandra;Suwal, Madan Krishna;Bhatta, Sijar;Bhuju, Dinesh Raj
    • Journal of Ecology and Environment
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    • 제44권3호
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    • pp.196-206
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    • 2020
  • Background: The Himalayan forests are of great importance to sustain the nature and community resource demands. These forests are facing pressures both from anthropogenic activities and ongoing global climatic changes. Poor natural regeneration has been considered a major problem in mountainous forests. To understand the population structure and regeneration status of Larix (Larix griffithiana and Larix himalaica), we conducted systematic vegetation surveys in three high-altitude valleys namely Ghunsa (Kanchenjunga Conservation Area, KCA), Langtang (Langtang National Park, LNP), and Tsum (Manaslu Conservation Area, MCA) in Nepal Himalaya. The average values of diameter at breast height (DBH), height, and sapling height were compared for three sites and two species using Kruskal-Wallis test. Population structure was assessed in terms of proportion of seedlings, saplings, and trees. Regeneration was analyzed using graphical representation of frequencies of seedlings, saplings, and trees in histograms. Results: The results showed that the population structure of Larix in terms of the proportion of seedling, sapling, and tree varied greatly in the three study areas. KCA had the highest record of seedling, sapling, and tree compared to other two sites. Seedlings were the least among three forms and many plots were without seedlings. We found no seedling in MCA study plots. The plot level average DBH variation among sites was significant (Kruskal-Wallis χ2 = 7.813, df = 2, p = 0.02) as was between species (Kruskal-Wallis χ2 = 5.9829, df = 1, p = 0.014). Similarly, the variation in average tree height was significant (Kruskal-Wallis χ2 = 134.23, df = 2, p < 0.001) among sites as well as between species (Kruskal-Wallis χ2 = 128.01, df = 1, p < 0.001). All the sites showed reverse J-shaped curve but more pronounced for KCA and MCA. In comparing the two species, Larix griffithiana has clear reverse J-shaped diameter distribution but not Larix himalaica. Conclusion: The varied responses of Larix manifested through regeneration status from spatially distinct areas show that regeneration limitations might be more pronounced in the future. In all the three studied valleys, regeneration of Larix is found to be problematic and specifically for Larix griffithiana in MCA and Larix himalaica in LNP. To address the issues of disturbances, especially serious in LNP, management interventions are recommended to sustain the unique Himalayan endemic conifer.

DNA 분석에 의한 팔색조의 암수 구분 및 암수별 피해 현황 그리고 크기 차이에 관한 연구 (The Study on the Sexual Difference in the Cause and the Time of Casualty and in the Size of the Fairy Pitta (Pitta nympha) through DNA Analysis in Republic of Korea)

  • 김은미;전연선;정길상;김세재;강창완;오미래;노푸름;원현규
    • 한국환경과학회지
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    • 제23권8호
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    • pp.1447-1453
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    • 2014
  • The differentiation of sex is important for species preservation. However, Fairy Pitta is sexually monomorphic and sex of an individual is indistinguishable with its external characteristics. We determined the sex of Fairy Pitta through DNA analysis and investigated the causes and time of injury and mortality and the size based on sex. We collected 21 samples at Jeju Island, Korean Peninsula from 2004 to 2013 and extracted DNA from them and amplified chromo helicase DNA-binding gene from Z and W chromosomes through Polymerase Chain Reaction (PCR). We confirmed their sex with the banding pattern through Agarose gel electrophoresis, i.e. male (ZZ): one banded and female (ZW) two banded. We distinguished the sex of 17 of 21 samples resulting in 9 males and 8 females. Most casualties were recorded in adult of both sexes. Causes of injury and mortality proved that female casualties occurred from window strikes, dehydration, car accident, predation by natural enemies, and male occurred from window strikes, car accident and dehydration. The time of injury and mortality in adults differ by sex. There was no difference between sexes in any of the six size parameters. As the time of injury and mortality differ by sex, the survey on the role and ecological nature by sex in breeding season must be carried out in the future. External measurements may not be reliable for sexing of Fairy Pitta and other traits such as vocal or characteristics are required to identify the sex of individuals in the field.

문헌정보학과 WWW홈페이지의 필요성과 준비에 관한 연구- 한국과 북미주 지역 대학을 중심으로 -

  • 박일종
    • 한국도서관정보학회지
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    • 제24권
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    • pp.413-448
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    • 1996
  • Nowadays, the World Wide Web (WWW) has become an important resource of timely information for the information-related people such as information scientists, librarians, and students in Library and Information Sciences area. They are information professionals who navigate the information on the internet. Also, they need to be information providers who build a WWW homepage. This paper is a study of the necessity, preparation, and building WWW Homepage files for school of Library and Information Sciences in the age of competition among disciplines. It is particularly focused on the colleges and universities in Republic of Korea (ROK) and North America area. The purpose of this study is to provide various kinds of reference information to prepare a homepage in the future as utilizing information on the internet effectively. Even though a Web page was necessary for a school of Library and Information Sciences to show news, and introduce the purpose of the disciplines and the curriculum of the school, and the professors of a class etc., it was not well-prepared yet in ROK. However, a web page was used well enough and prosperous in North America area (Canada, the United States, and Puerto Rico) comparatively. Those web pages were analyzed and studied to prepare for a good designing of homepages for school of Library and Information Sciences in Korea and for the age of competition among disciplines in this paper. Suggestions for designing a good homepage and guidelines for preparing a best one were studied after both reviewing literature and utilizing experiences by the author who currently serves in the School of Library and Information Sciences in Keimyung University and builds homepage for the school. As a result, the major suggestions are ; premiered, and they are as follows: (1) English version of a homepage is necessary, (2) Provide a multimedia presentation about the nature of a school (3) Incorporate a place to let people make suggestions on the contents (of a homepage), (4) Bear in mind that potential users must be familiar with abbreviations you used, (5) Absolutely do not use abbreviations that may make the content more difficult to understand, (6) Add a feature on the every single page that will take the user back to the main page, (7) Use clear, short and well-structured sentences and remember to divide text into paragraphs, (8) Date with a creation or modification date in the homepage to indicate the updated date, (9) Being a multimedia environment, use colors effectively (the guidelines were also suggested), and (10) Put colleges' name into the title of bookmarks to find out them easily.

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우리나라 도시공원 관련 초기 법률 입안과 「공원법(1967~1980년)」 시행과정에서 나타난 유보지로서 도시공원에 관한 제도의 문제 (Legal Issues of Urban Parks as a Reservation Area in the Initial Legislation on Urban Parks in Korea and the Implementation of the Park Act (1967~1980))

  • 오창송
    • 한국조경학회지
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    • 제46권3호
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    • pp.103-116
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    • 2018
  • "공원법"은 도시공원을 규정한 우리나라 최초의 법률이다. 그러나 당시의 도시공원은 규제만 가해진 후 다른 목적으로 사용하는 유보지와 유사하였다. 과거 '유보지로서 도시공원'은 지금의 공원문제로도 반복되고 있기에, 그 원인을 제공하는 초기 제도의 문제에 관한 고찰이 필요하다. 이러한 관점에서 본 연구는 "공원법(안)"들을 수집하여 도시공원을 유보하게 된 제도화 과정과 1960 70년대 공원문제와 "공원법"과의 사실관계를 분석하였다. 분석결과, 자연공원의 법률에 이질적인 도시공원을 수용하게 된 이유는 민간의 무분별한 용지 사용을 억제하여 유보할 수 있도록 "도시계획법" 이외의 부수적 규제 장치가 필요하였기 때문이다. 그러나 제정된 "공원법"은 공권력으로 도시공원의 잠식을 용인할 수 있는 문제점을 담고 있었다. (1) "공원법"은 도시공원을 폐지할 수 있는 광범위한 경우를 설정하였다. (2) 불명확한 공권력 범위의 설정은 도시공원을 남용할 수 있었다. (3) 미흡한 관련 기준은 대형 수익시설로 도시공원을 침식할 수 있었다. (4) (도시)공원위원회의 무기력은 공원문제에 대한 민주적 의사결정과 전문적인 판단력을 축소시켰다. 따라서, "공원법"은 도시공원에 대한 환경과 권리에 관한 침해 속성이 내제 되었고 공원설치와 시민 이용에 소극적인 태도를 취하였다. 동시에 "공원법"은 도시공원의 특성과 개념을 정립하여 선도하기 위한 독립법으로 한계가 있었다.

2007년 3월 한국 서해안에 발생한 해양장파의 형성과 성장과정 (Generation and Growth of Long Ocean Waves along the West Coast of Korea in March 2007)

  • 최병주;박용우;권경만
    • Ocean and Polar Research
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    • 제30권4호
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    • pp.453-466
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    • 2008
  • In order to examine the generation mechanism of long ocean waves along the west coast of Korea and to understand the amplification process of the long ocean waves, sea level, atmospheric pressure and wind data observed every minute from 2007 March 29 to 2007 April 1 were analyzed and onedimensional numerical ocean model experiments were performed. An atmospheric pressure jump propagated southeastward from Backryungdo to Yeonggwang along the west coast of Korea with speed of $13{\sim}27\;m/s$ between 2007 March 30 23:00 and 2007 April 1 1:30. Average magnitude of pressure jump was 4.2 hPa. As a moving atmospheric jump propagated from north to south along the coast, long ocean waves were generated and the sea level abnormally rose or fell at Anheung, Kunsan, Wido and Yeonggwang. Average amplitude of sea level rise (or fall) was about 113.6 cm. In a one-dimensional numerical ocean model, nonlinear shallow water equations were numerically integrated and a moving atmospheric pressure jump with traveling speed of 24 m/s was used as an external force. While the atmospheric pressure jump travels over 60 m depth ocean, a long ocean wave is generated. Because the propagation speed of the atmospheric jump is almost equal to that of the long ocean wave, Proudman resonance occurs and the long ocean wave amplifies. As the atmospheric pressure jump moves into the coastal area shallower than 60 m, the speed of the long ocean wave decreases and Proudman resonance effect decreases. However, the amplitude of the long ocean wave increases and wave length becomes shorter because of shoaling effect. When the long ocean wave hits the land boundary, amplitude of the long ocean wave drastically amplifies due to reflection. Data analysis and numerical experiments suggest that the southeastward propagation of an atmospheric pressure jump over the shallow ocean, which is a necessary condition for Proudaman resonance, generated the long ocean waves along the west coast of Korea on 2007 March 31 and the ocean waves amplified due to shoaling effect in the coastal area and reflection at the shore.