• 제목/요약/키워드: Proximity degree

검색결과 69건 처리시간 0.03초

인구변화 및 노년인구에 관한 한국과 일본의 비교연구 (A Comparative Study on the Population Change and the Aged in Korea and Japan)

  • 조혜종
    • 대한지리학회지
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    • 제36권4호
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    • pp.356-381
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    • 2001
  • 본 연구는 세가지 목적을 갖는다. 하나는 한국과 일본의 인구요소를 분석함에 있어 비교규준을 제공해주는 신말사스론과 풍요론의 양립할 수 없는 개념을 분석하는 것이며. 다른 하나는 다양한 인구요소들이 한국과 일본이라고 하는 특정지역과 어떻게 관련되고 있는가를 구명하는 것이다. 마지막으로 50세 이상의 노령인구의 거주선호유형과 장래의 근심도를 비교, 분석하는 것이다. 다양한 인구요소의 분석을 통해서 일본은 한국보다 인구선진형이지만 양자간의 격차는 매년 줄어져감을 알 수 있다. Willer의 이동기대치는 한국이 일본보다 월등 높다는 사실이 광주.전남과 히로시마현의 사례지역에서 발견된다. 일본의 매장문화는 이미 사라졌으나 한곽은 화장률이 아직도 30% 수준 밖에 되지 않아 사망으로부터 오는 인구감소효과를 상실하고 있다. 50세 이상 노인(또는 예비노인)의 거주선호유형에 관한 사례연구를 통해 일본이 한국보다 더 의존형이며, 독거의 외로움이 그 첫째 이유가 되는 것은 양국의 공통적 현상이다 미래에 대한 근심도 역시 일본이 한국보다 현저히 높다. 이것들은 여러측면에서 연령.학력.지역(시.군)과 관련된다. 노령사회에서의 노동력부족이라는 일반적 인식은 잘못된 관념에 불과하다. 그것은 노동력 부재가 아닌, 노인으로부터의 노동력 탈취에서 오는 것이기 때문이다. 인구현상에는 관성의 법칙이 적용되므로 미세한 인구변화에도 주의를 요한다. 말사스적 사고는 아직도 유효하며, 인구.자원.환경문제는 더 이상 개인이나 지역문제가 아닌 전 지구촌의 문제라는 인식이 중요하다.

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해상풍력 전용항만 입지선정 평가항목에 관한 연구 (The Analysis of Assessment Factors for Offshore Wind Port Site Evaluation)

  • 고현정
    • 한국항만경제학회지
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    • 제28권3호
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    • pp.27-44
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    • 2012
  • 세계 각국은 신재생 에너지 가운데 해상풍력 발전에 국가적 역량을 집중하면서 해상풍력 터빈의 용량을 대형화하고 있다. 특히 해상풍력 터빈은 부피와 중량이 큰 특징이 있어 육상운송에 어려움이 있어 해상풍력 전용항만이 필요하다. 따라서 본 연구에서는 국내 해상풍력 단지가 성공적으로 조성 및 운영될 수 있도록 최적의 전용항만 입지선정에 영향을 끼치는 평가항목을 분석하여 국가정책 의사결정에 올바른 방향을 제시하고자 하였다. 이를 위해 Fuzzy-AHP 기법을 적용하여 평가항목 별 중요도를 도출하였다. 평가항목은 수준 I에서는 5가지, 즉 집적 요인, 지역 요인, 경제 요인, 입지 요인, 컨소시엄 요인이 선정되었다. 이 가운데 집적 요인 37.4%, 입지 요인 34.2%, 경제 요인 24.5%가 주요한 항목으로 분석되었다. 그리고 수준 II에서는 각 요인에 3가지 항목이 선정되어 모두 15개 평가항목이 선정되었다. 분석 결과를 보면, 해상풍력 전용항만 입지 선정에 있어서 핵심적으로 고려되어야 할 항목은 풍력산업의 집적도, 항만운영의 경제성을 확보하는 물동량 규모, 해상풍력 관련 산업의 발달 정도, 그리고 개발될 해상풍력 단지와의 근접성으로 나타났다. 즉 해상풍력 전용항만 건설은 항만건설 측면과 해상풍력 터빈 제조기업의 입지 선호지역을 복합적으로 고려해야 한다는 의미이다. 따라서 정부가 해상풍력 전용항만을 건설함에 있어서 풍력터빈 제조기업의 의견을 충분히 반영하는 것이 요구된다.

Characteristic Distributions of Hydrogen Peroxide and Methyl Hydroperoxide and over the North Pacific Ocean

  • Lee, Meehye;Brian G. Heikes
    • Journal of Korean Society for Atmospheric Environment
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    • 제18권E2호
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    • pp.85-95
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    • 2002
  • Hydrogen peroxide and methyl hydroperoxide were measured over the northwestern Pacific Ocean during NASA's PEM (Pacific Exploratory Mission) -West. The first experiment (PEM -West A) was conducted in the fall of 1991 and PEM-West B in the early spring of 1994. Hydroperoxide data were obtained on board the NASA DC -8 aircraft through the entire depth of the troposphere. Average concentrations of both H$_2$O$_2$and CH$_3$OOH were higher during PEM -West A than B. The seasonal difference in hydroperoxide distribution was determined by the degree of photochemical activities and the strength and location of jetstream, which led to extensive and rapid continental outflow during the PEM-West B. While for H$_2$O$_2$distribution, a longitudinal gradient was more apparent than a latitudinal gradient, it was opposite for the CH$_3$OOH distribution. The longitudinal gradient indicates the proximity to the anthropogenic sources from the Asian continent, but the latitudinal gradient reflects photochemical activity. During PEM -West B, the ratio of C$_2$H$_2$/CO, a tracer for continental emission was raised and high concentrations of H$_2$O$_2$were associated with high ratios. The flux of hydroperoxide toward the North Pacific was also enhanced in the early spring. The eastward fluxes of H$_2$O$_2$ were 9% and 17% of the average photochemical production over the Pacific Basin between 140°E and 130°W during PEM-West A and B, respectively. For CH$_3$OOH, these ratios were 8% and 13%. Considering the lifetime of hydroperoxide and the rapid transport of pollutants, the export of hydroperoxide with other oxidants would have a significant influence on oxidant cycles over the North Pacific during winter/spring.

선박 조종 시뮬레이션을 통한 스마트폰 사용이 항행안전에 미치는 영향에 관한 연구 (A Study on the effect of the uses smart phone is ship navigation safety through Ship Handling Simulation)

  • 신대운;박영수;박진수
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2016년도 춘계학술대회
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    • pp.103-105
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    • 2016
  • 신(2015) 등이 발표한 선박 당직 중 스마트폰 사용이 당직수행에 미치는 영향에 관한 선행연구에서 설문조사를 통해 선박에서 스마트폰을 사용할 수 있는 환경(항해 중 36%)이 마련되었음을 확인하였고, 항해사들의 위험도 조사 설문에서 스마트폰 사용이 사용 전보다 약 2배 위험하다고 분석되었다. 본 연구는 일정기간 항해사로 승선 경험을 가진 자들을 실험 대상자로 시뮬레이션을 실시하여 해상교통안전진단상 선박 조종 시뮬레이션 평가 분석 항목인 선박의 근접도 평가, 선박의 제어도 평가, 조종자의 주관적 평가를 기초로 스마트폰의 사용이 항행안전에 미치는 위험도를 평가하였다. 또한 스마트폰 사용 유무에 따른 위험 상황 인지 시간을 측정하여 스마트폰의 위험성을 정량적으로 나타내었다.

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Characteristics of the Major Atmospheric Aromatic Hydrocarbons in the Yellow Sea

  • Park, Seung-Myung;Kim, Jeong-Soo;Lee, Gangwoong;Jang, Yuwoon;Lee, Meehye;Kang, Chang Hee;Sunwoo, Young
    • Asian Journal of Atmospheric Environment
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    • 제9권1호
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    • pp.57-65
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    • 2015
  • We measured the concentrations of five aromatic hydrocarbons (benzene, toluene, ethylbenzene, m,p-xylene, and styrene) in the atmosphere during four seasonal campaigns at Deokjeok and Jeju Islands in the Yellow Sea from October 2005 to June 2006. Toluene was the most abundant aromatic hydrocarbon, with median of 0.24 ppb at Deokjeok and 0.20 ppb at Jeju, followed by benzene (0.21 ppb, 0.15 ppb) and m,p-xylene (0.06 ppb, 0.06 ppb). Aromatic hydrocarbon measurements exhibited the typical seasonality of the major emission sources, such as vehicle exhaust, solvent evaporation, and regional circulation patterns. The ratios of m,p-xylene/ethylbenzene of 1.57 at Deokjeok and 1.05 at Jeju reflected the degree of proximity to outflows of each source region, South Korea and China. The toluene/benzene ratios of 1.0 were consistently both on field observations and on the 3-D chemical model simulation, which is slightly higher than that in the Western Pacific area. It implied that the air over the Yellow Sea was influenced to a great extent by the surrounding areas. We confirmed that current emission inventories of aromatic hydrocarbons in Northeast Asia reasonably reproduced temporal and spatial variations of toluene and benzene over the Yellow Sea.

Effect of Multiple Copies of Cohesins on Cellulase and Hemicellulase Activities of Clostridium cellulovorans Mini-cellulosomes

  • Cha, Jae-Ho;Matsuoka, Satoshi;Chan, Helen;Yukawa, Hideaki;Inui, Masayuki;Doi, Roy H.
    • Journal of Microbiology and Biotechnology
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    • 제17권11호
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    • pp.1782-1788
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    • 2007
  • Cellulosomes in Clostridium cellulovorans are assembled by the interaction between the repeated cohesin domains of a scaffolding protein (CbpA) and the dockerin domain of enzyme components. In this study, we determined the synergistic effects on cellulosic and hemicellulosic substrates by three different recombinant mini-cellulosomes containing either endoglucanase EngB or endoxylanase XynA bound to mini-CbpA with one cohesin domain (mini-CbpAl), two cohesins (mini-CbpA12), or four cohesins (mini-CbpAl234). The assembly of EngB or XynA with mini-CbpA increased the activity against carboxymethyl cellulose, acid-swollen cellulose, Avicel, xylan, and com fiber 1.1-1.8-fold compared with that for the corresponding enzyme alone. A most distinct improvement was shown with com fiber, a natural substrate containing xylan, arabinan, and cellulose. However, there was little difference in activity between the three different mini-cellulosomes when the cellulosomal enzyme concentration was held constant regardless of the copy number of cohesins in the cellulosome. A synergistic effect was observed when the enzyme concentration was increased to be proportional to the number of cohesins in the mini-cellulosome. The highest degree of synergy was observed with mini-CbpAl234 (1.8-fold) and then mini-CbpAl2 (1.3-fold), and the lowest synergy was observed with mini-CbpAl (1.2-fold) when Avicel was used as the substrate. As the copy number of cohesin was increased, there was more synergy. These results indicate that the clustering effect (physical enzyme proximity) of the enzyme within the mini-cellulosome is one of the important factors for efficient degradation of plant cell walls.

농업용 저수지 유역의 보전전략 수립을 위한 특성평가지표 개발 (Development of Evaluation Indices for Preservation Strategies for Agricultural Reservoir Watersheds)

  • 장병관;황보철;황국웅
    • 한국조경학회지
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    • 제35권6호
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    • pp.14-20
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    • 2008
  • The agricultural reservoir watershed plan suggests three specific indices or ways to measure the potential for maintaining reservoir quality in balance with existing or proposed uses: an index of the reservoir's vulnerability to accelerated eutrophication, an index of the degree of land use intensity in reservoir watersheds, and an index of present water quality. Three items that contribute to reservoir eutrophication are included in the vulnerability index: the ratio of reservoir volume to drainage-basin area, shoreline configuration, and mean depth. The watershed land-use intensity index is based on road proximity and upland watershed land-use intensity. Water quality can be given a COD level. All six indicators are considered separately and then rated as follow: low (1), medium (2), or high (3). Five out of 30survey sites were less than 8points, 17sites were less than 11points and 8sites were less than 14points. This study suggests that the sites in the first ranking were potential areas for preservation, sites in the second ranking were potential areas for environmental friendly planning and sites in the third ranking were potential areas for residential need oriented planning. The advantage of this study is the low cost of gathering data for the development of local policy for the planning, management and protection of reservoir basin.

무극 함금석영맥광상 주변모암에서의 모암변질과 원소들의 일차분산 (Wallrock Alteration and Primary Dispersion of Elements in the Vicinity of the Mugeug Gold-bearing Quartz Veins)

  • 황인호;전효택
    • 자원환경지질
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    • 제27권4호
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    • pp.387-396
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    • 1994
  • Mineralogical and geochemical studies on gold-bearing quartz veins and wallrock from the Mugeug mine were carried out in order to investigate the variation of mineralogical composition and the geochemical behavior of elements with distance from the gold-bearing quartz veins. Gold-bearing quartz veins occur in early Cretaceous medium- to coarse-grained biotite granite. The unaltered wallrock is composed mainly of quartz, plagioclase, orthoclase, microcline, biotite and hornblende with accessory minerals of sphene and apatite. Mineralogical changes in altered wallrock around the gold-bearing quartz veins were observed as follows; 1) biotite and hornblende altered into chlorite, and next to sericite, 2) plagioclase, orthoclase and microcline altered into sericite, and 3) calcite and quartz introduced into wallrock. Contents of $K_2O$, Rb, Cs, Au, As and Sb in altered wallrock increase, whereas those of $Na_2O$, CaO, Ba, and Sr decrease with proximity to the gold-bearing quartz veins. The loss on ignition also increases with the increase of alteration mineral. The width of primary dispersion increases in order $Au=SiO_2<As=Cs=Rb<K_2O=Sb$ and $MnO<Na_2O=CaO=Ba<Sr$. The sericitization index, $K_2O/(K_2O+Na_2O)$, is an important indicator to interpret the degree of alteration at the Mugeug mine, which is more than 0.8 in strongly and moderately altered granite, 0.5~0.8 in wea altered granite, and less than 0.5 in unaltered granite. Alteration indices for major and trace elements, and the ratio of Rb/Sr are also useful to discriminate alteration zones.

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가중치가 부여된 공간변수에 의거하여 USN 루트노드 최소화 방안 -대학 캠퍼스를 사례로- (Minimizing Redundant Route Nodes in USN by Integrating Spatially Weighted Parameters: Case Study for University Campus)

  • 김진택;엄정섭
    • 대한지리학회지
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    • 제45권6호
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    • pp.788-805
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    • 2010
  • 현재 유비쿼터스 센서 네트웍(USN: Ubiquitous Sensor Networks)의 노드를 배치하는 방식은 위치 적정성의 관점에서 많은 한계를 가지고 있다. 본 연구는 가시권 분석, 셀중심에 대한 인접성, 도로 밀도, 건물밀도, 셀중첩 비율을 GIS 데이터베이스로 구축하고 공간변수별 가중치에 의거하여 USN루트 노드 설치를 최소화하는 방안을 제시하였다. 기존의 전형적인 격자형 방식에 의거한 USN에서 24개의 루트노드가 필요하였지만 공간가중치에 의한 분석방법은 11개의 노드만으로 네트웍의 구성이 가능하였다. 11개의 노드만으로 구성된 USN에서 신호강도(RSSI: Received Signal Strength Indicator)는 다양한 지점에서 급격한 변동을 보이지 않고 노드의 연결성에 대한 성능평가 기준을 충족하였다. 공간가중치를 반영한 노드의 배치는 USN노드 배치에서 격자형방식이나 무작위로 설치하는 관행을 개선될 수 있는 계기가 되어 USN의 운영과정에서 신호강도를 확보할 수 있는 중요한 참고자료가 될 수 있을 것으로 사료된다.

면역세포 활성에 대한 Substance P의 영향 (Effects of Substance P on the Activities of Immune Cell)

  • 김형섭;오귀옥;임종득
    • Journal of Periodontal and Implant Science
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    • 제26권2호
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    • pp.376-395
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    • 1996
  • The neuropeptide substance P(SP) has been recognized to modulate immune systems, with close proximity between peptidergic sensory nerve endings and immune cells. These include the macrophage and neutrophil activation, IL-2 production in T cell, augmentation of Ig synthesis, mast cell degranulation, $PGE_2$ and collagenase secretion in synoviocytes. In this study I examined SP-induced various biological activities such as antimicrobial action, cytokine production, and mast cell degranulation in the presence or absence of other inflammatory cell activators. Antimicrobial studies showed that undifferentiated HL-60 cells were not affected by SP. However, SP significantly enhanced antimicrobial action of TPA-treated or dbcAMP-treated HL-60 cells which had been differentiated into PMN or macrophage/monocyte. I could not find synergistic relationship between SP and LPS in parallel experiments of the above. SP did not induce IL-l production from murine macrophage cell line RAW264.7 whether costimulated with LPS or not. Mast cell degranulation was occured only when stimulated with high dose ($10^{-5}M$) of SP and the degree of this activation was slightly reduced by simultaneous application of $MIP-1{\alpha}$. In addition, CGRP which is known to be a common coexisting neuropeptide with SP within specific fibers did not augment the function of SP on mast cell degranulation. These results suggest that immunoregulatory activities of SP could be mediated through direct upregulation of various functions of immune cells and also upregulation of responsiveness of immune cells to other immune activators.

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