• 제목/요약/키워드: Total Variation

검색결과 3,703건 처리시간 0.034초

BIOCHEMICAL STUDIES ON THE RIBOFLAVIN IN GREENBEANS DURING GERMINATION

  • 이철준;정동효
    • Applied Biological Chemistry
    • /
    • 제2권
    • /
    • pp.29-35
    • /
    • 1961
  • The daily variation in the total quantity of flavin compounds (FAD, FMN, FR) in greenbean during its germination were measured by Yagi's methods. The results obtained were as follow. 1. The total quantity of flavin compounds of the greenbean sprouts was increased with growth of sprouts until the 8th days. After this period its contents were decreased slightly. 2. The flavin compounds of greenbean sprouts were comfirmed to be synthesized as free riboflavin during its germination. 3. FAD was the major pat of total flavin compounds in cotyledon but there was significant variation in the contents of FAD, FMN and FR in hypocotyl.

  • PDF

Concentration and Seasonal Variation of Particle PCBs in Air

  • Yeo Hyun-Gu;Chun Man-Young
    • Journal of Korean Society for Atmospheric Environment
    • /
    • 제21권E1호
    • /
    • pp.13-21
    • /
    • 2005
  • Atmospheric concentrations of PCBs were monitored in Ansung-city, Kyonggi province during the 2001/2002 to characterize the concentration distribution and seasonal variation of particle polychlorinated biphenyls (PCBs). Average concentration of particle bound PCB showed maximum value for penta-CBs and minimum value for octa-CBs. Seasonal contributions $(%\)$ of total particle PCBs showed the highest value in winter months and lowest value in summer month, This result indicated that concentration of total particle PCBs increased with decreasing temperature in the atmosphere. Therefore, particle PCBs were easily formed by the condensation of gas phase PCBs in winter months. The total particle PCBs exhibited an inverse correlation with temperature (p<0.01) which suggested that particle PCBs were easily formed by condensation of gaseous PCBs in winter months.

NC 선반가공에서 공구 조정주기의 경제적 설계 (Economic Design of Tool Resetting Period in NC Machining)

  • 배문택;윤원영;목학수
    • 한국정밀공학회지
    • /
    • 제15권6호
    • /
    • pp.33-39
    • /
    • 1998
  • This paper is related to economic design of tool-resetting period in NC machining. In NC lathe machining, the mean and variance of components dimension fluctuate in slow time and we should reset tool program to compensate the variation from the fluctuation. In this paper. we propose the procedure determining the optimal resetting period based on the total expected operating cost which consists of resetting cost and the quality cost related to dimension variation. As a case study, using experimental data about dimension changes of a lathe machining, we obtain the regression equations of mean and variance of the dimension fluctuation, total expected operating cost, and optimal resetting period.

  • PDF

남극 세종기지에서의 지자기 모니터링 (Geomagnetic Field Monitoring at King Sejong Station, Antarctica)

  • 김동일;진영근;남상헌;이주한
    • 지구물리
    • /
    • 제7권1호
    • /
    • pp.11-21
    • /
    • 2004
  • The variation of geomagnetic field and absolute magnetic field at the geomagnetic observatory of King Sejong Station has been measured with 3-component ring core fluxgate magnetometer, proton magnetometer and D-I magnetometer. With data obtained from King Sejong Station during 2003, thediurnal and annual variations of geomagnetic field were researched and compared with those at other observatories. The deviation of daily variation of magnetic field in antarctica decreased gradually during winter season due to sun effect. The rates of componental annual variation of magnetic field at King Sejong Station were calculated using the least-square method under the assumption that the annual variation of magnetic field is linear. The rates are -55.93 nT/year in horizontal intensity, -0.87 min./year in declination, 58.30 nT/year in vertical intensity, and -69.85 nT/year in total intensity of magnetic field. A remarkable variation was caused by the magnetic storms occurred on 29~30 October, which were so powerful that the variation was observed in mid latitudes as well as high latitudes. The values of variation are generally 1500 2000 nT in Antarctica including King Sejong Station, 350 500 nT in East Asia. The measurement of absolute magnetic field shows that ring core fluxgate magnetometer has relatively large error range under cold temperature.

  • PDF

Evaluation of Gloss Variation with a Novel Method

  • Sung, Yong-Joo;D. Steven Keller
    • 펄프종이기술
    • /
    • 제34권2호
    • /
    • pp.73-83
    • /
    • 2002
  • Gloss is very important optical property influencing the perceived quality of the paper surface as well as the surface after printing. Although the average gloss level of paper products or printed images is important to meet end use specifications, the occurrence of gloss mottle, or non-uniformity of gloss, is often of greater concern for meeting quality requirements, especially for the high gloss paper. Gloss variation originates from the irregularities of paper surface, especially surface roughness of paper. Roughness of paper can be divided into micro-roughness (under $1\mu m$ scale in variation) and macro-roughness (over $1\mu m$ scale in variation) depending on the scale of the irregularities. A clearer understanding of the gloss variation of paper can be achieved by separating the contributions of these two scales of roughness, and characterizing them independently. In order to do this, a novel gloss measuring method was introduced. This can detect local gloss with very high resolution. The effect of macro-roughness on gloss variation, which was identified by the measurable surface topography, was separated from the total gloss variation by using this method. The effect of micro-roughness was then estimated indirectly. The local gloss variations of various paper samples were then evaluated to demonstrate the utility of this approach.

Clock Mesh Network Design with Through-Silicon Vias in 3D Integrated Circuits

  • Cho, Kyungin;Jang, Cheoljon;Chong, Jong-Wha
    • ETRI Journal
    • /
    • 제36권6호
    • /
    • pp.931-941
    • /
    • 2014
  • Many methodologies for clock mesh networks have been introduced for two-dimensional integrated circuit clock distribution networks, such as methods to reduce the total wirelength for power consumption and to reduce the clock skew variation through consideration of buffer placement and sizing. In this paper, we present a methodology for clock mesh to reduce both the clock skew and the total wirelength in three-dimensional integrated circuits. To reduce the total wirelength, we construct a smaller mesh size on a die where the clock source is not directly connected. We also insert through-silicon vias (TSVs) to distribute the clock signal using an effective clock TSV insertion algorithm, which can reduce the total wirelength on each die. The results of our proposed methods show that the total wirelength was reduced by 12.2%, the clock skew by 16.11%, and the clock skew variation by 11.74%, on average. These advantages are possible through increasing the buffer area by 2.49% on the benchmark circuits.

유역특성에 따른 하천에서의 존재형태별 질소 분포 특성 비교 (Distribution Characteristics of Total Nitrogen Components in Streams by Watershed Characteristics)

  • 박지형;손수민;김용석
    • 한국물환경학회지
    • /
    • 제30권5호
    • /
    • pp.503-511
    • /
    • 2014
  • The temporal and spatial analyses of total nitrogen (TN) fractionation were conducted in order to understand 1) total nitrogen components in streams and 2) their patterns in rainy and dry seasons. The result showed that the concentration of nitrogen components in stream water was lower in non-urban area and getting higher in urban area. Dissolved total nitrogen (DTN) was 95~97.7% of total nitrogen in streams, and the proportion of dissolved organic nitrogen (DON) and ammonia nitrogen ($NH_3-N$) was higher with increasing urban area. The concentration of total nitrogen and nitrate nitrogen ($NO_3-N$) were highest in winter among four seasons. The result was showed that concentration of $NH_3-N$ was same variation as concentrations of TN and $NO_3-N$ in urban-rural complex and urban areas, except rural areas. During rainy season, concentrations of particulate organic nitrogen (PON) and $NH_3-N$ increased in rural areas and decreased in both urban-rural complex and urban areas. Correlation between total nitrogen components and land uses was positively correlated with site > paddy, and negatively correlated with forest. The variation of total nitrogen concentration was determined by $NO_3-N$ in non-urban areas, by $NO_3-N$ and $NH_3-N$ in urban-rural complex and by $NH_3-N$ in the urban areas.

한국내 솜양지꽃의 집단 유전 구조 (Population Genetic Structure of Potentilla discolor Bunge, Rosaceae in Korea)

  • 허만규
    • 생명과학회지
    • /
    • 제16권6호
    • /
    • pp.898-903
    • /
    • 2006
  • 한국내 분포하는 장미과의 솜양지꽃(Potentilla discolor Bunge) 15집단에 대한 19 알로자임 대립유전자좌위에서 유전적 다양성과 집단구조를 분석하였다. 조사한 좌위에 대해 약 73.7%가 다형성을 나타내었다. 종과 집단 수준에서 유전적 다양도는 각각 0.215, 0.196이었으며, 집단간 분화정도는 낮았다$(G_{ST}\;=\;0.069)$. 전체 유전적 다양성은 0${\sim}$0.656이며 평균 0.292였다. 유전적 다양도 중 집단내 변이는 높았다$(H_{S}\;=\;0.274)$. 전체 유전적 변이에서 집단간 차이는 Pgm-2에서 0.010, Pgd-2에서 0.261로 평균 0.069였다. 이는 전체 알로자임 변이 중 약 6.9%가 집단간에 있음을 의미한다. 솜양지꽃의 특성으로 광범위한 분포, 다년생 초본, 여러 세대의 존재 등이 높은 유전적 다양성을 나타내는데 기여하는 것으로 설명된다. 조사한 솜양지꽃 집단에서 세대당 이주하는 개체수는 3.36으로 평가되었다.

한국내 세잎양지꽃의 유전적 다양성과 집단구조 (Genetic Diversity and Population Structure of Potentilla freyniana in Korea)

  • 허만규
    • 생명과학회지
    • /
    • 제17권7호통권87호
    • /
    • pp.877-881
    • /
    • 2007
  • 전분 젤 전기영동을 사용하여 한국내 분포하는 세잎양지꽃 8개 집단에서 유전적 다양성과 집단구조를 평가하였다. 종수준에서 효소내 다형현상을 나타내는 대립유전자좌위는 68.4%였다. 집단 수준에서 유전적 다양도는 유사한 생활사를 가진 초본류의 평균값에 비해 높았다. 전체 유전적 다양도는 조사한 8개 집단에 대해 0.190과 0.584사이에 있었으며 평균은 0.371이였다. 집단내 유전적 다양도는 0.354였다. 집단간 분화정도는 비교적 낮았다($G_{ST}$ = 0.065). 고정지수 분석 결과 많은 집단과 대립유전자좌위에서 이형접합체의 결핍이 있었다. 이는 세잎양지꽃은 줄기에서 꽃을 형성하여 종자번식을 하는 타가수분방식과 분지하여 새로운 개체를 형성하는 영양번식을 영위할 수 있는 다양한 번식법을 가지고 있는 클론 식물의 특성에 기인한 것으로 사료된다. 따라서 같은 집단에서 다양한 세대의 존재하여 내교잡(inbreeding)이 발생한 것으로 볼 수 있다.

공간분석 기법을 이용한 만리포 유분의 시·공간 변동 패턴 분석 (A Spatio-Temporal Variation Pattern of Oiling Status Using Spatial Analysis in Mallipo Beach of Korea)

  • 김태훈;최현우;김문구;심원준
    • 한국지리정보학회지
    • /
    • 제15권4호
    • /
    • pp.90-103
    • /
    • 2012
  • 만리포는 2007년 12월 허베이 스피리트호 유류유출 사고로 유류오염 피해를 입은 대표적인 해변이다. 본 연구는 만리포 전체 영역과 5개로 분할된 영역을 대상으로 유분(TPH: Total Petroleum Hydrocarbon)의 시 공간적 변화 패턴에 대해 두 계절(동계와 하계)의 차이를 비교하고자 한다. 만리포 전체 영역에서 4년간 시간에 따른 유분농도의 감소율은 동계가 하계보다 약 두 배 크게 나타났다. 유분농도의 가중공간중심(weighted mean center)과 가중표준거리(weighted standard distance)를 이용한 유분분포의 공간적 변화 패턴 분석 결과, 동계에는 유분이 만리포의 남서 해변으로 군집된 패턴을 보인 반면, 하계에는 전 영역으로 분산된 패턴을 보였다. 만리포 내 분할 영역에서 유분의 시간적 변동은 동계에 모든 영역에서 농도가 지속적으로 감소한 반면, 하계에는 2009년 이후 남서 해변을 제외한 모든 영역에서 농도 변화를 보이지 않았다. 따라서 유류오염의 진행 상황을 평가하고 예측하기 위해서는 동계와 하계와 같이 시기를 구분하여 공간분석 기법을 이용한 유분의 시 공간 변동 패턴 분석이 필요하다. 또한, 지역적으로 불균등한 유분분포의 시간적 변동 패턴을 해석하기 위해서는 전체 해변에서 보다는 공간분할을 통한 지역 규모에서의 시계열적 분석이 유용하다.