• 제목/요약/키워드: Planar fit

검색결과 21건 처리시간 0.035초

경사진 KoFlux 산림유역에서 에디공분산 플럭스 산출에 미치는 좌표회전의 효과 (The Effect of Coordinate Rotation on the Eddy Covariance Flux Estimation in a Hilly KoFlux Forest Catchment)

  • 렌민 유안;강민석;박성빈;홍진규;이동호;김준
    • 한국농림기상학회지
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    • 제9권2호
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    • pp.100-108
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    • 2007
  • 험준한 산지에 위치한 광릉 KoFlux 슈퍼사이트는 기복이 진 지형과 산골 순환으로 인해 풍속이 약한 것이 특징이다. 따라서 에디 공분산 방법을 이용한 플럭스 관측에 좌표회전이 미치는 효과를 이해하는 것이 필수적이다. 본 논문에서는 세 가지의 직교 좌표 체제 (이중, 삼중 및 planar fit 회전)의 특징을 살펴 보고, 이들을 광릉 슈퍼사이트에서 관측된 플럭스 자료에 적용하였다. 'Planar Fit(PF)' 좌표회전으로부터 유추해 낸 초음파 풍속계의 연직 풍속의 평균 차감은 대략 $\pm0.05ms^{-1}$이었다. 바람이 부는 경우, 이중 회전 $(\bar{v}=\bar{w}=0)$에서 산출된 열, 수증기 및 $CO_2$의 난류 플럭스는 PF 회전에서 나온 결과와 거의 같았다. 그러나 바람이 잔잔한 경우에는 이중 회전이 큰 값의 편의를 나타내었다. 대기 지표층의 중요한 스케일링 모수인 마찰 속도는 좌표 회전 방법의 선택에 따라 더 민감하게 반응하였다.

Planar Optical Waveguide Temperature Sensor Based on Etched Bragg Gratings Considering Nonlinear Thermo-optic Effect

  • Ahn, Kook-Chan;Lee, Sang-Mae;Jim S. Sirkis
    • Journal of Mechanical Science and Technology
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    • 제15권3호
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    • pp.309-319
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    • 2001
  • This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

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Home-built Solid-state NMR Probe for Membrane Protein Studies

  • Kim, Yong-Ae;Hwang, Jung-Hyun;Park, Jae-Joon
    • Bulletin of the Korean Chemical Society
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    • 제24권9호
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    • pp.1281-1283
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    • 2003
  • Proteins in highly oriented lipid bilayer samples are useful to study membrane protein structure determination. Planar lipid bilayers aligned and supported on glass slide were prepared. These stack of glass slide with planar lipid bilayers are not well fit for commercial solid-state NMR probe with round coil. Therefore, homebuilt solid-state NMR probe was built and used for a stack of thin glass plates and RF coil is wrapping directly around the flat square sample. The overall filling factor of the coil is much better and the large surface area enhances the extent to orientation by providing uniform environments for the phospholipids and the high ratio of circumference to area reduces edge effects. $^1H\;and\;^{15}N$ double resonance probe for 400 MHz NMR (9.4T) with a flat coil (coil size: 11 mm ${\times}$ 20 mm ${\times}$ 4 mm) is constructed and tested.

조선 후기와 현대의 여자한복 형태 비교 -Delong의 복식형태 분류체계를 적용하여 (A Comparison on the Form in Women's Hanbok between the Later Chosun Dynasty and Modern Times- Applying Delong's Dividing System for Apparel Body Construct)

  • 김순영;남윤자
    • 복식
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    • 제52권5호
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    • pp.61-77
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    • 2002
  • The purpose of this study is to investigate difference and likeness on the form in women's Hanbok between the later Chosun Dynasty and modern times based on Belong's observing system for 'Apparel-Body Construct'. Belong's framework is composed 5 pairs of contrast word -'Closed or Open', 'Whole or Par', 'Planar Separation or Planar integration'. 'Flat or Rounded', and 'Determinate or Indeterminate'. Major findings of this study are as follows. First, the form of women's Hanbok in later Chosun Dynasty is 'Variably Closed', 'Part' and 'Rounded', whereas that in modern is 'Open', 'Whole' and 'Flat' Women's Hanbok of modern is lesser convex, and more open than that of later Chosun Dynasty according to increasing use of transparent textiles. Moreover, in comparison with old style, that of modern has the tendency of perceiving primarily whole feature by organic linkage of parts. Because of loose fit of Jeogori and rigid DongJong etc, characteristic of 'Plat' strengthened in modern Hanbok. Secondly, women's Hanbok in the later Chosun Dynasty and modern has common properties of 'Planar Seperation' and 'Determinate'. Women's Hanbok belongs to 'Planar Seperation', because the effect cognized to figure and ground. can be found between small parts and whole of Jegori, or can be found between the head and face. Jeuori and waist band, and Chima and under ware. Further more. it can be classified into 'Determinate'. because it use textiles which have no pattern un it or which show a subtle surface effect by texture changing.

18세기 여성 의복에 나타난 트리밍을 응용한 네일아트 디자인 연구 - 브레이드, 레이스, 리본을 중심으로 - (A study on nail art design based on the application of trimmings in the 18th century women's clothes - Focus on braids, laces, and ribbons -)

  • 조한솔;이영주
    • 한국의상디자인학회지
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    • 제21권4호
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    • pp.127-137
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    • 2019
  • Nail art, which has been popularized recently, has increased convenience in the direction of nail art design harmonized with clothing and the increased interest and usage of nail art decoration. This study set out to propose practical planar and three-dimensional nail art designs in harmony with modern clothes by applying trimmings common in 18th century women's clothing, which used a variety of attachable decorations. As for the methodology, the investigator examined theories in previous studies, literature, and analyzed the types of trimming in female portraits from the 18th century at the museum at the Palace of Versailles in France. Planar and three-dimensional nail art designs were created for each of the top three trimming types- braids, laces, and ribbons, which were identified through analysis. The study applied the trimmings of the 18th century women's clothes to nail art design and had the following results: First, the top three trimming types were identified based on the analysis of the 18th century portraits. They were then used as motifs in the production of planar and three-dimensional nail art designs. The results show that the motifs of the clothes trimmings were fit for and had practical possibilities for expression in nail art designs. Secondly, diversity and the expansion of ideas in the study of nail art design were promoted. In addition, elements were increased to have mutually complementary effects with clothes. Finally, the study made various attempts at nail design methods by adopting a range of nail art expression techniques including hand painting, 2D & 3D art techniques, and using planar and three-dimensional nail decorations, thus proposing a positive direction for the organization of a curriculum to make use of 18th century women's clothing motifs in nail art education.

비균질 도시 지표에서 측정된 에디 공분산 난류 플럭스의 불확실성 분석: 좌표계 편향 영향 (Uncertainty Analysis of the Eddy-Covariance Turbulent Fluxes Measured over a Heterogeneous Urban Area: A Coordinate Tilt Impact)

  • 이두일;이재형;이상현
    • 대기
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    • 제26권3호
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    • pp.473-482
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    • 2016
  • An accurate determination of turbulent fluxes over an urban area is a challenging task due to its morphological diversity and associated flow complexity. In this study, an eddy covariance (EC) method is applied over a highly heterogeneous urban area in a small city (Gongju), South Korea to investigate the quantitative influence of 'coordinate tilt' in determining the turbulent fluxes of sensible heat, latent heat, momentum, and carbon dioxide mass. Two widely-used coordinate transform methods are adopted and applied to eight directional sections centered on the site to analyze a 1-year period EC measurement obtained from the urban site: double rotation (DR) and planar fit (PF) transform. The results show that mean streamline planes determined by the PF method are distinguished from the sections, representing morphological heterogeneity of the site. The sectional pitch angles determined by the DR method also compare well with those in the PF method. Both the PF and DR methods show large variabilities in the determined streamline planes at each directional section, implying that flow patterns may form in a complicate way due to the surface heterogeneity. Resulting relative differences of the turbulent fluxes, defined by $(F_{DR}-F_{PF})/F_{DR}$, are found on average +13% in sensible heat flux, +21% in latent heat flux, +37% in momentum flux, and +26% in carbon dioxide mass flux, which are larger values than those reported previously for fairly homogeneous natural sites. The fractional differences depend significantly on wind direction, showing larger differences in northerly winds at the measurement site. It is also found that the relative fractional differences are negatively correlated with the mean wind speed at both stable/unstable atmospheric conditions. These results imply that EC turbulent fluxes determined over heterogeneous urban areas should be carefully interpreted with considering the uncertainty due to 'coordinate tilt' effect in their applications.

에디공분산 관측시스템을 이용한 용담댐 시험유역 증발산량 산정연구 (Evapotranspiration Estimation by The Eddy-Covariance in The Yongdam Dam Experimental Basin)

  • 김용국;이현석;채효석;김영성
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.274-274
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    • 2012
  • 증발산량 관측은 오랜 기간 연구되어 왔으며, 미기상 관측 시스템의 최적화와 상호 공동비교 실험 및 자료 처리의 일관성을 유지를 위해 한국에는 KoFlux라고 하는 플럭스 네트워크가 2002년 1월에 구축되었다. 이를 시작으로 미기상 관측에 대한 관심이 많은 연구자들이 관측망 구축에 힘쓰고 있으며, 에디공분산 방법을 이용해 증발산량을 산정하고 있다. 에디 공분산 방법은 다른 방법에 비해 연직농도 차이가 적은 산림 위에서의 플럭스 값을 측정 할 수 있으며, 측정 시 식물 환경에 방해를 주지 않는 등의 장점이 있다. 하지만 자료 처리와 품질관리에 있어 연구자의 주관성에 의해 상당 부분 불확실성을 초래한다. 또한 다른 관측지점과의 일관적인 비교를 위해 좌표보정을 수행하며, 일반적으로 바람이 평평한 지역 위로 분다는 가정 하에 이루어진다. 좌표보정은 일반적으로 Planar Fit Rotation방법을 사용하며, 평판 분할은 지형에 따라 12개까지 분할하여 분석한다. 하지만 덕유산 플럭스관측 타워지점처럼 산지 특성이 뚜렷하고 1 m/s이하의 풍속 데이터의 빈도가 큰 경우 평판 분할 수의 제한이 발생한다. 이러한 문제를 해결하기 위해 좌표보정계수산정 방법에 따라 등간격의 평판분할 방법(Scenario A), 주풍향을 고려한 평판분할 방법(Scenario B)과 빈도에 의한 평판분할방법(Scenario C)으로 수행하였다. 또한 각 Scenario는 풍속의 제한 조건에 따라 CASE A(0.5 m/s 이상), CASE B(1.0 m/s이상)로 구분하여 분석하였다. 본 연구를 통해 제안 한 자료처리 절차는 첫째, 바람자료의 빈도 분석을 통한 지역특성 파악 둘째, 풍속제한 조건 설정 셋째, 바람과 수증기의 공분산 계산으로 요약된다. 덕유산 플럭스관측 타워지점의 경우 풍속 제한을 1.0 m/s이상에서 0.5 m/s이상으로 하향 조정하였으며, 평판 분할 방법은 Scenario C의 평판 수 12개를 채택하였다.

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실내 디지털 TV용 평면 안테나 특성 측정에 관하여 (On the measurement of characteristics of planar antennas for indoor digital TV)

  • 이종익;여준호;김수민;양명규;은장수
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2014년도 춘계학술대회
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    • pp.45-46
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    • 2014
  • 본 논문에서는 포트 임피던스가 75옴인 실내 디지털 TV (DTV)용 안테나의 특성 측정 방법에 대해 소개하였다. 일반적인 RF (혹은 마이크로파) 시스템과 측정장비의 기준 임피던스는 거의 대부분 50옴이다. 이에 비해 실내 디지털 TV용 안테나의 기준 임피던스는 75옴이므로 기준 임피던스가 50옴인 측정 장비를 이용하여 직접 특성을 측정할 수 없다. 50옴을 기준으로 하는 장비를 이용하여 75옴에 적합하도록 설계된 안테나의 특성(임피던스, 복사패턴 및 이득)을 측정방법에 대해 소개하였다.

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Test Results of WADGPS System using Satellite-based Ionospheric Delay Model for Improving Positioning Accuracy

  • So, Hyoungmin;Jang, Jaegyu;Lee, Kihoon;Song, Kiwon;Park, Junpyo
    • Journal of Positioning, Navigation, and Timing
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    • 제5권4호
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    • pp.213-219
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    • 2016
  • Most existing studies on the wide-area differential global positioning system (WADGPS) employed a grid ionosphere model for error correction in the ionospheric delay. The present study discusses the application of satellite-based ionospheric delay model that provides an error model as a plane function with regard to individual satellites in order to improve accuracy in the WADGPS. The satellite-based ionospheric delay model was developed by Stanford University in the USA. In the present study, the algorithm in the model is applied to the WADGPS system and experimental results using measurements in the Korean Peninsula are presented. Around 1 m horizontal accuracy was exhibited in the existing planar fit grid model but when the satellite-based model was applied, correction performance within 1 m was verified.

단층변위를 이용한 단층의 총 이동량 계산법 (A New Method Calculating Total Slip of Fault with Fault Separation)

  • 황재하
    • 자원환경지질
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    • 제31권6호
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    • pp.547-555
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    • 1998
  • A new trigonometrical method for calculating total slip (T) of faulting is presented. The parameters for the calculations are used rake of fault striation, strike and dip of fault and of index planar structure such as bedding plane. The faults are groupped into three types. The direction of plunging of fault striation is out of a range ${\pm}90^{\circ}$ to the bedding dip direction in $360^{\circ}$ system, which is groupped into the type I. Meanwhile, the case of the direction lies in the above range can be separated into two different types, type II and type III, according to relative largeness of the angles rake of fault striation and i (see text). The type II has smaller rake than angle i and the type III has larger rake than angle i. Here I propose a few equations for calculating not only total slip (T) but strike slip (L) or dip slip (S) of the faulting. The equations are adapted selectively to the types of fault mentioned before. The limitation of the method is that the equations do not fit to polyphase faulting.

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