• 한국측량학회지
• /
• 제4권1호
• /
• pp.37-42
• /
• 1986

This paper deals with comparison of simultaneous geodetic networks between with geographical coordinates and with plane coordinates. The adjustment computation is performed by variation of coordinates. Provisional values for observation equations are computed by extended Guass mid-latitude formula using, official coordinates ($\varphi,\lambda$) in geographical network abjustment, measurements are reduced to plane by origin scale factor (＝1.0000) Bessel ellipsoid and unit weight are adopted, and geographical coordinates are projected by Guass conformal double projection. The processing results of a test-network by distances yield the average root mean square error of position 6ㆍ2cm for adjustment with $\varphi,\lambda$ and 5.8cm for adjustment with X, Y. RMSE of discrepancy between two methods is 1.7cm. This result conform to required accracy.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.320-323
• /
• 2001

A computer simulation was performed to distinguish quantitatively a color reaction in a urine analysis systems by using the spectral power distribution of LEDs, the spectral reflectance of a urine strip, and the spectral sensitivity of photodiode. The CIE tristimulus values and CIE chromaticity coordinates ware modified to be conformable with real color reactions in a urine strips. Results on color simulation showed a of real color in comparison with those obtained by Colorimeter CM2C(Color Savvy).

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.328-331
• /
• 2001

Color simulation on a portable colorimeter was performed to distinguish quantitatively a chromaticity coordinates on a color guide of a urine strips by using the spectral power distribution of chip LED, the spectral reflectance of printed objects, and the spectral sensitivity of photodiode. The CIE tristimulus values and chromaticity coordinates realized by a colorimeter were modified to be conformable with real color reactions. Experimental results showed a real color in comparison with those obtained by Colorimeter CM2C(Color Savvy).

• 대한토목학회논문집
• /
• 제11권4호
• /
• pp.163-170
• /
• 1991

SPOT 위성영상을 이용한 3차원 위치결정에는 해석적사진측량과 수치적사진 측량방법에서의 번들조정이 적용되며, 이를 위해서는 정밀한 상좌표관측과 정확한 지상기준점좌표가 요구된다. 본 연구에서는 지상측량성과의 비교하여 축척에 따른 지형도의 디지타이징된 평면좌표 정확도와 보간된 높이좌표 정확도를 분석하였고, 또한 지상기준점좌표의 획득방법 및 SPOT 영상자료의 형태를 조합하여 번들조정으로 결정된 3차원좌표의 정확도을 비교 분석하였다.

• 한국소음진동공학회논문집
• /
• 제16권7호
• /
• pp.712-719
• /
• 2006

This paper is concerned with the comparison of substructure synthesis methods based on global and local coordinates. The substructure synthesis methods based on the global coordinates were first proposed for the dynamic analysis of complex structure and the substructure synthesis method based on the local coordinates was proposed to solve the dynamic problem of tree-like structure. However, the conceptual difference between two methods in solving the dynamic problem has never been explained. In this paper, a structure consisting of two beams is considered to show the conceptual difference of two methods. The dynamic formulation shows the characteristics and differences of two methods explicitly. The procedure for choosing proper substructure modes in each method is also explained in detail. In addition, the advantage of the substructure synthesis method based on the local coordinate system is discussed based on the numerical example. Numerical examples show how two methods are applied to the addressed problem.

• 한국의학물리학회지:의학물리
• /
• 제10권1호
• /
• pp.47-54
• /
• 1999

목적 : CT 영상에 나타난 환부의 표적에 대한 BRW 좌표가 방사선수술기구 (XKnife) 하드웨어의 한계범위를 벗어나는지 신속하게 확인하고, XKnife 컴퓨터로 영상전환시 rod 탐지, 해부학적 구조 변환, 변환방정식 등이 성공적으로 전환되었는지를 입증을 하고자 한다. 대상 및 방법 : 13 명 환자에 대한 표적의 BRW 좌표를 스크린 영상 및 필름 위치결정 과정을 통해 SCS1 컴퓨터로 계산하였고, 표적 및 특이점에 대하여 SCS1 컴퓨터로 계산한 BRW 좌표를 전환된 영상을 근거로 한 XKnife localizer로 구한 BRW 좌표와 비교하였다. 결과 : 13명 환자에 대한 표적의 위치가 BRW 좌표의 VERT 성분에서 모두 -50 mm 보다 크게 나타나 XKnife 하드웨어의 한계범위 내에 존재하였다. SCS1 컴퓨터와 XKnife localizer로 구한 13명 환자의 표적 및 특이점의 BRW 좌표차이의 평균값은 스크린 영상을 이용한 XKnife-SCS1과 필름을 이용한 XKnife-SCS1 두 경우 모두 AP 및 LAT 성분이 1 mm이내, VERT 성분은 0.5 mm 이내였다. 결론 : SCS1 컴퓨터는 표적의 BRW 좌표를 신속 정확하게 계산할 수 있는 수단임이 입증되었고, SCS1 컴퓨터와 XKnife localizer로 구한 BRW 좌표를 비교한 결과 XKnife 컴퓨터로의 영상전환은 성공적으로 수행되었다.

• 대한기계학회논문집B
• /
• 제20권5호
• /
• pp.1613-1623
• /
• 1996

In this paper, two discretization methods, hybrid and QUICK, are tested for the Navier-Stokes equations written in general nonorthogonal body fitted coordinates. Comparison is made by calculating two laminar flows at low Reynolds numbers of 10 - 100. One is a two-dimensional channel of gradually expanding cross section and the other is an axisymmetric flow through a circular tube having a circular constriction. Results show that the QUICK scheme results in a numerical solution more accurate than that of hybrid. The QUICK scheme also shows faster convergence for both test cases. As the number of grid points increases, all numerical solutions converge with more oscillation. The number of grid points in the y-direction(cross stream direction) is also shown to play a significant role in the approximation of convection term within separated flow zone.

• 대한의용생체공학회:의공학회지
• /
• 제17권4호
• /
• pp.469-478
• /
• 1996

In the conventional digital ultrasound scanner, the reflected signal is sampled either in polar coordinates of R-$\theta$ method, or in Cartesian coordinates of uniform ladder algorithm (ULA). The R-$\theta$ scan method necessitates a coordinate transform process which makes hardware complex in comparison with ULA scan mrthoA In spite of this complexity, R-$\theta$ method has a good resolution in ultrasonographic (US) image, since scan direction of the US imaging is a radial direction. In this paper, a new digital scan converter is proposed, which is named the radius uniform ladder algorithm (RULA). The RULA has the rome scan direction as the US scanning in the radial direction and as the display space in the $\theta$ direction. In tllis new approach, sampled points we uniformly distributed in each horizontal line i.n well as in each radial ray so that the data are displayed in the Cartesian coordinates by the 1-D interpolation process. The propped algorithm has an uniform resolution in the periphery and the center field in comparison with equi-angle ULA and equi-interval ULA. To extend the scan angle, concentric square raster sampling (CSRS) is adopted with reduction of discontinuities on the junctions between horizontal scan and vertical scan. The discontinuities are reduced by using the hmction filtering along the $\theta$ direction.

• 한국측량학회지
• /
• 제19권4호
• /
• pp.415-423
• /
• 2001

본 연구는 GPS상시관측소의 기준좌표계별 절대좌표 산정을 위한 적합한 방안의 결정을 위해 수행되었으며, 성균관대학교 구내에 설치된 상시관측소를 연구대상으로 하였다. 본 논문에서 ITRF97성과는 정밀도 0.001ppm의 정밀단독측위기법으로 GPS 데이터를 해석하여 산정하였고. WGS84와 대한민국 좌표계 성과는 결정된 ITRF97성과를 이미 제공되어 있는 파라메터들로 변환하여 산정하였다. ITRF97 성과의 경우 제트추진연구소에서 개발한 위치결정 알고리즘과 GIPSY-OASIS II(이하 GOA II)를 사용하여 산정하였다. WGS84와 대한민국 좌표계 성과는 IERS에서 전 지구적으로 계산한 좌표변환 계수와 2000년도 국립지리원에서 시행한 사업인 한국 지구중심 기준좌표계의 결정 사업을 통해 산정된 좌표변환 계수를 이용하여 산정하였으며, 이를 지역적인 GPS 데이터 해석을 통해 산정된 성과와 비교하여 그 활용성을 검증하였다.

• 한국기계가공학회지
• /
• 제3권4호
• /
• pp.7-12
• /
• 2004

Inspection and analysis are essential process to determine whether a completed product is in given specification or not. Analysis of products with very complicated shape is difficult to carry out direct comparison between inspected coordinate and designed coordinates. So process called as matching or registrations is needed to solve this problem. By defining error between two coordinates and minimizing the error, registration is done. Registration consists of translation, rotation and scale transformations. Error must be defined to express feature of inspected product. In this paper, registration algorithm is developed to determine pose of sub-frame at assembly with body of automobile by defining error between two coordinates considering geometric feature of sub-frame.