• Title/Summary/Keyword: 공선식

Search Result 53, Processing Time 0.051 seconds

Shrinkage Structure of Ridge Partial Least Squares Regression

  • Kim, Jong-Duk
    • Journal of the Korean Data and Information Science Society
    • /
    • v.18 no.2
    • /
    • pp.327-344
    • /
    • 2007
  • Ridge partial least squares regression (RPLS) is a regression method which can be obtained by combining ridge regression and partial least squares regression and is intended to provide better predictive ability and less sensitive to overfitting. In this paper, explicit expressions for the shrinkage factor of RPLS are developed. The structure of the shrinkage factor is explored and compared with those of other biased regression methods, such as ridge regression, principal component regression, ridge principal component regression, and partial least squares regression using a near infrared data set.

  • PDF

Development of 3-D Volume PIV (3차원 Volume PIV의 개발)

  • Choi, Jang-Woon;Nam, Koo-Man;Lee, Young-Ho;Kim, Mi-Young
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.27 no.6
    • /
    • pp.726-735
    • /
    • 2003
  • A Process of 3-D Particle image velocimetry, called here, as '3-D volume PIV' was developed for the full-field measurement of 3-D complex flows. The present method includes the coordinate transformation from image to camera, calibration of camera by a calibrator based on the collinear equation, stereo matching of particles by the approximation of the epipolar lines, accurate calculation of 3-D particle positions, identification of velocity vectors by 3-D cross-correlation equation, removal of error vectors by a statistical method followed by a continuity equation criterior, and finally 3-D animation as the post processing. In principle, as two frame images only are necessary for the single instantaneous analysis 3-D flow field, more effective vectors are obtainable contrary to the previous multi-frame vector algorithm. An Experimental system was also used for the application of the proposed method. Three analog CCD camera and a Halogen lamp illumination were adopted to capture the wake flow behind a bluff obstacle. Among 200 effective particle s in two consecutive frames, 170 vectors were obtained averagely in the present study.

Analysis of the Accuracy of Quaternion-Based Spatial Resection Based on the Layout of Control Points (기준점 배치에 따른 쿼터니언기반 공간후방교회법의 정확도 분석)

  • Kim, Eui Myoung;Choi, Han Seung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.36 no.4
    • /
    • pp.255-262
    • /
    • 2018
  • In order to determine the three-dimensional position in photogrammetry, a spatial resection is a pre-requisite step to determine exterior orientation parameters. The existing spatial resection method is a non-linear equation that requires initial values of exterior orientation parameters and has a problem that a gimbal lock phenomenon may occur. On the other hand, the spatial resection using quaternion is a closed form solution that does not require initial values of EOP (Exterior Orientation Parameters) and is a method that can eliminate the problem of gimbal lock. In this study, to analyze the stability of the quaternion-based spatial resection, the exterior orientation parameters were determined according to the different layout of control points and were compared with the determined values using existing non-linear equation. As a result, it can be seen that the quaternionbased spatial resection is affected by the layout of the control points. Therefore, if the initial value of exterior orientation parameters could not be obtained, it would be more effective to estimate the initial exterior orientation values using the quaternion-based spatial resection and apply it to the collinearity equation-based spatial resection method.

표지선 주기관 개방검사 면제에 대한 고찰 < 기관(ENG') 개방검사 면제로 11억원을 벌다! >

  • Kim, Hyeong-Jun;Song, Mun-Cheol;No, Gyeong-Sik
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2018.11a
    • /
    • pp.81-82
    • /
    • 2018
  • 선박안전법에 따라 대다수의 관공선 주기관은 8년마다 정기 개방검사를 해야 한다. 주기관 특성상 개방검사는 많은 예산 소요 및 엔진 효율성의 저하가 우려되어 이를 해결하고자 관련법에 따라 8년간 개방검사 면제 사전 준비로 예산을 절감하고 기관의 성능을 최적화 시켰다.

  • PDF

Effects of the Substrate Temperature on the Properties of Ni-Zn-Cu Ferrite Thin Films Deposited by RF Magnetron Sputtering (RF Magnetron Sputtering에 의해 증착된 Ni-Zn-Cu Ferrite 박막의 물성에 미치는 기판온도의 영향)

  • 공선식;조해석;김형준;김경용
    • Journal of the Korean Ceramic Society
    • /
    • v.29 no.5
    • /
    • pp.383-390
    • /
    • 1992
  • We investigated the effect of substrate on the properties of the Ni-Zn-Cu ferrite thin films deposited on SiO2 (1000∼3000${\AA}$) / Si (100) substrate at various conditions by rf magnetron sputtering. A disktype Ni-Zn-Cu ferrite sintered by conventional ceramic process and argon gas were used as a target and a sputtering gas, repectively. The compositions of the thin films measured by EPMA were similar to target composition (Fe: 65.8 at%, Ni: 12.7 at%, Cu: 6.7 at%, Zn: 14.8 at%) irrespective of substrate temperature. Amorphous thin films were deposited when substrate was not intentionally heated, but the films came to crystallize with increasing substrate temperature, and crystalline thin films were deposited at substrate temperature above 200$^{\circ}C$. Below 250$^{\circ}C$ saturation magnetization (Ms), remanence (Mr) and coercivity (Hc) of the ferrite thin film increased with the substrate temperature due to the increase of grain size and the improvement of crystallinity. And above 250$^{\circ}C$, Ms, Mr increased slightly, but Hc of the amorphous thin films increased due to crystallization, whereas that of the crystalline thin films decreased because of grain growth and stress release.

  • PDF