• Title/Summary/Keyword: Surface fitting

검색결과 395건 처리시간 0.025초

Unveiling the Properties of FLS 1718+59: A Galaxy-Galaxy Gravitational Lens System

  • Taak, Yoon Chan;Im, Myungshin
    • 천문학회보
    • /
    • 제39권1호
    • /
    • pp.36.2-36.2
    • /
    • 2014
  • We present results of the analysis of FLS 1718+59, a galaxy-galaxy gravitational lens system in the Spitzer First Look Survey (FLS) Field. A background galaxy (z = 0.245) is severely distorted by an elliptical galaxy (z = 0.08), by gravitational lensing. We analyze this system by several methods, including Ellipse and Galfit fitting, gravitational lens modeling (gravlens), and SED fitting. Properties of the lens galaxy can be obtained: from Galfit we measure the effective radius and the average surface brightness inside it, and from gravlens we estimate the total mass inside the Einstein radius (lensing mass). We use these parameters to check that the lens galaxy is located on the Fundamental Plane. Also, we conduct SED fitting for the lens galaxy and estimate the stellar mass, and compare this with the lensing mass of the lens galaxy to check the M-L relation.

  • PDF

Digital Tolansky 간섭계의 개발과 이를 활용한 Surface Topography (Surface Topography by Using Digital Tolansky Interferometer)

  • 정영욱
    • 한국광학회:학술대회논문집
    • /
    • 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
    • /
    • pp.177-181
    • /
    • 1990
  • Digital Tolansky interferometer which is Tolansky interferometer interfaced to the computer through CCD TV-camera, is developed and applied to the surface topography. First, resolution of this system is determined by minimum measurable thickness of thin film. Theoretical analysis and experimenatal results are compared. Second, surface topographic picture of thin is obtained by two orthogonal fringes. Using linear fitting method, height distribution of specimen is obtained and 3-dim. picture is plotted.

  • PDF

The Confidence Regions for the Logistic Response Surface Model

  • Cho, Tae-Kyoung
    • 품질경영학회지
    • /
    • 제25권2호
    • /
    • pp.102-111
    • /
    • 1997
  • In this paper I discuss a method of constructing the confidence region for the logistic response surface model. The construction involves a, pp.ication of a general fitting procedure because the log odds is linear in its parameters. Estimation of parameters of the logistic response surface model can be accomplished by maximum likelihood, although this requires iterative computational method. Using the asymptotic results, asymptotic covariance of the estimators can be obtained. This can be used in the construction of confidence regions for the parameters and for the logistic response surface model.

  • PDF

자동차용 실리콘 와이어 씰의 조립과정에 관한 변형해석 (Deformation Analysis on Assembly Process of Silicone Wire Seal for Automobile)

  • 김진광
    • 동력기계공학회지
    • /
    • 제21권6호
    • /
    • pp.86-93
    • /
    • 2017
  • Silicone rubber wire seals are widely used in automotive connector systems for waterproofing and so on. The purpose of this paper is to predict and evaluate the sealing performance of wire seals using finite element analysis. The material properties of the rubber seals were determined by the curve fitting of uniaxial tensile test and equibiaxial tensile test data. The response surface method was used to determine the optimum shape of the wire seal. In order to verify the accuracy and reliability of the simulations on the deformation prediction of wire seals, experiments were also carried out.

Computation of partial derivatives from an image

  • Yang, Woo-Suk;Han, Inhwan
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
    • /
    • pp.526-531
    • /
    • 1992
  • Partial derivatives are easily computed analytically assuming that all the geometric information is known. However, there are computational difficulties in getting accurate partial derivatives directly from a range image since an image is a discrete version of continuous data contaminated with some noise. In this paper, we develop a general window function to compute partial derivatives based on the least square surface fitting method. A dynamic selective surface fitting method is introduced to make the window less sensitive to noise. Any degree of partial derivative can be obtained by a simple convolution between an image and window functions.

  • PDF

UNVEILING THE PROPERTIES OF FLS 1718+59: A GALAXY-GALAXY GRAVITATIONAL LENS SYSTEM

  • TAAK, YOON CHAN;IM, MYUNGSHIN
    • 천문학논총
    • /
    • 제30권2호
    • /
    • pp.401-403
    • /
    • 2015
  • We present the results of the analysis of FLS 1718+59, a galaxy-galaxy gravitational lens system in the Spitzer First Look Survey (FLS) field. A background galaxy ($z_s=0.245$) is severely distorted by a nearby elliptical galaxy ($z_l=0.08$), via gravitational lensing. The system is analysed by several methods, including surface brightness fitting, gravitational lens modeling, and spectral energy distribution fitting. From Galfit and Ellipse we measure basic parameters of the galaxy, such as the effective radius and the average surface brightness within it. gravlens yields the total mass inside the Einstein radius ($R_{Ein}$), and MAGPHYS gives us an estimate of the stellar mass inside $R_{Ein}$. By comparing these parameters, we confirm that the lens galaxy is an elliptical galaxy on the Fundamental Plane and calculate the stellar mass fraction inside $R_{Ein}$, and discuss the results with regards to the initial mass function.

밀착형 셔츠 설계를 위한 피부변형의 3차원 측정 (3D Measurement of Skin Deformation for the Design of a Tight-fitting Torso Pattern)

  • 박혜준;오염군;홍경희
    • 한국의류학회지
    • /
    • 제34권11호
    • /
    • pp.1824-1835
    • /
    • 2010
  • This study develops tight-fitting torso patterns for performance garments by taking into account the skin deformation generated directly from a 3D scan during arm movements. The skin deformation caused during the arm movements was scanned after scanning the skin surface stamped with a circle. To create a torso pattern in response to skin deformation, the ratio and direction of the skin deformation were first measured and analyzed so that the 3D human body could be segmented. After translating, the 3D skin surface was segmented into 2D flat patterns, designing nude patterns and reducing them as well as tight-fitting shirts: the skin deformation segment shirts were made in response to the skin deformation. The features of the fabric deformation and the garment pressure were analyzed and evaluated. In comparison with a clothing construction segment shirt, the diameter of the skin deformation segment shirt was smaller as well the ratios of extension and reduction was less. The garment pressure of the skin deformation segment shirt was higher. The skin deformation segment shirt fitted more tightly compared to a clothing construction segment shirt as it covered the body more thoroughly and was as comfortable as the other shirts with less fabric deformation made as the body moved.

Na+/MgO 촉매상에서 메탄의 Oxidative Coupling 반응의 속도론적 해석 (Kinetic Analysis of Oxidative Coupling of Methane over Na+/MgO Catalyst)

  • 서호준;선우창신;유의연
    • 공업화학
    • /
    • 제5권4호
    • /
    • pp.580-587
    • /
    • 1994
  • 고정층 상압 유통식 반응기에서 메탄의 전화율 10% 미만의 범위에서 $Na^+(50wt%)/MgO$ 촉매를 사용하여 반응온도 710, 730, 750, 770, $790^{\circ}C$에서 메탄과 산소의 분압을 변화시켜 가면서 메탄의 oxidative coupling반응을 수행하여 이산화탄소와 에탄의 생성속도를 구하고 curve fitting으로 속도식을 증명하였다. Langmuir-Hinshelwood, Rideal-Redox, Eley-Rideal형 반응 메카니즘 중에서 Langmuir-Hinshelwood형 반응 메카니즘이 실험 결과와 가장 잘 일치하였으며, $CH_3{\cdot}$의 생성에 관여하는 산소종은 촉매 표면의 $O_2{^-}$ 또는 $O_2{^{2-}}$으로 제시할 수 있었고, 이때의 활성화 에너지는 약 39.3kcal/mol이었다. 또한, curve fitting결과 $CO_x$을 생성하는 산소의 화학 양론계수 x는 약 1.5이었으며, 이로부터 $CH_3{\cdot}$의 일부가 표면산소에 의해서 산화반응을 거쳐 $CH_3O_2{\cdot}*$ 형성을 추측할 수 있었다.

  • PDF

일메나이트 중 철의 선택적 염화와 선광된 TiO2의 추가 염화반응에 대한 글로벌 피팅함수 (Global Fitting Functions for Kinetics of Fe-Selective Chlorination in Ilmenite and Successive Chlorination of Beneficiated TiO2)

  • 정동규;원용선;김용하;정은진;송덕용
    • 한국재료학회지
    • /
    • 제29권7호
    • /
    • pp.412-424
    • /
    • 2019
  • Global fitting functions for Fe-selective chlorination in ilmenite($FeTiO_2$) and successive chlorination of beneficiated $TiO_2$ are proposed and validated based on a comparison with experimental data collected from the literature. The Fe-selective chlorination reaction is expressed by the unreacted shrinking core model, which covers the diffusion-controlling step of chlorinated Fe gas that escapes through porous materials of beneficiated $TiO_2$ formed by Fe-selective chlorination, and the chemical reaction-controlling step of the surface reaction of unreacted solid ilmenite. The fitting function is applied for both chemical controlling steps of the unreacted shrinking core model. The validation shows that our fitting function is quite effective to fit with experimental data by minimum and maximum values of determination coefficients of $R^2$ as low as 0.9698 and 0.9988, respectively, for operating parameters such as temperature, $Cl_2$ pressure, carbon ratio and particle size that change comprehensively. The global fitting functions proposed in this study are expressed simply as exponential functions of chlorination rate(X) vs. time(t), and each of them are validated by a single equation for various reaction conditions. There is therefore a certain practical merit for the optimal process design and performance analysis for field engineers of chlorination reactions of ilmenite and $TiO_2$.

2차원 물체영상으로부터의 새로운 면 분할 및 특징표현기법 (New Surface Segmentation and Feature Description Technique from 2-D object image)

  • 이부형
    • 전자공학회논문지T
    • /
    • 제36T권4호
    • /
    • pp.1-8
    • /
    • 1999
  • 본 논문에서는 2차원 물체영상으로부터 면을 분할하고 분할된 면의 형태에 대한 정보를 추출하는 새로운 면 분할 및 표현 알고리즘을 제안한다. 본 논문에서 사용된 signature기법은 물체나 면의 중심을 구하고 중심점으로부터 반시계방향으로 360도 회전하면서 중심점과 경계선까지의 거리 D를 회전각도 ${\theta}$의 함수로 표현하는 방법으로, 물체영상에 적용했을 때 면의 위치에 따라 signature영역에서 하나의 회전각도에 대응하여 2개 이상의 거리값을 갖는 구간들이 존재하게 되며, 이들 거리값들은 각 구간 내에서 면의 개수 만큼의 폐곡선을 형성한다. 이와 같은 특징을 이용하여 면을 분할할 수 있으며, 분할된 면으로부터 꼭지점의 수, 모서리의 수, 오목특성 등과 같은 면의 특성을 얻을 수 있다. 제안된 알고리즘은 면의 일부분이 손실된 경우에도 curve fitting방법을 적용하여 손실된 부분을 용이하게 복구할 수 있다는 장점을 갖는다.

  • PDF