• 제목/요약/키워드: Surface Fitting

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

  • Taak, Yoon Chan;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.36.2-36.2
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    • 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.

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

  • 정영욱
    • Proceedings of the Optical Society of Korea Conference
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    • 1990.02a
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    • pp.177-181
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    • 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.

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The Confidence Regions for the Logistic Response Surface Model

  • Cho, Tae-Kyoung
    • Journal of Korean Society for Quality Management
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    • v.25 no.2
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    • pp.102-111
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    • 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.

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

  • Kim, Jin-Kwang
    • Journal of Power System Engineering
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    • v.21 no.6
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    • pp.86-93
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    • 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
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    • 1992.10b
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    • pp.526-531
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    • 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.

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

  • TAAK, YOON CHAN;IM, MYUNGSHIN
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.401-403
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    • 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.

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

  • Park, Hye-Jun;Wu, Yanjun;Hong, Kyung-Hi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.11
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    • pp.1824-1835
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    • 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.

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

  • Seo, Ho-Joon;Sunwoo, Chang-Shin;Yu, Eui-Yeon
    • Applied Chemistry for Engineering
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    • v.5 no.4
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    • pp.580-587
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    • 1994
  • The oxidative coupling of methane was studied kinetically using $Na^+(50wt%)/MgO$ catalyst at 710, 730, 750, 770 and $790^{\circ}C$ in a fixed bed flow reactor at the atmospheric pressure under differential conversion conditions. Through curve fitting, it was found that the Langmuir-Hinshelwood type mechanism was fitted to this reaction rather than Rideal-Redox type or Eley-Rideal type mechanism. Therefore, it was proposed that the $O_2{^-}$ or $O_2{^{2-}}$ species on the surface was related to the production of $CH_3{\cdot}$. The estimated activation energy of $CH_3{\cdot}$ production was about 39.3kcal/mol. Moreover, as the result of curve fitting, the stoichiometric coefficient of $O_2$ for the production of $CH_3{\cdot}$ to produce $CO_x$was approximately 1.5. Accordingly, it could be concluded that the $CH_3O_2{\cdot}*$ was prouduced through the partial oxidation of $CH_3{\cdot}$ with the surface oxygen.

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

  • Chung, Dong-Kyu;Won, Yong Sun;Kim, Yong-Ha;Jung, Eun-Jin;Song, Duk-Yong
    • Korean Journal of Materials Research
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    • v.29 no.7
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    • pp.412-424
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    • 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 $TiO_2$.

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

  • Lee, Boo-Hyoung
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.4
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    • pp.1-8
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    • 1999
  • This paper presents a new algorithm for surface segmentation and feature description. In the first stage of proposed algorithm, the signature of an edge image of object is extracted. The signature technique represents a surface using the distance from the mass center to the boundary of the image as a function of angle rotating counterclockwise. If there exists a range in the angle axis where more than two signatures form a closed curve, we can conclude there is a surface inside the range. Using this feature of the signature, surface can be segmented. The surface features such as number of vertices, number of edges, convex and type of surface can also be extracted from segmented surfaces. This algorithm has distinguished advantages; it can easily recover the lost part in the edge image using the curve fitting method; it extracts surface features correctly regardless of the rotation of the surface in 3-D space.

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