• Title/Summary/Keyword: geometrical form

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New mathematical approach to calculate the geometrical efficiency using different radioactive sources with gamma-ray cylindrical shape detectors

  • Thabet, Abouzeid A.;Hamzawy, A.;Badawi, Mohamed S.
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1271-1276
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    • 2020
  • The geometrical efficiency of a source-to-detector configuration is considered to be necessary in the calculation of the full energy peak efficiency, especially for NaI(Tl) and HPGe gamma-ray spectroscopy detectors. The geometrical efficiency depends on the solid angle subtended by the radioactive sources and the detector surfaces. The present work is basically concerned to establish a new mathematical approach for calculating the solid angle and geometrical efficiency, based on conversion of the geometrical solid angle of a non-axial radioactive point source with respect to a circular surface of the detector to a new equivalent geometry. The equivalent geometry consists of an axial radioactive point source with respect to an arbitrary elliptical surface that lies between the radioactive point source and the circular surface of the detector. This expression was extended to include coaxial radioactive circular disk source. The results were compared with a number of published data to explain how significant this work is in the efficiency calibration procedure for the γ-ray detection systems, especially in case of using isotropic radiating γ-ray sources in the form of point and disk shapes.

A Study on the Ornaments Design of Jewels by CAD System (CAD를 활용한 귀금속 장신구의 DESIGN에 관한 연구)

  • 김은주;최덕환
    • Journal of the Korean Society of Costume
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    • v.41
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    • pp.23-47
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    • 1998
  • Ornaments is a province of the fashion. It usually express noble metals and jewel's adorn-ment as the symbol of status and riches for a long time. The ornament design of Jewels drawing project and a product by computer are increased development and as exertion as a realization of automation. Through the use of CAD software(Auto CAD R 13 & Jewel CAD) \circled1 A design development of the jewels in industrial society \circled2 A metals art & design on the dress and it's ornaments - Study about application of principle(liberal curve, arrangement of repeated form, gradual unity, rhythmical harmony) Although Auto CAD don't various expression of Jewels than a Jewel CAD, formative.scientific.funtional development of geometrical form is free. That is (to say), geometrical form is given much weigh in the general CAD, but Jewel CAD made concentrate software on the jewels design for the expression of liberal form. The CAD/CAM software for jewellery program is composed of main menu, icons, hotkeys. Changing form is derived from a definite point, curve elements of a drawing. \circled1 3-Dimensional \circled2 Easy and flexible \circled3 Bulit-in and self created library \circled4 From simple wire frame to full color images. As a CAD can practice all the creation activity effectively, from Design & Drafting Software to Rendering generally can present precise results. A point of view of the connection the scientist and art, this practicableness of CAD have a lot of possiblity of development. That will do much for the related fields of industry. Consequently, subjective intension of a creator & humanity with value plays role in practical application of the design.

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A Study on Ex-Formal Expression Observed in Space.Form of Korean Modern Architecture (한국 현대건축의 공간.형태에서 나타난 탈정형적 표현에 관한 연구)

  • Jang, Hoon-Ick
    • Journal of The Korean Digital Architecture Interior Association
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    • v.9 no.3
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    • pp.85-93
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    • 2009
  • In this study, the ex-formal expressions observed in space form of Korean modern architecture are distributed for characteristic analysis based on the period and type. The result of the study is certified by the work analysis and the result is as follows. Initially, due to the limited materials and influence of western brutalism, the works developed during 1960~70 tend to be plastic and contain expressionism. Around 1980's, the works tend to show forms of amusement and popularity. In 1990's the works show significance in deconstructive expression. From after 2000, ecological concept of architecture was introduced and organic expression started increasing Secondly, the ex-formal expressions are found to be in four different types. The organic expression is shown regardless of the period. In modern days, not only the physical properties of materials, but also the ecological concept is combined with the organic expression and is in increase. The plural expression started appearing after the 1980's and the sculptural diversity is enhancing with the addition of decorative factors or modification of geometrical form. The ex-construction and deconstructive expression show significance in some characteristics such as folding, inclination, and geometrical explosion. The free form and nonlinear expression tend to increase dramatically based on the development of structure technology as well as execution and introduce of the digital design technique.

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Sample Size Determination and Evaluation of Form Errors

  • Chang, Sung Ho;Kim, Sunn Ho
    • Journal of Korean Society for Quality Management
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    • v.22 no.3
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    • pp.85-98
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    • 1994
  • In current coordinate measuring machine practice, there are no commonly accepted sample sizes for estimating form errors which have a statistical confidence. Practically, sample size planning is important for the geometrical tolerance inspection using a coordinate measuring machine. We determine and validate appropriate sample sizes for form error estimation. Also, we develop form error estimation methods with certain confidence levels based on the obtained sample sizes in various form errors: straightness, flatness, circularity, and cylindericity.

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GUI for Initial Proncipal Dimensions and Hull form factor Inference using Neurofuzzy System (뉴로퍼지 시스템을 이용한 초기 주요 치수 및 선형 요소 추론의 GUI 구현)

  • 김현철;이충렬;김수영
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.10a
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    • pp.237-240
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    • 1997
  • This paper is to arrange systematically the geometrical & physical data for real ships and to develop the graphic user interface program for initial hull design using NFHFD, which save the distributed information about hull form database and can output multi-variables.

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A study on Abstract Expression Showed in Modern Art and Modern Costume (현대예술과 현대복식에 나타난 추상적 표현에 관한 연구)

  • Lee, Eun-Young
    • The Journal of Natural Sciences
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    • v.4
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    • pp.221-231
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    • 1991
  • We have thought artistic charactics of modern form is abstract expression and purity and unity sight. Specially, modern sculpture form has strict geometrical form as showed in primitive art. In this circumstances, modern costume has stylized more artistic form in pure sight. Artistic characteristics showed in those collections are picturesque in material and sculpture in shillouette. Picturesque material pointed in decoretive function and simple shillouette pointed in sculpturesque body in modern costume.

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Mesh topological form design and geometrical configuration generation for cable-network antenna reflector structures

  • Liu, Wang;Li, Dong-Xu;Jiang, Jian-Ping
    • Structural Engineering and Mechanics
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    • v.45 no.3
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    • pp.411-422
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    • 2013
  • A well-designed mesh shape of the cable net is of essential significance to achieve high performance of cable-network antenna reflectors. This paper is concerned with the mesh design problem for such antenna reflector structure. Two new methods for creating the topological forms of the cable net are first presented. Among those, the cyclosymmetry method is useful to generate different polygon-faceted meshes, while the topological mapping method is suitable for acquiring triangle-faceted meshes with different mesh grid densities. Then, the desired spatial paraboloidal mesh geometrical configuration in the state of static equilibrium is formed by applying a simple mesh generation approach based on the force density method. The main contribution of this study is that a general technical guide for how to create the connectivities between the nodes and members in the cable net is provided from the topological point of view. With the new idea presented in this paper, multitudes of mesh configurations with different net patterns can be sought by a certain rule rather than by empiricism, which consequently gives a valuable technical reference for the mesh design of this type of cable-network structures in the engineering.

Analysis of Jacobian and Singularity of Planar Parallel Robots Using Screw Theory (스크류 이론을 이용한 평면형 병렬로봇의 자코비안 및 특이점 해석)

  • Choi, Jung-Hyun;Lee, Jeh-Won;Lee, Hyuk-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.11
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    • pp.1353-1360
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    • 2012
  • The Jacobian and singularity analysis of parallel robots is necessary to analyze robot motion. The derivations of the Jacobian matrix and singularity configuration are complicated and have no geometrical earning in the velocity form of the Jacobian matrix. In this study, the screw theory is used to derive the Jacobian of parallel robots. The statics form of the Jacobian has a geometrical meaning. In addition, singularity analysis can be performed by using the geometrical values. Furthermore, this study shows that the screw theory is applicable to redundantly actuated robots as well as non-redundant robots.

A Study on the Geometrical Expression Shown in the Architecture of Guarino Guarini - Focusing on the Analysis of Spatial Form in Guarino Guarini's Church of San Lorenzo- (구아리노 구아리니 건축에 나타난 기하학적 표현에 관한 연구 - 그의 산 로렌쪼 성당의 공간형태 분석을 중심으로 -)

  • Han Myoung-Sik
    • Korean Institute of Interior Design Journal
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    • v.14 no.3 s.50
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    • pp.95-102
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    • 2005
  • Guarini's architectural contribution has simply focused on the dome structure that has been known to us; however, his geometric and spatial construction has been overlooked so far Through this study, it has been demonstrated that the dome structure was simply part of geometrical forms that Guarini wanted to express ultimately and it functioned as a geometrical element such as the network combined with the entire spatial structure. The purpose of this study is to reevaluate Guarini's architectural thought by means of investigating the ultimate principles of spatial composition appeared in the late Baroque architecture through the analysis of the principles of spatial composition and organized formal Idioms by Guarini's geometrical concepts. Besides, it has been assumed that such geometrical concepts by Guarini's mathematical proportion and his reiteration and change of diagrams could be clearly distinguished from the Classical geometry in the Renaissance and Guarini. suggested a way to create a new space through more active and amusing application and transformation. In this aspect, Guarini's principles of geometric composition will be one of the role models that need to be seriously reconsidered in chaotic reality of modern architecture.

Fingerprint Identification Using Voronoi Diagram (보르노이 다이어그램을 이용한 지문정합 알고리즘)

  • 김승훈;최태영
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.301-304
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    • 2003
  • This raper propose a matching algorithm using voronoi diagram for rotation and translation invariant fingerprint identification. The proposed algorithm extracts geometrical structures that ate derived from voronoi diagram of a fingerprint image. Then distances and angles are extracted from the geometrical structure and saved indexing form for fingerprint matching. Experimental results show that the proposed algorithm invariant to fingerprint rotation and translation requirements and matching time.

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