• 제목/요약/키워드: geometrical shapes

검색결과 168건 처리시간 0.026초

Estimation of missing landmarks in statistical shape analysis

  • Sang Min Shin;Jun Hong Kim;Yong-Seok Choi
    • Communications for Statistical Applications and Methods
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    • 제30권1호
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    • pp.37-48
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    • 2023
  • Shape analysis is a method for measuring, describing and comparing the shape of objects in geometric space. An important aspect is to obtain Procrustes distance based on least square method. We note that the shape is all the geometrical information that remains when location, scale and rotational effects are filtered out from an object. However, and unfortunately, when we cannot measure some landmarks which are some biologically or geometrically meaningful points of any object, it is not possible to measure the variation of all shapes of an object, including that of the incomplete object. Hence, we need to replace the missing landmarks. In particular, Albers and Gower (2010) studied the missing rows of configurations in Procrustes analysis. They noted that the convergence of their approach can be quite slow. In this study, alternatively, we derive an algorithm for estimating the missing landmarks based on the pre-shapes. The pre-shape is invariant under the location and scaling of the original configuration with the centroid size of the pre-shape being one. Therefore we expect that we can reduce the amount of total computing time for obtaining the estimate of the missing landmarks.

마리오 보타 작품에서 보여지는 실내공간의 특성에 관한 연구 - 공공건물을 중심으로 - (A Study on the Characteristics of Interior Space in the Works of Mario Botta -Focused on Public Buildings-)

  • 김용립
    • 한국실내디자인학회논문집
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    • 제28호
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    • pp.33-43
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    • 2001
  • Mario Botta is one of the modern architects who established his own architectural world on the basis of the architectural spirit of Modernism. His works have been a good theme not only for those who study architecture but also for those who study the relationship between architecture and the surrounding environment and there have been many published papers and reports on his works. However, most of them stressed on the importance of the external appearance of architecture or on the relationship between architecture and the surrounding environment. There have been relatively few studies that have dealt intensively with interior space. The aim of this study is to find the characteristics of interior space in public buildings that were designed by Botta and to analyze them from the view design principles and design elements. For this purpose, the five most important public buildings were selected and the public space of the building like the central hall, the lobby, and the foyer were analyzed. Through this study, the followings are realized. A) Spatial features: $\circled1$ Refined and graceful interiors where the principle of symmetry was applied, $\circled2$ Centripetal interiors surrounded by thick walls, $\circled3$ Interior design lit by skylights above the central area, B) Formative features: $\circled1$ The shapes of the external and internal spaces are identical, $\circled2$ Simple geometrical shapes were applied in defining the shapes of internal spaces, $\circled3$ Skylights and light wells were combined and were utilized as form elements, $\circled4$ Architectural vocabularies of Corbusier such as stairs, round pillars, and bridges were developed and utilized, $\circled5$ Utilized the geometry that resembled his architecture as a form element to the furniture, C) material pattern features: $\circled1$ Plainly expressed the patterns of bricks that appear in the course of construction, $\circled2$ Made and used horizontal stripe patterns using stones of different colors.

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기하학적 방법을 이용한 초기 박판형상 추정 (Prediction of Initial Blank Shape by Using Geometrical Method)

  • 정동원;이상제
    • 한국해양공학회지
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    • 제13권3호통권33호
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    • pp.12-20
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    • 1999
  • In this paper, method for mapping a three-dimensional shape into the two-dimensional plane will be introduced. This method is referred to geometric modelling and means a transformation between the flat sheet and final surface. The initial blank shape represents the original configuration of the final shape formed into three dimensional surface. The initial constant constant area mapping hypothesis was used in this paper. This technique will be applied to the basic data for an interactive computer design capable of dealing with typical stamping process, including deep parts and complex shapes.

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합금강 표면결함의 잔류누설자장에 관한 연구 (A Study on the Residual Leakage Field in the Surface Defect of Alloy Steel)

  • 이인선;박은수
    • 비파괴검사학회지
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    • 제9권1호
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    • pp.22-29
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    • 1989
  • The important point of MPI is the analysis of leakage field in the defective regions. The analysis of leakage field depends on many factors such like geometry and character of defect. In general the calculation of magnetic leakage fields arising from such defects presents an extremely complicated mathematical problem and is practically insoluable, since the inhomogeneities have complex geometrical shapes and may differ in physical nature. Therefore, this paper describes Hall probe measurements of residual leakage field around artificial flaws in alloy steel bar, and shows how the results to recent developments in 2D dipole and analytic models of the magnetic field defect interaction.

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제동시간이 통풍형 디스크 브레이크 시스템의 건전성에 미치는 영향 (Influence of the Braking Time on the Soundness of Ventilated Disc Brake Systems)

  • 곽우경;홍창기;김윤제
    • 자동차안전학회지
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    • 제8권1호
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    • pp.7-12
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    • 2016
  • In order to analyze the soundness of ventilated disc brake systems, numerical study was performed with various vane shapes. In particular, two different vane type, and the braking time from 3.0 s to 4.5s with the interval of 0.5s were considered. Transient temperature distributions on the ventilated disc brake assembly were calculated using ANSYS CFX ver. 16.1. To elucidate the soundness of ventilated disc brake systems, moreover, the heat transfer coefficients were evaluated. Results were graphically depicted with different geometrical vane configurations and braking time.

20세기 초반 러시아 아방가르드 미술가의 의상디자인 활동 - 구성주의를 중심으로 - (The fashion Design of the Avantgarde Artists during the Early Twentieth Century - Focus on the Constructivism -)

  • 오선희
    • 복식
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    • 제51권3호
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    • pp.59-73
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    • 2001
  • This paper is to examine the meaning of activities of a number of artists who belong to Constructivism in the fashion design area during early twentieth century. After Russian Revolution, the artists like Nadeshda Lamanowa, Ljubow Popowa and Warwara Stepanova decided to devote to practical art area for many People. It's very meaningful for them to jump into real work places like a textile mill and a clothing workshop instead of staying in fine art area. Constructivism is more related to social interest rather than individual thing. The artists tried to apply their modeling principles in fine art to dress making. We can see the geometrical lines and shapes and big differences In colors and material in their dress. The artists had also shown personal tastes to dress works. This idea of togetherness with their time and even to create the style of it. was very renovative at that time and gave an influence on the later styles.

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차량 부밍 소음 저감을 위한 중공축 개발 (Development of Tubular Shaft for Reduction of Booming Noise in Vehicle Interior)

  • 고강호;국형석;이재형
    • 한국자동차공학회논문집
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    • 제10권1호
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    • pp.203-208
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    • 2002
  • In order to reduce the booming noise caused by first bending mode of a drive shaft, this paper proposes a simulation program for prediction of the bending mode frequency of any tubular shaft. This program consists of a pre-processor for modeling of geometrical shape of the drive shaft with boundary conditions of various joints, a processor for constructing of global finite element matrices using beam elements and an eigen-solver based on MATLAB program. Using this simulation program, the effective and accurate FE model far a shaft attached to vehicle can be obtained by aid of database for stiffness of each joint. Thus the resonance frequencies and mode shapes of a shaft can be calculated accurately. Because the effect of the resonance on interior noise can be verified, more improved shaft will be proposed at the early stage of design.

토폴로지 정보가 없는 CAD 곡면의 꺾인 모서리 탐색 (Convex Sharp Edge Detection of CAD Surfaces without Topology)

  • 박정환;이정근
    • 한국정밀공학회지
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    • 제17권2호
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    • pp.73-79
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    • 2000
  • The part-surface of mold or stamping-dies consists of a compound surface which consists of lots of composite surfaces, and may have various types of feature shapes including convex sharp edge (CSE). Those CSE features should be considered with care in machining the surface, which necessitates extraction of CSE curves on a compound surface. This work can be done rather easily for a solid model which has a complete topology information. In case of the compound surface without topology information, however, such CSE curves must be gathered through some geometrical calculations paying much computation time. In the paper, extracting CSE curves by the construction of a CSE region-map which can reduce time, and detecting various common edge types are presented.

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드릴링 자유도를 가진 매크로 삼각형 요소를 이용한 평면 응력 해석 (Construction of a macro plane stress triangle element with drilling d.o.f.'s)

  • 엄재성;김영태;이병채
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.886-889
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    • 2004
  • A simple macro triangle with drilling d.o.f.'s is proposed for plane stress problems based on IET(Individual element test) and finite element template. Three-node triangular element has geometrical advantages in preprocessing but suffers from bad performance comparing to other shapes of elements -especially quadrilateral. Main purpose of this study is to construct a high-performance linear triangular element with limited supplementary d.o.f.'s. A triangle is divided by three sub-triangles with drilling d.o.f.'s. The sub-triangle stiffness come from IET passing force-lumping matrix, so this assures the consistency of the element. The macro element strategy takes care of the element‘s stability and accuracy like higher-order stiffness in the F.E. template. The resulting element fits on the uses of conventional three-node. Benchmark examples show proposed element in closed form stiffness from CAS (Computer algebra system) gives the improved results without more computational efforts than others.

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3D 프린팅에 의한 충진물 제조 및 성능평가 (Manufacturing of Packing Materials for 3D Printing and Evaluation of their Performances)

  • 이화영;최영민;홍연기
    • 융복합기술연구소 논문집
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    • 제5권2호
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    • pp.33-36
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    • 2015
  • In this paper, the development history of random packings for several generations was briefly introduced. We demonstrate the application of 3D printing to the fabrication of Pall rings, directly using computer aided design (CAD) models. The CAD was used to design Pall rings with different number of blades. The models were then printed by using UV curing of acrylonitrile-butadiene-styrene (ABS) resins. The results show that 3D printing is a promising method for producing precisely controlled packing materials. It is also expected that 3D printing is helpful for the fundamental studies of highly efficient packing materials with complex geometrical shapes.