• 제목/요약/키워드: Arbitrary shape

검색결과 345건 처리시간 0.02초

Simple Recursive Approach for Detecting Spatial Clusters

  • Kim Jeongjin;Chung Younshik;Ma Sungjoon;Yang Tae Young
    • Communications for Statistical Applications and Methods
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    • 제12권1호
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    • pp.207-216
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    • 2005
  • A binary segmentation procedure is a simple recursive approach to detect clusters and provide inferences for the study space when the shape of the clusters and the number of clusters are unknown. The procedure involves a sequence of nested hypothesis tests of a single cluster versus a pair of distinct clusters. The size and the shape of the clusters evolve as the procedure proceeds. The procedure allows for various growth clusters and for arbitrary baseline densities which govern the form of the hypothesis tests. A real tree data is used to highlight the procedure.

T-접합 도파관의 수치적 해석 (Numerical Analysis of Waveguide T-Junction)

  • 천창율;정진교
    • 산업기술연구
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    • 제13권
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    • pp.25-31
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    • 1993
  • This paper presents an analysis of microwave device component. An H-Plane waveguide component with arbitrary shape is analyzed using finite element method(FEM) cooperated with boundary element method(BEM). The finite element method(FEM) is applied to the junction region and the boundary element method(BEM) to the waveguide region. For the application of BEM in the waveguide structure, a ray representation of the waveguide Green's function is used. The proposed technique was applied to the analysis of the waveguide inductive junction to compare the numerical result with the result of the mode matching technique. The comparison showed good agreements between the two results. Transmitted powers were also computed in T-junction waveguides for the various shape of the junction area.

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수평 및 수직방향 지진력을 받는 단층 래티스 돔의 동적 거동 특성에 관한 연구 (A Study on the Dynamic Characteristics of Single Layer Latticed Domes under Horizontal and Vertical Earthquake Motions)

  • 한상을;정명채;이진섭;이갑수;유용주
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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    • pp.151-158
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    • 1999
  • The single layer latticed domes have various behaviors with each geometrical shape and scale, and they are affected by vertical component as well as horizontal component of the dynamic load. And they represent very different earthquake responses under each ground acceleration compared with another structural systems. Generally, all of the members of latticed domes undergo three dimensional deflections if they are subjected to arbitrary one dimensional horizontal load under earthquake motions. And their response characteristics are very different to their shapes, rise/span ratios, and damping mechanisms. In this study the .earthquake response behavior is verified according to the factor of each shape, rise/span ratio, ana damping ratio of latticed domes, which undergo horizontal and vertical earthquake motions by numerical approaches.

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원형 단면 부품조립에서의 비전 기반 부품형상 및 상대오차 측정 (Vision-Based Part Shape and Misalignment Measurement in Cylindrical Peg-in-Hole Tasks)

  • 조형석;김진영
    • 제어로봇시스템학회논문지
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    • 제11권7호
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    • pp.615-620
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    • 2005
  • For successful deformable part assembly, information about its deformation as well as possible misalignment between the hole and its respective mating part are essential. Such information can be mainly acquired from visual sensors. In this paper, part deformation and misalignment in deformable cylindrical peg-in-hole tasks are measured by using a visual sensing system. First, a series of experiments to measure the position of an arbitrary point are performed. Next, an algorithm to measure misalignment and part shape as part deformation are presented, and a series of experiments on them are performed. Experimental results show that the proposed algorithms and the system are effective in measuring part deformation and misalignment.

Octree 모델에 근거한 고속 3차원 물체 인식 (Octree model based fast three-dimensional object recognition)

  • 이영재;박영태
    • 전자공학회논문지C
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    • 제34C권9호
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    • pp.84-101
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    • 1997
  • Inferring and recognizing 3D objects form a 2D occuluded image has been an important research area of computer vision. The octree model, a hierarchical volume description of 3D objects, may be utilized to generate projected images from arbitrary viewing directions, thereby providing an efficient means of the data base for 3D object recognition. We present a fast algorithm of finding the 4 pairs of feature points to estimate the viewing direction. The method is based on matching the object contour to the reference occuluded shapes of 49 viewing directions. The initially best matched viewing direction is calibrated by searching for the 4 pairs of feature points between the input image and the image projected along the estimated viewing direction. Then the input shape is recognized by matching to the projectd shape. The computational complexity of the proposed method is shown to be O(n$^{2}$) in the worst case, and that of the simple combinatorial method is O(m$^{4}$.n$^{4}$) where m and n denote the number of feature points of the 3D model object and the 2D object respectively.

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균열을 내재한 회전체의 에너지방출률 (The Energy Release Rate for Cracks in a Rotating Continuum)

  • 이태원
    • 대한기계학회논문집
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    • 제19권2호
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    • pp.330-337
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    • 1995
  • For a rotating body with cracks, the new energy release rate equation is presented. The derived equation is different from the other researcher's results. It is a path-independent integral which excluded the derivatives of displacements near the crack tip, thereby improving the numerical accuracy of the energy release rate computation. Moreover, as the equation was derived on basis of the energy principle and non-linear elasticity without assumptions, it can applied to the cracked body with arbitrary shape under elastic-plastic deformation. Several examples are treated to demonstrate the efficiency and accuracy of the proposed method compared to existing methods.

Aeroelastic model test of a 610 m-high TV tower with complex shape and structure

  • Ding, Quanshun;Zhu, Ledong
    • Wind and Structures
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    • 제25권4호
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    • pp.361-379
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    • 2017
  • In view of the importance of the wind-structure interaction for tall and slender structures, an aeroelastic model test of the 610m-high TV tower with a complex and unique structural configuration and appearance carried out successfully. The assembled aeroelastic model of the TV tower with complex shape and structure was designed and made to ensure the similarities of the major natural frequencies and the corresponding mode shapes. The simulation of the atmospheric boundary layer with higher turbulent intensity is presented. Since the displacement and acceleration responses at several measurement sections were directly measured in the wind tunnel test, a multi-mode approach was presented to indirectly estimate the displacement and acceleration responses at arbitrary structural floors based on the measured ones. It can be seen that it is remarkable for the displacement and acceleration responses of the TV tower in the two horizontal directions under wind loads and is small for the dynamic response of the torsional displacement and acceleration.

임의의 절점 추가에 의한 개선 유한요소법 (An Improved Finite Element Method by Adding Arbitrary Nodes in a Domain)

  • 김현규
    • 대한기계학회논문집A
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    • 제30권12호
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    • pp.1626-1633
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    • 2006
  • In the present paper, in the context of the meshless interpolation of a moving least squares (MLS) type, a novel method which uses primary and secondary nodes in the domain and on the global boundary is introduced, in order to improve the accuracy of solution. The secondary nodes can be placed at any location where one needs to obtain a better resolution. The support domains for the shape functions in the MLS approximation are defined from the primary nodes, and the secondary nodes use the same support domains. The shape functions based on the MLS approximation, in an integration domain, have a single type of a rational function, which reduces the difficulty of numerical integration to evaluate the weak form. The present method is very useful in an adaptive calculation, because the secondary nodes can be easily added and moved without an additional mesh. Several numerical examples are presented to illustrate the effectiveness of the present method.

다중 시점 영상 시퀀스를 이용한 강인한 행동 인식 (Robust Action Recognition Using Multiple View Image Sequences)

  • 아마드;이성환
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (B)
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    • pp.509-514
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    • 2006
  • Human action recognition is an active research area in computer vision. In this paper, we present a robust method for human action recognition by using combined information of human body shape and motion information with multiple views image sequence. The principal component analysis is used to extract the shape feature of human body and multiple block motion of the human body is used to extract the motion features of human. This combined information with multiple view sequences enhances the recognition of human action. We represent each action using a set of hidden Markov model and we model each action by multiple views. This characterizes the human action recognition from arbitrary view information. Several daily actions of elderly persons are modeled and tested by using this approach and they are correctly classified, which indicate the robustness of our method.

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초음파 진동 절삭공구 혼(tool horn)의 설계에 관한 연구 (A Study on the Design of Ultrasonic Vibration Cutting Tool Horn)

  • 강종표
    • 한국정밀공학회지
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    • 제8권3호
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    • pp.55-63
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    • 1991
  • Transforming small ultrasonic energy into large mechanical energy is the essential feature of ultrasonic vibration in various application fields. This energy amplification can be obtained by achieving resonance condition between booster or tool horn and transducer. When it has uniform section with small sectional area, one dimensional analysis provides good estimation of the natural frequency of the horn. But, for arbitrary shape of horn, one dimensional analysis can no longer be applied. At present, designing tool horn whose natural frequency is identical to that of transducer requires serveral stages of trial and error in actual manufacturing process. In this paper, frequency analysis program is developed to easily predict the natural frequency of ultrasonic vibration cutting tool with axisymmetry and 3- dimensional shape using finite element method.

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