• Title/Summary/Keyword: polygonal model

Search Result 80, Processing Time 0.025 seconds

Determination of Cutting Direction for Tool Path Minimization in Zigzag Milling Operation (Zigzag 밀링가공에서 공구경로 최소화를 위한 가공방향 결정방법)

  • Kim, Byoung-Keuk;Park, Joon-Young
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.27 no.1
    • /
    • pp.69-88
    • /
    • 2001
  • In the zigzag milling operation, an important issue is to design a machining strategy which minimizes the cutting time. An important variable for minimization of cutting time is the tool path length. The tool path is divided into cutting path and non-cutting path. Cutting path can be subdivided into tool path segment and step-over, and non-cutting path can be regarded as the tool retraction. We propose a new method to determine the cutting direction which minimizes the length of tool path in a convex or concave polygonal shape including islands. For the minimization of tool path length, we consider two factors such as step-over and tool retraction. Step-over is defined as the tool path length which is parallel to the boundary edges for machining area and the tool retraction is a non-cutting path for machining any remaining regions. In the determination of cutting direction, we propose a mathematical model and an algorithm which minimizes tool retraction length in complex shapes. With the proposed methods, we can generate a tool path for the minimization of cutting time in a convex or concave polygonal shapes including islands.

  • PDF

3D Mesh Watermarking Using PEGI (PEGI를 이용한 3D 메쉬 워터마킹)

  • 이석환;김태수;김병주;권기룡;이건일
    • Proceedings of the Korea Multimedia Society Conference
    • /
    • 2003.05b
    • /
    • pp.263-266
    • /
    • 2003
  • 본 논문에서는 패치별 EGI 분포를 이용한 3D 다각형 메쉬 모델 (polygonal mesh model) 워터마킹 알고리즘을 제안하였다 제안한 알고리즘에서는 기하학적 변형에 견고하기 위하여 3D 메쉬 모델을 6개 패치로 분할한다. 그리고 위상학적 변형에 견실한 특성을 가지는 EGI 분포를 각 패치별로 구한다. 그리고 동일한 워터마크 비트열을 각 패치의 EGI 분포 중에서 길이가 큰 면체에 투영된 메쉬 법선 벡터들에 각각 삽입한다. 본 논문에서 제안한 워터마킹 알고리즘의 성능 평가를 위한 모의 실험에서 워터마크가 삽입된 모델의 비가시성 및 다양한 공격에 대한 견고성이 우수함을 확인하였다.

  • PDF

Maximal United Utility Degree Model for Fund Distributing in Higher School

  • Zhang, Xingfang;Meng, Guangwu
    • Industrial Engineering and Management Systems
    • /
    • v.12 no.1
    • /
    • pp.36-40
    • /
    • 2013
  • The paper discusses the problem of how to allocate the fund to a large number of individuals in a higher school so as to bring a higher utility return based on the theory of uncertain set. Suppose that experts can assign each invested individual a corresponding nondecreasing membership function on a close interval I according to its actual level and developmental foreground. The membership degree at the fund $x{\in}I$ is called utility degree from fund x, and product (minimum) of utility degrees of distributed funds for all invested individuals is called united utility degree from the fund. Based on the above concepts, we present an uncertain optimization model, called Maximal United Utility Degree (or Maximal Membership Degree) model for fund distribution. Furthermore, we use nondecreasing polygonal functions defined on close intervals to structure a mathematical maximal united utility degree model. Finally, we design a genetic algorithm to solve these models.

The Voxelization of Surface Objects using File handling and Parallel Processing (파일 및 병렬 처리를 이용한 표면 객체의 복셀화 방안)

  • Lee, Su-Yeol;Ahn, Eun-Young
    • Journal of Korea Multimedia Society
    • /
    • v.18 no.2
    • /
    • pp.113-119
    • /
    • 2015
  • This paper suggests an efficient method for making the high resolution volexlized model from a polygonal surface object. A distinctive strength of the method is that a surface model, however complex one, can be transformed and formed an absolute voxelized solid model in a various resolution. It caused by producing a voxel by integrating the informations for the candidated voxels separately detected in each 3D-axial direction. This method reduces memory complexity by storing the information of voxels that is produced during the 2-phase volxelization(surface and inner voxelization) of a surface object in a binary file. For the computational efficiency, a parallel process using multi-threads is applied in the process of the inner voxelization, it also takes advantage of time complexity.

Nonlinear hysteretic behavior of hybrid beams consisted of reinforced concrete and steel (철근콘크리트와 철골조로 이루어진 혼합구조보의 비선형 이력거동에 관한 연구)

  • 이은진;김욱종;문정호;이리형
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1999.10a
    • /
    • pp.19-26
    • /
    • 1999
  • This paper describes an analytical study on nonlinear hysteretic behavior of hybrid steel beam with reinforced concrete ends. Two types of analytical model, Polygonal Model[PM] and Hybrid Model[HM], were used to represent the nonlinear hysteretic behavior PM used three parameters, HM used an additional parameter to consider the initial stiffness reduction. The parameters calibrated comparing the hysteretic performance obtained from experiments. The purpose of this study is to develop an analytical model which can take into account the initial stiffness reduction of the hybrid members and to represent exactly the hysteretic performance for the hybrid structures with RC and steel. The analytical study showed PM tends to overestimate initial stiffness and strength. However, HM which is capable to consider the initial stiffness reduction gave good prediction on initial stiffness, post-yielding performance, strength, pinching response and so on.

  • PDF

Representation of Three-dimensional Polygonal Mesh Models Using Hierarchical Partitioning and View dependent Progressive Transmission (계층적 분할을 이용한 삼차원 다각형 메쉬 모델의 표현 및 인간 시점에 따른 점진적 전송 방법)

  • 김성열;호요성
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.40 no.6
    • /
    • pp.132-140
    • /
    • 2003
  • In this paper, we propose a new scheme for view-dependent transmission of three-dimensional (3-D) polygonal mesh models with hierarchial partitioning. In order to make a view-dependent representation of 3-D mesh models, we combine sequential and progressive mesh transmission techniques. By setting higher priorities to visible parts than invisible parts, we can obtain good qualify of 3-D models in a limited transmission bandwidth. In this paper, we use a multi -layer representation of 3-D mesh models based on hierarchical partitioning. After representing the 3-D mesh model in a hierarchical tree, we determine resolutions of partitioned submeshes in the last level. Then, we send 3-D model data by view-dependent selection using mesh merging and mesh splitting operations. By the partitioned mesh merging operation, we can reduce the joint boundary information coded redundantly in the partitioned submeshes. We may transmit additional mesh information adaptively through the mesh spritting operation.

Recognition and positioning of occuluded objects using polygon segments (다각형 세그먼트를 이용한 겹쳐진 물체의 인식 및 위치 추정)

  • 정종면;문영식
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • v.33B no.5
    • /
    • pp.73-82
    • /
    • 1996
  • In this paper, an efficient algorithm for recognizing and positioning occuluded objects in a two-dimensional plane is presented. Model objects and unknown input image are approximated by polygonal boundaries, which are compactly represented by shape functions of the polygons. The input image is partitioned into measningful segments whose end points are at the locations of possible occlusion - i.e. at concave vertices. Each segment is matched against known model objects by calculating a matching measure, which is defined as the minimum euclidean distance between the shape functions. An O(mm(n+m) algorithm for computing the measure is presentd, where n and m are the number of veritces for a model and an unknown object, respectively. Match results from aprtial segments are combined based on mutual compatibility, then are verified using distance transformation and translation vector to produce the final recognition. The proposed algorithm is invariant under translation and rotation of objects, which has been shown by experimental results.

  • PDF

LOD Representation for the Realtime Simulation of Flocking Objects (군집행동개체의 실시간 애니메이션을 위한 단계별 상세화 표현)

  • Cho S.H.;Chai Y.H.
    • Korean Journal of Computational Design and Engineering
    • /
    • v.10 no.5
    • /
    • pp.339-348
    • /
    • 2005
  • In this paper, LOD (Level Of Detail) for flocking, which is the real-time simulation on the movement or some groups such as fighting soldiers, moving fishes and flying birds, is presented. And a flocking LOD algorithm that uses factors such as the speed of fish, direction, and shape is proposed. Model data is modified for LOD in advance, so as to reduce strange edge collapse and unwanted holes. The errors of model data were identified by transforming polygonal model into octree-based cubes and revised before rendering. Experimental results show that the proposed algorithm considering flocking characteristics shows fast frame rates as compared with the conventional continuous LOD algorithm.

Analysis of plane frame structure using base force element method

  • Peng, Yijiang;Bai, Yaqiong;Guo, Qing
    • Structural Engineering and Mechanics
    • /
    • v.62 no.1
    • /
    • pp.11-20
    • /
    • 2017
  • The base force element method (BFEM) is a new finite element method. In this paper, a degenerated 4-mid-node plane element from concave polygonal element of BFEM was proposed. The performance of this quadrilateral element with 4 mid-edge nodes in the BFEM on complementary energy principle is studied. Four examples of linear elastic analysis for plane frame structure are presented. The influence of aspect ratio of the element is analyzed. The feasibility of the 4 mid-edge node element model of BFEM on complementary energy principles researched for plane frame problems. The results using the BFEM are compared with corresponding analytical solutions and those obtained from the standard displacement finite element method. It is revealed that the BFEM has better performance compared to the displacement model in the case of large aspect ratio.

(Algorithm for Recognizing Bulb in Cluster) (계기판 벌브 인식 알고리즘)

  • 이철헌;설성욱;김효성
    • Journal of the Institute of Electronics Engineers of Korea TE
    • /
    • v.39 no.1
    • /
    • pp.37-45
    • /
    • 2002
  • This paper proposes new features for recognizing telltale bulb in a cluster. A typical feature employed in model-based pattern recognition is polygonal approximation points of object. But recognition using these dominant points has many mismatching counts in small model such as telltale bulb. To reduce mismatching counts, proposed features are the circle distribution of object pixel and the ratio of distance from center to boundary in object. This Paper also proposes new decision function using three features. In simulation result, we make a comparison mismatching counts between recognition using dominant points and the new recognition algorithm using three features.