• 제목/요약/키워드: topological dimensions

검색결과 17건 처리시간 0.019초

ON THE PRIME SPECTRUM OF A MODULE OVER A COMMUTATIVE NOETHERIAN RING

  • Ansari-Toroghy, H.;Sarmazdeh-Ovlyaee, R.
    • 호남수학학술지
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    • 제29권3호
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    • pp.351-366
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    • 2007
  • Let R be a commutative ring and let M be an R-module. Let X = Spec(M) be the prime spectrum of M with Zariski topology. Our main purpose in this paper is to specify the topological dimensions of X, where X is a Noetherian topological space, and compare them with those of topological dimensions of $Supp_{R}$(M). Also we will give a characterization for the irreducibility of X and we obtain some related results.

CAD시스템을 위한 컴퓨터원용 설계도면검도 -기계부품도의 치수검도방법 - (Computer Aided Drawing Check for CAD Systems A Method for the Checking of Dimensions in Mechanical Part Drawings)

  • 이성수
    • 한국CDE학회논문집
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    • 제1권2호
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    • pp.97-106
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    • 1996
  • Existing CAD systems do not provide advanced functions for automatic checking design and drafting errors in mechanical drawings. If the knowledge of checking in mechanical ddrsfting can be implemented into computers, CAD systems could automatically check for design and drafting errors. This paper describes a method for systematic checking of dimension errors. such as deficiency and/or redundancy of dimension input-errors in dimension figures and symbols, etc. The logic for finding dimensional errors is written by using a proccedural language. A geometric model and a topological-graph model are used in this method. Checking for deficiency and redundancy of dimensions is based upon graph Theory.

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Three Dimensional Spatial Object Model

  • Lee, Sun-Jun;Kim, Sang-Ho;Lee, Seong-Ho;Chung, Jae-Du;Ryu, Keun-Ho
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.885-890
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    • 2002
  • As Geographic Information Systems represents three-dimensional topological Information, the systems provide accurate and delicate services for user. In order to execute three-dimensional topological operations, a dimensional transformation and heterogeneous spatial models should be used. However, the existing systems that use the dimensional transformation and the heterogeneous models, are not only difficult to operate the spatial operators, but also happened to support non- interoperability. Therefore, in order to support the spatial operation as well as interoperability between dimensions, we propose three-dimensional spatial operators for the proposed models. We defined the three-dimensional spatial operators prior to designing the proposed model. We also implemented the operators of proposed model and evaluated the implemented model on the component environment. Finally, the proposed model is able to not only support interoperability among systems but also execute spatial queries efficiently on three-dimensional spatial objects.

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선택저장 자료구조를 이용한 복합다양체 모델의 불리언 작업 (Boolean Operation of Non-manifold Model with the Data Structure of Selective Storage)

  • 유병현;한순흥
    • 한국CDE학회논문집
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    • 제5권4호
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    • pp.293-300
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    • 2000
  • The non-manifold geometric modeling technique is to improve design process and to Integrate design, analysis, and manufacturing by handling mixture of wireframe model, surface model, and solid model in a single data structure. For the non-manifold geometric modeling, Euler operators and other high level modeling methods are necessary. Boolean operation is one of the representative modeling method for the non-manifold geometric modeling. This thesis studies Boolean operations of non-manifold model with the data structure of selective storage. The data structure of selective storage is improved non-manifold data structure in that existing non-manifold data structures using ordered topological representation method always store non-manifold information even if edges and vortices are in the manifold situation. To implement Boolean operations for non-manifold model, intersection algorithm for topological cells of three different dimensions, merging and selection algorithm for three dimensional model, and Open Inventor(tm), a 3D toolkit from SGI, are used.

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Feature-Based Image Retrieval using SOM-Based R*-Tree

  • Shin, Min-Hwa;Kwon, Chang-Hee;Bae, Sang-Hyun
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2003년도 Proceeding
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    • pp.223-230
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    • 2003
  • Feature-based similarity retrieval has become an important research issue in multimedia database systems. The features of multimedia data are useful for discriminating between multimedia objects (e 'g', documents, images, video, music score, etc.). For example, images are represented by their color histograms, texture vectors, and shape descriptors, and are usually high-dimensional data. The performance of conventional multidimensional data structures(e'g', R- Tree family, K-D-B tree, grid file, TV-tree) tends to deteriorate as the number of dimensions of feature vectors increases. The R*-tree is the most successful variant of the R-tree. In this paper, we propose a SOM-based R*-tree as a new indexing method for high-dimensional feature vectors.The SOM-based R*-tree combines SOM and R*-tree to achieve search performance more scalable to high dimensionalities. Self-Organizing Maps (SOMs) provide mapping from high-dimensional feature vectors onto a two dimensional space. The mapping preserves the topology of the feature vectors. The map is called a topological of the feature map, and preserves the mutual relationship (similarity) in the feature spaces of input data, clustering mutually similar feature vectors in neighboring nodes. Each node of the topological feature map holds a codebook vector. A best-matching-image-list. (BMIL) holds similar images that are closest to each codebook vector. In a topological feature map, there are empty nodes in which no image is classified. When we build an R*-tree, we use codebook vectors of topological feature map which eliminates the empty nodes that cause unnecessary disk access and degrade retrieval performance. We experimentally compare the retrieval time cost of a SOM-based R*-tree with that of an SOM and an R*-tree using color feature vectors extracted from 40, 000 images. The result show that the SOM-based R*-tree outperforms both the SOM and R*-tree due to the reduction of the number of nodes required to build R*-tree and retrieval time cost.

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무게절감을 위한 차량 최적 설계 기법 (The Optimized Design Method of Vehicle for Weight-Reduction)

  • 이정익
    • 한국CDE학회논문집
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    • 제12권5호
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    • pp.376-381
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    • 2007
  • The geometric configuration in the weight-reduced structure is very required to be started from the conceptual design with low cost, high performance and quality. In this point, a structural-topological shape concerned with conceptual design of structure is important. The method used in this paper combines three optimization techniques, where the shape and physical dimensions of the structure and material distribution are hierachically optimized, with the maximum rigidity of structure and lightweight.

CAD 시스템에 의하여 작성된 기계도면의 자동검증시스템에 관한 연구 (A Computer Aided Automatic Verification System for Mechanical Drawings Drawn with CAD System)

  • Lee, S.S.
    • 한국정밀공학회지
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    • 제13권8호
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    • pp.60-71
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    • 1996
  • Mostof existing CAD systems do not provide the advanced function for systematic checking of design and drafting errors in mechanical drawings. We have reported a computer aided drawing check system to single plane projection drawings made by a CAD system. This paper describes a checking method of dimensioning errors in mechanical drawings. The checking items are deficiency and redundancy of dimensions, input-errors in dimension figures and symbols, etc. Checking for deficiency and redundancy of global dimensions has been performed applying Graph Theory. This system has been applied to several examples and we have confirmed the feasibility of this checking method.

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도형의 정의에 관한 한 연구 (A Study on the Definitions of Some Geometric Figures)

  • 최영한
    • 한국수학교육학회지시리즈A:수학교육
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    • 제6권2호
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    • pp.1-9
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    • 1968
  • In mathematics, a definition must have authentic reasons to be defined so. On defining geometric figures, there must be adequencies in sequel and consistency in the concepts of figures, though the dimensions of them are different. So we can avoid complicated thoughts from the study of geometric property. From the texts of SMSG, UICSM and others, we can find easily that the same concepts are not kept up on defining some figures such as ray and segment on a line, angle and polygon on a plane, and polyhedral angle and polyhedron on a 3-dimensionl space. And the measure of angle is not well-defined on basis of measure theory. Moreover, the concepts for interior, exterior, and frontier of each figure used in these texts are different from those of general topology and algebraic topology. To avoid such absurdness, I myself made new terms and their definitions, such as 'gan' instead of angle, 'polygonal region' instead of polygon, and 'polyhedral solid' instead of polyhedron, where each new figure contains its interior. The scope of this work is hmited to the fundamental idea, and it merely has dealt with on the concepts of measure, dimension, and topological property. In this case, the measure of a figure is a set function of it, so the concepts of measure is coincided with that of measure theory, and we can deduce the topological property for it from abstract stage. It also presents appropriate concepts required in much clearer fashion than traditional method.

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