• 제목/요약/키워드: topological structure

검색결과 292건 처리시간 0.021초

Intuitionistic Interval-Valued Fuzzy Topological Spaces

  • Lim, Pyung-Ki;Kim, Sun-Ho;Hur, Kul
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • 제22권1호
    • /
    • pp.126-134
    • /
    • 2012
  • By using the concept of intuitionistic interval-valued fuzzy sets, we introduce the notion of intuitionistic interval-valued fuzzy topology. And we study some fundamental properties of intuitionistic interval-valued fuzzy topological spaces: First, we obtain analogues[see Theorem 3.11 and 3.12] of neighborhood systems in ordinary topological spaces. Second, we obtain the result[see Theorem 4.9] corresponding to "the 14-set Theorem" in ordinary topological spaces. Finally, we give the initial structure on intuitionistic interval-valued fuzzy topologies[see Theorem 5.9].

Improving Performance of Region-Based ACM with Topological Change of Curves (곡선의 위상구조 변경을 이용한 영역 기반 ACM의 성능개선 기법 제안)

  • Hahn, Hee Il
    • Journal of Korea Multimedia Society
    • /
    • 제20권1호
    • /
    • pp.10-16
    • /
    • 2017
  • This paper proposes efficient schemes for image segmentation using the region-based active contour model. The developed methods can approach the boundaries of the desired objects by evolving the curves through minimization of the Mumford-Shah energy functionals, given arbitrary curves as initial conditions. Topological changes such as splitting or merging of curves should be handled for the methods to work properly without prior knowledge of the number of objects to be segmented. This paper introduces how to change topological structure of the curves and shows experimental results by applying the methods to the images.

Effective Coupling of a Topological Corner-state Nanocavity to Various Plasmon Nanoantennas

  • Ma, Na;Jiang, Ping;Zeng, You Tao;Qiao, Xiao Zhen;Xu, Xian Feng
    • Current Optics and Photonics
    • /
    • 제6권5호
    • /
    • pp.497-505
    • /
    • 2022
  • Topological photonic nanocavities are considered to possess outstanding optical performance, and provide new platforms for realizing strong interaction between light and matter, due to their robustness to impurities and defects. Here hybrid plasmonic topological photonic nanocavities are proposed, by embedding various plasmon nanoantennas such as gold nanospheres, cylinders, and rectangles in a topological photonic crystal corner-state nanocavity. The maximum quality factor Q and minimum effective mode volume Veff of these hybrid nanocavities can reach the order of 104 and 10-4 (𝜆/n)3 respectively, and the high figures of merit Q/Veff for all of these hybrid nanocavites are stable and on the order of 105 (𝜆/n)-3. The relative positions of the plasmon nanoantennas will influence the coupling strength between the plasmon structures and the topological nanocavity. The hybrid nanocavity with gold nanospheres possesses much higher Q, but relatively large Veff. The presence of a gold rectangular structure can confine more electromagnetic energy within a smaller space, since its Veff is smallest, although Q is lowest among these structures. This work provides an outstanding platform for cavity quantum electrodynamics and has a wide range of applications in topological quantum light sources, such as single-photon sources and nanolasers.

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
    • /
    • 제45권3호
    • /
    • pp.411-422
    • /
    • 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.

Topological Mapping and Navigation in Indoor Environment with Invisible Barcode (바코드가 있는 가정환경에서의 위상학적 지도형성 및 자율주행)

  • Huh, Jin-Wook;Chung, Woong-Sik;Chung, Wan-Kyun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • 제30권9호
    • /
    • pp.1124-1133
    • /
    • 2006
  • This paper addresses the localization and navigation problem using invisible two dimensional barcodes on the floor. Compared with other methods using natural/artificial landmark, the proposed localization method has great advantages in cost and appearance, since the location of the robot is perfectly known using the barcode information after the mapping is finished. We also propose a navigation algorithm which uses the topological structure. For the topological information, we define nodes and edges which are suitable for indoor navigation, especially for large area having multiple rooms, many walls and many static obstacles. The proposed algorithm also has an advantage that errors occurred in each node are mutually independent and can be compensated exactly after some navigation using barcode. Simulation and experimental results. were performed to verify the algorithm in the barcode environment, and the result showed an excellent performance. After mapping, it is also possible to solve the kidnapped case and generate paths using topological information.

A Study on Extraction and its Storage method of Topological Information from Common 2-D CAD Using The Boundary-Representation Method (범용 2D MCAD 상에서 경계표현법을 이용한 위상 정보 추출 및 그 저장방식에 관한 연구)

  • Hong, Sang-Hoon;Han, Seong-Young;Kim, Yong-Yun
    • Journal of the Korean Society for Precision Engineering
    • /
    • 제16권9호
    • /
    • pp.25-34
    • /
    • 1999
  • In spite of the advance of 3D solid modeling technology, there are some distinct areas where 2D CAD S/W are still dominant, and more competent comparing with 3D CAD S/W. For example, in the manufacturing of 2D-shaped electrical parts, most related manufacturing tools have 2D geometric features by nature, and 3D solid models applied to these parts have substantial overheads. Nevertheless, most 2D CAD S/W have no topological inquiry services because they have no such information on their geometrical database inherently. Thus, it is needed to extract such information from 2D CAD database for developing more advanced application such as automated drafting/design S/W. In this paper, the extraction of topological information from 2D CAD has been performed in general way using concept of B-rep. A general extraction algorithm, data structure and meta file format for 2D topological object have been developed and successfully applied to the development of the automated lead frame die design system in Samsung Aerospace. it is also possible to provide a flexible, powerful topology-oriented functionality on any common 2D CAD S/W.

  • PDF

Topology-aware Virtual Network Embedding Using Multiple Characteristics

  • Liao, Jianxin;Feng, Min;Li, Tonghong;Wang, Jingyu;Qing, Sude
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제8권1호
    • /
    • pp.145-164
    • /
    • 2014
  • Network virtualization provides a promising tool to allow multiple heterogeneous virtual networks to run on a shared substrate network simultaneously. A long-standing challenge in network virtualization is the Virtual Network Embedding (VNE) problem: how to embed virtual networks onto specific physical nodes and links in the substrate network effectively. Recent research presents several heuristic algorithms that only consider single topological attribute of networks, which may lead to decreased utilization of resources. In this paper, we introduce six complementary characteristics that reflect different topological attributes, and propose three topology-aware VNE algorithms by leveraging the respective advantages of different characteristics. In addition, a new KS-core decomposition algorithm based on two characteristics is devised to better disentangle the hierarchical topological structure of virtual networks. Due to the overall consideration of topological attributes of substrate and virtual networks by using multiple characteristics, our study better coordinates node and link embedding. Extensive simulations demonstrate that our proposed algorithms improve the long-term average revenue, acceptance ratio, and revenue/cost ratio compared to previous algorithms.

Level Set Based Topological Shape Optimization of Hyper-elastic Nonlinear Structures using Topological Derivatives (위상 민감도를 이용한 초탄성 비선형 구조의 레벨셋 기반 위상 및 형상 최적설계)

  • Kim, Min-Geun;Ha, Seung-Hyun;Cho, Seonho
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • 제25권6호
    • /
    • pp.559-567
    • /
    • 2012
  • A level set based topological shape optimization method for nonlinear structure considering hyper-elastic problems is developed. To relieve significant convergence difficulty in topology optimization of nonlinear structure due to inaccurate tangent stiffness which comes from material penalization of whole domain, explicit boundary for exact tangent stiffness is used by taking advantage of level set function for arbitrary boundary shape. For given arbitrary boundary which is represented by level set function, a Delaunay triangulation scheme is used for current structure discretization instead of using implicit fixed grid. The required velocity field in the actual domain to update the level set equation is determined from the descent direction of Lagrangian derived from optimality conditions. The velocity field outside the actual domain is determined through a velocity extension scheme based on the method suggested by Adalsteinsson and Sethian(1999). The topological derivatives are incorporated into the level set based framework to enable to create holes whenever and wherever necessary during the optimization.