68,865 research outputs found

    Recoverable DTN Routing based on a Relay of Cyclic Message-Ferries on a MSQ Network

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    An interrelation between a topological design of network and efficient algorithm on it is important for its applications to communication or transportation systems. In this paper, we propose a design principle for a reliable routing in a store-carry-forward manner based on autonomously moving message-ferries on a special structure of fractal-like network, which consists of a self-similar tiling of equilateral triangles. As a collective adaptive mechanism, the routing is realized by a relay of cyclic message-ferries corresponded to a concatenation of the triangle cycles and using some good properties of the network structure. It is recoverable for local accidents in the hierarchical network structure. Moreover, the design principle is theoretically supported with a calculation method for the optimal service rates of message-ferries derived from a tandem queue model for stochastic processes on a chain of edges in the network. These results obtained from a combination of complex network science and computer science will be useful for developing a resilient network system.Comment: 6 pages, 12 figures, The 3rd Workshop on the FoCAS(Fundamentals of Collective Adaptive Systems) at The 9th IEEE International Conference on SASO(Self-Adaptive and Self-Organizing systems), Boston, USA, Sept.21, 201

    Integration of highly probabilistic sources into optical quantum architectures: perpetual quantum computation

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    In this paper we introduce a design for an optical topological cluster state computer constructed exclusively from a single quantum component. Unlike previous efforts we eliminate the need for on demand, high fidelity photon sources and detectors and replace them with the same device utilised to create photon/photon entanglement. This introduces highly probabilistic elements into the optical architecture while maintaining complete specificity of the structure and operation for a large scale computer. Photons in this system are continually recycled back into the preparation network, allowing for a arbitrarily deep 3D cluster to be prepared using a comparatively small number of photonic qubits and consequently the elimination of high frequency, deterministic photon sources.Comment: 19 pages, 13 Figs (2 Appendices with additional Figs.). Comments welcom

    Topological Theory in Bioconstructivism

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    In the essay “Landscapes of Change: Boccioni’s Stati d’animo as a General Theory of Models,” in Assemblage 19, 1992, Sanford Kwinter proposed a number of theoretical models which could be applied to computer-generated forms in Bioconstructivism. These included topological theory, epigenesis, the epigenetic landscape, morphogenesis, catastrophe and catastrophe theory. Topological theory entails transformational events or deformations in nature which introduce discontinuities into the evolution of a system. Epigenesis entails the generation of smooth landscapes, in waves or the surface of the earth, for example, formed by complex underlying topological interactions. The epigenetic landscape is the smooth forms of relief which are the products of the underlying complex networks of interactions. Morphogenesis describes the structural changes occurring during the development of an organism, wherein forms are seen as discontinuities in a system, as moments of structural instability rather than stability. A catastrophe is a morphogenesis, a jump in a system resulting in a discontinuity. Catastrophe theory is a topological theory describing the discontinuities in the evolution of a system in nature. A project which applies these models, and which helps to establish a theoretical basis for Bioconstructivism by applying topological models, is a design for a theater by Amy Lewis in a Graduate Architecture Design Studio directed by Associate Professor Andrew Thurlow at Roger Williams University, in Spring 2011. In the project, moments of structural stability are juxtaposed with moments of structural instability, to represent the contradiction inherent in self-generation or immanence. The singularity of the surfaces of the forms in the epigenetic landscape contradicts the complex network of interactions of topological forces from which they result. Actions in the environment on unstable, unstructured forms, and undifferentiated structures, result in stable, structured forms, and differentiated structures

    Simplification of Internet Ossification through Software Defined Network Approach

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    Software-Defined Networking (SDN) has received great responses from software industry in recent years. SDN has introduced number of technical symposium and technical discussions on computer network paradigm and topological design, along with research and scientific contributions. Fellow researchers, system administrators and engineers working on computer network, and hardware service providers are trying to establish new standards and provide guidelines for proper accomplishment and exploitation of such fresh approach. Now a day�s efforts have been made in the southbound of the SDN architecture, while the northbound interface still needs improvements. Focusing in the SDN northbound, this paper is concentrating on relative study of the body of acquaintance and discusses the challenges for developing SDN software.SDN also inspect and focused on the existing solutions and to search out trends and challenge on programming for SDN environments. In this paper the vision developments on techniques, provision, and methodologies for programmable networks, with the correct view in respect or aspect from the field of emerging software engineering is discussed.

    The Local Computer Network in Tohoku District, Japan

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    This Working Paper gives an outline of the local computer network in the Tohoku district of Japan, in which the design and implementation I participated in during 1974 at the Research Institute of Electrical Communication, Tohoku University, Japan. At present IIASA is planning its own inter-European computer network, which will be able to interconnect with many existing computer networks, including EIN and those existing in Eastern Europe. This program has already commenced with the interconnection of three computer centres, IIASA, Bratislava (Czechoslovakia) and Budapest (Hungary) using a European public switched telephone line. It is planned to use: a line switching technique to interconnect two computer centres; packets as a unit of information transmission on telephone lines; an asynchronous serial data transmission technique; a half duplex communication facility; and 1200 baud communication speed. I should mention here that the above techniques, computer centre facilities and the topological location of the computer centres are very similar to the computer network in the Tohoku district, and this is the reason why I am writing this paper. I will describe briefly the design of this computer network, which consists of the following five sections

    A knowledge-based system with learning for computer communication network design

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    Computer communication network design is well-known as complex and hard. For that reason, the most effective methods used to solve it are heuristic. Weaknesses of these techniques are listed and a new approach based on artificial intelligence for solving this problem is presented. This approach is particularly recommended for large packet switched communication networks, in the sense that it permits a high degree of reliability and offers a very flexible environment dealing with many relevant design parameters such as link cost, link capacity, and message delay

    Surface networks

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    © Copyright CASA, UCL. The desire to understand and exploit the structure of continuous surfaces is common to researchers in a range of disciplines. Few examples of the varied surfaces forming an integral part of modern subjects include terrain, population density, surface atmospheric pressure, physico-chemical surfaces, computer graphics, and metrological surfaces. The focus of the work here is a group of data structures called Surface Networks, which abstract 2-dimensional surfaces by storing only the most important (also called fundamental, critical or surface-specific) points and lines in the surfaces. Surface networks are intelligent and “natural ” data structures because they store a surface as a framework of “surface ” elements unlike the DEM or TIN data structures. This report presents an overview of the previous works and the ideas being developed by the authors of this report. The research on surface networks has fou

    Repairing triangle meshes built from scanned point cloud

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    The Reverse Engineering process consists of a succession of operations that aim at creating a digital representation of a physical model. The reconstructed geometric model is often a triangle mesh built from a point cloud acquired with a scanner. Depending on both the object complexity and the scanning process, some areas of the object outer surface may never be accessible, thus inducing some deficiencies in the point cloud and, as a consequence, some holes in the resulting mesh. This is simply not acceptable in an integrated design process where the geometric models are often shared between the various applications (e.g. design, simulation, manufacturing). In this paper, we propose a complete toolbox to fill in these undesirable holes. The hole contour is first cleaned to remove badly-shaped triangles that are due to the scanner noise. A topological grid is then inserted and deformed to satisfy blending conditions with the surrounding mesh. In our approach, the shape of the inserted mesh results from the minimization of a quadratic function based on a linear mechanical model that is used to approximate the curvature variation between the inner and surrounding meshes. Additional geometric constraints can also be specified to further shape the inserted mesh. The proposed approach is illustrated with some examples coming from our prototype software
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