Information flow and cooperative control of vehicle formations

We consider the problem of cooperation among a collection of vehicles performing a shared task using intervehicle communication to coordinate their actions. Tools from algebraic graph theory prove useful in modeling the communication network and relating its topology to formation stability. We prove a Nyquist criterion that uses the eigenvalues of the graph Laplacian matrix to determine the effect of the communication topology on formation stability. We also propose a method for decentralized information exchange between vehicles. This approach realizes a dynamical system that supplies each vehicle with a common reference to be used for cooperative motion. We prove a separation principle that decomposes formation stability into two components: Stability of this is achieved information flow for the given graph and stability of an individual vehicle for the given controller. The information flow can thus be rendered highly robust to changes in the graph, enabling tight formation control despite limitations in intervehicle communication capability

On (2,2)-Domination in Hexagonal Mesh Pyramid

Network topology plays a key role in designing an interconnection network. Various topologies for interconnection networks have been proposed in the literature of which pyramid network is extensively used as a base for both software data structure and hardware design. The pyramid networks can efficiently handle the communication requirements of various problems in graph theory due to its inherent hierarchy at each level. Domination problems are one of the classical types of problems in graph theory with vast application in computer networks and distributed computing. In this paper, we obtain the bounds for a variant of the domination problem namely (2,2)-domination for a pyramid network called Hexagonal mesh pyramid

System level modeling methodology of NoC design from UML-MARTE to VHDL

International audienceThe evolution of the semiconductor technology caters for the increase in the System-on-Chip (SoC) complexity. In particular, this complexity appears in the communication infrastructures like the Network-on-Chips (NoCs). However many complex SoCs are becoming increasingly hard to manage. In fact, the design space, which represents all the concepts that need to be explored during the SoC design, is becoming dramatically large and difficult to explore. In addition, the manipulation of SoCs at low levels, like the Register Transfer Level (RTL), is based on manual approaches. This has resulted in the increase of both time-to-market and the development costs. Thus, there is a need for developing some automated high level modeling environments for computer aided design in order to handle the design complexity and meet tight time-to-market requirements. The extension of the UML language called UML profile for MARTE (Modeling and Analysis of Real-Time and Embedded systems) allows the modeling of repetitive structures such as the NoC topologies which are based on specific concepts. This paper presents a new methodology for modeling concepts of NoC-based architectures, especially the modeling of topology of the interconnections with the help of the repetitive structure modeling (RSM) package of MARTE profile. This work deals with the ways of improving the effectiveness of the MARTE standard by clarifying and extending some notations in order to model complex NoC topologies. Our contribution includes a description of how these concepts may be mapped into VHDL. The generated code has been successfully evaluated and validated for several NoC topologies

Design and Simulation of Worldwide Interoperability for Microwave Access Computer Network for 3×3 Km Universal Sample of Building Campus

The aim of this study to design a wireless computer network of a particular network as a large-scale company or university to improve mobility and to let the teachers and students of the university, for example, stay interacted and connected at any time in any campus location or site. Therefore, This study needed to cover the overall area of this campus with efficient wireless coverage that exceeds the university boundaries to maintain wireless signal strength. To do that, the researchers thought that it is very significant to design a Worldwide Interoperability for Microwave Access (WiMax) computer network with the most powerful and advanced hardware component capabilities to full fit teachers’ and students’ requirements of fast net browsing and files’ download. After designing the university campus of computer network, simulation has done by OPNET 14 Modular to determine the WiMax network design parameters. The purpose of the current research is to find if the design of the campus network is efficient or not and also to determine the performance of theimplemented network

A Hardware approach to neural networks silicon retina

The primary goal of this thesis was to emulate the function of the biological eye in silicon. In both neural and silicon technologies, the active devices occupy approximately 2 percent of the space, wire fills the entire remaining space. The silicon retina was modeled on the distal portion of the vertebrate retina. This chip generates, in real time, outputs that correspond directly to signals observed in the corresponding levels of the biological retinas. The design uses the principles of signal aggregation. It demonstrates a tolerance for device imperfection that is characteristic of a collective system. The digital computer is extremely effective at producing precise answers to well-defined questions. The nervous system accepts fuzzy, poorly conditioned input, performs a computation that is ill-defined, and produces approximate output