Some studies on the multi-mesh architecture.

In this thesis, we have reported our investigations on interconnection network architectures based on the idea of a recently proposed multi-processor architecture, Multi-Mesh network. This includes the development of a new interconnection architecture, study of its topological properties and a proposal for implementing Multi-Mesh using optical technology. We have presented a new network topology, called the 3D Multi-Mesh (3D MM) that is an extension of the Multi-Mesh architecture [DDS99]. This network consists of n3 three-dimensional meshes (termed as 3D blocks), each having n3 processors, interconnected in a suitable manner so that the resulting topology is 6-regular with n6 processors and a diameter of only 3n. We have shown that the connectivity of this network is 6. We have explored an algorithm for point-to-point communication on the 3D MM. It is expected that this architecture will enable more efficient algorithm mapping compared to existing architectures. We have also proposed some implementation of the multi-mesh avoiding the electronic bottleneck due to long copper wires for communication between some processors. Our implementation considers a number of realistic scenarios based on hybrid (optical and electronic) communication. One unique feature of this investigation is our use of WDM wavelength routing and the protection scheme. We are not aware of any implementation of interconnection networks using these techniques.Dept. of Computer Science. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .A32. Source: Masters Abstracts International, Volume: 43-03, page: 0868. Adviser: Subir Bandyopadhyay. Thesis (M.Sc.)--University of Windsor (Canada), 2004

Interconnection networks for parallel and distributed computing

Parallel computers are generally either shared-memory machines or distributed- memory machines. There are currently technological limitations on shared-memory architectures and so parallel computers utilizing a large number of processors tend tube distributed-memory machines. We are concerned solely with distributed-memory multiprocessors. In such machines, the dominant factor inhibiting faster global computations is inter-processor communication. Communication is dependent upon the topology of the interconnection network, the routing mechanism, the flow control policy, and the method of switching. We are concerned with issues relating to the topology of the interconnection network. The choice of how we connect processors in a distributed-memory multiprocessor is a fundamental design decision. There are numerous, often conflicting, considerations to bear in mind. However, there does not exist an interconnection network that is optimal on all counts and trade-offs have to be made. A multitude of interconnection networks have been proposed with each of these networks having some good (topological) properties and some not so good. Existing noteworthy networks include trees, fat-trees, meshes, cube-connected cycles, butterflies, Möbius cubes, hypercubes, augmented cubes, k-ary n-cubes, twisted cubes, n-star graphs, (n, k)-star graphs, alternating group graphs, de Bruijn networks, and bubble-sort graphs, to name but a few. We will mainly focus on k-ary n-cubes and (n, k)-star graphs in this thesis. Meanwhile, we propose a new interconnection network called augmented k-ary n- cubes. The following results are given in the thesis.1. Let k ≥ 4 be even and let n ≥ 2. Consider a faulty k-ary n-cube Q(^k_n) in which the number of node faults f(_n) and the number of link faults f(_e) are such that f(_n) + f(_e) ≤ 2n - 2. We prove that given any two healthy nodes s and e of Q(^k_n), there is a path from s to e of length at least k(^n) - 2f(_n) - 1 (resp. k(^n) - 2f(_n) - 2) if the nodes s and e have different (resp. the same) parities (the parity of a node Q(^k_n) in is the sum modulo 2 of the elements in the n-tuple over 0, 1, ∙∙∙ , k - 1 representing the node). Our result is optimal in the sense that there are pairs of nodes and fault configurations for which these bounds cannot be improved, and it answers questions recently posed by Yang, Tan and Hsu, and by Fu. Furthermore, we extend known results, obtained by Kim and Park, for the case when n = 2.2. We give precise solutions to problems posed by Wang, An, Pan, Wang and Qu and by Hsieh, Lin and Huang. In particular, we show that Q(^k_n) is bi-panconnected and edge-bipancyclic, when k ≥ 3 and n ≥ 2, and we also show that when k is odd, Q(^k_n) is m-panconnected, for m = (^n(k - 1) + 2k - 6’ / ‘_2), and (k -1) pancyclic (these bounds are optimal). We introduce a path-shortening technique, called progressive shortening, and strengthen existing results, showing that when paths are formed using progressive shortening then these paths can be efficiently constructed and used to solve a problem relating to the distributed simulation of linear arrays and cycles in a parallel machine whose interconnection network is Q(^k_n) even in the presence of a faulty processor.3. We define an interconnection network AQ(^k_n) which we call the augmented k-ary n-cube by extending a k-ary n-cube in a manner analogous to the existing extension of an n-dimensional hypercube to an n-dimensional augmented cube. We prove that the augmented k-ary n-cube Q(^k_n) has a number of attractive properties (in the context of parallel computing). For example, we show that the augmented k-ary n-cube Q(^k_n) - is a Cayley graph (and so is vertex-symmetric); has connectivity 4n - 2, and is such that we can build a set of 4n - 2 mutually disjoint paths joining any two distinct vertices so that the path of maximal length has length at most max{{n- l)k- (n-2), k + 7}; has diameter [(^k) / (_3)] + [(^k - 1) /( _3)], when n = 2; and has diameter at most (^k) / (_4) (n+ 1), for n ≥ 3 and k even, and at most [(^k)/ (_4) (n + 1) + (^n) / (_4), for n ^, for n ≥ 3 and k odd.4. We present an algorithm which given a source node and a set of n - 1 target nodes in the (n, k)-star graph S(_n,k) where all nodes are distinct, builds a collection of n - 1 node-disjoint paths, one from each target node to the source. The collection of paths output from the algorithm is such that each path has length at most 6k - 7, and the algorithm has time complexity O(k(^3)n(^4))

Integration of tools for the Design and Assessment of High-Performance, Highly Reliable Computing Systems (DAHPHRS), phase 1

Systems for Space Defense Initiative (SDI) space applications typically require both high performance and very high reliability. These requirements present the systems engineer evaluating such systems with the extremely difficult problem of conducting performance and reliability trade-offs over large design spaces. A controlled development process supported by appropriate automated tools must be used to assure that the system will meet design objectives. This report describes an investigation of methods, tools, and techniques necessary to support performance and reliability modeling for SDI systems development. Models of the JPL Hypercubes, the Encore Multimax, and the C.S. Draper Lab Fault-Tolerant Parallel Processor (FTPP) parallel-computing architectures using candidate SDI weapons-to-target assignment algorithms as workloads were built and analyzed as a means of identifying the necessary system models, how the models interact, and what experiments and analyses should be performed. As a result of this effort, weaknesses in the existing methods and tools were revealed and capabilities that will be required for both individual tools and an integrated toolset were identified

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

Wireless Sensor Networks

The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks

Cryptographic key distribution in wireless sensor networks: a hardware perspective

In this work the suitability of different methods of symmetric key distribution for application in wireless sensor networks are discussed. Each method is considered in terms of its security implications for the network. It is concluded that an asymmetric scheme is the optimum choice for key distribution. In particular, Identity-Based Cryptography (IBC) is proposed as the most suitable of the various asymmetric approaches. A protocol for key distribution using identity based Non-Interactive Key Distribution Scheme (NIKDS) and Identity-Based Signature (IBS) scheme is presented. The protocol is analysed on the ARM920T processor and measurements were taken for the run time and energy of its components parts. It was found that the Tate pairing component of the NIKDS consumes significants amounts of energy, and so it should be ported to hardware. An accelerator was implemented in 65nm Complementary Metal Oxide Silicon (CMOS) technology and area, timing and energy figures have been obtained for the design. Initial results indicate that a hardware implementation of IBC would meet the strict energy constraint of a wireless sensor network node

Efficient Passive Clustering and Gateways selection MANETs

Passive clustering does not employ control packets to collect topological information in ad hoc networks. In our proposal, we avoid making frequent changes in cluster architecture due to repeated election and re-election of cluster heads and gateways. Our primary objective has been to make Passive Clustering more practical by employing optimal number of gateways and reduce the number of rebroadcast packets

Internal in-service inspection of petrochemical storage tank floors to detect underside corrosion with Non-Destructive Testing Robot

This research develops a new robotics technology for the in-service inspection of floor plates of the majority for the world’s petrochemical storage tanks. The new robotic system aims to decrease inspection cost, reduce human inspector exposure to chemical and hazard environment during the inspection and eliminate tank outage entirely if the floor is found to contain no corrosion. The research focus is on the design and development of a Non-Destructive Testing Robot (NDTBOT) prototype that uses active buoyancy control for its locomotion mechanism and uses NDT ultrasound to measure floor plate thickness as an indication of corrosion thinning. The NDTBOT hops from one location of the floor to another location to make ultrasound thickness measurements of a tank floor, thus avoiding issues of motion on a dirty tank floor (due to oil sludge). Also, a novel radio frequency (RF) data communication system is investigated and developed that can operate while submerged in oil. This system allows control commands to be sent to the NDTBOT by an operator outside the tank and NDT data to be recovered for analysis. To evaluate the performance of the NDTBOT making thickness measurement in the tank, three types of measurement techniques were used. First, the real thickness was measured using a Vernier caliper, the second method used a standard hand-held ultrasonic thickness measurement instrument and finally the in-service inspection thickness measurements were made with the NDTBOT operating in a water tank. The NDTBOT thickness measurements with an immersion ultrasound probe obtained more accurate results than hand-held contact ultrasonic testing. Petrochemical storage tank size varies from 20 to 200 meters in diameter, rapid corrosion inspection in such tanks with a swarm of robots requires that a number of NDTBOTs be deployed inside the tank to perform the NDT. Such deployment needs coordination and control work between the robots to send the NDT data to the NDT inspector. Therefore, an investigation and experimental radio frequency wireless transmission is done in order to compare different radio frequency communication. Simulation with commercial software CADFEKO is used to perform simulation of RF wave transmission in petroleum and vegetable oil with selected radio frequencies of 200 MHz, 300 MHz, and 433 MHz. The experimental work and simulation results give confidence. The RF communication in petroleum medium is feasible for both control of NDTBOTs inside the tank and NDT data transmission back to a technician’s console placed outside the tank

Code 777: Australia and the US defense satellite communications system (DSCS)

There are currently installed in Australia eight satellite ground terminals that operate either as integral parts of or in connection with the US Defence Satellite Communications System (DSCS). One of these is at North West Cape, Western Australia; two are at Nurrungar, South Australia; two are at Pine Gap, Northern Territory; one is at the Weapons Research Establishment (WRE), Salisbury, South Australia; and two are at Watsonia Barracks in Melbourne. Despite the critical importance of this satellite system to US global military and intelligence operations, and the fact that Australian involvement in the system began more than two decades ago, there remains in Australia no public description of this system nor any discussion of the implications of Australia's involvement in it for various aspects of Australia's national security. This monograph describes the US Defence Satellite Communications System (DSCS) and its various missions and discusses Australia's role in the system. It concludes that Australia has had insufficient control over the DSCS deployments and operations in this country; that the Australian Government has been remiss in informing the public about the extent of Australia's role in the DSCS system and the implications of this involvement; and that Australia should take advantage of the DSCS facilities to support our own defence communication requirements