Analysis and design of circuit switching interconnection networks using 4×4 nodes

Multistage interconnection networks are used as a medium for interconnecting processors and memories in multiprocessor systems. Multistage interconnection networks are an effective substitute for crossbar switches, used in telephone network systems and parallel computers, due to their low cost, better performance and easy maintainability. In this paper, we propose new fault-tolerant hybrid multistage interconnection networks obtained from shuffle exchange gamma interconnection network (SEGIN) and logical neighborhood network named as shuffle exchange gamma logical neighborhood interconnection network (SEGLNIN). We evaluated the performance of SEGLNIN in terms of disjoint paths, reliability and hardware cost and compared it with some well-known MINs like shuffle exchange network (SEN), shuffle exchange network with one extra stage (SEN +) and shuffle exchange network with two extra stages (SEN + 2), SEGIN-1, and SEGIN-2. The results illustrate that the performance of the proposed SEGLNIN is better than that of the compared networks in terms of reliability and disjoint paths.

The increasing availability of dynamically growing digital data that can be used for extracting social networks has led to an upsurge of interest in the analysis of dynamic social networks. One key aspect of social network analysis is to understand the central nodes in a network. However, dynamic calculation of centrality values for rapidly growing networks might be unfeasibly expensive, especially if it involves recalculation from scratch for each time period. This paper proposes an incremental algorithm that effectively updates betweenness centralities of nodes in dynamic social networks while avoiding re-computations by exploiting information from earlier computations. Our performance results suggest that our incremental betweenness algorithm can achieve substantial performance speedup, on the order of thousands of times, over the state of the art, including the best-performing non-incremental betweenness algorithm and a recently proposed betweenness update algorithm.

In multiprocessor systems, the interconnection network design is critical for overall system performance. In this paper, we show the modified hierarchical ring network, called as Torus ring, and deeply evaluate the performance of the Torus ring. The Torus ring has an advantage over the hierarchical ring when the destination of network packet is the adjacent local ring, especially to the backward direction, by exploiting the memory access locality. Further, the performance gain of the Torus ring is expected to increase, due to the spatial locality of the applications and the efficient utilization of link bandwidth. In the simulation results, the overall execution time of Torus ring is reduced, up to 4.5% with moderate ring utilization ratios, compared to the hierarchical ring.

Parallel processing system -Harray-

Little is known about geographic properties of large-scale social networks. In this paper, we examine the geospatial attributes of a planetary-scale social network of 240 million people and 1.3 billion edges. We study the interplay among topological, geographical, and algorithmically generated paths connecting pairs of nodes in a social network. Starting in the realm of cyberspace, we find that topologically shortest paths of average length of 6.6 exist between pairs of nodes in the network and that the average degree of separation among nodes is robust to removal of hub nodes. Moving to the realm of locations and distances in geographic space, we find that topologically shortest paths in the social graph grow with increasing geographic distance between path's endpoint nodes. We discover that shortest topological paths are geographically inefficient, but that geography provides an important cue for local algorithmic policies for navigating between source and target nodes. Local algorithmic strategies for navigating the larger network structure in the absence of global navigation procedures have varying success. At the early stages of the navigation, navigating to a hub node helps, while in the middle stage, geography provides the most important clue. While local algorithms for navigating have trouble reaching the target node, they are successful in reaching nodes that are geographically close to the target. Taken together, our results demonstrate a complex interplay between topological and geographical properties of social networks and explain the success of local strategies for navigating such networks.

Many problems today need the computing power that is only available by using large‐scaleparallel processing. For a significant number of these problems, the density of theglobal communications between the individual processors dominates the performance ofthe whole parallel implementation on a distributed memory multiprocessor system. In thesecases, the design of the interconnection network for the processors is known to play asignificant part in the efficient implementation of real problems. Important criteria to optimisethe efficiency of a configuration are the maximum and average distance a message hasto travel between processors. Minimum path systems are irregular multiprocessor computerarchitectures which optimise these criteria. These architectures provide an efficient alternativeto the more common regular topologies for solving real applications in parallel. Thispaper presents new results for two combinatorial problems that occur during the generationof these optimal irregular configurations. These are: (1) The design of the optimum interconnection network between the processors for configurationscontaining up to 128 processors. (2) The design of the routing tables to provide the optimal routing of messages withinthese irregular networks. The paper shows how these combinatorial problems have been solved, using genetic algorithmsfor the first problem and a random local search procedure for the second. It alsoincludes a comparison with the results obtained for regular topologies, for example: hypercubes,tori, and rings.

We study two-party communication in the context of directed dynamic networks that are controlled by an adaptive adversary. This adversary is able to change all edges as long as the networks stay strongly-connected in each round. In this work, we establish a relation between counting the total number of nodes in the network and the problem of exchanging tokens between two communication partners which communicate through a dynamic network. We show that the communication problem for a constant fraction of n tokens in a dynamic network with n nodes is at most as hard as counting the number of nodes in a dynamic network with at most 4n + 3 nodes. For the proof, we construct a family of directed dynamic networks and apply a lower bound from two-party communication complexity.

Nonequivalence of multistage interconnection networks is established by obtaining a reduced graph model and then partitioning it into several bipartite subgraphs. This is shown to transform nonequivalence to nonisomorphism, which can be easily determined by examining the intrinsic characteristics of undirected loops. A reverse process allows the design of nonequivalent networks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This paper describes a real-time robotic system. It runs on a heterogeneous multiprocessor system and the system communicates with the robot via RS232 link or infrared link. The multiprocessing system is a IBM personal computer and a i860 add-on card. There are several tasks required for a high performance real-time robotics system: (1) An efficient decision-making task to fulfil the real-time requirement such as supervision, coordination and local control of the robot (2) A real-time graphics task to display the robot's location and its environment (3) A real-time alerting task to alert the system software to perform efficient recovery when the robot is not in its controlling environment (4) Other nonreal-time tasks such as auditing and scheduling (5) Tasks for communication between the robot and the host. In this paper, a multiprocessing distributed system is designed such that the tasks 1 to 4 is handled on the IBM, and the graphics display system is handled by the i860 because of its extremely good graphics performance. The software and hardware design for the system to have a good real-time performance is also discussed. >

Using 1995 results from the NASA Parallel Benchmarks, this paper compares the sustained performance (as opposed to peak performance) and cost per unit of sustained performance for state-of-the-art Parallel processing systems that use Micro-Processors (MPP) versus those that use Custom-designed Processors (PVP). This comparison shows that MPPs approach, but seldom surpass, PCPs with respect to either metric. This paper also discusses the merits and demerits of “clusters” of workstation. Ironically, recently introduced low-cost, parallel systems can also be viewed as “virtual workstation clusters” that offer comparable, if not superior, capabilities. Finally, this paper explores the question of whether it will be economically feasible for computer manufacturers to continue building PVPs, or are MPPs the only economically viable option for building parallel systems?

The construction of smart green city promotes the development of efficient energy use. The development and utilization of user-side demand response resources has become one of the key and difficult problems to be solved urgently in urban sustainable development. This paper first analyzes the multi-dimensional decision-making of multi-objects such as energy demand, distributed renewable power, energy storage device, etc., and then analyzes the "incentive guidance-output correction" between the demand response implementer and the responder. The continuous and interactive process, and then proposes a two-layer topology model that uses the upper layer to guide the lower layer and the lower layer to feedback the upper layer to characterize the user side demand response. Consider the overall goal of maximizing social welfare based on cost considerations, and establish a two-layer topology model designed by user-side demand response incentive mechanism. The validity of the two-layer topology model proposed in this paper is verified by a numerical example. The benefits of the demand response and the influencing factors of the incentive mechanism are discussed. Based on this model, the topology design of the energy interconnection network is proposed. Principles and two new types of energy Internet topologies- the star topology of primary energy plus auxiliary energy and the ring topology with multiple distributed energy systems. Finally, a typical application scenario is selected for analysis and description of the user-side energy interconnection network topology in a typical scenario, and a feasible optimal configuration scheme and network topology are provided.

A multiprocessor system is a computer with two or more central processing units (CPUs) with each one sharing the common main memory as well as the peripherals. Multiprocessor system is either homogeneous or heterogeneous system. A homogeneous system is a cluster of processors joined to a high speed network for accomplishing the required task; also it is defined as parallel computing system. Homogeneous is a technique of parallel computing system. A heterogeneous system can be defined as the interconnection of a number of processors, having dissimilar computational speed. Load balance is a method of distributing work between the processors fairly in order to get optimal response time, resource utilization, and throughput. Load balancing is either static or dynamic. In static load balancing, work is distributed among all processors before the execution of the algorithm. In dynamic load balancing, work is distributed among all processors during execution of the algorithm. So problems arise when it cannot statistically divide the tasks among the processors. To use multiprocessor systems efficiently, several load balancing algorithms have been adopted widely. This paper proposes an efficient load balance algorithm which addresses common overheads that may decrease the efficiency of a multiprocessor system. Such overheads are synchronization, data communication, response time, and throughput.

In this chapter, the author will first introduce in Section 4.1 a brief overview of various approaches and processes for network analysis, architecture, and design. Details of the network analysis, architecture, and design processes will be sequentially presented in Sections 4.2-4.4.As a typical network-design model, the hierarchical design approach will be discussed in detail in Section 4.5 along with its layers in Section 4.6. Various network-design approaches and their evolution will be summarized in Section 4.7. Finally, Section 4.8 will provide further discussion on network management and security.

APINetworks: A general API for the treatment of complex networks in arbitrary computational environments

Interconnection networks: Physical design andperformance analysis