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On the Power of Arrays with Reconfigurable Optical Buses
, 1996
"... This paper examines some computational aspects of different arrays enhanced with optical pipelined buses. The array processors with optical pipelined buses (APPB) are shown to be extremely flexible, as demonstrated by their ability to efficiently simulate different variants of PRAMs and bounded degr ..."
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Cited by 13 (2 self)
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This paper examines some computational aspects of different arrays enhanced with optical pipelined buses. The array processors with optical pipelined buses (APPB) are shown to be extremely flexible, as demonstrated by their ability to efficiently simulate different variants of PRAMs and bounded degree networks. A model of computation is introduced, the array with reconfigurable optical buses (AROB), which combines some of the advantages and characteristics of the classical reconfigurable networks (RN) and the APPB. A number of applications of the APPB and AROB are presented, and their power is investigated. It is shown that beside AROB's capability of simulating classical reconfigurable networks, the enhanced communication mechanisms allow for an important system reduction when compared with the classical RNs. Keywords: optical interconnections, pipelined optical buses, reconfigurable networks, bounded degree networks, PRAM models. 1 Introduction Interprocessor communication networks...
Routing and Sorting on Meshes with Row and Column Buses
, 1994
"... of the 27th Annual IEEE Symposium on Foundations of Computer Science, pages 264273, 1986. [50] T. Suel. Routing and sorting on meshes with row and column buses. In Proceedings of the 8th International Parallel Processing Symposium, April 1994. [51] B. Wang and G. Chen. Constant time algorithms fo ..."
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Cited by 13 (1 self)
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of the 27th Annual IEEE Symposium on Foundations of Computer Science, pages 264273, 1986. [50] T. Suel. Routing and sorting on meshes with row and column buses. In Proceedings of the 8th International Parallel Processing Symposium, April 1994. [51] B. Wang and G. Chen. Constant time algorithms for the transitive closure and some related graph problems on processor arrays with reconfigurable bus systems. IEEE Transactions on Parallel and Distributed Systems, 1:500507, 1990. [27] M. Kunde. Block gossiping on grids and tori: Deterministic sorting and routing match the bisection bound. In Proceedings of the 1st Annual European Symposium on Algorithms, September 1993. [28] R. E. Ladner, J. Lampe, and R. Rogers. Vector prefix addition on subbus mesh computers. In Proceedings of the 5th Annual ACM Symposium on Parallel Algorithms and Architectures, pages 387396, June 1993. [29] F. T. Leighton. Tight bounds on the com
Reconfigurable Meshes: Theory and Practice
 In Reconfigurable Architectures Workshop, RAW'97
, 1997
"... Configurable computing has recently gained much attention with the promise of delivering an order of magnitude performance improvement over general purpose processors. In this paper we contrast the abstract models of reconfigurable architectures and actual hardware available for configurable computi ..."
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Cited by 10 (6 self)
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Configurable computing has recently gained much attention with the promise of delivering an order of magnitude performance improvement over general purpose processors. In this paper we contrast the abstract models of reconfigurable architectures and actual hardware available for configurable computing systems. There is a wealth of ideas related to abstract models of reconfigurable architectures and fast parallel algorithms which exploit the reconfiguration potential in nontrivial ways. We summarize these abstract models and illustrate the power of these models using several example algorithms. We identify the practical problems in implementing these models in VLSI and describe some prototype implementations. Commercial FPGA devices which are being touted as the solution for building configurable computing systems are also examined. The MAARC 2 project at USC endeavors to bridge this gap between the abstract and the real worlds. 1 This work was supported by DARPA under contract DABT...
Permutation routing and sorting on the reconfigurable mesh
 International Journal of Foundations of Computer Science
, 1992
"... Abstract In this paper we demonstrate the power of reconfiguration by presenting efficient randomized algorithms for both packet routing and sorting on a reconfigurable mesh connected computer. The run times of these algorithms are better than the best achievable time bounds on a conventional mesh. ..."
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Cited by 9 (3 self)
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Abstract In this paper we demonstrate the power of reconfiguration by presenting efficient randomized algorithms for both packet routing and sorting on a reconfigurable mesh connected computer. The run times of these algorithms are better than the best achievable time bounds on a conventional mesh. Many variations of the reconfigurable mesh can be found in the literature. We define yet another variation which we call as Mr. Wealsomakeuseofthestandard PARBUS model. We showthat permutation routing problem can be solved on a linear array Mr of size n in 3n steps, whereas n ā 1 is the best possible run time without recon4 figuration. A trivial lower bound for routing on Mr will be n 2.OnthePARBUS linear array, n is a lower bound and hence any standard nstep routing algorithm will be optimal. We also showthat permutation routing on an n Ć n reconfigurable mesh Mr can be done in time n + o(n) using a randomized algorithm or in time 1.25n + o(n) deterministically. In contrast, 2n ā 2 is the diameter of a conventional mesh and hence routing and sorting will need at least 2nā2 steps on a conventional mesh. A lower bound of n 2 is in effect for routing on the 2D mesh Mr as well. On the other 1 hand, n is a lower bound for routing on the PARBUS and our algorithms have the same time bounds on the PARBUS as well. Thus our randomized routing algorithm is optimal upto a lower order term. In addition we show that the problem of sorting can be solved in randomized time n + o(n) onMr as well as on PARBUS. Clearly, this sorting algorithm will be optimal on the PARBUS model. The time bounds of our randomized algorithms hold with high probability.
Routing on Meshes with Buses
"... We consider the problem of routing packets on an n \Theta \Delta \Delta \Delta \Theta n MIMD meshconnected array of processors augmented with row and column buses. We give lower bounds and randomized algorithms for the problem of routing kpermutations (where each processor is the source and desti ..."
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Cited by 9 (3 self)
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We consider the problem of routing packets on an n \Theta \Delta \Delta \Delta \Theta n MIMD meshconnected array of processors augmented with row and column buses. We give lower bounds and randomized algorithms for the problem of routing kpermutations (where each processor is the source and destination of exactly k packets) on a ddimensional mesh with buses, which we call the (k; d)routing problem. We give a general class of "hard" permutations which we use to prove lower bounds for the (k; d)routing problem, for all k; d 1. For the (1; 1) and (1; 2)routing problems the worstcase permutations from this class are identical to ones published by other authors, as are the resulting lower bounds. However, we further show that the (1; d) routing problem requires 0:72 \Delta n steps for d = 3, 0:76 \Delta n steps for d = 4 and slightly more than (1 \Gamma 1=d) \Delta n steps for all d 5. We also obtain new lower bounds for the (k; d)routing problem for k; d ? 1, which improve on t...
Gossiping in VertexDisjoint Paths Mode in dDimensional Grids and Planar Graphs (Extended Abstract)
 Information and Computation
, 1993
"... Juraj Hromkovic y , Ralf Klasing, Elena A. Stohr, Hubert Wagener z Department of Mathematics and Computer Science University of Paderborn, 33095 Paderborn, Germany Abstract The communication modes (oneway and twoway mode) used for sending messages to processors of interconnection networks via ..."
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Cited by 8 (2 self)
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Juraj Hromkovic y , Ralf Klasing, Elena A. Stohr, Hubert Wagener z Department of Mathematics and Computer Science University of Paderborn, 33095 Paderborn, Germany Abstract The communication modes (oneway and twoway mode) used for sending messages to processors of interconnection networks via vertexdisjoint paths in one communication step are investigated. The complexity of communication algorithms is measured by the number of communication steps (rounds). Here, the complexity of gossiping in grids and in planar graphs is investigated. The main results are the following: 1. Effective oneway and twoway gossip algorithms for ddimensional grids, d 2, are designed. 2. The lower bound 2 log 2 n \Gamma log 2 k \Gamma log 2 log 2 n \Gamma 2 is established on the number of rounds of every twoway gossip algorithm working on any graph of n nodes and vertex bisection k. This proves that the designed twoway gossip algorithms on ddimensional grids, d 3, are almost optimal, and it al...
Constant Time Algorithms for Computing the Contour of Maximal Elements on the Reconfigurable Mesh
"... There has recently been an interest in the introduction of reconfigurable buses to existing parallel architectures. Among them Reconfigurable Mesh (RM) draws much attention because of its simplicity. This paper presents two O(1) time algorithms to compute the contour of the maximal elements of N pla ..."
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Cited by 8 (5 self)
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There has recently been an interest in the introduction of reconfigurable buses to existing parallel architectures. Among them Reconfigurable Mesh (RM) draws much attention because of its simplicity. This paper presents two O(1) time algorithms to compute the contour of the maximal elements of N planar points on the RM. The first algorithm employs an RM of size N \Theta N while the second one uses a 3D RM of size p N \Theta p N \Theta p N . 1 Introduction It is wellknown that interprocessor communications and simultaneous memory accesses often act as bottlenecks in presentday parallel machines. Bus systems have been intro Corresponding author. duced recently to a number of parallel machines to address this problem. Examples include the Bus Automaton [15], the Reconfigurable Mesh (RM) [11], the content addressable array processor [16], and the Polymorphic torus [9]. A bus system is called reconfigurable if it can be dynamically changed according to either global or local i...
Overview of Mesh Results
 MAXPLANCK INSTITUT FUR INFORMATIK, SAARBRUCKEN
, 1995
"... This paper provides an overview of lower and upper bounds for algorithms for meshconnected processor networks. Most of our attention goes to routing and sorting problems, but other problems are mentioned as well. Results from 1977 to 1995 are covered. We provide numerous results, references and ..."
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Cited by 8 (0 self)
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This paper provides an overview of lower and upper bounds for algorithms for meshconnected processor networks. Most of our attention goes to routing and sorting problems, but other problems are mentioned as well. Results from 1977 to 1995 are covered. We provide numerous results, references and open problems. The text is completed with an index. This is a workedout version of the author's contribution to a joint paper with Miltos D. Grammatikakis, D. Frank Hsu and Miro Kraetzl on multicomputer routing, submitted to the Journal of Parallel and Distributed Computing.
Integer Sorting and Routing in Arrays with Reconfigurable Optical Buses
, 1996
"... In this paper we present deterministic algorithms for integer sorting and online packet routing on arrays with reconfigurable optical buses. The main objective is to identify the mechanisms specific to this type of architectures that allow us to build efficient integer sorting, partial permutation ..."
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Cited by 8 (0 self)
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In this paper we present deterministic algorithms for integer sorting and online packet routing on arrays with reconfigurable optical buses. The main objective is to identify the mechanisms specific to this type of architectures that allow us to build efficient integer sorting, partial permutation routing and hrelations algorithms. The consequences of these results on the PRAM simulation complexity are also investigated. Keywords: Optical pipelined buses, reconfigurable array, sorting, routing. 1. Introduction In largescale general purpose parallel machines based on connection networks, efficient communication capabilities are essential in order to solve most of the problems of interest in a timely manner. Interprocessor communication networks are often the main bottlenecks in parallel machines. One important limitation of these networks concerns the exclusive access to the bus resources, which limits throughput to a function of the endtoend propagation time. Optical communicati...
Efficient Self Simulation Algorithms for Reconfigurable Arrays
, 1995
"... There are several reconfiguringnetwork models of parallel computation that are considered in the published literature, depending on their switching capabilities. Can these reconfigurable models be the basis for the design of massively parallel computers? Perhaps the most fundamental related issue i ..."
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Cited by 7 (1 self)
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There are several reconfiguringnetwork models of parallel computation that are considered in the published literature, depending on their switching capabilities. Can these reconfigurable models be the basis for the design of massively parallel computers? Perhaps the most fundamental related issue is virtual parallelism, or the self simulation problem: given an algorithm which is designed for a large reconfigurable mesh, can it be executed efficiently on a smaller reconfigurable mesh? In this work we give several positive answers to the self simulation problem. We show that the simulation of a reconfiguring mesh by a smaller one can be carried optimally and using standard methods on the model in which buses are established along rows or along columns. A novel technique is shown to achieve asymptotically optimal self simulation on models which allow buses to switch column and row edges, provided that a bus is a "linear" path of connected edges. Finally, for models in which a bus is any ...