An algebra of Petri nets for the dynamic specification of the distributed semantics of task synchronization in hierarchical multiagent robotic systems is developed. the proposed algebra allows for the hierarchical spe...
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An algebra of Petri nets for the dynamic specification of the distributed semantics of task synchronization in hierarchical multiagent robotic systems is developed. the proposed algebra allows for the hierarchical specification of the flow of control and the temporal order of task execution by multiagent systems. Each level of the resulting hierarchies horizontally contains the synchronization structure of task execution and vertically is a generalization of the level below and a specialization of the level above. the horizontal synchronization structures developed by the proposed Petri net model maintain the desirable properties of safeness and liveness by construction. the model utilizes a modularization of complex kinematic chains, a classification of primitive tasks, and a concept of functional time dependency.< >
A hierarchical design methodology for decentralized integrated control of a hypersonic vehicle is described. A hierarchical design methodology is developed for an integrated model comprising many subsystems. the desig...
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A hierarchical design methodology for decentralized integrated control of a hypersonic vehicle is described. A hierarchical design methodology is developed for an integrated model comprising many subsystems. the design objective for the higher level of augmentation is to compensate for subsystems' interactions by making the subsystems as weakly coupled as possible through this level of augmentation. With a reduced coupling strength between subsystems, individual subsystems can be augmented separately and independently irrespective of their interactions. the combination of the two levels of augmentation results in an integrated control scheme with reduced complexity in boththe design and structure of the controller. the design methodology is applied to an integrated dynamic model of an engine and airframe for a hypersonic vehicle. the derived control laws are compared with a nonintegrated design technique for an identical design objective. It is shown that the proposed integrated control scheme reduces the stabilizing surface deflection requirements in control power partitioning.< >
Summary form only given. the issue of ease of using shared data in a data-intensive parallel computing environment is discussed. An approach is investigated for transparently supporting data sharing in a loosely coupl...
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ISBN:
(纸本)0818619155
Summary form only given. the issue of ease of using shared data in a data-intensive parallel computing environment is discussed. An approach is investigated for transparently supporting data sharing in a loosely coupled parallel computing environment, where a moderate to a large number of individual computing elements are connected via a high-bandwidth network without necessarily physically sharing memory. A system called VOYAGER is discussed which serves as the underlying system facility that supervises the distributed shared virtual memory. VOYAGER allows shared-data parallel applications to take advantage of parallel and distributedprocessing with relative ease. the application program merely maps the shared data onto its virtual address space and replicates itself on distributed machines and spawns appropriate execution threads;the threads would automatically be given coordinated access to the shared data distributed in the network. Multiple computation threads migrate and populate the processors of a number of computing elements, making use of the multiple processors to achieve a high degree of parallelism. the low-level resource management chores are made available once and for all in the underlying facility VOYAGER, usable by many different data-intensive applications.
the proceedings contains 99 papers. the following topics are dealt with: probabilistic algorithms;learning theory and algorithms;graph theory and algorithms;computational geometry;network flow problems;operations rese...
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ISBN:
(纸本)0818619821
the proceedings contains 99 papers. the following topics are dealt with: probabilistic algorithms;learning theory and algorithms;graph theory and algorithms;computational geometry;network flow problems;operations research;query languages;logics;parallelprocessing;complexity;cryptography;mathematical programming;automata;interconnection networks;distributed computing;data structures.
A scientific parallel processor called the R256 has been developed. the R256 is composed of 16 × 16 processing elements and has the outstanding features of a distributedparallel network as well as an ieee 80-bit...
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ISBN:
(纸本)9780897913195
A scientific parallel processor called the R256 has been developed. the R256 is composed of 16 × 16 processing elements and has the outstanding features of a distributedparallel network as well as an ieee 80-bit extended-floating-point computation ability. the computation accuracy, required by an exhaustive number of iterations in scientific computations, is resolved by the dedicated 80-bit VLSI processor, which was developed for the R256. the innovative distributedparallel network was designed to resolve heavy communication problems, which are found in applications based on the Monte Carlo simulation technique. the R256 network was very economical at a hardware cost of √ N-fold (16-fold in this case) that of an ideal full-crossbar switch, while the rates were kept comparable to that of an ideal switch. the R256 demonstrates 2-Gb/s data transfer rates and 500-MFLOPS (million-floating-point-operations/s) computation rates on a semiconductor-device-simulation application.
Given an undirected graph G with N vertices and a set P of N points in the plane, the geometric embedding problem consists of finding a bijection from the vertices of G to the points in the plane which minimize the su...
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ISBN:
(纸本)0818619821
Given an undirected graph G with N vertices and a set P of N points in the plane, the geometric embedding problem consists of finding a bijection from the vertices of G to the points in the plane which minimize the sum total of edge lengths of the embedded graph. Fast approximation algorithms are given for embedding d-dimensional grids in the plane within a factor of O(log N) times optimal cost for d > 2 and O(log2N) for d = 2. It is shown that any embedding of a hypercube, butterfly, or shuffle-exchange graph must be within an O(log N) factor of optimal cost. When the points of P are randomly distributed or arranged in a grid, a polynomial-time algorithm that can embed arbitrary weighted graphs in these points with cost within an O(log2N) factor of optimal is given. It is shown how the algorithms developed for geometric embeddings can be used to give O(log2N) times optimal solutions to problems of performance optimization for parallel processors.
A novel method that provides extremely fast Input/Output (I/O) data transfer to a RISC-like graphics engine is presented. this method employs a combined two-port / two-access and a three-port / three-access register f...
ISBN:
(纸本)9780897913195
A novel method that provides extremely fast Input/Output (I/O) data transfer to a RISC-like graphics engine is presented. this method employs a combined two-port / two-access and a three-port / three-access register file used for concurrent processing and I/O data transfer. the three-port cell employed is only 25 % larger than the two-port cell, offering considerable advantages over alternative approaches, such as FIFOs or register *** paper discusses some methods that can provide highly fast I/O data transfer in parallel with execution and focuses on the design and implementation of the CMOS-2um register file *** Terms - Computer Architecture, Reduced Instruction Set Computers, VLSI Design, Computer Image Generation, Interprocessor Communication.
the proceedings contain 17 papers. the topics discussed include: the generation of Ada and an associated PDL from a higher-level representation;non-technical aspects of using Ada ® solution of elliptic partial di...
the proceedings contain 17 papers. the topics discussed include: the generation of Ada and an associated PDL from a higher-level representation;non-technical aspects of using Ada ® solution of elliptic partial differential equations using parallelprocessing and tasks in Ada language;should the DOD mandate a standard software development process?;the role of explicit type management schemes in the implementation of abstract data types in Ada;translation of VHDL to Ada;programming paradigms involving exceptions: a software quality approach;the impact of the Ada∗ language resource allocation, programmer productivity, and project performance;an automated method of referencing Ada∗ reusable code using LIL;mechanisms for abstraction in Ada∗ functional specifications of reusable MIS software in Ada;interactive discrete event simulation in Ada∗;analysis of Ada∗ for a crucial distributed application;selection and use of and Ada®-based program design language;configuration control in an programming support environment;and a compiler independent approach to test and configuration management for Ada.
the following topics are dealt with: algorithms;data structures;computational complexity;parallelprocessing;distributedprocessing;search methods;cryptology;sorting;and graph theory. 54 papers were presented, all of ...
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ISBN:
(纸本)0818607408
the following topics are dealt with: algorithms;data structures;computational complexity;parallelprocessing;distributedprocessing;search methods;cryptology;sorting;and graph theory. 54 papers were presented, all of which are published in full in the present proceedings.
the proceedings contain 47 papers. the topics discussed include: ALKAHEST III: automatic analysis of periodic weakly nonlinear ODES;limitations to algorithm solvability: Galois methods and models of computation;code g...
ISBN:
(纸本)0897911997
the proceedings contain 47 papers. the topics discussed include: ALKAHEST III: automatic analysis of periodic weakly nonlinear ODES;limitations to algorithm solvability: Galois methods and models of computation;code generation for hybrid mixed mode formulation in finite element analysis;algebraic decomposition of regular curves;algebraic decomposition of regular curves;fast parallel algorithms for similarity of matrices;summation of binomial coefficients using hypergeometric functions;MathScribe: a user interface for computer algebra systems;applications of a software interconnection system in mathematical problem solving environments;divide-and-conquer in computational group theory;PowerMath - a system for the macintosh;how to compute multivariate PADE approximants?;there is no 'Uspensky's method';a numerical code generation facility for reduce;usage of reduce for computations of group-theoretical weight of Feynman diagrams in non- abeliangauge theories;a sp4rse distributed representation using prime numbers;simplification of algebraic expression by multiterm rewriting rules;and dialogue in reduce experience and development.
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