Showing papers on "Modularity (networks) published in 1980"

Exploiting structure in piecewise-linear homotopy algorithms for solving equations

Abstract: We consider the recent algorithms for computing fixed points or zeros of continuous functions fromRn to itself that are based on tracing piecewise-linear paths in triangulations. We investigate the possible savings that arise when these fixed-point algorithms with their usual triangulations are applied to computing zeros of functionsf with special structure:f is either piecewise-linear in certain variables, separable, or has Jacobian with small bandwidth. Each of these structures leads to a property we call modularity; the algorithmic path within a simplex can be continued into an adjacent simplex without a function evaluation or linear programming pivot. Modularity also arises without any special structure onf from the linearity of the function that is deformed tof.

A New Protocol for a Distributed Loop Communication Network

Abstract: This paper presents a new loop structure and its associated protocol for a mini-micro computer communication network. The proposed structure consists of two loops, both of which are used for control and data transmission one in the clockwise direction and the other in the counter-clockwise direction. This topology has all the advantages of ring structures such as simplicity, cost modularity, space modularity, concurrent service and high reliability. In addition, it provides better line utilization and traffic regulation than previously proposed loops because a) it has a distributed control mechanism and b) it allows two stations to communicate for long periods of time without blocking completely communication between other stations. Furthermore, it allows limited communication in case that a break occurs in the line. The loop protocol is based on the SDLC frame format. This has made possible the use of the latest LSI technology that disasembles and reassembles the character of this frame.

A framework for data-flow distributed processing

Abstract: A framework for data-flow distributed processing is established through the definition of a data-flow model and a set of language constructs for concurrent programming. The proposed approach is based on the following characteristics: i) the exploitation of parallelism at the operation level leads to the efficient and natural exploitation of parallelism at the program level, and ii) parallelism, communication, nondeterminism and history sensitivity are primitive concepts. The aim of the defined data-flow constructs is to enhance modularity and parallelism of programs. Two structuring levels are introduced, called «modules» and «frames», to permit both symmetric and asymmetric communication. Single assignment and guarded commands are employed inside modules. Examples of tipical programming problems, including shared resources management, are given together with a short account of a distributed data-flow architecture able to support data-flow distributed processing efficiently.

Modularity in Non-Procedural Languages through Abstract Data Types.

Abstract: : This dissertation presents abstract data types as a means of introducing modularity in non-procedural languages. Non-procedural languages based on equational specifications have been proposed in recent years to improve programmer productivity reliability. Issues of structured programming (i.e. disciplined use of the control structure) have no meaning in the context of these languages because these are devoid of any control structure. Statements in a specification can be given in any order; the sequence of execution is determined after an analysis of the specification. Modularity, however, still remains an important issue in the context of these languages, as it allows specifications to be written and processed independently. data types are proposed as a means of introducing modularity. Notion of module for the specification of abstract data types is introduced and its denotational semantics is given. Nopal, a non-procedural language for the specification of testing of electrical circuits, has been chosen in which abstract data types are introduced for modularity. The abstract data types also allow specification of virtual devices in testing.