Showing papers on "Modularity (networks) published in 1998"

MOCHA: Modularity in Model Checking

Abstract: R. Alur1, T.A. Henzinger2, F.Y.C. Mang2, S. Qadeer2, S.K. Rajamani2, and S. Tasiran2 1 Computer & Information Science Department, University of Pennsylvania, Philadelphia, PA 19104. Computing Science Research Center, Bell Laboratories, Murray Hill, NJ 07974. alur@cis.upenn.edu 2 Electrical Engineering & Computer Sciences Department, University of California, Berkeley, CA 94720. ftah,fmang,shaz,sriramr,serdarg@eecs.berkeley.edu

Modularity in design of products and systems

Abstract: Modularity refers to the use of common units to create product variants. This paper aims at the development of models and solution approaches to the modularity problem for mechanical, electrical, and mixed process products (e.g., electromechanical products). To interpret various types of modularity, e.g., component-swapping, component-sharing and bus modularity, a matrix representation of the modularity problem is presented. The decomposition approach is used to determine modules for different products. The representation and solution approaches presented are illustrated with numerous examples. The paper presents a formal approach to modularity allowing for optimal forming of modules even in the situation of insufficient availability of information. The modules determined may be shared across different products.

Evolutionary Psychology and the Massive Modularity Hypothesis

Abstract: In recent years evolutionary psychologists have developed and defended the Massive Modularity Hypothesis, which maintains that our cognitive architecture—including the part that subserves 'central processing'—is largely or perhaps even entirely composed of innate, domain-specific computational mechanisms or 'modules'. In this paper I argue for two claims. First, I show that the two main arguments that evolutionary psychologists have offered for this general architectural thesis fail to provide us with any reason to prefer it to a competing picture of the mind which I call the Library Model of Cognition. Second, I argue that this alternative model is compatible with the central theoretical and methodological commitments of evolutionary psychology. Thus I argue that, at present, the endorsement of the Massive Modularity Hypothesis by evolutionary psychologists is both unwarranted and unmotivated.

Modularity-In-Design: An Analysis Based On the Theory Of Real Options

Abstract: This paper investigates the economic role of modularity in the design of new products and processes. We construct a formal model of the design process based on the financial theory of options, and analyze the benefits and costs of breaking apart a complex design into independent modules linked by pre-established interfaces. The model provides a rigorous framework for dealing with the effects of uncertainty, and shows how modular designs, independent experiments and testing technologies interact to create economic value. The model also shows how modularity rests on and contributes to the knowledge and organizational structure of a company.

RL-TOPS: An Architecture for Modularity and Re-Use in Reinforcement Learning

Abstract: This paper introduces the RL-TOPs architecture for robot learning, a hybrid system combining teleo-reactive planning and reinforcement learning techniques. The aim of this system is to speed up learning by decomposing complex tasks into hierarchies of simple behaviours which can be learnt more easily. Behaviours learnt in this way can subsequently be re-used to solve a variety of problems, reducing the need to learn every new task from scratch. It is even possible to learn multiple behaviours simultaneously, thus making more eecient use of experience. We demonstrate these advantages in a simple simulated environment.

RTP Payload Format for Bundled MPEG

Abstract: This document describes a payload type for bundled, MPEG-2 encoded video and audio data that may be used with RTP, version 2. Bundling has some advantages for this payload type particularly when it is used for video-on-demand applications. This payload type may be used when its advantages are important enough to sacrifice the modularity of having separate audio and video streams.

Design for Variety

Abstract: Companies seek various methods to stay competitive; one possible method to gain customers and enhance competitiveness is to offer increased variety to the marketplace However, increasing the amount of variety within a company has costs, which the company of course seeks to reduce In this chapter we first discuss some specific challenges that companies such as Boeing, Denso, HP, and Seagate have with increased variety We then present our Design for Variety (DFV) research It focuses on methodologies that will help companies quantify the costs of providing variety and will qualitatively guide designers in developing products that incur minimum variety costs Our proposed tools incorporate both quantitative indices and qualitative design charts

Rank Reordering Strategy for MPI Topology Creation Functions

Abstract: A large fraction of all parallel applications use process topologies Mapping of those topologies onto hardware architecture has been studied for long time Meanwhile, many current multiprocessor systems are implemented in modular architecture This paper presents a new mapping strategy that takes advantage of this modularity The idea was implemented in MPI's topology creation functions and found to be very effective

Reusable coordinator modules for massively concurrent applications

Abstract: Isolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability and reusability of parallel and/or distributed software. MANIFOLD is a pure coordination language that encourages this separation. We use real, concrete, running ANIFOLD programs to demonstrate the concept of pure coordination modules and the advantage of their reuse in applications of different natures. Performance results for the examples presented in this paper show that the overhead of using MANIFOLD to achieve this enhanced modularity and reusability is in practice small, compared to the more conventional paradigms for the design and programming of parallel and distributed software

Identification of Limiting Factors for Improving Design Modularity

Abstract: In previous work, the idea of designing for the life cycle (DFLC) was investigated through the improvement of product architectures with an emphasis on increasing modularity. In this paper, that work is extended by developing a method for suggesting changes to the product to improve the correspondence between modules from different life-cycle viewpoints. Based on an analogy to the determination of critical paths in network analysis, the identification of limiting factors in a candidate design is intended to assist the designer in recognizing design changes that have the greatest impact on improving recyclability. The purpose of this paper is to illustrate how the identification of limiting factors can be used to improve product recyclability during configuration design. A general method for identifying and prioritizing the limiting factors is presented and applied in the context of improving recyclability. This method is shown to be capable of efficiently determining effective design changes to improve product modularity and recyclability. It is argued that the concept of limiting factors and the developed method are applicable to many different configuration design issues and not limited to recycling or even other DFLC issues. A validation of the limiting factor identification method is presented using a Genetic Algorithm and an exhaustive search.

A 2.56-Tb/s multiwavelength and scalable switch-fabric for fast packet-switching networks

Abstract: We propose an implementation of a terabits-per-second crossbar-equivalent switch-fabric for packet-switching networks. It consists of switch-modules employing semiconductor optical amplifier gates (SOAGs), arrayed waveguide grating routers, and multiple wavelength-channels. It offers large modularity and a small internal loss. The number of SOAGs in a 256/spl times/256 switch-fabric is one-eighth that of a conventional switch-fabric. Scalability up to 2.56 Tb/s is demonstrated by a 10 Gb/s transmission experiment in which the input level into the switch-module was observed to possess a dynamic range of 6 dB.

An approach to object system modeling by state-based object petri nets

Abstract: For many years, Petri nets have been used for modeling the behavior of various types of concurrent systems. While these net models are especially well suited to capture the behavior of concurrent systems, it is still the case that net models do not easily capture some important structural aspects of a system, such as modularity. In terms of software systems for distributed applications, the object-oriented paradigm has become a standard for defining modularity and reuse of software. Thus, an evolving direction in Petri net technology is the blending of net features with object-oriented capability. This paper discusses one such approach for state-based object systems.

Modularity of Termination Using Dependency pairs

Abstract: The framework of dependency pairs allows automated termination and innermost termination proofs for many TRSs where such proofs were not possible before. In this paper we present a refinement of this framework in order to prove termination in a modular way. Our modularity results significantly increase the class of term rewriting systems where termination resp. innermost termination can be proved automatically. Moreover, the modular approach to dependency pairs yields new modularity criteria which extend previous results in this area. In particular, existing results for modularity of innermost termination can easily be obtained as direct consequences of our new criteria.

Modularity, mental retardation and speed of processing

Abstract: This paper briefly outlines Anderson's (1992) theory of the minimal cognitive architecture underlying intelligence and development and briefly discusses its application to understanding mental retardation and specific cognitive deficits. An experiment on the relationship between face perception and mental retardation serves as an illustration of how the theory might be informative about the relationship between intelligence and cognitive architecture.

Modular drawer system

Abstract: A modular drawer system is particularly adapted for installation on vehicular load-carrying surfaces such as the beds of pickup trucks and the cargo-supporting floors of utility vehicles to transport and store tools, machinery parts, building materials and the like in an orderly, easily-accessible manner. The system's modularity provides highly variable alternative stacked configurations and volumes to accommodate different vehicles. Although lightweight and easily installable, the system nevertheless is highly resistant to displacement under the dynamic forces typically experienced in vehicular applications, and is also highly resistant to vertical loading.

Method of extracting timing characteristics of transistor circuits, storage medium storing timing characteristic library, lsi designing method, and gate extraction method

Abstract: A method of extracting timing characteristics from transistor circuit data of modularity design products (a module) such as a CPU core in which the extracted timing characteristics are used for the timing verification of a circuit including a module to be extracted and timing constraints when logical synthesis or timing-driven layout is made. Particularly, since conditions fit for a timing rule of the module are included in timing characteristics when timing verification is executed by simulation, verification free of pseudo error is enabled. Also, the configuration of a timing characteristic library, a storage medium storing it and an LSI designing method using the storage medium are provided.

Categorical term rewriting : monads and modularity

Abstract: Term rewriting systems are widely used throughout computer science as they provide an abstract model of computation while retaining a comparatively simple syntax and semantics. In order to reason within large term rewriting systems, structuring operations are used to build large term rewriting systems from smaller ones. Of particular interest is whether key properties are modular, that is, if the components of a structured term rewriting system satisfy a property, then does the term rewriting system as a whole? A body of literature addresses this problem, but most of the results and proofs depend on strong syntactic conditions and do not easily generalize. Although many specific modularity results are known, a coherent framework which explains the underlying principles behind these results is lacking. This thesis posits that part of the problem is the usual, concrete and syntaxoriented semantics of term rewriting systems, and that a semantics is needed which on the one hand elides unnecessary syntactic details but on the other hand still possesses enough expressive power to model the key concepts arising from the term structure, such as substitutions, layers, redexes etc. Drawing on the concepts of category theory, such a semantics is proposed, based on the concept of a monad, generalising the very elegant treatment of equational presentations in category theory. The theoretical basis of this work is the theory of enriched monads. It is shown how structuring operations are modelled on the level of monads, and that the semantics is compositional (it preserves the structuring operations). Modularity results can now be obtained directly at the level of combining monads without recourse to the syntax at all. As an application and demonstration of the usefulness of this approach, two modularity results for the disjoint union of two term rewriting systems are proven, the modularity of confluence (Toyama’s theorem) and the modularity of strong normalization for a particular class of term rewriting systems (non-collapsing term rewriting systems). The proofs in the categorical setting provide a mild generalisation of these results.

A Transmutable Telecom System

Abstract: We have developed a novel transmutable system for telecommunications, which features both reconfigurability and high performance. There are two key innovations. One is a board-level modularity concept that allows different functions to be implemented on different boards individually. The other is a high-speed serial link mechanism that provides excellent inter-board communications without sacrificing performance. Our system is distinguished from conventional ASIC emulators by its ability to provide a real-world execution environment, which enables us to connect the system to other telecommunications systems directly.

A Language for Specifying the Composition of Reliable Distributed Applications

Abstract: This paper describes the design of a scripting language aimed at expressing task (unit of computation) composition and inter-task dependencies of distributed applications whose execution could span arbitrary large durations. This work is motivated by the observation that an increasingly large number of distributed applications are constructed by composing them out of existing applications and are executed in an heterogeneous environment. The resulting applications can be very complex in structure, containing many notification and dataflow dependencies between their constituent applications. The language enables applications to be structured with the properties of modularity, interoperability, dynamic reconfigurability and fault-tolerance.

Program transformation in calculational form

Abstract: Correctness-preserving program transformation has recently received a particular attention for compiler optimization in functional programming [Kelsey and Hudak 1989; Appel 1992; Peyton Jones 1996]. By implementing a compiler using many passes, each of which is a transformation for a particular optimization, one can attain a modular compiler. It is no surprise that the modularity would increase if transformations are structured, i.e. constructed in a modular way. Indeed, the program transformation in calculational form (or program calculation) can help us to attain this goal.

P-R IO : A M odular Parallel-Programming Environment

Abstract: o exploit parallelism, developers have based the softwareof many powerful multicomputer architectures on sequen-tial pieces of computation that act concurrently and inter-act for communication and synchronization. In most mes-sage-passing-based programming environments, theinteractions are specified through explicit language constructs embeddedin the text of the program modules. Consequently, when the interactionpatterns are not trivial, the overall program structure is concealed, mak-ing the structure difficult to recognize and complicating performanceoptimization. Also, these environments show little regard for propertiesof great concern in software engineering, such as reuse, modularity, andsoftware maintenance.To address these issues, we designed the Parallel Reconfigurable Inter-connectable Objects environment, which offers a graphical programmingtool, modular construction, high portability, a separate configuration lan-guage, and runtime support mechanisms for parallel programs. P-RIO is,in principle, independent of the programming language, operating system,and communication architecture that the programmer adopts.

A Modular and Scalable Simulation Tool for Large Wireless Networks

Abstract: This paper describes a modular and scalable simulation environment, called GloMoSim, to evaluate end-to-end performance of integrated wired and wireless networks. GloMoSim has been implemented on sequential and parallel computers and can be used to simulate networks with a large number of nodes. It is designed as a set of library modules, each of which simulates protocols within a specific layer of the communication stack. Common APIs have been specified between neighboring layers on the protocol stacks. The modularity facilitates the study of the interaction between layers as well as the evaluation and comparison of different layers. The parallel structure of the simulator enables the scaling to large network sites without compromising the accuracy. Two sets of experiments (parallel scaling; TCP and MAC layer interaction) illustrate the features of the GloMoSim platform.

An artificial modular neural network and its basic dynamical characteristics

Abstract: This work contains a proposition of an artificial modular neural network (MNN) in which every module network exchanges input/output information with others simultaneously. It further studies the basic dynamical characteristics of this network through both computer simulations and analytical considerations. A notable feature of this model is that it has generic representation with regard to the number of composed modules, network topologies, and classes of introduced interactions. The information processing of the MNN is described as the minimization of a total-energy function that consists of partial-energy functions for modules and their interactions, and the activity and weight dynamics are derived from the total-energy function under the Lyapunov stability condition. This concept was realized by Cross-Coupled Hopfield Nets (CCHN) that one of the authors proposed. In this paper, in order to investigate the basic dynamical properties of CCHN, we offer a representative model called Cross-Coupled Hopfield Nets with Local And Global Interactions (CCHN-LAGI) to which two distinct classes of interactions – local and global interactions – are introduced. Through a conventional test for associative memories, it is confirmed that our energy-function-based approach gives us proper dynamics of CCHN-LAGI even if the networks have different modularity. We also discuss the contribution of a single interaction and the joint contribution of the two distinct interactions through the eigenvalue analysis of connection matrices.

A language for specifying the composition of reliable distributed applications

Abstract: This paper describes the design of a scripting language aimed at expressing task (unit of computation) composition and inter-task dependencies of distributed applications whose execution could span arbitrary large durations. This work is motivated by the observation that an increasingly large number of distributed applications are constructed by composing them out of existing applications and are executed in an heterogeneous environment. The resulting applications can be very complex in structure, containing many notification and dataflow dependencies between their constituent applications. The language enables applications to be structured with the properties of modularity, interoperability, dynamic reconfigurability and fault-tolerance.