Showing papers on "Modularity (networks) published in 2000"

Modularity in development and evolution.

Abstract: This work offers a sustained exploration of modules from developmental and evolutionary perspectives. Contributors discuss what modularity is, how it can be identified and modeled, how it originated and evolved, and why it matters.

Move! : a minimalist theory of construal

Abstract: Preface. 1. The Minimalist Program. 2. Movement and Control. 3. Adjunct Control and Parasitic Gaps. 4. Attract and Sidewards Movement. 5. Is the Binding Theory Necessary?. 6. Case, C--command and Modularity. Bibliography.

Modularity in Development and Why It Matters to Evo-Devo1

Abstract: The concept of modularity is fundamental to research in both evolutionary and developmental biology, though workers in each field use the idea in different ways. Although readily and intuitively recognized, modularity is difficult to define precisely. Most definitions of modularity are operational and implicit, particularly in developmental biology. Examination of several proposed definitions points to some general characteristics of developmental modules, for example their internal integration, and suggests the importance of devising a definition applicable at different levels of the biological hierarchy. Modules, like homologs, must be defined with respect to a specified level of the hierarchy, and a general definition should support both analyses of the evolving causal relationships between levels, and studies of the interconnections between modules of the same type. The designation of a developmental structure, process, or function as a “module” is a testable hypothesis; this hypothesis is confirmed in the case of the dorsal marginal zone of the amphibian gastrula, which acts as a morphogenetic module. Discussions of developmental modularity can provide a meeting place for developmental and evolutionary biologists by helping us articulate key questions at the intersection of the two fields, and design experiments to begin answering them.

Product design for modularity

Abstract: Contents. List of Figures. List of Tables. Acknowledgements. Preface. 1. Product Development Process: An Introduction. 2. Modular Design. 3. Design for Modularity. 4. Decomposition analysis of a Four-Gear speed reducer design: DFMo case study. 5. Design for Manufacture and Assembly. 6. Flexible and Modular Cell Design. References. Index.

Technologies and architectures for scalable dynamic dense WDM networks

Abstract: Wavelength-division multiplexing has been recognized for a number of years as a promising and applied technology that can be used to increase the aggregate system bit rate. More attention has been given to devices and technologies that can be exploited to enable WDM to move from being a pure transmission technology into a state where it can be applied in transparent all-optical networks. In particular, devices and technologies such as wavelength routing switches, switched sources, tunable sources, tunable filters, and wavelength converters have all been developed and demonstrated. This article gives a description of the technologies, subsystems, and network architectures that rely on multiple wavelengths to achieve full transparent all-optical connectivity joined, in many instances, with features like scalability, modularity, and survivability. Exposure is also given to most of the current WDM demonstrators.

Functional Complexity in Organisms: Parts as Proxies

Abstract: The functional complexity, or the number of functions, of organisms hasfigured prominently in certain theoretical and empirical work inevolutionary biology. Large-scale trends in functional complexity andcorrelations between functional complexity and other variables, such assize, have been proposed. However, the notion of number of functions hasalso been operationally intractable, in that no method has been developedfor counting functions in an organism in a systematic and reliable way.Thus, studies have had to rely on the largely unsupported assumption thatnumber of functions can be measured indirectly, by using number ofmorphological, physiological, and behavioral “parts” as a proxy. Here, amodel is developed that supports this assumption. Specifically, the modelpredicts that few parts will have many functions overlapping in them, andtherefore the variance in number of functions per part will be low. If so,then number of parts is expected to be well correlated with number offunctions, and we can use part counts as proxies for function counts incomparative studies of organisms, even when part counts are low. Alsodiscussed briefly is a strategy for identifying certain kinds of parts inorganisms in a systematic way.

Cross-paradigm analysis of autonomous agent architecture

Abstract: Autonomous agent architectures are design methodologies—collections of knowledge and strategies which are applied to the problem of creating situated intelligence. This article attempts to integrate this knowledge across several architectural traditions, paying particular attention to features which have tended to be selected under the pressure of extensive use in real-world systems. We determine that the following strategies provide significant assistance in the design of autonomous intelligent agents: (i) modularity, which simplifies both design and control; (ii) hierarchically organized action selection, which focusses attention and provides prioritization when different modules conflict; and (iii) parallel environment monitoring which allows a system to be responsive and opportunistic by allowing attention to shift and priorities to be re-evaluated. We offer a review of four architectural paradigms: behaviour-based AI; two- and three-layered systems; belief, desire and intention architectures (particu...

Modular control of composed systems

Abstract: Modular supervisory control of composed systems is investigated. The composed systems are discrete event systems represented by the composition of smaller subsystems. This paper refines the modular control by exploiting aspects of modularity of specifications and of plant, aiming to incorporate the least necessary number of sub-systems in each control module. Then, a more efficient approach to verify modularity and synthesize modular controllers for composed systems is formulated and illustrated by an example.

A coupling-guided cluster analysis approach to reengineer the modularity of object-oriented systems

Abstract: Describes a validation experiment of a quantitative approach to the modularization of object-oriented systems. The approach used is based on cluster analysis, a statistical technique used in many fields of science to group items. In this case, the clusters are modules and the items are classes. A sample of some relatively large object-oriented systems was used in this experiment. The calculation of the dissimilarity between classes is based on their relative couplings combined through six different rating schemes. These couplings are classified according to a taxonomy framework where categories were assigned weights. The coupling data were obtained with the MOODKit G2 tool. The results obtained allow conclusions concerning the applicability of the proposed approach. This work was developed in the realm of the MOOD (Modularization of Object-Oriented Systems) project, which aims to deliver a quantitative framework to support the design of object-oriented systems.

Influence of modularity and economy-of-scale effects on design of mesh-restorable DWDM networks

Abstract: This work is motivated by interest in restorable mesh architectures for WDM optical networking DWDM technology is expected to create an extremely modular capacity-planning situation and to produce potentially strong nonlinear economy-of-scale effects in capacity. How will this influence the design of cost-optimized mesh-restorable networks? Will it be essential to do true modular design optimization, or will the traditional rounding-up procedure still be adequate? Can a true modular design method exploit these effects for capital cost savings in the network design? What influence would strong modularity and economy-of-scale have on the evolution of the fiber facilities graph topology for these networks? We address these questions with three mathematical programming formulations that allow a comparative study of these issues in terms of the cost and architectural differences between networks designed with different treatments of the modularity issue. Results show that there are worthwhile savings to be had by bringing modularity aspects directly into the basic design formulation, rather than postmodularizing a continuous integer result, as done in most prior practice. The most significant research finding may be the demonstration of topology reduction (or paring down of the facilities graph) arising spontaneously in optimized designs under the combined effects of high modularity and economy-of-scale. This is the first quantitative indication and explanation of why less highly connected graph topologies may be preferred (at least from an economic standpoint) in future WDM networks, even though the spare capacity efficiency for mesh-based restoration is improved by higher connectivity.

Wirelesss network and methods to be used therein

Abstract: The invention is concerned with a modular wireless network architecture comprising one or more modular wireless terminals, one or more modular base stations, a public network and service providers. The modularity is concerned with intelligent functions for establishing one or more radio connections between the modular wireless terminal and a modular base station, and for allowing the modular wireless terminals to be directly connected to the public network via a modular base station. The invention is also concerned with methods in such networks for establishing different connections.

Modularity of a Certain Calabi-Yau Threefold

Abstract: The Langlands program predicts that certain Calabi-Yau threefolds are modular in the sense that their L-series correspond to the Mellin transforms of weight 4 newforms. Here we prove that the L-function of the threefold given by is , the unique normalized eigenform in .

Modular Product Architecture

Abstract: This paper presents an approach to architecting a family of products that share inter-changeable modules. Rather than a fixed product platform upon which derivative products are created through substitution of various add-on modules, the approach here permits the platform itself to be one of several possible sizes or types. Thus, the system is a collection of modules, each of which can be one of several types. We begin by developing function structures of each product in the portfolio, where each embodies a specific physical principle underlying the common technology. Different function structure systems can be used for each physical principle under consideration. These function structures are then compared to determine common and unique modules. Product modularity rules (i.e. dominant flow, branching, and conversion) are then applied to determine further possible modules. Application of any consistent set of modularity rules defines a feasible portfolio architecture. Each portfolio architecture is represented using a modularity matrix of functions versus products, with shared/unique function levels indicated in the matrix. Possible product modules are indicated with boxes while possible portfolio modules are indicated with shading. This method provides a systematic approach to generating possible portfolio architectures and serves as a communication aid for design team deliberations.

The modularity conjecture for rigid Calabi-Yau threefolds over Q

Abstract: We formulate the modularity conjecture for rigid Calabi-Yau threefolds defined over the field Q of rational numbers. We establish the modularity for the rigid Calabi-Yau threefold arising from the root lattice A_3. Our proof is based on geometric analysis.

Routing extensions for telecommunication network system and method

Abstract: A distributed features system is disclosed which permits a telecommunication network to accommodate the creation of open multimedia services. It is an object of the present invention to create an architecture that facilitates modularity and compositional service creation. It is another object of the present invention to support multimedia services, e.g. services that include voice, graphics, video and text components. It is another object of the present invention to provide an architecture that is general, flexible, permits third party feature development, and can interact with other networks.

Decentralized track fusion in dynamic networks

Abstract: Decentralized systems merit a detailed analysis in view of the potential advantages that they offer. These include significant improvements in fault tolerance, modularity and scalability. Such attributes are required by a number of systems that are currently being planned within the defence and civil aerosense sectors. A recognized difficulty with the decentralized network architecture is the potential it creates for redundant data to proliferate as a result of cyclic information flows. This can lead to estimation biases and divergence. Solutions which require the network information sources to be tagged in some way are not generally possible without relaxing some of the constraints on which the decentralized paradigm is founded. This paper consequently investigates a different approach. Specifically, it examines the application of the Covariance Intersection (CI) data fusion technique. CI is relevant to the redundant data problem because it guarantees consistent estimates without requiring correlations to be maintained. The estimation performance of CI is compared here, with respect to a restricted Kalman approach, for a dynamic multi-platform network example. It is concluded that a hybrid CI/Kalman approach offers the best solution, since it exploits known independent information and unknown correlated information without having to relax the decentralized constraints.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

MOCHA: Exploiting Modularity in Model Checking

Abstract: : MOCHA is a growing interactive software environment for specification, simulation and verification of concurrent systems. The main objective MOCHA is to exploit the modularity in the design structure during model checking. It is intended as a vehicle for development of new verification algorithms and approaches. MOCHA is available in two versions, cMOCHA (Version 1.0.1) and jMOCHA (Version 2.0). This paper describes jMOCHA (for an introduction to cMOCHA, see [2]). Like its predecessor, jMOCHA offers the following capabilities: * System specification in the language of ReaCTIVE MODULES. Reactive modules allow the formal specification of heterogeneous systems with synchronous and asynchronous components. Reactive Modules support modular and hierarchical structuring and reasoning * System executive by randomized or manual trace generation. In the manual mode, the user may choose at each step one of the possible next state of the system. * Requirement verification by invariant checking. MOCHA supports both symbolic and enumerative search. The symbolic model checker is based on BDD engines developed by the UC Berkeley VIS project. * Implementation verification by checking trace containment between implementation and specification modules. The check can be performed automatically if the specification module has no private variables, and otherwise, the user has to supply a witness module defining the refinement mapping. For decomposing proofs, MOCHA supports an assume-guarantee principle.

Decomposition in energy system synthesis/design optimization for stationary and aerospace applications

Abstract: A number of multilevel methods for energy system synthesis/design optimization exist. Of these approaches the local-global decomposition methods (LGO and ILGO) allow for the modularity and discipline/technology autonomy required for solving large multidisciplinary synthesis/design problems. An example of a large-scale problem for a military aircraft is used to discuss the features of LGO and ILGO. The similarities between these methods and those used by the aerospace multidisciplinary design optimization community are briefly explored. It is believed that the commonalties which exist between the different approaches will permit future synergies and a genuine interdependence at an optimization level between the different disciplines

Delay-Insensitivity and Semi-Modularity

Abstract: The study of asynchronous circuit behaviors in the presence of component and wire delays has received a great deal of attention. In this paper, we consider asynchronous circuits whose components can be any non-deterministic sequential machines of the Moore type, and describe a formal model for these circuits and their behaviors under the inertial delay model. We model an asynchronous circuit C by a network N of modules with delays associated with its components and/or wires. We compute the behavior of N assuming arbitrary inertial delays in the modules, and take this behavior to be correct. We define N to be strongly delay-insensitive if its behavior remains correct in the presence of arbitrary stray delays, where correctness is defined through the notion of observational equivalence (or bisimulation), one of the strongest forms of behavioral equivalence. We introduce the notion of quasi semi-modularity, which generalizes Muller's definition of semi-modularity to non-deterministic networks. We prove that a circuit, with all the wire delays taken into account, is strongly delay-intensitive if and only if its behavior is quasi semi-modular.

The role of modularity in document authoring systems

Abstract: Modularity is a fundamental concept in documents and document development as well as in programming. I hypothesized that the effectiveness of writing professionals could be increased by providing a working environment to support explicit modularity in documents and document development. This paper briefly describes an environment designed to enable testing this hypothesis and evaluates it by means of discussions with professional writers who used it for large, real-world, development projects.

Modularity in Meta-Languages

Abstract: A meta-language for semantics has a high degree of modularity when descriptions of individual language constructs can be formulated independently using it, and do not require reformulation when new constructs are added to the described language. The quest for modularity in semantic meta-languages has been going on for more than two decades. Here, most of the main meta-languages for operational, denotational, and hybrid styles of semantics are compared regarding their modularity. A simple bench-mark is used: describing the semantics of a pure functional language, then extending the described language with references, exceptions, and concurrency constructs. For each style of semantics, at least one of the considered meta-languages appears to provide a high degree of modularity.

An object oriented approach to load flow in distribution systems

Abstract: The peculiar characteristics of distribution systems require the development of specific load flow models and solving techniques. The aim of the studies presented in literature is usually to enhance computational efficiency and convergence characteristics of the algorithms. Yet, thanks to the increase of the capacity of modern computing environments, new approaches can be adopted that give preference to flexibility, extensibility and maintainability of the software rather than to computational efficiency. In the paper, the object-oriented paradigm is applied to distribution load flow. The electrical system modeling is structured in a hierarchy of classes; for each class, data and methods are defined to implement local processing of a Newton-Raphson distribution load flow algorithm decomposed into modules; information hiding guarantees modularity and flexibility. The features of a software tool implemented in an open software CAD environment are presented. Numerical applications to a test system evidence the convergence characteristics of the algorithm.

Low-level type systems for modularity and object-oriented constructs

Abstract: ly, an object file consists of three components:

An artificial life model for investigating the evolution of modularity

Abstract: To i n vestigate the issue of how modularity emerges in nature, we present an Artiicial Life model that allow us to reproduce on the computer both the organisms (i.e., robots that have a genotype, a nervous system, and sensory and motor organs) and the environment in which organisms live, behave and reproduce. In our simulations neural networks are evolutionarily trained to control a mobile robot designed to keep an arena clear by p i c king up trash objects and releasing them outside the arena. During the evolutionary process modular neural networks, which control the robot's behavior, emerge as a result of genetic duplications. Preliminary simulation results show that duplication-based modular architecture outperforms the nonmod-ular architecture, which represents the starting architecture in our simulations. Moreover, an interaction between mutation and duplication rate emerges from our results. Our future goal is to use this model in order to explore the relationship between the evolutionary emergence of modularity and the phenomenon of gene duplication.

A Study on Fuzzy AHP Method in Green Modularity Design

Abstract: Green Design and Manufacturing is a proactive approach to minimize wastes, protect the environment and conserve the resources during a product's design stage. In this paper, a theoretical scheme of multi-objective modularity analysis for discrete electromechanical product design is proposed. Product physical architecture is represented by a fuzzy graph, where fuzzy relationships contain environmental objectives and influence module formulation. Finally,the optimal product modules combining all objectives need to be searched by a clustering algorithm.