Reconfigurable Asynchronous Logic Automata (RALA)

Computer science has served to insulate programs and programmers from knowledge of the underlying mechanisms used to manipulate information, however this fiction is increasingly hard to maintain as computing devices decrease in size and systems increase in complexity. Manifestations of these limits appearing in computers include scaling issues in interconnect, dissipation, and coding. Reconfigurable Asynchronous Logic Automata (RALA) is an alternative formulation of computation that seeks to align logical and physical descriptions by exposing rather than hiding this underlying reality. Instead of physical units being represented in computer programs only as abstract symbols, RALA is based on a lattice of cells that asynchronously pass state tokens corresponding to physical resources. We introduce the design of RALA, review its relationships to its many progenitors, and discuss its benefits, implementation, programming, and extensions.National Science Foundation (U.S.) Center for Bits and AtomsUnited States. Army Research Office (Grant number W911NF-08-1-0254)United States. Army Research Office (Grant number W911NF-09-1-0542

Civilising Globalism: Transnational Norm-Building Networks—A Research Programme

Decentralised, self-organised cross-border activities are increasingly shaping global policymaking. While state actors have lost ground, policy and economic networks have emerged as key actors, transforming international relations as well as national spheres. Academic discourse is following their activity, often focusing on "advocacy networks" and on the role of transnational actors within the transformation of the world economy and world polity. In contrast to these research activities, the approach proposed here extends the scope of inquiry to include the role of transnational networks in norm-building and norm-implementation. The networks under scrutiny here do not confine themselves to the articulation of particular interests, the resolution of particular conflicts, or compliance with legal norms. It is presumed here that a variety of networks which are fundamentally concerned with the creation of norms have emerged. The predominance of the nation-state, one of the main characteristics of modern democratic thinking, has eroded to the point where the fundamental nexus of voice (democratic participation) and entitlement (legal and social rights and duties) has been weakened or even broken. We presume that this decentration has fundamentally changed the option of voice as one of the most important responses by citizens to crisis and change. This comes to the fore with the emergence and effectiveness of transnational norm-building networks. The article develops a research programme, the outcome of which will shed light on this new resource for the development of a democratised world polity.networks, norms, world polity, globalisation, global civil society

Simulation of concurrent process with Petri-Markov nets

Abstract. Mathematical apparatus of Petri-Markov nets is described. Petri-Markov simple subnets are introduced. Structures for the simulation of parallelism based on the simple subnets are proposed. Mathematical relationships for the evaluation of the time characteristics of algorithms for a wide class of concurrent computing systems are described. [Ivutin A.N Introduction Currently, a parallelism is a prevailing paradigm of computational processes organisation. In the specialised computer sphere, the idea of parallelism has been used in practice for more than fifty years (CDC-6600 1964 [1] consists of ten independent functional devices operated in parallel), with up-to-date concurrent computations being used in practice in both multi-core processors and computer networks In The methodology of the modelling of concurrent processes was elaborated in the works by C. Petri, W. Reisig, J. Peterson, and V.E

Invariants and Home Spaces in Transition Systems and Petri Nets

This lecture note focuses on comparing the notions of invariance and home spaces in Transition Systems and more particularly, in Petri Nets. We also describe how linear algebra relates to these basic notions in Computer Science, how it can be used for extracting invariant properties from a parallel system described by a Labeled Transition System in general and a Petri Net in particular. We endeavor to regroup a number of algebraic results dispersed throughout the Petri Nets literature with the addition of new results around the notions of semiflows and generating sets. Examples are given to illustrate how invariants can be handled to prove behavioral properties of a Petri Net. Some additional thoughts on invariants and home spaces will conclude this note.Comment: 83 page

Compositional modelling: The formal perspective

We provide a formal framework within which an Information System (IS) could be modelled, analysed, and verified in a compositional manner. Our work is based on Interval Temporal Logic (ITL) and its programming language subset, Tempura. This is achieved by considering IS, of an enterprise, as a class of reactive systems in which it is continually reacting to asynchronously occurring events within a given period of time. Such a reactive nature permits an enterprise to pursue its business activities to best compete with others in the market place. The technique is illustrated by applying it to a small case study from Public Service Systems (PSS).Funding received from the UK Engineering and Physical Sciences Research Council (EPSRC) through the Research Grant GR/M/0258

Using Migration Monitoring Data to Assess Bird Population Status and Behavior in a Changing Environment

Across the world, researchers use migration banding stations to document bird migration and study the phenomenon. In this dissertation, I focus on ways of analyzing bird migration banding data and the utility migrating birds as indicators of ecosystem health that make these monitoring efforts more useful to answering ecological questions and managing migratory species. In Chapter 1, we provide background on hierarchical modeling and an overview of our findings. In Chapter 2, we developed and validated new methods to estimate daily changes in migratory population size while controlling for changes in detectability due to environmental conditions. In Chapter 3, this modeling technique was then employed to evaluate the continental-scale and the local-scale determinants of migratory population size for ten species of migrants using a Key Biscayne, FL site for migratory stopover in the fall. Species showed diverse relationships between abundance and local weather conditions. Wet conditions on the breeding grounds consistently increased migratory onset and dry conditions on the non-breeding grounds from the previous winter consistently reduced population size across all species. In Chapter 4, we looked at how daily changes in migrant density influenced the stopover behavior of seven songbirds at the Key Biscayne stopover site. Density-dependence had positive and negative effects on mass gain across species, the chance of that effect being negative increased with the average daily stopover population size of the species. Density-dependence was hypothesized to be a function of overall migrant abundance at the site, with only highly abundance species showing negative effects. Finally, in Chapter 5 migrating birds are used to tell us about contaminant exposure in their breeding and non-breeding environments. We found higher amount of mercury in fall than the spring and there was evidence that fall mercury exposure was altering migratory behavior. These patterns provide the first evidence that Hg exposure alters migratory physiology in songbirds. Overall, this dissertation suggests that migration monitoring is useful for both basic and applied research and provide a tool for understanding the complicated life cycles of migratory animals

Cyclic Ordering through Partial Orders *

International audienceThe orientation problem for ternary cyclic order relations has been attacked in the literature from combinatorial perspectives, through rotations , and by connection with Petri nets. We propose here a twofold characterization of orientable cyclic orders in terms of symmetries of partial orders as well as in terms of separating sets (cuts). The results are inspired by properties of non-sequential discrete processeses, but also apply to dense structures of any cardinality

Rhythms and Evolution: Effects of Timing on Survival

The evolution of metabolism regulation is an intertwined process, where different strategies are constantly being developed towards a cognitive ability to perceive and respond to an environment. Organisms depend on an orchestration of a complex set of chemical reactions: maintaining homeostasis with a changing environment, while simultaneously sending material and energetic resources to where they are needed. The success of an organism requires efficient metabolic regulation, highlighting the connection between evolution, population dynamics and the underlying biochemistry. In this work, I represent organisms as coupled information-processing networks, that is, gene-regulatory networks receiving signals from the environment and acting on chemical reactions, eventually affecting material flows. I discuss the mechanisms through which metabolism control is improved during evolution and how the nonlinearities of competition influence this solution-searching process. The propagation of the populations through the resulting landscapes generally point to the role of the rhythm of cell division as an essential phenotypic feature driving evolution. Subsequently, as it naturally follows, different representations of organisms as oscillators are constructed to indicate more precisely how the interplay between competition, maturation timing and cell-division synchronisation affects the expected evolutionary outcomes, not always leading to the \"survival of the fastest\"