12,785 research outputs found
Distributed Simulation of Heterogeneous and Real-time Systems
This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily composeable. Evaluating such large systems requires tools that integrate all components in a systematic, well-defined manner. This work leverages existing frameworks to facilitate the integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation
New resonance approach to competitiveness interventions in lagging regions: the case of Ukraine before the armed conflict
Regional competitiveness is considered to be an alternative basis for the determination of regional interventions. However, the composite competitiveness indicator is quite sensitive to the weights of sub-indicators, no matter what methodology is being used. To avoid this uncertainty in the determination of regional interventions, we proposed a new non-compensatory resonance approach that is focused on the hierarchical coincidence between weaknesses of NUTS 1 and NUTS 2 regions measuring the extensive and intensive components of competitiveness. Such a coincidence, being perceived as a resonance effect, is supposed to increase the effectiveness of interventions triggering synergetic effects and stirring up local regional potentials. The components of competitiveness are obtained through synthesising DEA methodology and Hellwig's index, correspondingly focusing on the measurement of technical efficiency and resource level. In analysing Ukrainian regions, no correlation between resonance interventions and the composite competitiveness indicator or GDP per capita was found, pointing toward a completely different direction in resonance approach. In western Ukraine, the congestion of six NUTS 2 regions was defined as a homogeneous area of analogous resonance interventions focused on improving business efficiency.Web of Science171562
CoInDiVinE: Parallel Distributed Model Checker for Component-Based Systems
CoInDiVinE is a tool for parallel distributed model checking of interactions
among components in hierarchical component-based systems. The tool extends the
DiVinE framework with a new input language (component-interaction automata) and
a property specification logic (CI-LTL). As the language differs from the input
language of DiVinE, our tool employs a new state space generation algorithm
that also supports partial order reduction. Experiments indicate that the tool
has good scaling properties when run in parallel setting.Comment: In Proceedings PDMC 2011, arXiv:1111.006
A Contraction Theory Approach to Stochastic Incremental Stability
We investigate the incremental stability properties of It\^o stochastic
dynamical systems. Specifically, we derive a stochastic version of nonlinear
contraction theory that provides a bound on the mean square distance between
any two trajectories of a stochastically contracting system. This bound can be
expressed as a function of the noise intensity and the contraction rate of the
noise-free system. We illustrate these results in the contexts of stochastic
nonlinear observers design and stochastic synchronization.Comment: 23 pages, 2 figure
Measuring Globalization: A hierarchical network approach
This paper investigates the business cycle co-movement across countries and regions since the middle of the last century as a measure for quantifying the ongoing globalization process of the world economy. Our methodological approach is based on analysis of a correlation matrix and the networks it contains. Such an approach summarizes the interaction and interdependence of all elements and it represents a more accurate measure of the global interdependence involved in the economic system. Our results show (1) that the dynamics of globalization has been more driven by synchronization in regional growth patterns than by the synchronization of the world economy as a whole in contrast with other empirical works and (2) that world crisis periods increase dramatically the global co movement in the world economy.Globalization, regionalism, correlation matrix, clustering, synchronization
A query description model based on basic semantic unit composite Petri-Net for soccer video
Digital video networks are making available increasing amounts of sports video data. The volume of material on offer means that sports fans often rely on prepared summaries of game highlights to follow the progress of their favourite teams. A significant application area for automated video analysis technology is the generation of personalized highlights of sports events. One of the most popular sports around world is soccer. A soccer game is composed of a range of significant events, such as goal scoring, fouls, and substitutions. Automatically detecting these events in a soccer video can enable users to interactively design their own highlights programmes. From an analysis of broadcast soccer video, we propose a query description model based on Basic Semantic Unit Composite Petri-Nets (BSUCPN) to automatically detect significant events within soccer video. Firstly we define a Basic Semantic Unit (BSU) set for soccer videos based on identifiable feature elements within a soccer video, Secondly we design Composite Petri-Net (CPN) models for semantic queries and use these to describe BSUCPNs for semantic events in soccer videos. A particular strength of this approach is that users are able to design their own semantic event queries based on BSUCPNs to search interactively within soccer videos. Experimental results
based on recorded soccer broadcasts are used to illustrate the potential of this approach
Chimeras in Leaky Integrate-and-Fire Neural Networks: Effects of Reflecting Connectivities
The effects of nonlocal and reflecting connectivity are investigated in
coupled Leaky Integrate-and-Fire (LIF) elements, which assimilate the exchange
of electrical signals between neurons. Earlier investigations have demonstrated
that non-local and hierarchical network connectivity often induces complex
synchronization patterns and chimera states in systems of coupled oscillators.
In the LIF system we show that if the elements are non-locally linked with
positive diffusive coupling in a ring architecture the system splits into a
number of alternating domains. Half of these domains contain elements, whose
potential stays near the threshold, while they are interrupted by active
domains, where the elements perform regular LIF oscillations. The active
domains move around the ring with constant velocity, depending on the system
parameters. The idea of introducing reflecting non-local coupling in LIF
networks originates from signal exchange between neurons residing in the two
hemispheres in the brain. We show evidence that this connectivity induces novel
complex spatial and temporal structures: for relatively extensive ranges of
parameter values the system splits in two coexisting domains, one domain where
all elements stay near-threshold and one where incoherent states develop with
multileveled mean phase velocity distribution.Comment: 12 pages, 12 figure
Toward a Formal Semantics for Autonomic Components
Autonomic management can improve the QoS provided by parallel/ distributed
applications. Within the CoreGRID Component Model, the autonomic management is
tailored to the automatic - monitoring-driven - alteration of the component
assembly and, therefore, is defined as the effect of (distributed) management
code. This work yields a semantics based on hypergraph rewriting suitable to
model the dynamic evolution and non-functional aspects of Service Oriented
Architectures and component-based autonomic applications. In this regard, our
main goal is to provide a formal description of adaptation operations that are
typically only informally specified. We contend that our approach makes easier
to raise the level of abstraction of management code in autonomic and adaptive
applications.Comment: 11 pages + cover pag
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