•We study multistability in a master-slave piecewise linear system.•We investigate the collective behavior of systems with unidirectional links and ring topology.•Symbolic dynamics of the nodes is ...useful to detect synchronization.•Itinerary synchronization is used to analyze and classify multistable behavior.•ε Itinerary synchronization is displayed in a ring topology network.
In this paper the collective dynamics of N-coupled piecewise linear (PWL) systems with different number of scrolls is studied. The coupling is in a master-slave sequence configuration, with this type of coupling we investigate the synchrony behavior of a ring-connected network and a chain-connected network both with unidirectional links. Itinerary synchronization is used to detect synchrony behavior. Itinerary synchronization is defined in terms of the symbolic dynamics arising by assigning different numbers to the regions where the scrolls are generated. A weaker variant of this notion, ϵ-itinerary synchronization is also introduced and numerically investigated. It is shown that in certain parameter regimes if the inner connection between nodes takes account of all the state variables of the system (by which we mean that the inner coupling matrix is the identity matrix), then itinerary synchronization occurs and the coordinate motion is determined by the node with the smallest number of scrolls. Thus the collective behavior in all the nodes of the network is determined by the node with least scrolls in its attractor. Results about the dynamics in a directed chain topology are also presented. Depending on the inner connection properties, the nodes present multistability or preservation of the number of scrolls of the attractors.
The main limitation on designing epidemic control strategies lies in their economic and social costs. Thus, a practical and efficient approach takes into consideration these factors. Most epidemics ...evolve in a structured population, being the geographical structure the most evident. In this situation, having a criteria for identifying the most effective locations where control measures can optimize available resources is desirable. In this paper, a regional index based on the final epidemic size predicted by a metapopulation model is proposed. An efficient algorithm to calculate explicit index values was developed, and different control strategies that used the recommended index were compared with others that do not take the index information into account. We found that the proposed index represents an easy and fast criterion to guide simple control strategies. This type of index offers a new powerful approach where the information encoded in a deterministic mathematical model can be summarized to guide realistic and practical control strategies for disease spreading and epidemics.
•An iterative algorithm to estimate the epidemic final size is proposed.•We propose a methodology to select and control the most affected patches•We numerically analyze the effectiveness of the patch selection with our methodology
There is an increasing worldwide concern on the several diseases transmitted by vectors like Dengue, Zika, or Chikungunya. Thus, in recent years studies about the calculation of summary measurements ...such as the final size of the epidemic have acquired importance. In particular, this quantity allows estimating the impact that the disease has on the affected population. However, advances in calculating analytical expressions to estimate this measure in the case of infectious transmitted by vectors have been scarce. Most of the applicability of this quantity has been limited to the classic epidemiological model of Kermack McKendrick. This article proposes a methodology to estimate the final size of a vector-borne epidemic. The methodology can be generalized to meta-population models and thus be applied to extended geographical regions. The methodology for a vector-borne disease is presented, and then the case of two distinct geographic regions connected by human mobility is shown. Numerical simulations were carried out to compare with the precision of the analytical approximation. It was observed that the proposed methodology provides a good estimate for the two analyzed cases.
•The final size relation for a vector-borne disease is obtained.•Final size relations for a vector-borne disease in two geographic regions connected by human mobility are obtained.•The obtained relations give a very good approximation for the final size of the epidemic.•The methodology can be generalized to obtain the final size relation of more general metapopulation models.
Front end electronics and first results of the ALICE V0 detector Zoccarato, Y.; Tromeur, W.; Aguilar, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2011, Volume:
626
Journal Article
Peer reviewed
This paper gives a detailed description of the acquisition and trigger electronics especially designed for the V0 detector of ALICE at LHC. A short presentation of the detector itself is given before ...the description of the Front End Electronics (FEE) system, which is completely embedded within the LHC environment as far as acquisition (DAQ), trigger (CTP), and detector control (DCS) are concerned. It is able to detect on-line coincident events and to achieve charge (with a precision of 0.6 pC) and time measurements (with a precision of 100
ps). It deploys quite a simple architecture. It is however totally programmable and fully non-standard in discriminating events coming from Beam–Beam interaction and Beam-Gas background. Finally, raw data collected from the first LHC colliding beams illustrate the performance of the system.
•A network of nearly identical coupled chaotic oscillators is described and implemented electronically to probe its physical validation.•The network considered a tolerance variation in the parameters ...of each individual node, to present nearly identical states that resembles more accurately physical systems instead of identical simulated ones.•The nearly identical nodes achieve practical synchronous behavior although the tolerance in their parameters.
This work addresses a circuit architecture for a dynamical network composed of a type of chaotic hybrid oscillator based on Unstable Dissipative Systems (UDS). Implementing that system reveals the possibility of selecting a network topology with its link attributes. Moreover, from the experimental side, we study the practical synchronous collective behaviour phenomena. Additionally, based on the theory of dynamical networks, a mathematical model of the circuit is described, taking into account the natural tolerance of the electronic components. The network is analyzed both numerically and experimentally according to the parameters mismatch between nodes.
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Belousov-Zhabotinsky chemical reactions and new variants were developed and studied at 277.5 K, 296.15 K, and 341.15 K using potassium bromate, sodium bromide, malonic acid, and ...ferroin as an indicator for the oscillating reaction. This reaction type is a minimal oscillator, which belongs to the fifth “uncatalyzed” family known as minimal bromate oscillators. A mathematical model is a proposal from the reaction mechanism of Zhabotinsky, the Oregonator model, and the modified Arrhenius equation. The control parameters of the mathematical model are the activation enthalpies of the oscillating reaction. Experimental and numerical results at 341.15 K show an increase in the amplitude and frequency of chemical oscillations and a decrease in the total oscillation time, while at 277.15 K the opposite mechanism happens.
We investigate the effects of structural evolution on the stability of synchronized behavior in complex networks. By structural evolution we mean processes that change the topology of the network. In ...particular, we consider structural evolution as two simultaneous processes: on one hand, the topology changes according to an arbitrary switching law among a set of admissible patterns of connection; on the other hand, the strength of connection evolves according to an adaptive law. Our results show that by constraining the admissible patterns of connection, and using an adaptive law based on the difference between the nodes, we can guarantee the stability of the synchronized solution of the network despite structural changes. Additionally, we extend our results by considering alternative structural evolution processes, namely, a node-based adaptive strategy and a resetting switching law. We illustrate our results with numerical simulation.
•We investigate the effects of structural evolution on the synchronization in complex networks.•Synchronization is achieved if network structures are constraining and the couplings strengths are updating according to an adaptive law.•We extend our results by considering a node-based adaptive strategy and a resetting switching law.
The basic reproduction number R0 is an index worldwide commonly used by public health organizations as a key estimator of the severity of a given epidemic. In this work we use a Lagrangian approach ...to model vector-borne diseases (SIR-SI) into a metapopulation network in order to derive an expression of the basic reproduction number and we analyze its dependency on human mobility. We prove that this index can be computed by evaluating the spectral radius of the risk matrix W, whose entries Wij are the number of secondary cases in patch j produced by the inclusion of a single infected human in patch i. Based on the risk matrix, we propose a risk index which locally describes the epidemic vulnerability, while R0 give us an estimation of the global vulnerability. Further, we numerically analyze the effect of human mobility over the values of R0 in a system composed of two and three patches, and for a network connected in a star topology configuration.
The basic reproduction number R0 is an index worldwide commonly used by public health organizations as a key estimator of the severity of a given epidemic. In this work we use a Lagrangian approach ...to model vector-borne diseases (SIR-SI) into a metapopulation network in order to derive an expression of the basic reproduction number and we analyze its dependency on human mobility. We prove that this index can be computed by evaluating the spectral radius of the risk matrix W, whose entries Wij are the number of secondary cases in patch j produced by the inclusion of a single infected human in patch i. Based on the risk matrix, we propose a risk index which locally describes the epidemic vulnerability, while R0 give us an estimation of the global vulnerability. Further, we numerically analyze the effect of human mobility over the values of R0 in a system composed of two and three patches, and for a network connected in a star topology configuration.
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