Delusions are one of the most classical symptoms described in schizophrenia. However, despite delusions are often emotionally charged, they have been investigated using tasks involving non-affective material, such as the Beads task. In... more
Delusions are one of the most classical symptoms described in schizophrenia. However, despite delusions are often emotionally charged, they have been investigated using tasks involving non-affective material, such as the Beads task. In this study we compared 30 patients with schizophrenia experiencing delusions with 32 matched controls in their pattern of responses to two versions of the Beads task within a Bayesian framework. The two versions of the Beads task consisted of one emotional and one neutral, both with ratios of beads of 60:40 and 80:20, considered, respectively, as the “difficult” and “easy” variants of the task. Results indicate that patients showed a greater deviation from the normative model, especially in the 60:40 ratio, suggesting that more inaccurate probability estimations are more likely to occur under uncertainty conditions. Additionally, both patients and controls showed a greater deviation in the emotional version of the task, providing evidence of a reasoni...
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time, hazard time Epidemiological models have been proposed to study the spread of com-puter viruses. To deal this subject, there exists a mathematical approach based on deterministic models defined in terms of differential equations.... more
time, hazard time Epidemiological models have been proposed to study the spread of com-puter viruses. To deal this subject, there exists a mathematical approach based on deterministic models defined in terms of differential equations. Other mathematical approach is based on stochastic models that employ Markov chains, branching and diffusion processes,... The model proposed here belongs to this last approach. It is a stochastic susceptible-infected-removed-susceptible (SIRS) model, where immune computers send warn-ing signals to reduce the propagation of the virus among the rest of comput-ers in the population. An analysis of the quasi-stationary distribution, the number of infections, the extinction time and the hazard time is performed for this model. Eventually, some numerical results for these characteristics are presented.
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Epidemiological models have been proposed to study the spread of computer viruses. To deal this subject, there exists a mathematical approach based on deterministic models dened in terms of differential equations.Other mathematical... more
Epidemiological models have been proposed to study the spread of computer viruses. To deal this subject, there exists a mathematical approach based on deterministic models dened in terms of differential equations.Other mathematical approach is based on stochastic models that employ Markov chains, branching and difusion processes. The model proposed here belongs to this last approach. It is a stochastic susceptible-infected-removed-susceptible (SIRS) model, where immune computers send warning signals to reduce the propagation of the virus among the rest of computers in the population. An analysis of the quasi-stationary distribution, the number of infections, the extinction time and the hazard time is performedfor this model. Eventually, some numerical results for these characteristics are presented.
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The aim of this work is to describe a stochastic epidemic model for computer viruses, the SIRA model, with the help of a continuous time Markov chain. It is a modification of the stochastic SIR model and it considers antidotal computers... more
The aim of this work is to describe a stochastic epidemic model for computer viruses, the SIRA model, with the help of a continuous time Markov chain. It is a modification of the stochastic SIR model and it considers antidotal computers that are equipped with totally effective anti-virus. In the stochastic SIRA model the infection becomes extinct with probability one, regardless of the parameters of the model. Under the assumption that the extinction has not occurred yet, it is interesting to study the number of infected computers, which is done in terms of the quasi-stationary distribution. Other descriptors are also analyzed, such as the extinction time, the number of cases of infections until the eradication of the virus and the number of infections during a period of time. Finally, some numerical results illustrate the analysis of these descriptors.
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The phenomenon of repeated attempts arises naturally in telecommunication and computer networks. One aspect of the retrial feature is considered in this paper, where we investigate the transient behavior of the successful and blocked... more
The phenomenon of repeated attempts arises naturally in telecommunication and computer networks. One aspect of the retrial feature is considered in this paper, where we investigate the transient behavior of the successful and blocked events made by the primary customers and the retrial customers.
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Abstract Modeling and understanding virus spreading is a crucial issue in computer security. Epidemiological models have been proposed to deal with this problem. We investigate the dynamics of computer virus spreading by considering an... more
Abstract Modeling and understanding virus spreading is a crucial issue in computer security. Epidemiological models have been proposed to deal with this problem. We investigate the dynamics of computer virus spreading by considering an stochastic susceptible-infected-removed-susceptible (SIRS) model where immune computers send warning signals to reduce the propagation of the virus among the rest of the computers in the network. We perform an exhaustive analysis of the main indicators of the spread and persistence of the infection. To this end, we provide a detailed study of the quasi-stationary distribution, the number of cases of infection, the extinction time and the hazard time.
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Research Interests: Mathematics, Applied Mathematics, Numerical Analysis, Communication Networks, Algorithm, and 10 moreApplied Mathematics and Computational Science, Queuing, Investigación Operativa, Numerical Analysis and Computational Mathematics, System performance, Electrical And Electronic Engineering, Queue, Retrial Queue, Distribution Function, and Queuing System
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The aim of this paper is to contribute to the connection between computer viruses spreading and epidemiological models. To this end, the block-structured state-dependent event (BSDE) approach is used to study the number of cases of... more
The aim of this paper is to contribute to the connection between computer viruses spreading and epidemiological models. To this end, the block-structured state-dependent event (BSDE) approach is used to study the number of cases of infection in a computer network. The goal of the BSDE approach is the possibility of dealing with non-exponential models with correlated flows, but keeping tractable the dimensionality of the underlying Markov chain. The obtained results are illustrated by numerical experiments which show how the BSDE approach is helpful to strengthen the computer security when it is used in connection with a warning mechanism. An application to the propagation of the CodeRed-II virus is also included.