Identification of Hidden Failures in Process Control Systems Based on the HMG Method

We will continue here the research work, the goal of which was to introduce the notion of nondeterministic aggregation operators and study their properties, even in relation to classification systems and the associated learning problem. Here we will concentrate mostly on the notion of the nondeterministic aggregation system and its relation with deterministic ones. We will also see how such a model extends a discretized version of a model of participatory learning with an arousal background mechanism

Modeling Copper Price: A Regime-Switching Approach

This paper explores the virtues of Markov-Switching models to characterize the behavior of copper price. In particular, we study the performance of several univariate specifications of this type of models, both in and out of sample, comparing them also with constant parameter models such as ARMA and GARCH. The main finding is that allowing for a regime-switching variance in the error term is most relevant in explaining the behavior of this price.

Steady self-diffusion in classical gases

A steady self-diffusion process in a gas of hard spheres at equilibrium is analyzed. The system exhibits a constant gradient of labeled particles. Neither the concentration of these particles nor its gradient are assumed to be small. It is shown that the Boltzmann-Enskog kinetic equation has an exact solution describing the state. The hydrodynamic transport equation for the density of labeled particles is derived, with an explicit expression for the involved self-diffusion transport coefficient. Also an approximated expression for the one-particle distribution function is obtained. The system does not exhibit any kind of rheological effects. The theoretical predictions are compared with numerical simulations using the direct simulation Monte Carlo method and a quite good agreement is found

Continuous-time random walks with reset events: Historical background and new perspectives

In this paper, we consider a stochastic process that may experience random reset events which relocate the system to its starting position. We focus our attention on a one-dimensional, monotonic continuous-time random walk with a constant drift: the process moves in a fixed direction between the reset events, either by the effect of the random jumps, or by the action of a deterministic bias. However, the orientation of its motion is randomly determined after each restart. As a result of these alternating dynamics, interesting properties do emerge. General formulas for the propagator as well as for two extreme statistics, the survival probability and the mean first-passage time, are also derived. The rigor of these analytical results is verified by numerical estimations, for particular but illuminating examples.Comment: 11 pages, 5 figure

Evaluación de la motivación en equipos de proyectos

People carry out the projects and the performance of the human team is a key success factor. This communication reflects the results of measuring satisfaction in different project teams, applying the theory of expectations. The study focuses on a questionnaire based on the theory developed by the psychologist Vroom. Different aspects of motivation are analysed, grouped into three main blocks: intrinsic motivation, extrinsic motivation and transcendent motivation. In each of them, the valence and expectation that members have is evaluated. The results obtained are considered for each group analyzed.Los proyectos los realizan personas y el desempeño del equipo humano es un factor clave de éxito. Esta comunicación refleja los resultados de medir la satisfacción en distintos equipos de proyectos, aplicando la teoría de las expectativas. El estudio se centra en un cuestionario basado en la teoría desarrollada por el psicólogo Vroom. Se analiza distintos aspectos de la motivación, agrupados en tres grandes bloques: motivación intrínseca, motivación extrínseca y motivación trascendente. En cada uno de ellos se evalúa la valencia y la expectativa que los miembros tienen. Los resultados obtenidos se consideran para cada grupo analizado

Anomalous self-diffusion in a freely evolving granular gas near the shearing instability

The self-diffusion coefficient of a granular gas in the homogeneous cooling state is analyzed near the shearing instability. Using mode-coupling theory, it is shown that the coefficient diverges logarithmically as the instability is approached, due to the coupling of the diffusion process with the shear modes. The divergent behavior, which is peculiar of granular gases and disappears in the elastic limit, does not depend on any other transport coefficient. The theoretical prediction is confirmed by molecular dynamics simulation results for two-dimensional systems

Uniform self-diffusion in a granular gas

A granular gas composed of inelastic hard spheres or disks in the homogeneous cooling state is considered. Some of the particles are labeled and their number density exhibits a time-independent linear profile along a given direction. As a consequence, there is a uniform flux of labeled particles in that direction. It is shown that the inelastic Boltzmann-Enskog kinetic equation has a solution describing this self-diffusion state. Approximate expressions for the transport equation and the distribution function of labeled particles are derived. The theoretical predictions are compared with simulation results obtained using the direct Monte Carlo method to generate solutions of the kinetic equation. A fairly good agreement is found