Work producing reservoirs: Stochastic thermodynamics with generalized Gibbs ensembles

We develop a consistent stochastic thermodynamics for environments composed of thermodynamic reservoirs in an external conservative force field, that is environments described by the Generalized or Gibbs canonical ensemble. We demonstrate that small systems weakly coupled to such reservoirs exchange both heat and work by verifying a local detailed balance relation for the induced stochastic dynamics. Based on this analysis, we help to rationalize the observation that nonthermal reservoirs can increase the efficiency of thermodynamic heat engines.Comment: 6 pages, 1 figure, plus 3 page

Ethical judgment and radical business changes: the role of entrepreneurial perspicacity

This study examines the implications of practical reason for entrepreneurial activities. Our study is based on Thomas Aquinas’ interpretation of such virtue, with a particular focus on the partition of practical reason in potential parts such as synesis, or common sense, and gnome, or perspicacity. Since entrepreneurial acts and actions deal with extremely uncertain situations, we argue that only this perspicacity, as the ability of correctly judging in exceptional cases, has the power to find wisdom under such blurred conditions. Perspicacity frees entrepreneurs from their cognitive schemata rendering them able to be truly entrepreneurial. Based on this vision and thanks to a semantic analysis of the meaning of the Greek word gnome, we construct an interpretative model for entrepreneurial judgment composed of three dimensions, specifically, knowledge-cognitive, external-affective and personal-reflective. The model highlights how a ‘successful’ entrepreneurial judgment is also such from a holistic point of view

Connection Between System Parameters and Localization Probability in Network of Randomly Distributed Nodes

This article deals with localization probability in a network of randomly distributed communication nodes contained in a bounded domain. A fraction of the nodes denoted as L-nodes are assumed to have localization information while the rest of the nodes denoted as NL nodes do not. The basic model assumes each node has a certain radio coverage within which it can make relative distance measurements. We model both the case radio coverage is fixed and the case radio coverage is determined by signal strength measurements in a Log-Normal Shadowing environment. We apply the probabilistic method to determine the probability of NL-node localization as a function of the coverage area to domain area ratio and the density of L-nodes. We establish analytical expressions for this probability and the transition thresholds with respect to key parameters whereby marked change in the probability behavior is observed. The theoretical results presented in the article are supported by simulations.Comment: To appear on IEEE Transactions on Wireless Communications, November 200

Uncertainty modelling in reliable preliminary space mission design

In the early phase of the design of a space mission, it is generally desirable to investigate as many feasible alternative solutions as possible. At this particular stage, an insufficient consideration for uncertainty would lead to a wrong decision on the feasibility of the mission. Traditionally a system margin approach is used in order to take into account the inherent uncertainties within the subsystem budgets. The reliability of the mission is then independently computed in parallel. An iteration process between the solution design and the reliability assessment should finally converge to an acceptable solution. By combining modern statistical methods to model uncertainties and global search techniques for multidisciplinary design, the present work proposes a way to introduce uncertainties in the mission design problem formulation. By minimising the effect of these uncertainties on both constraints and objective functions, while optimising the mission goals, the aim is to increase the reliability of the produced results

Does gender matter for public spending? Empirical evidence from Italian municipalities.

This paper studies whether municipal expenditure in Italy is influenced by female representation in city councils. To correctly capture the causal relation we use the instrumental variable technique. Our instrument is based on a temporary change in the Italian normative occurred between 1993 and 1995 that reserved a gender quota in party lists for municipal elections, causing an exogenous change in the number of women elected in city councils. We take advantage of the fact that not all the municipalities have been treated by the law, due to its short period of enforcement. Despite the existence of gender specific preferences in the society, we find no evidence that the allocation of resources among different spending categories is affected by the gender of politicians. Our results are consistent with the Median voter theorem. Alternatively, they may suggest that the gender is not a determinant of politicians’ voting behaviour, implying that the preferences of the women involved in political activities are close to those of their male colleagues.gender, political representation, municipal expenditure

First-Principles Modeling of Pt/LaAlO3/SrTiO3 Capacitors Under an External Bias Potential

We study the electrical properties of Pt/LaAlO3/SrTiO3 capacitors under the action of an external bias potential, using first-principles simulations performed at constrained electric displacement field. A complete set of band diagrams, together with the relevant electrical characteristics (capacitance and built-in fields), are determined as a function of LaAlO3 thickness and the applied potential.We find that the internal field in LaAlO3 monotonically decreases with increasing thickness; hence, the occurrence of spontaneous Zener tunneling is ruled out in this system.We discuss the implications of our results in the light of recent experimental observations on biased LaAlO3/SrTiO3 junctions involving metallic top electrodes.Comment: 5 pages, 4 figure

A Model of the IEEE 802.11 DCF in Presence of Non Ideal Transmission Channel and Capture Effects

In this paper, we provide a throughput analysis of the IEEE 802.11 protocol at the data link layer in non-saturated traffic conditions taking into account the impact of both transmission channel and capture effects in Rayleigh fading environment. Impacts of both non-ideal channel and capture become important in terms of the actual observed throughput in typical network conditions whereby traffic is mainly unsaturated, specially in an environment of high interference. We extend the multi-dimensional Markovian state transition model characterizing the behavior at the MAC layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel, along with a state characterizing the system when there are no packets to be transmitted in the buffer of a station.Comment: Accepted for oral presentation to IEEE Globecom 2007, Washington D.C., November 200