Comparison between different electrical configurations of emergency diesel generators for redundancy and reliability improving

The failure of an emergency diesel generator could cause a blackout with economic or human losses, especially if it occurs in a hospital. The authors performed an up to date statistic on diesel generators fails has been investigated in a hundred of hospitals. Although standard maintenance operation has been correctly performed, it has been found a 6 % of failures for the genset per year. MTBF of generators and main components have been investigated and updated values are reported in this paper. Components reliability is proved to be at its maximum technological value, consequently an innovative solution is here proposed. Often neighboring buildings or different electrical systems have separated emergency generators. Nowadays, in case of genset failure, most of the electrical installations are not designed to be fed from other generators. Several electrical configurations for diesel generators interconnections have been studied, in order to guarantee the mutual succor between them and therefore improving reliability. Two innovative schemes for emergency generators connection are here proposed for a more reliable electrical design

Timed Soft Concurrent Constraint Programs: An Interleaved and a Parallel Approach

We propose a timed and soft extension of Concurrent Constraint Programming. The time extension is based on the hypothesis of bounded asynchrony: the computation takes a bounded period of time and is measured by a discrete global clock. Action prefixing is then considered as the syntactic marker which distinguishes a time instant from the next one. Supported by soft constraints instead of crisp ones, tell and ask agents are now equipped with a preference (or consistency) threshold which is used to determine their success or suspension. In the paper we provide a language to describe the agents behavior, together with its operational and denotational semantics, for which we also prove the compositionality and correctness properties. After presenting a semantics using maximal parallelism of actions, we also describe a version for their interleaving on a single processor (with maximal parallelism for time elapsing). Coordinating agents that need to take decisions both on preference values and time events may benefit from this language. To appear in Theory and Practice of Logic Programming (TPLP)

Superadiabatic driving of a three-level quantum system

We study superadiabatic quantum control of a three-level quantum system whose energy spectrum exhibits multiple avoided crossings. In particular, we investigate the possibility of treating the full control task in terms of independent two-level Landau-Zener problems. We first show that the time profiles of the elements of the full control Hamiltonian are characterized by peaks centered around the crossing times. These peaks decay algebraically for large times. In principle, such a power-law scaling invalidates the hypothesis of perfect separability. Nonetheless, we address the problem from a pragmatic point of view by studying the fidelity obtained through separate control as a function of the intercrossing separation. This procedure may be a good approach to achieve approximate adiabatic driving of a specific instantaneous eigenstate in realistic implementations.Comment: 11 pages, 7 figure

Biometric Standards Survey

This document presents a quick survey on the most important standards regarding biometric technologies, concentrating mainly in those concerning the smartcard environment

I Documenti Elettronici nel Panorama Italiano

This document presents a short survey on the Italian electronic identity documents using biometric technology: \u27Carta d\u27Identit? Elettronica\u27 (CIE), \u27Carta Multiservizi della Difesa\u27 (CMD), \u27Permesso di Soggiorno Elettronico\u27 (PSE) and \u27Passaporto Elettronico\u27 (E-Passport)

Designing a Nonmonotonic Soft Concurrent Constraint Language for SLA Management

We present an extension of the Soft Concurrent Constraint language to allow the nonmonotonic evolution of the constraint store. To accomplish this, we introduce some new operations: the retract(c) reduces the current store by c, the updateX(c) transactionally relaxes all the constraints of the store that deal with the variables in X set, and then adds a constraint c (usually with support = X); the nask(c) tests if c is not entailed by the store.We present this framework as a possible solution to the management of resources (e.g. web services and network resource allocation) that need a given Quality of Service (QoS). The QoS requirements of all the parties should converge, through a negotiation process, on a formal agreement defined as the Service Level Agreement, which specifies the contract that must be enforced. The main advantage is to have a preference (or cost) measure directly embedded in the language, and to have a highly flexible and parametric abstraction