Towards A Theory Of Quantum Computability

We propose a definition of quantum computable functions as mappings between superpositions of natural numbers to probability distributions of natural numbers. Each function is obtained as a limit of an infinite computation of a quantum Turing machine. The class of quantum computable functions is recursively enumerable, thus opening the door to a quantum computability theory which may follow some of the classical developments

Quantum Turing Machines Computations and Measurements

Contrary to the classical case, the relation between quantum programming languages and quantum Turing Machines (QTM) has not being fully investigated. In particular, there are features of QTMs that have not been exploited, a notable example being the intrinsic infinite nature of any quantum computation. In this paper we propose a definition of QTM, which extends and unifies the notions of Deutsch and Bernstein and Vazirani. In particular, we allow both arbitrary quantum input, and meaningful superpositions of computations, where some of them are "terminated" with an "output", while others are not. For some infinite computations an "output" is obtained as a limit of finite portions of the computation. We propose a natural and robust observation protocol for our QTMs, that does not modify the probability of the possible outcomes of the machines. Finally, we use QTMs to define a class of quantum computable functions---any such function is a mapping from a general quantum state to a probability distribution of natural numbers. We expect that our class of functions, when restricted to classical input-output, will be not different from the set of the recursive functions.Comment: arXiv admin note: substantial text overlap with arXiv:1504.02817 To appear on MDPI Applied Sciences, 202

Does water utilities' ownership matter in water pricing policy? An analysis of endogenous and environmental determinants of water tariffs in Italy

Owing to the growing importance of efficient water management, it has become crucial to understand water utilities' characteristics and the environmental factors affecting water pricing, so as to provide guidance to policy-makers. The analysis of factors influencing water tariffs is a challenging task in a context in which companies providing the service are characterized by different ownership features. Moreover, environmental factors and companies' characteristics may simultaneously influence both the decision to privatize the service and the water tariff level. Using a treatment effects model, where privatization is considered as an endogenous binary treatment variable, this paper analyzes whether and how certain relevant variables affect the tariffs levied by water utilities in Italy. The results show that higher tariffs are set in order to cover a greater amount of investments; furthermore, abundant water availability, measured by the average annual rainfall, significantly reduces prices. The data surprisingly show that tariffs are higher where the income level is lower. Significantly, after accounting for the endogeneity due to the fact that water firms are not randomly distributed between totally publicly or not totally publicly owned, our results seem to suggest that ownership does not influence the tariffs levied by water utilities

ECOLOGIA DEGLI OSTRACODI DI UN'AREA PROSPICIENTE LA CITTA' DI LIVORNO

E’ datato 1977, ad opera di Bonaduce et al., il più recente lavoro dedicato all’ostracofauna bentonica del Mar Ligure ed erano quindi circa trenta anni che non venivano pubblicati lavori riferiti a tale argomento; in base a queste considerazioni, essendo venuti a disposizione di un numero sufficientemente rappresentativo di campioni, relativi ad un’area prospiciente la città di Livorno, comprendente oltre ad una piccola subarea antistante il Calambrone ed una posta all’esterno delle dighe foranee, i due habitat principali, cioè il Porto e le Secche della Meloria,, si è deciso di studiarne l’ecologia dell’ostracofauna attuale. In base a ciò si è focalizzato l’attenzione sulle peculiarità e diversità ambientali di quest’ultimi due habitat, considerabili come due unità fisiografiche distinte, con l’obiettivo di evidenziare (associando anche dati sui Foraminiferi), l’esistenza di un trend nella distribuzione delle associazioni ad Ostracodi che le caratterizzano, passando attraverso l’analisi delle subaree di transizione sopra citate. In ultima analisi i dati ottenuti da questa indagine, che rappresenta il primo studio con tale intento per l’area in esame, hanno consentito di ampliare le conoscenze sulle ostracofaune del piano infralitorale del Mar Ligure fornendoci un range di informazioni ad ampio spettro, quali: a) caratterizzazione delle associazioni ad Ostracodi in un ambiente paralico artificiale, contaminato e con limitati scambi verso l’esterno come il Porto, b) studio dell’ostracofauna di un habitat geomorfologicamente peculiare, con elevata ricchezza biotica (vegetale ed animale) e con elevato idrodinamismo come le Secche, sottoposto inoltre all’azione “stressante” del Porto stesso e all’influenza dei corsi d’acqua che sfociano in mare nelle sue vicinanze ( in particolare il Fiume Arno ed il Torrente Ugione). c) indicazioni sulle correlazioni tra le ostracofaune del Porto e delle subaree esterne di mare franco, sia nell’ambito del Porto stesso, in zone dove si immettano direttamente scarichi reflui urbani/industriali o corpi idrici (variazioni di salinità, inquinanti etc.) E’ da sottolineare inoltre che a tali considerazioni deve essere aggiunto un ulteriore elemento di interesse scientifico in quanto rappresentando questa indagine uno lavoro pionieristico per l’area in esame, i risultati ottenuti possono costituire un primo momento di conoscenza da usarsi per un eventuale monitoraggio futuro

Il cambiamento del sistema di controllo. Uno schema di analisi

Il lavoro, dopo aver inquadrato il sistema di controllo di gestione, descrive la problematica del cambiamento, coniugando aspetti teorici e riferimenti empirici. Piu' in particolare, il secondo capitolo analizza i fattori che inducono il cambiamento di un sistema di controllo; il terzo descrive il percorso di cambiamento, articolato nelle fasi di analisi preliminare, check up, disegno del nuovo modello, implementazione informatica ed organizzativa e follow up; infine, l'ultimo capitolo presenta alcuni strumenti chiave da utilizzare durante il processo di revisione, come l'analisi di bilancio, le carte di lavoro ed i test sulla reportistica e sui sistemi informativ

Water pollution in wastewater treatment plants: An efficiency analysis with undesirable output

The environmental efficiency of 96 Tuscan (Italian) wastewater treatment plants (WWTPs) is investigated taking into account the quality of the outgoing water in terms of pollutant. In this regard, the presence of the residual nitrogen in the outgoing treated water is considered as undesirable output. The efficiency analysis is performed by applying a novel integrated Analytic Hierarchy Process/Non-radial Directional Distance Function (AHP/NDDF) approach, combining the benefits of the two techniques. Similarly to the standard NDDF approach, the suggested model allows to include simultaneously inputs, desirable and undesirable outputs and not to overestimate the efficiency scores. At the same time, the AHP inclusion gives the possibility to directly take into account the decision maker preferences in the weighting system and to encompass some existing directional distance function models as special cases.The obtained results are then used to identify the efficiency explanatory variables: among them, the facilities' capacity, the percentage of wastewater discharged by the industrial and agricultural activities and the level of compliance with the pollutant concentration threshold set by the legislator have a significant impact on the WWTP performance. The integrated performance assessment allows the water authorities to combine the WWTP efficiency together with the environmental sustainability issue and it has the potential for further promising environmental inspections

PALEOBIOLOGY FROM MUSEUM COLLECTIONS: COMPARING HISTORICAL AND NOVEL DATA ON UPPER MIOCENE MOLLUSCS OF THE LIVORNO HILLS

The upper Miocene mollusc collection from Monti Livornesi, Italy, collected more than a century ago, is confronted with new collections coming from the same localities of Popogna and Quarata. The study concerns the comparison of abundance data of three distinct fossil assemblages from the three vertically-stacked stratigraphic units called Luppiano, Rosignano and Raquese, of upper Tortonian-early Messinian age. Literature and museological data allowed to attribute most museum specimens to one and only one fossil assemblage. Museum collections preserve roughly the same dominant species, with similar ranks as the new quantitative field collections. Significant differences are however evident in the Luppiano assemblage from brackish-water, shallow subtidal bottoms, because new samples yield many species of small size, some of which with high dominance, that are completely lacking in museum collections, suggesting a bias due to size sorting and hinting at the overwhelming contribution of small-sized species to global mollusc diversity. On the other hand the Raquese assemblage, from an open marine shelf setting, can be similarly interpreted from the study of either the museum of new collection, yielding a similar species list and rank. The Rosignano mollusc assemblage, from a bioclastic bottom near a coral patch reef and characterised by fossils with a distinct taphonomic signature, is insufficiently represented in both historical and new collections. The systematics of the three assemblages are revised. The study contributes to the growing literature on museum “dark data” by showing that museum collections may yield abundance data significant for paleobiological analysis

Displacement Demand for Nonlinear Static Analyses of Masonry Structures: Critical Review and Improved Formulations

This paper discusses different formulations for calculating earthquake-induced displacement demands to be associated with nonlinear static analysis procedures for the assessment of masonry structures. Focus is placed on systems with fundamental periods between 0.1 and 0.5 s, for which the inelastic displacement amplification is usually more pronounced. The accuracy of the predictive equations is assessed based on the results from nonlinear time-history analyses, carried out on single-degree-of-freedom oscillators with hysteretic force–displacement relationships representative of masonry structures. First, the study demonstrates some limitations of two established approaches based on the equivalent linearization concept: the capacity spectrum method of the Dutch guidelines NPR 9998-18, and its version outlined in FEMA 440, both of which overpredict maximum displacements. Two codified formulations relying on inelastic displacement spectra are also evaluated, namely the N2 method of Eurocode 8 and the displacement coefficient method of ASCE 41-17: the former proves to be significantly unconservative, while the latter is affected by excessive dispersion. A non-iterative procedure, using an equivalent linear system with calibrated optimal stiffness and equivalent viscous damping, is then proposed to overcome some of the problems identified earlier. A recently developed modified N2 formulation is shown to improve accuracy while limiting the dispersion of the predictions

Chemical shift imaging at 4.7 tesla of brown adipose tissue.

In vivo distinction between small deposits of brown adipose tissue (BAT) and surrounding tissues may be difficult. In this article, we propose an experiment paradigm, based on techniques of chemical shift magnetic resonance imaging (CSI), which can improve the methods presently available for the study of BAT. Male rats were examined in an imager-spectrometer equipped with a 4.7 T magnet. Proton spectra of isolated BAT deposits showed that both fat and water protons contributed significantly to the genesis of the magnetic resonance signal. An equivocal definition of BAT deposits was obtained by three (respectively, spin-echo, water-selective, and fat-selective) images. The spin-echo (SE), T1-weighted image provided the best anatomical description of the structures. The images selective for fat-protons displayed the degree of lipid accumulation in each area. The images selective for water-protons provided an internal control of adipose tissue localization. The proposed paradigm allows an unequivocal definition of BAT deposits and appears particularly useful in studies where experimental manipulation (i.e., cold acclimation or drug treatment) produces changes in this issue