322 research outputs found

    A quantum computational semantics for epistemic logical operators. Part I: epistemic structures

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    Some critical open problems of epistemic logics can be investigated in the framework of a quantum computational approach. The basic idea is to interpret sentences like “Alice knows that Bob does not understand that π is irrational” as pieces of quantum information (generally represented by density operators of convenient Hilbert spaces). Logical epistemic operators (to understand, to know. . .) are dealt with as (generally irreversible) quantum operations, which are, in a sense, similar to measurement-procedures. This approach permits us to model some characteristic epistemic processes, that concern both human and artificial intelligence. For instance, the operation of “memorizing and retrieving information” can be formally represented, in this framework, by using a quantum teleportation phenomenon

    Role of intermodality in global sourcing and offshore outsourcing: maritime transport and new rail connections between Europe and Asia

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    The work deals with the technical possibility of using railway connections between Europe and Asia - by way of the rail links under renewal in relation also with some United Nations’ plans - for changing the commercial relationships between the two continents. Maritime transport has already undertaken, in the last years, different relationships, which elude in many connections the Suez Canal, therefore possibly the Mediterranean Sea; valorising the global sourcing and the offshore outsourcing in the vision of the Europe-Russia-Western and Eastern Asia new relationships by rail may reconfigure a renewed and faster international transport of goods as well as create commercial corridors based on trains beside full-container ships: these have, on their side, distinguished the last half century of freight, mainly thanks to standardisation of the loading units and given energy reasons. According to the authors, the economical outcomes are well worth devoting commercial and offshore outsourcing attention

    A first-order epistemic quantum computational semantics with relativistic-like epistemic effects

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    Quantum computation has suggested new forms of quantum logic, called quantum computational logics. In these logics well-formed formulas are supposed to denote pieces of quantum information: possible pure states of quantum systems that can store the information in question. At the same time, the logical connectives are interpreted as quantum logical gates: unitary operators that process quantum information in a reversible way, giving rise to quantum circuits. Quantum computational logics have been mainly studied as sentential logics (whose alphabet consists of atomic sentences and of logical connectives). In this article we propose a semantic characterization for a first-order epistemic quantum computational logic, whose language can express sentences like "Alice knows that everybody knows that she is pretty". One can prove that (unlike the case of logical connectives) both quantifiers and epistemic operators cannot be generally represented as (reversible) quantum logical gates. The "act of knowing" and the use of universal (or existential) assertions seem to involve some irreversible "theoretic jumps", which are similar to quantum measurements. Since all epistemic agents are characterized by specific epistemic domains (which contain all pieces of information accessible to them), the unrealistic phenomenon of logical omniscience is here avoided: knowing a given sentence does not imply knowing all its logical consequences

    Characterization of quantum states in predicative logic

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    We develop a characterization of quantum states by means of first order variables and random variables, within a predicative logic with equality, in the framework of basic logic and its definitory equations. We introduce the notion of random first order domain and find a characterization of pure states in predicative logic and mixed states in propositional logic, due to a focusing condition. We discuss the role of first order variables and the related contextuality, in terms of sequents.Comment: 14 pages, Boston, IQSA10, to appea

    Role of COVID-19 and motionless communication on expected trends of mobility: Evidence from Italian and Turin data

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    The 2020-2021 pandemic has changed everyday mobility for part of the world. One of the main elements of change is the consolidation of distance working, which further prompted communications without mobility. The emergency-induced reduction of systematic travel demand has been counterbalanced by the increased volume of web traffic. As a result, communications which formerly required mobility have been regularly performed virtually during the lockdowns. This paper quantifies this phenomenon, with a focus on the Italian city of Turin, in Italy, which was one of the first countries hit by COVID-19, soon after China. Local mobility data trends before and during the lockdown are presented and compared. Implications for the "new normal" ahead are discussed. The paper provides directions for further transport policies, with the aim of advancing knowledge of this transportation topic

    Un’analisi dei tram di Torino: effetti della priorità semaforica ed ITS sui consumi energetici

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    Nello studio condotto sono stati raccolti ed elaborati dati relativi alla cinematica e ai consumi energetici di un campione dei tram attualmente in servizio sulla linea 4 di Torino, al fine di stimare il beneficio energetico atteso dalla prioritĂ  semaforica. L’intera flotta di mezzi operanti sulle linee gestite dalla GTT Ăš monitorata costantemente al fine di garantire la regolaritĂ  del servizio e gestire nel minor tempo possibile eventuali guasti ed emergenze. A ogni operatore della centrale operativa Ăš affidata la gestione e il monitoraggio di alcune linee, raffigurate graficamente su terminali delle postazioni di lavoro. In virtĂč dell’esistenza di un sistema di regolazione semaforica adattativo, con la prioritĂ  semaforica per i mezzi pubblici il ciclo semaforico puĂČ variare continuamente, mitigando anche i ritardi delle correnti di traffico veicolare. Se un semaforo interrompe il moto di un tram, di fatto ne raddoppia indicativamente il consumo tra due fermate. Il beneficio sui tempi Ăš quasi scontato, ma comunque emerge dallo studio, che si concentra prevalentemente sull’aspetto del consumo energetico

    Contextual logic for quantum systems

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    In this work we build a quantum logic that allows us to refer to physical magnitudes pertaining to different contexts from a fixed one without the contradictions with quantum mechanics expressed in no-go theorems. This logic arises from considering a sheaf over a topological space associated to the Boolean sublattices of the ortholattice of closed subspaces of the Hilbert space of the physical system. Differently to standard quantum logics, the contextual logic maintains a distributive lattice structure and a good definition of implication as a residue of the conjunction.Comment: 16 pages, no figure

    On the nature of continuous physical quantities in classical and quantum mechanics

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    Within the traditional Hilbert space formalism of quantum mechanics, it is not possible to describe a particle as possessing, simultaneously, a sharp position value and a sharp momentum value. Is it possible, though, to describe a particle as possessing just a sharp position value (or just a sharp momentum value)? Some, such as Teller (Journal of Philosophy, 1979), have thought that the answer to this question is No -- that the status of individual continuous quantities is very different in quantum mechanics than in classical mechanics. On the contrary, I shall show that the same subtle issues arise with respect to continuous quantities in classical and quantum mechanics; and that it is, after all, possible to describe a particle as possessing a sharp position value without altering the standard formalism of quantum mechanics.Comment: 26 pages, LaTe

    Algebras of Measurements: the logical structure of Quantum Mechanics

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    In Quantum Physics, a measurement is represented by a projection on some closed subspace of a Hilbert space. We study algebras of operators that abstract from the algebra of projections on closed subspaces of a Hilbert space. The properties of such operators are justified on epistemological grounds. Commutation of measurements is a central topic of interest. Classical logical systems may be viewed as measurement algebras in which all measurements commute. Keywords: Quantum measurements, Measurement algebras, Quantum Logic. PACS: 02.10.-v.Comment: Submitted, 30 page
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