238 research outputs found

    Formal concept analysis and structures underlying quantum logics

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    A Hilbert space HH induces a formal context, the Hilbert formal context H\overline H, whose associated concept lattice is isomorphic to the lattice of closed subspaces of HH. This set of closed subspaces, denoted C(H)\mathcal C(H), is important in the development of quantum logic and, as an algebraic structure, corresponds to a so-called ``propositional system'', that is, a complete, atomistic, orthomodular lattice which satisfies the covering law. In this paper, we continue with our study of the Chu construction by introducing the Chu correspondences between Hilbert contexts, and showing that the category of Propositional Systems, PropSys, is equivalent to the category of ChuCorsH\text{ChuCors}_{\mathcal H} of Chu correspondences between Hilbert contextsUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A New Linear Logic for Deadlock-Free Session-Typed Processes

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    The π -calculus, viewed as a core concurrent programming language, has been used as the target of much research on type systems for concurrency. In this paper we propose a new type system for deadlock-free session-typed π -calculus processes, by integrating two separate lines of work. The first is the propositions-as-types approach by Caires and Pfenning, which provides a linear logic foundation for session types and guarantees deadlock-freedom by forbidding cyclic process connections. The second is Kobayashi’s approach in which types are annotated with priorities so that the type system can check whether or not processes contain genuine cyclic dependencies between communication operations. We combine these two techniques for the first time, and define a new and more expressive variant of classical linear logic with a proof assignment that gives a session type system with Kobayashi-style priorities. This can be seen in three ways: (i) as a new linear logic in which cyclic structures can be derived and a CYCLE -elimination theorem generalises CUT -elimination; (ii) as a logically-based session type system, which is more expressive than Caires and Pfenning’s; (iii) as a logical foundation for Kobayashi’s system, bringing it into the sphere of the propositions-as-types paradigm

    Conway games, algebraically and coalgebraically

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    Using coalgebraic methods, we extend Conway's theory of games to possibly non-terminating, i.e. non-wellfounded games (hypergames). We take the view that a play which goes on forever is a draw, and hence rather than focussing on winning strategies, we focus on non-losing strategies. Hypergames are a fruitful metaphor for non-terminating processes, Conway's sum being similar to shuffling. We develop a theory of hypergames, which extends in a non-trivial way Conway's theory; in particular, we generalize Conway's results on game determinacy and characterization of strategies. Hypergames have a rather interesting theory, already in the case of impartial hypergames, for which we give a compositional semantics, in terms of a generalized Grundy-Sprague function and a system of generalized Nim games. Equivalences and congruences on games and hypergames are discussed. We indicate a number of intriguing directions for future work. We briefly compare hypergames with other notions of games used in computer science.Comment: 30 page

    Development and Validation of the False Disorder Score: The Focal Scale of the Inventory of Problems

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    This article introduces the Inventory of Problems (IOP)-a new, computerized, 181-item tool designed to discriminate bona fide from feigned mental illness and cognitive impairment-and presents the development and validation of its focal, feigning scale, the False Disorder Score (IOP-FDS). The initial sample included (a) 211 patients and 64 offenders who took the IOP under standard conditions, and (b) 210 community volunteers and 64 offenders who feigned mental illness. We split this sample into three subsamples. The first

    Process types as a descriptive tool for interaction

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    We demonstrate a tight relationship between linearly typed π-calculi and typed λ-calculi by giving a type-preserving translation from the call-by-value λµ-calculus into a typed π-calculus. The λµ-calculus has a particularly simple representation as typed mobile processes. The target calculus is a simple variant of the linear π-calculus. We establish full abstraction up to maximally consistent observational congruences in source and target calculi using techniques from games semantics and process calculi

    Immune Dysregulation and Self-Reactivity in Schizophrenia: Do Some Cases of Schizophrenia Have an Autoimmune Basis?

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    Schizophrenia affects 1% of the world's population, but its cause remains obscure. Numerous theories have been proposed regarding the cause of schizophrenia, ranging from developmental or neurodegenerative processes or neurotransmitter abnormalities to infectious or autoimmune processes. In this review, findings suggestive of immune dysregulation and reactivity to self in patients with schizophrenia are examined with reference to criteria for defining whether or not a human disease is autoimmune in origin. Associations with other autoimmune diseases and particular MHC haplotypes, increased serum levels of autoantibodies, and in vivo and in vitro replication of some of the functional and ultrastructural abnormalities of schizophrenia by transfer of autoantibodies from the sera of patients with schizophrenia suggest that, in some patients at least, autoimmune mechanisms could play a role in the development of disease. Recent findings regarding specific autoimmune responses directed against neurotransmitter receptors in the brain in patients with schizophrenia will also be reviewed

    Association of Down's syndrome and water fluoride level: a systematic review of the evidence

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    BACKGROUND: A review of the safety and efficacy of drinking water fluoridation was commissioned by the UK Department of Health to investigate whether the evidence supported a beneficial effect of water fluoridation and whether there was any evidence of adverse effects. Down's syndrome was one of the adverse effects reported. The aim of this review is to examine the evidence for an association between water fluoride level and Down's syndrome. METHODS: A systematic review of research. Studies were identified through a comprehensive literature search, scanning citations and online requests for papers. Studies in all languages which investigated the incidence of Down's syndrome in areas with different levels of fluoride in their water supplies were included. Study inclusion and quality was assessed independently by 2 reviewers. A qualitative analysis was conducted. RESULTS: Six studies were included. All were ecological in design and scored poorly on the validity assessment. The estimates of the crude relative risk ranged from 0.84 to 3.0. Four studies showed no significant associations between the incidence of Down's syndrome and water fluoride level and two studies by the same author found a significant (p < 0.05) positive association (increased Down's syndrome incidence with increased water fluoride level). Only two of the studies controlled for confounding factors and only one of these presented summary outcome measures. CONCLUSIONS: The evidence of an association between water fluoride level and Down's syndrome incidence is inconclusive

    Male and female physical intimate partner violence and socioeconomic position: a cross-sectional international multicentre study in Europe

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    Objectives: This work explores the association between socioeconomic position (SEP) and intimate partner violence (IPV) considering the perspectives of men and women as victims, perpetrators and as both (bidirectional). Study Design: Cross-sectional international multicentre study. Methods: A sample of 3496 men and women, (aged 18-64 years), randomly selected from the general population of residents from six European cities was assessed: Athens, Budapest, London, Östersund, Porto and Stuttgart. Their education (primary, secondary and university), occupation (upper white-collar, lower white-collar and blue collar) and unemployment duration (never, ≤12 months and >12 months) were considered as SEP indicators and physical IPV was measured with the Revised Conflict Tactics Scales. Results: Past year physical IPV was declared by 17.7% of women (3.5% victims, 4.2% perpetrators and 10.0% bidirectional) and 19.8% of men (4.1% victims, 3.8% perpetrators and 11.9% bidirectional). Low educational level (primary vs. university) was associated with female victimization (adjusted Odds Ratio, 95% confidence interval: 3.2, 1.3-8.0) and with female bidirectional IPV (4.1, 2.4-7.1). Blue collar occupation (vs. upper white) was associated with female victimization (2.1, 1.1-4.0), female perpetration (3.0, 1.3-6.8) and female bidirectional IPV (4.0, 2.3-7.0). Unemployment duration was associated with male perpetration (> 12 months of unemployment vs. never unemployed: 3.8, 1.7-8.7) and with bidirectional IPV in both sex (women: 1.8, 1.2-2.7; men: 1.7, 1.0-2.8). Conclusions: In these European centers, physical IPV was associated with a disadvantaged socioeconomic position. A consistent socioeconomic gradient was observed in female bidirectional involvement, but victims or perpetrators-only presented gender specificities according to levels of education, occupation differentiation and unemployment duration potentially useful for designing interventions

    Quantum walks: a comprehensive review

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    Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa

    Constructive Hybrid Games

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    Hybrid games are models which combine discrete, continuous, and adversarial dynamics. Game logic enables proving (classical) existence of winning strategies. We introduce constructive differential game logic (CdGL) for hybrid games, where proofs that a player can win the game correspond to computable winning strategies. This is the logical foundation for synthesis of correct control and monitoring code for safety-critical cyber-physical systems. Our contributions include novel static and dynamic semantics as well as soundness and consistency.Comment: 60 pages, preprint, under revie
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