65 research outputs found

    A cookbook for temporal conceptual data modelling with description logic

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    We design temporal description logics suitable for reasoning about temporal conceptual data models and investigate their computational complexity. Our formalisms are based on DL-Lite logics with three types of concept inclusions (ranging from atomic concept inclusions and disjointness to the full Booleans), as well as cardinality constraints and role inclusions. In the temporal dimension, they capture future and past temporal operators on concepts, flexible and rigid roles, the operators `always' and `some time' on roles, data assertions for particular moments of time and global concept inclusions. The logics are interpreted over the Cartesian products of object domains and the flow of time (Z,<), satisfying the constant domain assumption. We prove that the most expressive of our temporal description logics (which can capture lifespan cardinalities and either qualitative or quantitative evolution constraints) turn out to be undecidable. However, by omitting some of the temporal operators on concepts/roles or by restricting the form of concept inclusions we obtain logics whose complexity ranges between PSpace and NLogSpace. These positive results were obtained by reduction to various clausal fragments of propositional temporal logic, which opens a way to employ propositional or first-order temporal provers for reasoning about temporal data models

    Non-Rigid Designators in Epistemic and Temporal Free Description Logics (Extended Version)

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    Definite descriptions, such as 'the smallest planet in the Solar System', have been recently recognised as semantically transparent devices for object identification in knowledge representation formalisms. Along with individual names, they have been introduced also in the context of description logic languages, enriching the expressivity of standard nominal constructors. Moreover, in the first-order modal logic literature, definite descriptions have been widely investigated for their non-rigid behaviour, which allows them to denote different objects at different states. In this direction, we introduce epistemic and temporal extensions of standard description logics, with nominals and the universal role, additionally equipped with definite descriptions constructors. Regarding names and descriptions, in these languages we allow for: possible lack of denotation, ensured by partial models, coming from free logic semantics as a generalisation of the classical ones; and non-rigid designation features, obtained by assigning to terms distinct values across states, as opposed to the standard rigidity condition on individual expressions. In the absence of the rigid designator assumption, we show that the satisfiability problem for epistemic free description logics is NExpTime-complete, while satisfiability for temporal free description logics over linear time structures is undecidable

    SINGING BOUNDARIES: TOWARD AN UNDERSTANDING OF VOCALITY AND THE PERFORMANCE OF IDENTITIES IN THE CANT VALENCIÀ D'ESTIL

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    The cant valencia or cant valencia d'estil of Valencia is one of the four main living monodic expressive song traditions of Spain. Comprised of non-metric cant d'estil and metric albaes songs mostly used in street serenades, it features a distinctive vocality characterized by a highly-projected, clear, inflected, and flexible voice as well as two melodic styles, of which the more ornamented cant requintat developed at the turn of the twentieth century. I take a historical, theoretical, and ethnographic approach to this Valencian vocal genre and explore the ways in which vocality can help us to understand it better. After examining the origins of the cant valencia and the antiquarian, journalistic, folkloristic, and (ethno)musicological approaches to it, I probe the notion of vocality in a transdisciplinary way: drawing on ethnomusicological theory, anthropology, folklore, semiotics, and other disciplines I show its significance for the development of a musical anthropology of the voice productively based on the ethnographic exploration of the iconicity of style and of two sets of central vocal issues: on the one hand, identity, gender, authority, and sonic histories and geographies; on the other, acoustemology, interpellation, and transcendence. Vocality not only expands usefully the scope of vocal or singing style by encompassing larger bodily-dependent traits of the human voice as central or salient means of aesthetic and ethical production of meanings, but also acknowledges its pre-eminent position in the hierarchy of musical values, since the material/textural qualities of (vocal) sounds iconically shape our first sonorous perceptions and identifications and are thus paramount for communication. I make a first approach to vocality and the performance of collective identities in the cant valencia by showing that its modern stylistic development is linked to two diachronic frameworks: the moments of modern radical situational change in Europe and the construction of Spanish national identity. I also explore how issues of interpellation and transcendence bear on the formation of personal identities of the cantadors d'estil, the specialized cant valencia singers. I show that an emically-informed, etic approach to vocality can afford an understanding of how people can create their own history and affirm their own collective or personal identities in response to larger social processes

    Genre in Archaic and Classical Greek Poetry: Theories and Models

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    Genre in Archaic and Classical Greek Poetry brings together a range of innovative approaches to the question of genre, what it means, and how to think about it for Greek poetry from the eighth to the fourth centuries BCE. Readership: Students and scholars across the Humanities who are concerned with questions of genre and the history of lyric, and anyone interested in ancient Greek poetry

    Labelled Superposition for {PLTL}

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    This paper introduces a new decision procedure for PLTL based on labelled superposition. Its main idea is to treat temporal formulas as infinite sets of purely propositional clauses over an extended signature. These infinite sets are then represented by finite sets of labelled propositional clauses. The new representation enables the replacement of the complex temporal resolution rule, suggested by existing resolution calculi for PLTL, by a fine grained repetition check of finitely saturated labelled clause sets followed by a simple inference. The completeness argument is based on the standard model building idea from superposition. It inherently justifies ordering restrictions, redundancy elimination and effective partial model building. The latter can be directly used to effectively generate counterexamples of non-valid PLTL conjectures out of saturated labelled clause sets in a straightforward way

    A Temporal Framework for Hypergame Analysis of Cyber Physical Systems in Contested Environments

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    Game theory is used to model conflicts between one or more players over resources. It offers players a way to reason, allowing rationale for selecting strategies that avoid the worst outcome. Game theory lacks the ability to incorporate advantages one player may have over another player. A meta-game, known as a hypergame, occurs when one player does not know or fully understand all the strategies of a game. Hypergame theory builds upon the utility of game theory by allowing a player to outmaneuver an opponent, thus obtaining a more preferred outcome with higher utility. Recent work in hypergame theory has focused on normal form static games that lack the ability to encode several realistic strategies. One example of this is when a player’s available actions in the future is dependent on his selection in the past. This work presents a temporal framework for hypergame models. This framework is the first application of temporal logic to hypergames and provides a more flexible modeling for domain experts. With this new framework for hypergames, the concepts of trust, distrust, mistrust, and deception are formalized. While past literature references deception in hypergame research, this work is the first to formalize the definition for hypergames. As a demonstration of the new temporal framework for hypergames, it is applied to classical game theoretical examples, as well as a complex supervisory control and data acquisition (SCADA) network temporal hypergame. The SCADA network is an example includes actions that have a temporal dependency, where a choice in the first round affects what decisions can be made in the later round of the game. The demonstration results show that the framework is a realistic and flexible modeling method for a variety of applications

    Logic and the Foundations of Game and Decision Theory (LOFT 7)

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    This volume collects together revised papers originally presented at the 7th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2006). LOFT is a key venue for presenting research at the intersection of logic, economics and computer science, and the present collection gives a lively and wide-ranging view of an exciting and rapidly growing area
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