1,720,974 research outputs found
Symmetries, local names and dynamic (de)-allocation of names
No full textThe semantics of name-passing calculi is often defined employing coalgebraic models over presheaf categories This elegant theory lacks finiteness properties hence it is not apt to implementation Coalgebras over named sets, called history-dependent automata are better suited for the purpose due to locality of names A theory of behavioural functors for named sets is still lacking the semantics of each language has been given in an ad-hoc way and algorithms were implemented only for the pi-calculus Existence of the final coalgebra for the pi-calculus was never proved We introduce a language of accessible functors to specify history-dependent automata in a modular way leading to a clean formulation and a generalisation of previous results and to the proof of existence of a final coalgebra in a wide range of cases (C) 2010 Elsevier Inc All rights reserve
Towards a Spatial Model Checker on GPU
No full textThe tool VoxLogicA merges the state-of-the-art library of computational imaging algorithms ITK with the combination of declarative specification and optimised execution provided by spatial logic model checking. The analysis of an existing benchmark for segmentation of brain tumours via a simple logical specification reached very high accuracy. We introduce a new, GPU-based version of VoxLogicA and present preliminary results on its implementation, scalability, and applications
Experimental Analysis of the Thermo-Mechanical Properties of Recycled PET Fiber Reinforced Concrete
No full textEvent-Based Choreography
No full textAn important feature of the service-oriented approach is the ability to aggregate, through programmable coordination patterns, the activities involved in service interactions. Two different approaches can be adopted to tackle service coordination: orchestration and choreography. In this paper, we introduce a formal methodology to handle coordination among services from the perspective of a global observer, in the spirit of choreography models. In particular, we address the problem of verifying compliance and consistency between the design of service interactions and the choreography constraints
Towards Model Checking Video Streams Using VoxLogicA on GPUs
No full textWe present a feasibility study on the use of spatial logic model checking for real-time analysis of high-resolution video streams with the tool VoxLogicA. VoxLogicA is a voxel-based image analyser based on the Spatial Logic for Closure Spaces, a logic catered to deal with properties of spatial structures such as topological spaces, graphs and polyhedra. The underlying language includes operators to model proximity and reachability. We demonstrate, via the analysis of a series of video frames from a well-known video game, that it is possible to analyse high-resolution videos in real-time by exploiting the speed-up of VoxLogicA-GPU, a recently developed GPU-based version of the tool, which is 1–2 orders of magnitude faster than its previous iteration. Potential applications of real-time video analysis include medical imaging applications such as ultrasound exams, and other video-based diagnostic techniques. More broadly speaking, this work can be the first step towards novel information retrieval methods suitable to find information in a declarative way, in possibly large collections of video streams
On Binding in the Spatial Logics for Closure Spaces
No full textWe present two different extensions of the spatial logic for closure spaces (SLCS), and its spatio-temporal variant (τSLCS), with spatial quantification operators. The first concerns the existential quantification on individual points of a space. The second concerns the quantification on sets of points. The latter amounts to a form of quantification over atomic propositions, thus without the full power of second order logic. The spatial quantification operators are useful for reasoning about the existence of particular spatial objects in a space, their spatial relation with respect to other spatial objects, and, in the spatio-temporal setting, to reason about the dynamic evolution of such spatial objects
in time and space, including reasoning about newly introduced items. In this preliminary study we illustrate the expressiveness of the operators by means of several small, but representative, examples
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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