29,884 research outputs found
»It contained harbours that pleased me like sonnets«. Kleine Poetik der diegetischen Karte
No full textIn this article, Federico Italiano explores the relationship between literature and cartography. Beginning with Stevenson’s Treasure Island, the author frames the topic through a general theoretical lens on the spatial dimension of literary texts. He then focuses on a specific phenomenon of literary "carticity"—the diegetic presence of the map, that is, the map as an integral element of the narrative structure. Among others, Italiano examines the works of Houellebecq and Cormac McCarthy
Experimental Analysis of Dynamic All Pairs Shortest Path Algorithms
No full textWe present the results of an extensive computational study on dynamic algorithms for all pairs shortest path problems. We describe our implementations of the recent dynamic algorithms of King [1999] and of Demetrescu and Italiano [2006], and compare them to the dynamic algorithm of Ramalingam and Reps and to static algorithms on random, real-world and hard instances. Our experimental data suggest that some of the dynamic algorithms and their algorithmic techniques can be really of practical value in many situations
Giornale Italiano di Cardiologia
No full textIl Giornale Italiano di Cardiologia è l’organo ufficiale in lingua italiana della Federazione Italiana di Cardiologia e della Società Italiana di Chirurgia Cardiaca.La rivista è diretta dal dottor Giuseppe Di Pasquale e ha una periodicità mensile.
I contenuti comprendono editoriali, rassegne, messe a punto sulle più recenti acquisizioni nei vari campi della cardiologia a scopo informativo ed educazionale; studi epidemiologici ed osservazionali; linee guida cliniche; casi clinici ed immagini nel settore cardiovascolare; valutazioni di politica sanitaria ed economica; management in cardiologia, analisi di appropriatezza e di qualità; commenti ed opinioni su tutti i campi della cardiologia clinica; rassegne bibliografiche guidate; corrispondenz
Mantaining dynamic matrices for fully dynamic transitive closure
No full textIn this paper we introduce a general framework for casting fully dynamic transitive closure into the problem of reevaluating polynomials over matrices. With this technique, we improve the best known bounds for fully dynamic transitive closure. In particular, we devise a deterministic algorithm for general directed graphs that achieves O(n(2)) amortized time for updates, while preserving unit worst-case cost for queries. In case of deletions only, our algorithm performs updates faster in O(n) amortized time. We observe that fully dynamic transitive closure algorithms with O(1) query time maintain explicitly the transitive closure of the input graph, in order to answer each query with exactly one lookup (on its adjacency matrix). Since an update may change as many as Omega(n(2)) entries of this matrix, no better bounds are possible for this class of algorithms
Fully dynamic all pairs shortest paths with real edge weights
No full textAbstractWe present the first fully dynamic algorithm for maintaining all pairs shortest paths in directed graphs with real-valued edge weights. Given a dynamic directed graph G such that each edge can assume at most S different real values, we show how to support updates in O(n2.5Slog3n) amortized time and queries in optimal worst-case time. This algorithm is deterministic: no previous fully dynamic algorithm was known before for this problem. In the special case where edge weights can only be increased, we give a randomized algorithm with one-sided error that supports updates faster in O(S⋅nlog3n) amortized time. We also show how to obtain query/update trade-offs for this problem, by introducing two new families of randomized algorithms. Algorithms in the first family achieve an update bound of O˜(S⋅k⋅n2)1 and a query bound of O˜(n/k), and improve over the previous best known update bounds for k in the range (n/S)1/3⩽k<(n/S)1/2. Algorithms in the second family achieve an update bound of O˜(S⋅k⋅n2) and a query bound of O˜(n2/k2), and are competitive with the previous best known update bounds (first family included) for k in the range (n/S)1/6⩽k<(n/S)1/3
Giornale italiano di farmacoeconomia e farmacoutilizzazione
No full textll Giornale Italiano di Farmacoeconomia e Farmacoutilizzazione, rivista ufficiale del SEFAP, si propone come strumento di informazione e approfondimento in merito all'appropriatezza di prescrizione e di utilizzo dei farmaci, alla valutazione dei profili di rischio-beneficio e costo-efficacia delle terapie e alle tematiche di economia e politiche sanitarie.
Obiettivo della nostra rivista è fornire rassegne e recensioni indipendenti, autorevoli e chiare sugli argomenti ritenuti più importanti dal board editoriale
MAI : MetaOPAC Azalai Italiano
No full textMAI (MetaOPAC Azalai Italiano) is a virtual union catalogue of Italian libraries developed through co-operation between the Italian Library Association (Associazione Italiana Biblioteche, AIB) and the Consorzio Interuniversitario Lombardo per l’Elaborazione Automatica (CILEA). This paper presents the components of the MAI and the organisational, management, planning and implementation tools developed by the team since 1999. MAI provides access to Italian OPACs, offering a directory and metasearch functionality. The search engine, Azalai, performs metasearching, which also involves a converter as part of the system. The architecture of the system, the search engine and converter, is based on a database in which all the Italian OPACs are recorded. Three different interfaces, designed for specific types of users, provide access to the system. Members of the MAI Editorial Board are responsible for keeping the database updated and this automatically generates the Directory of Italian Online Catalogues. MAI is divided into five distinct sections, integrated with a range of tools and services intended for different categories of user
Dynamic shortest paths and transitive closure: algorithmic techniques and data structures
No full textIn this paper, we survey fully dynamic algorithms for path problems on general directed graphs. In particular, we consider two fundamental problems: dynamic transitive closure and dynamic shortest paths. Although research on these problems spans over more than three decades, in the last couple of years many novel algorithmic techniques have been proposed. In this survey, we will make a special effort to abstract some combinatorial and algebraic properties, and some common data-structural tools that are at the base of those techniques. This will help us try to present some of the newest results in a unifying framework so that they can be better understood and deployed also by non-specialists. © 2005 Elsevier B.V. All rights reserved
Fenomeno della dipendenza a lungo termine nel mercato finanziario italiano
No full textLo scopo del presente lavoro è quello di testare la presenza di una sorta di dipendenza a lungo termine nelle serie storiche dei tassi di rendimento relativi ai principali indici e titoli azionari del mercato finanziario italiano. A tal fine viene applicata l'analisi rescaled range, sia nella sua versione classica proposta da Hurst ed ampliata da Mandelbrot, sia nella sua versione modificata elaborata da Lo per tener conto di una distorsione dovuta alla presenza di una eventuale dipendenza a breve termine
A new approach to dynamic all pairs shortest paths
No full textWe study novel combinatorial properties of graphs that allow us to devise a completely new approach to dynamic all pairs shortest paths problems. Our approach yields a fully dynamic algorithm for general directed graphs with non-negative realvalued edge weights that supports any sequence of operations in O(n time per update and unit worst-case time per distance query, where n is the number of vertices. We can also report shortest paths in optimal worst-case time. These bounds improve substantially over previous results and solve a long-standing open problem. Ou
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