268 research outputs found
High-Level Petri Nets as Type Theories in the Join Calculus
No full textWe study the expressiveness of the join calculus by comparison with (generalised, coloured) Petri nets and using tools from type theory. More precisely, we consider four classes of nets of increasing expressiveness, , introduce a hierarchy of type systems of decreasing strictness, , , and we prove that a join process is typeable according to if and only if it is (strictly equivalent to) a net of class . In the details, and contain, resp., usual place/transition and coloured Petri nets, while and propose two natural notions of high-level net accounting for dynamic reconfiguration and process creation and called reconfigurable and dynamic Petri nets, respectively
Toward a Game-Theoretic Model of Grid Systems
No full textComputational Grid is a promising platform that provides a vast range of heterogeneous resources for high performance computing. To grasp the full advantage of Grid systems, efficient and effective resource management and Grid job scheduling are key requirements. Particularly, in resource management and job scheduling, conflicts may arise as Grid resources are usually owned by different organizations, which have different goals. In this paper, we study the job scheduling problem in Computational Grid by analyzing it using game theoretic approaches. We consider a hierarchical job scheduling model that is formulated as a repeated non-cooperative game among Grid sites, which may have selfish concerns. We exploit the concept of Nash equilibrium as a stable solution for our game which eventually is convenient for every player
Adaptive Fuzzy-valued Service Selection
No full textService composition concerns both integration of heterogeneous distributed applications and dynamic selection of services. QoS-aware selection enables a service requester with certain QoS requirements to classify services according to their QoS guarantees. In this paper we present a method that allows for a fuzzy-valued description of QoS parameters. Fuzzy sets are suited to specify both the QoS preferences raised by a service requester such as 'response time must be as lower as possible and cannot be more that 1000ms' and approximate estimates a provider can make on the QoS capabilities of its services like 'availability is roughly between 95% and 99%'. We propose a matchmaking procedure based on a fuzzy-valued similarity measure that, given the specifications of QoS parameters of the requester and the providers, selects the most appropriate service among several functionally-equivalent ones. We also devise a method for dynamical update of service offers by means of runtime monitoring of the actual QoS performance
A Category of Explicit Fusions
No full textName passing calculi are nowadays an established field on
its own. Besides their practical relevance, they offered an intriguing challenge,
since the standard operational, denotational and logical methods
often proved inadequate to reason about these formalisms. A domain
which has been successfully employed for languages with asymmetric
communication, like the π-calculus, are presheaf categories based on (injective)
relabelings, such as SetI. Calculi with symmetric binding, in the
spirit of the fusion calculus, give rise to new research problems. In this
work we examine the calculus of explicit fusions, and propose to model
its syntax and semantics using the presheaf category SetE, where E is the
category of equivalence relations and equivalence preserving morphisms
Grazia Deledda’s autobiographical masks
No full textAll’interno della produzione di Grazia Deledda, Cosima è il personaggio più autobiografico, come si può notare dagli esempi riportati. È anche possibile scorgere assonanze tra l’autrice ed altre tre figure femminili protagoniste delle sue opere: Regina, protagonista di Nostalgie, Nina di Il Paese del Vento e Maria Concezione di La chiesa della solitudine.Among Grazia Deledda’s characters, Cosima is the most autobiographical one, as we can notice from the examples. Concordance can be noticed between the author and the female characters of her works: Regina is the main character of Nostalgie, Nina in Il Paese del Vento and Maria Concezione in La chiesa della solitudine
Maria Grazia Turri, Gli oggetti che popolano il mondo. Ontologia delle relazioni, Roma, Carocci, 2012, pp. 239
No full textThe text offers a Critical Review of "Gli oggetti che popolano il mondo. Ontologia delle relazioni" by Maria Grazia Turri. The author critically reflects on the book by considering its methodologies, its arguments, and its relation with other books of the same type and on the same subject.Il testo propone una Lettura Critica del libro "Gli oggetti che popolano il mondo. Ontologia delle relazioni" di Maria Grazia Turri. L'autrice riflette criticamente sul libro considerandone le metodologie, gli argomenti e il nesso con altri libri dello stesso tipo e sullo stesso argomento
LE MASCHERE AUTOBIOGRAFICHE DI GRAZIA DELEDDA
No full textWithin the production of Grazia Deledda, Cosima is the most autobiographical character, as can be seen from the examples shown. It is also possible to see similarities between the author and three other female figures protagonists of her works: Regina, protagonist of Nostalgie, Nina of The Country of the Wind and Maria Concezione of The church of solitude.All’interno della produzione di Grazia Deledda, Cosima è il personaggio più autobiografico, come si può notare dagli esempi riportati. È anche possibile scorgere assonanze tra l’autrice ed altre tre figure femminili protagoniste delle sue opere: Regina, protagonista di Nostalgie, Nina di Il Paese del Vento e Maria Concezione di La chiesa della solitudine.
Abstract
Within the production of Grazia Deledda, Cosima is the most autobiographical character, as can be seen from the examples shown. It is also possible to see similarities between the author and three other female figures protagonists of her works: Regina, protagonist of Nostalgie, Nina of The Country of the Wind and Maria Concezione of The church of solitude
Appunti per una storia dello spazio: piazza Tahrir e reti virtuali nell'Egitto della rivoluzione
No full textIl lavoro si presenta come un’analisi della rivoluzione di piazza Tahrir, alla riscoperta della riappropriazione dello spazio della piazza da parte della popolazione, attraverso l’utilizzo combinato dei social network e dei media tradizionali. La prima parte a cura di Mattia Bonfanti analizza il contesto dei 18 giorni di rivoluzione al Cairo. Il mancato ascolto delle istanze democratiche e un contesto politico affetto da cronica corruzione e miopia della classe dirigente egiziana, ha portato allo scoppio della protesta di piazza Tahrir il 25 gennaio 2011, i cui esiti restano a tutt’oggi controversi. La seconda parte a cura di Maria Grazia Montella si delinea come una riflessione sull’exploit dei social media come “ritorno alla fisicità” e riscoperta delle manifestazioni spaziali e fisiche del dissenso. La connessione tra lo spazio virtuale della rete e lo spazio fisico della piazza è storica, politica e culturale e si innesta nelle riflessioni prese in prestito da Lefebvre e Foucault.The work presents an analysis of the Egyptian uprising and of its most known rich place Tahrir Square. The process of re-appropriation of the space of the square through the combined use of social networks and traditional media is traced through the division in two parts. The first one outlines the political context and the eighteen days of the uprising in Cairo. The author identifies the principal causes of the revolution burst in the failure in listening the people’s request for democracy and in the chronic corruption of the government. The second part argues that the massive usage of the social networks has to be seen as a back to the physical, a revival of spatial and physic demonstration of the dissent. The connection between the virtual space of the internet and the real space of the square is historical, political, and cultural and it has to be sought in Foucault and Lefebvre reflections
Contracts for Abstract Processes in Service Composition
No full textContracts are a well-established approach for describing and analyzing behavioral aspects of web service
compositions. The theory of contracts comes equipped with a notion of compatibility between
clients and servers that ensures that every possible interaction between compatible clients and servers
will complete successfully. It is generally agreed that real applications often require the ability of exposing
just partial descriptions of their behaviors, which are usually known as abstract processes. We
propose a formal characterization of abstraction as an extension of the usual symbolic bisimulation
and we recover the notion of abstraction in the context of contracts
Migration as a risk for security. Risk frames in the Italian news on the Libya war and its aftermath
No full textDi fronte a crisi e conflitti internazionali che ridefiniscono i movimenti migratori verso l’Europa, esaminare la rappresentazione delle migrazioni nei mezzi di comunicazione può essere di grande utilità per comprendere come i rischi per la sicurezza sono percepiti, valutati e messi in connessione nel discorso pubblico. L’autrice offre un contributo in questa direzione attraverso l’analisi del framing delle notizie della stampa italiana durante e dopo l’intervento internazionale in Libia (2011-2012). Pur se molteplici aspetti della relazione migrazioni-sicurezza coesistono nei media, l’analisi automatica del contenuto degli articoli di cinque quotidiani nazionali consente di evidenziare la prevalenza di un frame delle migrazioni come rischio per i paesi di destinazione. L’enfasi su questioni di sicurezza come il terrorismo, la criminalità e l’ordine pubblico, inoltre, contribuiscono a caratterizzare le migrazioni come una vera e propria minaccia, riaffermando la dominanza di un discorso noi-centrico e securitario sul fenomeno migratorio.As crises and conflicts in the Middle East and across Africa reshape migration flows to Europe, looking how migration are represented in the media is of crucial importance to understand how multiple risks to security are understood, evaluated and connected to each other in the public discourse. The author contributes to this effort by analysing the framing of migration risks in the Italian press in a two-year period during and following the international military intervention in Libya in 2011. The examination of frames concerning various security risks through automated content analysis, allows to assess the relative relevance of a migration-as-a-risk frame in the press coverage. Albeit frames dealing with different aspects of the security-migration binomial coexist, the author shows how those concerned with direct threats to destination societies are the most frequent, thus revealing the dominance of a we-centric discourse over migration in the media
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