1435 research outputs found
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BPEL2YAWL: Transalating BPEL processes into YAWL workflows
No full textThe availability of several languages for the description of Web service behaviour (viz., protocols) hinders (automated) Web service aggregation, discovery, and adaptation as currently there are no tools for the (automated) translation of service protocols.
In this paper we motivate the choice of YAWL as lingua-franca to express the behaviour of Web services. Furthermore, we describe a methodology for translating BPEL processes into YAWL workflows,thus paving the way for the formal analysis, aggregation, discovery, and adaptation of BPEL processes. Roughly, our methodology defines a YAWL pattern for each BPEL activity. The translation of a BPEL process reduces then to suitably instantiating and interconnecting the patterns of its activities
Critical behavior of two-dimensional fully frustrated XY systems
No full textWe study the phase diagram of the two-dimensional fully frustrated XY model
(FFXY) and of two related models, a lattice discretization of the
Landau-Ginzburg-Wilson Hamiltonian for the critical modes of the FFXY model,
and a coupled Ising-XY model. We present Monte Carlo simulations on square
lattices , . We show that the low-temperature phase
of these models is controlled by the same line of Gaussian fixed points as in
the standard XY model. We find that, if a model undergoes a unique transition
by varying temperature, then the transition is of first order. In the opposite
case we observe two very close transitions: a transition associated with the
spin degrees of freedom and, as temperature increases, a transition where
chiral modes become critical. If they are continuous, they belong to the
Kosterlitz-Thouless and to the Ising universality class, respectively. Ising
and Kosterlitz-Thouless behavior is observed only after a preasymptotic regime,
which is universal to some extent. In the chiral case, the approach is
nonmonotonic for most observables, and there is a wide region in which
finite-size scaling is controlled by an effective exponent . This explains the result of many previous
studies using smaller lattices
Lossless Filter for Long Multiple Repetitions with Edit Distance
No full textIdentifying local similarity between two or more sequences, or identifying repetitions occurring at least twice in a sequence, is an essential part in the analysis of biological sequences and of their phylogenetic relationship. Finding fragments that are conserved among several given sequences, or inside a unique sequence, while allowing for a certain number of insertions, deletions, and substitutions, is however known to be a computationally expensive task, and consequently exact methods can usually not be applied in practice. The filter we introduce in this paper, called Ed'Nimbus, provides a possible solution to this problem. It can be used as a preprocessing step to any multiple alignment method, eliminating an important fraction of the input that is guaranteed not to contain any approximate repetition. It consists in the verification of a strong necessary condition. This condition concerns the number and order of exactly repeated words shared by the approximate repetitions. The efficiency of the filter is due to this condition, that we show how to check in a fast way. The speed of the method is achieved thanks also to the use of a simple and efficient data structure, that we describe in this paper, as well as its linear time and space construction. Our results show that using Ed'Nimbus allows us to sensibly reduce the time spent in a local multiple alignment.The Ed'Nimbus software is freely available on the web:http://igm.univ-mlv.fr/peterlon/officiel/ednimbus
Methods Passed as Parameters in Java: A Pre-processing Approach
No full textIn this paper we investigate the possibility of adding
higher order functionalities to Java, that is passing methods as
parameters to other methods. The approach is based on a mechanism which offers a restricted, disciplined, form of function abstraction but suitable to the integration of high order and Object Oriented programming. We discuss how the expressive power of the language is increased. A new syntax is introduced for formal and actual parameters, hence the paper shows an implementation of the extentions based on a preprocessing technique tha maps programs of the extended language into programs of ordinary Java
Q-NiGHT: Adding QoS to Data Centric Storage in Non-Uniform Sensor Networks
No full textStorage of sensed data in wireless sensor networks is essential when the sink node is unavailable due to failure and/or disconnections, but it can also provide efficient access to sensed data to multiple sink nodes. Recent approaches to data storage rely on Geographic Hash Tables for efficient data storage and retrieval. These approaches however do not support different QoS levels for different classes of data as the programmer has no control on the level of redundancy of data (and thus on data dependability). Moreover, they result in a great unbalance in the storage usage in each sensor, even when sensors are uniformly distributed. This may cause serious data losses, waste energy and shorten the overall lifetime of the sensornet. In this paper, we propose a novel protocol, Q-NiGHT, which (1) provides a direct control on the level of QoS in the data dependability, and (2) uses a strategy similar to the rejection method to build a hash function which scatters data approximately with the same distribution as sensors. The benefits of QNiGHT are assessed through a detailed simulation experiment, also discussed in the paper. Results show its good performance on different sensors distributions on terms of both protocol costs and load balance between sensors
Lo standard Openurl: evoluzioni e applicazioni
No full textUna rassegna delle degli sviluppi, delle realizzazione e delle problematiche relative alla tecnologia degli openresolver e allo standard Openurl (Niso Z39-88
Restauri in Lituania. Vilnius capitale della cultura europea 2009
Get PDFRIASSUNTO Nel 2009 Vilnius, capitale della Lituania, diventerà la capitale della cultura europea. Tra le iniziative promosse dalla Lituania per questo evento, il centro storico della città e i suoi principali monumenti sono stati restaurati. SUMMARY In 2009 Vilnius, capital of Lithuania, will be the capital of the European Culture. Among the initiatives promoted by the Lithuanian Country for this event, the historical centre of the city has been restored and its main monuments have been renewed
Strumenti ed indagini conoscitive applicate nella chiesa di S. Pietro in Vinculis in Pisa
Get PDFRIASSUNTO Lo studio dell’architettura, negli ultimi decenni, ha visto collaborare insieme ambiti disciplinari differenti ma il cui crescente dialogo ha reso possibile una conoscenza sempre più approfondita dei manufatti edilizi, sia monumentali che non, mediante l’apporto di metodologie e il supporto di tecnologie diagnostiche sempre più innovative. In tale contesto i metodi della fisica, della chimica e della matematica applicati non solo all’archeologia ma anche allo studio delle opere d’arte mobili e all’architettura hanno posto le basi per un’analisi del manufatto non solo come documento storico ma soprattutto valutato in relazione alla sua consistenza materica e al suo intrinseco valore sociale e culturale. In tale contesto scientifico un esempio di ricerca e di lavoro interdisciplinare è stato eseguito per indagare stratigraficamente le murature della chiesa di S. Pietro in Vinculis in Pisa, mediante un’analisi diagnostica preliminare al progetto di restauro conservativo eseguito tra il 2001 ed il 2004. SUMMARY Abstract in inglese In the last decades the study of the architecture has been based on the cooperation among different disciplines whose connection has allowed growing knowledge of the buildings, whether monumental than not, through the use of diagnostic methodologies and innovative technologies. In this context the results reached in physics, chemistry, mathematics can be applied not only in archaeology but even in the study of works of art and in architecture. They represent the foundations upon which to study the materials of the buildings that are not only intended as historical documents but even their value, both social and cultural, is evaluated. A great example of interdisciplinary research is given from the preliminary diagnostic analysis of S. Pietro in Vinculis in Pisa, realized from the 2001 to 2004, to study the wall layer of the church
Le prime docenti dell’Università di Pisa
No full textRIASSUNTO. La storia delle docenti dell'Università di Pisa inizia solo negli anni Trenta del Novecento. La causa era la quasi totale esclusione della donna dalla maggior parte degli ambiti sociali e lavorativi: lo Stato, la Chiesa e il campo dell'istruzione, infatti, erano regolati da leggi che ne ostacolavano l'emancipazione. Con la prima guerra mondiale e un gran numero di uomini al fronte, però, le donne ebbero modo di prendere parte a quelle attività da cui erano sempre state escluse, come appunto l'insegnamento. Inoltre, con la caduta del regime fascista, iniziò una lenta ma continua emancipazione del genere femminile, a partire dalla concessione del voto alle donne nel 1946, che continua ancora oggi. Comparvero quindi nell'ateneo pisano le prime donne, prima con mansioni di "assistente" e poi come docenti: dal 1932 E. Francini ottenne la cattedra di Botanica, nel 1936 E. Calabresi quella di Entomologia agraria, G. De Guidi quella di Geologia e mineralogia e M. Ciccone quella di Fisica sperimentale. Dal 1941 A. Squarcetta insegnò Clinica pediatrica, dal 1944 L. Riva Sanseverino insegnò Diritto corporativo e nel 1942 B. Giglioli ottenne la cattedra di Lingua e letteratura inglese. SUMMARY The story of the university women teachers in Pisa began only in the thirties, cause of the total exclusion of women from almost every social and working field by the authorities and the popular way of thinking of the time. With the first World War the situation began slowly to change, because men went to the front, and women had the right/duty to take part to all those activities from which, till that moment, were been excluded: like university teaching. Then ,with the fall of fascism, emancipation of women achieved one of his most important goal: the right to vote in 1946. In the meanwhile, in the University of Pisa, women that were ever been employed as “assistant” began to have assigned their professorship: in 1932, in fact, E. Francini began to teach Botany. In 1936 E. Calabresi began to teach Agrarian Entomology, G. De Guidi Geology and Mineralogy, and M.Ciccone Experimental Physics. Then, in 1942, B. Giglioli gave her course of English Literature, and in 1944 L.Riva Sanseverino teached Corporative Law
Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment?
No full textSUMMARY We investigate the parametric fluctuations in the quantum survival
probability of an open version of the delta-kicked rotor model in the deep
quantum regime. Spectral arguments [Guarneri I and Terraneo M 2001 Phys. Rev. E
vol. 65 015203(R)] predict the existence of parametric fractal fluctuations
owing to the strong dynamical localisation of the eigenstates of the kicked
rotor. We discuss the possibility of observing such dynamically-induced
fractality in the quantum survival probability as a function of the kicking
period for the atom-optics realisation of the kicked rotor. The influence of
the atoms' initial momentum distribution is studied as well as the dependence
of the expected fractal dimension on finite-size effects of the experiment,
such as finite detection windows and short measurement times. Our results show
that clear signatures of fractality could be observed in experiments with cold
atoms subjected to periodically flashed optical lattices, which offer an
excellent control on interaction times and the initial atomic ensemble