1,721,053 research outputs found
Integrating Two Towers and GreatSPN
No full textWe describe the integration of the EMPA based software tool TwoTowers and the GSPN based software tool GreatSPN, in order to fully realize a multiparadigm approach to the functional and performance modeling and analysis of concurrent and distributed systems. The integration is achieved via an improved semantics mapping EMPA terms onto GSPN models
L’EMBOLIZZAZIONE PORTALE PREOPERATORIA NELLA CHIRURGIA DELLE METASTASI EPATICHE DA CARCINOMA COLO-RETTALE. ESPERIENZA PERSONALE
No full textIntroduzione: Lo scopo del presente lavoro è di riportare i risultati della nostra esperienza nell’utilizzo della embolizzazione portale controlaterale preoperatoria in pazienti con metastasi epatiche da carcinoma colo-rettale.
Materiali e Metodi: dal gennaio 2002 al dicembre 2007 9 pazienti portatori di metastasi epatiche da ca colorettale sono stati sottoposti ad embolizzazione portale destra in previsione di un intervento di epatectomia destra allargata ed in presenza di un volume epatico residuo previsto inferiore al 30% del totale.
Risultati: la manovra è stata portata a termine con successo in tutti i pazienti ed abbiamo registrato 2 complicanze (22%): in un caso un voluminoso ematoma intraparenchimale che ha richiesto una ospedalizzazione prolungata, ma non ha compromesso il successivo intervento, mentre nel secondo caso una iperpiressia transitoria. In tutti i casi il trattamento chemioterapico neoadiuvante è stato proseguito nell’intervallo tra embolizzazione e intervento di resezione epatica. In 1 paziente si è verificato un aumento volumetrico di una l lesione secondaria del IV segmento. In 1 caso l’embolizzazione è stata allargata anche ai rami del IV segmento. In 3 pazienti (33%) l’embolizzazione portale è stata utilizzata come preparazione ad un intervento di reepatectomia. In nessun paziente abbiamo documentato una ipertrofia insufficiente del fegato residuo. Il controllo dell’ipertrofia è stato sempre eseguito dopo 30 giorni ed abbiamo registrato un aumento medio del volume epatico residuo del 29,2%. Otto pazienti sono stati sottoposti ad intervento chirurgico e non abbiamo documentato alcun caso di insufficienza epatica post-operatoria. In un caso l’intervento è stato annullato a causa della progressione della malattia metastatica.
Conclusioni: anche nella nostra limitata esperienza la PVE si è dimostrata sicura ed efficace. Riteniamo che le sue indicazioni possano essere in futuro allargate trovandoci a trattare chirurgicamente pazienti dopo prolungata chemioterapia con maggior rischio di insufficienza epatica post-operatoria. In particolare in questi casi riteniamo opportuno attendere anche 45 giorni per l’intervento chirurgico onde consentire una completo processo di ipertrofia del fegato residuo
Characterizing workflow nets using regions
No full textThe target of workflow mining is to obtain a workflow management systems from a possibly complete set of event logs of the system. This gives a fruitful support for developing complex business transaction sequences and business collaboration applications,
possibly filling the gap from the theoretical design and the real instances.
An algorithm (the alpha-algorithm) has been proposed in literature to rediscover a Workflow (Petri) Net that generated a given event log. This algorithm have some drawback as it fails in rediscovering the correct net.
We investigate on how the theory of regions, used to synthesize nets from marking graphs, can be used to mine Workflow Nets, discussing the behaviour of region based net synthesis on some cases that turn out to be problematic for the alpha-algorithm. We also briefly discuss on how transitions systems can be obtained by event logs
Integrating TwoTowers and GreatSPN through a Compact Net Semantics
No full textStochastic process algebras (SPAs) and stochastic Petri nets (SPNs) are two well known formal methods for the functional and performance modeling and analysis of computer, communication and software systems. Starting from the mappings from process algebras to Petri nets proposed in the literature to provide a truly concurrent semantic framework to concurrent programming languages, in this paper we define a new SPN semantics for SPAs in order to facilitate the integration and the cross fertilization between the two formalisms. We then prove that our net semantics is correct via a retrievability result. Afterwards, we demonstrate that it improves on the previously proposed net semantics with respect to the size of the resulting SPNs and on the standard interleaving semantics because of the detection of system symmetries. Furthermore, we illustrate its usefulness by showing how to reinterpret at the SPA level the results efficiently obtainable at the SPN level. Finally, we describe the implementation of our net semantics that has been realized to integrate the EMPAgr based software tool TwoTowers with the GSPN based software tool GreatSPN
A distributed implementation of mobile nets as mobile agents
Full text linkMobile nets arise as a combination of the name managing techniques of the π-calculus with the representation of concurrency and locality of Petri nets. We propose MAGNETs, a variant of mobile nets that are suitable for an effective, distributed implementation. Such implementation extends an implementation of the Join calculus virtual machine with dynamic reconfiguration features
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
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