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Service Composition in Dynamic Environments: From Theory to Practice
No full textIn recent years, service-oriented architecture (SOA) has become one of the leading paradigms in software design. Among the key advantages behind SOA is service composition, the ability to create new services by reusing the functionality of pre-existing ones. Despite the availability of standard languages and related design and development tools, ``manual'' service composition remains to be an extremely error-prone and time-consuming task. No surprise, the automation of service composition process has been and still is a hot topic in the area of service computing.
In addition to high complexity, modern service-based systems tend to be dynamic. The most common examples of dynamic factors are constantly evolving set of available services, volatile execution context, frequent revision of business policies, regulations and goals, etc. Since dynamic changes of the execution environment can invalidate service compositions predefined within a service-based system, the cost of software maintenance in this case may increase dramatically. Unfortunately, the existing automated service composition approaches are not of much help here. Being design-time by their nature, they intensively involve IT experts, especially for analysing the changes and respecifying formal composition requirements in new conditions, which is still a considerable effort. To make service-based systems more agile, a new composition approach is needed that could automatically perform all composition-related tasks at run time, from deriving composition requirements to generating new compositions to deploying them.
In this dissertation, we propose a novel service composition framework that (i) handles stateful and nondeterministic services that interact asynchronously, (ii) allows for rich control- and data-flow composition requirements that are independent from the details of service implementations (iii) exploits advanced planning techniques for automated reasoning and (iv) exploits modeling methodology that is applicable in dynamic environment.
The corner stone of the framework is the explicit context model that abstracts composition requirements and constraints away from the details of service implementations. By linking services to the context model on the one side, and by expressing composition requirements and constraints in terms of the context model on the other side, we create a formal setting in which abstract requirements and constraints, though being implementation-independent, can always be grounded to available service implementations. Consequently, we show that in such framework it is possible to move most human activities to design time so that the run-time management of the composition life cycle is completely automated. To the best of our knowledge, it is the first composition approach to achieve this goal.
A significant contribution of the dissertation is the investigation of the problem of dynamic adaptation of service-based business processes. Here, our solution is based on the composition approach proposed. Within the thesis, the problem of process adaptation plays the role of the key motivator and evaluation use case for our composition-related research.
The most part of the ideas discussed in the thesis are implemented and evaluated to prove their practical applicability
A General Framework for Exploiting Background Knowledge in Natural Language Processing
No full textThe two key aspects of natural language processing (NLP) applications based on machine learning techniques are the learning algorithm and the feature representation of the documents, entities, or words that have to be manipulated.
Until now, the majority of the approaches exploited syntactic features, while semantic feature extraction suffered from low coverage of the available knowledge resources and the difficulty to match text and ontology elements.
Nowadays, the Semantic Web made available a large amount of logically encoded world knowledge called Linked Open Data (LOD). However, extending state-of-the-art natural language applications to use LOD resources is not a trivial task due to a number of reasons, including natural language ambiguity and heterogeneity and ambiguity of the schemes adopted by different LOD resources.
In this thesis we define a general framework for supporting NLP with semantic features extracted from LOD. The main idea behind the framework is to (i) map terms in text to the unique resource identifiers (URIs) of LOD concepts through Wikipedia mediation; (ii) use the URIs to obtain background knowledge from LOD; (iii) integrate the obtained knowledge as semantic features into machine learning algorithms. We evaluate the framework by means of case studies on coreference resolution and relation extraction.
Additionally, we propose an approach for increasing accuracy of the mapping step based on the "one sense per discourse" hypothesis. Finally, we present an open-source Java tool for extracting LOD knowledge through SPARQL endpoints and converting it to NLP features
Keeping Information Systems alive: participation, work and maintenance-in-use in a welfare department
No full textThrough the case study of a regional welfare information system, I analize how the process of keeping information systems workable and operational unfolded
Studi esegetici intorno ai titoli I-XIII del libro XLIX del Digesto: profili problematici e soluzioni giurisprudenziali in tema di 'appellatio'
No full textLa ricerca, dal carattere spiccatamente esegetico, muove dalla traduzione dei tituli 1-13 del libro XLIX dei Digesta.
Il tema dell'appellatio, inteso come studio del rimedio di impugnazione di provvedimenti giurisdizionali, è stato oggetto di poco estesa attenzione da parte della dottrina. Il carattere frammentario delle fonti e la necessità di tracciare i contorni dell'istituto in una dinamica di formazione alluvionale dei processi extra ordinem ha perlopiù diretto gli studi della giusromanistica verso gli istituti del processo formulare; la maggior parte dei contributi della dottrina vertono pertanto su singoli aspetti degli istituti tipici della cognitio extra ordinem.
Nonostante la relativa scarsezza e frammentarietà delle fonti a noi pervenute, l'istituto dell'appello, così come si delinea a partire dall'età augustea e che vede sempre più direttamente coinvolta la figura del principe nella funzione, propria o delegata, di giudice di gravame definitivo, porta con sé numerose problematiche, che emergono spiccatamente nel momento di applicazione giurisprudenziale, tutt'oggi al centro dell'attenzione degli studiosi delle materie processualistiche.
Da un punto di vista metodologico la ricerca si propone di partire dal dato testuale delle fonti, compiendo una traduzione diretta di esse, per ricostruire e far emergere le problematiche che la prassi dell'istituto ha portato con sé nella dimensione applicativa.
Parallelamente all'emersione dei nodi fondamentali, si vuole porre in luce la riflessione giurisprudenziale che intorno a quegli stessi problemi si forma e che tenta, secondo una tradizione ininterrotta nell'arco dello sviluppo del diritto romano, di avere sempre come proprio punto di riferimento la soluzione del caso concreto di volta in volta sottoposto al giurista, nel nostro caso spesso consigliere diretto del princeps.
Si tenterà pertanto di fornire una trattazione dettagliata, analitica e puntuale dell'istituto dell'appello, tanto nei suoi aspetti procedurali, quanto nei principi di diritto che emergono dalla riflessione dei giuristi, offrendo in tal modo un quadro unitario e di sintesi, il quale andrà rivisitato idealmente alla luce dei contrasti e dei problemi esegetici che emergeranno al termine della ricerca. A conclusione della prima parte, si porranno in evidenza le soluzioni pacifiche all'interno della giurisprudenza che ha riflettuto su problematiche legate alle applicazioni pratiche delle impugnazioni, dando conto altresì dei problemi che, al contrario, risultano ancora dibattuti dalla dottrina e che costituiscono pertanto fonte di ius controversum.
A tal fine, si darà sempre privilegio alle fonti tradotte rispetto alle soluzioni prospettate dalla dottrina, la quale verrà così sottoposta ad un esame critico alla luce dell'esegesi compiuta. Il lavoro seguirà pertanto un iter di continuo confronto tra le soluzioni e le questioni emergenti dall'analisi dei Digesta, intendendoli come luogo di reperimento del ius controversum, e l’importanza di tali soluzioni alla luce della loro collocazione originaria, ricercata attraverso un’analisi di tipo palingenetico, cui è dedicata la prima parte del lavoro, per verificare se si sia persa o meno la problematicità e la complessità delle questioni a vantaggio della funzione di sintesi cui è votata l'opera giustinianea, fornendo pertanto le linee di una ricostruzione tanto diacronica quanto sincronica dei testi
Terrorismo e conflitto generazionale nel romanzo italiano
No full textLa mia ricerca si divide in due parti. La prima parte si apre con una premessa in cui, rifacendomi agli studi recenti di due psicologi contemporanei, Luigi Zoja e Massimo Recalcati, metto in discussione l’opportunità di ricorrere alle categorie del complesso edipico e del parricidio per interpretare le rivolte degli anni Settanta e le loro rappresentazioni artistiche. Nei successivi quattro capitoli che compongono questa prima parte effettuo un’analisi dei romanzi, dei quali propongo una classificazione in base al modo in cui il terrorismo è calato all’interno del contesto familiare e nei rapporti generazionali, a seconda, dunque, che il terrorista sia il figlio, il fratello/sorella, il coniuge-amante o il genitore. Nella seconda parte, nettamente più breve, affronto alcune questioni che riguardano trasversalmente tutti i romanzi che ho preso in esame, ovvero il significato dei ruoli di genere e il carattere stereotipato dei personaggi, con particolare riferimento alla figure dei terroristi e delle vittime.
Nelle conclusioni metto in luce i limiti e i punti deboli che hanno caratterizzato fino ad ora la rappresentazione letteraria degli anni di piombo
On the Performance of Super-Long Integral Abutment Bridges: Parametric Analyses and Design Optimization
Get PDFThe concept of "integral abutment bridge" has recently become a topic of remarka-ble interest among bridge engineers, not only for newly built bridges but also during refurbishment processes. The system constituted by the substructure and the superstructure can achieve a composite action responding as a single structural unit; the elimination of expansion joint and bearings on the abutments, greatly reduce the construction and maintenance costs. To maximize the benefits from integral abutment bridges, the direct way is to achieve the super-long integral abutment bridge. However, as the environment temperature changes, the lengths of superstructure increase and decrease, pushing the abutment against the approach fill and pulling it away. The responses of bridge superstructure, the abutment, the approach system, the foundation/piles and the foundation soil are all different. And it's important to understand their interactions effective design and satisfactory performance of integral abutment bridges.
In order to build longer integral abutment bridges, therefore in this research, the lit-erature survey on the applications of integral abutment bridges in worldwide, espe-cially the current development of super-long integral abutment bridges was carried out firstly. Another literature review on soil-structure interaction was conducted to find out the most suitable methods in considering this kernel issue in design of integral abutment bridge. Through proposing finite element models for integral abutment bridges that could involve the soil-structure interaction, thermal actions, non-linearity in materials and so on, structural study was performed on an existing super-long integral abutment bridge, including parametric analysis, pushover analysis, and dynamic tests. Then, the performance of integral abutment bridge was better understood, and no critical structural problem was found for integral abutment bridge. Based on that, length limit for this kind of bridge was evaluated and investigated in an analytical way. Considering capacities of abutments and piers, and under the conditions of an existing integral abutment bridge, the length limit was found to be around 540m. With this super length, the piles need to be designed with capacity of large lateral displacement. Therefore, an effective optimization approach, associating the finite element method with global optimization algorithm was presented for pile shape design. At the end, considerations accounted in the design of super-long integral abutment bridges were discussed, making construction of super-long integral abutment bridge of great possibility
Asymptotic behavior of thin elastic interphases
No full textThe asymptotic behavior of a linearly elastic composite material that contains a thin interphase is described and analyzed by means of two complementary methods: the asymptotic expansions method and the study of the weak form using variational methods on Sobolev spaces.
We recover the solution of the system of linearized elasticity in the two dimensional vectorial case and we find limit transmission conditions.
The same steps are followed for harmonic oscillations of the elasticity system, and different solutions are found for concentrated mass
densities. The cases in which the elastic coefficients depend on the thickness of the small parameter, for soft as well as stiff materials are considered.
An approximated solution is found for harmonic oscillations of the elasticity system and limit transmission conditions are derived.
Considering a bounded rectangular composite domain, with a thin interphase, we describe the weak formulation of the linearized system of elasticity. In the case of constant elastic coefficients,
we estimate the bounds of the strain tensor and so, the energetic functional in the rescaled domain.
We perform a variational formulation of the system of linearized elasticity and find estimates for the energetic functional of the system
End-to-End Discourse Parsing with Cascaded Structured Prediction
Get PDFParsing discourse is a challenging natural language processing task.
In this research work first we take a data driven approach to identify arguments of explicit discourse connectives.
In contrast to previous work we do not make any assumptions on the span of arguments and consider parsing as a token-level sequence labeling task. We design the argument segmentation task as a cascade of decisions based on conditional random fields (CRFs). We train the CRFs on lexical, syntactic and semantic features extracted from
the Penn Discourse Treebank and evaluate feature combinations on the commonly used test split. We show that the best combination of features includes syntactic and semantic features. The comparative error analysis investigates the performance variability over connective types and argument positions. We also compare the results of cascaded pipeline with a non-cascaded structured prediction setting that shows us definitely the cascaded structured prediction is a better performing method for discourse parsing.
We present a novel end-to-end discourse parser that, given a plain text document in input, identifies the discourse relations in the text, assigns them a semantic label and detects discourse arguments spans. The parsing architecture is based on a cascade of decisions supported by Conditional Random Fields (CRF). We train and evaluate three different parsers using the PDTB corpus. The three system versions are compared to evaluate their robustness with respect to deep/shallow and automatically extracted syntactic features.
Next, we describe two constraint-based methods that can be used to improve the recall of a shallow discourse parser based on conditional random field chunking.
These method uses a set of natural structural constraints as well as others that follow from the annotation guidelines of the Penn Discourse Treebank.
We evaluated the resulting systems on the standard test set of the PDTB and achieved a rebalancing of precision and recall with improved F-measures across the board. This was especially notable when we used evaluation metrics taking partial matches into account; for these measures, we achieved F-measure improvements of several points.
Finally, we address the problem of optimization in discourse parsing.
A good model for discourse structure analysis needs to account both for local dependencies at the token-level and for global dependencies and statistics. We present techniques on using inter-sentential or sentence-level(global), data-driven, non-grammatical features in the task of parsing discourse.
The parser model follows up previous approach based on using token-level (local) features with conditional random fields for shallow discourse parsing, which is lacking in structural knowledge of discourse.
The parser adopts a two-stage approach where first the local constraints are applied and then global constraints are used on a reduced weighted search space (-best). In the latter stage we experiment with different rerankers trained on the first stage -best parses, which are generated using lexico-syntactic local features. The two-stage parser yields significant improvements over the best performing model of discourse parser on the PDTB corpus
Sunspaces for passive building heating: calculation models and utilization of empirical data
No full textThe thesis deals with sunspaces, considered as a particular passive solar system. Solar systems exploit solar radiation in order to decrease the use of non-renewable energy sources. Therefore their importance is both environmental and economic. According to “The passive solar energy books” (1979) of Edward Mazria the difference between “active systems” and “passive systems” is that in the latter the heat flows happen without mechanical equipment. The present research focuses on the reduction of winter energy requirements due to the presence of a sunspace, it analyses the involved physical phenomena, and it considers tools to design sunspaces and to optimize them from the point of view of energy requirements.
Particular attention is given to the quasi-steady-state methods, which are the most used by the designers. The thesis critically analyses calculation methods, identifies their problematic aspects and provides some indications to improve the method of the technical standard EN ISO 13790:2008.
As well as by the theoretical part, in the research a fundamental role is played by experimental campaigns. In fact, empirical data have been collected in relation both to existing sunspaces and to sunspaces which were specifically constructed for the research. Two sunspaces, one having the dimensions of a small room and the other one which is its scale model, with halved dimensions, were created and were the object of an experimental campaign. This experimental study has allowed to observe how the physical behaviour of sunspaces changes by changing their dimensions and to achieve a deep comprehension of sunspaces through quantitative analyses of involved physical quantities. A virtual model of the sunspaces was created and validated.
Because of the long renovation cycle for buildings, the improvement of the energy performance of existing buildings is fundamental. That is the reason why part of the research concerns the refurbishments of verandas which are closed with elements having a large glazed surface. The concept is the same as for the sunspaces: the presence of an adjacent not heated space which works as “solar collector” can decrease the heating requirements. An existing building in Freiburg (Germany), which was renovated between 1997 and 1999 (among other things, by closing the veranda with windows, improving the insulation, and adding a solar air collector for the supply air entering the veranda and a mechanical air extraction system), was monitored (in collarboration with Fraunhofer ISE) and the data were analysed critically. Considering the experience with the past renovation, design proposals for future refurbishments have been considered. The energy performances of different possibilities are calculated and compared among them. Attention is paid to thermal insulation, to exploitation of the solar radiation and to ventilation strategies (also mechanical and integrated with heat recovery systems).
A guided procedure for the proper design of sunspaces is presented. Its goal is to present clearly and with a logical sequence what aspects the designers have to take into account to design sunspaces properly. Both new constructions and refurbishments are considered. Aspects such as the relationship between building shape and heating requirements, local context, insulation, thermal inertia, overheating, ventilation, and so on are dealt with.
The technology to build a sunspace is simple, but a rigorous study of its behaviour is complex. Future researches about the thermal behaviour of sunspaces could develop further the possibility to improve the quasi-steady-state methods, taking in consideration, also from a quantitative point of view, a lot of different cases. The utilization of CFD software, in order to better estimate the convective heat coefficients and to evaluate the ventilation from a sunspace, could be another development of this subject
Nostalgia e politiche della memoria: Austria, Germania e Italia nella "Questione trentina e sudtirolese" (1870-1914)
No full textSe si prende in considerazione il passato come un argomento della comunicazione politica, allora qual è l'effetto che i sentimenti producono sulla memoria? È possibile parlare di "nostalgia politica" all'interno di una realtà regionalistica? Il nazionalismo è oggetto della ricerca sul regionalismo? Nel Trentino Alto Adige, la regione di confine dominata dal plurilinguismo, la messa in scena dei sentimenti storici rivestì un'importanza particolare durante i decenni dei nazionalismi e regionalismi. Possiamo definire "nostalgici" quei sentimenti che implicavano forme di critica della civiltà di tipo conservativo e che contribuirono allo sviluppo di una coscienza della Heimat. Per mostrare il modo in cui le concezioni o le opinioni personali furono integrate o escluse dai luoghi propri della comunicazione interregionale, sarà necessario sviscerare le forme di espressione politica della nostalgia, intesa come sentimento di trasmissione della memoria