Istituto di Scienza e Tecnologie
dell’Informazione “A. Faedo”

Speakers:

Michele Coscia

Referent:

Andrea Esuli

In the last few years many real-world networks have been found to show a so-called community structure organization. Much effort has been devoted in the literature to develop methods and algorithms that can efficiently highlight this hidden structure of the network, traditionally by partitioning the graph. Since network representation can be very complex and can contain different variants in the traditional graph model, each algorithm in the literature focuses on some of these properties and establishes, explicitly or implicitly, its own definition of community. According to this definition it then extracts the communities that are able to reflect only some of the features of real communities. The aim of this survey is to provide a manual for the community discovery problem. Given a meta definition of what a community in a social network is, our aim is to organize the main categories of community discovery based on their own definition of community. Given a desired definition of community and the features of a problem (size of network, direction of edges, multidimensionality, and so on) this review paper is designed to provide a set of approaches that researchers could focus on.

NOTE: This seminar is the sixth one of the series of six seminars presented by the winners of the prize "Young researchers ISTI 2013". Michele Coscia placed second in the Young Researcher category.

Speakers:

Anastasios Noulas (Cambridge University)

Referent:

Fabrizio Silvestri

In this talk I will be sharing my experience of mining, analysing and modeling user mobility in location-based social networks in the past couple of years. We will initially present an agent based modeling approach that captures fundamental properties of human urban movement in 34 metropolitan cities. The work that is based on a dataset comprised of millions of Foursquare user check-ins will shed light on the role of geography and the spatial density of settlements in human mobility. Subsequently, we will consider two different mobile application scenarios. First we will formulate a mobile recommendation task where the goal is to accurately new places a user will visit in future time periods. We shall see how a random walk on a graph that connects users with places can offer good recommendations in an extremely sparse data context. Next, we shall formulate an even more challenging problem where we try to predict the next check-in of a user in real time. Exploiting a supervised learning approach that employs synchronously multiple layers of mobility data, we will show that accurate predictions of user whereabouts can be attained if models are trained appropriately. Finally, we will discuss on the feedback loop between abstract models and applications and how mutual benefits emerge in two seemingly distant areas of research in human mobility.

Biografia: Anastasios Noulas is a PhD candidate in the Computer Laboratory at Cambridge University. He holds an MEng in Computer Science (2009) from University College London. His research interests are focused on the analysis and modelling of human movement and geographic social networks, with techniques that span the areas of Complex Systems, Data Mining and applied Machine Learning. In 2012 he joined Telefonica Research in Spain for a research fellowship participating in a project on Smart Cities that exploited Call Detail Records and data sourced from location-based services to infer activities in urban environments. As of 2013 he has joined the EPSRC project GALE that aims to the development of the next generation of mobile recommender systems and urban neighbourhood modelling for the provision of local knowledge to remote visitors of an area. More details are available http://www.cl.cam.ac.uk/~an346/

Speakers:

Cristina Muntean

Referent:

Andrea Esuli

Touristic applications stirred an increased interest in the last years due to the intense use of mobile devices and location based applications. Our outlook on this matter is directed towards the next point of interest (PoI) prediction task. We tackle the problem of predicting the “next” geographical position of a tourist, given her history (i.e., the prediction is done accordingly to the tourist’s current trail) by means of supervised learning techniques.
We test our methods on three datasets built using geo-tagged pictures downloaded from Flickr, each collection corresponding to a popular touristic area. We adopt two popular Machine Learning methods, namely Gradient Boosted Regression Trees and Ranking SVM for learning to rank the next PoI, on the basis of an object space represented by a multi-dimensional feature vector, specifically designed for tourism related data. We define a set of 68 different features, broadly classified into two main categories, namely “Session” and “PoI”. Session features are meant to model the tourist behavior and capture concepts like groups of PoIs visited, distances among PoIs and other characteristics of a user session (trail). On the other hand, PoI features model the characteristics of a candidate PoI, also taking into account the past activities of the tourist.
We propose a thorough comparison of several methods that are considered state-of-the-art in touristic recommender and trail prediction systems (WhereNext, Random Walk with Restart), as well as a strong popularity baseline. As experiments show, the methods we propose constantly outperform, with up to 300% in terms of prediction accuracy, our baselines and provide strong evidence of the performance and robustness of our solutions.

NOTE: This seminar is the fifth one of the series of six seminars presented by the winners of the prize "Young researchers ISTI 2013". Cristina Muntean placed third in the PhD student category.

Speakers:

Laura Nenzi (IMT Lucca)

Referent:

Mieke Massink

We present a new approach for the design of a synthetic biological circuit whose behavior is specified in terms of signal temporal logic (STL) formulae. We first show how to characterize with STL formulae the input/output behavior of biological modules miming the classical logical gates (AND, NOT, OR). Hence, we provide the regions of the parameter space for which these specifications are satisfied. Given a STL specification of the target circuit to be designed and the networks of its constituent components, we propose a methodology to constrain the behavior of each module, then identifying the subset of the parameter space in which those constraints are satisfied, providing also a measure of the robustness for the target circuit design. This approach, which leverages recent results on the quantitative semantics of Signal Temporal Logic, is illustrated by synthesizing a biological implementation of an half-adder.

Speakers:

Roberta Lanziani (IMT Lucca)

Referent:

Mieke Massink

In this talk we investigate the use of Central Limit Approximation of Continuous Time Markov Chains to verify collective properties of large population models, describing the interaction of many similar individual agents. More precisely, we specify properties in terms of individual agents by means of deterministic timed automata with a single global clock (which cannot be reset), and then use the Central Limit Approximation to estimate the probability that a given fraction of agents satisfies the local specification.

Speakers:

Alessio Ferrari

Referent:

Andrea Esuli

We present a novel approach for pragmatic ambiguity detection in natural language (NL) requirements specifications defined for a specific application domain. Starting from a requirements specification, we use a Web-search engine to retrieve a set of documents focused on the same domain of the specification. From these domain-related documents, we extract different knowledge graphs, which are employed to analyse each requirement sentence looking for potential ambiguities. To this end, an algorithm has been developed that takes the concepts expressed in the sentence and searches for corresponding "concept paths" within each graph. The paths resulting from the traversal of each graph are compared and, if their overall similarity score is lower than a given threshold, the requirements specification sentence is considered ambiguous from the pragmatic point of view. A proof of concept is given throughout the presentation to illustrate the soundness of the proposed strategy.

NOTE: This seminar is the fourth one of the series of six seminars presented by the winners of the prize "Young researchers ISTI 2013". Alessio Ferrari placed first in the Young researcher category.

Speakers:

Simon Davies ( LSE Enterprise, a wholly owned subsidiary of The London School of Economics and Political Science, London, UK)

Referent:

Diego Latella

Europe - along with much of the developing world - is ready to implement a new and robust regime of data protection. The IT industry is carefully considering the challenges and the opportunities that these new legal regulations may create. Data protection provides a pillar of trust necessary to nurture emerging services and products. Even so, concern has been expressed that the new rules could hinder innovation and create barriers to design and engineering. Some companies believe the regulatory bar has now been set too high and that data protection will create substantial problems. In this talk veteran privacy expert Simon Davies discusses whether the proposed rules have struck the right formula.

Simon Davies is the Founder of Privacy International and Associate Director of LSE Enterprise. He has been a Visiting Fellow in Law at both the University of Greenwich and the University of Essex, and spent 13 years at LSE, where he taught the groundbreaking MSc Masters course in "Privacy & Data Protection". He is also co-director of LSE’s Policy Engagement Network. Simon Davies is widely acknowledged as one of the most influential data protection and internet rights experts in the world and is a pioneer of the international privacy arena. His work in consumer rights and technology policy has spanned over 25 years and has directly influenced the development of law and public policy in more than 40 countries. He has advised a wide range of corporate, government and professional bodies, including the United Nations High Commissioner for Refugees. Recently, Simon Davies has been tasked by cross-party rapporteurs of the European Parliament to conduct a wide-ranging external assessment of the European Commission's proposed reforms to the EU data protection framework. He brings a unique interface with global stakeholders, from major international corporations to government and civil society.

Nota: Martedi 21 maggio, cioè il giorno prima del seminario, alle ore 15, in Aula Faedo, verrà proiettata la registrazione di una puntata del programma Cyborg City della CNN che comprende, tra l'altro, un'intervista a Simon Davies.

Speakers:

Giacomo Berardi

Referent:

Andrea Esuli

Suppose an organization needs to classify a set D of textual documents, and suppose that D is too large to be classified manually, so that resorting to some form of automated text classification (TC) is the only viable option. Suppose also that the organization has strict accuracy standards, so that the level of effectiveness obtainable via state-of-the-art TC technology is not sufficient. In this case, the most plausible strategy to follow is to classify D by means of an automatic classifier F, and then to have a human editor inspect the results of the automatic classification, correcting misclassifications where appropriate. The human annotator will obviously inspect only a subset D' of D (since it would not otherwise make sense to have an initial automated classification phase). We call this scenario Semi-Automated Text Classification (SATC). An automated system can support this process by ranking the automatically labelled documents in a way that maximizes the expected increase in effectiveness that derives from inspecting D'. An obvious strategy is to rank D so that the documents that F has classified with the lowest confidence are top-ranked. In this work we show that this strategy is suboptimal. We develop a new utility-theoretic ranking method based on the notion of inspection gain, defined as the improvement in classification effectiveness that would derive by inspecting and correcting a given automatically labelled document. We also propose a new effectiveness measure for SATC-oriented ranking methods, based on the expected reduction in classification error brought about by partially inspecting a list generated by a given ranking method.
We report the results of experiments showing that, with respect to the baseline method above, and according to the proposed measure, our ranking method can achieve substantially higher expected reductions in classification error.

NOTE: This seminar is the third one of the series of six seminars presented by the winners of the prize "Young researchers ISTI 2013". Giacomo Berardi placed first in the PhD student category.

Speakers:

Midhat Ali (University of Camerino)

Referent:

Andrea Polini

Platform providers establish marketplace ecosystems to sell to end users services and applications running on the platform. Very prominent examples of these marketplaces are the Google Play Store and Apple AppStore, among others. Application Developers can use these marketplaces to offer services and applications to end users.
Advanced Security Service cERTificate (ASSERT) for SOA (ASSERT4SOA) is a Framework designed to associate certificates of Security properties with the applications and services. This framework offers services like verification of ASSERTs and matching those ASSERTs to Security Properties specified in an appropriate query language. ASSERT Enabled Marketplace is a prototype to qualitatively evaluate and illustrate the use of ASSERT4SOA Framework in a marketplace which sells business applications, which have certificates issued for certain security properties. This marketplace is designed based on a typical user story of buying business applications based on the organization’s security requirements, comparing and choosing the best option based on the requirements.

Speakers:

Anthony Murkar (Masters student, Department of Psychology, Trent University, Ontario, Canada)

Referent:

Umberto Barcaro

The seminar presentation will discuss how dreams relate to memory. It is not fully understood how dreams are generated by the brain, but recent research has uncovered relationships between sleep, dreams, and memory function (Peigneux et al., 2004; Wamsley et al., 2010). Implications for understanding how brain activity relates to dreaming are discussed.

Speakers:

Nicolle Miller (Masters level student, Department of Psychology, Trent University, Ontario, Canada)

Referent:

Umberto Barcaro

The current study examined the effects of meditation on waking day depression levels (BDI), waking day trait anxiety levels (BAI-T) and dream imagery in University students. The Storytelling Method was used to conduct dream interpretations, using word associations and story narrative. This seminar will address the results, which are consistent with past research, as well as the implications and applications of dream work and meditation in clinical and applied practice.

Speakers:

Allyson Dale (PhD student, Department of Psychology, Trent University, Ontario, Canada)

Referent:

Umberto Barcaro

Dream content and discovery have been studied comparing soldiers with operational experience in Afghanistan with an age matched sample of male civilians. Soldiers' dreams contained a higher frequency of aggression, threat, and military imagery, consistent with the continuity hypothesis.Dream interpretation for soldiers led to discovery about specific events from tours overseas and about aggressive behaviours.Further research compared the dream content of students, soldiers, and heavy gamers and results revealed significant differences in dream imagery for soldiers when compared to both students and gamers.

Speakers:

Rossano Venturini

Referent:

Andrea Esuli

Given a set of integer keys from a bounded universe along with associated data, the dictionary problem asks to build a data structure able to answer efficiently two queries: membership and retrieval.
Membership has to tell whether a given element is in the dictionary or not; Retrieval has to return the data associated with the searched key.
This seminar will describe a recent result presented at ACM-SIAM SODA 2013 which provides time and space optimal solutions for three well-established relaxations of this basic problem: (Compressed) Static functions, Approximate membership and Relative membership.

NOTE: This seminar is the second one of the series of six seminars presented by the winners of the prize "Young researchers ISTI 2013". Rossano Venturini placed third in the Young researcher category.

Speakers:

Richard Connor (University Of Strathclyde, Glasgow, Uk)

Referent:

Fausto Rabitti

Over the years a number of competing models have been introduced attempting to solve the central IR problem of ranking documents given textual queries. These models, however, tend to require the inclusion of heuristics and the estimation of collection-specific parameter values in order to be effective. We define a new model that we do not believe has yet been explored. In terms of the categorisation of IR models, it is a probabilistic model and has no term inter-dependencies, thus allowing calculation from inverted indices. It is based upon a simple core hypothesis, directly calculating a ranking score in terms of probability theory and does not require the estimation of any parameters. We show initial tests in comparison with a number of standard baseline IR models, and show that the new model is at least credible, often outperforming the Language Model with Dirichlet smoothing.

Our contributions are twofold: first, we believe the new model is worthy of further investigation and that its performance could be improved significantly; and secondly, we believe the observation that the Jensen-Shannon metric can be evaluated over inverted indices in a sparse space is also more generally applicable.

Speakers:

Giulio Rossetti

Referent:

Giulio Rossetti

Community discovery in complex networks is an interesting problem with a number of applications, especially in the knowledge extraction task in social and information networks. However, many large networks often lack a particular community organization at a global level. In these cases, traditional graph partitioning algorithms fail to let the latent knowledge embedded in modular structure emerge, because they impose a top-down global view of a network. DEMON is a simple local-first approach to community discovery, able to unveil the modular organization of real complex networks. This is achieved by democratically letting each node vote for the communities it sees surrounding it in its limited view of the global system, i.e. its ego neighborhood, using a label propagation algorithm; finally, the local communities are merged into a global collection.

NOTE: This seminar is the first one of the series of six seminars presented by the winners of the prize "Young researchers ISTI 2013". Giulio Rossetti placed second in the PhD student category.

Speakers:

Elvira Locuratolo

Referent:

Elvira Locuratolo

The approach to introduce innovative evaluations of quality is based on two different methods: the former is a vertical mapping which starts from the formal specification of a database application and achieves the conceptual model of the ASSO methodology. The latter is a horizontal mapping which starts from a graph of conceptual classes and achieves the resulting model of the previous approach. The innovative evaluation is based on the following points:

• Achievement of the quality desiderata.
• Numerical evaluation of the consistency costs.
• Conceptual evaluation of the resulting model.

The Numerical evaluation of the consistency costs expresses the cost of what has been explicitly specified/proven in terms of variable and constant cardinality. The conceptual evaluation of the model is a set of hidden classes which are implicitly specified within graphs of conceptual classes. This evaluation expresses the saving that you get for what has been implicitly specified/proved. The quantitative evaluation of the consistency costs can be determined starting from the conceptual evaluation of the model. The vice-versa is not possible.

Speakers:

Luca Maria Cassano

Referent:

Luca Maria Cassano

SRAM-based FPGAs are increasingly relevant in a growing number of safety-critical application fields, ranging from automotive to aerospace. These application fields are characterized by a harsh radiation environment that can cause the occurrence of Single Event Upsets (SEUs) in digital devices. Designing safety-critical applications requires accurate methodologies to evaluate the system’s sensitivity to SEUs as early as possible during the design process. Moreover it is necessary to detect the occurrence of SEUs during the system life-time. In this talk we present a set of software tools that could be used by designers of SRAM-based FPGA safety-critical applications to assess the sensitivity to SEUs of the system and to generate test patterns for in-service testing. In particular three tools have been designed and developed: (i) ASSESS: Accurate Simulator of SEuS affecting the configuration memory of SRAM-based FPGAs; (ii) UA2TPG: Untestability Analyzer and Automatic Test Pattern Generator for SEUs Affecting the Configuration Memory of SRAM-based FPGAs; and (iii) GABES: Genetic Algorithm Based Environment for SEU Testing in SRAM-FPGAs.

Speakers:

Claudio Schifani, Rudy Rossetto (Scuola Superiore Sant'Anna)

Referent:

Paolo Mogorovich

La gestione delle risorse idriche, attualmente soggette ad una crescente pressione antropica ed alle crisi ricorrenti legate ai cambiamenti climatici, costituisce una delle problematiche ambientali cui si deve porre maggiore attenzione. In questo senso numerose raccomandazioni relative alla necessità di un nuovo approccio verso le metodologie e procedure di gestione delle risorse idriche sono state emanate recentemente anche dall’Agenzia Europea dell’Ambiente. L’assenza di strumenti condivisi che permettano la gestione integrata della risorsa idrica conduce ad un approccio prettamente qualitativo che spesso genera conflitti tra i vari utilizzatori di difficile risoluzione per le autorità competenti.

Inoltre, la tradizionale separazione nell’analisi quantitativa dei bilanci idrici fra le acque superficiali e quelle sotterranee conduce spesso a valutazioni non condivise sulla disponibilità della risorsa idrica. Non è così possibile valutare gli impatti legati alle variazioni dell'uso del suolo e dei cambiamenti climatici sul ciclo dell’acqua e le relative conseguenze sui sistemi socio-economici e naturali. In questo scenario si colloca il progetto di ricerca SID&GRID (Simulazione e sistemi IDroinformatici per la Gestione delle Risorse Idriche), il cui obiettivo principale è di progettare e sviluppare un framework per l’integrazione del mondo GIS con la modellistica idrologica ed idrogeologica, attraverso l'operatività di un DSS (Decision Support System) per la pianificazione e gestione condivisa degli usi della ricorsa idrica da parte di Enti pubblici e società preposte a tale ruolo.

Speakers:

Franco Mazzanti

Referent:

Franco Mazzanti

The seminar will present the underlying basic ideas and the current status of the UMC/FMC/CMC/VMC modellling and verification framework developed at ISTI. A railway scenario will be used to illustrate in more detail the features of UMC.

Speakers:

Stefano Ricci (Università degli Studi di Roma "La Sapienza")

Referent:

Alessandro Fantechi

Cenni sulla Teoria delle Reti di Petri. Algebra e formalismo grafico delle Reti di Petri, Formulazione analitico matriciale, Situazioni fondamentali in una Rete di Petri,Tipologie di Reti di Petri, Estensioni della teoria delle Reti di Petri e problemi di standardizzazione. Le Reti di Petri utilizzabili nelle applicazioni ferroviarie. Reti di Petri estese, Proprietà estese delle marche, Proprietà estese delle transizioni, Proprietà estese dei posti , Reti di Petri e modelli gerarchici, Reti di Petri colorate. Architettura dei modelli per le analisi dell'esercizio ferroviario. Obiettivi e limiti dei modelli di simulazione, Struttura "object oriented", Reti estese mediante programmazione, Reti colorate e finestra di simulazione, Limiti nella possibilità di rappresentazione e simulazione, Elementi rappresentati e Classi costitutivi dei modelli, Funzionamento dei modelli. Esempio di modello per la tratta Roma-Formia. Descrizione della linea fini della sua rappresentazione nel modello, Cenni sui sistemi di comando e controllo, Rappresentazione nel modello, Simulazione dell'orario teorico nelle ore di punta, Simulazioni in regime perturbato nelle ore di punta, Effetto della cinematica del treno sulle simulazioni. Altre possibili applicazioni. Analisi dei passaggi a livello, Valutazione della capacità di circolazione nei nodi, Risoluzione dei conflitti ai nodi. Conclusioni. Obiettivi raggiunti, lacune da colmare, applicazioni possibili, sviluppi futuri.

Speakers:

Mauricio Soto Alvarez (Technical Research Centre of Finland)

Referent:

Fabrizio Falchi

Visual tracking represents the basic processing step for most Video Analytics applications where the aim is to automatically understand the actions occurring in a monitored scene. Consequently, the performances of these applications are significantly dependent on the accuracy and robustness of the tracking algorithm. Bayesian state estimation and Probabilistic Graphical Models (PGMs) have proved to be very powerful and appropriate mathematical tools to efficiently solve the inference problem of motion estimation by combining object dynamics and observations. In this seminar, an efficient algorithm for Extended Visual Object Tracking (EVOT) is shown. The word extended refers to the fact that the tracker exploits multiple measurements yield by each target. In particular, the presented technique integrates local interest points with global color in order to provide a rich representation of the target and a robust tracker developed under the Bayesian Probabilistic Graphical Model framework.

Speakers:

Davide Chiarugi

Referent:

Ercan Kuruoglu

Signalling pathways are a set of inerconnected biochemical reactions that, in living organisms, are dedicated to the transduction of signals coming from the environment. They represent fundamental structures for all living entities, ranging from prokaryotes to eukaryotic cells. Due to their pivotal role, in the last decades signalling pathways have been intensively studied. Particular attention has been devoted to eukaryotic pathways because of their role in cancer etiology and pathogenesis. In this context computational modelling is becoming increasingly important. Indeed "in silico" models can provide usefull insights on the dynamics of signalling pathways complementing and organising the information obtained "in vitro".

Recently there has been significant interest in stochastic models of biochemical systems, mainly because of experimental evidences that stochasticity at the molecular level plays an important role in determining the overall behaviour of living organisms. In this talk we will report on the methods and algorithms that we are using or we are going to use for developing stochastic models of signalling pathways. In particular we will describe some of the obtained results as well as problems and possible solutions emerging in our challenging research topic.

Speakers:

Marco Cornolti (Dipartimento di Informatica, Università di Pisa )

Referent:

Fabrizio Sebastiani

We have implemented a benchmarking framework for fair and exhaustive comparison of entity-annotation systems. The framework is based upon the definition of a set of problems related to the entity-annotation task (which formalize the primary issues arising in this task), a set of measures to evaluate systems performance, and the inclusion of all publicly available datasets, containing texts of various types: news, tweets and Web pages. Our framework is easily-extensible with novel entity annotators, datasets and evaluation measures for comparing systems, and it will be released to the public. The intent of this framework is to set the ground for further developments in this challenging task, being a basis on which new annotators can be developed.

Speakers:

Alessio Ferrari

Referent:

Alessio Ferrari

We present a novel approach for pragmatic ambiguity detection in natural language (NL) requirements specifications defined for a specific application domain. Starting from a requirements specification, we use a Web-search engine to retrieve a set of documents focused on the same domain of the specification. From these domain-related documents, we extract different knowledge graphs, which are employed to analyse each requirement sentence looking for potential ambiguities. To this end, an algorithm has been developed that takes the concepts expressed in the sentence and searches for corresponding "concept paths" within each graph. The paths resulting from the traversal of each graph are compared and, if their overall similarity score is lower than a given threshold, the requirements specification sentence is considered ambiguous from the pragmatic point of view. A proof of concept is given throughout the presentation to illustrate the soundness of the proposed strategy.

Speakers:

Andrea Polini

Referent:

Andrea Polini

no abstract.

Speakers:

Mieke Massink

Referent:

Mieke Massink

A formal approach to analyse swarm robotics systems is presented based on Bio-PEPA. Bio-PEPA is a process algebraic language originally developed to analyse biochemical systems. Its main advantage is that it allows different kinds of analyses of a swarm robotics system starting from a single description. In general, to carry out different kinds of analysis, it is necessary to develop multiple models, raising issues of mutual consistency. With Bio-PEPA, instead, it is possible to perform stochastic simulation, fluid flow analysis and statistical model checking based on the same system specification. This reduces the complexity of the analysis and ensures consistency between analysis results. Bio-PEPA is well suited for swarm robotics systems, because it lends itself well to modelling distributed scalable systems and their space-time characteristics. We demonstrate the validity of Bio-PEPA by modelling collective decision-making as an emergent phenomenon in a swarm robotics system and we evaluate the result of different analyses.

Speakers:

Paolo Barsocchi, Stefano Chessa, Francesco Antonio Potortì

Referent:

Francesco Antonio Potortì

Il seminario sarà un excursus sulle passate e presenti attività di ricerca del gruppo Wnlab nel campo della localizzazione in interni e nel riconoscimento dell'attività di persone. Entrambe le attività sfruttano la misura della potenza del segnale ricevuto (RSS) da piccoli ed economici sensori equipaggiati con radio IEEE 802.15.4 (Zigbee).

Le attività future vanno attualmente concentrando nello studio dei sistemi passivi, che non richiedono cooperazione da parte della persona localizzata.

Speakers:

Oronzo Giorgio Spagnolo

Referent:

Oronzo Giorgio Spagnolo

Communications-based Train Control (CBTC) systems are the new frontier of automated train control and operation. Currently developed CBTC platforms are actually very complex systems including several functionalities. Furthermore, every installed system, developed by a different company, varies in extent, scope and number of them. International standards have emerged, but they remain at a quite abstract level, mostly setting terminology. The paper that will be presented into seminar reports intermediate results in an effort aimed at defining a global model of CBTC, by mixing semi-formal modelling and product line engineering. The effort has been based on an in-depth market analysis, not limiting to particular aspects but considering as far as possible the whole picture. The adopted methodology is discussed.

Speakers:

Jiang Wang (Ph.D degree in Chinese Academy of Sciences in 2006; currently ERCIM fellow at NTNU, Norway)

Referent:

Roberto Scopigno

An FPGA and VLSI oriented stereo and virtual view synthesis engine is designed for the autostereoscopic display in the distributed multimedia plays application. To acquire the believable rendering not only for the stereo but also for the distant virtual view synthesis, the depth image based rendering (DIBR) is applied in the referenced depth and texture images. The homogeneous depth continuity is statistically analyzed and the corresponding texture is compensated for the hole filling. To meet the real time constraints, computation and memory access intensive modules are realized by hardware accelerating, and the processing is in raster scan pixel line stream rather than frame buffer bulk or macro block line. The simulation and implementation show that based on the correlation of depth in referenced images, the believable rendering is acquired in real time. Also, there exists the challenges for complicated scenario rendering.

Speakers:

Domenico Saccà (Dipartimento DEIS, Università della Calabria)

Referent:

Fosca Giannotti

Speakers:

Carlo Zaniolo (UCLA Computer Science Department, Los Angeles)

Referent:

Fosca Giannotti

Speakers:

Matteo Magnani (Data Intensive Systems group, Dept. of Computer Science, Aarhus University, Denmark)

Referent:

Fosca Giannotti

One of the reasons behind the tremendous success of Social Network Analysis (SNA) methods in various research disciplines is a very general and simple graph model that enables the representation and study of extremely heterogeneous scenarios, ranging from workplace dynamics to the spreading of diseases or hyper-text documents in the World Wide Web. While this generality still constitutes a great value, it has recently become apparent that to model specific contexts and to enable accurate analyses it may be important to enrich simple network models with additional modeling constructs representing the complex nature of human relationships. The talk will be organized in three parts. First, I will briefly illustrate some case studies showing how cultural parameters may influence social media data with respect to, e.g., information propagation. Then, I will show how these aspects may influence information retrieval activities, leading to the definition of "conversation retrieval" queries. Finally, I will conclude this presentation of human-influenced data modeling and querying discussing the hypothesis that a single concept of social connection or social network is not sufficient to satisfy the sociability requirements of human beings. Decades before the advent of Social Network Sites this had already been theorized by Goffman and other researchers in social sciences, for which individuals (or actors) perform on multiple stages, creating a sort of sociologically fragmented personality whose different components relate to different audiences (and thus networks). This has recently led to the definition of multi-layer (or multi-modal) network models for the analysis of social media data.

Biography of the speaker: Matteo Magnani graduated in Computer Science at the University of Bologna in 2002 (110/110 with mention). He studied at the University of Marne la Vallée (undergraduate level) and the Imperial College London (postgraduate research level). In 2006 he obtained a PhD in Computer Science (Bologna) where in 2011 he also graduated in Violin (110/110 with mention). He has received a Rotary Prize for the best student of the Science Faculty (UniBO), a Best Paper Award at ASONAM 2011, a Funniest Presentation award at SBP 2010, the French qualification for Maître de Conférence positions, the Italian "idoneità" for CNR researcher positions and his mother is very proud of him (or at least this is what she officially says). Until May 2012 he was a researcher (RTD) at the Dept. of Computer Science, University of Bologna and he currently holds a position at research assistant professor level at the Data Intensive Systems group, Dept. of Computer Science, Aarhus University, Denmark.

His main research interests span Database and Information Management systems, specifically uncertain information management and multidimensional database queries, and Social Computing. He has written around 1.5 Kg of papers on these topics (when printed on heavy A4 size sheets). He is currently the joint coordinator of the #sigsna research group on social network analysis, and has successfully attracted funding from Working Capital (Telecom Italia), PRIN and FIRB (MIUR - Italian Ministry for education, University and Research) schemes.

Speakers:

Matteo Magnani (Data Intensive Systems group, Dept. of Computer Science, Aarhus University, Denmark )

Referent:

Fosca Giannotti

Which basketball player has been the Most Valuable Player in the last NBA season? Which materials should we use to build a product in a short time, that is cheap but is still appreciated by our customers? Which hotels are cheap but also not too far from the beach? These are all examples of queries involving multiple criteria, e.g., (1) cost and (2) distance to the beach. Only if the importance of each criterion is known (how far am I willing to walk for each saved euro?) we can compute a ranking of the best records (hotels). Otherwise, the "skyline" (aka Pareto front) consists of all the best records for all possible weighing of the criteria, thereby giving an overview over all the best options in the data.

In this talk I will introduce the skyline database operator for the selection of records under multiple criteria. Then I will discuss two important limitations of this operator: skyline queries can produce a very large result and require high computation time. I will thus present the main status of the research on the fast selection of "stars", i.e., a small set of records providing a good representation of the whole skyline.

Biography of the speaker: Matteo Magnani graduated in Computer Science at the University of Bologna in 2002 (110/110 with mention). He studied at the University of Marne la Vallée (undergraduate level) and the Imperial College London (postgraduate research level). In 2006 he obtained a PhD in Computer Science (Bologna) where in 2011 he also graduated in Violin (110/110 with mention). He has received a Rotary Prize for the best student of the Science Faculty (UniBO), a Best Paper Award at ASONAM 2011, a Funniest Presentation award at SBP 2010, the French qualification for Maître de Conférence positions, the Italian "idoneità" for CNR researcher positions and his mother is very proud of him (or at least this is what she officially says). Until May 2012 he was a researcher (RTD) at the Dept. of Computer Science, University of Bologna and he currently holds a position at research assistant professor level at the Data Intensive Systems group, Dept. of Computer Science, Aarhus University, Denmark.

His main research interests span Database and Information Management systems, specifically uncertain information management and multidimensional database queries, and Social Computing. He has written around 1.5 Kg of papers on these topics (when printed on heavy A4 size sheets). He is currently the joint coordinator of the #sigsna research group on social network analysis, and has successfully attracted funding from Working Capital (Telecom Italia), PRIN and FIRB (MIUR - Italian Ministry for education, University and Research) schemes.

Speakers:

Alessio Ferrari

Referent:

Alessio Ferrari

We present a novel approach for pragmatic ambiguity detection in natural language (NL) requirements specifications defined for a specific application domain. Starting from a requirements specification, we use a Web-search engine to retrieve a set of documents focused on the same domain of the specification. From these domain-related documents, we extract different knowledge graphs, which are employed to analyse each requirement sentence looking for potential ambiguities. To this end, an algorithm has been developed that takes the concepts expressed in the sentence and searches for corresponding "concept paths" within each graph. The paths resulting from the traversal of each graph are compared and, if their overall similarity score is lower than a given threshold, the requirements specification sentence is considered ambiguous from the pragmatic point of view. A proof of concept is given throughout the presentation to illustrate the soundness of the proposed strategy.

Speakers:

Denis Zorin (New York University )

Referent:

Nico Pietroni

In this talk I will review recent progress in global parametrization and quadrangulation algorithms, focusing on our recent work emphasizing optimization of parametrization quality. We have pursued several directions, the two main ones being the choice of topological structure of the global parametrization to minimize distortion, and the second one is controlling conformal and more generally isometric distortion locally. Global parametrization of surfaces requires singularities (cones) to keep distortion minimal. In general, the problem of choosing cone locations and associated cone angles minimizing distortion is a special case of a general nonlinear mixed-integer problem which does not admit efficient computational solutions. We have designed an approximate method based on the idea of evolving the metric of the surface, starting with the original metric so that a growing fraction of the area of the surface is constrained to have zero Gaussian curvature; the curvature becomes gradually concentrated at a small set of vertices which become cones. We demonstrate that the resulting parametrizations have significantly lower metric distortion compared to previously proposed methods. The second direction is aiming to design efficient algorithms for controlling local distortion, specifically, deviation of the map from conformality. Our approach is based on the theory of extremal quasiconformal maps, i.e. maps, that for given set of constraints (e.g. fixed boundaries or points in the interior) minimize the worst-case distortion. Remarkably such maps are unique in many relevant cases, and have a number of properties that allows us to compute them efficiently.

Speakers:

Matthias Buechler (Technische Universität München Institute of Informatics)

Referent:

Eda Marchetti

Web applications are a major target of attackers. The increasing complexity of such applications and the subtlety of today’s attacks make it very hard for developers to manually secure their web applications. Penetration testing is considered an art; the success of a penetration tester in detecting vulnerabilities mainly depends on his skills. Recently, model-checkers dedicated to security analysis have proved their ability to identify complex attacks on web-based security protocols. However, bridging the gap between an abstract attack trace output by a model-checker and a penetration test on the real web application is still an open issue. We present here a methodology for testing web applications starting from a secure model. First, we mutate the model to introduce specific vulnerabilities present in web applications. Then, a model-checker outputs attack traces that exploit those vulnerabilities. Next, the attack traces are translated into concrete test cases by using a 2-step mapping. Finally, the tests are executed on the real system using an automatic procedure that may request the help of a test expert from time to time. A prototype has been implemented and evaluated on WebGoat, an insecure web application maintained by OWASP. It successfully reproduced Role-Based Access Control (RBAC) and Cross-Site Scripting (XSS) attacks.

Speakers:

Francisco Soler, Maria Victoria Luzón (ETS Ingenierías Informática y de Telecomunicación, Univ. of Granada, Spain)

Referent:

Roberto Scopigno

Dealing with cultural heritage sites or artifacts usually involves a large volume of heterogeneous information to be managed, accessed and analyzed by specialists. In this way we present Chisel: a cultural heritage information system based on information layers. To organize information, Chisel makes use of the traditional GIS technology but applying it on 3D meshes from cultural heritage artifacts instead of 2D maps.

Speakers:

Michael Wand (MPI - Saarbrücken)

Referent:

Nico Pietroni

The talk will discuss recent work that has been done within the "Statistical Geometry Processing" group at MPI Informatics and Saarland University. We are working on "shape understanding" algorithms, i.e., algorithms that aim at discovering structure in geometric data sets and utilize it for analysis and modeling. Humans understand shapes already at an intuitive level. However, finding a formal model that explains "structure" in shapes is a major scientific challenge. In addition to being able to capture meaningful aspects, the models also need to be simple enough to permit efficient and robust algorithms for discovering such structure in data.

The talk will focus on correspondence analysis as one low-level approach to this problem: First, we establish correspondences between shapes, i.e., detect pieces of geometry that are essentially similar and relate these to each other. I will discuss various techniques to efficiently and robustly compute correspondences between shapes, allowing for different types of invariance. Second, we can go up one level of abstraction and look at the structure of the obtained correspondences: Assuming we have discovered multiple, potentially overlapping pairs of regions of equivalence within a piece of geometry, what does this tell us about the shape? This question is addressed by "inverse procedural modeling" techniques that characterize families of shapes that are similar to an example piece. We use correspondence information to derive shape docking rules and, alternatively, algebraic invariants to describe such shape spaces in a constructive manner.

Speakers:

Fermín Cruz Mata (Departamento de Lenguajes y Sistemas Informáticos - Universidad de Sevilla (visiting ISTI-CNR throughout June 2012) )

Referent:

Fabrizio Sebastiani

In this talk I will present the random-walk ranking algorithm named PolarityRank. This algorithm is inspired in PageRank, and generalizes it to deal with graphs having not only positive but also negative weighted arcs. Besides the definition of the algorithm, I will show a pair of problems we have addressed through it: automatic expansion of opinion lexicons and trust and reputation computation in social networks. I intend to convey the idea of which problems are suitable to be solved using PolarityRank. It can be summarized in three prerrequisites: the problem has to be representable using a graph, where nodes are some entities and arcs represent some relations between them; some a-priori information must be available for a subset of the entities, and also about the "similarities" and "differences" between them (in terms of what that information represents); and the solution of the problem might be seen as a propagation of the a-priori information, consisting of a set of induced values for the rest of entities.

Speakers:

John Granzow (Centre for Computer Research in Music and Acoustics, Stanford University )

Referent:

Matteo Dellepiane

The dynamics of musical instruments are simulated to approximate their waveform for digital synthesis. In addition to this largely deductive process, the development of the model also includes an inductive phase of listening where the sound of the existing instrument and the digital sound from the model are compared. When the desired outcome is known (i.e, a clarinet), the ear can fine-tune the model for perceptual dimensions such as timbre. Yet one of the primary advantages of physical modeling is to generate novel sounds from virtual geometries and dynamics that do not necessarily correspond to existing instruments or performance traditions. 3d printing is discussed as a means to quickly manufacture these novel acoustic instruments with limitations that are rapidly receding; now we can quickly hear both the digital synthesis derived from physics and the physical object printed from those very models.

Speakers:

Hijung Valentina Shin (Massachusetts Institute of Technology)

Referent:

Roberto Scopigno

We analyze the fracture patterns observed in wall paintings excavated at Akrotiri, a Bronze Age Aegean settlement destroyed by a volcano on the Greek island of Thera around 1630 BC. We use interactive programs to trace detailed fragment boundaries in images of manually reconstructed wall paintings. Then, we use geometric analysis algorithms to study the shapes and contacts of those fragment boundaries, producing statistical distributions of lengths, angles, areas, and adjacencies found in assembled paintings. The result is a statistical model that suggests a hierarchical fracture pattern, where fragments break into two pieces recursively along cracks nearly orthogonal to previous ones. This model is tested by comparing with simulation results of a hierarchical fracture process. The model could be useful for predicting fracture patterns of other wall paintings and/or for guiding future computer-assisted reconstruction algorithms.

Speakers:

Michael Nebeling (ETH Zurich)

Referent:

Fabio Paternò

The growing range and diversity of new devices makes it increasingly difficult for web developers to cater for the large variety of viewing and interaction contexts. While there is a great body of work on desktop-to-mobile adaptation, my research specifically looks at the adaptation to large, high-resolution display settings. Some of the contributions include a set of adaptivity metrics and an adaptive layout template to support more flexible web designs. The central idea behind the proposed solutions is to leverage and extend, rather than replace, existing web languages and to build, in particular, on new technologies such as HTML5 and CSS3. To further support developers, I have also investigated a crowdsourcing approach and designed different methods of complementing developer-specified adaptations with end-user contributions. In the talk, I would first like to give a general overview of my work and then present topics of potential interest in more detail.

Speakers:

Alessandra Donnini (Etcware S.r.l.)

Referent:

Roberto Trasarti

SKOSware è un sistema per la gestione condivisa e per la pubblicazione di thesaurus SKOS prodotto dalla EtcWare s.r.l. . SKOS (Simple Knowledge Organization System) è un formalismo per rappresentare appunto thesaurus, in cui i termini vengono identificati da URI.

SKOSware offre una interfaccia amministrativa per operare sui thesaurus e una interfaccia programmatica, API REST e API java per integrare la gestione thesaurus in CMS o applicazioni di knowledge management. Nel seminario verrà presentata una applicazione del sistema SKODware per la catalogazione e l'arricchimento semantico dei contenuti nel portale baseculturale.it. Il prodotto è stato sviluppato a valle di un progetto di ricerca finanziato dalla regione Lazio (bando POR FESR 2008-2013 Asse I).

La EtcWare è una Piccola Impresa Innovativa in crescita fondata da professionisti di vasta e diversificata esperienza nel settore ICT.

Speakers:

Laura Spinsanti (Joint Research Centre, Ispra)

Referent:

Chiara Renso

This seminar present a conceptual workflow for assessing the quality of geographic user-generated content (GUGC) or volunteered geographic information (VGI) in the context of crisis events like forest fires. We briefly recapitulate the main challenges in using VGI in the context of crisis management and our proposed approach to tackle them, and we present the proof-of-concept prototype CONAVI (CONtextual Analysis of Volunteered Information) that implements the core functionality: retrieval, geo-coding, content analysis, geographic context analysis, and spatio-temporal clustering of VGI from two sources, the micro-blogging service Twitter and the online photo-sharing service Flickr in the South Europe context.

Speakers:

Oscar Täckström (SICS / Uppsala University, Sweden)

Referent:

Fabrizio Sebastiani

The ability to predict the linguistic structure of sentences or documents is central to the study of natural language processing. While annotated resources for parsing and several other tasks are available in a number of languages, we cannot expect to have access to labeled resources for all tasks in all languages. In this talk I will describe how cross-lingual word clusters can be used as a way to sidestep this problem, focusing on the important tasks of syntactic dependency parsing and named-entity recognition (NER). First, I will show how monolingual word clusters can be used to improve parsing and NER for a range of different languages, across families. I will then describe an algorithm for inducing cross-lingual word clusters using large corpora and word alignments and how these clusters can significantly improve the accuracy of cross-lingual structure prediction. Specifically, I will show how an English dependency parser and NER system can be transferred to a range of other languages, without any need for target language training data.

Speakers:

Alessandro Rizzi (Dipartimento di Informatica e Comunicazione, Università degli Studi di Milano )

Referent:

Roberto Scopigno

Il passaggio dall'imaging tradizionale a quello ad alta dinamica non consiste semplicemente nell'aumentare il numero di bit del singolo pixel. Nel passaggio verso una immagine in grado di acquisire, trattare e riprodurre dettagli in un vasto range di luminanza ci si scontra con una serie di limitazioni ottiche molto severe tipiche di ogni sistema di imaging, incluso il nostro sistema visivo. Il seminario vuole presentare i limiti nella dinamica, che abbiamo misurato, sia del nostro sistema visivo che di vari sistemi di acquisizione di immagini, e partendo da questi proporre e discutere un approccio alternativo per la gestione delle immagini HDR.

Speakers:

Daniele Marini (Dipartimento di Informatica e Comunicazione, Università degli Studi di Milano)

Referent:

Roberto Scopigno

An emerging problem in IT is how human communication, mediated by computer systems, evolves in new and unexpected ways. Diffusion of social networks, virtual reality, videogames, e-learning, mobile communication are changing the way, in particular, teen and young people interact and exchange experience and emotions. To understand and explore the effects on human beings of the new communication paradigms is a challenge that can be tackled by studying it by multiple viewpoints, from perception to high cognitive and psychological levels and recurring to advanced signal processing methods. The availability of low cost Electroencephalography (EEG) recording devices allows us to perform a large amount of experiments, providing the possibility of sound data interpretation, and setting up simulated and real environmental experiment set up. We are less interested in the study of non-elementary perceptual phenomena, rather focused to study interpersonal or human-computer communication processes, by observing brain behaviour through EEG signal analysis. As a matter of fact, visual and auditory perception, still remain the primary means of such communication processes, but higher level brain phenomena are possibly more appealing. Experiments on EEG already demonstrate that not only a visual, motor or auditory stimulus can be detected, but also the imagination of the stimulus itself can also be detected, so opening the road to brain computer interaction. In this paper we will present some preliminary results from experiments on music, colour perception and mono vs. stereo video viewing.

Speakers:

Bixin Li (Southeast University, Nanjing, China)

Referent:

Antonia Bertolino

Web Service is a mature and widely-used implementation technique under the new paradigm of Service-Oriented Architecture (SOA). This work aims to identify any gap in current research and suggest some fruitful areas for further study on regression testing of Web Service. We perform a broad manual and automatic search on publication from many journals, conference/workshop proceedings in selected electronic databases published from 2000 to 2010. A total of 18 papers have been selected as primary studies for answering our research questions. Our results indicate that service integrator is the most important stakeholder of regression testing. Uncontrollability of service evolution, non-observability of service source code, high testing cost and concurrency issue are most cited difficulties in regression testing. To overcome these challenges, test case prioritization and selection are the most commonly proposed techniques where thirty-one prioritization strategies and eight selection methods have been published, respectively. Finally, it has been observed that many studies have not been theoretically proven or experimentally analyzed. Although we have found only 18 studies that address issues of regression testing in the context of Web Service, they represent a reasonable and representative sample to understand the state of research in this important area of software engineering. The results of this study provide a body of knowledge that clearly illustrates gaps in improving the quality of regression testing techniques for Web Service.

Speakers:

Erik de Vink (Eindhoven University of Technology & CWI Amsterdam, The Netherlands)

Referent:

Maurice ter Beek

We present a formal analysis of ribosome kinetics using probabilistic model checking with the tool Prism. We compute different parameters of the model, like probabilities of translation errors and average insertion times per codon. The model predicts a strong correlation to the quotient of the concentrations of the so-called cognate and near-cognate tRNAs, in accord with experimental findings and other studies. Using piecewise analysis of the model, we are able to give an analytical explanation of this observation.

Speakers:

Richard Connor (University of Strathclyde - Scotland, United Kingdom)

Referent:

Fausto Rabitti

The similarity of objects is one of the most fundamental concepts in any collection of complex information; similarity, along with techniques for storing and indexing sets of values based on it, is a concept of ever increasing importance as inherently unordered data sets become ever more common. Examples of such datasets include collections of images, multimedia, and semi-structured data. There are however two, largely separate, classes of related research. On the one hand, techniques such as clustering and similarity search give general treatments over sets of data. Results are domain-independent, typically relying only on the existence of an anonymous distance metric over the set in question.

On the other hand, results in the domain of similarity measurement are often limited to the context of pairwise comparison over individual objects, and are not typically set in a wider context. Published algorithms are scattered over various demand-led subject areas, including for example bioinformatics, library sciences, and crime detection. Few, if any, of the published algorithms have the distance metric properties.

We have identified a distance metric, Ensemble Distance, which we believe can help to bridge this gap. Strongly grounded in information theory, Ensemble Distance is a vector-based distance metric which we believe can be used in the treatment of many classes of structured data. For any complex type where a useful characterisation exists in the form of an ensemble, we can produce a distance metric for that type.

Speakers:

Jorge Fox (ERCIM fellow, FMT, ISTI-CNR)

Referent:

Maurice ter Beek

The use of a cloud service requires a company to trust the vendor to comply with given Service-level Agreements (SLA). This work proposes a framework for modelling and maintaining Quality of Service levels expressed as SLA's through the definition of families of clouds as software service line organisations. By systematically exploiting the commonalities within related cloud systems while managing variations for specific customers, we relate variability to SLA's facilitating their monitoring, controlling and enforcement. Coupling the abstraction capabilities of product line approaches and SLA's to ensure Quality of Service in Cloud Computing is a novel approach, which offers the possibility to support dynamic negotiation of QoS parameters.

In the long run, our work aims to provide a generic framework for non-functional requirements enforcement in the Cloud.

Speakers:

Maurice ter Beek

Referent:

Maurice ter Beek

We propose an emerging solution technique and a support tool for modelling and analysing variability in product families. First we illustrate how to manage variability in a formal framework consisting of a Modal Transition System (MTS) and an associated set of formulae expressed in the variability and action-based branching-time temporal logic vaCTL. We then introduce the tool VMC, which accepts as input the specification of a product family in a CCS-like process algebra, possibly with an additional set of variability constraints. We show how VMC can be used to automatically generate all valid products of this family, defined in the same process algebra, as well as to visualise the family (products) as modal (labelled) transition systems. Finally, we show how VMC can efficiently verify functional properties expressed as formulae in vaCTL, over products and families alike, by means of its on-the-fly model-checking algorithm.

This is joint work with FMT members Patrizia Asirelli, Alessandro Fantechi, Stefania Gnesi, Franco Mazzanti, and Aldi Sulova

Speakers:

Peter Herrmann (Department of Telematics (ITEM) - Norwegian University of Science and Technology (NTNU) )

Referent:

Maurice ter Beek

Model-based software engineering techniques are suited for the rapid and cheap service development. Our approach SPACE and its tool set Arctis use collaborative models each describing a possibly distributed sub-service instead of a single physical component. An advantage of this proceeding is its high potential for reuse since many distributed systems in a certain domain are realized by a limited number of sub-services which, however, are composed in quite different ways. Such, we could achieve a reuse rate of about 70% in average for our developments.

As a modeling technique, we use UML2 collaborations and activities enabling service specifications in an intelligible graphical notation. Our modeling tool Arctis transforms the collaborative models into Java code running among others on J2EE, Sun SPOTS and Google Android telephones. We can further apply model checking to analyze the models for design errors. This verification is carried out in a way that the user does not need any knowledge about the formalism as the errors are directly visualized on the graphical descriptions.

My presentation will introduce SPACE and Arctis and discuss model transformation and model checker-based analysis.

Speakers:

Alessio Ferrari

Referent:

Maurice ter Beek

This talk reports the experience of a railway signaling manufacturer in introducing the SysML notation within its development process by means of the TOPCASED tool. Though the tool was later substituted by MagicDraw, the experience was useful to understand the potentials of the notation for requirements formalization and analysis, together with the advantages and drawbacks of using an open-source tool in an industrial setting.

Speakers:

José María Noguera (University of Jaén (Spain), Department of Computer Sciences, Graphics and Geomatics Research Group. )

Referent:

Roberto Scopigno

The recent advent of low energy GPUs has boosted the graphics capabilities of mobile devices, such as smartphones, tablets or PDAs. However, this kind of devices still has several restrictions and limitations both in performance and in the storage of 3D data. In this talk, I will describe a client-server technique for remote adaptive streaming and rendering of huge 3D terrains on mobile devices. The technique has been designed to achieve an interactive rendering performance on resource-limited mobile devices connected to a low-bandwidth wireless network such as GPRS or UMTS. This technology opens new promising research lines in e-tourism. The ubiquitous nature of mobile devices turns them into an attractive platform for assisting on-the-move tourists to obtain 3D information according to their physical location. I will end this talk describing some applications to mobile e-tourism that we are currently working on.

Speakers:

Erik de Vink (Eindhoven University of Technology & CWI Amsterdam, The Netherlands)

Referent:

Maurice ter Beek

Dynamic system evolution of cooperating software components can be modeled in the Paradigm language. Paradigm provides layers of granularity, allowing to describe component interaction at a higher level of abstraction. A special component called McPal gradually changes the interaction at the abstract level, guiding the dynamics of the system from the old AsIs situation into the new ToBe situation without the need for a system shutdown.

Paradigm models can be systematically translated into the process algebra mCRL2. An extensive toolset is available for mCRL2, including LTS visualization and symbolic model checking. Thus, exploiting this connection, tool-supported verification of system migration has become within reach. The approach is illustrated for a simple producer/consumer example. If time allows a demo of the use of mCRL2 is included in this talk.

Joint work with Luuk Groenewegen and Suzana Andova.

Speakers:

Diego Latella

Referent:

Maurice ter Beek

Process Algebras are one of the most successful formalisms for modeling concurrent systems and proving their properties. Due to the growing interest in the analysis of shared-resource systems, stochastic process algebras have received great attention. The main aim has been the integration of qualitative descriptions with quantitative (especially performance) ones in a single mathematical framework by building on the combination of Labeled Transition Systems and Continuous-Time Markov Chains. In this talk a unifying framework is introduced for providing the semantics of some of the most representative stochastic process languages; aiming at a systematic understanding of their similarities and differences. The used unifying framework is based on so called State to Function Labelled Transition Systems, FuTSs for short, that are state-transition structures where each transition is a triple of the form (s,α,P). The first and the second components are the source state and the label of the transition while the third component, P, is the continuation function associating a value of a suitable type to each state s’. A non-zero value may represent the cost to reach s’ from s via α. The FuTSs framework is used to model represenative fragments of major stochastic process calculi and the costs of continuation function do represent the rate of the exponential distribution characterizing the execution time of the performed action. In the talk, first the FuTSs are introduced and then the semantics for a simple language used to directly describe (unlabeled) CTMCs.

Speakers:

Anatoliy Gorbenko (Department of Computer Systems and Networks (503) National Aerospace University "KhAI", Kharkiv, Ukraine )

Referent:

Felicita Di Giandomenico

Dealing with uncertainty inherent in the very nature of service-oriented architectures, is one of the main challenges in building dependable service architectures. This uncertainty needs to be treated as a threat in a way similar to and in addition to faults, errors and failures, traditionally dealt with by the research community. The lack of sufficient evidence about the characteristics of the communication medium, components and their possible dependencies makes it extremely difficult to achieve and predict (composite) service dependability which can vary over a wide range in a very random manner. This uncertainty of services running over the Internet and clouds exhibits itself through the unpredictable response times of messages and data transfers, difficulty to diagnose the root cause of failures, unknown common mode failures, etc.

Speakers:

Prof. Dr. Ir. Joost-Pieter Katoen (RWTH Aachen University, (Aquisgrana, Germania))

Referent:

Diego Latella

In this talk, we will argue that (deterministic) timed automata are a natural specification formalism for practically relevant measures on stochastic processes. It will be discussed how DTA specifications can be checked on continuous-time Markov chains, an important class of stochastic processes used in the performance and dependability community, by using a product construction. We'll provide encouraging empirical results for checking single-clock DTA specifications and indicate how parallelization as well as bisimulation minimization can be naturally exploited in this setting. Finally, we shortly discuss the model checking of DTA specifications on a richer class of stochastic processes: continuous-time Markov decision processes (CTMDPs).

Speakers:

Anne-Marie Kermarrec (INRIA, Rennes (France))

Referent:

Ranieri Baraglia

WhatsUp is an instant news system aimed for a large scale network with no central bottleneck, single point of failure or censorship authority. Users express their opinions about the news items they receive by operating a like-dislike button. WhatsUp's collaborative filtering scheme leverages these opinions to dynamically maintain an implicit social network and ensures that users subsequently receive news that are likely to match their interests. Users with similar tastes are clustered using a similarity metric reflecting long-standing and emerging (dis)interests. News items are disseminated through a heterogeneous epidemic protocol that (a) biases the choice of the targets towards those with similar interests and (b) amplifies the dissemination based on the interest of every actual news item. The push and asymmetric nature of the network created by WhatsUp provides a natural support to limit privacy breaches.

The evaluation of through large-scale simulations, a ModelNet emulation on a cluster and a PlanetLab deployment on real traces collected both from Digg as well as from a real survey, show that WhatsUp consistently outperforms centralized and decentralized alternatives in terms of accurate and complete delivery of relevant news.

Anne-Marie Kermarrec is a senior researcher at INRIA Rennes where she leads the distributed systems group. She is the Principal Investigator of the ERC project Gossple and the chair of the ACM System software Award committee. She received the Monpetit award from the French Academy of Science in 2011. Before joining INRIA in February 2004, she was with Microsoft Research in Cambridge as a Researcher since March 2000. Before that, she obtained my Ph.D. from the University of Rennes (FRANCE) in October 1996 (thesis). She also spent one year (1996-1997) in the Computer Systems group of Vrije Universiteit in Amsterdam (The Netherlands) in collaboration with Maarten van Steen and Andrew. S. Tanenbaum. Her research interests are in peer to peer distributed systems, epidemic algorithms, social networks, Web Science."

Speakers:

Oscar Viveros (Università di Veracruz, Messico)

Referent:

Ercan Kuruoglu

Urban growth generates interesting problems in emerging economies, these problems are generally due to the lack of land planning. Remote Sensing has proved to be a good analysis technique adapted to study the urban growth.

In this talk, an information extraction methodologie will be shown, which is capable of extracting urban information from satellite images (SPOT and ERS-1). Also, the ways of implementation and some results will be exposed. The methodology is based on image classification and urban texture analysis focusing on pixel based probabilistic tools, taking into account the diffulties in obtaining the satellite data.

Speakers:

Marco Comerio (Universita degli Studi Milano-Bicocca)

Referent:

Donatella Castelli

Web services promise universal interoperability and integration of services developed by independent providers to execute business processes by discovering and composing services distributed over the Internet. This means that a key factor to build complex and valuable processes among cooperating organizations relies on the efficiency of discovering appropriate Web services and composing them. The increasing availability of Web services that offer similar functionalities requires mechanisms to go beyond the pure functional discovery and composition of Web services.

A promising solution towards the automatic enactment of valuable processes consists in enhancing Web service discovery and composition with the evaluation of semantic contracts that define non-functional properties (NFPs) and applicability conditions associated with a Web service. Nevertheless, currently there is a lack of tools and algorithms that fully support this solution due to several open issues. First, existing languages do not show the expressivity necessary for Web service contract specifications. Second, there is a lack of standard languages that determines heterogeneity in Web service contract specifications raising interoperability issues. Third, pure semantic approaches to enhance Web service discovery allows for detailed descriptions but present performance problems due to current limitations of semantic tools when dealing with reasoning tasks. Fourth, Web service contract compatibility evaluation is not supported by existing composition tools when combining different services from different providers. This talk addresses these open issues and proposes solutions in terms of models, algorithms and tools.

Speakers:

Patrick Marais (Department of Computer Science at the University of Cape Town (UCT))

Referent:

Roberto Scopigno

I will present a brief overview of the research activity on Computer Graphics of the Computer Science Department at the University of Cape Town, as well as some information on my own research interests. I will then detail the work I am doing with a colleague on sketch-based constraints for procedural generation. Specifically, I will review our previous work on "Terrain sketching" (2009) and present the current state of our work on "City Sketching". Both these techniques are intended to allow easy generation of content for VFX and computer games.

Speakers:

Fabio Viola (Consulente indipendente )

Referent:

Fabrizio Silvestri

Ogni anno nella sola Italia si spendono 1.1 miliardi di euro in videogiochi. Ogni mese 3 miliardi di ore vengono investite nel mondo video giocando. Ogni giorno sul social Game "Farmville" entrano oltre 20 milioni di persone. L'avvento di nuove piattaforme, dai mobile application stores a Facebook passando per le smart tv, ha allargato la base utenza facilitando l'alfabetizzazione di oltre 500 milioni di individui ormai familiari con termini come punti, livelli, vadge, virtual good e currency etc etc....

Oltre il 70% delle TOP 2000 corporation/organizzazioni si doterà di almeno un prodotto "gamificato" (Gartner) per risolvere problemi interni o creare engagement e loyalty. Analizzeremo con esempi concreti decine di business idea ed i modelli di monetizzazione

Speakers:

Filippo Simini (Northeastern University)

Referent:

Fosca Giannotti

The gravity law, widely used to predict the number of commuters between two geographic locations or administrative areas, has played a central role in the past half century in epidemic forecast, urban planning and transportation research. Despite its widespread use, it relies on adjustable parameters that vary from region to region and some of its predictions are demonstrably at odds with reality. We introduce a stochastic process capturing local mobility decisions that helps us analytically derive an alternative to the gravity model. The parameter-free radiation model we derive predicts mobility patterns that are statistically indistinguishable from the real mobility and transport patterns in a wide range of phenomena, from hourly mobility and long-term migration patterns to commodity flows and the volume of communication between different regions. Given its parameter-free nature, the model can be applied in areas where we lack previous flux measurements, offering the potential to significantly improve the predictive accuracy of most of phenomena affected by transport and mobility patterns.

Speakers:

Luca Passani (ScientiaMobile )

Referent:

Malko Bravi

Device Fragmentation è l'espressione indicata per identificare il fatto che non ci sia un telefonino o palmare uguale all'altro: larghezza dello schermo, sistema operativo, browser, larghezza di banda, codec e container per i contenuti video, sono solo esempi delle "dimensioni" in cui si esplica la diversità dei vari dispositivi mobili sul mercato.

Se oramai gli sviluppatori sanno come gestire le differenze tra i browser WWW tradizionali, creando pagine che appaiono uguali sugli schermi di tutti i PC, lo stesso non può essere detto per il "mobile web", fratello minore (ma non per molto) del web classico come lo conosciamo noi da anni. Per gli sviluppatori "mobile" la situazione è più complessa. Pochi hanno ancora trovato il mitico "silver bullet" (http://en.wikipedia.org/wiki/Silver_bullet#Idiomatic_usage) in grado di risolvere il problema in modo semplice ed efficace. Quelli che lo hanno fatto, lo devono per lo piu' a Luca Passani e al suo lavoro in quest'area nel decenio passato.

Luca, CTO di ScientiaMobile e creatore di WURFL, The Wireless Universal Resource FiLe, illustra il problema della Device Fragmentation e le soluzioni che sono state proposte negli anni (CC/PP, UAProf, Transcoders, etc...). Dopo aver illustrato i concetti di base delle DDR (Device Description Repository), Luca illustrerà WURFL ed alcuni case-studies che mostrano come WURFL ha risolto problemi nel mondo reale, incluso Telecom Italia a Facebook, anch'essi utilizzatori di WURFL.

Speakers:

Rene van Noort (FLIR Systems B.V.)

Referent:

Claudio Schifani

Technical discussion (particularly the combination/integration of the eligible FLIR products);

Extensive demostration/test of the camera (TAU), in combination with the different available lens-dimension, to find out what the best solution will be for your specific application. The difference in frame rates and demostration of practical accessories/features, software support, graphical user interface. Discussion of our (future) roadmap.

Speakers:

Fabrizio Silvestri

Referent:

Fabrizio Silvestri

In this paper we analyze the efficiency of various search re- sults diversification methods. While efficacy of diversification approaches has been deeply investigated in the past, response time and scalability issues have been rarely addressed. A unified framework for studying performance and feasibility of result diversification solutions is thus proposed. First we define a new methodology for detecting when, and how, query results need to be diversified. To this purpose, we rely on the concept of “query refinement” to estimate the probability of a query to be ambiguous. Then, relying on this novel ambiguity detection method, we deploy and compare on a standard test set, three different diversifica- tion methods: IASelect, xQuAD, and OptSelect. While the first two are recent state-of-the-art proposals, the latter is an original algorithm introduced in this paper. We evalu- ate both the efficiency and the effectiveness of our approach against its competitors by using the standard TREC Web diversification track testbed. Results shown that OptSelect is able to run two orders of magnitude faster than the two other state-of-the-art approaches and to obtain comparable figures in diversification effectiveness. This seminar will present results from the paper "Efficient Diversification of Web Search Results" that will be presented at the upcoming VLDB conference in Seattle. This is joint work with: Gabriele Capannini, Franco Maria Nardini, and Raffaele Perego.

Speakers:

Suzanne Little (Knowledge Media Institute, The Open University, UK )

Referent:

Davide Moroni

Electronic media is a valuable and ever increasing resource for information seekers and learners. So much information can be contained in a picture, explained by a diagram or demonstrated in a video clip. But how can you find what you are looking for if you don't understand it well enough to describe it? What can you do if you are faced with a mountain of multimedia learning material? Are there other ways of exploring open educational resources then sticking to the well defined paths of text search and hyperlinks?

This talk will present recent work applying content-based multimedia similarity search to find related educational material by using images to query a collection. It will describe the use of local features in images, 'keypoints', identified using an approach called Scale-Invariant Feature Transforms (SIFT), and the implementation of a nearest neighbour based indexing system to find visually similar images. The resulting content-based media search tool (cbms) has been applied in the context of the SocialLearn project [1] to help learners find and explore connected web pages, presentations or documents. It is also the basis of the Spot&Search [2] iPhone application that can be used to explore artwork installations on the OU Walton Hall campus.

[1] http://www.sociallearn.org

[2] http://spotandsearch.kmi.open.ac.uk

Speakers:

Fabrizio Lillo (Scuola Normale Superiore di Pisa, Dipartimento di Fisica, Università di Palermo & Santa Fe Institute, U.S.A.)

Referent:

Fosca Giannotti

Networks are a powerful tool to explore the interaction structure of many complex systems. In the vast majority of studied networks a link between two nodes identifies a direct interaction (e.g. trading activity, credit relation, etc) between the two nodes. Similarity based networks are a different class of networks where the presence of a link identifies a similarity between the two nodes. Here I consider two important applications of similarity based networks to financial markets. In the first one the nodes are stocks traded in a financial market and a link identifies a similarity in price dynamics. This network allows to identify clusters of stocks with similar price comovement and it is therefore useful in monitoring the whole market dynamics and in portfolio optimization. In the second case I consider similarity based networks of investors in the Finnish stock market. A suitably designed methodology allows to identify in an unsupervised way classes of investors with a common investment behavior. We study the investment behavior of these identified classes and we consider their interaction. In both cases a special emphasis is given to the behavior of similarity based financial networks in the presence of extreme market movements.

Speakers:

Rosa Gini (ARS - Agenzia Regionale dela Sanità della Toscana )

Referent:

Massimo Coppola

Il seminario presenta il progetto Mattoni/Matrice dell'Agenzia Nazionale per i Servizi Sanitari Regionali (Agenas) nel quadro del programma Mattoni per la costruzione del sistema informativo del sistema sanitario nazionale (Nuovo Sistema Informativo Sanitario, NSIS).

Il progetto Matrice prevede il disegno, la sperimentazione, la validazione e l'applicazione ad alcuni casi di studio di un software open source di integrazione dei flussi sanitari amministrativi per produrre flussi secondari. I casi di studio saranno incentrati sulla gestione di alcune patologie croniche.

Nel seminario saranno descritte le caratteristiche dei dati amministrativi disponibili all'interno del sistema sanitario italiano, la struttura del progetto e il ruolo dei partner.

Speakers:

Davide Chiarugi (Dipartimento di Scienze Matematiche e Informatiche, Università di Siena)

Referent:

Ercan Kuruoglu

Gillespie's Stochastic Simulation Algorithm (SSA) is probably the most used method for the stochastic simulation of biochemical reactions. The results of some recent wet-lab experiments on single enzyme molecules suggest that the theoretical framework on which the SSA grounds could not be adequate in the case of anzymatically catalysed reactions. Some proposals aiming at finding new methods for the stochastic simulation of biochemical reactions will be presented.

Speakers:

Isabel Meirelles (Northeastern University, Boston, MA, USA )

Referent:

Fosca Giannotti

New technologies have increased the possibilities of communicative expression and expanded processes and procedures of accessing, organizing and communicating information. If in the past it was possible to manually structure and visualize data, nowadays computation methods are intrinsic to how we deal with very large data sets, whether in the design of exploratory analytical tools or for communication purposes. The term Big Data well expresses the state of the field and the challenges ahead of us. A central question is how to prepare not only future generations, but ourselves included, to deal with the data proliferation: from learning how to structure and analyze data to developing skills and methods for effectively visualizing information. It is critical to foster understanding of relationships between visual thinking, visual representation, and visual communication. How can we promote informed criteria to support the design process of data visualization?

Speakers:

Alberto Montresor (Università di Trento, Dipartimento di Ingegneria e Scienza dell'Informazione )

Referent:

Massimo Coppola

Peer-to-peer (P2P) and cloud computing, two of the Internet trends of the last decade, hold similar promises: the (virtually) infinite availability of computing and storage resources. But there are important differences: the cloud provides highly-available resources, but at a cost; P2P resources are for free, but their availability is shaky. Several academic and commercial projects have explored the possibility of mixing the two, creating a large number of \emph{peer-assisted} applications, particularly in the field of content distribution, where the cloud provides a highly-available and persistent service, while P2P resources are exploited for free whenever possible to reduce the economic cost. While executing active servers on elastic computing facilities like Amazon EC2 and pairing them with user-provided peers is definitely one way to go, this talk proposes a novel approach that further reduces the economic cost. Here, a passive storage service like Amazon S3 is exploited not only to distribute content to clients, but also to build and manage the P2P network linking them. An effort is made to guarantee that the read/write load imposed on the storage remains constant, regardless of the number of peers/clients. These two choices allows us to keep the monetary cost of the cloud always under control, in the presence of just one peer or with a million of them. We show the feasibility of our approach by discussing two cases studies for content distribution.

Speakers:

Elvira Locuratolo

Referent:

Elvira Locuratolo

La teoria dei concetti pone in risalto la distinzione tra il livello intensionale e il livello estensionale di un concetto. Il livello intensionale, detto anche concept level, è il livello del pensiero umano mentre il livello estensionale, detto anche set-theoretical level, è il livello dell'informatica. Al livello intensionale sono modellati i concetti; al livello estensionale le classi/gli insiemi di oggetti. Poichè un insieme di oggetti cade sotto molti differenti concetti, esiste un collegamento orientato dagli aspetti intensionali agli aspetti estensionali dei concetti e non viceversa. Algoritmi per mappare grafi di classi supportate dai modelli semantici in grafi di classi supportate dai sistemi ad oggetti, nel seguito detti partitioning, sono stati definiti a livello set-theoretical per essere utilizzati in informatica e in ingegneria dell'informazione. Questi algoritmi non possono essere applicati a livello intensionale poichè tale livello riguarda i concetti e non le classi; tuttavia, essi possono essere trasportati al concept level utilizzando una metodologia appropriata. Tale metodologia consiste nell'individuare opportune restrizioni del concept level che consentono di stabilire una corretta corrispondenza tra la restrizione del concept level e il set-theoretical level del partitioning. Essa fornisce gli strumenti per:

• definire strutture di concetti iniziali;
• costruire gerarchie di generalizzazione di concetti corrispondenti ad algoritmi di partizionamento di grafi di classi semantiche;
• fornire una rete di concetti che comprende:
• tutti e soli i concetti correlati ad un concetto generale e a concetti di base tutte e sole le relazioni di inclusione intensionale tra i concetti costruiti;
• stabilire l'aggancio tra la rete di concetti e le classi ad oggetti;
• definire un grafo rappresentativo delle classi ad oggetti;
• trasformare il grafo delle classi ad oggetti in un grafo rappresentativo delle classi semantiche.

L'idea di trasportare il partitioning in ambito teoria dei concetti è importante per le seguenti ragioni:

• al concept level è disponibile un background formale consolidato, ma mancano algoritmi per costruire strutture di concetti correlate a classi di oggetti supportate da sistemi informatici;
• l'approccio proposto rende possibile relazionare ogni classe di oggetti con tutti e soli i concetti che possono essere costruiti partendo da un universo del discorso e da concetti di base.

Possibili sviluppi futuri della ricerca presente sono delineati (Slide del seminario)

Speakers:

Gabriele Tolomei

Referent:

Fabrizio Silvestri

The research challenge addressed in this paper is to devise effective techniques for identifying task-based sessions, i.e. sets of possibly non contiguous queries issued by the user of a Web Search Engine for carrying out a given task. In order to evaluate and compare different approaches, we built, by means of a manual labeling process, a ground-truth where the queries of a given query log have been grouped in tasks. Our analysis of this ground-truth shows that users tend to perform more than one task at the same time, since about 75% of the submitted queries involve a multi-tasking activity. We formally define the Task-based Session Discovery Problem (TSDP) as the problem of best approximating the manually annotated tasks, and we propose several variants of well known clustering algorithms, as well as a novel efficient heuristic algorithm, specifically tuned for solving the TSDP. These algorithms also exploit the collaborative knowledge collected by Wiktionary and Wikipedia for detecting query pairs that are not similar from a lexical content point of view, but actually semantically related. The proposed algorithms have been evaluated on the above ground-truth, and are shown to perform better than state-of-the-art approaches, because they effectively take into account the multi-tasking behavior of users.

Speakers:

Ozgur Tamer (Norwegian University of Science and Technology )

Referent:

Roberto Scopigno

The Distributed Multimedia Plays Systems Architecture (DMP) provides 3D multiview video and 3D sound collaboration between performers over packet networks. To guarantee the end-to-end time delay less than 10-20 milliseconds, and obtain high network resource utilization, the perceived quality of audio-visual content is allowed to vary with the traffic in the network. Several parameters that are included in the quality concept, and can be controlled adaptively. To approach the natural level of human perception, the quality has to be increased to levels that temporarily require data rates of Giga bits per second between users. Actual DMP applications from arts are jazz sessions, song lessons, and distributed opera. Other applications are in forthcoming generations TV (MHP extended with DMP), games, education, and near natural-seeing virtual meetings.

Speakers:

Mustafa Althinkaya ( Izmir Institute of Technology )

Referent:

Ercan Kuruoglu

Nowadays, outdoor location systems have been used extensively in all fields of human life from military applications to daily life. However, these systems cannot operate in indoor applications. This presentation considers an indoor location system that aims to locate an object within an accuracy of about 2 cm using ordinary and inexpensive off-the-shelf devices and that was designed and tested in an office room to evaluate its performance.

In order to compute the distance between the transducers (speakers) and object to be localized (microphone), Time-of-Arrival measurements of acoustic signals consisting of Binary Phase Shift Keying modulated Gold sequences are performed. This DS-CDMA scheme assures accurate distance measurements and provides immunity to noise and interference.

Two methods have been proposed for location estimation. The first method takes the average of four location estimates obtained by trilateration technique. In the second method, only a single robust position estimate is obtained using three distances while the least reliable fourth distance measurement is not taken into account.

The performance of the system is evaluated at positions from two height levels using system parameters determined by preliminary experiments. The precision distributions in the work area and the precision versus accuracy plots are obtained. The established system provides location estimates of better than 2 cm accuracy with 99 % precision.

Speakers:

Guglielmo Cresci, Luciano Fortunati, Marco Righi

Referent:

Guglielmo Cresci

Nell’ambito di un complesso e articolato progetto di innovazione e trasferimento di conoscenza per le realtà produttive della Sicilia Occidentale (ICT-E3), l’IAMC ha delegato all’ISTI la progettazione e la realizzazione di un complesso di iniziative di automazione a supporto delle proprie attività scientifiche e gestionali. In questo ambito ISTI ha progettato e realizzato:

• il portale pubblico dell’Istituto;
• la Intranet del portale;
• il sistema informativo gestionale integrato nella Intranet;
• il sistema di supporto decisionale per le attività scientifiche

Il sistema, realizzato con software aperto, ha caratteristiche di modularità e scalabilità e presenta soluzioni di potenziale interesse per altri Istituti CNR. Il seminario riassume le caratteristiche salienti della realizzazione con possibili dimostrazioni di alcune funzionalità.

Speakers:

Ilan Shimshoni (Information Systems dept, University of Haifa)

Referent:

Matteo Dellepiane

Archaeological artifacts are of vital importance in archaeological research. At present there is a drive to scan these artifacts and store the scanned objects on the internet making them accessible to the whole research community. We propose a new approach for automatic processing of these 3D models. Given such an artifact our first goal is to find edges termed relief edges on the surface. The 3D curves that we defined are the 3D equivalent of Canny Edges in images. These edges can be used to illustrate the object replacing the human illustrator or at least helping him produce accurate illustrations efficiently using an interactive computerized tool.

Based on these curves we have defined a new direction field on surfaces (a normalized vector field), termed the prominent field. We demonstrate the applicability of the prominent field in two applications. The first is surface enhancement of archaeological artifacts, which helps enhance eroded features and remove scanning noise. The second is artificial coloring that can replace manual artifact illustration in archaeological reports.

Speakers:

Luca Bortolussi (Università di Trieste)

Referent:

Mieke Massink

We will consider two apparently different techniques for deterministic approximation of Markov Chains: fluid-flow approximation and mean field analysis. Fluid limits, or fluid-flow approximation, has received a lot of attention in recent years as a technique to approximate the evolution of stochastic process algebras, when the numerosity of all components is large. Mean field techniques, on the other hand, are often used to provide a deterministic approximation of the collective behavior of systems with many identical copies of the same object, both in discrete and continuous time. We will comment on similarities and differences, discussing if the fluid limit and the mean field approximation for a PEPA model (without synchronization) are the same, and if and how the theory of mean field approximation can be useful for the analysis of Stochastic Process Algebra models.

Speakers:

Elvira Locuratolo, Jari Palomaki (Tampere University of Technology/Pori)

Referent:

Elvira Locuratolo

The seminar aims to present the research results achieved in transporting to the concept theory algorithms for mapping graphs of classes supported by semantic data models to graphs of classes supported by object systems. The concept theory comprises the distinction between the intensional and extensional aspects of concepts. The former is referred to the information contents of concepts, whereas the latter is referred to the sets of objects which fall under the concepts. These two aspects of concepts define two different levels of representation, called intensional/concept level and extensional/set-theoretical level, respectively. It is correct to go from the concept level to the set-theoretical level, but not vice versa.

The partitioning algorithms employed in computer science and information engineering have been defined at the set-theoretical level.

These algorithms cannot be applied to the concept level; however, they can be transported to this level. Really, our approach, which is based on the construction of concepts and on the decomposition of objects, allows:

• Defining the process of concept construction.
• Providing a network of concepts enclosing:
  • All and only the concepts related with a Universe of Discourse and basic concepts
  • All and only the intensional inclusion relations.
• Recognizing the concepts that can be mapped to the extensional level.
• Organizing the set of classes at the extensional level into a graph of object classes.
• Transforming it into a graph of semantic classes.

Differently from other approaches, which can be found in information modeling and knowledge bases, and in formal context analysis, our approach makes it possible to relate each extension with all and only the concepts which can be constructed starting from a Universe of Discourse and basic concepts. Possible application fields of our approach are outlined.

Speakers:

Alexander Lamb (Freelance)

Referent:

Tommaso Bolognesi

As more and more theories in particle physics begin to explore the possibility of discrete space-time, the smaller the gap becomes between physics and computer science. Can computer science provide useful tools and algorithms to help facilitate the search for the ‘theory of everything?’. This talk argues the case, and shows how simple algorithms can be used to reproduce many critically important symmetries observed in nature.

Starting with a simple demonstration of linear motion and rotational invariance, this talk will cover work that duplicates key physical phenomena, such as special relativity and quantum interference. The current project here at CNR on models for discrete space-time will also be outlined and preliminary results shared. This talk requires no formal training in physics, but is suitable for anyone interested in taking their knowledge of computation and using it to explore open topics such as quantum gravity.

Speakers:

Carles Bosch (REVES/INRIA Sophia Antipolis, France)

Referent:

Roberto Scopigno

Accurately modeling material appearance and surface details is essential for realistic image synthesis. In this talk, I will describe different solutions we have been working in this direction. The first part will be centered on simulating aging and weathering phenomena, with a special interest on scratches and related features, and the use of images to guide weathering simulation in general. We will then overview some approaches for procedural modeling of surface details, where our recent work on Gabor Noise-based detail representation will be introduced. Future directions and other related projects will also be described.

Speakers:

Peter Stanchev (Kettering University, Flint, MI, USA)

Referent:

Fausto Rabitti

A key characteristic of visual arts’ objects is that they are created by a cognitive process. The artwork is not merely an objective presentation, but also communicates one or more subjective messages, "delivered" from the creator to the observer. Every touch to the artwork helps to build bridges between cultures and times.

Since its first publication in 1962 Janson's History of Art is one of the most valuable sources of information spanning the spectrum of Western art history from the Stone Age to the 20th century. It became a prominent introduction to art for children and a reference tool for adults trying to recall the identity of some familiar image. The colorful design and numerous illustrations of exceptional quality are far from being a means for providing dry information; they also contribute to experience a deep emotional fulfillment.

But now online search engines have whetted web surfers' appetites for context and information, there are a host of digital databases and repositories offering easy access to digital items, presenting the colorfulness of art history as well as to connected metadata, giving all additional information from pure technical details, connected with the way of creating the artifacts, to deep personal details from the life of the creators, which help the observers to understand input message in the masterpieces.

The digital repositories of cultural heritage objects can employ similar techniques as generic ones in order to provide standard functionality for searching objects. The cultural heritage objects are rich in content, describing events, monuments, places, people; they are distributed across different locations. The users can formulate queries using different modalities such as free text, similarity matching, or metadata. The specifics of observed objects profile some additional tasks, which are interesting to be observed. In area of art paintings retrieval the sensitive, semantic and aesthetic gaps are quite actual problem. In the current years, very actual stands the problems of semantic, syntactic and profile interoperability and constructing reference layers; additional area to explore is linked data which allow to contextualize objects in the cultural heritage domain.

In this seminar a succinct overview of the development of repositories of digital art images and then highlighted the specialized search methods in this domain are presented. Compared to other cultural heritage materials, to improve the accessibility of digitized art images, a transition in the methods is needed from approaches involving only textual metadata towards "hybrid" approaches of retrieval using content based image retrieval jointly with the metadata.

The seminar is organized in the following way. First a brief overview of the main directions of presentation and analysis of artworks is given. An attempt for describing the taxonomy of art image content is proposed. Our approach for extracting attributes, concerning different aspects of image content in order to receive discriminating profiles for describing abstraction specifics of artists, schools or movements is presented. A description of the program realization and conducted experiments over a dataset, which contains artworks of Western and contemporary Israel artists is analyzed. Finally some conclusions and future research directions are highlighted.

Speakers:

Lorenzo Sarti (Dipartimento di Ingegneria dell'Informazione - Università di Siena)

Referent:

Fosca Giannotti

We present Similarity Neural Networks (SNNs), a neural network model able to learn a similarity measure for pairs of patterns, exploiting a binary supervision on their similarity/dissimilarity relationships. Pairwise relationships, referred to also as pairwise constraints, generally contain less information than class labels, but, in some contexts, are easier to obtain from human supervisors.

The SNN architecture guarantees the basic properties of a similarity measure (symmetry and non negativity) and, differently from the majority of the metric learning algorithms proposed so far, it can model non-linear relationships among data and can deal with non-transitivity of the similarity criterion. The theoretical properties of SNNs and their application to Semi­Supervised Clustering will be presented.

In particular, we introduce a novel technique that allows the clustering algorithm to compute the optimal representatives of a data partition by means of Backpropagation on the input layer, biased by a L2 norm regularizer. An extensive set of experimental results will be reported, in order to compare SNNs with state-of-the art similarity learning algorithms. Both on benchmarks and real world data, SNNs and SNN-based clustering show improved performances, assessing the advantage of the proposed neural network approach to similarity measure learning.

Speakers:

Denis Zorin (New York University)

Referent:

Nico Pietroni

Quadrangulation methods aim to approximate surfaces by semi-regular meshes with as few extraordinary vertices as possible. A number of techniques employ the harmonic parameterization to control angle distortion, or Poisson-based techniques to align to prescribed features. However, both techniques create near-isotropic quads. To keep the approximation error low, various approaches have been suggested to align the isotropic quads with principal curvature directions.

A different promising way is to allow for anisotropic elements, which are well- known to have significantly better approximation quality. In this work we present a simple and efficient technique to add curvature-dependent anisotropy to harmonic and Poisson parameterization and improve the approximation error of the quadrangulations. We use a metric derived from the shape operator which results in a more uniform error distribution, decreasing the error near features.

Speakers:

Claudio Schifani

Referent:

Salvatore Rinzivillo

Negli ultimi anni si è assistito ad un crescente interesse della comunità scientifica allo sviluppo di soluzioni GIS free e open source. Tale percorso ha delineato uno scenario in cui un utente GIS è in grado di scegliere tra molteplici ambienti GIS per eseguire analisi sia nel mondo vector che nel mondo raster. Parallelamente si sta assistendo al diffondersi di tecnologie Web dotate di interfacce utenti per la pubblicazione dei dati geografici con standard definiti dall'Open Geospatial Consortium, oltre che per l'erogazione di servizi di analisi spaziali basati sullo standard Web Processing Service. Sarà presentata una sintesi del contesto evolutivo delle soluzioni GIS disponibili oggi sia in ambiente desktop che web ed in relazione al tipo di utenza e potenzialità di analisi vector e raster.

Speakers:

Denis Zorin , Hijung Valentina Shin (Massachusetts Institute of Technology)

Referent:

Nico Pietroni

Many engineering and computer graphics applications require computing surface deformations minimizing an energy or solving an equation of motion. This type of deformations are used to model free-form surfaces in computer-aided design systems, to create animated characters, to simulate cloth or analyze stresses in a car body.

Complex surfaces are commonly represented by meshes, that is, piecewise-linear functions which cannot be differentiated directly. At the same time, the equations that we need to solve often involved derivatives of order four or higher. Approximating high-order derivatives on meshes with sufficient accuracy is difficult, and often requires costly computations. These computations may be prohibitively expensive in the context of interactive modeling and simulation. In many cases, cheap, but inaccurate approximations are available, resulting in faster algorithms, but less reliable results.

In this talk, I will discuss how mesh deformations can be computed efficiently while maintaining accuracy, and demonstrate several applications in geometric modeling and animation.

I will review several complimentary approaches that we have explored, in particular, taking advantage of geometric relations to simplify the equations we need to solve, decomposing higher-order problems into several low-order problems, and representing the solution of a general problem as a combination of solutions of special-case simpler problems.

Speakers:

Claudio Gennaro

Referent:

Claudio Gennaro

Content-based image retrieval is becoming a popular way for searching the web as the amount of available multimedia data increases. However, the cost of developing from scratch a robust and reliable system with content-based image retrieval facilities is quite prohibitive.

In the talk I will present an extremely simple algorithm that converts low level image features (such as colors and textures) into a textual form, which allows us to use Lucene's off-the-shelf indexing and searching abilities with a little implementation effort. In this way, we are able to set up a robust information retrieval system that combines full-text search with content-based image retrieval capabilities. This idea will be demonstrated by an image content-based retrieval over a dataset of 106 million images indexed by five MPEG-7 descriptors from Cophir.

Speakers:

Cesar Federico Caiafa (LABSP-Brain Science Institute, RIKEN, Japan)

Referent:

Emanuele Salerno

In modern signal processing, data mining and other applications, we are frequently faced to the problem of dealing with huge-size datasets (large-scale problems). Moreover, datasets usually have a multi-way (N-way) array structure where each dimension (mode) has a particular physical meaning such as time, frequency, space, etc. N-way arrays (tensors) generalize the mathematical concept of vectors and matrices to higher dimensions (N>2) and have some attractive properties that make them useful for representing and processing N-dimensional data by decomposing them in factors. While many advances were achieved on algorithms for tensor decomposition during the last decade, nowadays one of the main challenges is to keep the computational load as low as possible achieving fast algorithms and using limited memory resources.

In this talk, an introduction to multi-way decomposition tools will be presented with focus on 'Tucker models', one of the possible generalization to higher dimensions of the useful Singular Value Decomposition (SVD) of matrices. We will present some recent results and a new algorithm, namely the Fiber Sampling Tensor Decomposition (FSTD) algorithm [1], that allows one to reconstruct an N-way array (with arbitrary N>2) from a reduced subset of its entries. As a generalization of the classical column-row matrix decomposition (also known as CUR or 'skeleton' decomposition), which approximates a matrix from a subset of its rows and columns, our result provides a new method for the approximation of a high dimensional tensor by using only the information contained in a subset of its 'n-mode fibers' (n=1,2,..,N). The properties of this method will be analyzed and discussed. We will also discuss about its potential applications for signal processing for cases where datasets are highly redundant, i.e. they can be can be compressed by using a low rank tensor decomposition such as the case of the 'Tucker model'. Simulation results will be shown to illustrate the properties and the potential of this method.