The Free University of Bozen-Bolzano is a university primarily located in Bolzano, Italy. It was founded on 31 October 1997 and is organized into five Faculties.The Free University of Bozen-Bolzano aims to offer students a multilingual, practice-oriented education that meets the demands of the local and the European labour market. Lectures and seminars are held in German, Italian and English. The only exception is the Faculty of Education, which offers German, Italian and Ladin speaking students separate training sections. The university offers study programmes ranging from bachelor's degrees to doctorates.The emphasis of teaching is to provide theoretically sound and practice-orientated training. A large proportion of educational activities take place as seminars, lectures given by guest speakers, practical training and workshops. Within the framework of the academic exchange program students are encouraged to spend one or more semesters at universities abroad. Wikipedia.
Cirac J.I.,Max Planck Institute of Quantum Optics |
Maraner P.,Free University of Bozen Bolzano |
Pachos J.K.,University of Leeds
Physical Review Letters | Year: 2010
We demonstrate that Dirac fermions self-interacting or coupled to dynamic scalar fields can emerge in the low energy sector of designed bosonic and fermionic cold atom systems. We illustrate this with two examples defined in two spacetime dimensions. The first one is the self-interacting Thirring model. The second one is a model of Dirac fermions coupled to a dynamic scalar field that gives rise to the Gross-Neveu model. The proposed cold atom experiments can be used to probe spectral or correlation properties of interacting quantum field theories thereby presenting an alternative to lattice gauge theory simulations. © 2010 The American Physical Society.
Ngo N.,Free University of Bozen Bolzano
Proceedings of the ACM SIGMOD International Conference on Management of Data | Year: 2016
Query answering over databases with conceptual constraints is an important problem in database theory. To deal with the problem, the ontology-based data access approach uses ontologies to capture both constraints and databases. In this approach, databases are considered under open-world assumption which creates many issues including the necessity of restricting to only positive queries, and the failure of query composition. In our research, we focus on a combined approach that allows data in databases stays completely as under closed-world assumption while knowledge providing by conceptual constraints can be incomplete. We first study the complexity of query answering problem under description logic constraints in the presence of complete data and show that complete data makes query answering become harder than query answering over incomplete data only. We then provide a query rewriting technique that supports deciding the existence of a safe-range first-order equivalent reformulation of a query in terms of the database schema, and if so, it provides an effective approach to construct the reformulation. Since the reformulation is a safe-range formula, it is effectively executable as an SQL query. At the end, we study the definability abduction problem which aims to characterize the least committing extensions of conceptual constraints to gain the exact rewritable of queries. We also apply this idea to data exchange-where we want to characterize the case of lossless transformations of data. © 2016 ACM.
Kaminskas M.,Free University of Bozen Bolzano |
Ricci F.,Free University of Bozen Bolzano
Computer Science Review | Year: 2012
Increasing amount of online music content has opened new opportunities for implementing new effective information access services-commonly known as music recommender systems-that support music navigation, discovery, sharing, and formation of user communities. In the recent years a new research area of contextual (or situational) music recommendation and retrieval has emerged. The basic idea is to retrieve and suggest music depending on the user's actual situation, for instance emotional state, or any other contextual conditions that might influence the user's perception of music. Despite the high potential of such idea, the development of real-world applications that retrieve or recommend music depending on the user's context is still in its early stages. This survey illustrates various tools and techniques that can be used for addressing the research challenges posed by context-aware music retrieval and recommendation. This survey covers a broad range of topics, starting from classical music information retrieval (MIR) and recommender system (RS) techniques, and then focusing on context-aware music applications as well as the newer trends of affective and social computing applied to the music domain. © 2012 Elsevier Inc.
Maraner P.,Free University of Bozen Bolzano
Annals of Physics | Year: 2014
In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer's speed to the speed of light, further suppressed by the ratio of the interferometer's arms length to the radius of rotation and depends on the interferometer's position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth's rotated kilometer-scale Fabry-Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. © 2014 Elsevier Inc.
Serina I.,Free University of Bozen Bolzano
Artificial Intelligence | Year: 2010
Case-based planning can take advantage of former problem-solving experiences by storing in a plan library previously generated plans that can be reused to solve similar planning problems in the future. Although comparative worst-case complexity analyses of plan generation and reuse techniques reveal that it is not possible to achieve provable efficiency gain of reuse over generation, we show that the case-based planning approach can be an effective alternative to plan generation when similar reuse candidates can be chosen. In this paper we describe an innovative case-based planning system, called OAKplan, which can efficiently retrieve planning cases from plan libraries containing more than ten thousand cases, choose heuristically a suitable candidate and adapt it to provide a good quality solution plan which is similar to the one retrieved from the case library. Given a planning problem we encode it as a compact graph structure, that we call Planning Encoding Graph, which gives us a detailed description of the topology of the planning problem. By using this graph representation, we examine an approximate retrieval procedure based on kernel functions that effectively match planning instances, achieving extremely good performance in standard benchmark domains. The experimental results point out the effect of the case base size and the importance of accurate matching functions for global system performance. Overall, we show that OAKplan is competitive with state-of-the-art plan generation systems in terms of number of problems solved, CPU time, plan difference values and plan quality when cases similar to the current planning problem are available in the plan library. © 2010 Elsevier B.V. All rights reserved.
Pawlik M.,Free University of Bozen Bolzano |
Augsten N.,Free University of Bozen Bolzano
Proceedings of the VLDB Endowment | Year: 2011
We consider the classical tree edit distance between ordered labeled trees, which is dened as the minimum-cost sequence of node edit operations that transform one tree into another. The state-of-the-art solutions for the tree edit distance are not satisfactory. The main competitors in the eld either have optimal worst-case complexity, but the worst case happens frequently, or they are very ecient for some tree shapes, but degenerate for others. This leads to unpredictable and often infeasible runtimes. There is no obvious way to choose between the algorithms. In this paper we present RTED, a robust tree edit distance algorithm. The asymptotic complexity of RTED is smaller or equal to the complexity of the best competitors for any input instance, i.e., RTED is both ecient and worst-case optimal. We introduce the class of LRH (Left-Right-Heavy) algorithms, which includes RTED and the fastest tree edit distance algorithms presented in literature. We prove that RTED outperforms all previously proposed LRH algorithms in terms of runtime complexity. In our experiments on synthetic and real world data we empirically evaluate our solution and compare it to the state-of-the-art. © 2011 VLDB Endowment.
Ngo N.,Free University of Bozen Bolzano
Proceedings of the VLDB Endowment | Year: 2013
A schema mapping is a high-level specification in which the relationship between two database schemas is described. In data exchange, schema mappings are one-way mappings that describe which data can be brought from source data to target data. Therefore, given a source instance and a mapping, there might be more than one valid target instance. This fact causes many problems in query answering over target data for non-conjunctive queries. To make query answering feasible for all queries, we focus on a methodology for extending the original schema mapping to guarantee the uniqueness of target instance corresponding to a source instance. To this end, we introduce a theoretical framework where the problem is transformed to an abduction problem, namely, definability abduction. We apply the framework to relational data exchange setting and solve the problem by pointing out minimal solutions according to a specific semantic minimality criterion. © 2013 VLDB Endowment.
Comiti F.,Free University of Bozen Bolzano
Earth Surface Processes and Landforms | Year: 2012
Historical, human-induced channel adjustments in lowland gravel-bed rivers have been documented in several geographical contexts worldwide. In particular, it is now widely accepted that the vast majority of European rivers are far from any natural, reference state prior to anthropic disturbances, and a 'complete' restoration is hardly achievable. However, few investigations have addressed changes that have occurred in mountain rivers of the Alps, and these channels are commonly reckoned quite 'natural' by society. This paper intends to describe how human pressure on Italian Alpine basins has been quite relevant for several centuries - in terms of land-use variations, in-channel structures, timber transport (splash damming) and riparian vegetation management - such that nowadays 'reference conditions' cannot be found even in small mountain creeks. In addition, recent natural climatic variations (e.g. the Little Ice Age) are superimposed on human disturbances, thus defying the definition of any 'equilibrium' morphological conditions even under 'human-free' states. A summary of published as well as unpublished works on historical channel adjustments in rivers of the Italian Alps is presented in order to document the impacts deriving from human pressure at different basin scales and for different river morphologies, from steep confined streams to large unconfined rivers. General options for river management and restoration actions aiming to combine geomorphological functionality and flood hazard mitigation are discussed, in the light of the current European legislative context. © 2011 John Wiley & Sons, Ltd.
Rodriguez-Muro M.,Free University of Bozen Bolzano |
Calvanese D.,Free University of Bozen Bolzano
13th International Conference on the Principles of Knowledge Representation and Reasoning, KR 2012 | Year: 2012
Current techniques for query answering over DL-Lite ontologies have severe limitations in practice, since they either produce complex queries that are inefficient during execution, or require expensive data pre-processing. In light of this, we present two complementary sets of results that aim at improving the overall peformance of query answering systems. We show how to create ABox repositories that are complete w.r.t. a significant portion of DL-Lite TBoxes, including those expressed in RDFS, but where the data is not explicitly expanded. Second, we show how to characterize ABox completeness by means of dependencies, and how to use these and equivalence to optimize DL-Lite TBoxes. These results allow us to reduce the cost of query rewriting, often dramatically, and to generate highly efficient queries. We have implemented a novel system for query answering over DL-Lite ontologies that incorporates these techniques, and we present a series of data-intensive evaluations that show their effectiveness. Copyright © 2012, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved.
Ricci F.,Free University of Bozen Bolzano
WWW'12 - Proceedings of the 21st Annual Conference on World Wide Web Companion | Year: 2012
It is our great pleasure to present you the technical programme of WWW 2012. The call for papers attracted a breath-taking number of 885 full paper submissions. 521 PC members and 235 supporting reviewers evaluated these papers. Based on 3247 reviews and meta-reviews as well as many discussions held online, the 27 track chairs and deputy chairs met with us for two full days in order to discuss and decide upon final acceptance of full papers. In the end, 108 papers - only 12% of the submissions - could be accommodated in the technical programme. These papers represent a well-balanced mix over the 13 tracks listed in the call for papers. Though the different tracks received very different numbers of submissions, our principal selection criterion was quality; hence, we neither enforced a proportional share of acceptances among the tracks nor did we favor tracks with lower numbers of submissions.