2024-03-29T12:58:34Z
http://eprints.biblio.unitn.it/cgi/oai2
oai:eprints.biblio.unitn.it:64
2012-02-28T14:27:03Z
oai:eprints.biblio.unitn.it:74
2012-02-28T14:27:04Z
oai:eprints.biblio.unitn.it:431
2012-02-28T14:16:38Z
7374617475733D707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Coordination, Division of Labor, and Open Content Communities: Template Messages in Wiki-Based Collections
Loris, Gaio
den Besten, Matthijs
Rossi, Alessandro
Dalle, Jean-Michel
Q360 Information Theory
In this paper we investigate how in commons based peer production a large community of contributors coordinates its efforts towards the production of high quality open content. We carry out our empirical analysis at the level of articles and focus on the dynamics surrounding their production. That is, we focus on the continuous process of revision and update due to the spontaneous and largely uncoordinated sequence of contributions by a multiplicity of individuals. We argue that this loosely regulated process, according to which any user can make changes to any entry, while allowing highly creative contributions, has to come into terms with potential issues with respect to the quality and consistency of the output. In this respect, we focus on emergent, bottom up organizational practice arising within the Wikipedia community, namely the use of template messages, which seems to act as an effective and parsimonious coordination device in emphasizing quality concerns (in terms of accuracy, consistency, completeness, fragmentation, and so on) or in highlighting the existence of other particular issues which are to be addressed. We focus on the template "NPOV" which signals breaches on the fundamental policy of neutrality of Wikipedia articles and we show how and to what extent imposing such template on a page affects the production process and changes the nature and division of labor among participants. We find that intensity of editing increases immediately after the "NPOV" template appears. Moreover, articles that are treated most successfully, in the sense that "NPOV" disappears again relatively soon, are those articles which receive the attention of a limited group of editors. In this dimension at least the distribution of tasks in Wikipedia looks quite similar to what is know about the distribution in the FLOSS development process.
2009-07
Departmental Technical Report
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/431/1/03.pdf
Loris, Gaio and den Besten, Matthijs and Rossi, Alessandro and Dalle, Jean-Michel (2009) Coordination, Division of Labor, and Open Content Communities: Template Messages in Wiki-Based Collections. UNSPECIFIED.
http://eprints.biblio.unitn.it/431/
oai:eprints.biblio.unitn.it:485
2012-02-28T14:16:50Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
CDMA Radio Network Planning: A Comparison of Different Interference Evaluation Methods
Severina, D.
Lo Cigno, R.
Q360 Information Theory
The target of this work is the comparison of different approximation thechniques for the evaluation of the level of interference, and the consequent errors on data frames transmitted on the channel, generated by the sum of interfering signals. The interference, also known as MAI (Multiple Access Interference), is caused by presence of other users in the same cell of the reference user or in neighboring cells. The system considered is a generic spread-spectrum communication system, whose spreading technique can be described as CDMA (Code Division Multiple Access), with of without rake receivers, with a direcr or indirect spreading technique. Although the analysis techniques considered are extremely "broad" in their application, mainly as a consequence of their high level of abstraction and approximation, all the examples and numerical evaluation are done in the context of the UTRAN (UMTS-Terrestrial Radio Access NEtwork) interface, which uses a DS-CDMA (Direct Spreading CDMA}) technique with a superposition of spreading and scrambling codes. The analisy of behaviour of DS-CDMA system is done with different approximation: SGA, IGA, SEIGA and Fourier Series Expansion. The SGA (Standard Gaussian Approximation) is the most diffused approximation: it considers one useful signal while all the others are considered as white Gaussian noise over the band in exam. This algorithm is based on Central Limit Theorem: a sum of a large number of independent and identically distributed (iid) variables is a Gaussian variable. Is a rough approximation, but it allows easy and fast computation. The IGA (Improved Gaussian Approximation) is based on Central Limit Theorem too. In this case the MAI is a Gaussian variable conditionally to users states, defined by delay and phase. The SEIGA (Simplified Expression of Improved Gaussian Approximation) is similar to IGA and introduces simplification in the integral computation using Taylor Series and differences rather than derivatives. The Fourier Series Expansion is not based on Central Limit Theorem and does not use Gaussian Approximation for the MAI. In this case the hypothesis of a big number of users in a cell is not necessary and the approximation allows to study multi-service systems. The algorithms that use Gaussian approximation can not be used for multi-service systems because the hypothesis of iid variable can not be satisfied. These approximations allow to define parameters as SIR (Signal to Interference Ratio) and BER (Bit Error Rate}) to estimate performances of communication on up-link channel. For each of these approximations two different channel models are considered: no-fading (AWGN, Additive White Gaussian Noise) one and fading one.For each of these channel models three different classes of power control are considered: perfect one, imperfect one and absent one.
2003
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/485/1/TR%2DDIT%2D03%2D79.pdf
Severina, D. and Lo Cigno, R. (2003) CDMA Radio Network Planning: A Comparison of Different Interference Evaluation Methods. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/485/
oai:eprints.biblio.unitn.it:553
2013-01-30T08:59:21Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
74797065733D6F74686572
Coordinating Semantic Peers
Bonifacio, Matteo
Bouquet, Paolo
Serafini, Luciano
Zanobini, Stefano
Q360 Information Theory
The problem of finding an agreement on the meaning of heterogeneous knowledge sources is one of the key issues in the development of the distributed knowledge management applications. In this paper, we propose a new algorithm for discovering semantic mappings across heterogeneous schemas. This approach shifts the problem of semantic coordination from the problem of computing linguistic or structural similarities (what most other proposed approaches do) to the problem of deducing relations between sets of logical formulas that represent the meaning of nodes belonging to different schemas. We show how to apply the approach and the algorithm to an interesting family of schemas, namely hierarchical classifications. Finally, we argue why this is a significant improvement on previous approaches.
2004
Other
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/553/1/AMKM%2D04.pdf
Bonifacio, Matteo and Bouquet, Paolo and Serafini, Luciano and Zanobini, Stefano (2004) Coordinating Semantic Peers. [Other] (Unpublished)
http://eprints.biblio.unitn.it/553/
oai:eprints.biblio.unitn.it:554
2012-02-28T14:17:09Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Improving CtxMatch by means of grammatical and ontological knowledge - in order to handle attributes
Zanobini, Stefano
Q360 Information Theory
No Abstract -
2003-09
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/554/1/ctxmatch2.pdf
Zanobini, Stefano (2003) Improving CtxMatch by means of grammatical and ontological knowledge - in order to handle attributes. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/554/
oai:eprints.biblio.unitn.it:628
2012-02-28T14:17:27Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Multi-Carrier Code Division Multiplexing of Multi-Layered MPEG4 Video Signals for Real-time Mobile Streaming Applications
Sacchi, Claudio
Conci, Nicola
Berlanda Scorza, Giovanni
De Natale, Francesco G.B.
Q360 Information Theory
In this report, a novel methodology for the efficient multiplexing and transmission of MPEG4- coded video signals over wireless networks will be presented and discussed. The proposed approach relies on the joint exploitation of variable-bit-rate (VBR) multicarrier code-division multiplexing (MC-CDM), together with MPEG4 coding with Fine-Grain-Scalability (FGS) in order to provide unequal error protection to the transmitted video stream.The innovative scheme proposed employs a shared bandwidth partitioned into orthogonal sub-channels in order to multiplex different layers of MPEG-4-coded signals. The highest number of sub-channels (and hence an increased frequency diversity) is assigned to the lowest-bit-rate base layer and the lowest number of sub-channels is assigned to the highest bit-rate enhancement layer. In such a way, base layer information contents are more protected against channel degradations than information contained in FGS enhancement layers, which can only yield a refinement of the quality of the decoded streams. A 2GHz LEO multicast satellite transmission to mobile users has been regarded as the application testbed for the proposed method. Results achieved in terms of PSNR point out that the VBR MC-CDM technique can provide better results than a conventional MPEG-4 single-layer MC-SS transmission.In the framework of a full-digital implementation of reconfigurable multimedia transceivers, the proposed VBR MC-CDM technique may be regarded as an interesting solution for reliable multimedia transmissions in mobile environments.
2004-07
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/628/1/DIT%2D04%2D083.pdf
Sacchi, Claudio and Conci, Nicola and Berlanda Scorza, Giovanni and De Natale, Francesco G.B. (2004) Multi-Carrier Code Division Multiplexing of Multi-Layered MPEG4 Video Signals for Real-time Mobile Streaming Applications. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/628/
oai:eprints.biblio.unitn.it:706
2012-02-28T14:17:50Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Semantic Coordination of Hierarchical Classifications with Attributes
Sceffer, Simone
Serafini, Luciano
Zanobini, Stefano
Q360 Information Theory
Semantic coordination, namely the problem of finding an agreement on the meaning of heterogeneous schemas, is one of the key issues in the development of the Semantic Web. In this paper, we propose a method for discovering semantic mappings across hierarchical classifications with attributes based on a new approach, which shifts the problem of semantic coordination from the problem of computing linguistic or structural similarities (what most other proposed approaches do) to the problem of deducing relations between sets of logical formulae that represent the meaning of concepts belonging to different schema. We show how to apply the approach and the algorithm to an interesting family of schemas, namely hierarchical classifications, and present the results of preliminary tests on two types of hierarchical classifications, web directories and catalogs. Finally, we argue why this is a significant improvement on previous approaches.
2004-12
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/706/1/ctxmatch2.pdf
Sceffer, Simone and Serafini, Luciano and Zanobini, Stefano (2004) Semantic Coordination of Hierarchical Classifications with Attributes. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/706/
oai:eprints.biblio.unitn.it:993
2012-02-28T14:19:03Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
7375626A656374733D51:5141:51413735
74797065733D746563687265706F7274
Implicit culture: an approach for experiential reasoning
Birukou, Aliaksandr
Giorgini, Paolo
Q360 Information Theory
QA075 Electronic computers. Computer science
Usually, people tend to use knowledge acquired with the experience for their daily activities. Very often this knowledge is implicit and highly personalized, and it is very hard to make it explicit in information bases. Transferring knowledge to new community members or making it available for another community is a challenging problem. In this paper, we describe the Implicit Culture approach that uses learning techniques to facilitate the transfer of implicit knowledge and the reuse of previously accumulated experience.We briefly describe current applications of Implicit Culture and show how it relates to Experiential Reasoning.
2006-04
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/993/1/020.pdf
Birukou, Aliaksandr and Giorgini, Paolo (2006) Implicit culture: an approach for experiential reasoning. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/993/
oai:eprints.biblio.unitn.it:1001
2012-02-28T14:19:05Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
7375626A656374733D51:5141:51413735
7375626A656374733D51:5141:51413736
74797065733D746563687265706F7274
Reactive and dynamic local search for Max-Clique, does the complexity pay off?
Battiti, Roberto
Mascia, Franco
Q360 Information Theory
QA075 Electronic computers. Computer science
QA076 Computer software
This paper presents some preliminary results of an ongoing investigation about how different algorithmic building blocks contribute to solving the Maximum Clique problem. In detail, we consider greedy constructions, plateau searches, and more complex schemes based on dynamic penalties and/or prohibitions, in particular the recently proposed technique of Dynamic Local Search and the previously proposed Reactive Local Search. The experimental results consider both the empirical hardness, measured by the iterations needed to reach empirical maxima, and the CPU time per iteration.
2006-04
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1001/1/techrep.pdf
Battiti, Roberto and Mascia, Franco (2006) Reactive and dynamic local search for Max-Clique, does the complexity pay off? UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/1001/
oai:eprints.biblio.unitn.it:1029
2012-02-28T14:27:16Z
oai:eprints.biblio.unitn.it:1202
2012-02-28T14:20:01Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
7375626A656374733D51:5141:51413735
7375626A656374733D51:5141:51413736
74797065733D746563687265706F7274
Reactive local search for maximum clique: A new implementation
Battiti, Roberto
Mascia, Franco
Q360 Information Theory
QA075 Electronic computers. Computer science
QA076 Computer software
This paper presents algorithmic and implementation enhancements of Reactive Local Search algorithm for the Maximum Clique problem [3]. In addition, we build an empirical complexity model for the CPU time required for a single iteration, and we show that with a careful implementation of the data structures one can achieve a speedup of at least an order of magnitude difference for large size graphs.
2007-05
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1202/1/newclique.pdf
Battiti, Roberto and Mascia, Franco (2007) Reactive local search for maximum clique: A new implementation. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/1202/
oai:eprints.biblio.unitn.it:1220
2012-02-28T14:20:08Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
7375626A656374733D51:5141:51413736
7375626A656374733D51:5141:51413736:514137362E37
74797065733D746563687265706F7274
From Early Requirements Analysis towards Secure Workflows
Frankova, Ganna
Massacci, Fabio
Seguran, Magali
Q360 Information Theory
QA076.7 Programming Languages - Semantics
QA076 Computer software
Requirements engineering is a key step in the software development process that has little counterpart in the development of business processes for web services. Furthermore, the existing design methodologies for web services do not address the issue of developing secure web services, secure business processes and secure workflows. This paper presents a methodology that allows a business process designer to derive the skeleton of the concrete secure business processes from the early requirements analysis. The proposed refinement methodology aims to obtain an appropriate coarse grained secure business process that can be further refined into workflows. We introduce a specification language for secure business processes, which is a dialect of WS-BPEL for the functional parts and abstracts away low level implementation details from WS-Security and WS-Federation specifications. To make the discussion more concrete, we illustrate the proposal with an e-business banking case study.
2007-05
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1220/1/SecureBPEL_FrankovaMassacciSeguran.pdf
Frankova, Ganna and Massacci, Fabio and Seguran, Magali (2007) From Early Requirements Analysis towards Secure Workflows. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/1220/
oai:eprints.biblio.unitn.it:1222
2012-02-28T14:20:09Z
7374617475733D756E707562
7375626A656374733D51:5141:51333630
7375626A656374733D51:5141:51413736
74797065733D746563687265706F7274
From Early Requirements to Business Processes with Service Level Agreements
Frankova, Ganna
Yautsiukhin, Artsiom
Seguran, Magali
Q360 Information Theory
QA076 Computer software
When designing a service-based business process employing loosely-coupled services, one is not only interested in guaranteeing a certain flow of work, but also in how the work will be performed. This involves the consideration of non-functional properties which go from execution time, costs, up to security and trust. Ideally, a designer would like to have guarantees over the behavior of the services involved in the process. These guarantees are the object of Service Level Agreements. We propose a methodology to design service-based business processes together with service level agreements that guarantee a certain quality of execution, with particular emphasis on the security aspects. Starting from an early requirements analysis modeled in the SI* formalism, we provide a set of user-guided transformations and reasoning tools which final output is a set of processes, in the form of Secure BPELs, together with a set of service level agreements to be signed by participating services. To show the potential impact on security guarantees, we illustrate the functioning of the methodology on a e-business banking example inspired by an actual industrial case.
2007-06
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1222/1/BPSLA_FrankovaYautsiukhinSeguran.pdf
Frankova, Ganna and Yautsiukhin, Artsiom and Seguran, Magali (2007) From Early Requirements to Business Processes with Service Level Agreements. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/1222/
oai:eprints.biblio.unitn.it:1291
2012-02-28T14:20:32Z
7374617475733D707562
7375626A656374733D51:5141:51333630
7375626A656374733D51:5141:5141313530
74797065733D746563687265706F7274
Sraffa's Mathematical Economics - A Constructive Interpretation
Velupillai, Kumaraswamy
QA152 Algebra
Q360 Information Theory
The claim in this paper is that Sraffa employed a rigorous logic of mathematical reasoning in his book, Production of Commodities by Means of Commodities (PCC), in such a way that the existence proofs were constructive. This is the kind of mathematics that was prevalent at the beginning of the 19th century, which was dominated by the concrete, the constructive and the algorithmic. It is, therefore, completely consistent with the economics of the 19th century, which was the fulcrum around which the economics of PCC was conceived.
2007-02
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1291/1/2_07_velupillai.pdf
Velupillai, Kumaraswamy (2007) Sraffa's Mathematical Economics - A Constructive Interpretation. UNSPECIFIED.
http://eprints.biblio.unitn.it/1291/
oai:eprints.biblio.unitn.it:1292
2012-02-28T14:20:32Z
7374617475733D707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Variations on the Theme of Conning in Mathematical Economics
Velupillai, Kumaraswamy
Q360 Information Theory
The mathematization of economics is almost exclusively in terms of the mathematics of real analysis which, in turn, is founded on set theory (and the axiom of choice) and orthodox mathematical logic. In this paper I try to point out that this kind of mathematization is replete with economic infelicities. The attempt to extract these infelicities is in terms of three main examples: dynamics, policy and rational expectations and learning. The focus is on the role and reliance on standard xed point theorems in orthodox mathematical economics.
2007-03
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1292/1/3_07_velupillai.pdf
Velupillai, Kumaraswamy (2007) Variations on the Theme of Conning in Mathematical Economics. UNSPECIFIED.
http://eprints.biblio.unitn.it/1292/
oai:eprints.biblio.unitn.it:1436
2012-02-28T14:21:47Z
7374617475733D756E707562
7375626A656374733D51:5141:5141323639
7375626A656374733D51:5141:51333630
7375626A656374733D54:544B:544B37383835
7375626A656374733D54:544B:544B353130352E35
7375626A656374733D51:5141:51413735
74797065733D746563687265706F7274
Analysis of TCP/MAC Interactions Using the Game Theory
Facchini, Christian
Granelli, Fabrizio
QA269 Game theory
TK7885 Computer Engineering
Q360 Information Theory
TK5105.5 Computer Networks
QA075 Electronic computers. Computer science
ISO/OSI and TCP/IP protocol stacks provide networks and devices interoperability by exploiting the principle of layering, where every layer is characterized by specific functionalities and is allowed to interact only with adjacent layers by means of standardized interfaces. However, while such principle provides freedom in implementation of the protocols at different layers, it limits the control on the interaction among protocols at different layers. In this framework, it is necessary to develop efficient model to capture the interaction of protocols with a single communication device in order to underline such forms of “indirect” interaction – which may lead to unforeseen performance degradations. The proposed work aims at proposing the usage of the game theory for capturing the interactions within the protocol stack of a single node, with the goal of allowing to determine the “steady state” or the operating point of the system in a given scenario (TCP over IEEE 802.11).
2008-05
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1436/1/DISI%2D08%2D025.pdf
Facchini, Christian and Granelli, Fabrizio (2008) Analysis of TCP/MAC Interactions Using the Game Theory. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/1436/
oai:eprints.biblio.unitn.it:1445
2012-02-28T14:21:52Z
7374617475733D7375626D6974746564
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Delayed Theory Combination vs. Nelson-Oppen for Satisfiability Modulo Theories: a Comparative Analysis
Bruttomesso, Roberto
Cimatti, Alessandro
Franzen, Anders
Griggio, Alberto
Sebastiani, Roberto
Q360 Information Theory
Most state-of-the-art approaches for Satisfiability Modulo Theory (SMT(T)) rely on the integration between a SAT solver and a decision procedure for sets of literals in the background theory T (T-solver). Often T is the combination (T1 U T2) of two (or more) simpler theories (SMT(T1 U T2)), s.t. the specific Ti-Solvers must be combined. Up to a few years ago, the standard approach to SMT(T1 U T2) was to integrate the SAT solver with one combined (T1 U T2)-solver, obtained from two distinct Ti-Solvers by means of evolutions of Nelson and Oppen's (NO) combination procedure, in which the Ti-Solvers deduce and exchange interface equalities. Nowadays many state-of-the-art SMT solvers use evolutions of a more recent SMT(T1 U T2) procedure called Delayed Theory Combination (DTC), in which each Ti-Solver interacts directly and only with the SAT solver, in such a way that part or all of the (possibly very expensive) reasoning effort on interface equalities is delegated to the SAT solver itself. In this paper we present a comparative analysis of DTC vs. NO for SMT(T1 U T2). On the one hand, we explain the advantages of DTC in exploiting the power of modern SAT solvers to reduce the search. On the other hand, we show that the extra amount of Boolean search required to the SAT solver can be controlled. In fact, we prove two novel theoretical results, for both convex and non-convex theories and for different deduction capabilities of the Ti-Solvers, which relate the amount of extra Boolean search required to the SAT solver by DTC with the number of deductions and case-splits required to the Ti-Solvers by NO in order to perform the same tasks: (i) under the same hypotheses of deduction capabilities of the Ti-Solvers required by NO, DTC causes no extra Boolean search; (ii) using Ti-Solvers with limited or no deduction capabilities, the amount of extra Boolean search required can be reduced down to a negligible amount by controlling the quality of the T-conflict sets returned by the T-solvers.
2008-06
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1445/1/dtr%2D08%2D028.pdf
Bruttomesso, Roberto and Cimatti, Alessandro and Franzen, Anders and Griggio, Alberto and Sebastiani, Roberto (2008) Delayed Theory Combination vs. Nelson-Oppen for Satisfiability Modulo Theories: a Comparative Analysis. UNSPECIFIED. (Submitted)
http://eprints.biblio.unitn.it/1445/
oai:eprints.biblio.unitn.it:1663
2012-02-28T14:23:02Z
7374617475733D707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
Wikibugs: the practice of template messages in open content collections
Gaio, Loris
den Besten, Matthijs
Rossi, Alessandro
Dalle, Jean-Michel
Q360 Information Theory
In the paper we investigate an organizational practice meant to increase the quality of commons-based peer production: the use of template messages in wiki collections to highlight editorial bugs and call for intervention. In the context of SimpleWiki, an online encyclopedia of the Wikipedia family, we focus on {complex}, a template which is used to flag articles disregarding the overall goals of simplicity and readability. We characterize how this template is placed on and removed from articles and we use survival analysis to study the emergence and successful treatment of these bugs in the collection.
2009-07
Departmental Technical Report
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1663/1/04.pdf
Gaio, Loris and den Besten, Matthijs and Rossi, Alessandro and Dalle, Jean-Michel (2009) Wikibugs: the practice of template messages in open content collections. UNSPECIFIED.
http://eprints.biblio.unitn.it/1663/
oai:eprints.biblio.unitn.it:1907
2013-01-25T11:14:59Z
7374617475733D707562
7375626A656374733D51:5141:51333630
74797065733D746563687265706F7274
The dynamics of consensus in group decision making: investigating the pairwise interactions between fuzzy preferences
Fedrizzi, Mario
Fedrizzi, Michele
Marques Pereira, Ricardo Alberto
Brunelli, Matteo
Q360 Information Theory
In this paper we present an overview of the soft consensus model in group decision making and we investigate the dynamical patterns generated by the fundamental pairwise preference interactions on which the model is based. The dynamical mechanism of the soft consensus model is driven by the minimization of a cost function combining a collective measure of dissensus with an individual mechanism of opinion changing aversion. The dissensus measure plays a key role in the model and induces a network of pairwise interactions between the individual preferences. The structure of fuzzy relations is present at both the individual and the collective levels of description of the soft consensus model: pairwise preference intensities between alternatives at the individual level, and pairwise interaction coefficients between decision makers at the collective level. The collective measure of dissensus is based on non linear scaling functions of the linguistic quantifier type and expresses the degree to which most of the decision makers disagree with respect to their preferences regarding the most relevant alternatives. The graded notion of consensus underlying the dissensus measure is central to the dynamical unfolding of the model. The original formulation of the soft consensus model in terms of standard numerical preferences has been recently extended in order to allow decision makers to express their preferences by means of triangular fuzzy numbers. An appropriate notion of distance between triangular fuzzy numbers has been chosen for the construction of the collective dissensus measure. In the extended formulation of the soft consensus model the extra degrees of freedom associated with the triangular fuzzy preferences, combined with non linear nature of the pairwise preference interactions, generate various interesting and suggestive dynamical patterns. In the present paper we investigate these dynamical patterns which are illustrated by means of a number of computer simulations.
Università degli Studi di Trento
2010-07
Departmental Technical Report
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1907/1/04.pdf
http://www.unitn.it/disa/10528/working-papers-anno-2010
Fedrizzi, Mario and Fedrizzi, Michele and Marques Pereira, Ricardo Alberto and Brunelli, Matteo (2010) The dynamics of consensus in group decision making: investigating the pairwise interactions between fuzzy preferences. DISA Working Paper; 4 . Trento : Università degli Studi di Trento.
http://eprints.biblio.unitn.it/1907/
oai:eprints.biblio.unitn.it:3969
2012-08-20T08:14:30Z
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Sparse Color Interest Points for Image Retrieval and Object Categorization
Stöttinger, Julian
Hanbury, Allan
Sebe, Nicu
Gevers, Theo
Q360 Information Theory
QA075 Electronic computers. Computer science
QA076 Computer software
TK7885 Computer Engineering
Interest point detection is an important research area in the field of image processing and computer vision. In particular, image retrieval and object categorization heavily rely on interest point detection from which local image descriptors are computed for image matching. In general, interest points are based on luminance, and color has been largely ignored. However, the use of color increases the distinctiveness of interest points. The use of color may therefore provide selective search reducing the total number of interest points used for image matching.
This paper proposes color interest points for sparse image representation. To reduce the sensitivity to varying imaging conditions, light invariant interest points are introduced. Color statistics based on occurrence probability lead to color boosted points which are obtained through a saliency-based feature selection. Further, a PCA-based scale selection method is proposed which gives a robust scale estimation per interest point.
From large scale experiments, it is shown that the proposed color interest point detector has a higher repeatability than a luminance-based one. Further, in the context of image retrieval, a reduced and predictable number of color features shows an increase in performance compared to state-of-the-art interest points. Finally, in the context of object recognition, for the Pascal VOC 2007 challenge, our method gives comparable performance to state-of-the-art methods using only a small fraction of the features, reducing the computing time considerably.
Università di Trento
Thrasyvoulos N. , Pappas
2012-01-26
Departmental Technical Report
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/3969/1/techrep09.pdf
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6140972
Stöttinger, Julian and Hanbury, Allan and Sebe, Nicu and Gevers, Theo (2012) Sparse Color Interest Points for Image Retrieval and Object Categorization. Trento : Università di Trento, pp. 1-12.
http://eprints.biblio.unitn.it/3969/
info:eu-repo/semantics/report
ARRAY(0xbb0a4fb0)
info:eu-repo/semantics/openAccess