Flow-based reputation: more than just ranking

The last years have seen a growing interest in collaborative systems like electronic marketplaces and P2P file sharing systems where people are intended to interact with other people. Those systems, however, are subject to security and operational risks because of their open and distributed nature. Reputation systems provide a mechanism to reduce such risks by building trust relationships among entities and identifying malicious entities. A popular reputation model is the so called flow-based model. Most existing reputation systems based on such a model provide only a ranking, without absolute reputation values; this makes it difficult to determine whether entities are actually trustworthy or untrustworthy. In addition, those systems ignore a significant part of the available information; as a consequence, reputation values may not be accurate. In this paper, we present a flow-based reputation metric that gives absolute values instead of merely a ranking. Our metric makes use of all the available information. We study, both analytically and numerically, the properties of the proposed metric and the effect of attacks on reputation values

Mode doubling and tripling in reaction-diffusion patterns on growing domains: A piece-wise linear model

Reaction-diffusion equations are ubiquitous as models of biological pattern formation. In a recent paper [4] we have shown that incorporation of domain growth in a reaction-diffusion model generates a sequence of quasi-steady patterns and can provide a mechanism for increased reliability of pattern selection. In this paper we analyse the model to examine the transitions between patterns in the sequence. Introducing a piecewise linear approximation we find closed form approximate solutions for steady-state patterns by exploiting a small parameter, the ratio of diffusivities, in a singular perturbation expansion. We consider the existence of these steady-state solutions as a parameter related to the domain length is varied and predict the point at which the solution ceases to exist, which we identify with the onset of transition between patterns for the sequence generated on the growing domain. Applying these results to the model in one spatial dimension we are able to predict the mechanism and timing of transitions between quasi-steady patterns in the sequence. We also highlight a novel sequence behaviour, mode-tripling, which is a consequence of a symmetry in the reaction term of the reaction-diffusion system

Bayesiaanse geïntegreerde bepaling van de effectieve ionaire lading via remstralings- en ladingsuitwisselingsspectroscopie in tokamakplasma's

Dit doctoraatswerk is gekaderd in de ontwikkeling van gecontroleerde thermonucleaire fusie als een schone, veilige en nagenoeg onuitputtelijke energiebron. Het is geconcentreerd op magnetische opsluiting in de tokamakconfiguratie. In een eerste, experimenteel gedeelte werd een nieuwe diagnostiek ontwikkeld voor remstralingsspectroscopie in het zichtbare aan de TEXTOR-tokamak (Institut fuer Plasmaphysik, Forschungszentrum Juelich, Duitsland). De diagnostiek voorziet 24 zichtlijnen gekoppeld aan een gekoelde CCD-camera, waardoor de voordelen van zowel een relatief hoge tijdsresolutie als ruimtelijke resolutie worden gecombineerd. Emissiviteitsprofielen van remstraling kunnen gereconstrueerd worden door een Abel-inversie. De betrouwbaarheid van de gereconstrueerde profielen werd vergroot door Tikhonov- en Maximum Entropie-regularisatie. Op die manier kunnen samen met profielen van de elektrondichtheid en de elektrontemperatuur, profielen voor de effectieve ionaire lading Zeff afgeleid worden. Een nieuwe methode voor de relatieve calibratie van het systeem werd bedacht en getest, gebaseerd op de consistentievereiste van profielen onder een verandering van zichtgeometrie. In een tweede deel van het doctoraatswerk werd Bayesiaanse waarschijnlijkheidsrekening gebruikt met het oog op de oplossing van het aloude probleem van de incompatibiliteit van Zeff-schattingen afgeleid uit remstralingsspectroscopie enerzijds en uit de gewogen sommatie van individuele onzuiverheidsconcentraties verkregen door ladingsuitwisselingsspectroscopie (CXS) anderzijds. Een probabilistisch model werd opgezet dat metingen van zowel remstralingsspectroscopie als CXS integreert. Inherente statistische en systematische onzekerheden in de metingen werden op een behoorlijke manier in rekening gebracht. Hierdoor werd het mogelijk een meest waarschijnlijke waarde voor Zeff op de magnetische as af te leiden, die consistent is met beide sets metingen en met kleinere foutenmarges dan voordien. Het uiteindelijke doel is de betrouwbaarheid en robuustheid van Zeff-profielen te verbeteren over de volledige plasmadoorsnede, terwijl consistentheid met alle beschikbare ruwe metingen behouden blijft. Een gelijkaardige Bayesiaanse analyse kan toegepast worden op vele (sets van) fusiediagnostieken en dit heeft een aanzienlijk potentieel om in het fusieonderzoek de algemene consistentie en nauwkeurigheid van data te verbeteren

Advances and Applications of Dezert-Smarandache Theory (DSmT) for Information Fusion (Collected Works), Vol. 4

The fourth volume on Advances and Applications of Dezert-Smarandache Theory (DSmT) for information fusion collects theoretical and applied contributions of researchers working in different fields of applications and in mathematics. The contributions (see List of Articles published in this book, at the end of the volume) have been published or presented after disseminating the third volume (2009, http://fs.unm.edu/DSmT-book3.pdf) in international conferences, seminars, workshops and journals. First Part of this book presents the theoretical advancement of DSmT, dealing with Belief functions, conditioning and deconditioning, Analytic Hierarchy Process, Decision Making, Multi-Criteria, evidence theory, combination rule, evidence distance, conflicting belief, sources of evidences with different importance and reliabilities, importance of sources, pignistic probability transformation, Qualitative reasoning under uncertainty, Imprecise belief structures, 2-Tuple linguistic label, Electre Tri Method, hierarchical proportional redistribution, basic belief assignment, subjective probability measure, Smarandache codification, neutrosophic logic, Evidence theory, outranking methods, Dempster-Shafer Theory, Bayes fusion rule, frequentist probability, mean square error, controlling factor, optimal assignment solution, data association, Transferable Belief Model, and others. More applications of DSmT have emerged in the past years since the apparition of the third book of DSmT 2009. Subsequently, the second part of this volume is about applications of DSmT in correlation with Electronic Support Measures, belief function, sensor networks, Ground Moving Target and Multiple target tracking, Vehicle-Born Improvised Explosive Device, Belief Interacting Multiple Model filter, seismic and acoustic sensor, Support Vector Machines, Alarm classification, ability of human visual system, Uncertainty Representation and Reasoning Evaluation Framework, Threat Assessment, Handwritten Signature Verification, Automatic Aircraft Recognition, Dynamic Data-Driven Application System, adjustment of secure communication trust analysis, and so on. Finally, the third part presents a List of References related with DSmT published or presented along the years since its inception in 2004, chronologically ordered

Innovative Transactional Pedagogies

Our law schools are embracing in a more powerful way innovative transactional pedagogies that address not only theory, policy, and doctrine, but also legal skills. This transcribed panel discussion explores three of these pedagogies – teaching corporate finance as advanced contract drafting, teaching numeracy, and teaching substance and skill in contract drafting through the use of in-office meetings and analytical memos – and describes how they are being implemented in law teaching. The panel was part of the “Transactional Education: What’s Next?” conference hosted by the Emory University School of Law’s Center for Transactional Law and Practice on June 4-5, 2010

Proceedings of the second "international Traveling Workshop on Interactions between Sparse models and Technology" (iTWIST'14)

The implicit objective of the biennial "international - Traveling Workshop on Interactions between Sparse models and Technology" (iTWIST) is to foster collaboration between international scientific teams by disseminating ideas through both specific oral/poster presentations and free discussions. For its second edition, the iTWIST workshop took place in the medieval and picturesque town of Namur in Belgium, from Wednesday August 27th till Friday August 29th, 2014. The workshop was conveniently located in "The Arsenal" building within walking distance of both hotels and town center. iTWIST'14 has gathered about 70 international participants and has featured 9 invited talks, 10 oral presentations, and 14 posters on the following themes, all related to the theory, application and generalization of the "sparsity paradigm": Sparsity-driven data sensing and processing; Union of low dimensional subspaces; Beyond linear and convex inverse problem; Matrix/manifold/graph sensing/processing; Blind inverse problems and dictionary learning; Sparsity and computational neuroscience; Information theory, geometry and randomness; Complexity/accuracy tradeoffs in numerical methods; Sparsity? What's next?; Sparse machine learning and inference.Comment: 69 pages, 24 extended abstracts, iTWIST'14 website: http://sites.google.com/site/itwist1