123,516 research outputs found
The MAGIC Experiment
No full textThe Magic Cherenkov Telescope is located at the Observatory of the Roque de los
Muchachos (ORM) and since 2004 is operative, in may 2005 was started the first yearly
campaign of data taking named Cycle I. During this period the telescope reported signals
from galactic and extragalactic AGN sources. In this report we will describe the
technique for the detection of Very High Energy (VHE) gammas by this class o
Paradigms and scenarios for the dark matter phenomenon
No full textWell known scaling laws among the structural properties of the dark and the luminous matter in disc systems are too complex to be arisen by two inert components that just share the same gravitational field. This brings us to critically focus on the 30-year-old paradigm, that, resting on a priori knowledge of the nature of Dark Matter (DM), has led us to a restricted number of scenarios, especially favouring the collisionless Λ Cold Dark Matter one. Motivated by such observational evidence, we propose to resolve the dark matter mystery by following a new Paradigm: the nature of DM must be guessed/derived by deeply analyzing the properties of the dark and luminous mass distribution at galactic scales. The immediate application of this paradigm leads us to propose the existence of a direct interaction between Dark and Standard Model particles, which has finely shaped the inner regions of galaxies
Staged in situ aorto-iliac hybrid technique: an original technique to treat complex juxtarenal and iliac aneurysms
No full textBackground: To report a novel staged hybrid technique to treat complex juxtarenal abdominal aortic aneurysm (JAAA) associated with at least one iliac artery aneurysm (IA) with no adequate distal fixation zone. Methods: The novel technique herein described has two main “staged” steps. The first step consists in creating an adequate distal fixation zone by endovascular means; after hypogastric embolization an iliac stent-graft has placed from 5 mm above the aortic bifurcation to the external iliac artery. The second step is the surgical resection of the JAAA and graft placement sutured distally to the stent-graft which was always performed the day after. Results: The five cases included (mean age 74 years), were rejected for fenestrated or branched endovascular aortic repair or iliac branch devices. Four tube grafts and one aorto-bi-iliac graft were sutured to one stent-graft (N.=3), two stent-grafts in iliac kissing configuration (N.=1) and to a main body of a bifurcated stent-graft (N.=1). Mean follow-up duration was 14 (4-27) months with no mortality. Technical success was obtained in all cases (2 suprarenal clamping). Postoperative complications included two pleural effusions, two transient gluteal intermittent claudications, and one renal failure. Conclusions: The technique herein described seems to be a feasible and cost-effective alternative treatment for selected concomitant complex JAAAs and IAs unsuitable for totally endovascular treatment
A KDD process for discrimination discovery
No full textThe acceptance of analytical methods for discrimination discovery by practitioners and legal scholars can be only achieved if the data mining and machine learning communities will be able to provide case studies, methodological refinements, and the consolidation of a KDD process. We summarize here an approach along these directions
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
THE TRIGGER SYSTEM OF THE MAGIC TELESCOPE: ON-LINE SELECTION STRATEGIES FOR CHERENKOV TELESCOPES
No full textThe Major Atmospheric Gamma-ray Imaging Cherenkov Telescope aims at the detection of very low energy gamma-rays (E > 10 GeV) through the atmospheric emission of Cherenkov light. The high background rate originated by various sources sets a serious challenge to this goal. Application of topological selection cuts at trigger level can contribute to the background reduction, allowing the telescope to operate at lower thresholds and reducing the minimum detectable energy
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