3,980 research outputs found

    SSGN

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    As budget challenges put increasing pressure on the operational forces, the ability to deter both potential adversary nations and terrorists will require the warfighting platforms of the United States to be ready to perform diverse missions in parallel. Transformation of operational and tactical precepts will be required to support these increasing demands. The nuclear-powered guided-missile (actually, cruise-missile) submarine, or SSGN, is just such a transformational asset

    A treatise on Web 2.0 with a case study from the financial markets

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    There has been much hype in vocational and academic circles surrounding the emergence of web 2.0 or social media; however, relatively little work was dedicated to substantiating the actual concept of web 2.0. Many have dismissed it as not deserving of this new title, since the term web 2.0 assumes a certain interpretation of web history, including enough progress in certain direction to trigger a succession [i.e. web 1.0 → web 2.0]. Others provided arguments in support of this development, and there has been a considerable amount of enthusiasm in the literature. Much research has been busy evaluating current use of web 2.0, and analysis of the user generated content, but an objective and thorough assessment of what web 2.0 really stands for has been to a large extent overlooked. More recently the idea of collective intelligence facilitated via web 2.0, and its potential applications have raised interest with researchers, yet a more unified approach and work in the area of collective intelligence is needed. This thesis identifies and critically evaluates a wider context for the web 2.0 environment, and what caused it to emerge; providing a rich literature review on the topic, a review of existing taxonomies, a quantitative and qualitative evaluation of the concept itself, an investigation of the collective intelligence potential that emerges from application usage. Finally, a framework for harnessing collective intelligence in a more systematic manner is proposed. In addition to the presented results, novel methodologies are also introduced throughout this work. In order to provide interesting insight but also to illustrate analysis, a case study of the recent financial crisis is considered. Some interesting results relating to the crisis are revealed within user generated content data, and relevant issues are discussed where appropriate

    Power of Web 2.0 mass collaboration in computational intelligence and its’ uses, an example from finance

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    One of the main issues of concern within world wide web is the emergence of web 2.0 mass collaboration systems and our understanding of this new phenomenon. Web 2.0 systems have gained enormous popularity in recent years, however as is often case with novel technologies, the real merits sometime stay somewhat obscured to many researchers. In this short paper web 2.0 applications are lightly introduced, with parallels to computational intelligence being drawn and some experimental results from the financial markets presented, to illustrate value of web 2.0. This paper highlights a number of important issues that deserve academic attention. We hope this paper will serve as a light and not too technical introduction towards encouraging others in computational intelligence to consider leveraging web 2.0

    Surges and Si IV bursts in the solar atmosphere. Understanding IRIS and SST observations through RMHD experiments

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    Surges often appear as a result of the emergence of magnetized plasma from the solar interior. Traditionally, they are observed in chromospheric lines such as Hα\alpha 6563 \AA and Ca II 8542 \AA. However, whether there is a response to the surge appearance and evolution in the Si IV lines or, in fact, in many other transition region lines has not been studied. In this paper we analyze a simultaneous episode of an Hα\alpha surge and a Si IV burst that occurred on 2016 September 03 in active region AR12585. To that end, we use coordinated observations from the Interface Region Imaging Spectrograph (IRIS) and the Swedish 1-m Solar Telescope (SST). For the first time, we report emission of Si IV within the surge, finding profiles that are brighter and broader than the average. Furthermore, the brightest Si IV patches within the domain of the surge are located mainly near its footpoints. To understand the relation between the surges and the emission in transition region lines like Si IV, we have carried out 2.5D radiative MHD (RMHD) experiments of magnetic flux emergence episodes using the Bifrost code and including the non-equilibrium ionization of silicon. Through spectral synthesis we explain several features of the observations. We show that the presence of Si IV emission patches within the surge, their location near the surge footpoints and various observed spectral features are a natural consequence of the emergence of magnetized plasma from the interior to the atmosphere and the ensuing reconnection processes.Comment: 13 pages, 8 figures. The Astrophysical Journal (Accepted

    Media sharing websites and the US financial markets

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    Recently, one of the main issues of concern within the world wide web is the understanding of web 2.0 mass collaboration systems. These systems have emerged in recent years and gained enormous popularity. It must, however, be pointed out, that the potential and practical application of web 2.0 are still not well understood and deserve academic attention. In this paper we investigate the online media sharing collaborative community and its applications for uses in stock market analysis and prediction. Specifically, we look at Youtube.com, one of the most popular social media sharing websites. The association with stock market behaviour and usage patterns are investigated. This work became of more interest and significance with the recent credit crunch crisis. The data under investigation is novel, and to our knowledge, this paper reports the first investigation of its kind to the use of collaborative media sharing website for stock market analysis. We find significant association between video meta-data and textual data using a content driven sentiment text mining approach. The results are very encouraging and importantly highlight efficient information transfer to online media sharing communities as there seems to be predictive value in youtube data

    Beta-blocker therapy is not associated with mortality after intracerebral hemorrhage

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    BackgroundBeta-blocker therapy has been suggested to have neuroprotective properties in the setting of acute stroke; however, the evidence is weak and contradictory. We aimed to examine the effects of pre-admission therapy with beta-blockers (BB) on the mortality following spontaneous intracerebral hemorrhage (ICH). MethodsRetrospective analysis of the Helsinki ICH Study database. ResultsA total of 1013 patients with ICH were included in the analysis. Patients taking BB were significantly older, had a higher premorbid mRS score, had more DNR orders, and more comorbidities as atrial fibrillation, hypertension, diabetes mellitus, ischemic heart disease, and heart failure. After adjustment for age, pre-existing comorbidities, and prior use of antithrombotic and antihypertensive medications, no differences in in-hospital mortality (OR 1.1, 95% CI 0.8-1.7), 12-month mortality (OR 1.3, 95% CI 0.9-1.9), and 3-month mortality (OR 1.2, 95% CI 0.8-1.7) emerged. ConclusionPre-admission use of BB was not associated with mortality after ICH.Peer reviewe

    Linear response within the projection-based renormalization method: Many-body corrections beyond the random phase approximation

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    The explicit evaluation of linear response coefficients for interacting many-particle systems still poses a considerable challenge to theoreticians. In this work we use a novel many-particle renormalization technique, the so-called projector-based renormalization method, to show how such coefficients can systematically be evaluated. To demonstrate the prospects and power of our approach we consider the dynamical wave-vector dependent spin susceptibility of the two-dimensional Hubbard model and also determine the subsequent magnetic phase diagram close to half-filling. We show that the superior treatment of (Coulomb) correlation and fluctuation effects within the projector-based renormalization method significantly improves the standard random phase approximation results.Comment: 17 pages, 7 figures, revised versio
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