131,257 research outputs found
The Observance and the Confrontation with Early Protestantism
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Exceptional flux compactifications
Full text linkWe consider type II (non-)geometric flux backgrounds in the absence of brane sources, and construct their explicit embedding into maximal gauged D = 4 supergravity. This enables one to investigate the critical points, mass spectra and gauge groups of such backgrounds. We focus on a class of type IIA geometric vacua and find a novel, nonsupersymmetric and stable AdS vacuum in maximal supergravity with a non-semisimple gauge group. Our construction relies on a non-trivial mapping between SL(2) × SO(6, 6) fluxes, SU(8) mass spectra and gaugings of E7(7) subgroups.
Geometry of four-dimensional Killing spinors
Full text linkThe supersymmetric solutions of N = 2, D = 4 minimal ungauged and gauged supergravity are classified according to the fraction of preserved supersymmetry using spinorial geometry techniques. Subject to a reasonable assumption in the 1/2-supersymmetric time-like case of the gauged theory, we derive the complete form of all supersymmetric solutions. This includes a number of new 1/4- and 1/2-supersymmetric possibilities, like gravitational waves on bubbles of nothing in AdS4.
Duality orbits of non-geometric fluxes
Full text linkCompactifications in duality covariant constructions such as generalised geometry and double field theory have proven to be suitable frameworks to reproduce gauged supergravities containing non-geometric fluxes. However, it is a priori unclear whether these approaches only provide a reformulation of old results, or also contain new physics. To address this question, we classify the T- and U-duality orbits of gaugings of (half-)maximal supergravities in dimensions seven and higher. It turns out that all orbits have a geometric supergravity origin in the maximal case, while there are non-geometric orbits in the half-maximal case. We show how the latter are obtained from compactifications of double field theory.
Imaging through a scanner, darkly: spectral imaging for sentinel lymph node biopsies
No full textBreast cancer is the single most prevalent form of cancer in the UK today, accounting for around 16% of all diagnoses, and around 31% of diagnoses in women. The survival rates are good. However, the prognosis is heavily dependent on the stage to which the cancer has progressed at diagnosis. In order to help accurately determine this stage, the sentinel lymph node of patients undergoing tumour resection surgery is removed and examined cytologically for the presence of cancerous cells. This examination of the lymph node is currently the rate-limiting step in the operation as a whole. There is evidence in the literature to suggest that cancerous tissue has a measurably different infrared spectrum from healthy tissue owing to chemical and morphological differences in the tissue. There is further evidence to suggest that in the visible and near infrared region, the spectra of healthy lymph node tissue is different from that of cancerous tissue. This thesis details a project, performed in collaboration with a surgical team at St Mary's Hospital, Newport, Isle of Wight, to analyse spectral images taken in the visible and near infrared, of biopsied lymph node tissue. In the course of the project, an unsupervised classification technique, based on an extension to the well established 'spectral angle', was developed to analyse the spectral images.Psoriasis affects 2-3% of the UK population causing itchy and/or painful plaques on the skin. One of the main treatments for psoriasis is UV phototherapy, exposure to which is a risk factor for burning and the development of cancers. This thesis details an investigation into the possibility of developing a targeted UV phototherapy system based on spectral imaging to delineate the plaques and a proposed new UV laser for treatment
MeSH term explosion and author rank improve expert recommendations
Full text linkInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Regression testing Ajax applications: Coping with dynamism
No full textNote: This paper is a pre-print of: Danny Roest, Ali Mesbah and Arie van Deursen. Regression Testing AJAX Applications: Coping with Dynamism. In Proceedings of the 3rd International Conference on Software Testing, Verification and Validation (ICST’10), Paris, France. IEEE Computer Society, 2010. There is a growing trend to move desktop applications towards the web using advances made in web technologies such as AJAX. One common way to provide assurance about the correctness of such complex and evolving systems is through regression testing. Regression testing classical web applications has already been a notoriously daunting task because of the dynamism in web interfaces. AJAX applications pose an even greater challenge since the test case fragility degree is higher due to extensive run-time manipulation of the DOM tree and asynchronous client/server interactions. In this paper, we propose a technique, in which we automatically generate test cases and apply pipelined oracle comparators along with generated DOM templates, to deal with dynamic non-deterministic behavior in AJAX user interfaces. Our approach, implemented in CRAWLJAX, is open source and provides a set of generic oracle comparators, template generators, and visualizations of test failure output. We describe two case studies evaluating the effectiveness, scalability, and required manual effort of the approach.Software Computer TechnologyElectrical Engineering, Mathematics and Computer Scienc
Invariant-Based Automatic Testing of Modern Web Applications
No full textAJAX-based Web 2.0 applications rely on stateful asynchronous client/server communication, and client-side run-time manipulation of the DOM tree. This not only makes them fundamentally different from traditional web applications, but also more error-prone and harder to test. We propose a method for testing AJAX applications automatically, based on a crawler to infer a state-flow graph for all (client-side) user interface states. We identify AJAX-specific faults that can occur in such states (related to e.g., DOM validity, error messages, discoverability, back-button compatibility) as well as DOM-tree invariants that can serve as oracles to detect such faults. Our approach, called ATUSA, is implemented in a tool offering generic invariant checking components, a plugin-mechanism to add application-specific state validators, and generation of a test suite covering the paths obtained during crawling. We describe three case studies, consisting of six subjects, evaluating the type of invariants that can be obtained for AJAX applications as well as the fault revealing capabilities, scalability, required manual effort, and level of automation of our testing approach. This paper is a pre-print of: Ali Mesbah, Arie van Deursen and Danny Roest. Invariant-Based Automatic Testing of Modern Web Applictions. IEEE Transactions on Software Engineering, 2011.Software TechnologyElectrical Engineering, Mathematics and Computer Scienc
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