4,684 research outputs found

    Random template banks and relaxed lattice coverings

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    Template-based searches for gravitational waves are often limited by the computational cost associated with searching large parameter spaces. The study of efficient template banks, in the sense of using the smallest number of templates, is therefore of great practical interest. The "traditional" approach to template-bank construction requires every point in parameter space to be covered by at least one template, which rapidly becomes inefficient at higher dimensions. Here we study an alternative approach, where any point in parameter space is covered only with a given probability < 1. We find that by giving up complete coverage in this way, large reductions in the number of templates are possible, especially at higher dimensions. The prime examples studied here are "random template banks", in which templates are placed randomly with uniform probability over the parameter space. In addition to its obvious simplicity, this method turns out to be surprisingly efficient. We analyze the statistical properties of such random template banks, and compare their efficiency to traditional lattice coverings. We further study "relaxed" lattice coverings (using Zn and An* lattices), which similarly cover any signal location only with probability < 1. The relaxed An* lattice is found to yield the most efficient template banks at low dimensions (n < 10), while random template banks increasingly outperform any other method at higher dimensions.Comment: 13 pages, 10 figures, submitted to PR

    Analysis of food supplement with unusual raspberry ketone content

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    In recent years food supplement market increased constantly, including slimming products and against obesity. The case of rasberry ketone (RK) is here reported. HPTLC and HPLC-DAD analyses on a marketed product containing raspberry juice evidenced an abnormal quantity of RK, not in accordance with the juice natural content. The reported data confirm the need of adequate controls on marketed food supplements and the necessity of a complete adherence between labelling and real constitution of the product. Practical Applications: Determining the natural origin and assuring the consumers' safety for raspberry-based food supplement

    Breast metastasis and lung large-cell neuroendocrine carcinoma: first clinical observation

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    The lung Large-cell neuroendocrine carcinoma (LCNEC) is a very rare aggressive neuroendocrine tumor with a high propensy to metastasize and very poor prognosis. We report an atypical presentation of lung large-cell neuroendocrine carcinoma was diagnosed from a metastatic nodule on the breast. Our patient is a 59 years-old woman that presented in March 2014 non productive cough. A CT scan showed multiple brain, lung, adrenal gland and liver secondary lesions; moreover, it revealed a breast right nodule near the chest measuring 1.8 cm. The breast nodule and a lung lesions were biopsied and their histology and molecular diagnosis were LCNEC of the lung. To our knowledge, this is the first documented case of breast metastasis from LCNEC of the lung. Furthermore, breast metastasis from extramammary malignancy is uncommon and its diagnosis is difficult but important for proper management and prediction of prognosis. Therefore, a careful clinical history with a thorough clinical examination is needed to make the correct diagnosis. Moreover, metastasis to the breast should be considered in any patient with a known primary malignant tumor history who presents with a breast lump. Anyhow, pathological examination should be performed to differentiate the primary breast cancer from metastatic tumor. Therefore, an accurate diagnosis of breast metastases may not only avoid unnecessary breast resection, more importantly it is crucial to determine an appropriate and systemic treatment

    Data analysis of gravitational-wave signals from spinning neutron stars. V. A narrow-band all-sky search

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    We present theory and algorithms to perform an all-sky coherent search for periodic signals of gravitational waves in narrow-band data of a detector. Our search is based on a statistic, commonly called the F\mathcal{F}-statistic, derived from the maximum-likelihood principle in Paper I of this series. We briefly review the response of a ground-based detector to the gravitational-wave signal from a rotating neuron star and the derivation of the F\mathcal{F}-statistic. We present several algorithms to calculate efficiently this statistic. In particular our algorithms are such that one can take advantage of the speed of fast Fourier transform (FFT) in calculation of the F\mathcal{F}-statistic. We construct a grid in the parameter space such that the nodes of the grid coincide with the Fourier frequencies. We present interpolation methods that approximately convert the two integrals in the F\mathcal{F}-statistic into Fourier transforms so that the FFT algorithm can be applied in their evaluation. We have implemented our methods and algorithms into computer codes and we present results of the Monte Carlo simulations performed to test these codes.Comment: REVTeX, 20 pages, 8 figure

    Accessibility instruments for planning practice: A review of European experiences

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    Although a large body of literature has been produced on the theoretical definitions and measurements of accessibility, the extent to which such indicators are used in planning practice is less clear. This research explores the gap between theory and application by seeking to understand what the new wave of accessibility instruments (AIs) prepared for spatial and transport planning practice purports to offer the users of AIs. Starting from the question of how urban and transport planners are designing AIs, the article analyzes and describes the AIs developed over the last decade (mainly in Europe), offering a structured overview and a clear categorization of how accessibility measures can be applied. The paper identifies AI characteristics, and considers their usability, based on AI developer perceptions

    BIM-ORIENTED ALGORITHMIC RECONSTRUCTION OF BUILDING COMPONENTS FOR EXISTING HERITAGE

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    Abstract. This study is part of a more complex research aimed at establishing guidelines to simplify the digitalization process used to manage existing building heritage. Working in a BIM environment, this paper will present two different algorithms: a modelling algorithm, a data analysis algorithm, and relative applications in the digitalization of a contemporary building. All the archival data required for the digitalization process was collected and those in two-dimensional digital vector format have aroused particular interest because they enabled initiation of the reconstruction process of the BIM model. One of the two algorithms allowed us to identify recurrent elements in a CAD drawing, based on geometric 2D primitives. The final outcome of the first phase involves quadrilateral or circular surfaces and can be viewed in algorithmic environment. The next phase involves applying a unique coloured sign to the identified sections and then export them all in a BIM software. This tool produced unexpected positive results: the presence of a small coloured grid emphasized the discrepancies created between the two-dimensional drawings and the vertical elements. We were thus able to identify the objects with these inconsistencies: they were verified using accurate surveys and then corrected.</p

    Accessibility Instruments In Planning Practice: Bridging The Implementation Gap

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    Accessibility concepts are increasingly acknowledged as fundamental to understand cities and urban regions. Accordingly, accessibility instruments have been recognised as valuable support tools for land-use and transport planning. However, despite the relatively large number of instruments available in the literature, they are not widely used in planning practice. This paper aims to explore why accessibility instruments are not widely used in planning practice. To this end, we focus our research on perceived user-friendliness and usefulness of accessibility instruments. First, we surveyed some instrument developers, providing an overview of the characteristics of accessibility instruments available and on developers’ perceptions of their user-friendliness in planning practice. Second, we brought together developers and planning practitioners in some local workshops across Europe and Australia, where participants were asked to use insights provided by accessibility instruments for the development of planning strategies. We found that most practitioners are convinced of the usefulness of accessibility instruments in planning practice, as they generate new and relevant insights for planners. Findings suggest that not only user-friendliness problems but mainly organisational barriers and lack of institutionalisation of accessibility instruments, are the main causes of the implementation gap. Thus user-friendliness improvement may provide limited contributions to the successful implementation of accessibility concepts in planning practice. In fact, there seems to be more to gain from the active and continued engagement of instrument developers with planning practitioners and the institutionalisation of accessibility planning

    Optimal directed searches for continuous gravitational waves

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    Wide parameter space searches for long lived continuous gravitational wave signals are computationally limited. It is therefore critically important that available computational resources are used rationally. In this paper we consider directed searches, i.e. targets for which the sky position is known accurately but the frequency and spindown parameters are completely unknown. Given a list of such potential astrophysical targets, we therefore need to prioritize. On which target(s) should we spend scarce computing resources? What parameter space region in frequency and spindown should we search? Finally, what is the optimal search set-up that we should use? In this paper we present a general framework that allows to solve all three of these problems. This framework is based on maximizing the probability of making a detection subject to a constraint on the maximum available computational cost. We illustrate the method for a simplified problem

    Exact Results for Thermodynamics of the Classical Field Theories: Sine- and Sinh-Gordon Models

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    Using the recently obtained exact results for the expectation values of operators in the sine- and sinh-Gordon models [A. B. Zamolodchikov and S. Lukyanov, Nucl. Phys. B{\bf 493}, 571 (1997), V. Fateev, S. Lukyanov, A. B. Zamolodchikov and Al. B. Zamolodchikov, Phys. Lett. B{\bf 406}, 83 (1997)] we calculate the specific heat of the corresponding two dimensional Euclidean (classical) models. We show that the temperature dependence of the specific heat of the sine-Gordon model, in the commensurate phase, has a maximum well below the Kosterlitz-Thouless transition and that the sinh-Gordon model is thermodynamically unstable in the strong coupling regime. We give also the temperature dependence of the specific heat in the incommensurate phase of the sine-Gordon model.Comment: 14 pages, including 6 figures; updated version; submitted to Phys. Rev.
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