731 research outputs found

    On the Differential Geometry of GLq(11)GL_q(1| 1)

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    The differential calculus on the quantum supergroup GLq(11)_q(1| 1) was introduced by Schmidke {\it et al}. (1990 {\it Z. Phys. C} {\bf 48} 249). We construct a differential calculus on the quantum supergroup GLq(11)_q(1| 1) in a different way and we obtain its quantum superalgebra. The main structures are derived without an R-matrix. It is seen that the found results can be written with help of a matrix R^\hat{R}Comment: 14 page

    Application of Neural Networks (NNs) for Fabric Defect Classification

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    The defect classification is as important as the defect detection in fabric inspection process. The detected defects are classified according to their types and recorded with their names during manual fabric inspection process. The material is selected as “undyed raw denim” fabric in this study. Four commonly occurring defect types, hole, warp lacking, weft lacking and soiled yarn, were classified by using artificial neural network (ANN) method. The defects were automatically classified according to their texture features. Texture feature extraction algorithm was developed to acquire the required values from the defective fabric samples. The texture features were assessed as the network input values and the defect classification is obtained as the output. The defective images were classified with an average accuracy rate of 96.3%. As the hole defect was recognized with 100% accuracy rate, the others were recognized with a rate of 95%

    Fabric defect detection using linear filtering and morphological operations

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    An algorithm with linear filters and morphological operations has been proposed for automatic fabric defect detection. The algorithm is applied off-line and real-time to denim fabric samples for five types of defects. All defect types have been detected successfully and the defective regions are labeled. The defective fabric samples are then classified by using feed forward neural network method. Both defect detection and classification application performances are evaluated statistically. Defect detection performance of real time and off-line applications are obtained as 88% and 83% respectively. The defective images are classified with an average accuracy rate of 96.3%

    Critical Dialog: Response to Rachel M. Gillum’s Review of The Politics of the Headscarf in the United States

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    A Critical Dialog between the reviewer, Rachel M. Gillum, of The Politics of the Headscarf in the United States and the authors, Bozena C. Welborne, Aubrey L. Westfall, Özge Çelik Russell, and Sarah A. Tobin. Ithaca: Cornell University Press, 2018. 264p

    Children's Foreign Language Anxiety Scale: Preliminary Tests of Reliability and Validity

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    Foreign language anxiety (FLA), which constitutes a serious problem in the foreign language learning process, has been mainly seen as a research issue regarding adult language learners, while it has been overlooked in children. This is because there is a lack of appropriate tools to measure FLA among children, whereas there are many studies on the scales that aim to measure anxiety levels among adult learners. Thus, the current study aims to conduct the preliminary tests of reliability and validity of the Children's Foreign Language Anxiety Scale (CFLAS) and to report on the pilot examination of reliability, validity and factor structure of the CFLAS. The findings of the pilot study show that CFLAS is a reliable and valid tool to measure FLA levels among children who learn English as a foreign language (EFL) within the age range of 7-12 in a Turkish EFL context

    The Armenian and NW Anatolian ophiolites: new insights for the closure of the Tethys domain and obduction onto the South Armenian Block and Anatolian-Tauride Platform before collision through dynamic modeling

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    International audienceIn the Lesser Caucasus three main domains are distinguished from SW to NE: (1) the South Armenian Block (SAB), a Gondwanian-derived continental terrane; (2) scattered outcrops of ophiolites coming up against the Sevan-Akera suture zone; and (3) the Eurasian plate. The Armenian ophiolites represent remnants of an oceanic domain which disappeared during Eurasia-Arabia convergence. Previous works using geochemical whole-rock analyses, 40Ar/39Ar and paleontological dating have shown that the ophiolite outcrops throughout this area were emplaced during the Late Cretaceous as one non-metamorphic preserved ophiolitic nappe of back-arc origin that formed during Middle to Late Jurassic. From these works, tectonic reconstructions include two clearly identified subductions, one related to the Neotethys subduction beneath the Eurasian margin and another to intra-oceanic subduction responsible for the opening of the back-arc basin corresponding to the ophiolites of the Lesser Caucasus. The analysis of the two stages of metamorphism of the garnet amphibolites of the ophiolite obduction sole at Amasia (M1: HT-LP peak of P = 6-7 kbar and T > 630°C; M2; MP-MT peak at P = 8-10 kbar and T = 600°C) has allowed us to deduce the onset of subduction of the SAB at 90 Ma for this locality, whichage coincides with other paleontological ages at the obduction front. A preliminary paleomagnetic survey has also brought quantification to the amount of oceanic domain which disappeared by subduction between the SAB and Eurasia before collision. We propose a dynamic finite element model using ADELI to test the incidence of parameters such as the density of the different domains (or the interval between the densities), closing speed (or speeds if sporadic), the importance and interactions of mantle discontinuities with the subducting lithosphere and set a lithospheric model. Our field observations and analyses are used to validate combinations of factors. The aim is to better qualify the predominant factors and quantify the conditions leading to the onset of obduction, the paradox of dense oceanic lithosphere emplaced on top of a continental domain, after subduction and prior to collision. The results of this modeling are also compared to new observations of the assumed eastward extension of this ophiolitic nappe in NW Anatolia. Analyses of the Refahiye ophiolites show similar geochemical signatures as the Armenian ophiolites, due to a similar setting of formation (back-arc). The impact of the obduction of such a vast oceanic domain is not to be taken for granted when considering the following collision stage

    Properties of 42 Solar-type Kepler Targets from the Asteroseismic Modeling Portal

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    Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only a few such data sets were available for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds of new targets. This rapid expansion in observational capacity has been accompanied by a shift in analysis and modeling strategies to yield uniform sets of derived stellar properties more quickly and easily. We use previously published asteroseismic and spectroscopic data sets to provide a uniform analysis of 42 solar-type Kepler targets from the Asteroseismic Modeling Portal (AMP). We find that fitting the individual frequencies typically doubles the precision of the asteroseismic radius, mass and age compared to grid-based modeling of the global oscillation properties, and improves the precision of the radius and mass by about a factor of three over empirical scaling relations. We demonstrate the utility of the derived properties with several applications.Comment: 12 emulateapj pages, 9 figures, 1 online-only extended figure, 1 table, ApJS accepted (typo corrected in Eq.8

    The Legacy of Rolf Hagedorn: Statistical Bootstrap and Ultimate Temperature

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    In the latter half of the last century, it became evident that there exists an ever increasing number of different states of the so-called elementary particles. The usual reductionist approach to this problem was to search for a simpler infrastructure, culminating in the formulation of the quark model and quantum chromodynamics. In a complementary, completely novel approach, Hagedorn suggested that the mass distribution of the produced particles follows a self-similar composition pattern, predicting an unbounded number of states of increasing mass. He then concluded that such a growth would lead to a limiting temperature for strongly interacting matter. We discuss the conceptual basis for this approach, its relation to critical behavior, and its subsequent applications in different areas of high energy physics.Comment: 25 pages, 5 figures; to appear in R. Hagedorn and J. Rafelski (Ed.), "Melting Hadrons, Boiling Quarks", Springer Verlag 201

    Incorporation of a global perspective into data-driven analysis of maritime collision accident risk

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    Ship collision accidents are one of the most frequent accident types in global maritime transportation. Nevertheless, conducting an in-depth analysis of collision prevention poses a formidable challenge due to the constraints of limited Risk Influential Factors (RIFs) and available datasets. This paper aims to incorporate a global perspective into a new data-driven risk model, scrutinize the root causes of collision accidents, and advance measures for their mitigation. Additionally, it seeks to analyze the spatial distribution and conduct a comprehensive comparative study on collision characteristics for both pre- and post-COVID-19, utilizing the real accident dataset collected from two reputable organizations: Global Integrated Shipping Information System (GISIS) and Lloyd's Register Fairplay (LRF). The research findings and implications encompass several crucial aspects: 1) the constructed model demonstrates its reliability and accuracy in predicting collision accidents, as evident from its prediction performance and various scenario analysis; 2) the most hazardous voyage segment for collision accidents is identified to provide valuable guidance to different stakeholders; and 3) the hierarchical significance of various ship types in the context of collision accident is highlighted regarding the most probable scenario for collision occurrences; 4) During the pandemic, the rise in collision probabilities, particularly involving older vessels and bulk carriers, implies heightened operational challenges or maintenance issues for these ship types; (5) The prominence of favorable and adverse sea conditions in collision reports underscores the significant influence of weather on accidents during the pandemic. These findings and implications help enhance safety protocols, ultimately reducing the frequency of collision accidents in the global maritime domain
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