Image Quality Assessment Using Edge Correlation

In literature, oriented filters are used for low-level vision tasks. In this paper, we propose use of steerable Gaussian filter in image quality assessment. Human visual system is more sensitive to multidirectional edges present in natural images. The most degradation in image quality is caused due to its edges. In this work, an edge based metric termed as steerable Gaussian filtering (SGF) quality index is proposed as objective measure for image quality assessment. The performance of the proposed technique is evaluated over multiple databases. The experimental result shows that proposed method is more reliable and outperform the conventional image quality assessment method

Higher Derivative Corrections to Non-supersymmetric Extremal Black Holes in N=2 Supergravity

Using the entropy function formalism we compute the entropy of extremal supersymmetric and non-supersymmetric black holes in N=2 supergravity theories in four dimensions with higher derivative corrections. For supersymmetric black holes our results agree with all previous analysis. However in some examples where the four dimensional theory is expected to arise from the dimensional reduction of a five dimensional theory, there is an apparent disagreement between our results for non-supersymmetric black holes and those obtained by using the five dimensional description. This indicates that for these theories supersymmetrization of the curvature squared term in four dimension does not produce all the terms which would come from the dimensional reduction of a five dimensional action with curvature squared terms.Comment: LaTeX file, 29 pages; v2: minor change

Effects of different orientations of winglet arrays on the performance of plate-fin heat exchangers

Numerical investigations pertaining to heat transfer enhancement of a plate-fin heat exchanger using two rows of winglet type vortex generators (VG) have been performed in this work. Five different strategic placements of the VG, namely, common-flow up in series (CFU CFU), common-flow down in series (CFD–CFD), combined (CFD–CFU), inline rows of winglet (IRW) and staggered rows of winglet (SRW), were considered. Performance parameters in terms of Nusselt number and quality factor were evaluated from the velocity and temperature data obtained from the solutions of full Navier–Stokes and energy equations. The Reynolds number was varied in the range of 250–1580. Results show that amongst the different types of arrangements of the VG, performance of CFU–CFU configuration is best in terms of heat transfer as well as quality factor

Estimating the spectral measure of an extreme value distribution

Let (X1, Y1), (X2, Y2),..., (Xn, Yn) be a random sample from a bivariate distribution function F which is in the domain of attraction of a bivariate extreme value distribution function G. This G is characterized by the extreme value indices and its spectral measure or angular measure. The extreme value indices determine both the marginals and the spectral measure determines the dependence structure. In this paper, we construct an empirical measure, based on the sample, which is a consistent estimator of the spectral measure. We also show for positive extreme value indices the asymptotic normality of the estimator under a suitable 2nd order strengthening of the bivariate domain of attraction condition.Dependence structure Empirical process Estimation Functional central limit theorem Multivariate extremes Vapnik-Cervonenkis (VC) class

Stable Tricyclic Antitubercular Ozonides Derived from Artemisinin

New, highly stable tricyclic antitubercular ozonides <b>9</b> and <b>10</b> derived from artemisinin are reported in 39 and 9% yields, respectively. The ozonide groups of <b>9</b> and <b>10</b> were found to be stable under strong basic and acidic conditions. The absolute configuration of ozonides <b>9</b> was confirmed by X-ray crystallography. Ozonide <b>10</b> shows promising antitubercular activity against <i>M. tuberculosis</i> H₃₇Ra and <i>M. tuberculosis</i> H₃₇Rv with MIC values of 0.39 and 3.12 μg/mL, respectively