39,563 research outputs found

    Phase Diagram of Bilayer Composite Fermion States

    Full text link
    We construct a class of composite fermion states for bilayer electron systems in a strong transverse magnetic field, and determine quantitatively the phase diagram as a function of the layer separation, layer thickness, and electron density. We find, in general, that there are several transitions, and that the incompressible phases are separated by compressible ones. The paired states of composite fermions, described by Pfaffian wave functions, are also considered.Comment: 12 pages, 7 figure

    Eigenvalue spectrum for single particle in a spheroidal cavity: A Semiclassical approach

    Full text link
    Following the semiclassical formalism of Strutinsky et al., we have obtained the complete eigenvalue spectrum for a particle enclosed in an infinitely high spheroidal cavity. Our spheroidal trace formula also reproduces the results of a spherical billiard in the limit η1.0\eta\to1.0. Inclusion of repetition of each family of the orbits with reference to the largest one significantly improves the eigenvalues of sphere and an exact comparison with the quantum mechanical results is observed upto the second decimal place for kR07kR_{0}\geq{7}. The contributions of the equatorial, the planar (in the axis of symmetry plane) and the non-planar(3-Dimensional) orbits are obtained from the same trace formula by using the appropriate conditions. The resulting eigenvalues compare very well with the quantum mechanical eigenvalues at normal deformation. It is interesting that the partial sum of equatorial orbits leads to eigenvalues with maximum angular momentum projection, while the summing of planar orbits leads to eigenvalues with Lz=0L_z=0 except for L=1. The remaining quantum mechanical eigenvalues are observed to arise from the 3-dimensional(3D) orbits. Very few spurious eigenvalues arise in these partial sums. This result establishes the important role of 3D orbits even at normal deformations.Comment: 17 pages, 7 ps figure

    Unconstrained Scene Text and Video Text Recognition for Arabic Script

    Full text link
    Building robust recognizers for Arabic has always been challenging. We demonstrate the effectiveness of an end-to-end trainable CNN-RNN hybrid architecture in recognizing Arabic text in videos and natural scenes. We outperform previous state-of-the-art on two publicly available video text datasets - ALIF and ACTIV. For the scene text recognition task, we introduce a new Arabic scene text dataset and establish baseline results. For scripts like Arabic, a major challenge in developing robust recognizers is the lack of large quantity of annotated data. We overcome this by synthesising millions of Arabic text images from a large vocabulary of Arabic words and phrases. Our implementation is built on top of the model introduced here [37] which is proven quite effective for English scene text recognition. The model follows a segmentation-free, sequence to sequence transcription approach. The network transcribes a sequence of convolutional features from the input image to a sequence of target labels. This does away with the need for segmenting input image into constituent characters/glyphs, which is often difficult for Arabic script. Further, the ability of RNNs to model contextual dependencies yields superior recognition results.Comment: 5 page

    Radii of Starlikeness Associated with the Lemniscate of Bernoulli and the Left-Half Plane

    Full text link
    A normalized analytic function f defined on the open unit disk in the complex plane is in the class SL if zf'(z)/f(z) lies in the region bounded by the right-half of the lemniscate of Bernoulli given by |w^2 - 1| < 1. In the present investigation, the SL-radii for certain well-known classes of functions are obtained. Radius problems associated with the left-half plane are also investigated for these classe

    Diverse Yet Efficient Retrieval using Hash Functions

    Full text link
    Typical retrieval systems have three requirements: a) Accurate retrieval i.e., the method should have high precision, b) Diverse retrieval, i.e., the obtained set of points should be diverse, c) Retrieval time should be small. However, most of the existing methods address only one or two of the above mentioned requirements. In this work, we present a method based on randomized locality sensitive hashing which tries to address all of the above requirements simultaneously. While earlier hashing approaches considered approximate retrieval to be acceptable only for the sake of efficiency, we argue that one can further exploit approximate retrieval to provide impressive trade-offs between accuracy and diversity. We extend our method to the problem of multi-label prediction, where the goal is to output a diverse and accurate set of labels for a given document in real-time. Moreover, we introduce a new notion to simultaneously evaluate a method's performance for both the precision and diversity measures. Finally, we present empirical results on several different retrieval tasks and show that our method retrieves diverse and accurate images/labels while ensuring 100x100x-speed-up over the existing diverse retrieval approaches.Comment: 10 page

    Electromagnetic Form Factors and the Localization of Quark Orbital Angular Momentum in the Proton

    Full text link
    A new picture is given of generalized parton distributions probed in experiments in which the probe scale Q2Q^{2} and the momentum transfer \DD^{2} are well separated. Application of this picture to the Q2Q^{2} dependence of the form factors F1,F2F_{1}, F_{2} shows that gauge invariant quark orbital angular momentum can be measured and indeed {\it localized} in the transverse profile of the proton. A previous prediction that Q2F2(Q2)/F1(Q2)const.\sqrt{Q^{2}}F_{2}(Q^{2})/F_{1}(Q^{2}) \sim const. is generalized to GPD language. This prediction appears to have been confirmed by recent CEBAF data.Comment: 6 pages, 1 figure. To appear in DIS 2001, 9th International Workshop on Deep Inelastic Scattering, Bologna, 27 April - 1 May, 200

    Understanding the role of social media in political corporate branding research in the context of Indian politics

    Get PDF
    This paper seeks to explore how political actors within the Bharatiya Janata Party (BJP) use social media in their communication campaigns and how these social media platforms are understood by citizens following the 2014 Indian General Election. This research attempts to address the limited understanding of social media in the context of politics (Barnard and Kreiss, 2013; Burton and Shea, 2010; Cogburn and Espinoza-Vasquez 2011; Ganz, 2009; Gulati and Williams, 2007; Kumar 2009; Owen and Davis 2008). Furthermore, the limited research on political branding and social media has predominantly focused a western context negating eastern perspectives including the republic of India. This study will use the adapted Kapferer’s (2008) brand identity prism developed by Pich et al. (2014) to a political setting. This framework will ground the study and offer the opportunity to examine the role of social media from an internal brand identity and external brand image perspective. The findings will have implications not only for political parties but also for politicians, candidates and other parties interested in social media. This study will offer organisations a mechanism that will allow them understand how their social media is projected and understood and allow them to investigate whether their projected brand identity is coherent with the understood external brand image

    Adaptation dynamics of the quasispecies model

    Full text link
    We study the adaptation dynamics of an initially maladapted population evolving via the elementary processes of mutation and selection. The evolution occurs on rugged fitness landscapes which are defined on the multi-dimensional genotypic space and have many local peaks separated by low fitness valleys. We mainly focus on the Eigen's model that describes the deterministic dynamics of an infinite number of self-replicating molecules. In the stationary state, for small mutation rates such a population forms a {\it quasispecies} which consists of the fittest genotype and its closely related mutants. The quasispecies dynamics on rugged fitness landscape follow a punctuated (or step-like) pattern in which a population jumps from a low fitness peak to a higher one, stays there for a considerable time before shifting the peak again and eventually reaches the global maximum of the fitness landscape. We calculate exactly several properties of this dynamical process within a simplified version of the quasispecies model.Comment: Proceedings of Statphys conference at IIT Guwahati, to be published in Praman
    corecore