29,496 research outputs found

    Quasi-Degenerate Neutrino Masses with Normal and Inverted Hierarchy

    Full text link
    The effects of CP-phases on the three absolute quasi-degenerate Majorana neutrino (QDN) masses are stud-ied with neutrino mass matrices obeying {\mu} - {\tau} symmetry for normal as well as inverted hierarchical mass patterns. We have made further investigations on 1) the prediction of solar mixing angle which lies below tri-bimaximal mixing value in consistent with neutrino oscillation observational data, 2) the prediction on absolute neutrino mass parameter (mee) in 0{\nu}{\beta}{\beta} decay, and 3) cosmological bound on the sum of the three absolute neutrino masses. The numerical analysis is carried out through the parameterization of neu- trino mass matrices using only two unknown parameters ({\epsilon}, {\eta}) within {\mu} - {\tau} symmetry. The results show the validity of QDN mass models in both normal and inverted hierarchical patterns. These models are far from discrimination and hence not yet ruled out. The results presented in this article are new and have subtle ef- fects in the discrimination of neutrino mass models.Comment: 8 pages, gave a contributory Talk at Ist IAS-CERN Singpore, Jan 2012; Journal of Modern Physics (JMP), Vol 2. No.11, November 2011 US

    Non-magnetic impurities in two- and three- dimensional Heisenberg antiferromagnets

    Full text link
    In this paper we study in a large-S expansion effects of substituting spins by non-magnetic impurities in two- and three- dimensional Heisenberg antiferromagnets in a weak magnetic field. In particular, we demonstrate a novel mechanism where magnetic moments are induced around non-magnetic impurities when magnetic field is present. As a result, Curie-type behaviour in magnetic susceptibility can be observed well below the Neel temperature, in agreement with what is being observed in La2Cu1xZnxO4La_2Cu_{1-x}Zn_{x}O_4 and Sr(Cu1xZnx)2O3Sr(Cu_{1-x}Zn_x)_2O_3 compounds.Comment: Latex fil

    Precedence-type Test based on Progressively Censored Samples

    Get PDF
    In this paper, we introduce precedence-type tests for testing the hypothesis that two distribution functions are equal, which is an extension of the precedence life-test rst proposed by Nelson (1963), when the two samples are progressively Type-II censored. The null distributions of the test statistics are derived. Critical values for some combination of sample sizes and censoring schemes for the proposed tests are presented. Then, we present the exact power functions under the Lehmann alternative, and compare the exact power as well as simulated power (under location-shift) of the proposed precedence test based on nonparametric estimates of CDF with other precedence-type tests. We then examine the power properties of the proposed test procedures through Monte Carlo simulations. Two examples are presented to illustrate all the test procedures discussed here. Finally, we make some concluding remarks.Precedence test; Product-limit estimator; Type-II progressive censoring; Life-testing; level of significance; power; Lehmann alternative; Monte Carlo simulations

    Enhancing academic performance: The impact of active learning in mathematical economics

    Full text link
    This paper explores the impact of active learning in mathematical economics on students' academic performance (assessment scores). An experimental design involving foundation students enrolled in the arts and business and management foundation programmes in a British university located in Malaysia was adopted. The control group underwent the more traditional lecture method with the students taking on a passive role of listening to information disseminated by the instructor. The treatment group, in contrast, was given minimum explanation with the bulk of learning coming from students actively solving problems presented in case studies based on real-world events. Results show that the 189 students in the treatment group performed significantly better than the 146 students in the control group.Comment: 4 pages, 1 figure, 2 tables, 12 reference

    Topological spin excitations of Heisenberg antiferromagnets in two dimensions

    Full text link
    In this paper we discuss the construction and the dynamics of vortex-like topological spin excitations in the Schwinger-boson description of Heisenberg antiferromagnets in two dimensions. The topological spin excitations are Dirac fermions (with gap) when spin value SS is a half-integer. Experimental and theoretical implications of these excitations are being investigated.Comment: Latex file, no figur

    Challenging Digital Capitalism: SACOM’s Campaigns against Apple and Foxconn as Monopoly Capital

    Get PDF
    “Utopia or dystopia—to where will the ‘digital revolution’ lead human society?” is a question that remains unanswered. Negotiating between two opposing standpoints, this article, looking at a form of trans-border activism originally driven by suicides and protests of Foxconn workers who produce iPhones, iPads and many other i-gadgets for the world’s consumers, is an attempt to explore a politics of online/offline resistance against anti-digital capitalism. Based in Hong Kong (HK), SACOM is a leftist student group which works to support Chinese workers in campaigning against corporate power and generating trans-border networks through media exposure, international activism, and localized organization. Combining online and offline activism, SACOM strives to extend the reach of their worker-consumer campaign to the worldwide audience by transgressing the Chinese state’s dominance of capital and political control. The most intriguing question to us is could this proactive activism be possible and, if so, how could it act at the grid of China’s transformation and incorporation into global capitalism

    HAT: De novo variant calling for highly accurate short-read and long-read sequencing data

    Get PDF
    MOTIVATION: de novo variants (DNVs) are variants that are present in offspring but not in their parents. DNVs are both important for examining mutation rates as well as in the identification of disease-related variation. While efforts have been made to call DNVs, calling of DNVs is still challenging from parent-child sequenced trio data. We developed Hare And Tortoise (HAT) as an automated DNV detection workflow for highly accurate short-read and long-read sequencing data. Reliable detection of DNVs is important for human genomics and HAT addresses this need. RESULTS: HAT is a computational workflow that begins with aligned read data (i.e. CRAM or BAM) from a parent-child sequenced trio and outputs DNVs. HAT detects high-quality DNVs from Illumina short-read whole-exome sequencing, Illumina short-read whole-genome sequencing, and highly accurate PacBio HiFi long-read whole-genome sequencing data. The quality of these DNVs is high based on a series of quality metrics including number of DNVs per individual, percent of DNVs at CpG sites, and percent of DNVs phased to the paternal chromosome of origin. AVAILABILITY AND IMPLEMENTATION: https://github.com/TNTurnerLab/HAT
    corecore