22,495 research outputs found

    Big Data Analytics In The Public Sector: A Case Study Of NEET Analysis For The London Boroughs

    Get PDF
    For decades, the issue of young people who are aged 16 -18 and not in employment, education, or training (NEET) has been a major concern for governments and local authorities. In this paper, a big data perspective is taken to examine the NEET issue in order to highlight factors that are correlated with NEET, the negative consequences and causes of NEET, and potential solutions to NEET. The NEET dataset about the 33 London Boroughs has been considered along with other seven datasets relating to population, crime offences, benefits claimants, median property price, active businesses, immigrants, and conception under 18. All the datasets are public-accessible and comprise a data collection of the same period of time from 2009 to 2013. Each of them represents a particular measure. Hierarchical variable clustering, k-means clustering, and correlation analysis have been conducted using SAS Enterprise Miner and Tableau in this work. These tools enable us to analyse the problem in a multi-dimensional, hierarchical, integrated, and longitudinal way. The research has demonstrated that a) The NEET issue is much more severe in outer London than in inner London; b) The main factors correlated with NEET vary from inner London to outer London; c) Each of the measures considered has a certain correlation strength with the NEET rate, and amongst them, median property price is a simple and seemingly accurate indicator of areas likely to suffer from NEET and thus to take appropriate precautions in order to reduce the likelihood of further increases in NEET; and d) The London Boroughs can be grouped based on similarities in terms of a set of given measures, and the memberships of the groups remain stable

    Diamagnetism versus Paramagnetism in charged spin-1 Bose gases

    Full text link
    It has been suggested that either diamagnetism or paramagnetism of Bose gases, due to the charge or spin degrees of freedom respectively, appears solely to be extraordinarily strong. We investigate magnetic properties of charged spin-1 Bose gases in external magnetic field, focusing on the competition between the diamagnetism and paramagnetism, using the Lande-factor gg of particles to evaluate the strength of paramagnetic effect. We propose that a gas with g<1/8g<{1/\sqrt{8}} exhibits diamagnetism at all temperatures, while a gas with g>1/2g>{1/2} always exhibits paramagnetism. Moreover, a gas with the Lande-factor in between shows a shift from paramagnetism to diamagnetism as the temperature decreases. The paramagnetic and diamagnetic contributions to the total magnetization density are also calculated in order to demonstrate some details of the competition.Comment: 6 pages, 5 figure

    Why Does China Allow Freer Social Media? Protests Versus Surveillance And Propaganda

    Get PDF
    In this paper, we document basic facts regarding public debates about controversial political issues on Chinese social media. Our documentation is based on a dataset of 13.2 billion blog posts published on Sina Weibo--the most prominent Chinese microblogging platform--during the 2009-2013 period. Our primary finding is that a shockingly large number of posts on highly sensitive topics were published and circulated on social media. For instance, we find millions of posts discussing protests, and these posts are informative in predicting the occurrence of specific events. We find an even larger number of posts with explicit corruption allegations, and that these posts predict future corruption charges of specific individuals. Our findings challenge a popular view that an authoritarian regime would relentlessly censor or even ban social media. Instead, the interaction of an authoritarian government with social media seems more complex.published_or_final_versio

    Field trial of a 15 Tb/s adaptive and gridless OXC supporting elastic 1000-fold all-optical bandwidth granularity

    Get PDF
    An adaptive gridless OXC is implemented using a 3D-MEMS optical backplane plus optical modules (sub-systems) that provide elastic spectrum and time switching functionality. The OXC adapts its architecture on demand to fulfill the switching requirements of incoming traffic. The system is implemented in a seven-node network linked by installed fiber and is shown to provide suitable architectures on demand for three scenarios with increasing traffic and switching complexity. In the most complex scenario, signals of mixed bit-rates and modulation formats are successfully switched with flexible per-channel allocation of spectrum, time and space, achieving over 1000-fold bandwidth granularity and 1.5 Tb/s throughput with good end-to-end performance

    Two types of softening detected in X-ray afterglows of Swift bursts: internal and external shock origins?

    Full text link
    The softening process observed in the steep decay phase of early X-ray afterglows of Swift bursts has remained a puzzle since its discovery. The softening process can also be observed in the later phase of the bursts and its cause has also been unknown. Recently, it was suggested that, influenced by the curvature effect, emission from high latitudes would shift the Band function spectrum from higher energy band to lower band, and this would give rise to the observed softening process accompanied by a steep decay of the flux density. The curvature effect scenario predicts that the terminating time of the softening process would be correlated with the duration of the process. In this paper, based on the data from the UNLV GRB group web-site, we found an obvious correlation between the two quantities. In addition, we found that the softening process can be divided into two classes: the early type softening (ts,max≤"4000"st_{s,max}\leq "4000"s) and the late type softening (ts,max>"4000"st_{s,max} > "4000"s). The two types of softening show different behaviors in the duration vs. terminating time plot. In the relation between the variation rates of the flux density and spectral index during the softening process, a discrepancy between the two types of softening is also observed. According to their time scales and the discrepancy between them, we propose that the two types are of different origins: the early type is of internal shock origin and the late type is of external shock origin. The early softening is referred to the steep decay just following the prompt emission, whereas the late decay typically conceives the transition from flat decay to late afterglow decay. We suspect that there might be a great difference of the Lorentz factor in two classes which is responsible for the observed discrepancy.Comment: 20 pages, 5 figures, 2 tables, Accepted for Publication to Journal of Cosmology and Astroparticle Physics (JCAP

    Probing and modelling the localized self-mixing in a GaN/AlGaN field-effect terahertz detector

    Get PDF
    In a GaN/AlGaN field-effect terahertz detector, the directional photocurrent is mapped in the two-dimensional space of the gate voltage and the drain/source bias. It is found that not only the magnitude, but also the polarity, of the photocurrent can be tuned. A quasistatic self-mixing model taking into account the localized terahertz field provides a quantitative description of the detector characteristics. Strongly localized self-mixing is confirmed. It is therefore important to engineer the spatial distribution of the terahertz field and its coupling to the field-effect channel on the sub-micron scale.Comment: 12 pages, 4 figures, submitted to AP

    Radiative and Collisional Jet Energy Loss in a Quark-Gluon Plasma

    Full text link
    We calculate radiative and collisional energy loss of hard partons traversing the quark-gluon plasma created at RHIC and compare the respective size of these contributions. We employ the AMY formalism for radiative energy loss and include additionally energy loss by elastic collisions. Our treatment of both processes is complete at leading order in the coupling, and accounts for the probabilistic nature of jet energy loss. We find that a solution of the Fokker-Planck equation for the probability density distributions of partons is necessary for a complete calculation of the nuclear modification factor RAAR_{AA} for pion production in heavy ion collisions. It is found that the magnitude of RAAR_{AA} is sensitive to the inclusion of both collisional and radiative energy loss, while the average energy is less affected by the addition of collisional contributions. We present a calculation of RAAR_{AA} for π0\pi^0 at RHIC, combining our energy loss formalism with a relativistic (3+1)-dimensional hydrodynamic description of the thermalized medium.Comment: 4 pages, 4 figures, contributed to Quark Matter 2008, Jaipur, Indi

    Possible effects of color screening and large string tension in heavy quarkonium spectrum

    Full text link
    Possible effects of the color screened confinement potential are investigated. Color screened linear potential with a large string tension T=(0.26−0.32)GeV2T=(0.26-0.32)GeV^2 is suggested by a study of the ccˉc\bar c and bbˉb\bar b spectra. The ψ(4160)\psi (4160) and ψ(4415)\psi (4415) are respectively assigned as the ψ(4S)\psi (4S)-dominated and the ψ(5S)\psi (5S) ccˉc\bar c states. Satisfactory results for the masses and leptonic widths (with QCD radiative corrections) of ccˉc\bar c and bbˉb\bar b states are obtained.Comment: 11 pages in Late
    • …
    corecore