866 research outputs found

    On minimizing coding operations in network coding based multicast: an evolutionary algorithm

    Get PDF
    In telecommunications networks, to enable a valid data transmission based on network coding, any intermediate node within a given network is allowed, if necessary, to perform coding operations. The more coding operations needed, the more coding resources consumed and thus the more computational overhead and transmission delay incurred. This paper investigates an efficient evolutionary algorithm to minimize the amount of coding operations required in network coding based multicast. Based on genetic algorithms, we adapt two extensions in the proposed evolutionary algorithm, namely a new crossover operator and a neighbourhood search operator, to effectively solve the highly complex problem being concerned. The new crossover is based on logic OR operations to each pair of selected parent individuals, and the resulting offspring are more likely to become feasible. The aim of this operator is to intensify the search in regions with plenty of feasible individuals. The neighbourhood search consists of two moves which are based on greedy link removal and path reconstruction, respectively. Due to the specific problem feature, it is possible that each feasible individual corresponds to a number of, rather than a single, valid network coding based routing subgraphs. The neighbourhood search is applied to each feasible individual to find a better routing subgraph that consumes less coding resource. This operator not only improves solution quality but also accelerates the convergence. Experiments have been carried out on a number of fixed and randomly generated benchmark networks. The results demonstrate that with the two extensions, our evolutionary algorithm is effective and outperforms a number of state-of-the-art algorithms in terms of the ability of finding optimal solutions

    Decreasing the use of edible oils in China using WeChat and theories of behavior change: study protocol for a randomized controlled trial.

    Get PDF
    The consumption of edible oils in China has increased rapidly in recent years, and the total amount of edible-oil intake in the country has ranked first in the world. The choice and intake of edible oils, as a source of fats, are important factors that affect people's health. Many chronic diseases are closely associated with high-calorie and saturated-fat intake. The influence of traditional concepts that promote the use of edible oils among women, particularly housewives, plays a key role in a household's diet and nutrition because the diet-related knowledge, attitude and behaviour of housewives are dominant factors in planning and preparing their family's meals. WeChat, which was developed by Tencent, is a multipurpose messaging, social media and mobile payment application (app) in China. Described by Forbes as one of the world's most powerful apps, WeChat provides considerable convenience in disseminating knowledge. Accordingly, this study aims to design a pilot intervention to decrease the use of edible oils in Chinese households. The intervention, which is based on theories of behaviour change, will be implemented through WeChat. The study design is a randomised controlled trial that adopts knowledge, attitude and practice, social cognitive and stages of change theories as theoretical models. A total of 800 housewives between the ages of 25 and 45 years will be recruited on WeChat and from the communities in four areas (including rural and urban) in Chongqing, China. A self-administered questionnaire will be used to collect information regarding age, educational level, occupation, family members, edible-oil intake habits, knowledge of edible oils and WeChat usage habits. A total of 200 participants will be selected and randomly assigned to two equal-sized groups: group A (the intervention group) and group B (the control group). Group A will receive health education regarding edible oils for four consecutive weeks, whereas group B will be treated as the blank control. Each participant will complete a battery of knowledge, attitude and behaviour tests immediately, 3 months and 6 months after the intervention. In addition, weight, moisture rate, fat rate, visceral fat level and body mass index will be calculated using a multifunctional weighing scale, namely, Tanita BC-601 (Japan). The study is currently in the design stage. This study aims to increase knowledge and awareness of the appropriate use of edible oils, thereby encouraging participants to change behaviour by decreasing the intake of unhealthy levels of edible oils. It will be the first intervention to investigate the use of edible oils in China through WeChat. We predict that receiving health education regarding edible oils through WeChat will substantially improve the knowledge and attitude of the respondents. The members of the intervention group will have increased awareness and will be willing to decrease their use of edible oils to remain healthy. Results of this study may provide scientific evidence for the effect of health education through WeChat on edible oil-intake behaviour, thereby offering a comprehensive intervention to decrease the use of edible oils and promote a healthy lifestyle. Chinese Clinical Trial Registry (primary registry in the World Health Organisation registry network): ChiCTR-IOR-17013472 . Registered on 21 November 2017

    Measurement of the proton form factor by studying e+eppˉe^{+} e^{-}\rightarrow p\bar{p}

    Full text link
    Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of e+eppˉe^{+}e^{-}\rightarrow p\bar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal (GE=GM)(|G_{E}|= |G_{M}|). In addition, the ratio of electric to magnetic form factors, GE/GM|G_{E}/G_{M}|, and GM|G_{M}| are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at s=\sqrt{s}= 2232.4 and 2400.0 MeV and a combined sample at s\sqrt{s} = 3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30\%. The GE/GM|G_{E}/G_{M}| ratios are close to unity and consistent with BaBar results in the same q2q^{2} region, which indicates the data are consistent with the assumption that GE=GM|G_{E}|=|G_{M}| within uncertainties.Comment: 13 pages, 24 figure

    l=0 to l=1 Transition Form Factors

    Full text link
    A method is proposed to extend the hard scattering picture of Brodsky and Lepage to transitions between hadrons with orbital angular momentum l=0 and l=1. The use of covariant spin wave functions turns out to be very helpful in formulating that method. As a first application we construct a light-cone wave function of the nucleon resonance N(1535)N^*(1535) in the quark-diquark picture. Using this wave function and the extended hard scattering picture, the NN--NN^* transition form factors are calculated at large momentum transfer and the results compared to experimental data. As a further application of our method we briefly discuss the π\pi--a1a_1 form factors in an appendix.Comment: 27 pages, 6 PS-figures in uuencoded compressed file, Latex, WU-B 93-29, MZ-TH/93-2

    An amplitude analysis of the π0π0\pi^{0}\pi^{0} system produced in radiative J/ψJ/\psi decays

    Get PDF
    An amplitude analysis of the π0π0\pi^{0}\pi^{0} system produced in radiative J/ψJ/\psi decays is presented. In particular, a piecewise function that describes the dynamics of the π0π0\pi^{0}\pi^{0} system is determined as a function of Mπ0π0M_{\pi^{0}\pi^{0}} from an analysis of the (1.311±0.011)×109(1.311\pm0.011)\times10^{9} J/ψJ/\psi decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the π0π0\pi^0\pi^0 system while making minimal assumptions about the properties or number of poles in the amplitude. Such a model-independent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of J/ψγπ0π0J/\psi \to \gamma \pi^{0}\pi^{0} is determined to be (1.15±0.05)×103(1.15\pm0.05)\times10^{-3}, where the uncertainty is systematic only and the statistical uncertainty is negligible.Comment: Submitted to Phys. Rev. D 19 pages, 4 figure

    Observation of the isospin-violating decay J/ψϕπ0f0(980)J/\psi \to \phi\pi^{0}f_{0}(980)

    Get PDF
    Using a sample of 1.31 billion J/ψJ/\psi events collected with the BESIII detector at the BEPCII collider, the decays J/ψϕπ+ππ0J/\psi \to \phi \pi^{+}\pi^{-}\pi^{0} and J/ψϕπ0π0π0J/\psi \to \phi \pi^{0}\pi^{0}\pi^{0} are investigated. The isospin violating decay J/ψϕπ0f0(980)J/\psi \to \phi \pi^{0} f_{0}(980) with f0(980)ππf_{0}(980) \to \pi\pi, is observed for the first time. The width of the f0(980)f_{0}(980) obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the π0f0(980)\pi^{0} f_{0}(980) mass spectrum, there is evidence of f1(1285)f_1(1285) production. By studying the decay J/ψϕηJ/\psi \to \phi\eta', the branching fractions of ηπ+ππ0\eta' \to \pi^{+}\pi^{-}\pi^{0} and ηπ0π0π0\eta' \to \pi^{0}\pi^{0}\pi^{0}, as well as their ratio, are also measured.Comment: 10 pages, 10 figures, published in Phys. Rev.

    A multivariate morphometric investigation to delineate stock structure of gangetic whiting, Sillaginopsis panijus (Teleostei: Sillaginidae)

    Get PDF
    This study was conducted to delineate the stock structure of Sillaginopsis paniijus based on morphometric characters of the species. A total of 194 specimens were collected from the Meghna, Tentulia and Baleswar rivers located in the southern coastal zone of Bangladesh. Data were subjected to univariate ANOVA, multivariate ANOVA, discriminate function analysis (DFA), and principal component analysis. Mean variations of ten morphometric characters; HD, HBD, LBD, PsOL, ED, SnL, SPrDL, HAF, LSDB and LPB showed significant differences (p < 0.05) among 27 morphometric traits that were selected for the study. In DFA, the overall assignments of individuals into their correctly classified original groups were 71.1 and 70.6 % for male and female, respectively. A scatter plot of the first two discriminant functions was used to visually depict the discrimination among the populations. The results showed different stocks of S. panijus in the rivers of Baleswar, Tentulia and Meghna in southwest coast of Bangladesh

    Agrobacterium rhizogenes-Mediated Transformation of the Parasitic Plant Phtheirospermum japonicum

    Get PDF
    Background: Plants within the Orobanchaceae are an agriculturally important group of parasites that attack economically important crops to obtain water and nutrients from their hosts. Despite their agricultural importance, molecular mechanisms of the parasitism are poorly understood. Methodology/Principal Findings: We developed transient and stable transformation systems for Phtheirospermum japonicum, a facultative parasitic plant in the Orobanchaceae. The transformation protocol was established by a combination of sonication and acetosyringone treatments using the hairy-root-inducing bacterium, Agrobacterium rhizogenes and young seedlings. Transgenic hairy roots of P. japonicum were obtained from cotyledons 2 to 3 weeks after A. rhizogenes inoculation. The presence and the expression of transgenes in P. japonicum were verified by genomic PCR, Southern blot and RT-PCR methods. Transgenic roots derived from A. rhizogenes-mediated transformation were able to develop haustoria on rice and maize roots. Transgenic roots also formed apparently competent haustoria in response to 2,6dimethoxy-1,4-benzoquinone (DMBQ), a haustorium-inducing chemical. Using this system, we introduced a reporter gene with a Cyclin B1 promoter into P. japonicum, and visualized cell division during haustorium formation. Conclusions: We provide an easy and efficient method for hairy-root transformation of P. japonicum. Transgenic marker analysis revealed that cell divisions during haustorium development occur 24 h after DMBQ treatment. The protocol
    corecore