870 research outputs found

    Egyptian electronic government: The university enrolment case study

    Get PDF
    E-government projects have potential for greaterefficiency and effectiveness of government operations. For thisreason, many developing countries governments have investedheavily in this agenda and an increasing number of e- governmentprojects are being implemented. However, there is a lack of clearcase material, which describes the potentialities and consequenceexperienced by organizations trying to manage with this change. TheMinistry of State for Administrative Development (MSAD) is theorganization responsible for the e- Government program in Egyptsince early 2004. This paper presents a case study of the process ofadmission to public universities and institutions in Egypt which is ledby MSAD. Underlining the key benefits resulting from the initiative,explaining the strategies and the development steps used toimplement it, and highlighting the main obstacles encountered andhow they were overcome will help repeat the experience in otheruseful e-government projects.Keywords—Case studies, Egypt, Electro

    Random Walk Model on a Hyper-Spherical Lattice

    Full text link
    We use a one-dimensional random walk on DD-dimensional hyper-spheres to determine the critical behavior of statistical systems in hyper-spherical geometries. First, we demonstrate the properties of such walk by studying the phase diagram of a percolation problem. We find a line of second and first order phase transitions separated by a tricritical point. Then, we analyze the adsorption-desorption transition for a polymer growing near the attractive boundary of a cylindrical cell membrane. We find that the fraction of adsorbed monomers on the boundary vanishes exponentially when the adsorption energy decreases towards its critical value. We observe a crossover phenomenon to an area of linear growth at energies of the order of the inverse cell radius.Comment: to appear in NPB Proc. Suppl. of LATTICE'94, 3 pages, ps-file uuencoded, 2 figures included, NO-NUM-

    Phase diagram of a dilute ferromagnet model with antiferromagnetic next-nearest-neighbor interactions

    Full text link
    We have studied the spin ordering of a dilute classical Heisenberg model with spin concentration xx, and with ferromagnetic nearest-neighbor interaction J1J_1 and antiferromagnetic next-nearest-neighbor interaction J2J_2. Magnetic phases at absolute zero temperature T=0T = 0 are determined examining the stiffness of the ground state, and those at finite temperatures T0T \neq 0 are determined calculating the Binder parameter gLg_L and the spin correlation length ξL\xi_L. Three ordered phases appear in the xTx-T phase diagram: (i) the ferromagnetic (FM) phase; (ii) the spin glass (SG) phase; and (iii) the mixed (M) phase of the FM and the SG. Near below the ferromagnetic threshold xFx_{\rm F}, a reentrant SG transition occurs. That is, as the temperature is decreased from a high temperature, the FM phase, the M phase and the SG phase appear successively. The magnetization which grows in the FM phase disappears in the SG phase. The SG phase is suggested to be characterized by ferromagnetic clusters. We conclude, hence, that this model could reproduce experimental phase diagrams of dilute ferromagnets Fex_xAu1x_{1-x} and Eux_xSr1x_{1-x}S.Comment: 9 pages, 23 figure

    Simple Asymmetric Exclusion Model and Lattice Paths: Bijections and Involutions

    Full text link
    We study the combinatorics of the change of basis of three representations of the stationary state algebra of the two parameter simple asymmetric exclusion process. Each of the representations considered correspond to a different set of weighted lattice paths which, when summed over, give the stationary state probability distribution. We show that all three sets of paths are combinatorially related via sequences of bijections and sign reversing involutions.Comment: 28 page

    Critical frontier of the Potts and percolation models in triangular-type and kagome-type lattices I: Closed-form expressions

    Full text link
    We consider the Potts model and the related bond, site, and mixed site-bond percolation problems on triangular-type and kagome-type lattices, and derive closed-form expressions for the critical frontier. For triangular-type lattices the critical frontier is known, usually derived from a duality consideration in conjunction with the assumption of a unique transition. Our analysis, however, is rigorous and based on an established result without the need of a uniqueness assumption, thus firmly establishing all derived results. For kagome-type lattices the exact critical frontier is not known. We derive a closed-form expression for the Potts critical frontier by making use of a homogeneity assumption. The closed-form expression is new, and we apply it to a host of problems including site, bond, and mixed site-bond percolation on various lattices. It yields exact thresholds for site percolation on kagome, martini, and other lattices, and is highly accurate numerically in other applications when compared to numerical determination.Comment: 22 pages, 13 figure

    Precise calculation of the threshold of various directed percolation models on a square lattice

    Full text link
    Using Monte Carlo simulations on different system sizes we determine with high precision the critical thresholds of two families of directed percolation models on a square lattice. The thresholds decrease exponentially with the degree of connectivity. We conjecture that pcp_{c} decays exactly as the inverse of the coodination number.Comment: 2 pages, 2 figures and 1 tabl
    corecore