9,151 research outputs found

    Overcoming observability problems in distributed test architectures

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    This paper investigates conditions that must be satisfied by an FSM for the existence of input sequences that can be applied in a distributed test architecture without encountering controllability and observability problems and without using external coordination messages. Such conditions have two potential values. First, they can be used to determine whether we require coordination messages and thus a network that connects the testers. Second, if we wish to avoid the use of coordination messages in testing then these conditions can be seen as testability conditions that can inform the design process. Results given in this paper differ from those in the following ways. First, the conditions are strictly weaker than those in since we are less restrictive in the ways we achieve our goals. Second, only considered observability problems; we consider both controllability and observability problems. In addition, only considered a particular type of observability problem and we generalize this. Finally, we investigate the situation in which we need only add input sequences to complement a given test/checking sequence ρ and prove that the conditions for this problem are equivalent to those for the original problem

    Phase transition in a spring-block model of surface fracture

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    A simple and robust spring-block model obeying threshold dynamics is introduced to study surface fracture of an overlayer subject to stress induced by adhesion to a substrate. We find a novel phase transition in the crack morphology and fragment-size statistics when the strain and the substrate coupling are varied. Across the transition, the cracks display in succession short-range, power-law and long-range correlations. The study of stress release prior to cracking yields useful information on the cracking process.Comment: RevTeX, 4 pages, 4 Postscript figures included using epsfi

    Heavy flavor production in pA collisions

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    Heavy quark production in high-energy proton-nucleus (pA) collisions is described in the framework of the Color Glass Condensate. kT factorization is broken even at leading order albeit a more general factorization in pA holds at this order in terms of 2, 3 and 4 point correlators of Wilson lines in the nuclear target. The x-evolution of these correlators is computed in the large A and large N mean field limit of the Balitsky-Kovchegov equation. We show results for heavy quark production at RHIC and LHC energies.Comment: Talk given at QM2006. 4

    Investigation of stakeholders commitment to information security awaremess programs

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    Organisations have become increasingly dependent on technology in order to compete in their respective markets. As IT technology advances at a rapid pace, so does its complexity, giving rise to new IT security vulnerabilities and methods of attack. Even though the human factors have been recognized to have a crucial role in information security management, the effects of weakness of will and lack of commitment on the stakeholders (i.e., employers and employees) parts has never been factored into the design and delivery of awareness programs. To this end, this paper investigates the impacts of the availability of awareness programs and end-user drive and lack of commitment to information security awareness program design, delivery and success.<br /

    Re-orientation Transition in Molecular Thin Films: Potts Model with Dipolar Interaction

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    We study the low-temperature behavior and the phase transition of a thin film by Monte Carlo simulation. The thin film has a simple cubic lattice structure where each site is occupied by a Potts parameter which indicates the molecular orientation of the site. We take only three molecular orientations in this paper which correspond to the 3-state Potts model. The Hamiltonian of the system includes: (i) the exchange interaction JijJ_{ij} between nearest-neighbor sites ii and jj (ii) the long-range dipolar interaction of amplitude DD truncated at a cutoff distance rcr_c (iii) a single-ion perpendicular anisotropy of amplitude AA. We allow Jij=JsJ_{ij} =J_s between surface spins, and Jij=JJ_{ij}=J otherwise. We show that the ground state depends on the the ratio D/AD/A and rcr_c. For a single layer, for a given AA, there is a critical value DcD_c below (above) which the ground-state (GS) configuration of molecular axes is perpendicular (parallel) to the film surface. When the temperature TT is increased, a re-orientation transition occurs near DcD_c: the low-TT in-plane ordering undergoes a transition to the perpendicular ordering at a finite TT, below the transition to the paramagnetic phase. The same phenomenon is observed in the case of a film with a thickness. We show that the surface phase transition can occur below or above the bulk transition depending on the ratio Js/JJ_s/J. Surface and bulk order parameters as well as other physical quantities are shown and discussed.Comment: 7 pages, 11 figures, submitted for publicatio

    Flexible electron field emitters fabricated using conducting ultrananocrystalline diamond pyramidal microtips on polynorbornene films

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    [[abstract]]High performance flexible field emitters made of aligned pyramidal shaped conducting ultrananocrystalline diamond (C-UNCD) microtips on polynorbornene substrates is demonstrated. Flexible C-UNCD pyramidal microtips show a low turn-on field of 1.80 V/μm with a field enhancement factor of 4580 and a high emission current density of 5.8 mA/cm2 (at an applied field of 4.20 V/μm) with life-time stability of 210 min. Such an enhancement in the field emission is due to the presence of sp 2-graphitic sheath with a nanowire-like diamond core. This high performance flexible C-UNCD field emitter is potentially useful for the fabrication of diverse, flexible electronic devices.[[booktype]]紙本[[booktype]]電子

    Dijet Cross Section and Longitudinal Double Spin Asymmetry Measurements in Polarized Proton-proton Collisions at \sqrt{s}=200 GeV at STAR

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    These proceedings show the preliminary results of the dijet cross sections and the dijet longitudinal double spin asymmetries A_LL in polarized proton-proton collisions at \sqrt{s} = 200 GeV at the mid-rapidity |eta| < 0.8. The integrated luminosity of 5.39 pb^{-1} collected during RHIC Run-6 was used in the measurements. The preliminary results are presented as functions of the dijet invariant mass M_jj. The dijet cross sections are in agreement with next-to-leading-order pQCD predictions. The A_LL is compared with theoretical predictions based on various parameterizations of polarized parton distributions of the proton. Projected precision of data analyzed to date from Run-9 are shown.Comment: 8 pages, 5 figures, Proceedings of the SPIN2010 conference (Juelich, Germany, 2010
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