891 research outputs found

    TKEY Vulnerability in BIND DNS Server

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    The Domain Naming System (DNS) has been a core technology to the usefulness of the Internet since the beginning of its public introduction. The ability to associate an English-readable fully qualified domain name (FQDN) with an IPv4 address is crucial to its user-friendliness. Due to its age, several flaws have been discovered in its code, one of the more recent being referenced as CVE-2015-5477, which affects all versions of Berkeley Internet Naming Daemon (BIND) available before July 31, 2015. We will cover what this error is, describe and test its effectiveness against an older BIND v. 9.9.6 server, and discuss options for resolving the issue

    Effects of Self-Hypnosis Training Sessions on Pre-Competition Anxiety Levels of Collegiate Wrestlers

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    Members of the athletic coaching profession have long been concerned with obtaining the maximum physical and mental performance from their athletes. This concern has been evidenced through the many studies that have been completed involving methods of enhancing motor performance. Research finding from these studies have influenced changes in training programs and ways of preparing for athletic competition, but these changes have been concerned with primarily with physical development. Although being ready physically is very important for maximum performance, it is not the only factor to be considered. Mental conditioning also plays an important role in the success of any athletic event. The purpose of this study was to determine the effects of training sessions involving self-hypnosis on the anxiety levels of varsity wrestlers, as measured by pulse rates recorded at selected intervals prior to competition

    A NOVEL LOOK AT THE MICHAEL LATTICE SUM RULES

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    We reconsider the derivation of the Michael lattice sum rules, which relate the energy and action stored in a flux tube of a quark-antiquark pair to the static interquark potential, and show that they require essential corrections. We then find, using the coupling constant sum rule of Karsch, that the total Minkowski field energy does not match the interquark potential, if one follows conventional notions. The implications of this result are discussed.Comment: 8 pages, Plain Te

    Lattice sum rules for the colour fields

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    We analyse the sum rules describing the action and energy in the colour fields around glueballs, torelons and static potentials.Comment: 9 pages LATEX, (typos corrected, to appear in Phys Rev D

    Scaling Properties of the Energy Density in SU(2) Lattice Gauge Theory

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    The lattice data for the energy density of SU(2)SU(2) gauge theory are calculated with \nop~derivatives of the coupling constants. These derivatives are obtained from two sources : i) a parametrization of the \nop~beta function in accord with the measured critical temperature and Δβ\Delta\beta-values and ii) a \nop~calculation of the presssure. We then perform a detailed finite size scaling analysis of the energy density near TcT_c. It is shown that at the critical temperature the energy density is scaling as a function of VT3VT^3 with the corresponding 3d3d Ising model critical exponents. The value of ϵ(Tc)/Tc4\epsilon(T_c)/T^4_c in the continuum limit is estimated to be 0.256(23). In the high temperature regime the energy density is approaching its weak coupling limit from below, at T/Tc2T/T_c \approx 2 it has reached only about 70%70\% of the limit.Comment: 15 pages + 9 figures, BI-TP 94/3

    Non-perturbative determination of beta-functions and excited string states from lattices

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    We use lattice sum rules for the static quark potential to determine the beta-function for symmetric and asymmetric lattices non-perturbatively. We also study the colour field distributions in excited gluonic states.Comment: 9 pages, LATEX, 1 postscript figur

    Flux-tube Structure, Sum Rules and Beta-functions in SU(2)

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    Action and energy flux-tube profiles are computed, in SU(2) with beta=2.4,2.5, for two quarks up to 1 fm apart and for which the colour fields are in their ground state (A_1g) and the first (E_u) and higher (A'_1g) excited gluonic states. When these profiles are integrated over all space, a scaling comparison is made between the beta=2.4 and 2.5 data. Using sum rules, these integrated forms also permit an estimate to be made of generalised beta-functions giving b(2.4)=-0.312(15), b(2.5)=-0.323(9), f(2.4)=0.65(1) and f(2.5)=0.68(1). When the profiles are integrated only over planes transverse to the interquark line and assuming underlying string features, scaling comparisons are again made near the centres of the interquark line for the largest interquark distances. For the A'_{1g} case, some of the profiles exhibit a 'dip-like' structure characteristic of the Isgur-Paton model.Comment: 3 pages, 6 eps figures. Presented at LATTICE9

    The pressure of the SU(N) lattice gauge theory at large-N

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    We calculate bulk thermodynamic properties, such as the pressure, energy density, and entropy, in SU(4) and SU(8) lattice gauge theories, for the range of temperatures T <= 2.0Tc and T <= 1.6Tc respectively. We find that the N=4,8 results are very close to each other, and to what one finds in SU(3), and are far from the asymptotic free-gas value. We conclude that any explanation of the high-T pressure (or entropy) deficit must be such as to survive the N-->oo limit. We give some examples of this constraint in action and comment on what this implies for the relevance of gravity duals.Comment: 16 pages, 5 figures. Small changes to the calculation of the finite lattice spacing errors. Added references. Results and conclusions do not chang

    High mobility dry-transferred CVD bilayer graphene

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    We report on the fabrication and characterization of high-quality chemical vapor-deposited (CVD) bilayer graphene (BLG). In particular, we demonstrate that CVD-grown BLG can mechanically be detached from the copper foil by an hexagonal boron nitride (hBN) crystal after oxidation of the copper-to-BLG interface. Confocal Raman spectroscopy reveals an AB-stacking order of the BLG crystals and a high structural quality. From transport measurements on fully encapsulated hBN/BLG/hBN Hall bar devices we extract charge carrier mobilities up to 180,000 cm2^2/(Vs) at 2 K and up to 40,000 cm2^2/(Vs) at 300 K, outperforming state-of-the-art CVD bilayer graphene devices. Moreover, we show an on-off ration of more than 10,000 and a band gap opening with values of up to 15 meV for a displacement field of 0.2 V/nm in such CVD grown BLG.Comment: 5 pages, 4 figure

    Scaling in the Positive Plaquette Model and Universality in SU(2) Lattice Gauge Theory

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    We investigate universality, scaling, the beta-function and the topological charge in the positive plaquette model for SU(2) lattice gauge theory. Comparing physical quantities, like the critical temperature, the string tension, glueball masses, and their ratios, we explore the effect of a complete suppression of a certain lattice artifact, namely the negative plaquettes, for SU(2) lattice gauge theory. Our result is that this modification does not change the continuum limit, i.e., the universality class. The positive plaquette model and the standard Wilson formulation describe the same physical situation. The approach to the continuum limit given by the beta-function in terms of the bare lattice coupling, however, is rather different: the beta-function of the positive plaquette model does not show a dip like the model with standard Wilson action.Comment: 35 pages, preprint numbers FSU-SCRI-94-71 and HU Berlin-IEP-94/1
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