257,656 research outputs found

    Competing contact processes in the Watts-Strogatz network

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    We investigate two competing contact processes on a set of Watts--Strogatz networks with the clustering coefficient tuned by rewiring. The base for network construction is one-dimensional chain of NN sites, where each site ii is directly linked to nodes labelled as i±1i\pm 1 and i±2i\pm 2. So initially, each node has the same degree ki=4k_i=4. The periodic boundary conditions are assumed as well. For each node ii the links to sites i+1i+1 and i+2i+2 are rewired to two randomly selected nodes so far not-connected to node ii. An increase of the rewiring probability qq influences the nodes degree distribution and the network clusterization coefficient C\mathcal{C}. For given values of rewiring probability qq the set N(q)={N1,N2,,NM}\mathcal{N}(q)=\{\mathcal{N}_1, \mathcal{N}_2, \cdots, \mathcal{N}_M \} of MM networks is generated. The network's nodes are decorated with spin-like variables si{S,D}s_i\in\{S,D\}. During simulation each SS node having a DD-site in its neighbourhood converts this neighbour from DD to SS state. Conversely, a node in DD state having at least one neighbour also in state DD-state converts all nearest-neighbours of this pair into DD-state. The latter is realized with probability pp. We plot the dependence of the nodes SS final density nSTn_S^T on initial nodes SS fraction nS0n_S^0. Then, we construct the surface of the unstable fixed points in (C,p,nS0)(\mathcal{C}, p, n_S^0) space. The system evolves more often toward nST=1n_S^T=1 for (C,p,nS0)(\mathcal{C}, p, n_S^0) points situated above this surface while starting simulation with (C,p,nS0)(\mathcal{C}, p, n_S^0) parameters situated below this surface leads system to nST=0n_S^T=0. The points on this surface correspond to such value of initial fraction nSn_S^* of SS nodes (for fixed values C\mathcal{C} and pp) for which their final density is nST=12n_S^T=\frac{1}{2}.Comment: 5 pages, 5 figure

    The human, primate and rabbit ultraviolet action spectra

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    A 5000 watt xenon-mercury high pressure lamp was used to produce a continuous ultraviolet spectrum. Human and animal exposures were made to establish the photokeratitis threshold and abiotic action spectrum. The lower limit of the abiotic action spectrum was 220 nm while the upper limit was 310 nm. The radiant exposure threshold at 270 nm was 0.005 watts/sq cm for the rabbit, 0.004 watts/sq cm for the primate, and 0.004 watts/ sq cm for the human. The rabbit curve was bi-peaked with minimums at 220 nm, 240 nm and 270 nm. The primate curve was tri-peaked with minimums at 220 nm, 240 nm and 270 nm. The human data showed a rather shallow curve with a minimum at 270 nm. Formulas and calculations are given to predict minimum exposure times for ocular damage to man in outer space, to establish valid safety criteria, and to establish protective design criteria

    byron C. Watts v. Ardith D. Watts : Respondent\u27s Brief

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    Appeal from the Judgment of the Third District Court in and for Salt Lake County, Utah the Honorable D. Frank Wilkins, Judg

    Mary Nelson Watts v. Wayne D. Watts : Appellant\u27s Brief

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    D-branes, Orientifolds and K-theory

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    The complete D-brane spectrum in ZZ[squared] orientifolds is computed. Stable non-BPS D-branes with both integral and torsion charges are found. The relation to K-theory is discussed and a new K-theory relevant to orientifolds is suggested

    byron C. Watts v. Ardith D. Watts : Appellant\u27s Brief

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    Appeal from the Judgment of the Third District Court in and for Salt Lake County, Utah the Honorable D. Frank Wilkins, Judg

    Order-disorder phase transition in a cliquey social network

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    We investigate the network model of community by Watts, Dodds and Newman (D. J. Watts et al., Science 296 (2002) 1302) as a hierarchy of groups, each of 5 individuals. A homophily parameter α\alpha controls the probability proportional to exp(αx)\exp(-\alpha x) of selection of neighbours against distance xx. The network nodes are endowed with spin-like variables si=±1s_i = \pm 1, with Ising interaction J>0J>0. The Glauber dynamics is used to investigate the order-disorder transition. The transition temperature TcT_c is close to 3.8 for α<0.0\alpha < 0.0 and it falls down to zero above this value. The result provides a mathematical illustration of the social ability to a collective action {\it via} weak ties, as discussed by Granovetter in 1973.Comment: 10 pages, 7 figure

    Hermetic-coaxial package design for microwave transistors

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    Semiconductor package has been developed for high power semiconductor devices that operate in the GHz-frequency range at several watts. Package includes stud, insulating ring, electrically conductive washer, insulating washer, braze ring, and cap. It is mechanically strong and can be used with variety of circuits
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