Opinion dynamics on directed small-world networks

In this paper, we investigate the self-affirmation effect on formation of public opinion in a directed small-world social network. The system presents a non-equilibrium phase transition from a consensus state to a disordered state with coexistence of opinions. The dynamical behaviors are very sensitive to the density of long-range interactions and the strength of self-affirmation. When the long-range interactions are sparse and individual generally does not insist on his/her opinion, the system will display a continuous phase transition, in the opposite case with high self-affirmation strength and dense long-range interactions, the system does not display a phase transition. Between those two extreme cases, the system undergoes a discontinuous phase transition.Comment: 6 pages, 5 figure

Spectral Efficiency Analysis of Multi-Cell Massive MIMO Systems with Ricean Fading

This paper investigates the spectral efficiency of multi-cell massive multiple-input multiple-output systems with Ricean fading that utilize the linear maximal-ratio combining detector. We firstly present closed-form expressions for the effective signal-to-interference-plus-noise ratio (SINR) with the least squares and minimum mean squared error (MMSE) estimation methods, respectively, which apply for any number of base-station antennas $M$ and any Ricean $K$-factor. Also, the obtained results can be particularized in Rayleigh fading conditions when the Ricean $K$-factor is equal to zero. In the following, novel exact asymptotic expressions of the effective SINR are derived in the high $M$ and high Ricean $K$-factor regimes. The corresponding analysis shows that pilot contamination is removed by the MMSE estimator when we consider both infinite $M$ and infinite Ricean $K$-factor, while the pilot contamination phenomenon persists for the rest of cases. All the theoretical results are verified via Monte-Carlo simulations.Comment: 15 pages, 2 figures, the tenth International Conference on Wireless Communications and Signal Processing (WCSP 2018), to appea

Calculation of Exposed Length of Anchor Bolts in Shear I: Monotonic Loading

This report describes a study of stand-off anchors in shear with various exposed lengths. Anchor bolts embedded in concrete are commonly used in construction, and often leveling nuts are used to adjust the position of attached steel components. In this case, a portion of anchor bolts may be exposed as in a typical column footing connection without grouting. Such anchor bolts in shear are subjected to combined bending, shear and tension depending upon the stand-off heights, concrete compressive strength, and anchor diameter. The shear capacity of exposed anchors is critically related to the total exposed length, including the stand-off height and the depth of crushed concrete, because the bending moment applied to anchor shaft is directly related to the applied shear by the the exposed length. This is the focus of this study. A group of shear tests of anchors made of ASTM F1554 Grade 55 threaded rods were conducted to simulate the behavior of exposed anchors in shear. Finite element analyses using TNO DIANA® were conducted to explore key parameters, including the concrete and anchor materials, the anchor diameters, and the stand-off heights. The study indicated that the exposed length reduces with an increase in concrete compressive strength and the stand-off heights while increases with an increase in anchor diameter and strength. Equations were proposed for estimation of total exposed length based on the experimental and numerical results. Design equations were proposed for the shear capacity of stand-off/exposed anchors and the equations are verified by 90 tests collected from four sources in the literature