Synchronization of One Dimensional Array of Point Josephson Junctions Coupled to a Common Load

We study the synchronization in a one dimensional array of point Josephson junctions coupled to a common capacitor, which establishes a long-range interaction between junctions and synchronizes them. The stability diagram of synchronization in a noise-free system is obtained. The current when junctions transform from resistive state into superconducting state, is then calculated and its dependence on the shunt parameters and the dissipation of junctions is revealed. In the presence of thermal noise, the synchronized oscillations are destroyed at a critical temperature and the system undergoes a continuous phase transition of desynchronization. A possible stability diagram of the synchronized oscillations with respect to thermal noise, current, dissipations and shunt capacitance is then constructed. Finally we investigate the dynamic relaxation from random oscillations into synchronized state. The relaxation time increases with the system size and temperature, but is reduced by the shunt capacitor.Comment: 11.2 pages, 14 figure

Opacity in Internet of Things with Cloud Computing

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Internet of Things (IoT) with Cloud Computing (CC) is a new paradigm incorporating a pervasive presence of a wide range of things/objects which can interact with each other and cooperate, creating new services and reaching common goals. This will lead to more intelligent smart environments in a wide range of applications. In this context, protecting the Internet of Things with Cloud Computing (IoTwCC) against interference, including service attacks and viruses, becomes paramount. In this paper, we introduce a transition system representation to capture the information flow in IoTwCCs, and then investigate the opacity of the information flow model. In addition, we introduce a threat model to describe the actions of the system, and propose entropy as a security metrics to quantify the amount of information related to a service that might be exposed to other users or adversaries. It turns out that the opacity of the system is affected by the availability of the services. As a result, the trade-off between opacity and service availability can be analyzed

B\"{a}cklund transformations for the KP and mKP hierarchies with self-consistent sources

Using gauge transformations for the corresponding generating pseudo-differential operators $L^n$ in terms of eigenfunctions and adjoint eigenfunctions, we construct several types of auto-B\"{a}cklund transformations for the KP hierarchy with self-consistent sources (KPHSCS) and mKP hierarchy with self-consistent sources (mKPHSCS) respectively. The B\"{a}cklund transformations from the KPHSCS to mKPHSCS are also constructed in this way.Comment: 22 pages. to appear in J.Phys.

Mass movement susceptibility mapping using satellite optical imagery compared with InSAR monitoring: Zigui County, Three Gorges region, China

Mass movements on steep slopes are a major hazard to communities and infrastructure in the Three Gorges region, China. Developing susceptibility maps of mass movements is therefore very important in both current and future land use planning. This study employed satellite optical imagery and an ASTER GDEM (15 m) to derive various parameters (namely geology; slope gradient; proximity to drainage networks and proximity to lineaments) in order to create a GIS-based map of mass movement susceptibility. This map was then evaluated using highly accurate deformation signals processed using the Persistent Scatterer (PS) InSAR technique. Areas of high susceptibility correspond well to points of high subsidence, which provides a strong support of our susceptibility map

Spin photocurrent, its spectra dependence, and current-induced spin polarization in an InGaAs/InAlAs two-dimensional electron gas

Converse effect of spin photocurrent and current induced spin polarization are experimentally demonstrated in the same two-dimensional electron gas system with Rashba spin splitting. Their consistency with the strength of the Rashba coupling as measured from beating of the Shubnikov-de Haas oscillations reveals a unified picture for the spin photocurrent, current-induced spin polarization and spin orbit coupling. In addition, the observed spectral inversion of the spin photocurrent indicates the system with dominating structure inversion asymmetry.Comment: 13 pages, 4 figure

Spin-1/2 Heisenberg-Antiferromagnet on the Kagome Lattice: High Temperature Expansion and Exact Diagonalisation Studies

For the spin-$\frac{1}{2}$ Heisenberg antiferromagnet on the Kagom\'e lattice we calculate the high temperature series for the specific heat and the structure factor. A comparison of the series with exact diagonalisation studies shows that the specific heat has further structure at lower temperature in addition to a high temperature peak at $T\approx 2/3$. At $T=0.25$ the structure factor agrees quite well with results for the ground state of a finite cluster with 36 sites. At this temperature the structure factor is less than two times its $T=\infty$ value and depends only weakly on the wavevector $\bf q$, indicating the absence of magnetic order and a correlation length of less than one lattice spacing. The uniform susceptibility has a maximum at $T\approx 1/6$ and vanishes exponentially for lower temperatures.Comment: 15 pages + 5 figures, revtex, 26.04.9