1,547 research outputs found

    Similarity Analysis of Nonlinear Equations and Bases of Finite Wavelength Solitons

    Full text link
    We introduce a generalized similarity analysis which grants a qualitative description of the localised solutions of any nonlinear differential equation. This procedure provides relations between amplitude, width, and velocity of the solutions, and it is shown to be useful in analysing nonlinear structures like solitons, dublets, triplets, compact supported solitons and other patterns. We also introduce kink-antikink compact solutions for a nonlinear-nonlinear dispersion equation, and we construct a basis of finite wavelength functions having self-similar properties.Comment: 18 pages Latex, 6 figures ep

    Magnetic Field Induced Insulating Phases at Large rsr_s

    Full text link
    Exploring a backgated low density two-dimensional hole sample in the large rsr_s regime we found a surprisingly rich phase diagram. At the highest densities, beside the ν=1/3\nu=1/3, 2/3, and 2/5 fractional quantum Hall states, we observe both of the previously reported high field insulating and reentrant insulating phases. As the density is lowered, the reentrant insulating phase initially strengthens, then it unexpectedly starts weakening until it completely dissapears. At the lowest densities the terminal quantum Hall state moves from ν=1/3\nu=1/3 to ν=1\nu=1. The intricate behavior of the insulating phases can be explained by a non-monotonic melting line in the ν\nu-rsr_s phase space

    Phase separation and vortex states in binary mixture of Bose-Einstein condensates in the trapping potentials with displaced centers

    Full text link
    The system of two simultaneously trapped codensates consisting of 87Rb^{87}Rb atoms in two different hyperfine states is investigated theoretically in the case when the minima of the trapping potentials are displaced with respect to each other. It is shown that the small shift of the minima of the trapping potentials leads to the considerable displacement of the centers of mass of the condensates, in agreement with the experiment. It is also shown that the critical angular velocities of the vortex states of the system drastically depend on the shift and the relative number of particles in the condensates, and there is a possibility to exchange the vortex states between condensates by shifting the centers of the trapping potentials.Comment: 4 pages, 2 figure

    Single electron charging of impurity sites visualized by scanning gate experiments on a quantum point contact

    Full text link
    A quantum point contact (QPC) patterned on a two-dimensional electron gas is investigated with a scanning gate setup operated at a temperature of 300 mK. The conductance of the point contact is recorded while the local potential is modified by scanning the tip. Single electron charging of impurities induced by the local potential is observed as a stepwise conductance change of the constriction. By selectively changing the state of some of these impurities, it is possible to observe changes in transmission resonances of the QPC. The location of such impurities is determined, and their density is estimated to be below 50 per \mu m^2, corresponding to less than 1 % of the doping concentration

    Disease diagnosis in smart healthcare: Innovation, technologies and applications

    Get PDF
    To promote sustainable development, the smart city implies a global vision that merges artificial intelligence, big data, decision making, information and communication technology (ICT), and the internet-of-things (IoT). The ageing issue is an aspect that researchers, companies and government should devote efforts in developing smart healthcare innovative technology and applications. In this paper, the topic of disease diagnosis in smart healthcare is reviewed. Typical emerging optimization algorithms and machine learning algorithms are summarized. Evolutionary optimization, stochastic optimization and combinatorial optimization are covered. Owning to the fact that there are plenty of applications in healthcare, four applications in the field of diseases diagnosis (which also list in the top 10 causes of global death in 2015), namely cardiovascular diseases, diabetes mellitus, Alzheimer’s disease and other forms of dementia, and tuberculosis, are considered. In addition, challenges in the deployment of disease diagnosis in healthcare have been discussed

    Elastic moduli, dislocation core energy and melting of hard disks in two dimensions

    Full text link
    Elastic moduli and dislocation core energy of the triangular solid of hard disks of diameter σ\sigma are obtained in the limit of vanishing dislocation- antidislocation pair density, from Monte Carlo simulations which incorporates a constraint, namely that all moves altering the local connectivity away from that of the ideal triangular lattice are rejected. In this limit, we show that the solid is stable against all other fluctuations at least upto densities as low as ρσ2=0.88\rho \sigma^2 = 0.88. Our system does not show any phase transition so diverging correlation lengths leading to finite size effects and slow relaxations do not exist. The dislocation pair formation probability is estimated from the fraction of moves rejected due to the constraint which yields, in turn, the core energy E_c and the (bare) dislocation fugacity y. Using these quantities, we check the relative validity of first order and Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) melting scenarios and obtain numerical estimates of the typical expected transition densities and pressures. We conclude that a KTHNY transition from the solid to a hexatic phase preempts the solid to liquid first order transition in this system albeit by a very small margin, easily masked by crossover effects in unconstrained ``brute-force'' simulations with small number of particles.Comment: 17 pages, 8 figure

    Longitudinal and transverse dissipation in a simple model for the vortex lattice with screening

    Full text link
    Transport properties of the vortex lattice in high temperature superconductors are studied using numerical simulations in the case in which the non-local interactions between vortex lines are dismissed. The results obtained for the longitudinal and transverse resistivities in the presence of quenched disorder are compared with the results of experimental measurements and other numerical simulations where the full interaction is considered. This work shows that the dependence on temperature of the resistivities is well described by the model without interactions, thus indicating that many of the transport characteristics of the vortex structure in real materials are mainly a consequence of the topological configuration of the vortex structure only. In addition, for highly anisotropic samples, a regime is obtained where longitudinal coherence is lost at temperatures where transverse coherence is still finite. I discuss the possibility of observing this regime in real samples.Comment: 9 pages, 7 figures included using epsf.st

    Universal temperature dependence of the conductivity of a strongly disordered granular metal

    Full text link
    A disordered array of metal grains with large and random intergrain conductances is studied within the one-loop accuracy renormalization group approach. While at low level of disorder the dependence of conductivity on log T is nonuniversal (it depends on details of the array's geometry), for strong disorder this dependence is described by a universal nonlinear function, which depends only on the array's dimensionality. In two dimensions this function is found numerically. The dimensional crossover in granular films is discussed.Comment: 6 pages, 6 figures, submitted to JETP Letter

    Wigner crystallization and metal-insulator transition of two-dimensional holes in GaAs/AlGaAs at B=0

    Full text link
    We report the transport properties of a low disorder two-dimensional hole system (2DHS) in the GaAs/AlGaAs heterostructure, which has an unprecedentedly high peak mobility of 7×105cm2/Vs7\times 10^5cm^2/Vs, with hole density of 4.8×109cm2<p<3.72×1010cm24.8\times 10^9 cm^{-2}<p<3.72\times 10^{10}cm^{-2} in the temperature range of 50mK<T<1.3K50mK<T<1.3K. From their T, p, and electric field dependences, we find that the metal-insulator transition in zero magnetic field in this exceptionally clean 2DHS occurs at rs=35.1±0.9r_s=35.1\pm0.9, which is in good agreement with the critical rsr_s for Wigner crystallization rsc=37±5{r_s}^c=37\pm 5, predicted by Tanatar and Ceperley for an ideally clean 2D system.Comment: 4 pages, 4 Postscript figure

    Hospital Performance on Percutaneous Coronary Intervention Process and Outcomes Measures

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139090/1/jah32022_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139090/2/jah32022.pd
    corecore