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This paper considers a competing risks model for right-censored and length-biased survival data from prevalent sampling. We propose a nonparametric quantile inference procedure for cause-specific residual life distribution with competing risks data. We also derive the asymptotic properties of the proposed estimators of this quantile function. Simulation studies and the unemployment data demonstrate the practical utility of the methodology.

Porous, phosphate-silicate glass with high-conductivity and nano-size pores was synthesized through a xero-gel route, using non-ionic surfactant polyethylene glycol monocetyl ether (Brij 56) to control pore size. The influences of Brij 56 concentration on pore size and conductivity under different humidity were studied by measuring conductivity and calculating the volume ratio of adsorbed-water to pore volume. Samples prepared with 0.1 wt% Brij 56 had 5.2 nm pore size, 0.91 volume ratio, and narrower pore size distribution than other samples. The nano-size pores were filled with water, which in pores of 5.2 nm is mostly chemically bonded with the hydroxyl groups on the pore surfaces, resulting in higher conductivity than other samples in high relative humidity (over 55%).

We analyze left-truncated and right-censored data using Cox proportional hazard models with long-term survivors. The estimators of covariate coefficients and the long-term survivor proportion are obtained by the partial likelihood method, and their asymptotic properties are also established. Simulation studies demonstrate the performance of the proposed estimators, and an application to a real dataset is provided.

We review the historical, geological, tide-gauge, GPS and gravimetric evidence advanced in favour of, or against, continuing land uplift around Hudson Bay, Canada. We also reanalyse the tide-gauge and GPS data for Churchill using longer time series than those available to previous investigators. The dependence of the mean rate of relative sea-level change obtained from the tide-gauge record on the length and mid-epoch of the observation interval considered is investigated by means of a newly developed linear-trend analysis diagram. For studying the shorter-period variability of the tide-gauge record, the wavelet transform is used. The mean rate of land uplift obtained from GPS is based on a new analysis using IGS solutions of GFZ. To include the post-glacial land uplift, sea-level indicators from the Churchill region representing the relative sea-level history during the past 8000 years are also used. Finally, the values of the four observables are jointly inverted in terms of mantle viscosity. The optimum values are ~3.2 × 1020 Pa s and ~1.6 × 1022 Pa s for the upper- and lower-mantle viscosities, respectively.

The transport properties in ultrasmall single-wall carbon nanotubes (SWCNTs) under tensile strain have been theoretically investigated. The regular negative differential resistance (NDR) induced by the strain undergoes a process from enhancement to weakening in the zigzag (3,[Formula: see text]0) SWCNT. The NDR achieves maximum with applying 4% tensile strain. Compared to the case of (3,[Formula: see text]0) SWCNT, that NDR cannot be manipulated by applying strain clearly in (4,[Formula: see text]0) and (5,[Formula: see text]0) ultrasmall SWCNTs with tensile strain lower than 10%. It proposes this strain-induced NDR effect to demonstrate the possibility of finding potential applications in SWCNT-based NDR nanodevices such as in memory devices, oscillators and fast switching devices.

Variance component estimation (VCE) is applied to precise orbit determination (POD) of the ERS-2 satellite. Twenty 5-day long arcs in the early three months in 1998 were calculated using the SLR and PRARE data. In the data the adjacent arcs overlap for two days except the intervals for orbit maneuver. The effect of VCE orbit determination on the calculation is investigated by an analysis of residuals and comparison of overlapping arcs, and the mean a posteriori standard deviation of each group of measured residuals is given. It is shown by the residuals analysis that the fitting of the measurements is significantly improved by VCD. However, according to Abbey criterion, VCD is not able to eliminate the systematic errors due to errors in the dynamic and geometric models. The results of the comparison of the overlapping arcs show that (1) VCE reduces the mean range deviation of overlapping arcs, especially where there are obviously unreasonable deviations, so that the orbit obtained has a more uniform precision; (2) By using VCE, adjacent arcs tend to close up and this is more apparent in the transverse direction. From the mean a posteriori standard error of each group of measurements, it can be seen that as far as the single normal point measurement is concerned, the data of some SLR stations are more important than other measurements in POD calculation. Generally speaking, determination of weighting by using VCE is more reasonable than by using initial standard deviation.

The Chebyshev-collocation method is briefly presented in a manner favorable for solving ODEs in geophysics depending on geocentric distance and singular at the Earth center. The main advantage of this method is that it is not needed to treat the ODEs particularly at the Earth center as is traditionally done when using the Runge-Kutta method. Comparisons of spheroidal free oscillation periods and load Love numbers with earlier works show very close agreement.

A statistical study has been made for the variations along the Hubble sequence, os such parameters as the degree of tightness of winding of spiral arm λ, the pitch angle μ, the flatness of the disk H/D25 and the thickness H along the Hubble sequence for 365 spiral galaxies published in A&Ap Supplement Series. The mean values of these quantities for the various Hubble types have been obtained for the first time. The results of the statistics show clearly 1) that the Hubble classification of spiral galaxies is one which has only a qualitative and statistical significance, and 2) that the dispersion relation in the density wave theory is valid for most spiral galaxies, i.e., the arms of most spiral galaxies satisfy the requirements of being tightly wound.

We investigate the band structure of narrow armchair-edge graphene nanoribbons (AGNRs) under tensile strain by means of an extension of the Extended Hückel method. The strain-induced band gap modulation presents asymmetric behavior. The asymmetric modulation of band gap is derived from the different changes of conduction and valence bands near Fermi level under tensile strain. Further analysis suggests that the asymmetric variation of band structure near Fermi level only appear in narrow armchair-edge graphene nanoribbons.