On the feasibility of applying capture–recapture experiments for web evolution estimations

This paper proposes a novel application for estimating the size and evolution of web page populations, based on the capture–recapture methodology, which is mainly used in wildlife biological studies. Firstly, we present the necessary modifications and amendments needed for the web capture–recapture paradigm, and then we discuss the limitations confronted. The paper provides the implementation details of the proposed web capture recapture model along with its initial assessment. The anticipated outcome was to examine whether we can conduct capture–recapture experiments on the web (or a web sub-universe such as an Internet search engine directory), in order to further estimate evolution rates in web page populations.     

Pionic deuterium

Data taking of the PIONIC HYDROGEN project has been completed with a high statistics study of the strong-interaction effects in πD by measuring the Kβ X-radiation for three different target densities with a high resolution Bragg crystal spectrometer. The πD hadronic shift will provide a constraint for the πN isospin scattering lengths extracted from the πH measurement. The hadronic width is directly related to pion production at threshold.     

Precision Measurement of the Charged Pion Mass by High Resolution X-Ray Spectroscopy

A new experiment for a high-precision measurement of the pion mass at a 1 ppm level is presented. It combines an improved cyclotron trap that produces pionic and muonic atoms in a small volume with a doubly focusing crystal spectrometer to measure the corresponding exotic X-ray transitions with high accuracy and a novel type of CCD detector. The muonic X-rays lines serve as highly accurate calibration lines. The measurement has been accomplished recently. A detailed analysis of the data is on the way. This revised version was published online in July 2006 with corrections to the Cover Date.     

The intermittent behavior of a second-order non-linear non-autonomous oscillator

The experimental time-series produced by a second-order non-linear, non-autonomous, closed-loop electronic circuit were recorded and subsequently evaluated. The correlation and embedding dimensions, as well as the corresponding Kolmogorov entropies of the oscillating system, have been numerically calculated and compared to the corresponding Lyapunov exponents.     

K X-ray satellites of uranium bombarded with 500 MeV neon

K X-ray satellite spectra produced during the bombardment of uranium with 500 MeV neon, have been investigated with a high resolution crystal spectrometer. The experimental results are compared with theoretical predictions for vacancy production computed in the semiclassical separate atom perturbation theory and corrected forL subshell coupling and electron transfer from targetL shell into projectileK shell. The agreement between theory and experiment is rather good. It turns out, that the reduction ofL vacancy production due toL subshell coupling is essentially compensated by theL electron transfer from target to projectile. The present work is an extension of a previous study of theK α₁ satellite spectra of tantalum bombarded with 403 MeV nitrogen.     

Iron(II) and iron(III) complexes of 2,4-dithiobiuret

Summary Ferrous and ferric complexes of 2,4-dithiobiuret (Dtb) of the type Fe(Dtb)_m Xn where m, n = 1-3, and X = CI^–, Br^–, I^– and SO ₄ ^2– , and a neutral Fe(Dtb-H)2 complex have been synthesized and characterised by elemental analyses, magnetic susceptibility, i.r., electronic and Mössbauer spectroscopic studies. From its i.r. spectrum Dtb was found to act as a S,S-coordinating bidentate chelate. The magnetic moment, electronic and Massbauer spectra are consistent with a low spin distorted octahedral structure for the ferric complexes and a high spin form for ferrous complexes.     

The solution space of the unitary matrix model string equation and the Sato Grassmannian

The space of all solutions to the string equation of the symmetric unitary one-matrix model is determined. It is shown that the string equation is equivalent to simple conditions on pointsV ₁ andV ₂ in the big cell Gr⁽⁰⁾ of the Sato Grassmannian Gr. This is a consequence of a well-defined continuum limit in which the string equation has the simple form matrices of differential operators. These conditions onV ₁ andV ₂ yield a simple system of first order differential equations whose analysis determines the space of all solutions to the string equation. This geometric formulation leads directly to the Virasoro constraintsL _n (n0), whereL _n annihilate the two modified-KdV -functions whose product gives the partition function of the Unitary Matrix Model.     

A framework of incorporating confidence levels to deal with uncertainty in pairwise comparisons

Central European Journal of Operations Research - Pairwise comparison is a key ingredient in multi-criteria decision analysis. The method is based on a set of comparisons conducted by a group of...