Applications of concurrent access patterns in web usage mining

This paper builds on the original data mining and modelling research which has proposed the discovery of novel structural relation patterns, applying the approach in web usage mining. The focus of attention here is on concurrent access patterns (CAP), where an overarching framework illuminates the methodology for web access patterns post-processing. Data pre-processing, pattern discovery and patterns analysis all proceed in association with access patterns mining, CAP mining and CAP modelling. Pruning and selection of access pat-terns takes place as necessary, allowing further CAP mining and modelling to be pursued in the search for the most interesting concurrent access patterns. It is shown that higher level CAPs can be modelled in a way which brings greater structure to bear on the process of knowledge discovery. Experiments with real-world datasets highlight the applicability of the approach in web navigation

Phenomenological Analysis of pppp and pˉp\bar{p}p Elastic Scattering Data in the Impact Parameter Space

We use an almost model-independent analytical parameterization for $pp$ and $\bar{p}p$ elastic scattering data to analyze the eikonal, profile, and inelastic overlap functions in the impact parameter space. Error propagation in the fit parameters allows estimations of uncertainty regions, improving the geometrical description of the hadron-hadron interaction. Several predictions are shown and, in particular, the prediction for $pp$ inelastic overlap function at $\sqrt{s}=14$ TeV shows the saturation of the Froissart-Martin bound at LHC energies.Comment: 15 pages, 16 figure

Galaxy Ecosystems: gas contents, inflows and outflows

We use a set of observational data for galaxy cold gas mass fraction and gas phase metallicity to constrain the content, inflow and outflow of gas in central galaxies hosted by halos with masses between $10^{11} M_{\odot}$ to $10^{12} M_{\odot}$. The gas contents in high redshift galaxies are obtained by combining the empirical star formation histories of Lu et al. (2014) and star formation models that relate star formation rate with the cold gas mass in galaxies. We find that the total baryon mass in low-mass galaxies is always much less than the universal baryon mass fraction since $z = 2$, regardless of star formation model adopted. The data for the evolution of the gas phase metallicity require net metal outflow at $z\lesssim 2$, and the metal loading factor is constrained to be about $0.01$, or about $60\%$ of the metal yield. Based on the assumption that galactic outflow is more enriched in metal than both the interstellar medium and the material ejected at earlier epochs, we are able to put stringent constraints on the upper limits for both the net accretion rate and the net mass outflow rate. The upper limits strongly suggest that the evolution of the gas phase metallicity and gas mass fraction for low-mass galaxies at $z < 2$ is not compatible with strong outflow. We speculate that the low star formation efficiency of low-mass galaxies is owing to some preventative processes that prevent gas from accreting into galaxies in the first place.Comment: 15 pages, 10 figures, submitted to MNRA

Elastic Properties of Carbon Nanotubes and Nanoropes

Elastic properties of carbon nanotubes and nanoropes are investigated using an empirical force-constant model. For single and multi-wall nanotubes the elastic moduli are shown to be insensitive to details of the structure such as the helicity, the tube radius and the number of layers. The tensile Young's modulus and the torsion shear modulus calculated are comparable to that of the diamond, while the the bulk modulus is smaller. Nanoropes composed of single-wall nanotubes possess the ideal elastic properties of high tensile elastic modulus, flexible, and light weight.Comment: 10 page

(m,n)-String-Like Dp-Brane Bound States

An (m, n)-string bound state (with m, n relatively prime integers) in type IIB string theory can be interpreted from the D-string worldsheet point of view as n D-strings carrying m units of quantized electric flux or quantized electric field. We argue, from the D-brane worldvolume point of view, that similar Dp-brane bound states should also exist for $2 \le p \le 8$ in both type IIA (when $p$ is even) and type IIB (when $p$ is odd) string theories. As in $p = 1$ case, these bound states can each be interpreted as $n$ Dp-branes carrying m units of quantized constant electric field. In particular, they all preserve one half of the spacetime supersymmetries.Comment: 16 pages, Revtex, typos corrected and references adde

A Note on N=2 Superstrings

In this note we investigate the generalised critical $N=2$ superstrings in $(1,2p)$ spacetime signature. We calculate the four-point functions for the tachyon operators of these theories. In contrast to the usual $N=2$ superstring in $(2,2)$ spacetime, the four-point functions do not vanish. The exchanged particles of the four-point function are included in the physical spectrum of the corresponding theory and have vanishing fermion charge.Comment: 8 pages, CTP TAMU-57/92, EFI-92-3