20,880 research outputs found
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
The Spin Stiffness and the Transverse Susceptibility of the Half-filled Hubbard Model
The spin stiffness and the transverse susceptibility of the square lattice half-filled Hubbard model are calculated as a
function of the Hubbard parameter ratio by series expansions around the
Ising limit. We find that the calculated spin-stiffness, transverse
susceptibility, and sublattice magnetization for the Hubbard model smoothly
approach the Heisenberg values for large . The results are compared for
different with RPA and other numerical studies.Comment: 9 Revtex pages, 3 Postscript figures, Europhys. Lett. in pres
Competition between Normal Superfluidity and Larkin-Ovchinnikov Phases of Polarized Fermi Gases in Elongated Traps
By applying the recently proposed antisymmetric superfluid local density
approximation (ASLDA) to strongly interacting polarized atomic gases at
unitarity in very elongated traps, we find families of Larkin-Ovchinnikov (LO)
type of solutions with prominent transversal oscillation of pairing potential.
These LO states coexist with a superfluid state having a smooth pairing
potential. We suggest that the LO phase could be accessible experimentally by
increasing adiabatically the trap aspect ratio. We show that the local
asymmetry effects contained in ASLDA do not support a deformed superfluid core
predicted by previous Bogoliubov-de Gennes treatments.Comment: 4 pages, 4 figures; revision; accepted for publication in Phys.Rev.A
(Rapid Communication
Linear relations among 4-point functions in the high energy limit of string theory
The decoupling of zero-norm states leads to linear relations among 4-point
functions in the high energy limit of string theory. Recently it was shown that
the linear relations uniquely determine ratios among 4-point functions at the
leading order. The purpose of this paper is to extend the validity of the same
approach to the next-to-leading order and higher orders.Comment: 17 pages, references added, minor modificatio
- …