A unified method for statistical anomaly detection in intrusion detection systems is theoretically introduced. It is based on estimating a dispersion measure of numerical or symbolic data on successive moving windows in time and finding the times when a relative change of the dispersion measure is significant. Appropriate dispersion measures, relative differences, moving windows, as well as tec...

Dispersion in porous media is currently an important subject that occurs in different domains (processes, environment, oil recovery...). We have used the nuclear magnetic resonance, and more precisely the Pulsed Field Gradient (PFG-NMR) techniques to characterize this phenomenon. A PGSTE sequence (Pulsed Field Gradient Stimulated Echo) is used to measure longitudinal and transversal displacemen...

A new measure of dispersion is introduced as a representation of consensus (agreement) and dissention (disagreement). Building on the generally accepted Shannon entropy, this measure utilizes a probability distribution and the distance between categories to produce a value spanning the unit interval. The measure is applied to the Likert scale (or any ordinal scale) to determine degrees of conse...

The Fallbrook Low-Frequency Immediate Response Telescope (FLIRT) is an experiment designed to detect prompt radio counterparts to gamma ray bursts (GRBs) at 74 MHz. FLIRT is notiied of GRBs by the BACODINE and radio observations begin as early as one minute after the detection of a GRB. The goal of FLIRT is to detect radio counterparts to GRBs and measure their distances by measuring the disper...

In this paper we investigate the relationship between price dispersion and inflation; we use weekly retail scanner data from 2009 to 2011 to measure price dispersion and inflation for several dairy products. We implement a linear model to investigate the linkage between price dispersion and consumer price indexes. As in the previous literature, we obtain mixed results with respect to the relati...

Hydrocarbon contamination of unsaturated soils has been a serious environmental problem for decades. Two of the most common methods of remediating these sites are soil vapour extraction (SVE) and bioventing. Predictive models have been developed for the SVE and bioventing processes in order to estimate mass transfer coefficients for experimental systems and clean up times for field sites. These...

Performance of optical interconnects using volume holographic gratings and substrate-guided waves is subject to source wavelength detuning which originates from laser chirping and operating temperature changes. In this letter, we characterize and measure the dispersion of commonly used surface-normal volume holographic gratings. Dispersion characteristics of a 20 mm thick photopolymer volume ho...

An approximate confidence interval is proposed for a robust measure of relative dispersion—the coefficient of quartile variation. The proposed method provides an alternative to interval estimates for other measures of relative dispersion. © 2005 Elsevier B.V. All rights reserved.