A decision theoretic analysis of the unit root hypothesis using mixtures of elliptical models

Time Series;Unit Root

A Formal Theory of Key Conjuring

Key conjuring is the process by which an attacker obtains an unknown, encrypted key by repeatedly calling a cryptographic API function with random values in place of keys. We propose a formalism for detecting computationally feasible key conjuring operations, incorporated into a Dolev-Yao style model of the security API. We show that security in the presence of key conjuring operations is decidable for a particular class of APIs, which includes the key management API of IBM’s Common Cryptographic Architecture (CCA)

The components of output growth: A cross-country analysis

Economic Growth;Output;Productivity

Hospital efficiency analysis through individual effects: A Bayesian approach

Monte Carlo Technique;Hospitals;Bayesian Statistics;Markov Chains;Panel Data

Bayesian efficiency analysis with a flexible form: The aim cost function

Sampling;Bayesian Statistics

A wireless ultrasonic NDT sensor system

Ultrasonic condition monitoring technologies have been traditionally utilized in industrial and construction environments where structural integrity is of concern. Such techniques include active systems with either single or multiple transmit-receiver combinations used to obtain defect positioning and magnitude. Active sensors are implemented in two ways; in a thickness operation mode, or as an area-mapping tool operating over longer distances. In addition, passive ultrasonic receivers can be employed to detect and record acoustic emission activity. Existing equipment requires cabling for such systems leading to expensive, complicated installations. This work describes the development and operation of a system that combines these existing ultrasonic technologies with modern wireless techniques within a miniaturized, battery-operated design. A completely wireless sensor has been designed that can independently record and analyze ultrasonic signals. Integrated into the sensor are custom ultrasonic transducers, associated analogue drive and receive electronics, and a Texas Instruments Digital Signal Processor (DSP) used to both control the system and implement the signal processing routines. BlueTooth wireless communication is used for connection to a central observation station, from where network operation can be controlled. Extending battery life is of prime importance and the device employs several strategies to do this. Low voltage transducer excitation suffers from poor signal-to-noise ratios, which can be enhanced by signal processing routines implemented on the DSP. Routines investigated include averaging, digital filtering and pulse compression

Estimating end-use demand: A Bayesian approach

Eliminating negative end-use or appliance consumption estimates and incorporating direct metering information into the process of generating these estimates; these are two important aspects, of conditional demand analysis (CDA) that will be the focus of this raper. In both cases a Bayesian approach seems a natural way of proceeding. What needs to be investigated is whether it is also a viable and effective approach. In addition, such a framework naturally lends itself to prediction. Our application involves the estimation of electrical appliance consumptions for a sample of Australian households. This application is designed to illustrate the viability of a full Bayesian analysis of the problem

A Stochastic Frontier Analysis of Output Level and Growth in Poland and Western Economies

This paper uses Bayesian stochastic frontier methods to measure the productivity gap between Poland and Western countries that existed before the beginning of the main Polish economic reform. Using data for 20 Western economies, Poland and Yugoslavia (1980-1990) we estimate a translog stochastic frontier and make inference about individual efficiencies. Following the methodology proposed in our earlier work, we also decompose output growth into technical, efficiency and input changes and examine patterns of growth in the period under consideration.Bayesian inference;efficiency;Gibbs sampling;productivity analysis;technical change

Proposal for an Integrated Raman-free Correlated Photon Source

We propose a dual-pump third-order nonlinear scheme for producing pairs of correlated photons that is less susceptible to Raman noise than typical spontaneous four wave mixing methods (SFWM). Beginning with the full multimode Hamiltonian we derive a general expression for the joint spectral amplitude, from which the probability of producing a pair of photons can be calculated. As an example, we demonstrate that a probability of 0.028 pairs per pulse can be achieved in an appropriately designed fused silica microfiber. As compared with single pump SFWM in standard fiber, we calculate that our process shows significant suppression of the spontaneous Raman scattering and an improvement in the signal to noise ratio.Comment: 7 pages, 3 figures (two containing 2 subfigures