Book Review

Abstract

Data Base Directions, The Next Steps. John L. Berg, Editor. U. S. Department of Commerce, National Bureau of Standards. (Order from Superintendent of Documents, U. S. Government Printing Office, Washington, DC, 20402. Ask f o r SD Cat.No. C13.10:451.) 158 pages; $2.45.     

Free inductive K-semialgebras

We consider rational power series over an alphabet Σ with coefficients in a ordered commutative semiring K and characterize them as the free ordered semialgebras in various classes defined by the least pre-fixed point rule and its dual. The results are generalizations of Kozen’s axiomatization of regular languages.     

Mixture and non-mixture cure fraction models based on the generalized modified Weibull distribution with an application to gastric cancer data

The cure fraction models are usually used to model lifetime time data with long-term survivors. In the present article, we introduce a Bayesian analysis of the four-parameter generalized modified Weibull (GMW) distribution in presence of cure fraction, censored data and covariates. In order to include the proportion of “cured” patients, mixture and non-mixture formulation models are considered. To demonstrate the ability of using this model in the analysis of real data, we consider an application to data from patients with gastric adenocarcinoma. Inferences are obtained by using MCMC (Markov Chain Monte Carlo) methods.     

Point Defects in CdZnTe Crystals Grown by Different Techniques

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps’ energies and densities.