Salford Systems (United States)

A generalized maximum entropy estimator is developed for the linear simultaneous equations model. Monte Carlo sampling experiments are used to evaluate the estimator’s performance in small and medium sized samples, suggesting contexts in which the current generalized maximum entropy estimator is superior in mean square error to two and three stage least squares. Analytical results are provided relating to asymptotic properties of the estimator and associated hypothesis testing statistics. Monte Carlo experiments are also used to provide evidence on the power and size of test statistics. An empirical application is included to demonstrate the practical implementation of the estimator.

Mobile phone customers face many choices regarding handset hardware, add-on services, and features to subscribe to from their service providers. Mobile phone companies are now increasingly interested in the drivers of migration to third generation (3G) hardware and services. Using real world data provided to the 10th Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD) 2006 Data Mining Competition we explore the effectiveness of Friedman’s stochastic gradient boosting (Multiple Additive Regression Trees [MART]) for the rapid development of a high performance predictive model.

Ferric chloride induced ring expansion-cyclisation of cyclopropyl silyl ether derivitives provided access to functionalised [4.3.0] and [6.3.0] carbocycles.

Factors from the social history of male psychopaths were examined in relation to their success or failure as measured by re-convictions of psychiatric hospital re-admissions 2-3 years after treatment at Henderson Hospital. From these data a weighted prediction formula was calculated and was tested out on a further cohort of patients. As a prediction instrument it was found to be reliable to a degree of significance just above the 1 per cent level. Other aspects of the subsequent career of treated patients are noted, in particular a tendency to early but often short-lived relapse and then longer standing success.