Considerate Approaches to Achieving Sufficiency for ABC model selection

For nearly any challenging scientific problem evaluation of the likelihood is problematic if not impossible. Approximate Bayesian computation (ABC) allows us to employ the whole Bayesian formalism to problems where we can use simulations from a model, but cannot evaluate the likelihood directly. When summary statistics of real and simulated data are compared --- rather than the data directly --- information is lost, unless the summary statistics are sufficient. Here we employ an information-theoretical framework that can be used to construct (approximately) sufficient statistics by combining different statistics until the loss of information is minimized. Such sufficient sets of statistics are constructed for both parameter estimation and model selection problems. We apply our approach to a range of illustrative and real-world model selection problems

Redesigning the Intermediate Course in Software Design

Learning to design software ahead of directly constructing it is a significant hurdle in a Software Engineering education. Our University has run a course in software design for second-year undergraduate students since 1994. We describe the evaluation and improvement of the course as it evolved from 2000 to 2003, from a focus on reverse engineering to forward design, to add design patterns and associated programming tasks, then has redefined its objectives and re-aligned the assessment tasks with them. We evaluated the course in four ways: by the distribution of final grades, subjective evidence on the quality of answers in the final examination, student satisfaction surveys, and comparison of students' final grades with other computing courses taken at the same time. The attempt to improve the course by introducing homework tasks on design patterns did not improve the outcomes. But re-aligning the assessment with the objectives, and introducing a component on requirements specification, improved on most measures

A pressure based charge control system for the DSPSE NiH2 CPV battery

The following topics are discussed: the Electrical Power Subsystem; the Eclipse Energy Requirements; the NiH2 CPV battery; and the battery pressure transducer. The discussion is presented in viewgraph format