Elicitation of prior distributions of variable-selection problems in regression

This paper addresses the problem of quantifying expert opinion about a normal linear regression model when there is uncertainty as to which independent variables should be included in the model. Opinion is modeled as a mixture of natural conjugate prior distributions with each distribution in the mixture corresponding to a different subset of the independent variables. It is shown that for certain values of the independent variables, the predictive distribution of the dependent variable simplifies from a mixture of $t$-distributions to a single $t$-distribution. Using this result, a method of eliciting the conjugate distributions of the mixture is developed. The method is illustrated in an example

High Resolution Rapid Response observations of compact radio sources with the Ceduna Hobart Interferometer (CHI)

Context. Frequent, simultaneous observations across the electromagnetic spectrum are essential to the study of a range of astrophysical phenomena including Active Galactic Nuclei. A key tool of such studies is the ability to observe an object when it flares i.e. exhibits a rapid and significant increase in its flux density. Aims. We describe the specific observational procedures and the calibration techniques that have been developed and tested to create a single baseline radio interferometer that can rapidly observe a flaring object. This is the only facility that is dedicated to rapid high resolution radio observations of an object south of -30 degrees declination. An immediate application is to provide rapid contemporaneous radio coverage of AGN flaring at {\gamma}-ray frequencies detected by the Fermi Gamma-ray Space Telescope. Methods. A single baseline interferometer was formed with radio telescopes in Hobart, Tasmania and Ceduna, South Australia. A software correlator was set up at the University of Tasmania to correlate these data. Results. Measurements of the flux densities of flaring objects can be made using our observing strategy within half an hour of a triggering event. These observations can be calibrated with amplitude errors better than 15%. Lower limits to the brightness temperatures of the sources can also be calculated using CHI.Comment: 6 pages, 6 figures, 1 table. Accepted for publication in A&

An Elementary Continuous-Type Nonparametric Distribution Esimate

1 online resource (PDF, 10 pages

Properties of Multivariate Cauchy and Poly-Cauchy Distributions with Bayesian g-Prior Applications

1 online resource (PDF, 21 pages

Moments of the Product-Cauchy Density and Bayesian Applications

1 online resource (PDF, 9 pages

Graduate Keynote. Golf Grip Force Evaluation in Individuals with and without Hand Arthritis Using a New Wearable Sensor Technology

BACKGROUND Hand osteoarthritis (H-OA) is the most common type of osteoarthritis largely affecting individuals over 45. H-OA involves pain, loss of grip strength and limiting participation in recreational activities such as golf. Currently, a number of ‘arthritic’ grips are designed using joint protection principles to ‘reduce hand forces and tight gripping’. However, no comprehensive examinations in their effectiveness have been conducted. HYPOTHESIS The purpose of this study is to systematically analyse the hand forces produced from various golf grips and arthritis grips at the distal-phalanges of the hand-grip interface in individuals with and without hand arthritis using new wearable sensor technology. METHODS The finger forces in the hand were measured using Pressure Profiles FingerTPS system for participant’s bottom gripping hand thumb, index, middle and ring fingers. The participants performed 3 golf shots using a real ball on artificial turf with 12, mid-iron clubs fitted with various types of standard and arthritis grips. RESULTS Preliminary results of 4 healthy participants demonstrated that serrated style golf grips designed for players with arthritis produced some of the highest forces. Also, players with larger hand length measures produce higher forces in smaller diameter grips and small hand length measures in larger diameter grips. DISCUSSION These preliminary results demonstrate the possibility that ‘arthritic’ golf grips are not appropriately designed for the given user along with the potential relationship between grip geometry and hand size to finger forces. In better understanding the mechanics of arthritis and its relation to sports, the design of more advanced sporting equipment can be developed

Extending Families of Densities by Special-Function Factors

1 online resource (PDF, 29 pages