Building prior distributions to support Bayesian reliability growth modelling using expert judgement

A sound methodology for the elicitation of subjective expert judgement is a pre-requisite for specifying prior distributions for the parameters of reliability growth models. In this paper, we describe an elicitation process that is developed to ensure valid data are collected by suggesting how possible bias might be identified and managed. As well as discussing the theory underpinning the elicitation process, the paper gives practical guidance concerning its implementation during reliability growth testing. The collection of subjective data using the proposed elicitation process is embedded within a Bayesian reliability growth modelling framework and reflections upon its practical use are described.     

Bit-swapping LFSR for low-power BIST

A modified linear feedback shift register (LFSR) is presented that reduces the number of transitions at the inputs of the circuit-under-test by 25% using a bit-swapping technique. Experimental results on ISCAS'85 and 89 benchmark circuits show up to 45% power reduction during test. They also show that the proposed design can be combined with other techniques to achieve a very substantial power reduction of up to 63%.     

Changes in blood glucose, nonesterified fatty acids, and ketones in response to weaning and feed intake in young calves

Effects of weaning age on blood glucose, ketones, and nonesterified fatty acids were examined using 16 Holstein heifer calves. Animals entered the study at 6 +/- 3.5 d of age and were fed 1.8 kg of milk twice daily to 28 (early weaning) or 56 d (late weaning) and a commercial pelleted calf starter from 0 (early) or 28 d (late). Blood was sampled once weekly for 14 wk and analyzed for beta-hydroxybutyrate and acetoacetate. Plasma was analyzed for glucose and nonesterified fatty acids. Blood beta-hydroxybutyrate increased with increasing grain intake and was greater during wk 0 to 4 and 5 to 8 in calves weaned early than in those weaned late. Blood acetoacetate followed trends similar to beta-hydroxybutyrate and averaged 23.8 and 16.1 microM in calves weaned early and late, respectively. Plasma glucose and nonesterified fatty acids declined with age and were lower during 5 to 8 wk in calves weaned early. Data suggest that ketone concentrations resulted from alimentary ketogenesis, which increased rapidly after weaning.     

Modelling to assist in wastewater collection system odour and corrosion potential evaluations.

Odour emissions and corrosion concerns can be a constant focus for many wastewater treatment and collection system owners, usually from the first day that their collection systems begin operation. Many sewer systems are reaching the end of their useful life, or have experienced either odour or corrosion issues. This paper shows a link between odour generation and corrosion potential, and how modelling can be used to assist in odour/corrosion assessments of existing wastewater collection systems. A model has been developed that is capable of predicting liquid-phase sulphide generation and subsequent release to overlying sewer headspace as hydrogen sulphide (H2S), where it can be the source of either odour or corrosion problems. This paper presents an overview of the model, and uses a case study involving both odour and corrosion issues to demonstrate the utility in modelling. The model was used to identify potential locations within the system where odour/corrosion may be problematic, as well as assisting in the evaluation of potential odour control alternatives.     

Sodium bicarbonate and yeast culture effects on ruminal fermentation, growth, and intake in dairy calves.

Sodium bicarbonate and yeast culture effects on ruminal fermentation, intake, and growth were evaluated in young calves. In trail 1, nine ruminally cannulated Holstein calves averaging 12 wk of age were fed control starter (17% CP) or starters containing 3% sodium bicarbonate or .2% yeast (Saccharomyces cerevisiae) culture in a 3 x 3 Latin square. Calves were fed for ad libitum consumption for 10 d and then at 85% of ad libitum intake to d 14. Ruminal fluid taken at 0 h postfeeding tended to have higher pH and a greater proportion of acetate when calves were fed sodium bicarbonate, but other ruminal and blood parameters did not differ among treatments. By 4 h after feeding, ruminal VFA had increased to 120.7 mM, molar proportions of individual acids were altered, and blood ketones and VFA increased in treated calves. In trial 2, 42 Jersey calves were fed experimental starters for ad libitum consumption during a 12-wk study. Calves began the study at 3 to 5 d of age. There were no significant effects of yeast culture or sodium bicarbonate on DMI or intake of starter, rates of gain, or feed efficiency. Plasma urea N was reduced when sodium bicarbonate was fed. Both sodium bicarbonate and yeast culture affected blood and ruminal metabolites when calves were limit-fed but did not influence intake or daily gain when calves were fed for ad libitum consumption.     

Cochlear implants in children

Cochlear implants are no longer considered new or experimental technology. Difficulty in evaluating the degree of hearing loss and response to traditional forms of amplification in young children makes pediatric cochlear implant candidacy a complex issue. Cochlear implantation and, in particular, pediatric cochlear implantation, requires a team commitment with contributions from surgeons, audiologists, speech pathologists, psychologists, and special educators. Elements discussed include assessment and candidacy issues, surgical technique, elements of a cochlear implant team, outcome assessment, and potential complications. The decision to perform pediatric cochlear implantation should not be undertaken without serious consideration to the enormous commitment required in both financial and personnel terms.