Birk Pettersson (capbike39)

Electronic circuits and systems employed in mission- and safety-critical applications such as space, aerospace, nuclear plants etc. tend to suffer from multiple faults due to radiation and other harsh external phenomena. To overcome single or multiple faults from affecting electronic circuits and systems, progressive module redundancy (PMR) has been suggested as a potential solution that recommends the use of different levels of redundancy for the vulnerable portions of a circuit or system depending upon their criticality. According to PMR, triple modular redundancy (TMR) can be used where a single fault is likely to occur and should be masked, and quintuple modular redundancy (QMR) can be used where double faults are likely to occur and should be masked. In this article, we present asynchronous QDI majority voter designs for QMR and state which are preferable from cycle time (i.e., speed), area, power, and energy perspectives. Towards this, we implemented example QMR circuits in a robust QDI asynchronous design style by employing a delay insensitive dual rail code for data encoding and adopting four-phase handshake protocols for data communication. Based on physical implementations using a 32/28nm CMOS process, we find that our proposed QMR majority voter achieves improved optimization in speed and energy.Dendrochronology, the study of annual rings formed by trees and woody plants, has important applications in research of climate and environmental phenomena of the past. Since its inception in the late 19th century, dendrochronology has not had a way to quantify uncertainty about the years assigned to each ring (dating). There are, however, many woody species and sites where it is difficult or impossible to delimit annual ring boundaries and verify them with crossdating, especially in the lowland tropics. Rather than ignoring dating uncertainty or discarding such samples as useless, we present for the first time a probabilistic approach to assign expected ages with a confidence interval. It is proven that the cumulative age in a tree-ring time series advances by an amount equal to the probability that a putative growth boundary is truly annual. Confidence curves for the tree stem radius as a function of uncertain ages are determined. A sensitivity analysis shows the effect of uncertainty of the probability that a recognizable boundary is annual, as well as of the number of expected missing boundaries. Furthermore, we derive a probabilistic version of the mean sensitivity of a dendrochronological time series, which quantifies a tree's sensitivity to environmental variation over time, as well as probabilistic versions of the autocorrelation and process standard deviation. A computer code in Mathematica is provided, with sample input files, as supporting information. Further research is necessary to analyze frequency patterns of false and missing boundaries for different species and sites.[This corrects the article DOI 10.1371/journal.pone.0097342.]. To develop and validate a 4-item child oral health-related quality of life (OHRQoL) instrument that might be more amenable for uptake in large scale, multifaceted surveys of children's health and wellbeing than current, longer-form child OHRQoL instruments. Data were obtained from a study of the South Australian School Dental Service population designed to investigate OHRQoL among school children aged 8-13 years in 2002-2003. The Child Perception Questionnaire (CPQ8-10 and CPQ11-14) was utilised, which comprises 25 & 37 items representing four conceptual domains oral symptoms, functional limitations, emotional wellbeing and social wellbeing. Initially, the psychometric properties of the short form 8-item CPQ were tested in both age groups using Confirmatory Factor Analysis. The rationale was that, if the 8-item CPQ8-10 and CPQ11-14 did not display good psychometric properties, there was no reason to proceed with further shortening into 4-item versions. Follow