A Survey of Monte Carlo Tree Search Methods

Monte Carlo tree search (MCTS) is a recently proposed search method that combines the precision of tree search with the generality of random sampling. It has received considerable interest due to its spectacular success in the difficult problem of computer Go, but has also proved beneficial in a range of other domains. This paper is a survey of the literature to date, intended to provide a snapshot of the state of the art after the first five years of MCTS research. We outline the core algorithm's derivation, impart some structure on the many variations and enhancements that have been proposed, and summarize the results from the key game and nongame domains to which MCTS methods have been applied. A number of open research questions indicate that the field is ripe for future work

Anniversary Paper: A sampling of novel technologies and the role of medical physicists in radiation oncology

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135037/1/mp1006.pd

Neuropsychological health in F-111 aircraft maintenance workers

Objective: To contrast subjective and objective measures of neuropsychological health in F-111 aircraft Deseal/Reseal maintenance personnel, against two appropriate comparison groups. Methods: Exposed and comparison participants completed a postal questionnaire which included a validated memory questionnaire and additional questions relating to possible cognitive symptoms. They also underwent a comprehensive neuropsychological assessment and screening for a past or current disturbance of mood. Multiple linear or logistic regression was conducted for each outcome using exposure group and potential confounders as explanatory variables. Results: There was a strong and consistent excess of self-reported cognitive problems among the exposed group relative to the comparison groups including a 2.8–4.3-fold increase in self-reported symptoms of forgetfulness, loss of concentration and difficulty finding the right word. On detailed neuropsychological testing, the exposed group performed significantly worse than comparisons on tests of psychomotor speed, executive functioning, and new learning/memory. These findings could not be accounted for by disturbances of mood or other potential confounders. Conclusions: There was a strong and consistent increase in self-reported cognitive problems among the exposed, and small but significant exposure-specific differences on objective tests of cognitive functioning. The findings are consistent with the development of adverse neuropsychiatric changes related to occupational exposure to solvents

Quantitative Light Fluorescence (QLF) and Polarized White Light (PWL) assessments of dental fluorosis in an epidemiological setting

<p>Abstract</p> <p>Background</p> <p>To determine if a novel dual camera imaging system employing both polarized white light (PWL) and quantitative light induced fluorescence imaging (QLF) is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods.</p> <p>Methods</p> <p>Subjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3) participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean’s and Thylstrup and Fejerskov (TF) Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean’s and TF indices by raters and fluorescence images were automatically scored using software.</p> <p>Results</p> <p>Data from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean’s and TF index. Agreement (measured by weighted Kappa’s) between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92.</p> <p>Conclusions</p> <p>The study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.</p