Error correcting code using tree-like multilayer perceptron

An error correcting code using a tree-like multilayer perceptron is proposed. An original message \mbi{s}^0 is encoded into a codeword \boldmath{y}_0 using a tree-like committee machine (committee tree) or a tree-like parity machine (parity tree). Based on these architectures, several schemes featuring monotonic or non-monotonic units are introduced. The codeword \mbi{y}_0 is then transmitted via a Binary Asymmetric Channel (BAC) where it is corrupted by noise. The analytical performance of these schemes is investigated using the replica method of statistical mechanics. Under some specific conditions, some of the proposed schemes are shown to saturate the Shannon bound at the infinite codeword length limit. The influence of the monotonicity of the units on the performance is also discussed.Comment: 23 pages, 3 figures, Content has been extended and revise

Security and confidentiality approach for the Clinical E-Science Framework (CLEF)

Objectives: CLEF is an MRC sponsored project in the E-Science programme that aims to establish methodologies and a technical infrastructure for the next generation of integrated clinical and bioscience research. Methods: The heart of the CLEF approach to this challenge is to design and develop a pseudonymised repository of histories of cancer patients that can be accessed by researchers. Robust mechanisms and policies have been developed to ensure that patient privacy and confidentiality are preserved while delivering a repository of such medically rich information for the purposes of scientific research. Results: This paper summarises the overall approach adopted by CLEF to meet data protection requirements, including the data flows, pseudonymisation measures and additional monitoring policies that are currently being developed. Conclusion: Once evaluated, it is hoped that the CLEF approach can serve as a model for other distributed electronic health record repositories to be accessed for research

Security and confidentiality approach for the Clinical E-Science Framework (CLEF)

CLEF is an MRC sponsored project in the E-Science programme that aims to establish policies and infrastructure for the next generation of integrated clinical and bioscience research. One of the major goals of the project is to provide a pseudonymised repository of histories of cancer patients that can be accessed by researchers. Robust mechanisms and policies are needed to ensure that patient privacy and confidentiality are preserved while delivering a repository of such medically rich information for the purposes of scientific research. This paper summarises the overall approach adopted by CLEF to meet data protection requirements, including the data flows and pseudonymisation mechanisms that are currently being developed. Intended constraints and monitoring policies that will apply to research interrogation of the repository are also outlined. Once evaluated, it is hoped that the CLEF approach can serve as a model for other distributed electronic health record repositories to be accessed for research

Developing Interventions for Children's Exercise (DICE): a pilot evaluation of school-based exercise interventions for primary school children aged 7 to 8 years.

BACKGROUND: Developing Interventions for Children's Exercise (DICE) is an initiative aimed at determining effective school-based exercise programs. To assess feasibility, we conducted a pilot study of exercise sessions which varied in duration and frequency. METHODS: Exercise interventions were delivered to Year 3 pupils (age 7-8 years; n = 73) in primary schools within Yorkshire, UK. Evaluations were conducted using focus group sessions, questionnaires and observations. RESULTS: The study revealed positive aspects of all interventions, including favorable effects on children's concentration during lessons and identified the value of incorporation of the DICE concept into curriculum lessons. Children appeared enthused and reported well-being and enjoyment. Areas requiring attention were the need for appropriate timetabling of sessions and ensuring the availability of space. CONCLUSION: The concept and sessions were well-accepted by teachers who confirmed their full support of any future implementation There appears to be potential for the encouragement and empowerment of teachers to support physical activity and healthy school environments, and to take an interest in the health of their pupils. Ultimately, these findings should assist in the design of successful exercise interventions in the school setting

Photon counting strategies with low light level CCDs

Low light level charge coupled devices (L3CCDs) have recently been developed, incorporating on-chip gain. They may be operated to give an effective readout noise much less than one electron by implementing an on-chip gain process allowing the detection of individual photons. However, the gain mechanism is stochastic and so introduces significant extra noise into the system. In this paper we examine how best to process the output signal from an L3CCD so as to minimize the contribution of stochastic noise, while still maintaining photometric accuracy. We achieve this by optimising a transfer function which translates the digitised output signal levels from the L3CCD into a value approximating the photon input as closely as possible by applying thresholding techniques. We identify several thresholding strategies and quantify their impact on photon counting accuracy and effective signal-to-noise. We find that it is possible to eliminate the noise introduced by the gain process at the lowest light levels. Reduced improvements are achieved as the light level increases up to about twenty photons per pixel and above this there is negligible improvement. Operating L3CCDs at very high speeds will keep the photon flux low, giving the best improvements in signal-to-noise ratio.Comment: 7 pages, accepted by MNRA

\u27Texas Maroon’ Bluebonnet

The Texas state flower, the bluebonnet, encompasses all six of the Lupinus species native to Texas. The most widespread and popular bluebonnet, Lupinus texensis Hook., is a winter annual that produces violet-blue [violet-blue group 96A, Royal Horticultural Society (RHS), 1982] racemes in early to midspring and is predominately self-pollinating. The Texas Dept. of Transportation uses this species widely for floral displays along roadsides throughout much of the state (Andrews, 1986). Rare white and even rarer pink variants exist in native populations, and a breeding project was initiated in 1985 to develop bluebonnets with novel flower colors for use as bedding plants. ‘Abbott Pink’ was the first seed-propagated cultivar to be developed from this program (Parsons and Davis, 1993). The second cultivar, ‘Barbara Bush’ with novel lavender shade flowers, was developed more recently (Parsons et al., 1994). As with the cultivars previously developed, we used recurrent phenotypic selection to develop ‘Texas Maroon’. This cultivar is intended for use as a bedding plant for maroon flower color

Quantum walks in higher dimensions

We analyze the quantum walk in higher spatial dimensions and compare classical and quantum spreading as a function of time. Tensor products of Hadamard transformations and the discrete Fourier transform arise as natural extensions of the quantum coin toss in the one-dimensional walk simulation, and other illustrative transformations are also investigated. We find that entanglement between the dimensions serves to reduce the rate of spread of the quantum walk. The classical limit is obtained by introducing a random phase variable.Comment: 6 pages, 6 figures, published versio