In recent years, there has been significant momentum in applying deep learning (DL) to machine health monitoring (MHM). It has been widely claimed that DL methodologies are superior to more traditional techniques in this area. This paper aims to investigate this claim by analysing a real-world dataset of helicopter sensor faults provided by Airbus. Specifically, we will address the problem of machine sensor health unsupervised classification. In a 2019 worldwide competition hosted by Airbus, Fujitsu Systems Europe (FSE) won first prize by achieving an F1-score of 93% using a DL model based on generative adversarial networks (GAN). In another comprehensive study, various modified and existing image encoding methods were compared for the convolutional auto-encoder (CAE) model. The best classification result was achieved using the scalogram as the image encoding method, with an F1-score of 91%. In this paper, we use these two studies as benchmarks to compare with basic statistical analysis methods and the one-class supporting vector machine (SVM). Our comparative study demonstrates that while DL-based techniques have great potential, they are not always superior to traditional methods. We therefore recommend that all future published studies of applying DL methods to MHM include appropriately selected traditional reference methods, wherever possible.

Anaemia is a public health problem in Ghana. We sought to identify factors associated with haemoglobin concentration (Hb) and anaemia among school-attending adolescents. We analysed data from 2948 adolescent girls and 609 boys (10–19 years) selected from 115 schools from regions of Ghana as a secondary analysis of baseline surveys conducted at two time-points. We measured Hb, malaria from capillary blood, anthropometry and used a modified food frequency questionnaire to assess diet. Multivariable linear and Poisson regression models were used to identify predictors of Hb and anaemia. The prevalence of anaemia, malaria and geophagy were 24, 25, and 24 %, respectively, among girls and 13, 27 and 6 %, respectively, among boys. Girls engaging in geophagy had a 53 % higher adjusted prevalence of anaemia and 0⋅39 g/dl lower Hb. There were similar results among those who tested positive for malaria (+52 % anaemia; −0⋅42 g/dl Hb). Among girls, lower anaemia prevalence and higher Hb were associated with consumption of foods rich in haeme iron (−22 %; +0⋅18 g/dl), consumption of iron-fortified cereal/beverages consumed with citrus (−50 %; +0⋅37 g/dl) and being overweight (−22 %; +0⋅22 g/dl). Age was positively associated with anaemia among girls, but negatively associated among boys. Boys who tested positive for malaria had 0⋅31 g/dl lower Hb. Boys who were overweight or had obesity and consumed flour products were also more likely to be anaemic (119 and 56 %, respectively). Factors associated with Hb and anaemia may inform anaemia reduction interventions among school-going adolescents and suggest the need to tailor them uniquely for boys and girls.

Shiga toxin-producing Escherichia coli (STEC) infection can cause serious illness including haemolytic uraemic syndrome. The role of socio-economic status (SES) in differential clinical presentation and exposure to potential risk factors amongst STEC cases has not previously been reported in England. We conducted an observational study using a dataset of all STEC cases identified in England, 2010–2015. Odds ratios for clinical characteristics of cases and foodborne, waterborne and environmental risk factors were estimated using logistic regression, stratified by SES, adjusting for baseline demographic factors. Incidence was higher in the highest SES group compared to the lowest (RR 1.54, 95% CI 1.19–2.00). Odds of Accident and Emergency attendance (OR 1.35, 95% CI 1.10–1.75) and hospitalisation (OR 1.71, 95% CI 1.36–2.15) because of illness were higher in the most disadvantaged compared to the least, suggesting potential lower ascertainment of milder cases or delayed care-seeking behaviour in disadvantaged groups. Advantaged individuals were significantly more likely to report salad/fruit/vegetable/herb consumption (OR 1.59, 95% CI 1.16–2.17), non-UK or UK travel (OR 1.76, 95% CI 1.40–2.27; OR 1.85, 95% CI 1.35–2.56) and environmental exposures (walking in a paddock, OR 1.82, 95% CI 1.22–2.70; soil contact, OR 1.52, 95% CI 2.13–1.09) suggesting other unmeasured risks, such as person-to-person transmission, could be more important in the most disadvantaged group.

Recreational saltwater anglers from the mid-Atlantic through the Gulf of Mexico commonly target red drum. Due to concerns about overharvesting within South Carolina coupled with regional management actions, South Carolina explored the technical feasibility of stocking hatchery-produced juvenile red drum as a technique to augment the abundance of South Carolina stock. In order to assess a continued program, in 2005 a mail survey was used to collect data for estimating the economic benefits with the contingent valuation method. The theoretical validity of willingness to pay was assessed by comparison to the value of a change in red drum fishing trips that would result from the program. Benefits were compared to estimated, explicit stocking costs. We illustrate how a certainty recode approach can be used in sensitivity analysis. The net present values (NPVs) for the stocking program are positive suggesting that the program would have been economically efficient relative to no program.

The aerodynamic performance of a multi-elementhigh-lift system has a critical influence on thedirect operating cost of a subsonic civil transportaircraft. A thorough understanding of theaerodynamic characteristics of these multi-elementaerofoils and wings allows aircraft companies todesign and build more competitive aircraft withhigh-lift systems that are less complex and lighterfor given high-lift performance or that haveimproved lift and drag characteristics for givensystem complexity and weight. Flight experiments onNASA Langley's B737-100 aircraft have been conductedto further enhance the understanding of the complexflows about multi-element high-lift systems atfull-scale flight conditions. In this paper, anoverview of the flight program is provided, followedby highlights of experimental results andcomputational analysis. Measurements includedsurface pressures on the slats, main element andflap elements using flush pressure ports andpressure belts, surface shear stresses using Prestontubes, off-surface velocity distributions usingboundary layer/wake rakes, aeroelastic deformationsof the flap elements using an optical positioningsystem, and boundary layer transition detectionusing hot-film anemometers and an infrared imagingsystem. Boundary layer transition measurements onthe slat using hot-film sensors are correlated withthe flow visualisation results from an infraredimaging technique. Extensive application of severalcomputational techniques and comparisons with flightmeasurements are shown for a limited number ofcases. This program has generated an extensive setof data, much of which are still being analysed.

In the first half of the paper some of the basic aerodynamic engineering and piloting problems that have been encountered during the design and development of modern naval deck landing aircraft are enumerated and described. Such aircraft, of basically swept-wing configurations and high transonic or supersonic performance, have to be capable of being flown comfortably under full pilot control at the low speeds expected for carrier deck landings.

In Part II, the many devices of aerodynamic and engineering design will be described which have been evolved in an attempt to overcome or minimise the problems.

The North Carolina Agriculture Survey was designed to estimate the willingness to pay for agricultural research and extension programs. We find that North Carolina households are willing to pay between $218 and $401 million for food production programs and between $251 and $698 million for water quality programs annually. We find evidence of divergent validity and differences in the willingness to pay estimates from the single-bound and multiple-bound data.

Convection from an isolated heat source in a chamber has been previously studied numerically, experimentally and analytically. These have not covered long time spans for wide ranges of Rayleigh number Ra and Prandtl number Pr. Numerical calculations of constant viscosity convection partially fill the gap in the ranges $\mathit{Ra}= 1{0}^{3} {{\unicode{x2013}}}1{0}^{6} $ and $\mathit{Pr}= 1, 10, 100, 1000$ and $\infty $ . Calculations begin with cold fluid everywhere and localized hot temperature at the centre of the bottom of a square two-dimensional chamber. For $\mathit{Ra}\gt 20\hspace{0.167em} 000$ , temperature increases above the hot bottom and forms a rising plume head. The head has small internal recirculation and minor outward conduction of heat during ascent. The head approaches the top, flattens, splits and the two remnants are swept to the sidewalls and diffused away. The maximum velocity and the top centre heat flux climb to maxima during head ascent and then adjust toward constant values. Two steady cells are separated by a vertical thermal conduit. This sequence is followed for every value of $Pr$ number, although lower Pr convection lags in time. For $\mathit{Ra}\lt 20\hspace{0.167em} 000$ there is no plume head, and no streamfunction and heat flux maxima with time. For sufficiently large Ra and all values of Pr, an oscillation develops at roughly $t= 0. 2$ , with the two cells alternately strengthening and weakening. This changes to a steady flow with two unequal cells that at roughly $t= 0. 5$ develops a second oscillation.

Between 4 to 6 million twins exist in the US today who offer scientists a valuable potential resource for conducting behavioral and biomedical research. However, unlike many other countries, there is no national system in the US for identifying twins and eliciting their participation in these important research programs. Therefore, the National Institute of Environmental Health Sciences (NIEHS) is conducting a study to determine the feasibility of creating a national, population-based twin registry in the US. The major goal is to estimate the potential size and characteristics of a national twin registry based on the current twin population in the US, our ability to ascertain and enrol them, and their willingness to participate. Existing US twin cohorts are also being examined in this study as well as alternatives for improving US twin resources should a national twin registry be deemed infeasible. The various options will be compared in terms of possible source populations, generalizability and adequacy for statistically powering various types of etiological studies. Two expert advisory panels have been assembled to assist in the conduct of this study. The Scientific Advisory Panel is charged with providing expertise concerning study goals, design and methodology, and evaluating the study's conclusion. A separate Ethics Advisory Panel is charged with providing expertise on the ethical, legal, and social issues that might be encountered if a national twin registry is ultimately pursued. Having a national population-based twin registry in the US would be advantageous to US scientists and those worldwide. It would provide ample numbers of twin pairs to conduct various types of environmental genomic studies currently not possible with existing US twin resources. It would also allow US scientists to select for characteristics (race, ethnicity, environments, and so on) inherent in our own population. Finally and foremost, it would help to meet the worldwide demand for twin resources which is expected to increase over time, as new genomic and analytical tools become available and new hypotheses emerge concerning the complex interplay between genes, lifestyles and environment.