Shock reflection and surface effects in the shock tube

A thin-film resistance thermometer, mounted on the end-wall of a shock tube, is used to record surface temperatures and heat transfer rates following reflection of the primary shock wave. This information is combined with the results of theoretical investigations to produce simultaneous information about surface accommodation effects and gas thermal conductivities at high pressures and moderate temperatures

Air Traffic Control Operating Modes and the Management of Complexity

This report describes research exploring the relationship between structure and cognitive complexity in Air Traffic Control (ATC). Current work on structure and cognitive processes in ATC is reviewed leading to an ATC process model. Based on observations of the performance of the ATC system it appears that air traffic controllers have the ability to manipulate structure and structure-based abstractions in order to regulate the complexity of an ATC situation. The management of complexity has been integrated into the Controller Process Model through a Complexity Manager. It is hypothesized that the Complexity Manager operates by commanding switches between operating modes. In order to explore whether these operating modes can be observed in a simple ATC task, an experiment was designed. Participants were given scenarios with varying traffic levels. Their commands and their performance have been collected and analyzed. The experimental results show participants appeared to use each of the hypothesized operating modes. The use of the structure in each mode was also as expected

Compression of tetrahedrally bonded SiO2 liquid and silicate liquid‐crystal density inversion

We have investigated the response to pressure of liquid SiO2 by performing a quantitatively realistic Monte Carlo simulation. The model liquid was restricted to at most four‐fold Si‐O coordination by the effective imposition of an infinite potential barrier to a fifth bond. We thus obtained an unambiguous comparison of the compression mechanisms of solid and liquid tetrahedral networks. In spite of this restriction, the density of the simulated liquid exceeds that of the corresponding models of quartz, coesite and cristobalite at high pressure. The efficient compression of the liquid results from a continuous restructuring of the network that leaves the mean Si‐Si distance virtually unchanged and does not require an increase in the coordination number. The restructuring is effected by local breaking and reconnecting of bonds, a mechanism that is not available to a perfect crystal

Visualising the structure of document search results: A comparison of graph theoretic approaches

This is the post-print of the article - Copyright @ 2010 Sage PublicationsPrevious work has shown that distance-similarity visualisation or ‘spatialisation’ can provide a potentially useful context in which to browse the results of a query search, enabling the user to adopt a simple local foraging or ‘cluster growing’ strategy to navigate through the retrieved document set. However, faithfully mapping feature-space models to visual space can be problematic owing to their inherent high dimensionality and non-linearity. Conventional linear approaches to dimension reduction tend to fail at this kind of task, sacrificing local structural in order to preserve a globally optimal mapping. In this paper the clustering performance of a recently proposed algorithm called isometric feature mapping (Isomap), which deals with non-linearity by transforming dissimilarities into geodesic distances, is compared to that of non-metric multidimensional scaling (MDS). Various graph pruning methods, for geodesic distance estimation, are also compared. Results show that Isomap is significantly better at preserving local structural detail than MDS, suggesting it is better suited to cluster growing and other semantic navigation tasks. Moreover, it is shown that applying a minimum-cost graph pruning criterion can provide a parameter-free alternative to the traditional K-neighbour method, resulting in spatial clustering that is equivalent to or better than that achieved using an optimal-K criterion

On some aspects of the noise propagation from supersonic aircraft

The noise problem associated with an aircraft flying at supersonic speeds is shown to depend primarily on the shock wave pattern formed by the aircraft. The noise intensity received by a ground observer from a supersonic aircraft flying at high as well as low altitudes, is shown to be high although it is of a transient nature. Continues

An interprofessional nurse-led mental health promotion intervention for older home care clients with depressive symptoms.

BackgroundDepressive symptoms in older home care clients are common but poorly recognized and treated, resulting in adverse health outcomes, premature institutionalization, and costly use of health services. The objectives of this study were to examine the feasibility and acceptability of a new six-month interprofessional (IP) nurse-led mental health promotion intervention, and to explore its effects on reducing depressive symptoms in older home care clients (≥ 70 years) using personal support services.MethodsA prospective one-group pre-test/post-test study design was used. The intervention was a six-month evidence-based depression care management strategy led by a registered nurse that used an IP approach. Of 142 eligible consenting participants, 98 (69%) completed the six-month and 87 (61%) completed the one-year follow-up. Outcomes included depressive symptoms, anxiety, health-related quality of life (HRQoL), and the costs of use of all types of health services at baseline and six-month and one-year follow-up. An interpretive descriptive design was used to explore clients', nurses', and personal support workers' perceptions about the intervention's appropriateness, benefits, and barriers and facilitators to implementation.ResultsOf the 142 participants, 56% had clinically significant depressive symptoms, with 38% having moderate to severe symptoms. The intervention was feasible and acceptable to older home care clients with depressive symptoms. It was effective in reducing depressive symptoms and improving HRQoL at six-month follow-up, with small additional improvements six months after the intervention. The intervention also reduced anxiety at one year follow-up. Significant reductions were observed in the use of hospitalization, ambulance services, and emergency room visits over the study period.ConclusionsOur findings provide initial evidence for the feasibility, acceptability, and sustained effects of the nurse-led mental health promotion intervention in improving client outcomes, reducing use of expensive health services, and improving clinical practice behaviours of home care providers. Future research should evaluate its efficacy using a randomized clinical trial design, in different settings, with an adequate sample of older home care recipients with depressive symptoms.Trial registrationClinicaltrials.gov identifier: NCT01407926

The Role of Quantitative Analysis in the Information Security Systems Development Lifecycle

Today’s numerous Quantitative Analysis (QA) tools have been successfully utilized to solve business problems in diverse applications. However, the application of QA tools in solving information security problems has been sparse. Devising the means and ways to use QA tools in resolving industry-wide security problems has the potential to yield enormous global economic benefit. The purpose of this paper is to explore the use of QA tools as a means of improving the processes involved in the Information Security Systems Development Lifecycle (SecSDL). Information security professionals use the SecSDL as a guide for formulating a comprehensive information security program. The paper examines the fit between QA tools and the processes of the SecSDL. A case application illustrates an example of QA tools applied specifically to risk assessment in the SecSDL

The effect of relationship status on communicating emotions through touch

Research into emotional communication to date has largely focused on facial and vocal expressions. In contrast, recent studies by Hertenstein, Keltner, App, Bulleit, and Jaskolka (2006) and Hertenstein, Holmes, McCullough, and Keltner (2009) exploring nonverbal communication of emotion discovered that people could identify anger, disgust, fear, gratitude, happiness, love, sadness and sympathy from the experience of being touched on either the arm or body by a stranger, without seeing the touch. The study showed that strangers were unable to communicate the self-focused emotions embarrassment, envy and pride, or the universal emotion surprise. Literature relating to touch indicates that the interpretation of a tactile experience is significantly influenced by the relationship between the touchers (Coan, Schaefer, & Davidson, 2006). The present study compared the ability of romantic couples and strangers to communicate emotions solely via touch. Results showed that both strangers and romantic couples were able to communicate universal and prosocial emotions, whereas only romantic couples were able to communicate the self-focused emotions envy and pride

Nonmetric Unfolding of Marketing Data: Degeneracy and Stability

Nonmetric unfolding is a powerful (nonparametric) analytical tool generating a preference-based joint display of subjects (e.g., customers) and objects (e.g., brands or products). Systematic patterns in customers’ preferences can be directly inferred from this display, and may provide valuable input for making important marketing decisions such as deciding what new product to launch. Unfortunately, nonmetric unfolding frequently produces degenerate unfolding solutions (i.e., unfolding solutions showing close-to-perfect model fit irrespective of the data analyzed). As a degenerated display shows ill-positioned customers and brands/products, the chance of making an incorrect marketing decision (e.g., launching the wrong product) is very high. To solve this problem adequately, we combine bootstrapping with penalized nonmetric unfolding (Prefscal) to obtain an accurate, nondegenerate and stable unfolding solution

Is anaphoric resolution instruction more effective than existing instruction at improving the reading comprehension achievement of secondary students with poor reading comprehension?

This study examined the effect of teaching anaphoric resolution skills on the reading comprehension of Year 10 students with poor reading comprehension. Two direct teaching programmes, an anaphoric resolution programme (A.R.Programme) and a reading comprehension skills programme based on the Unit curriculum objectives of the Ministry of Education of Western Australia (U.C. Programme), were developed and taught to two groups of eleven Year 10 poor reading comprehenders. The two groups were pretested and posttested for anaphoric resolution skill and reading comprehension achievement, and the increases in mean scores were compared for significant differences using Analysis of Variance (ANOVA). The Anova results showed that the A.R. Programme was significantly more effective at increasing both anaphoric resolution skill and reading comprehension achievement. After consideration of limitations these results are tentatively accepted