Jacobian-free Newton-Krylov methods with GPU acceleration for computing nonlinear ship wave patterns

The nonlinear problem of steady free-surface flow past a submerged source is considered as a case study for three-dimensional ship wave problems. Of particular interest is the distinctive wedge-shaped wave pattern that forms on the surface of the fluid. By reformulating the governing equations with a standard boundary-integral method, we derive a system of nonlinear algebraic equations that enforce a singular integro-differential equation at each midpoint on a two-dimensional mesh. Our contribution is to solve the system of equations with a Jacobian-free Newton-Krylov method together with a banded preconditioner that is carefully constructed with entries taken from the Jacobian of the linearised problem. Further, we are able to utilise graphics processing unit acceleration to significantly increase the grid refinement and decrease the run-time of our solutions in comparison to schemes that are presently employed in the literature. Our approach provides opportunities to explore the nonlinear features of three-dimensional ship wave patterns, such as the shape of steep waves close to their limiting configuration, in a manner that has been possible in the two-dimensional analogue for some time.

A comparison of finite difference and finite volume methods for solving the space-fractional advection-dispersion equation with variable coefficients

Transport processes within heterogeneous media may exhibit non- classical diffusion or dispersion which is not adequately described by the classical theory of Brownian motion and Fick’s law. We consider a space-fractional advection-dispersion equation based on a fractional Fick’s law. Zhang et al. [Water Resources Research, 43(5)(2007)] considered such an equation with variable coefficients, which they dis- cretised using the finite difference method proposed by Meerschaert and Tadjeran [Journal of Computational and Applied Mathematics, 172(1):65-77 (2004)]. For this method the presence of variable coef- ficients necessitates applying the product rule before discretising the Riemann–Liouville fractional derivatives using standard and shifted Gru ̈nwald formulas, depending on the fractional order. As an alternative, we propose using a finite volume method that deals directly with the equation in conservative form. Fractionally-shifted Gru ̈nwald formulas are used to discretise the Riemann–Liouville fractional derivatives at control volume faces, eliminating the need for product rule expansions. We compare the two methods for several case studies, highlighting the convenience of the finite volume approach.

Novel sequential methods in dose-finding designs : extensions of the continual reassessment method

Dose-finding trials are a form of clinical data collection process in which the primary objective is to estimate an optimum dose of an investigational new drug when given to a patient. This thesis develops and explores three novel dose-finding design methodologies. All design methodologies presented in this thesis are pragmatic. They use statistical models, incorporate clinicians' prior knowledge efficiently, and prematurely stop a trial for safety or futility reasons. Designing actual dose-finding trials using these methodologies will minimize practical difficulties, improve efficiency of dose estimation, be flexible to stop early and reduce possible patient discomfort or harm.

A survey of control allocation methods for underwater vehicles

A control allocation system implements a function that maps the desired control forces generated by the vehicle motion controller into the commands of the different actuators. In this article, a survey of control allocation methods for over-actuated underwater vehicles is presented. The methods are applicable for both surface vessels and underwater vehicles. The paper presents a survey of control allocation methods with focus on mathematical representation and solvability of thruster allocation problems. The paper is useful for university students and engineers who want to get an overview of state-of-the art control allocation methods as well as advance methods to solve more complex problems.

Reply to the comments on “A study of the phosphate mineral kapundaite NaCa(Fe3+)4(PO4)4(OH)3·5(H2O) using SEM/EDX and vibrational spectroscopic methods” by Frost et al. (2014)

"The authors agree with the statements made by Mills and Christy on the study of kapundaite [1]. These authors are correct and have removed any confusion about the origin of the sample kapundaite. The authors (Frost et al.) confirm the sample of kapundaite studied in this work is from the Tom‘s quarry, Australia and can be considered a type material. The authors do not accept the statements by Mills and Christy on “type minerals”. The sample of kapundaite from the Australian source is from the collection of the Geology Department of the Federal University of Ouro Preto, Minas Gerais, Brazil with sample code SAC-111. At least if our mineral sample is not a co-type mineral, our sample is from the same origin as the type mineral. Samples..."--publisher website.

Higher uptake of long-acting reversible and permanent methods of contraception by Australian women living in rural and remote areas

Objectives: To examine factors associated with the uptake of i) long-acting reversible, ii) permanent and iii) traditional contraceptive methods among Australian women. Methods: Participants in the Australian Longitudinal Study on Women's Health born in 1973–78 reported on their contraceptive use at three surveys: 2003, 2006 and 2009. The participants were 5,849 women aged 25–30 in 2003 randomly sampled from Medicare. The main outcome measure was current contraceptive method at age 28–33 years categorised as long-acting reversible methods (implant, IUD, injection), permanent (tubal ligation, vasectomy), and traditional methods (oral contraceptive pills, condoms, withdrawal, safe period). Results: Compared to women living in major cities, women in inner regional areas were more likely to use long-acting (OR=1.26, 95%CI 1.03–1.55) or permanent methods (OR=1.43, 95%CI 1.17–1.76). Women living in outer regional/remote areas were more likely than women living in cities to use long-acting (OR=1.65, 95%CI 1.31–2.08) or permanent methods (OR=1.69, 95%CI 1.43–2.14). Conclusions: Location of residence is an important factor in women's choices about long-acting and permanent contraception in addition to the number and age of their children. Implications: Further research is needed to understand the role of geographical location in women's access to contraceptive options in Australia.

Quantitative fit analysis of orthopedic bone plates : methods, criteria and approach

Studies on quantitative fit analysis of precontoured fracture fixation plates emerged within the last few years and therefore, there is a wide research gap in this area. Quantitative fit assessment facilitates the measure of the gap between a fracture fixation plate and the underlying bone, and specifies the required plate fit criteria. For clinically meaningful fit assessment outcome, it is necessary to establish the appropriate criteria and parameter. The present paper studies this subject and recommends using multiple fit criteria and the maximum distance between the plate and underlying bone as fit parameter for clinically relevant outcome. We also propose the development of a software tool for automatic plate positioning and fit assessment for the purpose of implant design validation and optimization in an effort to provide better fitting implant that can assist proper fracture healing. The fundamental specifications of the software are discussed.

Stimulating organizational ingenuity with design methods

Organizations invest in ways to stimulate new ideas for new products and services for the benefit of the organization, engaging in tournaments and competitions to generate new ideas or to combine existing ideas in new ways for new products and services (Terweisch and Uhlrich, 2009). Specifically, some large companies have developed platforms for posting intractable problems to tap into the ideas and problem solving abilities of a broader range of people (Huston and Sakkab, 2006; Morgan and Wang, 2010), and to develop new and elegant solutions often in an open innovation approach (Chesbrough, 2003). The notion of ingenuity is often applied to individuals who create innovative solutions in situations of constraint, where ingenuity in the form of elegant solutions can be understood as one form of resourcefulness (Young, 2011). However, the notion of organizational ingenuity locates ingenuity more centrally to an organization's strategic decision making and implementation, embedding ingenuity into the company's culture. Studies of organizations displaying ingenuity indicate a range of possibilities from extreme ingenuity (Baker and Nelson, 2005) to less dramatic but substantial changes (Thomke, 2003), sometimes in an experimental phase or as part of a move towards a new and distinct identity for ongoing innovation.

Part 1 MOO methods for multidisciplinary design using parallel evolutionary algorithms, game theory and hierarchical topology. (Part 1.) Theoretical aspects

Two lecture notes describe recent developments of evolutionary multi objective optimization (MO) techniques in detail and their advantages and drawbacks compared to traditional deterministic optimisers. The role of Game Strategies (GS), such as Pareto, Nash or Stackelberg games as companions or pre-conditioners of Multi objective Optimizers is presented and discussed on simple mathematical functions in Part I , as well as their implementations on simple aeronautical model optimisation problems on the computer using a friendly design framework in Part II. Real life (robust) design applications dealing with UAVs systems or Civil Aircraft and using the EAs and Game Strategies combined material of Part I & Part II are solved and discussed in Part III providing the designer new compromised solutions useful to digital aircraft design and manufacturing. Many details related to Lectures notes Part I, Part II and Part III can be found by the reader in [68].

Methods for isolation and cultivation of filamentous fungi

Filamentous fungi are important organisms for basic discovery, industry, and human health. Their natural growth environments are extremely variable, a fact reflected by the numerous methods developed for their isolation and cultivation. Fungal culture in the laboratory is usually carried out on agar plates, shake flasks, and bench top fermenters starting with an inoculum that typically features fungal spores. Here we discuss the most popular methods for the isolation and cultivation of filamentous fungi for various purposes with the emphasis on enzyme production and molecular microbiology.

Losing sleep : examining the cascading effects of supervisors' experience of injustice on subordinates' psychological health

In this paper, we identify two types of injustice as antecedents of abusive supervision and ultimately of subordinate psychological distress and insomnia. We examine distributive justice (an individual's evaluation of their input to output ratio compared to relevant others) and interactional injustice (the quality of interpersonal treatment received when procedures are implemented). Using a sample of Filipinos in a variety of occupations, we identify two types of injustice experienced by supervisors as stressors that provoke them to display abusive supervision to their subordinates. We examine two consequences of abusive supervision - subordinate psychological distress and insomnia. In addition, we identify two moderators of these relationships, namely, supervisor distress and subordinate self-esteem. We collected survey data from multiple sources including subordinates, their supervisors, and their partners. Data were obtained from 175 matched supervisor-subordinate dyads over a 6-month period, with subordinates' partners providing ratings of insomnia. Results of structural equation modelling analyses provided support for an indirect effects model in which supervisors' experience of unfair treatment cascades down the organization, resulting in subordinate psychological distress and, ultimately in their insomnia. In addition, results partially supported the proposed moderated relationships in the cascading model. © 2010 Taylor & Francis.

Physical inactivity remains the greatest public health problem of the 21st century : evidence, improved methods and solutions using the '7 investments that work' as a framework

In 2009, BJSM's first editorial argued that ‘Physical inactivity is the greatest public health problem of the 21st century’.1 The data supporting that claim have not yet been challenged. Now, 5 years after BJSM published its first dedicated ‘Physical Activity is Medicine’ theme issue (http://bjsm.bmj.com/content/43/1.toc) we are pleased to highlight 23 new contributions from six countries. This issue contains an analysis of the cost of physical inactivity from the US Centre for Diseases Control.2 We also report the cost-effectiveness of one particular physical activity intervention for adults.3

Can the use of quality assurance tools reduce the impact of surgical complications on the well-being of obstetricians and gynaecologists in Australia and New Zealand?

Background While adverse events primarily affect the patient, surgeons involved can also experience considerable distress. Aims The aim of the survey was to assess the impact of complications on the day-to-day life, work and health of Australian and New Zealand obstetricians and gynaecologists and to evaluate existing support systems and coping strategies. Methods A 43-question survey on self-assessment, quality assurance (QA) tools, impact of complications on individuals’ health and relationships, and support available was emailed to fellows, trainees, subspecialists and subspecialty trainees of the Royal Australian and New Zealand College of Obstetrics and Gynaecology (RANZCOG). We collected 606 responses from a target population of 2296 (response rate 26.3%). Results When complications occur, sleep was affected of 80%, family and social relationships of 55% and physical health of 48% of respondents. The major sources of support were from colleagues (83%), family (82%) and medical defence organisations (73%), with professional bodies perceived as providing least support. Nearly 80% of respondents felt the need to talk to someone they trust during times of complications. Overall, 100% of respondents used at least one QA tool (62% used two, 26% three and 9% four QA strategies). There were significant differences between respondent groups in use of the QA tools. Conclusions Surgical complications have a significant impact on the well-being of Australian and New Zealand obstetricians and gynaecologists. Existing support comes from colleagues and family, but structured, unbiased support for surgeons from a professional source is urgently warranted.

Sleep-related eye symptoms and their potential for identifying driver sleepiness

The majority of individuals appear to have insight into their own sleepiness, but there is some evidence that this does not hold true for all, for example treated patients with obstructive sleep apnoea. Identification of sleep-related symptoms may help drivers determine their sleepiness, eye symptoms in particular show promise. Sixteen participants completed four motorway drives on two separate occasions. Drives were completed during daytime and night-time in both a driving simulator and on the real road. Ten eye symptoms were rated at the end of each drive, and compared with driving performance and subjective and objective sleep metrics recorded during driving. ‘Eye strain’, ‘difficulty focusing’, ‘heavy eyelids’ and ‘difficulty keeping the eyes open’ were identified as the four key sleep-related eye symptoms. Drives resulting in these eye symptoms were more likely to have high subjective sleepiness and more line crossings than drives where similar eye discomfort was not reported. Furthermore, drivers having unintentional line crossings were likely to have ‘heavy eyelids’ and ‘difficulty keeping the eyes open’. Results suggest that drivers struggling to identify sleepiness could be assisted with the advice ‘stop driving if you feel sleepy and/or have heavy eyelids or difficulty keeping your eyes open’.