Sampling Techniques in Bayesian Finite Element Model Updating

Recent papers in the field of Finite Element Model (FEM) updating have highlighted the benefits of Bayesian techniques. The Bayesian approaches are designed to deal with the uncertainties associated with complex systems, which is the main problem in the development and updating of FEMs. This paper highlights the complexities and challenges of implementing any Bayesian method when the analysis involves a complicated structural dynamic model. In such systems an analytical Bayesian formulation might not be available in an analytic form; therefore this leads to the use of numerical methods, i.e. sampling methods. The main challenge then is to determine an efficient sampling of the model parameter space. In this paper, three sampling techniques, the Metropolis-Hastings (MH) algorithm, Slice Sampling and the Hybrid Monte Carlo (HMC) technique, are tested by updating a structural beam model. The efficiency and limitations of each technique is investigated when the FEM updating problem is implemented using the Bayesian Approach. Both MH and HMC techniques are found to perform better than the Slice sampling when Young's modulus is chosen as the updating parameter. The HMC method gives better results than MH and Slice sampling techniques, when the area moment of inertias and section areas are updated.Comment: Paper Accepted in the 25th International Modal Analysis Conference, 201

Learning styles among nursing students, the implications for higher education institutions: A systematic review

Understanding the learning styles of nursing students has been highlighted as an area in the scholarship of teaching that needs attention. The aim of this review was to determine the common learning styles of nursing students and the appropriate teaching styles needed. A search was conducted using various databases and journals for the period from 2000 to 2013. Two reviewers independently evaluated the methodological quality of the studies reviewed. The results are presented in a narrative. The 11 articles included in the review represented four continents and were primarily descriptive studies. The review highlighted that nursing students prefer the kinaesthetic and multimodal learning styles. Kinaesthetic learners prefer live examples and lots of interaction. Interactive and real-life experiences as teaching methodologies are the preferred methods of nursing students and are seen as a holistic approach that incorporates all of their senses of seeing, feeling, smelling, hearing and sometimes tasting.DHE

Finite Element Model updating using Hamiltonian Monte Carlo techniques

Abstract: Bayesian techniques have been widely used in finite element model (FEM) updating. The attraction of these techniques is their ability to quantify and characterise the uncertainties associated with dynamic systems. In order to update an FEM, the Bayesian formulation requires the evaluation of the posterior distribution function. For large systems this function is difficult to solve analytically. In such cases the use of sampling techniques often provides a good approximation of this posterior distribution function. The hybrid Monte Carlo (HMC) method is a classic sampling method used to approximate high-dimensional complex problems. However, the acceptance rate (AR) of HMC is sensitive to the system size, as well as to the time step used to evaluate the molecular dynamics (MD) trajectory. The shadow HMC technique (SHMC), which is a modified version of the HMC method, was developed to improve sampling for large-system sizes by drawing from a modified shadow Hamiltonian function. However, the SHMC algorithm performance is limited by the use of a non-separable modified Hamiltonian function. Moreover, two additional parameters are required for the sampling procedure, which could be computationally expensive. To overcome these weaknesses the separable shadow HMC (S2HMC) method has been introduced. This method uses a transformation to a different parameter space to generate samples. In this paper we analyse the application and performance of these algorithms, including the parameters used in each algorithm, their limitations and the effects on model updating. The accuracy and the efficiency of the algorithms are demonstrated by updating the finite element models of two real mechanical structures. It is observed that the S2HMC algorithm has a number of advantages over the other algorithms; for example, the S2HMC algorithm is able to efficiently sample at larger time steps while using fewer parameters than the other algorithms

Interprofessional learning through 3D printing of assistive devices

Emerging technologies in the rehabilitative component of patient care in community settings continue to grow. One of the emerging technological fields in the health sciences arena is 3D printing. It is particularly useful in rehabilitation services in the production of assistive devices. Degerli et al.1 define assistive devices, as any commercially developed, modified or customised system, component or product used to improve or preserve the functional capabilities of a person not able to engage in all their daily living activities. Currently, assistive devices are not easily customizable. Off-the-shelf devices do not meet the individual needs of the customer; they are costly, lack individual compatibility and not always in stock. In minimising these challenges, technologies of the Fourth Industrial Revolution (4IR) such as 3D printing have been offered as a practical solution at a local university in South Africa

The impact of a faculty development programme for health professions educators in sub-Saharan Africa: an archival study

BACKGROUND: In 2008 the sub-Saharan FAIMER Regional Institute launched a faculty development programme aimed at enhancing the academic and research capacity of health professions educators working in sub-Saharan Africa. This two-year programme, a combination of residential and distance learning activities, focuses on developing the leadership, project management and programme evaluation skills of participants as well as teaching the key principles of health professions education-curriculum design, teaching and learning and assessment. Participants also gain first-hand research experience by designing and conducting an education innovation project in their home institutions. This study was conducted to determine the perceptions of participants regarding the personal and professional impact of the SAFRI programme. METHODS: A retrospective document review, which included data about fellows who completed the programme between 2008 and 2011, was performed. Data included fellows’ descriptions of their expectations, reflections on achievements and information shared on an online discussion forum. Data were analysed using Kirkpatrick’s evaluation framework. RESULTS: Participants (n=61) came from 10 African countries and included a wide range of health professions educators. Five key themes about the impact of the SAFRI programme were identified: (1) belonging to a community of practice, (2) personal development, (3) professional development, (4) capacity development, and (5) tools/strategies for project management and/or advancement. CONCLUSION: The SAFRI programme has a positive developmental impact on both participants and their respective institutions.National Research FoundationDepartment of HE and Training approved lis

Legacy beliefs across generations: Comparing views of older parents and their adult children

This mixed-methods study examined legacy beliefs (i.e., anticipated remembrances and linkages to the self after death) as understood in 14 older parent and adult child pairs. This work validates and expands on a 2005 typology of legacy beliefs from gerontologists, Elizabeth Hunter and Graham Rowles. A structured interview was administered separately to parents and children, coded for legacy examples (i.e., those unique to the parent, overlapping, unique to the child), and analyzed with respect to expectations of similarity reported by each participant. Most predicted moderate to high overlap in mutual understanding of parent legacy. This was not the case, as there were far more unique legacy examples given than shared. Pairs agreed least with respect to material legacies, with half showing no agreement. All reported finding the structured discussion of legacy to be beneficial, with some indicating an intention to continue these discussions further. This work may constitute a new approach to intervention

The emergence of insecticide resistance in central Mozambique and potential threat to the successful indoor residual spraying malaria control programme

Background: Malaria vector control by indoor residual spraying was reinitiated in 2006 with DDT in Zambézia province, Mozambique. In 2007, these efforts were strengthened by the President’s Malaria Initiative. This manuscript reports on the monitoring and evaluation of this programme as carried out by the Malaria Decision Support Project. Methods: Mosquitoes were captured daily through a series of 114 window exit traps located at 19 sentinel sites, identified to species and analysed for sporozoites. Anopheles mosquitoes were collected resting indoors and tested for insecticide resistance following the standard WHO protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 15 years. Results: A total of 3,769 and 2,853 Anopheles gambiae s.l. and Anopheles funestus, respectively, were captured from window exit traps throughout the period. In 2010 resistance to the pyrethroids lambda-cyhalothrin and permethrin and the carbamate, bendiocarb was detected in An. funestus. In 2006, the sporozoite rate in An. gambiae s.s. was 4% and this reduced to 1% over 4 rounds of spraying. The sporozoite rate for An. funestus was also reduced from 2% to 0 by 2008. Of the 437 Anopheles arabiensis identified, none were infectious. Overall prevalence of P. falciparum in the sentinel sites fell from 60% to 32% between October 2006 and October 2008. Conclusion: Both An. gambiae s.s. and An. funestus were controlled effectively with the DDT-based IRS programme in Zambézia, reducing disease transmission and burden. However, the discovery of pyrethroid resistance in the province and Mozambique’s policy change away from DDT to pyrethroids for IRS threatens the gains made here