1,379 research outputs found

    Higher Order, Hybrid BEM/FEM Methods Applied to Antenna Modeling

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    In this presentation, the authors address topics relevant to higher order modeling using hybrid BEM/FEM formulations. The first of these is the limitation on convergence rates imposed by geometric modeling errors in the analysis of scattering by a dielectric sphere. The second topic is the application of an Incomplete LU Threshold (ILUT) preconditioner to solve the linear system resulting from the BEM/FEM formulation. The final tOpic is the application of the higher order BEM/FEM formulation to antenna modeling problems. The authors have previously presented work on the benefits of higher order modeling. To achieve these benefits, special attention is required in the integration of singular and near-singular terms arising in the surface integral equation. Several methods for handling these terms have been presented. It is also well known that achieving ~he high rates of convergence afforded by higher order bases may als'o require the employment of higher order geometry models. A number of publications have described the use of quadratic elements to model curved surfaces. The authors have shown in an EFIE formulation, applied to scattering by a PEC .sphere, that quadratic order elements may be insufficient to prevent the domination of modeling errors. In fact, on a PEC sphere with radius r = 0.58 Lambda(sub 0), a quartic order geometry representation was required to obtain a convergence benefi.t from quadratic bases when compared to the convergence rate achieved with linear bases. Initial trials indicate that, for a dielectric sphere of the same radius, - requirements on the geometry model are not as severe as for the PEC sphere. The authors will present convergence results for higher order bases as a function of the geometry model order in the hybrid BEM/FEM formulation applied to dielectric spheres. It is well known that the system matrix resulting from the hybrid BEM/FEM formulation is ill -conditioned. For many real applications, a good preconditioner is required to obtain usable convergence from an iterative solver. The authors have examined the use of an Incomplete LU Threshold (ILUT) preconditioner . to solver linear systems stemming from higher order BEM/FEM formulations in 2D scattering problems. Although the resulting preconditioner provided aD excellent approximation to the system inverse, its size in terms of non-zero entries represented only a modest improvement when compared with the fill-in associated with a sparse direct solver. Furthermore, the fill-in of the preconditioner could not be substantially reduced without the occurrence of instabilities. In addition to the results for these 2D problems, the authors will present iterative solution data from the application of the ILUT preconditioner to 3D problems

    Using hospital discharge data to identify incident pregnancy-associated cancers: a validation study

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    BACKGROUND: Pregnancy-associated cancer is associated with maternal morbidities and adverse pregnancy outcomes, and is reported to be increasing. Hospital discharge data have the potential to provide timely information on cancer incidence, which is central to evaluation and improvement of clinical care for women. This study aimed to assess the validity of hospital data for identifying incident pregnancy-associated cancers compared with incident cancers from an Australian population-based statutory cancer registry. METHODS: Birth data from 2001–2008, comprised 470,277 women with 679,736 maternities, were linked to cancer registry and hospitalisation records to identify newly diagnosed cancers during pregnancy or within 12 months of delivery. Two hospital-identified cancer groups were examined; “index cancer hospitalisation” – first cancer admission per woman per pregnancy and “all cancer hospitalisations” –the total number of hospitalisations with a cancer diagnosis and women could have multiple hospitalisations during pregnancy. The latter replicates a scenario where identification of individuals is not possible and hospitalisations are used as the unit of analysis. RESULTS: The incidence of pregnancy-associated cancer (according to cancer registry) was 145.4/100,000 maternities. Incidence of cancer was substantially over-estimated when using hospitalisations as the unit of analysis (incidence rate ratio, IRR 1.7) and under-estimated when using the individual (IRR 0.8). Overall, the sensitivity of “index cancer hospitalisation” was 60.4%, positive predictive value (PPV) 77.7%, specificity and negative predictive value both 100%. Melanoma ascertainment was only 36.1% and breast cancer 62.9%. For other common cancers sensitivities ranged from 72.1% to 78.6% and PPVs 56.4% to 87.3%. CONCLUSION: Although hospital data provide another timely source of cancer identification, the validity is insufficient to obtain cancer incidence estimates for the obstetric population

    Dissemination and implementation science training needs: Insights from practitioners and researchers

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    INTRODUCTION: Dissemination and implementation research training has great potential to improve the impact and reach of health-related research; however, research training needs from the end user perspective are unknown. This paper identifies and prioritizes dissemination and implementation research training needs. METHODS: A diverse sample of researchers, practitioners, and policymakers was invited to participate in Concept Mapping in 2014–2015. Phase 1 (Brainstorming) gathered participants' responses to the prompt: To improve the impact of research evidence in practice and policy settings, a skill in which researchers need more training is… The resulting statement list was edited and included subsequent phases. Phase 2 (Sorting) asked participants to sort each statement into conceptual piles. In Phase 3 (Rating), participants rated the difficulty and importance of incorporating each statement into a training curriculum. A multidisciplinary team synthesized and interpreted the results in 2015–2016. RESULTS: During Brainstorming, 60 researchers and 60 practitioners/policymakers contributed 274 unique statements. Twenty-nine researchers and 16 practitioners completed sorting and rating. Nine concept clusters were identified: Communicating Research Findings, Improve Practice Partnerships, Make Research More Relevant, Strengthen Communication Skills, Develop Research Methods and Measures, Consider and Enhance Fit, Build Capacity for Research, and Understand Multilevel Context. Though researchers and practitioners had high agreement about importance (r =0.93) and difficulty (r =0.80), ratings differed for several clusters (e.g., Build Capacity for Research). CONCLUSIONS: Including researcher and practitioner perspectives in competency development for dissemination and implementation research identifies skills and capacities needed to conduct and communicate contextualized, meaningful, and relevant research

    Educational crowdsourcing to support the learning of computer programming

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    Technology has been used in the last three decades to support teaching and learning. However, educational software has frequently been under investigation to check the validity of their benefits. There is a demand for increasingly intelligent pedagogically-grounded computer technology. In this paper, we discuss adaptive, crowd sourced, and primarily educational technology; targeted at software development students. The proposed technology caters for either individual or group learning. It differentiates itself from other tutoring and programming support technologies as it will continually monitor and assess students’ performance in each phase of the educating process. It will also guide them in their learning through interactive feedback and adaptive curriculum delivery that suits both their current levels of learning and preferred learning styles. Keywords: Technology and Education; Coding; Teaching and Learning; Computer Programming; Adaptive Software

    Customer Focus in European Higher Education Systems

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    This article looks at the idea and practice of “customer focus” in higher education. As a global trend with origins in the business and corporate world, customer focus has come to increasingly shape public services worldwide. Influenced by business thinking, terminology, and practices, governmental organizations across policy areas have used customer focus to reform public services in order to bring them closer to the demands and expectations of their users. The paper particularly analyzes changes in customer focus understanding and its implications for the European higher education policies. The aim of the article is to contribute to a better conceptualization and policy understanding of this growing approach to higher education reform.fi=vertaisarvioitu|en=peerReviewed

    Realizability of Polytopes as a Low Rank Matrix Completion Problem

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    This article gives necessary and sufficient conditions for a relation to be the containment relation between the facets and vertices of a polytope. Also given here, are a set of matrices parameterizing the linear moduli space and another set parameterizing the projective moduli space of a combinatorial polytope

    Incidence and outcomes of pregnancy-associated cancer in Australia, 1994?2008: a population-based linkage study

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    OBJECTIVE: To determine trends in pregnancy-associated cancer and associations between maternal cancer and pregnancy outcomes. DESIGN: Population-based cohort study. SETTING: New South Wales, Australia, 1994–2008. POPULATION: A total of 781 907 women and their 1 309 501 maternities. METHODS: Cancer and maternal information were obtained from linked cancer registry, birth and hospital records for the entire population. Generalised estimating equations with a logit link were used to examine associations between cancer risk factors and pregnancy outcomes. MAIN OUTCOME MEASURES: Incidence of pregnancy-associated cancer (diagnosis during pregnancy or within 12 months of delivery), maternal morbidities, preterm birth, and small- and large-for-gestational-age (LGA). RESULTS: A total of 1798 new cancer diagnoses were identified, including 499 during pregnancy and 1299 postpartum. From 1994 to 2007, the crude incidence rate of pregnancy-associated cancer increased from 112.3 to 191.5 per 100 000 maternities (P < 0.001), and only 14% of the increase was explained by increasing maternal age. Cancer diagnosis was more common than expected in women aged 15–44 years (observed-to-expected ratio 1.49; 95% CI 1.42–1.56). Cancers were predominantly melanoma (33.3%) and breast cancer (21.0%). Women with cancer diagnosed during pregnancy had high rates of labour induction (28.5%), caesarean section (40.0%) and planned preterm birth (19.7%). Novel findings included a cancer association with multiple pregnancies (adjusted odds ratio 1.52, 95% CI 1.13–2.05) and LGA (aOR 1.47, 95% CI 1.14–1.89). CONCLUSIONS: Pregnancy-associated cancers have increased, and this increase is only partially explained by increasing maternal age. Pregnancy increases women’s interaction with health services and the possibility for diagnosis, but may also influence tumour growth

    An exploratory cluster randomised controlled trial of knowledge translation strategies to support evidence-informed decision-making in local governments (The KT4LG study)

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    Background: Childhood overweight and obesity is the most prevalent and, arguably, politically complex child health problem internationally. Governments, communities and industry have important roles to play, and are increasingly expected to deliver an evidence-informed system-wide prevention program. However, efforts are impeded by a lack of organisational access to and use of research evidence. This study aims to identify feasible, acceptable and ideally, effective knowledge translation (KT) strategies to increase evidence-informed decision making in local governments, within the context of childhood obesity prevention as a national policy priority.Methods/Design: This paper describes the methods for KT4LG, a cluster randomised controlled trial which is exploratory in nature, given the limited evidence base and methodological advances. KT4LG aims to examine a program of KT strategies to increase the use of research evidence in informing public health decisions in local governments. KT4LG will also assess the feasibility and acceptability of the intervention. The intervention program comprises a facilitated program of evidence awareness, access to tailored research evidence, critical appraisal skills development, networking and evidence summaries and will be compared to provision of evidence summaries alone in the control program. 28 local governments were randomised to intervention or control, using computer generated numbers, stratified by budget tertile (high, medium or low). Questionnaires will be used to measure impact, costs, and outcomes, and key informant interviews will be used to examine processes, feasibility, and experiences. Policy tracer studies will be included to examine impact of intervention on policies within relevant government policy documents.Discussion: Knowledge translation intervention studies with a focus on public health and prevention are very few in number. Thus, this study will provide essential data on the experience of program implementation and evaluation of a system-integrated intervention program employed within the local government public health context. Standardised programs of system, organisational and individual KT strategies have not been described or rigorously evaluated. As such, the findings will make a significant contribution to understanding whether a facilitated program of KT strategies hold promise for facilitating evidence-informed public health decision making within complex multisectoral government organisations.<br /

    Uncovering Tacit Knowledge: A Pilot Study to Broaden the Concept of Knowledge in Knowledge Translation

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    BACKGROUND: All sectors in health care are being asked to focus on the knowledge-to-practice gap, or knowledge translation, to increase service effectiveness. A social interaction approach to knowledge translation assumes that research evidence becomes integrated with previously held knowledge, and practitioners build on and co-create knowledge through mutual interactions. Knowledge translation strategies for public health have not provided anticipated positive changes in evidence-based practice, possibly due in part to a narrow conceptualization of knowledge. More work is needed to understand the role of tacit knowledge in decision-making and practice. This pilot study examined how health practitioners applied tacit knowledge in public health program planning and implementation. METHODS: This study used a narrative approach, where teams from two public health units in Ontario, Canada were conveniently selected. Respondents participated in individual interviews and focus groups at each site. Questions were designed to understand the role of tacit knowledge as it related to the program planning process. Data were analyzed through a combination of content analysis and thematic comparison. RESULTS: The findings highlighted two major aspects of knowledge that arose: the use of tacit knowledge and the integration of tacit and explicit knowledge. Tacit knowledge included: past experiences, organization-specific knowledge, community contextual knowledge, and the recognition of the tacit knowledge of others. Explicit knowledge included: research literature, the Internet, popular magazines, formal assessments (surveys and interviews), legislation and regulations. Participants sometimes deliberately combined tacit and explicit knowledge sources in planning. CONCLUSIONS: This pilot demonstrated that front-line public health workers draw upon both tacit knowledge and explicit knowledge in their everyday lived reality. Further, tacit knowledge plays an important role in practitioners\u27 interpretation and implementation of explicit research findings. This indicates a need to broaden the scope of knowledge translation to include other forms of knowledge beyond explicit knowledge acquired through research. Strategies that recognize and support the use of tacit knowledge, such as communities of practice or networks, may be important components of a comprehensive approach to knowledge translation. This study provides support for further investigation of the role of tacit knowledge in the planning and delivery of effective public health services

    A knowledge management tool for public health: health-evidence.ca

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    <p>Abstract</p> <p>Background</p> <p>The ultimate goal of knowledge translation and exchange (KTE) activities is to facilitate incorporation of research knowledge into program and policy development decision making. Evidence-informed decision making involves translation of the best available evidence from a systematically collected, appraised, and analyzed body of knowledge. Knowledge management (KM) is emerging as a key factor contributing to the realization of evidence-informed public health decision making. The goal of health-evidence.ca is to promote evidence-informed public health decision making through facilitation of decision maker access to, retrieval, and use of the best available synthesized research evidence evaluating the effectiveness of public health interventions.</p> <p>Methods</p> <p>The systematic reviews that populate health evidence.ca are identified through an extensive search (1985-present) of 7 electronic databases: MEDLINE, EMBASE, CINAHL, PsycINFO, Sociological Abstracts, BIOSIS, and SportDiscus; handsearching of over 20 journals; and reference list searches of all relevant reviews. Reviews are assessed for relevance and quality by two independent reviewers. Commonly-used public health terms are used to assign key words to each review, and project staff members compose short summaries highlighting results and implications for policy and practice.</p> <p>Results</p> <p>As of June 2010, there are 1913 reviews in the health-evidence.ca registry in 21 public health and health promotion topic areas. Of these, 78% have been assessed as being of strong or moderate methodological quality. Health-evidence.ca receives approximately 35,000 visits per year, 20,596 of which are unique visitors, representing approximately 100 visits per day. Just under half of all visitors return to the site, with the average user spending six minutes and visiting seven pages per visit. Public health nurses, program managers, health promotion workers, researchers, and program coordinators are among the largest groups of registered users, followed by librarians, dieticians, medical officers of health, and nutritionists. The majority of users (67%) access the website from direct traffic (e.g., have the health-evidence.ca webpage bookmarked, or type it directly into their browser).</p> <p>Conclusions</p> <p>Consistent use of health-evidence.ca and particularly the searching for reviews that correspond with current public health priorities illustrates that health-evidence.ca may be playing an important role in achieving evidence-informed public health decision making.</p
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