8,280 research outputs found

    Survey of currently available high-resolution raster graphics systems

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    Presented are data obtained on high-resolution raster graphics engines currently available on the market. The data were obtained through survey responses received from various vendors and also from product literature. The questionnaire developed for this survey was basically a list of characteristics desired in a high performance color raster graphics system which could perform real-time aircraft simulations. Several vendors responded to the survey, with most reporting on their most advanced high-performance, high-resolution raster graphics engine

    Prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in general practice setting: cross sectional survey

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    Objective: To assess the prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in the general practice setting by echocardiographic assessment of ventricular function. Design: Cross sectional survey. Setting: Four centre general practice in Poole, Dorset. Subjects: 817 elderly patients aged 70-84 years. Main outcomes: Echocardiographic assessment of left ventricular systolic function including measurement of ejection fraction by biplane summation method where possible, clinical symptoms, and signs of left ventricular dysfunction. Results: The overall prevalence of left ventricular systolic dysfunction was 7.5% (95% confidence interval 5.8% to 9.5%); mild dysfunction (5.0%) was considerably more prevalent than moderate (1.6%) or severe dysfunction (0.7%). Measurement of ejection fraction was possible in 82% of patients (n=667): in patients categorised as having mild, moderate, or severe dysfunction, the mean ejection fraction was 48% (SD 12.0), 38% (8.1), and 26% (7.9) respectively. At all ages the prevalence was much higher in men than in women (odds ratio 5.1, 95% confidence interval 2.6 to 10.1). No clinical symptom or sign was both sensitive and specific. In around half the patients with ventricular dysfunction (52%, 32/61) heart failure had not been previously diagnosed. Conclusions: Unrecognised left ventricular dysfunction is a common problem in elderly patients in the general practice setting. Appropriate treatment with angiotensin converting enzyme inhibitors has the potential to reduce hospitalisation and mortality in these patients, but diagnosis should not be based on clinical history and examination alone. Screening is feasible in general practice, but it should not be implemented until the optimum method of identifying left ventricular dysfunction is clarified, and the cost effectiveness of screening has been shown

    IDMB archaeology case study: Summary

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    Knowledge practices in design: The role of visual representations as 'epistemic objects'

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    We use a detailed study of the knowledge work around visual representations to draw attention to the multidimensional nature of `objects'. Objects are variously described in the literatures as relatively stable or in flux; as abstract or concrete; and as used within or across practices. We clarify these dimensions, drawing on and extending the literature on boundary objects, and connecting it with work on epistemic and technical objects. In particular, we highlight the epistemic role of objects, using our observations of knowledge work on an architectural design project to show how, in this setting, visual representations are characterized by a `lack' or incompleteness that precipitates unfolding. The conceptual design of a building involves a wide range of technical, social and aesthetic forms of knowledge that need to be developed and aligned. We explore how visual representations are used, and how these are meaningful to different stakeholders, eliciting their distinct contributions. As the project evolves and the drawings change, new issues and needs for knowledge work arise. These objects have an `unfolding ontology' and are constantly in flux, rather than fully formed. We discuss the implications for wider understandings of objects in organizations and for how knowledge work is achieved in practice

    Students’ Perceptions of Their Teachers’ Performance in Teaching Engineering Drawing in Nigerian Tertiary Institutions

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    There have been concerns about the performance of Nigerian school teachers’ in delivering occupational related courses. However, there are currently limited empirical data on this phenomenon – in particular with respect to the teaching of engineering drawing – to justify further actions from educational managers and policy makers. The aim of this study was to assess teachers’ performance in teaching engineering drawing using students’ perception as indicator of teachers’ performance. The study utilized a cross-sectional research design method with the target population of technical education students drawn from four (4) Federal Colleges of education (Technical) in Northern Nigeria. Stratified proportionate sampling technique was used to arrive at the study sample of 253 technical education students. A specifically designed instrument, the Students’ Perceptions of Teachers’ Performance Scales (SPTPS) was used to gather data on the three performance dimensions namely contextual, task and adaptability performance. The exploratory factor analysis and confirmatory factor analysis methods were conducted to validate the performance constructs. The instrument has a high reliability of 0.90 based on the Cronbach Alpha method. The result of the analysis using estimation method indicates that students perceive their teachers’ performance to be at a slightly above average level (M= 3.51 ± 0.05 at the 95% confidence level). The teachers’ task performance, in particular, is found to be the least developed among the three dimension of performance while their adaptability performance is the highest while still being less than excellent. The data support the conclusion that there are aspects of teachers’ performance in teaching engineering drawing that is less than excellent and in need of further enhancements

    Students’ Perceptions of Their Teachers’ Performance in Teaching Engineering Drawing in Nigerian Tertiary Institutions

    Get PDF
    There have been concerns about the performance of Nigerian school teachers’ in delivering occupational related courses. However, there are currently limited empirical data on this phenomenon – in particular with respect to the teaching of engineering drawing – to justify further actions from educational managers and policy makers. The aim of this study was to assess teachers’ performance in teaching engineering drawing using students’ perception as indicator of teachers’ performance. The study utilized a cross-sectional research design method with the target population of technical education students drawn from four (4) Federal Colleges of education (Technical) in Northern Nigeria. Stratified proportionate sampling technique was used to arrive at the study sample of 253 technical education students. A specifically designed instrument, the Students’ Perceptions of Teachers’ Performance Scales (SPTPS) was used to gather data on the three performance dimensions namely contextual, task and adaptability performance. The exploratory factor analysis and confirmatory factor analysis methods were conducted to validate the performance constructs. The instrument has a high reliability of 0.90 based on the Cronbach Alpha method. The result of the analysis using estimation method indicates that students perceive their teachers’ performance to be at a slightly above average level (M= 3.51 ± 0.05 at the 95% confidence level). The teachers’ task performance, in particular, is found to be the least developed among the three dimension of performance while their adaptability performance is the highest while still being less than excellent. The data support the conclusion that there are aspects of teachers’ performance in teaching engineering drawing that is less than excellent and in need of further enhancements

    Visual communication in urban planning and urban design

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    This report documents the current status of visual communication in urban design and planning. Visual communication is examined through discussion of standalone and network media, specifically concentrating on visualisation on the World Wide Web(WWW).Firstly, we examine the use of Solid and Geometric Modelling for visualising urban planning and urban design. This report documents and compares examples of the use of Virtual Reality Modelling Language (VRML) and proprietary WWW based Virtual Reality modelling software. Examples include the modelling of Bath and Glasgow using both VRML 1.0 and 2.0. A review is carried out on the use of Virtual Worldsand their role in visualising urban form within multi-user environments. The use of Virtual Worlds is developed into a case study of the possibilities and limitations of Virtual Internet Design Arenas (ViDAs), an initiative undertaken at the Centre for Advanced Spatial Analysis, University College London. The use of Virtual Worlds and their development towards ViDAs is seen as one of the most important developments in visual communication for urban planning and urban design since the development plan.Secondly, photorealistic media in the process of communicating plans is examined.The process of creating photorealistic media is documented, examples of the Virtual Streetscape and Wired Whitehall Virtual Urban Interface System are provided. The conclusion is drawn that although the use of photo-realistic media on the WWW provides a way to visually communicate planning information, its use is limited. The merging of photorealistic media and solid geometric modelling is reviewed in the creation of Augmented Reality. Augmented Reality is seen to provide an important step forward in the ability to quickly and easily visualise urban planning and urban design information.Thirdly, the role of visual communication of planning data through GIS is examined interms of desktop, three dimensional and Internet based GIS systems. The evolution to Internet GIS is seen as a critical component in the development of virtual cities which will allow urban planners and urban designers to visualise and model the complexity of the built environment in networked virtual reality.Finally a viewpoint is put forward of the Virtual City, linking Internet GIS with photorealistic multi-user Virtual Worlds. At present there are constraints on how far virtual cities can be developed, but a view is provided on how these networked virtual worlds are developing to aid visual communication in urban planning and urban design

    Conceptual design study for an advanced cab and visual system, volume 2

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    The performance, design, construction and testing requirements are defined for developing an advanced cab and visual system. The rotorcraft system integration simulator is composed of the advanced cab and visual system and the rotorcraft system motion generator, and is part of an existing simulation facility. User's applications for the simulator include rotorcraft design development, product improvement, threat assessment, and accident investigation
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