29 resultados para Heads.


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      This thesis examines the mechanism of wear occuring to the video head and their effect on signal reproduction. in particular it examines the wear occuring to manganese-zinc ferrite heads in sliding contact with iron oxide media.       A literature survey is presented, which covers magnetic recording technologies, focussing on video recording. Existing work on wear of magnetic heads is also examined, and gaps in the theoretical account of wear mechanisms presented in the literature are identified.       Pilot research was carrried out on the signal degradation and wear associated witha number of commercial video tapes, containing a range of head cleaning agents. From this research, the main body of the research was identified. A number of methods of wear measurement were examined for use in this project. Knoop diamond indentation was chosen because experimentation showed it to be capable of measuring wear occuring in situ. This technique was then used to examine the wear associated with different levels of A12O3 and Cr2O3 head cleaning agents.      The results of the research indicated that, whilst wear of the video head increases linearly with increasing HCA content, signal degradation does not vary significantly. The most significant differences in wear and signal reproduction were observed between the two HCAs. The signal degradation of heads worn with tape samples containing A12O3 HCA was found to be lower than heads worn with tapes containing Cr2O3 HCA.      The results also indicate that the wear to the head is an abrasive process characterised by ploughing of the ferrite surface and chipping of the edges of the head gap. Both phenomena appear to be caused by poor iron oxide and head cleaning particles, which create isolated asperities on the tape surface.   

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Objectives: To assess the extent of teaching about the Committee on Safety of Medicine's Yellow Card scheme and adverse drug reactions within UK Schools of Medicine and Pharmacy. Methods: A self-completed questionnaire sent to all heads of undergraduate schools of medicine and pharmacy within the UK. Results: The majority of undergraduate syllabuses feature the Yellow Card Scheme. Knowledge of the Yellow Card Scheme was assessed in 79% of pharmacy programmes and 57% of medical schools. Specialist speakers on the Yellow Card Scheme were infrequently used. Fewer than half of respondents provided students with a guide to reporting ADRs (43% pharmacy and 43% medical). There is some disagreement about the value of supplying students with printed material about the Yellow Card Scheme. Half of medical Schools did not think that supplying 'Current Problems In Pharmacovigilance' would be useful. Conclusions: It was found that in both medicine and pharmacy, courses differed substantially in teaching about the Yellow Card Scheme and adverse drug reactions (ADRs). There is scope for increased involvement of the Medicines and Healthcare products Regulatory Agency in undergraduate education, in line with recommendations from the National Audit Office.

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We analysed evoked magnetic responses to moving random dot stimuli, initially using a 19-channel magnetoencephalography (MEG) system, and subsequently using a 151-channel MEG system. Random dot displays were used to construct complex motion sequences, which we refer to as expansion, contraction, deformation, and rotation. We also investigated lateral translation and a condition in which the directions of the dots were randomised. In all stimulus conditions, the dots were first stationary, then traveled for a brief period (317s or 542 ms), and were then stationary again. In all conditions, evoked magnetic responses were observed with a widespread bilateral distribution over the observers' heads. Initial recordings revealed a substantially larger evoked magnetic response to the expansion condition than the other conditions. In a revised study, we used a 151-channel MEG system and two stimulus diameters (9.3 and 48 deg), the smaller comparable with the first experiment. The responses were analysed using a nonparametric approach and confirmed our initial observations. In a third study, speed gradients were removed and a new design permitted direct comparisons between motion conditions. The results from all three experiments are consistent with the greater ecological validity of the expansion stimulus. © 2004 Elsevier B.V. All rights reserved.

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An analysis is made of the conceptions which serving teachers have of their role, though no attempt is made to relate this to their practice of teaching. A series of role items was collected to afford a description of the teacher's role in terms of school and society expectations as well as classroom behaviours. These were taken from the literature and from interviews with teachers, and confirmed in a preliminary survey. Presented as a questionnaire, replies to the main investigation were made by 881 teachers, working in a variety of schools from nurseries to comprehensives. Two attempts have been made to construct a role model. The first, depending on the judgement of items fitting theoretically derived roles, failed, due to diffuseness in the role of teacher. The second used factor analysis; six factors were extracted which represent meaningful and distinct areas of role. The analysis has depended largely on examination of scores taken from these factors. Teachers in all types of school have similar conceptions of discipline. Nursery-infant and junior staff generally agree on the other areas investigated, but the concepts of secondary teachers are distinct. They are more conservative and less child-centered. When the class being taught is held constant, few differences in role conception are found to be related to sex, being a parent, graduate status, or personality, as measured in terms of the extrovert and neurotic dimensions. The first few years of teaching bring considerable changes in role conception, and further changes occur with prolonged experience. Deputy heads in junior schools and nursery nurses have quite distinct role conceptions; those of all other teachers, including those holding senior posts in secondary schools, are similar. The perception of school climate influences the role conception of primary teachers directly, but it does not influence that of secondary teachers. The greatest variation in role conception is related to scores on the radical scale of Oliver and Butcher. Primary school teachers experience little constraint, but that reported by secondary school teachers is considerable, especially that coming from the head. Despite difficulties caused by the wide division between primary and secondary education, teachers have an accurate perception of the roles their colleagues adopt. A few misunderstandings may be due to a feeling of idealism amongst nursery and infant teachers. There is evidence in their conception of role that would enhance the professional standing of teachers, but this is not in a form which is likely to be recognised by the public.

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The performance of wireless networks is limited by multiple access interference (MAI) in the traditional communication approach where the interfered signals of the concurrent transmissions are treated as noise. In this paper, we treat the interfered signals from a new perspective on the basis of additive electromagnetic (EM) waves and propose a network coding based interference cancelation (NCIC) scheme. In the proposed scheme, adjacent nodes can transmit simultaneously with careful scheduling; therefore, network performance will not be limited by the MAI. Additionally we design a space segmentation method for general wireless ad hoc networks, which organizes network into clusters with regular shapes (e.g., square and hexagon) to reduce the number of relay nodes. The segmentation methodworks with the scheduling scheme and can help achieve better scalability and reduced complexity. We derive accurate analytic models for the probability of connectivity between two adjacent cluster heads which is important for successful information relay. We proved that with the proposed NCIC scheme, the transmission efficiency can be improved by at least 50% for general wireless networks as compared to the traditional interference avoidance schemes. Numeric results also show the space segmentation is feasible and effective. Finally we propose and discuss a method to implement the NCIC scheme in a practical orthogonal frequency division multiplexing (OFDM) communications networks. Copyright © 2009 John Wiley & Sons, Ltd.

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This study critically discusses findings from a research project involving four European countries. The project had two main aims. The first was to develop a systematic procedure for assessing the balance between knowledge and competencies acquired in higher, further and vocational education and the specific needs of the labor market. The second aim was to develop and test a set of meta-level quality indicators aimed at evaluating the linkages between education and employment. The project was designed to address the lack of employer input concerning the requirements of business graduates for successful workplace performance and the need for more specific industry-driven feedback to guide administrative heads at universities and personnel at quality assurance agencies in curriculum development and revision. Approach: The project was distinctive in that it combined different partners from higher education, vocational training, industry and quality assurance. Project partners designed and implemented an innovative approach, based on literature review, qualitative interviews and surveys in the four countries, in order to identify and confirm key knowledge and competency requirements. This study presents this step-by-step approach, as well as survey findings from a sample of 900 business graduates and employers. In addition, it introduces two Partial Least Squares (PLS) path models for predicting satisfaction with work performance and satisfaction with business education. Results: Survey findings revealed that employers were not very confident regarding business graduates’ abilities in key knowledge areas and in key generic competencies. In subsequent analysis, these graduate abilities were tested and identified as important predictors of employers’ satisfaction with graduates’ work performance. Conclusion: The industry-driven approach introduced in this study can serve as a guide to assist different types of educational institutions to better align study programs with changing labor market requirements. Recommendations for curriculum improvement are discussed.

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In the light of the financial crisis and the radically changed conditions in the market place, international leadership development is facing new demands. The Danish-based International Leadership Institute Mannaz has researched the new conditions in collaboration with the Institute of Executive Development in the United States. The research, conducted in 2008 and 2009, combines, in an innovative way, quantitative and qualitative inputs, from both current and future perspectives, from some 111 senior Corporate Executives, Heads of Human Resources and of Learning and Organisational Development in large international corporations headquartered in Europe and the United States; together with the thoughts of some 50 experienced practitioners involved in executive coaching as well as in designing, developing and facilitating leadership development programmes. Also we include a section summarising the key findings from recently published research from other leadership development surveys. Conclusions reveal that the crisis has propelled a long-awaited decline of the traditional classroom-based educational approach to leadership development. Instead, effective leadership development is suggested to build on experiential learning approaches rooted in real life, real time and allowing for more immediate impact and providing for considerably higher relevance and motivation. Coaching, leaders teaching leaders, stretch assignments, action learning, peer networking, customer insights and selective use of technology are seen as important contributors to the leadership development process going forward.

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Emerging vehicular comfort applications pose a host of completely new set of requirements such as maintaining end-to-end connectivity, packet routing, and reliable communication for internet access while on the move. One of the biggest challenges is to provide good quality of service (QoS) such as low packet delay while coping with the fast topological changes. In this paper, we propose a clustering algorithm based on minimal path loss ratio (MPLR) which should help in spectrum efficiency and reduce data congestion in the network. The vehicular nodes which experience minimal path loss are selected as the cluster heads. The performance of the MPLR clustering algorithm is calculated by rate of change of cluster heads, average number of clusters and average cluster size. Vehicular traffic models derived from the Traffic Wales data are fed as input to the motorway simulator. A mathematical analysis for the rate of change of cluster head is derived which validates the MPLR algorithm and is compared with the simulated results. The mathematical and simulated results are in good agreement indicating the stability of the algorithm and the accuracy of the simulator. The MPLR system is also compared with V2R system with MPLR system performing better. © 2013 IEEE.

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The measurement of different aspects of information society has been problematic over along time, and the International Telecommunication Union (ITU) is spearheading in developing a single ICT index. In Geneva during the first World Summit on Information Society (WSIS) in December 2003, the heads of states declared their commitment to the importance of benchmarking and measuring progress toward the information society. Consequently, they re-affirmed their Geneva commitments in their second summit held in Tunis in 2005. In this paper, we propose a multiplicative linear programming model to measure Opportunity Index. We also compared our results with the common measure of ICT opportunity index and we found that the two indices are consistent in their measurement of digital opportunity though differences still exist among regions.

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Book revew: Marketinggeschichte: die Genese einer modernen Sozialtechnik [Marketing history: The genesis of a modern social technique], edited by Hartmut Berghoff, Frankfurt/Main, Campus Verlag, 2007, 409 pp., illus., [euro]30.00 (paperback), ISBN 978-3-593-38323-1. This edited volume is the result of a workshop at Göttingen University in 2006 and combines a number of different approaches to the research into the history of marketing in Germany's economy and society. The majority of contributions loosely focus around the occurrence of a ‘marketing revolution’ in the 1970s, which ties in with interpretations of the Americanisation of German business. This revolution replaced the indigenous German idea of Absatzwirtschaft (the economics of sales) with the American-influenced idea of Marketing, which was less functionally oriented and more strategic, and which aimed to connect processes within the firm in order to allow a greater focus on the consumer. The entire volume is framed by Hartmut Berghoff's substantial and informative introduction, which introduces a number of actors and trends beyond the content of the volume. Throughout the various contributions, authors provide explanations of the timing and nature of marketing revolutions. Alexander Engel identifies an earlier revolution in the marketing of dyes, which undergoes major change with the emergence of chemical dyes. While the natural dyestuff had been a commodity, with producers removed from consumers via a global network of traders, chemical dyes were products and were branded at an early stage. This was a fundamental change in the nature of production and sales. As Roman Rossfeld shows in his contribution on the Swiss chocolate industry (which focuses almost exclusively on Suchard), even companies that produced non-essential consumer goods which had always required some measure of labelling grappled for years with the need to develop fewer and higher impact brands, as well as an efficient sales operation. A good example for the classical ‘marketing revolution’ of the 1970s is the German automobile industry. Ingo Köhler convincingly argues that the crisis situation of German car manufacturers – the change from a seller's to a buyer's market, appreciation of the German mark which undermines exports, the oil crises coupled with higher inflation and greater frugality of consumers and the emergence of new competitors – lead companies to refocus from production to the demands of the consumer. While he highlights the role of Ford in responding most rapidly to these problems, he does not address whether the multinational was potentially transferring American knowledge to the German market. Similarly, Paul Erker illustrates that a marketing revolution in transport and logistics happened much later, because the market remained highly regulated until the 1980s. Both Paul Erker and Uwe Spiekermann in their contribution, present comparisons of two different sectors or companies (the tire manufacturer Continental and the logistics company Dachser, and agriculture and trade, respectively). In both cases, however, it remains unclear why these examples were chosen for comparison, as both seem to have little in common and are not always effectively used to demonstrate differences. The weakest section of the book is the development of marketing as an academic discipline. The attempt at sketching the phases in the evolution of marketing as an academic discipline by Ursula Hansen and Matthias Bode opens with an undergraduate-level explanation on the methodology of historical periodisation that seems extraneous. Considerably stronger is the section on the wider societal impact of marketing, and Anja Kruke shows how the new techniques of opinion research was accepted by politics and business – surprisingly more readily by politicians than their commercial counterparts. In terms of contemporary personalities, Hans Domizlaff emerges as one fascinating figure of German marketing history, which several contributors refer to and whose career as the German cigarette manufacturer Reemtsma is critically analysed by Tino Jacobs. Domizlaff was Germany's own ‘marketing guru’, whose successful campaigns led to the wide-ranging reception of his ideas about the nature of good branding and marketing. These are variously described as intuitive, elitist, and sachlich, a German concept of a sober, fact-based, and ‘no frills’ approach. Domizlaff did not believe in market research. Rather, he saw the genius of the individual advertiser as key to intuitively ascertaining the people's moods, wishes, and desires. This seems to have made him peculiarly suited to the tastes of the German middle class, according to Thomas Mergel's contribution on the nature of political marketing in the republic. Especially in politics, any form of hard sales tactics were severely frowned upon and considered to demean the citizen as incapable of making an informed choice, a mentality that he dates back to the traditions of nineteenth-century liberalism. Part of this disdain of ‘selling politics like toothpaste’ was also founded on the highly effective use of branding by the National Socialists, who identified their party through the use of an increasingly standardised image of Adolf Hitler and the swastika. Alexander Schug extends on previous research that criticised the simplistic notion of Hitler's charisma as the only explanation of the popular success and distances his approach from those who see it in terms of propaganda and demagogy. He argues that the NSDAP used the tools of advertising and branding precisely because they had to introduce their new ideology into a political marketplace dominated by more established parties. In this they were undoubtedly successful, more so than they intended: as bakers sold swastika cookies and butchers formed Führer heads out of lard, the NSDAP sought to regain control over the now effectively iconic images that constituted their brand, which was in danger of being trivialised and devalued. Key to understanding the history of marketing in Germany is on the one hand the exchange of ideas with the United States, and on the other the impact of national-socialist policies, and the question whether they were a force of modernisation or retardation. The general argument in the volume appears to favour the latter explanation. In the 1930s, some of the leading marketing experts emigrated to the USA, leaving German academia and business isolated. The aftermath of the Second World War left a country that needed to increase production to satisfy consumer demand, and there was little interest in advanced sales techniques. Although the Nazis were progressive in applying new marketing methods to their political campaign, this retarded the adoption of sales techniques in politics for a long time. Germany saw the development of idiosyncratic approaches by people like Domizlaff in the 1930s and 1940s, when it lost some leading thinkers, and only engaged with American marketing conceptions in the 1960s and 1970s, when consumers eventually became more important than producers.

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We demonstrate an idealized method for the fabrication of regenerated type IA fibre Bragg gratings using commonly available apparatus. We use this technique to show that gratings written in the same fibre with the same period may have central wavelengths which are 14.4 nm apart and have an + 11.5% and - 1.2% difference in temperature and strain coefficients, respectively. We use these results to show that temperature compensated dual grating sensor heads, of an arbitrary length, may be quickly and consistently manufactured. © 2004 IOP Publishing Ltd.

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Emerging vehicular comfort applications pose a host of completely new set of requirements such as maintaining end-to-end connectivity, packet routing, and reliable communication for internet access while on the move. One of the biggest challenges is to provide good quality of service (QoS) such as low packet delay while coping with the fast topological changes. In this paper, we propose a clustering algorithm based on minimal path loss ratio (MPLR) which should help in spectrum efficiency and reduce data congestion in the network. The vehicular nodes which experience minimal path loss are selected as the cluster heads. The performance of the MPLR clustering algorithm is calculated by rate of change of cluster heads, average number of clusters and average cluster size. Vehicular traffic models derived from the Traffic Wales data are fed as input to the motorway simulator. A mathematical analysis for the rate of change of cluster head is derived which validates the MPLR algorithm and is compared with the simulated results. The mathematical and simulated results are in good agreement indicating the stability of the algorithm and the accuracy of the simulator. The MPLR system is also compared with V2R system with MPLR system performing better. © 2013 IEEE.

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Magnetoencephalography (MEG) offers significant opportunities for the localization and characterization of focal and generalized epilepsies, but its potential has so far not been fully exploited, as the evidence for its effectiveness is still anecdotal. This is particularly true for pediatric epilepsy. MEG recordings on school-age children typically rely on the use of MEG systems that were designed for adults and children's smaller head-size and stature can cause significant problems. Reduced signal-to-noise ratio when recording from smaller heads, increased movement, reduced sensor coverage of anterior temporal regions and incomplete insertion into the MEG helmet can all reduce the quality of data collected from children. We summarize these challenges and suggest some practical solutions.

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This thesis investigates Content and Language Integrated Learning (CLIL) in German undergraduate programmes in the UK. At its core is a study of how one German department integrates the teaching of language and content in its undergraduate programmes and how instructors and students experience this approach. This micro-context is embedded in the wider macro-context of UK Higher Education and subject to outside forces - be they political, economic, socio-cultural - whose effects will manifest in more or less obvious ways. Data was collected via an online survey of Heads of German at British universities to determine the status quo of CLIL in UK Higher Education and to investigate how certain institutional parameters determine the introduction of CLIL in Higher Education. This project employs a mixed-method case study approach and is based on student questionnaires and semi-structured interview with German teaching staff. The study brings to light a number of significant aspects. For example, contrary to popular belief, content provision in the L2 is rather common at British universities, which is currently not reflected in the research. Student data indicates that German students perceive clear advantages in the university’s approach to CLIL. They consider German-taught content classes challenging yet beneficial for their language development. Staff interviews have yielded intriguing information about perceived advantages and disadvantages of CLIL, about its implications for classroom practice, and about instructors’ attitude towards teacher training, which echo findings from similar investigations in European contexts. Finally, the results of the macro-analysis and the case study are compared and contrasted with findings from European research on ICLHE/CLIL to determine differences and similarities with the British context, a set of recommendations is made regarding CLIL practice at the case study institution, and some implications these indings may have for the future of CLIL in British higher education are discussed.