366 resultados para degree of approximation
Resumo:
The widespread use of business planning in combination with the mixed theoretical and empirical support for its effect suggest research is needed that takes a deeper into the quality of plans and how they are used. In this study we longitudinally examine use vs. non-use; degree of formalizations; revision of plans, and moderation of planning effects by product novelty,among nascent firms. We relate these to attainment of profitability after 12 months. We find that business planning is negatively related to profitability, but that revising plans is positively related to profitability. Both these effects are stronger under conditions of high product novelty.
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From 27 January to 8 February during the summer of 2009, southern Australia experienced one of the nation‘s most severe heatwaves. Governments, councils, utilities, hospitals and emergency response organisations and the community were largely underprepared for an extreme event of this magnitude. This case study targets the experience and challenges faced by decision makers and policy makers and focuses on the major metropolitan areas affected by the heatwave — Melbourne and Adelaide. The study examines the 2009 heatwave‘s characteristics; its impacts (on human health, infrastructure and human services); the degree of adaptive capacity (vulnerability and resilience) of various sectors, communities and individuals; and the reactive responses of government and emergency and associated services and their effectiveness. Barriers and challenges to adaptation and increasing resilience are also identified and further areas for research are suggested. This study does not include details of the heatwave‘s effects beyond Victoria and South Australia, or its economic impacts, or of Victoria‘s 'Black Saturday‘ bushfires.
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In mobile videos, small viewing size and bitrate limitation often cause unpleasant viewing experiences, which is particularly important for fast-moving sports videos. For optimizing the overall user experience of viewing sports videos on mobile phones, this paper explores the benefits of emphasizing Region of Interest (ROI) by 1) zooming in and 2) enhancing the quality. The main goal is to measure the effectiveness of these two approaches and determine which one is more effective. To obtain a more comprehensive understanding of the overall user experience, the study considers user’s interest in video content and user’s acceptance of the perceived video quality, and compares the user experience in sports videos with other content types such as talk shows. The results from a user study with 40 subjects demonstrate that zooming and ROI-enhancement are both effective in improving the overall user experience with talk show and mid-shot soccer videos. However, for the full-shot scenes in soccer videos, only zooming is effective while ROI-enhancement has a negative effect. Moreover, user’s interest in video content directly affects not only the user experience and the acceptance of video quality, but also the effect of content type on the user experience. Finally, the overall user experience is closely related to the degree of the acceptance of video quality and the degree of the interest in video content. This study is valuable in exploiting effective approaches to improve user experience, especially in mobile sports video streaming contexts, whereby the available bandwidth is usually low or limited. It also provides further understanding of the influencing factors of user experience.
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Little is known about the psychological underpinnings of young people’s mobile phone behaviour. In the present research, 292 young Australians, aged 16–24 years, completed an online survey assessing the effects of self-identity, in-group norm, the need to belong, and self-esteem on their frequency of mobile phone use and mobile phone involvement, conceptualised as people’s degree of cognitive and behavioural association with their mobile phone. Structural equation modelling revealed that age (younger) and self-identity significantly predicted the frequency of mobile phone use. In contrast, age (younger), gender (female), self-identity and in-group norm predicted young people’s mobile phone involvement. Neither self-esteem nor the need to belong significantly predicted mobile phone behaviour. The present study contributes to our understanding of this phenomenon and provides an indication of the characteristics of young people who may become highly involved with their mobile phone.
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It has now been over a decade since the concept of creative industries was first put into the public domain through the Creative Industries Mapping Documents developed by the Blair Labour government in Britain. The concept has developed traction globally, but it has also been understood and developed in different ways in Europe, Asia, Australia, New Zealand and North America, as well as through international bodies such as UNCTAD and UNESCO. A review of the policy literature reveals that while questions and issues remain around definitional coherence, there is some degree of consensus emerging about the size, scope and significance of the sectors in question in both advanced and developing economies. At the same time, debate about the concept remains highly animated in media, communication and cultural studies, with its critics dismissing the concept outright as a harbinger of neo-liberal ideology in the cultural sphere. This paper couches such critiques in light of recent debates surrounding the intellectual coherence of the concept of neo-liberalism, arguing that this term itself possesses problems when taken outside of the Anglo-American context in which it originated. It is argued that issues surrounding the nature of participatory media culture, the relationship between cultural production and economic innovation, and the future role of public cultural institutions can be developed from within a creative industries framework, and that writing off such arguments as a priori ideological and flawed does little to advance debates about 21st century information and media culture.
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It is widely contended that we live in a „world risk society‟, where risk plays a central and ubiquitous role in contemporary social life. A seminal contributor to this view is Ulrich Beck, who claims that our world is governed by dangers that cannot be calculated or insured against. For Beck, risk is an inherently unrestrained phenomenon, emerging from a core and pouring out from and under national borders, unaffected by state power. Beck‟s focus on risk's ubiquity and uncontrollability at an infra-global level means that there is a necessary evenness to the expanse of risk: a "universalization of hazards‟, which possess an inbuilt tendency towards globalisation. While sociological scholarship has examined the reach and impact of globalisation processes on the role and power of states, Beck‟s argument that economic risk is without territory and resistant to domestic policy has come under less appraisal. This is contestable: what are often described as global economic processes, on closer inspection, reveal degrees of territorial embeddedness. This not only suggests that "global‟ flows could sometimes be more appropriately explained as international, regional or even local processes, formed from and responsive to state strategies – but also demonstrates what can be missed if we overinflate the global. This paper briefly introduces two key principles of Beck's theory of risk society and positions them within a review of literature debating the novelty and degree of global economic integration and its impact on states pursuing domestic economic policies. In doing so, this paper highlights the value for future research to engage with questions such as "is economic risk really without territory‟ and "does risk produce convergence‟, not so much as a means of reducing Beck's thesis to a purely empirical analysis, but rather to avoid limiting our scope in understanding the complex relationship between risk and state.
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Impedance cardiography is an application of bioimpedance analysis primarily used in a research setting to determine cardiac output. It is a non invasive technique that measures the change in the impedance of the thorax which is attributed to the ejection of a volume of blood from the heart. The cardiac output is calculated from the measured impedance using the parallel conductor theory and a constant value for the resistivity of blood. However, the resistivity of blood has been shown to be velocity dependent due to changes in the orientation of red blood cells induced by changing shear forces during flow. The overall goal of this thesis was to study the effect that flow deviations have on the electrical impedance of blood, both experimentally and theoretically, and to apply the results to a clinical setting. The resistivity of stationary blood is isotropic as the red blood cells are randomly orientated due to Brownian motion. In the case of blood flowing through rigid tubes, the resistivity is anisotropic due to the biconcave discoidal shape and orientation of the cells. The generation of shear forces across the width of the tube during flow causes the cells to align with the minimal cross sectional area facing the direction of flow. This is in order to minimise the shear stress experienced by the cells. This in turn results in a larger cross sectional area of plasma and a reduction in the resistivity of the blood as the flow increases. Understanding the contribution of this effect on the thoracic impedance change is a vital step in achieving clinical acceptance of impedance cardiography. Published literature investigates the resistivity variations for constant blood flow. In this case, the shear forces are constant and the impedance remains constant during flow at a magnitude which is less than that for stationary blood. The research presented in this thesis, however, investigates the variations in resistivity of blood during pulsataile flow through rigid tubes and the relationship between impedance, velocity and acceleration. Using rigid tubes isolates the impedance change to variations associated with changes in cell orientation only. The implications of red blood cell orientation changes for clinical impedance cardiography were also explored. This was achieved through measurement and analysis of the experimental impedance of pulsatile blood flowing through rigid tubes in a mock circulatory system. A novel theoretical model including cell orientation dynamics was developed for the impedance of pulsatile blood through rigid tubes. The impedance of flowing blood was theoretically calculated using analytical methods for flow through straight tubes and the numerical Lattice Boltzmann method for flow through complex geometries such as aortic valve stenosis. The result of the analytical theoretical model was compared to the experimental impedance measurements through rigid tubes. The impedance calculated for flow through a stenosis using the Lattice Boltzmann method provides results for comparison with impedance cardiography measurements collected as part of a pilot clinical trial to assess the suitability of using bioimpedance techniques to assess the presence of aortic stenosis. The experimental and theoretical impedance of blood was shown to inversely follow the blood velocity during pulsatile flow with a correlation of -0.72 and -0.74 respectively. The results for both the experimental and theoretical investigations demonstrate that the acceleration of the blood is an important factor in determining the impedance, in addition to the velocity. During acceleration, the relationship between impedance and velocity is linear (r2 = 0.98, experimental and r2 = 0.94, theoretical). The relationship between the impedance and velocity during the deceleration phase is characterised by a time decay constant, ô , ranging from 10 to 50 s. The high level of agreement between the experimental and theoretically modelled impedance demonstrates the accuracy of the model developed here. An increase in the haematocrit of the blood resulted in an increase in the magnitude of the impedance change due to changes in the orientation of red blood cells. The time decay constant was shown to decrease linearly with the haematocrit for both experimental and theoretical results, although the slope of this decrease was larger in the experimental case. The radius of the tube influences the experimental and theoretical impedance given the same velocity of flow. However, when the velocity was divided by the radius of the tube (labelled the reduced average velocity) the impedance response was the same for two experimental tubes with equivalent reduced average velocity but with different radii. The temperature of the blood was also shown to affect the impedance with the impedance decreasing as the temperature increased. These results are the first published for the impedance of pulsatile blood. The experimental impedance change measured orthogonal to the direction of flow is in the opposite direction to that measured in the direction of flow. These results indicate that the impedance of blood flowing through rigid cylindrical tubes is axisymmetric along the radius. This has not previously been verified experimentally. Time frequency analysis of the experimental results demonstrated that the measured impedance contains the same frequency components occuring at the same time point in the cycle as the velocity signal contains. This suggests that the impedance contains many of the fluctuations of the velocity signal. Application of a theoretical steady flow model to pulsatile flow presented here has verified that the steady flow model is not adequate in calculating the impedance of pulsatile blood flow. The success of the new theoretical model over the steady flow model demonstrates that the velocity profile is important in determining the impedance of pulsatile blood. The clinical application of the impedance of blood flow through a stenosis was theoretically modelled using the Lattice Boltzman method (LBM) for fluid flow through complex geometeries. The impedance of blood exiting a narrow orifice was calculated for varying degrees of stenosis. Clincial impedance cardiography measurements were also recorded for both aortic valvular stenosis patients (n = 4) and control subjects (n = 4) with structurally normal hearts. This pilot trial was used to corroborate the results of the LBM. Results from both investigations showed that the decay time constant for impedance has potential in the assessment of aortic valve stenosis. In the theoretically modelled case (LBM results), the decay time constant increased with an increase in the degree of stenosis. The clinical results also showed a statistically significant difference in time decay constant between control and test subjects (P = 0.03). The time decay constant calculated for test subjects (ô = 180 - 250 s) is consistently larger than that determined for control subjects (ô = 50 - 130 s). This difference is thought to be due to difference in the orientation response of the cells as blood flows through the stenosis. Such a non-invasive technique using the time decay constant for screening of aortic stenosis provides additional information to that currently given by impedance cardiography techniques and improves the value of the device to practitioners. However, the results still need to be verified in a larger study. While impedance cardiography has not been widely adopted clinically, it is research such as this that will enable future acceptance of the method.
Resumo:
Driver aggression is an increasing concern for motorists, with some research suggesting that drivers who behave aggressively perceive their actions as justified by the poor driving of others. Thus attributions may play an important role in understanding driver aggression. A convenience sample of 193 drivers (aged 17-36) randomly assigned to two separate roles (‘perpetrators’ and ‘victims’) responded to eight scenarios of driver aggression. Drivers also completed the Aggression Questionnaire and Driving Anger Scale. Consistent with the actor-observer bias, ‘victims’ (or recipients) in this study were significantly more likely than ‘perpetrators’ (or instigators) to endorse inadequacies in the instigator’s driving skills as the cause of driver aggression. Instigators were significantly more likely attribute the depicted behaviours to external but temporary causes (lapses in judgement or errors) rather than stable causes. This suggests that instigators recognised drivers as responsible for driving aggressively but downplayed this somewhat in comparison to ‘victims’/recipients. Recipients and instigators agreed that the behaviours were examples of aggressive driving but instigators appeared to focus on the degree of intentionality of the driver in making their assessments while recipients appeared to focus on the safety implications. Contrary to expectations, instigators gave mean ratings of the emotional impact of driving aggression on recipients that were higher in all cases than the mean ratings given by the recipients. Drivers appear to perceive aggressive behaviours as modifiable, with the implication that interventions could appeal to drivers’ sense of self-efficacy to suggest strategies for overcoming plausible and modifiable attributions (e.g. lapses in judgement; errors) underpinning behaviours perceived as aggressive.
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The importance of the first year experience (FYE) to success at university is well documented and supported with the transition into university regarded as crucial. While there is also support for the notion that a successful FYE should have a whole-of-institution focus and models have been proposed, many institutions still face challenges in achieving institution-wide FYE program implementation. This paper discusses the origins, theoretical and empirical bases and structure of an institution-wide approach to the FYE. It uses a case study of the Transitions In Project (TIP) at the Queensland University of Technology to illustrate how institution-wide FYE program implementation can be achieved and sustained. TIP had four inter-related projects focussing on at-risk students, first year curriculum, learning resources and staff development. The key aim of TIP was to identify good practice and institutionalise it in a sustainable way. The degree of success in achieving this is evaluated.
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An understanding of physical growth and maturation is relevant to many disciplines, including exercise and sport science, anthropology, human biology, medicine, psychology and education. Growth and maturation is governed by a complex interaction between genetic and environmental factors. There is increasing evidence that physical activity plays an important role in normal growth, development, health and well-being of children and youth, however, caution is required in the activity setting so that growth and maturation is not jeopardised. To appreciate the impact of physical activity and/or exercise on growth and maturation, a thorough understanding of the general principles of auxology is useful. Following an introduction to terminology, an overview of physical growth and development is provided in the context of morphological changes. Detailed information is provided regarding individual variability in growth and development along with sexual dimorphism. A small degree of sexual dimorphism exists at birth however striking differences develop during the pubertal years. Sexual dimorphism in body composition is largely regulated by endocrine factors with critical roles played by growth hormone and gonadal steroids.
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This paper presents the results of a pilot study examining the factors that impact most on the effective implementation of, and improvement to, Quality Mangement Sytems (QMSs) amongst Indonesian construction companies. Nine critical factors were identified from an extensive literature review, and a survey was conducted of 23 respondents from three specific groups (Quality Managers, Project Managers, and Site Engineers) undertaking work in the Indonesian infrastructure construction sector. The data has been analyzed initially using simple descriptive techniques. This study reveals that different groups within the sector have different opinions of the factors regardless of the degree of importance of each factor. However, the evaluation of construction project success and the incentive schemes for high performance staff, are the two factors that were considered very important by most of the respondents in all three groups. In terms of their assessment of tools for measuring contractor’s performance, additional QMS guidelines, techniques related to QMS practice provided by the Government, and benchmarking, a clear majority in each group regarded their usefulness as ‘of some importance’.
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The concept of non-destructive testing (NDT) of materials and structures is of immense importance in engineering and medicine. Several NDT methods including electromagnetic (EM)-based e.g. X-ray and Infrared; ultrasound; and S-waves have been proposed for medical applications. This paper evaluates the viability of near infrared (NIR) spectroscopy, an EM method for rapid non-destructive evaluation of articular cartilage. Specifically, we tested the hypothesis that there is a correlation between the NIR spectrum and the physical and mechanical characteristics of articular cartilage such as thickness, stress and stiffness. Intact, visually normal cartilage-on-bone plugs from 2-3yr old bovine patellae were exposed to NIR light from a diffuse reflectance fibre-optic probe and tested mechanically to obtain their thickness, stress, and stiffness. Multivariate statistical analysis-based predictive models relating articular cartilage NIR spectra to these characterising parameters were developed. Our results show that there is a varying degree of correlation between the different parameters and the NIR spectra of the samples with R2 varying between 65 and 93%. We therefore conclude that NIR can be used to determine, nondestructively, the physical and functional characteristics of articular cartilage.
Resumo:
The behavioral theory of “entrepreneurial bricolage” attempts to understand what entrepreneurs do when faced with resource constraints. Prior research suggests that bricolage behaviors enable firms to “make do” through recombining existing resources and may assist in the development of firms that are better able to manage market uncertainties, survive and perhaps even flourish despite resource constraints. Using a new survey measure we further theorize and test the moderating effects of firm strategic change and innovativeness on bricolage and firm performance. Our findings suggest that changes in core elements of the business and degree of innovation reduce the positive effects of bricolage in young firm performance.
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Inspection aircraft equipped with cameras and other sensors are routinely used for asset location, inspection, monitoring and hazard identification of oil-gas pipelines, roads, bridges and power transmission grids. This paper is concerned with automated flight of fixed-wing inspection aircraft to track approximately linear infrastructure. We propose a guidance law approach that seeks to maintain aircraft trajectories with desirable position and orientation properties relative to the infrastructure under inspection. Furthermore, this paper also proposes the use of an adaptive maneuver selection approach, in which maneuver primitives are adaptively selected to improve the aircraft’s attitude behaviour. We employ an integrated design methodology particularly suited for an automated inspection aircraft. Simulation studies using full nonlinear semi-coupled six degree-of-freedom equations of motion are used to illustrate the effectiveness of the proposed guidance and adaptive maneuver selection approaches in realistic flight conditions. Experimental flight test results are given to demonstrate the performance of the design.
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Background: Untreated Chlamydia trachomatis infections in women can result in disease sequelae such as salpingitis and pelvic inflammatory disease (PID), ultimately culminating in tubal occlusion and infertility. Whilst nucleic acid amplification tests can effectively diagnose uncomplicated lower genital tract (LGT) infections, they are not suitable for diagnosing upper genital tract (UGT) pathological sequelae. As a consequence, this study aimed to identify serological markers that can, with a high degree of sensitivity and specificity, discriminate between LGT infections and UGT pathology. Methods: Plasma was collected from 73 women with a history of LGT infection, UGT pathology due to C. trachomatis or no serological evidence of C. trachomatis infection. Western blotting was used to analyse antibody reactivity against extracted chlamydial proteins. Sensitivity and specificity of differential markers were also calculated. Results: Four antigens (CT157, CT423, CT727 and CT396) were identified and found to be capable of discriminating between the infection and disease sequelae state. Sensitivity and specificity calculations showed that our assay for diagnosing LGT infection had a sensitivity and specificity of 75% and 76% respectively, whilst the assay for identifying UGT pathology demonstrated 80% sensitivity and 86% specificity. Conclusions: The use of these assays could potentially facilitate earlier diagnoses in women suffering UGT pathology due to C. trachomatis.