938 resultados para Image quality


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We address the problem of face recognition on video by employing the recently proposed probabilistic linear discrimi-nant analysis (PLDA). The PLDA has been shown to be robust against pose and expression in image-based face recognition. In this research, the method is extended and applied to video where image set to image set matching is performed. We investigate two approaches of computing similarities between image sets using the PLDA: the closest pair approach and the holistic sets approach. To better model face appearances in video, we also propose the heteroscedastic version of the PLDA which learns the within-class covariance of each individual separately. Our experi-ments on the VidTIMIT and Honda datasets show that the combination of the heteroscedastic PLDA and the closest pair approach achieves the best performance.

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In the past fifteen years, increasing attention has been given to the role of Vocational Education and Training (VET) in attracting large numbers of international students and its contribution to the economic development of Australia. This trend has given rise to many challenges in vocational education, especially with regard to providing quality education that ensures international students’ stay in Australia is a satisfactory experience. Teachers are key stakeholders in international education and share responsibility for ensuring international students gain quality learning experiences and positive outcomes. However, the challenges and needs of these teachers are generally not well understood. Therefore, this paper draws on the dilemmas faced by teachers of international students associated with professional, personal, ethical and educational aspects. This paper reports on a Masters Research project that is designed to investigate the dilemmas that teachers of international students face in VET in Australia, particularly in Brisbane. This study uses a qualitative approach within the interpretive constructivist paradigm to gain real-life insights through responsive interviewing and inductive data analysis. While the data collection has been done, the analysis of data is in progress. Responsive interviews with teachers of VET with different academic and national backgrounds, ages, industry experience have identified particular understandings, ideologies and representations of what it means to be a teacher in today's multicultural VET environment; provoking both resistances and new pedagogical understanding of teacher dilemmas and their work environment through the eyes of teachers of international students. The paper considers the challenges for the VET practitioners within the VET system while reflecting on the theme for the 2011 AVETRA conference, “Research in VET: Janus- Reflecting Back, Projecting Forward” by focusing particularly on “Rethinking pedagogies and pathways in VET work through the voice of VET workers”.

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Background Although physical activity is associated with health-related quality of life (HRQL), the nature of the dose-response relationship remains unclear. This study examined the concurrent and prospective dose-response relationships between total physical activity (TPA) and (only) walking with HRQL in two age cohorts of women. Methods Participants were 10,698 women born in 1946-1951 and 7,646 born in 1921-1926, who completed three mailed surveys for the Australian Longitudinal Study on Women's Health. They reported weekly TPA minutes (sum of walking, moderate, and vigorous minutes). HRQL was measured with the Medical Outcomes Study Short-Form 36 Health Status Survey (SF-36). Linear mixed models, adjusted for socio-demographic and health-related variables, were used to examine associations between TPA level (none, very low, low, intermediate, sufficient, high, and very high) and SF-36 scores. For women who reported walking as their only physical activity, associations between walking and SF-36 scores were also examined. Results Curvilinear trends were observed between TPA and walking with SF-36 scores. Concurrently, HRQL scores increased significantly with increasing TPA and walking, in both cohorts, with increases less marked above sufficient activity levels. Prospectively, associations were attenuated although significant and meaningful improvements in physical functioning and vitality were observed across most TPA and walking categories above the low category. Conclusion For women in their 50s-80s without clinical depression, greater amounts of TPA are associated with better current and future HRQL, particularly physical functioning and vitality. Even if walking is their only activity, women, particularly those in their 70s-80s, have better health-related quality of life.

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Existing secure software development principles tend to focus on coding vulnerabilities, such as buffer or integer overflows, that apply to individual program statements, or issues associated with the run-time environment, such as component isolation. Here we instead consider software security from the perspective of potential information flow through a program’s object-oriented module structure. In particular, we define a set of quantifiable "security metrics" which allow programmers to quickly and easily assess the overall security of a given source code program or object-oriented design. Although measuring quality attributes of object-oriented programs for properties such as maintainability and performance has been well-covered in the literature, metrics which measure the quality of information security have received little attention. Moreover, existing securityrelevant metrics assess a system either at a very high level, i.e., the whole system, or at a fine level of granularity, i.e., with respect to individual statements. These approaches make it hard and expensive to recognise a secure system from an early stage of development. Instead, our security metrics are based on well-established compositional properties of object-oriented programs (i.e., data encapsulation, cohesion, coupling, composition, extensibility, inheritance and design size), combined with data flow analysis principles that trace potential information flow between high- and low-security system variables. We first define a set of metrics to assess the security quality of a given object-oriented system based on its design artifacts, allowing defects to be detected at an early stage of development. We then extend these metrics to produce a second set applicable to object-oriented program source code. The resulting metrics make it easy to compare the relative security of functionallyequivalent system designs or source code programs so that, for instance, the security of two different revisions of the same system can be compared directly. This capability is further used to study the impact of specific refactoring rules on system security more generally, at both the design and code levels. By measuring the relative security of various programs refactored using different rules, we thus provide guidelines for the safe application of refactoring steps to security-critical programs. Finally, to make it easy and efficient to measure a system design or program’s security, we have also developed a stand-alone software tool which automatically analyses and measures the security of UML designs and Java program code. The tool’s capabilities are demonstrated by applying it to a number of security-critical system designs and Java programs. Notably, the validity of the metrics is demonstrated empirically through measurements that confirm our expectation that program security typically improves as bugs are fixed, but worsens as new functionality is added.

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A system is described for calculating volume from a sequence of multiplanar 2D ultrasound images. Ultrasound images are captured using a video digitising card (Hauppauge Win/TV card) installed in a personal computer, and regions of interest transformed into 3D space using position and orientation data obtained from an electromagnetic device (Polbemus, Fastrak). The accuracy of the system was assessed by scanning 10 water filled balloons (13-141 ml), 10 kidneys (147  200 ml) and 16 fetal livers (8  37 ml) in water using an Acuson 128XP/10 (5 MHz curvilinear probe). Volume was calculated using the ellipsoid, planimetry, tetrahedral and ray tracing methods and compared with the actual volume measured by weighing (balloons) and water displacement (kidneys and livers). The mean percentage error for the ray tracing method was 0.9 ± 2.4%, 2.7 ± 2.3%, 6.6 ± 5.4% for balloons, kidneys and livers, respectively. So far the system has been used clinically to scan fetal livers and lungs, neonate brain ventricles and adult prostate glands.

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Until recently, standards to guide nursing education and practice in Vietnam were nonexistent. This paper describes the development and implementation of a clinical teaching capacity building project piloted in Hanoi, Vietnam. The project was part of a multi-component capacity building program designed to improve nurse education in Vietnam. Objectives of the project were to develop a collaborative clinically-based teaching model that encourages evidence-based, student-centred clinical learning. The model incorporated strategies to promote development of nursing practice to meet national competency standards. Thirty nurse teachers from two organisations in Hanoi participated in the program. These participants attended three workshops, and completed applied assessments, where participants implemented concepts from each workshop. The assessment tasks were planning, implementing and evaluating clinical teaching. On completion of the workshops, twenty participants undertook a study tour in Australia to refine the teaching model and develop an action plan for model implementation in both organisations, with an aim to disseminate the model across Vietnam. Significant changes accredited to this project have been noted on an individual and organisational level. Dissemination of this clinical teaching model has commenced in Ho Chi Minh, with further plans for more in-depth dissemination to occur throughout the country.

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A wireless sensor network collected real-time water-quality measurements to investigate how current irrigation practices—in particular, underground water salination—affect the environment. New protocols provided high end-to-end packet delivery rates in the hostile deployment environment.

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Urban stormwater quality is multifaceted and the use of a limited number of factors to represent catchment characteristics may not be adequate to explain the complexity of water quality response to a rainfall event or site-to-site differences in stormwater quality modelling. This paper presents the outcomes of a research study which investigated the adequacy of using land use and impervious area fraction only, to represent catchment characteristics in urban stormwater quality modelling. The research outcomes confirmed the inadequacy of the use of these two parameters alone to represent urban catchment characteristics in stormwater quality prediction. Urban form also needs to be taken into consideration as it was found have an important impact on stormwater quality by influencing pollutant generation, build-up and wash-off. Urban form refers to characteristics related to an urban development such as road layout, spatial distribution of urban areas and urban design features.

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It would be a rare thing to visit an early years setting or classroom in Australia that does not display examples of young children’s artworks. This practice serves to give schools a particular ‘look’, but is no guarantee of quality art education. The Australian National Review of Visual Arts Education (NRVE) (2009) has called for changes to visual art education in schools. The planned new National Curriculum includes the arts (music, dance, drama, media and visual arts) as one of the five learning areas. Research shows that it is the classroom teacher that makes the difference, and teacher education has a large part to play in reforms to art education. This paper provides an account of one foundation unit of study (Unit 1) for first year university students enrolled in a 4-year Bachelor degree program who are preparing to teach in the early years (0–8 years). To prepare pre-service teachers to meet the needs of children in the 21st century, Unit 1 blends old and new ways of seeing art, child and pedagogy. Claims for the effectiveness of this model are supported with evidence-based research, conducted over the six years of iterations and ongoing development of Unit 1.

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Objectives: To measure tear film surface quality (TFSQ) using dynamic high-speed videokeratoscopy during short-term (8 hours) use of rigid and soft contact lenses. Methods: A group of fourteen subjects wore 3 different types of contact lenses on 3 different non-consecutive days (order randomized) in one eye only. Subjects were screened to exclude those with dry eye. The lenses included a PMMA hard, an RGP (Boston XO) and a soft silicone hydrogel lens. Three 30 second long high speed videokeratoscopy recordings were taken with contact lenses in-situ, in the morning and again after 8 hours of contact lens wear, both in normal and suppressed blinking conditions. Recordings were also made on a baseline day with no contact lens wear. Results: The presence of a contact lens in the eye had a significant effect on the mean TFSQ in both natural and suppressed blinking conditions (p=0.001 and p=0.01 respectively, repeated measures ANOVA). TFSQ was worse with all the lenses compared to no lens in the eye (in the afternoon during both normal and suppressed blinking conditions (all p<0.05). In natural blinking conditions, the mean TFSQ for the PMMA and RGP lenses was significantly worse than the baseline day (no lens) for both morning and afternoon measures (p<0.05). Conclusions: This study shows that both rigid and soft contact lenses adversely affect the TFSQ in both natural and suppressed blinking conditions. No significant differences were found between the lens types and materials. Keywords: Tear film surface quality, rigid contact lens, soft contact lens, dynamic high-speed videokeratoscopy

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The National Road Safety Strategy 2011-2020 outlines plans to reduce the burden of road trauma via improvements and interventions relating to safe roads, safe speeds, safe vehicles, and safe people. It also highlights that a key aspect in achieving these goals is the availability of comprehensive data on the issue. The use of data is essential so that more in-depth epidemiologic studies of risk can be conducted as well as to allow effective evaluation of road safety interventions and programs. Before utilising data to evaluate the efficacy of prevention programs it is important for a systematic evaluation of the quality of underlying data sources to be undertaken to ensure any trends which are identified reflect true estimates rather than spurious data effects. However, there has been little scientific work specifically focused on establishing core data quality characteristics pertinent to the road safety field and limited work undertaken to develop methods for evaluating data sources according to these core characteristics. There are a variety of data sources in which traffic-related incidents and resulting injuries are recorded, which are collected for a variety of defined purposes. These include police reports, transport safety databases, emergency department data, hospital morbidity data and mortality data to name a few. However, as these data are collected for specific purposes, each of these data sources suffers from some limitations when seeking to gain a complete picture of the problem. Limitations of current data sources include: delays in data being available, lack of accurate and/or specific location information, and an underreporting of crashes involving particular road user groups such as cyclists. This paper proposes core data quality characteristics that could be used to systematically assess road crash data sources to provide a standardised approach for evaluating data quality in the road safety field. The potential for data linkage to qualitatively and quantitatively improve the quality and comprehensiveness of road crash data is also discussed.

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While researchers strive to improve automatic face recognition performance, the relationship between image resolution and face recognition performance has not received much attention. This relationship is examined systematically and a framework is developed such that results from super-resolution techniques can be compared. Three super-resolution techniques are compared with the Eigenface and Elastic Bunch Graph Matching face recognition engines. Parameter ranges over which these techniques provide better recognition performance than interpolated images is determined.

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This thesis is about defining participation in the context of fostering research cohesion in the field of Participatory Design. The systematic and incremental building of new knowledge is the process by which science and research is advanced. This process requires a certain type of cohesion in the way research is undertaken for new knowledge to be built from the knowledge provided by previous projects and research. To support this process and to foster research cohesion three conditions are necessary. These conditions are: common ground between practitioners, problem-space positioning, and adherence to clear research criteria. The challenge of fostering research cohesion in Participatory Design is apparent in at least four themes raised in the literature: the role of politics within Participatory Design epistemology, the role of participation, design with users, and the ability to translate theory into practice. These four thematic challenges frame the context which the research gap is situated. These themes are also further investigated and the research gap – a general lack of research cohesion – along with one avenue for addressing this gap – a clear and operationalizable definition for participation – are identified. The intended contribution of this thesis is to develop a framework and visual tool to address this research gap. In particular, an initial approximation for a clear and operationalizable definition for participation will be proposed such that it can be used within the field of Participatory Design to run projects and foster research cohesion. In pursuit of this contribution, a critical lens is developed and used to analyse some of the principles and practices of Participatory Design that are regarded as foundational. This lens addresses how to define participation in a way that adheres to basic principles of scientific rigour – namely, ensuring that the elements of a theory are operationalizable, falsifiable, generalizable, and useful, and it also treats participation as a construct rather than treating the notion of participation as a variable. A systematic analysis is performed using this lens on the principles and practices that are considered foundational within the field. From this analysis, three components of the participation construct – impact, influence, and agency – are identified. These components are then broken down into two constituent variables each (six in all) and represented visually. Impact is described as the relationship between the quality and use of information. Influence is described as the relationship between the amount and scope of decision making. Agency is described as the relationship between the motivation of the participant and the solidarity of the group. Thus, as a construct, participation is described as the relationship between a participant’s impact, influence, and agency. In the concluding section, the value of this participation construct is explored for its utility in enhancing project work and fostering research cohesion. Three items of potential value that emerge are: the creation of a visual tool through the representation of these six constituent variables in one image; the elaboration of a common language for researchers based on the six constituent variables identified; and the ability to systematically identify and remedy participation gaps throughout the life of the project. While future research exploring the applicability of the participation construct in real world projects is necessary, it is intended that this initial approximation of a participation construct in the form of the visual tool will serve as the basis for a cohesive and rigorous discussion about participation in Participatory Design.

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In this study the interplay effects for Enhanced Dynamic Wedge (EDW) treatments are experimentally investigated. Single and multiple field EDW plans for different wedge angles were delivered to a phantom and detector on a moving platform, with various periods, amplitudes for parallel and perpendicular motions. A four field 4D CT planned lung EDW treatment was delivered to a dummy tumor over four fractions. For the single field parallel case the amplitude and the period of motion both affect the interplay resulting in the appearance of a step function and penumbral cut off with the discrepancy worst where collimator-tumor speed is similar. For perpendicular motion the amplitude of tumor motion is the only dominant factor. For large wedge angle the dose discrepancy is more pronounced compared to the small wedge angle for the same field size and amplitude-period values. For a small field size i.e. 5 × 5 cm2 the loss of wedged distribution was observed for both 60º and 15º wedge angles for of parallel and perpendicular motions. Film results from 4D CT planned delivery displayed a mix of over and under dosages over 4 fractions, with the gamma pass rate of 40% for the averaged film image at 3%/1 mm DTA (Distance to Agreement). Amplitude and period of the tumor motion both affect the interplay for single and multi-field EDW treatments and for a limited (4 or 5) fraction delivery there is a possibility of non-averaging of the EDW interplay.

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This Exceptional Teachers for Disadvantaged Schools (ETDS) project sets out to design a new model of Australian teacher education responding to recent demands for quality education in low SES and disadvantaged schools. The project moves teacher education from the ‘missionary’ (Larabee, 2010) or deficit (Comber and Kamler 2004; Flessa, 2007) approaches, towards a focus on notions of quality and academic excellence. Rice (2008, p.1) argues for a need to place more of the “very best teachers into the most challenging schools”, yet the problem is not merely one of training more teachers, for disadvantaged schools already receive disproportionate numbers of beginning teachers (Connell, 1994; Vickers & Ferfolja, 2006). Rather, Grossman and Loeb (2010, p. 245) argue the problem centers on the common practice of “[p]lacing the least experienced teachers with the most needy students”. This paper reports on the first year trial of the project. The ETDS project is at present, the only mainstream Australian teacher education model that targets cohorts of academically high achieving pre-service teachers with the overt aim of preparing graduates of the program to teach in disadvantaged schools. At the end of its first year, the ETDS program graduated 20 new teachers, each of whom had over the previous 18 months engaged with a specialized curriculum and carefully monitored/scaffolded practicum placements in disadvantaged schools around Brisbane, Australia.