350 resultados para Numbers, Divisibility of.
Resumo:
This PhD research investigates the critical resources and Internet capabilities utilized by firms for leveraging global performance in entrepreneurial firms. Firm resources have been identified as important firm assets, which contribute to the firm's competitive global position. The Internet is a critical resource for a new generation of small and medium sized enterprise (SME) in pursuing international opportunities. By facilitating international business, the Internet has the ability to increase the quality and speed of communications, lower transaction costs, and facilitate the development of networks. Despite the increasing numbers of firms utilizing the Internet to pursue international opportunities, limited research remains. Adopting multiple case study methodology and structural equation modelling, the research identified the firm-level resources, which coincide with capabilities in a model predicting how international performance in firms is achieved.
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This paper aims to explore the experiences of newly qualified teachers and their supervising principals who work in schools situated in various high-poverty areas of Queensland, Australia. It is informed by data collected in the context of an Australian teacher education program, Exceptional Teachers for Disadvantaged Schools (ETDS). Now in its third year, this program was designed to prepare highly skilled pre-service teachers to work in schools that have large numbers of students from disadvantaged or low socio-economic status (SES) backgrounds. Addressing the oft-stated need to prepare high-quality teachers for low SES schools, high-achieving undergraduate education students were invited to participate in two years of specialised curriculum to prepare them for the schools that need them the most, which are also the schools that are often difficult to staff. Pre-service teachers in this program do all their teaching practicum placements in challenging or complex schools. In 2011, some of this cohort did their practicum teaching in schools with large numbers of Indigenous students and several went on to teach in remote communities after graduation. These graduates and the leaders of the schools they work in are the primary informants for this paper.
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We propose the progressive mechanical expansion of cell-derived tissue analogues as a novel, growth-based approach to in vitro tissue engineering. The prevailing approach to producing tissue in vitro is to culture cells in an exogenous “scaffold” that provides a basic structure and mechanical support. This necessarily pre-defines the final size of the implantable material, and specific signals must be provided to stimulate appropriate cell growth, differentiation and matrix formation. In contrast, surgical skin expansion, driven by increments of stretch, produces increasing quantities of tissue without trauma or inflammation. This suggests that connective tissue cells have the innate ability to produce growth in response to elevated tension. We posit that this capacity is maintained in vitro, and that order-of-magnitude growth may be similarly attained in self-assembling cultures of cells and their own extracellular matrix. The hypothesis that growth of connective tissue analogues can be induced by mechanical expansion in vitro may be divided into three components: (1) tension stimulates cell proliferation and extracellular matrix synthesis; (2) the corresponding volume increase will relax the tension imparted by a fixed displacement; (3) the repeated application of static stretch will produce sustained growth and a tissue structure adapted to the tensile loading. Connective tissues exist in a state of residual tension, which is actively maintained by resident cells such as fibroblasts. Studies in vitro and in vivo have demonstrated that cellular survival, reproduction, and matrix synthesis and degradation are regulated by the mechanical environment. Order-of-magnitude increases in both bone and skin volume have been achieved clinically through staged expansion protocols, demonstrating that tension-driven growth can be sustained over prolonged periods. Furthermore, cell-derived tissue analogues have demonstrated mechanically advantageous structural adaptation in response to applied loading. Together, these data suggest that a program of incremental stretch constitutes an appealing way to replicate tissue growth in cell culture, by harnessing the constituent cells’ innate mechanical responsiveness. In addition to offering a platform to study the growth and structural adaptation of connective tissues, tension-driven growth presents a novel approach to in vitro tissue engineering. Because the supporting structure is secreted and organised by the cells themselves, growth is not restricted by a “scaffold” of fixed size. This also minimises potential adverse reactions to exogenous materials upon implantation. Most importantly, we posit that the growth induced by progressive stretch will allow substantial volumes of connective tissue to be produced from relatively small initial cell numbers.
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The modern day Australian law school is expected to educate and engage law students. Ideally law school will instil a sense of passion (or at least appreciation) for the law, promote a positive professional identity, foster a sense of community, and provide general support to law students. Collectively, the Australian legal academy is struggling with these goals. Significant numbers of students feel isolated, disconnected and unengaged throughout their tertiary legal education. Teaching students from increasingly diverse backgrounds, who spend less time on campus and less face-to-face time in class, many law academics feel ill-equipped to respond to the challenge of engaging law students in time and cost efficient ways. Intentionally learning and using student names has potential to humanise the law school experience, build community, and positively impact upon the wellbeing of students and staff.
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Transition zones between bridge decks and rail tracks suffer early failure due to poor interaction between rail vehicles and sudden changes of stiffness. This has been an ongoing problem to rail industry and yet still no systematic studies appear to have been taken to maintain a gradually smoothening transmission of forces between the bridge and its approach. Differential settlement between the bridge deck and rail track in the transition zone is the fundamental issue, which negatively impacts the rail industry by causing passenger discomfort, early damage to infrastructure and vehicle components, speed reduction, and frequent maintenance cycles. Identification of mechanism of the track degradation and factors affecting is imperative to design any mitigation method for reducing track degradation rate at the bridge transition zone. Unfortunately this issue is still not well understood, after conducting a numbers of reviews to evaluate the key causes, and introducing a wide range of mitigation techniques. In this study, a comprehensive analysis of the available literature has been carried out to develop either a novel design framework or a mitigation technique for the bridge transition zone. This paper addresses three critical questions in relation to the track degradation at transition zone: (1) what are the causes of bridge transition track degradation?; (2) what are the available mitigation techniques in reducing the track degradation rate?; (3) what are the factors affecting on poor performance of the existing mitigation techniques?. It is found that the absence of soil-water response, dynamic loading response, and behaviour of geotechnical characteristics under long-term conditions in existing track transition design frameworks critically influence on the failures of existing mitigation techniques. This paper also evaluates some of the existing design frameworks to identify how each design framework addresses the track degradation at the bridge transition zone.
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Current military conflicts are characterized by the use of the improvised explosive device. Improvements in personal protection, medical care, and evacuation logistics have resulted in increasing numbers of casualties surviving with complex musculoskeletal injuries, often leading to lifelong disability. Thus, there exists an urgent requirement to investigate the mechanism of extremity injury caused by these devices in order to develop mitigation strategies. In addition, the wounds of war are no longer restricted to the battlefield; similar injuries can be witnessed in civilian centers following a terrorist attack. Key to understanding such mechanisms of injury is the ability to deconstruct the complexities of an explosive event into a controlled, laboratory-based environment. In this article, a traumatic injury simulator, designed to recreate in the laboratory the impulse that is transferred to the lower extremity from an anti-vehicle explosion, is presented and characterized experimentally and numerically. Tests with instrumented cadaveric limbs were then conducted to assess the simulator’s ability to interact with the human in two mounting conditions, simulating typical seated and standing vehicle passengers. This experimental device will now allow us to (a) gain comprehensive understanding of the load-transfer mechanisms through the lower limb, (b) characterize the dissipating capacity of mitigation technologies, and (c) assess the bio-fidelity of surrogates.
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Suppose two parties, holding vectors A = (a 1,a 2,...,a n ) and B = (b 1,b 2,...,b n ) respectively, wish to know whether a i > b i for all i, without disclosing any private input. This problem is called the vector dominance problem, and is closely related to the well-studied problem for securely comparing two numbers (Yao’s millionaires problem). In this paper, we propose several protocols for this problem, which improve upon existing protocols on round complexity or communication/computation complexity.
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The television quiz program Letters and Numbers, broadcast on the SBS network, has recently become quite popular in Australia. This paper explores the potential of this game to illustrate and engage student interest in a range of fundamental concepts of computer science and mathematics. The Numbers Game in particular has a rich mathematical structure whose analysis and solution involves concepts of counting and problem size, discrete (tree) structures, language theory, recurrences, computational complexity, and even advanced memory management. This paper presents an analysis of these games and their teaching applications, and presents some initial results of use in student assignments.
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The Internet Corporation for Assigned Names and Numbers (ICANN) is an institution besieged. It has endeavored to be democratic but its attempts to do so have been disastrous. The typical explanation for this is that the problem is with ICANN: it fails to meet its democratic obligations. My view is that the problem is with our understanding of "democracy." Democracy is an empty concept that fails to describe few, if any, of our genuine political commitments. In the real world, the failings inherent in "democracy" have been papered over by some unusual characteristics of the physical political process. However, in online trans-national institutions like ICANN, democracy is exposed as a poor substitute for a number of other conceptions of our political commitments. This Article seeks to articulate these political commitments and to explain why democracy and ICANN are such a poor mix. It begins by charting the rise of ICANN and its attempts to be democratic. It then explains why democracy is an empty shell of a concept. It then explores some features of democracy and ICANN, explaining why the online world exposes limitations in implications of democracy such as the nature of the demos, the idea of constituencies, direct democracy, voting, and the like. It concludes that ICANN's example demonstrates that democracy is in fact anything but a coherent general theory of political action. We need to consider, then, whether we should continue to berate ICANN for its undemocratic actions.
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Alternative schools are an emerging model of education offered to young people who have been disenfranchised from conventional schooling opportunities. The body of literature on alternative schools in Australia has not identified how many Indigenous young people are engaged with alternative schools and how alternative schools are supporting Indigenous young people to remain engaged in education. It is well documented that Aboriginal and Torres Strait Islander people experience significant disadvantage including poorer educational outcomes than their non-Indigenous peers. This study seeks to contribute to improving educational outcomes for Aboriginal and Torres Strait Islander young people through exploring Aboriginal and Torres Strait Islander interactions with alternative schools in Queensland and investigating the practices of alternative school leaders in terms of how they are supporting Indigenous young people to remain engaged in education. Critical race theory informed the development of this study. An Aboriginal researcher sought to shift the focus of this study away from Indigenous young people to Principals; to explore their perspective of their own knowledge and practices in supporting Aboriginal and Torres Strait Islander young people at their school. Using survey methodology, a web-based questionnaire was developed to survey Principals’ providing data on alternative schools in Queensland including the demographics of the alternative school; self-reported knowledge of Indigenous cultures and communities and practices that support Aboriginal and Torres Strait Islander young people at their alternative school. There are nine key findings that emerged through the analysis of this study: key finding one is the high percentage of Aboriginal and Torres Strait Islander young people enrolled in schools surveyed; key finding two is there is a high percentage of Aboriginal and Torres Strait Islander staff employed in the schools; key finding three is the majority of the schools are located in low socio-economic areas; key finding four is the strong willingness of Principals’ in this study to engage in self-directed learning in relation to Aboriginal and Torres Strait Islander cultures; key finding five is the limited demonstration of understandings of Aboriginal and Torres Strait Islander cultures and communities; key finding six is the most prevalent practice of Principals’ in this study is the celebration of cultural events and cultural activities; key finding seven is the limited Principal engagement with Aboriginal and Torres Strait Islander young people, their families and the local community; key finding eight is the practice of alternative schools provides limited support and nurturing of Aboriginal and Torres Strait Islander young person’s cultural identity and key finding nine is that Principals’ are relying heavily on informal discussions with staff to know what their staff’s knowledge and skills are in relation to supporting Aboriginal and Torres Strait Islander young people. There are multiple implications that have arisen from this study. The data demonstrated high numbers of Aboriginal and Torre Strait Islander students and staff. The data also revealed that Principal’s demonstration of knowledge in relation to Indigenous cultures and communities was limited, as well as limited Principal engagement with Indigenous young peoples, families and communities. Therefore a major practical implication of this study is the urgent need for quality cultural learning opportunities for leaders of alternative schools to improve practices. Additionally, the implications of this study support an urgent need for further research on the role alternative schools are playing in supporting Indigenous young people to remain engaged in education.
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Immigrant entrepreneurs tend to start businesses within their ethnic enclave (EE), as it is an integral part of their social and cultural context and the location where ethnic resources reside (Logan, Alba, & Stults, 2003). Ethnic enclaves can be seen as a form of geographic cluster, China Towns are exemplar EEs, easily identified by the clustering of Chinese restaurants and other ethnic businesses in one central location. Studies on EE thus far have neglected the life cycles stages of EE and its impact on the business experiences of the entrepreneurs. In this paper, we track the formation, growth and decline of a EE. We argue that EE is a special industrial cluster and as such it follows the growth conditions proposed by the cluster life cycle theory (Menzel & Fornahl, 2009). We report a mixed method study of Chinese Restaurants in South East Queensland. Based on multiple sources of data, we concluded that changes in government policies leading to a sharp increase of immigrant numbers from a distinctive culture group can lead to the initiation and growth of the EE. Continuous incoming of new immigrants and increase competition within the cluster mark the mature stage of the EE, making the growth condition more favourable “inside” the cluster. A decline in new immigrants from the same ethnic group and the increased competition within the EE may eventually lead to the decline of such an industrial cluster, thus providing more favorable condition for growth of business outside the cluster.
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A defining characteristic of contemporary welfare governance in many western countries has been a reduced role for governments in direct provision of welfare, including housing, education, health and income support. One of the unintended consequences of devolutionary trends in social welfare is the development of a ‘shadow welfare state’ (Fairbanks, 2009; Gottschalk, 2000), which is a term used to describe the complex partnerships between statebased social protection, voluntarism and marketised forms of welfare. Coupled with this development, conditional workfare schemes in countries such as the United States, Canada, the UK and Australia are pushing more people into informal and semi-formal means of poverty survival (Karger, 2005). These transformations are actively reshaping welfare subjectivities and the role of the state in urban governance. Like other countries such as the US, Canada and the UK, the fringe lending sector in Australia has experienced considerable growth over the last decade. Large numbers of people on low incomes in Australia are turning to non-mainstream financial services, such as payday lenders, for the provision of credit to make ends meet. In this paper, we argue that the use of fringe lenders by people on low incomes reveals important theoretical and practical insights into the relationship between the mixed economy of welfare and the mixed economy of credit in poverty survival.
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Introduction Given the known challenges of obtaining accurate measurements of small radiation fields, and the increasing use of small field segments in IMRT beams, this study examined the possible effects of referencing inaccurate field output factors in the planning of IMRT treatments. Methods This study used the Brainlab iPlan treatment planning system to devise IMRT treatment plans for delivery using the Brainlab m3 microMLC (Brainlab, Feldkirchen, Germany). Four pairs of sample IMRT treatments were planned using volumes, beams and prescriptions that were based on a set of test plans described in AAPM TG 119’s recommendations for the commissioning of IMRT treatment planning systems [1]: • C1, a set of three 4 cm volumes with different prescription doses, was modified to reduce the size of the PTV to 2 cm across and to include an OAR dose constraint for one of the other volumes. • C2, a prostate treatment, was planned as described by the TG 119 report [1]. • C3, a head-and-neck treatment with a PTV larger than 10 cm across, was excluded from the study. • C4, an 8 cm long C-shaped PTV surrounding a cylindrical OAR, was planned as described in the TG 119 report [1] and then replanned with the length of the PTV reduced to 4 cm. Both plans in each pair used the same beam angles, collimator angles, dose reference points, prescriptions and constraints. However, one of each pair of plans had its beam modulation optimisation and dose calculation completed with reference to existing iPlan beam data and the other had its beam modulation optimisation and dose calculation completed with reference to revised beam data. The beam data revisions consisted of increasing the field output factor for a 0.6 9 0.6 cm2 field by 17 % and increasing the field output factor for a 1.2 9 1.2 cm2 field by 3 %. Results The use of different beam data resulted in different optimisation results with different microMLC apertures and segment weightings between the two plans for each treatment, which led to large differences (up to 30 % with an average of 5 %) between reference point doses in each pair of plans. These point dose differences are more indicative of the modulation of the plans than of any clinically relevant changes to the overall PTV or OAR doses. By contrast, the maximum, minimum and mean doses to the PTVs and OARs were smaller (less than 1 %, for all beams in three out of four pairs of treatment plans) but are more clinically important. Of the four test cases, only the shortened (4 cm) version of TG 119’s C4 plan showed substantial differences between the overall doses calculated in the volumes of interest using the different sets of beam data and thereby suggested that treatment doses could be affected by changes to small field output factors. An analysis of the complexity of this pair of plans, using Crowe et al.’s TADA code [2], indicated that iPlan’s optimiser had produced IMRT segments comprised of larger numbers of small microMLC leaf separations than in the other three test cases. Conclusion: The use of altered small field output factors can result in substantially altered doses when large numbers of small leaf apertures are used to modulate the beams, even when treating relatively large volumes.
Resumo:
The reporting and auditing of patient dose is an important component of radiotherapy quality assurance. The manual extraction of dose-volume metrics is time consuming and undesirable when auditing the dosimetric quality of a large cohort of patient plans. A dose assessment application was written to overcome this, allowing the calculation of various dose-volume metrics for large numbers of plans exported from treatment planning systems. This application expanded on the DICOM-handling functionality of the MCDTK software suite. The software extracts dose values in the volume of interest by using a ray casting point-in-polygon algorithm, where the polygons have been defined by the contours in the RTSTRUCT file...
Resumo:
The aim of this study was to explore the feasibility of an exercise scientist (ES) working in general practice to promote physical activity (PA) to 55 to 70 year old adults. Participants were randomised into one of three groups: either brief verbal and written advice from a general practitioner (GP) (G1, N=9); or individualised counselling and follow-up telephone calls from an ES, either with (G3, N=8) or without a pedometer (G2, N=11). PA levels were assessed at week 1, after the 12-wk intervention and again at 24 weeks. After the 12-wk intervention, the average increase in PA was 116 (SD=237) min/wk; N=28, p < 0.001. Although there were no statistically significant between-group differences, the average increases in PA among G2 and G3 participants were 195 (SD=207) and 138 (SD=315) min/wk respectively, compared with no change (0.36, SD=157) in G1. After 24 weeks, average PA levels remained 56 (SD=129) min/wk higher than in week 1. The small numbers of participants in this feasibility study limit the power to detect significant differences between groups, but it would appear that individualised counselling and follow-up contact from an ES, with or without a pedometer, can result in substantial changes in PA levels. A larger study is now planned to confirm these findings.