945 resultados para heterogeneous porous media
Resumo:
Oxygen enriched, porous fuel injection has been numerically investigated in this study with the aim of understanding mixing and combustion enhancements achievable in a viable scramjet engine. Four injection configurations were studied: a fuel only case, a pre-mixed case and two staged injection cases where fuel and oxidiser were injected independently. All simulations were performed on a flight scale vehicle at Mach 8 flow conditions. Results show that the addition of oxygen with the fuel increases the mixing efficiency of the engine, however, is less sensitive to the method of oxygen addition: premixed versus staged. When the fuel-oxidiser-air mixture was allowed to combust, the method of additional oxygen delivery had a more significant impact. For pre-mixed fuel and oxidiser, the engine was found to choke, whereas in contrast, in the staged enrichment cases the engine failed to ignite. This result indicates that there exists an optimised configuration between pre-mixed and staged oxygen enrichment which results in a started, and combusting engine.
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High-Order Co-Clustering (HOCC) methods have attracted high attention in recent years because of their ability to cluster multiple types of objects simultaneously using all available information. During the clustering process, HOCC methods exploit object co-occurrence information, i.e., inter-type relationships amongst different types of objects as well as object affinity information, i.e., intra-type relationships amongst the same types of objects. However, it is difficult to learn accurate intra-type relationships in the presence of noise and outliers. Existing HOCC methods consider the p nearest neighbours based on Euclidean distance for the intra-type relationships, which leads to incomplete and inaccurate intra-type relationships. In this paper, we propose a novel HOCC method that incorporates multiple subspace learning with a heterogeneous manifold ensemble to learn complete and accurate intra-type relationships. Multiple subspace learning reconstructs the similarity between any pair of objects that belong to the same subspace. The heterogeneous manifold ensemble is created based on two-types of intra-type relationships learnt using p-nearest-neighbour graph and multiple subspaces learning. Moreover, in order to make sure the robustness of clustering process, we introduce a sparse error matrix into matrix decomposition and develop a novel iterative algorithm. Empirical experiments show that the proposed method achieves improved results over the state-of-art HOCC methods for FScore and NMI.
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The first year experience for students within Higher Education institutions has become increasingly important as these institutions strive to improve student retention rates. With many universities also focusing on transforming teaching and learning in an effort to attract and retain students, there is a growing demand to understand and respond to individual student requirements, such as the need to feel a sense of belonging. The literature identifies a sense of belonging as being paramount to a students satisfaction with the institution and it is within this context that this paper reports on a three year study of how first year pre-service education students use social media and mobile technologies in their personal lives and their formal education. More specifically, the study identifies trends in the use of these technologies and the growing need for students to use digital media sharing tools to connect and engage with their peers. The paper contrasts the differences in use between these groups as it seeks to identify the role these technologies can play in their teaching and learning, as well as in promoting an overall positive first year experience.
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This paper offers a definition of elite media arguing their content focus will sufficiently meet social responsibility needs of democracy. Its assumptions come from the Finkelstein and Leveson Inquiries and regulatory British Royal Charter (2013). These provide guidelines on how media outlets meet ‘social responsibility’ standards, e.g. press has a ‘responsibility to be fair and accurate’ (Finkelstein); ethical press will feel a responsibility to ‘hold power to account’ (Leveson); news media ‘will be held strictly accountable’ (RC). The paper invokes the British principle of media opting-in to observe standards, and so serve the democracy. It will give examples from existing media, and consider social responsibility of media more generally. Obvious cases of ‘quality’ media: public broadcasters, e.g. BBC, Al-Jazeera, and ‘quality’ press, e.g. NYT, Süddeutscher Zeitung, but also community broadcasters, specialised magazines, news agencies, distinctive web logs, and others. Where providing commentary, these abjure gratuitous opinion -- meeting a standard of reasoned, informational and fair. Funding is almost a definer, many such services supported by the state, private trusts, public institutions or volunteering by staff. Literature supporting discussion on elite media will include their identity as primarily committed to a public good, e.g. the ‘Public Value Test’, Moe and Donders (2011); with reference also to recent literature on developing public service media. Within its limits the paper will treat social media as participants among all media, including elite, and as a parallel dimension of mass communication founded on inter-activity. Elite media will fulfil the need for social responsibility, firstly by providing one space, a ‘plenary’ for debate. Second is the notion of building public recognition of elite media as trustworthy. Third is the fact that elite media together are a large sector with resources to sustain social cohesion and debate; notwithstanding pressure on funds, and impacts of digital transformation undermining employment in media more than in most industries.
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This study provides proposed core elements of social media policy that specifically designed for academic libraries.Evaluation of social media policies from five organisations and a review of the literature were used for data collection.There are 15 proposed core elements recommended: policy objectives; policy definition; scope of the policy;university’s vision and mission; policy users; disclaimer; confidentiality; copyright; privacy; workflow; publicinformation; the use of professional language; the accuracy of the information; rule for links; and university andlibrary’s voices. The results of this study provide important aspects in the development of social media policy. Theproposed core elements of the social media policy discussed in this paper is specifically designed for the academiclibraries, but can also be used for other library types. Kajian ini memuat usulan kerangka kebijakan penggunaan media sosial dari elemen-elemen inti yang disusun khusus untuk perpustakaan perguruan tinggi. Evaluasi kebijakan penggunaan media sosial dari lima organisasi dan kajian literatur digunakan untuk pengumpulan data. Ada 15 elemen inti kebijakan yang diusulkan, yaitu: tujuan kebijakan; definisi kebijakan; lingkup kebijakan; visi dan misi universitas; sasaran pengguna kebijakan; disclaimer; kerahasiaan; hak cipta; privasi; alur kerja; informasi publik; penggunaan bahasa professional; keakuratan informasi; kaidah tautan; serta suara universitas dan perpustakaan. Hasil kajian ini menyediakan aspek penting dalam pengembangan kebijakan penggunaan media sosial. Usulan elemen inti kebijakan yang diusulkan dalam kajian ini secara khusus dirancang untuk perpustakaan perguruan tinggi, tetapi dapat juga digunakan untuk perpustakaan jenis lainnya.
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This paper explores how traditional media organizations (such as magazines, music, film, books, and newspapers) develop routines for coping with an increasingly productive audience. While previous studies have reported on how such organizations have been affected by digital technologies, this study makes a contribution to this literature by being one of the first to show how organizational routines for engaging with an increasingly productive audience actually emerge and diffuse between industries. The paper explores to what extent routines employed by two traditional media organizations have been brought in from other organizational settings, specifically from so-called ‘software platform operators’. Data on routines for engaging with productive audiences have been collected from two information-rich cases in the music and the magazine industries, and from eight high-profile software platform operators. The paper concludes that the routines employed by the two traditional media organizations and by the software platform operators are based on the same set of principles: Provide the audience with (a) tools that allow them to easily generate cultural content; (b) building blocks which facilitate their creative activities; and (c) recognition and rewards based on both rationality and emotion.
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Successful prediction of groundwater flow and solute transport through highly heterogeneous aquifers has remained elusive due to the limitations of methods to characterize hydraulic conductivity (K) and generate realistic stochastic fields from such data. As a result, many studies have suggested that the classical advective-dispersive equation (ADE) cannot reproduce such transport behavior. Here we demonstrate that when high-resolution K data are used with a fractal stochastic method that produces K fields with adequate connectivity, the classical ADE can accurately predict solute transport at the macrodispersion experiment site in Mississippi. This development provides great promise to accurately predict contaminant plume migration, design more effective remediation schemes, and reduce environmental risks. Key Points Non-Gaussian transport behavior at the MADE site is unraveledADE can reproduce tracer transport in heterogeneous aquifers with no calibrationNew fractal method generates heterogeneous K fields with adequate connectivity
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Whilst the dynamics informing processes have taken time to become clear, civic resistance initiated by young people using new media began in Egypt in 2010 against the Mubarak regime, soon widened to Tunisia, Yemen and Libya. Known as the 'Arab Spring', this phenomenon re-ignited discussion about the political role of digital space and its democratic potential. While parallels between authoritarian regimes and universities and educational institutions might seem overdrawn to some readers, I suggest there is value in considering the 'Digital Spring' (apropos the 'Arab Spring') as a metaphor to suggest the possibility that similar processes are taking place in schools and universities. This invites discussion about the political significance of digital space and its democratic potential in those institutions. To assess how some young people engage in digitally mediated politics within schools and universities, I identify five propositions which amalgamate descriptive and normative elements derived from Habermas and Dahlgren. These propositions offer an ideal taxonomy of normative and descriptive elements to establish whether digital technology promotes participation and debate in ways that sustain democratic practice.
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We present a rigorous validation of the analyticalAmadei solution for the stress concentration around arbitrarily orientated borehole in general anisotropic elastic media. First, we revisit the theoretical framework of the Amadei solution and present analytical insights that show that the solution does indeed contain all special cases of symmetry, contrary to previous understanding, provided that the reduced strain coefficients β11 and β55 are not equal. It is shown from theoretical considerations and published experimental data that the β11 and β55 are not equal for realistic rocks. Second, we develop a 3D finite-element elastic model within a hybrid analyticalnumerical workflow that circumvents the need to rebuild and remesh the model for every borehole and material orientation. Third, we show that the borehole stresses computed from the numerical model and the analytical solution match almost perfectly for different borehole orientations (vertical, deviated and horizontal) and for several cases involving isotropic and transverse isotropic symmetries. It is concluded that the analytical Amadei solution is valid with no restrictions on the borehole orientation or elastic anisotropy symmetry.
Resumo:
The print media play a vital role in informing the public about child abuse and neglect. This information helps build broad support for laws and system developments that enable the state to intervene into private family lives and ensure that children are protected from maltreatment. Print media coverage usually sets the daily media agenda. It therefore influences public understandings of child abuse and neglect and what people believe should be done about it. Media impact on policy agendas should not be underestimated. This article outlines the results of a study of all major Australian newspaper stories covering abuse and neglect matters during an 18-month period in 2008–2009. A range of issues are identified concerning how well these stories inform the public about the nature of the problem and the current national reform agenda for protective systems that promotes early intervention and prevention...
Resumo:
Since the 2000s, teachers in an increasing number of Australian schools have been learning how to support students with refugee backgrounds. For some of these students, entry into the Australian school system is not easy. English literacy is integral to some of the challenges confronting the students. In response, educators have been developing and researching ways of engaging with the students’ language and literacy learning. Much of the focus has been on traditional print-based school literacies. In contrast, I look here at student engagement in digital literacies in an after-school media club. Several concepts from the theory of French sociologist, Pierre Bourdieu are useful for understanding the position of students of refugee background in the Australian school system. Like other conflict theories, Bourdieusian theory has sometimes been criticised as ‘pessimistic’, that is, for suggesting that schools necessarily reproduce social disadvantage. However, others have used Bourdieusian theory to analyse and critique the reproductive work of schooling for groups of students who experience educational disadvantage. I align myself with this latter tradition. Specifically, I use Bourdieu’s triad of concepts to explain aspects of the literacy education experiences of some young people of refugee background: field, capital and habitus. In particular, I look at questions of the legitimation of students’ competences as capital in literate fields within and beyond the school context. Data are drawn from an Australian Research Council-funded project, Digital Learning and Print Literacy: A design experiment for the reform of low socio-economic, culturally diverse schools (2009-14). The data analysed in this chapter include interviews and observations relating to the participation of two Congolese girls in an after school media club. Implications are drawn for teachers of literacy in culturally and linguistically diverse contexts. Consideration is made of early childhood, primary and secondary settings.
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In this chapter, we draw on our experiences facilitating community storytelling workshops in regional Queensland in partnership with the Queensland branch of Oral History Association of Australia (OHAA Qld) in order to develop a best practice model for promoting creative approaches to recording oral narratives using digital tools, informed by creative writing practice and embedded evaluation (Klaebe 2012 & 2013). These experiences offer an insight into how creative approaches to training can facilitate the sharing and preservation of stories in regional communities.