983 resultados para Study of Geometry
Resumo:
In this paper, we consider the problem of document ranking in a non-traditional retrieval task, called subtopic retrieval. This task involves promoting relevant documents that cover many subtopics of a query at early ranks, providing thus diversity within the ranking. In the past years, several approaches have been proposed to diversify retrieval results. These approaches can be classified into two main paradigms, depending upon how the ranks of documents are revised for promoting diversity. In the first approach subtopic diversification is achieved implicitly, by choosing documents that are different from each other, while in the second approach this is done explicitly, by estimating the subtopics covered by documents. Within this context, we compare methods belonging to the two paradigms. Furthermore, we investigate possible strategies for integrating the two paradigms with the aim of formulating a new ranking method for subtopic retrieval. We conduct a number of experiments to empirically validate and contrast the state-of-the-art approaches as well as instantiations of our integration approach. The results show that the integration approach outperforms state-of-the-art strategies with respect to a number of measures.
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The work of Gilles Deleuze has influenced an increasing number of music scholars and practicing musicians, particularly those interested in experimental, electronic and popular music. This is despite the notoriously complex nature of his writings, and the specialised theoretical vocabulary that he employs. This thesis both demystifies some of the key terms and concepts of this vocabulary, before demonstrating how Deleuze’s ideas may be put to work in new and fruitful ways; this is achieved with specific reference to the relationships that music has with thought, time and machines. In Chapter 1, Deleuze’s understanding of the power of thought is examined, in particular his approach to communication, transcendence and immanence, and the “powers of thought.” Each of these concepts helps us to understand Deleuze’s work within broad problem of how to think about music immanently: that is, how to maintain that thought and music are both immanent aspects of life and experience. Chapter 2 examines time within a Deleuzian framework, linking his work on cinema with the concept of the “refrain”; both of these areas prove crucial to his understanding of music, as seen in Deleuze’s approach to the work of Varese, Messiaen, and Boulez. In addition, Deleuze’s understanding of time proves fruitful in examining various aspects of music production, as seen in contemporary electronic dance music. Finally, Chapter 3 looks at the concept of the machine, as developed by Deleuze and Guattari, with reference to the sorts of “machinic” connections that a Deleuzian approach encourages us to seek out in music. Once again, examples from contemporary electronic music are presented, in relation to the notions of becoming and subjectivity. Throughout these chapters, Deleuze’s broad understanding of philosophy as the “creation of concepts” is deployed. This means introducing new ideas and specific types of music that encourage creative and novel engagements with the study of music.
Resumo:
Objective To examine the impact of applying for funding on personal workloads, stress and family relationships. Design Qualitative study of researchers preparing grant proposals. Setting Web-based survey on applying for the annual National Health and Medical Research Council (NHMRC) Project Grant scheme. Participants Australian researchers (n=215). Results Almost all agreed that preparing their proposals always took top priority over other work (97%) and personal (87%) commitments. Almost all researchers agreed that they became stressed by the workload (93%) and restricted their holidays during the grant writing season (88%). Most researchers agreed that they submitted proposals because chance is involved in being successful (75%), due to performance requirements at their institution (60%) and pressure from their colleagues to submit proposals (53%). Almost all researchers supported changes to the current processes to submit proposals (95%) and peer review (90%). Most researchers (59%) provided extensive comments on the impact of writing proposals on their work life and home life. Six major work life themes were: (1) top priority; (2) career development; (3) stress at work; (4) benefits at work; (5) time spent at work and (6) pressure from colleagues. Six major home life themes were: (1) restricting family holidays; (2) time spent on work at home; (3) impact on children; (4) stress at home; (5) impact on family and friends and (6) impact on partner. Additional impacts on the mental health and well-being of researchers were identified. Conclusions The process of preparing grant proposals for a single annual deadline is stressful, time consuming and conflicts with family responsibilities. The timing of the funding cycle could be shifted to minimise applicant burden, give Australian researchers more time to work on actual research and to be with their families.
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Current federal government policy initiatives in Aboriginal education and social welfare reform are based on assumptions about the relationship between increased attendance and increased student performance on standardized tests. There are empirical assumptions underlying these policy interventions and their accompanying public debates. Our aim here is to empirically explore the relationships between patterns of student attendance and patterns of student achievement in schools with significant cohorts of Aboriginal and/or Torres Strait Islander students at the school level. Based on an analysis of the publicly available data reported on the ‘MySchool’ website, we find that reforms and policies around attendance have not and are unlikely to generate patterns of improved achievement. Questions about the rationale and rhetoric of government policy focused at the school level as opposed to the need to focus on pedagogy and curriculum are discussed.
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"The authors agree with the statements made by Mills and Christy on the study of kapundaite [1]. These authors are correct and have removed any confusion about the origin of the sample kapundaite. The authors (Frost et al.) confirm the sample of kapundaite studied in this work is from the Tom‘s quarry, Australia and can be considered a type material. The authors do not accept the statements by Mills and Christy on “type minerals”. The sample of kapundaite from the Australian source is from the collection of the Geology Department of the Federal University of Ouro Preto, Minas Gerais, Brazil with sample code SAC-111. At least if our mineral sample is not a co-type mineral, our sample is from the same origin as the type mineral. Samples..."--publisher website.
Resumo:
Raman and infrared spectra of two well-defined fluellite samples, Al2(PO4)F2(OH)�7H2O, from the Krásno near Horní Slavkov (Czech Republic) and Kapunda, South Australia (Australia) were studied and tentatively interpreted. Observed bands were assigned to the stretching and bending vibrations of phosphate tetrahedra, aluminum oxide/hydroxide/fluoride octahedra, water molecules and hydroxyl ions. Approximate O–H���O hydrogen bond lengths were inferred from the Raman and infrared spectra.
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The mineral lulzacite from Saint-Aubin des Chateaux mine, France, with theoretical formula Sr2Fe2+(Fe2+,Mg)2Al4(PO4)4(OH)10 has been studied using a combination of electron microscopy with EDX and vibrational spectroscopic techniques. Chemical analysis shows a Sr, Fe, Al phosphate with minor amounts of Ga, Ba and Mg. Raman spectroscopy identifies an intense band at 990 cm�1 with an additional band at 1011 cm�1. These bands are attributed to the PO3� 4 m1 symmetric stretching mode. The m3 antisymmetric stretching modes are observed by a large number of Raman bands. The Raman bands at 1034, 1051, 1058, 1069 and 1084 together with the Raman bands at 1098, 1116, 1133, 1155 and 1174 cm�1 are assigned to the m3 antisymmetric stretching vibrations of PO3� 4 and the HOPO2� 3 units. The observation of these multiple Raman bands in the symmetric and antisymmetric stretching region gives credence to the concept that both phosphate and hydrogen phosphate units exist in the structure of lulzacite. The series of Raman bands at 567, 582, 601, 644, 661, 673 and 687 cm�1 are assigned to the PO3� 4 m2 bending modes. The series of Raman bands at 437, 468, 478, 491, 503 cm�1 are attributed to the PO3� 4 and HOPO2� 3 m4 bending modes. No Raman bands of lulzacite which could be attributed to the hydroxyl stretching unit were observed. Infrared bands at 3511 and 3359 cm�1 are ascribed to the OH stretching vibration of the OH units. Very broad bands at 3022 and 3299 cm�1 are attributed to the OH stretching vibrations of water. Vibrational spectroscopy offers insights into the molecular structure of the phosphate mineral lulzacite.
Resumo:
We have studied the molecular structure of the mineral glaucocerinite (Zn,Cu)5Al3(SO4)1.5(OH)16�9(H2O) using a combination of Raman and infrared spectroscopy. The mineral is one of the hydrotalcite supergroup of natural layered double hydroxides. The Raman spectrum is characterised by an intense Raman band at 982 cm�1 with a low intensity band at 1083 cm�1. These bands are attributed to the sulphate symmetric and antisymmetric stretching mode. The infrared spectrum is quite broad with a peak at 1020 cm�1. A series of Raman bands at 546, 584, 602, 625 and 651 cm�1 are assigned to the m4 (SO4)2� bending modes. The observation of multiple bands provides evidence for the reduction in symmetry of the sulphate anion from Td to C2v or even lower symmetry. The Raman band at 762 cm�1 is attributed to a hydroxyl deformation mode associated with AlOH units. Vibrational spectroscopy enables aspects of the molecular structure of glaucocerinite to be determined.
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Vibrational spectroscopy has been used to study the rare earth mineral churchite of formula (REE)(PO4)-⋅2H2O. The mineral contains a range of rare earth metals including yttrium depending on the locality. The Raman spectra of churchite-(REE) are characterized by an intense sharp band at 984 cm-1 assigned to the v1 (PO¾-) symmetric stretching mode. A lower intensity band observed at around 1067 cm-1 is attributed to the v3 (PO¾-) antisymmetric stretching mode. The (PO¾-) bending modes are observed at 497 cm-1 (v2) and 565 cm-1(v4). Raman bands at 649 and 681 cm-1 are assigned to water librational modes. Vibrational spectroscopy enables aspects of the structure of churchite to be ascertained.
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We have studied the hydrated hydroxyl silicate mineral inesite of formula Ca2(Mn,Fe)7Si10O28(OH)⋅5H2O using a combination of scanning electron microscopy with EDX and Raman and infrared spectroscopy. SEM analysis shows the mineral to be a pure monomineral with no impurities. Semiquantitative analysis shows a homogeneous phase, composed by Ca, Mn2+, Si and P, with minor amounts of Mg and Fe. Raman spectrum shows well resolved component bands at 997, 1031, 1051, and 1067 cm-1 attributed to a range of SiO symmetric stretching vibrations of [Si10O28] units. Infrared bands found at 896, 928, 959 and 985 cm-1 are attributed to the OSiO antisymmetric stretching vibrations. An intense broad band at 653 cm-1 with shoulder bands at 608, 631 and 684 cm-1 are associated with the bending modes of the OSiO units of the 6- and 8-membered rings of the [Si10O28] units. The sharp band at 3642 cm-1 with shoulder bands at 3612 and 3662 cm-1 are assigned to the OH stretching vibrations of the hydroxyl units. The broad Raman band at 3420 cm-1 with shoulder bands at 3362 and 3496 cm-1 are assigned to the water stretching vibrations. The application of vibrational spectroscopy has enabled an assessment of the molecular structure of inesite to be undertaken.
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In this paper, we provide the results of a field study of a Ubicomp system called CAM (Cooperative Artefact Memory) in a Product Design studio. CAM is a mobile-tagging based messaging system that allows designers to store relevant information onto their design artefacts in the form of messages, annotations and external web links. From our field study results, we observe that the use of CAM adds another shared ‘space’ onto these design artefacts – that are in their natural settings boundary objects themselves. In the paper, we provide several examples from the field illustrating how CAM helps in the design process.
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TiO2 spheres assembled by nanorods, nanoplates and nanosheets were fabricated by facile hydrothermal/solvothermal methods. The three samples were thoroughly characterised by scanning electron microscopy, X-ray diffraction, the Brunauer–Emmett–Teller method and UV spectroscopy. The surface area of spheres assembled by nanosheets was 83.9 m2g–1, which is larger than that obtained for nanorods (10.8 m2g–1) and nanoplates (6.31 m2g–1). Their photocatalytic performance was evaluated in terms of the decomposition rate of methyl orange in these three samples under UV irradiation. The best photoactivity was observed in the samples constructed from nanosheets.
Resumo:
Built environment design around the world faces a number of 21st Century challenges such as rising urban heat island effect and rising pollution, which are further worsened by consequences of climate change and increasing urban populations. Such challenges have caused cities around the globe to investigate options that can help to significantly reduce the environmental pressures from current and future development, requiring new areas of innovation. One such area is ‘Biophilic Urbanism’, which refers to the use of natural elements as design features in urban centres to assist efforts to address climate change issues in rapidly growing economies. Singapore is an illustration of a thriving economy that exemplifies the value of embedding nature into its built environment. The significance of urban green space has been recognised in Singapore as early as the 1960s when Lee Kuan Yew embarked on the ‘Garden City’ concept. 50 years later, Singapore has achieved its Garden City goal and is now entering a new era of sustainability, to create a ‘City in a Garden’. Although the economics of such efforts is not entirely understood, the city of Singapore has continued to pursue visions of becoming a biophilic city. Indeed, there appears to be important lessons to be learned from a city that has challenged the preconceived notion that protecting vegetation in a city is not economically viable. Hence, this paper will discuss the case study of Singapore to highlight the drivers, along with the economic considerations identified along the way. The conclusions have implications for expanding the notion of biophilic urbanism, particularly in the Australian context by discussing the lessons learned from this city. The research is part of Sustainable Built Environment National Research Centre, and has been developed in collaboration with the Curtin University Sustainability Policy Institute.
Resumo:
Globally, cities face a convergence of complex and rapidly evolving challenges, including climate change, resource shortages, population growth and urbanization, and financial pressures. Biophilic urbanism is an emerging design principle capable of considering the multidimensional and interdependent complexities of urban systems and infrastructure, which through the use of natural design features, can meet society’s inherent need for contact with nature, and assist efforts to respond to these growing challenges. Considering the imperative for addressing these challenges, this paper proposes that significant lessons can be learned from existing examples of biophilic urbanism, avoiding ‘re-invention of the wheel’ and facilitating accelerated innovation in other areas. Vauban is a 38-hectare brownfield development located 3 kilometers from the centre of Germany’s ‘ecological capital’ of Freiburg city. It was developed using an innovative process with strong community participation and reinterpreted developer roles to produce an example of integrated sustainability. Innovation in transport, energy, housing, development and water treatment has enabled a relatively high-density, mixed-use development that integrates a considerable amount of nature. This paper discusses Vauban in light of research undertaken over the last two years through the Sustainable Built Environment National Research Centre in Australia, to investigate emerging elements of ‘biophilic urbanism’ (nature-loving cities), and their potential to be mainstreamed within urban environments. The paper considers the interplay between the policies, community dynamics and innovations in Vauban, within the context of the culture, history and practice of sustainability in Germany, and how these have enabled nature to be integrated into the urban environment of Vauban while achieving other desirable goals for urban areas. It highlights potential applications from Vauban for Australian cities.
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Time- and position-resolved synchrotron small angle X-ray scattering data were acquired from samples of two Australian coal seams: Bulli seam (Bulli 4, Ro=1.42%, Sydney Basin), which naturally contains CO2 and Baralaba seam (Ro=0.67%, Bowen Basin), a potential candidate for sequestering CO2. This experimental approach has provided unique, pore-size-specific insights into the kinetics of CO2 sorption in the micro- and small mesopores (diameter 5 to 175 Å) and the density of the sorbed CO2 at reservoir-like conditions of temperature and hydrostatic pressure. For both samples, at pressures above 5 bar, the density of CO2 confined in pores was found to be uniform, with no densification in near-wall regions. In the Bulli 4 sample, CO2 first flooded the slit pores between polyaromatic sheets. In the pore-size range analysed, the confined CO2 density was close to that of the free CO2. The kinetics data are too noisy for reliable quantitative analysis, but qualitatively indicate faster kinetics in mineral-matter-rich regions. In the Baralaba sample, CO2 preferentially invaded the smallest micropores and the confined CO2 density was up to five times that of the free CO2. Faster CO2 sorption kinetics was found to be correlated with higher mineral matter content but, the mineral-matter-rich regions had lower-density CO2 confined in their pores. Remarkably, the kinetics was pore-size dependent, being faster for smaller pores. These results suggest that injection into the permeable section of an interbedded coal-clastic sequence could provide a viable combination of reasonable injectivity and high sorption capacity.