991 resultados para Space Flight
Resumo:
Real estate markets in Chinese cities are in transition. Advertising for new developments in these markets often reflects changing city aspirations and branding rather than environmental and social experience. This paper investigates real estate marketing as a site of potential ethical transformation of values related to new urban development. It uses Kenneth Burke’s rhetorical analysis as an approach to coding real estate representations from in-flight magazine advertisements as a means of capturing environmental and social viewpoints in China during 2008 - 2009. Both Chinese and foreign participants coded representations into four code modalities. These were based on anthropocentric - non-anthropocentric environmental orientations and nationalistic - universal social orientations. The results suggested that new developments in China are more likely to be understood as based on environmental resource use for continued national economic expansion rather than for a more sustainable world. Emerging patterns in coded representations have opened up the possibility of greater social choices that were however difficult to unambiguously decode from Chinese real estate advertising. From this it is concluded that it may take some time before real estate demand shifts in response to representations of Chinese eco-cities being promoted by Chinese policy makers in the 2000s.
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In the context of ambiguity resolution (AR) of Global Navigation Satellite Systems (GNSS), decorrelation among entries of an ambiguity vector, integer ambiguity search and ambiguity validations are three standard procedures for solving integer least-squares problems. This paper contributes to AR issues from three aspects. Firstly, the orthogonality defect is introduced as a new measure of the performance of ambiguity decorrelation methods, and compared with the decorrelation number and with the condition number which are currently used as the judging criterion to measure the correlation of ambiguity variance-covariance matrix. Numerically, the orthogonality defect demonstrates slightly better performance as a measure of the correlation between decorrelation impact and computational efficiency than the condition number measure. Secondly, the paper examines the relationship of the decorrelation number, the condition number, the orthogonality defect and the size of the ambiguity search space with the ambiguity search candidates and search nodes. The size of the ambiguity search space can be properly estimated if the ambiguity matrix is decorrelated well, which is shown to be a significant parameter in the ambiguity search progress. Thirdly, a new ambiguity resolution scheme is proposed to improve ambiguity search efficiency through the control of the size of the ambiguity search space. The new AR scheme combines the LAMBDA search and validation procedures together, which results in a much smaller size of the search space and higher computational efficiency while retaining the same AR validation outcomes. In fact, the new scheme can deal with the case there are only one candidate, while the existing search methods require at least two candidates. If there are more than one candidate, the new scheme turns to the usual ratio-test procedure. Experimental results indicate that this combined method can indeed improve ambiguity search efficiency for both the single constellation and dual constellations respectively, showing the potential for processing high dimension integer parameters in multi-GNSS environment.
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In the era of global knowledge economy, urban regions—seeking to increase their competitive edge, become destinations for talent and investment, and provide prosperity and quality of life to their inhabitants—have little chance achieving their development goals without forming effective knowledge-based urban development strategies. This paper aims to shed light on the planning and development processes of the knowledge-based urban development phenomenon with respect to the construction of knowledge community precincts aimed at making space for knowledge generation and place for knowledge communities. Following to a thorough review of the literature on knowledge-based urban development and strategic asset-based planning, the paper undertakes policy and best practice analyses to learn from the planning and development processes of internationally renowned knowledge community precincts—from Copenhagen, Eindhoven and Singapore. In the light of the analyses findings, this paper scrutinises major Australian knowledge community precinct initiatives—from Sydney, Melbourne and Brisbane—to better understand the dynamics of national practices, and benchmark them against the international best practice cases. The paper concludes with a discussion on the study findings and recommendations for successfully establishing space and place for both knowledge economy and society in Australian cities.
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Conference curatorial outline The focus of this symposium was to question whether interior design is changing relative to local conditions, and the effect globalization has on the performance of regional, particularly Southern hemisphere identities. The intention being to understand how theory and practice is transposed to ‘distant lands’, and how ideas shift from one place to another. To this extent the symposium invited papers on the export, translation and adoption of theories and practices of interior design to differing climates, cultures, and landscapes. This process, sometimes referred to as a shift from ‘the centre to the margins’, seeks new perspectives on the adoption of European and US design ideas abroad, as well as their return to their place of origin. Papers were invited from a range of perspectives including the export of ideas/attitudes to interior spaces, history of interior spaces abroad, and the adoption of ideas/processes to new conditions. Paralleling this trafficking of ideas are broader observations about interior space that emerge through specificity of place. These include new and emerging directions and differences in our understanding of interiority; both real and virtual, and an ever-changing relationship to city, suburb and country. Keeping within the Symposium theme the intention was to examine other places, particularly on the margins of the discipline’s domain. Semantic slippage aside, there are a range of approaches that engage outside events and practices enabling a transdisciplinary practice that draws from other philosophical and theoretical frameworks. Moreover as the field expands and new territories are opened up, the virtual worlds of computer gaming, animations, and interactive environments, both rely on and produce new forms of expression. This raises questions about the extent such spaces adopt or translate existing theory and practice, that is the transposition from one area to another and their return to the discipline.
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Distributed space-time coding (DSTC) exploits the concept of cooperative diversity and space-time coding to offer a powerful bandwidth efficient solution with improved diversity. In this paper, we evaluate the performance of DSTC with slotted amplify-and-forward protocol (SAF). Relay nodes between the source and the destination nodes are grouped into two relay clusters based on their respective locations and these relay clusters cooperate to transmit the space-time coded signal to the destination node in different time frames. We further extend the proposed Slotted-DSTC to Slotted DSTC with redundant code (Slotted-DSTC-R) protocol where the relay nodes in both relay clusters forward the same space-time coded signal to the destination node to achieve a higher diversity order.
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Cost implications related to the physical resources such as land and building in organisation is significant. Management entity of government or private sectors has often ignored the importance and the contribution gained from the physical resources towards their organisation. This source is a precious asset that can generate income if properly managed. This paper aims to explore the current trends in space management internationally, both from the government and private sector perspectives. A case study is conducted to study the level of effectiveness of space management in one of the government institutions in Malaysia. The findings from the case study will be compared with the current international trend of space management. The study will enrich the current understanding of space management in government properties, as well as to compare the level of space management effectiveness of government properties in Malaysia with the international trends and proposed suggestions to improve current practices of space management of Malaysian government’s properties. Keywords:
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We consider the space fractional advection–dispersion equation, which is obtained from the classical advection–diffusion equation by replacing the spatial derivatives with a generalised derivative of fractional order. We derive a finite volume method that utilises fractionally-shifted Grünwald formulae for the discretisation of the fractional derivative, to numerically solve the equation on a finite domain with homogeneous Dirichlet boundary conditions. We prove that the method is stable and convergent when coupled with an implicit timestepping strategy. Results of numerical experiments are presented that support the theoretical analysis.
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Presentation Structure: - THEORY - CASE STUDY 1: Southbank Institute of Technology - CASE STUDY 2: QUT Science and Technology Precinct - MORE IDEAS - ACTIVITY
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A review of 291 catalogued particles on the bases of particle size, shape, bulk chemistry, and texture is used to establish a reliable taxonomy. Extraterrestrial materials occur in three defined categories: spheres, aggregates and fragments. Approximately 76% of aggregates are of probable extraterrestrial origin, whereas spheres contain the smallest amount of extraterrestrial material (approx 43%). -B.M.
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The future emergence of many types of airborne vehicles and unpiloted aircraft in the national airspace means collision avoidance is of primary concern in an uncooperative airspace environment. The ability to replicate a pilot’s see and avoid capability using cameras coupled with vision based avoidance control is an important part of an overall collision avoidance strategy. But unfortunately without range collision avoidance has no direct way to guarantee a level of safety. Collision scenario flight tests with two aircraft and a monocular camera threat detection and tracking system were used to study the accuracy of image-derived angle measurements. The effect of image-derived angle errors on reactive vision-based avoidance performance was then studied by simulation. The results show that whilst large angle measurement errors can significantly affect minimum ranging characteristics across a variety of initial conditions and closing speeds, the minimum range is always bounded and a collision never occurs.
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A body of research in conversation analysis has identified a range of structurally-provided positions in which sources of trouble in talk-in-interaction can be addressed using repair. These practices are contained within what Schegloff (1992) calls the repair space. In this paper, I examine a rare instance in which a source of trouble is not resolved within the repair space and comes to be addressed outside of it. The practice by which this occurs is a post-completion account; that is, an account that is produced after the possible completion of the sequence containing a source of trouble. Unlike fourth position repair, the final repair position available within the repair space, this account is not made in preparation for a revised response to the trouble-source turn. Its more restrictive aim, rather, is to circumvent an ongoing difference between the parties involved. I argue that because the trouble is addressed in this manner, and in this particular position, the repair space can be considered as being limited to the sequence in which a source of trouble originates.
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We develop a fast Poisson preconditioner for the efficient numerical solution of a class of two-sided nonlinear space fractional diffusion equations in one and two dimensions using the method of lines. Using the shifted Gr¨unwald finite difference formulas to approximate the two-sided(i.e. the left and right Riemann-Liouville) fractional derivatives, the resulting semi-discrete nonlinear systems have dense Jacobian matrices owing to the non-local property of fractional derivatives. We employ a modern initial value problem solver utilising backward differentiation formulas and Jacobian-free Newton-Krylov methods to solve these systems. For efficient performance of the Jacobianfree Newton-Krylov method it is essential to apply an effective preconditioner to accelerate the convergence of the linear iterative solver. The key contribution of our work is to generalise the fast Poisson preconditioner, widely used for integer-order diffusion equations, so that it applies to the two-sided space fractional diffusion equation. A number of numerical experiments are presented to demonstrate the effectiveness of the preconditioner and the overall solution strategy.
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The method of lines is a standard method for advancing the solution of partial differential equations (PDEs) in time. In one sense, the method applies equally well to space-fractional PDEs as it does to integer-order PDEs. However, there is a significant challenge when solving space-fractional PDEs in this way, owing to the non-local nature of the fractional derivatives. Each equation in the resulting semi-discrete system involves contributions from every spatial node in the domain. This has important consequences for the efficiency of the numerical solver, especially when the system is large. First, the Jacobian matrix of the system is dense, and hence methods that avoid the need to form and factorise this matrix are preferred. Second, since the cost of evaluating the discrete equations is high, it is essential to minimise the number of evaluations required to advance the solution in time. In this paper, we show how an effective preconditioner is essential for improving the efficiency of the method of lines for solving a quite general two-sided, nonlinear space-fractional diffusion equation. A key contribution is to show, how to construct suitable banded approximations to the system Jacobian for preconditioning purposes that permit high orders and large stepsizes to be used in the temporal integration, without requiring dense matrices to be formed. The results of numerical experiments are presented that demonstrate the effectiveness of this approach.
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We consider a two-dimensional space-fractional reaction diffusion equation with a fractional Laplacian operator and homogeneous Neumann boundary conditions. The finite volume method is used with the matrix transfer technique of Ilić et al. (2006) to discretise in space, yielding a system of equations that requires the action of a matrix function to solve at each timestep. Rather than form this matrix function explicitly, we use Krylov subspace techniques to approximate the action of this matrix function. Specifically, we apply the Lanczos method, after a suitable transformation of the problem to recover symmetry. To improve the convergence of this method, we utilise a preconditioner that deflates the smallest eigenvalues from the spectrum. We demonstrate the efficiency of our approach for a fractional Fisher’s equation on the unit disk.