1,721,216 research outputs found
Fustat reconsidered: urban housing and domestic life in a medieval Islamic city
No full textThe domestic architecture of Fustat, Egypt’s first capital under Muslim rule, has been revealed through various large-scale archaeological excavations over the preceding century. The archaeological remains represent an exceptional resource for understanding urbanism and daily life in one of the foremost cities of the early Islamic world.This thesis explores the potential use and meaning of domestic space in the excavated houses of Fustat. An assessment of previous scholarship on the houses reveals that their form has principally been understood as a style of architecture imported to Egypt by foreign élites. While certain assumptions about life in the houses have been made based on generalised notions of the traditional ‘Arab house’, there has been little critical consideration of the activities and agency of inhabitants by archaeologists. This study therefore aims to re-interpret the architecture in terms of how inhabitants conceptualised and used the space.Fustat represents a highly problematic dataset due the circumstances of its excavation and recording, its vast size and longevity, and the extensive modern depredation of the archaeological remains. Thus, the potential of a range of archaeological approaches to the social interpretation of architectural space is assessed, considering the limitations of the available data. The analytical approach taken consists of exploratory spatial analysis of archaeological features across two of the excavated areas. These spatial patterns are considered in light of the evidence for daily life and domestic architecture from the Cairo Geniza, the collection of documents from the city’s medieval Jewish community
The accuracy of the actuator disc-RANS approach for modelling performance and wake characteristics of a horizontal axis tidal stream turbine
No full textTidal stream energy has the potential to supply power with low carbon dioxide emissions, but the technology is still being developed. Horizontal axis tidal stream turbines have seen the greatest development, and to generate energy at a commercial scale they will be installed in multi-device arrays. In the array, performance of downstream devices will be affected by the wake of those upstream. The actuator disc-RANS model can be used to optimise array configuration. A review of previous studies which used actuator disc-RANS showed that the model has been implemented with a wide range of parameters (boundary conditions, turbulence model, turbine model and dimensions), and predictions of velocity magnitudes in the wake of a turbine varied between similar published studies. The accuracy of the model for tidal turbines has not been demonstrated, and appropriate parameters for applying the model are not apparent from previous work. Without validation the model may not be applied to arrays with confidence. The purpose of this thesis is to identify appropriate parameters, and to demonstrate their accuracy through verification and validation studies. The first aspect of the work is to identify parameters which achieve accurate predictions using the uniform turbine model. If the k - f turbulence model, turbulence sources at the disc, and a free-slip wall to model the free surface are used, the model produces accurate results. Comparison to centreline velocities measured experimentally in the wake of a porous disc (acting as a turbine simulator) gives a coefficient of determination of 0.61-0.97 depending on the turbine thrust coefficient, with a maximum discretization error of 1.5%. Comparison to centreline velocities measured in the wake of a scaled tidal stream turbine gives a coefficient of determination of 0.92 at a thrust coefficient of 1, and a maximum discretization error of 9%. When the blade-element actuator disc turbine model is used comparison to measured cen- treline wake velocities gives a coefficient of determination of 0.94 at a thrust coefficient of 1, and a maximum discretization error of 9%. Comparison of turbine power coefficient shows that the model under predicts experimental data by between 2% at low tip speed ratio, and 9% at high tip speed ratio. The second aspect examines the capability of the turbine models to predict the power output from an array. A comparison between the uniform, and blade element actuator disc models finds that the blade element model predicts 13% higher power output due to compounded differences between the models over the array. Modelling the support structure increases predicted power output by 0.2%. Results also show that if ambient turbulence intensity is increased from 15% to 40%, overall power output from the array increases by 14%. The results provide array modellers with appropriate parameters to achieve accurate predic- tions using actuator disc-RANS. They demonstrate that the model may be used with confidence provided these parameters are used, discretization errors are minimised, and Froude number and blockage ratio are similar to the cases tested. The results also demonstrate the difference be- tween turbine models when estimating the power from an array, and a requirement to accurately characterise turbulence intensity at a tidal site and represent this data in the model.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Alien Registration- Harrison, Matthew L. (Bath, Sagadahoc County)
Full text linkhttps://digitalmaine.com/alien_docs/9316/thumbnail.jp
Time and frequency domain modelling of vehicle intake and exhaust systems
No full textSIGLEAvailable from British Library Document Supply Centre- DSC:DX183221 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
School of Architecture Advisory Council, Arthur J. Godfrey, William McMinn, R. B. Clopton, Thomas Smith, Robert Harrison, Matthew Virden, Richard Dean, Emmett Malvaney
Full text linkMembers of the School of Architecture Advisory Council are pictured. They are (sitting, from left) Arthur J. Godfrey, Dean William McMinn, R. B. Clofton, (standing, from left) Thomas Smith, Robert Harrison, Matthew Virden, Richard Dean, and Emmett Malvaney.https://scholarsjunction.msstate.edu/ua-photo-collection/4415/thumbnail.jp
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Simple, efficient and robust techniques for automatic multi-objective function parameterisation: Case studies of local and global optimisation using APSIM
No full textSeveral techniques for automatic parameterisation are explored using the software PEST. We parameterised the biophysical systems model APSIM with measurements from a maize cropping experiment with the objective of finding algorithms that resulted in the least distance between modelled and measured data (φ) in the shortest possible time. APSIM parameters were optimised using a weighted least-squares approach that minimised the value of φ. Optimisation techniques included the Gauss-Marquardt-Levenberg (GML) algorithm, singular value decomposition (SVD), least squares with QR decomposition (LSQR), Tikhonov regularisation, and covariance matrix adaptation-evolution strategy (CMAES). In general, CMAES with log transformed APSIM parameters and larger population size resulted in the lowest φ, but this approach required significantly longer to converge compared with other optimisation algorithms. Regularisation treatments with log transformed parameters also resulted in low φ values when combined with SVD or LSQR; LSQR treatments with no regularisation tended to converge earliest. In addition to an analysis of several PEST algorithms, this study provides a narrative on how methodologies presented here could be generalised and applied to other models
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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