1,631 research outputs found
Alternative Urbanism in the Historic City Centre: A Transnational Perspective on Theory and Practice
Historic city centres are characterised by the tension between the local, represented by authentic spaces of everyday life, and the global, responding to the needs of tourism industry and capital flows. Under the neoliberal paradigm, state-led urban regeneration projects often benefit developers and private investors with little regard to the socio-economic dynamics of existing communities. Recently, this approach has been challenged by alternative practices of placemaking that represent a transition from top-down imposition of urban change to the co-production of space. Such practices are characterised by a more temporary, flexible and tactical approach to the design of space. They represent a collective desire that involves several actors, from local residents and business owners, to civil society organisations and design professionals in the role no longer of the exclusive author but as facilitators and mediators of change. Observing the development of such practice in the western world, and the corresponding theorisation attempts developed mostly by western scholars, this paper looks further to its applications in the global South, with evidence drawn from empirical research in London, UK and Cairo, Egypt. The paper suggests that alternative urbanism may be indicative of a longer-term transition towards a more equitable urban planning practice
Parallel eigenanalysis of finite element models in a completely connected architecture
A parallel algorithm is presented for the solution of the generalized eigenproblem in linear elastic finite element analysis, (K)(phi) = (M)(phi)(omega), where (K) and (M) are of order N, and (omega) is order of q. The concurrent solution of the eigenproblem is based on the multifrontal/modified subspace method and is achieved in a completely connected parallel architecture in which each processor is allowed to communicate with all other processors. The algorithm was successfully implemented on a tightly coupled multiple-instruction multiple-data parallel processing machine, Cray X-MP. A finite element model is divided into m domains each of which is assumed to process n elements. Each domain is then assigned to a processor or to a logical processor (task) if the number of domains exceeds the number of physical processors. The macrotasking library routines are used in mapping each domain to a user task. Computational speed-up and efficiency are used to determine the effectiveness of the algorithm. The effect of the number of domains, the number of degrees-of-freedom located along the global fronts and the dimension of the subspace on the performance of the algorithm are investigated. A parallel finite element dynamic analysis program, p-feda, is documented and the performance of its subroutines in parallel environment is analyzed
Eigensolution of finite element problems in a completely connected parallel architecture
A parallel algorithm for the solution of the generalized eigenproblem in linear elastic finite element analysis, (K)(phi)=(M)(phi)(omega), where (K) and (M) are of order N, and (omega) is of order q is presented. The parallel algorithm is based on a completely connected parallel architecture in which each processor is allowed to communicate with all other processors. The algorithm has been successfully implemented on a tightly coupled multiple-instruction-multiple-data (MIMD) parallel processing computer, Cray X-MP. A finite element model is divided into m domains each of which is assumed to process n elements. Each domain is then assigned to a processor, or to a logical processor (task) if the number of domains exceeds the number of physical processors. The macro-tasking library routines are used in mapping each domain to a user task. Computational speed-up and efficiency are used to determine the effectiveness of the algorithm. The effect of the number of domains, the number of degrees-of-freedom located along the global fronts and the dimension of the subspace on the performance of the algorithm are investigated. For a 64-element rectangular plate, speed-ups of 1.86, 3.13, 3.18 and 3.61 are achieved on two, four, six and eight processors, respectively
Educational Games in Geriatric Medicine Education: A Systematic Review
OBJECTIVE: To systematically review the medical literature to assess the effect of geriatric educational games on the satisfaction, knowledge, beliefs, attitudes and behaviors of health care professionals. METHODS: We conducted a systematic review following the Cochrane Collaboration methodology including an electronic search of 10 electronic databases. We included randomized controlled trials (RCT) and controlled clinical trials (CCT) and excluded single arm studies. Population of interests included members (practitioners or students) of the health care professions. Outcomes of interests were participants' satisfaction, knowledge, beliefs, attitude, and behaviors. RESULTS: We included 8 studies evaluating 5 geriatric role playing games, all conducted in United States. All studies suffered from one or more methodological limitations but the overall quality of evidence was acceptable. None of the studies assessed the effects of the games on beliefs or behaviors. None of the 8 studies reported a statistically significant difference between the 2 groups in terms of change in attitude. One study assessed the impact on knowledge and found non-statistically significant difference between the 2 groups. Two studies found levels of satisfaction among participants to be high. We did not conduct a planned meta-analysis because the included studies either reported no statistical data or reported different summary statistics. CONCLUSION: The available evidence does not support the use of role playing interventions in geriatric medical education with the aim of improving the attitudes towards the elderly.Society of General Internal Medicin
Test Outline for Flutter Analysis of Rectangular Panels in Rarefied Flow Conditions
Jet plume impingement forces acting on large flexible space structures may precipitate dynamically unstable behavior during space flights. Typical operating conditions in space involve rarefied gas flow regimes which are intrinsically distinct from continuum gas flow and are normally modeled using the kinetic theory of gas flow. Docking and undocking operations of the Space Shuttle with the Russian Mir space laboratory represent a scenario in which the stability boundaries of solar panels may be of interest. Extensive literature review of research work on the dynamic stability of rectangular panels in rarefied gas flow conditions indicated the lack of published reports dealing with this phenomenon. A recently completed preliminary study for NASA JSC dealing with the mathematical analysis of the stability of two-degree-of-freedom elastically supported rigid panels under the effect of rarefied gas flow was reviewed. A test plan outline is prepared for the purpose of conducting a series of experiments on four rectangular rigid test articles in a vacuum chamber under the effect of continuous and pulsating Nitrogen jet plumes. The purpose of the test plan is to gather enough data related to a number of key parameters to allow the validation of the two-degree-of-freedom mathematical model. The hardware required careful design to select a very lightweight material while satisfying rigidity and frequency requirements within the constraints of the test environment. The data to be obtained from the vacuum chamber tests can be compared with the predicted behavior of the theoretical two-degree-of-freedom model. Using the data obtained in this study, further research can identify the limitations of the mathematical model. In addition modifications to the mathematical model can be made, if warranted, to accurately predict the behavior of rigid panels under rarefied gas flow regimes
Parallel Eigenvalue extraction
A new numerical algorithm for the solution of large-order eigenproblems typically encountered in linear elastic finite element systems is presented. The architecture of parallel processing is utilized in the algorithm to achieve increased speed and efficiency of calculations. The algorithm is based on the frontal technique for the solution of linear simultaneous equations and the modified subspace eigenanalysis method for the solution of the eigenproblem. Assembly, elimination and back-substitution of degrees of freedom are performed concurrently, using a number of fronts. All fronts converge to and diverge from a predefined global front during elimination and back-substitution, respectively. In the meantime, reduction of the stiffness and mass matrices required by the modified subspace method can be completed during the convergence/divergence cycle and an estimate of the required eigenpairs obtained. Successive cycles of convergence and divergence are repeated until the desired accuracy of calculations is achieved. The advantages of this new algorithm in parallel computer architecture are discussed
Forcasting the Clinical Outcome: Artificial Neural Networks or Multivariate Statistical Models?
Regionalizing healthcare: a vision for transforming Lebanon into a regional academic hub
<p>Abstract</p> <p>Background</p> <p>Lebanon suffers from a large scale emigration of physicians coupled with an oversaturation of the physician job market. Lebanon is currently witnessing an expansion of its medical education capacity with the establishment of new private medical schools, raising the fears of a worsening market oversaturation.</p> <p>Discussion</p> <p>The neighboring Arabian Gulf countries are suffering from a serious shortage of clinicians and academicians. In spite of their enormous investments in educational, clinical and research collaborative initiatives with some of the most renowned North American medical schools and institutions, their ability to recruit and retain highly qualified clinicians and academicians remains a major challenge. Lebanese universities have the opportunity to establish triangular collaborations with the Gulf regional medical centers and their North American partners. They could achieve this goal by tapping into the globalized and high quality Lebanese physician workforce and consequently regionalize healthcare delivery in the Middle East.</p> <p>Summary</p> <p>By recruiting its globalized and high quality physician workforce to establish collaborations with the Gulf regional, Lebanon could become a regional "academic hub".</p
Use of 3D Laser Scanner for Rock Fractures Mapping
In the process of investigation, design and upgrading of rock slopes, the orientation and
spacing of the structural discontinuities or joints in the rock mass are thoroughly mapped in
the field so that any unstable blocks can be identified and stabilization measures designed.
The orientation of the structural discontinuities is traditionally measured manually using
geological compass placed directly at the exposed surfaces. Scaffolding is usually erected so
that the geologist can physically access the exposed rock surface. A large number of
measurements are usually required in order to obtain a statistical mean of the fracture
orientation. With the ongoing advances of digital technology, 3D laser scanning technique
can be used to replace direct physical access and large number of manual measurements can
be completely eliminated. A prototype system is described in this paper that combines the
non-contact measurement technologies of photogrammetric imaging and 3D laser scanning to
create dimensionally accurate and pictorially correct 3 dimensional models and orthoimages
of a rock fractures. By taking photographs from at least two different locations, lines of sight
are mathematically intersected to produce the 3D coordinates of the key reference points in a
rock face. Automatic 3D laser scanning unit is then used to produce the 3D coordinates of the
entire rock surface. By overlapping the images rectified from photogrammetry technique with
the coordinates from 3D laser scanning in an Autodesk 3D Studio Max environment, the
coordinates of any objects in the photographs can be selected and their orientation such as dip
angle and dip direction calculated automatically. A case study is presented to compare the
orientations of fracture planes measured using geological compass and the orientations from
the prototype system developed.published_or_final_versio
Monitoring Slope Failure at Kadoorie Agricultural Research Centre with a 3D Laser Scanner
A loosely compacted fill slope with an angle of 33° was constructed at the Kadoorie
Agricultural Research Centre of The University of Hong Kong. The height and width were
4.75 m and 9 m respectively. It was constructed by end-tipping method and resulted in a
loose state with an initial dry density of 70% of the maximum dry density. Two rows of
grouted nails were installed at a grid of 1.5 m x 1.5 m at an inclination of 20° from the
horizontal. The slope was brought to failure by subjecting it to surcharge at the slope crest in
combination with induced rise in groundwater table and precipitation. Heavy instrumentation
comprised in-place inclinometer, vibrating wire piezometers, vibrating wire extensometer,
earth pressure cell, tensiometer and strain gauges along soil nails and they had been
monitored throughout the test. Surface movement was monitored using a GPS system and a
3D laser scanner.
This paper focuses on the use of 3D laser scanner in capturing the formation of cracks and
surface movement during the failure. It is found that by overlapping the point clouds
generated from the scanner at different time intervals, the surface movement of the slope can
be accurately recorded without the need of physically accessing the slope surface.
When the slope reaches failure, the use of laser scanning can safely and quickly record the
movement and dimension of washout and cracks, providing advantages over conventional
survey method. This study shows that the movement obtained from the scanner agrees very
well with that from conventional inclinometer reading at the surface. The travel distance of
the surcharge block can be easily measured and point cloud can be easily modeled into
geometrical shape for further rendering.published_or_final_versio
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