761 research outputs found
Stack-run adaptive wavelet image compression
We report on the development of an adaptive wavelet image coder based on stack-run representation of the quantized coefficients. The coder works by selecting an optimal wavelet packet basis for the given image and encoding the quantization indices for significant coefficients and zero runs between coefficients using a 4-ary arithmetic coder. Due to the fact that our coder exploits the redundancies present within individual subbands, its addressing complexity is much lower than that of the wavelet zerotree coding algorithms. Experimental results show coding gains of up to 1:4dB over the benchmark wavelet coding algorithm
Crop-based irrigation operations in the North West Frontier Province of Pakistan. Vol.II: Research approach and interpretation. Final Report
Irrigation management / Crop-based irrigation / Research / Irrigation canals / Water demand / Performance evaluation / Agricultural production / Pakistan / North West Frontier Province
The learners\u27 perspective on internal medicine ward rounds: a cross-sectional study
Background: Ward rounds form an integral part of Internal Medicine teaching. This study aimed to determine the trainees\u27 opinions regarding various aspects of their ward rounds, including how well they cover their learning needs, how they would like the rounds to be conducted, and differences of opinion between medical students and postgraduates. Methods: A cross-sectional study was conducted on a total of 134 trainees in Internal Medicine, comprising medical students, interns, residents and fellows, who were asked to fill in a structured, self-designed questionnaire. Most of the responses required a rating on a scale of 1-5 (1 being highly unsatisfactory and 5 being highly satisfactory). Results: Teaching of clinical skills and bedside teaching received the lowest overall mean score (Mean +/- SD 2.48 +/- 1.02 and 2.49 +/- 1.12 respectively). They were rated much lower by postgraduates as compared to students (p \u3c 0.001). All respondents felt that management of Patients was the aspect best covered by the current ward rounds (Mean +/- SD 3.71 +/- 0.72). For their desired ward rounds, management of Patients received the highest score (Mean +/- SD 4.64 +/- 0.55), followed by bedside examinations (Mean +/- SD 4.60 +/- 0.61) and clinical skills teaching (Mean +/- SD 4.50 +/- 0.68). The postgraduates desired a lot more focus on communication skills, counselling and medical ethics as compared to students, whose primary focus was teaching of bedside examination and management. A majority of the respondents (87%) preferred bedside rounds over conference room rounds. Even though the duration of rounds was found to be adequate, a majority of the trainees (68%) felt there was a lack of individual attention during ward rounds. Conclusions: This study highlights important areas where ward rounds need improvement in order to maximize their benefit to the learners. There is a need to modify the current state of ward rounds in order to address the needs and expectations of trainees
Challenges of providing timely feedback to Residents: Faculty perspectives
Objective
To explore faculty\u27s perceptions of challenges in providing verbal feedback to the Residents and suggest ways to overcome the barriers.
Methods
As part of a larger study on feedback assessment, five focus group discussions were conducted at the Department of Medicine, Aga Khan University Hospital, Karachi, during faculty development workshops held from January to June 2010. Qualitative grounded theory was used to explore faculty perceptions of challenges in providing verbal feedback to the Residents.
Results
Of the 54 faculty members, 49(91%) participated. Four themes that emerged were \u27time constraint\u27 indicating high patient load; \u27faculty related issues\u27 indicating faculty\u27s apprehension about its own evaluation by Residents; \u27educational issues\u27 indicating that the importance of feedback was not emphasised; and \u27system and logistic issues\u27 indicating that the assessment form used for assessing Residents was ambiguous.
Conclusion
Work load of the faculty and the expectations with respect to patient care responsibilities may have an impact on the quality, timing, content and delivery of the feedback provided to the Residents
Moving Finite Element Solution of Discontinuous Open Channel Flow
Over the years, rapidly varying channel flow and discontinuities in the solution of fluid mechanics problems have provided stimulation and challenge to numerical modelers. Traditional finite difference and finite element methods produce accurate but oscillatory solutions. Attempts to selectively eliminate these parasitic waves have been only partially successful in that the cost of a smoother profile was a lower accuracy solution. It is common to employ either internal and external dissipation parameters or a provision of dispersive interface. In this thesis, the problem of rapidly varying open channel flow is represented by a pair of nonlinear partial differential equations which are solved by a powerful moving finite element technique. The method developed in this research is based on the linking of a novel Lagrangian mode solution with the convenience of the Eularian grid at each time step. This second order scheme was employed in solving a variety of devised and reported open channel flow problems with near discontinuities. Comparisons with solutions obtained using the finite difference and finite element methods with Crank-Nicholson centred weightings demonstrates the quality improvements which have been achieved by this moving element scheme. The basic scheme was further generalized in both spatial and temporal dimensions. Sensitivity analysis of these generalized parameters established the grid size relaxations for a variety of problems. The moving element technique solved near discontinuous and gradually varied flow problems both in supercritical and subcritical regimes. An alternate form of Petrov-Galerkin weighting function was tested and found to give promising results. Further experimentation and testing are required before implementation. The robustness of the solution procedure is indicated by the adaptation of the model from the numerical and laboratory experiment stage to field problems. The model was successfully applied to the Teton Dam break flood and flood routing problem in the (Ontario) Grand River basin. Sensitivity analysis with very mild sloped channels with topographical features such as sudden expansions and offchannel storage suggest that the Eulerian-Lagrangian mode algorithm provides the missing link between the fluid mechanics of discontinuities and a practical tool for the modelling of rapidly varying open channel flow.Doctor of Philosophy (PhD
The CMS Integration Grid Testbed
The CMS Integration Grid Testbed (IGT) comprises USCMS Tier-1 and Tier-2
hardware at the following sites: the California Institute of Technology, Fermi
National Accelerator Laboratory, the University of California at San Diego, and
the University of Florida at Gainesville. The IGT runs jobs using the Globus
Toolkit with a DAGMan and Condor-G front end. The virtual organization (VO) is
managed using VO management scripts from the European Data Grid (EDG). Gridwide
monitoring is accomplished using local tools such as Ganglia interfaced into
the Globus Metadata Directory Service (MDS) and the agent based Mona Lisa.
Domain specific software is packaged and installed using the Distrib ution
After Release (DAR) tool of CMS, while middleware under the auspices of the
Virtual Data Toolkit (VDT) is distributed using Pacman. During a continuo us
two month span in Fall of 2002, over 1 million official CMS GEANT based Monte
Carlo events were generated and returned to CERN for analysis while being
demonstrated at SC2002. In this paper, we describe the process that led to one
of the world's first continuously available, functioning grids.Comment: CHEP 2003 MOCT01
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
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Refining the accuracy of validated target identification through coding variant fine-mapping in type 2 diabetes.
We aggregated coding variant data for 81,412 type 2 diabetes cases and 370,832 controls of diverse ancestry, identifying 40 coding variant association signals (P < 2.2 × 10-7); of these, 16 map outside known risk-associated loci. We make two important observations. First, only five of these signals are driven by low-frequency variants: even for these, effect sizes are modest (odds ratio ≤1.29). Second, when we used large-scale genome-wide association data to fine-map the associated variants in their regional context, accounting for the global enrichment of complex trait associations in coding sequence, compelling evidence for coding variant causality was obtained for only 16 signals. At 13 others, the associated coding variants clearly represent 'false leads' with potential to generate erroneous mechanistic inference. Coding variant associations offer a direct route to biological insight for complex diseases and identification of validated therapeutic targets; however, appropriate mechanistic inference requires careful specification of their causal contribution to disease predisposition
Evaluation of three accelerometer devices for physical activity measurement amongst south Asians and Europeans
We recruited 62 South Asians and 40 Europeans aged 25 to 75 years, to assess the potential validity of three physical activity accelerometers for use amongst South Asians. Participants completed an exercise treadmill test (following Bruce protocol) while wearing the 3 accelerometers: Actigraph GT3X+ [GT3X+] and Geneactiv [GA] on ankle, waist and wrist; and Actiheart [AH] on chest. We compared relationships between energy expenditure (EE) measured by accelerometers (Measured) and actual EE on the treadmill (Actual) in the two ethnicities and tested for potential confounding effects. All accelerometers under-reported EE. Difference between Measured and Actual EE was smallest for GT3X+ankle (Measured – Actual at peak exercise [Mets]: GT3X+ankle –6.52 (1.77); GT3X+waist –8.46 (1.29); GT3X+wrist –11.17 (1.03); GAankle –8.17 (1.19); GAwaist –10.24 (0.64); GAwrist –11.21 (1.10); AHchest –9.09 (1.43), P 0.05). Relationship between Measured and Actual EE was not influenced by age, gender, height, waist, weight or waist-hip ratio (all P > 0.05). Amongst the devices and positions tested, GT3X+ankle is the most accurate device for measuring EE during an exercise treadmill test. Accelerometer performance is similar in South Asians and Europeans and is not influenced by anthropometric differences between the two populations
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