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Selected AbstractsFibre Bragg grating interrogation based on high-birefringence fibre loop mirror for strain temperature discriminationMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2006O. Frazão Abstract In this work, we present a fiber Bragg grating interrogation based on high-birefringence fiber loop mirror for strain,temperature discrimination. Due to spectral response of the optical filters it is possible to determine the variation of the wavelength and the optical power of the Bragg grating sensor when subject to strain or temperature. Maximum errors of ±0.4°C and ±12 ,, are reported over 80°C and 2000 ,, measurement ranges. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2326,2328, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21894 [source] Projected slabs: approximation of perspective projection and error analysis,COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2001A. Vilanova Bartrolí Abstract Virtual endoscopy is a promising medical application for volume-rendering techniques where perspective projection is mandatory. Most of the acceleration techniques for direct volume rendering use parallel projection. This paper presents an algorithm to approximate perspective volume rendering using parallel projected slabs. The introduced error due to the approximation is investigated. An analytical study of the maximum and average error is made. This method is applied to VolumePro 500. Based on the error analysis, the basic algorithm is improved. This improvement increases the frame rate, keeping the global maximum error bounded. The usability of the algorithm is shown through the virtual endoscopic investigation of various types of medical data sets. Copyright © 2002 John Wiley & Sons, Ltd. [source] Numerical analysis of the rectangular domain decomposition methodINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 7 2009Younbae Jun Abstract When solving parabolic partial differential equations using finite difference non-overlapping domain decomposition methods, one often uses the stripwise decomposition of spatial domain and it can be extended to the rectangular decomposition without further analysis. In this paper, we analyze the rectangular decomposition when the modified implicit prediction (MIP) algorithm is used. We show that the performance of the rectangular decomposition and the stripwise decomposition is different. We compare spectral radius, maximum error, efficiency, and total operations of the rectangular and the stripwise decompositions. We investigate the accuracy of the interface of the rectangular decomposition and the effects of the correction phase of the rectangular decomposition. Numerical experiments have been done in both two and three spatial dimensions and show that the rectangular decomposition is not better than the stripwise decomposition. Copyright © 2008 John Wiley & Sons, Ltd. [source] 1H NMR spectroscopic method for diagnosis of malabsorption syndrome: a pilot studyNMR IN BIOMEDICINE, Issue 2 2004Lakshmi Bala Abstract Despite its well-documented limitations, colorimetry has been commonly used for the d -xylose test in the diagnosis of malabsorption syndrome (MAS). With a possibility of overcoming its limitations, the use of 1H NMR spectroscopy for D -xylose test is explored herein. Urine samples from 35 adults with suspected MAS were obtained before and after oral ingestion of D -xylose. The diagnosis of MAS was based on fecal fat (72,h excretion using Van de Kamer's technique, normal <,7,g/24,h and/or Sudan III stain of spot stool specimen, normal,10 droplets/high power field) and/or endoscopic duodenal biopsy. Urinary excretion of D -xylose over 5,h after consumption of 5,g D -xylose, using both colorimetry and NMR was compared (normal,1,g/5,g/5,h). In vitro experiments on the standard specimens of D -xylose were also performed independently using both methods. Colorimetry showed a lower value for the quantity of D -xylose excreted in urine than NMR [median 0.73 (0.17,1.89,g) vs 1.37 (0.17,3.23,g), respectively; p<0.0001, Wilcoxon's signed ranks test]. Colorimetry and NMR correctly diagnosed 11/12 and 10/12 (p=N.S.) patients with MAS and 14/23 and 20/23 (p<0.05) without MAS, respectively. Sensitivity and specificity of colorimetry and NMR were 91.6 and 60.7% vs 83.3 and 86.9%, respectively. In in vitro experiments, the values obtained for standard xylose using NMR showed a maximum error of 7%, whereas the colorimetric method showed 20%. The NMR method is simple and may be more accurate for the D -xylose absorption test. Colorimetry was found to be inferior as compared with NMR due to its low specificity. Copyright © 2004 John Wiley & Sons, Ltd. [source] Combustion modeling of blended coal in a 300-MW tangentially fired boiler using a two-mixture-fraction modelASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2009Qing-Yan Fang Abstract The combustion process in a 300-MW tangentially fired boiler furnace fired with a blended coal has been numerically simulated. The blended coal contains a low-quality bituminous coal and anthracite and it was injected into the furnace from different burner nozzles. In order to better capture the combustion characteristics, a two-mixture-fraction model has been developed to model the combustion process of each individual coal of the blend. The two mixture fractions were used to separately track the combustion processes of the two component coals to reveal the effect of the combustion of the two coals on the chemical reactions in local zones of the furnace. The sum of the two mixture fractions was used to calculate the gas-phase turbulent combustion. Temperature measurements in the furnace were carried out by a flame image processing technique for model validation. Simulation results show that the temperature and oxygen concentration on the horizontal cross-sections close to the primary air burner nozzles in the furnace are nonuniformly, but symmetrically distributed across the four corners. The temperatures predicted by the simulation agree well with those measured by the flame image processing technique with a maximum error of 8.65%. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] A New Approach for Health Monitoring of Structures: Terrestrial Laser ScanningCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2007H. S. Park Three-dimensional (3D) coordinates of a target structure acquired using TLS can have maximum errors of about 10 mm, which is insufficient for the purpose of health monitoring of structures. A displacement measurement model is presented to improve the accuracy of the measurement. The model is tested experimentally on a simply supported steel beam. Measurements were made using three different techniques: (1) linear variable displacement transducers (LVDTs), (2) electric strain gages, and (3) a long gage fiber optic sensor. The maximum deflections estimated by the TLS model are less than 1 mm and within 1.6% of those measured directly by LVDT. Although GPS methods allow measurement of displacements only at the GPS receiver antenna location, the proposed TLS method allows measurement of the entire building's or bridge's deformed shape, and thus a realistic solution for monitoring structures at both structure and member level. Furthermore, it can be used to create a 3D finite element model of a structural member or the entire structure at any instance of time automatically. Through periodic measurements of deformations of a structure or a structural member and performing inverse structural analyses with the measured 3D displacements, the health of the structure can be monitored continuously. [source] | ||||||||||