761,126 research outputs found
Soot volume fraction profiling of asymmetric diffusion flames through tomographic imaging
This paper presents the 3-D (three-dimensional) reconstruction of soot volume fraction of diffusion flames based on tomographic imaging and image processing techniques. Eight flexible imaging fiber bundles and two RGB (Red, Green and Blue) CCD (Charge-coupled Device) cameras are used to obtain concurrently the 2-D (two-dimensional) image projections of the flame from eight different angles of view around the burner. Algorithms which combine the tomographic and two-color pyrometric techniques are utilized to reconstruct the soot volume fraction distributions on both cross- and longitudinal-sections of the flame. A series of experiments were carried out on a gas-fired combustion rig for the determination of soot volume fraction using the algorithms proposed. Test results demonstrate the effectiveness of the developed algorithms
Symbol table algorithms - Computer evolution project, volume 2, no. 1
Algorithms for accessing symbol tables in compile
Evaluation of registration, compression, and classification algorithms. Volume 2: Documentation
There are no author-identified significant results in this report
Qualitative comparison of several phase correction algorithms in single-image in-line X-ray phase contrast tomography
In recent years, phase contrast has gained importance in the field of X-ray imaging and more particular in high-resolution X-ray computed tomography or micro-CT. For phase propagation imaging, no additional hardware or specific setup is required, which makes the effect inherent to micro-CT where it is manifested as an edge-enhancement effect. As such, it can be beneficial for qualitative analysis of a 3D volume. Nevertheless, it induces unreal gray values and is thus often considered as an imaging artefact which hinders proper quantitative 3D analysis. Several methods exist to reduce this phase contrast effect or to retrieve the phase information from the mixed phase-and-amplitude images. In this presentation, a comparison will be made between 2 phase retrieval algorithms and 2 phase correction algorithms. Of these 2 latter, one can be performed on the reconstructed volume, which clearly facilitates the operation of phase correction
Development of visible/infrared/microwave agriculture classification and biomass estimation algorithms, volume 2
Agricultural crop classification models using two or more spectral regions (visible through microwave) were developed and tested and biomass was estimated by including microwave with visible and infrared data. The study was conducted at Guymon, Oklahoma and Dalhart, Texas utilizing aircraft multispectral data and ground truth soil moisture and biomass information. Results indicate that inclusion of C, L, and P band active microwave data from look angles greater than 35 deg from nadir with visible and infrared data improved crop discrimination and biomass estimates compared to results using only visible and infrared data. The active microwave frequencies were sensitive to different biomass levels. In addition, two indices, one using only active microwave data and the other using data from the middle and near infrared bands, were well correlated to total biomass
Feasibility study of using the overlap-Dirac operator for hadron spectroscopy
We investigate a number of algorithms that calculate the quark propagators
for the overlap-Dirac fermion operator. The QCD simulations were performed at
beta = 5.9 with a lattice volume of 16**3*32.Comment: LATTICE99(Chiral Fermions) 3 pages, 2 figures. A problem with the
incorrect definition of the overlap mass has been corrected. The results have
changed, but not the conclusions of the pape
Cost of Generalised HMC Algorithms for Free Field Theory
We study analytically the computational cost of the Generalised Hybrid Monte
Carlo (GHMC) algorithm for free field theory. We calculate the autocorrelation
functions of operators quadratic in the fields, and optimise the GHMC momentum
mixing angle, the trajectory length, and the integration stepsize. We show that
long trajectories are optimal for GHMC, and that standard HMC is much more
efficient than algorithms based on the Second Order Langevin (L2MC) or Kramers
Equation. We show that contrary to naive expectations HMC and L2MC have the
same volume dependence, but their dynamical critical exponents are z=1 and
z=3/2 respectively.Comment: LATTICE99(Algorithms and Machines) - 3 pages, 1 PostScript figur
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