8,688 research outputs found
Three-dimensional Image Processing of Identifying Toner Particle Centroids
Powder-based 3D printed products are composed of fine particles. The structure formed by the particles in the powder is expected to affect the performance of the final products constructed from them (Finney, 1970; Dinsmore, 2001; Chang, 2015; Patil, 2015). A prior study done by Patil (2015) demonstrated a method for determining the centroids and radii of spherical particles and consequently reconstructed the structure formed by the particles. Patil’s method used a Confocal Laser Scanning Microscope to capture a stack of cross-sections of fluorescent toner particles and Matlab image analysis tools to determine the particle centroid positions and radii. Patil identified each particle centroid’s XY coordinates and particle radius layer by layer, called “frame-by-frame” method; where the Z-position of the particle centroid was estimated by comparing the radius change at different layers. This thesis extends Patil’s work by automatically locating particle centroids in 3D space.
The researcher built an algorithm, named “3D particle sighting method,” for processing the same stacks of two-dimensional images that Patil used. The algorithm at first, created a three-dimensional image matrix and then processed it by convolving with a 3D kernel to locate local maxima, which pinpointed the centroid locations of the particles. This method treated the stack of images as a 3D image matrix and the convolution operation automatically located the particle centroids. By treating Patil’s results as the ground truth, the results revealed that the average delta distance between the particle centroids identified through Patil’s method and the automated method was 1.02 microns (+/- 0.93 microns). Since the diameter of the particles is around 10 microns, this error is small compared to the size of the particles, and the results of the 3D particle sighting method are acceptable. In addition, this automated method need 1/5 of the processing time compared to Patil’s frame-by-frame method
Chlorido{N-[(diethylamino)dimethylsilyl]anilido-κN}(N,N,N′,N′-tetramethylethane-1,2-diamine-κ2 N,N′)cobalt(II)
In the title cobalt(II) compound, [Co(C12H21N2Si)Cl(C6H16N2)], the ethane-1,2-diamine donor molecule coordinates the metal atom in an N,N′-chelating mode, with Co—N distances of 2.136 (2) and 2.140 (3) Å. An anilide ligand connects to the CoII atom with a σ–bond, the Co—Nanilide distance being 1.931 (2) Å. The four-coordinate CoII atom demonstrates a slightly distorted tetrahedral geometry
Collective Flows in a Transport Approach
We introduce a transport approach at fixed shear viscosity to entropy ratio
\etas to study the generation of collective flows in ultra-relativistic
heavy-ion collisions. Transport theory supplies a covariant approach valid also
at large \etas and at intermediate transverse momentum , where
deviations from equilibrium is no longer negligible. Such an approach shows
that at RHIC energies a temperature dependent \etas enhances significantly
the respect to the case of constant \etas. Furthermore if NJL
chiral dynamics is self-consistently implemented we show that it does not
modify the relation between and \etas.Comment: 4 pages, 4 figures, Proceedings of Hot Quarks 2010, 21-26 June 2010
Las Londe Les Maures; to appear in Journal of Physics: Conference Serie
Local polynomial regression for circular predictors
We consider local smoothing of datasets where the design space is the d-dimensional (d >= 1) torus and the response variable is real-valued. Our purpose is to extend least squares local polynomial fitting to this situation. We give both theoretical and empirical results
Interplay of phase boundary anisotropy and electro-autocatalytic surface reactions on the lithium intercalation dynamics in LiFePO platelet-like nanoparticles
Experiments on single crystal LiFePO (LFP) nanoparticles indicate
rich nonequilibrium phase behavior, such as suppression of phase separation at
high lithiation rates, striped patterns of coherent phase boundaries,
nucleation by binarysolid surface wetting and intercalation waves. These
observations have been successfully predicted (prior to the experiments) by 1D
depth-averaged phase-field models, which neglect any subsurface phase
separation. In this paper, using an electro-chemo-mechanical phase-field model,
we investigate the coherent non-equilibrium subsurface phase morphologies that
develop in the - plane of platelet-like single-crystal platelet-like
LiFePO nanoparticles. Finite element simulations are performed for 2D
plane-stress conditions in the - plane, and validated by 3D simulations,
showing similar results. We show that the anisotropy of the interfacial tension
tensor, coupled with electroautocatalytic surface intercalation reactions,
plays a crucial role in determining the subsurface phase morphology. With
isotropic interfacial tension, subsurface phase separation is observed,
independent of the reaction kinetics, but for strong anisotropy, phase
separation is controlled by surface reactions, as assumed in 1D models.
Moreover, the driven intercalation reaction suppresses phase separation during
lithiation, while enhancing it during delithiation, by electro-autocatalysis,
in quantitative agreement with {\it in operando} imaging experiments in
single-crystalline nanoparticles, given measured reaction rate constants
CLR-DRNets: Curriculum Learning with Restarts to Solve Visual Combinatorial Games
We introduce a curriculum learning framework for challenging tasks that require a combination of pattern recognition and combinatorial reasoning, such as single-player visual combinatorial games. Our work harnesses Deep Reasoning Nets (DRNets) [Chen et al., 2020], a framework that combines deep learning with constraint reasoning for unsupervised pattern demixing. We propose CLR-DRNets (pronounced Clear-DRNets), a curriculum-learning-with-restarts framework to boost the performance of DRNets. CLR-DRNets incrementally increase the difficulty of the training instances and use restarts, a new model selection method that selects multiple models from the same training trajectory to learn a set of diverse heuristics and apply them at inference time. An enhanced reasoning module is also proposed for CLR-DRNets to improve the ability of reasoning and generalize to unseen instances. We consider Visual Sudoku, i.e., Sudoku with hand-written digits or letters, and Visual Mixed Sudoku, a substantially more challenging task that requires the demixing and completion of two overlapping Visual Sudokus. We propose an enhanced reasoning module for the DRNets framework for encoding these visual games We show how CLR-DRNets considerably outperform DRNets and other approaches on these visual combinatorial games
USCID fourth international conference
Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Studying the impact of microtopography on irrigation performance is important for improving the management of basin irrigation systems. However, the limitation of field experiments will restrict the studies on the impact of microtopography spatial variability on basin irrigation performance. Thus, firstly this paper analyzed the spatial variability characteristics of field-measured Surface Relative Elevations (SRE). The correlations between the field geometry parameters and the spatial variability characteristics of SRE were evaluated, and the estimation methods for parameters of the semi-variogram of SRE were determined. Secondly, a microtopography stochastic generating model was built up based on the Monte-Carlo and the Kriging interpolation techniques. Lastly, the effect of spatial variability of microtopography on the performance of basin irrigation was evaluated by using of the numerical simulation model. Results showed that the microtopography undulation degree and the spatial distribution difference of undulation location had obvious effect on the basin irrigation performance. The average irrigation depth (Z'avg), corresponding to the water just cover the whole basin surface is increased while the irrigation application efficiency (Ea) and the irrigation uniformity (CU) is decreased when the field elevation non-uniformity, measured by the standard deviation of SRE (Sd) is increased. The effect of spatial distribution of undulation location on the irrigation performance was dependent upon the microtopography undulation degree, when Sd is less than 2cm the impacts can be neglected, while Sd is greater than 2cm, the influence should be considered
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