6,190 research outputs found
The Fourier Singular Complement Method for the Poisson problem. Part II: axisymmetric domains
This paper is the second part of a threefold article, aimed at solving
numerically the Poisson problem in three-dimensional prismatic or axisymmetric
domains. In the first part of this series, the Fourier Singular Complement
Method was introduced and analysed, in prismatic domains. In this second part,
the FSCM is studied in axisymmetric domains with conical vertices, whereas, in
the third part, implementation issues, numerical tests and comparisons with
other methods are carried out. The method is based on a Fourier expansion in
the direction parallel to the reentrant edges of the domain, and on an improved
variant of the Singular Complement Method in the 2D section perpendicular to
those edges. Neither refinements near the reentrant edges or vertices of the
domain, nor cut-off functions are required in the computations to achieve an
optimal convergence order in terms of the mesh size and the number of Fourier
modes used
The Fourier Singular Complement Method for the Poisson problem. Part I: prismatic domains
This is the first part of a threefold article, aimed at solving numerically
the Poisson problem in three-dimensional prismatic or axisymmetric domains. In
this first part, the Fourier Singular Complement Method is introduced and
analysed, in prismatic domains. In the second part, the FSCM is studied in
axisymmetric domains with conical vertices, whereas, in the third part,
implementation issues, numerical tests and comparisons with other methods are
carried out. The method is based on a Fourier expansion in the direction
parallel to the reentrant edges of the domain, and on an improved variant of
the Singular Complement Method in the 2D section perpendicular to those edges.
Neither refinements near the reentrant edges of the domain nor cut-off
functions are required in the computations to achieve an optimal convergence
order in terms of the mesh size and the number of Fourier modes used
Scan Strategy Interpolation for Laser Powder Bed Fusion in Manufacturing Applications
Laser Powder Bed Fusion (L-PBF) is a technique within additive manufacturing which uses a high power density laser to build parts from fused powdered metal alloy. This technology is well equipped to produce complex parts with otherwise impossible features such as hidden voids or lattice structures. Alongside capability, reliability and quality are key characteristics considered when choosing a manufacturing method, and these are gaining attention as this method becomes more prevalent in industry. One main indicator of a stable L-PBF process is consistent melt pool geometry, the properties of which are likely to determine the quality of the part produced. As computing power and sensing technologies become more advanced, this melt pool geometry could be studied in real time. Therefore, the loop could be closed on process monitoring in order to achieve optimal quality. This work addresses that challenge by capitalizing on machine learning techniques to reduce the latency between sending process commands and receiving process validation.
This thesis presents a novel application of a k-nearest neighbor (k-NN) model to identify key parameters within melt pool imagery and predict significant process parameters. The k-NN model was trained on data provided by the National Institute of Standards and Technology (NIST). This approach was used to accurately infer the energy density of unseen layers within the same part. The algorithm was subsequently tested with unique scan strategies and found to reasonably estimate the process parameters of different parts. A 5-fold cross validation found the algorithm to be consistently predicting the class of 95.42% of the in-situ melt pool images.M.S
Illinois in the War of 1812
Review of: Illinois in the War of 1812, by Gillum Ferguson
Indian Nations of Wisconsin: Histories of Endurance and Renewal
Review of: Indian Nations of Wisconsin: Histories of Endurance and Renewal. Loew, Patty
Boone, Black Hawk, and Crockett in 1833: Unsettling the Mythic West
Review of: Boone, Black Hawk, and Crockett in 1833: Unsettling the Mythic West, edited by Michael A. Lofaro
Indian Nations of Wisconsin: Histories of Endurance and Renewal
Review of: Indian Nations of Wisconsin: Histories of Endurance and Renewal. Loew, Patty
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