269 research outputs found
Finite element approximation of steady flows of generalized Newtonian fluids with concentration-dependent power-law index
We consider a system of nonlinear partial differential equations describing
the motion of an incompressible chemically reacting generalized Newtonian fluid
in three space dimensions. The governing system consists of a steady
convection-diffusion equation for the concentration and a generalized steady
power-law-type fluid flow model for the velocity and the pressure, where the
viscosity depends on both the shear-rate and the concentration through a
concentration-dependent power-law index. The aim of the paper is to perform a
mathematical analysis of a finite element approximation of this model. We
formulate a regularization of the model by introducing an additional term in
the conservation-of-momentum equation and construct a finite element
approximation of the regularized system. We show the convergence of the finite
element method to a weak solution of the regularized model and prove that weak
solutions of the regularized problem converge to a weak solution of the
original problem.Comment: arXiv admin note: text overlap with arXiv:1703.0476
Finite element approximation of an incompressible chemically reacting non-Newtonian fluid
We consider a system of nonlinear partial differential equations modelling
the steady motion of an incompressible non-Newtonian fluid, which is chemically
reacting. The governing system consists of a steady convection-diffusion
equation for the concentration and the generalized steady Navier-Stokes
equations, where the viscosity coefficient is a power-law type function of the
shear-rate, and the coupling between the equations results from the
concentration-dependence of the power-law index. This system of nonlinear
partial differential equations arises in mathematical models of the synovial
fluid found in the cavities of moving joints. We construct a finite element
approximation of the model and perform the mathematical analysis of the
numerical method in the case of two space dimensions. Key technical tools
include discrete counterparts of the Bogovski\u{\i} operator, De Giorgi's
regularity theorem in two dimensions, and the Acerbi-Fusco Lipschitz truncation
of Sobolev functions, in function spaces with variable integrability exponents.Comment: 40 page
A novel approach for wafer defect pattern classification based on topological data analysis
In semiconductor manufacturing, wafer map defect pattern provides critical
information for facility maintenance and yield management, so the
classification of defect patterns is one of the most important tasks in the
manufacturing process. In this paper, we propose a novel way to represent the
shape of the defect pattern as a finite-dimensional vector, which will be used
as an input for a neural network algorithm for classification. The main idea is
to extract the topological features of each pattern by using the theory of
persistent homology from topological data analysis (TDA). Through some
experiments with a simulated dataset, we show that the proposed method is
faster and much more efficient in training with higher accuracy, compared with
the method using convolutional neural networks (CNN) which is the most common
approach for wafer map defect pattern classification. Moreover, our method
outperforms the CNN-based method when the number of training data is not enough
and is imbalanced
Organ Transplants and Governmental Regulations Restricting Individual Bodies
Honors (Bachelor's)Asian StudiesUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/98946/1/chanbaik.pd
SIZE MODIFICATION AND COATING OF TITANIUM DIOXIDE USING A PREMIXED HYDROGEN/AIR FLAME
A study was conducted of the effect of flame processing on the size distribution of
titania nanoparticles, and a flame process was developed for producing TiO2/SiO2 coreshell
particles from aqueous suspensions of TiO2 and SiO2 nanoparticles. Both were
performed using a premixed hydrogen/air flame. At the adiabatic flame temperature of
2400 K, the number mean diameter of titania primary particle increased considerably
from an initial value of 44 nm to 96 nm, presumably by atomic diffusion, and viscous
flow coalescence. Moreover, the majority of product particles from this high flame
temperature were smooth and spherical. Based on the results of size modification
experiments, coating experiments were performed. The dominant morphology observed
in the product particles from coating experiments was silica coated titania. The silica
coating was very smooth and dense. The total particle size and the shell volume of the
product particles were in reasonable agreement with values predicted from the atomized
droplet size distribution and the droplet concentration
Robotic Interestingness via Human-Informed Few-Shot Object Detection
Interestingness recognition is crucial for decision making in autonomous
exploration for mobile robots. Previous methods proposed an unsupervised online
learning approach that can adapt to environments and detect interesting scenes
quickly, but lack the ability to adapt to human-informed interesting objects.
To solve this problem, we introduce a human-interactive framework,
AirInteraction, that can detect human-informed objects via few-shot online
learning. To reduce the communication bandwidth, we first apply an online
unsupervised learning algorithm on the unmanned vehicle for interestingness
recognition and then only send the potential interesting scenes to a
base-station for human inspection. The human operator is able to draw and
provide bounding box annotations for particular interesting objects, which are
sent back to the robot to detect similar objects via few-shot learning. Only
using few human-labeled examples, the robot can learn novel interesting object
categories during the mission and detect interesting scenes that contain the
objects. We evaluate our method on various interesting scene recognition
datasets. To the best of our knowledge, it is the first human-informed few-shot
object detection framework for autonomous exploration
DramaQA: Character-Centered Video Story Understanding with Hierarchical QA
Despite recent progress on computer vision and natural language processing,
developing video understanding intelligence is still hard to achieve due to the
intrinsic difficulty of story in video. Moreover, there is not a theoretical
metric for evaluating the degree of video understanding. In this paper, we
propose a novel video question answering (Video QA) task, DramaQA, for a
comprehensive understanding of the video story. The DramaQA focused on two
perspectives: 1) hierarchical QAs as an evaluation metric based on the
cognitive developmental stages of human intelligence. 2) character-centered
video annotations to model local coherence of the story. Our dataset is built
upon the TV drama "Another Miss Oh" and it contains 16,191 QA pairs from 23,928
various length video clips, with each QA pair belonging to one of four
difficulty levels. We provide 217,308 annotated images with rich
character-centered annotations, including visual bounding boxes, behaviors, and
emotions of main characters, and coreference resolved scripts. Additionally, we
provide analyses of the dataset as well as Dual Matching Multistream model
which effectively learns character-centered representations of video to answer
questions about the video. We are planning to release our dataset and model
publicly for research purposes and expect that our work will provide a new
perspective on video story understanding research.Comment: 21 pages, 10 figures, submitted to ECCV 202
- …