2 research outputs found
On the 3-Dimensional Fluid-Structure Interaction of Flexible Fibers in a Flow
We discuss the equilibrium configurations of a flexible fiber clamped to a spherical body and immersed in a flow of fluid moving with a speed ranging between 0 and 50 cm/s. Experimental results are presented with both two-dimensional and three-dimensional numerical simulations used to model this problem. We present the effects of flow speed and initial configuration angle between the fiber and the direction of the flow. Investigations reveal that both the orientation of the fiber and the fiber length have a significant impact on the deformation of the fiber as well as on the forces it experiences. Specifically, we measure the drag and lift experienced by the system and measure them against known values in literature. We note, additionally, that longer fibers (i) bend significantly more than shorter fibers and (ii) display oscillatory or flapping motion at much lower flow speeds than their shorter counterparts. In the two-dimensional simulations we reveal that the drag on the fiber is noticeably affected by the size of the sphere. The analysis of the drag is done in terms of Vogel exponents, computed in both 2-D and 3-D, and is compared with the literature. The validity of the reduction of dimensionality is tested against the three-dimensional simulations and qualitatively compared. Both mesh density and convergence studies are performed in 2-D and 3-D to balance the accuracy and convergence rates. We also discuss the robustness of the three-dimensional model and the practicalities of using a lower-dimensional model
Detection of pulmonary tuberculosis using deep learning convolutional neural networks
If Pulmonary Tuberculosis (PTB) is detected early in a patient, the greater the chances of treating
and curing the disease. Early detection of PTB could result in an overall lower mortality rate.
Detection of PTB is achieved in many ways, for instance, by using tests like the sputum culture
test. The problem is that conducting tests like these can be a lengthy process and takes up precious
time. The best and quickest PTB detection method is viewing the chest X-Ray image (CXR) of
the patient. To make an accurate diagnosis requires a qualified professional Radiologist. Neural
Networks have been around for several years but is only now making ground-breaking
advancements in speech and image processing because of the increased processing power at our
disposal. Artificial intelligence, especially Deep Learning Convolutional Neural Networks
(DLCNN), has the potential to diagnose and detect the disease immediately. If DLCNN can be
used in conjunction with the professional medical institutions, crucial time and effort can be saved.
This project aims to determine and investigate proper methods to identify and detect Pulmonary
Tuberculosis in the patient chest X-Ray images using DLCNN. Detection accuracy and success
form a crucial part of the research. Simulations on an input dataset of infected and healthy patients
are carried out. My research consists of firstly evaluating the colour depth and image resolution of
the input images. The best resolution to use is found to be 64x64. Subsequently, a colour depth of
8 bit is found to be optimal for CXR images. Secondly, building upon the optimal resolution and
colour depth, various image pre-processing techniques are evaluated. In further simulations, the
pre-processed images with the best outcome are used. Thirdly the techniques evaluated are transfer
learning, hyperparameter adjustment and data augmentation. Of these, the best results are obtained
from data augmentation. Fourthly, a proposed hybrid approach. The hybrid method is a mixture
of CAD and DLCNN using only the lung ROI images as training data. Finally, a combination of
the proposed hybrid method, coupled with augmented data and specific hyperparameter
adjustment, is evaluated. Overall, the best result is obtained from the proposed hybrid method
combined with synthetic augmented data and specific hyperparameter adjustment.Electrical and Mining Engineerin