2002
GSTC
Graduate Student Thesis Abstracts
University
of Calgary 2000-2001
Department of Mechanical and Manufacturing Engineering
|
| A
Psychovisually-Based Objective Image Quality Evaluator for DCT-Based Lossy Data
Compression | Ruby
Wai Shan Chan | RubyChan@smarttech.com | Dr.
Peter Goldsmith | | ABSTRACT |
| In
this thesis, we propose an algorithm for evaluating the quality of DCT-based compressed
images, called the Psychovisually-Based Objective Image Quality Evaluator (POIQE).
The POIQE evaluates the image quality using two psychovisually-based fidelity
indexes: blockiness and similarity. Blockiness measures the patterned square artifact
created as a by-product of the lossy DCT-based compression technique used by JPEG
and MPEG, while similarity measures the perceivable detail remaining after compression.
The blockiness and similarity are combined into a single POIQE index used to assess
quality. The POIQE model is tuned using subjective assessment results from five
subjects evaluating six sets of images. Then, the capability of the model is verified
by validation experiments involving four new subjects and five new sets of images. |
| Dynamics
of Pipelines with a Finite Element Method | Jawad
Nadeem Durrani | durrani@enme.ucalgary.ca | Dr.
Mansa Singh | | ABSTRACT |
| N/A |
| Solitary
waves in fluid-filled elastic tubes. | Clifton
Reed Johnston | crjonst@ucalgary.ca | Dr.
Marcelo Epstein | | ABSTRACT |
| The
propagation of solitary waves in fluid-filled elastic tubes was investigated by
direct analysis of the governing field equations. The primary advantage of this
approach over the widely used asymptotic techniques is that, for a specified wave
speed, the solution of the `exact' amplitude of the solitary waves only requires
the roots of an algebraic equation. The shape of the wave can be found to any
required degree of accuracy numerically. This approach can be applied beyond the
long-wave approximation for any amplitude of wave. The presented direct approach
was used to consider a fluid-filled elastic thin-walled tube where axial displacements
were neglected and the velocity of the fluid was averaged over the tube radius.
It was shown that errors can become as large as 20\% for displacements up to 25\%
of the tube radius when the reductive perturbation technique is used. The direct
approach was also used to investigate a problem in plasma physics, specifically
ion-acoustic waves, to illustrate a broader application of the proposed technique.
The kinematically exact shell equations for the tube, including both axial and
radial displacements were considered and it was shown that, by casting the problem
in a variational framework, it becomes possible to find explicit first integrals
of the governing equations. The first integrals then allowed the speed, amplitude
and shape of the resulting solitary wave to be determined `exactly' using the
proposed direct approach. The results showed that the wave amplitude calculated
using the exact displacements were an order of magnitude greater than found when
axial displacements were neglected. It was subsequently shown that the axial strain
was of the same order as the magnitude of the radial strain and that in the prestressed
reference configuration their relationship was approximately linear. Exploiting
this approximate linear relationship, a linear function was found from the axial
first integral, permitting the reduction of the governing equations to a problem
of one equation in one dependent variable, while still retaining a contribution
for the axial displacement. The amplitude predicted using this approximate approach
was found to differ from the exact value by as little as 3%. Finally, the tube
wall pressure predicted from our inviscid, incompressible one-dimensional fluid
model was compared to a two-dimensional flow, simulated using a modified discrete-vortex
method. The tube geometries examined corresponded to the solitary wave profiles
for four representative wave speeds. It was shown that the predicted pressures
from the existing one-dimensional model compared well with the two-dimensional
flow. Based upon this, it should be expected that solitary waves predicted using
a two-dimensional fluid model will be in close agreement with the results presented
in this dissertation. |
| Performance
of the Pulse-Tube Cryocooler: Theoretical Model and Experimental Results. | Paul
Pavel Mayzus | ppmayzus@enme.ucalgary.ca | Dr.
Luc Bauwens | | ABSTRACT |
| N/A |
| Quantification
of Patellofemoral Contact Area Using MR Imaging, a Validation and Comparative
Study. | Rebecca
Tegan Moss | rtmoss@powersurfr.com | Dr.
Janet Ronsky | | ABSTRACT |
| Abnormal
joint contact mechanics are commonly speculated to be an initiating factor in
cartilage degeneration. Magnetic resonance imaging (MRI) has been used as a non-invasive
measurement tool for evaluating cartilage thickness, deformation and contact area
in-vivo and in-vitro. However, specific evaluation of the sources of error and
their magnitude are limited. This study evaluates the use of MRI and surface modeling
with thin plate splines for the determination of joint contact area in a loaded
patellofemoral joint. In the absence of a gold standard, a comparative measure
with staining and multi-station digital photogrammetry was used to evaluate the
accuracy and repeatability of the MRI, digitization and modeling procedures. The
technique presented provides a successful method to obtain surface geometry and
contact area of the patellofemoral joint non-invasively and in the in-vivo, loaded
condition using MRI. |
| An
Intelligent Optimal Product Distribution Scheduling Approach. | Huicheng
Wang | hwang@ucalgary.ca | Dr.
Deyi Xue | | ABSTRACT |
| This
research is devoted to develop an intelligent optimal scheduling approach for
product distribution considering real world constraints. Many artificial intelligence
and optimization techniques, including search, fuzzy c-means clustering method,
and genetic algorithm, are used for improving the quality and efficiency of delivery
scheduling. The intelligent scheduling system is composed of two modules - a short-distance
delivery scheduling module and a long-distance delivery scheduling module. Short-distance
delivery scheduling is conducted at three different levels considering one driver
and one load, one driver and multiple loads, and multiple drivers and multiple
loads. Long-distance delivery scheduling is also conducted at three levels, including
identification of the delivery demand patterns, creation of delivery zones, and
zone-based delivery scheduling. The system was implemented using Visualworks,
an object oriented programming language, and tested using examples for a local
manufacturing company. |
| Beyond
Science: An Exploration of Values in Engineering Education and Practice. | Paul
Martin Winkelman | winkelma@enme.ucalgary.ca | Dr.
O R Fauvel | | ABSTRACT |
| Contemporary
engineering programs at Canadian universities place a heavy emphasis on science
and mathematics. At the same time, these programs offer little critique of either
discipline, and the values they embrace are left unspoken. Recently, however,
the Canadian Engineering Accreditation Board has required that an open-ended design
course be included in the curriculum. This new requirement implies that design
cannot be adequately taught through science and mathematics alone and, by extension,
design is neither mathematics nor science. The central thesis of this research
is that design is best considered as distinct from science. In light of the presumed
epistemic superiority of science, a validation of the design paradigm demands
a deeper understanding of the values of science. To this end, I developed a critique
of science as it pertains to the practice of engineering and design by drawing
on philosophy, linguistics, and literature. Philosophy reveals some of the assumptions
of the Enlightenment which undergird science. By emphasizing the role of language
in human thought, linguistic theories cast doubt on the validity of many assumptions
of science, such as objectivity. Finally, works such as Mary Shelley's Frankenstein
can illustrate some of the dangers that may arise when (scientific) values are
not questioned. However, another source of critique may be closer to home. By
viewing science through the design lens, one may develop many of the critiques
offered by philosophy and linguistics. The significance of this approach is that,
coming from within engineering, it is more accessible to engineers. Unlike science,
for example, design values the co-existence of multiple, competing solutions to
a single problem. The relevance of this research lies in its implications for
the advancement of professional education and for understanding engineering identity.
Case studies that were conducted revealed that engineers relate thought to visualization
skills rather than linguistic capabilities. Engineers also displayed a love-hate
relationship with science. On the other hand, they showed great respect for mathematics,
according it perfect powers of description. These case studies suggest that the
engineering identity and education could be enhanced by increased exposure to
design and its values. |
| Axiomatic
Approach to the Modeling of Product Conceptual Design Processes Using Set Theory. | Yong
Zeng | yzeng@enme.ucalgary.ca | Dr.
Peihua Gu | | ABSTRACT |
| This
thesis presents an axiomatic approach to the modeling of product conceptual design
processes using set theory. It can be divided into three parts: the axiomatic
system, the nature of the design problem and design processes, and applications.
The first part aims to establish the theory whereas the latter two test and justify
the theory. The axiomatic system consists of two axioms: axiom of bounded rationality
and axiom of object structuring. The axiom of bounded rationality states that
human recognition is not perfect while the axiom of object structuring indicates
what should be a full picture of an object. These two axioms deal with human and
natural parts in the design process respectively. Set theory is used as the language
to represent axioms, theorems, and facts appearing in the theory. Based on this
theory, formal models of the product-environment system, design requirements,
and the design process are derived following logical steps. These formal models
are characterized by: the dynamic and evolving nature of product descriptions
and product performances, the uniform representation of design requirements, and
an environment decomposition-based conceptual design process. These three parts
constitute an integral formal model of product design. It supports the overall
design process from the abstract and general state to the concrete and specific.
A design governing equation, which captures the ill-structured nature of design
problem, is obtained from the axiomatic system. This equation implies that design
problem solving is a process looking for fixed points under the design function,
which is nonlinear in nature. This associates designing to nonlinear dynamics
and leads to an explanation of design creativity. In this way, the randomness
and uncertainty of design creativity could have a position in a scientific framework
with determined laws. These are the three routes to creative designs presented
in the thesis. To illustrate and test the ideas in this theory, a rivet setting
tool design case study is used throughout the thesis. This thesis also presents
a mechanism design software developed based on the principles implied in the established
theory. The software automatically generates multiple design concepts for changing
straight-line motions merely with the performance knowledge. This software prototype
demonstrates the usefulness of the theory in the development of conceptual design
tools in aiding design engineers. | |
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