identifier: Razi, Mohammad  (2014) Analysis of Rotor Dynamics Acceptance Criteria in Large Industrial Rotors.  Masters thesis, Concordia University.

abstract:
Rotating machinery is extensively used in the industry today. The dynamics of rotating machines and the critical issues associated with them have been the principal focus of a large part of the research and development in industry in recent times. The rotating machines are one of the most essential components of machinery in industry as they play a vital role in the process of transferring power from one place to another.
The assemblies of the important industrial machinery such as gas turbines, compressors, hydroelectric systems, locomotives, vehicles etc. are made of different rotating parts. Therefore it becomes necessary to analyze the dynamic behavior of the rotating systems in order to understand the level of stresses to which these components are subjected to during their operation. This pre-design phase analysis can greatly contribute to the trouble shooting of the critical issues. However, the dynamic behavior of rotating machinery is quite complex which necessitates the need for understanding the mechanics behind the operation of these devices thoroughly. The complexity of the analysis increases further whenever there is an unbalance in the rotating components which leads to an undesirable whirling response. The gyroscopic effects present in the rotating disks amplify at higher rotating speeds of shafts thereby inducing some undesirable stresses in the components. Due to the complexity of these rotating structures, they are subjected to stresses during the industrial processes. So, it becomes necessary to perform the vibration analysis for predicting their behavior prior to their application phase. This analysis would be of great aid in determining the natural frequencies and the associated mode shapes of the system. Initially, a free vibration analysis is carried out which is followed by the forced vibration analysis to predict their behavior when subjected to the excitations arising from the residual unbalance and any other external excitations.
The primary goal of this dissertation is to analyze the dynamic behavior of the industrial rotors and address the critical issues associated with them. Initially, a simple Jeffcott rotor is analyzed in detail to determine its natural frequencies, critical speeds from the Campbell diagram, the forward and backward whirl modes. This is followed by the analysis of an actual industrial rotor in ANSYS in order to understand its dynamic behavior which involves the detailed analysis of the Campbell diagrams, critical speeds, effect of the gyroscopic moments etc. The phenomenon called ‘Curve veering’ was observed from the inspection of the obtained natural frequencies of the system and discussed. Campbell diagrams are obtained and critical speeds, effect of the gyroscopic moments etc. are identified and discussed.


identifier: Mashayekh, Nassim  (2013) Fabrication of Silicon Nanowires and the Effects of Different Parameters on The Fabrication Results.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract:
In today’s world everything is going toward speed and comfort. This includes different
technologies which their improvement leads to an easier life for human beings. One of these
technologies is nanotechnology that deals with fabrication and structures of objects in nanometer
scale.
Today’s technology and science has proved that nanowires are excellent candidates for
fabrication of many different devices and their components. These devices take less space while
having high performance. Nanowires are one-dimensional structures that have many applications
including a variety of sensors, transistors as well as energy-storage devices like solar cells and
Li-ion batteries.
Fabrication of nanowires is still under research and many universities and institutes are trying to
find methods that are both time- and cost-efficient. This is a challenging subject since there are
many parameters involved in the process and each of these parameters affect the final results of
fabrication.
The concentration of this work is on fabrication of silicon nanowires. Silicon is the second-most
abundant element on the earth and therefore has a more reasonable price compare to other
elements.
There are many different techniques to fabricate silicon nanowires but most of these methods are
expensive and time consuming.
In this work we have used a top-down method which is time and cost efficient compare to other
fabrication methods. There are three main steps in our work; anisotropic etching to texture the
surface of the silicon wafer, electrochemical etching to produce the nanowires and a post-etching
process in order to clean the surface of the sample. Wafer type, etching duration, temperature,
and the applied current are the parameters that are studied during the experiments. The fabricated
nanowires are captured and characterized using scanning electron microscopy.


identifier: Oyono Ngou, Polynice  (2014) Fourier methods for numerical solution of FBSDEs with applications in mathematical finance.  PhD thesis, Concordia University.

abstract: We present a Fourier analysis approach to numerical solution of forward-backward stochastic differential equations (FBSDEs) and propose two implementations. Using the Euler time discretization for backward stochastic differential equations (BSDEs), Fourier analysis allows to express the conditional expectations included in the time discretization in terms of Fourier integrals. The space discretization of these integrals then leads to expressions involving discrete Fourier transforms (DFTs) so that the FFT algorithm can be used. We quickly presents the convolution method on a uniform space grid. Locally, this first implementation produces a truncation error, a space discretization error and an additional extrapolation error. Even if the extrapolation error is convergent in time, the resulting absolute error may be high at the boundaries of the uniform space grid. In order to solve this problem, we propose a tree-like grid for the space discretization which suppresses the extrapolation error leading to a globally convergent numerical solution for the BSDE. The method is then extended to FBSDEs with bounded coefficients, reflected FBSDEs and higher order time discretizations of FBSDEs. Numerical examples from finance illustrate its performance.


identifier: Jabbari, Farzad  (2014) Modeling of Suspension Plasma Spraying.  Masters thesis, Concordia University.

title: Modeling of Suspension Plasma Spraying

abstract: Plasma Spraying is a coating process designed to deposit accelerated molten or semi-molten coating materials on prepared substrates. Suspension Plasma Spraying (SPS) is one type of Plasma Spraying with enhanced characteristics. Numerical modeling of this process helps us to find optimum operating parameters such as suspension injection position and standoff distance for substrates. A three-dimensional model of a plasma spraying system with radial suspension injection is studied in this work. To model turbulent flow of plasma, Reynolds Stress Model (RSM) is utilized. In addition, Lagrangian approach is used to track particles and two-way coupling is used to consider the effect of suspension on the gas flow. It should be mentioned that when mass flow rate of suspension is very high, the plasma plume cannot melt all particles that fly near the centerline. It is found that with optimum suspension mass flow rate, in general, almost all particles flying near the centerline are melted and reach high temperature. Furthermore, the effect of angle of suspension injection is studied. One can find that angles toward the gun give more penetration of suspension in the plasma plume, resulting in better melting and higher speed of particles. Finally, particle temperature, velocity and size distributions are studied at different standoff distances with respect to the plasma gun exit.  It is shown that optimum standoff distance for the studied particles and plasma plume properties is between 3 to 6 cm. Less than 3 cm standoff distance, particles have no time to reach the melting point and the base liquid would not evaporate completely; and with more than 6 cm standoff distance, particles’ velocity will be significantly reduced. It should be mentioned that trajectory and penetration of suspension completely depends on velocity of suspension on one hand, and on the other hand temperature and velocity of the plasma plume. It is clear that for each condition, mass flow rate and velocity of plasma, the related modeling should be done to find velocity and temperature of particles.


identifier: Hosseini Rooteh, Ensieh Sadat  (2013) Tool wear monitoring for face milling process with intelligent algorithms.  Masters thesis, Concordia University.

abstract:
Today, machining processes are among the most common and important industrial operations. Considering the wide applications of the machining processes, the importance
of having an accurate and reliable monitoring system is clear. Therefore, several researches and studies have been performed to respond to this demand. Despite considerable efforts in this field, the achievement is not satisfactory and still the request for having an accurate, reliable,
automatic, inexpensive and robust monitoring algorithm is remained without a good answer. This study tries to design monitoring algorithms with aforementioned specifications.
The monitoring algorithms predict the amount of tool flank wear in the face milling process. They are designed based on the pattern recognition concept. The algorithms analyze
signals in four steps: preprocessing, feature extraction, feature selection and classification. Descriptors, wavelet transform and S-Transform are applied for feature extraction. Principal component analysis (PCA) and independent component analysis (ICA) perform the feature selection step. Neural network (NN), which is an artificial intelligence method, classifies the data and makes the algorithms intelligent. By combining these methods, five
intelligent algorithms are developed. The results show that the most accurate algorithm between these five algorithms is the combination of S-Transform, ICA and NN. Results also
confirm the good performance of S-Transform for feature extraction comparing with the wavelet transform or descriptors. Applying the best designed algorithm, the effect of sensor fusion on the accuracy of algorithm and the ability of monitoring algorithm for working in different operating conditions are studied as well. It is also shown that the accuracy of the best designed algorithm for indicating the tool status, sharp or dull, is better than the accuracy of predicting the value of the tool wear. Applying S-Transform for machining monitoring and designing five intelligent, practical, inexpensive and accurate                              algorithms for tool wear prediction can be considered as the key outcomes of this thesis.


identifier: Dawson, Travis J  (2014) Microbial Communities Transforming Dissolved Organic Matter In a Large Estuarine Ecosystem.  Masters thesis, Concordia University.

abstract: Heterotrophic bacteria are responsible for degrading dissolved organic matter (DOM), and process 50% or more of Earth’s net primary production. Although integral to global nutrient cycling, the complexity of bacterial communities makes it difficult to resolve the mechanisms by which they degrade DOM. Adding to the complexity of this interaction is the compositional diversity of DOM. The St. Lawrence Estuary (SLE) is an important repository for DOM, produced both internally by phytoplankton and externally by terrestrial plants. I aim to identify the bacterial taxa that respond to differential DOM inputs using 16S rRNA abundance as a proxy for metabolic activity. A microcosm experiment was conducted in the SLE in which marine DOM and terrestrial DOM were extracted by ultrafiltration and solid-phase extraction. DOM extracts were amended to microcosms of raw SLE water and incubated at 7°C and 25°C for 32 hours. The Gammaproteobacterial lineage Pseudoalteromonas experienced a 70% increase in metabolic activity in response to HMW marine DOM at both 7°C and 25°C, which was not observed in any other DOM treatment. Terrestrial DOM treatments resulted in a significant increase in alpha-diversity within the bacterial community at 25ºC, indicating a relative increase in the activity of rare bacteria in response to freshwater DOM. Microcosm experiments such as this aim to provide a better understanding of how DOM composition can influence bacterial community structure and metabolism. Considerations for future experiments include transcriptomics analysis to describe the metabolic pathways involved in DOM degradation.


identifier: Boateng, Stephen  (2013) C–H∙∙∙O participation in the dimer of aromatic N-sulfinylhydrazines.  Masters thesis, Concordia University.

abstract:
To assess the substituent effect on the stability of hydrogen-bonded dimers from N-phenyl-N’-sulfinylhydrazines (Ph–NH–NSO), and to confirm the suggested participation of Co–H∙∙∙O interactions in the dimer from protons in ortho position, 1H NMR (proton nuclear magnetic resonance) dilution studies were carried out on the unsubstituted and the meta- and para-methyl substituted compounds. The 1H NMR spectra of the solutions in CDCl3, recorded from the limit of detectability in dilute solution to the solubility limit, at room and low temperature, show characteristic chemical shift changes to lower field, in the resonances of the N–H as well as of the Co–H protons. Upon dilution, a dissociation equilibrium exists, and both the monomer and dimer chemical shifts, for
N–H and Co–H, can be obtained from the concentration-dependence regression curves, which allows to establish a measure of the strength of the hydrogen bonding network in the dimer through the equilibrium (dimerization or association) constant. For dimer formation using the 1H NMR data, a small substituent effect is observed in meta- and para-methyl substituted Ph–NH–NSO, whose dimers are both destabilized to approximately the same degree compared to the stability of the unsubstituted dimer. From the studies, and as had been suggested earlier from computational work, it is clear that the Co–H∙∙∙O interaction is indeed involved in the hydrogen-bonding network in the dimers of unsubstituted and methyl-substituted Ph–NH–NSO’s, based on the characteristic deshielding of the protons that are specifically involved in the hydrogen bond formation. Finally, the experimental 1H NMR results obtained show a remarkable agreement with those obtained from computational work at the density-functional theory


identifier: Prattipati, Soni  (2014) Image Compression using ITT and ICT and a Novel Variable Quantization Technique.  Masters thesis, Concordia University.

abstract:
The need for novel transform coding techniques promising improved reconstruction and reduced computational complexity in the field of image and data compression is undeniable. Currently, there is a prevalent use of the integer adaptation of the popular discrete cosine transform (DCT) with fixed quantization in the video compression domain due to its ease of computation and adequate performance. However, there cannot be a single method or technique that would not only provide maximum compression possible, but also offer the best quality for different types of images. The influence of specific features of the image, such as its structure and content, on the quality of reconstructed image after decompression cannot be ignored. This thesis intends to utilize this aspect and identify areas where an alternative to integer DCT (ICT) for image compression can be proposed. There exist polynomial-based orthogonal transforms like discrete Tchebichef transform (DTT), which possess valuable properties like energy compaction, but are potentially unexploited in comparison with DCT. This thesis examines, in detail, where DTT stands as a viable alternative to DCT for lossy image compression based on various image quality parameters. It introduces a multiplier-free fast implementation of integer DTT (ITT) of size 8×8 that significantly reduces the computational complexity.
Normally, images have detail spread across them in a non-homogenous manner. Hence, when the image is divided into blocks, some blocks might have intricate detail, whereas the amount of detail in some might be very sparse. This feature is exploited in this thesis by proposing a technique to adapt the quantization performed during compression according to the characteristics of the image block. The novelty of this variable quantization is that it is simple to implement without much computational or transmission overhead. The image compression performance of ITT and ICT, using both variable and fixed quantization, are evaluated and compared for a variety of images. Eventually, the cases suitable for ITT-based image compression employing variable quantization are identified.


identifier: Tran, Lor Shirley  (2014) Environmental Journalism: A Case Study of the Canadian Bituminous Sands.  Masters thesis, Concordia University.

abstract: This thesis examined news content on the Albertan bituminous sands to document a Canadian contemporary issue and to improve the available conceptual frameworks for analyzing environmental issues covered in the news media. There is currently limited research on the topic from a journalistic perspective, despite a body of literature on environmental journalism that predicts (and cautions that) the environmental news coverage of bitumen will be event-driven, overly simplified, increasingly politicised and economically framed. Building on these predictions, the project uses a case study approach as a bounded illustration of environmental journalism, in combination with content analysis to reflect on the intrinsic, multifaceted and complex attributes of environmental affairs in the news coverage. A typology developed in this thesis allowed for an examination of 409 news articles from five Canadian newspapers from the years 2007 to 2009, and gave evidence: for a sustained interest from the newspapers to report on Alberta bitumen; for an evenly distributed and broad variety, albeit asymmetrical presence of news sources that favored politicians, industrial and environmental interests; and for the presence of multiple types of information in the examined news, though concentrated mostly on economic aspects of bitumen, and lesser on ecological, political, scientific and other dimensions.


identifier: Sadid, Md Waselul Haque  (2014) Quantitatively-Optimal Communication Protocols for Decentralized Supervisory Control of Discrete-Event Systems.  PhD thesis, Concordia University.

abstract:
In this thesis, decentralized supervisory control problems which cannot be solved without some communication among the controllers are studied. Recent work has focused on finding minimal communication sets (events or state information) required to satisfy the specifications. A quantitative analysis for the decentralized supervisory control and communication problem is pursued through which an optimal communication strategy is obtained. Finding an optimal strategy for a controller in the decentralized control setting is challenging because the best strategy depends on the choices of other controllers, all of whom are also trying to optimize their own strategies. A locally-optimal strategy is one that minimizes the cost of the communication protocol for each controller. Two important solution concepts in game theory, namely Nash equilibrium and Pareto optimality, are used to analyze optimal interactions in multi-agent systems. These concepts are adapted for the decentralized supervisory control and communication problem.

A communication protocol may help to realize the exact control solution in decentralized supervisory control problem; however, the cost may be high. In certain circumstances, it can be advantageous, from a cost perspective, to reduce communication, but incur a penalty for synthesizing an  approximate control solution. An exploration of the trade-off between the cost and accuracy of a decentralized discrete-event control solution with synchronously communicating controllers in a multi-objective optimization problem is presented. A widely-used evolutionary algorithm (NSGA-II) is adapted to examine the set of Pareto-optimal solutions that arise for this family of decentralized discrete-event systems (DES).

The decentralized control problem is synthesized first by considering synchronous communication among the controllers. In practice, there are non-negligible delays in communication channels which lead to undesirable effects on controller decisions. Recent work on modeling communication delay between controllers only considers the case when all observations are communicated. When this condition is relaxed, it may still be possible to formulate communicating decentralized controllers that can solve the control problem with reduced communications. Instead of synthesizing reduced communication protocols under bounded delay, a procedure is developed for testing protocols designed for synchronous communications (where not all observations are communicated) for their robustness under conditions when only an upper bound for channel delay is known.

Finally a decentralized discrete-event control problem is defined in timed DES (TDES) with known upper-bound for communication delay. It is shown that the TDES control problem with bounded delay communication can be converted to an equivalent problem with no delay in communication. The latter problem can be solved using the algorithms proposed for untimed DES with synchronous communication.


identifier: Enns, Leah N.  (2013) Emotional Flexibility and Shared Expressions in High-Risk Dyads: Unpacking the Processes Underlying Mother-Child Nonverbal Emotion Communication in Middle Childhood.  PhD thesis, Concordia University.

abstract:
The present dissertation was designed to unpack the moment-to-moment processes of mother-child nonverbal interactions during middle childhood. Through innovative methodological and statistical procedures, the structure (emotional flexibility) and content (expressions) of positive, neutral, and negative processes underlying nonverbal emotion communication between mothers and their school-age children were captured.
Participants were mothers and their 9- to 13-year-old children (Study 1: n = 51; Study 2; n = 75) from the Concordia Longitudinal Risk Project: a prospective, intergenerational study of high-risk children from disadvantaged neighbourhoods. Boys and girls from the Concordia Project (the mothers in this dissertation) were rated on measures of aggression and social withdrawal in childhood and followed into parenthood.
Observational measures were used to code moment-to-moment displays of mother and child nonverbal behaviors (e.g., facial expressions, eye movements, gestures, vocalizations) during videotaped conflict (Study 1) and game-playing (Studies 1 and 2) tasks. Study 1 included positive, neutral, and negative facial expressions, while Study 2 clustered discrete nonverbal behaviors into positive and neutral nonverbal emotion communication constructs (Enjoyment, Enthusiasm, and Engagement).
Results from Study 1 indicated that mothers’ childhood histories of aggression predicted less maternal emotional flexibility and shorter durations of shared expressions. Similarly, mothers’ childhood histories of aggression and withdrawal predicted less maternal flexibility. Mothers and children with greater emotional flexibility shared longer durations of positive expressions. Furthermore, greater child emotional flexibility, longer positive expressions, and shorter negative expressions were associated with better mother-child relationship quality and fewer child behavior problems. Neutral expressions were found to be adaptive for the conflict task but maladaptive for the game-playing task. Results from Study 2 indicated that, in general, greater dyadic or individual flexibility (more transitions, greater dispersion, less average mean duration) was related to more frequently shared enjoyment, enthusiasm and engagement. Similarly, greater flexibility was associated with longer durations of enjoyment and enthusiasm, but shorter engagement. Results from comparison analyses varied based on the valence of the nonverbal emotion behaviors and whether the flexibility variables were dyadically or individually measured.
Results highlight the need for detailed examination of the emotional flexibility and expressions displayed during mother-child interactions to better understand the mechanisms underlying how (dys)functional relationships are perpetuated across development.


identifier: Akhshi, TK  (2013) Identifying Cues that Regulate the Position of the Contractile Ring during Cytokinesis.  Masters thesis, Concordia University.

abstract: Cytokinesis is the process where a mother cell cleaves into two daughter cells and is driven by the constriction of an actomyosin ring. Formation and ingression of the contractile ring is regulated by the mitotic spindle to couple cytokinesis with the segregation of sister chromatids. The central spindle forms in anaphase and recruits Ect2, a GEF that activates RhoA, for F-actin polymerization and nonmuscle myosin activation to assemble the ring in the equatorial plane. However, the molecular mechanism that regulates the localization of contractile proteins is poorly understood. For example, astral microtubules exclude the localization of contractile proteins at the polar cortex, but the molecular pathway is not known. Furthermore, other cues likely regulate the localization of contractile proteins at the polar cortex. In this study, I investigated the role of chromatin in mediating the polar exclusion of contractile proteins in Hela cells. First, I measured the minimum distance between chromatin and the boundary of accumulated contractile proteins during cytokinesis in control cells, and in cells treated with different conditions that affect the central spindle and/or astral microtubules. I found that chromatin position closely correlates with the localization of contractile proteins within 3-4 µm of the cortex. This suggests that chromatin has a diffusible cue that can regulate the organization of actomyosin. I also found that over-expression of active Ran targeted to the equatorial membrane alters anillin localization and causes asymmetric furrow ingression or oscillation. In addition, inactivating Ran-GTP results in the global localization of myosin and cytokinesis phenotypes. My data supports the idea that chromatin, likely via Ran-GTP, works in combination with the central spindle and astral microtubules to ensure that the contractile ring forms at the correct time and location during cytokinesis.


identifier: Barzegar, Ali  (2014) Dynamically Reconfigurable Active Cache Modeling.  Masters thesis, Concordia University.

abstract: This thesis presents a novel dynamically reconfigurable active L1 instruction and data cache model, called DRAC. Employing cache, particularly L1, can speed up memory accesses, reduce the effects of memory bottleneck and consequently improve the system performance; however, efficient design of a cache for embedded systems requires fast and early performance modeling. Our proposed model is cycle accurate instruction and data cache emulator that is designed as an on-chip hardware peripheral on FPGA. The model can also be integrated into multicore emulation system and emulate multiple caches of the cores. DRAC model is implemented on Xilinx Virtex 5 FPGA and validated using several benchmarks. Our experimental results show the model can accurately estimate the execution time of a program both as a standalone and multicore cache emulator. We have observed 2.78% average error and 5.06% worst case error when DRAC is used as a standalone cache model in a single core design. We also observed 100% relative accuracy in design space exploration and less than 13% absolute worst case timing estimation error when DRAC is used as multicore cache emulator.


identifier: Perez Buendia, Jesus Rogelio  (2014) A Crystalline Criterion for Good Reduction on Semi-stable K3-Surfaces over a p-Adic Field.  PhD thesis, Concordia University.

abstract:
In this thesis we prove a $p$-adic analogous of the Kulikov-Persson-Pinkham classification theorem for the central fibre of a degeneration of $K3$-surfaces in terms of the nilpotency degree of  the monodromy of the family \citep{Persson:1981wp}.

 Namely, let $X_K$ be a be a smooth, projective $K3$-surface which has a minimal semistable model $X$ over $\mcal O_K$.
 If we let $N_{st}$ be the monodromy operator on $D_{st}(H^2_{\et}(X_{\oln K},\Qp))$, then we prove that the degree of nilpotency of $N_{st}$ determines the type of the special fibre of $X$. As a consequence we give a criterion for the good reduction of the semi-stable $K3$-surface $X_K$ over the $p$-adic field $K$ in terms of its $p$-adic representation $H^2_{\et}(X_{\oln K},\Qp)$, which is similar to the criterion of good reduction for $p$-adic abelian varieties and curves given by \citep{Coleman:1997vg} and \citep{Iovita:2013ts}.


identifier: Acemian, Nancy  (2013) The impact of learner-controlled blended instruction on academic achievement: A mixed method exploratory case study.  PhD thesis, Concordia University.

abstract:
ABSTRACT
The impact of learner-controlled blended instruction on academic achievement:
A mixed method exploratory case study
Nancy Acemian, Ph. D
Concordia University 2013

To date blended learning designs for university courses range from complementing the face-to-face class experience to replacing parts of the face-to-face contact time with online modules. The design is usually set by the instructor and/or instructional designer of the course and all students use the prescribed model. In introductory courses, typically first year courses, students’ prior knowledge of the course topic range from limited to substantial, especially in a computer programming course. Having all students in such a course confined to the same course structure is unlikely to respond to differential student needs. The design proposed and studied in this research paper thus deviates from this approach. The face-to-face course was supplemented by lecture capture and a number of learning objects available online for students to use whenever and wherever they want. Students chose to attend or not attend classes, and chose which online tools to use and when. That is, they could switch throughout the term between being a face-to-face student or a blended/hybrid student based on their varying learning needs at different points in the term. They only needed to be present for summative evaluations.
The study was exploratory in nature, looking at the relationship between students’ attendance records and their use of the online learning tools with their performance on summative evaluations. By examining the most successful usage patterns, the goal was to establish guidelines for students on how to best study in an introductory computer programming course.
The results showed that the attendance was not greatly affected by the availability of the lecture capture and learning tools online. Students initially used the online tools to supplement the in-class experience but not to replace it. Of the resources available online, the most popular was the lecture capture (a passive information tool) followed by the formative evaluation quizzes (an active cognitive tool). Students’ usage pattern of the tools changed during the term. Most students started off as a predominantly face-to-face student but many switched to being hybrid or blended learners. Many students never used the online environment and remained face-to-face learners. Of those who did use the online tools, three usage patterns emerged: the distributed user, the massed user and the one-time user. Results show that the distributed user significantly outperformed the massed users. The non-users, of which many had prior programming experience, also outperformed the massed users.
A secondary focus of this research was the role that math background played on the performance of students in the course. The literature addressing this issue yielded contradictory results, ranging from having no impact to giving an edge. While no relationship was found with math background and achievement, student’s ability to follow instructions, one of the skills tested for in the thinking skills measure, was a significant indicator of performance. Overall, the wide variability in use of the online learning environment demonstrated that this pedagogical model can effectively attend to differing needs of a heterogeneous student population. Encouraging students with low prior knowledge to make frequent use the online tools emerged as a recommendation for instructors and students alike.


identifier: Tayari, Vahid  (2014) Quantum charge transport in 10-nanometer scale suspended graphene transistors.  PhD thesis, Concordia University.

abstract:
Since the discovery of graphene there has been a growing interest in fabricating and studying nanometer scale graphene devices for future nanoelectronic applications.
We developed a nanoetching technique called electromigration to fabricate approximately 10 nm scale suspended and clean graphene quantum dots (QD) and ballistic transistors. Because these devices are so small, we were able to explore the fundamental quantum properties of their relativistic-like charge carriers.
Using our electromigration technique, we tailored the shape and size of suspended graphene channels, forming ultra-short devices which behave as graphene QDs if they are narrow (approximately 30 nm) or ballistic transistors if they are wider (approximately 100 nm). Our approximately 30x30 nm suspended graphene QDs are, to our knowledge, the smallest suspended graphene QDs made to date. We measured electron transport across these devices and observed a variable charging energy as a function of the charge occupation of the dot, as expected due to the chaotic billiard transport of Dirac fermions. We observed signatures of electron-vibron (e-v) coupling in our suspended QDs and measured their self-actuated out-of-plane vibron resonances (bending mode), whose frequencies range up to 100 GHz.
We used a gold film to locally gate graphene and create ultra-short p-n junctions. We fabricated approximately 20-100 nm long suspended graphene ballistic transistors and measured n-p-n junctions (down to approximately 10 nm p-n junctions). We observed coherent ballistic transport in agreement with the theory of Dirac fermions, and measured Fabry-Perot interferences in our devices. We measured coherence lengths up to approximately 700 nm in our graphene transistors, which is much longer than the length of the channels
of the transistors. This showed that the graphene contacts (gold covered) are also ballistic.
The fabrication method we developed to make ultra-short suspended graphene devices, combined with the observation of clear signatures of quantum coherent transport, opens the way to explore graphene physics and applications at the 10 nm scale.


identifier: Elayan, Abdallah Muneer  (2013) Robust Watermarking Schemes for Digital Images.  Masters thesis, Concordia University.

abstract:
With the rapid development of multimedia and the widespread distribution of digital data over the internet networks, it has become easy to obtain the intellectual properties. Consequently, the multimedia owners need more than ever before to protect their data and to prevent their unauthorized use. Digital watermarking has been proposed as an effective method for copyright protection and an unauthorized manipulation of the multimedia. Watermarking refers to the process of embedding an identification code or some other information called watermark into digital multimedia without affecting the visual quality of the host multimedia. Such a watermark can be used for several purposes including copyright protection and fingerprinting of the multimedia for tracing and data authentication.
The goal in a watermarking scheme is to embed a watermark that is robust against various types of attacks while preserving the perceptual quality of the cover image. A variety of schemes have been proposed in the literature to achieve these goals for watermarking of images. These schemes either provide good imperceptibility of the watermark without sufficient resilience to certain types of attacks or provide good robustness against attacks at the expense of degraded perceptual quality of the cover images. The objective of this work is to develop image watermarking schemes with performance that is superior to those of existing schemes in terms of their robustness against various types of attacks while preserving the perceptual of the cover image. In this thesis, two new digital image watermarking schemes are proposed.
In the first scheme, an Arnold transform integrated DCT-SVD based image watermarking scheme is developed. The main idea in this scheme is to improve the robustness of the watermarking further by scrambling the watermark data using the Arnold transform while still preserving the good perceptibility of the watermarked image furnished by a DCT-SVD based embedding. Also, it is shown that considerable savings in the computation time to recover the original watermark image can be provided by using the anti-Arnold transform in the watermark extraction process.
In the second scheme, a DWT-SVD digital image watermarking scheme that makes use of visual cryptography to embed and extract a binary watermark image is developed. The use of visual cryptography in the proposed watermarking scheme is intended to provide improved robustness against attacks along with furnishing security to the content of the embedded data.
Extensive experiments are conducted throughout this investigation in order to examine the performance of the proposed watermarking schemes. It is shown that the two proposed watermarking schemes developed in this thesis provide a performance superior to that of the existing schemes in terms of robustness against various types of attacks while preserving the perceptual quality of the cover image.


identifier: Mousavi, Seyed Milad  (2014) Numerical study of Effervescent atomization.  Masters thesis, Concordia University.

abstract:
Atomization is a process where the bulk of liquid jet disintegrates into liquid sheets, ligaments and droplets. It has enormous applications in industries and processes such as combustion, heat transfer systems, transport, biological systems and particularly our interest, coating processes. The Effervescent nozzle is a type of twin-fluid atomizer and has shown a superior performance in handling and spraying different liquids without any clogging issues; which is particularly interesting in thermal spray. In spite of significant number of experimental works, a few numerical works have been carried out. That makes it crucial to conduct a comprehensive numerical study on Effervescent atomizer.
The complex internal and external behaviors of Effervescent atomizer are governing the behavior of the flow. The latter is a turbulent and compressible multiphase flow. It is studied numerically by employing a three-dimensional compressible Eulerian method along with Volume of Fluid (VOF) surface-tracking method coupled with the Large Eddy Simulation (LES) turbulence model. The numerical study is conducted by using OpenFoam library, an open-source package introduced by Open-CFD.
In this study, the effect of varying the gas to liquid ratio (GLR) and the suspension (i.e. effect of viscosity, density and surface tension), on the structure of internal flow and consequently, the external flow is studied numerically. It is observed that the increase in GLR is accompanied with an evolution of the internal flow from a complex bubbly flow to an annular flow. This reduces the liquid film thickness at the discharge orifice. Further studies on internal pressure illustrated the critical condition, choked flow and pressure oscillations at the discharge orifice. The examination of increasing the GLR and evolving of internal flow resulted in changing in primary atomization parameters such as shortening the breakup length and widening the spray cone angle. Furthermore, the existence of a slip velocity between the two phases in the external flow results in dominant aerodynamic forces at high GLRs. Moreover, alternation of the liquid properties illustrated the higher spray velocity and wider cone angle of the spray, which demonstrates the superior performance of the Effervescent atomizer.


identifier: Alameddine, Wafic  (2013) Energy efficient relay selection schemes for cooperative uniformly distributed wireless sensor networks.  Masters thesis, Concordia University.

abstract:
Wireless sensor networks (WSNs) are commonly used in many applications. The energy efficiency of the system has become the subject of extensive research lately. In this thesis we will introduce relay selection schemes that attempt to optimize the transmission of data. We use a two phase WSN model where a message is broadcasted from the source then relayed by the overhearing sensors (nodes) to a fusion center (FC). These schemes will reduce the number of bits transmitted from the sensors to the destination as well as minimize the activity of these sensors and lead to a more energy efficient system. The main idea is to have the smallest subset of sensors that contain the entire information relay the message; in an ideal situation the subset will only contain a pair of sensors.

We then investigate the addition of error correcting codes (ECCs) to the node-FC channels. We observe the outage probability of the relay selection schemes using turbo codes on the node-FC channels. We also examine the expected number of bits (including extra parity bits) in the transmissions. We show that under certain channel conditions introducing turbo codes to the node-FC channels leads to longer sensor lifetimes.


identifier: Gasse, Michael  (2014) The Tannase Gene: Metaphylogenomics, Global Distribution and Presence in the Midgut Flora of the Forest Tent Caterpillar Malacosoma disstria Hübner.  Masters thesis, Concordia University.

abstract:
Tannase enzymes hydrolyze tannins, a class of plant polyphenolics that defend against herbivory. Prior to the 1980’s, most studies were focused on the tannase gene in fungi owing to the interest surrounding their industrial value. Since then a large number of bacterial tannase genes have also been discovered. I performed phylogenetic analysis on 110 fungal and bacterial tannase reference sequences in an effort to observe the relationships between fungal and bacterial tannase. The generated maximum likelihood tree shows eight strongly supported tannase clades, with a rift among fungal tannases, which either align with proteobacterial tannase or actinobacterial tannase. Metagenomes were used to assess the biogeographical distribution of the tannase clades, revealing that they may have environmental specificity.

An unpublished observation made by the Despland lab of Concordia University suggested that forest tent caterpillars (Malacosoma disstria) from western Canada are unable to survive on tannin-rich sugar maple foliage (Acer saccharum), whereas populations in eastern Canada develop on sugar maple. In Chapter 2 I examine this observation, and explore the possibility of tannase-expressing secondary symbionts in eastern M. disstria. For the first time, the microbiome of M. disstria has been described using 16S rRNA gene sequencing and is shown to contain several genera known for expressing the tannase gene.


identifier: Ronis, Eric  (2013) The Demands of Character: Performances of Authenticity and Virtue in Marginalized Group Street Protests 1976-2000.  PhD thesis, Concordia University.

abstract:
This dissertation investigates the means of persuasion available to marginalized identity groups who protest against the state. “Performances of authenticity and virtue” provide one theoretical framework to explain how a group’s very identity as “marginalized other” can be leveraged rhetorically for claim-making against the state and as a way of creating social/political change. Protest groups frequently harness the power of radical street performance. Because of the theatricality of the protest, a focus on “character” rather than “identity” seems more appropriate. An audience’s judgment of protestor character as “authentic” or “virtuous” requires a horizon against which such evaluation can occur. The street performances therefore require recognizable character “types,” characters inherited from various cultural narratives, and such characters make their own demands on the protestors. Aristotle’s treatment of character as rhetorical ethos (Rhetoric), as dramatis persona (Poetics), and as one’s virtuous or vicious nature (Nichomachean Ethics) serves as a basic division, structurally, in this thesis. Stanislavski’s approach to theatrical performance offers insights into how the inhabiting of character and meeting the demands of a script function for protests. His premises that actors need to be in belief and fully committed to their performances are vital to successful performances of authenticity. Erving Goffman, in sociology, relies on these same premises. Special emphasis is placed on the tactics used by protestors–these are their rhetorical pisteis, the appeals that actually persuade the audience. These tactics are intimately tied to the identities and specific situations of the protestors themselves. There is a clear connection between ethos and logos. I apply Burke’s concept of “impious rhetoric” here. The sense of “what goes with what” is violated according to the rules of the public sphere, but justified in another sense by the collective character of the protesting group.
This dissertation represents an intersection among three academic areas: rhetoric, theatre and sociology. Concepts from one discipline help solve theoretical problems and fill in lacunae existing in the other disciplines.


identifier: Voruganti, Aravind  (2014) Assigning and Scheduling Partially Overlapping Channels in Wireless Mesh Networks.  Masters thesis, Concordia University.

abstract:
The design and the management of Wireless Mesh Networks (WMNs) are currently associated with the most active research area within the current wireless networking paradigms. WMNs inherit features from existing wireless networking technologies such as WLANs, mobile ad hoc networks. Because WMNs are easy to deploy and with low power consumption, there is a phenomenal growing interest in seeing WMNs as the next wireless backhaul networks, and an alternative to the existing wired infrastructure.

The earliest development of WMNs had begun with single-channel single-radio mesh networks. This technology then evolved towards multi-channel single-radio mesh networks, and then to multi-channel multi-radio mesh networks. WMNs operate in North America on IEEE 802.11 2.4 GHz spectrum, which provides up to 11 channels. Despite the availability of 11 channels, only 3 (1, 6, 11) orthogonal channels can be used concurrently. The efficiency of multi-channel multi-radio wireless mesh networks can be improved with the increase of the number of channels used concurrently and of multiple radios. In this study, we investigate how to design a scalable channel assignment and a scheduling algorithm, which both exploit partially overlapping channels in order to increase the throughput in comparison with the one that can be obtained only using three orthogonal channels. In order to accurately take into account the radio interferences, we use the physical interference model to estimate the interferences among wireless links. We then introduce the definition of transmission configurations, which are sets of links, which can transmit concurrently. These links can be assigned with channels of overlapping or orthogonal in nature. We then design a TDMA based scheduling allowing a transmission configuration to transmit concurrently in a time slot.

Finally, we evaluate all our algorithms through extensive simulations. Our numerical experiments show that we can gain up to 25% for the throughput by appropriately managing all the available channels.


identifier: Aissiou, Tayeb  (2013) Determinants of Pseudo-Laplacians on compact Riemannian manifolds and uniform bounds of eigenfunctions on tori.  PhD thesis, Concordia University.

abstract: In the first part of this thesis, we derive comparison formulas relating the zeta-regularized determinant of an arbitrary self-adjoint extension of the Laplace operator with domain consisting of smooth functions compactly supported on the complement of a point $P$, to the zeta-regularized determinant of the Laplace operator on $X$. Here  $X$ is a compact Riemannian manifold of dimension 2 or 3; $P\in X$. In the second part, we provide a proof of a conjecture by Jakobson, Nadirashvili, and Toth stating that on an n-dimensional flat torus, the Fourier transform of squares of the eigenfunctions $|phi_j|^2$ of the Laplacian have uniform $l^n$ bounds that do not depend on the eigenvalue $\lambda_j$. The thesis is based on two published papers that can be found in the bibliography.


identifier: Chadha, Mandeep Roshi  (2013) Inuit Art as Cultural Diplomacy between Canada and India Sanaugavut: Inuit Art from the Canadian Arctic.  Masters thesis, Concordia University.

abstract:
ABSTRACT
Inuit Art as Cultural Diplomacy between Canada and India
Sanaugavut: Inuit Art from the Canadian Arctic
On the 27th of September, 2010 an exhibition of Inuit Art entitled Sanaugavut: Inuit Art from the Canadian Arctic, organized by the National Gallery of Canada, opened at the National Museum of India. Canada gained visibility with the Indian public as well as an international audience as the inauguration of Sanaugavut coincided with the opening of the Commonwealth Games in India.
An exploration of Sanaugavut contributes to the understanding of the way that Inuit art, as an artform and through the medium of exhibition, has been used by the Canadian government in furthering political and economic aspirations. The focus of this thesis then, is the study of the use of Inuit art in cultural diplomacy internationally and specifically in the case of Sanaugavut, between Canada and India.
Cultural diplomacy can be defined as an opportunity to foster mutual understanding by presenting cultural knowledge and furthering an understanding of a nation. The opportunity is the essence of the ‘soft power’ of an exhibition - its ability to present the mood of the country, providing an awareness of the characteristics of its societies and a landscape in which its politics operate. Sanaugavut, as an example of soft-power, was used as a tool in the promotion of Canada’s nationhood.


identifier: Stoenescu, Stefan  (2013) Optical Characterization of Plasmonic Anisotropic Nanostructures by Modeling and Spectroscopic Verification.  PhD thesis, Concordia University.

abstract: This thesis attempts to characterize the optical properties of plasmonic anisotropic nanostructures through modeling and verification. Two nanostructures with important applications are selected for characterization. First, uniaxially aligned gold nanorods (AuNRs) embedded in polyvinyl alcohol (PVA) films are realized by determining suitable heating conditions during stretching, using PVA of high molecular weight mixed with plasticizer to improve the plastic deformability, and stretching the composite film. A high stretch ratio of seven is attained and the induced alignment of the rods is quantified statistically by an order parameter of 0.92 and an average angle of 3.5°. The stretched composite film is shown to have dichroic optical properties, which confirmed the good alignment. Since the statistical quantification requires destructive examinations, a novel non-destructive method is developed based on a probabilistic approach, computational simulations, and spectrometric measurements. The new method yields results in agreement with the statistical method and applies to all dichroic particles. The second nanostructure is a gold nanostar (AuNS) – polydimethylsiloxane (PDMS) composite platform. This nanostructure is characterized by using a typical AuNS of average dimensions and idealized as consisting of a sphere and radially oriented truncated cones representing its core and branches. Using branches defined parametrically by their number, length, aperture angle and orientation, and gradually attaching branches to a core, their ensemble spectra of increasing complexity are simulated. The absorptive contribution of each component is analyzed, demonstrating the large tunability of the AuNS and allowing for finding the most effective way to tune its fundamental resonant excitation. Using plasmon hybridization theory, the plasmonic interaction between structural elements is demonstrated in three different geometries.


identifier: Leonard, Charles Patrick Thomas  (2014) A Twisted Frame: Gu Xiong's Barricade of Bicycles (1991), Dissident Pop and The National Gallery of Canada.  Masters thesis, Concordia University.

abstract: The acquisition of artwork by national institutions may heighten the relationship between a nation's publics and its domestic culture. However, such acquisitions are not devoid of an interpretive process in which dominant discourses guide institutionalization. This thesis examines the National Gallery of Canada's 1996 accession of Chinese-born Canadian artist Gu Xiong's Barricade of Bicycles, June 4, 1989 (1990) as situated within a complex set of values that were conferred to the work by the institution through the processes of selection, accession and exhibition. Originally presented as part of an installation, the ink and acrylic on paper contour drawing was the first work by a Chinese contemporary artist purchased for the National Gallery's permanent collection. The figurative style of the drawing typifies currents of 1980s Chinese modernism and Political Pop. This thesis argues that the acquisition of Barricade of Bicycles, June 4, 1989 privileged the object's political content because of the global awareness of China's complex socio-political and cultural conditions following the 1989 Tiananmen Square massacre. The thesis begins with a description and exhibition history of Barricade of Bicycles in relation to its contexts of production and the artist’s migration story. The following section considers the reception of contemporary Chinese art in Western contexts. Focusing on Political Pop and the theme of destruction in relation to Xiamen Dada, it proposes the term “Dissident Pop” to refer to these discussions. The thesis concludes with a consideration of the Gallery’s purchase in relation to these contexts as well as the politics of representation and Canada’s foreign policy at the time of the work’s acquisition.


identifier: Saffari Farsani, Mahdi  (2013) Structural Health Monitoring of Truss Structures Using Statistical Approach.  Masters thesis, Concordia University.

abstract:
Structural Health Monitoring (SHM) has drawn attention of many researchers recently. The reason is its huge effect on reduction in maintenance costs as well as increasing reliability of mechanical devices.
In this thesis the concept of SHM is explained and a damage detection methodology is proposed using Auto Regressive (AR) parameters for truss type structures.
The AR parameters of a healthy case are assumed to be the reference baseline data. A Damage Index is then defined to be the standard deviation of any other unknown signal from the baseline data. The proposed index provides an effective tool to detect the damage in the structure.
Sensor arrangement optimization has been performed as another part of this thesis which is a study on finding the optimum sensor arrangement to interrogate the most useful data given a limited number of sensors.
The localization process needs data classification techniques and has been conducted using Support Vector Machine (SVM) in this research for the first time. It is shown that SVM can successfully classify different signals that are extracted from a 3D sample truss structure. This accomplished through generating large sets of simulated data forwarded to SVM tool to construct a Meta model which further is used to predict the unknown signals and find the most correlated “known” category and reports its case label as the best match for the “unknown” signal.
At the end, an extensive sensitivity analysis has been performed to study the effect of parameter changes to the detection and localization processes.


identifier: Taheri, Siavash  (2014) Steering Control Characteristics of Human Driver Coupled with an Articulated Commercial Vehicle.  PhD thesis, Concordia University.

abstract:
Road safety associated with vehicle operation is a complex function of dynamic interactions between the driver, vehicle, road and the environment. Using different motion perceptions, the driver performs as a controller to satisfy key guidance and control requirements of the vehicle system. Considerable efforts have been made to characterize cognitive behavior of the human drivers in the context of vehicle control. The vast majority of the reported studies on driver-vehicle interactions focus on automobile drivers with little or no considerations of the control limits of the human driver. The human driver's control performance is perhaps of greater concern for articulated vehicle combinations, which exhibit significantly lower stability limits. The directional dynamic analyses of such vehicles, however, have been limited either to open-loop steering and braking inputs or simplified path-following driver models. The primary motivations for this dissertation thus arise from the need to characterize human driving behavior coupled with articulated vehicles, and to identify essential human perceptions for developments in effective driver-assist systems and driver-adaptive designs.
In this dissertation research, a number of reported driver models employing widely different control strategies are reviewed and evaluated to identify the contributions of different control strategies as well as the most effective error prediction and compensation strategies for applications to heavy vehicles. A series of experiments was performed on a driving simulator to measure the steering and braking reaction times, and steering and control actions of the drivers with varying driving experience at different forward speeds. The measured data were analyzed and different regression models are proposed to describe driver’s steering response time, peak steer angle and peak steer rate as functions of driving experience and forward speed.
A two-stage preview driver model incorporating curved path geometry in addition to essential human driver cognitive elements such as path preview/prediction, error estimation, decision making and hand-arm dynamics, is proposed. The path preview of the model is realized using near and far preview points on the roadway to simultaneously maintain central lane position and vehicle orientation. The driver model is integrated to yaw-plane models of a single-unit vehicle and an articulated vehicle. The coupled driver-articulated vehicle model is studied to investigate the influences of variations in selected vehicle design parameters and driving speed on the path tracking performance and control characteristics of the human driver. The driver model parameters are subsequently identified through minimization of a composite cost function of path and orientation errors and target directional dynamic responses subject to limit constraints on the driver control characteristics. The significance of enhancing driver's perception of vehicle motion states on path tracking and control demands of the driver are then examined by involving different motion cues for the driver. The results suggest that the proposed model structure could serve as an effective tool to identify human control limits and to determine the most effective motion feedback cues that could yield improved directional dynamic performance and the control demands. The results are discussed so as to serve as guidance towards developments in DAS technologies for future commercial vehicles.


identifier: Danila, Nicolae Ionel  (2013) NUMERICAL MODELING AND DESIGN OF LOW-RISE CONCENTRICALLY BRACED FRAMES WITH DOUBLE-PIN DISSIPATIVE CONNECTIONS.  Masters thesis, Concordia University.

abstract:
Concentrically braced frames, CBFs, are the most popular systems used in seismic areas in Canada, due to their large stiffness. However, after braces buckle in compression, their stiffness is significantly reduced and their hysteresis response, displayed in terms of force-displacement, shows an asymmetric behavior. To overcome this drawback, researchers proposed to add fuses that were conceived to be installed either in braces or brace-to-frame connections. The purpose of these fusses is to dissipate the earthquake input energy, while preserving braces to respond in elastic range. In this thesis, a new type of fuse, designed to be installed in brace-to-frame connections, is proposed. This device is labeled dissipative pin connection. Depending on the level of axial tension/ compression force that has to be transferred from the brace to the connection, this device can be manufactured in single-pin, double-pin and multi-pin configurations.
The objective of this thesis was two-fold: i) to develop design rules for double-pin connections displayed in-line and in-parallel and ii) to study the seismic response of a 4-storey CBF building with and without dissipative connections, located in Victoria, BC.
In this thesis, the computations were carried out by means of OpenSees (open system for earthquake engineering simulation). The numerical model developed for single-pin connection was calibrated based on experimental tests carried out at the Technical University of Lisbon. Similarly, the double-pin connection was calibrated using the same approach. Based on experimental test results conducted on single pin connections, design rules were proposed. It was concluded that by doubling the pin member and employing the parallel configuration, the load-carrying capacity of the dissipative connection increases two times, while the deflection is similar to that experienced by an equivalent single-pin device.
The second part of this thesis emphasizes comparative results, in terms of seismic response of a 4-storey CBF building with and without dissipative connections.  Building design was conducted according to S16-2009 and NBCC 2010 provisions. The seismic response was studied under two sets of ground motions that are representative for Victoria, BC: crustal and subduction events.
The results have shown that forces generated in structural members were reduced due to an increase in building period and system ductility. Thus, by lowering the axial force developed in the CBF columns, a reduction of foundation size can be achieved which implies reduction in the overall building cost. The effect of earthquake type on the building response is also discussed. However, to prove the efficiency of double-pin connections displayed in-line and in-parallel, further experimental tests are required.


identifier: Roofigari Esfahani, Narges  (2013) Control and Fault Accommodation for Attitude Control Subsystem of Formation Flying Satellites Subject to Constraints.  Masters thesis, Concordia University.

abstract:
Stringent precision requirements, communication limitations and automated fault accommodation are three important considerations that need to be taken into account in design of formation control of satellites. In this work a more accurate relative state modeling for the attitude dynamics is developed and a semi-decentralized control strategy is proposed that is accomplished by the model predictive control (MPC) scheme. The proposed MPC incorporates the effects of the actuator constraints in design of the control laws. Furthermore, a semi-decentralized active system recovery scheme is proposed that uses on-line fault information to compensate for the identified characteristics losses under actuator fault conditions.

Simulation results for a team of four satellites in formation are presented and the formation precision is compared with the centralized scheme. The results verify that the proposed semi-decentralized strategy yields a quite satisfactory formation performance in a sense that the team behaves similar to a centralized MPC control scheme, however without imposing significant computational complexity that is associated with solving the problem of high dimension with stringent communication requirement as in the centralized scheme.

Moreover, the performance of our proposed semi-decentralized recovery scheme is compared with the centralized recovery scheme subject to the reaction wheel (RW) faults in the attitude control subsystem (ACS) of the formation flying satellites. The proposed semi-decentralized recovery scheme satisfies the formation recovery specifications and also imposes lower fault compensation control effort cost as compared with the centralized recovery scheme. It has been validated through multiple fault severity scenarios.


identifier: Setayeshgar, Shayan  (2014) Improving Safety on Construction Sites Using BIM-Based Dynamic Virtual Fences and Ultra-Wideband Technology.  Masters thesis, Concordia University.

abstract: The identification of potential accidents on construction sites has been a major concern in the construction industry and it needs a proactive safety plan to reduce the risk of accidents. There are no efficient methods for checking if safety measures are taken properly on construction sites. Consequently, workers on site are not given enough awareness about dangerous areas. In addition, construction sites are dynamic and on-site situations are changing in terms of permanent and temporary structures and facilities.  This information can be represented using Building Information Modeling (BIM). The present research aims to investigate a new method for the automatic generation of Dynamic Virtual Fences (DVFs) as part of a BIM-based prevention program for construction safety following the Safety Code of Quebec Provence in Canada. First, the Safety Code is reviewed to identify the information that has spatial aspects and can be represented in BIM. Then, a method is proposed for automatic identification of falling and collision risks to generate DVFs for them. In this method, workspaces are generated in BIM based on Work Breakdown Structure (WBS) deliverables, the project schedule, the dimensions of equipment, and the geometry of the building. One set of DVFs for collision prevention is generated based on the defined workspaces. Another set of DVFs is generated where physical barriers are needed for fall prevention. The generated DVFs are used coupled with Real-time Location System (RTLS) tracking of workers and physical fences to check safety requirements and to provide safety warnings.


identifier: Altamimi, Ahmad  (2014) A Comprehensive Data Security Framework for OLAP Domains.  PhD thesis, Concordia University.

abstract:
Online Analytical Processing (OLAP) has become an increasingly important and prevalent component of enterprise Decision Support Systems. OLAP is associated with a data model known as a Cube, a multi-dimensional representation that allows for the extraction and intuitive visualization of broad patterns and trends that would
otherwise not be obvious to the user. One must note, however, that not all of the collected data should be universally accessible. Specifically, DW/OLAP systems
almost always house confidential and sensitive data — identification information, medical data, or even religious beliefs and ideologies — that must, by definition, be
restricted to authorized users. In this thesis, we provide models and algorithms for protecting the data in multi-dimensional data cube spaces.
To this end, the thesis addresses three distinct but related themes. In the opening part of this study, we propose an authentication and authorization framework
that builds upon an algebra designed specifically for OLAP domains. It relies on robust query re-writing rules to ensure consistent data access across all levels of
the conceptual data cube model. In the second part, we present a framework for controlling malicious inferences caused by unprotected access to coarser level aggregations.
Our framework prevents complicated inferences through a combination of initial query restrictions and the removal of the remaining inferences. In the final part,
we enhance the core framework with an object-oriented security design model and client side language extensions that collectively produce a more intuitive and usable
infrastructure.
The purpose of this study is to design a comprehensive end-to-end framework for OLAP security that is flexible, intuitive, and powerful. In short, the framework allows
administrators to associate security policies with an intuitive conceptual model that maps directly to the model that users see. Restrictions then can be propagated
transparently from users to all the hierarchical data. Moreover, the framework provides an automatic form of inference control that is fast enough in practice to
not affect query time.
To ground our conceptual work, we have integrated our research themes on the top of an OLAP-specific DBMS server (Sidera). Sidera gives us the opportunity to
explore performance and correctness issues that would not be possible without such direct access to a DBMS. In addition, we have evaluated its efficiency with a pair
of common industrial DBMS, a row-based DBMS (PostgreSQL) and a column-store DBMS (MonetDB). The evaluation is done using two common benchmarks (e.g., SSB and APB). The results show the ratio of checking time to execution time varies considerable, depending on the specification of the underlying query. These times are acceptable, particularly given that checking costs do not grow with data set size.


identifier: Sisley, Mélanie L.  (2013) Self-Directed Learning in the Age of Digital Networks: The Learning Patterns of Knowledge Workers in the Knowledge Economy.  Masters thesis, Concordia University.

abstract:
This dissertation presents a qualitative analysis of the self-directed learning patterns of knowledge workers within the context of digital networks. The study seeks to address some tensions that exist among educational perspectives on the use of digital networks for learning. Namely that digital networks provide more ‘authentic’ learning experiences by virtue of its quasi immediate access to information for problem solving as well as its more tailored information gathering affordances. On the opposite spectrum, digital networks are said to be diluting critical instincts, ‘herding’ users into like-minded groups and even impairing certain crucial cognitive features. In order to shed light on the debate, this study interviewed eight individuals of the knowledge working community who perform an occupation for which they have no formally recognized certification—therefore creating a natural context for self-directed learning. The
assumption was that these individuals may possess tacit skills to harness and/or mediate the features of digital learning. The participants of the study were asked to provide a ‘recipe’ or a list of ‘ingredients’ for effective self-teaching as well as describe, in general, their learning journeys. The interviews were then analyzed using a qualitative methodology to let emerge a dialectal
account of the themes that surrounded this experience. These themes were classified using Bouchard’s (2009) four-dimensional framework of learning autonomy. The model aims to characterize the elements of autonomy through the conative (motivational), algorithmic (mechanic), semantic (interpretive) and economic dimensions. While recognizing that motivation and mechanics have been the main focus of most educational research of a learning account, the
Bouchard model also includes the role of “meaning making” or the new interpretive implications of rich media as well as the mediating role of economics as a new dimensions that emerged due to digital networks. The results yielded a more comprehensive portrait of the issues that surround
learner autonomy as well as a nuanced characterization of the notion of ‘value’ of learning.


identifier: Wright, Justin  (2014) RD20/CLO3, a stress-induced calcium-binding protein, acts as a negative regulator of GPA1 in Arabidopsis through GAP activity.  Masters thesis, Concordia University.

abstract: G-protein and calcium signaling have both been shown to play a role in the response to environmental abiotic stress in plants; however, the interaction between calcium-binding proteins and G-protein signaling molecules remains elusive. This study examines the interactions between RD20/CLO3 and Gα (the alpha subunit of the G-protein complex) from Arabidopsis, and their closest homologs, Ta-CLO3 and Ta-GA3 in wheat (Triticum aestivum). Using in vitro GTPase assays, it is demonstrated that RD20/CLO3 and Ta-CLO3 have GTPase-activating protein (GAP) activity toward GPA1 and Ta-GA3, respectively, and this activity is potentiated by high calcium levels indicative of stress conditions. Phenotypic examination of mutant plants reveals a pattern of phenotypes congruent with the hypothesis of RD20/CLO3 acting as a downregulator of GPA1 activity. These findings reveal a novel role for RD20/CLO3 in regulating plant stress response. Furthermore, this work sheds light on the molecular mechanisms involved in controlling stomatal density under abiotic stress. In vivo interactions were tested through bimolecular fluorescence complementation (BiFC) with other caleosin proteins to further characterize the caleosin gene family. The work contributes to the understanding of G-protein signaling in response to environmental stress conditions.


identifier: Rafiee, Mahsa  (2014) Improving Indoor Security Surveillance by Fusing Data from BIM, UWB and Video.  Masters thesis, Concordia University.

abstract: Indoor physical security, as a perpetual and multi-layered phenomenon, is a time-intensive and labor-consuming task. Various technologies have been leveraged to develop automatic access control, intrusion detection, or video monitoring systems. Video surveillance has been significantly enhanced by the advent of Pan-Tilt-Zoom (PTZ) cameras and advanced video processing, which together enable effective monitoring and recording. The development of ubiquitous object identification and tracking technologies provides the opportunity to accomplish automatic access control and tracking. Intrusion detection has also become possible through deploying networks of motion sensors for alerting about abnormal behaviors. However, each of the above-mentioned technologies has its own limitations. This thesis presents a fully automated indoor security solution that leverages an Ultra-wideband (UWB) Real-Time Locating System (RTLS), PTZ surveillance cameras and a Building Information Model (BIM) as three sources of environmental data. Providing authorized persons with UWB tags, unauthorized intruders are distinguished as the mismatch observed between the detected tag owners and the persons detected in the video, and intrusion alert is generated. PTZ cameras allow for wide-area monitoring and motion-based recording. Furthermore, the BIM is used for space modeling and mapping the locations of intruders in the building. Fusing UWB tracking, video and spatial data can automate the entire security procedure from access control to intrusion alerting and behavior monitoring. Other benefits of the proposed method include more complex query processing and interoperability with other BIM-based solutions. A prototype system is implemented that demonstrates the feasibility of the proposed method.


identifier: Gottschall, Richard  (2014) Aligning Family Human Capital and Innovation Strategy in Family Firms.  PhD thesis, Concordia University.

abstract:
Research suggests that families control the majority of firms in most economies. The number of family firms, the many people they impact, and their differences from other types of firms make them an important economic institution to study. In such a large population of firms there is the potential for variation in behaviors and performance that stymies general theories about “family firms.” Recent reviews of the family business literature suggest the investigation of factors that moderate and mediate the influence of family-control on a firm.

The questions addressed in this study are: Does the human capital of family employees influence organizational innovation in small family firms, and if so, how?

Primary survey data was collected from a single respondent in 94 small family firms on: the number of family employees, their levels of education and years of experience working outside the family firm, their role in identifying and leading the firm’s “most-important” innovation activities (championing innovation), and the level of innovation in the small family firm. The results of this small, exploratory study should be interpreted carefully, but human capital and the championing of innovation do appear to moderate and partially-mediate family employees’ influence on organizational innovation. Significant relationships were found between lower levels of family human capital and less organizational innovation. However, higher levels of family human capital were associated with both less and more organizational innovation, resulting in insignificant relationships. The directions of the relationships are consistent with an alignment of the family human capital resources and levels of organizational innovation and evidence of strong family influence in all firms.

The contributions of this study are to: 1) support the value of pursuing mediators and moderators of family influence; 2) the holistic operationalization and measurement of family influence, in the championing construct, that accounted for all family employees; 3) the measured influence of family human capital on the family firm. In conclusion, more questions about family human capital are raised than answered, but further investigation appears to be warranted by the results of this study.


identifier: ASSA, HIRBOD  (2014) HEDGING AND PRICING IN INCOMPLETE MARKETS: THEORY AND APPLICATIONS.  PhD thesis, Concordia University.

abstract:
This thesis consists of three essays in financial econometrics. In the first part of the thesis, motivated by different applications of hedging methods in the literature, we propose a general theoretical framework for hedging and pricing. First, we review briefly different strands of literature on hedging which have been developed in various
fields such as finance, economics, operations research and mathematics, and then try to come up with a tractable way for hedging and pricing in this paper. By introducing
different market principles, we study conditions under which the hedging problem has a solution and pricing is possible. We will conduct an in-depth theoretical analysis
of hedging strategies with shortfall risks as well as the spectral risk measures, in particular those associated with Choquet expected utility. We show that asymmetric information results in incorrect risk assessment and pricing. In the second part of the thesis, we will apply our results in the first part to construct an economic
risk hedge. We also introduce a general method to estimate the stochastic discount factors associated with different risk measures and different financial models. The
third part of the thesis modifies the speculative storage model by embedding staggered price features into the structural model of Deaton and Laroque (1996). In an attempt to replicate the stylized facts of observed commodity price dynamics, we add an additional source of intertemporal linkage to Deaton and Laroque (1996), namely speculation in intermediate-good inventories. The introduction of this type of friction into the model is motivated by its ability to increase price stickiness which gives rise to an increased persistence in the first and higher conditional moments of commodity prices. By incorporating intermediate risk neutral speculators and a final bundler with a staggered pricing rule in the spirit of Calvo (1983) into the storage model, we are able to capture a high degree of serial correlation and conditional heteroskedasticity, which are observed in actual data. The structural parameters of both Deaton
and Laroque (1996) and our modified models are estimated using actual prices for 8 agricultural commodities. Simulated data are then employed to assess the effects of
our staggered price approach on the time-series properties of commodity prices. Our results lend empirical support to the possibility of staggered prices.


identifier: Miscio, Cinzia  (2014) Influence of Age, Computer Self-Efficacy, and Educational Level On Computer Training Outcome.  PhD thesis, Concordia University.

abstract:
It is well known that throughout the 1980s and 1990s, with the growth of computer use in the workplace, older workers had greater difficulties than younger workers in learning new computer skills. Not only were older workers having more difficulties in acquiring new computer skills, but research revealed that their self-efficacy beliefs were also lower, having an adverse effect on their ability to learn and develop new skills. Also, there have been some conflicting results with regards to the mediating effects or influence that educational level has on the acquisition of skills. With a large baby-boom population in Canada, and despite some reaching retirement age, many older workers are choosing to remain in the workforce for various reasons. Since most jobs today require computer skills, it is important to investigate whether older workers are still having the same difficulties, since this may have important implications for organizations.
This study proposes five hypotheses to examine how age, computer self-efficacy, and educational level influence computer training outcome. Ninety-two participants, aged 18 to 66 (M = 37.6, SD = 12.7), took part in a two-hour computer training session. Demographic data were collected, followed by measures of pre-training computer self-efficacy and pretest of computer skills. Participants received computer skills instruction, and completed posttest and post-training computer self-efficacy measures.
Findings revealed that age negatively influenced computer training outcome, but no correlation was found between age and pre-training computer self-efficacy (and this remained consistent with the post-training self-efficacy measure). An ANCOVA indicated a significant effect of pre-training computer self-efficacy on computer training outcome. While age had a negative effect on training outcome, the absence of a relationship between age and pre-training computer self-efficacy ruled out the possibilities of mediation. Similarly, the absence of a relationship between age and educational level and between educational level and computer training outcome, ruled out the possibility of mediation. Post-training self-efficacy predicted both pretest and posttest results, but age had a significant negative weight, indicating that after accounting for post-training computer self-efficacy, older participants were expected to have lower posttest scores. Results are discussed in terms of implications, limitations, and future research.


identifier: Wei, Wei  (2014) Performance Measurement of Manufacturing Supply Chain.  Masters thesis, Concordia University.

abstract:
In order to achieve a fully integrated manufacturing supply chain and to maximize its effectiveness and efficiency, the manufacturing supply chain needs to be assessed for its performance. My thesis has two main objectives: 1. To develop a new methodology for the performance measurement of manufacturing supply chain. 2. To evaluate manufacturing supply chain performance and carry out a comparative analysis of existing supply chains.

To accomplish the first objective a simple, generic and comprehensive tool for measuring the performance of supply chains was developed. The tool was validated by several interviews from various industries.

In order to achieve the second objective the proposed tool was used as a basis for a questionnaire, and a survey of the manufacturing supply chains across various countries and industries was conducted. The results show that even though performance measurement in the whole supply chain is considered as critical by many respondents, some supply chains have not implemented any performance measurement system. A four-factor index for the assessment of the supply chain performance was developed and used. The results suggest that the supply chains which use performance measurement systems are perceived as better performing than those which do not use any performance measurement systems. Also, the weighted performance scores for the national supply chains were higher than the scores for the international ones. Finally, supply chains with strategic alliance showed better performance than those which do not have strategic alliance.


identifier: Rattray, Michael Frederick  (2014) Functional Anarchism(s) and the Theory of Global Contemporary Art.  PhD thesis, Concordia University.

abstract:
Functional Anarchism(s) and the Theory of Global Contemporary Art investigates the intersection of art and anarchist philosophy in order to shed light on the phenomenon of global contemporary art. Many scholars have addressed the impact of anarchism upon modern art, yet such studies tend to stop short of the contemporary era and do not consider that anarchist philosophy is a latent influence upon contemporary art. This thesis explores how anarchist ideas continue to pervade contemporary art practices and discourses, and I argue that anarchist philosophy is increasingly relevant to a contemporary art world in the process of becoming globalized. This thesis therefore provides a critical re-reading of anarchist literature, select avant-garde theories, and art historical scholarship, in order to provide a newly relevant genealogy that helps to account for a theory of the global contemporary art world. Much of this thesis focuses on a critical reassessment of the modern art paradigm in order to show that there is a viable theoretical foundation for a discussion of today’s global art world as a kind of anarchism.

The intersection of art and anarchism opens a theoretical trajectory that I call functional anarchism(s). This trajectory explores the freedom of the artist to evade institutional coercion and to provide alternative models that problematize the status of the art object and the role the artist plays in contemporary life. Functional anarchism(s) is a theory that explains the latent presence of anarchism in the art world. I argue there is an anarchist moral kernel of free creativity that is intended to produce social betterment and this moral kernel is commensurate with the moral conscience required of the artist in the theory of global art and the global contemporary artist. Following anarchist thought, the artist produces a unique labour and I posit that the zone of freedom current contemporary global art enjoys is a kind of creative nothing where the unique labour of the artist is actualized. As such, this study seeks to account for a debordered contemporary art that is transnational, individualized, discontinuous, and shifting in formation. This study argues that the contemporary global art world is a place where anarchism is not only functioning, but also expected and normalized to such a degree that many do not notice its presence.


identifier: Mehreen, Rushdia  (2013) How are inner-city population densities affected by freeways? A study of eight Canadian cities.  Masters thesis, Concordia University.

abstract: Freeways (limited-access high speed roadways) have long been considered as contributing to low density housing and dispersed urban development (sprawl). Sprawl is known to be unsustainable for the environment, biodiversity and energy use. Metropolitan areas in Canada differ in the level of sprawl, in growth and decline in central city population as well as in the level of freeway provision. This study analyzes census data and the level of freeway provision to explore to what degree the change in inner-city population density between 1956 and 2006 in Canada can be explained by freeways. This research examines changes in inner-city densities in over 200 census tracts in the eight inner-cities of Toronto, Montreal, Vancouver, Quebec City, Ottawa, Edmonton, Winnipeg and Victoria. The results show that over a fifty year period, inner-city population densities declined in 74% of the census tracts. The census tracts where densities declined strongly were overwhelmingly located within a four-kilometre distance from freeways, a threshold identified by the present study. Beyond the four-kilometre threshold, a pattern is observed where census tracts at a moderate distance from freeways gained in population density and those further away from freeways lost. Additionally, aggregate inner-city population densities declined in four cities, barely increased in two, however rose in Vancouver and Victoria, where urban freeways were close to non-existent or not as prevalent. These findings contribute to our understanding of why freeways should not be built in areas where higher densities are desired. The study also contributes to the existing debate on the causes of decline in central city population.


identifier: Shepherd, Gyde F.  (2013) Conveying traditional Indigenous culture: From ethnographic film to community-based storytelling.  Masters thesis, Concordia University.

abstract: In the following chapters, I discuss several works of film, video and photography made since the early twentieth century depicting Inuit and other Indigenous peoples of North America. Their creators have been motivated by a desire to produce a record, through various methods of reconstruction, of past ways of life of their Indigenous subjects. In the context of these efforts, the question of how to structure the material to attract and hold the attention of an audience has been a primary concern. The films discussed in chapters two and three exemplify ethnographic filmmaking as a visual and narrative practice of salvage ethnography. In contrast, the films and videos discussed in chapters four and five are examples of Indigenous media—that is to say, media produced by Indigenous people and communities—that make use of ethnographic, or simply cultural, reconstruction in a way that assumes the continuing vitality of Indigenous cultures and a healthy balance between past and present. Focusing on the example of Canada’s first Inuit-made feature-length fiction film, Atanarjuat: The Fast Runner, I argue that the film’s success and significance is grounded in a respect for traditional Inuit storytelling practices and an experiential approach to teaching that uses video as a proxy for directly “showing how,” an effort to make traditional Inuit cultural memory and stories relevant to Inuit and wider audiences in the present and future.


identifier: AZAB, TAHER  (2014) DIFFERENTIALLY PRIVATE TRAFFIC PADDING FOR WEB APPLICATIONS.  Masters thesis, Concordia University.

abstract:
The wide adoption of Web applications in various sectors of our society, such as government, finance, education, health care, media, etc., has implicitly introduced new security
challenges. Among such challenges are side channel attacks that may disclose private user inputs from encrypted raffic. Such attacks might have a serious impact upon user privacy in such applications. In this thesis, we propose a new concept and algorithms that can preserve user privacy in Web applications. In order to achieve this, we define a new privacy
model based on a well known concept, namely, differential privacy. The intent is to make
padded traffic differentially private such that adversaries cannot infer private user inputs
even when they possess prior knowlege about such inputs. At the same time, we intent
to achieve a balance bewteen privacy and the incurred communication overhead. In order
to demonstrate the usefulness of our model, we implement the proposed algorithms and
conduct experiments based on data collected from well known Web applications.


identifier: SULTAN, NEHA  (2014) A Study on an Automatic System for Analyzing the Facial Beauty of Young Women.  Masters thesis, Concordia University.

abstract:
A Study on an Automatic System for Analyzing the Facial Beauty of Young Women

Neha Sultan

Beauty is one of the foremost ideas that define human personality. However, only recently has the concept of beauty been scientifically analyzed. This has mostly been due to extensive research done in the area of face recognition and image processing on identification and classification of human features as contributing to facial beauty. Current research aims at precisely and conclusively understanding how humans classify a given individual's face as beautiful. Due to the lack of published theoretical standards and ground truths for human facial beauty, this is often an ambiguous process. Current methods of analysis and classification of human facial beauty rely mainly on the geometric aspects of human facial beauty. The classifiers used in current research include the k-nearest neighbor algorithm, ridge regression, and basic principal component analysis.

In this research, various approaches related to the comprehension and analysis of human beauty are presented and the use of these theories is outlined. Each set of theories is translated into a feature model that is tested for classification. Selecting the best set of features that result in the most accurate model for the representation of the human face is a key challenge. This research introduces the combined use of three main groups of features for classification of female facial beauty, to be used with classification through support vector machines. The classifier utilized is Support Vector Machine (SVM) and the accuracy obtained through this classifier is 86%. Current research in the field has produced algorithms with percentages of accuracy that are in the range of 75-85%. The approach used is one of analysis of the central tenets of beauty, the successive application of image processing techniques, and finally the usage of relevant machine learning methods to build an effective system for the automatic assessment of facial beauty. The ground truths used for verifying results are derived from ratings extracted from surveys conducted.

The proposed methodology involves a novel algorithm for the representation of facial beauty, which combines the use of geometric, textural, and shape based features for the analysis of facial beauty. This algorithm initially develops an overall landmark model of the entire human face. A significant advantage of this methodology is the accurate model of the human face which synthesizes the geometric, textural and shape-related aspects of the face. The landmark model is then used for extracting critical characteristics which are then used in a feature vector for training using machine learning. The features extracted help to represent facial characteristics in three major areas. Geometric features help to represent the symmetrical properties and ratio-based properties of landmarks on the face. Textural features extracted help capture information related to skin texture and composition. Finally, face shape and outline features help to categorize the overall shape of a given face, which helps to represent the given female face shape and outline for further analysis of any deviations from the basic face shapes. These features are then used in a classifier to appropriately categorize each image. The database used for the source of images contains images of female subjects from a variety of backgrounds and levels of attractiveness.


identifier: Abdul Khalek, Karim  (2013) Modeling of Preemptive RTOS Scheduler with Priority Inheritance.  Masters thesis, Concordia University.

abstract: This work describes an approach to generate accurate system-level model of embedded software on a targeted Real-Time Operating System (RTOS). We design a RTOS emulation layer, called RTOS_SC, on top of the SystemC kernel. The system level model can be used for software optimization in the early stage of a processor design. The model precision is obtained by integrating key features which are provided in typical RTOS schedulers. We first discuss a case study which shows the impact of the implemented features on a priority-driven scheduler. We then present the abstraction of tasks scheduling and communication mechanisms. To validate the accuracy of our model we use the tasks response time metric with industrial-size examples such as MP3, Vocoder and Jpeg encoder. The experimental results show a significant improvement compared to existing RTOS models.