identifier: Liu, Sining  (2013) Motion Control of Smart Material Based Actuators: Modeling, Controller Design and Experimental Evaluation.  PhD thesis, Concordia University.

abstract:
Smart material based actuators, such as piezoelectric, magnetostrictive, and shape memory alloy actuators, are known to exhibit hysteresis effects. When the smart actuators are preceded with plants, such non-smooth nonlinearities usually lead to poor tracking performance, undesired oscillation, or even potential instability in the control systems. The development of control strategies to control the plants preceded with hysteresis actuators has become to an important research topic and imposed a great challenge in the control society. In order to mitigate the hysteresis effects, the most popular approach is to construct the inverse to compensate such effects. In such a case, the mathematical descriptions are generally required. In the literature, several mathematical hysteresis models have been proposed. The most popular hysteresis models perhaps are Preisach model, Prandtl-Ishlinskii model, and Bouc-Wen model. Among the above mentioned models, the Prandtl-Ishlinskii model has an unique property, i.e., the inverse Prandtl-Ishlinskii model can be analytically obtained, which can be used as a feedforward compensator to mitigate the hysteresis effect in the control systems. However, the shortcoming of the Prandtl-Ishlinskii model is also obvious because it can only describe a certain class of hysteresis shapes. Comparing to the Prandtl-Ishlinskii model, a generalized Prandtl-Ishlinskii model has been reported in the literature to describe a more general class of hysteresis shapes in the smart actuators. However, the inverse for the generalized Prandtl-Ishlinskii model has only been given without the strict proof due to the difficulty of the initial loading curve construction though the analytic inverse of the Prandtl-Ishlinskii model is well documented in the literature. Therefore, as a further development, the generalized Prandtl-Ishlinskii model is re-defined and a modified generalized Prandtl-Ishlinskii model is proposed in this dissertation which can still describe similar general class of hysteresis shapes. The benefit is that the concept of initial loading curve can be utilized and a strict analytical inverse model can be derived for the purpose of compensation. The effectiveness of the obtained inverse modified generalized Prandtl-Ishlinskii model has been validated in the both simulations and in experiments on a piezoelectric micropositioning stage. It is also affirmed that the proposed modified generalized Prandtl-Ishlinskii model fulfills two crucial properties for the operator based hysteresis models, the wiping out property and the congruency property.

Usually the hysteresis nonlinearities in smart actuators are unknown, the direct open-loop feedforward inverse compensation will introduce notably inverse compensation error with an estimated inverse construction. A closed-loop adaptive controller is therefore required. The challenge in fusing the inverse compensation and the robust adaptive control is that the strict stability proof of the closed loop control system is difficult to obtain due to the fact that an error expression of the inverse compensation has not been established when the hysteresis is unknown. In this dissertation research, by developing the error expression of the inverse compensation for modified generalized Prandtl-Ishlinskii model, two types of inverse based robust adaptive controllers are designed for a class of uncertain systems preceded by a smart material based actuator with hysteresis nonlinearities. When the system states are available, an inverse based adaptive variable structure control approach is designed. The strict stability proof is established thereafter. Comparing with other works in the literature, the benefit for such a design is that the proposed inverse based scheme can achieve the tracking without necessarily adapting the uncertain parameters (the number could be large) in the hysteresis model, which leads to the computational efficiency. Furthermore, an inverse based adaptive output-feedback control scheme is developed when the exactly knowledge of most of the states is unavailable and the only accessible state is the output of the system. An observer is therefore constructed to estimate the unavailable states from the measurements of a single output. By taking consideration of the analytical expression of the inverse compensation error, the global stability of the close-loop control system as well as the required tracking accuracy are achieved. The effectiveness of the proposed output-feedback controller is validated in both simulations and experiments.


identifier: El-Sawi, Azeldin  (2013) Centralized Thermal Storage Systems Model for Buildings of the Future: Development and Validation.  PhD thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract:
Thermal energy storage system (TES) is a promising technology for buildings heating and cooling applications. Energy storage systems have been widely used for reducing energy use from peak-demand to off-peak times. Among the various thermal storage technologies, phase change materials (PCMs) are the most commonly used approaches for storing thermal energy for buildings heating and cooling application. These materials enable buildings to store and retrieve a considerable amount of energy, typically by being integrated into structural components through a wide variety of TES techniques. A centralized energy storage system can provide a part of the heating and cooling requirements of a low-energy building. Relatively little general information pertaining to the thermal characteristics of latent heat thermal energy storage (LHTES) systems are available; further investigation is required to analyze the thermal performance of centralized LHTES systems in buildings. In this dissertation, a 3-dimensional mathematical model of a centralized LHTES system is conducted and validated for both a quasi-steady state and a transient conjugate heat transfer problem. The model is then used to carry out a parametric study to investigate the effect of geometrical parameters, charging and discharging times and mass flow rates on the long-term system performance.
Based on the parameters that could affect the long-term system performance, artificial neural networks (ANN) are developed not only to reduce the computational time but also to relate the outlet air-temperature to the inlet air-temperature of LHTES. The database obtained from the numerical solution is first used to train the ANN and then utilized to evaluate the accuracy of the trained ANN. The developed model is then integrated with a building’s mechanical ventilation system to investigate the potential improvement in occupants’ thermal comfort level and energy efficiency arising from the integration of the LHTES. It was found that the temperature difference between the air as a heat transfer fluid (HTF) and the PCM melting point has a significant effect on the performances of a LHTES system. The thermal energy retrieved from the centralized LHTES system is the highest when the inlet air temperature is about 10K higher than the PCM mean melting temperature.


identifier: Matout, Nagham  (2013) Estimation of the Influence of Artificial Roadway Lighting on Road Collision Frequency.  Masters thesis, Concordia University.

abstract: Road accidents in Quebec registered a total of 104,070 collisions with 39,541 victims of injuries and 436 fatalities in 2012 alone. Driving in dark environments increases the risk of accident likelihood for which artificial roadway lighting is typically seen as a countermeasure. However, it is unknown if non-standard levels of lighting help in reducing collision frequency, representing the case for many inconsistently illuminated roads under municipal jurisdiction. This research collected illuminance measurements for the Arthabasca region in Quebec. The collected data was combined with available operational and geometrical characteristics as well as collision frequency, to investigate what variables explain nighttime road crashes and how different levels of artificial lighting correlate with them. It was found that the presence of an intersection and having a slippery road surface produced more collisions. Roads with a complex geometry as well as traffic volume explain higher collision rates. Either standard or non-standard illuminated roads resulted in an increase of road collision frequency as compared to dark sites. Definition of standard illumination seems not to correspond to the statistical evidence herein found. Increasing the minimum level of illuminance for standard lighting helps in reducing collision frequency at standard lit sites as illuminance levels were raised.  Quebec warrant grid system seems to give preference to illuminate roads at either urban locations or in the proximity to an intersection. A good correlation between all illuminated sites and a variable containing urban and suburban land uses was found. Empirical evidence also suggests that dark locations correspond mostly to rural sites (possibly with lower volumes of cars) which observe lower frequency of road collisions.


identifier: Errounda, Fatima Zahra  (2013) Towards Cloud-Based Architectures for Robotic Applications Provisioning.  Masters thesis, Concordia University.

abstract:
Robotic applications are widely used in various domains, such as healthcare, precision agriculture, and disaster management. However, provisioning them in a cost-efficient manner remains an uphill task. Cloud computing is changing the way applications are provisioned. It is a new paradigm with three key facets: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). Access anytime, anywhere, rapid application development through third party application re-use, and efficient use of resources are among cloud computing’s expected benefits. All these expected benefits can potentially lead to cost efficiency in robotic applications provisioning.
This thesis defines a set of requirements for cost-efficient robotic application provisioning. It starts by reviewing the state of the art. A key issue from business perspective is how robotic application and third party application clouds could interact for cost efficient robotic applications provisioning purpose.  This thesis proposes a business model that can potentially solve the issue. It is made up of four categories of actors: the end-users, the robotic cloud providers, the third party cloud providers and the cloud interaction framework provider. It is actually the cloud interaction framework provider that enables the interactions between robotic application clouds and third party application clouds. We also propose a peer to peer (P2P) overlay network as the basis of the architecture of the interaction framework provider role. It is a P2P overlay network in which each cloud provider (i.e. robotic cloud and third party cloud providers) is represented by a node for publication, discovery, activation, and execution of applications purposes.
As a proof of concept, we implemented the P2P overlay based architecture including the P2P overlay network with its nodes. We have also implemented a robotic application (i.e., wildfire suppression) and the third party applications it re-uses (i.e., fire detection and supply management) with robotic application and third party applications residing in separate clouds. In addition, performance measurements have also been made.


identifier: Liu, Jun  (2013) Dynamic Modeling and Gain Scheduling Control of a Chilled Water Cooling System.  Masters thesis, Concordia University.

abstract:
ABSTRACT

Dynamic Modeling and Gain Scheduling Control of a Chilled Water Cooling System

Jun Liu

In this thesis, a dynamic model of a chilled water (ChW) cooling system with a stratified ChW tank was developed. The model-based analysis of the energy consumption and the cost under different control strategies were studied. The dynamic model consists of a zone, a cooling coil, a chiller, a stratified ChW tank, and a cooling tower. Nonlinear differential equations were written to describe and evaluate the performance of the entire chiller plant with the ChW tank.

A PI-based gain scheduling (GS) control was designed and its performance was compared with the constant gain PI control by subjecting to setpoint changes and load disturbances. The simulation results showed that the system with GS control gives good control and has more stable performance.

Five different operation strategies were simulated for comparing the energy consumption and the cost of the ChW cooling system under full load and partial load conditions. The results showed that the operating strategy with optimized chilled water setpoint saved 7.16% energy (21.5% cost) compared to the case with constant setpoint. These savings were more significant (36%) under partial load conditions.

The gain scheduling control with optimal setpoint has great potential for energy savings as demonstrated by the results presented in the thesis.


identifier: Chowdhury, Syed Hasibul Hassan  (2013) On Low Dimensional Galilei Groups and Their Applications.  PhD thesis, Concordia University.

abstract:
This thesis consists of two main parts. The first part focuses on the (1+1) and (2+1) dimensional Galilei groups and their applications to signal analysis and noncommutative quantum mechanics. Various groups used in the current literature of signal analysis and image processing turn out to possess deep connections with the (1+1)-dimensional Galilei group, which, on the other hand, is the physical kinematical symmetry group of a non-relativistic system in one spatial and one time dimensions. To study this remarkable representation theoretic similarity of structures is one of the many goals of this thesis. The (1+1)-affine Galilei group, a 2-fold noncentral extension of the Galilei group, is precisely responsible for the above-mentioned bridging.  Wigner functions associated with another extension of (1+1) affine Galilei group are computed and their support properties are subsequently discussed along with a comparative study of those related to various centrally extended (1+1)-Galilei groups. The remainder of the first part of the thesis is devoted to the study of the (2+1)-Galilei group and its relationship to non-commutative quantum mechanics (NCQM). We show that a certain triple central extension of the abelian group of translations in $\mathbb{R}^{4}$ can be considered to be the {\em defining group} of NCQM in the same spirit as the Weyl-Heisenberg group is considered for the case of standard 2-dimensional quantum mechanics. The representations associated with various gauges studied in NCQM along with those of standard QM are all found to be sitting inside the unitary dual of the \textit{triply extended group of translations in $\mathbb{R}^{4}$}.\\
The second part of the thesis, which concerns an entirely separate problem, involves a study of Poisson brackets between traces of monodromy matrices computed along free homotopy classes of loops on a compact Riemann surface $\Sigma$. We consider a 3-manifold $\Sigma\times\mathbb{R}$ with the connection 1-forms taking their values in the Lie algebra $\mathcal{G}$ associated to the structure Lie group $G$ of a principal $G$-bundle defined on the base manifold $\Sigma\times\mathbb{R}$. First we apply the Hamiltonian formulation of the Chern-Simons theory to compute the Atiyah-Bott brackets between the relevant $\mathcal{G}$-valued relevant gauge connections. The quotient of this infinite dimensional space of flat connections by the action of gauge transformations is what one calls the {\em moduli space of flat connections}. Traces of monodromies computed along the free homotopy classes of loops on $\Sigma$ are the underlying gauge invariant observables. We compute Poisson brackets between observables of this sort by applying the Hamiltonian formalism of soliton theory for various real structure Lie groups, e.g. $GL(n,\mathbb{R})$, $SL(n,\mathbb{R})$, $U(n)$, $SU(n)$ and $Sp(2n,\mathbb{R})$. The formulae, thus obtained, are found to be in exact agreement with the ones computed by Goldman in \cite{goldmant}.


identifier: Al-Khayat, Muna  (2014) Learning-Based Arabic Word Spotting Using a Hierarchical Classifier.  PhD thesis, Concordia University.

abstract:
The effective retrieval of information from scanned and written documents is becoming essential with the increasing amounts of digitized documents, and therefore developing  efficient means of analyzing and recognizing these documents is of significant interest. Among these methods is word spotting, which has recently become an active research area. Such systems have been implemented for Latin-based and Chinese languages, while few of them have been implemented for Arabic handwriting. The fact that Arabic writing is cursive by nature and unconstrained, with no clear white space between words, makes the processing of Arabic handwritten documents a more challenging problem.

In this thesis, the design and implementation of a learning-based Arabic handwritten word spotting system is presented. This incorporates the aspects of text line extraction, handwritten word recognition, partial segmentation of words, word spotting and finally validation of the spotted words.

The Arabic text line is more unconstrained than that of other scripts, essentially since it also includes small connected components such as dots and diacritics that are usually located between lines. Thus, a robust method to extract text lines that takes into consideration the challenges in the Arabic handwriting is proposed. The method is evaluated on two Arabic handwritten documents databases, and the results are compared with those of two other methods for text line extraction. The results show that the proposed method is effective, and compares favorably with the other methods.

Word spotting is an automatic process to search for words within a document. Applying this process to handwritten Arabic documents is challenging due to the absence of a clear space between handwritten words. To address this problem, an effective learning-based method for Arabic handwritten word spotting is proposed and presented in this thesis. For this process, sub-words or pieces of Arabic words form the basic components of the search process, and a hierarchical classifier is implemented to integrate statistical language models with the segmentation of an Arabic text line into sub-words.

The holistic and analytical paradigms (for word recognition and spotting) are studied, and verification models based on combining these two paradigms have been proposed and implemented to refine the outcomes of the analytical classifier that spots words.

Finally, a series of evaluation and testing experiments have been conducted to evaluate the effectiveness of the proposed systems, and these show that promising results have been obtained.


identifier: Longpré, Philomène  (2013) Video Screen as Matrix of Sensations. A Multisensory Approach to the Artistic Development of Responsive Video Membranes.  PhD thesis, Concordia University.

abstract:
The immateriality of moving images is manifest on a plethora of surfaces, shapes, and formats. Artists have access to a cornucopia of tools and medium to develop different forms of interactivity between the body and media, space, and time. Thus, since the 1960s artists have been pushing the limits of both the virtual and the physical worlds, expanding and transforming the static, two-dimensional frame while utterly, attempting to escape its tangibility. But, what if the video screens evolve into a responsive video membrane specifically designed for chosen moving images? How could this catalyst of sensations push creativity forward? And how would people embrace this innovative form of visualization as it moves them even closer to its subjects?

In addition to involving an transdisciplinary inquiry into the artistic development of two responsive video membranes for projected moving images, this doctoral research comprised the ethnographic investigations on how the video display’s materiality, spatiality, and interactivity are key factors in altering perception and augmenting sensory, affective, and cognitive responses to a moving image.

Finally, I propose a multisensory approach to the design of responsive video membranes where an emphasis is placed on the interplay among sensory modalities, sensory memories, associations and the sensory imagination. This realization emerges from studies in the fields of fine arts, anthropology of the senses, computer science, and mechanical engineering.


identifier: Kozlick, Stuart Brahm  (2013) Effect of Cryogenic Treatment on the Mechanical Properties of Nickel-Titanium Shape Memory Alloys.  Masters thesis, Concordia University.

abstract:
This experimental program investigated the effects of cryogenic temperature treatment on the mechanical properties and microstructure of Nickel-Titanium shape memory alloys. Mechanical testing including tensile and hardness were carried out after having undergone various cryogenic temperature treatment conditions, and the results were compared.
Experimental results showed an increase in material hardness was observed when compared to untreated materials. With both steady-state and cyclical conditioning, an increase of approximately 2.0% and 8.7% was observed, respectively. Furthermore, with respect to the cyclical temperature treatment exposures, an increase in both estimated final yield and tensile strengths was also observed, resulting in relative increases of 9.5% and 3.2%, respectively, when again compared to as-received materials. It was concluded these increases in mechanical properties were primarily due to both an increase in the formation of austenite throughout the material’s microstructure, and the overall reduction in martensite grain size structure throughout the sample. The material’s inherent twinning process of the microstructure, coupled with thermally stress-induced martensite plate growths at the martensite transformation temperature are potential contributors to this transformation in the microstructure, resulting in the observed change in mechanical properties.


identifier: Majdi, Iman  (2013) Comparative evaluation of PROMETHEE and ELECTRE with application to sustainability assessment.  Masters thesis, Concordia University.

abstract:
The selection of robust method for sustainability assessment of companies is a challenging decision, particularly for manufacturers with high safety requirements and large number of consumers such as aerospace, automotive components and, oil & gas companies. These overriding industries consider environmental, social and governance (ESG) criteria as well as non-financial factors that have direct effect on infrastructure investments to reach monetary value for its stakeholders and development of a sustainable long term strategy for their portfolio company. These factors however may be often associated with internal and external uncertainties making it difficult to obtain precise sustainability measurement. Actually, the problem comes from addressing 'how' and 'which' questions to select a solid ranking method for sustainability assessment.
In this thesis, we investigate the application of outranking based Multi-Criteria Decision Making (MCDM) methods called ELECTRE III and PROMETHEE I & II for sustainability assessment of industrial organizations. ELECTRE III is a preference based method that considers pseudo-criteria which can be applied for uncertain, imprecise and ill-determined data. PROMETHEE I is a positive and negative flow based multi-criteria method that generates partial rankings. PROMETHEE II is net flow based method and generates complete ranking for alternatives. PROMETHEE methods are more compatible with human judgments.
To compare the performance of ELECTRE III and PROMETHEE I & II, we conducted a sustainability assessment case study and performed model verification and robustness analysis, model validation and sensitivity analysis. The data for the study was obtained from Sustainalytics, a firm specializing in sustainability. The results of our study show that ELECTRE III method outperforms PROMETHEE I & II and is therefore recommended for sustainability assessment of industrial organizations.


identifier: Gong, Sha  (2013) Pixel Classification Algorithms for Noise Removal and Signal Preservation in Low Pass Filtering.  Masters thesis, Concordia University.

abstract:
Contrast enhancement is essential to improve the image quality in most of image pre-processing. A histogram equalization process can be used to achieve a high contrast. It causes, however, also noise generation. Involving a low-pass filtering process is an effective way to achieve a high-quality contrast enhancement with low-noise, but it leads to the conflict between noise removal and signal preservation. To perform discriminative low-pass filtering operations with the presence of noises and signal variations in different regions, it is thus necessary to develop good algorithms to classify the pixels.
    In this thesis, two classification algorithms are proposed. They aim at low-contrast images where gradient signals are severely degraded by various causes during the acquisition process. They are to classify the pixels according to the initial gray-level homogeneity of their regions. The basic classification method is done by gradient thresholding, and the threshold values are generated by means of gradient distribution analysis. To tackle the problems of various gradient degradation patterns in low-contrast images, image pixels are grouped in a particular way that, in the same group, pixels in homogeneous regions can be easily distinguished from those in non-homogeneous regions by the basic method of simple gradient thresholding. Two algorithms based on different grouping methods are proposed. The first algorithm aims at high dynamic range images. The pixels are first grouped according to their gray-level ranges, as the gradient degradation is, in such a case, gray-level-dependent. The gradient distribution of each sub-range is obtained and a pixel classification is then made to adapt to their original gray-level signals in the sub-range. The other algorithm is to tackle a wider range of low-contrast images. In this algorithm, a gray-level histogram thresholding is performed to divide the pixels into two groups according to their likelihood to homogeneous, or non-homogeneous, pixels. Thus, in one group a majority of homogeneous pixels is established and in the other group the majority is of non-homogeneous pixels. The classification done in each group is to identify those in the minority.
    Both proposed algorithms are very simple in computation and each of them is incorporated into the contrast enhancement procedure to make the integrated low-pass filters effectively remove the noise generated in the histogram equalization while well preserving the signal details. The simulation results demonstrates, by subjective observation and objective measurements, that the proposed algorithms lead to a superior quality of the contrast enhancement for varieties of images, with respect to two advanced enhancement schemes.


identifier: Shahrokhi Shahraki, Hamed  (2013) An Efficient Soft Computing Based Method for Calibration of Vehicular Microscopic Simulation Models.  Masters thesis, Concordia University.

abstract: In recent years, due to the advances in computation technology, microscopic vehicular traffic simulation has become one of the main tools used by transportation professionals to solve various design and analysis problems (e.g. safety performance evaluation of highways, impact of different design scenarios in units of safety and efficiency, etc.). The effective use of any of the existing simulation models is limited by the calibration of specific parameters that are based on observed real-life conditions. However, because the calibration of the simulation models is a time consuming and resource intensive process, one might resort to using the default parameter values. In this study, a soft computing-based methodology which synergistically combines Artificial Neural Networks and Genetic Algorithm (GA) applications, is proposed as an alternative for calibration methodology that considerably reduces the computation time in comparison to other commonly used methods. First, a Latin Hypercube Sampling method is used to select representative sets of values for VISSIM’s main calibration parameters.  Second, the effect of each set of parameter values on the simulated traffic stream speed is recorded.  Third, a neural-network is trained to determine the relationship between the input parameter values and the output vehicular speed. Finally, a genetic-algorithm uses the trained neural-network in its fitness function to determine the appropriate set of values for the calibration parameters. The proposed methodology allows for the calibration of microscopic traffic models with fewer computational resources than is commonly used. The feasibility of the method and its applicability to real-world traffic conditions is proved by employing the model using a real-world High Occupancy Vehicle (HOV) lane along a freeway segment. The results of proposed calibration method are compared with those from GA-only based calibration method.. It is concluded that the proposed method performs faster than the GA based calibration method while maintinaing a certain level of accuracy. To highlight the potential benefits of the proposed calibration method, a before-and-after calibration conflict analysis is presented. It is recommended to apply the proposed method to urban environments and to consider other performance measures (travel time, queue length, etc.) to investigate proposed method’s generality.


identifier: Jeyhani, Morteza  (2013) Left Ventricular Flow Patterns after Percutaneous Edge-to-Edge Mitral Valve Repair: An in vitro Study.  Masters thesis, Concordia University.

abstract:
Percutaneous mitral valve edge-to-edge repair is a viable solution in high-risk patients with severe symptomatic mitral regurgitation. However, the generated double-orifice configuration poses challenges for the evaluation of the hemodynamic performance of the mitral valve and may alter flow patterns in the left ventricle during diastole. The purpose of the present in vitro study is to provide new insight into the spatial-temporal hemodynamics of the flow distal to simulated percutaneous edge-to-edge repair by employing a high resolution, flow diagnostic method, Phase Locked and Time Resolved Digital Particle Image Velocimetry inside the LV.

A custom-made mitral valve was developed and two configurations were tested: a single orifice valve with mitral regurgitation and a double-orifice mitral valve configuration. The hemodynamic performance of the valve was evaluated using Doppler echocardiography and catheterization. The flow patterns in the left ventricle were investigated using Particle Image Velocimetry.

Edge-to-edge repair significantly reduced the regurgitant volume. There was a good agreement between Doppler and catheter transmitral pressure gradients. There was a good match between maximal velocity measured by Doppler and particle image velocimetry. Vortex development in the left ventricle during diastole was significantly different after repair.

There was a good agreement between Doppler and catheter measurements of transmitral pressure gradient following simulated edge-to-edge repair. Flow in the left ventricle was significantly altered by the repair and led to higher energy dissipation during diastole.


identifier: Fan, Wentao  (2013) High-Dimensional Non-Gaussian Data Clustering using Variational Learning of Mixture Models.  PhD thesis, Concordia University.

abstract:
Clustering has been the topic of extensive research in the past. The main concern is to automatically divide a given data set into different clusters such that vectors of the same cluster are as similar as possible and vectors of different clusters are as different as possible. Finite mixture models have been widely used for clustering since they have the advantages of being able to integrate prior knowledge about the data and to address the problem of unsupervised learning in a formal way. A crucial starting point when adopting mixture models is the choice of the components densities. In this context, the well-known Gaussian distribution has been widely used. However, the deployment of the Gaussian mixture implies implicitly clustering based on the minimization of Euclidean distortions which may yield to poor results in several real applications where the per-components densities are not Gaussian. Recent works have shown that other models such as the Dirichlet, generalized Dirichlet and Beta-Liouville mixtures may provide better clustering results in applications containing non-Gaussian data, especially those involving proportional data (or normalized histograms) which are naturally generated by many applications. Two other challenging aspects that should also be addressed when considering mixture models are: how to determine the model's complexity (i.e. the number of mixture components) and how to estimate the model's parameters. Fortunately, both problems can be tackled simultaneously within a principled elegant learning framework namely variational inference. The main idea of variational inference is to approximate the model posterior distribution by minimizing the Kullback-Leibler divergence between the exact (or true) posterior and an approximating distribution. Recently, variational inference has provided good generalization performance and computational tractability in many applications including learning mixture models.

In this thesis, we propose several approaches for high-dimensional non-Gaussian data clustering based on various mixture models such as Dirichlet, generalized Dirichlet and Beta-Liouville. These mixture models are learned using variational inference which main advantages are computational efficiency and guaranteed convergence. More specifically, our contributions are four-fold. Firstly, we develop a variational inference algorithm for learning the finite Dirichlet mixture model, where model parameters and the model complexity can be determined automatically and simultaneously as part of the Bayesian inference procedure; Secondly, an unsupervised feature selection scheme is integrated with finite generalized Dirichlet mixture model for clustering high-dimensional non-Gaussian data; Thirdly, we extend the proposed finite generalized mixture model to the infinite case using a nonparametric Bayesian framework known as Dirichlet process, so that the difficulty of choosing the appropriate number of clusters is sidestepped by assuming that there are an infinite number of mixture components; Finally, we propose an online learning framework to learn a Dirichlet process mixture of Beta-Liouville distributions (i.e. an infinite Beta-Liouville mixture model), which is more suitable when dealing with sequential or large scale data in contrast to batch learning algorithm. The effectiveness of our approaches is evaluated using both synthetic and real-life challenging applications such as image databases categorization, anomaly intrusion detection, human action videos categorization, image annotation, facial expression recognition, behavior recognition, and dynamic textures clustering.


identifier: Kara, Abdullah Mert  (2013) Malicious Payload Distribution Channels in Domain Name System.  Masters thesis, Concordia University.

abstract:
Botmasters are known to use different protocols to hide their activities under the radar. Throughout the past years, several protocols have been abused and recently Domain Name System (DNS) also became a target of such malicious activities. In this dissertation, we analyze the use of DNS as a malicious payload distribution channel. To the best of our knowledge, this is the first comprehensive analysis of these payload distribution channels via DNS. We present a system to characterize such channels in the passive DNS (pDNS) traffic by modelling DNS query and response patterns. Then, we analyze the Resource Record (RR) activities of these channels to build their DNS zone profiles. Finally, we detect and assign levels of intensity for payload distribution channels by using a fuzzy logic theory. Our work is based on an extensive analysis of malware datasets for one year, and a near real-time feed of pDNS traffic. The experimental results reveal few long-running hidden domains used by Morto worm to distribute malicious payloads. We also found that some of these payloads are in cleartext, without any encoding or encryption. Our experiments on pDNS traffic indicate that our system can detect these channels regardless of the payload format.

Passive DNS is a useful data source for DNS based research, and it requires to be stored in a database for historical data analysis, such as the work we present in this dissertation. Once this database is established, it can be used for any sort of threat analysis that requires DNS oriented intelligence. Our aim is to create a scalable pDNS database, that contains potentially valuable security intelligence data. We present our pDNS database by discussing the database design, implementation challenges, and the evaluation of the system.


identifier: Karka, Darius  (2013) An investigation of learning grammatical gender in French at the beginner stages: does the L1 make a difference?  Masters thesis, Concordia University.

abstract:
ABSTRACT

An Investigation of Learning Grammatical Gender in French at the Beginner Stages: Does the L1 Make a Difference?									 Darius Karka

	Research has demonstrated that learning grammatical gender in French for English speakers is difficult (Lyster, 2004; Lyster & Izqueirdo, 2009), and does not easily progress from item learning to system learning (Bell & Collins, 2009; Harley, 1998). This is usually explained by the absence of grammatical gender in English, but research on the facilitative effects of L1 for gender are contradictory (Sabourin, Stowe, & Haan, 2006; White, Valenzuela, Kozlowska-MacGregor, & Leung, 2004) and have not examined the actual learning process in the initial stages. These issues are addressed by comparing the learning of two reliable noun ending cues for gender (-eau for masculine and –tion for feminine) in French by speakers whose L1 marks grammatical gender (Spanish) with those whose L1 does not (English).

	Beginner-level English (n=12) and Spanish (n=16) speakers were exposed to the noun endings via crossword puzzle and picture-matching activities. A pre-post-test design examined their ability to assign gender to both familiar and novel nouns, measured via a 3-choice preference task and a picture identification task. Post-task interviews probed learners’ awareness of the noun-ending cues for gender. Analyses of variance with Time and Performance on novel and familiar items as an indication of item vs. system learning revealed significant gains by both groups, particularly on the familiar items, but no differences between groups, nor did the groups differ in their awareness of noun-ending gender cues.


identifier: Saeidi Dehaghani, Ebrahim  (2013) Well-to-wheels energy efficiency analysis of plug-in electric vehicles including varying charging regimes.  Masters thesis, Concordia University.

abstract:
ABSTRACT
Well-to-Wheels Energy Efficiency Analysis and Optimal Energy Management Strategy for Varying Electric Vehicle Operational Characteristics
Ebrahim Saeidi Dehaghani
Transition to electric vehicles (EVs) is already under way. EVs were demonstrated to be the most fuel economic and emission free among other propulsion technologies. Electric and plug-in hybrid electric vehicles (EVs/PHEVs) can have a large impact on greenhouse gases (GHGs) reduction, increase in fuel economy and higher fuel efficiency. This thesis seeks to investigate the Well-to-Wheels (WTW) energy efficiency analysis of Electric Vehicles (EVs) in Canada. The main idea behind this research work is to analyze step by step energy efficiency, which is one of the key factors for EVs technology acceptance. Penetration of battery electric and more electric vehicles (BEVs/MEVs) into vehicle fleet, affects load demand as well as electricity market. Smart charging of EVs can remove a lot of stress from electricity grid. Effect of home charging of EVs/PHEVs on electricity demand in the province of Quebec was analyzed. More recently, EVs have been looked at as distributed sources of energy, whereby they could back up the power grid during critical high demand periods. With the help of an on-board battery pack, EVs can act as distributed generators and feedback energy to the AC grid. However, efficiency of energy conversion could become an issue in this power flow. Hence, in this thesis stage-by-stage efficiency of vehicle-to-grid (V2G) power flow was evaluated. In addition, feasibility of using EVs in international islanding to sustain the local grid in the event of an emergency was analyzed.


identifier: Kordestani, Ario  (2010) RIDE VIBRATION AND COMPACTION DYNAMICS OF VIBRATORY SOIL COMPACTORS.  Masters thesis, Concordia University.

abstract:
This study explores the ride dynamics of typical North-American vibratory soil compactors via analytical and experimental methods. In-plane ride dynamic models of the vehicle are formulated to evaluate ride vibration responses of the vehicle in the transit mode on undeformable terrain surfaces with the roller vibrator off. An in-plane dynamic model is also formulated to study the compaction mode dynamics at lower speeds on elasto-plastic soil subject to roller induced vibration. Field measurements were conducted to characterize the ride vibration environments during the two modes of operations.
The ride dynamic models of the soil compactor are thus analyzed to study its whole-body vibration environment while operating on undeformable random terrain surfaces. The modeling of the equipment in compaction mode of operation, however, gives insight over the efficiency of the compactor as a tool aimed to perform compaction of soil layers by plastic deformation (compression). The ride vibration environment of the vehicle and its compaction capability is subsequently assessed using the ISO-2631-1 (1997) guidelines and commonly accepted compaction criteria, respectively. The validity of the proposed model is demonstrated by comparing the model responses with the measured data. Comprehensive parametric analyses were subsequently performed to study the influences of variations in various design and operating parameters on the ride quality and the compaction efficiency of the mobile equipment. The results of the study are utilized to propose desirable design and operating parameters of the vibratory soil compactor for enhancement of its ride vibration environment and compaction performance.


identifier: Bucking, Scott  (2013) Pathways to Net-Zero Energy Buildings: An Optimization Methodology.  PhD thesis, Concordia University.

abstract:
Building Performance Simulation (BPS) is frequently used by decision-makers to estimate building energy consumption at the design stage. However, the true potential of BPS remains unrealized if trial and error methods of building simulation are used to identify combinations of parameters to reduce energy use. Optimization techniques combined with BPS offer many benefits such as: (i) identification of potential optimal designs which best achieve desired performance objectives; (ii) system level component integration by simultaneously considering conflicting trade-offs; and (iii) a process-oriented simulation tool that is complementary to BPS, eliminating the need for repetitive userinitiated model evaluations. However, the capability of optimization algorithms to effectively map out the entire solution space and discover information is farther reaching than building design. As shown in this thesis, optimization datasets are also a valuable resource for conducting uncertainty and sensitivity analyses and evaluating policies to incentivize low-energy building design.

Two performance criteria are considered in this thesis: net-energy consumption and life-cycle cost. The term ‘performance-optimized’ refers to the extreme of these two criteria that is Net-Zero Energy (NZE) and cost-optimized buildings. A Net-Zero Energy Building (NZEB) generates at least as much renewable energy on-site as it consumes in a given year. A cost-optimized building has the lowest life-cycle cost over a considered period. A focus of this thesis is identifying optimal pathways to NZE and cost-optimized building designs.

This thesis proposes the following approaches to identify pathways to net-zero energy: (i) a redesign case-study of an existing near-Net-Zero Energy Home (NZEH) archetype using a proposed optimization methodology; (ii) the development of an information-driven hybrid evolutionary algorithm for optimal building design; (iii) a methodology for identifying the influence of design variations on building energy performance; (iv) a methodology to evaluate the effect of incentives on life-cycle energy-cost curves; and (v) effect of a time-of-use feed-in tariff on optimal net-zero energy home design.

The optimization methodology consists of: (i) an energy model; (ii) a cost model; (iii) a custom optimization algorithm; (iv) a database; and (v) a statistics module. Several new simulation techniques are proposed to identify pathways to performanceoptimized net-zero energy buildings: (i) probability distribution functions extracted from previous simulations; (ii) back-tracking searches; and (iii) importance factors to summarize back-tracking search results.

This thesis provides valuable information related to: (i) the development of performancebased energy codes for buildings; (ii) systematic design of cost-optimized NZEHs; (iii) systematic analysis of the impact of different design parameters on energy consumption and cost; (iv) the study of incentive measures for NZEHs.


identifier: Mohammadi, Babak  (2013) Development of Concrete Water Absorption Testing for Quality Control.  Masters thesis, Concordia University.

abstract:
Concrete durability can be evaluated by a number of properties - such as water absorption and chloride diffusion. Each of these properties can be measured using Standardized methods. Water absorption can be linked to porosity and therefore to eventual deterioration.  Tests based on absorption have the potential to be simple and rapid tests for placed concrete. However, it is impossible to provide the Standard conditions for in-situ measurements. Water absorption is strongly affected by environmental temperature and concrete moisture content. These different conditions may cause incorrect evaluation of concrete performance.
In this thesis, several samples were taken from three different construction projects in the Montréal region. These samples were taken to the laboratory, conditioned in different relative humidity and temperature environments and later water absorption tests were performed on them to investigate the effect of these two factors. In addition, three samples of each concrete mixture were placed outdoors and were tested in different environmental situations. Lastly, in-situ water absorption tests were performed on real concrete elements for one of the projects in actual field conditions.
It was found that the concrete water absorption rate increases linearly with increasing temperature and decreasing moisture content. In addition, surface relative humidity was found as an accurate and practical indicator of concrete moisture content. These relationships were verified by additional exposed and in-situ measurements. It is suggested to perform several water absorption tests along with temperature and concrete surface relative humidity measurements to arrive at a Standardized value for quality control purposes.


identifier: Singh, Abha  (2013) Voicing the Body.  PhD thesis, Concordia University.

title: Voicing the Body

abstract:
This qualitative narrative research explores the in-depth clinical cases of three young Hindu South Asian Indian immigrant women (two Indian Hindu, Punjabi and one Indian Hindu, Gujarati) living in a shelter for domestic violence in Canada, using a culturally modified clinical art therapy modality as part of their therapeutic process. These traumatized women of a different cultural/ethnic background from the host Canadian culture, originate from a society where mental health issues are highly stigmatized. Resistance to seek help outside of the extended family system or outside of the community is often an obstacle to seeking treatment. While the incidence of trauma is high in the South Asian community, modalities of treatment are limited. A clinical art therapy protocol developed for this research uses a 12 week program of individual audio-recorded sessions over a five month period, with a therapist of the same cultural/ethnic background as the women. These women are pre-diagnosed by mental health professionals and exhibit distinct symptoms of harm which manifest in three self-harming categories: superficial self-harm, somatization, and self-defined negative body images. The internalized issues of these women are examined. Furthermore, the use of art therapy as another route to embodiment and changes to the self in a bicultural predicament are also explored. Focus is given to the challenges of culture and traditions in treating this particular group. Theoretical literature is reviewed, and the personal meanings the women gained from the art process and the images produced from it are examined. A projective drawing test - the draw-a-person assessment tool was used to interpret self-perceptions, and a questionnaire-based interview at the end of the study was utilized and analyzed to address functioning and symptoms to support this research.
The results of this research pilot project indicate that the act of creating art in the context of clinical art therapy helped inform and transform the participant’s traumatic experiences and re-engaged their coping strategies. By representing their trauma(s) as symbolic creations in the artwork(s), the women gained awareness of their feelings, thoughts, emotions, and symptoms of suffering. The creative process helped facilitate the emergence of insight into their traumatic experience(s) and healing on both a conscious and unconscious level and through verbal and non-verbal communication. The clinical art therapy modality provided detailed explanations on the women’s internalizations and traumas; association between cumulative trauma and embodiment issues; the significance of culture and changes gained through art therapy. This clinical art therapy modality contributes to the trauma treatment of women who are the victims of violence and can be applied across cultural communities.
More specifically, in the description of their experience and response to domestic violence and to the art they have created, an awareness of art as a healing process in their recovery might be elicited.


identifier: Sokol, Eva  (2013) The Effects of Exposure to Non-Canonical Equations on Children’s Understanding of the Equal Sign.  Masters thesis, Concordia University.

abstract: It has been established that many children perceive the equal sign as an operational symbol rather than a relational one, and as a result, they have trouble solving non-canonical equations. In the present study, I investigated whether exposure to non-canonical equations would result in students’ ability to solve such equations and acquire a relational view of the equal sign. Fifty three (N = 53) second- and third-grade students were tested for their ability to solve non-canonical problems and whether they viewed the equal sign as a relational symbol before and after an exposure intervention, during which students practiced solving different types of equations. In one condition, the students practiced solving canonical equations; in a second condition, the students practiced solving non-canonical part-whole equations; and in a third condition, they practiced solving non-canonical identity equations. The students were required to solve the problems in their condition without receiving any type of feedback on their work or any explanations on the meaning of the equal sign. All the students improved significantly on their ability to solve non-canonical problems regardless of the type of problem to which they were exposed during the intervention. The students did not, however, improve on their ability to generate relational definitions of the equal sign. The analysis also revealed a significant effect of problem type. Students were more successful on canonical problems than non-canonical ones. As well, students were more successful at solving identity problems than part-whole problems. The study’s limitations and pedagogical implications are discussed.


identifier: Wen, Xiao-Nan  (2013) Computer Simulation of Solar Combisystem Based on the Second Law Analysis.  Masters thesis, Concordia University.

abstract:
This thesis presents the development of a Second Law model of a solar combisystem for residential applications. The work presented in the thesis includes: 1) A methodology for the development of a combisystem computer model; 2) The mathematical models of a solar combisystem components; 3) The features of an EES-based computer model of a solar combisystem being developed; 4) The simulated operation of a solar combisystem; and 5) The analysis of the performance of a simulated solar combisystem based on the Second Law of thermodynamics.
The solar combisystem had an annual system Coefficient of Performance (COP) of 3.98, an annual system exergetic COP of 0.17, an annual system energy efficiency of 42.0%, an annual system exergy efficiency of 40.7%, an annual overall solar energy contribution of 89.5%, an annual overall solar exergy contribution of 88.8%, an annual input solar energy contribution of 82.7%, and an annual input solar exergy contribution of 26.5%. Compared to an electric heating system, the solar combisystem had an annual solar energy fraction of 1.3 and an annual solar exergy fraction of 0.1.


identifier: Tabach, Afaf  (2013) IT Governance Impact on Business Unit Performance.  PhD thesis, Concordia University.

abstract:
The main objective of this thesis is to investigate the impact and role of implementing information technology (IT) governance practices on the business value driven from IT. The proposed research model encompasses the use of configurational theory in order to find different gestalts of IT governance practices. This research also looks at the links between these gestalts and the performance of business units from a financial and non-financial perspective. To test the model, 57 matched surveys were collected from North America and the Middle East.
Different clusters of IT governance practices have emerged from this study with distinct yet significant impact on business unit non-financial performance. However, no significant impact on the business unit financial performance was found.
The findings show that implementing different sets of IT governance practices within organizations can result in different levels of performance at the business unit level in terms of business processes, decision making and legal and ethical compliance.


identifier: Langlois, Marc  (2013) A Comparative Study Of Community Youth Development Projects, & Innovations For Community Enterprising.  PhD thesis, Concordia University.

abstract:
ABSTRACT

A Comparative Study Of Community Youth Development Projects, &
Innovations For Community Enterprising

Marc Langlois
2013

The broad area of study of the thesis is the engagement of young people in community development. The thesis is organized in two parts. The first is a comparative study of nine community and youth development projects that had significant elements in common: program design, applied dissemination and structure. The second part introduces emerging practices, and a framework and a practical social enterprise design for community enterprising.

The researcher developed a working theory, with action-oriented research and developmental evaluation. Open Systems Theory (Emery, F. & Trist, 1965) provides a theoretical foundation. The research demonstrates limitations to conventional approaches to the assessment, convening and backbone support of comprehensive community and youth development projects. The thesis builds on theory, findings and previous experience in the field to identify conditions for engagement, and a new paradigm for organizing community development that includes criteria for convening. Part B discusses a set of practices for facilitation and developmental evaluation, and a whole-systems framework to guide community builders. The research concludes with the completed design of a social enterprise model intended to generate and fuel a chain reaction of community enterprising.

Key words: community enterprising, youth engagement, community youth development, comprehensive community youth development, intervene, developmental evaluation, facilitation, convening, backbone support, community development, social enterprise, social franchise, open systems theory


identifier: Yu, Zhe  (2013) Development of a bioassay for engineered nanoparticles (ENPs) in the environment.  Masters thesis, Concordia University.

abstract: As the global production and use of the nanoparticles increases, it is certain that the engineered nanoparticles will be released into the environment. However, their effects on the humans, other organisms, and ecosystems are still unknown. In order to understand the potential toxicity and bioavailable concentration of the metal-based engineered nanoparticles or toxic trace metals in the environment, Chlamydomonas rehardtii was utilized as a study model to construct the bioassay. Although C. reinhardtii primarily serves as a model organism in biology research, the prevalent reporter genes such as GFP or luciferase are poorly expressed in this organism. No efficient bioluminescent or biofluorescent reporters are available for constructing our bioassay, thus, an endogenous gene, the CRLpcr-1 gene which encodes protochlorophyllide oxidoreductase, as a reporter gene was first evaluated and expected to be served as a useful and robust reporter gene in C. reinhardtii. The 4.9 kb transgene including the nickel inducible promoter, the Cyc6 promoter, the reporter gene, the CRLpcr-1 gene, and the selectable marker was assembled using homologous recombination in Saccharomyces cerevisiae. The results showed that C. reinhardtii failed to express the CRLpcr-1 transgene probably due to the transcriptional gene silencing mechanism. In future, a new strain that is defective in transcriptional silencing which is genetic crossed with a new mutant strain (pc1, y7, cw15, arg7) with flagella could be employed to construct our bioassay.


identifier: Mahboubi, Hamid  (2013) Deployment Strategies for Target Monitoring and Coverage Improvement in Mobile Sensor Networks.  PhD thesis, Concordia University.

abstract: Efficient sensor deployment strategies are developed in this work for target monitoring and coverage improvement in collaborative wireless mobile sensor networks. The objective of the target monitoring problem is to compute the desired sensing and communication radii of sensors as well as their location at every time instant such that a set of prescribed specifications such as connectivity preservation and low energy consumption are satisfied. An energy-efficient strategy is also proposed for tracking a moving target in a sensing field, using a grid of sufficiently small rectangular cells. The grid is converted to a graph with properly weighted edges.  A shortest-path algorithm is subsequently used to route information from target to destination by a subset of sensors. In the problem of coverage improvement in mobile sensor networks, on the other hand, the objective is to place each sensor in the field using available local information about its neighbors in such a way that the area covered by sensors is as large as possible, while some important criteria are taken into consideration. Both cases of identical and nonidentical sensors (in terms of sensing radii) are considered, and different iterative algorithms are developed which are shown to be convergent. The relocation algorithms are based on the relative position of each sensor w.r.t. the boundaries of its cell or the corresponding corner point. The algorithms are extended to the case of limited communication range of sensors (leading to inaccurate Voronoi cells), an environment with prioritized sensing (mathematically characterized by a weighting function for different points), and an environment with obstacles (leading to some invisible areas). Simulation results are provided to validate the effectiveness of the proposed algorithms.


identifier: Magalhaes, Mona  (2013) I'm From Here and There: Dual Citizenship for the Second Generation in Montreal and its Implications for Identity, Plurality and Mobility.  Masters thesis, Concordia University.

abstract: The ability to acquire and retain dual citizenship has become increasingly accepted among states worldwide over the last several decades, and this has resulted in a significant expansion of the number of people who acquire dual or multiple citizenships at birth. While dual citizenship is regarded as a status that at once enables migrant integration into the host state and the maintenance of cultural and familial ties with the country of origin, the extent to which this is relevant to subsequent generations remains unknown. It is also not known to what extent dual citizenship status inspires transnational mobility for the second generation. Applying citizenship and transnational theoretical and conceptual approaches, in this thesis I examine what dual citizenship can mean to second generation Canadians who also hold the European citizenships of their parents, primarily focusing on southern and former Soviet bloc states that are members of the European Union. I investigate life stories and family migration histories and describe the ways in which individualized notions of national and cultural identity are formed through the relationships fostered within local and transnational familial and social networks. In addition, this form of dual citizenship implies that the second generation have access and membership to not only their family’s country of origin, but also to other states within the European Union. Within this context, I demonstrate how contemporary global capitalism adds an instrumental dimension to dual citizenship as the second generation consider key life decisions such as residence, education, and career trajectories, and whether to embark on mobility to achieve these goals.


identifier: Hmood, Aseel  (2013) A Unified Metamodel for Assessing and Predicting Software Evolvability Quality.  PhD thesis, Concordia University.

abstract: Software quality is a key assessment factor for organizations to determine the ability of software ecosystems to meet the constantly changing requirements. Many quality models exist that capture and assess the changing factors affecting the quality of a software product. Common to these models is that they, contrary to the software ecosystems they are assessing, are not evolvable or reusable. The thesis first defines what constitutes a unified, evolvable, and reusable quality metamodel. We then introduce SE-EQUAM, a novel, ontological, quality assessment metamodel that was designed from the ground up to support quality unification, reuse, and evolvability. We then validate the reus-ability of our metamodel through instantiating a domain specific quality assessment model called OntEQAM that assesses evolvability as a non-functional software quality based on product and com-munity dimensions. A fuzzy logic based assessment process that addresses uncertainties around score boundaries supports the evolvability quality assessment. The presented assessment process also uses the unified representation of the input knowledge artifacts, the metamodel, and the model to provide a fuzzy assessment score. Finally, we further interpret and predict the evolvability as-sessment scores using a novel, cross-disciplinary approach that re-applies financial technical analy-sis, which are indicators, and patterns typically used for price analysis and the forecasting of stocks in financial markets. We performed several case studies to illustrate and evaluate the applicability of our proposed evolvability score prediction approach.


identifier: DeWeese-Frank, Michael G.  (2013) Quand des imaginaires sociolinguistiques se croisent. La rencontre symbolique des mondes anglophone et francophone dans trois romans de Jacques Poulin.  Masters thesis, Concordia University.

abstract: Ce mémoire de maîtrise porte sur la rencontre symbolique des imaginaires sociolinguistiques dans les trois derniers romans de Jacques Poulin : La traduction est une histoire d’amour (2006), L’anglais n’est pas une langue magique (2009) et L’homme de la Saskatchewan (2011). Il s’appuie principalement sur la théorie du colinguisme élaborée par Catherine Leclerc dans Des langues en partage? (2010). Alors que Leclerc analyse la cohabitation de l’anglais et du français dans la langue du texte, la présente étude aborde plutôt la mise en contact des imaginaires liés à ces deux langues dans l’univers romanesque du corpus poulinien. Chacun des trois romans privilégie une exploration de cette rencontre qui lui est propre, car chaque narrateur-personnage exerce un métier langagier (traductrice, lecteur sur demande et écrivain fantôme) qui influence la nature du rapport qui s’établit symboliquement entre les imaginaires anglophone et francophone. Néanmoins, les trois récits demeurent fortement interreliés, et en analysant l’ensemble du corpus primaire, on tentera enfin de tracer les contours de la vision poulinienne de la place du monde francophone en Amérique du Nord.


identifier: Zheng, Yingjie  (2013) A Flow Field Study of a Film Cooling Hole Featuring an Orifice.  Masters thesis, Concordia University.

abstract:
Film cooling is a jet-in-crossflow application in gas turbines used to protect high temperature parts. Understanding the physical phenomena in the flow field, for example the detrimental counter-rotating vortex pair, is highly critical. Experimental investigations were conducted using stereoscopic PIV to study the flow field downstream from film cooling holes featuring an orifice, under blowing ratios from 0.5 to 2.0. The original geometry of a short injection hole that was proposed in a previous numerical study was examined. The results reported a significant reduction in counter-rotating vortex pair strength of nozzle hole injection in comparison with cylindrical hole injection. The streamwise vorticity of the nozzle hole jet averaged a drop of 55% at a low blowing ratio of 0.5, and a 30%–40% drop at high blowing ratios of 1.0, 1.5 and 2.0. Due to the reduction in counter-rotating vortex pair strength, a round jet bulk was observed forming from the two legs of a typical kidney-shaped jet. The merged jet bulk delivered better coverage over the surface.
    The effect of the geometrical parameters of the orifice and the effect of the blowing ratio were also investigated using long injection hole geometry to isolate the impact of the short hole length. It was found that under high blowing ratio conditions, no structural difference occurred in the jet when altering the value of blowing ratio. The most important geometrical parameters were the opening width and the in-hole position of the orifice. The measurement results suggested that the width of the orifice had a major impact on downstream counter-rotating vortex pair strength, and the in-hole position of the orifice mainly affected the penetration characteristics of the jet. The mechanism of the counter-rotating vortex suppressing effect of the orifice was studied from the flow field data. It is proven that the orifice greatly eliminated the hanging vortices developing from the in-hole boundary layer vorticity, which was the major contributor to counter-rotating vortex formation in inclined jets.


identifier: Tousignant Gauthier, Martine  (2013) Labelling Identities: the Views and Experiences of Second Generation Pacific Peoples in New Zealand.  Masters thesis, Concordia University.

abstract: The second half of the twentieth century saw a large scale migration of peoples from Samoa, Tonga and the Cook Islands to New Zealand, to the extent that they now represent more than 7% of the total population of that country. It was only after their arrivals to New Zealand that they experienced being grouped together and labelled in panethnic terms. Second-generation Pacific peoples, though born in New Zealand, have faced their own set of challenges in regards to establishing their identity in their new homeland. This research investigates how second generation Pacific peoples negotiate and articulate their identity as New Zealander and as Pacific peoples. Through exploring identity labels (i.e. Fresh of the boat and plastic), I examine these negotiations and articulations both in terms of assimilation and in terms of panethnicity (i.e. Pacific Islanders, Pacific peoples, Pasifika). Nineteen individual and one group interview were conducted with Wellington University students of Samoan, Tongan and Cook Islands background. The narratives reveal a paradox surrounding these identity labels: while they are a creation of outsiders and are criticised for being pejorative, they are also embraced by some members of the group to whom they apply. I argue that the acceptance and usage of controversial identity labels (in this case, panethnic labels and Fresh off the boat) by in-group members is attributable to an ongoing re-appropriation process whereby individuals or groups reclaim a term and redefine it in their own words in order to give it a more positive meaning.


identifier: Shafiee, Arya  (2013) Phase Flow Diagram: A New Execution Trace Visualization Technique.  Masters thesis, Concordia University.

abstract:
Software maintenance tasks are known to be costly and challenging. The main challenge is that software maintenance must understand how the software system works before making any changes to it. This is due to lack of adequate documentation if it exists at all. Program analysis techniques aim to reduce the impact of this problem. In this thesis, we focus on the ones that permit the understanding of the behavioural aspects of software. These techniques operate on execution traces, generated from the system under study.
Traces are difficult to work with because of their size. One way to reduce their complexity is to automatically divide their content into meaningful clusters, each representing a particular execution phase. This is known as trace segmentation. Trace segmentation research is relatively new. The focus has been on building robust algorithms that achieve acceptable accuracy.
In this thesis, we introduce a new trace visualization technique called Phase Flow Diagram to represent the execution phases and the relationship between them in a visual manner. The diagram has a number of notations that can be used by software engineers to represent a trace as a flow of execution phases instead of mere events. We introduce a supporting tool for the diagram. The new diagram and the tool are validated through a user study that involves several users.


identifier: Courchesne, Alexandra  (2013) Beyond the Songs: Women Performers of Ethnic Music in Contemporary Istanbul.  Masters thesis, Concordia University.

abstract: Music has often had a political aspect but its power has increased since the formation of the modern state. In Turkey, music has been an instrument for the nation-building project but also a tool for members of the civil society. With the release of the ban that prohibited ethnic music in the public arena in 1990, women performers of this music genre have managed to carve out their niche on the public stage as well as to gain social respectability in the process. Drawing on a three-month fieldwork in Istanbul, this thesis seeks to present the strategies and obstacles women performers of ethnic music employ to break with the image of the ‘entertainer’, to advocate for the rights of the ethnic minorities, and to re-define inter-gender relationships. This thesis is an exercise in engagement with these questions: How do women use ethnic music in order to carve out their place in the public arena while gaining and maintaining social respectability? More particularly, how were they able to do it in the peculiar constantly evolving socio-political landscape of the Ottoman Empire first and then of the Turkish Republic? What were the obstacles they faced at various stages and what strategies they employed to challenge, circumvent, overcome, co-opt or neutralize these obstacles?


identifier: Abdou, Tamer  (2013) Managing Software Test Process in Open Source Software.  PhD thesis, Concordia University.

abstract:
First, we present a Conceptual Framework for Open-source Software Testing, developed by studying the test process and the project artifacts in open-source software projects and using
ISO/IEC and IEEE standards for software testing as a guideline. By using the standards, we confirmed/observed that from the theoretical viewpoint the test process in open-source software projects is similar to those in the standards. However, test activities are not necessarily performed as described in the project artifacts.

Second, we present a Management Model for Open-source Software Testing Knowledge that is intended to provide an understanding of the testing domain in open-source software. Moreover, the model shows how to manage knowledge in open-source software through different test process activities.

Third, we present an Assessment Framework for Open-source Software Testing that can be used to manage disciplinary issues through evaluating corrective actions to closure in an open-source software test process.

Lastly, we present a Maturity Model for Open-source Software Testing that can be used to understand the impact of open-source software practices on software testing adequacy criteria.

The main contributions of the thesis are the two frameworks, a knowledge management model, and a maturity model.


identifier: Mehra, Kushal  (2014) Automatic Data Migration into the Cloud.  Masters thesis, Concordia University.

title: Automatic Data Migration into the Cloud

abstract:
Relational databases have been used for decades to store data. Using scale up, relational databases require a bigger and bigger server with more CPUs, more memory, and more disk storage to keep all the tables to support more concurrent users. However, big servers tend to be highly complex, proprietary, and disproportionately expensive, unlike the low-cost, commodity hardware. Therefore, it becomes important to store data efficiently and compute with massive amount of data, providing high scalability, providing high performance and availability at low costs. This leads to
the invention of cloud databases, for instance NoSQL databases. NoSQL databases have many advantages such as reading and writing data quickly, supporting massive
storage and low cost. The scaling approach in cloud databases is scale out, which is used to add multiple servers, and the data structure of storage is in the form of
key-value pairs. However, it can be a challenge for enterprises to migrate existing relational databases to highly scalable NoSQL databases on clouds.

In this thesis, we propose an automatic data migration model which will assist enterprises to migrate their relational databases efficiently and transparently to the
cloud databases. We propose four migration methods to migrate data in four different ways. Each migration method is independent of the others and stores the migrated
relational database in different formats in the cloud database. We design a system to implement the automatic data migration model. As a proof of concept, we successfully migrated a relational database from Microsoft SQL
Server to a cloud database Amazon SimpleDB using four different migration methods. Furthermore, we have conducted extensive experiments on Amazon SimpleDB to evaluate the performance of our model in terms of computational time, storage cost, sharding and redundancy. Based on these experiments and detailed analysis of each migration method, our system allows enterprises to determine which method is
suitable for their data migration. Furthermore, our experimental evaluation shows that our solution is promising and can migrate data from the relational databases to
the cloud databases.


identifier: Ghoreishi, Mehrafarid  (2013) STRUCTURAL RESPONSE OF REINFORCED CONCRETE FLAT SLAB EXPOSED TO HEAT.  PhD thesis, Concordia University.

abstract:
Over the past century, fire protection design approaches have been traditionally based on prescriptive fire resistance ratings achieved from standard tests. Standard approaches do not consider a wide range of typical structural conditions such as size, restrain conditions and loadings that are encountered in real practice. On the other hand, fire resistance behaviour of a single structural member is different from that of complete structure because of factors such as continuity, interaction between members and moment redistribution which are present in the whole structure. In the past few decades, there has been significant progress in structural fire safety analysis and design. However, such analysis relies on simplified methods and experimental data related to structural components, not of the complete structure. There has been very limited attention given on fire safety evaluation at the whole structure level.
Two-way concrete flat slabs provide a number of benefits for office buildings and apartments – for example, reducing formwork, flexibility of partitions, relatively high ceiling, and prompt erection. The fire resistance of concrete flat slab structures is affected by many factors including concrete cover, cross section of the structural elements and the material properties of concrete and reinforcing steel bars which is not essentially constant during fire exposure. Concrete has fairly excellent fire resistance properties; however, the strength of concrete reduces as temperature rises. There is a lack of studies, both analytical and experimental, on flat plate concrete slabs in the literature.
This thesis presents a review of the available experimental and numerical studies on structural systems under fire, and identifies the research gaps in this area. Ultimate punching and moment capacity of concrete flat slab systems are studied numerically and experimentally. The numerical study includes the investigation of the effects of different parameters such as concrete and reinforced steel bars behaviour and the structural behaviour of two-way slab at elevated temperature.
The fire performance of a concrete flat plate slab at elevated temperature is complicated. The existing concrete codes cannot predict the capacity under fire exposure and detail investigation is needed to predict fire resistance of flat slabs. Structural concrete design for fire is still in the developing stage in various parts of the world. There is a lack of experimental studies, mainly because of the difficulties associated with a setup for high temperature and high cost of experiments. The main work of this study is the experimental and numerical analysis of slab prototype under combined elevated temperatures and gravity loading. Thermal exposure may cause sudden failure of the concrete slab structures. An experimental program conducted on six concrete, slab-column assemblies are presented to investigate their performance in high and ambient temperature. A numerical model is also presented and compared against test results.
One of the main costs is the additional specification or protection required to provide adequate safety in the event of a fire. Current structural fire protection systems focus on limiting the rate of temperature rise of formwork and concrete cover. This work addresses the parameters that can affect the slab behaviour under fire exposure to prevent collapse. Fire protection by fire barrier or structural modifications is concerned with safeguarding the occupants in the building where the fire may occur. Structural modification should be investigated in detail because some of them have direct effect where others do not have significant effects.


identifier: Moarref, Miad  (2013) Sampled-data Networked Control Systems: A Lyapunov-Krasovskii Approach.  PhD thesis, Concordia University.

abstract:
The main goal of this thesis is to develop computationally efficient methods for stability analysis and controller synthesis of sampled-data networked control systems. In sampled-data networked control systems, the sensory information and feedback signals are exchanged among different components of the system (sensors, actuators, and controllers) through a communication network. Stabilization of sampled-data networked control systems is a challenging problem since the introduction of multirate sample and holds, time-delays, and packet losses into the system degrades its performance and can lead to instability. A diverse range of systems with linear, piecewise affine (PWA), and nonlinear vector fields are studied in this thesis. PWA systems are a class of state-based switched systems with affine vector field in each mode. Stabilization of PWA networked control systems are even more challenging since they simultaneously involve switches due to the hybrid vector fields (state-based switching) and switches due to the sample and hold devices in the network (event-based switching).
The objectives of this thesis are: (a) to design controllers that guarantee exponential stability of the system for a desired sampling period; (b) to design observers that guarantee exponential convergence of the estimation error to the origin for a desired sampling period; and (c) given a controller, to find the maximum allowable network-induced delay that guarantees exponential stability of the sampled-data networked control system. Lyapunov-Krasovskii based approaches are used to propose sufficient stability and stabilization conditions for sampled-data networked control systems. Convex relaxation techniques are employed to cast the proposed stability analysis and controller synthesis criteria in terms of linear matrix inequalities that can be solved efficiently.


identifier: Kiakojoori, Saba  (2014) Jet engine prognosis using dynamic neural networks.  Masters thesis, Concordia University.

abstract:
Jet engine related costs and the need for high performance reliability have resulted in considerable interest in advanced health and condition-based maintenance techniques. This thesis attempts to design fault prognosis schemes for aircraft jet engine using intelligent-based methodologies to ensure flight safety and performance. Two different artificial neural networks namely, non-linear autoregressive neural network with exogenous input (NARX) and the Elman neural network are introduced for this purpose.  The NARX neural network is constructed by using a tapped-delay line from the inputs and delayed connections from the output layer to the input layer to achieve a dynamic input-output map. Consequently, the current output becomes dependent on the delayed inputs and outputs.  On the other hand, the Elman neural network uses the previous values of the hidden layer neurons to build memory in the system.

Various degradations may occur in the engine resulting in changes in its components performance. Two main degradations, namely compressor fouling and turbine erosion are modelled under various degradation conditions. The proposed dynamic neural networks are developed and applied to capture the dynamics of these degradations in the jet engine. The health condition of the engine is then predicted subject to occurrence of these deteriorations.

In both proposed approaches, various scenarios are considered and extensive simulations are conducted. For each of the scenarios, several neural networks are trained and their performances in predicting multi-flights ahead turbine output temperature are evaluated. The difference between each network output and the measured jet engine output are compared and the best neural network architecture is obtained. The most suitable neural network for prediction is selected by using normalized Bayesian information criterion model selection. Simulation results presented, demonstrate and illustrate the effective performance of the proposed neural network-based prediction and prognosis strategies.


identifier: Rabah, Sleiman  (2014) A Resource Publication and Discovery Framework and Broker-Based Architecture for Network Virtualization Environment.  Masters thesis, Concordia University.

abstract:
The Internet has received a phenomenal success over the past few decades. However, the increasing demands on the Internet usage and the rapid evolution of the applications and services provided over the Internet have demonstrated that the current Internet architecture is unsuitable for supporting many types of applications.  Moreover, its ubiquity and multi-provider nature make nearly impossible the introduction of radical changes or improvements without coordination and consensus between many providers. Thus, any technological changes in the current Internet architecture could result in unintended consequences on the overall Internet usage.
Network virtualization is considered as promising, yet challenging, solution to overcome these limitations. It commonly refers to the creation of several isolated logical networks that can coexist on the same shared physical network infrastructures. Its key concept is to enable several network architectures to run concurrently in a multi-role-oriented environment in which the role of the traditional Internet Service Provider (ISP) is decoupled into several roles such as infrastructure provider (InP), virtual network provider (VNP) and service provider (SP). Despite the promising benefits, this concept is associated with many challenges. These, among others, include the description and publication as well as discovery of resources on which virtual networks are deployed.
In this thesis, we define a broker-based architecture that provides functions for publishing, discovering and negotiating as well as instantiating and managing resources in network virtualization environment. We proposed an information model that assists various providers in describing the resources and services they offer and we implemented a proof of concept prototype to demonstrate the feasibility of the proposed architecture. Moreover, we have conducted extensive experiments to evaluate the performance and the scalability of the implemented system.


identifier: Atia, Ahmed  (2013) Parameter Identification of Biomechanical Model Using Measured Vibration Response to Walking Generated Excitations with Optimization.  Masters thesis, Concordia University.

abstract:
Normal birth is defined as when a child is born between 37 and 42 completed weeks of pregnancy. If the child is born before 37 weeks of pregnancy, the birth is considered preterm. The causes of preterm births are still not understood properly and research is being carried out to identify the causes and to prevent preterm birth. Preterm birth has serious effects on preterm children. The child born preterm is prone to defective physical growth and also subject to poor psychological growth.  Preterm birth is associated with deterioration in the cervical resistance. Cervical fatigue may be caused by static loads during extended periods of standing, dynamic loads while working which involve a lot of moving around and walking, or impulse loads caused by sudden jerky movements.
The present study is concerned with developing biomechanical models of the pregnant woman in order to study the biomechanical behavior of the pregnant woman under different types of loads. Previously developed 3-Degree of Freedom and 5-Degree of Freedom models are used to obtain the response of the pregnant woman to vertical vibration, and also to predict the cervical loads in the seated position. A 9-Degree of Freedom model is developed in this study in order to obtain the response of the woman’s body to walking generated excitation, and to predict the cervical loads.
Results from the 3 developed models are obtained at two different conditions, preterm “exactly at 37 weeks of pregnancy” and term “exactly at 42 weeks of pregnancy” conditions. The results from the 2 seated models are compared to the results obtained from the 9-Degree of Freedom walking model, in terms of cervical loads. The comparison shows that the cervical loads are higher in the walking position. Therefore, it is decided to identify the parameters of the walking model. The model consists of 7-Degree of Freedom for the woman’s body and 2-Degree of Freedom for the fetus and the uterus combination. As identifying all the 9 parameters of a 9-DOF pregnant woman through measurements is extremely difficult, it is decided that the identification process will take place on the 7-Degree of Freedom model. To identify such a model, experimental measurements are carried out on a walking individual. The error between the computed and experimental results is minimized using genetic algorithm. Parameters of the 7-Degree of Freedom model are identified through the optimization process. After identifying the 7-Degree of Freedom model parameters, the other 2-Degree of Freedom are added.
The optimized biomechanical model is used to obtain the response of the pregnant mother to dynamic environmental loads that the pregnant woman is normally subjected to during her daily activities. The results are presented and discussed, in order to get a better understanding of the loads bearing on the cervix. The results show that there is not much difference between the experimented model and the nominal model.


identifier: Dinh, Tran Thai Son  (2014) Mining Cyber Security Intelligence from Spam Data.  Masters thesis, Concordia University.

abstract:
Nowadays, information and communication technologies have been used to support and control almost every aspect of human life including health, finance, transportation, communication, work and recreation. Recent events have demonstrated that individuals and organizations can be victims of large-scale, astonishing and disrupting attacks, which may lead to severe consequences such as financial and time losses, ruined reputations and even life-threatening situations. Consequently, the security of information and communication technologies must be considered as one of the key roles in the operation of every organization. The first and foremost task is to gather as much information about cyber threats as possible so that cyber attacks can be detected, mitigated, predicted and prevented. Among various data sources used for inferring cyber threat intelligence, spam email data is one of the critical sources because spam emails, which are disseminated by botnets as spam campaigns, act as the pivotal instrument for several cyber-based criminal activities.
In this thesis, we emphasize the importance of cyber security intelligence for the purpose of detecting, mitigating, predicting and preventing cyber attacks. We also concentrate on the correlation of different data sources to draw a big picture of cyber-crime activities around the globe. More precisely, we design and implement two software frameworks for detecting, analyzing and predicting cyber threats, which are phishing and spam campaigns. Regarding phishing attacks, we design and implement a near real-time phishing attack detection and assessment system that identifies phishing attacks targeting specific organizations. Moreover, we propose a novel method which, to the best of our knowledge, is the first contribution to assess the severity of phishing attacks as well as to reveal prospective phishing attempts. By correlating spamtrap and passive DNS data, we are able to infer other organizations that are targeted by the same phishing attack that we have detected. On the other hand, we design and implement another software framework for detecting, analyzing and investigating spam campaigns. Our system identifies spam campaigns on-the-fly, gathers external information about spam campaigns and reveals the characteristics of spam campaigns by labeling and scoring them. The latter system has been adopted by a governmental organization and used by law enforcement officials to pursuit spammers, take down spamming servers and reduce spam volume, which contribute to a cleaner and more secure online world.


identifier: Hoseini, Salman  (2013) Software Feature Location in Practice: Debugging Aircraft Simulation Systems.  Masters thesis, Concordia University.

abstract: In this thesis, we report on a study that we have conducted at CAE, one of the largest civil aircraft simulation companies in the world, in which we have developed a feature location approach to help software engineers debug simulation scenarios. A simulation scenario consists of a set of software components, configured in a certain way. A simulation fails when it does not behave as intended. This is typically a sign of a configuration problem. To detect configuration errors, we propose FELODE (Feature Location for Debugging), an approach that uses a single trace combined with user queries. When applied to CAE systems, FELODE achieves in average a precision of 50% and a recall of up to 100%.


identifier: Guo, Feng  (2013) Analysis of Sybil Attack in Kademlia based P2P Botnets.  Masters thesis, Concordia University.

abstract: This thesis focused on Sybil attack analysis in Peer-to-Peer botnet based on Kademlia network protocol and architecture. With the consideration of the node space may not be full, each node location was assumed to have a probability p to be taken. The objective of this research is to theoretically evaluate such botnet/network’s robustness under two types of malicious attack - random Sybil attack and fake target attack. Probability of successfully finding a target node that can be possibly locating anywhere in the network is taken as the main evaluation factor. With different key parameters, mathematical models are established and partial closed-form formulas have been proposed. Numerical results generated by Matlab are demonstrated and analyzed to conclusion.


identifier: Sadri, Sahba  (2013) Towards Migrating Security Policies along with Virtual Machines in Cloud.  Masters thesis, Concordia University.

abstract:
Multi-tenancy and elasticity are important characteristics of every cloud. Multi-tenancy can be economical; however, it raises some security concerns. For example, contender companies may have Virtual Machines (VM) on the same server and have access to the same resources. There is always the possibility that one of them tries to get access to the opponent's data. In order to address these concerns, each tenant in the cloud should be secured separately and firewalls are one of the means that can help in that regard. Firewalls also protect virtual machines from the outside threats using access control lists and policies. On the other hand, virtual machines migrate frequently in an elastic cloud and this raises another apprehension about what happens to the security policies that are associated with the migrated virtual machine.
In this thesis, we primarily contribute by proposing a novel framework that coordinates the mobility of the associated security policies along with the virtual machine in Software-Defined Networks (SDN). We then design and develop a prototype application called Migration Application (MigApp), based on our framework that moves security policies and coordinates virtual machine and security policy migration. MigApp runs on top of SDN controllers and uses a distributed messaging system in order to interact with virtual machine monitor and other MigApp instances. We integrate MigApp with Floodlight controller and evaluate our work through simulations.
In addition, we prepare a test-bed for security testing in clouds that are based on traditional networks. We focus on virtual machine migration and use open-source utilities to equip this test-bed. We design an architecture based on GNS3 network emulator in order to provide a distributed testing environment. We then propose a virtual machine migration framework on Oracle VirtualBox; and finally, we enrich the security aspect of framework by adding firewall rule migration and security verification mechanisms into it.