identifier: Jian Xia., Yan  (2008) A survey of the state of bridge management in Canada.  Masters thesis, Concordia University.

abstract: With the aging of its infrastructure, Canada is facing a critical problem to deal with the complex and fragmental issues existing in current infrastructure management. Because Bridge Management Systems (BMSs) are not used in a systematic way in some provinces in Canada, this research aims at reviewing the current state of BMSs in Canada and suggesting an initiative to build a Canadian National Bridge Inventory. For example, The Bridge Expert Analysis and Decision Support (BEADS) system currently used in Alberta is different from the BMSs of other provinces in its system structure and scope. BEADS is an important part of a comprehensive system--Transportation Infrastructure Management System (TIMS). The Ontario BMS integrates the deterioration model, cost model, and business rules for treatment selection and costing, and an analytical framework for calculating and representing information relevant to the decision at hand. The Quebec BMS has three main models (Deterioration Model, Treatment Model, and Cost Model) that are used to create work alternatives at the element, project, and program levels. After comparing the above BMSs, the research discusses a new research project at Concordia University to build a Canadian National Bridge Inventory (CNBI) similar to the NBI used in the U.S.A.   As a case study about the information that can be used in the CNBI, the database of Quebec BMS has been analyzed in detail and a graphical user interface (GUI) of Quebec bridge database has been developed. The inventory part of this database is proposed as an example that can be modified in the future to be used as the base for the Canadian BNI.   Next, the database is used to perform some calculations related to replacement cost of bridges. The effect of three factors on the replacement cost of Quebec bridges are studied including the age of bridges, their structural type, and location. However, the current data are not enough to analyze the replacement cost. Therefore, personal records for each bridge to monitor bridge status from the design stage to the end of design service life should be included in bridge database.  Finally, a method for assessing Quebec bridges is explained. In addition, a new depreciation method is introduced based on the traditional straight line method and considering the effects of traffic volume. As the example demonstrated, the annual depreciation value and the depreciation period are related more closely to actual use. The proposed depreciation method would result in a more accurate assessment of bridge assets as capital stock.


identifier: Ahmed Shiblee., Noman  (2008) Application of vibration based methods and statistical pattern recognition techniques to structural health monitoring.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: The primary objective of Structural Health Monitoring (SHM) is to diagnose structures for damage, take necessary measures if any damage occurs, and estimate their degradation rate.   Conventional non-destructive evaluation methods are not always practical for implementation of a continuous health monitoring system. Vibration Based Damage Identification (VBDI) methods applied to SHM can be useful in interpreting the global vibration response of a structure to identify local changes. Due to complicated features of real life structures there are some uncertainties related to input parameters such as measured frequencies and mode shape data, where output is sensitive to errors in modal parameters. As all VBDI processes rely on experimental data with their inherent uncertainties, statistical procedures are helpful if one is to interpret the vibration response mixed with other ambient affects.   The objective of this study is the detection of damage by VBDI methods and statistical pattern recognition techniques. Here, two practical structures, the Crowchild Bridge in Calgary, and a 3D-Space Frame have been tested with two VBDI algorithms. The Damage Index and Matrix Update methods have been selected to study simulated damage cases on the numerical models of the selected structures. For the application of statistical pattern recognition techniques to damage identification, another in-service structure, the Portage Creek Bridge in Victoria, Canada has been tested. The classification of the patterns has been performed using outlier analysis. Alternatively, damage detection by pattern comparison using residual errors has been applied.


identifier: Turkmen, Banu  (2008) Revenue management in airline operations : booking systems and aircraft maintenance services.  PhD thesis, Concordia University.

abstract: Although the principles of Revenue Management (RM) have vaguely been used in business for a long time, an increasing number of organizations are implementing well structured RM systems in the last few decades due to the developments in science and technology, especially in economics, statistics, operations research and computer science. The improvements in information and telecommunication technologies, wide use of Internet, rise of e-commerce and successful supply chain management strategies have enabled organizations to model and solve complex RM problems.   This dissertation research concentrates on airlines, the earliest and leading user of RM. Today, airlines face serious financial problems due to the increasing costs and competition. They continuously explore new opportunities especially in terms of RM to make profit and survive. In this study, two problems are analyzed within this scope; airline booking process with adapted options approach and aircraft maintenance order control through RM.   First; a new approach, financial options approach, is proposed to sell tickets in airline reservation systems. The options are used to overcome the uncertainty in air travel demand and competitors' actions. The seat inventory control problem is formulated with overbooking and embedded options respectively. Then a simulation study is conducted the potential of using options in airlines booking process. Accordingly, empirical results show that they present an opportunity both to utilize capacity more efficiently and to value seats more precisely compared to overbooking approach.   Secondly; a peak load pricing concept is applied for aircraft maintenance order control problem. Aircraft maintenance centers face with peak loads in some seasons and the capacity is underutilized in other seasons. A peak load pricing model is proposed to shift some of the price elastic demand from peak seasons to off-peak seasons to balance demand and supply around the year. A dynamic programming algorithm is developed to solve the model and a code is written in C++. Results show that the model improves both annual capacity loading factors and revenues without causing a discomfort from the perspective of the customers. The details of both studies are presented in this dissertation research. [PUBLICATION ABSTRACT]


identifier: Alawieh, Basel  (2008) Exploring spatial reuse effects on performance enhancements in wireless multihop networks.  PhD thesis, Concordia University.

abstract: Recent years have witnessed a remarkable interest in wireless multihop ad hoc networks that need little or no infrastructure support. Such networks have enabled the existence of various applications ranging from the monitoring of herds of animals to supporting communication in military battle-fields and civilian disaster recovery scenarios as well as providing an emergency warning system for vehicles on the road. Currently, the distributed coordination function (DCF) of the IEEE is the industry dominant MAC protocol for wireless multihop ad hoc environment due to its simple implementation and distributed nature. Nevertheless, the DCF access method does not make efficient use of the shared channel due to its inherent conservative approach in assessing the level of interference. Moreover, the implementation of DCF in multihop ad hoc networks suffers from the exposed and hidden terminal problems; both of these problems highly affect the spectrum spatial reuse and accordingly causes serious throughput deterioration. To date, various methods have been proposed to enhance the throughput of the DCF; namely, tuning the carrier sensing threshold, the transmission attempt probability through changing the binary exponential backoff, controlling the frame transmit power, adapting the physical transmission rate of data frame, and the use of directional antennas. In this thesis, we develop mathematical tools to study the effectiveness of the interplay among the various tunable parameters and propose suitable protocols for achieving better utilization of the wireless spectrum.


identifier: Koodiani, Sadegh Farzaneh  (2008) Novel hardware implementation and adaptive beamforming algorithms for microwave beamforming structure.  PhD thesis, Concordia University.

abstract: Using beamforming in a wireless communication channel increases its capacity. A major challenge in deploying beamforming in commercial wireless communications is the high implementation cost. Microwave beamforming (MBF) is a low complexity alternative due to using only one radio frequency (RF) down-conversion and analog to digital converter (ADC). However, traditional MBF structures employ a phase shifter and a gain control block per antenna element which are expensive and bulky. Moreover, signal processing for MBF structures is more difficult due to lack of an antenna array signal vector in the processor.   This thesis investigates both the microwave hardware and the signal processing issues associated with the MBF structures. It introduces a new low-complexity beamforming implementation technique, the microwave sampling beamformer (MSBF). In addition, a new perturbation technique based on array signal estimation is devised for application of advanced signal processing to the MBF structures. Throughout this research different RF implementation and signal processing issues are jointly taken into account.   In the proposed MSBF structure, phase shift and amplitude attenuation are controlled through switching of the antenna array signals using control pulses with adjusted time delay and pulse width. Both the phase shift and amplitude attenuation are controlled over the full range in one simple block. The proposed structure is validated in the frequency and time domains with microstrip and wire antenna arrays. Different MSBF issues such as switch design, finite duration pulse train, and image replica rejection are investigated. A four-element prototype of the MSBF structure composed of the microwave and control hardware is constructed and tested. The beamforming structure is designed to have eight bits phase shifter resolution and 12 bits amplitude resolution. The whole prototype is examined for beam steering, side-lobe level (SLL) control, and null-forming.   In the new perturbation technique the antenna array signal vector is estimated based on the array signal temporal correlation. The temporal correlation is provided by a fast perturbation rate or receiver bandwidth reduction. Single-port adaptive unconstrained least mean square (ULMS) beamforming and multiple signal classification (MUSIC) DOA algorithms are investigated and they outperform the corresponding multi-port algorithms depending on the channel scenario.


identifier: Fattah, Shaikh Anowarul  (2008) AR and ARMA system identification techniques under heavy noisy conditions and their applications to speech analysis.  PhD thesis, Concordia University.

abstract: System identification under noisy environment has axiomatic importance in numerous fields, such as communication, control, and signal processing. The system identification is to estimate and validate the parameters of the system from its output observations, a task that becomes very difficult when the system output is heavily noise-corrupted. The major objective of this research is to develop novel system identification techniques for an accurate estimation of the parameters of minimum phase autoregressive (AR) and autoregressive moving average (ARMA) systems in practical situations where the system input is not accessible and only noise-corrupted observations are available. Unlike conventional system identification methods in which only the white noise excitation is considered, both the white noise and periodic impulse-train excitations are taken into account in the methodologies developed with an aim of directly using them in speech analysis.   A new ARMA correlation model is developed, based on which a two-stage correlation-domain ARMA system identification method is proposed. In the first stage, the new model in conjunction with a residue based least-squares (RBLS) model-fitting optimization algorithm is used to estimate the AR parameters. In the second stage, the moving average (MA) parameters are estimated from the residual signal obtained by filtering the observed data using the estimated AR parameters. With a view to overcome the adverse affect of noise on the MA part, a noise-compensation scheme using an inverse autocorrelation function (IACF) of the residual signal is also proposed.   Cepstrum analysis has been popular in speech and biomedical signal processing. In this thesis, several cepstral domain techniques are developed to identify AR and ARMA systems in noisy conditions. First, a ramp-cepstrum model for the one-sided autocorrelation function (ACF) of the AR and ARMA signals is proposed, which is then used for the estimation of the parameters of AR or ARMA systems using the RBLS algorithm. It is shown that for the estimation of the MA parameters of the ARMA systems, either a direct ramp-cepstrum model-fitting based approach or a noise-compensation based approach can be adopted. Considering that, in the case of real signals, discrete cosine transform is more attractive than the Fourier transform (FT) in terms of the computational complexity, a ramp cosine cepstrum model is also proposed for the identification of the AR and ARMA systems.   In order to overcome the limitations of the conventional low-order Yule-Walker methods, a noise-compensated quadratic eigenvalue method utilizing the low-order lags of the ACF, is proposed for the estimation of the AR parameters of the ARMA system along with the noise variance. For the estimation of the MA parameters, the new noise-compensation method, in which, a spectral factorization of the resulting noise-compensated ACF of the residual signal is used, is employed. In order to study the effectiveness of the proposed identification techniques, extensive simulations are carried out by considering synthetic AR and ARMA systems of various orders under heavy noisy conditions. The results demonstrate the significant superiority of the proposed techniques over some of the existing methods even under very low levels of SNR. Simulation results on the identification of human vocal-tract systems using natural speech signals are also provided, showing a superior performance of the new techniques.   As an illustration of application of the proposed AR and ARMA system identification techniques to speech analysis, noise robust schemes for the estimation of formant frequencies are developed. Synthetic and natural phonemes including some naturally spoken sentences in noisy environments are tested using the new formant estimation schemes. The experimental results demonstrate a performance superior to that of some of state-of-the-art methods at low levels of SNR.


identifier: Gawanmeh, Amjad  (2008) On the formal verification of group key security protocols.  PhD thesis, Concordia University.

abstract: The correctness of group key security protocols in communication systems remains a great challenge because of dynamic characteristics of group key construction as we deal with an open number of group members. Therefore, verification approaches for two parties protocols cannot be applied on group key protocols. Security properties that are well defined in normal two-party protocols have different meanings and different interpretations in group key distribution protocols, and so they require a more precise definition before we look at how to verify them. An example of such properties is secrecy, which has more complex variations in group key context: forward secrecy, backward secrecy, and key independence.   In this thesis, we present a combination of three different theorem-proving methods to verify security properties for group-oriented protocols. We target regular group secrecy, forward secrecy, backward secrecy, and collusion properties for group key protocols. In the first method, rank theorems for forward properties are established based on a set of generic formal specification requirements for group key management and distribution protocols. Rank theorems imply the validity of the security property to be proved, and are deducted from a set of rank functions we define over the protocol. Rank theorems can only reason about absence of attacks in group key protocols. In the second method, a sound and complete inference system is provided to detect attacks in group key management protocols. The inference system provides an elegant and natural proof strategy for such protocols compared to existing approaches. It complements rank theorems by providing a method to reason about the existence of attacks in group key protocols. However, these two methods are based on interactive higher-order logic theorem proving, and therefore require expensive user interactions. Therefore, in the third method, an automation sense is added to the above techniques by using an event-B first-order theorem proving system to provide invariant checking for group key secrecy property and forward secrecy property. This is not a straightforward task, and should be based on a correct semantical link between group key protocols and event-B models. However, in this method, the number of protocol participants that can be considered is limited, it is also applicable on a single protocol event. Finally, it cannot model backward secrecy and key independence. We applied each of the developed methods on a different group protocol from the literature illustrating the features of each approach.


identifier: Alshibani, Adel  (2008) Optimizing and controlling earthmoving operations using spatial technologies.  PhD thesis, Concordia University.

abstract: This thesis presents a model designed for optimizing, tracking, and controlling earthmoving operations. The proposed model utilizes, Genetic Algorithm (GA), Linear Programming (LP), and spatial technologies including Global Positioning Systems (GPS) and Geographic Information Systems (GIS) to support the management functions of the developed model. The model assists engineers and contractors in selecting near optimum crew formations in planning phase and during construction, using GA and LP supported by the Pathfinder Algorithm developed in a GIS environment. GA is used in conjunction with a set of rules developed to accelerate the optimization process and to avoid generating and evaluating hypothetical and unrealistic crew formations. LP is used to determine quantities of earth to be moved from different borrow pits and to be placed at different landfill sites to meet project constraints and to minimize the cost of these earthmoving operations. On the one hand, GPS is used for onsite data collection and for tracking construction equipment in near real-time. On the other hand, GIS is employed to automate data acquisition and to analyze the collected spatial data.   The model is also capable of reconfiguring crew formations dynamically during the construction phase while site operations are in progress. The optimization of the crew formation considers: (1) construction time, (2) construction direct cost, or (3) construction total cost. The model is also capable of generating crew formations to meet, as close as possible, specified time and/or cost constraints.   In addition, the model supports tracking and reporting of project progress utilizing the earned-value concept and the project ratio method with modifications that allow for more accurate forecasting of project time and cost at set future dates and at completion. The model is capable of generating graphical and tabular reports. The developed model has been implemented in prototype software, using Object-Oriented Programming, Microsoft Foundation Classes (MFC), and has been coded using visual C++ V.6. Microsoft Access is employed as database management system. The developed software operates in Microsoft windows' environment. Three example applications were analyzed to validate the development made and to illustrate the essential features of the developed model.


identifier: Abu Dabous, Saleh  (2008) A decision support methodology for rehabilitation management of concrete bridges.  PhD thesis, Concordia University.

abstract: Managing the existing bridge infrastructure has become a major social and economic concern in North America. This is due to the critical conditions of the deteriorated bridges and the limited funds available to repair their deficiencies. Most transportation agencies make bridge investment decisions based on a combination of some form of quantitative data analysis and the subjective judgments of decision and policy makers. The subjective nature of the decision making process easily raises questions about whether the investment decisions are being developed in a fair, equitable and systematic manner. This dissertation presents a decision support methodology developed for the rehabilitation management of concrete bridges in general, and for bridge decks in particular. A probabilistic bridge condition assessment method is developed. This method is consistent with the current practice in bridge inspection and the Markovian approach to model deterioration. A means to rank bridge projects is presented, which makes use of a hierarchy structure to represent the problem and rank the different bridge projects using the Multi Attribute Utility Theory (MAUT). A method to evaluate the available rehabilitation strategies is discussed. This method uses a modified Analytic Hierarchy Process (AHP) and the Monte Carlo simulation technique to evaluate the weights for the different rehabilitation strategies available for each project. A decision making technique to select a recommended work program that maximizes benefits to the network and to the users is developed. The developed methodology has the potential to be extended to other bridge components and to be the foundation for a comprehensive bridge management system. The significant features of this methodology can be summarized as follows: (1) It is consistent with the current practice in bridge management condition assessment and deterioration modeling. (2) It employs a multiple-criteria decision making process; (3) it has the flexibility to allow engineers to utilize their experience and judgment in the decision making process; and (4) It combines the network and the project levels of the bridge management process and performs effectively within a limited budget.


identifier: Zelmer, Kyle  (2008) Perceptions of food risk and labeling.  Masters thesis, Concordia University.

title: Perceptions of food risk and labeling

abstract: Consumption of foods labeled in certain ways entails an array of social, economic, political, and ethical considerations which go beyond the simple provision of sustenance. The extent of the relationship between food politics and the social construction of the self is analyzed in this thesis. Risk perceptions regarding genetically modified foods and the recent explosion in the significance of the organic food market are explored. Canadian food labeling regulations, corporate strategies for promotion of food biotechnology, and grocery merchants' strategies for the expansion of organic, free range, fair trade, and genetically modified food markets are evaluated through textual analysis. Semi-structured interviews are then conducted with experts in the fields of philosophy, natural science, and business to explore rationalities for consumption of these types of foods.


identifier: Racicot, Simon  (2008) Pharmacological and social smoke exposure as differential predictors of smoking risk in never-smoking youth.  Masters thesis, Concordia University.

abstract: Studies investigating smoking risk among children and adolescents have typically focused on social smoke exposure via parents, siblings, and peers. Recently, researchers found that second-hand smoke exposure measured with biomarkers among never-smokers uniquely predicted smoking initiation and greater endorsement of withdrawal sensations. Based on these findings, researchers posited a physiological pathway between second-hand smoke exposure and smoking behaviour may exist. The aim of the present study was to simultaneously investigate whether social smoke exposure and pharmacological exposure to nicotine both uniquely contribute to greater smoking risk among never-smoking youth.   Participants included 338 never-smoking youth (53.5% females) aged 11-13 years (M = 12.68, SD = 0.67) attending 6 th or 7th grade in French-speaking schools. Participants completed self-report questionnaires measuring their own smoking behaviours, social smoke exposure (parents, siblings, peers, school), and known risk factors for eventual smoking (smoking expectancies, smoking susceptibility, perceived nicotine dependence). Each participant also provided a saliva sample and an expired breath sample, from which cotinine and carbon monoxide biomarkers were derived, to objectively measure second-hand exposure.   Structural equation modeling was used to test the research hypotheses. Pharmacological exposure was not associated with smoking risk. Social smoke exposure of parental and peer smoking were significantly associated with smoking risk. When considered simultaneously, despite having models with acceptable to good fit, pharmacological and social smoke exposure together largely explained only a small proportion of the variance in smoking risk (1.4-4.7%), with the exception of peer smoking which explained considerable variance (58%). These findings do not suggest that pharmacological and social smoke exposure are differential predictors of smoking risk. Further, they do not support the possibility of a physiological pathway from second-hand exposure to smoking behaviour. Rather, the results suggest biomarkers may actually be a good proxy for social smoke exposure. To better evaluate the possibility of a physiological pathway, future studies should aim to recruit participants with a wider range of smoke exposure (i.e., low, moderate, or high exposure) and to more precisely measure longer-term exposure to second-hand smoke (e.g., hair nicotine, DNA encoding for CYP2A6, CYP2B6, and CYP2E1 enzymes which metabolize nicotine).


identifier: O'Donnell, Jaynus  (2008) From aardvark to army, from Wales to zoos : using collage practice to examine messages in children's pictorial encyclopedias.  Masters thesis, Concordia University.

abstract: By engaging in art making and analytic activities I seek to answer the question: How can collage be used to examine, critique and interrupt the meaning of images and objects in individual visual and material culture experiences? Through the use of arts-based research methods and auto-ethnographic inquiry, I show that intellectual insights can be garnered through reflective art production and that this production is a form of inquiry and critique, particularly useful when examining individual encounters with visual and material culture. This method is essential in helping to answer the research question; engaging in art production using personal visual and material culture artifacts (children's pictorial encyclopedias) helps me connect with these objects in a way different from my initial childhood interactions and from my adult viewing and allows me to recognize recurring themes, which are utilized in the analytic process.


identifier: Lynch, Marianne  (2008) A perfect stranger : the development of Margaret Cavendish's natural philosophy.  PhD thesis, Concordia University.

abstract: The natural philosophy of Margaret Cavendish is a fragmented collection of texts and ideas. In this thesis, the multiple lenses of learning theory, writing theory, history and philosophy of science, and literary studies are employed to show the ultimate coherence of Cavendish's science. The mechanism of a taxonomy of cognitive processes is applied to explore the gradual evolution of her understanding of her material and ideas. Writing process theories further illuminate both the ways that her thinking develops as she composes and the ways that she comes to manipulate her texts in view of her changing relationship with her reading audience. Exploring the social and political influences affecting the development of early modern science further adds to an understanding of the opinions that Cavendish comes to hold. Finally, the literary and linguistic elements of her text, including their genre, structure, rhetorical devices and figurative language, contribute significantly to a full recognition of Cavendish's evolving scientific and epistemic beliefs. By examining her eight texts most concerned with natural philosophy as revelatory parts of a process rather than discrete meaning-entities, it is clear that Cavendish was responding to complex internal and external forces that simultaneously shaped her writing, her thinking, her social vision, her science, and her larger conception of nature and knowledge.


identifier: Burns, Catherine  (2008) The educator's role in preschool dramatic story reenactments : scaffolding in action.  Masters thesis, Concordia University.

abstract: This research study explored the role educators play in supporting Dramatic Story Reenactments. Dramatic Story Reenactments (DSRs) involve children re-creating or acting out familiar stories by themselves or with the guidance of a teacher (Martinez, 1993). It has been proposed that experiences with DSRs provide children with opportunities to practice language skills and enhance their understanding of story (Martinez, 1993).   The participants in this study were two experienced educators and their groups of ten 4- and 5-year-olds. The educators were asked to implement DSRs three times a week for four weeks with their groups of children in a daycare centre in Montreal. Prior to the DSR intervention the educators received a brief training session from the researcher. The stories read for the DSR were videotaped for analysis, as was the DSR process. Grounded theory methodologies were used to analyze the scaffolding strategies the educators used during the DSR process. The categories of scaffolding that emerged from the data were analyzed and described in order to generate a theory for best practices.   Findings from this study suggest that there were several interactive behaviours educators used when reading the story prior to the DSR that enhanced and supported the DSR process. Educator scaffolds were many and varied over the course of the DSR intervention and fell under four broad categories that included story structure supports, dramatization supports, story language supports, and positive guidance supports. Based on these findings, implications for practice are recommended and discussed.


identifier: Khabazian, Mehdi  (2008) A performance modeling of connectivity in vehicular ad hoc networks (VANETs).  PhD thesis, Concordia University.

abstract: An emerging new type of ad hoc networks is Vehicular Ad hoc NETworks (VANETs) which envision Inter-Vehicle Communications. Since, nodes in VANETs are both mobile as well as carrier of information; the network may not have full communication connectivity all the time and they may form several clusters where the nodes in each cluster may communicate with each other directly or indirectly. Multi-clustering happens whenever the minimum distance between two adjacent nodes becomes more than the transmission range of a node. Therefore, two important performance measures which affect the functionality in VANETs are communications connectivity and path availability .   In this thesis, we study the statistical properties of these performance measures in VANETs at the steady state. First, it is assumed that the nodes travel along a multi-lane highway which allows vehicles to overtake each other. We derive the probability distributions of the node population size and node's location in the highway segments. Then, we determine the mean population size in a cluster and probability that nodes will form a single cluster.   Then we extend the single highway model to a network of highways with arbitrary topology. We determine the joint distribution of the node populations in the highways' segments by application of the BCMP theorem. We model the number of clusters within the node population in a network path as a Markovian birth-death process. This model enables derivation of the probability distribution of the number of clusters and determination of mean durations of continuous communication path availability and unavailability times as functions of mobility and node arrival parameters. At the end, mean packet delay is presented for end to end communication in a path. We give numerical results which illustrate the effect of mobility on continuous communication path availability and communication delay. The results of this work may be helpful in studying the optimal node transmission range assignment, routing algorithms, network throughput, optimization of cross layer design schemes and MAC protocols in VANETs.


identifier: Hussein, Mohamed Hamed Zaki  (2008) Techniques for the formal verification of analog and mixed- signal designs.  PhD thesis, Concordia University.

abstract: Embedded systems are becoming a core technology in a growing range of electronic devices. Cornerstones of embedded systems are analog and mixed signal (AMS) designs, which are integrated circuits required at the interfaces with the real world environment. The verification of AMS designs is concerned with the assurance of correct functionality, in addition to checking whether an AMS design is robust with respect to different types of inaccuracies like parameter tolerances, nonlinearities, etc. The verification framework described in this thesis is composed of two proposed methodologies each concerned with a class of AMS designs, i.e., continuous-time AMS designs and discrete-time AMS designs. The common idea behind both methodologies is built on top of Bounded Model Checking (BMC) algorithms. In BMC, we search for a counter-example for a property verified against the design model for bounded number of verification steps. If a concrete counter-example is found, then the verification is complete and reports a failure, otherwise, we need to increment the number of steps until property validation is achieved. In general, the verification is not complete because of limitations in time and memory needed for the verification. To alleviate this problem, we observed that under certain conditions and for some classes of specification properties, the verification can be complete if we complement the BMC with other methods such as abstraction and constraint based verification methods. To test and validate the proposed approaches, we developed a prototype implementation in Mathematica and we targeted analog and mixed signal systems, like oscillator circuits, switched capacitor based designs, Delta-Sigma modulators for our initial tests of this approach.


identifier: Lei, Yu  (2008) Active site studies of DmpFG, a bifunctional aldolase/dehydrogenase from pseudomonas sp. strain CF600.  PhD thesis, Concordia University.

abstract: DmpFG, a bifunctional aldolase/dehydrogenase (acylating), comprises the last two enzymes of the (dimethyl)phenol degradation pathway in Pseudomonas sp. strain CF600. DmpG, a class II divalent cation dependent aldolase belonging to the HMGL-like family, cleaves 4-hydroxy-2-ketovalerate to pyruvate and acetaldehyde while DmpF, an NAD+ /CoA dependent aldehyde dehydrogenase (acylating), oxidizes the acetaldehyde to acetyl-CoA.   Studies of the DmpF active site focused on delineation of the coenzyme A binding site, and involvement of a conserved cysteine residue, Cys132, in catalysis and substrate-mediated inactivation. By coupling hydrogen-deuterium exchange experiments with peptic digest/mass spectrometric analysis, coenzyme A was shown to share the same binding site as NAD + . Cys132 was identified as an essential cysteine, and was shown to form an acetyl-Cys132 intermediate which was trapped and identified by mass spectrometry. Coenzyme A-mediated inactivation resulted from disulfide bond formation between thiol groups of Cys132 and coenzyme A. Loss of activity in the presence of acetaldehyde was incurred by the oxidation of Cys132 to cysteine sulfinic acid, as observed by mass spectrometry.   Studies of DmpG focused on the roles of metal ions and putative active site residues. Purified preparations contained a mixture of Fe, Mn, Zn and Cu, in order of decreasing content, with one mol total metal per mol protein. However, this tightly-bound metal could only support residual adolase activity, with full activity requiring high concentrations of Mn 2+ or Co2+ in the assay, suggesting two classes of metal binding sites. Site-directed mutagenesis was carried out on the three ligands to the tightly bound metal ion, Asp18, His200 and His202, as well as another three residues, potentially involved in catalysis, Arg17, His21 and Tyr291. D18N, H200A and H202A variants were depleted of bound metals, concomitant with complete loss of the residual aldolase activity. In the presence of Mn 2+ or Co2+ , aldolase activities of D18N and H200A variants remained very low in comparison with WT, but H202A aldolase activity was comparable to WT. Substitutions of Arg17 or His21 significantly impaired aldolase activity, while Tyr291 variants had activity similar to WT. Properties of these variants are discussed in relation to the family of HMGL-like enzymes.


identifier: Llama, Raquel  (2008) Cross-linguistic influence in third language acquisition : the roles of typology and L2 status.  Masters thesis, Concordia University.

abstract: Research has consistently identified two factors which affect how previously learned languages may influence the learning of a third: typological closeness and second language (L2) status. Although typology seems to play a more influential role in the acquisition of lexis in a third language (L3) (e.g., Rossi, 2006), the influence of L2 status has been observed in the acquisition of phonology (e.g., Williams & Hammarberg, 1998). However, these two factors are often confounded with each other, and with other variables such as proficiency. The aim of this study was to control for these variables and investigate the relative influences of L2 status and typology on lexis (lexical inventions) and phonology (aspiration) in L3 production. The research question addressed was: Which is a stronger predictor of the source language for lexical and phonological influence in L3 acquisition: L2 status or typology?   Two groups of L3-Spanish learners, 11 with English-L1 and French-L2, and 11 with French-L1 and English-L2 were recorded reading word lists and describing pictures in their L3. Paired samples t -test examined the frequency of French- and English-influenced instances of lexical inventions, as well as the presence or absence of aspiration in the word-initial voiceless stops /p t k/. Findings indicate that French, the typologically closer language to Spanish, had the greatest influence on lexical production, while L2 status had a more marked effect on L3 pronunciation than typology. The results suggest that the two factors investigated may affect different areas of language in different ways.


identifier: Duguay, Sylvain  (2008) Hybridités: Homosexualités de la scène á l'écran au Canada.  PhD thesis, Concordia University.

abstract: Les communautés queer changent rapidement et leur histoire doit être préservée afin de leur assurer une certaine continuité. Ces communautés sont nées d'un désir de changement et d'action, et il est important d'identifier les sources de diffusion de leur imaginaire social afin de les documenter et de les rendre accessibles. Mais comment la différence identitaire des sujets queer se manifeste-elle et comment tous ces sujets différents parviennent-ils à se regrouper en communauté?   Cette thèse démontre l'importance, pour les sujets queer, des signifiants spatiaux, temporels, corporels et langagiers, de même que le caractère hybride du processus identitaire. La recherche a été menée en analysant les treize adaptations de pièces de théâtre queer au cinéma, au Québec et au Canada, pour y relever les signifiants liés à l'espace, au temps, au corps et à la langue et décrire comment ils se transforment lors de l'adaptation. La sémiotique tensive phénoménologique de Fontanille a permis d'observer comment l'identité personnelle et communautaire du lecteur-spectateur est interpellée et potentiellement transformée par les oeuvres.   Il en ressort que l'hybridité du geste adaptatif, des signifiants et des identités permet aux gais, aux lesbiennes et aux autres sujets queer de connecter avec le discours en acte dans les oeuvres. Parfois des signifiants sont perdus lors de l'adaptation, ce qui résulte en un appauvrissement de l'imaginaire social qui affecte la mémoire collective, les utopies communes et le rapport aux idéologies dominantes.


identifier: Shulman, Deborah  (2008) Prisms of China : Canadian Women Missionaries in China, 1904-1945.  PhD thesis, Concordia University.

abstract: This thesis focuses on three remarkable Canadian women (Lena Jolliffe, Mary Lamb and Agnes Hilliard) who lived and worked in Sichuan, China as Christian missionaries during the chaotic first half of the twentieth century. The thesis is built around three overarching themes: the experiences of these three Westerners in China who were there as missionaries, as women and as Canadians; their contributions to China; and their impact back in Canada.   The thesis consists of five chapters. The first chapter introduces the study, provides an overview of the relevant historical context in China, and surveys the available English-language scholarly secondary source materials. Chapters Two, Three and Four deal respectively with each of the women, beginning with biographical sketches; providing overviews of the available archival materials; piecing together chronologically and thematically their individual China experiences and observations; and concluding with thematically-driven analytical overviews of their China experiences. Chapter Five thematically and comparatively revisits the China journeys of the three women. The sources on which this thesis is based are the letters and diaries of the women which have been deposited in the United Church of Canada archives in Toronto. The recipients of the letters were almost always family members or church friends. These three heroic Canadian women missionaries were effectively windows on China whose writings extend our understanding of China and its people. The thesis suggests that as missionaries, these women were more highly integrated into China than many other Westerners; that as missionary women, they were uniquely able to have direct and sustained contact with Chinese women; and that as Canadians, they were treated differently from other Westerners, occasionally serving as power brokers at the local level. These three women and their colleagues impacted upon China simply by being there as alternative role models; by their educational activities and public health instruction; and by initiating the liberation of Chinese women from their traditional restraints. They also had a significant impact upon Canada, particularly through their letters and furlough visits, which enhanced Canadian understanding of China.


identifier: Jolivet, Simon  (2008) Les deux questions irlandaises du Québec, 1898-1921 : des considérations canadiennes-françaises et irlando-catholiques.  PhD thesis, Concordia University.

abstract: This thesis explores two Québec's Irish questions: the first pertains to the survival of the ethnic sentiment of Irishness in the province of Québec at the beginning of the XX th century; the second looks at the impact of the political question of Ireland in Québec, between 1898 and 1921. The social, political and cultural upheavals that occurred in Ireland between 1898 and 1921--leading to the partition of the island and to the creation of the Irish Free State and of Northern Ireland--, were of concern to both French-Canadians and Irish-Catholics of Montréal and Québec City. It is no coincidence that the political question of Ireland had some impact in those communities. For numerous Irish-Catholic descendants of Québec, ±feeling Irish» and identifying themselves as full-members of the provincial Irish-Catholic community, encouraged them to stay in touch with the events occurring in Ireland. The survival of Irishness would lead many of them to actively support the struggle for Irish autonomy by investing both their time and money into the cause. For numerous French-Canadians, the rise of Home Ruler or Sinn Féiner nationalism in Ireland would also echo the rise of French-Canadian political and cultural nationalism. Members of these two communities, active in the Vieille Capitale and in the Canadian metropolis of the time, then worked--sometimes jointly, sometimes independently--, for the ambiguous cause of the ±liberty of Ireland». However, various tensions between Irish-Catholics and French-Canadians, in the province of Québec as well as in Canada, prevented the reconciliation of these important Catholic communities of Québec. While the Irish question helped to foster a better understanding of each other, the internal divisions concerning different questions (such as the political future of Canada, or the use of the English language in Canada's parishes and schools) would continue to create animosities between these two Québec coreligionists.


identifier: Lester, Peter  (2008) Cultural continuity and technological indeterminacy: itinerant 16mm film exhibition in Canada, 1918-1949.  PhD thesis, Concordia University.

abstract: This thesis charts the parallel historical trajectories of itinerant, non-theatrical forms of film exhibition practice and of 16mm projection technology, throughout the interwar years in Canada and into the post-World War II context. I argue that these two entities - a technology and a practice - developed in symbiosis with one another, and subsequently need to be understood in terms of this relationship. The cultural practice of traveling exhibition has often been considered a relic of the "early cinema" era, the first decade of the medium's development. It is a practice that was generally assumed to have long since perished in Canada, only to have been resuscitated in 1942 by the National Film Board. This thesis argues instead that itinerant film exhibition never actually ceased to exist in Canada, and that it in fact persisted, with varying degrees of frequency, throughout the interwar period, effectively demonstrating a continuity of screen practice that is generally not widely acknowledged. Concurrent to this, I argue that 16mm technology, although introduced as a medium for amateur employment and for exhibition in the domestic space, quickly charted an additional evolutionary tract, which in turn facilitated these numerous and varied traveling cinema operations. This thesis demonstrates that this was not an historical development that was by any means predetermined, nor was it met with enthusiasm by all sectors of the film industry. Discursive practices circulated within the industry and regulatory actions implemented by various levels of government attempted to both frame and contain the technology and its employment in non-theatrical arenas, but due to this involvement, they also served to legitimize and normalize them. The resulting narrative is at heart, therefore, essentially one of both technological indeterminacy but also of cultural continuity.


identifier: Powell, Alison  (2008) Co-productions of technology, culture and policy in North America's community wireless networking movement.  PhD thesis, Concordia University.

abstract: This thesis investigates the visions and realities of community WiFi's social and political impact, examining how communication technology and social forms are co-produced and providing a communication studies perspective on the transformation of social visions of technology into technological, social, and policy realities. By following the development of local WiFi projects and the emergence of broader policy-oriented mobilizations, it assesses the real outcomes of socially and politically progressive visions about information and communication technologies (ICTs). The visions of advocates and developers suggest that community WiFi projects can inspire greater local democratic engagement, while the realities suggest a more subtle bridging of influence from community WiFi actors into policy development spheres. The thesis describes local WiFi networks in Montreal and Fredericton, NB, and the North American Community Wireless Networking (CWN) movement as it has unfolded between 2004 and 2007, arguing that its democratic visions of technology and their institutional realities have been integral to the politicization of computing technology over the last four decades. Throughout the thesis, WiFi radio technology, a means of networking computers and connecting them to the internet by using unlicensed radio spectrum, acts as an example of how a technology's material form is co-produced along with its symbolic social and political significance.


identifier: Hart, Susan Elizabeth  (2008) Sculpting a Canadian hero : shifting concepts of national identity in Ottawa's core area commemorations.  PhD thesis, Concordia University.

abstract: The topic of collective memory or identity, as manifested in public commemorative monuments, offers rich possibilities for theoretical and analytical study. This thesis investigates the ongoing construction of national identity through a selection of major public monuments in what is referred to by the National Capital Commission as the "core area" of Canada's capital, an area defined by Confederation Boulevard. The figurative monuments studied include, but are not limited to, those located on Parliament Hill as well as monuments along Confederation Boulevard such as The Response (National War Memorial), Reconciliation (Peacekeeping Monument), the National Aboriginal Veterans Monument , and Terry Fox . Beginning with the first monument erected on Parliament Hill in 1885, and ending with the most recent additions in the new millennium, the thesis chronologically traces the identity-building process at work in the monuments through the overall theme of heroes, with specific themes of ethnicity and gender interwoven throughout the chapters. Using the monuments as primary sources, and drawing on insights from a number of deconstructive approaches, among them psychoanalytic and gender theory, I question and analyze the national identity-building process in order to assess how conceptions of "Canadianness" may have shifted over time. I conclude that although there appears to be a shift toward a more inclusive or diverse representation of Canadian identity in recent years, the underlying ideology has not changed significantly.


identifier: Couturier, Sonia  (2008) L'implication des amateurs d'art dans les réseaux artistiques et intellectuels en France au XVIIIe siècle : le cas de Claude-Henri Watelet (1718-1786).  PhD thesis, Concordia University.

abstract: L'activité des amateurs d'art dans les cercles intellectuels et artistiques représente un des phénomènes culturels les plus décisifs qui se sont épanouis en France au XVIII e siècle. Dans ce contexte, Claude-Henri Watelet s'impose comme une figure exemplaire. D'une part, nous remarquons que son profil correspond à une définition de l'amateur qui se distingue par ses contributions aux champs artistique et intellectuel de son temps. D'autre part, grâce à son action dans les différents milieux qu'il fréquente--notamment académiques et mondains--Watelet parvient à tisser un réseau de relations répondant à ses intérêts intellectuels, artistiques et personnels. Ce réseau s'inscrit dans un système d'échanges organisé selon une structure établie; toutefois, l'organisation de ce réseau peu varier selon les relations particulières entretenues par l'amateur avec les institutions--formelles ou informelles--et les individus--artistes, amateurs, administrateurs etc.--Aussi, l'activité artistique et intellectuelle devient-elle indissociable de l'activité sociale dans la quête d'une reconnaissance sociale du statut de l'amateur. Watelet vise par ailleurs la reconnaissance intellectuelle qu'il souhaite atteindre, entre autres, par la publication d'ouvrages variés. Dans cette perspective, l' Art de Peindre (1760), une trentaine d'articles sur les arts dans l'Encyclopédie (1754-1757) et l'Essai sur les jardins (1774) ont permis à Watelet de faire la démonstration de connaissances artistiques et littéraires acquises, de mettre à l'épreuve ses idées, mais aussi de faire preuve de créativité.


identifier: Ramachandran, Tanisha  (2008) Representing idols, idolizing representations : interpreting Hindu images from the nineteenth century to the early twentieth century.  PhD thesis, Concordia University.

abstract: At various points in history and in different geographical locations, the Hindu image has been signified and re-signified by Hindus and others. Hindu images serve a multitude of purposes--functioning politically, socially and religiously. To formulate an accurate social history or cultural biography of the Hindu image, it is necessary to examine the means, by which it travels, as well as the reception, placement and context of the object at various points on the route. It is my contention that while the trajectories that the images have traveled provide a significant cultural biography, it is discourse that not only paves the path it follows, but also gives the image significance. Using Foucauldian and postcolonial theories of representation that highlight avenues of knowledge production, this dissertation provides a social history of the Hindu image from the early nineteenth century until the early twentieth century in an Indian and Euro-American context. By examining texts produced by Orientalists, missionaries, art critics, Hindu reformers and Hindu nationalists, this dissertation will demonstrate how the Hindu image is signified through a series of discursive battles. Through these interactions we can trace the differing forms of the Hindu image as God, idol, art, and symbol. The overall aim of this dissertation is to demonstrate that the Hindu image does not have an essentialized meaning; rather it is the various textual strategies that construct the image's meaning and usage. While the materiality of the image is fundamental, it is the narrative that defines and sustains its existence--in effect, it is discourse that works to determine its form and function.


identifier: Bedair, Hatem  (2008) Forces induced in multi-storey framed concrete structures due to differential settlement of foundation elements.  PhD thesis, Concordia University.

abstract: A review of the international codes, including the National Building Code of Canada (NBCC), the American Association of State Highway and Transportation Officials (AASHTO) and the American Concrete Institute (ACI), indicates that these codes do not corporate the forces induced in the super-structural elements due to differential settlement of foundation elements in the design of multi-story structures. In fact the current design procedure, stipulates that foundation and superstructure are designed separately; furthermore, individual foundation elements may settle up to a total of one inch and 0.75 inch in differential settlement between the elements. It is then assumed that the adopted factor of safety for the superstructure will compensate for these additional stresses. This procedure may leads to a conservative design in some cases or serious cracks and damage.   This thesis presents a two-dimensional analytical model for multi-story structures subjected to differential settlement of the foundation elements. The objective of this research is create a dialogue between the superstructure and its foundation during the design stage, to allow designer to tradeoff between the additional stresses due to the differential settlements and the factor of safety of the superstructure. The results will leads to the choice of an allowable differential settlement and appropriate factor of safety of the superstructure, which will produce the most economical design for the building, without jeopardizing its safety.   In this study, 7 and 10-storey structures were analyzed using linear and non-linear techniques, (geometric and material nonlinearity). In this investigation, the computer program STAAD and ADINA were used to perform this analysis. The rigidity of the structure was represented by the relative slenderness ratio between beams and columns. Empirical formulae were developed and validated with the available analytical models to predict the stresses induced on the elements of the superstructure due to differential settlement of its foundation. These formulae will assist designers to include differential settlement as external load on its superstructure and further to perform a tradeoff between the superstructure and substructure to achieve the most economical design for the building. Detailed design examples were presented to demonstrate the proposed design procedure. The results of the present study will impact on the safety and economy of our building.   It should be noted herein that the differential settlements take place at the working load level, and accordingly, they are relatively small. Thus the only difference between linear and non-linear stress-strain (moment curvature) relationship is that the second accounts for the first crack which is insignificant.   It is hoped that the results and conclusions of this thesis to be incorporated in the current design codes for multi-story buildings.


identifier: Alouneh, Sahel A  (2008) On fault-tolerance and security in MPLS networks.  PhD thesis, Concordia University.

abstract: Multi-Protocol Label Switching (MPLS) is an evolving network technology that is used to provide Traffic Engineering (TE) and high speed networking. Internet service providers, which support MPLS technology, are increasingly required to provide high Quality of Service (QoS) guarantees and security.   One of the aspects of QoS is fault tolerance. It is defined as the property of a system to continue operating in the event of failure of some of its parts. Fault tolerance techniques are very useful to maintain the survivability of the network by recovering from failure within acceptable delay and minimum packet-loss while efficiently utilizing network resources. On the other hand, with the increasing deployment of MPLS networks, security concerns have been raised. The basic architecture of MPLS networks does not support security aspects such as data confidentiality, data integrity, and availability. MPLS technology has emerged mainly to provide high speed packet delivery. As a result security considerations have not been discussed thoroughly until recent demands for security have emerged by most providers and researchers.   In this thesis, we propose a new method that has a two-fold objective: to provide fault tolerance and to enhance the security in MPLS networks. Our approach uses a modified (k, n) threshold sharing scheme (TSS) combined with multi-path routing. An IP packet entering MPLS network is partitioned into n MPLS packets, which are each assigned to disjoint or maximally disjoint Label Switched Path (LSP) across the MPLS network. Receiving MPLS packets from k out of n LSPs are sufficient to reconstruct the original IP packet.   From the security point of view, the modified TSS provides data confidentiality, integrity, availability and IP spoofing. In addition, fault tolerance in MPLS is supported using reasonable resources. The recovery from node/link failure and/or transmission errors is provided with no delay or packet loss. Packet re-ordering may not be required if packets are lost due to failure. However, sequencing is considered in our approach to identify packets with transmission errors. In order to provide fault tolerance, our scheme requires n > k . However, for security purposes, if the target is only to provide data confidentiality, then only a modified (k, k ) TSS algorithm is sufficient and consequently no significant redundant bandwidth is required.  To verify that our approach does not require long processing time, we conducted simulations that show the modified TSS processing time does not significantly affect the packet transmission time. RSVP-TE is the MPLS signaling protocol used to establish LSPs. Extensions required to support multi-path routing in RSVP-TE are also studied.   The impact of multi-path routing and modified TSS on MPLS security and fault tolerance is investigated and compared with single routing. The connection intrusion probability and connection failure probability have shown lower values when multi-path routing is used. The application of IPSec security protocol in MPLS networks is also investigated.   Finally, we applied the modified threshold sharing scheme on MPLS multicast networks, where both the source specific tree approach and the group shared tree approach are considered.


identifier: Bonvin, Julie  (2008) Biochemical and biophysical characterization of a prephenate dehyodrogenase from the hyperthermophilic bacterium Aquifex aeolicus.  PhD thesis, Concordia University.

abstract: Prephenate dehydrogenase is a key enzyme from the TyrA protein family responsible for catalyzing the NAD+ -dependent oxidative decarboxylation of prephenate to hydroxylphenylpyruvate, one of the terminal steps in the biosynthesis of tyrosine (Tyr). To gain structural and biophysical information on this protein, PD from the thermophilic bacterium Aquifex aeolicus was expressed as a His-tagged protein in Escherichia coli and was purified by nickel affinity chromatography. The enzyme is susceptible to proteolysis at the N-terminal region of the protein and the exact site of cleavage was determined by mass spectrometry. Crystallography trials on several N-terminally truncated variants performed by our collaborators at the University of Toronto indicated that only the PD variant missing the first 19 amino acids (E19PD) yielded quality diffraction crystals. The biochemical and biophysical properties of the full-length PD were compared to E19PD also expressed recombinantly in E. coli . The enzyme functions as a cyclohexadienyl dehydrogenase, accepting prephenate (effectively) and L-arogenate (poorly) as substrates. Both forms of the enzyme are thermally stable and show maximal activity only at high temperatures, although E19PD is less stable but more active than the full-length protein. Low concentrations of the denaturant guanidinium hydrochloride (Gdn-HCl) activate the activity of E19PD, but at higher concentrations activity is lost concomitant with a multi-state pathway of denaturation which proceeds through unfolding of the dimer, oligomerization, then unfolding of monomers. Measurements of steady-state fluorescence intensity and its quenching by acrylamide in the presence of Gdn-HCl suggest that of the two tryptophan (Trp) residues per monomer, one is buried in a hydrophobic pocket and does not become solvent exposed until the protein unfolds, while the less buried Trp is at the active site. These findings are in accordance with the crystal structure of E19PD.   Site-directed mutagenesis and steady-state kinetic analyses of variant proteins were used to probe the roles of conserved residues. In accord with the crystal structure of the enzyme bound with NAD+ plus product and product analogues, His147 acted as a catalytic hydrogen bond acceptor while Ser216 was responsible for coordinating NAD+ and His147 to facilitate hydride transfer. Arg250 and His217 were responsible for binding prephenate in the active site. Additionally and most importantly, His217 in A. aeolicus PD and the homologous residue in E. coli CM-PD (His257) was shown to be critical for inhibition of activity by Tyr. Two assays were developed to assess Tyr binding to wild-type and variant enzymes. Our results are placed in context of crystal structures of PD bound with Tyr and indicate how TyrA proteins can accept hydroxyphenylpuruvate and Tyr in the active site of the enzyme.


identifier: Himada, Nasrin  (2008) Cinematic politics.  Masters thesis, Concordia University.

title: Cinematic politics

abstract: Available also on the Internet.


identifier: Khedri, Saeed  (2008) Design and implementation of a wind turbine emulator with extended dynamic characteristics.  Masters thesis, Concordia University.

abstract: The wind turbine emulator (WTE) is of concern due to the fact that the wind energy conversion system (WECS) is a growing industry and needs further improvement. It is a key component of a test bench which provides the opportunity to investigate the effect of wind turbine parameters and characteristics on the system responses by modeling the wind turbine and the drive train. Several WTEs have been proposed by the researchers with different capabilities and degrees of complexity. The most important factors which have significant impact on the dynamic behavior of the WECS, as considered in the literature, are the wind turbine mass moment of inertia, system's natural frequency, pulsating (oscillatory) torque, and damping constant. In general, at least the effect of one of these facts was not included or not discussed in the reported WTEs.   This Thesis addresses this problem while considering on a simplified model of a wind turbine which consists of a mass moment inertia (rotor and hub), a low speed side flexible shaft, an ideal gearbox, a high speed side rigid shaft, and an electric generator. The effect of the oscillatory torque is also considered in the model. The simulation results indicate that the simplified model of the wind turbine and the drive train allow the investigation of the above mentioned factors on the system responses. It also shows the different ways of exciting the system's mechanical mode. A 2-hp experimental set-up is implemented and tested with a dynamometer as a mechanical load and also with a self-excited induction generator operating in the regulated and unregulated stand-alone mode. The experimental results agree with the simulation results.


identifier: Saleh, Mohamed  (2008) Game semantics for the specification and analysis of security protocols.  PhD thesis, Concordia University.

abstract: Security protocols are communication protocols that are used when agents communicate sensitive information in hostile environments. They are meant to achieve security goals such as the secrecy of a piece of communicated information or the authenticity of an agent's identity. Their two main characteristics are the use of cryptographic operations such as encryption or digital signatures and the assumption that communication takes place in the presence of a malicious intruder. It is therefore necessary to make sure that the protocol design is correct and will thus achieve its security goals even when under attack by the intruder. Design verification for security protocols is no easy task; a successful attack on the Needham-Shroeder authentication protocol was discovered 17 years after the protocol had been published.   We present a, framework for the specification and analysis of security protocols. The specification language is close to the standard "arrow" notation used by protocol designers and practitioners, however, we add some constructs to declare persistent and fresh knowledge for agents. The analysis that we conduct consists of two stages: Modeling and verification. The model we use for protocols is based on game-semantics, in which the emphasis is put on interaction. The protocol is modeled as a game between the intruder and agents. Verification amounts to finding successful strategies for either the agent or the intruder. For instance, if the protocol goal is to achieve fairness in exchanges between possibly cheating agents, then the verification algorithm searches the game tree to insure that each non-cheating agent is not put at a disadvantage with respect to other agents. In order to he able to specify a wide range of security properties of strategies, we propose a logic having modal, temporal and linear characteristics. The logic is also equipped with a tableau-based proof system that serves as a basis for a model checking algorithm. To validate our approach, we designed and implemented a software environment that verifies protocol specifications against required properties. We use this environment to conduct case studies.


identifier: Bongiorno, Tony  (2008) How to combine influence tactics : using the elaboration likelihood model to guide sequencing of tactics.  Masters thesis, Concordia University.

abstract: This scenario study used a 3 (influence tactic) x 2 (strength of rational persuasion) experimental design to investigate what combination of proactive influence tactics was most effective in gaining commitment. It was only the second study after Barry and Shapiro (1992) to examine experimentally combinations of proactive influence tactics. It used the Elaboration Likelihood Model (ELM) to derive hypotheses. It tested 103 individuals (46 men and 57 women) who were on average 20.8 years old. Participants read a hypothetical e-mail by a co-manager. They rated the extent to which they would commit to the co-manager's request. They also listed their positive and negative thoughts about the issue. The results showed that: (1) Rational persuasion gained the same amount of commitment whether it was combined with ingratiation or apprising; (2) ingratiation and apprising did not affect how deeply participants scrutinized the issue (i.e., elaboration); (3) commitment was not related to participants' level of elaboration; and (4) the number of influence tactics used did not change the level of commitment. One hypothesis was supported: that stronger rational persuasion gains more commitment than weaker forms of rational persuasion. These results are consistent with some of the literature, which states that not all tactics can be effectively combined. These conclusions are explored in light of the study's limitations. Future lines of research using ELM are also discussed. [PUBLICATION ABSTRACT]


identifier: Alam, Rafiul  (2008) Designing and trusting multi-agent systems for B2B applications.  Masters thesis, Concordia University.

abstract: This thesis includes two main contributions. The first one is designing and implementing B usiness-to-B usiness (B2B ) applications using multi-agent systems and computational argumentation theory. The second one is trust management in such multi-agent systems using agents' credibility.   Our first contribution presents a framework for modeling and deploying B2B applications, with autonomous agents exposing the individual components that implement these applications. This framework consists of three levels identified by strategic, application, and resource, with focus here on the first two levels. The strategic level is about the common vision that independent businesses define as part of their decision of partnership. The application level is about the business processes, which are virtually integrated as result of this common vision. Since conflicts are bound to arise among the independent applications/agents, the framework uses a formal model based upon computational argumentation theory through a persuasion protocol to detect and resolve these conflicts. Termination, soundness, and completeness properties of this protocol are presented. Distributed and centralized coordination strategies are also supported in this framework, which is illustrated with an online purchasing case study followed by its implementation in Jadex, a java-based platform for multi-agent systems.   An important issue in such open multi-agent systems is how much agents trust each other. Considering the size of these systems, agents that are service providers or customers in a B2B setting cannot avoid interacting with others that are unknown or partially known regarding to some past experience. Due to the fact that agents are self-interested, they may jeopardize the mutual trust by not performing the actions as they are supposed to. To this end, our second contribution is proposing a trust model allowing agents to evaluate the credibility of other peers in the environment. Our multi-factor model applies a number of measurements in trust evaluation of other party's likely behavior. After a period of time, the actual performance of the testimony agent is compared against the information provided by interfering agents. This comparison process leads to both adjusting the credibility of the contributing agents in trust evaluation and improving the system trust evaluation by minimizing the estimation error.


identifier: Shaikh, Nasiruddin  (2008) An experimental investigation of the near surface flow structure over wind-sheared water surface.  PhD thesis, Concordia University.

abstract: The study of airside flow structure and its interaction with water at the air-water interface is important in order to understand the exchange of momentum, heat and mass fluxes between the two mediums. The present dissertation deals with the quantitative investigation of the near-surface flow above wind-sheared water surface through a series of laboratory experiments conducted over a wind speed range of 1.5 m s -1 to 4.4 m s-1 and at a fetch of 2.1 m. The two-dimensional velocity fields were measured using particle image velocimetry (PIV). To compare the airflow structure over the water surface with that over solid wall, the measurements were also made over the smooth and wavy walls at the same location, under identical conditions.   The results show a reduction in the mean velocity magnitudes and the tangential stresses when gravity waves appear on the water surface. An enhanced vorticity layer was observed immediately above the water surface that extended to a height of approximately two times of the significant wave height. A novel approach is used to separate the wave-induced component from the instantaneous velocity fields. The flow structure was analyzed as a function of wave phase. The phase-averaged profiles of wave-induced velocity, vorticity and Reynolds stress showed different behaviour on the windward and leeward sides of the wave in the near-surface region. The results also show that the turbulent Reynolds stress mainly supports downward momentum transfer whereas the wave-induced Reynolds stress is responsible for the upward momentum transfer from wave to wind.   This dissertation also provides first quantitative comparison of the mean, wave-induced and turbulent properties for the separated and non-separated flows over wind generated water waves. The maximum difference between the flow characteristics of the separated and non-separated flows is observed on the leeward side, within core of the separation region, where, higher magnitudes of the vorticity and turbulent properties were observed, indicating that the turbulence is significantly enhanced within the separation region.   The comparison of the flow over smooth and wavy water and solid surfaces showed that although the trends in profiles over water and solid surfaces are mostly similar, the relative magnitudes of turbulent properties and their level of enhancement towards the surface are different over water and solid surfaces. Thus, the models for the flow over solid surfaces may not accurately predict the flow properties over the water surface especially in the near-surface region.


identifier: Saleh, Wael Fairouz  (2008) Two-phase flow structure at header-channel junctions : PIV experiments and modeling.  PhD thesis, Concordia University.

abstract: The discharge of a two-phase flow from a stratified region through single or multiple branches is an important process in many industrial applications including the pumping of fluid from storage tanks, shell-and-tube heat exchangers, and the fluid flow through small breaks in cooling channels of nuclear reactors. Knowledge of the flow phenomena and flow structure involved during the onset of gas entrainments (OGE) in branches is essential for the design and/or performance prediction of such thermal systems.   In the present investigation, extensive data were generated for the two-phase flow structure at the onset of gas entrainment from an air-water stratified region through small branches (d = 6.35 mm) over a wide range of Froude numbers (0 to 100). The test sections were in close dimensional resemblance with that of a CANDU header-feeder system, with branches mounted at orientation angles of 0, 45 and 90 degrees from the horizontal. Three groups of new data were generated for single discharge, dual discharge and triple discharge configurations. The Particle Image Velocimetry (PIV) was used to provide detailed measurements of the two-phase flow field. In each of these measurements, the critical height at the onset of entrainment was first achieved, and the volume of interest close to the branch-header junctions was then determined and divided by a number of horizontal image planes. Each image plane required a separate spatial and temporal calibration for PIV measurements. The vorticity profile, stream lines, flow field development and coherent structure, were presented over a wide range of operating conditions.   A theoretical analysis for the onset of gas entrainment in a single downward discharge, from a stratified gas-liquid region, was developed. The discharge was modeled as a point-sink and Kelvin-Laplace's equation was used to incorporate surface tension effects. The dip geometry was experimentally investigated and a correlation was developed relating the dip radius of curvature to the discharge Froude number. The correlation was used in conjunction with the theoretical model. It was found that the predicted critical height demonstrated a good agreement with experimental data. The inclusion of surface tension improved the model's capability to predict the critical height, particularly at discharge Froude numbers below one. The single-discharge model was then extended to dual and triple discharge cases, with considering the branches as point sinks and two-dimensional slots. The results of dual and triple discharges were found to be a function of mass flow rate through the branches, and the position of the secondary branch (maintaining liquid phase flow only) with respect to the primary branch position (at which OGE occurs) and the angle between the branches. The present analysis applies to any two immiscible fluids with the term "gas entrainment" referring to the appearance of the lighter fluid through the upper branch.


identifier: Otrok, Hadi  (2008) Mechanism design and game theoretical models for intrusion detection.  PhD thesis, Concordia University.

abstract: In this thesis, we study the problems related to intrusion detection systems in Mobile Ad hoc Networks (MANETs). Specifically, we are addressing the leader election in the presence of selfish nodes, the tradeoff between security and IDS's resource consumption, and the multi-fragment intrusion detection via sampling. To balance the resource consumption among all the nodes and prolong the lifetime of a MANET, the nodes with the most remaining resources should be elected as the leaders. Selfishness is one of the main problems facing such a model where nodes can behave selfishly during the election or after. To address this issue, we present a solution based on the theory of mechanism design. More specifically, the solution provides nodes with incentives in the form of reputations to encourage nodes in participating honestly in the election process. The amount of incentives is based on the Vickrey-Clarke-Groves (VCG) mechanism to ensure that truth-telling is the dominant strategy of any node. To catch and punish a misbehaving elected leader, checkers are selected randomly to monitor the behavior of a leader. To reduce the false-positive rate, a cooperative game-theoretic model is proposed to analyze the contribution of each checker on the catch decision. A multi-stage catch mechanism is also introduced to reduce the performance overhead of checkers. Additionally, we propose a series of local election algorithms that lead to globally optimal election results. Note that the leader election model, which is known as moderate model is only suitable when the probability of attacks is low. Once the probability of attacks is high, victims should launch their own IDSs. Such a robust model is, however, costly with respect to energy, which leads nodes to die fast. Clearly, to reduce the resource consumption of IDSs and yet keep its effectiveness, a critical issue is: When should we shift from moderate to robust mode? Here, we formalize this issue as a nonzero-sum non-cooperative game-theoretical model that takes into consideration the tradeoff between security and IDS resource consumption. Last but not least, we consider the problem of detecting multi-fragments intrusions that are launched from a MANET targeting another network. To generalize our solution, we consider the intrusion to be launched from any type of networks. The detection is accomplished by sampling a subset of the transmitted packets over selected network links or router interfaces. Given a sampling budget, our framework aims at developing a network packet sampling strategy to effectively reduce the success chances of an intruder. Non-cooperative game theory is used to express the problem formally. Finally, empirical results are provided to support our solutions.


identifier: Wu, Jianguo  (2008) Executive IPO stock option compensation and IPO underpricing.  Masters thesis, Concordia University.

abstract: Do executives influence IPO underpricing when they stand to gain from the increased value of their IPO stock options? The present thesis examines this question for 422 U.S. software IPO firms from 1996 to 2000. The specificity of the software industry coupled with the bull market of the late 90s affects the cost-benefit tradeoff an executive faces with respect to the offer price of an IPO. I consider the possible interplay of traditional underpricing theories (signaling, asymmetric information, litigation and managerial influence) with high human capital intensity in a tight labor market. I correct for an exhaustive list of variables including: pre-IPO stock ownership, underwriter quality, VC backing, founder-manager. OLS regression results show no difference in underpricing between option-granting and non-option-granting firms; however, greater underpricing is significantly associated with higher total dollar value of stock options granted to top management and/or CEOs. After controlling for endogeneity, I find no evidence that there's relation between option grants and underpricing. However, the bubble years 1998-2000 have significant explanatory power, under all specifications, with regard to the greater IPO underpricing for software companies compared to the average level of all industries in the same period. [PUBLICATION ABSTRACT]


identifier: Safari Sharifabadi, Elaheh  (2008) Dynamic analysis of ada programs for comprehension and quality measurement.  Masters thesis, Concordia University.

abstract: During maintenance and particularly during corrective and perfective tasks, systems tend to exhibit a weight gain. As a result, their quality tends to degrade. Software comprehension is vital in order to assess system quality. In this research, we aim at deploying dynamic analysis of Ada programs for obtaining comprehension, and applying measurements to assess their quality. Program instrumentation is performed non-intrusively by AspectAda, an aspect-oriented extension to Ada. Events which are required for this analysis are captured as execution traces. We have defined a relational database schema to save execution traces, and a set of queries to obtain measures of quality metrics. New Ada-specific metrics are introduced and existing metrics have been adopted from the literature. Automation is also provided as a proof of concept through a prototypical tool which provides information on the run-time behavior of the system, performs measurements and provides visualization of the run-time behavior of the system through a call graph. An open source Ada program is used as a case study to demonstrate our approach.


identifier: Ismail, Nafissa  (2008) Role of context, arousal, and female availability in the conditioning of sexual behavior and ejaculatory preference in the male rat.  PhD thesis, Concordia University.

abstract: Although male rats are known to display greater unconditional sexual arousal and mating preference to copulate with a novel female compared to a familiar one, research has shown that males given repeated copulatory trials in bi-level chambers with a random almond-scented female develop a conditioned ejaculatory preference (CEP) for females bearing this odor cue. These findings suggest that male rats can learn to associate cues with sexual reward and display preferences for partners that bear those familiar cues. Examination of the effect of copulation in pacing chambers bisected by a divider that either had one hole or four holes at the bottom that only allowed the female to cross, revealed that in 1-hole pacing chambers, females spend more time away from the male than in 4-hole pacing chambers. Males copulating in 1-hole pacing chambers displayed longer ejaculation latencies than those in the 4-hole condition. Interestingly, when animals were changed environments, the differences in ejaculation latencies were maintained suggesting that the pattern of copulation in these males had become conditioned by their initial environment of copulation. An examination of the preferred environment of copulation showed that males prefer to copulate in 4-hole over 1-hole pacing chambers perhaps because males can achieve their optimal rates of copulation in 4-hole chambers. However, contrary to what would be expected, males trained to copulate in 4-hole pacing chambers, with the same almond-scented female at every trial, failed to develop CEP for their familiar female. Instead, it is the males that were trained to copulate in 1-hole pacing chambers that displayed CEP for their familiar female as opposed to the novel one. These findings suggest that copulation in environments in which the female withdraws away from the male for longer periods of time facilitate the development of CEP for a familiar scented female. An analysis of the components required for males to develop CEP for their familiar female revealed that copulation in 1-hole pacing chambers with the same female bearing an olfactory cue and of the same strain as their own are necessary conditions for males to display CEP for their familiar female. Examination of the brain areas involved in the development of CEP for a familiar female, using immunohistochemistry, demonstrated that males that developed CEP for their familiar female displayed significantly more Fos immunoreactivity in the ventral tegmental area (VTA) and in the arcuate nucleus of the hypothalamus (Arc). Pharmacological analyses of the neurochemical mechanisms important for the development of CEP showed that intact opioidergic, but not dopaminergic system, are necessary for the development of CEP in male rats. Examination of neural structures involved in the development of CEP revealed that the VTA and the Arc play an important role in the development of this preference. The present findings shed light on the effect of context on the development of male copulatory behavior and on the development of CEP for a familiar female and its underlying mechanism.


identifier: McLean, James S  (2008) A war room in Canada : politics, journalism, publics and the competition for credibility.  PhD thesis, Concordia University.

abstract: The central objective of A War Room in Canada is to develop a richer understanding of the subsumed motivations behind the practices of political war rooms, the organizations that drive political communication at election time. To do so, this dissertation examines the role of the war room of the New Democratic Party during the general election campaign of 2005-06, providing an insider's view with respect to the underlying stakes in play for political actors, journalists, and publics. It considers an arc of theoretical positions from Durkheim's notion of organic solidarity and its conceptual link to contemporary democracy, to neofunctionalism and its concern for legitimation and symbolic action. Theoretical gaps in the neofunctionalist view are employed as a platform to project a line of thought that brings together notions from Pierre Bourdieu's conceptualization of capitals and fields, scholarly debates arising from Jürgen Habermas's theorization of the public sphere, and recent conceptualizations of the relationship between publics and counterpublics. From these articulated theoretical relationships, the notion of credibility is posited as a specific form of symbolic capital, one that acts as a medium of exchange within and between the fields of politics, journalism, and the field of power/publics. A series of war-room communication measures, strategies and tactics mobilized through the competition for credibility, are then considered with respect to their resonance among voters and, ultimately, the exchange of credibility for votes and votes for constitutionally-credited power.


identifier: Davarpanah, Neginmalek  (2007) In-situ decontamination of surface water by filtration.  Masters thesis, Concordia University.


identifier: De Bellis, Tonia  (2007) Fungal community structure in the boreal mixed-wood forest.  PhD thesis, Concordia University.

abstract: Plant communities rely on the belowground microbial community for nutrient uptake, pathogen resistance, growth and establishment. Although the importance of soil microorganisms has been acknowledged for some time, the soil remains one of the least explored habitats on earth. In this thesis I examine the relationships between the aboveground plant community and three functionally different fungal communities in a boreal mixed-wood forest in Québec. The first group, the ectomycorrhizal fungi, are mutualists with many canopy tree species in the plots. As their host is their main carbon source, the communities of these fungi were significantly correlated with the aboveground tree community. These fungi were analyzed using morphological and DNA-based methods, and comparisons of these two techniques showed that each targeted certain groups of ectomycorrhizal fungi. Therefore, the best method to analyze the communities of these fungi would be a combined assessment based on both of these techniques. The second group was the arbuscular mycorrhizal fungi, which form mutualistic associations with the herbaceous plants in the plots. To target these fungi, Clintonia borealis, a herbaceous plant found in all the plots was sampled. DNA based identification methods showed that one fungal type was dominant, and was similar to one collected from varied environments and hosts from distant geographical locations. The last group, the saprophytic microfungi, is not mutualistic with plants but they are decomposers of dead plant material. Statistical analyses showed that the microfungi were most closely correlated with the understory plant species composition than with the soil chemistry or overstory tree species. Significant correlations between plant communities and each of the fungal communities were found, stressing the importance of analyzing both aboveground and belowground components in a combined approach in order to further enhance our understanding of terrestrial ecosystems.


identifier: Khoury, Sam [Samir]  (2007) An exploratory study of the multiple roles modelled by Teachers of English as Second Language in multicultural classrooms in Montreal.  Masters thesis, Concordia University.

abstract: This study was designed to explore and describe the main roles that teachers of English as Second Language (ESL teachers) are called upon to model in culturally diverse adult education classrooms in Montreal. Eleven ESL teachers participated in the study. The first group consisted of experienced ESL teachers who are currently enrolled in an MA program in an English language university in Montreal. The second group was drawn from ESL teachers currently employed by an International Language School in downtown Montreal attracting mainly new immigrant students.  Through a process of journaling and focus group discussions the ESL teachers arrived at a list of seven major roles in terms of centrality to their practice and chosen from among forty roles inventoried through the process. These seven roles are: expert/teacher, motivator, animator, listener/counsellor, culture broker, curriculum designer/evaluator, and guide/facilitator. Three major concerns related to these roles were identified: (a) the degree of involvement in the learners' lives, (b) excessive time and energy requirements of the job and (c) the question of ESL teacher's lack of choice with respect to resource materials for teaching and an imposed curriculum.  Two main recommendations emerged: (a) developing a cooperative and community-based peer-support system; (b) developing in-service education programs that incorporate issues of gender, age, race and sexual orientation, among others, so as to empower teachers not to fear and retreat when these issues arise in their classrooms.


identifier: Frigan, Zelina H  (2007) Hedonic orientation : an individual difference variable.  Masters thesis, Concordia University.

abstract: In marketing theory, hedonic pursuits are often associated with negatively perceived consumer traits such as impulsiveness, faulty self-control and guilt. Literature in psychology contradicts this line of reasoning and asserts that the capacity to experience pleasure contributes to the well-being of the individual.  In order to assess what motivates consumers to engage in hedonic consumption and what the outcomes of such consumption are this thesis identifies an individual difference variable - hedonic orientation - to assess an individual's propensity to engage in hedonic consumption and develops a scale for its measurement. Using this measure consumer values related to hedonic consumption such as impulsiveness, self-control, guilt, frugality, and the Protestant work ethic are examined to elucidate their role in the hedonic orientation of individuals. Additionally, this new measure of orientation toward hedonic pursuits is used to investigate the impact of hedonic orientation on consumer outcomes such as the amount of time and money individuals' spend on hedonic consumption, as well as, life satisfaction and positive long-term health behaviors.  This research results in a novel, 7-item measure of hedonic orientation which demonstrates acceptable reliability and convergent validity. Of potential use to academics for testing relationships not easily tested, the hedonic orientation measure may also be of interest to practitioners due to its success in identifying individuals prone to consume hedonically. This research also demonstrates that engaging in hedonic consumption does not necessarily indicate a lack of control or high levels of impulsiveness rather appears to be associated with greater well-being and health


identifier: Moschella, Jason F  (2007) Keeping an eye on the founders and a thumb on the mercenaries : a study of corporate governance in IPO firms.  Masters thesis, Concordia University.

abstract: Recent scandals and regulatory activity point to the importance of an empirical investigation into corporate governance and the factors that influence the decisions to adopt various governance practices. This study uses agency theory and stewardship theory to examine differences in governance structures between founder-led and professionally-led IPO firms. I examine firms at the time they are preparing to go public and the various governance provisions adopted at this crucial point in their development. I use a sample of 423 software firms that went public in the U.S. between 1996 and 2000 and examine the governance provisions they employ. I find that founder-led firms are more likely to be less shareholder-friendly than professionally-led firms.


identifier: Omelchak, Andrey  (2007) The benefits of time-varying asset allocation across hedge fund indices.  Masters thesis, Concordia University.

abstract: In this paper, the risk-adjusted performance of dynamic asset allocation strategies for hedge fund indices, based on minimum variance and maximum Sharpe ratio approaches, is examined and compared to the S&P500 index benchmark. Furthermore, the added benefits of using conditional volatility forecasting, namely an asymmetric generalized autoregressive conditionally heteroscedastic (asymmetric GARCH) process, are examined when constructing dynamic hedge fund index portfolios. The evaluation period is based on a monthly out-of-sample comparison from May 2002 to June 2006 for nine Credit Suisse First Boston/Tremont hedge fund indices. Weekly and daily rebalanced dynamic portfolios are examined on the out-of-sample data from December 2005 until the end of June 2006 for the three main sub-indices of Standard & Poor's Hedge Fund Index. A multivariate asymmetric GARCH model is also considered for portfolio construction using daily S&P Hedge Fund sub-indices data. Before transaction costs are included, results show that when hedge fund indices exhibit volatility clustering, accounting for forecasted next-period volatility generates portfolios with the best risk-return profile among all portfolios under consideration. After accounting for transaction costs, out-of-sample results indicate that all dynamic hedge fund indices portfolios largely outperform the S&P 500 index, both on a risk-adjusted and nominal basis.