identifier: Alam, Md. Mashiul  (2007) Modal characteristics of satellite appendages using on-orbit output-only modal testing.  Masters thesis, Concordia University.

abstract: Output-only modal testing is an attractive new technique with potential applications in civil, mechanical, and aerospace engineering. It may effectively be used for model validation, model updating, quality control, and health monitoring through the determination of modal characteristics of the structures. This approach to modal testing has great potential for ground and on-orbit modal testing of space hardware, especially for flexible structures such as membrane payloads where the operating excitations, such as firing of AC thrusters and ambient thermal shock, are difficult or impossible to measure. The latest versions of output only modal testing technique that considers a noise model to have better estimation of modal parameters from output response time series data is very new and can be very successfully employed to test satellite structures.  The main objective of this research is to validate the output-only modal technique approach to extract modal parameters of the appendages with the help of finite element transient analysis and to further verify it through experiments. This research includes a study of the dynamics of satellite appendages and associated excitation method to investigate analytically and experimentally the output-only modal testing approach. Application of the proposed method is investigated and the efficiency over traditional FRF modal testing approach is shown.  For identification of modal parameters, satellite solar panel, antennas or other satellite appendages are modeled as linear plate or beam models. It has been proven analytically that the multiple-point excitation is a better loading condition compared with driven base or single point excitation using output-only modal testing technique. It has also been established experimentally that the driven base excitation is better loading condition compared to single point excitation. The effect of using less number of nodal responses instead of using all the nodal response has been investigated.  Finally, it has been confirmed both analytically and experimentally that the new versions of output only modal testing approach can be employed to identify the modal parameters of satellite appendages on orbit efficiently.


identifier: Agrawal, Ashish Kumar  (2007) A dynamic programming approach for economic optimization of inspection strategies in a multi-stage manufacturing system.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: In the past several decades, significant amount of resources have been spent by many manufactures for product quality improvement. Quality improvement efforts involve mitigating the impact of manufacturing variation through robust design, statistical process control (SPC), and inspection. This research focuses on manufacturing system design issues related to inspection. The problem of determining the optimal inspection strategy for a given multi-stage manufacturing system i.e. inspection strategy that will result in the lowest total processing cost is modeled as a joint optimization of inspection location and type. Three inspection options considered in this work are no inspection, full inspection and sampling inspection. This thesis presents a generic mathematical model and employs dynamic programming to identify the optimal inspection plan with minimum total processing cost. Numerical examples are presented to describe the solution procedure. The conclusions are supported by a factorial experiment. A sensitivity analysis is also conducted to gauge the impact of inspection errors on the inspection strategy. The developed model is extensible and applicable to solving manufacturing and inspection allocation problems.  Keywords. Quality improvement, multistage manufacturing system, inspection strategy, full inspection, sampling inspection, dynamic programming


identifier: Rafat, Yasser  (2007) Ride dynamic analysis of guided pneumatic-tired subway car.  Masters thesis, Concordia University.

abstract: In the Montreal metro system, the metro cars operate on pneumatic tires as opposed to the steel wheels and rail tracks used in most subway systems. This type of traction system provides relatively quieter and smoother operation. Despite the use of pneumatic tires and a very smooth concrete track, the Montreal metro cars exhibit complex vibration environment, that arises from dynamic tire-track interactions, and coupled dynamics of vehicle components, namely, axle, bogie and the car body.  In this investigation, a 23 degrees-of-freedom, three dimensional ride dynamic mathematical model of the Montreal metro car is developed to study the ride performance under deterministic as well as measured track excitations. The model integrates excitations due to left- and right track surface roughness, and wheel non-uniformity. The wheel non-uniformity is modeled as a combination of an equivalent mass unbalance and out-of-roundness of the tread geometry. The validity of the model is demonstrated by comparing the response characteristics with available measured data. The ride quality of the vehicle at operator's level is assessed in relation to the proposed guidelines upon applying the recommended frequency-weighting filters. The ride responses revealed comprehensive vertical vibration in the vicinity of 6 Hz to which the human body is known to be more sensitive. High magnitude of vertical s vibration near 6 Hz became evident at near the nominal operating speed of 60 km/h, and was associated with wheel non-uniformity and vertical mode resonance of the bogie.  The influence of variations in design and operating variables on the ride performance of the metro car is investigated through a comprehensive parametric study. The variations in operating conditions include the forward speed of the metro car and passenger load. The parametric study on design variables includes the variations in the inertial properties of the vehicle components, namely, car body, bogie and axle and variations in suspension properties. The results of the study are discussed to highlight the contributions of these parameters on the ride quality, and to identify most desirable design and operating conditions. Finally, a set of optimal parameters is identified and then comparison is made between nominal and optimal set of design parameters.


identifier: Arumugam, Anandha Kumar  (2007) Reliability of center-notched and edge-notched composite laminates based on experimental investigation and stochastic finite element analysis.  Masters thesis, Concordia University.

abstract: The reliability of notched composite laminates is determined to find its worthiness for the intended application and it is affected by various factors, such as, application of fatigue loading, notch location, notch shape and size, etc. In the present work, an attempt has been made to study the effects of fatigue loading and notch location on the reliability of notched composite laminates. The reliability values of notched laminates are calculated by using the following parameters: the stress developed in the laminate due to external loading and the strength of the corresponding un-notched laminates. Since composite laminates exhibit stochastic variations in material properties, Stochastic Finite Element Analysis (SFEA) is used to calculate the stresses developed in the laminate. The ultimate strengths of the un-notched laminates are found out experimentally. Tests are conducted on specimens made of NCT301 graphite/epoxy material to determine the material properties that are required for the SFEA. The material properties are modeled using Markov model based on the test data by two dimensional stochastic processes. Tests are also conducted on center-notched laminates subjected to fatigue loading conditions, Edge-notched laminates and un-notched laminates to determine their ultimate strength values. In practical applications, it is difficult to achieve a perfect circular profile during the drilling operation of notched composite laminates and there is a possibility that the drilled hole is offset from the desired location. These imperfections affect the reliability of the notched laminate. In the present work the perturbation in the circular profile of the hole is modeled using a hypotrochoid variation and the location of the hole center is modeled using a Gaussian random variable. The ultimate strength values of center-notched laminates subjected to fatigue loading conditions, Edge-notched laminates and un-notched laminates, obtained from experiments are used to determine the sets of characteristic length values for both the point stress criterion and average stress criterion. The distributions of the strength and characteristic length of laminates are determined. Stochastic simulations are performed on the laminates by subjecting them to tensile load. Probabilistic moments of the point stress and average stress parameters are found out for controlled hole and un-controlled hole laminates. The reliability values are calculated for the center-notched laminates subjected to fatigue loading conditions and Edge-notched laminates using point stress criterion and average stress criterion by combining the SFEA and experimental results.


identifier: Yu, Bo  (2007) Negotiations or auctions : experimental comparison of two e-market mechanisms.  Masters thesis, Concordia University.

abstract: During the last decade, we have witnessed the rapid development of e-commerce, which has provided opportunities for organizations to facilitate transactions, improve trade efficiency, create competitive advantage, and reduce related costs through online transactions. Various kinds of market mechanisms, such as auction, catalogue and bargaining, can be used in these interactions. The growth of e-commerce stimulates design of electronic marketplaces and market mechanisms. We therefore need to study the differences in mechanism usage and their possible impact on users and transactions.  This study compares negotiations and auctions, two principal market mechanisms, to develop a deeper understanding of their similarities and differences in e-market. The expectation is that the study will expand e-commerce knowledge to ensure the appropriate use of market mechanisms, which will further increase social welfare and better satisfy the agents with improved online transaction experiences.  Empirical testing of the entire effective sample shows that participants in e-marketplaces are driven by the goal of own utility maximization. The amount of utility that participants gain positively impacts three types of satisfaction (i.e., satisfaction with outcome, self-performance, and process). Also, no significant effect attributed to differing mechanisms is found in economic measures or agents' satisfaction. Looking only at the winners (i.e. a sub-sample group), utility also has a significantly positive effect on participants' satisfaction. Gender as an individual characteristic is found to have a significant effect on the winners' satisfaction with outcome and self-performance. Non-winners' satisfaction with outcome is also significantly affected by mechanism type


identifier: Rahman, Sarker Md. Sajedur  (2007) Condition assessment tool for elements of drinking water treatment plant.  Masters thesis, Concordia University.

abstract: Condition assessment of aging assets and infrastructure is a growing concern in North America. The Canadian Water and Wastewater Association (CWWA) estimated that a $28 billion investment is needed for municipal water systems in Canada from 1997 to 2012. The condition of 43% of water supply systems in Canada is unacceptable. A systematic condition assessment is a pre-requisite of an effective asset and infrastructure management practice. The present study focuses on analyzing the principal factors that affect infrastructure condition, data requirement, and how the condition of a targeted element can be assessed.  The main objectives of this research are to develop condition assessment models for selected existing elements of Drinking Water Treatment Plant (DWTP) and develop condition rating scales and a web-based tool. The condition of five DWTP elements are studied in this research: settling tank, filtration tank, chlorination tank, raw water pump and clean water pump. Condition rating (CR) models are designed using Analytical Hierarchy Process (AHP) and Multi Attribute Utility Theory (MAUT) approaches. Evaluation results show that the top ranked category for tanks is 'Physical (design and construction stage)' with a relative importance of 32% and for pumps is 'Operational' with an importance of 34%. The preference level of each parameter is being measured on a numerical scale of 0-10.  Twenty five practical case studies are used to validate the developed models, which show robust results. Condition rating scales are developed for tanks and pumps and verified by municipal experts. A web-based condition rating tool is developed and coded with AHP.NET


identifier: Edelstein, Jason  (2007) Solar-driven vapor transport in lightweight walls in a hot and humid climate.  Masters thesis, Concordia University.

abstract: Over the last few decades, more and more attention has been given to moisture control in building envelopes. This includes better control of rain, moist-laden air leakage and water vapor diffusion. One aspect of moisture control that is still not quite mastered is the so called solar-driven vapor transport. When rain is absorbed by porous materials such as brick cladding, rapid drying due to solar radiation can lead to vapor pressure driven inward flows. These flows are magnified when the interior space is air-conditioned. Such flows can be important and lead to moisture accumulation in the wall assembly. However, the parameters that impact such flow and the role of thermal loading conditions have not been linked to the hygrothermal performance and durability of wall systems.  The overall goal of this study was to develop a greater understanding of the significance of solar-driven vapor flow, also known as summer condensation, specifically under what conditions it occurs and the negative effects it poses on the building envelope. This research presents the testing performed on a set of small-scale wall specimens under constant loading conditions and the development of an experimental approach to determine the effects of the simulated loading conditions on large-scale wall specimens. Both experimental procedures are successful in reproducing thermal and vapor pressure gradients across test specimens under summer conditions in hot and humid climates similar to those simulated by a heat, air and moisture modeling tool.  The results of these experiments indicate that the effects of solar-driven vapor diffusion are observed in cases where large thermal gradients act on wall assemblies with absorptive cladding repeatedly wetted by rain. The methods implemented in the design of the experimental procedure can be used to simulate these effects for further research


identifier: Palus, Ernest  (2007) Synthesis of 7-Deaza-deoxyguanosine analogs as probes to investigate DNA repair.  Masters thesis, Concordia University.

abstract: Interstrand cross-links can be introduced into DNA as a consequence of chemotherapy. These lesions are considered to be therapeutically relevant and responsible for the efficacy of bifunctional alkylating agents in cancer chemotherapy. There is considerable evidence that indicates interstrand cross-links are recognized by cells and that this recognition can either mediate repair of damage and survival, or accelerate cell death. Development of tumors resistant to these agents is an important factor in the lack of response by some patients to therapy with these agents. Relatively little is known about the mechanism by which interstrand cross-links are recognized and repaired. In order to investigate repair mechanisms, interstrand cross-linked DNA substrates of well defined structure are required. Such substrates are challenging to prepare in quantities sufficient for biochemical and biophysical studies.  A method to synthesize a chemically stable analog of the clinically relevant N7G-alkyl-N7G cross-link was explored. This structural analogue links the C7 atoms of two molecules of 7-iodo-7-deaza-2'-deoxyguanosine with an alkyldiyne linker to form a dimer via the Sonogashira reaction. Several nucleoside dimers were produced using this strategy as proof of principle that it could be employed in the synthesis of interstrand cross-linked DNA. However, in addition to the desired cross-coupling reaction it would appear that a copper catalyzed homocoupling side reaction can also occur


identifier: Carter, Mindy R  (2007) Drama and theatre as experiential learning tools for Canadian classrooms.  Masters thesis, Concordia University.

abstract: Students need to practice using their voices in a safe and nurturing classroom environment in order to learn about themselves and others in a mature and compassionate way. By providing opportunities for students to listen and dialogue with their peers, the potential for learning to consider the needs of others can develop. Drama and democratically based theatre models such as The Forum Theatre provide tools that the educator can use to incorporate dialogue and experiential learning into each classroom and subject area.  By examining the importance of experiential learning and making the link between experiential learning and drama/theatre as tools to be used for learning in classrooms, this thesis provides a foundation that can assist in the development of democratic learning


identifier: Rochon, Katherine  (2007) La robe est la métaphore: une expérience de studio en tant que modèle et témoignage d'un apprentissage.  Masters thesis, Concordia University.

abstract: Cette recherche a pour but d'explorer la métaphore conceptuelle dans une pratique artistique qui mènera à la réalisation de robes de papier représentatives de mon expérience d'apprentissage dans un contexte d'études supérieures en enseignement des arts visuels.  Les quatre chapitres. Le premier chapitre établit une définition de la métaphore conceptuelle en arts visuels. La littérature sélectionnée sert à dégager certaines des composantes de la métaphore conceptuelle qui seront retenues pour la recherche en studio. Le processus de transposition de la métaphore conceptuelle m'intéresse particulièrement parce qu'il met l'accent sur la cognition. Le procédé de langage de la métaphore est employé au chapitre quatre avec ma description des robes et mon témoignage d'étudiante.  Au chapitre deux, je détermine les critères qui guident ma méthode de recherche en studio en me basant sur deux modèles de recherche avec la métaphore conceptuelle en arts visuels. Je fais une description des deux modèles et une analyse qui met l'accent sur certains points précis en rapport avec mes expériences personnelles de designer graphique et d'artiste.  Le chapitre trois est une description de mon processus de recherche et de création. J'y décris le trajet de ma démarche de studio en réintégrant certains aspects déterminants de la théorie de la métaphore conceptuelle ainsi que les aspects retenus des modèles du chapitre deux. Entre autres, j'y fais la description de mon espace de travail, de mes outils, des matériaux, de ma banque d'informations et de mon processus créatif.  Le quatrième et dernier chapitre est composé d'un témoignage de mes expériences d'apprentissage aux études en enseignement des arts visuels et de la description des trois présentations de robes de papier. Ce chapitre me permet de conclure sur l'ensemble du processus de recherche et de parler du sens créé à travers l'expérience de recherche en studio qui combine mon témoignage d'apprentissage, les robes de papier et la métaphore conceptuelle.


identifier: Filotas, Zoli  (2007) Power and friendship : Plato and Aristotle on rule in interpersonal relationships.  Masters thesis, Concordia University.

abstract: This thesis explores rule or power [ archein ] in Plato and Aristotle's discussions of interpersonal relationships. I argue that the collectives and communities that are for both thinkers the most important elements of the social world are necessarily structured by power. To see this gives us a better grasp of the relationship between parts of ancient thought that are too often kept apart, and allows us to make sense of the point of view that sees them as continuous with each other.  I begin with Plato. His dialogues describe rule as a crucial object of philosophical study, run through with puzzles. Social problems are for Plato best understood by studying both the city and the soul as composite wholes made up of hierarchically arranged parts. And all this theory is realized dramatically in the character of Socrates. Chapter two focuses on what might now seem a puzzle. Aristotle claims that men rule over their wives by nature, but also that they can be virtue friends, which for him implies that they are equal. Using marriage as a case study, I show that for Aristotle there is no tension between equality and rule. Along the way, we see that, in his characteristic systematic manner, Aristotle develops many of the same theoretical materials as Plato. In my final pages, I suggest that modern political discourse's focus on equality makes it difficult to see the importance of rule. I suggest that the views of Plato and Aristotle can therefore make an important contribution to contemporary ethical thought.


identifier: Henry, Eugene M  (2007) In the shadow of the bomb's Apocalypse : American culture in the nuclear era, 1957-1963.  Masters thesis, Concordia University.

abstract: The period beginning with the launch of the Soviet satellite Sputnik in October 1957 up to the adoption of the Limited Test Ban in the fall of 1963 was an era marked with intense fear and uncertainty.  The American mainstream print media and prophetic writers from premillennial journals employed apocalyptic narrative structures when exploring nuclear issues. These distinct discourses developed through the utilization of traditional apocalyptic motifs to reconcile the existence and horrific potential of nuclear weapons. This thread is evident in both traditionally biblical forms, as well as a unique secular apocalyptic strain.  This thesis argues that in a time of fear and uncertainty, when the specter of nuclear war cast its foreboding shadow on everyday life, Americans turned to a well-established apocalyptic discourse to explain and understand the exigencies of their time


identifier: Pitsolantis, Nicole  (2007) Linking procedural and conceptual understandings of fractions during learning and instruction with fifth- and sixth-grade students : an evaluation of Herbert's Sites approach.  Masters thesis, Concordia University.

abstract: The study's objective was to empirically investigate an instructional approach (Hiebert, 1984) theorized to foster students' abilities to link conceptual and procedural understandings during the learning of mathematics. Seventy-two fifth- and sixth-grade students were randomly assigned to the treatment ( n = 36) and a control condition ( n = 36) and were administered a validated paper and pencil test (Saxe, Gearhart, & Nasir, 2001) of fractions knowledge and a researcher-developed fractions knowledge interview before and after instruction. Doubly multivariate analyses of covariance revealed that, consistent with the research hypotheses, students in the treatment condition demonstrated greater improvements in conceptual understandings of fractions ( p < .01) and in ability to link their knowledge of fractions procedures to their knowledge of fractions concepts ( p < .05). Contrary to the research hypotheses, control group students demonstrated comparable gains to students in the treatment group in procedural knowledge of fractions. The findings point to important instructional considerations for the effective support of students' development of conceptual knowledge and procedural skill related to specific points in the problem-solving process, and, more broadly, to a specific time in the course of their mathematics education.


identifier: Barratt, Neil  (2007) Chocolate milk is good for you? : video news releases, PR, and knowledge production in Canadian television journalism.  Masters thesis, Concordia University.

abstract: Journalism is surely one of society's great institutions. It has long been an important site of knowledge production, allowing audiences to make sense of their world. Today's journalism is a highly complex, expensive, and time-sensitive challenge to produce. This research investigates how these factors in the production process of Canadian television journalism affect the product.  Public relations has been using journalism as a means of publicity for nearly a century. With increasing pressure on news departments to make profits, PR sources gain an advantage in getting their material on the evening news. Video News Releases are the pinnacle of PR sourcing: fully produced, promotional news stories designed to blend in perfectly with other news content.  This thesis reviews existing literature examining news sourcing practices as well as the organizational and economic constraints that govern journalism's production processes. The research looks at Canadian television news through these lenses, as well as through the words of working Canadian journalists.  The interaction of PR and news is examined to understand how news stories get developed, where the content and resources presented in those stories come from, and who is benefiting from changing practices in the newsroom


identifier: Feuerhahn, Niels  (2007) Beasts (un)like us : thinking about the animalization of animals with Theodor W. Adorno and Jacques Derrida : or, From appropriating to appreciating animal others.  Masters thesis, Concordia University.

abstract: The objective of this thesis is twofold: On the one hand, this thesis is a critical assessment of the legacy of Western philosophy from the perspective of those beings that it has consistently excluded from its realm of concern: the so-called 'non-human animal'. In the first part I examine some parallels between the ideas that led to the Nazi Holocaust of over 6 million Jews and others and the ideologies and concepts that underlie the continuing murder of over 9 billion animals in North America's slaughterhouses every year. Starting out with the work of Theodor W. Adorno and Max Horkheimer, I attempt to show that there are more than a few accidental affinities between the ways the Nazis treated and conceptualized the Jews and the ways in which some of the most important philosophers in the history of Western philosophy have thought about animals. In the second part, through the work of Jacques Derrida I shall embark on a radical examination of the human-animal binary by taking a closer look at the function and genesis of the concept of 'the animal'. My main focus here is on the significance of our practices of "eating" animals. I shall analyze how the act of killing and eating animals communicates a certain self-understanding or truth about ourselves that needs to be decoded and analyzed if we want to lastingly subvert our oppressive-exploitative attitude towards nonhuman animals. The aim of both parts is to disrupt the veiling normalcy of the violence we continue to inflict upon literally countless animals every year and to devise and open possible forms of opposition against this violence.


identifier: Bye, Dorothea  (2007) Paths to positive affect in older adults : need for cognition as a motivational strength.  Masters thesis, Concordia University.

abstract: This study examines how need for cognition, or the tendency to enjoy effortful cognitive activity (Cacioppo, Petty, & Kao, 1984), relates to well-being in 355 adults experiencing the transition to retirement (age range 44-79 years, M = 60, SD = 5.5). Structural equation modeling was used to identify significant pathways between exogenous variables of conscientiousness, openness, and education to need for cognition. Mediators between need for cognition and positive affect were frequency of cognitive activity and problem-focus coping. Need for cognition and perceived control emerged as separate and distinct forms of motivation, contributing to positive affect in this model through differing patterns and to different degrees. Health contributed significantly in direct paths to both perceived control and positive affect. This well-fitting model helps to explain some of the psychological mechanisms instrumental to successful adaptation in change in adulthood. Additionally, this demonstration of the critical role of need for cognition in the prediction of positive affect provides support for Fredrickson's (1998) broaden-and-build theory, which posits a reciprocal relationship between positive emotions and broadened attention and cognition. An argument is made for consideration of need for cognition as a character strength with unique predictive value for older adults.


identifier: Harbour, Valerie  (2007) Uncoupling of Circadian oscillators in the central extended amygdala from the master clock during stable entrainment to an "exotic" light cycle.  Masters thesis, Concordia University.

abstract: The circadian clock in the hypothalamic suprachiasmatic nucleus (SCN) can be entrained by light cycles longer than the normal 24-h light cycle, but little is known about the effect of such exotic light cycles on circadian clocks outside the SCN. The present thesis sought to examine the effect of exposure to a 26-h light-dark (LD) T-cycle (T26; 1-h-25-h LD) on the expression of the clock protein PERIOD2 (PER2) in the SCN and four regions of the limbic forebrain known to exhibit circadian oscillations in PER2 expression, the oval nucleus of the bed nucleus of the stria terminalis (BNSTov), central nucleus of the amygdala (CEA), basolateral amygdala (BLA), and dentate gyrus (DG). Control rats housed under a 24h T-cycle (T24; 1-h-23-h LD) and rats housed under the T26 cycle showed stable entrainment of wheel-running activity rhythms. As previously shown, PER2 expression in the SCN was also stably entrained in all T24 and T26-housed rats, peaking at the beginning of the active phase of the cycle. In contrast, exposure to the T26 LD cycle for 30 and 60 days, uncoupled the rhythm of PER2 expression in the BNSTov and CEA from the SCN, whereas PER2 rhythms in the BLA and DG were mostly unaffected. These results show that exposure to exotic light cycles can uncouple circadian oscillators in the limbic forebrain from the master SCN clock and suggest that such cycles may be used to study the functional consequences of disruptions in the phase relationship between the SCN and subordinate oscillators.


identifier: Goulet, Isabelle  (2007) Learning to become dancing musicians : flamenco dancers going global.  Masters thesis, Concordia University.


identifier: Lagalisse, Erica  (2007) Desde abajo y a la izquierda : an ethnography of transnational activism.  Masters thesis, Concordia University.

abstract: Autonomist movements are unified across context through shared discourses of autonomy, direct action and radical democracy. Decentralized networks of autonomist collectives are responsible for the transnational activism often referred to as "grassroots globalization". This has largely fallen outside academic purview, however, as both marxist and liberal theoretical perspectives on social movements honour state-centric politics.  Mobilizing the concepts of "autonomy" and "counterpower", this experimental, multisited ethnography (Marcus 1999; 2006) introduces autonomist politics and investigates how commonality is built upon asymmetry (Moore 2006: 447) and conversation across difference (Tsing 2005: 2) in transnational activism by concentrating on collaboration among autonomist collectives, anarchist movements, and indigenous movements at four "moments of conjuncture" (Tsing 2005: 272): (1) cooperation among anarchists and indigenous ecologists in Venezuela; (2) the transnational solidarity movement surrounding the Asamblea Popular de los Pueblos de Oaxaca ; (3) solidarity activism with the Six Nations land reclamation in Canada; (4) the solidarity network of transnational Zapatismo.  By tracing the practices of collaboration and listening to the palabra of participants for overlapping discourse and practices, the research exposes and analyses congruency and disjuncture among movements as well as among principles and practice therein. Findings highlight the intersection of race, class and gender in participation dynamics as well as emergent discourses. The conclusion argues that anarchoindigenism and related solidarity projects constitute an important "conversation" in the global anticapitalist movement; however, the secular and "public" nature of politics as constructed within political economy (i.e. anarchism) precludes radical solidarity with indigenous peoples and women most generally


identifier: Belgroune, Wassila  (2007) Sociologie de la traduction (1927) de The murder of Roger Ackroyd (1926) d'Agatha Christie dans le champ français du roman policier.  Masters thesis, Concordia University.

abstract: The thesis analyses the sociological determinations of the French translation of Agatha Christie's detective novel The Murder of Roger Ackroyd. The novel published in English in 1926 and translated into French in 1927 by Miriam Dou-Desportes is the first of a long list published in the new collection ±Le Masque» (1927) established by Albert Pigasse at the Librairie des Champs Élysées. In the thesis, the sociological theory of Pierre Bourdieu adapted to translation is applied. The habitus, field, symbolic capital and illusio are discussed concerning The Murder of Roger Ackroyd, the author and the translator, the detective novel field and the considerable legitimacy built up from this novel. Their contrastive analysis submit some sociological hypotheses on the way Agatha Christie's novel was translated in France in the 1920s and the impact of the English author's work in France in spite of the defects of its translation.


identifier: Gol Tabaghi, Shiva  (2007) APOS analysis of students' understanding of logarithms.  Masters thesis, Concordia University.

abstract: This research is aimed at analyzing students' understanding of the concept of logarithms. Traditionally students are introduced to logarithmic functions as the inverse of exponential functions, even though logarithms were invented independently of exponents.  In this study, a review of the historical genesis of logarithms, the literature review on the understanding of exponential and logarithmic functions, and a review of several textbooks from different times and geographical places are presented. These reviews allow the identification of two notions of logarithms: arithmetic and functional. Even though current curriculum introduces the functional notion of logarithms, attained curriculum focuses on the arithmetic notion of logarithms. In addition, the importance of logarithms, that is, their use in converting multiplication of numbers into addition of logarithms of numbers, has not been highlighted.  I conducted six clinical interviews with students from prerequisite mathematics courses and a core mathematics course. This data is analyzed within the context of APOS theory to identify students' difficulties in understanding the concept of logarithms. The results reveal that most students' understanding of the arithmetic notion of logarithms does not go beyond the "process" level, since understanding the arithmetic notion of logarithms as undoing what exponentiation does require an understanding of exponentiation with real exponents.


identifier: Huang, Xiu Wu  (2007) Groups, grammars and designs : a mathematical analysis of artifactual patterns.  Masters thesis, Concordia University.

abstract: In keeping with other developments in the natural sciences, more and more researchers use mathematics to analyze the geometric and constructive principles hidden in works of art and then apply these principles to generate new patterns. This thesis is in line with trend. It develops tools for the analysis of the geometric patterns hidden in Bakuba textiles and Zillij mosaics. As such, it contributes to the interdisciplinary Generative Design project, which explores the mathematical structure of artifacts using groups, shape grammars, and other techniques. The thesis consists of six parts: (1) A brief introduction to background of the thesis. After introducing the project and geometric patterns in Bakuba textiles and Zillij mosaics, we discuss the structure of the Generative Design systems, discuss results the project team has obtained, and explore the possibility of applying groups to implement our goals. (2) An introduction to wallpaper groups, related theorems and results. After introducing the Crystallographic Restriction theorem, we provide a proof that establishes that there are precisely seventeen groups for creating wallpaper patterns from given geometric patterns. To understand these seventeen groups and to explain the relationship between groups and Bakuba textiles and Zillij mosaics, we illustrate these groups using motifs extracted from Bakuba and Zillij. (3) An illustration of the mathematical reconstruction of Bakuba and Zillij motifs using groups. After analyzing patterns in Bakuba Textiles and Zillij Mosaic, we show that we can use certain groups to reconstruct patterns with different motifs involving various parameters. This brings us closer to our goal. The groups considered at this stage are not necessarily wallpaper groups. (4) An illustration of the mathematical reconstruction of Bakuba and Zillij motifs using grammars. In this part, we use shape grammars defined by Stiny to reconstruct patterns in Bakuba and Zillij by defining suitable grammars and applying appropriate sequences of shape grammar rules. (5) A new method of creating new pattern. In this section, we compare and discuss the methods of group theory and shape grammars to extract motifs from classical artifacts and to generate new patterns. Then we develop a new method that enhances the two classical methods by generating new patterns from Bakuba and Zillij motifs using wallpaper groups. (6) The thesis ends with appendices in which technical definitions and basic proofs are given to make the thesis self-contained. In particular, the proof that there are precisely seventeen wallpaper groups is presented in detail for completeness and accessibility.


identifier: Sefidcon, Azimeh  (2007) Route selection for QoS over Mobile IP.  PhD thesis, Concordia University.

title: Route selection for QoS over Mobile IP

abstract: Influenced by the availability of powerful portable computers, and the expansion of Internet-based services, consumers demand mobile Internet. This implies supporting user mobility while sustaining network connectivity which in turn requires more sophisticated routing methods than simple static Internet protocol. Routing optimization is critical for the efficiency of mobile Internet as it directly impacts resource utilization in the network. On the other hand, while connected to the Internet, users want to enjoy real-time services. Granting quality of service for real-time multimedia applications is one of the major concerns for Internet Service Providers.  In the mobile Internet context, as a result of a signalling conflict, providing quality of service declines in presence of routing optimisation. This conflict must be resolved to achieve efficient resource utilization in the networks and provide quality of service for real-time Internet-based services.  This thesis presents a solution for resolving the aforementioned conflict. Initially a set of requirements are established for a new solution. The fundamental idea is developed based on exercising routing optimization according to quality of service requirements and network conditions. A new protocol architecture for Mobile IP (MIP) is built based on a cross-layer design technique. This design implies that a new data flow collects the necessary parameters in the network. This data is passed to a new entity in the network layer of the MIP protocol stack that inter-connects IP, routing, mobility and resource reservation protocols.  Based on network conditions and the quality of service requirements the optimal path is selected over which the resources are reserved for the duration of the connection. The new solution named MIP with Routing Optimization and QoS (MIP-ROQS) removes the signalling conflict and furthermore, results in increased network performance. Simulation of this solution demonstrates reduction in application end-to-end delay and delay variation, improved core network by reducing the amount of control traffic and dropped traffic and improved access network by reducing its delay.  Moreover, we integrate Multi Protocol Label Switching (MPLS) architecture and MIP-ROQS to take advantage of MPLS labelling mechanism to label the optimal path selected by MIP-ROQS for the duration of a session. This integration makes IP-in-IP tunnelling in data forwarding redundant. MPLS is used to switch packets and label the optimal path over which the resources are reserved. Using this approach, the transmission delay, and packet processing overhead are further reduced.


identifier: Raza, Syed Asif  (2007) Optimal pricing and seat allocation in the airline industry under the market competition.  PhD thesis, Concordia University.

abstract: The current practice of revenue management is either quantity based or price based. A quantity based revenue management is most commonly observed in the airline industry; whereas a price based revenue management is practiced in retail enterprises. Recent improvement of information technology has not only increased the market size, but also has increased market competition. In a competitive environment customers choose among substitutable products depending on several rationalities, however a paramount factor in most selections is price. This thesis investigates pricing issue in revenue management and makes three contributions.  First, price based revenue management is studied in the airline industry in a competitive market. Airlines compete for customers using their fare pricing strategies while having fixed capacity allocated in each fare class. The demand for each fare class of an airline is dependent on its fare price and the fare price offered by rival airline(s). A game theoretic approach is used to address the problem assuming both the deterministic and stochastic price sensitive customer demand for each fare class. The existence and uniqueness of Nash equilibrium for the game is shown for both deterministic and stochastic demands. A sensitivity analysis is carried out to determine fare pricing in each fare class considering various situations in the case of deterministic demand. The analysis is further extended to stochastic price sensitive demand, and a sensitivity analysis of the fare prices for each fare class is also reported.  Second, an integrated approach to price and quantity based revenue management with an application to the airline industry is presented. The models proposed enable joint control of fare pricing and seat allocation in a duopoly competitive market. Both non cooperative and cooperative bargaining games are studied. Numerical experimentation is performed to study both competitive and cooperative fare pricing along with seat inventory control assuming a nested control on booking limits. In the case of a non cooperative game, Nash equilibrium for the competing airlines is determined assuming both symmetric and asymmetric market competition. A sensitivity analysis based on a statistical design of experiments is also presented to study the behavior of the game. Statistical evidence is established which shows that cooperation improves the revenue to the competing airlines.  Lastly, a distribution free approach for pricing in revenue management is explored. The approach assumes the worst possible demand distribution and optimizes the lower bound estimate on revenue, while jointly controlling the price and capacity. The approach is first addressed to revenue management's most commonly observed standard newsvendor problem. Extensions to the problem are identified which can be applied to airline industry. Later the analysis is extended to consider the following cases: a shortage cost penalty; a holding and shortage cost; a recourse cost, with a second purchasing opportunity; and the case of random yields. An application of the approach is also suggested to capacity constrained industries facing restrictions such as limited budget. A numerical study reveals that the approach results in a near optimal estimate on revenue. Using a statistical comparison it is also shown that the outcomes of the standard newsvendor problem are significantly different than its extensions


identifier: Ngo, Tri-Dung  (2007) Understanding the effect of adding nanoclays into epoxies.  PhD thesis, Concordia University.

abstract: Different preparation methods and formulations of epoxy nanocomposites have been examined. The effects of each parameter, such as different types of clay, different types of curing agent, and processing conditions (temperature, time, speed), on dispersion of the clay particles were evaluated using different means, such as field emission gun scanning electron microscopy (FEGSEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and viscometer. Curing behavior was studied by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Thermal properties of epoxy nanocomposites were evaluated by thermogravimetric analysis (TGA), limiting oxygen index (LOI). Dynamic mechanical properties were studied by dynamic mechanical analysis (DMA). Tensile, flexural, compression, impact, surface hardness and fracture toughness were also examined. A new method to disperse organoclay into epoxy without using solvent, and using high speed mixing (TS), is proposed. The results obtained from this study provide a good understanding of the relationship between the formulation, processing conditions and performance. Significant improvement in stiffness and storage modulus was observed in nanocomposites formulated with better dispersion using TS. However, the extent of the improvement of the nanocomposites' performance depends on the type of the clay and the curing agent. In addition, the processing conditions have great effects on the final properties of epoxy nanocomposites.


identifier: Guzzo-McParland, Concetta  (2007) Girotondo.  Masters thesis, Concordia University.

title: Girotondo

abstract: Girotondo is the Italian name of the children's game, ring-around-a-rosy. The word giro has connotations in Italian, that this novel develops as symbolism. Giro may be translated as a turn, a tour or a circle, so fare un giro is to take a short ride with the aim of returning to the starting point. Gira e rigira is to go around in circles; mettere in giro , to spread rumors; while una presa in giro is to be taken for a ride or to be fooled. With these nuances in mind, the novel presents a group of people whose traditional lives have been disrupted by the process of immigration, and who live a somewhat disjointed existence.  In presenting the story of three women of different generations, all living in Montreal but connected by their origins in the same Italian village, and who have been traditionally kept silenced, the novel aims to reveal that the harmony of community was fractured as much by the mind-set present in the village of their past as by the realities of adjusting in a New World.  Added to the protagonist's search for her true identity and for self-realization is her obsessive need to write and record the phases of her family's immigrant journey. Through a discussion between an editor to whom she shows her work and the publisher of an ethnic press, the novel also attempts to raise questions related to the writing of the immigrant experience, as well as about living it.


identifier: Bhatt, Ajay  (2007) Generation of all-pole 2-D digital filters from the combination of all-pass filters.  Masters thesis, Concordia University.

abstract: Two-dimensional digital filters are applied in signal processing and pro-imaging process, as well as communication systems where the frequency domain characteristics of digital filters are required to be adjustable. The main objective of this thesis is to propose a new technique for designing all-pole 2-D digital filters with variable magnitude characteristics. In this thesis, 2-D digital filters starting from the identical analog 1-D second-order Butterworth lowpass filter are generated through the combination of all-pass filters in Category A and Category B. A new type of all-pole 2-D analog lowpass filter is designed through the combination of all-pass filters. The transfer functions of these filters are verified for stability. The 2-D analog lowpass filter has been transformed to the digital domain by applying generalized bilinear transformation. The design of the 2-D digital lowpass filter gives rise to 2-D digital highpass, bandpass and bandstop filters in Category A and Category B. The 2-D digital highpass and bandstop filters have been designed from the 2-D lowpass filter using appropriate generalized bilinear transformation in both the categories. The 2-D digital bandpass filter has been obtained by a combination of the 2-D digital lowpass and highpass filters in both the categories.  The effect of the coefficients of the generalized bilinear transformation on the 2-D digital filter's transfer function is studied in detail for Category A and Category B. In the end, an application of the proposed 2-D lowpass filter in Category A and Category B is illustrated in image processing. The designed 2-D low-pass filter has been used to reduce the effect of additive white Gaussian noise on digital images in both the categories


identifier: Klein, Reisa  (2007) Settling the dispute or disputing the settlements : representations of the disengagement plan in the Jerusalem Post.  Masters thesis, Concordia University.

abstract: Israeli settlements in the Occupied Territories have been a contentious issue within the Israeli-Palestinian conflict and a major obstacle towards bringing peace to the region. Beginning in April 2004, Israeli Prime Minister Ariel Sharon announced that Israel would withdraw all 21 of its settlements in the Gaza Strip and four settlements from the West Bank. The implementation of this disengagement plan began on August 15, 2005 and was completed less than 10 days later on August 24, 2005. On September 11, 2005 the last Israeli soldiers left Gaza and the settlements were officially handed over to the Palestinians the following day.  The news media became a crucial conduit through which the Israeli nation was informed about the disengagement of settlements. Through the application of a Critical Discourse Analysis (CDA) on Israel's largest English daily newspaper, the Jerusalem Post, I examine how the newspaper framed the disengagement of the settlements. I argue that the paper re-constitutes Israel as a democratic nation and postures itself as a public sphere and a fourth estate, giving the illusion of democratic deliberation, a strategy that works discursively to privilege Zionist and state hegemonic ideologies. Further, the Jerusalem Post reifies an Orientalist trope in which Palestinians are constructed as 'Other' and figured outside of the demos and public debate. I conclude that the newspaper arrests true democratic deliberation necessary for lasting peace in the region


identifier: Peters, Heather  (2007) Guilty contagions and innocent victims : adult sex workers in Canadian press coverage of Thailand's sex tourism industry.  Masters thesis, Concordia University.

abstract: Using a pro-sex workers' rights perspective, this thesis analyzes how and what mainstream, English-language Canadian newspapers contribute to the public, common sense knowledge of the adult, female sex workers in Thailand's sex tourism industry. It also considers the positions, actions, or policies with regard to the industry and its workers that this knowledge promotes or justifies. Through an analysis of newspaper articles about sex tourism published in three major newspapers between 1985 and 2005, I argue that the predominant discourses surrounding these sex workers are structured around ideas of guilt and innocence in ways that silence these women and negate the need to consider their concerns and demands with regard to the industry. Specifically, I demonstrate how the varying ascriptions of guilt or innocence in these newspaper articles intertwine with preexisting discourses and stereotypes so as to limit the portrayals of these women, positioning them as guilty contagions in need of control or, occasionally, childlike and therefore innocent victims in need of rescue. As these portrayals could easily help justify actions and policies that ignore sex workers' voices, I conclude with suggested changes to coverage of sex tourism that might aid the development of a common sense in which these women's demands are at the centre of any debate around the industry.


identifier: MacFarlane, John  (2007) Indecision-making : a rhetorical analysis of the Daily Show's 2004 U.S. presidential election campaign coverage.  Masters thesis, Concordia University.


identifier: Lithgow, Michael Andrew  (2007) Articulating counterpublics with community capital : a framework for evaluationg community television.  Masters thesis, Concordia University.

abstract: Community media performs various social roles including the production of collective identities, the construction of meaning, negotiating proximities to power, enriching networks of social bonds, and enhancing individual capacities. Evaluating these roles has emerged as an under-theorized and yet critical area of investigation for better understanding community media's role(s) in social formation and for articulating its social benefits to policy-makers and funding agencies. This thesis proposes a framework for evaluating community media's influence on social formation by mapping the influence community media outcomes have on collective capacities for determining social, political and economic outcomes (i.e. community capital).  An Outcomes Mapping Framework, which links community media outcomes to various forms of community capital, was tested for practicability in the field during the study of a small community television station in Cape Breton, Nova Scotia, Canada (Telile Community TV). This Framework proved useful in identifying: (i) the dynamic and varied ways that Telile TV has played a role in expanding local influence over social outcomes; (ii) indicators of social change causally linked to community television practice; and (iii) some of the strengths and weaknesses of extant community media practice within regional media ecologies. The field results also revealed the critical importance of ontological context for evaluative assessments of community media practice


identifier: Zhao, Lin  (2007) Modeling and assessment of produced water discharges emitted from offshore petroleum platforms in the East Coast of Canada.  Masters thesis, Concordia University.

abstract: The discharge of produced water accounts for the largest volume of waste associated with offshore oil and gas production operations. With the development and expansion of Canada's offshore oil and gas reserves, there is concern over the potential long-term impacts of produced water discharges in the ocean. Furthermore, recent evidence from other offshore oil fields in the world has suggested that production water discharges may impact the biota at greater distances from operational platforms than originally envisaged. To deal with this emerging issue, the present study focused on the development of tool for the assessment of environmental risks associated with produced water discharges based on the integration of ocean hydrodynamic and pollutant dispersion models.  Specifically, a numerical approach, POM-RW, is developed based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation for pollutant transport. The POM is employed to simulate the ambient oceanographic conditions. It provides three-dimensional (3D) hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water effluent stream at a regional spatial scale. Furthermore, a Monte Carlo approach, with the use of water quality standards, has been incorporated into the POM-RW to reflect uncertainties and to quantify the environmental risks associated with produced water discharges. Development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results demonstrated the utility of this model to support the effective management of produced water discharges in the future


identifier: Wilson, Melanie Hope Aberdeen  (2007) An investigation into the effects of orientation interventions on attrition for first-time distance learners in undergraduate courses.  Masters thesis, Concordia University.


identifier: Ilkbasaran, Deniz  (2007) Sign up! : development of an ASL board game for hearing families with deaf children.  Masters thesis, Concordia University.


identifier: Rayner, Vanessa  (2007) An examination of the type of instruction that facilitates preservice teachers' development of specialized content knowledge of division with fractions.  Masters thesis, Concordia University.

abstract: Ball, Hill, and Bass (2005) proposed that facilitating the development of preservice teachers' specialized content knowledge (SCK) warrants investigation. Specialized content knowledge is mathematical knowledge that is used to teach mathematics and should thus be uniquely understood by teachers. Moreover, the type of mathematics content knowledge (i.e., conceptual and procedural) that would enhance preservice teachers' SCK is not well understood. In line with Ball et al., objectives of the present study were to (a) examine whether content-focused instruction addressing division with fractions would enhance preservice teachers' SCK of this topic and (b) examine the impact of instructional content (i.e., conceptual content, and a combination of conceptual and procedural content) on preservice teachers' gains in SCK of division with fractions (SCK-DF).  Eight preservice teachers were assigned to one of two treatment conditions (i.e., conceptual content, and a combination of conceptual and procedural content) and their development of SCK-DF was measured using semi-structured pre- and post-interviews. The interview data were coded using the Analysis of Specialized Content Knowledge of Division with Fractions rubric, developed by the researcher.  In general, the results supported the hypothesis that (a) participants' overall SCK-DF was enhanced after instruction and (b) the participants who received the combination of conceptual and procedural instructional content demonstrated greater gains in their development in SCK-DF. Taken together, the results from the current study broaden the current understanding of ways to foster preservice teachers' SCK and have implications for future research in the area


identifier: Farris, Candace  (2007) The effects of message length, L2 proficiency and cognitive workload on performance accuracy and speech production in a simulated pilot navigation task.  Masters thesis, Concordia University.

abstract: The goal of the present study was to investigate the influence of L2 proficiency in controller-pilot communications under conditions of varying cognitive workload. The study therefore examined the effects of L2 proficiency and cognitive workload on performance accuracy and speech production in a simulated pilot navigation task. Three groups of 20 participants (one native-English speaking and two native-Mandarin speaking of relatively high and low levels of proficiency in English) took part in the experiment. Participants listened to, repeated and responded to "controller" messages (in English) of varying lengths in two conditions: clear and workload. In the workload condition, participants performed a concurrent arithmetic task while repeating the controller message.  The dependent variables were divided into two sets: performance accuracy (message repetition and navigation accuracy), and speech production (accentedness, comprehensibility, fluency and confidence, as perceived by 10 native-English speaking raters). Based on the results of the present study, it is recommended that air traffic controllers limit their messages to a length of 2 commands when communicating with L1 pilots under high workload conditions. When communicating with L2 pilots of low or intermediate L2 proficiency, it is recommended that controllers limit the length of their messages to 1 command under high cognitive workload conditions. A significant detriment to speech production due to increased message length was observed for the L2 groups for all speech production measures. A significant detriment to speech production due to increased cognitive workload was observed for the Low L2-proficiency group for the perceived fluency measure


identifier: Zhang, Yonggang  (2007) An ontology-based program comprehension model.  PhD thesis, Concordia University.


identifier: Kowaliw, Taras  (2007) A good number of forms fairly beautiful : an exploration of biologically-inspired automated design.  PhD thesis, Concordia University.

abstract: Artificial Embryogeny (AE) can be described as the use of a dynamical system as a mid-step in a design process; Through emulating Biological Embryogenesis, we hope to reach levels of complexity and robustness currently impossible. AE is a new field, and suffers from a lack of standards and meaningful means of evaluation. In this document, we review existing work, discussing motivations and merits of existing approaches. Throughout, we argue that a viewpoint which does not regard environment as a primary source of information risks taking a naïve view of evolution. We argue that "complexity" is vaguely and inconsistently defined, and propose several novel measures; Perhaps the simplest model of AE, the Terminating Cellular Automaton, is introduced, and used to compute and contrast our measures. Next, the Deva family of AE algorithms is introduced, a modular Cellular Automaton-like group. A domain of application from Civil Engineering is chosen as an interpretation of the grown organisms. It is initially shown that it is possible to use a Deva algorithm to evolve Plane 'Fusses successfully, this interpretation providing a discipline-independent measure of success. A series of empirical experiments is undertaken, showing the relative efficacy and effects of several model-level strategies in the context of the evolution of structural design. Finally, we explore the role of environment as a constraint on development of structural form. We demonstrate a strong resistance to environmental change by successfully re-growing the organisms in new environments, showing that some Deva organisms are adding information from the environment to their overall morphology; This provides an artificial analogue to the re-use of genes which characterizes biological development.


identifier: Sadeghian, Ramin Banan  (2007) A field effect gas sensor based on self-standing nanowire arrays.  PhD thesis, Concordia University.

abstract: In this thesis we have introduced a novel gas sensor that works by fingerprinting the ionization breakdown characteristics of the unknown gases. This technique provides excellent selectivity; it is well established that at a constant temperature and pressure, every gas displays a unique breakdown electric field. In addition, because this technique does not involve adsorption or desorption of gases, the sensor exhibits a fast response and is not limited by considerations of reversibility and recovery.  We employed vertically-aligned, self-standing arrays of gold nanowires (AuNWs) at one of the electrodes of a miniature parallel-plate ionization cell. The AuNW arrays were synthesized using a tailored version of the electrochemical template-assisted technique, resulting freestanding structures with controlled sparseness. Individual AuNWs, owing to their nanoscale tips, generate very high non-linear electric fields near their tips that provoke the breakdown process due to formation of a corona and allow self-sustaining discharges to be created at relatively low voltages.  In an alternative approach, we exploited the tunneling field ionization characteristics of the gases to identify the unknown gas type and measure its concentration. The phenomenon of field ionization consists of electron tunneling from gas atoms (molecules) through a potential barrier into a vacant energy level of the conduction band of a metal. It has been widely used in field-ion microscopy and mass spectrometry. However, the electric fields required to field-ionize gaseous species are in the range of 2-5 V/Å, orders of magnitude higher than the breakdown fields. With the provision of low voltage operation, this method can be utilized in detection of gases at very low concentrations. In this research, we also fabricated sensors using AuNWs with particular tip geometry and composition capable of field-ionizing gas particles at sub-10V voltages. The devices were successfully characterized using several gas species


identifier: Yang, Chun  (2007) New techniques for the design and implementation of efficient full-search algorithms for block-matching motion estimation.  PhD thesis, Concordia University.

abstract: The block-matching motion estimation (BME) is one of the most commonly used techniques for digital video compression in low to moderate bit rate environments. The full search for block-matching motion estimation, as compared to a partial search, provides a higher motion estimation accuracy, yet its computational cost is generally high. Hence, developing new techniques for an efficient implementation of full-search algorithms is of practical significance for the BME.  In this thesis, a new full search algorithm is proposed, wherein the mean squared error (MSE) is used as the matching criterion to provide a higher motion estimation accuracy for the BME than that by any algorithm based on the most commonly-used mean absolute difference. It is shown that the computation of the MSE in the Haar wavelet domain results in a computational complexity that is much lower than or of the same order as that of the best-performing full search algorithms available in the literature.  A new approach has been developed for the multi-reference-frame block-matching motion estimation, wherein a full search is performed in the spatial domain of the multi-reference-frame memory, and an early termination is imposed in the temporal domain using a novel strategy. It is shown that the computational complexity of the proposed full search method is significantly lower than that of any existing full search technique, and yet has a motion estimation accuracy which is about the same as that of the latter.  A new pseudo-spiral-scan data input scheme has been proposed, which can be used in any existing hardware architecture for the implementation of the successive-elimination-based block-matching motion estimation. This scheme results in significant power savings compared to the conventional raster-scan data input scheme. Several designs to implement the successive elimination algorithm have been given, some of which are shown to provide additional power savings.


identifier: Sokhanvar, Saeed  (2007) Micromachined multifunctional polyvinylidene fluoride tactile sensor for minimally invasive surgery graspers.  PhD thesis, Concordia University.

abstract: Promising results of Minimally Invasive Surgery, MIS, in the last two decades have been the main incentive of numerous researches in this area. However, despite numerous advantages of this relatively new technique, using of long tools inserted through small ports on the body deprive surgeons of the depth perception, dexterity, sense of touch, and straightforward hand-eye coordination that are accustomed to surgeons in open procedures. Many researches have been launched to rectify the mentioned shortcomings and some improvements, such as, excellent stereo visual feedback and satisfactory dexterity, have been made recently in robotic assisted surgical systems.  However, the current MIS tools whether in endoscopic surgery or in robotic assisted surgery are incapable of providing tactile feedback. The tactile information collected by the surgeon's hand in an open surgery is vital for success in complex and delicate operations. For instance, the ability to distinguish between different types of tissue in the body is of vital importance to a surgeon. Before making an incision into tissue, the surgeon must identify what type of tissue is being incised. Failure to classify properly the tissue can cause severe consequences.  There have been some attempts to develop smart MIS graspers with integrated sensors. However, many of these integrated sensors are limited to force or softness sensing. From a functional point of view, integrating several sensors each of them is responsible for measuring a specific quantity is difficult. In contrast, a multi-functional tactile sensor which would be able to address several concerns such as force measurement, determining position of the force, assessing softness of the grasped object, detecting any hidden lumps in bulk soft tissue is highly desirable. The transduction techniques used in the relevant researches have been reported as capacitive and piezoelectric techniques. In this study, the piezoelectric polymer Polyvinylidene Fluoride (PVDF) has been used as the transducer due to its unique features and also bio-compatibility.  This study aimed at introducing a multi-functional tactile sensor which would be able to address many of the required information in a surgery procedure. A unit of the proposed sensor is able to measure the applied force and its position along the length of the sensor system. In addition, it is also able to differentiate the softness of the contact objects. An array of sensor is able to locate the applied load or any hidden mass in a plane (i.e. xy plane). Integration of the sensors into both jaws of the grasper, enables the smart grasper to determine the depth of any hidden masses. Regardless of the type of the integrated sensor, the study of stress profile in the presence of a lump, at the contact surface of object-grasper is of importance. The behavior of the soft tissue highly influences the stress distribution at the contact surface of tissue and grasper. Although modeling all of the complex behavior of soft tissue is very difficult, in this study, the nonlinear characteristics of the tissue is considered. In the absence of the soft tissue the simulation and experiments are conducted on the elastomers which exhibit very similar behavior.  However, the ultimate objective is the integration of the proposed sensor with the existing MIS graspers. To do this, the sensor must be microfabricated. Therefore, in order to study the feasibility of micromachining of the proposed sensor, the microfabrication procedure for the tactile sensor was examined and the fabrication difficulties were identified. The conventional anisotropic wet etching has been used for micromachining the device.


identifier: Holt, Ann  (2007) Dr. Edward Mattil remembers Dr. Viktor Lowenfeld : an art education history in context.  Masters thesis, Concordia University.

abstract: This thesis is rooted in a personal desire to understand the history of the author's hometown and the history of her chosen profession. It is an examination of two decades of art education, 1940 to 1960, with a particular focus on the author's hometown of State College, Pennsylvania where Viktor Lowenfeld established and headed the art education department. This thesis investigates the life and ideas of Lowenfeld and Dr. Edward Mattil, Lowenfeld's former student, colleague and friend, in context of the social, political and educational realities in which their work was situated. The research in this study is conducted through conversations with Mattil and involved thorough consultation of archival materials as well as a range of literature from and about this particular period of history. The thesis demonstrates that factors such as politics, war, social and cultural issues, religion and technology greatly impacted the concepts and ideas that Viktor Lowenfeld held and taught.


identifier: Reid, Natasha  (2007) Developing gallery outreach policy : a collaborative process.  Masters thesis, Concordia University.

abstract: This research developed a framework for collaborative art education between art galleries and community groups in order to inform art gallery and museum outreach educational programming policy development. The objective of this process was to discover a means to effectively foster the development of a collaborative vision for socially inclusive programming between a gallery and a community group. The proposed framework was implemented through a collaboration between La Centrale Galerie Powerhouse and the Immigrant Workers Centre. Qualitative methods used in this research included a focus group meeting, an interview and a written reflection from the three collaborating members--the gallery programmer, the gallery educator and the community group facilitator. The data from these methods served as the basis for the discussion and analysis of the framework's efficacy through the fulfillment of the goals, effectiveness of the dialoguing processes and the inclusive nature of the project. This process resulted in recommendations for collaborative art gallery educational processes through the refinement of the proposed framework


identifier: El-Sheikh, Tammer  (2007) Paper cuts : life, death and "drags" in Andy Warhol's America.  Masters thesis, Concordia University.

abstract: This study aims to situate Andy Warhol's work from the 1960s in its cultural, material and critical context. The first chapter follows Hal Foster's influential "traumatic realist" interpretation of Warhol to identify its strengths and limits. Foster's engagement with both the cultural theory of trauma and aspects of the work of Roland Barthes and Jacques Lacan are considered. In light of this assessment a case is made for the cultural studies approach to Warhol's work advocated by Douglas Crimp.  The second chapter explores how Warhol's manipulation of images from Life 's archive engages the artist's work in a public discourse-- structured by the photographic codes of the illustrated press --on the issues of his day. In the framework of Allan Sekula's "archival paradigm" a measure of political agency for Warhol in the context of a public visual domain emerges. This understanding of Warhol's intervention is supported by Barthes's analyses of signifying practices in the cultural sphere and Walter Benjamin's description of the reproductive imaging technologies, on which such practices depend.  The third chapter focuses on the philosophical status of Warhol's work, as discussed by Arthur Danto and his critics. Warhol's artistic description seems to issue a prescription as well, to intervene in the public sphere by means of its own communicative resources. The political stakes of this prescriptive aspect of Warhol's work are examined in the context of the artist's involvement in the gay underworld of the 1960s and its representation in the popular press


identifier: Sohail, Abu Sayeed Md  (2007) Person independent classification of facial expressions using multi-class support vector machines.  Masters thesis, Concordia University.

abstract: This thesis describes a fully automated computer vision system for detection and classification of the seven basic facial expressions using Multi-Class Support Vector Machines (SVM). Facial expressions are communicated by subtle changes in one or more discrete features such as tightening the lips, raising the eyebrows, opening and closing of eyes or certain combination of them, which can be identified through monitoring the changes in muscles movements (Action Units), located around the regions of mouth, eyes and eyebrows. An analytic representation of face with fifteen feature points describing the geometric and physical (muscle) model of facial expression structure has been used that represents and identifies the principal muscle actions and also provides visual observation (sensing) of the discrete features responsible for each of the seven basic human emotions. Feature points from the region of mouth have been detected by segmenting the lip contour applying a newly introduced variational formulation of the existing level set method. In addition, a multi-detector approach of facial feature point detection has been utilized for identifying the points of interest from the regions of eyes, eyebrows and nose. The feature vector composed of fifteen features is then obtained with respect to the average representation of neutral face by calculating the degree of displacement of five different pairs of points, and measuring the deviations of ten points from a non-changeable rigid point. Finally, the obtained feature sets are used to train a Multi-Class SVM classifier. The proposed automated facial expressions classification system has been tested extensively on two publicly available facial expression databases and 92.04% and 86.33% of average successful classification rates have been achieved. Besides, satisfactory results have been obtained by comparing the proposed method with other previous methods of facial expression classification.


identifier: Hussain, H. M. Ishrar  (2007) Using text classification to automate ambiguity detection in SRS documents.  Masters thesis, Concordia University.

abstract: Software Requirements Specification (SRS) is one of the most important artifacts produced during the software development lifecycle. In practice, requirements specifications are initially written in natural language, which allows them to be corrupted with different forms of ambiguity that eventually may contribute to critical failure in the subsequent phases of the system's development, if they are not detected at the time of requirements validation. The objective of this work is to study possible automation of detecting ambiguity in SRS documents by means of a text classification system. The work is a part of a larger project aimed at applying Natural Language Processing (NLP) techniques to assess the quality of SRS documents.  In the absence of a standard annotated corpus, we collected SRS samples and carried out corpus annotation process to build corpora of our own, one at the sentence-level and the other at the discourse-level. The annotators were trained with an annotation guideline, which was written based on the quality model that we had developed. The process showed substantial level of inter-annotator agreement indicating the possibility of automating the task by a tool that can accurately emulate the human annotation process. The resultant corpus was then used for training and testing our text classification system.  We set the scope of this thesis to detect ambiguity at the level of surface understanding only, since the indicators of its possible existence in text can be realistically extracted by the currently available NLP tools. We developed two different decision-tree-based text classification systems that worked at the sentence-level and the discourse-level, and conducted a series of experiments training and testing the classifier with different sets of features. Finally, merging the two classifiers together yielded optimum results with an accuracy of 86.67% in detecting ambiguity at the level of surface understanding. To our knowledge, none of the previous work in the field of Requirements Engineering (RE) has tested the applicability or performance of using a text classification system to automate the detection of textual ambiguities. Our work, thus, provided significant evidence on the prospect and feasibility of using a text classifier to automate ambiguity detection in SRS documents.  Keywords. Software Requirements Specification, Text Classification, Natural Language Processing


identifier: Abraham, Rajiv  (2007) Model driven development : a comprehensive case study.  Masters thesis, Concordia University.

abstract: The major complexity in creating software systems lies in the understanding of the problem domain for which the software is developed. Models help analyzing the problem domain more effectively as they provide a higher level of abstraction by filtering out the low-level details. Model Driven Development is a methodology that advocates the use of models as the primary artifacts that drive the development of software instead of serving as informal sketches. In this thesis, we demonstrate the application of MDD to the development of a non-trivial software system using a state of the art tool: IBM's Rational Software Architect (RSA). We also investigate how MDD attempts to solve the problem of model-code synchronization through Round-Trip Engineering. With the help of this case study, we present the limitations and guidelines learned regarding the use of the state of the art for MDD, highlighting the difference between theory and practice.


identifier: Yang, Min  (2007) A two-stage multi-path searcher for WCDMA RAKE receivers.  Masters thesis, Concordia University.

abstract: The performance of a Universal Mobile Telecommunication System (UMTS) base station RAKE receiver is largely dependent on the accuracy of the estimate of the time-delay of the different paths. A commonly employed technique in a RAKE receiver is to use a multi-path searcher (MPS) to find the number of different strong paths and the time-delay of these paths.  The drawback of the existing MPS algorithms for UMTS base-station RAKE receiver is that their computational complexity is high or the probability of detection is low. The full search with full contribution MPS gives the best result in terms of the detection probability, but its complexity is high. To reduce the complexity, a full search with partial contribution MPS has been proposed, but the detection probability of this algorithm is low. In order to solve this problem, in this thesis, a two-stage MPS, based on a dual-dwell technique is proposed. In the proposed algorithm, all the delay offsets in the search window are first evaluated for possible true paths by using only part of the slots in the correlation period. This helps to quickly narrow down the number of search candidates with only a small amount of computation needed. Then, in the second stage, the M strongest candidates from the first stage are further evaluated by using all the slots in the correlation period.  The simulation results show that the proposed algorithm has a detection performance very close to that of the conventional full search with full contribution MPS, while at the same time it has a substantially lower computational complexity


identifier: Sugavaneswaran, Lakshmi  (2007) A novel enhanced compression scheme for digital images and its application for medical imaging.  Masters thesis, Concordia University.

abstract: With the advent of digital technology, the amount of digital medical images generated is increasing at an exponential rate. When used in interactive telemedicine applications, these raw images need a huge storage unit, thereby necessitating the use of highbandwidth medium for transmission. In order to reduce the cost of transmission and enable archiving, especially for medical applications, image compression is performed. Most of the existing research in compression is focused on minimizing mathematically tractable, easy to measure, distortion metrics like the peak signal-to-noise ratio (PSNR) for gray scale and root mean square error (RMSE) for color coded images. These metrics often poorly correlate with the visual quality of the image as the human visual sensitivity characteristics are not incorporated in these evaluation techniques. For digital images, especially for medical images, perceptual quality of image is important along with compression efficiency since diagnosis is done based on the visual attributes of the reconstructed image.  This thesis is concerned with the problem associated with obtaining an enhancement in the quality of the image with lossy compression schemes. An enhanced image compression scheme using the nearly-orthogonal wavelet to achieve an enhancement in the perceptual quality of the image is proposed. This approach differs from the conventional design scheme in that it incorporates the human visual system (HVS) characteristics directly in each sub-band of the wavelet decomposed image. The enhancement in the visual quality of the reconstructed image is achieved by using the newly derived contrast sensitivity function band peak-average (CSF-BPA) mask at each decomposition level during wavelet transformation phase in the compression system. The nearly-orthogonal wavelet is used to achieve improved compression performance for low and medium bit rate applications. The proposed scheme is further extended for perceptual medical image compression application for images such as x-ray, MRI and ultrasound scan. The dependency of the calculated PSNR to the observed visual quality has been addressed for some of the standard images as well as for medical images. The presence of additive white Gaussian noise (AWGN), which is the most common source for image artifacts, is considered during the evaluation of the performance of the scheme. The effectiveness of the proposed scheme is demonstrated and compared with that of the conventional scheme through extensive quantitative and qualitative assessments. Finally, a multiplier-less design for the implementation of the BNC 17/11 wavelet filter in a FPGA or ASIC hardware is proposed


identifier: Levine, David  (2007) Error resilient transmission of H.264 compressed video using CABAC entropy coding.  Masters thesis, Concordia University.

abstract: This thesis examines the transmission of H.264 compressed video over an Additive White Gaussian Noise (AWGN) channel when Context-based Adaptive Binary Arithmetic Coding (CABAC) is used as the entropy code.  First, several simulations were performed to examine the effect that bit errors have on H.264 decompression. The simulation results show that over 99% of the bit errors tested caused a semantic error to be detected. Further simulation results show that undetected bit errors (bit errors that don't cause semantic errors) were not observed to cause noticeable video quality degradation.  Then, two transmission schemes are proposed. The first proposed scheme uses soft bit information (at the receiver) along with H.264 semantic verification to detect and conceal errors during decompression. Note that this scheme does not involve channel coding. The second proposed scheme is an iterative joint source-channel decoding scheme. It combines a rate-歔 convolutional code with the semantic verification strategy of the first scheme. Information is passed from the channel decoder to the source decoder by soft channel decoding. The source decoder then feeds information back to the channel decoder by modifying its original soft values. Simulation results show that both schemes offer significant improvements in terms of subjective quality and in terms of objective quality using PSNR and BER as measures.  Keywords: Video transmission, H.264, CABAC, compression, slice candidates, joint source-channel decoding, semantic verification, soft values, semantic error detection


identifier: Sang, Wei Qian  (2007) Efficiency and stability of peer-to-peer file sharing systems.  Masters thesis, Concordia University.

abstract: In recent years, Peer-to-Peer (P2P) applications, from traditional file sharing to P2P live audio/video streaming, have become very popular. Among the P2P applications, P2P file sharing remains one of the most popular applications and its traffic has been dominating the Internet bandwidth for the past years. In this paper, I will mainly study the efficiency and stability of the P2P file sharing systems.  In the P2P file sharing networks, the upload bandwidth of each peer is a very important resource of the network. The efficient use of it will affect the system performance significantly. Motivated by this fact, a stochastic model for P2P file sharing networks is proposed and numerically solved to analyze how the performance of a P2P file sharing network is affected by different parameters such as the piece numbers of the file, the number of neighbours of a peer, and the seed departure rate etc. Based on this result, some useful guidelines are also provided on how to design an efficient P2P system.  Stability is another important issue in P2P file sharing systems. In this thesis, a simple fluid model is used to analyze the stability of BitTorrent-like P2P file sharing networks. The resulting fluid model is a switched linear system and it is proved that such a system is always globally stable. Numerical results based on extensive simulations are also provided to support the theoretical proof


identifier: Shah, Nikunj Mahesh  (2007) EMTP-RV simulation of a chain link STATCOM.  Masters thesis, Concordia University.

abstract: An advanced static VAr compensator (ASVC), using a voltage-source-converter (VSC), popularly known as a static synchronous compensator (STATCOM), is generally acknowledged as the next-generation reactive power controller in power systems. Its mode of operation is analogous to that of a rotating synchronous condenser and it provides dynamic voltage compensation, increased transient stability and damping for the power system. Several STATCOMs, based on high power semiconductor switches (e.g. Gate Turn Off thyristors, GTOs or Insulated Gate Bipolar Transistors, IGBTs) and a special zigzag transformer have been put into operation. These STATCOMs have advantages over conventional static VAr compensators (SVCs) of lower harmonic generation, improved performance and a smaller reactor size. However, the zigzag transformers used in these STATCOMs are bulky, expensive and as yet unreliable. An alternative method to eliminate the zigzag transformer and to increase the STATCOM rating with a corresponding reduction in harmonics is to use a multilevel converter, which produces a 'multi-stepped' output voltage waveform in a close approximation to a sine wave.  A recent addition to the multilevel converter based STATCOM family has been obtained by connecting a number of VSCs in series on the ac side of the system forming a 'chain' per phase. Each VSC is a 1-phase, full-bridge converter and forms a 'link' of a 'chain'. This STATCOM configuration is referred to as a 'Chain Link STATCOM' (CLS). In this thesis, a GTO is used as a switch for the CLS. However, any other high power semiconductor switch (e.g. IGBT) may also be used instead. Each GTO of the CLS, is switched on/off only once per cycle of the fundamental frequency by employing a sinusoidal pulse width modulation (SPWM) technique. Approximate models of a 3-phase CLS using dq -transformation are derived to design two cascaded controllers for controlling reactive current and ac voltage to stabilize the power system voltage at the point of common coupling (PCC). A novel technique, called the rotated gate signal pattern (RGSP), is used for balancing the voltages of the link do capacitors of the VSC. The performance investigation of the CLS system when used in a radial line transmission system is carried out under steady- and transient-state operating conditions by means of the simulation package EMTP-RV.  Index terms. Chain link STATCOM, VSC, SVC, STATCOM, FACTS, EMTP-RV.


identifier: Pendyala, Srinivasa Raghavendra  (2007) Modeling, analysis and testing of an electrostatically actuated waveguide based optical MEMS device for variable optical attenuation.  Masters thesis, Concordia University.

abstract: Electrostatic actuation is a promising solution for Micro Electro Mechanical Systems because of its good scaling properties in small dimensions, high-energy densities and relative ease of fabrication. Its low response time and compatibility with IC technologies make it even more suitable for the optical applications, such as, optical switching and Variable Optical Attenuators (VOAs) in telecommunications. Variable Optical Attenuators are very important components in fiber optic communication systems needed throughout the network to control optical power and prevent the saturation of receivers.  This thesis describes the design of a novel and simple electrostatically actuated variable optical attenuator that uses the electrostatic actuation of a cylindrical waveguide. The proposed device stands out from the existing conventional optical attenuators by directly moving the input waveguide for creating misalignment and thus eliminating the need for extra optical components required in free space. This model has capability for a high dynamic range of attenuation and has other advantages of low wavelength dependent loss and low back reflection. The optical MEMS device consists of a metal coated cylindrical waveguide positioned in a V-groove and overhanging at the end to act as a free standing cantilever.  This work presents modeling, analysis and testing of the proposed device. The system has been defined accurately using coupled electromechanical models that take into account the capacitance of the cylindrical electrode configuration. The static and dynamic analyses of the system have been performed using the Rayleigh Ritz energy method. The developed electromechanical model is generic and could be applied to any cylindrical electrostatic actuator. The generality of the method has been demonstrated in this work by performing static and dynamic analysis on a carbon nanotube actuator and nano resonator, respectively, using the above model. To verify the feasibility of the method for optical attenuation parametric study is presented and the resulting static deflections, pull-in voltages, natural frequencies and finally achieved attenuation have been presented.  Testing is a very vital component in the synthesis of a microsystem. Experimental testing is carried out in this work using non contact optical methods. Both static testing using optical microscope and dynamic testing using Laser Doppler Velocimetry have been performed on a prototype representing the proposed device. The experimental results of deflection were found to be in good agreement with the theoretical results from the model.


identifier: Roy, Niladri  (2007) Computer aided design approaches for certain classes of low-noise amplifiers.  Masters thesis, Concordia University.

abstract: Low-noise amplifiers (LNAs) are critical components to any modern electronic communications system. LNAs are usually placed at the beginning of a multistage system and are designed with high gain to suppress the noise contributions of subsequent stages. Aside from noise and gain, other performance criteria such as, distortion effects, power consumption, and circuit size have varying degrees of importance based on the LNA's destined application. It is the way in which the LNA is designed ( i.e. topology selection, design methodology, fine-tuning, etc.) that will determine how well the LNA performs. Currently, there is no unique or systematic approach for the design of these relatively complex circuits. Hence, the development of CAD tools for LNA design is an attractive alternative to traditional pen and paper approaches.  This thesis can be divided into two main parts; computer aided LNA design from an analog perspective and computer aided LNA design from a RF/microwave perspective. Analog engineers tend to work with traditional electronic components ( e.g. transistors, resistors, inductors, capacitors, etc.). In this work, a computer aided approach is devised which performs appropriate topology selection, design, and fine-tuning.  In the RF/microwave world, designers tend to work at higher operating frequencies, and thus use microwave oriented components such as micro-strips and waveguides. Given the S -parameters for a specified transistor, the proposed approach finds an input/output reflection coefficient that maximizes the LNA gain for a specified noise-figure. The proposed CAD approach exploits "constrained line search optimization" to increase the accuracy of the LNA circuit and to reduce the time needed in the design process.  The CAD approaches are illustrated via practical LNA examples. The resulting LNA designs are shown to have improved performance w.r.t the user-specifications.


identifier: Salloum, Tarek  (2007) Effect of fly ash replacement on alkali and sulphate resistance of mortars.  Masters thesis, Concordia University.

abstract: The use of fly ash as a supplementary cementing material in concrete and mortar has dramatically increased in recent years due to its improvement of concrete and mortar properties and its environmentally friendly impact. In this thesis, the sulfate resistance and alkali-silica reaction in mortars containing 0, 20, 40, 60, and 80% fly ash replacement levels were investigated to determine the effect of fly ash content on durability. Four types of cement and two types of fly ash were used in the tests, the cements used were of different alkali contents and with and without blended silica fume. The fly ashes consisted of medium and high calcium contents.  The results showed that the expansion resulting from sulfate attack as well as the alkali-silica reaction considerably decreased with the increase of fly ash content, but the strength of the mortar samples greatly decreased as well. The effectiveness of fly ash in both tests was highly dependent on their CaO content and on the chemistry of cements utilized. 20% Sundance fly ash replacement was sufficient to maintain the sulfate expansion after six months of exposure below CSA allowable expansion limit of 0.05% for high sulfate resistance cement and also below the Canadian limit of 0.1% in the ASR test. For Rockport fly ash, replacement levels at 40% were needed to maintain the expansion below the limit of 0.1% in ASR and sulfate test. The presence of silica fume blends significantly reduced the expansion due to alkali-silica reaction and sulfate attack; addition of fly ash to silica fume blended cements did not significantly improve performance.