identifier: Ait Abderrahmane, Hamid  (2008) Two cases of symmetry breaking of free surface flows.  PhD thesis, Concordia University.

abstract: The present thesis consists of two parts; both are devoted to two celebrated old problems in fluid dynamics. The first deals with symmetry breaking in a liquid layer flowing down an inclined plane. The second problem concerns the equilibrium and symmetry breaking of interfacial polygonal patterns generated by a system of vortices arranged on a circular ring.  The first problem dates back to Nusselt (1916) who obtained the solution for the basic flow. Since then, thin layers of liquid falling down inclined plane continues to be the subject of extensive studies for both their practical applications and theoretical value. In this thesis, the problem is approached analytically. Three new mathematical models are proposed. The first two involve three and four equations respectively. These produce linear stability results that agree fairly with past experimental outcomes and results obtained with similar models. For a deeper and qualitative analysis a lower dimension model that retains the physics is needed. Hence, a two-equation model (involving only two fundamental flow parameters namely the film thickness and flow rate) is derived. The new model taking account of the shear stress at the free surface is shown to be superior to the existing two-equation model of Usha and Uma in Phys Fluid (2004).  The influence of electrical and magnetic fields on the stability of falling film of an electrically conductor fluid is also investigated. In comparison with the model of Korsunsky ( Eur.J.F.M.1999 ) for higher Reynolds numbers. The proposed model takes account of the inertia terms, which are of second order with respect to a small parameter namely the long wave parameter. As shown through the chapter four of the part one, the proposed two-equation model improves significantly Korsunsky's model.  The second problem dates back to Kelvin (1867) who hypothesized atoms to be point vortices arranged in circular ring forming symmetrical polygonal patterns. Although, the atomic vortex model is long abandoned, the problem of system of point vortices has become of great interest in superfluidity and by analogy in plasma physics. Moreover, polygonal patterns, which are the signature of the presence of vortices, equally distributed in) rings were also observed in several engineering problems and geophysical flows in nature. In fluid dynamics, polygonal patterns become clearly visible in swirling flows where the vortex core is hollow. The empty core can eventually support polygonal shapes (up to hexagonal). The first experimental report on the phenomenon was by Vatistas in 1990. In this thesis the phenomenon is revisited using image-processing technique that allows a deeper and more precise investigation. The dynamics of the patterns is investigated and for the first time the transition from one pattern to another is explored in detail. The stability condition for a system of point vortices on circular ring derived first by J.J Thomson (1897) and generalized later by Havelock (1931) for N point vortices including the influence of circular boundaries surrounding the equilibrium is confirmed. Frequency locking between the pattern and the disk frequencies which are suspected in the previous experiments is established and quantified. Moreover, the transition from the elliptical to the hexagonal pattern is found that it follows a "devil's staircase" scenario. Due to the similarity between the problem under the scope and other fields of physics, the present experimental results are anticipated to go beyond the field of fluid mechanics.


identifier: Pacheco, Sabrina  (2008) The effect of cryopreservation on mitochondrial function in human skeletal muscle.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: The analysis of mitochondrial function is fundamental in the diagnosis of muscle pathologies. Long term preservation of human tissues for functional analysis is a frontier challenge in diagnostics but has potential benefits for inter-laboratory and interdisciplinary analyses. High resolution respirometry of permeabilized muscle fibers allows for quantification of mitochondrial function ex-vivo from small biopsy samples. Scientific studies on respirometry of cryopreserved muscle tissues have seldom been performed. In this study we investigated mitochondrial respiration of DMSO cryopreserved muscle tissue and compared oxygen flux rates to freshly harvested muscle from the same biopsy sample. The purpose of this study is to test the functional capacity of mitochondria in cryopreserved muscle tissue and to compare respirometry to fresh muscle mitochondrial tissue. Cryopreserved muscle showed robust coupled state 3 mitochondrial respiration comparable to fresh muscle. However, the magnitudes of state 3 (ADP-driven) respiration rates for complex I substrates with malate and glutamate and complex I and II with addition of succinate were lower than that of fresh muscle tissue. The significant increase in state 3 respiration upon addition of cytochrome c indicates that cryopreservation causes results in cytochrome c loss and potential disruption of the inner mitochondrial membrane. Optimization of the cryopreservation method will permit long-term storage of samples, allow mitochondrial function and energy metabolism to be analyzed and provide the potential for exchanging samples between research centers.


identifier: Martel, Claude  (2008) The effect of teaching metacognitive learning skills on the performance of online learners demonstrating different levels of self-regulated learning.  PhD thesis, Concordia University.

abstract: In this study participants were exposed to different approaches on how to apply metacognitive strategies within an online instructional context. Eighty-five participants were randomly assigned to one of three treatment groups. A self-regulated learning inventory was administered to determine the influence of this factor within the experiment.  This study used a posttest only control group design with three levels of the instructional independent variable. All groups received an instructional package on how to apply metacognitive skills in an instructional context. One group, the control group had no additional experimental intervention and went straight through the instructional material and posttests. This group provided the baseline data for comparison with the other treatments. The two other groups, the meta-cognitive strategy conditions, were prompted at key moments of the experiment and asked to apply the metacognitive strategies they had learned. Participation in these activities was optional for the second group and mandatory for the third.  Results obtained did not provide strong support for the first of the experimental hypotheses. No significant correlation was found between the self-regulated learning inventory used and the performance measures.  The experimental data showed that participants exposed to mandatory metacognitive activities obtained significantly better results than those exposed only to the instructional package on how to apply metacognitive skills. Analysis provides some preliminary support for the use of mandatory embedded metacognitive activities with an online instructional context.  Additional information was also gathered and discussed on the benefits and challenges of running an online experiment.


identifier: Peddle, Katrina M  (2008) Youth culture -- say what? : negotiating rural space in daily life in southern Labrador : a participatory photovoice project.  PhD thesis, Concordia University.

abstract: The dissertation explores how rural youth in Labrador make culture in their daily lives. I use photovoice to work with youth in four Labrador communities, and draw largely on critical scholarship on rurality, identity, race and cultural production, to focus on issues of race, identity, and sexuality. The role of space and place in the lives of rural youth is also critically examined.  This dissertation uses participatory methods to explore ideas of place and cultural production. I strongly critique the notion of culture as a city phenomenon, and elaborate on the ways in which youth employ local knowledge to make sense of their lives and to build a unique cultural space in their communities. I argue that rural youth, despite their invisibility as a political constituency and their lack of representation in popular culture, are indeed active producers of local culture. In exploring youths' understanding of racial identities from their perspective, issues of invisible whiteness, hybridity and Métis identity are examined.  In an effort to illuminate the strengths of youth and the challenges they face in their lives, the dissertation also employs a Foucauldian analysis of discipline to frame the context in which youth negotiate issues of safe sex and sexuality in a place where no one is a stranger. I demonstrate how the lack of anonymity in these communities contributes to the disciplining of youth sexualities, and offer policy suggestions to improve access to appropriate services to youth in small places. Most importantly, in this dissertation I gained understanding of the dynamism and determination that are characteristic of the lives of the young Labrador people who informed this work


identifier: Cueto, Diego C  (2009) Corporate governance and ownership structure in emerging markets : evidence from Latin America.  PhD thesis, Concordia University.

abstract: My dissertation explores the leading role of ownership structures in corporate governance for publicly traded firms in emerging markets. I analyze the relationships between ownership structures, corporate governance mechanisms, firm value and market liquidity for a sample of Latin American firms. The predominant highly concentrated ownership within a context of weak shareholder protection provides a rich environment to explore corporate governance practices in a regional setting. The period of analysis, 2000-2006, is characterized by economic growth sustained by the expansion of foreign direct investment in a post-privatization era. The region as a whole, rather than just individual markets, became an attractive investment destination. In addition the development of a private pension system initiated in Chile and subsequently expanded to more than 25 countries (the AFP system) reinvigorated the capital markets which have become more attractive as a means of diversification for global portfolios. Moreover, understanding the implications of concentrated ownership structures is fundamental for participants in a yet incipient mergers and acquisitions market. My dissertation consists of three related essays which collectively cohere to represent my research approach and understanding of the topic and they all benefit from the exploitation of a unique ownership database. This work serves to advance the finance literature in several dimensions: a) the manuscript examines at markets which have hitherto been ignored or at best simply characterized as having very weak governance structures; b) it addresses endogeneity problems from the initial design of this research project through the data collection process; c) furthermore, I extend the literature on the interactions between governance mechanisms and firm value; and d) it develops new corporate governance measures, including novel "effective" firm ownership variables for these markets. Dominant shareholders may have both the capability and the incentive to expropriate minority shareholders. Specifically, I examine performance effects that may be attributable to discrepancies between voting rights and cash-flow rights. I examine the extent to which dominant shareholders can divert resources for their own consumption, in turn reducing overall shareholder value. Given the large potential for private consumption, by the dominant shareholders, I also explore the motivations for outside investors to participate in the financing of the firms' activities.


identifier: Picard, Alan  (2009) The effect of futures markets on spot market volatility : empirical evidence from 3-month Canadian bankers' acceptances.  Masters thesis, Concordia University.

abstract: Futures markets have been blamed for higher volatility in the underlying asset market. A popular belief is that trading activity in futures markets encourage speculation, which destabilizes the spot market. The alleged destabilization takes the form of higher spot market volatility. On the other hand, a favorable view is that futures trading helps stabilizing the underlying market and leads to more complete markets and enhanced information flows. The numerous papers that have studied the effect of the introduction of derivatives on the underlying assets have obtained different results. This paper analyses the effect of the introduction of futures markets on the underlying market for Canadian bankers' acceptances. More specifically this study investigates the contention that the introduction of the futures (BAX) on the Montreal exchange on April 24 th 1988 has affected the volatility of the underlying asset. To study this effect, several models and approaches are used such as the GARCH process and others models and approaches formulated by several academics who studied this issue for other underlying spot markets


identifier: Jiang, Hui  (2008) The risk and return of active vs passive trading strategies with commodity futures.  Masters thesis, Concordia University.

abstract: This paper investigates relationships between profits from dynamic trading strategies, risk premium, convenience yields, and net hedging pressures for commodity futures. The term structure of oil, gold, copper and soybeans futures markets contains predictive power for the corresponding term premium. However, only oil futures and soybean futures lead their spot premium. Significant momentum profits are identified in both outright futures and spread trading strategies when the spot premium and the term premium are used to form winner and loser portfolios. Profits from active strategies based on winner and loser portfolios are conditioned on market structure and net hedging pressure effects. Dynamic trading strategies based on contracts with extreme backwardation, extreme contango, and extreme hedging pressures are also tested. On average, spread trading outperforms outright futures trading in capturing the term structure risk and hedging pressure risk. For such strategies, long-short the long-term spread offers the greatest and most significant return and it offers the only exploitable trading profits built on the past hedging pressure.


identifier: Recchia, Holly  (2009) Explaining variability in sibling conflict resolution strategies during middle childhood.  PhD thesis, Concordia University.

abstract: The goal of this dissertation was to identify the correlates of 4- to 10-year-olds' strategies for resolving actual sibling conflicts. A sample of62 sibling dyads participated in two sessions with their primary caregivers (54 mothers, 7 fathers, 1 legal guardian). Each child was interviewed privately about two recurring conflicts; in one session, siblings subsequently attempted to resolve the conflict in a dyadic negotiation, and in the other, during a triadic negotiation with their caregiver. Measures of siblings' conflict strategies in the home, social-cognitive abilities, and relationship quality were also administered. In Study 1, siblings' conflict strategies and outcomes were examined as a function of age, birth order, and parental interventions into children's conflict. Siblings' conflict strategies became more constructive with age. Further, parents' constructive intervention strategies (e.g., future planning, developing understanding) were related to siblings' independent use of constructive strategies and achievement of compromise outcomes, but especially when children liked each other. In Study 2, associations between children's social understanding and conflict strategies were tested. There were unique patterns of association for each measure of social-cognitive ability (i.e., second-order false belief, conflict interpretive understanding, and narrative references to conflict perspectives). However, links between younger siblings' social understanding and conflict behaviour typically depended on how much siblings liked each other. In Study 3, siblings' conflict outcomes were examined as a function of each sibling's description of conflict (i.e., issues, culpability, and emotions). Siblings compromised more when their narratives included references to physical hann and when they described feeling sad during conflict. Children were less likely to compromise when they (a) described fairness/right violations in their conflict narratives, and (b) believed that their sibling was solely culpable for a fight. In sum, to best explain variability in sibling conflict strategies, results highlight the need to consider features of siblings' (a) family system (e.g., behaviour socialized by parents), (b) individual characteristics (e.g., social understanding,), (c) dyadic motivations (e.g., relationship quality), and (d) descriptions of specific conflicts. In particular, results suggest that despite sophisticated social and cognitive skills, children will not engage in constructive sibling conflict strategies unless they are motivated to do so.


identifier: Brooker, Ivy  (2009) Infants' rational imitation : does the model's reliability matter?  Masters thesis, Concordia University.

abstract: The current study examined whether the reliability of an individual's gaze influences infants' decision to imitate her novel actions. Infants were first administered an object search task wherein they observed the experimenter display emotional signals while looking inside an empty container (unreliable condition) or a container with a toy inside (reliable condition). Infants in both conditions were then given the opportunity to imitate the same experimenter, who demonstrated turning on a press-on light using her forehead. Results from Experiment 1 revealed that 18-month-olds were capable of tracking a person's reliability, as their latency to open the container increased from the first to the last trial, only when exposed to the unreliable condition. Analyses of the proportion of infants who later imitated the experimenter's novel action showed no differences between the reliable and unreliable group, with both groups choosing to use their hands rather than their forehead. In Experiment 2, 14-month-olds were also able to track reliability as confirmed by the performance on the object search task. However, while infants in the unreliable group preferred to use their hands to turn on the light, those in the reliable group showed no preference for using either their forehead or hands. Taken together, these findings indicate that 14- month-olds, but not 18-month-olds, appear to be influenced by their previous exposure to a credible or non-credible looker. This suggests a developmental progression in infants' willingness to selectively learn from others, perhaps influenced by different age-dependent motivations.


identifier: Dubois, Marie-Ève  (2009) The effects of SES and maternal depressive symptoms on toddlers' motivation to learn : parental teaching as a mechanism of influence.  Masters thesis, Concordia University.

abstract: Maternal depression and socioeconomic status (SES) have both been linked to a range of cognitive and socioemotional outcomes in children. This study examines parental teaching strategies (amount of task information and quality of motivational support provided) as Potential mediators of the link SES and maternal depressive symptoms share with children's motivation to learn. Parent-child dyads attended two laboratory visits approximately one year apart (mean child age at wave 1=26 months; wave 2= 41 months). Cross-sectional and longitudinal mediation were examined. At W1, the amount of information and quality of motivational support provided by mothers in a learning task mediated the link between SES and children's motivation to learn. However, maternal depression had no effect on teaching or children's motivation to learn. At W2, an opposite pattern of results emerged: SES only predicted the amount of task information provided by mothers, whereas motivation support mediated the relation between maternal depression and child motivation to learn. Although no mediation was found in the longitudinal results, it was found that motivation support provided by mothers when children were 26 months predicted motivation to learn at 41 months, over and above the effects of children's motivation to learn at 26 months. This suggests a shift in the influence of SES and maternal depression on parenting and child outcomes, while emphasizing the importance of the motivation support provided by mothers in children of young age. More extended longitudinal work is needed to determine the developmental trajectories of the link between these factors.


identifier: Delalay, Marc-André  (2009) The covenant ritual in Genesis 15 : examining the nature of the covenant in light of its cultural and literary context.  Masters thesis, Concordia University.

abstract: This thesis analyzes the role of Abraham in the establishment of the covenant between God and himself in Genesis 15. It is also interested in the ongoing responsibility of the patriarch once the covenant is ratified. First, through a study of the literary context, it was demonstrated that Abraham shows a constant and active faithfulness in his relationship with God. It is because of his obedience that God could make a covenant with him and promise him an heir and a land. Second, by comparing the treaties in the Ancient Near East with the covenant in Genesis 15, it is concluded that the biblical text reflects the Hittite land grants of the 2 nd millennium BCE, with a suzerain bestowing favors on a vassal--in this case Abraham--who had showed exceptional loyalty. The grant, though, was given in perpetuity and unconditionally only at the corporate level: individuals among the descendants of the vassal may suffer punishment and death should they disobey, but the gift can not be taken completely away from the lineage; a remnant will always remain to enjoy it.


identifier: Hickey, Andria  (2009) In the wake of trauma : representing the unnameable in contemporary art.  Masters thesis, Concordia University.

abstract: Trauma is by its very nature an unnameable entity, one that defies language and instead exists in the realm of dreams, memories, and half-fictional shadows. Nonetheless, the events that form the aftereffects of trauma permeate Western media. As viewers of this media, by way of television, print and the Internet, we are all witnesses of traumatic events. This thesis addresses representations of trauma in contemporary art, with particular attention to their formation of the viewer as witness. Using a lens of trauma theory as a critical framework, an examination of the nature and reception of trauma in the work of contemporary artists Kara Walker and Walid Raad reveals how visual art can provide a complex language for communicating the many dimensions of historical and collective trauma. While Walker uses the traditional medium of the silhouette to investigate history of slavery and its effect on African American culture, Walid Raad has constructed a fictional archive in an attempt to explore the history of war in Lebanon. These strategies and others demonstrate the ways in which Kara Walker and Walid Raad disrupt the experience of viewing traumatic images and create the possibility for multifaceted empathic reactions in the viewer.


identifier: Popenova, Svetlana  (2009) Computational studies of substituted zirconocenium catalysts for olefin coordination polymerization.  Masters thesis, Concordia University.

abstract: Olefin coordination polymerization catalysts consisting of Group 4 metallocene dichloride have received considerable industrial interest, as they constitute a highly active and selective class of catalysts for [alpha]-olefin polymerization. For zirconocene dichlorides of general formula [Zr{{466} 5 -C 5 H 5-n R n } 2 Cl 2 ], the Zr atom is j 5 -coordinated to cyclopentadienyl rings that may be substituted or not (R = H, alkyl, aryl...).  When reacted with an excess of co-catalyst, the zirconocenium complexes [Zr{{466} 5 -C 5 H 5-n R n } 2 Me] + responsible for the polymerization activity are formed. The catalytic performance of these catalysts is greatly influenced by electronic and steric factors due to the R substituents on the cyclopentadienyl rings.  The aim of this work is to understand how the introduction of various length alkyl chains modified with Si and F atoms alters the coordination environment and the electronic properties of the active metal center, and how these changes may affect the olefin polymerization process. A combination of theoretical methods, such as density-functional theory with natural bond orbital analysis and the quantum theory of atoms in molecules, is used to explore these issues. The results of calculations for zirconocenium complexes with various substituents are reported, and the structure, energy, electron density distribution for the different species are examined, focusing on the factors that might control catalytic activity in order to identify optimal substituents. The nature of possible intramolecular interactions between substituents and the metal, as well as the influence of such interactions on catalytic performance, are also investigated.


identifier: Manioudakis, John  (2008) Investigating the ionization state and structure/function relationship of ionizable residues in Escherichia coli chorismate mutase-prephenate dehydrogenase and the catalytic trimer of aspartate transcarbamylase.  PhD thesis, Concordia University.

abstract: Modern mass spectrometry has gained tremendous attention III the field of enzymology, in particular as a tool for dissecting enzyme mechanism. In this thesis we use mass spectrometry in combination with chemical modification to help define the roles and ionization states of active site residues that are important for enzyme activity. Enzymes of particular interest are chorismate mutase-prephenate dehydrogenase (CM-PD), a bifunctional enzyme from Escherichia coli that catalyzes two consecutive steps in tyrosine biosynthesis, and the catalytic trimer of E. coli aspartate transcarbamylase (ATCase), which catalyzes the first committed step in the biosynthesis of pyrimidines. All three enzymes are of industrial or medical value as targets for the design of inhibitors that can act as either anti-neoplastic agents, antimicrobial agents or herbicides.  Three cysteine residues are found within each monomer of the dimeric CM-PD. Site-directed mutagenesis and kinetic analysis of variants of Cys95, Cys169 and Cys215 indicated that only Cys215 is important for both CM and PD activities. Chemical modification with cysteine-specific reagents, iodoacetamide and Ellman's Reagent, resulted in the loss of both activities but only Cys215 is protected against alkylation by ligands of the reaction and therefore near or in the active site. Time-dependent chemical modification followed by peptide mapping indicated that Cys95 is the most reactive and/or accessible cysteine followed by Cys215 and Cys169. The results are discussed in terms of a structural model of the E. coli PD domain; Cys215 is near His245, which appears to help orient the catalytic base of the dehydrogenase reaction, His197.  In E. coli , mutase activity is associated with the N-terminal domain of CM-PD. pH rate profiles of the mutase reaction show that there are two residues whose ionization states are important for catalysis and/or substrate binding. Studies examining the rates of chemical modification of the enzyme with a lysine-specific reagent and the stoichiometry of modification indicate that only one lysine residue per monomer, Lys37, is particularly reactive. Peptide mapping was used to determine the p K a of the [varepsilon]-amino group of Lys37 to be 7.5. Chemical modifications, kinetic and binding studies on Lys37Gln, an inactive variant, show that Lys37 is critical for CM activity. We propose that Lys37 participates in catalysis by protonating the ether oxygen of chorismate in the reaction's transition state.  ATCase is composed of 3 regulatory dimers and 2 catalytic trimers. Treatment with mercurial reagents dissociates the regulatory subunits (RSU) from the catalytic subunits (CSU) without compromising their functions. An improved purification scheme is outlined for the different subunits. Biophysical studies on an inactive CSU variant, Ser52Cys, indicated that the substitution resulted in a more thermally stable enzyme. Chemical modification by cysteine-specific reagents and mass spectrometric analysis indicated that Cys52 is very reactive/accessible and possesses a p K a of {598}5.6. The unusual characteristics of the Ser52Cys variant are attributed to the markedly depressed p K a of Cys52. The biophysical reasons for the ionization state of Cys52 are discussed in terms of the crystal structure of the unliganded E. coli CSU. 111


identifier: Adlam, Christopher  (2009) Seasonal and environmental variability of ground beetle (Coleoptera:Carabidae) assemblages at Mont St-Hilaire, QC.  Masters thesis, Concordia University.

abstract: In order to study the seasonal variation and habitat preference of carabids, I sampled using pitfall traps in various habitat types at Mont-St-Hilaire, southern Quebec, from the beginning of June until the end of October 2007. I caught 1193 individuals belonging to 53 species. Among the 16 most abundant species, nine were caught predominantly in early summer, five in mid summer, and four showed two peaks of activity, one in the early summer and one in the fall. There was no significant difference in terms of species richness or abundance between hardwood and mixed forests. On the other hand, ground beetle populations differed between wet and dry areas, and between forested and open or ecotonal areas. The ecotone between forest and meadow had the highest diversity and the highest abundance of carabids. Furthermore my analysis showed that several species were reliable indicators for various habitat characteristics such as proximity to a water body, forest type, and openness.


identifier: Atallah, Bassel  (2009) For that one creature's sake : post-courtly love in wuthering heights and great expectations.  Masters thesis, Concordia University.

abstract: This thesis examines the representation of post-courtly love in two Victorian novels, Emily Brontë's Wuthering Heights and Charles Dickens's Great Expectations. I define the post-courtly genre as literature from the nineteenth century that portrays the conflict between two ideologies of love, one that follows the courtly tradition of pursuing endless though unattainable love, and one that is expected to result in a marriage based on social Victorian values of domestic stability.  The Victorian realist novel aims to offer a study of how individuals function in society and how society can be positively and negatively affected by the actions of its individuals. My central argument is that Wuthering Heights and Great Expectations demonstrate this realism by portraying how courtly love conventions are at odds with the fictional worlds in which the novels are set. The social and emotional need for a physical union with his beloved will prevent the post-courtly lover from following the conventional trajectory of courtly Iove. This can lead to the emotional deterioration of the post-courtly lover, will hinder his social progress, and may even hinder the social progress of other characters within his community as well. The post-courtly lover will thus be obliged to adjust his approach to love in order to be capable of properly functioning in the social world, or be forced into isolation and alienation from the social community.


identifier: Charette, Carole  (2008) Recherche ethnographique sur le Design-Based-Learning (DBL) : le processus de design comme stratégie d'enseignement et d'apprentissage et comme stimulant à la pensée critique, à la résolution de problèmes et au transfert de connaissance.  PhD thesis, Concordia University.

abstract: This research presents the teaching methodology called Design-Based-Learning (DBL) and identifies what differentiates it from the traditional methods used in art and design education. This research aims to better understand the contribution of design to education not only as a discipline, but as a strategy for getting the learner to think about his/her environment, about his/her actions and their impact on the environment.   This research gives a nuanced description of the dialogue taking place between teacher and learner (any levels, any disciplines or between disciplines). The DBL approach contributes to increasing the learning perspective of students by proposing an active engagement with problems posed and solutions found. DBL offers a dramatic change in teaching approaches by proposing that learners be inventive and in terms of blooms taxonomy, that they operate at the highest levels of the taxonomy.   The study reveals that a majority of participants see in the DBL approach a tool that stimulates creativity and that favors critical thinking and problem solving skills. The results show that DBL increases the transfer of learning and the retention of knowledge within a given pedagogical environment. This transfer is facilitated by the development of concrete links between daily life activities of the students and their experiences of creation-invention in class. DBL reinforces the critical spirit, the observational, and problem solving capacity of students through creative stimulation and active engagement with uniquely formulated problems.   The DBL approach combines five teaching methodologies that enable students to be actively engaged and responsible of their learning process. The study shows that DBL applied to art and design education favors interdisciplinarity. The transfer of knowledge, and as such constitute an important new pedagogical model. The majority of DBL teachers interviewed in this study insisted that the benefits of the approach outweigh its liabilities.   Meredith Davis from North Carolina University is among the several design educators and researchers who support the DBL methodology. This research presentation will conclude with recommendations and suggestions for a future path for research in design education pedagogy.   Keys words: apprentissage par l'expérience, résolution de problèmes, enseignement des arts et du design, taxonomie de Bloom, processus de design.


identifier: Gedeon-Matusky, Julia  (2009) A case of twelve.  Masters thesis, Concordia University.

title: A case of twelve

abstract: A Case of Twelve by Julia Gedeon-Matusky is a fictional coming-of-age story that explores the challenges facing a teenaged boy and his Slovak-Canadian family during the politically and socially tumultuous period in Quebec from 1964 to 1967. The family struggles financially and personally as it witnesses its Slovak immigrant community dissipate into the anonymity of the larger society. The members ofthe Danco family resist adapting to an increasingly French milieu within Montreal because they consider themselves part of English Canada rather than Quebec. They become pitted against the frustration, anger and occasionally violent actions of some Quebecois who feel their French language, culture and business opportunities continue to be thwarted by the predominantly English business elite. The novel also relates how various ethnic cultures intersect daily within an increasingly cosmopolitan Montreal as the city prepares to welcome the world at Expo '67. At the same time, it conveys some of the prejudices that were alive and well against women, divorced parents, people with disabilities, homosexuals, and the hippie culture then coming into vogue. Marek Danco filters all these experiences as a 13-to-15-year-old boy who is striving to attain his personal space and freedom as well as sexual experience, all while trying to figure who might have abused a little girl who he helps to rescue from a manhole.


identifier: Gagnon, Gaétan  (2009) L'enseignement des arts plastiques au secondaire et l'art numérique : Étude multicas portant sur l'innovation pédagogique avec des technologies informatiques dans le contexte scolaire québécois.  PhD thesis, Concordia University.

abstract: Bien que l'ordinateur soit exploité pour l'enseignement des arts plastiques depuis plus de deux décennies, il est possible qu'aujourd'hui encore des enseignants innovent dans leur pratique pédagogique en y intégrant l'usage des technologies informatiques. Pour discerner l'objet de ce travail, la problématique jette un regard dans la littérature, identifie un problème de recherche, expose des questions de recherche, et justifie ce travail. La question principale se lit comme suit: au niveau de l'enseignement des arts plastiques à des élèves du secondaire au Québec, qu'est-ce qu'une innovation pédagogique impliquant l'usage des technologies de l'information et de la communication pour la production d'art numérique? Et les trois sous-questions sont : 1) Quels sont les principaux concepts rattachés à la question principale? 2) Selon des enseignants ayant innové avec les TIC, quelles sont les caractéristiques de l'innovation pédagogique lors d'activités de création en lien avec l'art numérique? 3) Quel est le processus que des enseignants en arts plastiques ont suivi pour concrétiser des innovations pédagogiques avec les TIC en classe? Ensuite, le cadre conceptuel décrit les notions et concepts présents dans ce travail et apporte des éléments de réponse à la première sous-question. Puis la méthodologie explique la façon de conduire ce travail. Par la suite, l'analyse et le traitement des données permet de les classer et de les organiser selon dix thèmes. De plus cette partie apporte des éléments de réponse à la deuxième et à la troisième sous-questions de cette recherche. Ce chapitre nous permet aussi de dégager une douzaine de généralisations. Subséquemment, on arrive à la discussion et à l'interprétation des résultats où nous apportons des remarques surtout en relation avec les généralisations. La conclusion entrevoit des recherches futures et exprime des suggestions pour favoriser des innovations pédagogiques intégrant les technologies informatiques.


identifier: Semsar-Kazerooni, Elham  (2009) Cooperative control of a network of multi-vehicle unmanned systems.  PhD thesis, Concordia University.

abstract: Development of unmanned systems network is currently among one of the most important areas of activity and research with implications in variety of disciplines, such as communications, controls, and multi-vehicle systems. The main motivation for this interest can be traced back to practical applications wherein direct human involvement may not be possible due to environmental hazards or the extraordinary complexity of the tasks. This thesis seeks to develop, design, and analyze techniques and solutions that would ensure and guarantee the fundamental stringent requirements that are envisaged for these dynamical networks.  In this thesis, the problem of team cooperation is solved by using synthesis-based approaches. The consensus problem is defined and solved for a team of agents having a general linear dynamical model. Stability of the team is guaranteed by using modified consensus algorithms that are achieved by minimizing a set of individual cost functions. An alternative approach for obtaining an optimal consensus algorithm is obtained by invoking a state decomposition methodology and by transforming the consensus seeking problem into a stabilization problem.  In another methodology, the game theory approach is used to formulate the consensus seeking problem in a "more" cooperative framework. For this purpose, a team cost function is defined and a min-max problem is solved to obtain a cooperative optimal solution. It is shown that the results obtained yield lower cost values when compared to those obtained by using the optimal control technique. In game theory and optimal control approaches that are developed based on state decomposition, linear matrix inequalities are used to impose simultaneously the decentralized nature of the problem as well as the consensus constraints on the designed controllers. Moreover, performance and stability properties of the designed cooperative team is analyzed in presence of actuator anomalies corresponding to three types of faults. Steady state behavior of the team members are analyzed under faulty scenarios. Adaptability of the team members to the above unanticipated circumstances is demonstrated and verified. Finally, the assumption of having a fixed and undirected network topology is relaxed to address and solve a more realistic and practical situation. It is shown that the stability and consensus achievement of the network with a switching structure and leader assignment can still be achieved. Moreover, by introducing additional criteria, the desirable performance specifications of the team can still be ensured and guaranteed.


identifier: Andreevskaia, Alina  (2009) Sentence-level sentiment tagging across different domains and genres.  PhD thesis, Concordia University.

abstract: The demand for information about sentiment expressed in texts has stimulated a growing interest into automatic sentiment analysis in Natural Language Processing (NLP). This dissertation is motivated by an unmet need for high-performance domain-independent sentiment taggers and by pressing theoretical questions in NLP, where the exploration of limitations of specific approaches, as well as synergies between them, remain practically unaddressed.  This study focuses on sentiment tagging at the sentence level and covers four genres: news, blogs, movie reviews, and product reviews. It draws comparisons between sentiment annotation at different linguistic levels (words, sentences, and texts) and highlights the key differences between supervised machine learning methods that rely on annotated corpora (corpus-based, CBA) and lexicon-based approaches (LBA) to sentiment tagging.  Exploring the performance of supervised corpus-based approach to sentiment tagging, this study highlights the strong domain-dependence of the CBA. I present the development of LBA approaches based on general lexicons, such as WordNet, as a potential solution to the domain portability problem.  A system for sentiment marker extraction from WordNet's relations and glosses is developed and used to acquire lists for a lexicon-based system for sentiment annotation at the sentence and text levels. It demonstrates that LBA's performance across domains is more stable than that of CBA. Finally, the study proposes an integration of LBA and CBA in an ensemble of classifiers using a precision-based voting technique that allows the ensemble system to incorporate the best features of both CBA and LBA. This combined approach outperforms both base learners and provides a promising solution to the domain-adaptation problem.  The study contributes to NLP (1) by developing algorithms for automatic acquisition of sentiment-laden words from dictionary definitions; (2) by conducting a systematic study of approaches to sentiment classification and of factors affecting their performance; (3) by refining the lexicon-based approach by introducing valence shifter handling and parse tree information; and (4) by development of the combined, CBA/LBA approach that brings together the strengths of the two approaches and allows domain-adaptation with limited amounts of labeled training data.


identifier: Esmaeilzadeh, Rayhaneh  (2009) Three essays in labour market mobility.  PhD thesis, Concordia University.

title: Three essays in labour market mobility

abstract: This dissertation contains three essays in labour market mobility. These essays employ a dynamic multinomial logit model with discrete factor approximation for the specification of unobserved individual heterogeneity and Wooldridge's approach for controlling the endogeneity problem of initial conditions. The dynamic structural of the model is assumed to follow a first order Markov process. The data is taken from longitudinal levels of Statistics Canada's Survey of Labour and Income Dynamics ( SLID ) and is restricted to males aged 25 to 55 between 1993 and 2004. I examine and discuss the importance of structural and spurious state dependence in three different aspects of labour market mobility. Relevant policy implications are discussed. The first essay compares immigrants and natives in self-employment transitions among four mutually exclusive and exhaustive states of paid-employment, self-employment, unemployment, and being out of the labour force. The second essay explores the factors explaining immigrant-native differences in stability, downward, and upward wage mobility rates. The final essay provides a comprehensive research on earnings dynamics of immigrants and natives within and between Canada and Denmark. This essay also employs Danish administrative registered dataset for the period 1994-2003. Empirical results show that state dependence exists in all states of labour market mobility with different degrees for immigrants and natives. Not all observed persistence is structural, some portion is due to the unobservable factors


identifier: Nami, Mitra  (2009) Elide : an interactive development environment for Erasmus language.  Masters thesis, Concordia University.

abstract: The process-oriented programming language Erasmus is being developed by Peter Grogono at Concordia University, Canada and Brian Shearing at The Software Factory in England. Erasmus is based on communicating processes. The latest version of the compiler is operating in command-line mode. As the compiler evolved, we recognized that there was a lack of an editor or an integrated development environment (IDE) for this new language. Our objective is to construct a suitable IDE for the Erasmus language called ELIDE by understanding the features of Erasmus language such as cells, processes, ports, protocols, messages, and message passing, which are the main heart of this programming language. At the same time we wanted to enable ELIDE with the features that are available in IDEs of languages like Ruby and Erlang. In this respect, after detailed studies on current text editors, IDEs and their features and evolution of IDEs, we designed and implemented an integrated development environment for Erasmus language.  To speed up the implementation process, we decided to choose one of the existing platforms as our base and develop Erasmus-specific features on top of it. There were many platforms available. Some of these platforms were under investigation and test. Among them we finally chose NetBeans. This thesis describes the development of this new tool for Erasmus programmers. It must be noted that the design of the ELIDE was an iterative process though what we present is the final result. ELIDE is a strong environment for a complete programming support for Erasmus language with built-in compile/debug/run ability. The most important features included in ELIDE are syntax coloring, Code folding, Code completion, Brace matching, Coding tips, Indentation and Annotations. ELIDE is capable of adding more features later in case there is a need. Furthermore ELIDE can be used for an easy integration of editing and visualising support for Erasmus language building block such as cells, processes, ports, protocols, messages, and message passing.  We also conducted a preliminary user survey of Erasmus and ELIDE involving a number of graduate students. The results were quite encouraging with respect to the group surveyed and current capabilities of Erasmus and newly designed ELIDE. This study confirmed that It was a must for the Erasmus language to have a customized IDE to empower Erasmus language capabilities as a process-oriented language teaching and research purposes


identifier: Sayeed, Ruhan  (2009) High performance analytics with the R3-cache.  Masters thesis, Concordia University.

abstract: Contemporary data warehouses now represent some of the world's largest databases. As these systems grow in size and complexity, however, it becomes increasingly difficult for brute force query processing approaches to meet the performance demands of end users. Certainly, improved indexing and more selective view materialization are helpful in this regard. Nevertheless, with warehouses moving into the multi-terabyte range, it is clear that the minimization of external memory accesses must be a primary performance objective. In this thesis, we describe the R 3 -cache, a natively multi-dimensional caching framework designed specifically to support sophisticated warehouse/OLAP environments. R 3 -cache is based upon an in-memory version of the R-tree that has been extended to support buffer pages rather than disk blocks. A key strength of the R 3 -cache is that it is able to utilize multi-dimensional fragments of previous query results so as to significantly minimize the frequency and scale of disk accesses. Experimental results demonstrate significant performance improvements relative to simpler alternatives


identifier: Atici, Mehmet  (2009) A 3-D numerical model for pullout capacity of single batter piles in sand.  Masters thesis, Concordia University.

abstract: Pile foundations are usually recommended when soil capacity is not sufficient for the expected loads of the structure with conventional foundation techniques. While the case . of vertical piles is reasonably documented in the literature, the case of batter piles in sand has received little attention from the researchers. This is mainly due to the complexity of modeling the earth pressure distribution around the pile's shaft. Attempts were made to model the pullout behavior of vertical piles numerically using two-dimensional approaches, which does not represent the field condition and accordingly the results are scattering.  In this study a 3D numerical model was developed to investigate the uplift capacity of single batter piles in sand. The model utilizes the powerful software "ABAQUS" version 6.6, which is capable to model such complex interaction in three-dimensional stress analysis. The model was validated with the prototype test results of Hanna and Afram (1986) and field work of Alewnah (1999)  Design procedure and design charts have been presented to assist foundation engineers to predict the uplift capacity of batter piles in sand.


identifier: Nguyen, Philon  (2009) Fast and scalable similarity and correlation queries on time series data.  Masters thesis, Concordia University.

abstract: Time series are ubiquitous in many fields ranging from financial applications such as the stock market to scientific applications and sensor data. Hence, there has been an increasing interest in time series indexing over the past years because there has been an increasing need for fast methods for analyzing and querying these datasets that are often too big for practical brute force analysis. We start with the main contributions to the field over the past decade and a half. We will then proceed by describing new solutions to correlation analysis on time series datasets using an existing index called the Compact Multi-Resolution Index (CMRI). We describe new algorithms for indexed correlation analysis using Pearson's product moment coefficient and using the multidimensional correlation coefficient and introduce a new measure called Dynamic Time Warping Correlation (DTWC) based on Dynamic Time Warping (DTW). In addition to these linear correlation algorithms, we propose an algorithm called rank order correlation on a non-linear/monotonic measure. To support these algorithms, we revised the Compact Multi-Resolution Index (CMRI) and propose a new index for time series datasets which improves over the sizes, speed and precision of CMRI. We call this index the reduced Compact Multi-Resolution Index (rCMRI). We evaluate the performance of rCMRI compared to CMRI for range queries and range query based queries.


identifier: Idle, Allen Michael  (2009) Chloride resistance of high volume fly ash concretes.  Masters thesis, Concordia University.

abstract: Costly reinforced concrete structures serve as foundations for the economic prosperity of a nation The continued deterioration of concrete structures, due to corrosion of steel reinforcing rebar, requires the implementation of vast multi-million dollar rehabilitation projects to maintain an adequate level of service in these systems. The process of corrosion in reinforced concrete is largely due to the ingress and build-up of chloride ions in the capillary pores of concrete caused by the use of road salts and from contact/spray from seawater. Lowering the water to cement ratio and incorporating Supplementary Cementing Material's (SCM's) are effective methods of lowering the permeability of concrete to harmful chloride ions. Fly ash is used commonly because it is environmental and economical. However, the amount of fly ash which can be used in concrete is limited, because there are concerns (controversy) over the long-term durability of such structures when fly ash is used in high volumes. This thesis will investigate the chloride resistance of two types of Portland cements and two silica fume blended Portland cement concretes. Each of the four cement types was replaced with two Type CI fly ashes, with coal sources from Sundance, Alberta and from Rockport, Indiana, at 0, 20, 40, 60, and 80 replacement percentages. The chloride resistance was determined by the Rapid Chloride Permeability Test (ASTM C 1202-08) for each combination made. The Sundance fly ash showed greater resistance to chloride permeability than the Rockport fly ash, assumingly because of its lower carbon content, higher fineness, and increased pozzolanic activity.


identifier: Pauls, Zeina  (2009) Punching shear failure of foundations on strong sand overlying deep weak deposit.  Masters thesis, Concordia University.

abstract: The ultimate bearing capacity of shallow foundations under axial vertical loads on dense sand overlying deep loose deposit has been investigated. In the literature, several theories can be found using simplified failure mechanisms in conjunction with the punching shear failure. Accordingly, assumptions were used to simplify the evaluation of the level of mobilization of the shear strength on the punching column. This is mainly due to the complexity of modeling the earth pressure distribution on the punching column.  In this study a numerical model was developed to investigate the case of continuous footing on dense sand overlying loose sand. The model utilizes the powerful software "PLAXIS" version 8.6, which is capable to model such complex interaction in two-dimensional stress analysis. The model was validated with the prototype test results of Meyerhof and Hanna (1978) and Hanna (1981- a). The results of this investigation showed that the shear strength mobilized on the punching column depends on the relative strength of the two layers, the width of the footing and the thickness and angle of shearing resistance of the upper layer.  Design procedure and design charts have been presented to assist foundation engineers to predict the bearing capacity of footing on dense sand overlying deep loose deposit.


identifier: Li, Wei  (2009) Distributed authorization in loosely coupled data federation.  Masters thesis, Concordia University.

abstract: The underlying data model of many integrated information systems is a collection of inter-operable and autonomous database systems, namely, a loosely coupled data federation. A challenging security issue in designing such a data federation is to ensure the integrity and confidentiality of data stored in remote databases through distributed authorization of users. Existing solutions in centralized databases are not directly applicable here due to the lack of a centralized authority, and most solutions designed for outsourced databases cannot easily support frequent updates essential to a data federation. In this thesis, we provide a solution in three steps. First, we devise an architecture to support fully distributed, fine-grained, and data-dependent authorization in loosely coupled data federations. For this purpose, we adapt the integrity-lock architecture originally designed for multilevel secure databases to data federations. Second, we propose an integrity mechanism to detect, localize, and verify updates of data stored in remote databases while reducing communication overhead and limiting the impact of unauthorized updates. We realize the mechanism as a three-stage procedure based on a grid of Merkle Hash Trees built on relational tables. Third, we present a confidentiality mechanism to control remote users' accesses to sensitive data while allowing authorization policies to be frequently updated. We achieve this objective through a new over-encryption scheme based on secret sharing. Finally, we evaluate the proposed architecture and mechanisms through experiments.


identifier: Hasan, Tahira  (2009) Finding usage patterns from generalized weblog data.  Masters thesis, Concordia University.

abstract: Buried in the enormous, heterogeneous and distributed information, contained in the web server access logs, is knowledge with great potential value. As websites continue to grow in number and complexity, web usage mining systems face two significant challenges - scalability and accuracy. This thesis develops a web data generalization technique and incorporates it into the web usage mining framework in an attempt to exploit this information-rich source of data for effective and efficient pattern discovery. Given a concept hierarchy on the web pages, generalization replaces actual page-clicks with their general concepts. Existing methods do this by taking a level-based cut through the concept hierarchy. This adversely affects the quality of mined patterns since, depending on the depth of the chosen level, either significant pages of user interests get coalesced, or many insignificant concepts are retained. We present a usage driven concept ascension algorithm, which only preserves significant items, possibly at different levels in the hierarchy. Concept usage is estimated using a small stratified sample of the large weblog data. A usage threshold is then used to define the nodes to be pruned in the hierarchy for generalization. Our experiments on large real weblog data demonstrate improved performance in terms of quality and computation time of the pattern discovery process. Our algorithm yields an effective and scalable tool for web usage mining.


identifier: Ghoneim, Khaled  (2009) Adaptive interaction protocol for multi-agent-based supply network.  Masters thesis, Concordia University.

abstract: Supply network is a special form of organization, where two paradigms are combined: market interaction and hierarchical structure. Because it includes different interdependent entities that should work together, supply network requires efficient tools to support coordination and improve the quality of interaction between these entities.  In this thesis, we propose a multi-agent-based interaction protocol for supply network formation. The main characteristic of this protocol is its adaptability to agent behavior during supply network formation. Such an adaptability is needed to form the most suitable organization structure. The novelty of the proposed protocol is the unification of contracting, auction and negotiation in a three-steps solution. Contracting is a planning tool aiming to facilitate solving network formation problem through task decomposition. Auction enables participating agents to jointly search an agreement space and check the contract feasibility. Finally, negotiation is the last resort for agents to reach an agreement. It is applicable when agents fail to reach an agreement due to lack of knowledge about the existing constraints. In fact, negotiation is used to release constraints when no realizable solution is obtained under auction. The second contribution of this thesis is the consideration of supply network formation within a general framework of coordinated distributed problem solving.  The proposed protocol and framework are simulated through a multi-agent system prototype serving as a proof of concept. The simulation results show the effectiveness of our three-steps solution protocol in terms of network formation success, customer satisfaction and the total gained rewards of the whole network.


identifier: Jakadeesan, Gopinatha  (2009) FT-PAS-A framework for pattern specific fault-tolerance in parallel programming.  Masters thesis, Concordia University.

abstract: Fault-tolerance is an important requirement for long running parallel applications. Many approaches are discussed in various literatures about providing fault-tolerance for parallel systems. Most of them exhibit one or more of these shortcomings in delivering fault-tolerance: non-specific solution (i.e., the fault-tolerance solution is general), no separation-of-concern (i.e., the application developer's involvement in implementing the fault tolerance is significant) and limited to inbuilt fault-tolerance solution. In this thesis, we propose a different approach to deliver fault-tolerance to the parallel programs using a-priori knowledge about their patterns. Our approach is based on the observation that different patterns require different fault-tolerance techniques (specificity). Consequently, we have contributed by classifying patterns into sub-patterns based on fault-tolerance strategies. Moreover, the core functionalities of these fault-tolerance strategies can be abstracted and pre-implemented generically, independent of a specific application. Thus, the pre-packaged solution separates their implementation details from the application developer (separation-of-concern). One such fault-tolerance model is designed and implemented here to demonstrate our idea. The Fault-Tolerant Parallel Architectural Skeleton (FT-PAS) model implements various fault-tolerance protocols targeted for a collection of (frequently used) patterns in parallel-programming. Fault-tolerance protocol extension is another important contribution of this research. The FT-PAS model provides a set of basic building blocks as part of protocol extension in order to build new fault- tolerance protocols as needed for available patterns. Finally, the usages of the model from the perspective of two user categories (i.e., an application developer and a protocol designer) are illustrated through examples.


identifier: Zhou, Yun  (2009) A visual modeling tool for the development of trustworthy component-based systems.  Masters thesis, Concordia University.

abstract: A rigorous development of Trustworthy Computing System (TCS) is an active research area in TROMLAB research group since TCS concept was initiated in 2002 by Microsoft Corporation. In TROMLAB research group a component-based development of TCS was initiated in 2005. Several tracks of research activities, including formal specification of components and component-based systems, formal assessment of trustworthiness properties, and a framework construction for developing trustworthy systems are in different stages of development, and completion. It is in this context this thesis has evolved. It contributes a Visual Modeling Tool (VMT), the front-end to the development framework, in which the developer can construct visual models of system components without being burdened by complex formalisms. The thesis identifies the functional and performance requirements of the VMT tool from the goal of TCS research in TROMLAB, provides a detailed design which itself is based on component technology, and illustrates with two case studies, CoCoME and Mine Drainage, the modeling steps and its user-centric features.


identifier: Meng, Lehan  (2009) Multichannel optical access networks : design and resource management.  Masters thesis, Concordia University.

abstract: At present there is a strong worldwide push towards bringing fiber closer to individual homes and businesses. The next evolutionary step is the cost-effective all-optical integration of fiber-based access and metro networks. STARGATE [1] is an all-optical access-metro architecture which does not rely on costly active devices, e.g., Optical Cross-Connects (OXCs) or Fixed Wavelength Converters (FWCs), and allow low-cost PON technologies to follow low-cost Ethernet technologies from EPON access into metro networks, resulting in significantly reduced cost and complexity. It makes use of an overlay island of transparency with optical bypassing capabilities. In this thesis we first propose Optical Network Unit (ONU) architectures, and discuss several technical challenges, which allow STARGATE EPONs (SG-EPONs) to evolve in a pay-as-you-grow manner while providing backward compatibility with legacy infrastructure and protecting previous investment. Second, and considering all the hardware constraints, we present the corresponding dynamic bandwidth allocation algorithm for effective resource management in these networks and investigate their performances (delay, throughput) through simulation experiments. We further investigate the problem of transmission grant scheduling in multichannel optical access networks using a scheduling theoretic approach. We show that the problem can be modeled as an Open Shop and we formulate the joint scheduling and wavelength assignment problem as a Mixed Integer Linear Program (MJLP) whose objective is to reduce the length of a scheduling period. Since the problem is known to be NP-hard, we introduce a Tabu Search based heuristic for solving the joint problem. Different other heuristics are also considered and their performances are compared with those of Tabu and MILP. Results indicate that by appropriately scheduling transmission grants and assigning wavelengths, substantial and consistent improvements may be obtained in the network performance. For example, Tabu shows a reduction of up to 29% in the schedule length with substantial reduction in channel idle gaps yielding to both higher channel utilization and lower queuing delays. Additionally, when the number of channels in the network is not small, the benefits of performing appropriate wavelength assignment, together with transmission scheduling, are observed and discussed. We further perform a packet-level simulation on the considered network to study the benefits of efficient grant scheduling; significant improvements are shown both in terms of system utilization and packet queuing delays.


identifier: Hou, Wenjuan  (2009) Probing the importance of active site residues of prephenate dehydrogenase from the hyperthermophilic bacterium Aquifex aeolicus.  Masters thesis, Concordia University.

abstract: Prephenate dehydrogenase is an enzyme within the TyrA protein family dedicated to tyrosine biosynthesis. It catalyzes the oxidative decarboxylation of prephenate to hydroxyphenylpyruvate (HPP) and CO 2 in the presence of NAD + ; HPP is then transaminated to L-tyrosine, an end product inhibitor of the pathway. Guided by the recently published crystal structures of a monofunctional prephenate dehydrogenase from the hyperthermophilic bacterium Aquifex aeolicus , amino acid residues Trp190, His217, Lys246' and Arg250 were targeted for mutagenesis in order to provide insights into how these side chains might participate in the chemistry of the reaction and contribute to the integrity of the active site. A revised purification protocol afforded excellent yields of variants. We identified Trp190, a completely buried side chain in the NAD + binding pocket, as the source of an unusual fluorescence emission peak at 317 nm. Analysis of variants of Lys246' and Arg250 allowed us to conclude that the two residues participated only in the binding of prephenate and not of NAD + or in catalysis. They are important residues but not essential for binding. In contrast, His217 is critical for prephenate binding and catalysis and for the inhibition of PD activity by tyrosine. Chemical and thermal denaturation studies also suggest that this residue helps to maintain the structural integrity of the active site. Our results are interpreted in light of the crystal structure of the enzyme bound with substrate analogues and tyrosine.


identifier: Motamedi, Ali  (2009) Framework for lifecycle management of facilities components using RFID technology.  Masters thesis, Concordia University.

abstract: The AECOO (Architecture, Engineering, Construction, Owner and Operator) industry is highly fragmented; therefore, efficient information sharing and exchange between various players are evidently needed. Furthermore, the information about facility components should be managed throughout the lifecycle and be easily accessible for all players in the AECOO industry. BIM is emerging as a method of creating, sharing, exchanging and managing the information throughout the lifecyc1e between all the stakeholders. Radio Frequency Identification (RFID), on the other hand, has emerged as an automatic data collection and information storage technology, and has been used in different applications in AECOO. This research proposes permanently attaching RFID tags to facility components where the memory of the tags is populated with accumulated lifecycle information of the components taken from a standard BIM database. This information is used to enhance different processes throughout the lifecycle. In addition, this research suggests storing other types of BIM information (e.g., floor plans) on RFID tags which is not necessarily related to the components themselves. Having BIM data chunks stored on tags provides a distributed database of BIM and allows data access for different players who do not have real-time access to a central database. In this research, a conceptual RFID-based system structure and data storage/retrieval design are elaborated. The value adding benefits and scope of impact of the proposed approach are discussed. To explore the technical feasibility of the proposed approach, two case studies have been implemented and tested.


identifier: Bandali, Hadi  (2008) Genetic structure and diversity of Rhododendron arboreum (Ericaceae) in protected and harvested forests in northeast India.  Masters thesis, Concordia University.

abstract: Rhododendron arboreum is an ecologically and economically important forest tree species in high altitude forests. In the Himalayan region of Northeast India, R. arboreum is extensively harvested as a source of fuelwood while selected forest stands have been set aside as protected forests by tribal groups resulting in a mosaic of harvested and protected forests. I assessed the genetic structure of R. arboreum in these forests using microsatellite markers that were originally developed for R. mettemichii . Out of eight pairs of primers evaluated, three primer pairs showed reliable amplification and polymorphism in R. arboreum . These three primer pairs or loci (RM1D1, RM2D2, and RM9D6) were used in assessing the genetic structure of R. arboreum in protected and harvested forests in the Eastern Himalayan region of Northeast India. Leaf samples collected from over 125 trees in five populations of R. arboreum representing two protected and three harvested forests, 35 different alleles were detected at three loci, with an average of 11.66 alleles per locus. There were no significant differences in number of alleles between populations. Over all populations, the mean observed and expected heterozygosity values were 0.801 and 0.804, respectively. A total of five private alleles were detected in two of the five populations (Pipraw Jang disturbed and Falokchar Mukto disturbed), suggesting private alleles are confined to harvested populations. The values of population differentiation (Fst) ranged between 0.015 and 0.057 with a corresponding gene flow (Nm) values of 15.8 and 4.1 respectively suggesting moderate levels of gene flow among populations. Population differentiation showed a significant correlation with the geographic distance.  The high level of heterozygosity suggests a predominantly outcrossing mating system in R. arboreum . Although the level of population differentiation is low, the significant correlation between population differentiation (Fst) and geographic distance within a short distance of about 5 km is striking. In order to capture and maintain maximum genetic diversity, representative populations of R. arboreum distributed throughout its geographic distribution range should be conserved. These populations may serve as a seed source for regeneration of adjacent harvested forests. Further studies are needed to gain insights into the source of these private alleles as well as average distance of gene flow to determine the optimal distance for establishing protected populations of R. arboreum


identifier: Shah, Muhammad Ismail  (2009) A novel image matching approach for word spotting.  Masters thesis, Concordia University.

abstract: Word spotting has been adopted and used by various researchers as a complementary technique to Optical Character Recognition for document analysis and retrieval. The various applications of word spotting include document indexing, image retrieval and information filtering. The important factors in word spotting techniques are pre-processing, selection and extraction of proper features and image matching algorithms. The Correlation Similarity Measure (CORR) algorithm is considered to be a faster matching algorithm, originally defined for finding similarities between binary patterns. In the word spotting literature the CORR algorithm has been used successfully to compare the GSC binary features extracted from binary word images, i.e., Gradient, Structural and Concavity (GSC) features. However, the problem with this approach is that binarization of images leads to a loss of very useful information. Furthermore, before extracting GSC binary features the word images must be skew corrected and slant normalized, which is not only difficult but in some cases impossible in Arabic and modified Arabic scripts. We present a new approach in which the Correlation Similarity Measure (CORR) algorithm has been used innovatively to compare Gray-scale word images. In this approach, binarization of images, skew correction and slant normalization of word images are not required at all. The various features, i.e., projection profiles, word profiles and transitional features are extracted from the Gray-scale word images and converted into their binary equivalents, which are compared via CORR algorithm with greater speed and higher accuracy. The experiments have been conducted on Gray-scale versions of newly created handwritten databases of Pashto and Dari languages, written in modified Arabic scripts. For each of these languages we have used 4599 words relating to 21 different word classes collected from 219 writers. The average precision rates achieved for Pashto and Dari languages were 93.18 % and 93.75 %, respectively. The time taken for matching a pair of images was 1.43 milli-seconds. In addition, we will present the handwritten databases for two well-known Indo- Iranian languages, i.e., Pashto and Dari languages. These are large databases which contain six types of data, i.e., Dates, Isolated Digits, Numeral Strings, Isolated Characters, Different Words and Special Symbols, written by native speakers of the corresponding languages.


identifier: Djaballah, Andrew Paul  (2009) Stanley Cavell's early writing on film, the emergence of academic film studies, and the interpretation of Alfred Hitchcock's Vertigo.  Masters thesis, Concordia University.

abstract: American philosopher Hillary Putnam has said that Stanley Cavell is the only philosopher to have made writing about movies a part of his philosophical project. Since 1971, with the publication of The World Viewed: Reflections on the Ontology of Film , Cavell has actively pursued questions concerning the physical medium of the movies - as well as its aesthetics, its history, and its criticism - as part of his reflections on our human experience of the world. This essay attempts to unearth some of the earliest of Cavell's insights into the movies through a study of certain short passages on Vertigo by framing Cavell's study with the examination of one of the most popular texts in Academic Film Studies, feminist film theorist Laura Mulvey's "Visual Pleasure and Narrative Cinema." The conclusions of this analysis are offset by a survey of the recent psychoanalytic studies of Vertigo by Lacanian cultural critic Slajov ZiZek. The conjunction of these two excursions away from Cavell sets the stage for a discussion of his interpretation of the film, pieced together from sections of The World Viewed and Pursuits of Happiness . Themes of the screen creation of women, of the transformative powers of the camera, and of the role of the movie director, together forecast the most admired contribution this American philosopher has offered to Academic Film Studies: the definition of the related genres of the Hollywood Comedy of Remarriage and the Hollywood Melodrama of the Unknown Woman.


identifier: Nguyen, Thanh An  (2009) Vision based curve reconstruction algorithms and their application to graphical password.  Masters thesis, Concordia University.

abstract: Curve reconstruction is the problem of approximating a curve or multiple curves from a point cloud. Curve reconstruction problem has received numerous attention over the last few decades due to its significant application in geometric modeling. In this thesis, based on the relationship between human vision and curve reconstruction, two Gestalt laws have been identified for the curve reconstruction: the law of proximity indicating that our vision tends to perceptually group near objects together and the law of continuation pointing out that objects following a consistent continuous direction are perceptually grouped together. Two algorithms have been proposed to implement these two laws in curve reconstruction. This first algorithm, DISCUR, connects points based on the law of proximity. The second algorithm, VICUR, considers both laws. The algorithms have been compared to the main curve reconstruction algorithms available in the literature.  Another contribution of this thesis is a new application of curve reconstruction in the field of cryptography. In the thesis, a new graphical password scheme is introduced. The proposed scheme requires users to create their secret by selecting individual points or by connecting points into curves from a given set of points. It is reasonable to assume that the users will connect points into curves that look natural to their vision so that they can recall easily. Consequently, the password may be a part of the reconstructed results of the human-vision based curve reconstruction algorithms and the attacker can use these results to crack the password. We present the application of curve reconstruction algorithm in the evaluation of our graphical password scheme.


identifier: Singh, Rajpal  (2009) Shear stress analysis of tubular composite beams subjected to bending by shear load.  Masters thesis, Concordia University.

abstract: Tubular composite beams are of increasing interest due to their growing applications in the offshore and aerospace industries. Most analysis work done on tubular composite beams has been limited to pure bending, uniform axial loads or uniform torsion. These are also limited to the analysis of uniform section, uniform material and uniform thickness beams. In real applications, transverse shear loads are usually present and add complexity to the analyses. When a beam is under distributed or concentrated transverse loadings, regardless of the boundary conditions, the distributions of bending moments and internal transverse shear loads vary through the length of the beam. Analysis of such beams is very complicated. In this research, a systematic approach is presented to evaluate shear stress distribution across the cross section of thin walled tubular beams made of non homogeneous sections. Variation of shear stress through the thickness is ignored. Exact equations for the analysis of shear stresses in thin wall composite beams are derived in local coordinate systems. The results are projected in global coordinate system to facilitate evaluation and comparison of shear stress distribution in different beams. The method is applied to analyze beams with T, Triangular, Hexagonal, Octagonal and Decagonal sections. The pattern behaviour and shear stress variation in these beams is studied to predict the maximum shear stress in beams with circular cross section that has the same radius as the circumscribed circle of multi-gonal beams


identifier: Zhang, Mei Mei  (2009) The differential impact of box office and DVD sale drivers in the motion picture industry.  Masters thesis, Concordia University.

abstract: Although theatrical box office results have traditionally been considered the most important measures of movie performances, the fact that movie studios' revenues are more dependent on the DVD retail sales rather than box office ticket sales ascertains the importance of investigating the DVD retail sales performance. While numerous studies explore the key drivers in theatrical performance, little is known about the specific drivers of DVD retail market performance. Therefore, this thesis aims to investigate: (1) whether the factors that have an impact on theatrical market also impact on DVD sales market and (2) whether certain factors are more (or less) important in DVD retail markets.  The research questions are addressed by adopting a linear regression modeling and a quantile regression modeling approach. The results show that (1) theatrical performance is the key predictor of DVD performance and (2) DVD performance is more influenced by "reputation" factors, while theatrical performance is more influenced by "signaling" factors.


identifier: Jamal, Amani  (2009) A UML framework for OLAP conceptual modeling.  Masters thesis, Concordia University.

abstract: Data warehouses are used by organizations around the world to store huge volumes of historical data. Ultimately, the purpose of the warehouse is to allow decision makers to assess both the history and, more importantly, the future of the organization. In practice, the capacity to make meaningful decisions is further supported through the use of Online Analytical Processing (OLAP) applications that provide more sophisticated representations of the warehouse data. In order to do this, OLAP systems rely on a multidimensional conceptual data model that represents the core elements of the data warehouse, as well as the relationships between them. Currently, there is no definitive conceptual model for this kind of environment. It is therefore quite difficult for data warehouse designers to express the kinds of complex analytical requirements which arise in real-world situations. In this thesis, we propose a robust and flexible conceptual model that can be used to represent multi-dimensional OLAP domains. Specifically, we present a profile extension of the Unified Modeling Language (UML) that consists of a set of stereotypes, constraints and tagged values that elegantly represent multi-dimensional properties at the conceptual level. We also make use of the Object Constraint Language (OCL) to ensure the correctness and completeness of the specification, thereby avoiding an arbitrary use of the basic components. Furthermore, we demonstrate how the new OLAP profile is utilized in MagicDraw, one of the leading UML development tools. The end result is an OLAP Modeling Environment (OME) that should significantly reduce development time, as well as improving the quality of the analytical interface for the end user.


identifier: Garcia, Juliana  (2009) Red blood cell derived vasodilators : determination and modulation.  Masters thesis, Concordia University.

abstract: A luciferin-luciferase chemiluminescence method was used to quantify extracellular adenosine triphosphate (ATP) released by red blood cells (RBCs) after stimulation with nitroglycerin, a potent vasodilatory drug. Attenuation in the amount of ATP released from RBCs was observed after treatment with increasing concentrations of nitroglycerin or nitrite. However, RBCs exposed to nitroglycerin or nitrite for < 5 min released increased amounts of ATP. A mechanism of blood flow regulation through an ATP-NO/NO 2 - pathway is proposed. Nitroglycerin-derived NO 2 - is converted within RBCs to NO, which might activate ATP release. In vivo, ATP will stimulate endothelial nitric oxide synthase (eNOS), increasing NO production and causing vasodilation. NO could diffuse into the blood stream where it is converted to NO 2 - and taken up by downstream RBCs, further increasing their ATP production. Thus, the original RBC-derived NO 2 - /NO signal could be amplified both by the action of ATP and NO.  Nitroglycerin was also shown to act as a "suicide substrate" for RBC glyceraldehyde 3-phosphate dehydrogenase (GAPDH). GAPDH reduced nitroglycerin to glyceryl dinitrates and NO 2 - using its active-site cysteines as electrons donors. This inactivation inhibited the bioconversion of nitroglycerin to NO 2 and caused an attenuation of the drug's effect. The dehydrogenase activity of GAPDH was also suppressed, thereby limiting the production of ATP and propagation of the vasodilation signal.  The extracellular profile of ATP-derived ADP, AMP and adenosine was additionally studied by LC-UV. Preliminary ESI mass spectrometric analysis of epoxyeicosatrienoic acids and prostacyclin, RBC vasodilators derived from arachidonic acid, was explored.


identifier: Farsiniamarj, Nasim  (2008) Combining integer programming and tableau-based reasoning : a hybrid calculus for the description logic SHQ.  Masters thesis, Concordia University.

abstract: Qualified cardinality restrictions are expressive language constructs which extend the basic description logic ALC with the ability of expressing numerical constraints about relationships. However, the well-known standard tableau algorithms perform weakly when dealing with cardinality restrictions. Therefore, an arithmetically informed approach seems to be inevitable when dealing with these cardinality restrictions. This thesis presents a hybrid tableau calculus for the description logic SHQ which extends ALC by qualified cardinality restrictions, role hierarchies, and transitive roles. The hybrid calculus is based on the so-called atomic decomposition technique and combines arithmetic and logical reasoning. The most prominent feature of this hybrid calculus is that it reduces reasoning about qualified number restrictions to integer linear programming. Therefore, according to the nature of arithmetic reasoning, this calculus is not affected by the size of numbers occurring in cardinality restrictions. Furthermore, we give evidence on how this method of hybrid reasoning can improve the performance of reasoning by organizing the search space more competently. An empirical evaluation of our hybrid reasoner for a set of synthesized benchmarks featuring qualified number restrictions clearly demonstrates its superior performance. In comparison to other standard description logic reasoners, our approach demonstrates an overall runtime improvement of several orders of magnitude.


identifier: Veres, Olga Erzsébet  (2009) On the complexity of polynomial factorization over P-adic fields.  PhD thesis, Concordia University.

abstract: Let p be a rational prime and Z( x ) be a monic irreducible polynomial in Z p [ x ]. Based on the work of Ore on Newton polygons (Ore, 1928) and MacLane's characterization of polynomial valuations (MacLane, 1936), Montes described an algorithm for the decomposition of the ideal [Special characters omitted.] over an algebraic number field (Montes, 1999).  We give a simplified version of the Montes algorithm with a full MAPLE implementation which tests the irreducibility of Z( x ) over Q p . We derive an estimate of the complexity of this simplified algorithm in the worst case, when Z( x ) is irreducible over Q p . We show that in this case the algorithm terminates in at most[Special characters omitted.] bit operations.  Lastly, we compare the "one-element" and "two-element" variations of the Zassenhaus "Round Four" algorithm with the Montes algorithm


identifier: Bedair, Rania  (2009) Comprehensive study of wind loads on parapets.  PhD thesis, Concordia University.

abstract: The current thesis aims at defining and evaluating the local (components and cladding) wind loads on parapets. For the first time, it was attempted to measure such loads in full-scale, in order to address the issues encountered in previous wind tunnel studies. Field testing was carried out using the full-scale experimental building (3.97 m long, 3.22 m wide and 3.1 m high) of Concordia University (located near the soccer field at the Loyola Campus). In order to define individual surface pressures as well as their combined effect from both parapet surfaces, simultaneous peak and mean wind-induced pressures were measured on both exterior and interior surfaces of a uniform perimeter parapet with a height of 0.5 m. Roof edge and comer pressures were also recorded. In addition, a complete wind flow simulation was performed in the Boundary Layer Wind Tunnel (BLWT) of Concordia University using a 1/50 scale model of the experimental building with two different parapet heights, equivalent to 0.5 and 1 m. The choice of geometric scale based on correctly modeling the turbulence intensity at the roof height. The wind tunnel results were compared with the field data for validation purposes. In general, the comparison shows good agreement, although some discrepancies were identified for critical wind directions.  In the past, it was difficult to directly model and record the parapet surface pressures, due to modeling limitations. Therefore, wind loads on parapets were mainly estimated from pressures measured on the wall and the roof of the building in the vicinity of a parapet. The current results demonstrate, in general, that the design method provided in the ASCE 7-05 overestimates the total load on the parapet. In addition, design recommendations are provided and can be considered by the standards.  Numerical simulation of the wind flow over the test building model with the parapet was also performed by using the CFD code Fluent 6.1.22. The steady-state RANS equations were solved with two modified k -[varepsilon] turbulence models, namely the RNG k -[varepsilon] model and the RLZ k -[varepsilon] model. Considering the current state-of-the-art, peak pressures are not predicted reliably by computational approaches. Therefore, in the present study only mean wind-induced pressures on the roof and on parapet surfaces were computed. The computational results show that parapets act to reduce high negative pressures on the leading edge and to make the distribution of mean pressures on the roof more uniform. The simulated pressures are generally in good agreement with the corresponding wind tunnel data


identifier: Hardy, Nadia  (2009) Students' models of the knowledge to be learned about limits in college level Calculus courses. The influence of routine tasks and the role played by institutional norms.  PhD thesis, Concordia University.

abstract: This thesis presents a study of instructors' and students' perceptions of the knowledge to be learned about limits of functions in a college level Calculus course, taught in a North American college institution. I have modeled these perceptions using a theoretical framework, which combines elements of the Anthropological Theory of Didactics, developed in mathematics education, with a framework for the study of institutions - the Institutional Analysis and Development framework - developed in political science. I describe the models and illustrate them with examples from the empirical data, on which they have been built: final examinations from the past six years (2001-2007), used in the studied College institution, and specially designed interviews with 28 students. While a model of the instructors' perceptions could be formulated mostly in mathematical terms, a model of the students' perceptions had to include an eclectic mixture of mathematical, social, cognitive and didactic norms . The analysis that I carry out shows that these students' perceptions have their source in the institutional emphasis on routine tasks and on the norms that regulate the institutional practices. Finally, I describe students' thinking about various tasks on limits from the perspective of Vygotsky's theory of concept development. Based on the 28 interviews that I have carried out, I will discuss the role of institutional practices on students' conceptual development.


identifier: Tadayon, Rahim  (2009) Modeling curvilinear flows in hydraulic structures.  PhD thesis, Concordia University.

abstract: The Study investigates the use of Computational Fluid Dynamics (CFD) to analyze the mean characteristics of curvilinear flows in selected hydraulic structures. Three chosen turbulence models are associated with the Volume of Fluid (VOF) scheme to predict the characteristics of the mean flow. Many hydraulic structures in engineering practice involve highly curvilinear flows. Five typical hydraulic structures commonly used for flow regulation or flow measurement are considered in the present study; cut-throat flumes, lateral weirs, sharp-crested weirs, circular spillways, and siphon spillways. Velocity distributions, pressure distributions, water surface profiles, secondary flows, and discharge coefficients are the mean characteristics of flows that are studied.  Presently, computing methods and high speed computers are strong tools for engineers. With the help of a properly validated numerical model, one can avoid the time consuming and expensive experimental tests based on the physical models to obtain the characteristics of highly curvilinear flows encountered in hydraulic practices. This is based on the fact that unlike physical models, it is far simpler to apply changing boundary conditions and flow parameters to a solved numerical model and obtain a flow characteristics for hydraulic structures associated with highly curvilinear flows.  The flows in hydraulic structures are turbulent. Hence, one needs to solve numerically the continuity equation and momentum equations, including turbulent stresses, as the governing equations of turbulent flows. Because the above mentioned flows are generally complex and highly curvilinear, the transport equations are needed to model the turbulent stresses in the momentum equations.  In the present study, three Reynolds-Averaged Navier-Stokes (RANS) schemes are used to simulate the turbulent flows. Specifically, the Reynolds stress model (RSM), the Standard k-[varepsilon] model, and the RNG k-[varepsilon] model were used in the present study. Further, the VOF scheme is adopted to find the shape of free surface profiles


identifier: Halachev, Mihail  (2009) Management of biological sequences using suffix trees.  PhD thesis, Concordia University.

abstract: The amount of available biological sequences, represented as strings over the DNA and protein alphabets, grows at phenomenal rate. Supporting various search tasks over such data efficiently requires development of sophisticated indexing techniques. Recently, suffix tree (ST) and suffix array (SA) received considerable attention as suitable data structures in this context. However, existing solutions often focus on either efficiency or scalability, but not both. Further, some of the solutions require advanced computational resources or are tailored towards a specific application.  We investigate, both theoretically and experimentally, ways to improve efficiency and scalability in management of biological sequence data. Our goal is to develop an indexing technique that is reasonable in construction time and space utilization, and supports efficiently versatile search applications in biological sequences of various sizes, running on a typical desktop computer.  The contributions of this research include development of a ST based indexing technique, called HST, together with exact and approximate search algorithms that use the index. The results of our experiments indicate that the index construction cost is comparable to other ST based techniques, such as TDD and Trellis, in terms of construction time and main memory requirement. While HST exhibits slower construction time than Vmatch, the best known SA based solution, with the same amount of main memory HST can handle sequences that are an order of magnitude longer. In terms of the index size, HST is comparable to TDD and Vmatch, which is half of the Trellis index size.  We also develop efficient and scalable search applications using HST, including exact match, k-mismatch, and structured motif search. Our experiments using real-life sequences indicated that for short sequences (e.g., human chromosomes), our exact match search is comparable to Vmatch, about 3 times faster than TDD, and more than 10 times faster than Trellis. Further, HST can be used to search directly in longer DNA sequences, as opposed to partitioning such a sequence and search in the parts - the only option to follow with Vmatch. We found that a direct exact match search using HST is twice faster when searching in the entire human genome, compared to using Vmatch on parts. Compared to Trellis, which can handle direct search in human genome, HST was more than 20 times faster. To further compare performance of HST and Vmatch, we considered k-mismatch search. Our results indicated significant improvement of the HST based solution over Vmatch, ranging from 2 to 9 times faster k-mismatch search on average, for short and long sequences, respectively. For structured motif search, HST was about 6 times faster than SMOTIF1, the best known structured motif search tool.