identifier: Pai, Cheng-Yu  (2006) Rate control and constant quality rate control for MPEG video compression and transcoding.  PhD thesis, Concordia University.

abstract: The focus of this thesis is the design of rate-control (RC) algorithms for constant quality (CQ) video encoding and transcoding, where CQ is measured by the variance of quality in PSNR (peak signal-to-noise ratio).  By modeling DCT coefficients as having Laplacian distributions, Laplacian rate/models are developed for MPEG-4 encoding and transcoding. These models accurately estimate the rate and distortion (in PSNR) of MPEG-4 compressed bitstreams. The rate model is applied to a CBR (constant bit rate) encoding algorithm. This algorithm offers a better or similar PSNR as compared to the Q2 [7] algorithm with a lower variation in bitrate. Thus, it outperforms Q2.  These models are then applied to CQ video coding and transcoding. Most CBR control algorithms aim to produce a bitstream that meets a certain bitrate with the highest quality. Due to the non-stationary nature of video sequences, the quality of the compressed sequence changes over time, which is not desirable to end-users. To provide a solution to this problem, six CQ encoding algorithms are proposed: the first two are VBR (variable bit rate) algorithms with a fixed target quality (FTQ), the next two are CBR algorithms with FTQ, and the last two are CBR algorithms with a dynamic target quality (DTQ). Within each group of two, the quality is controlled either at the frame level (using the Laplacian rate/distortion model) or at the macroblock level (using the actual distortions).  With the success of these algorithms, the CQ DTQ encoding algorithms are extended to MPEG-4 video transcoding (bitrate reduction with requantization). These CQ transcoding algorithms can handle the problems that are uniquely present in transcoders, such as the lack of the original sequence and requantization. Similar to their encoding counterparts, these CQ transcoding algorithms have an extra degree of freedom to balance the quality variation with the accuracy to the target bitrate and the average quality. Simulation results indicate that these algorithms offer lower PSNR variance while having similar/lower average PSNR and bitrate when compared with Q2T and TM5T (transcoding version of Q2 and TM5).  Besides proposing MPEG-4 CQ RC algorithms, an MPEG-2 rate-control algorithm is also developed based on TM5. It aims at improving the subjective quality measured by using Watson's DVQ (digital video quality) metric. When compared with TM5, it provides a better DVQ. However, since Watson's DVQ metric is not a standard way to estimate the subjective quality, PSNR is still used in the rest of the research


identifier: Wang, En Rong  (2005) Syntheses and analyses of semi-active control algorithms for a magneto-rheological damper for vehicle suspensions.  PhD thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract: Vehicle suspensions impose conflicting design requirements to satisfy the performance goals related to ride, handling and road holding. Semi-active damping suspensions, with their low cost and low power requirement, have been extensively investigated to achieve better compromises among different performance measures. The magneto-rheological (MR) fluid dampers offer superior potential to achieve rapid variations in the damping force and thus the wide bandwidth. The MR dampers, however, exhibit strong nonlinearities associated with force saturation and hysteresis, which affect the force-tracking performance of the controller in an adverse manner. This dissertation research focuses on characterization and modeling of the hysteretic force-velocity ( F-v ) characteristics of a MR-fluid damper, and analyses of different semi-active controller syntheses to achieve improved multi-objective vehicle suspension performance. The force-limiting and hysteresis properties of a prototype MR-damper are characterized in the laboratory as functions of applied magnetic field, and response and excitation variables. An asymmetric force generation algorithm is formulated and integrated into the command current circuit to achieve asymmetric force in compression and rebound from the symmetric damper hardware. The measured data are used to identify the low-speed pre-yield, post-yield, force-limiting and hysteretic force-velocity characteristics in both symmetric as well as asymmetric damping modes.  A generalized analytical model of the MR-damper is developed using symmetric and asymmetric sigmoid functions. The validity of the proposed model is demonstrated under wide ranges of control current and excitations. A number of control syntheses are formulated to achieve semi-active modulation in drive current of the MR-damper, including four different on-off and "skyhook"-based hi-lo, and "inverse-model"-based hi-lo and sliding-mode controllers. Continuous modulation (CM) and asymmetric damping force generation (ADFG) algorithms are proposed and integrated within the control policies to minimize switching transients in the symmetric and asymmetric modes


identifier: Shurkus, Marie Bridget  (2005) Appropriation art : moving images and presenting difference.  PhD thesis, Concordia University.

abstract: The dual nature of artworks has had a wrenching impact on art-historical scholarship. At one extreme, historians interpret visual artworks in terms of their historical eras, cultural conditions, and artists' biographies. At the other, historians receive artworks as aesthetic objects and interpret their formal structures. In the former construct artworks are understood as semiotic systems that operate like text. The latter focuses on the perceptual experience of viewing. This thesis addresses how postmodern appropriation art engages the dual nature of artworks to redefine visual representation as a translational and transformative event.  Postmodern appropriation art takes two different forms: art after media and art after art. Although this thesis focuses on the latter, the introduction reviews the development of both and establishes how material expression functions differently in each. Chapter one considers the emergence of rephotography in 1979 to demonstrate how even this---the most exact version of art after art---embodies difference at the material level. Applying Gilles Deleuze's insight that repetition expresses difference, this thesis then redefines appropriation art as the movement of images into new contextual and material expressions. The body of the thesis takes up each of these elements---context, image, and material---and specifically explores how they produce creative outcomes.  Throughout, this thesis examines how the practice of postmodern art after art demonstrates that visual artworks provide territories in which performative events occur. However, unlike what was suggested during Abstract Expressionism, this is not a performance between an authorial artist and the artwork; it is a performance between the artwork's material condition, which generates affective qualities, and its contextual frame, which sets up referential relationships that are tied to social and cultural forces. Through an analysis of individual artworks, this thesis demonstrates that these outcomes---the qualitative changes and new referential relationships---are neither predictable nor obvious in the source artworks, they must be actualized to become apparent. Thus, authorship is realigned with the art object, the artist is redefined as a viewer, and visual representation becomes a material event.


identifier: May, David  (2005) Wing tip vortex dependence with angle of attack.  Masters thesis, Concordia University.

abstract: This study examines Wing Tip Vortex flows, in the Near to Far Field. A Viscous Incompressible simulation of the NACA 0012 (with an aspect ratio of 6, operating at a free stream Reynolds number of 6.84 e 5) was made.  The Tip vortex parameters are compared with available, current, experimental data. Once the validity of the model is assessed, the fluid structures and dynamical processes are described, with the aid of solution visualizations. Characteristics of the flow that have not been studied in open literature are presented.  An analysis is conducted regarding the dependence of the Tip Vortex characteristics and their variation with Angle of Attack. Aspects of the, low wing loading, analysis of Moore and Saffman are summarized and assumed to apply in the Far Field Regime. Then, dimensional analysis is used to present reasonable arguments for the scaling of the observed Near Field data. A balance of these two scaling laws is made and is shown to apply in what will be called the Intermediate Field Regime, where dependence with various vortex characteristics display a logarithmic variation with Angle of Attack


identifier: Liu, Wei Ping  (2005) Epoxy-clay nanocomposites for structural applications.  PhD thesis, Concordia University.

abstract: High-performance epoxy-clay nanocomposites and hybrid epoxy nanocomposites modified with both organoclay and rubber were synthesized. The nanocomposites were characterized by optical microscopy, XRD, AFM, TEM and SEM. A new method to disperse organoclays into organic media, high pressure mixing (HPM), is proposed. TEM images show that organoclay agglomerates are broken down by the HPM method to form small particles consisting of 5{598}10 silicate layers. Adding organoclay into rubber-modified epoxies not only increases the degree of cure and T g , but also changes the morphology of the rubber phase.  Water uptake behavior of nanocomposites has been systematically studied with Fickian and non-Fickian diffusion models. Diffusion models for nanocomposites were developed. The diffusivity in nanocomposites decreases with increasing clay loading and improving dispersion quality of organoclay. Hybrid nanocomposites can decrease the effect of rubber on water uptake of epoxy resins at high environmental temperature.  The fracture toughness of epoxy systems is greatly enhanced by adding organoclay and by improving dispersion quality of organoclay in epoxy resins. The increased toughness is explained in terms of a crack-pinning mechanism and increased fracture surface area. There is a superposition effect on toughness of hybrid epoxy nanocomposites modified with both rubber and organoclay


identifier: Xu, Lugang  (2006) Cascaded refactoring for framework development and evolution.  PhD thesis, Concordia University.

abstract: This thesis addresses three problems of framework development and evolution: identification and realization of variability, framework evolution, and framework documentation. A solution, called the cascaded refactoring methodology, is proposed. The methodology is validated by a case study, the Know-It-All framework for relational Database Management Systems.  The cascaded refactoring methodology views framework development as framework evolution, which consists of framework refactoring followed by framework extension. A framework is specified by a set of models: feature model, use case model, architectural model, design model, and source code. Framework refactoring is achieved by a set of refactorings cascaded from the feature model, to use case model, architectural model, design model, and source code. The constraints of refactorings on a model are derived from the refactorings performed on its previous model. Alignment maps are defined to maintain the traceability amongst the models.  The thesis broadens the refactoring concept from the design and source code level to include the feature model, use case model, and architectural model. Metamodels and refactorings are defined for the feature model and architectural model. A document template is proposed to document the framework refactoring


identifier: Robichaud, Melisa  (2005) An in-depth investigation of social problem-solving ability.  PhD thesis, Concordia University.

abstract: Social problem solving, the resolution of daily life problematic situations with no readily available solution, is comprised of a series of skills that includes problem solving proper and one's general orientation towards problem solving. Researchers have contended that poor problem-solving ability is a necessary and sufficient condition for developing a psychological disorder. Despite the importance of the construct, current assessment tools have yielded inconsistent and at times contradictory results. The goal of the present research was to develop novel assessment techniques for the measurement of social problem solving.  In the first study, a new questionnaire for the assessment of negative problem orientation was translated from French and validated. Results revealed that the Negative Problem Orientation Questionnaire (NPOQ) was unifactorial, had excellent internal consistency, good test-retest reliability at 5 weeks, and demonstrated convergent and discriminant validity ( N = 201).  In the second study, the construct validity of the NPOQ was investigated by assessing the relationship between the NPOQ and measures of distress after controlling for conceptually similar personality variables. The measure continued to predict worry and depression scores when entered in the last step of multiple hierarchical regressions ( N = 148). Moreover, the NPOQ displayed greater specificity to worry (5.6% of the variance) than to depression (1.6%). Results suggested that negative problem orientation reflects a specific negative predisposition towards problem solving among worriers, compared to a by-product of a general negative thinking style in depression.  In the third study, a novel problem-solving interview was developed to measure performance on six problem-solving steps. Participants completed the interview for a hypothetical and a personal problem, and were separated into two groups according to intolerance of uncertainty levels, a cognitive predisposition linked to worry ( N = 62). Results revealed that among high intolerance of uncertainty participants, anxiety was related to poor performance on initial stages of problem solving, whereas depression was associated with poor performance on later more elaborative stages. These findings emerged only for the personally-relevant problem, and among individuals high in intolerance of uncertainty, suggesting the context-dependent nature of problem solving as well as the role of threat appraisals on constructive coping


identifier: Jessup, Heather  (2005) A derivative of light.  Masters thesis, Concordia University.

title: A derivative of light

abstract: A Derivative of Light is a prose-fiction account of Cold War Canada chronicled through the narrative of the Jacobs family, living in Malton, Ontario during the production of the CF-105 AVRO Arrow interceptor plane. The pivotal events in this family's life unfold in juxtaposition with broader international and national crises: the launch of Sputnik from the Baikanor Cosmodrome in Russia on October 4 th 1957, heralding the beginning of The Missile Age; and the cancellation of the CF-105 project on February 20 th , 1959 by Prime Minister Diefenbaker, subsequently unemploying Peter, the patriarch of the Jacobs family, along with 20,000 other skilled labourers.  On October 4 th 1957, the day of both Sputnik's launch and the CF-105s roll-out, Lucy Jacobs appears mysteriously in a field during a thunderstorm. A priest finds her pregnant, unconscious and suffering from burns. Peter must then cope with his wife's hospitalization, the care of his children, and eventually, the loss of his job.  The children of the Jacobs family: Kier, Andrew and Rose, grow up within the physical and cultural restrictions of a Toronto suburban setting at a time when the infinite force of nature and science---such as Lucy's brush with lightning, the expansive possibility of the CF-105 Arrow project, space and space-flight---further embody the paradoxes and pondering of the novel's themes: what does ordering and organization do against the vastness and randomness of spectacular technological and natural occurrences.  A Derivative of Light spans the period from 1945 to 2001 and is divided structurally into two sections. This M.A. thesis is the first half of those two sections.


identifier: Hall, Kate  (2006) The certainty dream.  Masters thesis, Concordia University.

title: The certainty dream

abstract: Descartes asked, how can I know that I am not now dreaming? The Certainty Dream deals with questions of identity, of reality and of the integrity of linguistic representation of the self through poetry. The poem, the mind, the body, and the world become an interrelating series of overlapping circles, all acting as containers for both knowledge and uncertainty. Eschewing the traditional language of philosophy, these poems operate by semiotic transference, allowing us to know something by first recognizing it as something else. Many of these poems employ loose associations, illogical connections, fragmented narratives and run-on syntax to postulate other ways of knowing.  Two primary threads inform the manuscript: a series of dream poems and the character 'Mynah'. Mynah is not a literal mynah bird but an aesthetic object that the speaker uses as a mirror for herself and the world. The dream world and the waking world blur together; the poems in each landscape are similarly strange and uncertain. In a world where "duplicity is always shining forth from ordinary objects," one is never sure whether an object, and by extension the poetic self, is real or a mimetic representation (i.e. part of a dreamscape). The dislocation is epistemological, and the poems thus become the speaker's visible negotiation of her own identity in the face of uncertainty. She is not convinced that she exists as more than a symbol, a representation of herself. Trapped in her own narrative, and her own mind, she isn't sure she has access to anything verifiable. Alongside that doubt, however, poetic language and associative leaps become a point of verification


identifier: John, Paul  (2006) Variable h-epenthesis in the interlanguage of francophone ESL learners.  Masters thesis, Concordia University.

abstract: This thesis investigates variable h-epenthesis by francophones in English (e.g., "I hurt my [h]ankle" vs. "my _ankle"). Speech samples from 15 francophones were analyzed via the statistical program GoldVarb. Since epenthetic segments are by definition absent from (and hence unfaithful to) input, h-epenthesis hypothetically results from the high ranking in interlanguage (IL) of the markedness constraint ONSET, which is commonly associated with consonant epenthesis. The finding of greater h-epenthesis in more formal speech, however, contradicts this analysis given that, cross-linguistically, the more formal the speech, the higher ranked the faithfulness constraints (Oostendorp, 1997). The solution lies in an output-output faithfulness constraint adapted from Bradley (to appear): MAX-OO-[h] ("An output [h] in native speaker (NS) English has an output correspondent in francophone IL output"). In this form of output-output correspondence, the output is generated not from the speaker's own input, as is usual, but from the prestige-variety NS output that the learner tries to duplicate, particularly in more formal contexts. Francophones strive to emulate NS output due to two realizations: they realize (1) that, given their pervasive h-deletion, a discrepancy exists between their own and NS output; and (2) that this discrepancy stems from the unreliability of their input forms, which lack underlying h due to francophones' (at least initial) inability to construct a phonemic representation for this non-native segment (Brown, 1997, 1998). Hypercorrect h-epenthesis is then generated because, rather than accurate NS output forms, speakers access an overly permissive output generalization


identifier: Broadhurst, Michael  (2005) Needs analysis in a corporate setting.  Masters thesis, Concordia University.

title: Needs analysis in a corporate setting

abstract: This project draws from materials related to Human Performance Technology. It looks at individual roles as well as corporate dynamics in assessing performance and driving change within the organisation. The initial project was designed to identify performance gaps within the Infusion Pharmacology and Neurotoxicology Department (IPN Department). The objective of the analysis was to identify areas for improvement within a functioning business environment and the organisation as a whole. The resulting recommendations lead to several improvement initiatives, one of which, the redesign of the corporate reporting process, is included in the discussion. The Reporting Process change illustrates implementation of a Human Performance Technology initiative using similar analytical methodologies. A reflection on this paper provides an overview of lessons learned and considerations for Concordia University's Educational Technology graduate program.


identifier: Koch, Denise  (2006) Theoretical studies of seeded water clusters : structure, thermodynamics and photochemistry.  PhD thesis, Concordia University.

abstract: This thesis provides a detailed and thorough theoretical investigation of the solvation structure of ions in water clusters and of solvation effects on photochemically-induced electron transfer processes occurring in seeded aqueous clusters. NaI(H 2 O) n clusters were chosen as a model system for the latter because the electronic structure of NaI is characterized by a curve crossing of ionic and covalent states, and the presence of solvent molecules can significantly affect the NaI electronic structure and photodissociation dynamics due to the differential solvation of these two states. Furthermore, the surface solvation state adopted by large halide ions determines to a great extent the solvation structure of alkali-metal halides in water clusters, and therefore significantly affect their photochemistry. The first-ever rigorous investigation of the solvation thermodynamics of halide-water clusters, presented here, reveals that entropy and polarization drive the ion from a surface to interior solvation structure by cluster size 20 for fluoride, and cluster size 60 for the heavier halides. The outcome of the simulations seems to depend strongly on the choice of model used to describe the system intermolecular interactions, and an array of first-principles simulation methodologies has been designed accordingly. Designing models that allow for solvent polarization and computationally efficient semiempirical methods that can properly describe weak interactions is shown to be essential throughout the thesis. Nonadiabatic simulation techniques were developed, in combination with an hybrid quantum-mechanics/molecular mechanics (QM/MM) model to describe intermolecular interactions, in order to investigate the photodissociation dynamics of NaI(H 2 O) n clusters. Simulation results suggest that the addition of only a few water molecules is sufficient to completely quench the oscillatory NaI dynamics observed in the gas phase, but that the process is dominated by rapid water evaporation. As a result, electron transfer in NaI(H 2 O) n is largely governed by the NaI large-amplitude motion, like in the gas phase, and the solvent only influences the nonadiabatic dynamics by mediating the Nal internuclear separation at which curve crossing occurs. When embedded in an argon matrix, however, the NaI(H 2 O) n nonadiabatic dynamics appears to involve an activationless or activated inverted electron transfer process along the solvent coordinate analogous to what may occur in solution.


identifier: Tong, Bing  (2005) A 3D modeling for detailed quantity take-off for building projects.  Masters thesis, Concordia University.

abstract: Quantity Take-off, the process of obtaining the dimensions and calculating the quantities from given plans and specifications, is perhaps the most basic and important phase in the detailed estimation of construction costs. The pricing strategies of cost estimation vary greatly in different situations. However, as the pricing changes, the quantity of the work involved in a particular project remains unchanged. A relatively accurate quantity take-off is thus a crucial element to successful bidding and project management.  This thesis presents a new methodology that can integrate AutoCAD with the quantity take-off during the detailed cost estimating process. Based on the designer's 2D AutoCAD drawings, and through interaction with a user, a customized AutoCAD module generates a 3D model of a project and exports the components' information into an external Access database which contains detailed quantity take-off information. The 3D model improves project visualization by allowing estimators to visualize the construction process as it would be actually built. Moreover, this customized module makes the quantity take-off much more efficient and effective.


identifier: Ip, Kai Wing  (2005) Bearing capacity for foundation near slope.  Masters thesis, Concordia University.

abstract: The bearing capacity of the foundation is a primary concern in the field of foundation engineering. The self weight of the structure and the applied loads are transferred to the soil safely and economically. The load at which the shear failure of the soil occurs is called the ultimate bearing capacity of the foundation.  Quite often, structures are built on or near a slope. This is due to land limitation, such as for bridges or for architectural purposes. The ultimate bearing capacity of the foundations for these buildings is significantly affected by the presence of the slope. Design of foundations under these conditions is complex and the information available in the literature is limited.  A numerical model was developed to simulate the case of strip foundation near slope, using the finite element technique together with the program "PLAXIS". The parameters believed to govern this behavior were examined individually to determine their effect on the ultimate bearing capacity of a strip footing. The superposition method was used in the analyses to calculate the bearing capacity factors, N c , N q , and N Þ , independently. The results produced by the present numerical model were compared with the available experimental data.  An analytical model was also developed for the problem stated to predict the ultimate bearing capacity of a strip footing. Design theory, design procedure and design charts are presented for practical use


identifier: Hoque, Mohammad Azizul  (2006) Coupled consolidation model for negative skin friction on piles in clay layers.  Masters thesis, Concordia University.

abstract: Piles driven in clay are often subjected to indirect loading as a result of the surcharge applied on the surrounding area. During the drained period, both the pile and the soil undergo downward movements caused by the axial and the surcharge loading, respectively. Depending on the relative movement of the pile/soil system, positive and negative skin friction develop on the pile's shaft. Negative skin friction is the drag force that may be large enough to reduce the pile capacity and/or to overstress the pile's material causing fractures or perhaps structural failure or possibly pulling out the pile from the cap.  A numerical model was developed to simulate the case of a single pile driven in soft clay layer overlying a deep deposit. Coupled consolidation method of analysis is adopted to predict time/settlement/skin friction distribution relationships. The model is an axisymmetric that uses the finite element technique combined with the soil responses according to Mohr-Coulomb criteria. The model was first tested against the results predicted by the classic theories for bearing capacity of pile foundations on clay. Furthermore, the model was validated with the results of three full scale field tests available in the literature


identifier: Salem, Sasan  (2006) Simulation of controller configurations for static synchronous series compensators & interline power flow controllers with EMTP-RV.  Masters thesis, Concordia University.

abstract: This thesis deals with Flexible AC Transmission Systems (FACTS) based on Voltage Source Converters (VSC). In particular, the emphasis is on series-connected VSC into transmission lines, known as Static Synchronous Series Compensator (SSSC) and Interline Power Flow Controller (IPFC). These are modern series compensators with fast response and high performance.  The SSSC and IPFC applications are simulated with the help of EMTP-RV software, where detailed models of the power system and controllers are implemented and the dynamic performances are considered.  The proposed VSC is based on a 3-level Neutral-Point-Clamped (NPC) VSC employing PWM techniques to generate firing pulses for the VSC switches. The VSC main circuit configuration, function and operating principles are first described.  The proposed VSC is used as the major building block of the SSSC. The detailed model of SSSC (with two different control strategies) is then presented. The controllers are designed to regulate the transmission line impedance by injecting a set of 3-phase voltages with controllable magnitude and phase angle.The stability of the proposed SSSC under various system conditions is investigated and the two different control strategies are compared.  Finally, two SSSCs with a common DC-link are used to configure an IPFC. The proposed IPFC is applied to two parallel transmission lines to regulate their impedances. The validity of the proposed control techniques under various system conditions is also investigated


identifier: Mandhare, Gaurav Pradeep  (2006) Distributed power control algorithms for WCDMA cellular systems.  Masters thesis, Concordia University.

abstract: In this thesis, we propose two power control algorithms, one signal-to-interference (SIR) based and the other bit-error-rate (BER) based. The proposed algorithms are of first order and have been devised for use as distributed power control algorithms for the uplink channel in wideband code division multiple access (WCDMA). The main feature of the proposed algorithms is that they use a nonlinear power update function which helps in improving the convergence speed of these algorithms. We study the convergence of the proposed algorithms and show that they always converge to a fixed point. We examine the algorithms in time varying multipath Rayleigh fading environments with a wide range of terminal mobilities. We demonstrate that the proposed algorithms converge faster than existing power control algorithms, including the 3GPP standard algorithms. We also demonstrate that the proposed algorithms result in gains in the required signal-to-noise ratio (SNR) between 1.0 dB to 1.5 dB for the SIR-based algorithm and about 1.0 dB for the BER-based algorithm, all relative to the 3GPP standard power control algorithms.


identifier: Liegl, Robert Mihael  (2005) A full potential solver for lifting flows on unstructured tetrahedral meshes.  Masters thesis, Concordia University.

abstract: The full potential model, though having known its major development through the 1970's into the 1980's, is currently used in a wide range of applications and it continues to be a valuable CFD tool proving certain advantages. The current approach, using an unstructured tetrahedral mesh and finite volume method, tries to take advantage of integrating a fast initializer (a linear potential Prandtl-Glauert corrected panel model) whose results are computationally very affordable while giving a good start for the actual full potential solver in terms of lift. As a result, the implementation of the Kutta condition will be of significantly lower computational cost, whereas it is reportedly known for damaging convergence. Also, the outer boundary of the computational domain can be set closer to the studied lifting body, as it will be aware of the lifting flow inside. Hence, a smaller computational domain can be used. Another full potential issue addressed here is the slow convergence of transonic solutions and a way of circumventing this problem has been proposed. Overall, the present full potential model implementation is intended as an accurate subsonic tool, with the capability to converge transonic solutions, while being at least one order of magnitude faster than an Euler solution on a similar mesh


identifier: Bowden, Robert Constantinos  (2006) Incipience of two-phase flow from a stratified gas-liquid region in multiple discharging branches : experimental investigation including PIV measurements.  Masters thesis, Concordia University.

abstract: The importance of predicting the incipience of two-phase flow from a stratified gas-liquid region in discharging branches has strong implications in industries where safe operation is of primary concern. This is particularly true in the nuclear reactor industry, where two-phase flow in the reactor cooling channels occurs due to a loss-of-coolant accident (LOCA). The incipience of two-phase flow can be characterized by the location of the gas-liquid interface relative to the discharging branch. If the gas-liquid interface is above the discharging branch, gas can entrain into the branch liquid flow by either vortex formation or vortex-free gas pull through. If the gas-liquid interface is below the discharging branch, liquid can entrain into the branch gas flow.  A semi-circular test section geometry, with three discharging branches, was used to simulate a typical CANDU header-feeder. The experimental investigation consisted of a two part study. In the first, the onset of liquid entrainment was investigated in multiple discharge scenarios. In the second, the liquid velocity flow field was investigated at the onset of gas entrainment in a single discharging bottom branch


identifier: Azizi, Seyyedmohsen  (2005) Distributed realization of differential-algebraic systems using decentralized sliding mode control.  Masters thesis, Concordia University.

abstract: Differential-algebraic Equation (DAE) systems present numerous difficulties in distributed simulation and control systems. The main problem is that most existing methods require an explicit state space model without algebraic constraints. One approach to address this problem is to reformulate the DAE system into an equivalent nonlinear control problem, in which the algebraic constraints are replaced by appropriate sliding manifolds. However, previous approaches based on this method are centralized leading to a great deal of computation and communication in distributed environments associated with inversion of the associated input decoupling matrix. In this work, this problem is addressed through application of decentralized sliding mode control. Relationships are developed for stability and performance in the presence of the neglected coupling terms. Inversion of the decoupling matrix is performed on a node basis. This allows the systematic division of the system into nodes that are more efficient for distributed computation. The new approach is applied to simulation of deformable surfaces in a real-time distributed computing environment.


identifier: Khajeh, Massoud  (2006) A new high performance LDPC code for DVB-S2.  Masters thesis, Concordia University.

abstract: In spite of their powerful error correcting capability, Low Density Parity Check codes (LDPC) have been ignored due to their high complexity. Around three decades after the invention of this code, researchers returned back their attention to it and tried to make some significant improvements in complexity. As the result, the LDPC codes were widely considered in the next generation error correcting codes in telecommunication systems. In 2005, the new standard for Digital Video Broadcasting (DVB-S2) used LDPC codes as its channel coding scheme. The features of the above mentioned code allow a transmission near the Shannon limit.  In this thesis, we first review the LDPC codes in general, and then we present the encoding and decoding scheme which is used in the DVB-S2 standard. We discuss regular and irregular LDPC codes and compare the advantages and disadvantages of these codes with each other.  In this thesis, we consider a higher block length for the LDPC code compared to DVB-S2 standard to improve the performance. We propose an efficient hybrid parity check matrix for this code. This parity check matrix has the same number of base addresses as the case for DVB-S2 which processes high block length with the same complexity. At the end, simulation results are provided to show the improvement in the performance


identifier: Huo, Wei  (2005) Survivable design and analysis of WDM mesh networks.  Masters thesis, Concordia University.

abstract: In this thesis, we are particularly interested in studying the impact of network element failure(s) on network survivability. Namely, we propose and analyze a series of models and schemes to protect and restore the affected services in the networks, thus achieve a better survivability in optical networks. In additions to an introduction of optical networks and a survey of the related work, this thesis first focuses on the problem of fast recovery in Chapter 3. By using the framework of Offset-Time restoration, a novel model based on time-driven scheduling is proposed. It substantially shortens the restoration time and can be applied in both single-link failure and dual-link failure scenarios. Next, capacity reprovisioning, as a simple and efficient mechanism to protect a network against multiple failures, is investigated and a new reprovisioning scheme is proposed in Chapter 4. Finally, the application of capacity reprovisioning in traffic grooming is considered. Two frameworks, i.e., lightpath level reprovisioning and connection level reprovisioning, are proposed in Chapter 5 to improve the survivability of optical networks with grooming capability.


identifier: Zheng, Qiang  (2005) Collocation methods for linear parabolic partial differential equations.  Masters thesis, Concordia University.

abstract: This thesis presents a new class of collocation methods for the approximate numerical solution of linear parabolic partial differential equations. In the time dimension, the partial derivative with respect to time is replaced by finite differences, to form the implicit Euler method. At each time step, a polynomial approximating the exact solution is calculated for each triangular finite element created by the Rivara algorithm. Polynomials of adjacent finite elements have matching values and matching normal derivatives at a set of discrete points, called "matching points". The method of nested dissection is used to eliminate all variables at the interior matching points of the domain. The maximum error of the solution is of the order of the time step size, which is O ( dt ), except when dt is sufficiently small. In that case, the maximum error can be very small, depending on the density of the space mesh.  An application based on OpenGL and Motif to visualize the solutions is also described in this thesis. Extensive numerical results, pictures of refined meshes, and 3 D representations of the solutions are given


identifier: Zhao, Zhijun  (2005) High speed multiple-pass cavity scanning optical delay line for real-time high resolution optical coherence tomography (OCT).  Masters thesis, Concordia University.

abstract: Firstly, the basic theory of the optical coherence tomography (OCT) is reviewed. Optical delay line is one of important parts in OCT. Several types of optical delay lines which were proposed and demonstrated are briefly described including their advantages and disadvantages.  In this work, a novel multiple-pass cavity optical delay line (MPC-ODL) is proposed and analyzed. The proposed delay line consists of four mirrors, one lens and one resonant scanner. In this proposed delay line, the path delay is obtained by scanning a tilting mirror and magnified by the multiple-pass optical cavity. Thus, for a small scanning angle, a large path delay can be obtained. This delay line is especially suitable for the OCT system that will generate the large dimension images at video rate with high resolution. However, due to multiple-pass cavity used in the proposed delay line, false interference signal may be created besides OCT signal. In order to reduce the false interference signal generation, some crucial parameters of the proposed delay line have to be carefully chosen. Principle of how to choose the optical component parameters is given.  The proposed delay line combined with OCT is verified by computer simulation. Characterization of the delay line is done by simulation and it is shown that the scanning repetition rate of 16 kHz, the total path delay of 3 mm, and the scan velocity of 71.3 m/s can be achieved. The proposed delay line can support OCT system with dynamic range over 110 dB.  The proposed delay line can support a further higher scanning repetition rate, such as 32kHz


identifier: Zarrabi, Houman  (2006) On the design and synthesis of differential clock distribution network.  Masters thesis, Concordia University.

abstract: This research work focuses mainly on the design and synthesis of Differential Clock Distribution Networks (DCDNs). The Clock Distribution Network (CDN) plays an important role in synchronous systems. The network is spread all over the chip to synchronize its sub-systems. The system performance is influenced by the performance of its clock network. As technology advances and the complexity increases, a drastic growth in the chip complexity in the near future is expected. Thus designing a reliable CDN is becoming a must, and therefore all the design efforts should be utilized to efficiently design clock distribution networks.  Of importance in chip design are low power and low noise concepts. Differential signaling scheme offers high noise immunity and since it is associated with signal amplitudes lower than the usual, it may contribute to reduce power consumption as well. Due to these potentials, the design and analysis of DCDN has been the focus of this research work.  First, a line equivalent delay model based on the decoupling method is proposed to be able to route DCDNs with minimum skew. This part refers to the routing and synthesis of DCDNS. Later, new configurations for differential buffers based on body-biased transistors are proposed, which show better performance for future low voltage applications.  Finally, a circuit and system design method that reduces the power consumption of DCDNs is proposed. This is accomplished in two steps: First circuit configurations that reduce the differential voltage swing giving less power consumption are introduced. Later, by reducing the supply voltage, a DCDN is designed which has the same power consumption as single-node CDNs, but has less skew variation in the presence of external noises such as power supply fluctuations.


identifier: Beisswanger, Steve  (2005) Nothing to declare! : Canada - US border management after NAFTA.  Masters thesis, Concordia University.

abstract: The traditional role of national boundaries is undergoing significant change as countries become increasingly interdependent. Efforts to reconcile exclusionary border security practices with the economic imperatives of globalisation and regional integration challenge policy-makers in the development of effective border control strategies. As a result, the policy discourse related to borders has evolved to the level of "high politics".  Using a process tracing methodology applied to Canada-US border management in the period following NAFTA and ending with the signature of the Security and Prosperity Partnership of North America , the main purpose of this essay is to determine the factors explaining the degree of integration of border management policies between both countries. The theoretical basis of the analysis relies on neofunctionalism, liberal intergovernmentalism, transgovernmentalism and realism. These theories are used to identify the key variables of interest and to serve as alternate explanations.  The findings suggest that the evolutionary process of Canada-US border policies does not precisely follow any theoretical framework. Rather, the factors influencing the level of integration of border management are driven by international security threats, international economic threats, and the interplay of powerful economic interest groups.  However, in response to an economic threat, the process predicted by liberal intergovernmentalism occurs, while in the particular case of a security-related threat, realism provides accurate insight. When both types of threat exist simultaneously, the threat considered dominant by the more powerful country drives the final policy outcome. Consequently, a continued focus by the US on "homeland security" favours a realist interpretation


identifier: Liu, Xuan  (2005) Causes and consequences of venture capitalist litigation.  Masters thesis, Concordia University.

abstract: Using a unique, hand-collected data set of lawsuits in which venture capitalists are named as co-defendants, we examine the relationship between venture capitalist litigation risk, on the one hand, and their reputation and monitoring intensity, on the other. We hypothesize that the likelihood of litigation will be decreasing with VC reputation and monitoring intensity. Further, we examine two measures of the merits of litigation, namely, lawsuit dismissal and the likelihood of a VC's continued financing of the firm after litigation. Finally, we examine the existence of reputational penalties for venture capitalists by studying the post-litigation fundraising by sued venture capitalists. We find a significant positive relationship between venture capitalist reputation and the likelihood of litigation, the finding consistent with deep pocket theory. At the same time, we also find some evidence that lawsuits are merited. In particular, we find that lawsuits against firms backed by more reputable venture capitalists are less likely to be dismissed and that sued venture-backed firms are less likely to continue receiving venture financing after the litigation. Also, venture capitalists named as co-defendants are less likely to maintain their rank in the fundraising hierarchy. Finally, we also find some evidence that more intensive monitoring by venture capitalists seems to decrease the likelihood of litigation


identifier: Khalil, Samer  (2005) Deferred compensation for outside directors in Canada : antecedents and consequences.  PhD thesis, Concordia University.

abstract: This thesis investigates the antecedents and consequences from adopting deferred compensation plans in corporate boardrooms. It focuses on the compensation paid to a class of directors, outside directors, that is mainly entrusted with monitoring managerial decision making, in addition to compensating, hiring, and firing top executives when circumstances warrant. Outside directors' compensation came under extreme scrutiny following the recent scandals and accounting irregularities in corporate America. Various stakeholders note that cash compensation does not lead to an effective monitoring of top management resulting in a significant trend toward equity based pay at the board level. Relying on agency and institutional theories, I develop a theoretical framework (chapter 4) to investigate the antecedents and consequences from adopting a deferred share unit plan for outside directors in Canada. From an agency perspective, I hypothesize that the adoption decision depends on the agency problem at the board level, and the ownership structure of the firm. I further hypothesize that the adoption results in a positive stock market reaction that varies with the degree to which the share unit plan resolves this problem. Within an institutional perspective, I propose that the adoption decision is associated with the institutional pressures a firm faces. I also hypothesize that adopting firms record positive abnormal returns with a magnitude that varies with the adopting firm category (early versus late adopter) and the theoretical perspective used to disclose the adoption decision.  Three essays provide evidence as follows. The first essay (chapter 5) includes a case study that investigates the antecedents and consequences in 11 firms operating in three different industries. The second essay (chapter 6) uses logit analysis to compare the agency and institutional characteristics of a sample of 123 adopting firms to that of a control sample matched based on firm size and industry. The third essay (chapter 7) relies on standard event study methodology and multiple regression analysis to examine the stock market reaction around the adoption announcement date.  Consistent with my propositions, results show that the likelihood of adoption is higher in firms that have a stronger moral hazard at the board level and in firms facing significant mimetic and normative pressures. Results also show that adopting firms record positive abnormal returns around the adoption announcement date that vary with the plans' attributes. These findings highlight the importance of integrating both economic and social perspectives when examining the antecedents and consequences from adopting organizational compensation practices


identifier: Grubisic, Katia  (2005) What if red ran out?  Masters thesis, Concordia University.

title: What if red ran out?

abstract: What if red ran out? is concerned with meaning formation in language and through association; with the possible role of poetry vis à vis political ideology; and with love, which, like poetry, is a reckless clamour in what Camus calls the "unreasonable silence of the world" ( The Myth of Sisyphus ). This collection of poems indirectly addresses, or rather inhabits, formal restrictions and liberties, as well as those of the elegiac mode. Eros and Thanatos are inevitably present, but they are here within a contemporary and occasionally humorous cultural context.  What if red ran out? questions absence, implying that it is not an absolute state but that the evocation of absence alters memory; it expands and iconises it into a collage. Lyric-narrative poetry particularly relies on associative metaphor, attempting to circumvent the inherent circularity of language and disrupting the reliable linearity of meaning. Wittgenstein fusses that "language gets its way of meaning from what it means from the world" ( Philosophical Occasions ); association complicates that relationship, resulting in elliptical syntax, manipulating space and time into other ways of meaning the world, and issuing invitations to apparently incompatible themes or images.  Each of the three sections of What if red ran out? summons a predominant idea: language, nature and urban nature, and love. On the whole, however, the collection is preoccupied with interrogation, with undermining the fixity and finality of home---  what if this weren't the end but only a footnote to some other abstraction?


identifier: Sanei, Abdollah  (2006) Antenna selection for space-time trellis codes over Rayleigh fading channels.  PhD thesis, Concordia University.

abstract: Employing multiple antennas in multiple-input multiple-output (MIMO) communication systems has many advantages over systems employing single-transmit and single-receive antennas. The most important of these advantages is the tremendous increase in channel capacity. However, employing multiple antennas results in a significant increase in the system complexity, and hence cost, since each employed antenna requires a separate radio frequency (RF) chain. Antenna selection has been introduced recently as a means to alleviate this complexity. The main idea behind antenna selection is to select at the transmitter and/or receiver a good subset of the available antennas. By this, the number of required RF chains reduces to as few as the number of selected antennas, thereby reducing the system complexity and its cost. Antenna selection has been considered for both space-time trellis codes (STTCs) and orthogonal space-time block codes (STTCs) with favorable results. However, all works in this area considered a particular channel model, namely, quasi-static Rayleigh fading.  In this thesis, we consider receive antenna selection for STTCs for generalized Rayleigh fading channels. Specifically, we derive explicit upper and lower bounds on the performance of STTCs with antenna selection over fast and block Rayleigh fading channels. The latter channel model is a good model for most wireless communication channels because it encompasses a wide range of mobility and data rates. For both channel models, we show that the diversity order deteriorates with antenna selection and it becomes proportional to the number of selected antennas and not the number of available antennas. However, having more antennas available, while keeping the number of selected antennas fixed, increases the coding gain, which naturally comes as a result of an increased average SNR due to antenna selection. This is unlike the case for quasi-static fading where the diversity order is maintained with antenna selection provided that the underlying STTC is full rank.  As for STBCs, it appears that the channel model has no impact on the resulting diversity order with antenna selection. It has been shown that the diversity order of STBCs with antenna selection is the same as that of the full complexity system. In light of the results of this thesis and existing results in this area, the conclusion is that, when antenna selection is considered, it is recommended to use STBCs when the channel is fast fading or block fading with high mobility (or low data rate). On the other hand, it is recommended to use STTCs with antenna selection when the channel is modeled by quasi-static fading or block fading with low mobility (or high data rate)


identifier: Shao, Bin  (2006) On K-broadcasting in graphs.  PhD thesis, Concordia University.

title: On K-broadcasting in graphs

abstract: Broadcasting is a fundamental information dissemination problem, wherein a message is sent from one vertex, the originator, to all other vertices in a graph. In k -broadcasting, an informed vertex can sends the message to at most k uninformed neighbors in each time unit. This thesis presents several algorithms to perform efficient k -broadcasting. The algorithm KBT generates the optimal k -broadcast scheme in trees, while the algorithm KBC finds the k -broadcast center of a given tree. This thesis presents an efficient heuristic for k -broadcasting. The heuristic has a low time complexity and generates fast k -broadcast schemes in many network topologies.  A k -broadcast graph G is a graph on n vertices where the k -broadcast time of G is [Special characters omitted.] log k +1 n [Special characters omitted.] . B k (n) stands for the minimum possible number of edges in a k -broadcast graph on n vertices. A k -broadcast graph on n vertices with B k (n) edges is a minimum k -broadcast graph, which is denoted by k -mbg. This thesis presents several new k -mbg's and an improved lower bound on B k (n)


identifier: Suryavanshi, Bhushan Shankar  (2006) A new class of techniques for Web personaliation.  Masters thesis, Concordia University.

abstract: Web personalization aims to provide content and services tailor-made to the needs of individual users usually from the knowledge gained through their (previous) interactions with the site. Typically, an access behavior model of users is learnt from the usage of the website which is then used to provide personalized recommendations to the current user(s). Clearly the performance of a recommender system will depend on the underlying model. Two fundamental challenges in personalization are effectiveness (accuracy) and efficiency (scalability) of recommender algorithms. In this thesis, we present a new class of techniques for efficient and effective web personalization. All the techniques are based on a new algorithm for fast mining of web usage data, called Relational Fuzzy Subtractive Clustering (RFSC). RFSC is scalable to large datasets, does not require user biased control parameters, is relatively more immune to noise which is inherent in usage data, and can capture overlapping user interest areas. Making innovative use of fuzzy grade of memberships and fuzzy prototypes of the access behavior model learnt through RFSC, we also propose improvements over cluster based and association rule based recommender models. Since browsing behavior of users on the web is not static but changes dynamically over time, we further propose a new maintenance scheme, which extends RFSC, to efficiently add new web usage data to an existing model in order to achieve adaptability over non-stationary volatile web environment. We validate our claims of effectiveness and efficiency through extensive experimentation on synthetic data as well as large datasets of web logs


identifier: Gao, Tiezhu  (2006) An empirical comparison of alternative stochastic volatility option pricing models : Canadian evidence.  Masters thesis, Concordia University.

abstract: In this thesis, I empirically compare the pricing performance of three classes of stochastic volatility option pricing models and the traditional Black-Scholes (1973) model in the pricing of S&P Canada 60 Index Options. The stochastic volatility models that I study are as follows: (1) the ad hoc Black and Scholes (1973) procedure that fits the implied volatility surface, (2) Madan et al.'s (1998) variance gamma model, and (3) Heston's (1993) continuous-time stochastic volatility model. I find that Heston's continuous-time stochastic volatility model outperforms the other models in terms of in-sample pricing and out-of-sample pricing. Second, the addition of the stochastic volatility term to the stochastic volatility model and variance gamma model does not resolve the "volatility smiles" effects, but it reduces the effects. Third, the Black-Scholes model performs adequately in pricing options, with the advantage of simplicity, although it suffers from the shortcoming of the "volatility smiles" effect. Finally, although it includes more parameters, the ad hoc Black and Scholes model does not perform as well as expected.


identifier: Lee, Shih-Ying  (2006) Pricing of weather derivatives.  Masters thesis, Concordia University.

title: Pricing of weather derivatives

abstract: Values of weather derivatives depend on weather outcomes, such as temperature or precipitation. Academics have differed on how to value this type of financial instrument, since weather is not tradeable and the No-Arbitrage Pricing Theory cannot be applied. Cao and Wei (2004) propose a valuation model and I test its predicting accuracy by comparing simulated futures prices to market prices, for cumulative Heating/Cooling Degree Day futures for New York City for contracts offered by the Chicago Mercantile Exchange.  The simulation of weather futures prices requires assumptions of values for the risk aversion parameter. Following Cao and Wei, the values -2, -10 and -40 are used. The simulation requires values for the speed of mean reversion of aggregate dividends. Following Cao and Wei, the values of 0.8, 0.9 and 0.99 are used. Due to the lack of a sufficiently long time series data to determine the daily correlation between temperature and aggregate dividends, Cao and Wei assume that the aggregate dividends depend on either the contemporaneous temperature or the 30 lagged temperatures. There are consequently 18 simulation settings.  Results indicate that Cao and Wei's (2004) model is useful in predicting weather derivative prices, especially when the risk aversion parameter is -10. Forecast accuracy is very sensitive to the risk aversion parameter, followed by the number of temperature lags that aggregate dividends depend on. The speed of mean reversion of aggregate dividends is not found to be a crucial parameter


identifier: Anglin, Emily  (2006) The Byron notebook and other stories.  Masters thesis, Concordia University.

title: The Byron notebook and other stories

abstract: The eleven stories of "The Byron Notebook and Other Stories" are told from the perspective of distinct but similar young female narrators as they wander surreal realms. The stories are generated primarily by voice, as opposed to plot or character. The title story concerns the diminution of a narrator consumed by an imaginary love affair with Lord Byron. The subtitle, "A Private Argument," refers to her struggle not with Byron, but with herself, as she negotiates the gap between interior and exterior reality. The narrators interpret the world from the remove of an almost isolated interiority, in a playful or sad exploration of imagination and subjectivity. The imaginative is often encountered in collage with the real.  Almost all the stories use first person perspective, a choice that is topical as well as formal. First person narration's double potential both to reveal and to conceal information is exploited, in enactments of alienation and epistemological skepticism. These first person narrators share information about their lives with the reader, but this knowledge may not be reliable; they are structurally and emotionally separated from the other characters and from the reader at the same time that reader-narrator intimacy is courted. Related to this limitation of perspective, much of the narration grapples explicitly with what can be known, or, more precisely, what cannot be: in "Catherine Irwin-Gibson" and "The Move," this epistemological concern borders on the genre of mystery. This concern relates to the way communication and love can be frustrated by language's limitations, a theme running throughout the project


identifier: Briscoe, Angela  (2005) Representations of Mohawk & native histories in high school textbooks : a comparative analysis of English-language & Mohawk textbooks in Quebec.  Masters thesis, Concordia University.

abstract: The study is a qualitative, explorative analysis of historical discourses used in education, borrowing theoretical and methodological principles from critical discourse analysis, conflict theory, critical pedagogy, and multicultural education. From a concern with socio-political relations and education, the overall research objective is to identify and articulate differences between Native and non-Native approaches to secondary level education about the history of Native peoples in Quebec and Canada. In addition to the frameworks of critical discourse analysis and conflict theory, this research is also grounded in the theoretical frameworks advanced by Native scholars and postmodern theorists concerned with methodological and epistemological issues affecting Native historiography and social science research. The analysis compares the Mohawk historical discourses in the Kahnawake Survival School's Seven Generations text, with those in Diverse Pasts , the English-language text approved for Secondary IV history education in the province of Quebec. The analysis points to the importance of discourses on sovereignty, nationhood and territory within Seven Generations , as well as explanations of the basis and rationale for the claims of the Mohawk and other Native nations in North America. The discourses on Mohawk, Iroquois and Native peoples---particularly with respect to sovereignty, nationhood and territory---are analyzed in each text to compare how they are represented and the implications of those representations for the overall education of both Mohawk and non-Native youth in Quebec.


identifier: Hess, Marina  (2006) Hogweed.  Masters thesis, Concordia University.

title: Hogweed

abstract: Hogweed consists of the first seven chapters of a novel in progress. Set in Toronto's Park-dale neighbourhood, the story follows the quotidian adventures of eleven year-old Clare Lowy and her best friend, Florian Weatherup. Clare and Florian enjoy a middle-class existence that is relatively carefree, though not without the prick of family tensions and the harassment of the class bully, Kevin R. They spend their after-school hours playing games in the alley behind their street and spying on the Pamphleteer, the outspoken activist next door. As Clare's twelfth birthday approaches, her greatest concern is the loss of imagination that she believes characterizes the passage into adulthood. But when a fantastical growth of plants and trees threatens Toronto's very foundations, Clare must also contend with the environmental, political, and personal repercussions of the disaster. As the domineering Mayor Lash limits civil freedoms in response to the uncontrollable growth, Clare finds the motivation in her relationships and her own imaginative powers to help create a more sustainable city. The focus of these chapters is the development of character and place, but the larger work will explore notions of community, responsibility, and agency.


identifier: Oancea, Ioan Mihai  (2006) Stochastic dominance option pricing : an alternative paradigm.  PhD thesis, Concordia University.

abstract: This thesis examines the pricing of options under several models with market incompleteness. The theoretical approach relies on the absence of stochastically dominating portfolios containing the underlying asset, the option and the riskless bond. The stochastic dominance approach provides two bounds on the equilibrium pricing of options by risk-averse investors. The two bounds are discounted conditional expectations of the option payoff under two probability measures.  This research generalizes the previous stochastic dominance pricing results in discrete time to non-i.i.d. underlying asset return processes and to contingent claims with non-convex payoffs. The new results are then used to examine the stochastic dominance pricing bounds for several discrete and continuous time processes of the underlying asset.  The continuous time bounds are obtained by constructing a sequence of discrete approximations that converge weakly to a given continuous time process. The weak convergence property provides the convergence of the two option bounds, which are discounted expectations of the option payoff. In the case of a univariate diffusion process, the two option bounds converge to a common limit. The two bounds converge to distinct limits when the underlying asset follows a jump-diffusion mixture.  The non-iid stochastic dominance pricing results are then applied to the pricing of options for a LARCH specification of the underlying asset returns. The two stochastic dominance bounds are obtained both for conditional normal and non-normal returns. The impact of the model estimation error is examined by generating a return sample from a known model and computing the stochastic dominance bounds implied by several estimated models.


identifier: James, Erica  (2006) The shapes of things.  Masters thesis, Concordia University.

title: The shapes of things

abstract: Looking at the ways that hope can be both self-sustaining and self-defeating, the stories in this collection focus on characters divided within relationships or situations over which they have no control. In each story, the character is challenged to choose between honouring her self (her perceptions, needs, desires) and honouring her need for safety and connection with others. That these are always antithetical positions forms the basis of tension and conflict in this work.


identifier: MacPhee, Carole  (2006) The effects of transformational leadership on career management.  Masters thesis, Concordia University.

abstract: Transformational leaders are believed to be able to take into account the needs of the organization and the individuals who are part of them. They are said to be able to communicate a vision of the organization and take into account the developmental and self-actualization needs of their followers. The processes that are required for the simultaneous development of the organization and individuals has an impact on career management, yet organizations appear to be shifting the responsibility onto the individuals' shoulders, claiming that they can no longer sustain these initiatives. This study attempts to determine whether transformational leaders impact the career management strategies that their followers adopt and whether these strategies lead to intentions to leave the organization. Using a framework proposed by Guthrie, Coate, and Schwoerer (1998) and transformational leadership theory, a web-based survey was conducted using a snowball sampling technique. One hundred and seventeen respondents rated their supervisor's leadership style, the career management strategies that they use, their aspirations, opportunities for advancement within their organization, and their intentions to leave. Findings suggest that transformational leaders influence career management strategies, yet these career management strategies do not impact intentions to leave. Implications and future research directions are discussed.


identifier: Goldbach, John  (2006) Smoking and six other stories.  Masters thesis, Concordia University.

title: Smoking and six other stories

abstract: Smoking and Six Other Stories comprises short fiction of various sorts: short shorts ("Odin Létourneau and Debbie Siskind's Second Date" and "Conversation at Four a.m."), longer stories ("Easter Weekend" and "The Sit"), a television cooking show transcript ("Emperor 'Q"), an interior monologue ("How Much Do They Know?"), and a story about a man reading a stop-smoking self-help book, while fighting with his partner ("Smoking"). These stories contain characters struggling with questions of faith, diet, sex, addiction, mortality, while often on the verge of---or in the midst of---cracking up. In "Emperor 'Q," for example, a cooking show host breaks down after a guest on his show refuses to eat barbequed pork spareribs. In "How Much Do They Know?," too, a young man starts to unravel, while drinking with friends at Christmastime, believing that they know secrets about him. Desperation, discomfort, loneliness, jealousy, and shame are some of the other themes explored in this collection. The stories are set in rural, urban, and tropical locales. Although the stories in this collection experiment with form, they return again and again to similar themes.


identifier: Pasian, Alexandra  (2006) Every day.  Masters thesis, Concordia University.

title: Every day

abstract: Every Day is a collection of lyric poems that grapples with the quotidian nature of language, motherhood, life. For the speaker in this collection, the quotidian does not mean mundane or ordinary. For this speaker, it is the daily struggle that is her greatest work. Every day she tries to make language her own. Every day she balances and weighs the images she creates, asking herself "Is this the stuff of poetry?" Every day she endeavours to engage with a literary tradition that includes the poetry of Paul Celan, Anne Sexton, William Carlos Williams, without becoming overwhelmed by the weight of their work. Every day she tries to embrace her world.


identifier: Hunting, Barbara  (2005) The social challenge of laptops in the learning environment.  Masters thesis, Concordia University.

abstract: This case study is an exploration of the social challenges surrounding laptops in the learning environment. Student engagement, the use of the laptop and professional development are the major components of this study. The ethnographic design methods of interviewing and attendance at a laptop conference all informed this case study.  The Eastern Townships School Board began implementing a laptop project in the Fall of 2003, it is the largest laptop integration in Canada and will be in full operation by the Fall of 2005 when grades 3--11 will be using Apple iBook laptops. The new laptop program is known as the Dennis McCullough Enhanced Learning Strategy (Enhanced Learning Strategy). The sample population of this research consisted of grade 5, grade 11 students, and teachers in the elementary and high schools with varying teaching experiences.  The use of laptops in the classroom is a new field of research, with very little research data available from a Canadian perspective. In addition to adding to this body of work, the thesis discusses the challenge the teachers were facing when blending instructionist (passive learning) and constructionist (active learning) teaching practices


identifier: Truskovsky, Alexander  (2005) Protocol and architecture for the secure delivery of high-value digital content.  Masters thesis, Concordia University.

abstract: Digital Rights Management (DRM) is used to control access to digitized intellectual property and sometimes to control how that property is used. In the media context, this often involves a player together with a (possibly incorporated) "set-top box". Historically, DRM schemes have been too fragile to protect high-value digital content. In this thesis, we remedy that problem. Through registration, a user's identity is bound to a tamper-proof set-top box storing shared secrets and running a hard-wired program. Encrypted content of interest is obtained by arbitrary means. The user activates the box to engage in a protocol with a remote server operated on behalf of the content owner. The server securely delivers the capability to display this content precisely once and records this fact. Keying information is hidden from the user in such a way that key distribution and authentication are radically simplified, resulting in an extremely robust security architecture.


identifier: Farnesi, Claudia  (2006) A mathematical contribution to dance notation : analysing Labanotation with Euclidean geometry, computing matrices for dance notation, and choreographing with crystallographic groups.  Masters thesis, Concordia University.

abstract: Dances consist of bodies moving through space and time, a concept established by the great choreographer Merce Cunningham. Dance notation is the recording of these movements on paper. This multidisciplinary research aims at bridging the gap between the sciences and the arts. We mathematically investigate an existing system of dance notation, and use mathematical tools to generate new ones.  The arts of dance and dance notation contain numerous mathematical concepts, mostly relating to Euclidean geometry. The first objective of this research is to identify these mathematical structures present in Labanotation. The second is to characterize dances using algebra. In one section, positions of partners in contradancing are defined by matrices and calculated through matrix multiplication using Homogeneous Coordinates. In another section, body movements are encoded into 4 x 6 matrices; the rows represent the four-dimensional coordinate space, and the columns the different body parts. After raising into 5 x 7 matrices using the concept of homogeneous coordinates, summing a sequence of matrices provides a choreography matrix representing the final position of a dancer as dictated by the sequence. The third objective is to choreograph using crystallographic groups (or wallpaper groups). Geometric shapes are designed to represent the basic steps of certain ballroom dances, and each group is applied to each symbol using Artlandia's SymmetryWorks in Adobe Illustrator. A brief discussion explains why only five groups are relevant, and the ensuing results illustrate that these groups applied to the dance symbols generate mostly feasible choreographic routines.


identifier: Milovan, Denise L  (2005) Neuropsychological functioning of migraine patients with- and without aura, and cerebral hemisphere laterality.  PhD thesis, Concordia University.

abstract: Differences in cognition between patients with migraines and healthy control subjects have been documented by several researchers, principally in the areas of attention, memory, and motor function. Patients with aura (MA) are more often reported to have interference with normal cognitive functioning and are thought to have a more severe neurological condition than do patients without aura (MO). We compared the cognitive profiles of 29 right-handed patients, recruited at the Montreal Neurological Hospital, and diagnosed with hemicranial MA and MO to that of 10 healthy control subjects (NC). Diagnosis was made according to the International Headache Society guidelines by a neurologist. From a personality perspective, higher levels of self-consciousness were documented in MA and M Left than in NC and MO (F = 2.67, p < .05). NC's response styles were more original while patients preferred more conservative ones (F = 4.65, p < .01). Examination of cognitive data from an extensive neuropsychological battery was performed. MA performed worse than NC and MO on a General Cognitive Index (F = 2.72, p< .05), Full Scale (F = 6.10, p < .001) and Verbal (F = 5.48, p < .01) IQ. Verbal IQ was also lower for MO than for NC (F = 10.69, p < .001). Compared to NC and left-hemisphere migraines (M Left ), right-hemisphere migraines (M Right ) demonstrated reduced attention (F = 3.96, p < .05), poorer constructional abilities (F = 4.38, p < .05), and lower visuo-spatial memory (F = 3.92, p < .05). M Right performed less well on executive functioning tasks (F = 2.65, p = .05). M Left was associated with lower Full Scale IQ (F = 8.34, p < .001) and Verbal IQ (F = 7.89, p < .001). MA (Right Hand: F = 3.90, p < .05; Left Hand: F = 4.10, p < .05) had poorer motor skills than NC. M Right (Left Hand: F = 3.61, p < .05) showed additional motor slowness. Thus, presence of aura and hemisphere lateralization of migraine headache can affect the cognitive and personality profiles of patients with migraine


identifier: Judith., Levy-Bencheton  (2006) A study of age group differences in multiple measures of executive functioning.  PhD thesis, Concordia University.

abstract: Recent empirical findings have shown difficulties in assessing age group differences in executive processes and their role in executive functioning. More specifically, inhibition is an executive control process whose role in executive functioning has been poorly defined. The purpose of the current study was to extend the findings of sequential action research by examining the processes that govern sequential behaviour (i.e., self-inhibition), and to relate these findings to other measures of executive functioning (Stroop task, Visual Span, Random Generation Task). We also investigated intraindividual variability and examined the correlations between intraindividual variability and level of performance in executive measures.  As hypothesized, individuals showed evidence of self-inhibition on the Sequential Action (SA) paradigm. Results on the other executive measures revealed that older adults performed significantly worse than younger adults, with modest intercorrelations between executive measures and the SA paradigm. This suggests that executive functioning is a multifaceted construct. Furthermore, these correlations were stronger for younger adults suggesting that executive functioning may be more differentiated in older adults. Older adults exhibited greater intraindividual variability on the SA paradigm. Intraindividual variability was correlated across only some measures. The pattern of correlations underscores the need to consider both intraindividual variability and level of performance when examining age group differences in executive functioning.


identifier: Murray, Kristine  (2005) Creating an identity : choosing self-employment in Montreal.  Masters thesis, Concordia University.

abstract: This thesis explores the reason why four Montreal based Internet web designers, who form part of what is considered "Generation X," would reject the notion of working for a corporation. Two of the designers studied owned the company in question, while the other two were employees.  It is based on fieldwork conducted over a three-month period, between February 2002 and May 2002. This thesis is based on information gathered through one on-line questionnaire, 16 formal interviews, and observations of day to day activities as well as 11 production meetings.  It is framed on the theoretical perspective of self-identity proposed by Anthony Giddens. In chapter one, a history of the anthropology of work is presented, pointing to a gap in studies on the Canadian self-employed workers. In chapter two, multidisciplinary literature on the corporate worker, situating the reader on the Taylorist working conditions is discussed. In chapter three I answer the question "Why become self-employed?" using academic literature on self-employment in Canada, as well as explain how the two business owners studied also answered and acted upon this question. In chapter four I again explore academic literature focusing on creativity. The four web designers studied considered creativity important, and I also explain why. In the final chapter I foresee the future of the Internet company studied, based on my fieldwork and theoretical perspective used in this thesis


identifier: Guang, Lei  (2006) Mac layer misbehaviors in mobile ad hoc networks.  Masters thesis, Concordia University.

abstract: MAC misbehavior in mobile ad hoc networks (MANET) is relatively new and unexplored in the literature. Different from traditional wireline networks, the unique nature of MANETs has opened new challenges in the network design. An Mobile Ad Hoc Network (MANET) is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. In such an environment, one mobile host may need the aid of other hosts to communicate with the destination. However, failed data transmission due to selfish or malicious or hybrid node misbehavior and faulty nodes can severely degrade the overall network performance. Hence, a well-behaved node needs to adaptively change its cooperation level to cope with node misbehavior. In this thesis, we first briefly overview the existing security issues in ad hoc network routing and MAC layers. We explain security methods such as economic incentives, secure routing by cryptography and detection system against greedy behavior alleviate some of the problems, but not all.


identifier: Ta, Truong  (2005) Web services for the dissemination of ambient information to I-centric applications.  Masters thesis, Concordia University.

abstract: Applications offered to end-users as value added services, or more simply services, are crucial to the success of future generations mobile communication systems. One important capability that will enable novel services is ambient awareness. The awareness of ambient information is usually acquired by a network of sensors and is related to end-users' context in terms of situation and environment. There exist several frameworks for the dissemination of sensor data to end-user applications. They range from low-level APIs to databases and include Web services. This thesis advocates Web services for the dissemination of ambient information to I-centric applications. It shows the shortcomings of the current dissemination frameworks and demonstrates the promises of Web services as a framework. High level of abstraction offered to application developers and ease of integration are among the key motivating factors. A set of Web services for bridging these applications and sensor networks are defined and implemented. They provide ambient information such as location, velocity, environmental data, physical presence and proximity. A generic functional architecture of the framework and a model for ambient information provide sensor interoperability and are implemented as part of the thesis. To ultimately show the feasibility of the Web service based framework, performance measurements are conducted with respect to network load and response time. The analysis shows that response time is increased while network load may decrease or increase depending on the type of ambient information requested. Ultimately, it is a small price to pay for benefiting from sensor interoperability and ease of application development.


identifier: Leng, Hongjie  (2005) Design and application of a novel driver condition monitoring device - smart wheel.  Masters thesis, Concordia University.

abstract: People never stop pursuing safer and more comfortable driving. An important approach to that goal includes acquiring information about the driver's condition. The vehicle can then respond. However, most previous technologies are not suitable for a driver to use during daily driving. The present research investigates the technologies and sensors that can be utilized to assess a driver's condition, and then employs a polyvinylidene fluoride (PVDF) film sensor, a semiconductor temperature sensor and a piezo-resistive sensor to develop a smart wheel. The smart wheel can conveniently and reliably measure the driver's pulse wave, breathing wave, skin temperature and gripping force and does not influence the driver's normal behavior and condition. The driver's condition can be evaluated by using the output of the smart wheel. To verify the wheel's design and how effective it is at measuring the driver's pulse rate, the experimentation behind the present research paper involved thirty subjects to perform 120 experiments under four factorial combinations of gripping force and vibration.


identifier: Hamidian, Behrooz  (2006) Convergence study of iterative multi-user detection for turbo-coded CDMA.  Masters thesis, Concordia University.

abstract: In this thesis, we mainly focus on the convergence of IMUD turbo-coded systems. The main interest is the possibility that the system converges to the near-single-user performance and the second important concern is the speed of the successful convergence.  The convergence thresholds of IMUD turbo-coded CDMA systems have been studied in [11] using conventional BER curves. However, BER curves do not have the ability to sufficiently describe the convergence behavior of iterative structures. Therefore in this thesis, we use the Variance Exchange Graph (VEG) as the methodology of analysis. VEG is a method that uses variance error of soft symbols as a measure to characterize the components in the IMUD structure. VEGs surpass BER curves for the purpose of convergence study by providing the possibility to analyze the system convergence from different angels. They also present a more detailed description of the iterative process comparing with BER curves.  In this thesis, convergence thresholds and convergence speed of the proposed system are analyzed.


identifier: Antonova, Slavka  (2005) Power dynamics in global communication governance : internet regulation and the case of ICANN (1998-2002).  PhD thesis, Concordia University.

abstract: The Internet Corporation for Assigned Names and Numbers (ICANN) was created by the U.S. government in October 1998 as an institutional innovation---a private non-profit corporation to govern global resources without government involvement, in the public interest. Through the creation of ICANN, the neoliberal governmentality of market self-regulation and "stakeholder collaboration by consensus" was introduced to the field of global communication. This is considered in the present thesis as a particularly important step towards the establishment of a new governance paradigm for the digital age.  ICANN is approached in the thesis as a network of interdependencies and a power-production network, while power is constituted as the focal variable of this investigation. In the first four years of ICANN's activity, the most significant policies on regulating a common pool resource---the Internet domain-name space---were put in place and the winners and losers of these policies emerged from the constant power struggle.  As a particular contribution to the conceptualization of the contemporary paradigmatic change in governance, this approach brings together theoretical constructs from Political Philosophy (Foucault's postmodern ontology of power), Political Science and International Relations (the globalization perspective), and Organization Studies (the organizational approach to power in multi-stakeholder formations).  By recreating the chronological process of ICANN's first four years and focusing on its power dynamics, it was concluded that the power holders within ICANN (the technical cadre as managers) compromised the very idea of self-governance as they allowed the process to divert from the innovative stakeholder-consensus-building formula and slip back to traditional top-down policymaking. The world's governments and international organizations were, virtually, invited to take over the policy-legitimizing role that an at-large membership and the consensus-reaching process had been intended to play.  This thesis takes on further significance---in light of the unfolding global debate on Internet governance that has emerged in the wake of the United Nations World Summit on the Information Society (WSIS). The thesis thus contributes to the conceptualization of 21 st century governmentality as "shared power" among diverse stakeholders in global public-policy (GPP) networks by proposing an original interpretation of these entities as networks of interdependencies, where transformative social energy is generated and accumulated. This, itself, constitutes a contribution to our understanding of social power and to the emerging field of global governance.


identifier: El-Khoury, Mario  (2006) The efficiency of the oil futures market and the hedging effectiveness of symmetric vs. asymmetric GARCH models during periods of extreme conditional volatility.  Masters thesis, Concordia University.

abstract: This paper investigates the efficiency of the NYMEX Division light sweet crude oil futures contract market during recent periods of extreme conditional volatility. Crude oil futures contract prices are found to be cointegrated with spot prices and unbiased predictors of future spot prices, including over the period prior the onset of the Iraqi war and until the formation of the new Iraqi government on April 2005. Both futures and spot prices exhibit asymmetric volatility characteristics. Hedging performance is improved when asymmetries are accounted for.


identifier: Carillo, Kévin D  (2006) Creating high-quality products in open content virtual communities : a functional group perspective based on the time, interaction, and performance theory.  Masters thesis, Concordia University.

abstract: This study examines the group input and group process factors that lead to high-quality products in open content communities. A theoretical model was developed, based on the Input-Process-Output approach of group research in social psychology and on the Time, Interaction, and Performance Theory proposed by McGrath (1991). The model tests the relationship between input variables: organizational (Organizational Support), group-related (Group Size, Shared Experience and Group Heterogeneity) and individual (Member Competency and Member Activeness); process variables: group production, group well-being and member support: and an output variable: group effectiveness. A quantitative study of the detailed activity logs of Wikipedia, an open content encyclopedia, was designed using a sample of 10,000 group tasks.  A partial least squared (PLS) statistical approach was used to test the theoretical model. This study shows the synergistic and overwhelming role played by group size and shared experience on both group process variables and group effectiveness. This project provides also evidence about (1) the positive effect of group heterogeneity on group production; (2) the positive effect of organizational support and member activeness on group well-being; (3) the positive effect of member activeness on member support; and finally, (4) the positive effect of organizational support and member activeness on group effectiveness.


identifier: Murad Musa., Al-Shibli  (2005) Modeling and control of a free-flying space robot interacting with a target satellite.  PhD thesis, Concordia University.

abstract: In the thesis a unified control-oriented modeling approach is proposed to deal with the kinematics, linear and angular momentum, contact constraints and dynamics of a free-flying space robot interacting with a target satellite. This developed approach combines the dynamics of both systems in one structure along with holonomic and nonholonomic constraints in a single framework. Furthermore, this modeling allows considering the generalized contact forces between the space robot end-effecter and the target satellite as internal forces rather than external forces. As a result of this approach, linear and angular momentum will form holonomic and nonholonomic constraints, respectively. Meanwhile, restricting the motion of the space robot end-effector on the surface of the target satellite will impose geometric constraints. The proposed momentum of the combined system under consideration is a generalization of the momentum model of a free-flying space robot.  A physical interpretation of holonomy/nonholonomic constraints is analyzed based on d'Almberts-Lagrange dynamics and reveals geometric conditions that generate such a behavior. Moreover, a nonholonomy criterion is proposed to verify the integrability of momentum constraints by using a linear transformation via orthogonal projection techniques and singular value decomposition. This criterion can be used to verify the holonomy of a free-flying space robot with or without interaction with a target satellite and to check whether these constraints or their initial conditions are violated.  Based on this unified model, three reduced models are developed. The first reduced dynamics can be considered as a generalization of a free-flying robot without contact with a target satellite. In this reduced model it is found that the Jacobian and inertia matrices can be considered as an extension of those of a free-flying space robot. Since control of the base attitude rather than its translation is preferred in certain cases, a second reduced model is obtained by eliminating the base linear motion dynamics. For the purpose of the controller development, a third reduced-order dynamical model is then obtained by finding a common solution of all constraints using the concept of orthogonal projection matrices.


identifier: Zhang, Cheng  (2006) Spatio-temporal visualization and analysis for infrastructure management systems.  Masters thesis, Concordia University.

abstract: There is much information needed to manage the activities that occur throughout the lifecycle of an infrastructure system, such as a bridge, including design, construction, inspection and maintenance activities. Conventional infrastructure management systems (IMSs) provide only limited support for representing, visualizing and analyzing the spatio-temporal relationships in this information, which could result in spatial constraints being ignored. Therefore, the spatio-temporal data should be integrated in the IMSs and be visualized and analyzed to improve the efficiency and usability of these systems.  The objective of this research is to propose new approaches and methods for visualizing and analyzing spatio-temporal information during the lifecycle of infrastructure systems. By integrating 4D modeling with several information technologies, the new approaches facilitate spatio-temporal representation in a more accurate and easily understood way


identifier: Chan, Angela  (2005) Unblocking performance blocks : an interdisciplinary approach towards an exploratory study on musical performance blocks in "late arriving" pianists.  PhD thesis, Concordia University.

abstract: This thesis critically examines performance blocks among late arriving pianists. In particular, this thesis tests the potential of the Bio-aesthetic Approach to Musical Performance (BAMP) developed by Phil Cohen, in reducing established performance blocks through an exploratory methodology.  BAMP is evaluated in terms of the performer's somatic and cognitive experiences in unblocking via the organization principle of sketch and test mode of verification. Specifically, this thesis considers the effectiveness of BAMP concepts in enhancing coherence in music performance---these include aesthetic order; cross-modal synchronization; expressive timing; homeokinesis; vocabulary; metaphoric imperative; paradoxical causality and delegated external I embodied conductor. Through a three-part research study---(1) case studies: one reflective, two participatory, and two observational; (2) a two-year case study with a late arriving pianist; and (3) interview studies with three career track concert pianists---a select number of tangible contributions to the formation of blocks have been examined. Effective unblocking processes have also been explored with late arriving pianists using concepts from BAMP. This study demonstrates that BAMP provides a useful perspective towards the study of musical performance blocks in late arriving pianists.  The subtext of the research is to encourage researchers, performance analysts, and pedagogues to re-examine existing assumptions about appropriate methodology, pedagogical practices and approaches to musical performance


identifier: Furlong, Matthew  (2006) Wittgenstein and Derrida : ethics of the name.  Masters thesis, Concordia University.

abstract: Similar tendencies in the work of philosophers Ludwig Wittgenstein and Jacques Derrida appear in their thoughts on language and lead to similarities in their respective ethical thought. Their views are such that the way in which they conceive the operation of meaning lead to a stance that rejects the possibility of total knowledge or command of concepts, and therefore refuses the idea of a "correct" account of meaning, morality, history, knowledge, and so on.  This thesis is an attempt to identify and elaborate the overlap between Wittgenstein and Derrida's work in light of the role that proper names play in their philosophies of language and ethics. The philosophical account of proper names is important because it clarifies the view of subjectivity and also serves as a model for understanding the general operation of language. The fact that we are revealed to be inextricably dependent on the "otherness" of other people in order for each of us to be "selves" implies we are indebted to others and therefore must initiate any ethical project based on that indebtedness. Furthermore, the instability of language insures that we cannot have the "correct" interpretation of all concepts and must therefore maintain a certain charity in our dialogical engagement with others. This thesis argues in favour of the ethical stance that results from Wittgenstein and Derrida's perspectives