identifier: Pu, Xinrui  (2017) Speech Dereverberation Based on Multi-Channel Linear Prediction.  Masters thesis, Concordia University.

abstract:
Room reverberation can severely degrade the auditory quality and intelligibility of the speech signals received by distant microphones in an enclosed environment. In recent years, various dereverberation algorithms have been developed to tackle this problem, such as beamforming and inverse filtering of the room transfer function. However, this kind of methods relies heavily on the precise estimation of either the direction of arrival (DOA) or room acoustic characteristics. Thus, their performance is very much limited. A more promising category of dereverberation algorithms has been developed based on multi-channel linear predictor (MCLP). This idea was first proposed in time domain where speech signal is highly correlated in a short period of time. To ensure a good suppression of the reverberation, the prediction filter length is required to be longer than the reverberation time. As a result, the complexity of this algorithm is often unacceptable because of large covariance matrix calculation. To overcome this disadvantage, this thesis focuses on the MCLP dereverberation methods performed in the short-time Fourier transform (STFT) domain.

Recently, the weighted prediction error (WPE) algorithm has been developed and widely applied to speech dereverberation. In WPE algorithm, MCLP is used in the STFT domain to estimate the late reverberation components from previous frames of the reverberant speech. The enhanced speech is obtained by subtracting the late reverberation from the reverberant speech. Each STFT coefficient is assumed to be independent and obeys Gaussian distribution. A maximum likelihood (ML) problem is formulated in each frequency bin to calculate the predictor coefficients. In this thesis, the original WPE algorithm is improved in two aspects. First, two advanced statistical models, generalized Gaussian distribution (GGD) and Laplacian distribution, are employed instead of the classic Gaussian distribution. Both of them are shown to give better modeling of the histogram of the clean speech. Second, we focus on improving the estimation of the variances of the STFT coefficients of the desired signal. In the original WPE algorithm, the variances are estimated in each frequency bin independently without considering the cross-frequency correlation. Thus, we integrate the nonnegative matrix factorization (NMF) into the WPE algorithm to refine the estimation of the variances and hence obtain a better dereverberation performance.

Another category of MCLP based dereverberation algorithm has been proposed in literature by exploiting the sparsity of the STFT coefficients of the desired signal for calculating the predictor coefficients. In this thesis, we also investigate an efficient algorithm based on the maximization of the group sparsity of desired signal using mixed norms. Inspired by the idea of sparse linear predictor (SLP), we propose to include a sparse constraint for the predictor coefficients in order to further improve the dereverberation performance. A weighting parameter is also introduced to achieve a trade-off between the sparsity of the desired signal and the predictor coefficients.

Computer simulation of the proposed dereverberation algorithms is conducted. Our experimental results show that the proposed algorithms can significantly improve the quality of reverberant speech signal under different reverberation times. Subjective evaluation also gives a more intuitive demonstration of the enhanced speech intelligibility. Performance comparison also shows that our algorithms outperform some of the state-of-the-art dereverberation techniques.


identifier: Marzban, Mostapha  (2017) Flow Force Augmented 3D Suspended Polymeric Microfluidic (SPMF3) Platform for Sensitive Diagnosis.  PhD thesis, Concordia University.

type: Thesis NonPeerReviewed


identifier: Duquette, P.A.  (2017) Demystifying Cruelty: Artaudian Intention in Art and Life.  Masters thesis, Concordia University.

abstract: This thesis paper revisits the early writings of theatre practitioner Antonin Artaud [1896-1948] while addressing two important influences in his vision for a theatre of cruelty: a) avant-garde theatrical theory during his life-time, and; b) typical experiences of schizophrenia, from which the artist suffered since adolescence. Understanding these factors, as they relate to his proposal for a mystical theatre experience, serves to clarify what was original among Artaud’s limit-exceeding intentions. This paper also briefly reviews select artists’ interpretations of Artaud’s theatrical prescriptions, where attempts have been made to translate theory into practice, arriving at both innovations and outcomes Artaud had not foreseen. While affirming his desire to mirror a collapse of all boundaries between art and life, as he had lived it, the artist’s polemic presents practical challenges that merit precaution if aspiring to emulate attributes of a theatre of cruelty. Lastly, as a point of departure for further discussion, I touch upon popular manifestations of cruel immersions and spectacles that contextualize the twenty-first century cultural conditions within which interdisciplinary and cross-disciplinary artists now experiment. Where new technologies increasingly enable the magical effects Artaud imagined, I question whether cruelty is necessary, or even fruitfully disruptive, in today’s cultural milieu.


identifier: Atallah, Ribal  (2017) The Next Generation Intelligent Transportation System: Connected, Safe and Green.  PhD thesis, Concordia University.

abstract:
Modern Intelligent Transportation Systems (ITSs) employ communication technologies in order to ameliorate the passenger's commuting experience. Vehicular Networking lies at the core of inaugurating an efficient transportation system and aims at transforming vehicles into smart mobile entities that are able to sense their surroundings, collect information about the environment and communicate with each other as well as with Roadside Units (RSUs) deployed alongside roadways. As such, the novel communication paradigm of vehicular networking gave birth to an ITS that embraces a wide variety of applications including but not limited to: traffic management, passenger and road safety, environment monitoring and road surveillance, hot-spot guidance, Drive Thru Internet access, remote region connectivity, and so forth. Furthermore, with the rapid development of computation and communication technologies, the Internet of Vehicles (IoV) promises huge commercial interest and research value, thereby attracting a significant industrial and academic attention.

This thesis studies and analyses fundamentally challenging problems in the context of vehicular environments and proposes new techniques targeting the improvement of the performance of ITSs envisioned to play a remarkable role in the IoV era. Unlike existing wireless mobile networks, vehicular networks possess unique characteristics, including high node mobility and a rapidly-changing topology, which should be carefully accounted for. Four major problems from the pool of existing vehicular networking persisting challenges will be addressed in this thesis, namely: a) establishing a connectivity path in a highly dynamic Vehicular Ad Hoc Network, b) examining the performance of Vehicle-to-Infrastructure communication Medium Access Control schemes, c) addressing the scheduling problem of a vehicular networking scenario encompassing an energy-limited RSU by exploiting machine learning techniques, particularly reinforcement learning, to train an agent to make appropriate decisions and develop a scheduling policy that prolongs the network's operational status and allows for acceptable Quality-of-Service levels and d) overcoming the limitations of reinforcement learning techniques in high-dimensional input scenarios by exploiting recent advances in deep learning in an effort to satisfy the driver's well-being as well as his demand for continuous connectivity in a green, balanced, connected and efficient vehicular network. These problems will be extensively studied throughout this thesis, followed by discussions that highlight open research directions worth further investigations.


identifier: Cree, Dylan J  (2017) Uselessness in Reserve? An exploration of the laugh track, “media” and the frivolous.  PhD thesis, Concordia University.

abstract:
Uselessness in Reserve?  An exploration of the laugh track, “media” and the frivolous

Dylan Cree, PhD
Concordia University, 2017

       Within contemporary media studies the notion uselessness is either under-examined or given short-play as representing quantifiable loss. Registered as material waste or as mechanical deficiency measured by what is useful that which is useless gets categorically parsed and dismissed as an irrelevant by-product of a medium’s operations. However, by definition, uselessness resists being instrumentalized and assigned a knowable role. Furthermore, as the thesis argues, when considered materially, what is deemed useless to the optimal workings of a technological medium, whether wanted or not, surreptitiously impacts the reserve of procedures that delimit the workings of a media formation. Though the notion uselessness, as informed by Jacques Derrida’s deconstruction of Etienne Bonnot de Condillac’s account of the frivolous/uselessness, is paradoxical in kind and indeterminate in effect, the thesis proposes that uselessness is far more integral to media formations than contemporary discourse permit. Accordingly, media theorists need to foster other approaches that allow engaging such an aporia.
       For directly exploring uselessness in media, the laugh track holds promise as an instance in which a media formation makes useless its production. However, to examine the laugh track by how it may be illogically constituted – as opposed to conventional examinations of how the laugh track functions or serves broader interests – requires deployment of certain expansive methods and discursive tools. Accordingly, Siegfried Zielinski’s media anarchaeology permits exploring the laugh track as its own paradoxical system. His approach helps to investigate the operational attributes that re-codify the laugh track’s material registry as a redundant system of archivation, a uselessness in reserve.
       Ultimately, Zielinski’s anarchic approach permits drawing radical implications beyond technological and communicative-governed formulations of media. The laugh track may be explored much like how Giorgio Agamben speculates about the gesture. For Agamben the gesture may be experienced as a “pure means” or an activity liberated from content and purpose dictated by apophantic principles. Accordingly, independently of means/end instrumentalist thinking the laugh track may be encountered by how it, integral to its mediatic operations, paradoxically maintains its productivity through a gesture – of never-ending archival actions – that renders its product useless.


identifier: Al-Hussaeni, Khalil  (2017) Preserving Privacy in High-Dimensional Data Publishing.  PhD thesis, Concordia University.

abstract: We are witnessing a continuous expansion of information technology that never ceases to impress us with its computational power, storage capacity, and agile mobility. Such technology is becoming more pervasive by the day and has enhanced various aspects of our daily lives. GPS-equipped devices, smart card automated fare collection systems, and sensory technology are but a few examples of advanced, yet affordable, data-generating technologies that are an integral part of modern society. To enhance user experience or provide better services, service providers rely on collecting person-specific information from users. Thus, the collected data is studied and analyzed in order to extract useful information. It is a common practice for the collected data to be shared with a third-party, e.g., a data mining firm, for data analysis. However, the shared data must not leak sensitive information about the individuals to whom the data belongs or reveal their identity. In other words, individuals’ privacy must be protected in the published data. Privacy-preserving data publishing is a research area that studies anonymizing person-specific data without compromising its utility for future data analysis. This thesis studies and proposes anonymization solutions for three types of high-dimensional data: trajectory streams, static trajectories, and relational data. We demonstrate through theoretical and experimental analysis that our proposed solutions, for the most part, outperform state-of-the-art methods in terms of utility, efficiency, and scalability.


identifier: Jia, Xiangdong  (2017) A High-speed and Low Power Electrical Link Transceiver.  Masters thesis, Concordia University.

abstract:
On-chip wires will present increasing latency and energy problems as VLSI technologies continue to scale. Interconnects have an RC-limited bandwidth approximately proportional to the area of the metal cross section and inversely proportional to the squared length. To overcome RC-limited channels, an energy-efficient on-chip transceiver is presented that contains a hybrid transmitter, a current-sense receiver, and self-testing blocks. The main goal of this research is having a relatively low-power transceiver, which can be used as an on-chip communication system.
By adding a pre-emphasis circuit in the transmitter, pre-cursor inter-symbol interference can be canceled. A hybrid transmitter which combines voltage-mode pre-emphasis with a current-mode main driver is used. This structure can save pre-emphasis current, and leads to reduced power dissipation especially in the static situation. A current-sense amplifier is implemented with a cross-coupled stage and an active inductor equalizer at the receiver, in order to boost the data rate while maintaining good energy efficiency. An offset cancelation circuit is incorporated to make a robust comparator for the receiver. According to simulation results, the transceiver has low power consumption with 1.2 V, 130 nm CMOS technology. The performance shows that it operates at 8 Gb/s over a 5 mm and 19 dB loss differential channel. The overall dynamic power consumption is 2.05 mW, without the PRBS generator/checker. Therefore, this transceiver has high data rate and low power consumption.


identifier: Al Faleh, Omar  (2017) Responsive Architecture: A Place Making Design Strategy.  Masters thesis, Concordia University.

abstract:
The area of responsive architecture is at the conceptual intersection of architecture, design, and technology. It presents an opportunity to investigate the potentials for engaging place-dwellers in an interactive exchange with each other and with the built environment, and can be regarded as an experimental medium for conceptual investigation. The concept of creating responsive architecture is synonymous to creating experiences in place, and for building site-specific interventions within the built environment that use computational technologies to choreograph or facilitate engaging experiences for visitors, spectators, and place-dwellers. From this perspective, responsive architecture can be regarded as a place-making design strategy that is informed the by theories and histories of architectural design practices, and also by concepts and studies on space, place, the body, experience, and perception.

This research attempts to present responsive architecture within the context of place-making and as a place-making design strategy. It conducts an overview which reads the history of experimentations in endowing architecture with feedback and adaptability in response to presence and interaction, and contextualizes this research by performing an inter-disciplinary reading in the history of arts and science to better understand the rise of these tendencies in the light of development of other forms of creation such as theatre, dance, and the advances in science and technology. This research also conducts a theoretical overview on the concepts of space and place, and their relation to active bodies and perception.

The second part of this thesis is a research-creation component which presents a design strategy that investigates the ways in which computational and digital media can be conceptualized, diffused, and used to create engaging and interactive experiences in place. It presents a set of experiments that were conducted by the author of this research, provides a conceptual pretext for the responsive design strategies that were used in each experiment, and draws similarities and distinction from the ensemble of the experiments that investigate a certain aspect of each strategy.


identifier: Gagné, Jean-Philippe ORCID: https://orcid.org/0000-0001-5803-0489 <https://orcid.org/0000-0001-5803-0489>  (2017) An experimental approach to understanding beliefs about losing control in obsessive-compulsive disorder.  Masters thesis, Concordia University.

abstract: Cognitive theories of obsessive-compulsive disorder (OCD) posit that maladaptive beliefs lead to the development and maintenance of symptoms. However, currently identified beliefs (about responsibility and threat overestimation, perfectionism and intolerance for uncertainty, and about the importance of and control over thoughts) do not sufficiently explain OCD symptomatology. Anecdotal and other reports have documented concerns among those diagnosed with OCD regarding a potential loss of control over their thoughts and behaviour, indicating that negative beliefs about losing control may be an important cognitive domain involved in the aetiology of OCD. In this study, 133 undergraduate participants received (positive or negative) false feedback about their capacity to stay in control during a bogus EEG session, and completed a computer task asking them to control the pace of a series of pictures. As hypothesized, participants provided with negative feedback about their capacity to stay in control (i.e., high negative beliefs about losing control) checked significantly more often which keys they should use to control the pictures, t(106.95) = 2.28, p = .02, d = .44, as compared to participants provided with positive feedback (i.e., low negative beliefs about losing control), demonstrating that manipulating beliefs about losing control can impact checking behaviour. Also, checking behaviour predicted a lower desire for control over the computer task’s pictures, r(131) = -.30, p < .001, such that compulsions may be seen as opportunities to re-establish disrupted perceptions of control. Results support the inclusion of beliefs about losing control in cognitive models of OCD.


identifier: Di Perna, Michael  (2017) An Optimal Control Approach to Flight Management Systems for Unmanned Aerial Vehicles.  Masters thesis, Concordia University.

abstract:
With unmanned aerial vehicles (UAVs) becoming increasingly present in military and commercial applications, the flight path efficiency and integration with current manned aircraft become important research topics to address in the coming years. This thesis considers three problems relating to UAVs: the optimal control of a single quadrotor UAV, a multi-agent coverage problem, and a software flight management system which can be used on UAVs.
The optimal control problem for a quadrotor UAV is considered with a tuning parameter, the cost index, used in flight management systems to trade-off between time and energy costs. A state-feedback control law is developed and simulation results are presented. A software flight management system (SFMS) using aerospace standard communication protocols is developed and validated with an industry flight simulator. The SFMS allows for the testing of algorithms which can be used on real aircraft (manned or unmanned) without requiring access to a costly commercial flight management system. An energy efficient coverage problem from previous work is considered and extended to include agents with second order dynamics using the backstepping technique. The extension to second order dynamics requires the analysis of the dynamics of Voronoi cells. A geometric interpretation is presented for the change in area and change in position of the center of mass for Voronoi cells. Simulation results are presented comparing the first order and second order agents.


identifier: Faddoul, Georgina  (2017) A TEMPORAL INVESTIGATION OF WITHIN-PERSON CHANGES IN OPTIMISM AND STRESS AS PREDICTORS FOR CHANGES IN WELL-BEING.  Masters thesis, Concordia University.

abstract: Meta-analytic studies have established dispositional optimism as a personality trait with clear positive effects on psychological and physical well-being (Rasmussen, Scheier, & Greenhouse, 2009; Solberg Ness & Segerstrom, 2006). Optimism may be most important when experiencing stress, since optimists use more adaptive coping strategies and have more resources available compared to pessimists (Segerstrom, 2007; Solberg Ness & Segerstrom, 2006). Traditionally, studies have assumed optimism to be a stable trait, however recent studies have found optimism to be unstable in certain circumstances (e.g., Segerstrom, 2007). Although instability in optimism has been identified, research examining changes in optimism and well-being have been correlational and unable to identify causal associations. Additionally, these studies have not considered stress as a potential third variable to account for the associations between changes in optimism, and changes in well-being and health. The present study accounted for these limitations by replicating past findings, accounted for stress as a third variable, and also investigated the possibility that changes in optimism and stress may interact to influence changes in well-being and health. This was done by temporally investigating changes in optimism and stress at one point in time to predict changes in well-being and health at a later point in time. Additionally, this study investigated the extent to which the interaction between changes in optimism and stress at one point in time may influence the interaction between changes in optimism and stress on well-being and health at a later point in time. Results were able to show that changes in optimism did predict changes in well-being and heath after controlling for stress, but changes in optimism at one point in time did not predict changes in well-being or health at a later point in time after controlling for stress.


identifier: Lahiouel, Ons  (2017) Enhancing Variation-aware Analog Circuits Sizing.  PhD thesis, Concordia University.

abstract:
Today's analog design and verification face significant challenges due to circuit complexity and short time-to-market windows. Moreover, variations in design parameters have an adversely impact on the correctness and performance of analog circuits. Circuit sizing consists in determining the device sizes
and biasing voltages and currents such that the circuit satisfies its specifications. Traditionally, analog circuit sizing has been carried out by optimization-based methods, which of course will still be
important in the future. Unfortunately, these techniques cannot guarantee an exhaustive coverage of the design search space and hence, are not able to ensure the non-existence of higher quality design solutions. The sizing problem becomes more complicated and computationally expensive under
design parameters fluctuation. Indeed, existing yield analysis methods are computationally expensive and still encounter issues in problems with a high-dimensional process parameter space.
In this thesis, we present new approaches for enhancing variation-aware analog circuit sizing. The circuit sizing problem is encoded using nonlinear constraints. A new algorithm using Satisfiability
Modulo Theory (SMT) solving techniques exhaustively explores the analog design space and computes a continuous set of feasible sizing solutions. Next, a yield optimization stage aims to select the candidate design solution with the highest yield rate in the presence of process parameters variation.
For this purpose, a novel method for the computation of parametric yield is proposed. The method combines the advantages of sparse regression and SMT solving techniques. The key idea is to characterize the failure regions as a collection of hyperrectangles in the parameters space. The yield
estimation is based on a geometric calculation of probabilistic volumes subtended by the located hyperrectangles. The method can provide very large speed-up over Monte Carlo methods, when a high prediction accuracy is required. A new approach for improving analog yield optimization is also proposed. The optimization is performed in two steps. First, a global optimization phase samples the most potential optimal sub-regions of the feasible design space. The global search locates a design
point near the optimal solution. Second, a local optimization phase uses the near optimal solution as a starting point. Also, it constructs linear interpolating models of the yield to explore the basin of convergence and to reach the global optimum. We illustrate the efficiency of the proposed methods on various analog circuits. The application of the yield analysis method on an integrated ring oscillator and a 6T static RAM proves that it is suitable for handling problems with tens of process parameters
and can provide speedup of 5X-2000X over Monte Carlo methods. Furthermore, the application of our yield optimization methodology on the examples of a two-stage amplifier and a cascode amplifier shows that our approach can achieve higher quality in analog synthesis and unrivaled coverage of the analog design space when compared to traditional optimization techniques.


identifier: Khanna, Abhimanyu  (2017) Towards usable and fine-grained security for HTTPS with middleboxes.  Masters thesis, Concordia University.

abstract:
Over the past few years, technology firms have inlined end-to-end encryption for their services and implored for increased in-network functionality. Most firms deploy TLS and middleboxes by performing man-in-the-middle (MITM) of network sessions. In practice, there are no official guidelines for performing MITM and often several tweaks are used resulting in less secure systems. TLS was designed for exactly two parties and introducing a third party by doing MITM breaks TLS and the security benefits it offers.
With increasing debate in finding a clean way to deploy middleboxes with TLS, our work surveys the literature and introduces a benchmark based on the Usability-Deployability-Security (UDS) framework for evaluating existing TLS middlebox interception proposals. Our benchmark encompasses and helps understand the current benefits, solutions and challenges in the existing solutions for incorporating TLS with middleboxes. We perform a comparative and qualitative evaluation for the schemes and summarize the results in a single table. We propose: Triraksha, an alternative to the currently deployed middlebox interception models. Triraksha provides a packet inspection service for end-to-end encrypted connections while maintaining fine-grained confidentiality for end points. We evaluate a prototype implementation of our scheme on local and remote servers and show that the overhead in terms of latency and throughput is minimal. Our scheme is easily deployable as only a few software additions are made at the middlebox and client end.


identifier: Khanna, Parul  (2017) Detecting Privacy Leaks Through Existing Android Frameworks.  Masters thesis, Concordia University.

abstract:
The Android application ecosystem has thrived, with hundreds of thousands of applications (apps) available to users; however, not all of them are safe or privacy-friendly. Analyzing these many apps for malicious behaviors is an important but challenging area of research as malicious apps tend to use prevalent stealth techniques, e.g., encryption, code transformation, and other obfuscation approaches to bypass detection. Academic researchers and security companies have realized that the traditional signature-based and static analysis methods are inadequate to deal with this evolving
threat. In recent years, a number of static and dynamic code analysis proposals for analyzing Android apps have been introduced in academia and in the commercial world. Moreover, as a single detection approach may be ineffective against advanced obfuscation techniques, multiple frameworks for privacy leakage detection have been shown to yield better results when used in conjunction. In this dissertation, our contribution is two-fold. First, we organize 32 of the most recent and promising privacy-oriented proposals on Android apps analysis into two categories: static and dynamic analysis. For each category, we survey the state of-the-art proposals and provide a high-level overview of the methodology they rely on to detect privacy-sensitive leakages and app behaviors. Second, we choose one popular proposal from each category to analyze and detect leakages in 5,000 Android apps. Our toolchain setup consists of IntelliDroid (static) to find and trigger sensitive API (Application Program Interface) calls in target apps and leverages TaintDroid (dynamic) to detect leakages in these apps. We found that about 33%
of the tested apps leak privacy-sensitive information over the network (e.g., IMEI, location, UDID), which is consistent with existing work. Furthermore, we highlight the efficiency of combining IntelliDroid and TaintDroid in comparison with Android Monkey and TaintDroid as used in most prior work. We report an overall increase in the frequency of leakage of identifiers. This increase may indicate that IntelliDroid is a better approach over Android Monkey.


identifier: Gagnon, Sarah-Danielle  (2017) Thérèse et Pierrette à l'école des Saints-Anges : oralité et carnavalesque dans la narration de Michel Tremblay.  Masters thesis, Concordia University.

abstract: Si la critique a toujours fait grand cas de l’œuvre théâtrale de Michel Tremblay, elle s’est un peu moins penchée sur sa production romanesque. Le présent mémoire a pour objet le deuxième roman des Chroniques du Plateau-Mont-Royal, soit Thérèse et Pierrette à l’école des Saints-Anges. L’analyse porte sur la polyphonie romanesque et sur le caractère intrinsèquement carnavalesque du récit. C’est cependant à une variation inédite de la polyphonie que le lecteur se voit confronté, tout comme à une représentation carnavalesque originale. En effet, la polyphonie, observable dès les premières pages du roman, divise les personnages non pas en classes sociales, comme pouvaient le concevoir les travaux fondateurs de Mikhaïl Bakhtine, mais en clans aux intérêts hétérogènes, soudés pourtant par une langue commune. Le français oral-populaire investit par le fait même l’espace romanesque : tout d’abord, par le biais d’une prise de parole récurrente — et quasi militante – des plus démunis; ensuite, par une contamination progressive de la langue même de la narration, ce qui témoigne d’un parti pris sans équivoque pour les personnages ainsi décrits. La narration va d’ailleurs jusqu’à prendre la forme d’une « langue mi-parlée », pour reprendre la notion forgée par André Brochu. Cette remise en question du pouvoir établi se voit mise en relief par la représentation péjorative du rituel religieux, où le carnavalesque — et le « ratage » dans l’imaginaire que celui-ci suppose — atteint des sommets. La prise de parole populaire, ainsi associée à une attitude contestataire et à de grands bouleversements symboliques, contribue à renforcer la position des personnages vis-à-vis du pouvoir en place, tout particulièrement celle des protagonistes féminins. Dans cette Chronique, Tremblay donne en effet voix aux femmes d’une manière remarquable, offrant un point de vue (proto) féministe indicateur — dans l’univers de la diégèse, situé tout juste avant la Révolution tranquille — des revendications à venir.


identifier: Conlan, Neil  (2017) Heuristic Algorithms For Broadcasting In Cactus Graphs.  Masters thesis, Concordia University.

abstract: Broadcasting is an information dissemination problem in a connected network, in which one node, called the originator, disseminates a message to all other nodes by placing a series of calls along the communication lines of the network. Once informed, the nodes aid the originator in distributing the message. Finding the broadcast time of a vertex in an arbitrary graph is NP-complete. The problem is solved polynomially only for a few classes of graphs. In this thesis, we study the broadcast problem in a class of graph called a Cactus Graph. A cactus graph is a connected graph in which any two simple cycles have at most one vertex in common. Equivalently, it is a connected graph in which every edge belongs to at most one simple cycle. We review broadcasting on subclasses of cactus graphs such as, the unicyclic graphs, necklace graphs, k-cycle graphs, 2-restricted cactus graphs and k-restricted cactus graphs. We then provide four heuristic algorithms that solves broadcasting on a k-cycle graph. A k-cycle graph is a collection of k cycles of arbitrary lengths all connected to a central vertex. Finally, we run simulations of these heuristic algorithms on diﬀerent sized k-cycle graphs to compare and discuss the results.


identifier: Aljumah, Feras Abdulaziz  (2017) Protocols for Secure Computation on Privately Encrypted Data in the Cloud.  PhD thesis, Concordia University.

abstract:
Cloud services provide clients with highly scalable network, storage, and computational resources. However, these service come with the challenge of guaranteeing the confidentiality of the data stored on the cloud. Rather than attempting to prevent adversaries from compromising the cloud server, we aim in this thesis to provide data confidentiality and secure computations in the cloud, while preserving the privacy of the participants and assuming the existence of a passive adversary able to access all data stored in the cloud.

To achieve this, we propose several protocols for secure and privacy-preserving data storage in the cloud. We further show their applicability and scalability through their implementations. we first propose a protocol that would allow emergency providers access to privately encrypted data in the cloud, in the case of an emergency, such as medical records. Second, we propose various protocols to allow a querying entity to securely query privately encrypted data in the cloud while preserving the privacy of the data owners and the querying entity. We also present cryptographic and non-cryptographic protocols for secure private function evaluation in order to extend the functions applicable in the protocols.


identifier: Beaudoin, Caroline  (2017) Everyday Landscapes: Picturing Places of Labour, Leisure, and Industry in Quebec's Eastern Townships, 1900-2015.  PhD thesis, Concordia University.

abstract:
Focusing on the Eastern Townships area of Quebec, this dissertation attends to the complex values that can be assigned to landscape as visual representation, and to landscape as place. The case-studies, beginning at the turn of the 20th-century, consider landscape in relation to a broad network of social relations and cultural meanings. Section I of the thesis starts by examining paintings and illustrations of loggers by F.S. Coburn as a way to address the logging industry in the Eastern Townships, and to consider the presence or absence of labour in landscape representation. Section II concentrates on early 20th-century postcards of towns, sites of leisure and asbestos mines in the region. I approach these postcards as modern material agents that articulate the everydayness of landscape and place through their imagery, as well as through their usage. Section III comes up to the present day through a discussion of an eco-park in Magog that negotiates the tension between ecological activism and eco-tourism, as the Eastern Townships struggles to achieve a post-industrial identity.

Organized into three chronological and overlapping sections that span 115 years of one region's history, the thesis develops an approach to landscape that is both art-historical and interdisciplinary. This study builds on recent scholarship within Canadian art history that challenges the association of landscape art with a myth about the country’s uninhabited wilderness; the region's landscapes studied here are inhabited, and imbued with  rural, industrial and bilingual histories. The visual culture methodology deployed here means that canonical modes of artistic landscape representations are addressed relative to landscape images circulating on postcards, newspaper and book illustrations, documentary photographs, a labour recruitment booklet and an ecopark's website for example.

The theoretical and scholarly foundation of this thesis has been constructed by drawing on discussions of landscape by art historians, but also by sociologists, geographers, anthropologists, and philosophers. It is this interdisciplinary breadth that allows landscapes to be regarded as sites of everyday human interactions, that inevitably intersect with collective, commercial and political motives, and with cultural ideals, interests, and values. The writings of Henri Lefebvre on the value of the everyday have been important for this thesis, as has his critique of capitalist practices of labour and leisure. Another key author is Félix Guattari who was also highly critical of capitalism, while turning his attention to the state of the world's post-industrial ecology. Likewise, this thesis calls attention to the role of capitalist initiatives in the production of everyday landscapes. This analysis of diverse landscape images is meant to shed light on the Eastern Townships' complex identity as it transitions from a former industrial modern era to its current post-industrial phase. This thesis asks what the term landscape has come to imply measured against social tensions relating to class differences, or economic and environmental imperatives, and how its range of meanings can encompass territory, property, picture, place, and environment.


identifier: Wang, Yushun  (2017) TenantGuard: Scalable Runtime Verification of Cloud-Wide VM-Level Network Isolation.  Masters thesis, Concordia University.

abstract:
The multi-tenancy of a cloud usually leads to security concerns over network isolation around each cloud tenant's virtual resources. However, verifying network isolation in cloud virtual networks poses several unique challenges. The
sheer size of virtual networks implies a prohibitive complexity, whereas the constant changes in virtual resources demand a short response time. To make things worse, such networks typically allow fine-grained (e.g., VM-level) and distributed (e.g., security groups) network access control. Those challenges can either invalidate existing approaches or cause an unacceptable delay which prevents runtime applications. In this thesis, we present TenantGuard, a scalable system for verifying cloud-wide, VM-level network isolation at runtime. We take advantage of the hierarchical nature of virtual networks, efficient data structures, incremental verification, and parallel computation to reduce the
performance overhead of security verification. We implement our approach based on OpenStack and evaluate its performance both in-house and on Amazon EC2, which confirms its scalability and efficiency (13 seconds for verifying 168 millions of VM pairs). We further integrate TenantGuard with Congress, an OpenStack
policy service, to verify the compliance of isolation results against
tenant-specific high level security policies.


identifier: El-khateeb, Laith  (2017) Defect-based Condition Assessment Model of Railway infrastructure.  Masters thesis, Concordia University.

abstract:
Railway infrastructure, such as rails, ballasts, sleepers, etc., condition should be always monitored and analyzed to ensure safety and quality of the ride for both passengers and freight. Railway infrastructure has various components from different materials which make it hard to assess and monitor its condition. The majority of the existing conditions assessment models are limited either in terms of components or techniques, many models focus on the assessment of the track geometry condition depending on only the data collected from the track recording cars and a few condition assessment models to evaluate the structural condition of the railway infrastructure. Other developed models take into consideration one component or focus in utilizing one inspection technique. Therefore, the development of a comprehensive condition assessment tool that covers the numerous railway infrastructure components and the different inspection techniques is needed to ensure the safety and the quality of the service for the public.
The objective of this research is to develop a defect-based condition assessment model of Railway infrastructure. This model aims to cover the structural and geometrical defects that are associated with the different components of railway infrastructure. The railway infrastructure was divided into five main components rails, sleepers (Ties), ballast, track geometry and insulated rail joints, for each component their defects were collected and categorized. Two main inputs have been used to develop the model, firstly the relative importance weights of the components, Defect Categories, and defects, secondly the defects severities. To obtain the relative importance weights the Analytic Network Process (ANP) model was adopted, ANP covers the interdependencies between the components and their defects. Fuzzification technique was used to uniform all the different defects criteria and to translate the linguistic condition assessment grading scale to a numerical score. Furthermore, the Weighted Sum Mean was used to integrate both the weights and severities to define the conditions and to evaluate the overall condition of the railway infrastructure. The data utilized in this research was obtained from railway condition classification manuals, previous research, and questionnaires distributed to professionals in Canada. The fruit of this fusion was also presented in a user-friendly automated tool using excel. The developed model was implemented in two case studies from Ontario, Canada. The model outputs and the decision made for the case studies were compared and the model gave a similar condition. This model helps in minimizing the inaccuracy of railway condition assessment through the application of severity, uncertainty mitigation, and robust aggregation. It also benefits asset managers by providing detailed condition of the Railway infrastructure, the condition of the components, defect categories and an overall condition for maintenance, rehabilitation, and budget allocation purposes.


identifier: Holden, Asha L.  (2017) Merging the mind and body: A bibliographic review of Embodiment as an integrative approach with Prolonged Exposure and Cognitive Processing Therapy working with Combat-Related Posttraumatic Stress Disorder.  Masters thesis, Concordia University.

abstract: The aim of this bibliographic research is to study embodying techniques and the U.S. Department of Veterans’ Affairs (VA)-approved Cognitive Behavioral Therapies (CBTs)—Prolonged Exposure (PE) and Cognitive Processing Therapy (CPT)—in relation to working with U.S. Veterans experiencing symptoms of combat-related Post-Traumatic Stress Disorder (PTSD).  The review of embodiment and CBT can help open doors to exploring a therapeutic approach that connects the mind and body when working with PTSD symptoms.  This study was inspired by the growing number U.S. Veterans struggling with combat-related PTSD and seeking help from the VA.  Literature has shown that while PE and CPT are supported by the VA, they have low participation and/or high attrition rates.  Current discussions in U.S. legislation have begun to explore the benefits of the Creative Arts Therapies (CATs) as Complementary and Alternative Medicines (CAMs) when working with U.S. Veterans (Americans for the Arts, AFTA, 2017).  A thorough investigation of the literature found that embodiment:  fosters reconnection with the body, improves life satisfaction and symptom reduction, and bypasses Alexithymia.  More research is needed to determine the specific ways embodiment can be incorporated in PE and/or CPT practices to encourage post-traumatic growth for U.S. Veterans and Service Members.


identifier: Huq, Iftekharul  (2017) Three Essays in Empirical Economics.  PhD thesis, Concordia University.

title: Three Essays in Empirical Economics

abstract:
This thesis consists of three essays in empirical economics. The first essay investigates how
the smoking behavior of an individual changes when faced with a change in income and taxes on
cigarettes in a price-tiered cigarette market structure. To explain the behavior of smokers a simple
two-period model is developed. The model makes certain predictions which have been tested with
a unique panel dataset from the International Tobacco Control (ITC) surveys. Findings from the
regression models illustrate that a change in price is negatively correlated with cigarette
consumption, whereas a change in income is positively correlated with the same variable. It is
further observed from the regression results that higher income increases the probability to uptrade
and reduces the probability to quit smoking. Besides, higher cigarette taxation raises the
probability to down-trade and reduces the probability to up-trade. Interestingly higher taxes do not
raise the probability to quit smoking. The findings of the paper hold strong policy relevance. It
reveals the need for overall cigarette taxes to be raised to an extent so that it off-sets any positive
effects of income growth. In addition, tier-taxes should be designed with caution so that higher
taxes do not encourage smokers to down-trade but rather pushes them to quit smoking altogether.
The second essay studies how a change in the Perception of Tobacco Risk (PTR) affects the
attitude of smokers and non-smokers towards smoking. Using the same panel data-set as the first
essay, a Perception of Tobacco Risk Index (PTRI) is developed for all smokers and non-smokers.
Results show that among all different types of smokers, quitters have the highest PTRI whereas
bidi (cheap local alternative to cigarettes) smokers have the lowest. Among the different sociodemographic
groups the higher income, more educated, and those living in urban areas display a
higher PTRI than their respective counterparts. However, when looking at a change in PTRI, it is
observed that the change is bigger among the lower income, less educated and those living in rural
areas. Analysis of panel data reveals that the change in PTRI is positively correlated with the
probability to quit smoking for most socio-demographic groups. However, increase in PTRI does
not significantly affect initiation of smoking and reduces cigarette consumption per day only for
the more educated group. Such results hold strong policy implications. First, they show that
changing PTR holds promising implications for controlling tobacco consumption concerning
raising quitting probability. Second, they bring into light, specific socio-demographic groups
where policies to change PTR should be targeted.
The final essay is a joint paper. In this essay, we explore the concepts of provincial gross, net
and share of net mobility rates across education and age groups using the Survey of Labor and
Income Dynamics (SLID, 1993-2011) of Canada. Our results show that provincial mobility of
young and more educated are more than their counterparts. The share of net mobility rates reveals
that young and less educated individuals mostly have one-way inter-provincial mobility.
Moreover, inter-provincial migration using gravity model shows that the effects of border and
population sizes of destination and original provinces have positive influences and distances have
the negative influence on provincial migration. We also identify a positive correlation between
provincial in- and out-migration in Canada. This shows that provinces that lose more people also
seem to attract more people. Our analysis further illustrates that net provincial mobility has a
stronger relationship with in-migration compared to out- migration.


identifier: ALWEHAIBI, SULTAN  (2017) On the Relationship Between Self-Admitted Technical Debt and Software Quality.  Masters thesis, Concordia University.

abstract:
Developers settle for a non-optimal solution under pressure to meet deadlines and quotas despite the potential pitfalls that might ensue at later stages in development, which has been referred to as “technical debt.” And like its financial analogue, if not carefully monitored and mediated, technical debt can compromise the very project it was intended to expedite. Several approaches have been proposed to aid developers in tracking the technical debt they incur. Traditionally, developers have relied on metric-based approaches, which use static analysis tools to identify technical debt based on thresholds defined on object-oriented metrics, e.g. code smells. Another technique, pioneered in a recent study, leverages source code comments to detect (self-admitted) technical debt. Therefore, in this thesis we use empirical studies to examine how self-admitted technical debt and code smells (God Classes) relate to software quality.

Preliminarily, we examine the relationship between self-admitted technical debt and software quality for five open-source projects. To measure this, we take into account three criteria commonly associated with quality: (i) on the file level, the relationship between defects and self-admitted technical debt (SATD); (ii) on the change level, the potential of SATD to introduce future defects and (iii) the complexity SATD changes impose on the system. The results of our study indicate that: (i) SATD files tend to have less defects than non-SATD files and (ii) SATD changes make the system less susceptible to future defects than non-SATD changes do, though (iii) SATD changes are more difficult to execute.
Until the advent of SATD, god classes were used to detect technical debt, and though others have studied the impact of metric-based approaches on software quality, this work has been limited to a small number of systems. Therefore, we conduct an extensive investigation that compares the relationship between both approaches and software quality on a larger number of projects. We assess how code smells—in particular, god classes (metric-based approach)—and SATD (comment-based approach) are associated with software quality by determining: (i) whether god and SATD files have more defects than non-god and non-SATD files, (ii) whether god and SATD changes induce future defects at a higher rate than non-god and non-SATD changes, (iii) whether god and SATD changes are more difficult to perform than non-god and non-SATD changes and (iv) how much the metric- and comment-based approaches to technical debt file identification overlap. Our results indicate that: (i) neither god nor SATD files are correlated with defects, (ii) introduction of future defects is higher for god- and SATD-related changes, (iii) god- and SATD-related changes are more difficult to perform and (iv) the metric-comment technical debt file overlap ranges from 11% to 34%.

Overall, our study indicates that although technical debt—whether measured by the SATD or god classes—may have negative effects, these do not include file-level defects. Rather, the detriments of technical debt are its tendencies to introduce future defects at an elevated rate and to make the system more difficult to change in the future. In terms of detection methods, our work advocates implementing both the comment- and metric-based approaches to maximize the sources of technical debt identified.


identifier: Stewart, Dane  (2017) The History of Sexuality: A Research-Creation Model for Generating Ethical Representations of Queerness through Verbatim Theatre.  Masters thesis, Concordia University.

abstract:
The History of Sexuality is a two-act play in the genre of fictionalized verbatim theatre.
The play was developed through a collaborative research-creation project engaging members of Montreal’s queer communities. Findings from the research-creation project suggest a methodological approach for creating queer fictionalized verbatim theatre which (1) exposes the inevitable impact of authorial subjectivity on processes of scholarly knowledge-production, and (2) suggests, through analysis of a research and playwrighting process, possibilities for ethical consideration in collaborating with and representing others in theatrical performance.


identifier: Herriot, Heather  (2017) Intra-Individual Cortisol Variability and Low-Grade Inflammation over 10 Years in Older Adults.  Masters thesis, Concordia University.

abstract: This study examined the associations between intra-individual variability in, and inter-individual levels of, diurnal cortisol secretion with a marker of low-grade inflammation (i.e., C-Reactive Protein; CRP). Reasoning that greater day-to-day cortisol variability could reflect a dysregulation of the HPA axis, we hypothesized that it would predict higher levels of CRP, above and beyond inter-individual differences in cortisol levels. A 10-year longitudinal study of 130 older adults examined diurnal cortisol secretion on three different days across each of the 6 waves of data collection and levels of CRP during the last 3 waves. Indicators of mean cortisol levels, short-term cortisol variability, and long-term cortisol variability were analyzed. Hierarchical linear modeling showed significant main effects, linking baseline mean cortisol levels, T-ratio = 2.25, p = 0.03, and long-term cortisol variability, T-ratio = 2.63, p = 0.01, with higher CRP values six to ten years after study entry. In addition, a two-way interaction demonstrated that short-term variability in cortisol were associated with higher levels of CRP among individuals who secreted relatively high, T-ratio = 2.68, p = 0.01, but not low, T-ratio = −1.09, p = 0.28, baseline levels of cortisol. Finally, a three-way interaction, T-ratio = 2.24, p = 0.03, suggested that the effect of long-term cortisol variability on CRP became stronger over time among participants who secreted high average levels of cortisol, whereas it became weaker among their counterparts who secreted low average levels of cortisol.


identifier: MacSwain, Kayleigh  (2017) Discourses and Practices of Whiteness in the Alternative Food Movement in Halifax, Nova Scotia.  Masters thesis, Concordia University.

abstract: The alternative food movement is a collaborative effort to build more environmentally and socially just food systems in order to enhance the health and resiliency of communities. Contemporary trends in food politics have emerged in Canada over the past 40 years, as people work to develop equitable alternatives to the dominant agrifood system. This thesis intervenes at this point and interrogates the discourses and practices within the alternative food movement with the aim of illustrating how race and class based oppressions can be unknowingly embedded in the workings of an organization. It does this through discourse analysis and participant observation, which forms the basis of a case study of The Food Action Committee (FAC) in Halifax, N.S. Drawing on an interdisciplinary literature with a particular emphasis on critical geography, this thesis demonstrates that the circulation of whitened discourses and practices in FAC can inadvertently naturalize and reinforce exclusionary processes which may engender particular exclusions. These forms of inequality - including historical processes of dispossession and racial and other exclusions – are felt most strongly in the marginal communities the committee aims to support. This occurs through an adherence in the organization to discourses of universalism and colour blindness, as well as to universalizing practices such as exclusionary conceptualizations of community and participation. While it is clear that FAC is well intentioned in regards to diversity within the organization, this critique opens a path towards a more genuine form of social inclusion in the organization and in the alternative food movement.


identifier: Donald, Lorraine  (2017) Temporary workers in Montréal's warehousing sector.  Masters thesis, Concordia University.

abstract: The warehouse is a key node in the commodity chain and its workers play a vital role in the delivery of goods to the market. The work is increasingly dependent upon the use of temporary workers in lieu of permanent staff. Although legislation secures minimum labour and safety standards, the complications that arise from a triangular work relationship make for unfavorable working conditions, and difficult enforcement and interpretation of labour laws. Through twelve in-depth, semi-structured interviews, document analysis and participant observation, this case study highlights the experiences of a group of warehouse and factory workers. The research questions focus on the varied obstacles the workers face navigating contingent relationships within the workplace. Through this sector specific analysis, the findings highlight pressing issues in terms of job security, working conditions and broader social and integration concerns caused and exacerbated by this precarious employment. The nature and extent of warehouse-related work is unique in the sense that it is fast-paced and controlled by agencies and client enterprises in ways that make workers especially vulnerable to certain on-the-job dangers, and unscrupulous business tactics. Foregrounding the diverse experiences that arise as a result of the lack of accountability measures in the industry also points to systemic problems that may affect temporary agency workers, more generally, with and beyond this specific sector. This data thus helps inform progressive labour regulation by demanding the implementation of staffing industry regulations, examining current policy and practice and finally, by acknowledging and supporting the work of social justice organizations. �


identifier: Charron, Renée  (2017) In-corporeal Diagrams: Drawing from Dance to Architecture.  Masters thesis, Concordia University.

abstract: This thesis examines drawing’s potential to revive the role of the body in architectural practices, by unveiling forces and processes that compose our bodies and intertwine with the corporeality of architecture. It establishes drawing as a form of dance and notation capable of inscribing the kinesthetic vitality of the live body into architecture. It looks at Frank Gehry’s sketches as dynamic tracings of embodied gestures that mediate body and landscape, interior and exterior. The sketches are addressed as the residue of forces generating potential bodies of space, as well as formative diagrams that operate as a prehension of the coming into being of building. Drawing’s heuristic role is substantiated by pedagogical and epistemological theories of dance, drawing and architecture education, which situate the affective/haptic kinesthetic body at the center of all in-corporeal experience, perception and conception. The thesis concludes by advancing potential heuristic approaches to embodied drawing in architecture education that could inform processes of conceptualization and enrich the act of sketching as a vital interface between body and architecture.


identifier: Jobin, Joelle  (2016) Adaptive Self-Regulation across Older Adulthood: The Complementary Roles of Dispositional Optimism and Goal Disengagement.  PhD thesis, Concordia University.

abstract:
Current demographics are shifting rapidly and the proportion of older adults in the population is growing. In addition, older adulthood now spans more than 30 years of life (Oeppen & Vaupel, 2002).  Old age is likely to be accompanied by increasing presence of age-related challenges along with diminishing opportunities to attain important life goals (Baltes & Smith, 2003; National Advisory Council on Aging, 2006). Such circumstances may trigger increased psychological stress in the short-term and may require long-term adaptations as important life goals become unattainable (Heckhausen, Wrosch, & Schulz, 2010). Two individual difference variables, dispositional optimism and goal disengagement have been found to be adaptive in the management of stressful life circumstances and may allow older adults to effectively negotiate changes in age-related opportunities and challenges (Scheier et al., 2010; Wrosch et al., 2013).
	Study 1 investigated the role of optimism in the regulation of stress across 6 years in a sample of 135 community dwelling older adults. This study examined the relation between dispositional optimism, perceived stress and cortisol by modelling both, with-in person and between-person associations. Within-person results showed that under circumstances when individuals perceived higher than typical stress levels, optimism buffered against increases across most indicators of cortisol (except CAR). Conversely, between-person results showed that among individuals with higher perceived stress, optimism was associated with a lower CAR. Findings showed that optimism facilitated the physiological management of short-term stress by guarding against increases in cortisol in older adulthood.
	Study 2 examined whether the emotional benefits of optimism vary across older adulthood with declining opportunities to overcome stressors. A total of 171 older adults were assessed over a 6 year period to determine how optimism was related to changes in depressive symptoms and perceived stress across older adulthood. Results showed that dispositional optimism protected participants in early phases of older adulthood from exhibiting elevations in depressive symptoms over time, but had reduced benefits among those in advanced old age. The age-related association between optimism and depressive symptoms was most evident during times of stress. These results suggest that the adaptive effects of dispositional optimism become reduced in advanced old age.
	Study 3 explored the age-related associations between goal disengagement capacities, emotional distress, and changes in disease severity across older adulthood.  This study examined 131 older adults to determine whether goal disengagement capacities protect older adults particularly in advanced old age against experienced illness by preventing emotional distress. Results indicated that goal disengagement capacities protected against 6-year increases in older adults’ self-reported cold symptoms, this effect was particularly pronounced among those in advanced old age. Changes in depressive symptoms were found to mediate the age-related association between goal disengagement and changes in cold symptoms. These findings suggest that as older adults advance in age, goal disengagement capacities may become increasingly important for protecting emotional well-being and physical health.
	Overall, the findings outlined have important implications for research in the areas of personality, aging and health.  Mechanisms through which dispositional optimism and goal disengagement facilitate the adaptive management of stress throughout older adulthood are highlighted. This research broadens existing life-span theories of motivation by integrating theories of personality with goal-specific processes and may reveal pathways to successful development in older adulthood.  Limitations and future directions are discussed.


identifier: Jun, Cheng  (2017) An Experimental and Computational Study of Natural and Hybrid Ventilation in Buildings.  Masters thesis, Concordia University.

abstract: This thesis presents a few empirical formulas established by previous studies and considers their viability for more general use to determine natural ventilation airflow rates under both ventilation strategies, i.e. single-sided ventilation and cross-ventilation. By utilizing computational fluid dynamics (CFD), a series of computational simulations are conducted to determine decisive ventilation variables such as the wind incidence angle and the height of the building. Both main turbulence models, the Reynolds-averaged Navier-Stokes (RANS) two-equation standard k-ε model and the Large Eddy Simulation (LES) model are used in CFD simulations for model validation and results are compared with experimental data under steady state. The natural ventilation energy saving potentials for both ventilation strategies are determined and compared based on the empirical equations with newly developed coefficients. Additionally, such a method of evaluating natural ventilation energy saving potential can be applied during the building’s early design stage as shown by a case study. Nevertheless, as a practical application of natural ventilation in a high-rise building, the hybrid ventilation system in Concordia University’s EV building is studied for greater understanding and optimization of its performance. Throughout the full-scale measurements and whole-building simulations (by CONTAM), it is determined that the five-zone simplified model is accurate and helpful for further developing predictive control strategies in real buildings. A demo case study of damper opening optimization is also presented.


identifier: Donegan, Eleanor  (2016) CBT and Interpretation Bias Modification for Generalized Anxiety Disorder: Examining the Roles of Intolerance of Uncertainty and Interpretation Bias in Symptom Reduction.  PhD thesis, Concordia University.

abstract:
ABSTRACT
CBT and Interpretation Bias Modification for Generalized Anxiety Disorder: Examining the Roles of Intolerance of Uncertainty and Interpretation Bias in Symptom Reduction

Eleanor Donegan, Ph.D.
Concordia University, 2016

	Generalized Anxiety Disorder (GAD) is characterized by excessive worry and anxiety (APA, 2013). Although cognitive behaviour therapy (CBT) is efficacious, 20-50% of individuals with GAD continue to meet diagnostic criteria following treatment (Hanrahan et al., 2013). To improve outcomes, it is essential that we develop a better understanding of the factors involved in symptom reduction and ensure that these factors are targeted effectively. Two factors that are associated with excessive worry and anxiety are intolerance of uncertainty (IU) and negative interpretation bias (Ladouceur et al., 2000; Rosen & Knaüper, 2009), both of which have been proposed to play a role in the maintenance of GAD symptoms (Hayes & Hirsch, 2007; Koerner & Dugas, 2006). In this program of research, the first goal was to examine the impact of an IU-focused CBT (Dugas & Ladouceur, 2000) on IU and negative interpretation bias and to determine whether these factors played a role in symptom reduction. In Study 1, 80 adults completed CBT for GAD. By post-treatment, CBT was associated with reductions in GAD symptoms, IU and negative interpretation bias. Moreover, reductions in negative interpretation bias predicted reductions in GAD symptoms and this effect was partially mediated by reductions in IU. Cognitive bias modification programs (CBM-I) have also been developed to target interpretation bias, primarily among socially anxious individuals, and have been proposed as low-cost alternatives to CBT (Amir & Taylor, 2012). The second goal in this program of research was to validate a new CBM-I program designed to target interpretation bias in GAD worry domains. In Study 2, participants who completed CBM-I (n = 16) exhibited greater reductions in negative interpretation bias than participants in an interpretation control condition (n = 14). However, CBM-I training did not lead to anticipated reductions in worry or anxiety. Overall, this program of research provided further support for an IU-focused CBT and insight into change processes during treatment. Although the CBM-I program examined here cannot yet be recommended as a stand-alone intervention, other clinical uses of CBM-I are discussed, including the possibility of implementing CBM-I as an adjunct intervention to enhance the efficacy of CBT.


identifier: Nassief, Wael  (2017) Cross-dock door assignments: models, algorithms and extensions.  PhD thesis, Concordia University.

abstract: In a cross-dock, goods coming from numerous origins get unloaded from incoming trucks, consolidated according to their destinations, and then loaded into outgoing trucks with little or no storage in between. We study a class of cross-dock door assignment problems where the assignments of origins (or incoming trucks) to inbound doors, and destinations (or outgoing trucks) to outbound doors are determined with the objective of minimizing the handling cost. Cross-dock door assignment problems are a fundamental class of optimization problems in cross-docking as they arise in more complex operational problems incorporating other decisions such as scheduling, routing, and workforce allocation. We first introduce several linear mixed integer programming formulations with Lagrangean relaxation and column generation algorithms based on some of these formulations. We then theoretically and computationally compare these formulations in terms of their linear, Lagrangean and combinatorial relaxations. Finally, we integrate the assignments with sequencing and selection decisions, based on our observations on a large cross-dock company in the USA, and introduce two new integer programming formulations. Where possible, our work is compared with existing ones, and new sets of instances are generated to either vary or enlarge the current data sets in the literature.


identifier: Danielski, Aleksander  (2017) Analytical Structure of Stationary Flows of an Ideal Incompressible Fluid.  Masters thesis, Concordia University.

abstract: The Euler equations describing the flow of an incompressible, inviscid fluid of uniform density were first published by Euler in 1757. One of the recent results of mathematical fluid dynamics was the discovery that the particle trajectories of such flows are real analytic curves, despite limited regularity of the initial flow (Serfati, Shnirelman, and others). Hence, the flow lines of stationary solutions to the Euler equations are real analytic curves. In this work we consider a two-dimensional stationary flow in a periodic strip. Our goal is to incorporate the analytic structure of the flow lines into the solution of the problem. The equation for the stream function is transformed to new variables, more appropriate for the further analysis. New classes of functions are introduced to take into account the partial analytic structure of solutions. This makes it possible to regard the problem as an analytic operator equation in a complex Banach space. The Implicit Function theorem for complex Banach spaces is applied to establish existence of unique solutions to the problem and the analytic dependence of these solutions on the parameters. Our approach avoids working in the Frechet spaces and using the Nash-Moser-Hamilton Implicit Function Theorem used by the previous authors (Sverak & Choffrut), and provides stronger results.


identifier: Bergamaschi, Francesca  (2017) Bad reduction of Hilbert modular varieties with parahoric level structure.  PhD thesis, Concordia University.

abstract:
Abelian varieties can be thought of as a higher dimensional analogue to elliptic curves. Over fields, they are defined as complete algebraic varieties with a compatible group structure. One of the most fertile fields in arithmetic geometry is concerned with the study of abelian varieties in prime characteristic. The fundamental reason why this area has become so central is that the many interesting phenomena arising in positive characteristic provide us with very powerful geometric tools. For instance, several results in characteristic zero can be derived studying the reduction to positive characteristic.

A very fruitful approach for describing such phenomena is to look at several abelian varieties at once. Roughly speaking, the abelian varieties of a given dimension are seen as points of a space, namely a \emph{moduli space}. In general, in order for these spaces to have \emph{nice} geometric properties, we will expect the abelian varieties to have additional structure, such as, for example, some data on the $N$-torsion (kernel of the multiplication by $N$ map, for some positive integer $N$), called a structure of level $N$. The fundamental example in this context is that of modular curves that is, spaces whose points parametrize (isomorphism classes of) elliptic curves with some level $N$ structure. The work of the author focuses on a generalization of modular curves, that is, Hilbert modular varieties, parametrizing abelian varieties with polarization, $N$-level structure and real multiplication, that is, an action by a suitable finite field extension of $\Q$.

The most immediate questions arising from the study of such spaces are purely of geometric nature. The geometry of Hilbert modular varieties is well understood in every characteristic $p$, as long as $p$ does not divide the level structure. When $p$ divides the level structure however, things get complicated. In this thesis we provide a description of Hilbert modular varieties in the case when $p$ divides the level $N$ (case of \emph{parahoric} level). In particular, we obtain an understanding of these spaces by giving a full description of the deformation of abelian varieties and by defining suitable \emph{stratifications} depending on the $p$-torsion of abelian varieties.


identifier: Capa, Canan  (2017) Conflict-Free Airport Operations Planning and Management.  Masters thesis, Concordia University.

abstract:
This thesis proposes conflict-free mathematical models and solution strategies for both gate scheduling and taxiway scheduling problems by taking account all meaningful airport and flight characteristics into consideration that are not yet extensively studied in current academic literature. Since gate schedule performance has a great impact on the performance of the taxiway, we consider gate scheduling as a bi-objective optimization problem, present mathematical models and propose a two-phase solution approach. We also propose a mixed integer programming (MIP) model that considers collision avoidance on the taxiways, separation distances between aircrafts, speed changes and exact travelling times without adapting a state-time network in which the decision variables are defined with time indices. Instead, the non-time segmented model proposed in this thesis, determines a taxi plan for each aircraft by identifying the sequence of taxiway intersections represented as nodes to be visited and determines the aircrafts’ exact arrival and departure times to these nodes, average speed used on the taxiway represented as links between two consecutive nodes while ensuring the safety conditions that avoid aircraft collisions. The cost incurred from arrival and departure delays with total taxiing time is minimized. The model enables collision free airport operations considering both airlines and airport controller’s objectives in continuous time where we know the exact arrival and departure times which is more accurate in tackling collision issues. However, accuracy comes with a cost of solution time. To overcome the difficulty to solve, strategies are proposed. The first strategy proposed, called the iterative-TSM, adopts a batch by batch policy and optimizes the TSM by solving it in an iterative way where in each iteration, schedules of the previous iteration are fixed. The second strategy proposed motivates from the idea of decomposition the model into two as routing and timing problem and incorporates a genetic algorithms with TSM. All the models proposed are tested on a hypothetical data and the results are presented. Main contributions of this thesis can be listed as follows:
•	A MILP model is presented for flight gate scheduling problem. The model is compared to modified version of one of the existing MILP model in literature and efficiency of the proposed model is evaluated. A two phase solution approach making use of the proposed MILP is also presented and the characteristics of the problem are analysed. While utilization of gates is maximized, on time performance is also considered.
•	A MILP that considers collision avoidance on the taxiways, separation distances between aircrafts, speed changes and exact travelling times without adapting a state-time network in which the decision variables are defined with time indices. Instead, all safety constraints are modeled with Big-Ms. This enables us to know the exact arrival and departure times for each flight on each link on the ground.
•	Collision free taxiway scheduling is achieved. Since the models in the existing literature either assumes arbitrary capacities on the nodes of the network or discretizes time, they do not guarantee collision avoidance.
•	Speed changes, rerouting, and holding at gates and taxiway intersections are used as control options.
•	Both airlines and airport authorities’ objectives are considered. Proposed models have the capability to be adopted as a decision support tool for the ground controllers and they allow airport traffic authorities to do what-if analysis in case of a change in the flight or airport network information. Proposed TSM also minimizes to total taxiing time which results in less costly taxiway schedules for airlines in terms of fuel costs and CO2 emissions.
•	Two solution strategies are proposed for the TSM: iterative TSM and GA-TSM. While iterative TSM decomposes the problem into batches of flights, solves each batch by fixing the schedules of the previous batch in each batch, GA-TSM decomposes the problem into routing and timing. While GA searches for the best set of routes for the flights, fixed TSM solves the timing problem for a given set of routes.


identifier: Kazma, Ghaith  (2017) Analysis of Single Event Upsets Propagation at Register Transfer Level in Combinational and Sequential Circuits Based on Satisfiability Modulo Theories.  Masters thesis, Concordia University.

abstract:
The progressive scaling of semiconductor technologies has led to significant performance improvements in digital designs. However, ultra-deep sub-micron technologies have increased the vulnerability of VLSI designs to soft errors. In order to allow a cost-effective reliability aware design process, it is critical to assess soft error reliability parameters in early design stages. This thesis proposes a new technique to model, analyze and estimate the propagation of Single Event Upsets (SEUs) in combinational and sequential designs described at the Register Transfer Level (RTL) using Satisfiability Modulo Theories (SMT). The propagation of SEUs through RTL bit-vector constructs is modeled as a Satisfiability problem using the SMT theory of bit-vectors.

At first, for combinational designs, two different analysis techniques, concrete and abstract modeling, are used in order to investigate the efficiency and accuracy of a data type reduction technique for soft error analysis. To analyze the vulnerability of the combinational circuits, we compute the Soft Error Rate (SER), which is a summation of the propagation probabilities. Concrete modeling uses two versions of the design, one faulty and one fault-free, in order to analyze SEU propagation. Abstract modeling uses a data type reduction technique to evaluate the difference in performance and accuracy over the first method. Experimental results demonstrate that the loss in accuracy due to abstract modeling depends on the design behavior. However, abstract modeling allows to reduce processing time significantly.

Following this first approach, the methodology is then extended to model and analyze SEU propagation in sequential circuits at RTL. In order to estimate the vulnerability of sequential circuits to soft errors, the methodology must be adapted to represent state transitions. To do so, we present an approach that uses circuit unrolling. This approach uses multiple unrolled copies of the design to represent the various state transitions. The fault propagation is then analyzed through a certain number of states. Useful information regarding the vulnerability to SEUs of the sequential circuit can then be generated. The propagation probabilities can be computed from the SEU injection cycle to multiple subsequent cycles. These results are then used to estimate the circuit Soft Error Rate (SER). Experimental results demonstrate the effectiveness and the applicability of the proposed approach.

Finally, we present a new methodology to estimate digital circuit vulnerability to soft errors at Register Transfer Level (RTL). Single Event Upsets (SEUs) propagation through RTL bit-vector operations is modeled and analyzed using a different modeling approach based on Satisfiability Modulo Theories (SMTs). The objective of this new approach is to improve the efficiency of the analysis. For instance, the bit-vector reduction operators and arithmetic operators were modeled in SMT to include the fault propagation properties. This approach uses only one copy of the design to do the analysis. This means that the fault propagation properties are embedded within the SMT equivalent of the RTL constructs themselves, and therefore does not require two-copies of the design to analyze. In order to illustrate the practical utilization of our work, we have analyzed different RTL combinational circuits. Experimental results demonstrate that the proposed framework is faster than other comparable contemporary techniques. Moreover, it provides more accurate and detailed results of the circuit vulnerability allowing a more efficient applicability of fault tolerance techniques.


identifier: Palys, Sylwester  (2017) A bioinformatics characterization of secondary metabolism and alkyl citric acid pathway reconstruction in Aspergillus niger NRRL3.  Masters thesis, Concordia University.

abstract: Secondary metabolites (SMs) from fungi have become an integral part of various scientific and medical fields as well as providing economic benefits.  The genes involved in the biosynthesis of fungal and bacterial SMs are often co-localized in closely linked clusters that are generally dormant under laboratory conditions.  Genomics technologies are being intensively used to identify SM gene clusters, and suggest methods to promote their expression.  These efforts have already been used to discover new natural products, reveal the biosynthetic underpinnings of known products, and establish methods to eliminate toxic substances from industrially relevant organisms.  An important aspect of SM gene cluster characterization is the development of methods to overproduce known compounds which are difficult to synthesize in the lab.  This thesis presents the annotation of SM gene clusters in the sequenced genome of Aspergillus niger NRRL3.   Using our cluster data as a guide to induce production of secondary metabolites through the overproduction of clustered transcription factors, we confirm the identity of the regulators that are involved in the biosynthesis of the fumonisins, TAN-1612/BMS-192548, and the azanigerones which were also used as positive controls.  Additionally, we discovered three previously uncharacterized regulators of compounds whose masses correspond to the malformins, pyrophen, and the alkyl citric acids hexylitaconic acid, 2-carboxymethyl-3-hexylmaleic acid and the tensyuic acids.   Selecting the alkyl citric acids for further investigation, we obtained a transcriptomic profile to define the genes of the alkyl citric acid gene cluster in A. niger.  Using the identified compounds from mass spectrometry and NMR as well as the functional annotations of our defined cluster, I reconstruct a biosynthetic pathway for the alkyl citrates I identified.  I then tested the robustness of my reconstruction by successfully predicting the accumulation of two early precursors, 2-hexylcitric acid (log2 fold change = 2.982 ± 0.15, p-value < 0.01) and its anhydride (log2 fold change = 3.792 ± 0.26, p-value < 0.01), as well as the elimination of all downstream compounds.


identifier: Zhu, Yajing  (2017) Dependence Modelling and Testing: Copula and Varying Coefficient Model with Missing Data.  PhD thesis, Concordia University.

abstract:
This thesis investigates three topics in theoretical econometrics: goodness-of-fit tests for copulas,
copula density estimators which preserve the copula property, and bias-correction for the naive
kernel local linear estimators in the two-sample varying coefficient model with missing data.
In the first topic a family of goodness-of-fit tests for copulas is proposed. The tests use generalizations
of the information matrix equality of White (1982). The asymptotic distribution of the
generalized tests is derived. In Monte Carlo simulations, the behavior of the new tests is compared
with several Cramer-von Mises type tests and the desired properties of the new tests are confirmed
in high dimensions. In the second topic, a semi-parametric copula density estimation procedure
that guarantees that the estimator is a genuine copula density is outlined. A simulation-based study
is constructed to examine the performance of the proposed copula density estimation method and
compare it with the leading copula density estimators in the literature. The method is also applied to
estimate copula densities in two empirical cases. The third topic shows that the naive kernel estimator
using matching data is not consistent in the two-sample varying coefficient model with missing
data. A bias-corrected consistent estimator is proposed and the asymptotic theory is discussed. A
simulation study is conducted to support the theoretical results.


identifier: Abdul Karim, Mahmoud  (2017) The Molecular Mechanisms Underlying Fusion Events at the Lysosome Membrane.  PhD thesis, Concordia University.

abstract:
Lysosome membrane fusion represents the last step of the endocytic pathway. During endocytosis, internalized surface proteins are delivered to endosomes where they are packaged into intraluminal vesicles (ILVs). Multiple rounds of ILV formation produce mature multivesicular body (MVB) that fuses with lysosomes to expose protein-laden ILVs to lumenal acid hydrolases for catabolism. Lysosomes also undergo homotypic membrane fusion for remodeling in response to cellular stress, or aging, or for organelle inheritance. A unique feature of homotypic lysosome fusion is the formation of IntraLumenal Fragments (ILF), whereby portions of the membranes are internalized and degraded upon merging. Although critical for homeostasis and remodeling, it is not clear how ILFs are formed during the homotypic lipid bilayer fusion reaction, nor is it clear whether similar molecular mechanisms orchestrate MVB-lysosome fusion.
         Using Saccharomyces cerevisiae and its vacuolar lysosome as a model, I show that coordinated interactions between the fusion protein machinery (Rab-GTPase Ypt7 and its effector Vps41), and the protein kinase Yck3, target hemifusion intermediates to control ILF formation upon vacuolar lysosome fusion. To do so, I introduced a point mutation in Ypt7 (D44N) that permits activation but impairs binding to Vps41 causing it to be phosphorylated by Yck3. Phosphorylated Vps41 causes the multisubunit tethering complex HOPS to dissociate from vacuolar lysosome membranes preventing efficient trans-SNARE pairing required for lipid bilayer pore formation. This stall in pore formation allows hemifusion diaphragms to expand across docked organelle interfaces causing fewer ILFs to form. Knocking out YCK3 stabilizes Vps41 and HOPS on membranes restoring fusion defects and ILF formation.
          With a better understanding of homotypic vacuolar lysosome fusion and ILF formation, I next determined if MVB-vacuolar lysosome fusion relies on a similar mechanism. By developing a new luminal β-lactamase complementation assay to measure MVB-vacuolar lysosome fusion in vitro, I show that both fusion events require Ypt7 and HOPS, but heterotypic fusion is distinct in that it uses a unique non-canonical Q-SNARE bundle composed of the endosomal Qa-SNARE Pep12, Qb-SNARE Vti1, and soluble Qc-SNARE Vam7, that complexes with the lysosomal R-SNARE Nyv1 to drive lipid bilayer merger. Loss-of-function mutations that impair MVB maturation-deleting the endosomal Na+(K+)/H+ exchanger NHX1 or components of the ESCRT machinery that drive ILV formation blocks heterotypic membrane fusion. Correcting luminal pH rescues the fusion impairment caused by deleting NHX1, whereas activating the Rab-GTPase Ypt7 rescues fusion defects caused by ESCRT dysfunction.
          Using new insights from these results, I present refined working models describing the molecular underpinnings of homotypic vacuolar lysosome and MVB-vacuolar lysosome fusion. Because all of the underlying machinery is conserved in all eukaryotic phyla, I anticipate that they will be used to help design strategies to treat human disorders linked to mutations in genes implicated in these pathways.


identifier: Andrus, Bruno Victor  (2017) Trajectoires fluides et croisements lumineux : histoire du verre d’art au Québec dans le contexte d’Expo 67.  PhD thesis, Concordia University.

abstract: The main objective of this thesis is to propose the first historical account and contextual narrative of the artistic practice of glassblowing in Québec. The analysis begins in 1960, with the founding of industrial units in Montréal by Venetian glassblowers and ends in 1990, with the establishment of the college-level glass program at Espace verre. Expo 67 was a major event in the development of this field of cultural production in Québec but also, more widely, in North America and in Europe. Indeed the world’s fair held in 1967 in Montréal played a crucial role with regard to the production, distribution, reception, teaching and institutionalization of glass art in Québec and internationally. This thesis thus traces the biographies of actors and networks of actors – consisting of people, objects and practices – all of which are connected in some way to Expo 67, as well as the effect of these intersecting trajectories on the subsequent development of glass. In the particular social context of Québec during and following the Quiet Revolution, artistic glassblowing mostly emerged within the larger category of métiers d’art. In this shifting socio-cultural landscape, artisanal productions were invested with different values, linked to the negotiation of status and identity. In a theoretical sense this thesis shows how the development of the field of artistic glassblowing was articulated through the shifting status of categories such as métiers d’art, design, industry, architecture, and the visual arts. In fact, the hybrid practices and spaces of convergences between these categories are emphasized in this account. The ambiguous cultural status of glassblowing in Québec necessitated an interdisciplinary approach, drawing on the scholarship of Arjun Appadurai and Igor Kopytoff (the biography of things), Bruno Latour (the actor-network theory), as well as that of sociologist Pierre Bourdieu.


identifier: Singh, Jai Puneet  (2017) Proportional Data Modeling using Unsupervised Learning and Applications.  Masters thesis, Concordia University.

abstract: In this thesis, we propose the consideration of Aitchison’s distance in K-means clustering algorithm. It has been used for initialization of Dirichlet and generalized Dirichlet mixture models. This activity is then followed by that of estimating model parameters using Expectation-Maximization algorithm. This method has been further exploited by using it for intrusion detection where we statistically analyze entire NSL-KDD data-set. In addition, we present an unsupervised learning algorithm for finite mixture models with the integration of spatial information using Markov random field (MRF). The mixture model is based on Dirichlet and generalized Dirichlet distributions. This method uses Markov random field to incorporate spatial information between neighboring pixels into a mixture model. This segmentation model is also learned by Expectation-Maximization algorithm using Newton-Raphson approach. The obtained results using real images data-sets are more encouraging than those obtained using similar approaches.


identifier: Lefevre, Kathleen Victoria  (2017) Play Histories of Seniors Seen Through Their Life Stories: Seniors' Playful Art Education.  Masters thesis, Concordia University.

abstract: This research asks: (a) how does the playful art education of three senior citizens in Montreal, who are ages sixty-five and over, relate to their stories of play from different developmental stages of life, and (b) how do each of these seniors define their play today? This study addresses the absence of play theory’s application to seniors’ art education. I observed, recorded, and analyzed play at three, distinct, art education settings for Montreal seniors. Observational visits to each site, and audio recorded interviews capturing glimpses of each participant’s “play history” provided insight into what play in art education means to each of the participants. This allowed details to emerge about each participant’s definition of play as a senior. My analysis looked at the meaning of these definitions within the context of each senior’s unique play history that she provided through stories. Stories allowed the participants’ voices to be amplified in this study. It is important that seniors’ voices are heard because Canada has a rising senior population that it must better support (Federation of Canadian Municipalities, 2013). Understanding how seniors define their play could help develop seniors’ playful art centred education (SPACE) as a form of support for the elderly. This research concludes that most of the participants’ past and present play experiences were: (a) highly individualized, (b) social, (c) culturally informed, (d) connected to nature, family, and income, and (e) intertwined with play histories. Yet, more research is needed to see how far these patterns extend across larger and more diverse senior populations. Play theory must work towards distinguishing non-seniors’ adult play from seniors’ play. Art education programs may be able to enhance seniors’ play by using seniors’ play histories as springboards for curriculum development, but caution is warranted here due to how much seniors’ play could be based on personal play preferences and individual temperaments.


identifier: Massey, William  (2017) Assessing the impact of riprap bank stabilization on fish habitat: A study of Lowland and Appalachian streams in Southern Québec.  Masters thesis, Concordia University.

abstract: There is a growing concern over the potential environmental impacts of riverbank stabilization using rock riprap as the occurrence of these structures continues to increase in river networks. Habitat diversity and quality are often used as a proxy for fish community health. Habitat assessments, however, frequently yield contrasting results between studies and it remains unclear how non-salmonid species in small streams may be affected by bank stabilization. The aim of this thesis was to evaluate how riprap structures impact fish habitat in small Lowland and Appalachian streams by combining quantitative and qualitative approaches. Metrics measured were: mesohabitat and in-stream cover proportions, Hydro-Morphological Index of Diversity (HMID), and a modified Qualitative Habitat Evaluation Index (QHEI). Results show that in more pristine Appalachian streams, QHEI scores are lower at stabilized reaches due to loss of in-stream cover and riparian vegetation. However, riprap stabilization had less impact on already altered, straightened Lowland streams. In this latter context, some possibly beneficial alterations of fish habitat were observed in riprapped reaches due to the coarsening of the substrate and an induced increase of slope. These positive effects are, however, limited to short stabilized reaches, and extensive (> 100 m) riprapping of the bed should be avoided as it can result in the drying of the bed during summer months, as was observed in this study in some tributaries of the Salvail River. Both metrics (HMID and QHEI) revealed the positive or neutral effect of riprap on increasing flow diversity and heterogeneity for Lowlands sites with a correlation of 0.72 (p <0.01). However their effect scores are inconsistent in the Appalachian streams as only QHEI showed a negative effect of riprap, suggesting caution when interpreting habitat quality results based on a single metric.


identifier: Lachance, Liam  (2017) Love Memory.  Masters thesis, Concordia University.

title: Love Memory

abstract:
Love Memory is a collection of stories told by two partners in a relationship challenged by a legacy of trauma, forcing them to question if they can stay together and overcome the weight of a history of childhood abuse.

The novella is told in a series of first person narrations that give voice to each side of a relationship conflict. This 'shared' address is fractured by an omniscient narrator, who interrupts the novella to tell a story that reveals what the characters have conveniently been forgetting to mention.

As a collection, Love Memory aims to shine light on themes of stoicism and masculinity with men who deal with Post-Traumatic Stress Disorder (PTSD), examine how these dynamics impact their romantic relationships, and open a dialogue on new ways to address the power dynamics and healing methods for survivors and those who date them.