identifier: Xiaodong, HE  (2020) Folding Photopolymerized Origami Sheets by Post-Curing.  Masters thesis, Concordia University.

abstract:
Origami,which is generally fabricated from one single sheet of paper by sequential folding, has enjoyed a high popularity during the past centuries. Because of the deployability and
ability to reconfigure its shape, it is a promising structural design technique that is utilized in
biomedical and aerospace engineering. The purpose of this paper is to present a novel manufacturing approach to fabricate origami based on 3D printing utilizing digital light processing.
Specifically, it is proposed to leave part of the model uncured during the printing step, and
then cure it in the post-processing shape-setting step in the folded configuration. While the
cured regions in the first step try to regain their unfolded shape, the regions cured in the second step try to keep their folded shape. As a result, the final shape will be obtained when
both regions stresses reach equilibrium. Finite element Analysis is performed in ANSYS to
obtain the stress distribution on common hinge designs. This proves that the square-hinge
has a lower maximum principal stress compared with elliptical and triangle hinges. Based
on the square-hinge and rectangular cavity two variables, the width of the hinge and height
of the cavity, are selected as principal variables to construct relationships between the two
parameters and final folding angle. In the end, experimental verification show that the developed method is valid and reliable to realize the proposed deformation and 3D development
of 2D hinges.


identifier: Ky, Sokphally  (2020) On Properties of Ruled Surfaces and Their Asymptotic Curves.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract:
Ruled surfaces are widely used in mechanical industries, robotic designs, and architecture in functional and fascinating constructions.
Thus, ruled surfaces have not only drawn interest from mathematicians, but also from many scientists such as mechanical engineers, computer scientists, as well as architects.  In this paper, we study ruled surfaces and their properties from the point of view of differential geometry, and we derive specific relations between certain ruled surfaces and  particular curves lying on these surfaces. We investigate the main features of differential geometric properties of ruled surfaces such as their metrics, striction curves, Gauss curvature, mean curvature, and lastly geodesics. We then narrow our focus to two special ruled surfaces: the rectifying developable ruled surface and the principal normal ruled surface of a curve. Working on the properties of these two ruled surfaces, we have seen that certain space curves like cylindrical helix and Bertrand curves, as well as Darboux vector fields on these specific ruled surfaces are  important elements in certain characterizations of these two ruled surfaces. This latter part of the  thesis centers around a paper by Izmuiya and Takeuchi, for which we have considered our own proofs. Along the way, we also touch on the question of uniqueness of striction curves of  doubly ruled surfaces.


identifier: Singh, Annick ORCID: https://orcid.org/0000-0001-5032-9822 <https://orcid.org/0000-0001-5032-9822>  (2020) Anti-predator response and neophobia in juvenile bluegill sunfish (Lepomis macrochirus) across an environmental gradient.  Masters thesis, Concordia University.

abstract: Microhabitats with high structural complexity can impede visual information of local predation threats. This can shape individual behaviour, resulting in more fearful behavioural phenotypes within complex microhabitats. In this experiment, I explored the impact of environmental complexity on shaping individual predator avoidance behaviour. I observed the behaviour of bluegill sunfish (Lepomis macrochirus) along an environmental gradient. I predicted that as visual complexity of the environment increases, antipredator and neophobic response also increases. I conducted in situ observations at Lake Opinicon, where I presented bluegill sunfish shoals with a novel object and one of three different chemosensory stimuli (water, alarm cue or novel odour). Multiple regression analysis found that the strongest predictor, in shaping predator avoidance behaviour, is vegetation diversity. Bluegill sunfish exposed to conspecific alarm cues exhibited stronger avoidance responses under higher diversity patches. Additionally, bluegill sunfish were not neophobic to neither the novel object nor the novel stimuli. Other environmental factors, such as the ratio of open area to visually obscured area, height of vegetation, and depth of the water were not significant predictors of behavioural response. Bluegill sunfish, under elevated risk of predation, have previously been observed to seek refuge in areas of high vegetation, avoiding open, low complexity patches. Instead, I found that in this population of bluegill sunfish, response was not associated with the amount of vegetation within a patch, but more so with an increase in vegetation diversity. Areas with higher vegetation diversity can contain plant species of different spatial structures (broad leaved plants vs thin leaves), potentially obscuring more visual information to the individual. This high diversity may increase visual obscurity in this system, leading prey to respond to conspecific alarm cues with a strong antipredator response.


identifier: Ouyang, Zhiheng  (2019) Single-Channel Speech Enhancement Based on Deep Neural Networks.  Masters thesis, Concordia University.

abstract:
Speech enhancement (SE) aims to improve the speech quality of the degraded speech. Recently, researchers have resorted to deep-learning as a primary tool for speech enhancement, which often features deterministic models adopting supervised training. Typically, a neural network is trained as a mapping function to convert some features of noisy speech to certain targets that can be used to reconstruct clean speech. These methods of speech enhancement using neural networks have been focused on the estimation of spectral magnitude of clean speech considering that estimating spectral phase with neural networks is difficult due to the wrapping effect.

As an alternative, complex spectrum estimation implicitly resolves the phase estimation problem and has been proven to outperform spectral magnitude estimation. In the first contribution of this thesis, a fully convolutional neural network (FCN) is proposed for complex spectrogram estimation. Stacked frequency-dilated convolution is employed to obtain an exponential growth of the receptive field in frequency domain. The proposed network also features an efficient implementation that requires much fewer parameters as compared with conventional deep neural network (DNN) and convolutional neural network (CNN) while still yielding a comparable performance.

Consider that speech enhancement is only useful in noisy conditions, yet conventional SE methods often do not adapt to different noisy conditions. In the second contribution, we proposed a model that provides an automatic "on/off" switch for speech enhancement. It is capable of scaling its computational complexity under different signal-to-noise ratio (SNR) levels by detecting clean or near-clean speech which requires no processing. By adopting information maximizing generative adversarial network (InfoGAN) in a deterministic, supervised manner, we incorporate the functionality of SNR-indicator into the model that adds little additional cost to the system.

We evaluate the proposed SE methods with two objectives: speech intelligibility and application to automatic speech recognition (ASR). Experimental results have shown that the CNN-based model is applicable for both objectives while the InfoGAN-based model is more useful in terms of speech intelligibility. The experiments also show that SE for ASR may be more challenging than improving the speech intelligibility, where a series of factors, including training dataset and neural network models, would impact the ASR performance.


identifier: Sultana, Ankhy  (2020) Numerical Assessment of Directional Energy Transfer for Geometric Structure.  Masters thesis, Concordia University.

abstract: Energy is the capacity to do work, and mechanical work is the amount of energy transferred by force. Hence, energy can be represented in the form of deformation obtained by the applied force. Energy transfer is defined in physics when the energy is moved from one place to another or energy is transferred from one form to another form. To make the energy transfer functional, energy should be moved in the right direction, at the right location, at the right time and large enough to produce a difference. If it is possible to make better use of the energy in the right direction at the right moment, the energy efficiency of the structure can be enhanced. This idea leads to the concept of directional energy transfer (DET), which refers to transferring energy from one direction to a specific direction. As force and deformation in the particular direction are responsible for the energy in that particular direction, structural properties like geometry or material can have an impact on DET property of the structure. With the recent development of additive manufacturing, complex structures can be applied to various applications to enhance performances, like a wheel and shoe mid-sole. For example, lattice structures are produced to attain lightweight, maintaining strength and specific mechanical properties. While many works are related to structural strength, there is limited research in DET. In this study, a theoretical approach is proposed to measure the DET of a structure based on the geometry of the structure, which can be used to evaluate the effectiveness of energy transfer. The purpose is to understand the energy transfer behaviour of a structure and to measure if a structure is able to transfer energy from one direction to the desired direction. The designs tested were inspired by lattice structures. However, the tested structures do not represent optimized DET structures. The contributions in this work are developing a more generalized mathematical model to implement the mathematical model to build the concept and measure the structure-property of directional energy transfer. And also the goal includes finding out the validity of the concept from the mathematical and experimental point of view.


identifier: Farhang Aghyari, Nima  (2020) Experimental Investigation of Vortex Solitons Transition and New Previously Unapproachable Kelvin Equilibria.  Masters thesis, Concordia University.

abstract:
A series of exploratory tests were conducted in a cylindrical vessel with a revolving disk at the bottom to investigate the behavior of solitary waves in oil vortices. The formation, transition, stability, symmetrically or asymmetrically rotation of stationarywaveswere explored via post image processing through MATLAB. Fast Fourier Transformation function was applied to investigate the performance of the solitary waves in the vortex pattern.

The Spindle oil with kinematic viscosity of 22.7 cSt was used as the working fluid. The experiments were conducted in a relatively shallow liquid situation with a 10 mm initial liquid
height above the rotating disk.

An abrupt disk velocity change was applied to explore the bifurcation or existence of multiple patterns under the same boundary conditions. Its influence on the formation, transition, and behavior of solitons had also been investigated. Eventually, the angular velocity range for the existence of solitons had been identified.

New Kelvin equilibrium states and also groups of the stationary waves were revealed. A demonstration of 1, 2, 3, 4, 11, 12, and 13 solitons rotating symmetrically around the pattern were also identified. Moreover, the possibility of asymmetrical rotation for solitons and the existence of multiple packets of solitary waves group is presented. The ratio between disk velocity and solitons’ frequency is also calculated and compared.

The Weber number was taken to analyze the results which showed the stability of solitons’ frequency and disk speed ratio at about 0.558 having a very low standard deviation.


identifier: ElHussini, Hossam  (2020) The Count of EV Charging: Attacking, Mitigating and Re-envisioning the Infrastructure.  Masters thesis, Concordia University.

abstract: For a genuinely connected smart world, the overlapping of the Internet of Things (IoT) services from different sectors becomes inevitable. One of the rather interesting collaborations is that between Intelligent Transportation Systems (ITS) and Smart Grids. Particularly, a perfect manifestation of such integration of services is the rise of Electric Vehicles (EVs) and their charging infrastructure. Although the full integration of ITS and smart grid services would alleviate the development of self-driving intelligent vehicles, there are major challenges that are yet to be resolved, one of crucial importance is their security. To contextualize such security issues, it is essential to have a clear understanding of the status-quo of EVs and charging ecosystem. In that regard, we survey the entities, protocols, deployment types and major manufacturers of Electric Vehicles Charging Stations (EVCS) and identify the key weaknesses causing security issues. Moreover, we propose a novel attack that exploit the vulnerabilities in the EVCS to create a botnet of them, tamper their schedules and cause frequency disturbances to the power grid. In order to mitigate such an attack, we explore the role of Artificial Intelligence (AI) and Blockchain individually and collaborate in both securing the EV charging ecosystem and efficiently manage the energy trading among EVs, EVCS and power grid. Consequently, we expand on the collaboration of AI and Blockchain and propose an anomaly detection engine to detect the proposed attack demonstrating is effectiveness in flagging anomalous charging behavior. Finally, we re-envision the EV charging ecosystem by integrating both AI and Blockchain to secure both public and private EVCS from the proposed attack.


identifier: Seabrook, Deborah  (2020) The Practice of Music Improvisation to Promote Mental Health and Well-Being: A Multidisciplinary Grounded Theory.  PhD thesis, Concordia University.

abstract:
In this thesis, I employed a constructivist grounded theory methodology to investigate current practices and perspectives among performing musicians, community musicians, and music therapists in order to develop a multidisciplinary understanding of how these practitioners use music improvisation to promote the mental health and well-being of their audiences, community members, and clients, respectively.

Ten participants, recruited through purposeful, snowball, and theoretical sampling, engaged in intensive semi-structured interviews. Of these, seven participants submitted an audio recording of themselves engaging in the practice under study. The musical data were used to guide the interviews for relevant participants. Interview data were analyzed with the support of NVivo software. This involved multidisciplinary, case-specific, cross-case, and theoretical analyses.

The main contribution of this thesis is the development of a substantive grounded theory of music improvisation to promote mental health and well-being as practiced by performing musicians, community musicians, and music therapists. Five grounded theory categories were devised based upon the data. Engaging in the Musical Interpersonal Relationship was identified as the Core Category. The remaining four categories were: (a) Bringing an Understanding of Mental Health and Well-Being; (b) Conceptualizing Links Between Music Improvisation and Mental Health and Well-Being; (c) Applying Intention; and (d) Acting in the Improvisatory Moment. The grounded theory explains that how a practitioner engages in the interpersonal musical relationship with those they are improvising with or for configures their practice of music improvisation to promote mental health and well-being. Furthermore, the theory identifies Affordances of the Relationship Type According to Discipline as a contingency within the Core Category that distinguishes the practice of music improvisation to promote mental health and well-being among disciplinary lines.

The findings of this research establish music improvisation to promote mental health and well-being as both a cross-disciplinary and discipline-specific practice. This may open new directions for relevant multidisciplinary collaboration based upon a mutual understanding of each discipline’s respective potential contributions. Recommendations for future research include inquiry that: (a) incorporates additional related disciplines; and (b) investigates further perspectives (e.g., of audience members, community music participants, and music therapy clients).


identifier: Mercado, Ryan  (2020) Between Crisis and Preservation: The Canadian Jewish Congress and the Quebec Nationalist Movement, 1976-1980.  Masters thesis, Concordia University.

abstract: In November 1976, the predominately English-speaking Jewish population of Quebec found itself in crisis. That month, René Lévesque led the nationalist-oriented Parti Québécois (PQ) to a majority government in the provincial election, promising to enact stricter language laws for the promotion of French and to hold an independence referendum. For the Jews, the prospect of living under a form of nationalism, especially considering their history of persecution under it, led to fear and panic. The governing institution of Canada’s Jewish community, the Canadian Jewish Congress (CJC), stepped in to advocate on behalf of the Jews and defend their civil rights in the face of the PQ. This thesis will examine the CJC as it reacted to three major events in the history of the first PQ government: the 1976 provincial election, the passage of Bill 101, and the 1980 sovereignty-association referendum. Documents from the CJC’s own archives are utilized with its content ultimately showing the CJC reacted in two ways. The Congress responded publicly in a ‘controlled manner’ so as to maintain a calm atmosphere and to reassure a visibly scared Jewish community, while showing its acceptance of some nationalist reforms. Internally, however, reactions ranged from unease and nervousness to outright fear of the direction Quebec society was headed, particularly in the areas of linguistic rights and possible independence. This resulted in the CJC taking actions and stances to calm the Jewish community, and the retention of the status quo in terms of linguistic and civil rights and Quebec’s place in Canada.


identifier: Kumar, Sonal  (2020) Three Essays on Ethical Corporate Behavior.  PhD thesis, Concordia University.

abstract:
The first essay extends the literature on how social and organizational discrimination in the form of glass ceiling, interact with managerial traits in shaping observed leadership effectiveness. We show that when the population of CEOs is stratified by ethnicity and gender, the colored female CEO emerges as the best performing while the white male CEO is consigned among the worst performers. Additionally, the transition from male to female CEOs seems to follow corporate down- turn and precede an upturn. Furthermore, the upswing is strongest following a transition from white male to colored female CEO. We attribute these observed differences between the groups to the existence of the glass ceiling. Discriminatory selection and promotion process potentially imposes much higher demands on candidates belonging to the discriminated group. Thus, the level of ability of the successful average colored female is much higher than those of the average white male CEO. These results potentially have important implications for both policy and research.

The second essay examines whether gender discrimination after women are elevated to positions of power impacts financial reporting quality. Specifically, we extend the literature by using role congruity theory and glass cliff hypothesis to examine the earnings management behavior of female chief executive officers (CEOs) conditional on the power they hold. We find that female CEOs do not necessarily reduce earnings management. For CEOs holding less power, women CEOs demonstrate lower earnings management relative to their male counterparts. However with increased power, we find women and male CEOs to exhibit similar earnings management behaviors. Thus, the earnings management behaviors of women CEOs are not solely dictated by their risk-taking and ethical attitudes, but by the existence of glass cliffs which imposes high demands on women CEOs to conform to their gender roles.

The final essay examines the stock price changes to the firm’s strategic choice towards symbolic and substantive CSR. Our results indicate that stock prices react differently to symbolic and substantive CSR. Symbolic CSR is used as a means to repair reputational damage following a corporate controversy and attracts a positive stock price change consistent with stakeholder wealth maximization theory. In contrast, substantive CSR, undertaken to conform long-term commitment towards CSR is perceived as over-investment by managers in the manifestation of agency leading to a negative stock return-substantive CSR relation. However, no such negative relation between stock returns and substantive CSR is found for a subset of family firms, where the controlling families have a personal interest in the long-term performance of the firm. Overall, the results indicate that the stock market responds to the nature of CSR activities.


identifier: Ahadzadeh Ghanad, Diba  (2020) Implementation of Agriculture Wastes in Different Construction Applications.  Masters thesis, Concordia University.

abstract: Due to the growing population and increasing demand for more construction, much attention has been paid to environmental issues and the devastating effects of overgrowth in nature. Many challenges, including the 2030 challenge, have united developed countries to come together for a better and cleaner future. Canada is one of the allies in this challenge. In recent years, many alternatives to the main components of concrete have been introduced, which is known as one of the most widely used building materials. The use of waste in concrete as a substitute for main natural components (such as aggregates and sand) is one of the most popular methods to reduce environmental pollution by construction during these years. The use of tires, electronic components and agricultural waste are among the uses of waste as an alternative to concrete. Due to its ecofriendly natural, low cost and easy access, agricultural waste has received more attention than others. Several agricultural wastes such as hemp, coconut shells, and others were utilized successfully in producing agro-concrete. However, the limited availability of in-service data and stability of agro-concrete in the agricultural environment, which is very aggressive, is halting its acceptance in the construction industry. Therefore, this dissertation focused on examining the potential of using agro-waste in different construction applications. Effects of various factors including shape, replacement rate and physical properties of used agriculture wastes, type of binding materials, and exposure conditions on mechanical performance were evaluated. Also, a special type of concrete, known as Controlled low strength materials (CLSM), was tested as a potential hosting for high amounts of agro-wastes. Two types of CLSM were evaluated: a cement-based CLSM (i.e. with ordinary Portland cement) and zero-cement CLSM (i.e. with alkali-activated binder). Results showed the high potential of implementing agro-wastes in various construction applications, including agro-concrete, controlled low strength concrete for filling applications and zero-emission materials (i.e. zero cement).Moreover, alkali-activated CLSM showed a greater potential to incorporate a high amount of agro-wastes than that of cement-based CLSM. The research results represent a crucial point in getting these materials as acceptable as construction materials. Also, it will allow the agriculture industry to effectively recycle/reuse the agro-waste, along with converting it to a valuable product. This will have a measurable impact on the Canadian specifications for concrete for farm and livestock buildings.


identifier: Krause, Sandra  (2020) "She was asking for it": An experimental investigation of mental contamination, perceived responsibility, and workplace harassment.  Masters thesis, Concordia University.

abstract:
Background and Objectives: Mental contamination (i.e., contamination concerns that arise in the absence of direct contact with a contaminant) is a common symptom in obsessive-compulsive disorder (OCD). Cognitive theories suggest that it results from individuals’ misinterpretations of perceived violations. Cognitive theories of OCD also highlight the importance of appraisals of inflated responsibility in the maintenance of other OCD symptoms. However, the role of responsibility in mental contamination has not yet been examined experimentally. The present study examined the role of perceived responsibility on the relationship between workplace sexual harassment imagery and subsequent mental contamination.
Methods: One hundred and forty-nine participants listened to a workplace sexual harassment imagery task, wherein responsibility was manipulated. Participants were randomly assigned to one of three conditions (high responsibility (HR), low responsibility (LR), no responsibility (NR)). Participants completed questionnaires assessing mental contamination and completed a hand washing task.
Results: Those in the NR condition reported significantly lower levels of responsibility than those in the LR or HR conditions. Accordingly, those in the NR condition also reported significantly lower levels of anxiety and dirtiness than in the LR condition. There were no significant differences between the LR and HR condition on variables of interest.
Limitations: The nature of the victim blaming used for the responsibility induction may have elicited compensatory responses from participants.
Conclusions: Findings may highlight the central role of perceptions of violation in the understanding and treatment of mental contamination.


identifier: Nasrollahi, Majid  (2019) Automated Bridge Inspection for Concrete Surface Defect Detection Using Deep Neural Network Based on LiDAR Scanning.  Masters thesis, Concordia University.

abstract: Structural inspection and maintenance of bridges are essential to improve the safety and sustainability of the infrastructure systems. Visual inspection using non-equipped eyes is the principal method of detecting surface defects of bridges, which is time-consuming, unsafe, and encounters inspectors falling risks. Therefore, there is a need for automated bridge inspection. Recently, Light Detection and Ranging (LiDAR) scanners are used for detecting surface defects. LiDAR scanners can collect high-quality 3D point cloud datasets. In order to automate the process of structural inspection, it is important to collect proper datasets and use an efficient approach to analyze them and find the defects. Deep Neural Networks (DNNs) have been recently used for detecting 3D objects within 3D point clouds. PointNet and PointNet++ are deep neural networks for classification, part segmentation, and semantic segmentation of point clouds that are modified and adapted in this work to detect surface concrete defects. The research contributions are: (1) Designing a LiDAR-equipped UAV platform for structural inspection using an affordable 2D scanner for data collection, and (2) Proposing a method for detecting concrete surface defects using deep neural networks based on LiDAR generated point clouds. Training and testing datasets are collected from four concrete bridges in Montréal and annotated manually. The point cloud dataset prepared in five areas, which contain more than 51 million points and 2,572 annotated defects in four classes of crack, light spalling, medium spalling, and severe spalling. The accuracies of 75% (adapted PointNet) and 79% (adapted PointNet++) in detecting defects are achieved in binary semantic segmentation.


identifier: Vincent-Boulay, Nicolas  (2020) A Neural Network Approach to Aircraft Performance Model Forecasting.  Masters thesis, Concordia University.

abstract: Performance models used in the aircraft development process are dependent on the assumptions and approximations associated with the engineering equations used to produce them. The design and implementation of these highly complex engineering models are typically associated with a longer development process. This study proposes a non-deterministic approach where machine learning techniques using Artificial Neural Networks are used to predict specific aircraft parameters using available data. The approach yields results that are independent of the equations used in conventional aircraft performance modeling methods and rely on stochastic data and its distribution to extract useful patterns. To test the viability of the approach, a case study is performed comparing a conventional performance model describing the takeoff ground roll distance with the values generated from a neural network using readily-available flight data. The neural network receives as input, and is trained using, aircraft performance parameters including atmospheric conditions (air temperature, air pressure, air density), performance characteristics (flap configuration, thrust setting, MTOW, etc.) and runway conditions (wet, dry, slope angle, etc.). The proposed predictive modeling approach can be tailored for use with a wider range of flight mission profiles such as climb, cruise, descent and landing.


identifier: He, Xiaodong  (2020) Folding Photopolymerized Origami Sheets by Post-Curing.  Masters thesis, Concordia University.


identifier: Eisenhauer, Zachary  (2020) Revisiting the restricted movement paradigm: the dispersal of Atlantic salmon fry from artificial redds.  Masters thesis, Concordia University.

abstract: According to the restricted movement paradigm (RMP), salmonid fry should typically disperse less than 50 m upstream and 500 m downstream from nests or stocking locations. However, recent evidence of juveniles dispersing up to 1600 m suggests that the RMP may be oversimplified for juvenile Atlantic salmon. To test the RMP, we implanted 679 997 eyed Atlantic salmon eggs (Salmo salar L.) into 19 artificial redds over six years in seven tributaries of a large river and then recovered fry via electrofishing to characterize their dispersal over their first summer of life. As expected, most fry dispersed downstream, but an average of 35% of fry moved upstream. Surprisingly, fry moved just as far upstream as downstream (medians = 403 and 404 m, respectively), with average maximum distances of 1.23 km and 2.14 km, respectively. Fry were larger at lower densities and farther from redd sites, consistent with density-dependent growth. After controlling for density, however, fry were larger upstream than downstream, suggesting that larger fry move upstream compared to downstream. While there was variation among streams and years, kurtosis values were largely consistent with a normal distribution around the redd site, with only two of the 19 distributions being leptokurtic. Tributaries had even mixtures of mobile and stationary individuals, indicating a largely homogeneous movement strategy. Our data suggests that salmon fry were more mobile than previously thought, which should facilitate their stocking or reintroduction to new habitats.


identifier: Rahimi, Mohammad  (2019) Discovery of New Oil-Degrading Bacteria with Biosurfactant Production Ability from Oily Tailings Pond Waste, Refinery-Contaminated Soil, Light and Heavy Crude Oils for Remediation of Crude Oil in Water.  Masters thesis, Concordia University.

abstract:
Abstract

Discovery of New Oil-Degrading Bacteria with Biosurfactant Production Ability from Oily Tailings Pond Waste, Refinery-Contaminated Soil, Light and Heavy Crude Oils for Remediation of Crude Oil in Water

Mohammad Rahimi, M.A.Sc.
Concordia University, 2019

Contamination of water and soil with crude oil and petroleum compounds frequently occurs. Removal of oil contamination is often not economically feasible by traditional remediation techniques. Therefore, the development of effective, fast, and bio-based remediation methods that can lessen the damaging effects of oil contamination and lower treatment costs are of great importance. Numerous oil-degrading bacteria with biosurfactant production ability have been isolated from oil-related environments. However, less attention has been given to the application of these compounds in the oil-related activities. The objectives of this study were to discover potential oil-degrading bacteria with biosurfactant (BS) production ability with potential application for crude oil bioremediation from oily tailings pond waste, refinery-contaminated soil, light and heavy crude oils by using the enrichment culture technique. The biodegradation tests were conducted in Erlenmeyer flasks containing water (350 mL, pH 7, salinity of 30 ppt) amended with nutrients and crude oil as the only carbon source (2 mL). The contribution of discovered oil-degrading bacteria in the crude oil biodegradation was determined at different periods of biodegradation by analysis of the remaining of total petroleum hydrocarbons using a gas chromatograph (GC-FID). Moreover, the production and properties of produced biosurfactants were assessed through surface tension (ST) and oil-displacement tests. A total of five oil-degrading bacteria species were discovered from oily tailings pond waste (1 species), refinery-contaminated soil (two species), light crude oil (one species) and heavy crude oil (one species). All species showed biosurfactant production ability. The lowest surface tensions of supernatants at the end of the biodegradation period were between 55 mN/m to 40 mN/m. The minimum ST belonged to the BS produced by species discovered from oily tailings pond waste (40 mN/m). Moreover, an average crude oil biodegradation of 70% was obtained with the isolated bacteria from samples following five weeks of incubation. This study confirmed the fast and effective biodegradation of crude oil by the isolated bacteria with the biosurfactant production as the main mechanism of oil uptake.


identifier: Song, Ziyang  (2019) Nonparametric Bayesian Models Based on Asymmetric Gaussian Distributions.  Masters thesis, Concordia University.

abstract:
Data clustering is a fundamental unsupervised learning approach that impacts several domains such as data mining, computer vision, information retrieval, and pattern recognition. Various clustering techniques have been introduced over the years to discover the patterns. Mixture model is one of the most promising techniques for clustering. The design of mixture models hence involves finding the appropriate parameters and estimating the number of clusters in the data.

The Gaussian mixture model has especially shown good results to tackle this problem. However, the Gaussian assumption is not ideal for modeling asymmetrical data. For achieving an accurate approximation, I investigate the asymmetric Gaussian distribution which is capable of modeling asymmetric data.

A prevalent challenge researchers face when applying mixture models is the correct identification of the adequate number of mixture components to model the data at hand. Hence, in this thesis, I propose statistical algorithms based on asymmetric Gaussian mixture models. I also present novel Bayesian inference frameworks to estimate parameters and learn model structure.

Here, I thoroughly investigate the Bayesian inference framework, including Markov chain Monte Carlo and variational inference approaches, to learn appropriate model structure and precisely estimate parameters. I also incorporate feature selection within the frameworks to choose relevant features set and avoid noisy influence from uninformative features. Furthermore, I investigate nonparametric hierarchical models by introducing Dirichlet process and Pitman-Yor process.


identifier: Smetana, Susanne  (2020) Forgiving and Wounding: A Theological Exploration on Forgiveness and Sexual Violence.  Masters thesis, Concordia University.

abstract:
The following thesis is intended to be an exploration on the current literature discussing forgiveness and applying it in the context of sexual abuse. While there are many Biblical commands to forgive and to love thy neighbour, sexual violence continues to be an issue in most parts of the world. This thesis looks at the Biblical applications of forgiveness, how certain applications of it have been harmful for Christian survivors, and and if it can be applied in a culturally sensitive and psychological helpful manner. This thesis also examines the nature of trauma, both in the psychology community and in Biblical narratives such as the Book of Job and the Rape of Tamar in 2 Samuel.
	The impacts of sexual abuse are numerous: the survivor is found with psychological impact (such as Post-Traumatic Stress Disorder), potential physiological impact, and a breakdown of the self and relationships in community and faith. This thesis found that the spiritual needs of survivors are unique because they run counter to Christian beliefs. While Christians are taught to see a loving, Father God, survivors may reflect their own trauma and instead, see an all-powerful dominating God. While calls to forgive abusers can be callous in some scenarios, the application of forgiveness of the self can be helpful in forging a restorative relationship with God.


identifier: Jones, Maxwell  (2019) Taking Stock of Canada's Approach to Food Insecurity.  Masters thesis, Concordia University.

abstract:
In 1998, the Department of Agriculture and Agri-food published a document entitled Canada’s Action Plan for Food Security, outlining seven commitments stemming from a 1996 World Food Summit in Rome. The goal was to reduce the number of undernourished people in the world by half by the year 2015. Instead, Canada witnessed a slow but steady growth of those identifying as food insecure in the two decades following the publication of the Action Plan. There are many hypotheses as to why that is the case, with the bulk of the literature focusing on a policy environment characterized by government inaction and
overburdened civil society organizations. This thesis argues that this policy environment was not an accident, but the result policy tools selected to address this social issue by successive federal governments. To that end, the thesis employs a policy tools analytical framework to categorize the types of tools chosen as either procedural or substantive in nature, and in doing so it assesses the amount of priority placed on household food insecurity. It quantifies the number of tools chosen to address food industry concerns versus those aimed at frontline service providers, and illustrates why the recently published National Food Policy was necessary to address an issue identified as worthy of government intervention two decades earlier.


identifier: Hébert, Antoine  (2020) Estimation of Road Accident Risk with Machine Learning.  Masters thesis, Concordia University.

abstract:
Road accidents are an important issue for our societies, responsible for millions of deaths and injuries every year representing a very high cost for society. In this thesis, we evaluate how machine learning can be used to estimate the risk of accidents in order to help address this issue.
Previous studies have shown that machine learning can be used to identify the times and areas of a road network with increased risk of road accidents using road characteristics, weather statistics, and date-based features. In the first part of this thesis, we evaluate whether more precise models estimating the risk for smaller areas can still reach interesting performances. We assemble several public datasets and build a relatively accurate model estimating the risk of accidents within an hour on a road segment defined by intersections.
In the second part, we evaluate whether data collected by vehicle sensors during driving can be used to estimate the risk of accidents of a driver. We explore two different approaches. With the first approach, we extract features from the time series and attempt to estimate the risk based on these features using classical algorithms. With the second approach, we design a neural network directly using the time series data to estimate the risk. After extensively tuning our models, we managed to reach encouraging performances on the validation set, however, the performances of our two models on the test set were disappointing. This led us to believe that this task might not be feasible, at least with the dataset used.


identifier: Zhong, Hanmo  (2020) Seeing is believing, but is it monitoring?  Masters thesis, Concordia University.

abstract: Prior studies conceptualize institutional monitoring by the terms “concentration of institutional investors” and “heterogeneity in institutional investors”. This paper focuses on the frequency of institutional investors’ corporate site visits (CSV) in relation to firms’ performance. In the context of acquisition, I hypothesize that bidding firms with more institutional investors’ CSV will have higher abnormal announcement-period return. However, the results indicate that more institutional investors’ CSV cannot predict better acquisition decisions, unless they meet firms’ CEO or high-level managements during site visits. The reason could be that internal communication in companies is not efficient due to the hierarchy of the organization. These findings survive a number of robustness tests, including tests after winsorizing data, alternative measures for corporate site visit, and alternative samples. Moreover, further analysis shows that institutional investor’ CSV and institutional ownership are complements of each other in terms of enhancing corporate governance.


identifier: Keddie, S. Leanne ORCID: https://orcid.org/0000-0001-9635-6746 <https://orcid.org/0000-0001-9635-6746>  (2020) Corporate Social Responsibility Performance-Based Incentives: Investigations Through the Lens of Corporate Governance.  PhD thesis, Concordia University.

abstract:
Structured around three essays, this dissertation investigates the use of Corporate Social Responsibility (CSR) performance-based incentives through the lens of corporate governance. Toward that end, it relies on both quantitative and qualitative research methodologies. The key data was hand collected from the proxy statements of S&P 500 firms for the fiscal year 2014 while the remaining data was obtained from various databases. Semi-structured interviews were also conducted with key executives and directors and add context to the quantitative results reported in the first paper. Findings reported in the first essay suggest that short-term view institutional shareholders are associated with less use of CSR performance-based incentives while long-term view institutional shareholders, according to the qualitative data only, appear to be working towards greater use. Furthermore, imitation appears to underlie greater use of CSR performance-based
incentives. Within the second essay, results are consistent with the notion that when the top management team has power, the use of these incentives is associated with excess compensation beyond what they would normally be expected to receive. Finally, in the third essay, knowledge transfer vis-à-vis directors’ experience on CSR committees as well as in environmentally sensitive industries appears to induce firms to expand their use of particular subcategories of quantitative CSR performance-based incentives. This work contributes to the literatures in executive compensation, CSR, knowledge transfer and to the emerging literature on CSR-driven corporate governance. It will be of interest to boards of directors, regulators, shareholders and other stakeholders interested in understanding more about who is influencing the use of CSR performance-based incentives and how these come into use in a firm.


identifier: Tahmid, Ahmad  (2020) FREQUENTLY REFACTORED CODE IDIOMS.  Masters thesis, Concordia University.

title: FREQUENTLY REFACTORED CODE IDIOMS

abstract:
It is important to refactor software source code from time to time to preserve its maintainability and understandability.
Despite this, software developers rarely dedicate time for refactoring due to deadline pressure or resource limitations.
To help developers take advantage of refactoring opportunities, researchers have been working towards automated refactoring recommendation systems for a long time.
However, these techniques suffer from low precision, as many of their recommendations are irrelevant to the developers.
As a result, most developers do not rely on these systems and prefer to perform refactoring based on their own experience and intuition.
To shed more light on the practice of refactoring, we investigate the characteristics of the code fragments that get refactored most frequently across software repositories.

Finding the most repeatedly refactored fragments can be very challenging due to the following factors:
i) Refactorings are highly influenced by the context of the code. Therefore, it is difficult to remove context-specific information and find similarities.
ii) Refactorings are usually more complex than simple code edits such as line additions or deletions. Therefore, basic source code matching techniques, such as token sequence matching do not produce good results.
iii) A higher level of abstraction is required to match refactored code fragments within projects of a different domain. At the same time, the structural detail of the code must be preserved to find accurate results.
In this study, we tried to overcome the above-mentioned challenges and explore several ways to compare refactored code from different contexts.
We transformed the refactored code to different source code representations and attempted to find non-trivial refactored code idioms, which cannot be identified using the standard code comparison techniques.

In this thesis, we are presenting the findings of our study, in which we examine the repetitiveness of refactorings on a large java codebase of 1,025 projects. We discuss how we analyze our dataset of 47,647 refactored code fragments using a combination of state-of-art code matching techniques. Finally, we report the most common refactoring actions and discuss the motivations behind those.


identifier: Mantis, Irene  (2020) Touch during mother-infant interactions: Influences of maternal unavailability and risk status.  PhD thesis, Concordia University.

abstract:
Mother-infant interactions are fundamental to infant social-emotional development. Touch is an influential channel through which mothers and their infants convey emotion and affection and establish a strong connection. In a series of two studies, the types of maternal touch and the functions of mutual touch during mother-infant interactions were investigated. Further, touch in at-risk populations (e.g., depressed mothers, VLBW/preterm infants) and the relationship between the quality of the dyadic relationship and touch were examined in order to elucidate the association between relationship indicators on tactile communication.
     Study 1 examined maternal touching in 41 mothers with and without depressive symptomatology. Mothers and their 4-month-old infants participated in the Still-Face (maternal emotional unavailability) and the Separation (maternal physical unavailability) procedures. The types of mother touch were coded using the Caregiver-Infant Touch Scale (CITS; Jean, Stack, & Fogel, 2009; Stack, 2010; Stack, LePage, Hains, & Muir, 1996). Study 2 examined the communicative functions of mutual touching during the Still-Face procedure between mothers and their 5½-month-old full-term (n = 40) and very low-birthweight/preterm (VLBW/preterm; n = 40) infants. The functions of mutual touch were coded using the Functions of Mutual Touch Scale (FMTS; Mantis, Burnside, & Stack, 2012) and the quality of the mother-infant relationship (emotional availability) was coded using an adapted version of the Emotional Availability Scales Coding Guidelines (EA Scales; Biringen, Robinson, & Emde, 1988, 1998), an observational and relational measure designed to rate dimensions of maternal emotional availability and child behavior.
     Results from Study 1 indicated that mothers with higher levels of depressive symptoms engaged in less touching following the perturbation in the Still-Face procedure, whereas mothers with lower levels of depressive symptoms maintained stable levels of touching across both interaction periods. Mothers with higher levels of depressive symptoms displayed less playful/stimulating types of touching. Results from Study 2 indicated that full-term infant-mother dyads spent significantly more time engaged in playful and regulatory mutual touch compared to VLBW/preterm infant-mother dyads who spent significantly more time engaged in attention-centered, unbalanced, and guided mutual touch. Higher levels of maternal sensitivity and regulatory mutual touch were associated for full-term infant-mother dyads, while lower levels of maternal sensitivity were associated with unbalanced mutual touch for VLBW/preterm infant-mother dyads.
     Together, the findings provide insight into how both mothers and infants participate in shaping and co-regulating their interactions through the use of touch. By identifying the patterns of maternal touch and the functions of mutual touch present during different contexts in both typically developing and at-risk dyads, we are able to identify disrupted patterns of communication.  Ultimately, findings have direct implications for parenting practices and for the design of preventative intervention programs of early touch stimulation for at-risk infants and their parents.


identifier: Shetty, Chaitra  (2020) Amphiphilic Block Copolymers: Application in Gene Delivery and In-vitro Biological Evaluation.  Masters thesis, Concordia University.

abstract:
Gene therapy holds a great promise in the treatment of acquired genetic disorders such as cancer because it shows fewer side effects compared to chemotherapy. In order for gene therapy to be successful, however, it is crucial to develop efficient and non-toxic gene carriers to overcome poor in vivo stability and low cellular uptake of nucleic acid therapeutic agents. My Master’s thesis research mainly focuses on the development of a new approach exploring a combination of hydrophobic modification with stimuli-responsive degradation (SRD) to synthesize novel amphiphilic block copolymer-based nanocarriers for controlled gene delivery. The block copolymer synthesized by atom transfer radical polymerization is designed with an acid-labile acetal linkage at the block junction and pendant disulfide group in a hydrophobic block. The incorporation of labile linkages enables both dual-location dual-acid/reduction-responsive degradation (DL-DSRD) and in situ disulfide-core-crosslinking. Further, the disulfide pendants integrated as hydrophobic moieties facilitate to condense the nucleic acids into nanometer-sized micelleplexes through electrostatic interaction of pendant dimethylamino groups with the anionic phosphate groups of the nucleic acids. Our results demonstrate that the hydrophobic modification approach through DL-DSRD is a robust platform in the development of gene delivery systems with enhanced colloidal stability, reduced cytotoxicity, and improved gene transfection efficiency.
Further, my research is interested in the biological evaluation of delivery nanocarriers to investigate their cellular interactions with various biological systems for tumor-targeted delivery. Four SRD-exhibiting amphiphilic block copolymer micelles were chosen for not only their various chemical compositions but also different positions of labile linkages cleavable in response to acidic pH and glutathione. The results from cytotoxicity and cellular uptake assays reveal that polymer composition and arrangement of monomers play an important role to determine the biological fate of SRD-exhibiting nanocarriers.


identifier: Araz, Jack Yakup ORCID: https://orcid.org/0000-0001-8721-8042 <https://orcid.org/0000-0001-8721-8042>  (2020) Exploring beyond the minimal supersymmetric model scenarios with dark matter and collider signals.  PhD thesis, Concordia University.

abstract:
This thesis presents a study on phenomenology of beyond the Standard Model (SM) in the context of extensions of supersymmetric realisations.  This extended framework allows us to accommodate viable dark matter (DM) candidates which the SM do not have, and it offers a unified gauge structure for all three nuclear forces. With this motivation, we investigated two possible extensions of MSSM and their predictabilities in future collider experiments.

First, we presented an extension of MSSM via vector-like (VL) supermultiplets which can provide new annihilation channels for dark matter. We investigate a simple extension with two VL pairs of weak doublets (lepton and down-type quark) and a pair of VL-neutrino singlets. Both neutralino and sneutrinos can emerge as viable DM candidates in such a framework. A complete analysis has been conducted on the DM. Furthermore, we investigate specific collider signatures that such construction can bring and demonstrate the enhanced production of events fortified with tau leptons.

Secondly, we investigated U(1) extensions of the MSSM framework within E6 gauge structure by conducting a detailed analysis of the parameter space that can emerge through a variety of U(1)' charge structures. Such a scenario predicts two DM candidates, neutralino and sneutrino. We presented a detailed analysis of low energy and cosmological observables. It is also vital to present the specific signatures that such gauge structure can bring into collider experiments. A heavy Z' boson is one of the identifying features of such a framework. We investigated possible loopholes in analyses where we observed that Z' mass bounds can be relaxed up to 300 GeV by changing the boundary conditions on the gauge couplings. We presented possible leptophobic scenarios which can be observed through supersymmetric cascade decays up to $7\sigma$ statistical significance at $ \sqrt{s}=14 $~TeV with 3 ab-1 integrated luminosity.

Finally, we revisited the current LHC bounds on supersymmetric particles in the light of theoretical uncertainties and studied high luminosity predictions. We investigated the effects of these uncertainties on gluino, squark mass limits and on coupling sensitivity of simplified s-channel DM models.


identifier: Kamel, Hiba  (2020) A recombinant mammalian TRAPP complex produced through bacteria.  Masters thesis, Concordia University.

abstract: The cellular trafficking machinery relies on interactions between tethering factors, Rab GTPases and their GEF activators. One well studied multi-subunit tethering factor with recognized GEF activity is the TRAnsport Protein Particle (TRAPP) complex of which mammals have two; the TRAPPII and the TRAPPIII complexes. While TRAPPIII is linked to autophagy, the role of the TRAPPII complex in mammals, although linked to Golgi trafficking, remains elusive. Part of the ambiguity comes from our lack of understanding of which Rab GTPase is activated by TRAPPII. To answer to this, this work attempts to produce the first recombinant mammalian TRAPPII complex using Escherichia coli. The assembly of the complex is then assessed through the co- expression and the co-fractionation of the TRAPPII subunits after affinity purification and gel filtration chromatography. Upon further validation, the produced complex could be used in GEF activity assays and for structural analysis in ways that would further our understanding of the role of the mammalian TRAPPII complex in vesicular trafficking.


identifier: kariminezhad, esmaeel  (2020) Electrokinetic-Induced Phase Separation of Petroleum Wastes: Evaluation of Oil Sediment Behavior and Solids Properties.  PhD thesis, Concordia University.

abstract:
The disposal of the oily wastes represents a serious threat to the environment. The treatment of such oily wastes poses significant challenges considering their physical and chemical properties. This study focuses on advanced electrokinetic methods as a technology to treat oily sediments through phase separation. The study comprises four objectives which are intimately linked to achieve the overall objective of exploring the electrokinetic method for treatment of water-in-oil emulsions. The first objective is finding the most efficient oil phase separation when four different regimes of electric fields are applied (namely constant direct current (CDC), pulsed direct current (PDC), incremental direct current (IDC) and decremental direct current (DDC)). The second objective is to investigate the factors affecting the electrokinetic process and dewaterability of different types of oily sludge. The third objective is investigating the effect of nanoparticles and synthesized catalysts on the phase separation efficiency within the electrokinetic system. The final objective was to elucidate the various mechanisms underlying the separation of oil, water and solids by thermal analysis of treated samples.
The results showed that the extent and quality of phase separation depend on the regime of electrical current applied. The DDC and IDC regimes resulted in the most efficient phase separation of the oil sediments, and even incurred a highly resolved separation of light hydrocarbons at the top anode.
X-ray photoelectron spectroscopy (XPS) analyses showed a decrease in the concentration of carbon from 99% in centrifuged samples to 63% on the surface of the solids treated by PDC. Wettability alteration studies showed an increase in the level of fine solids in the aqueous phase following electrokinetic treatment thereby enhancing the hydrophilicity of the solids.
The best performance of titanium dioxide (TiO2) nanoparticles and a synthesized catalyst reactors results were obtained with the synthesized catalyst as compared to the use of TiO2 nanoparticles. Activation energy emphasized the effect of additives on separation of phases and availability of oil. Hence, the synergistic effects of TiO2 or synthesized catalyst with electrokinetic treatment can lead to better phase separation and may reinforce the current applications of the electrokinetic method in treating oil sediments.


identifier: Salihu, Abdulrazaq Lemu  (2020) Impact of on-ground taxiing with electric powered tow-trucks on congestion, cost, and carbon emissions at Montreal-Trudeau international airport.  Masters thesis, Concordia University.

abstract: Everyday millions of litres of jet fuel are burnt during the aircraft’s on-ground taxiing operations, releasing tons of greenhouse gas emissions in the atmosphere. Aircraft manufacturers and researchers believe that replacing the current aircraft taxiing operation with more efficient on-ground taxiing operations could meet future market requirements. Multiple factors such as safety, airport throughput, energy efficiency, air emissions, and total cost need to be considered when designing airport taxi operations. This research reports on the performance of utilizing electric tow-trucks during on-ground taxiing operations. It builds on previous studies to assess the impact of the initial investment of implementing these alternative taxi system on congestion, cost and carbon emission on the on-ground taxi operations. We developed a Discrete Event Simulation model to schedule electric powered tow-trucks to provide taxiing services to aircrafts. The simulation enables aircrafts to request an available tow-truck or use aircraft engines to perform taxiing operations. The performance measurements of the taxiing operations were based on total fuel consumption, emission, traffic delays and total cost of implementing the operational strategy. Montreal-Pierre Elliot Trudeau International Airport was selected as a case study. Based on the presented methodology, the result exhibits that utilizing electric-powered tow-trucks to perform all on-ground taxiing operations is the best practical solution to meet the future market requirements. The conducted investigation indicates that this approach provides both economic and environmental benefits to the aviation industry. Three extensive sets of numerical analysis have been conducted to provide better insights into the problem. In each part of these analysis, different determinant factors such as the total cost, fuel consumption, delay and emissions have been used to compare the obtained results of the proposed approach with the current situation at the airport. After analyzing the results, an environmentally friendly and economically efficient approach is offered.


identifier: Gray, Claire  (2020) "In My Dreams I Was Almost There": Personal Music Players, Curated Soundscapes and the Contemporary Québécois Coming-Of-Age Film.  Masters thesis, Concordia University.

abstract:
In bridging the fields of sound studies, film studies, and Québécois studies, this thesis suggests a novel way of exploring national identity formation within the context of coming-of- age cinematic narratives. In many contemporary Québécois coming-of-age films, protagonists develop imaginary worlds into which they can escape from their oppressive social circumstances, but ultimately fail to reach adulthood in the way they desire. This thesis project applies two key elements in sound studies to the Québécois context: it examines how personal music players (e.g. a Walkman, an iPod, a vinyl player, etc.) and curated soundscapes (the imaginary worlds developed through interaction with said personal music players) are used by protagonists in coming-of-age films set in Québec. This study examines the ways that the personal music player and the curated soundscapes protagonists create are present in three recent coming-of-age films: C.R.A.Z.Y. (dir. Jean-Marc Vallée, 2005), Mommy (dir. Xavier Dolan, 2013) and Les êtres chers (dir. Anne Émond, 2015). Each of these films’ protagonists use the personal music player and the curated soundscape as a means to escape their marginalization in a socially oppressive Québécois society.
This project conceives of the coming-of-age journeys as manifested in Québecois cinema as a process with three nodes. In Chapter 1, this project examines how these protagonists interact with their personal music players and curated soundscapes, creating imaginary worlds which they can control. Chapter 2 explores how these protagonists develop their curated soundscapes so intensely that they recognize they can never be realized in an oppressive Québécois society, revealing the contradictions of the curated soundscape in Québec. Finally, in Chapter 3, this project considers how silence is present in each of these films after these characters abandon their personal music players and curated soundscapes. It argues that they use this silence as a bridge to adulthood, but ultimately fail to reach the ideals they developed within the curated soundscape.


identifier: Lamontagne-Cumiford, Mathieu  (2020) The End of the Road: An Ethnographic Account of Tourism Along the Inuvik-Tuktoyaktuk Highway.  Masters thesis, Concordia University.

abstract: Based on fieldwork conducted over three months in the Mackenzie Delta communities of Inuvik and Tuktoyaktuk, this thesis explores tourism in the Western Arctic as a product of a newly completed all season highway. The new Inuvik-Tuktoyaktuk Highway (ITH) connects the Hamlet of Tuktoyaktuk, a community of 900 people on the Beaufort Sea, to the North American public highway system and has led to a steady rush of road trippers, overlanders, motorcyclists, cycle-trekkers, and RVers into the region. Ostensibly an extension of the already famous Dempster Highway, the ITH has captured the imaginations of travellers and set online forums and blogs abuzz with accounts of a new Arctic destination. Narratives of adventure, of unspoilt wilderness and rugged frontier towns abound in the accounts of travellers, paired with an acute awareness of the explosive potential for change in communities seeing several times their residential numbers in visitors during the short summer months. Taking an approach centered on the stories told and the interactive intersections of infrastructure, material goods, and people, this project hopes to use a specific moment of touristic activity to speak to larger notions of leisure travel, engagement with nature, and the fetishization of particular places.


identifier: Gladu, Cheryl ORCID: https://orcid.org/0000-0003-3905-4455 <https://orcid.org/0000-0003-3905-4455>  (2020) The Good Fight: The development of dialogue in Canadian cohousing communities.  PhD thesis, Concordia University.

abstract: Deliberative processes and participative practices have received growing attention in business ethics, as well as in management, organization, and design studies. There is a sense that this "systemic turn" may have a role in fostering responsible business conduct and sustainable development. In this work, I examine dialogue as a central feature of deliberation and as a collaborative approach for developing shared understanding in conflictual situations. I examined the literature to better understand under what conditions dialogue is more likely to emerge, in order to understand how it may be induced to help address conflictual situations. As relational engagement is suggested as a moderator for the emergence of productive dialogue, I consider these issues by exploring a context whereby relational engagement is a central organizational aim, collaborative housing (cohousing) communities. Within such a context I can identify additional processes and mechanisms that help encourage dialogue in challenging situations. These not-for-profit intentional communities first materialize as real estate development corporations meant to develop high functioning neighborhoods for members. I chose to study the successful resolution of contentious issues within completed cohousing communities using an inductive embedded multiple cross-case analysis, and in so doing several processes and mechanisms that facilitate the emergence of dialogue are noted. The consensus-seeking nature of cohousing communities appears to direct members towards creative deliberative processes that can induce productive dialogue as tensions arise. The demands of working in a deliberative manner led to the creation of dialogical spaces and encouraged the proactive development of dialogical skills. Finally, the outcomes of these dialogues are not always agreement but can be agonistic, as it appears that the shared understanding created by productive dialogue allows community members to live with these differences. This study allows us to consider the antecedent and structural conditions that facilitate the emergence of dialogue when it's needed and reconsider the relationship between consensus and agonism.


identifier: Tchilinguirian, Patil  (2020) Felt sentiments: The representation of invisible struggles through wearable sound.  Masters thesis, Concordia University.

abstract: Through research-creation, this thesis presents imaginative perspectives from which critical stories about the “hidden Armenians” can be told and worn on the clothed body. These stories embed notions of Armenian collective memoires of cultural loss, and illustrate the complex relationship between cultural identity, oppression and expression, as they negotiate hidden political information to unveil unknown histories of suffering. These stories are materialized through textiles, which when enhanced with wearable technologies, become an archival interface that store tactile and acoustic material. In this project, tactility and sonification are used and intertwined to transform the clothed body into a space for cultural dialogue where narratives of social justice can be transmitted. As a result, alternative modes of cultural transmission are manifested by the marriage of the clothed body with fabric speaker technologies to elicit an emotional and immersive experience that accommodates representations of invisible struggles through wearable sound. Sound is employed to mitigate the tensions of visibility and to echo silenced voices, all the while amplifying the political struggle of the unheard to wider audiences. As such, this thesis postulates on the possibility of embedding a multilayered and non-linear system of meaning on the clothed body, further enhanced by wearable technologies, to create transcendental interpretations of wearable space. Seeking to inspire new questions and ideas on the different ways research-creation can engender alternative modes of cultural durability and transmission, through a practice-based and practice-led process, the corpus of work in this thesis evolved with an iterative design methodology that combed craft and technology as a creative process to interweave interactive storytelling and textile design.


identifier: Li, Pengcheng  (2020) Visual Calibration, Identification and Control of 6-RSS Parallel Robots.  PhD thesis, Concordia University.

abstract:
Parallel robots present some outstanding advantages in high force-to-weight ratio, better stiffness and theoretical higher accuracy compared with serial manipulators. Hence parallel robots have been utilized increasingly in various applications. However, due to the manufacturing tolerances and defections in the robot structure, the positioning accuracy of parallel robots is basically equivalent with that of serial manipulators according to previous researches on the accuracy analysis of the Stewart Platform [1], which is difficult to meet the precision requirement of many potential applications. In addition, the existence of closed-chain mechanism yields difficulties in designing control system for practical applications, due to its highly coupled dynamics.

Visual sensor is a good choice for providing non-contact measurement of the end-effector pose (position and orientation) with simplicity in operation and low cost compared to other measurement methods such as the coordinate measurement machine (CMM) [2] and the laser tracker [3]. In this research, a series of solutions including kinematic calibration, dynamic identification and visual servoing are proposed to improve the positioning and tracking performance of the parallel robot based on the visual sensor.

The main contributions of this research include three parts. In the first part, a relative pose-based algorithm (RPBA) is proposed to solve the kinematic calibration problem of a six-revolute-spherical-spherical (6-RSS) parallel robot by using the optical CMM sensor. Based on the relative poses between the candidate and the initial configurations, a calibration algorithm is proposed to determine the optimal error parameters of the robot kinematic model and external parameters introduced by the optical sensor. The experimental results demonstrate that the proposal RPBA using optical CMM is an implementable and effective method for the parallel robot calibration.

The second part focuses on the dynamic model identification of the 6-RSS parallel robots. A visual closed-loop output-error identification method based on an optical CMM sensor is proposed for the purpose of the advanced model-based visual servoing control design of parallel robots. By using an outer loop visual servoing controller to stabilize both the parallel robot and the simulated model, the visual closed-loop output-error identification method is developed and the model parameters are identified by using a nonlinear optimization technique. The effectiveness of the proposed identification algorithm is validated by experimental tests.

In the last part, a dynamic sliding mode control (DSMC) scheme combined with the visual servoing method is proposed to improve the tracking performance of the 6-RSS parallel robot based on the optical CMM sensor. By employing a position-to-torque converter, the torque command generated by DSMC can be applied to the position controlled industrial robot. The stability of the proposed DSMC has been proved by using Lyapunov theorem. The real-time experiment tests on a 6-RSS parallel robot demonstrate that the developed DSMC scheme is robust to the modeling errors and uncertainties. Compared with the classical kinematic level controllers, the proposed DSMC exhibits the superiority in terms of tracking performance and robustness.


identifier: Walid Fathi Helmy, Juhayna  (2020) Sustainable Financing in Journalism: Do Niche Journalism and Crowdfunding Offer a Way Forward?  Masters thesis, Concordia University.

abstract: This thesis examines financial sustainability in journalism through closely analyzing whether niche journalism is a type of journalism that can be supported by crowdfunding as a sustainable mean of financing. The focus of the research is the case of ZigZag, a US-based niche journalism podcast. Through this exemplar, I highlighted the themes of content, approach, diversified revenue streams, connections, and transparency as the factors that led to the podcast’s success. I analyzed these themes by placing them under the categories of niche journalism and financing to depict how both elements contributed to its success. This project provides a different perspective to the academic study of crowdfunding in journalism. There have been many studies that have analyzed different aspects of crowdfunding such as its categories, benefits, and drawbacks such as Aitamurto (2011, 2015), Carvajal, García-Avilés, and González (2012), Hunter (2016), Hunter & Bartolomeo (2018), Jian & Shin (2015), and Zaripova (2017), however, none have yet to examine whether there is a correlation between niche journalism and the financial sustainability of crowdfunding. This thesis adds to research in this area, by examining the potential correlation between niche journalism and the financial sustainability of crowdfunding.


identifier: Pace, Alexandre  (2020) A 211-year River Reconstruction of the Chic-Choc and McGerrigle Mountains of the Gaspésie from Tree-rings.  Masters thesis, Concordia University.

abstract: Long instrumental records are needed to serve as baselines in order to fully understand naturally occurring streamflow and climate variability, especially in this era of rapid anthropogenic climate change. In most remote parts of Canada, both instrumental streamflow and climate data are of relatively short duration, spanning approximately 50 years in duration. Barring annually laminated varved sediments, tree-ring reconstructions with their absolute dates are the only feasible way to infer streamflow and climate data of the past at an annual or sub-annual resolution in such places. Such inferred paleo-hydrological and paleo-climate data has proved useful for better natural resource management, providing a much-needed long-term context. Here we present a 211-year high-frequency tree-ring-based reconstruction of the Sainte-Anne River, Gaspésie, Québec. This reconstruction shows that the short 49-year instrumental record does not capture the full range of the natural variability of the river, especially that of the periods of sustained low flows. This river arises in the interior of the Gaspé Peninsula, a region that contains some of the highest mountains in Québec. The instrumental streamflow and climate records are particularly short in this alpine region, which is the location of the Parc national de la Gaspésie. This alpine region is the home of the critically endangered southernmost herd of caribou in Canada and many rare, endemic plants. The Sainte-Anne River is also the site of an important Atlantic salmon fishery. Hence, a longer-term moisture record can serve as a useful tool for management of these threatened fauna, flora and ecosystems.


identifier: Alballa, Munira  (2020) Predicting Transporter Proteins and Their Substrate Specificity.  PhD thesis, Concordia University.

abstract:
The publication of numerous genome projects has resulted in an abundance of protein sequences, a significant number of which are still unannotated. Membrane proteins such as transporters, receptors, and enzymes are among the least characterized proteins due to their hydrophobic surfaces and lack of conformational stability. This research aims to build a proteome-wide system to determine transporter substrate specificity, which involves three phases: 1) distinguishing membrane proteins, 2) differentiating transporters from other functional types of membrane proteins, and 3) detecting the substrate specificity of the transporters.

To distinguish membrane from non-membrane proteins, we propose a novel tool, TooT-M, that combines the predictions from transmembrane topology prediction tools and a selective set of classifiers where protein samples are represented by pseudo position-specific scoring matrix (Pse-PSSM) vectors. The results suggest that the proposed tool outperforms all state-of-the-art methods in terms of the overall accuracy and Matthews correlation coefficient (MCC).

To distinguish transporters from other proteins, we propose an ensemble classifier, TooT-T, that is trained to optimally combine the predictions from homology annotation transfer and machine learning methods. The homology annotation transfer components detect transporters by searching against the transporter classification database (TCDB) using different thresholds. The machine learning methods include three models wherein the protein sequences are encoded using a novel encoding psi-composition. The results show that TooT-T outperforms all state-of-the-art de novo transporter predictors in terms of the overall accuracy and MCC.

To detect the substrate specificity of a transporter, we propose a novel tool, TooT-SC, that combines compositional, evolutionary, and positional information to represent protein samples. TooT-SC can efficiently classify transport proteins into eleven classes according to their transported substrate, which is the highest number of predicted substrates offered by any de novo prediction tool. Our results indicate that TooT-SC significantly outperforms all of the state-of-the-art methods. Further analysis of the locations of the informative positions reveals that there are more statistically significant informative positions in the transmembrane segments (TMSs) than the non-TMSs, and there are more statistically significant informative positions that occur close to the TMSs compared to regions far from them.


identifier: Moradi, Saeed ORCID: https://orcid.org/0000-0003-4982-3000 <https://orcid.org/0000-0003-4982-3000>  (2020) Defect Detection and Classification in Sewer Pipeline Inspection Videos Using Deep Neural Networks.  PhD thesis, Concordia University.

abstract:
Sewer pipelines as a critical civil infrastructure become a concern for municipalities as they are getting near to the end of their service lives. Meanwhile, new environmental laws and regulations, city expansions, and budget constraints make it harder to maintain these networks. On the other hand, access and inspect sewer pipelines by human-entry based methods are problematic and risky. Current practice for sewer pipeline assessment uses various types of equipment to inspect the condition of pipelines. One of the most used technologies for sewer pipelines inspection is Closed Circuit Television (CCTV). However, application of CCTV method in extensive sewer networks involves certified operators to inspect hours of videos, which is time-consuming, labor-intensive, and error prone.
The main objective of this research is to develop a framework for automated defect detection and classification in sewer CCTV inspection videos using computer vision techniques and deep neural networks. This study presents innovative algorithms to deal with the complexity of feature extraction and pattern recognition in sewer inspection videos due to lighting conditions, illumination variations, and unknown patterns of various sewer defects. Therefore, this research includes two main sub-models to first identify and localize anomalies in sewer inspection videos, and in the next phase, detect and classify the defects among the recognized anomalous frames.
In the first phase, an innovative approach is proposed for identifying the frames with potential anomalies and localizing them in the pipe segment which is being inspected. The normal and anomalous frames are classified utilizing a one-class support vector machine (OC-SVM). The proposed approach employs 3D Scale Invariant Feature Transform (SIFT) to extract spatio-temporal features and capture scene dynamic statistics in sewer CCTV videos. The OC-SVM is trained by the frame-features which are considered normal, and the outliers to this model are considered abnormal frames. In the next step, the identified anomalous frames are located by recognizing the present text information in them using an end-to-end text recognition approach. The proposed localization approach is performed in two steps, first the text regions are detected using maximally stable extremal regions (MSER) algorithm, then the text characters are recognized using a convolutional neural network (CNN).  The performance of the proposed model is tested using videos from real-world sewer inspection reports, where the accuracies of 95% and 86% were achieved for anomaly detection and frame localization, respectively. Identifying the anomalous frames and excluding the normal frames from further analysis could reduce the time and cost of detection. It also ensures the accuracy and quality of assessment by reducing the number of neglected anomalous frames caused by operator error.
In the second phase, a defect detection framework is proposed to provide defect detection and classification among the identified anomalous frames. First, a deep Convolutional Neural Network (CNN) which is pre-trained using transfer learning, is used as a feature extractor. In the next step, the remaining convolutional layers of the constructed model are trained by the provided dataset from various types of sewer defects to detect and classify defects in the anomalous frames. The proposed methodology was validated by referencing the ground truth data of a dataset including four defects, and the mAP of 81.3% was achieved. It is expected that the developed model can help sewer inspectors in much faster and more accurate pipeline inspection. The whole framework would decrease the condition assessment time and increase the accuracy of sewer assessment reports.


identifier: Alizadehnohi, Masoumehzanan  (2020) ORF19.7060 and white-opaque switching in MTL a/α cells of Candida albicans.  Masters thesis, Concordia University.

abstract: Diploid C. albicans cells that are heterozygous for the MTL locus cannot mate, because they repress expression of the master regulatory protein Wor1 critical for activating the mating-competent opaque state. However, cells that lack or are heterozygous for sequences encompassing the shared promoter region of ORFs 19.7061 and 19.7060 can switch to the opaque state even when heterozygous at MTL. Transcriptome analysis of MTL heterozygous strains where one (MA40) or both (MA10) alleles of 5'-UTR of ORF19.7060 were deleted, shows that in spite of the formation of the a1-α2 repressor, the expression of WOR1 occurred, allowing the cells to undergo white-opaque switching. Further investigation revealed that transcription factors such as EFG1, RFG1 and specifically SFL2 were down regulated in both MA10 and MA40 strains. However, these two strains cannot mate properly due to the a1-α2 repression of the mating genes. The ability of the MTL a/α cells to switch to the opaque state appears dependent on the size of the deletions; large deletions in the 5'-UTR of ORF19.7060, even in the heterozygous state, permit switching to classical opaque cells, smaller deletions in this region permit switching to an opaque-like state that exhibits opaque cell morphology but does not express a characteristic opaque-specific epitope on the cell surface, and even smaller deletions are not permissive for white to opaque switching. ORF19.7060, which encodes a protein with sequence similarity to enzymes implicated in non-homologous end joining, is one of the C. albicans genes that have different transcripts in white and opaque cells.


identifier: Heidari, Mehdi  (2020) Reducing the risk for water biota by adsorption of pharmaceuticals and heavy metals using a fixed-bed column with a novel biochar.  Masters thesis, Concordia University.

abstract: Pharmaceuticals and heavy metals derived from point sources and non-point sources find their ways into water bodies. One of the important sources of such pollutants is wastewater or effluents from wastewater treatment plants. The presence of pharmaceuticals and heavy metals in the water bodies causes irreversible damages to flora, fauna and human health. Risk assessment plays a vital role in identifying the pollution intensity. The adsorption process is one of the most appropriate processes in eliminating such pollutants from wastewater. In this study, a fixed-bed column is used to verify the feasibility of using a novel biochar material to remove organic (pharmaceuticals) and inorganic (heavy metals) compounds. This study was conducted in 3 phases. In the first phase, the pollution intensity of pollutants in wastewater effluent was evaluated by risk assessment formulas. In the second phase, the impact of the initial concentration, flow rate and bed depth on the laboratory-scale adsorption column performance were investigated. In the third phase, the Adam-Bohart model was used to design the large-scale fixed-bed column. Moreover, the pollution intensity of pollutants was determined. The results clearly indicated that the presence of venlafaxine and heavy metals in wastewater effluent poses adverse effects on aquatic and marine organisms. The adsorption of venlafaxine, Ni, Pb and Cu on biochar in a laboratory-scale column was observed as well as in the larger-scale column. Increasing the initial concentration and bed depth along with decreasing the flow rate caused the adsorption capacity to be on the rise. The removal over 90% of venlafaxine, Ni, Pb and Cu was found at the breakthrough point where the adsorption capacity was increased from 0.8 to 5.4 mg/g for venlafaxine, from 1.92 to 18.24 µg/g for Ni, from 3.84 to 30.72 µg/g for Pb, and from 2.88 to 24 µg/g for Cu. The large-scale column, tested on real effluent at wastewater treatment plant, confirmed the feasibility of using biochar to eliminate 95% of venlafaxine and 90% of Ni, Pb and Cu at the breakthrough point. The adsorption capacity at the breakthrough point was 3051.406 ng/g for venlafaxine, 24.364 µg/g for Ni, 0.1296 µg/g for Pb, and 7.115 µg/g for Cu. The pollution intensity of venlafaxine, Ni, Pb and Cu to aquatic and marine organisms decreased from a high to low risk due to the utilization of novel biochar in the fixed-bed column.


identifier: Kipchumba, Mathew  (2020) The Meaning of מלא in Genesis 1:28 in Light of Primaeval History.  Masters thesis, Concordia University.

abstract: The divine promise in Genesis 1:28 marks the climax in the creation of humanity. In this text, God inaugurates humanity by blessing and issuing them with capacities necessary for the performance of their divine duty. Through a macro-syntactic analysis and a word study, this thesis returns to this text with the aim of establishing the meaning of the root מלא as used in the third imperative “to fill the earth.” Toward this goal, this thesis is asking; What is the meaning of  מלאin this context? How does the imperative function in relation to the rest of the imperatives? What underlying nuances are expressed or not expressed in this verb sequence? Why is it included here? In context, this study explores any explicit nuances in the verb מלא as used in Gen.1:28 with the purpose of giving a proper understanding of its meaning and function in relation to the divine image bearer. Based on the literature reviewed, the analysis of the use of מלא in the rest of primeval history and in Gen.1:26-28, this thesis has established that the meaning of מלא in Gen. 1:28 is the following: God’s desire for humanity to migrate or move across the earth for the purpose of “imaging” him by ruling over the creation. The results emphasize that human migration is a divine gift, a good gift that God issued volitionally to humanity at creation for His purpose.


identifier: Taylor, Miles  (2020) Overwhelmed and Underworked: Inherent Vice, Aproductivity, and Narrative.  Masters thesis, Concordia University.

abstract: This thesis proposes an artistic mode called aproductivity, which arises with the secular crisis of capitalism in the early 1970’s. It reads aproductivity as the aesthetic reification of Theodor Adorno’s negative dialectics, a peculiar form of philosophy that refuses to move forward, instead producing dialectics without synthesis. The first chapter examines the economic history aproductivity grows out of, as well as its relation to Francis Fukuyama’s concept of “The End of History.” After doing so, the chapter explores negative dialectics and aproductivity in relation to Adam Phillips’ concept of the transformational object. In the second chapter, the thesis looks at the Thomas Pynchon novel Inherent Vice (2009), as well as the 2014 Paul Thomas Anderson adaptation of the same name. It offers a reading of the two as allegories for life under late capitalism, with particular focus on the breakdown of narrative and the search for something that will make sense of a world where the logics of capitalism no longer function correctly.


identifier: Darabi, Mehdi  (2019) Non-linear dynamic instability analysis of uniform and thickness-tapered composite plates.  PhD thesis, Concordia University.

abstract:
Laminated composite plates and shells are being increasingly used in aerospace, automotive, and civil engineering as well as in many other applications of modern engineering structures. Tailoring ability of fiber-reinforced polymer composite (FRPC) materials for the stiffness and strength properties with regard to the reduction of structural weight made them superior compared with metals in such structures. In some specific applications such as aircraft wing skins composite structures need to be stiff at one location and flexible at another location. It is desirable to tailor the material and structural arrangements so as to match the localized strength and stiffness requirements by dropping the plies in laminates. Such laminates are called as tapered laminates.
In the dynamic instability that occurs in the structures subjected to harmonic in-plane loading not only the amplitude of the harmonic in-plane load but also the forcing frequencies make the structures fail at load amplitude that is much less than the static buckling load and over a range of forcing frequencies rather than at a single value. In this case, the bending deformations, the rotations and the strains are not small enough in comparison with unity, so the linear theory just provides an outline about the dynamically-unstable regions and is not capable to determine the amplitude of the steady-state vibration in these instability regions.
The main objective of this dissertation is to develop a geometric non-linear formulation and the corresponding solution method for uniform and internally-thickness-tapered laminated composite plates. This Ph.D. research work is completed by extension of this developed geometric non-linear formulation to the uniform laminated composite cylindrical shells as well. The novel parts of this Ph.D. dissertation are the geometric non-linear formulations and corresponding displacement-based solutions obtained using approximate analytical methods, for dynamic instability analysis of internally-thickness-tapered laminated composite plates and cylindrical panels. To the best of author knowledge, there is no non-linear dynamic instability study on internally-thickness-tapered laminated composite plates and cylindrical panels in literature. There is only one study on the linear dynamic instability of internally-thickness-tapered flat plates using the FEM and Ritz method.  Here the developed analytical geometric nonlinear formulation not only is capable of predicting the instability regions but also is capable of determining both stable- and unstable-solutions amplitudes of steady-state vibrations of such internally-thickness-tapered laminated composite plates and cylindrical panels in these dynamically-unstable regions. Furthermore, the effect of the influential parameters on the non-linear dynamic instability of laminated plates and cylindrical shells is extensively studied. These parametric studies were carried out on cross-ply laminated composite uniform plates, flat and cylindrical tapered plates, and uniform cylindrical shells. In this study, the non-linear von Karman strains associated with large deflections are considered. Considering the simply supported boundary condition the Navier’s double Fourier series with the time-dependent coefficient is chosen to describe the out-of-plane displacement function. For the uniform laminated composite rectangular plates and uniform laminated composite cylindrical shells, a combination of displacement and a stress-based solution is considered while for the internally-thickness-tapered laminated composites plates and cylindrical panels a displacement-based solution is considered to solve the equations of motion. Then the general Galerkin method is used for the moment-equilibrium equation of motion to satisfy spatial dependence in the partial differential equation of motion to produce a set of non-linear Mathieu-Hill equations. These equations are ordinary differential equations, with time-dependency. Finally, by applying the Bolotin’s method to these non-linear Mathieu-Hill equations, the dynamically-unstable regions, stable-, and unstable-solutions amplitudes of the steady-state vibrations in these dynamically-unstable regions are obtained for both the uniform and the internally-thickness-tapered laminated composites plates and uniform cylindrical shells.
A comprehensive parametric study on the non-linear dynamic instability of these simply supported cross-ply laminated composite uniform plates, flat and cylindrical internally-thickness-tapered plates and uniform cylindrical shells are carried out to examine and compare: the effects of the orthotropy in the laminated composite uniform plates, number of layers for symmetric and antisymmetric uniform cross-ply laminated composite plates and cylindrical shells, different taper configurations and  taper angles in both flat tapered plates and tapered cylindrical panels, magnitudes of both tensile and compressive axial loads in the uniform and tapered plates and uniform cylindrical shells, aspect ratios of the loaded-to-unloaded widths of the uniform plates, flat and cylindrical internally-thickness-tapered panels and length-to-radius ratio of the cylindrical shells, length-to-average-thickness ratio of the flat plates and cylindrical panels and radius-to-thickness ratio of the cylindrical shells, and curvature of the tapered cylindrical panels i.e. radius-to-loaded widths ratio on the instability regions and the parametric resonance particularly the steady-state vibrations amplitudes of cross-ply laminated composite uniform plates, flat and cylindrical internally-thickness-tapered plates and uniform cylindrical shells. The present results show good agreement with those available in the literature.


identifier: Mohammad, Hendijani Zadeh  (2020) Three Essays on Environmental, Social, and Governance Transparency.  PhD thesis, Concordia University.

abstract:
This dissertation is comprised of three essays on determinants and consequences of Environmental, Social, and Governance (ESG) Transparency. Transparency refers to high quantity of material and value relevant information about ESG issues. In the first essay, we explore the relationship between our two variables of interest (i.e., audit quality and public media exposure) and ESG transparency on a sample of publicly listed Canadian firms in in the S&P/TSX Index of the Toronto Stock Exchange. Results show that audit quality and public media exposure are two main drivers of ESG transparency, hence, commitment to high quality audits and exposure to high public media coverage drive firms to be more transparent about ESG issues. Finally, as a consequence of ESG transparency, we find a negative association between ESG transparency and firm–level investment inefficiency.

The second essay examine whether the transparency of environmental and social (E&S) information affects financial analysts’ forecast properties that reflect their information set. Focusing on a sample of non-financial and non-utility U.S. firms from the S&P 500 index, results suggest that the level of transparency vis-à-vis both E&S information is negatively related to analysts’ forecast errors as well as forecast dispersion. These negative relationships become more pronounced for firms with low financial reporting quality, low media coverage, and for those with weak governance. Finally, we find that E&S transparency relates with investment efficiency essentially via analysts` information environment, which thus acts as a mediating variable. This finding is consistent with financial analysts also playing a monitoring role in capital markets.

The third essay, we investigate how a firm’s (E&S) transparency relates with its cash holdings. Focusing on a large sample of S&P 500 firms, results show that a higher level of E&S transparency implies lower firm-level cash holdings. The negative relationship is more pronounced for firms suffering from high information asymmetry, with low financial reporting quality, and for those with weak governance. Further analyses document that the two channels and mechanisms by which E&S transparency affect firm-level cash holdings are the cost of debt and financial constraints. Finally, our findings suggest that E&S transparency increases the market value relevance of an additional dollar in cash holdings.