identifier: Heidarian, Shahin  (2021) Capsule Network-based COVID-19 Diagnosis and Transformer-based Lung Cancer Invasiveness Prediction via Computerized Tomography (CT) Images.  Masters thesis, Concordia University.

abstract: Early diagnosis and prognosis of life-threatening diseases such as the novel coronavirus infection (COVID-19) and Lung Cancer (LC), involves tackling critical challenges including but not limited to their undisclosed characteristics, non-stationary nature, significant inter-disease similarities, and intra-disease variations. In particular, within the context of a highly contagious disease such as COVID-19, early and reliable diagnosis is of significant importance. On the other hand, when it comes to diagnosis and prognosis of LC, an accurate prediction of the disease invasiveness becomes of primary importance. Recent advancements of Artificial Intelligence (AI) and Deep Learning (DL)-based architectures have resulted in a surge of interest in the utilization of medical images to develop decision support and stand-alone models to address the aforementioned challenges. In this context, the focus of the thesis is on the utilization of volumetric chest CT images to develop robust and fully automated diagnostic frameworks for COVID-19 diagnosis and LC invasiveness prediction. In particular, Capsule Network (CapsNet) and Transformer-based architectures are developed to expand the application of AI in this domain. More specifically, first, CT-CAPS and COVID-FACT frameworks are proposed to analyze CT images, identify slices demonstrating infection, and perform patient-level classification of COVID-19. The proposed frameworks are developed based on the CapsNet architecture, which unlike the widely-used Convolutional Neural Networks (CNNs), is capable of capturing spatial relations among instances in an image and being trained on small datasets. These characteristics are of utmost importance when analyzing a newly emerged disease with specific spatial patterns in its images. Furthermore, following the recent and ever-increasing interest in using Low-Dose and Ultra-Low-Dose CT scans (LDCT and ULDCT) for COVID-19 screening, the WSO-CAPS framework is proposed to enhance performance of the proposed models to deal with noisy and low-quality CT scans. In addition, given that CT scans acquired from multiple centers and cohorts mainly show different qualities and characteristics, which negatively affect the generalizability of DL-based models, a unique multi-center dataset of CT scans, referred to as the “SPGC-COVID Dataset”, is constructed, which incorporates CT scans of COVID-19, Community Acquired Pneumonia (CAP), and normal cases, obtained using standard and low-dose imaging protocols. An enhancement approach is then proposed to boost the performance of the developed classification frameworks when being tested on varied CT scans in the SPGC-COVID dataset. With respect to the second objective of this thesis (i.e., Lung Cancer invasiveness prediction), the CAE-Transformer framework is proposed, which utilizes image-driven features to predict the invasiveness of Lung Adenocarcinomas (LUACs) from non-thin 3D CT scans. The proposed framework introduces a new viewpoint in CT scan analysis, which relies on the sequential nature of the volumetric CT scans. More specifically, the CAE-Transformer adopts the transformer architecture, which was initially designed for sequential data, to capture inter-slice dependencies in an efficient and non-complex fashion.


identifier: Nazemi, Pouria  (2021) Communicating “CRISPR Cas-9” through online videos on YouTube.  Masters thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract:
The objective of this study is to investigate the communication of gene-editing technology (CRISPR Cas9) through online videos and on YouTube (or “the YouTube video sharing platform”). Despite much research on the communication of new and emerging technologies, CRISPR Cas9 and its representation on YouTube have never been examined in detail. The dynamic ecosystem of YouTube and the novelty of CRISPR Cas9 can help us investigate negotiations between an emerging/controversial technology and a visual media platform. This thesis thereby examined videos on YouTube about CRISPR Cas9 from its emergence in 2014 until the end of 2019. The focus was on what kind of CRISPR Cas9 videos are produced and published on YouTube, how these videos represent this technology, any tendency toward technophobia/technophilic among them, and which models – if any -  of science journalism stand out in these videos.

A multi-dimensional search method was used to extract 743 videos to address these issues. After primary analysis, three-time spikes– based on the number of videos published (52 videos)–were chosen to examine in detail. This research used qualitative content analysis (QCA) to focus on the videos’ narratives and graphics and their representation of various issues. This approach generated three significant findings: (1) the number of videos was found to be comparable with other topics related to new technologies; (2) most of the videos had a positive view on the future of CRISPR Cas9 technology, but there were concerns about ethical issues with native content tending to be more opinionated toward the subject than immigrant videos; (3) new models of science journalism were not evident in the sample, but interesting signs of a sub-model of the science literacy model were found. Overall, considering the evolving and increasing role of YouTube in science journalism, this study sheds new light on various paths forward for science journalism studies in digital visual media.


identifier: Roy, Timir Baran ORCID: https://orcid.org/0000-0001-9144-0068 <https://orcid.org/0000-0001-9144-0068>  (2021) Detection and Localization of Damage in Structures using Vibration-Based Technique.  PhD thesis, Concordia University.

abstract: Vibration-based techniques for Structural Health Monitoring (SHM) utilize the dynamic response of a structure measured using a set of sensors to identify the modal properties and potential structural deterioration or damage. Signal processing tools are widely used for analyzing and diagnosing these response signals obtained from a structure. Any changes in the dynamic characteristics of a structure indicates deterioration in the structure. However, a direct comparison of the vibration signals or modal properties at different periods of time may not be sufficient to identify the damages and their locations. Therefore, it is essential to analyze the vibration signals to extract the morphologies of the changes in these response signals and correlate them with the possible location of structural damage. Anomalies can exist in a structure’s response in the form of damage due to loss of stiffness in the structural and non-structural elements and these anomalies alter a structure’s behaviors and modal properties. For some decade researchers have been using experimental and operational modal analysis to estimate modal parameters to measure structural damages in experimental and operational conditions respectively employing vibration-based response of structures. In case of ambient vibration data, processing and estimating the exact location of damage are complex for being non-stationary and non-linear. In this work, a novel method is developed where response signals obtained from structures are decomposed into Intrinsic Mode Functions (IMF) using Empirical Mode Decomposition (EMD) technique. Those IMFs are then processed with Hilbert-Huang transform (HHT) to obtain their corresponding Hilbert Spectra (HS), which allows the estimation of the time-varying instantaneous properties of those response signals. Then for system identification, Singular Value Decomposition (SVD) is performed to obtain the Singular Hilbert Spectra (SHS), and for damage detection, Marginal Hilbert Spectrum (MHS) is estimated. This leads to estimation of coefficients to calculate associated damage indices (DI). Simultaneously, modal frequencies of the structure are obtained from time-frequency-amplitude domain plot of the Singular Hilbert Spectra (SHS). Subsequently, Finite Element (FE) model is constructed for the healthy and damaged structure and tuned moment of inertia of the assembled members, which correlate with the natural frequencies obtained during testing. Joint displacements obtained from the linear modal analysis of the healthy and damaged structures lead to estimation of Displacement Mode Shape (DMS) and Curvature Mode Shape (CMS), and their absolute difference between the healthy and damage structure help to locate damage from the model. Thus, a hybrid method comprising MHS-based damage index along with numerical model-based joint curvature mode shape is proposed. This proposed method is verified using experimental tests conducted on: (a) a cantilever steel beam, (b) five-storey scaled frame, and (c) an eight-storey full scale steel building. The present thesis shows that the results obtained from system identification and damage detection manifest the advantages of the HHT-based technique for health monitoring of structures. It is observed from the results that the damage can be localized effectively in single and multiple damage cases from the DI values obtained using the proposed method. Simultaneously, modal frequencies are estimated as a by-product of the damage detection algorithms. The present investigation indicates that MHS is a promising tool for SHM to assess any deterioration or anomaly by comparing with a baseline model. Data-driven techniques for SHM has been mostly limited to small scale tests in laboratories. To address the challenges in application of data-driven methods for real life structures, it is necessary to incorporate physics-based analysis of structure along with the non-model-based method. For data-driven methods it is absolutely necessary to employ modern instrumentation methodologies to obtain vibration-response from structures. To highlight the present work and advantages of the modern wireless sensors for vibration measurement, two different case studies are presented: (a) modal analysis of pre-cast concrete shear wall with wired Piezotronics sensor, and (b) modal analysis of sixteen-storey Concordia University EV building with modern wireless sensors and data acquisition (DAQ) wirelessly connected with android device. The wireless vibration sensors are found to be quite easy and flexible to use for capturing the frequency response of a structure to detect a range of modal frequencies. However, cost of those sensors could pose a challenge and positioning of optimum of sensors is important in testing of tall buildings or long span bridges. To mitigate the problem of limited number of sensors, multi set up and roving sensors methods were used in the past. That could be time consuming and error prone. Further research is required to make the process more efficient. Manual estimation of frequency band width from the SHS plot, complexity in estimating DI from MHS and time expensive manual iteration in the numerical modeling are some of the limitations for the current work.


identifier: Scirocco, Alyssa  (2021) Mindset and Morality: Adolescents' Implicit Theories of Morality.  PhD thesis, Concordia University.

abstract:
In adolescents’ everyday interactions, it is inevitable that they encounter morally-laden events. Arguably, adolescents’ essentialist vs. incremental moral mindsets, or whether they perceive moral qualities and traits as fixed or malleable, might be linked to how they make sense of moral experiences. In two studies, this dissertation examined links between mindsets and youths’ constructions of meaning about their own and others’ moral experiences. Both studies were based on a sample of 98 adolescents from the Montreal area. Study 1 investigated how adolescents’ moral mindsets varied across contexts depicting others’ prosocial and antisocial actions that were recurrent or nonrecurrent, as well as their judgments of others. Youth endorsed moral essentialism more in the prosocial domain. When youth made essentialist attributions in prosocial situations, they judged actors as more likable, their actions as more acceptable, and endorsed more praise and “good person” attributions. In antisocial situations, essentialism was linked to judging actors as more unlikable, their actions as more unacceptable, more endorsement of punishment, and “bad person” attributions. Study 2 examined how moral mindsets were linked to youths’ narrative accounts of their own morally-laden experiences and how these associations might differ across experiences in which youth described acting consistently and inconsistently with an important value. Individual differences in moral incrementalism were associated with adolescents’ construction of meanings in their narratives. Adolescents who endorsed moral incrementalism referred more to moral emotions, elaborated more on psychological interpretations, and engaged in more meaning-making in their narratives.
Furthermore, moral incrementalism was inversely linked with disengagement when youth narrated a time they acted inconsistently with a moral value. Both studies illuminate how moral mindsets are applied in nuanced ways across situations. Findings suggest that moral essentialism might be especially variable across contexts, and informs situation-specific ways in which adolescents make judgments of others. In turn, individual differences in moral incrementalism were more strongly associated with adolescents’ own moral self-constructions. This research contributes to scholarship on moral mindset during a crucial developmental period by illuminating inter- and intra-individual differences in adolescents’ judgments about others as well as meaning-making in relation to their own moral experiences.


identifier: Lu, Henry ORCID: https://orcid.org/0000-0002-5460-223X <https://orcid.org/0000-0002-5460-223X>  (2021) Effects of different climate generation methods on the hygrothermal performance of a wood-frame wall under current and projected future climates.  Masters thesis, Concordia University.

abstract: Climate change will subject the built environment in Canada to unprecedented climatic conditions in the future, which may result in adverse effects on the durability of buildings.  Therefore, it is vital to be able to accurately describe future climatic conditions and how buildings will perform under them. Hygrothermal simulation models are important tools for building practitioners to assess the moisture performance of wall assemblies. Hygrothermal simulations require a wide range of climate variables such as cloud cover, wind speed, wind direction, solar radiation, rainfall, snow cover, temperature, and humidity in high temporal frequency. Typically, recorded historical data was used for hygrothermal simulations, but they do not account for changes in climate excepted due to future global warming. Consequently, many climate data generation techniques have been developed to prepare climate data incorporating future projected climate change, which can be used to assess hygrothermal performance of buildings under current and future projected climates. The objective of this work is to evaluate the differences in the various future climate data generation methods and determine their impacts on the hygrothermal performance of a wood-frame wall assembly in the current and future projected climate. The analysis is performed on 6 cities, representing different climates across Canada and future projected climate data is prepared using morphing downscaling method, and two multivariate and a univariate bias correction method. Results indicate that morphed and bias corrected climate data perform better than RCM when compared to the observations. While this is generally true for the hygrothermal performance as well, the bias corrected data often fail to replicate the same degree of mould growth in the simulations with observational data. An analysis of the climate change scenario indicated that all the studied locations will experience warmer and wetter climatic conditions. For instance, the WDR deposited on the OSB in Montreal is expected to increase by at least 14%, resulting in increased MC and mould growth on the OSB. According to morphed climate data, the average MC in the OSB could increase by 54% while mould index exceeds 3.


identifier: Smith, Jolee  (2021) “It Washes Through”: Fibre Art and the Intertidal Zone in Contemporary Nova Scotia.  Masters thesis, Concordia University.

abstract:
This thesis investigates land-based fibre art practices that are carried out in the intertidal zones in the province of Nova Scotia, and the potential for such practices to generate an ecological worldview. To do so, the following pages focus on the processes of three artists, Alexa Bunnell, Doug Guildford, and Katrina Craig, who have all recently used fibre-based practices to engage with the specific character of the intertidal zones. This thesis weaves together evidence from secondary sources with primary material drawn from conversational interviews with the artists. My methodology draws from the diversity of approaches, including critical craft studies, ecocriticism, and new materialism.
This thesis briefly analyses different models for engaging with the landscape that were used in the Earth Art movement of the 60s and 70s, in order to locate a process that aligns with Tim Morton’s definition of developing “ecological awareness.” The body of this thesis analyses the themes that arose in the interviews. Firstly, the important role that bodies, materials and environments take in developing self-awareness and ecological awareness, as well as the unique traits of fibre-based processes that lend themselves to this process. Another section inquiries into the way Guildford, Bunnell, and Craig’s work hybridised the technical and artistic applications of fibre art. The last section explores the element of storytelling that takes place through their work, which lends itself to generating an ecological paradigm.
I contend that Bunnell, Guildford, and Craig’s art-making processes raise ecological awareness beyond the realm of art, in an exchange that social anthropologist Tim Ingold describes as “textility.” This creative modality allows these artists to contribute to generating an ecological paradigm.


identifier: Azadian, Payam  (2021) Computational Analysis of Non-Periodic Oscillations Using the Harmonic Balance Method.  Masters thesis, Concordia University.

abstract:
Computational Analysis of Non-Periodic Oscillations Using the Harmonic Balance Method

Payam Azadian

This thesis investigates different approaches for applying the harmonic balance (HB) method to study steady-state non-periodic motion. The HB method is based on approximating the response of a nonlinear system using a truncated Fourier series. It is an established, powerful technique for analyzing and predicting the steady-state response of nonlinear systems.
The HB method is very popular in engineering because it reduces the cost of computations compared to direct numerical integration of the governing equations. This reduction is particularly important in nonlinear systems because the computational cost for these systems is typically much higher. Furthermore, the HB method can be used to approximate the steady-state quasi-periodic response of different types of systems. The quasi-periodic motion is characterized by two or more harmonic components with incommensurate frequencies. This type of motion can emerge in a mechanical system in response to two harmonic excitations with an irrational frequency ratio. The excitations can be external, internal (parametric), or a combination of the two. Since quasi-periodic motion is not periodic, it cannot be represented by a simple Fourier series. Therefore, specialized formulations are required for using the HB method for the analysis of quasi-periodic motion.
The objective of this work is to investigate different approaches for approximating the steady-state quasi-periodic response of mechanical systems using the HB method. In particular, we focus on two techniques: the multidimensional HB method and the trained HB method. The results are verified with direct numerical analysis and published literature results to show that the approximation error is acceptable. The problem formulations are discussed in the non-dimensional form to keep the results general. Various case studies are used to better demonstrate how the algorithms work.


identifier: Valcourt, Tracy  (2021) Aerial Perspectives, Landscape, and Power: Politicized Images in Art and Visual Culture.  PhD thesis, Concordia University.

abstract: As aerial perspectives become increasingly prevalent in contemporary visual culture, it is essential to develop more fluency with the visual language that produces these views of the world. This thesis takes an interdisciplinary approach to consider the aerial perspective as a dominant twenty-first century visual paradigm, across art and multiple forms of visual culture. Using case studies drawn from contemporary art and politicized media images, including drone and satellite imagery, the frequently asymmetrical relationships between sky and ground are analyzed according to key concepts such as invisibility and visibility, omniscience, scale, distance, and resolution. Select artworks – by Trevor Paglen, Fazal Sheikh, Stephanie Comilang, and Sophie Ristelhueber – as well as projects undertaken by visual investigation teams, are able to reveal the relationship between top-down views and forms of power such as imperialism, capitalism, surveillance, and militarism. This contemporary visual paradigm is also historicized through examples of landscape art from the Western tradition, including targeted landscapes that depend on Renaissance one-point perspective, sixteenth-century “world landscapes,” and nineteenth-century Romantic landscapes. The thesis showcases the work of visual investigation teams that draw upon opensource analytic techniques to challenge state-driven narratives, while equipping digital citizens with the skills to do likewise. Ground-level testimony and mobile storytelling are also brought forward, as ways to dismantle the omniscient voice traditionally associated with the “god’s-eye” view.


identifier: Motaghi, Arman  (2021) Three Essays on The Role of Managers in The Application of Control Practices in Small and Medium-Sized Enterprises.  PhD thesis, Concordia University.

abstract:
This dissertation comprises three essays that investigate how managers apply controls, especially in small and medium-sized enterprises (SMEs). The first essay examines the role of managers, who evolve in a dynamic relationship with their work context, in the application of controls. More specifically, the application of a given control can either be the same or can vary across work contexts or between managers. Findings illustrate that managers use and apply controls based upon their prior learnings, conditionings, and style while operating within the rules and necessities of their work context. Variations in these personal elements or the rules and necessities of the work context lead to variation in practices. Findings also show that managers use controls to structure the field towards favorable conditions.
The second essay examines how managers adapt their use of controls in response to perceived employee variations in terms of commitment, respect for the rules and expectations, and their belief regarding the organization and its objectives. Findings show that managers use controls in the form of an exchange, to accommodate desired behavior and limit or control undesired behavior. Furthermore, managers develop an understanding (a perception) of employees’ commitment, attachment, and belief, which leads them to use controls differently in response to variation in these elements. Additional findings indicate that high commitment and attachment between managers and employees reduce managers' need to rely on control practices regarding their employees.
The third essay of this dissertation examines how managers can use controls to bully employees or to create an environment that fosters bullying. Findings show how managers' use of controls in a laissez-faire approach contributes toward an environment that fosters bullying while arbitrary use of controls to bully reinforces the act of bullying. Furthermore, informal use of controls facilitates the above uses.

Keywords: control practices, managers, practitioners, employee variation, commitment, attachment, belief, bullying, small and medium-sized enterprises (SMEs).


identifier: Wu, Xiuting  (2021) Life cycle assessment of solar district heating with borehole thermal energy storage in Nunavik.  Masters thesis, Concordia University.

abstract: Nunavik, a remote subarctic region covering the northern third of Quebec, Canada, relies heavily on diesel to meet residential heating demand. Solar district heating with borehole thermal energy storage (SDH-BTES) has been regarded as one of the most promising solutions that can break the dependence on fossil fuels and develop renewable energy resource locally. Whether to develop an SDH-BTES in Nunavik is not only a technical and economic consideration, but also an environmental deliberation. Even though SDH-BTES systems are considered as an environmentally friendly technique in other regions, it is crucial to analyze its environmental performance in Nunavik, considering the harsh weather condition, inconvenient transportation and backward infrastructure there. Therefore, in this study, a cradle-tograve life cycle assessment (LCA) of SDH-BTES in Nunavik is performed. A heating system for 20 single-family houses in Kuujjuaq, comprising a 1500 m 2 gross solar area and one hundred fifty 30–m–deep borehole heat exchangers, is modeled in SIMAPRO to analyze its environmental performance. The results are presented comparatively with the 20 conventional local household diesel furnaces. The present analyses show that SDH-BTES performs better than local diesel furnace regarding human health, climate change and resources. However, ecosystem quality impact of SDH-BTES system is remains higher than the conventional domestic diesel furnaces due to drilling process and the need to a large land occupation of underground thermal heat storage. Besides, 32418.80 kg GHG emission can be avoided per year using SDH-BTES system. In summary, the LCA results present the extent of the environmental benefits of SDH-BTES for adoption as a renewable energy shortage in Nunavik. The extent of adverse environmental impacts of the system is also characterized and estimated to provide a basis for prioritization and addressing of them.


identifier: Babahaji, Mina  (2021) Connectivity and Consensus in Multi-Agent Systems with Uncertain Links.  Masters thesis, Concordia University.

abstract: In the analysis and design of a multi-agent system (MAS), studying the graph representing the system is essential. In particular, when the communication links in a MAS are subject to uncertainty, a random graph is used to model the system. This type of graph is represented by a probability matrix, whose elements reflect the probability of the existence of the corresponding edges in the graph. This probability matrix needs to be adequately estimated. In this thesis, two approaches are proposed to estimate the probability matrix in a random graph. This matrix is time-varying and is used to determine the network configuration at different points in time. For evaluating the probability matrix, the connectivity of the network needs to be assessed first. It is to be noted that connectivity is a requirement for the convergence of any consensus algorithm in a network. The probability matrix is used in this work to study the consensus problem in a leader-follower asymmetric MAS with uncertain communication links. We propose a novel robust control approach to obtain an approximate agreement among agents under some realistic assumptions. The uncertainty is formulated as disturbance, and a controller is developed to debilitate it. Under the proposed controller, it is guaranteed that the consensus error satisfies the global L2-gain performance in the presence of uncertainty. The designed controller consists of two parts: one for time-varying links and one for time-invariant links. Simulations demonstrate the effectiveness of the proposed methods.


identifier: Leal, William  (2021) The Synthesis and Study of Perovskites in Novel Forms.  Masters thesis, Concordia University.

abstract:
The need for materials which aid in the production of clean energy has risen dramatically in recent years due to the looming threat of anthropogenic climate change. Perovskites have had a long history as a known material dating back to the 19th century and have seen an explosion of interest in the last 13 years as a material with great potential to oppose this threat when employed in devices for solar energy conversion. From the first perovskite-based photovoltaic to applications in photocatalysis, light emitting diodes, lasing, scintillation, and more, perovskite research moves on at a break-neck pace. Lead halide perovskites serve as the focus of much of this research as they possess unique optoelectronic properties which make them a prime candidate for application in solar energy conversion.
Though much work has been done to develop direct synthetic methods for producing lead halide perovskites, these methods offer little morphological variety, and it is well established that their optoelectronic properties are tied to their structure and morphology. As such, the present work aims to develop a synthetic procedure whereby CaCO3 microstructures are electrochemically deposited on a transparent conducting oxide glass substrate and subsequently converted to PbCO3 and then CsPbBr3, resulting in stratified microstructures with a surface layer of CsPbBr3 nanocrystals.
Lead halide perovskites also exhibit poor stability in the presence of moisture, which results in their degradation to PbX2 salts which pose a risk to the environment. Metal halide double
iv
perovskites of chemical formula A2BB'X6 have emerged as a lead-free alternative to lead halide perovskites, possessing a similar structure and comparable electronic properties. This thesis details the synthesis of Cs2NaYbCl6 as nanocrystals in order to merge the favorable optoelectronic properties of double perovskites with those associated with nanomaterials.


identifier: Afzali Arani, Mahsa Sadat  (2021) Human Activity Recognition: A Comparative Study to Assess the Contribution Level of Accelerometer and vital Signals.  Masters thesis, Concordia University.

abstract:
Inertial sensors (IMU) are widely used in the field of human activity recognition (HAR), since this source of information is the most informative time series among non-visual datasets. HAR researchers are actively exploring other approaches such as different feature extraction methods, machine learning models and classifiers, different sources of signals and sensor positioning to im- prove the performance of HAR systems.
Human physical activities have a significant impact on human body, specifically heart activity and oxygen delivery, thus, we explore heart activity related bio-signals to check if these signals are advantageous in the field of HAR research. In this thesis, we investigate the impact of combining bio-signals with dataset acquired from accelerometer on recognizing human daily activities. To achieve this aim, we used PPG-DaLiA dataset consisting of 3D-accelerometer (3D-ACC), electrocardiogram (ECG), photoplethysmogram (PPG) signals acquired from 15 individuals while per- forming daily activities. We extracted hand-crafted time and frequency domain features, then we applied correlation-based feature selection approach to reduce feature-set dimensionality. After introducing early fusion scenarios, we trained and tested random forest models with subject-dependent and subject-independent setups. Our results indicate that combining features extracted from 3D- ACC signal with ECG signal improve the classifier’s performance F1-scores by 2.72% and 3.00% (from 94.07% to 96.80%, and 83.16% to 86.17%) for subject-dependent and subject-independent approaches, respectively.


identifier: Chabelnik, Nina  (2021) Modernist Architecture and Religion in the Soviet Union: The Case of the Palace of the Soviets and the Cathedral of Christ the Saviour.  Masters thesis, Concordia University.

abstract: Although the Cathedral of Christ the Saviour and the Palace of Soviets represent two completely different styles and ideologies, they are deeply intertwined in their shared building site, histories, and architecture. These two monuments were produced out of a desire to establish a new Russian architectural style and serve as symbols of power. My thesis will address the architectural competition of the design of the Palace of the Soviets and its place in the broader religious context of the Soviet Union, examining the link between religion and nation-building architecture in twentieth-century Russia. I will be framing this analysis by comparing the architectural components of the original Cathedral and the Palace of the Soviets, arguing that the conception and architectural features of both buildings and the similarities in the religious and secular rites of the Russian Orthodox Church (ROC) and the Communist regime illustrate the lingering presence and influence of religion in the Soviet ethos. I will be positioning the competition for the design of the Palace of the Soviets within the context of style debates that were going on in the first half of the twentieth century and the gradual move away from modernist aesthetics towards socialist realism.


identifier: Abdellatif, Ahmad  (2021) Towards Understanding and Improving the Value of Chatbots in Software Engineering.  PhD thesis, Concordia University.

abstract:
Software chatbots have been around since 1966, where the first computer interacted with a human. Recently, advances in artificial intelligence and natural language processing and understanding led to the rise and widely use of chatbots in a variety of services (e.g., healthcare, e-commerce, customer service). Nowadays, chatbots have become the main conduit between humans and services. Through natural language, chatbots enable users to communicate with different services intuitively. Another reason for the increasing popularity of chatbots in several domains is their benefits in saving time, effort, and cost. These benefits and wide adoption of chatbots attract practitioners to implement chatbots that support software engineering tasks. Chatbots play an important role in various software development tasks from answering development questions to running tests and controlling services. While there are numerous chatbots and their capability of supporting software practitioners is encouraging, little is known about the development challenges and usage benefits of software engineering chatbots.

This thesis presents series of empirical studies that aim to understand the challenges of developing chatbots for the software engineering domain, highlight the value of using chatbots in software development, and proposes novel approaches to support developers at developing more efficient software engineering chatbots. More specifically, we tackle three aspects of chatbots in software engineering. First, we present an empirical study to explore the chatbot development challenges. We find that chatbot developers face several challenges that are related to chatbot integration, development, natural language understanding platforms (NLUs), user interaction, and user input.

Second, we propose a chatbot layered on top of software repositories to answer software project related questions in order to showcase the potential of chatbots in software development. We find that practitioners are able to complete their tasks more accurately (65.6% more completed tasks) and in less time (83.3% faster) when using chatbots compared to using conventional tools. During this work we find two critical challenges in chatbot development which are selecting an NLU model for the chatbot implementation and curating a high-quality dataset to train the NLU model.

Third, we propose guidelines and approaches to improve chatbots in the software engineering domain. First, we assess the performance of multiple widely used NLUs using representative software engineering tasks to guide chatbot developers in designing more efficient chatbots. We report a guideline for chatbot developers on the best performing NLUs for intents classification and entity extraction. Finally, we investigate an approach that combines synonyms replacement and paraphrasing techniques to augment the training dataset of SE chatbots, which helps chatbot developers create high-quality datasets for training the NLU models. We find that augmenting the dataset using the combined approach does not improve the NLU's performance for intents classification. Also, the results show that using the combined approach has a negligible effect on the NLU's confidence in its classification.


identifier: Toft, Ida  (2021) Brittle Configurations: Practical Explorations on Games and Vibrotactile Media.  PhD thesis, Concordia University.

abstract: This dissertation presents the written portion of a research-creation PhD exploring vibrotactile technology in the context of artistic and creative game development. Brittle Configurations: Practical Explorations on Games and Vibrotactile Media features four games that use vibrotactile technologies as a primary expressive modality. Vibratory expression crosses boundaries inexorably: materially, anatomically and semiotically. Focussing on the vibrotactile in the context of game development therefore allows for a refiguring of what Aubrey Anable has called the surface/depth dichotomy in game studies—a tendency to associate representation with the surface, and computation with depth. This dissertation details the development process of the four games mentioned above. Four chapters present these four respective development processes, introducing expressive, ethical, practical and technological concerns of artistic game development. These development chapters alternate with reflective chapters contextualizing and complementing the examined making processes. In seeking out a design strategy that not only accommodates difference but appreciates it, this dissertation articulates how I worked toward vibratory media that abandon the closed loop of signifier and signified and become open signifiers, hosting memories, speculation, imagination, poetry, and inquisitive thinking. A critical examination of the role of container-like metaphors in game studies offers new perspectives on how tasks and responsibilities (such as playing, executing, policing, evaluating, rewarding) are distributed throughout circuits of playful media. Together with non-verbal and non-human modes of communication, as well as a series of alien robotics, these examinations bring about reflections on what I call fragile games. A fragile game aesthetic features situated and relational game design as an alternative to universal guidelines of “good game design” and aesthetics of purity, stability, resilience, and individuality. The evolution of these explorations culminates with the development process of the game Where Stillness Breaks, an installation that explores memories, associations, and speculative connections in the space between felt vibration and words.


identifier: Krastel, Zachary  (2021) Cognitions and Effects of Music Consumption.  PhD thesis, Concordia University.

abstract:
Music plays an important role in our everyday lives, and constitutes a large consumer industry. However, research on music is fragmented across many disciplines, and lacks integration. In marketing, music is rarely the focus of study; it is predominantly examined in terms of its potential as an atmospheric element in retail settings, and is usually only applied as a moderating effect. This dissertation focuses on understanding music cognition by systematically deconstructing it, in order to better understand how music affects individuals and how it can be utilized to achieve specific goals in consumer contexts.

The first essay of this dissertation is a conceptual paper. It reviews the existing research on music and develops a comprehensive model of how music is processed by individuals. The model integrates music’s core compositional aspects (lyrics, pitch, and rhythm) with the types of processing that can result when individuals encounter music (semantic, referential, and social). These processing types are then linked to the outcomes of music seen in existing research. Overall, the model is able to explain how music can influence emotion and create cognitive effects for individuals; specific adjustments to a song’s core elements that can emphasize these effects are delineated. Research propositions are presented which aim to bring clarity and focus to future research using music.

The second essay focuses on a single relationship in this model: between rhythm and social connection. Anthropologists have hypothesized that the rhythm element of music may have evolved over time in human societies as a vehicle for social bonding. Across five experiments, I examine this relationship further. I vary the level of rhythm in a song and show how engaging with rhythmic music with a member of an organization creates a “synchrony effect”, where the two individuals feel closer to one another. Individuals’ prosociality and feelings towards the organization improve after these tasks. I also show how it can lead individuals to change their brand preferences to align with the other participant. This effect occurs even in experiments where a pre-recorded video was used, which improves the feasibility of implementing this research in practice.


identifier: Porro Suardiaz, Javier  (2021) A mechanistic approach to studying the antimicrobial and anticancer activity of GL13K-based peptides through their interaction with model membranes.  Masters thesis, Concordia University.

abstract: GL13K is a broad-spectrum antimicrobial peptide with selective bactericidal and antibiofilm activity, which makes it an attractive candidate for targeted antibiotic applications. Many antimicrobial peptides are multifunctional and have exhibited anticancer activity. Along with this precedent, GL13K’s potency on cancer has not been yet reported. Therefore, we proceeded to a preliminary assessment of anticancer activity for both D- and L-GL13K enantiomers in cancer cell lines. It emerged that D-GL13K showed selective toxicity in cancer cells. Such enantiomeric differences have previously been attributed to their resistance to proteolytic degradation. To probe if distinct mechanisms of interaction are involved in either their antibacterial vs anticancer activity, we evaluated the roles of peptide chirality and membrane composition by studying the interaction of D- and L-GL13K, as well as a newly designed GL28K peptide, with model membranes that mimic the lipid composition of those in human cancer, erythrocyte cells and bacteria. For this purpose, a combination of bulk and surface-specific biophysical techniques was used. The enantiomers showed differential interactions that can depend on the lipid composition in agreement with their activity (in the absence of proteases) as evidenced by greater binding and insertion in the cancer model membranes. However, in contrast to results in bacterial models neither enantiomer of GL13K displayed a crystalline beta-sheet conformation in presence of the eukaryotic cell model, despite this being a hallmark of their activity with bacterial models. The molecular origins and significance of these results will be discussed.


identifier: Abdelhamid, Mohamed  (2022) Dependability Analysis Methodology for FPGA-Based UAV Communication Protocols using UPPAAL-SMC.  Masters thesis, Concordia University.

abstract:
UAVs are multifaceted devices that have enormous versatility and flexibility in a plethora of various fields. Year over year, UAVs see a tremendous amount of research invested in it to make them more efficient and autonomous when performing a task. This increase in autonomy requires the UAVs to have a dependable link between them to exchange crucial information like current position and speed. These messages are transmitted to avoid collisions and perform missions efficiently. The communication between UAVs depends on several factors like the used telemetry device, distance between the UAVs, speed of the UAVs, and application environment. Hence, an UAV designer must analyze the reliability of the communication based on the desired application environment and necessary communication components in the UAV.
Faults can also propagate in UAV components built using the FPGA technology when they are placed in harsh radiation environments like radiation monitoring. These errors can lead to complications in the operation of an UAV communication component, and hence, FPGAs require techniques like blind scrubbing to mitigate these faults. The availability of the communication component can be impacted when using this mitigation approach. Therefore, investigating the optimal configuration to maintain high and consistent availability is crucial.

This thesis presents a methodology to perform high-level dependability analysis for UAV communication protocols using statistical model checking. First, we evaluate the reliability of a point-to-point UAV communication using the UAV-UAV framework. The main objective of this framework is to investigate the link reliability between UAVs based on the specifications of the telemetry device and the availability of the communication components. To accomplish this, we propose models to emulate the behavior of two UAVs in air, the condition of the transmitter and receiver, and the data exchange phase between two UAVs. Then, we analyze the availability of an UAV communication module in a harsh radiation environment using blind scrubbing as a mitigation approach. The peak availability of UAV-UAV and UAV-GCS communication components is investigated through the UAV-UAV and UAV-GCS frameworks. The two frameworks utilize the SEU rate computed from the RTL code of the communication component design. Then, implement crucial features like scrubbing interval and scrub time in the transmitter and receiver modules to find the optimal scrubbing interval when the UAV communications with other UAVs or the GCS. Finally, the effect of these faults and limitations of blind scrubbing is also investigated in our work.


identifier: Patel, Dimpykumari  (2021) Optimization of Free Piston Expander Based Organic Rankine Cycle.  Masters thesis, Concordia University.

abstract: Thanks to its simple design, operational flexibility and potentially higher thermal efficiency at higher pressure ratios, the free piston expander (FPE) is gaining popularity and attention from researchers. A lot of work is expanded to implement the FPE concept in the organic Rankine cycle (ORC) for waste heat recovery. However, steady-state models that predict the efficiency and power output of FPEs under varying conditions are not available. The main objective of this work is to build a steady-state model to optimize the FPE-based, waste heat recovery cycle using a suitable working fluid. A thermodynamic analysis is carried out to match the unsteadiness of the FPE with the steady heat rejection, pressurization, and heat recovery of the ORC. Entropy before condensation and internal energy after constant volume filling is optimized, keeping the thermodynamic state of the fluid coming out of the heat exchanger fixed on the saturated vapor line. From optimized values, work output and efficiency for a specified condition (hot and cold source temperatures) are calculated. Targeted power output, maximum allowable piston velocity, and frequency are constrained by the system, from which the sizing of an FPE is derived. The sizing criteria provides a mean for the selection of the optimum working fluid. The analytical results show that the efficiency increases with the increasing expansion ratio up to a certain value, but however has a negative effect on specific power. Increasing the initial volume, before the filling of the FPE takes place, decreases both the efficiency and specific power and should be minimized for optimal operation. Optimum fluid selection is also carried out for two test cases with varying hot source temperatures and maximum piston velocity.


identifier: Singh, Paramjot ORCID: https://orcid.org/0000-0003-3830-9583 <https://orcid.org/0000-0003-3830-9583>  (2021) Surface Study of Volatile Organic Compounds (VOCs) Biomarkers Adsorption on Functionalized Graphene and its Application in FET Based Biosensors.  Masters thesis, Concordia University.

abstract:
In this work, we have designed and simulated a graphene field-effect transistor, GFET, with the purpose of developing a sensitive biosensor for methanethiol, a biomarker for bacterial infections and ethyl butyrate, a biomarker for COVID-19.
The surface of a graphene layer is engineered by manipulation of its surface structure and best cases are used as the channel of the GFET. Three methods, doping the crystal structure of graphene, decorating the surface with transition metals like Platinum and Palladium and defected graphene nanoribbons are utilized to induce the bandgap in the graphene layers.
The techniques also change the surface chemistry of the graphene by enhancing its adsorption characteristics and make binding between graphene and biomarker possible. All the physical parameters are calculated for various variants of graphene in the absence and presence of the biomarker using counterpoise energy corrected density functional theory in Quantum ATK. The device was modelled using the finite element method in COMSOL Multiphysics. Our studies show that the sensitivity of the device is affected by the structural parameters of the device, the electrical properties of the graphene, and with adsorption of the biomarkers. It was found that the devices made of graphene layers decorated with transition metals show higher sensitivities toward detecting the biomarkers compared with those made by doped graphene layers and nanoribbons.


identifier: Valinejadshoubi, Mojtaba  (2021) Development of BIM-based Automated Methods for Building Management and Structural Safety Assessment.  PhD thesis, Concordia University.

abstract: Despite the progress made in modern project management methods, there is still a lack of appropriate automated tools that support digital integration over the project life cycle. There is considerable demand for fully embracing the latest technological opportunities such as Building Information Modeling (BIM), Internet of Things (IoT), Structural Health Monitoring (SHM), and prefabrication to support that digital transformation in construction. The aim of this study is to develop a set of automated management solutions and related tools to address the issues highlighted above. The thesis is presented as a collection of manuscripts of five peer-reviewed journal articles authored based on the present research. The first development is of a BIM-based method for 3D model visualization of buildings and their non-structural elements and their corresponding seismic risk levels and locations. It supports automated assessment of seismic risk of these elements. The second focuses on the development of a novel data-driven SHM technique to monitor the structural behavior of individual building modules to detect possible damages during their transportation. It consists of two main components, a sensor-based data acquisition (DAQ) and storage module, and an automated data analysis module that uses unsupervised machine learning techniques to identify damages during transportation using onboard captured acceleration data. It can be used to ascertain the safety of delivered modules before their assembly on site. The third accounts for the development of an automated BIM-based framework to facilitate effective data management and representation of sensory components of the SHM tool used in buildings. It allows for visualization of damages in building components based on the interpretation of the captured sensor data. It is designed to facilitate effective visualization capabilities for a rapid and efficient structural condition assessment. The fourth development is designed to dynamically update the thermal comfort data in monitored buildings by integrating their BIM models with captured sensor data. The default range utilized in this development is based on the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard. It is expected to provide a robust and practical tool for data collection, analysis, and visualization to facilitate intelligent monitoring of the thermal condition in buildings and help decision-makers take needed timely data-driven decisions. The fifth and last development is designed to alert IoT companies of malfunctioning of deployed sensors utilizing a BIM platform and a cloud database to process and transfer related actionable information.


identifier: Hannachi, Samar  (2021) Statistical Models for Short Text Clustering.  Masters thesis, Concordia University.

abstract:
A notable rise in the amounts of data collected, which were made available to the public, is witnessed. This allowed the emergence of many research problems among which extracting knowledge from short texts and their different related challenges. In this thesis, we elaborate new approaches to enhance short text clustering results obtained through the use of mixture models.
We deployed the collapsed Gibbs sampling algorithm previously used with the Dirichlet Multinomial mixture model on our proposed statistical models. In particular, we proposed the collapsed Gibbs sampling generalized Dirichlet Multinomial (CGSGDM) and the collapsed Gibbs sampling Beta-Liouville Multinomial (CGSBLM) mixture models to cope with the challenges that come with short texts. We demonstrate the efficiency of our proposed approaches on the Google News corpora. We compared the experimental results with related works that made use of the Dirichlet distribution as a prior.
Finally, we scaled our work to use infinite mixture models namely collapsed Gibbs sampling infinite generalized Dirichlet Multinomial mixture model (CGSIGDMM) and collapsed Gibbs sampling infinite Beta-Liouville Multinomial mixture model (CGSIBLMM). We also evaluate our proposed approaches on the Tweet dataset additionally to the previously used Google News dataset. An improvement of the work is also proposed through an online clustering process demonstrating good performance on the same used datasets. A final application is presented to assess the robustness of the proposed framework in the presence of outliers.


identifier: Parvizi Omran, Raha  (2021) Transcriptional profiling and Functional studies of Zinc cluster transcription factors in Candida albicans.  PhD thesis, Concordia University.

abstract:
The yeast Candida albicans is a commensal member of the gastrointestinal and urogenital tracts of most healthy humans. However, its capacity to function as an opportunistic pathogen allows it to cause systematic infections of immunocompromised individuals. Over the past two decades, the C. albicans zinc cluster transcription factor family (ZCFs) has been a fascinating subject of research – with studies identifying their roles in virulence, morphogenesis, biofilm formation, drug resistance and many other cellular processes. An understanding of these ZCFs may reveal new targets for therapeutic strategies.
My work focused on generating genome-wide transcriptional profiling for a large subset of 35 ZCF gain-of-function mutants (GOF) to elucidate the transcriptional profiles among the ZCFs, and on investigating in depth the function of some specific ZCFs in the fungal pathogen.
Transcriptional profiling revealed the target genes that are activated by the ZCF-GOF mutants and provided insight into the underlying roles of the factors. My study focused on establishing the transcriptional regulatory relationship among the ZCFs and understanding the function of some uncharacterized ZCFs. In chapter 2, I selected a set of 35 mostly uncharacterized ZCF, or little is known about them to explore their function using RNA-based transcriptional profiling in collaboration with professor M. Hallett lab. The network approach often shows a specific ZCF-GOF caused activation of expression of other ZCFs, which highlights the extensive interactions among ZCFs. We suggest that most expression changes can be the result of downstream longer-term adaptive responses that induce the expression of intermediate transcription factors.
In chapter 3, I characterized a new element involved in hyphal development regulation as a previously unstudied Candida-specific ZCF encoded by CaORF19.1604 that I named Rha1 (Regulator of Hyphal Activity). I identified Rha1 through screening a ZCF-GOF library and noting the Rha1-GOF strain was in a filamentous form under yeast growth conditions. I have characterized Rha1 inactivation mutants and GOF alleles, and I explored the Rha1 regulatory network involving Brg1 and Ume6, which are upregulated hyphal activators that appeared in the Rha1-GOF profile to show that Rha1 affects hyphal gene expression and upregulates Brg1/Ume6 and downregulates Nrg1.
In chapter 4, I investigated the role of ZCF4 in cell wall biogenesis, filamentation, biofilm formation, and drug resistance. I explored the ZCF4 function after noting its upregulation in most of the activated ZCF profiles like Rha1-GOF. Zcf4-GOF showed a severe filamentation defect on serum-based medium but exhibited normal filamentation under other cues. I have shown that ZCF4-influenced filamentation is nutrient dependent.
In chapter 5, I showed the robust ability of C. albicans to use proline as a carbon and nitrogen source by describing CaPut3 as a proline catabolism regulator. The functional studies demonstrated Put3 has a conserved role in regulating proline catabolism in C. albicans and Saccharomyces cerevisiae, but CaPut3 initiates the degradation of proline even in the presence of a rich nitrogen source such as ammonium sulphate.
Collectively, this study established a framework of functional study TFs and generated robust transcriptional data from an activated set of 35 ZCFs to help understand the biology of C. albicans, an important human pathogen.


identifier: Marino, Paola  (2021) Sustainable Synthesis of Metal–Organic Frameworks for Applications in Ophthalmic Drug Delivery.  Masters thesis, Concordia University.

abstract:
The work described herein explores an emerging class of hybrid porous materials known as metal–organic frameworks (MOFs), comprised of metal nodes bridged by organic linkers. This thesis explores the (i) sustainable synthesis and characterization of a series of structurally diverse MOFs, which include MOF-808, NU-1000, HKUST-1, and ZIF-8 using a green solvent alternative, STEPOSOL® MET-10U, (ii) the design, synthesis, and characterization of thiol-functionalized Zr6-based MOFs, Zr-UiO-66-(SH)2 and Zr-UiO-67-(SH)2, and (iii) the investigation of thiol-functionalized MOFs as an alternative platform for use in ophthalmic drug delivery applications, through assessing their mucoadhesive properties and drug loading capacity of flurbiprofen.

Chapter 2 explores the use of a plant-derived solvent, STEPOSOL® MET-10U, otherwise known as N,N-dimethyl-9-decenamide, for the synthesis and characterization of a diverse series of MOFs, MOF-808, NU-1000, HKUST-1 and ZIF-8, which are MOFs with different metal valency, varying metals nodes and organic linkers. The physical properties of the MOFs are assessed to verify that the materials are similar to those synthesized using the petroleum derived solvent N,N-dimethylformamide (DMF), and to verify the viability of the green solvent. Furthermore, synthesis of HKUST-1 on the gram-scale was performed using STEPOSOL® MET-10U to confirm that the method is scalable.

Chapter 3 delves into the synthesis and characterization of thiol-functionalized MOFs or thiolated MOFs, Zr-UiO-66-(SH)2 and Zr-UiO-67-(SH)2. These MOFs were chosen for this study as thiols are known to enhance mucoadhesive properties in drug delivery materials for biomedical applications. The mucoadhesive properties of Zr-UiO-66-(SH)2 and Zr-UiO-67-(SH)2 are presented with the goal of understanding their potential in ophthalmic drug delivery, in addition to verifying the drug loading capacity of these MOFs using a non-steroidal anti-inflammatory drug, flurbiprofen.


title: Connectivity and Consensus in Multi-Agent Systems with Uncertain Links


identifier: Etaat, Amirhossein  (2021) An Online Balance Training Application Using Pose Estimation and Augmented Reality.  Masters thesis, Concordia University.

abstract: The evolution of digitally connected devices and artificial intelligence has opened the door for novel health and fitness applications that can be used by individuals at a time and in an environment convenient to them. The purpose of our research was to develop a platform that requires no additional hardware to provide an online balance training program. Balance exercises are often prescribed for healthy aging to keep the body active, improve balance and coordination, and prevent falls and injuries, as well as, for those doing rehabilitation after injuries or diseases such as stroke. We developed a simple web application (BaART: Balance Augmented Reality Trainer) that uses PoseNet to determine a user's location and pose to count the number of repetitions that were done successfully. Furthermore, we looked at how augmented reality, and specifically adding a virtual chair, might impact a user's sense of balance. In a study of 20 participants with and without balance disorders, we found that the developed system was easy to use and many would consider using such a system, particularly our older participants who spend more time at home. However, we also found that the virtual object (i.e. chair) was not used by most people. Furthermore, those with balance issues felt they required a real chair for balance and some even felt that the virtual object was distracting from the exercise. In the future, we plan to explore other uses of augmented reality, such as feedback on exercise quality, gaming features, and a virtual avatar trainer.


identifier: Kohli, Gurmanak Singh  (2021) Cryptocurrency as a Gamble, Hedging Instrument, or Store of Value.  Masters thesis, Concordia University.

abstract: Since the launch of Bitcoin in 2008, cryptocurrencies have garnered a lot of attention in the financial world. This paper analyzes whether cryptocurrencies can be used as a hedging instrument or a store of value, or whether they are just highly volatile assets with gamble-like traits. To investigate this, I compare cryptocurrencies to lottery-like investments in the CRSP universe and find that the two major cryptocurrencies, bitcoin and ether, possess high idiosyncratic volatility and idiosyncratic skewness. This implies cryptocurrencies have lottery-like behavior and activities on these networks could be motivated by speculative behavior of investors. To examine hedging instrument traits of cryptocurrencies, I perform a spanning-test to determine if adding cryptocurrencies to the market portfolio reduces risk. The addition of cryptocurrencies to a traditional asset portfolio with assets such as S&P500 stocks, Gold, Silver, Real Estate, and commodities, is found to reduce portfolio risk, but expose investors to significantly high tail-risk due to the cryptocurrency’s intrinsic skewness. Adding cryptocurrencies shifts the portfolio frontier significantly to the left, but this better risk-return ratio is offset by exposure to high volatility of the test asset class. From the viewpoint of a store of value, cryptocurrencies may not possess characteristics like the store of value component in gold, but the results are weak and inadequate to draw any strong conclusions. Overall, the analysis seems to suggest that even though cryptocurrencies are not likely to possess attributes of a store of value, they offer diversification benefits to investors at the cost of exposure to larger potential losses.


identifier: Ajoyan, Zvart  (2021) Photophysical Properties of Rare-Earth Cluster-Based Metal–Organic Frameworks.  Masters thesis, Concordia University.

abstract:
The work described herein explores the field of metal–organic frameworks (MOFs) with a
particular emphasis on rare-earth (RE) cluster-based MOFs. MOFs are materials that are of interest
due to their permanent porosity, high surface areas, and tunable structures. This thesis focuses on
three different MOFs: RE-UiO-66 (UiO = University of Oslo), RE-CU-10 and RE-CU-27 (CU =
Concordia University). The synthesis, characterization, and photophysical properties of these
MOFs are presented.
Chapter 2 explores tuning of the RE-UiO-66 platform by synthesizing and characterizing
mono-, bi- and tri-metal RE-UiO-66 analogues where RE = Tb(III), Gd(III), and Eu(III), ultimately
leading to the formation of a white light emitting MOF. Furthermore, a study of the photophysical
properties of this series of MOFs is conducted and as a proof of concept, Tb:Gd:Eu-UiO-66 is
deposited on a UV light emitting diode (LED), leading to a white light emitting diode (WLED).
Chapter 3 describes a facile route for modulating the photoluminescent and
radioluminescent properties of Tb(III) cluster-based MOFs. By using Tb(III)-cluster nodes as Xray attenuators, and organic linkers with varying excited state energies as sensitizers, MOFs with
metal-based, linker-based, and metal+linker-based photo- and radioluminescence are reported.


identifier: Ghosh, Pronob Kumar  (2021) Effect of Shear Tab Connection on Lateral Torsional Buckling Capacity of W-Shape Beam.  Masters thesis, Concordia University.

abstract:
Steel shear tab connections are one of the most common types of connections used to connect steel beam to supporting columns and girders. Shear tab connections can be of two types: conventional shear tab (CST) and extended shear tab (EST). In EST connection, the shear tab is generally extended beyond the supporting member’s flange. While significant research has been conducted on conventional shear tab connections, research on extended shear tab connections is limited. First, this research presents the development of a three-dimensional (3D) finite element model (FEM) to study the behavior of shear tab connections, both conventional and extended shear tab, in W-Shape beam. Both material and geometric nonlinearities are considered in the FE model. The finite element model is validated against available experimental results on both conventional and extended shear tab connections. After validation of the FEM with experiments, a parametric study is carried out for W-shape beam with unstiffened CST and EST connections with supporting column web. In this parametric study, the effects of different parameters such as the number of bolts, length, and thickness of shear tabs on both CST and EST connections are studied.
Previously, some research has been conducted on the stability and strength of EST connections; however, to the best of this researcher’s knowledge, no research is currently available on the effect of extended shear tab connections on lateral torsional buckling (LTB) strength of the supported W-shape beam.  The classic LTB equation in all codes is derived assuming both ends as simply supported. Since extended shear tab connections have extended tab lengths and have partial rotational rigidity, they do not act as perfect simple supports. Thus, EST connections can affect the LTB strength of supported beam. Also, the LTB behavior of I-beam for extended beam-to-column connections with multiple vertical rows of bolts has not been investigated to date. This research also presents a finite element (FE) analysis-based study to investigate the effect of extended shear tab connections on the LTB capacity of I-beam. The following parameters are considered in the study: shear tab thickness, bolt configurations with a single and double vertical line of bolts and different bolt numbers, beam unbraced length, bolt group centroid distance from the face of the supporting member, and the effect of stabilizer plate. Finally, a shear tab connection using a standard channel section, instead of the conventional shear tab, is examined in this research. It is observed that the proposed channel type shear tab connection can potentially be used in steel construction instead of the conventional or extended shear tab connections currently used, and the channel type shear tab connection can improve the LTB capacity of W-shape beam when compared to the currently used shear tab connections.


identifier: Bertone, Vanessa  (2021) The Effects of Goal Orientation and Psychological Safety on Feedback Seeking, Changes in Performance, and Learning in Student Internships.  Masters thesis, Concordia University.

abstract:
Industrial and organizational psychology research has focused on improving employee performance. A large body of research has examined the seemingly critical relevance of goal orientations in predicting individual performance, however, the findings from this literature remain equivocal. An important aspect of performance is the acquiring of knowledge, or learning the skills needed to perform. Internships provide a context for students to learn or develop the skills needed for their future careers, and can therefore, provide an interesting context to study knowledge development and performance. Drawing from this, the goal of the present study was to assess the impact of goal orientation through feedback seeking on change in performance and learning in an internship context, and the role of psychological safety as a contextual boundary condition. University students and their supervisors were surveyed at several timepoints throughout their program internship. Students’ learning goal orientation was shown to have a positive effect on their learning through their feedback seeking, while their performance avoid goal orientation had a detrimental effect on their change in performance throughout their internship. It is concluded that in order for students to benefit from their learning experiences in an internship context, learning goal oriented behaviour should be encouraged, and performance avoid goal oriented behaviour should discouraged. Further practical and theoretical implications are discussed.

Keywords: goal orientation, feedback seeking, learning, performance, internship


identifier: Hajibabaei, Anahita  (2021) Gender-Specific Patterns in the Artificial Intelligence Scientific Ecosystem.  Masters thesis, Concordia University.

abstract:
Gender disparity in science is one of the most focused debating points among authorities and the scientific community. Over the last few decades, numerous initiatives have endeavored to accelerate gender equity in academia and research society. However, despite the ongoing efforts, gaps persist across the world, and more measures need to be taken. Using various methodologies such as social network analysis, statistical analysis, bibliometrics, natural language processing, and machine learning, in this study, we comprehensively analyzed gender-specific patterns in the highly interdisciplinary and evolving field of artificial intelligence for the period of 2000-2019. This work was completed in two main phases: First, we investigated the collaboration patterns of artificial intelligence (AI) scientists to shed light on team composition characteristics in interdisciplinary research teams from a gender perspective. Next, we identified highly central AI scientists and calculated a multi-dimensional feature vector at the author level that covered multiple characteristics of scientific activities to explore the effects of driving factors on acquiring key/central network positions and explain any possible gender differences.
Our findings suggest an overall increasing rate of mixed-gender collaborations. From the observed gender-specific collaborative patterns, the existence of disciplinary homophily at both dyadic and team levels is confirmed. However, a higher preference was observed for female researchers to form homophilous collaborative links. Our core-periphery analysis indicated a significant positive association between having diverse collaboration and scientific performance and experience. We found evidence in support of expecting the rise of new female superstar researchers in the artificial intelligence field. Moreover, our findings provided a deep understanding of the profiles of highly central AI scientists and revealed that various individual author-level factors could contribute differently to occupying certain strategic network roles in the AI co-authorship network. However, some of the notable and common characteristics of central researchers, regardless of their gender, are their highly collaborative behavior and high research productivity and impact.


identifier: Lesperance, Xavier  (2021) Effectiveness of Shock Capturing Methods in the Discontinuous Galerkin/Flux Reconstruction Scheme for Computational Fluid Dynamics.  Masters thesis, Concordia University.

abstract:
The development of various numerical methods capable of accurately simulating fluid flow has evolved greatly over
time. In the past years, discontinuous Galerkin methods have seen great interest for problems such as Large Eddy
Simulations, Aeroacoustics, incompressible and even compressible flows. These methods attractiveness some from their
ability to easily increase the order of accuracy thus yielding more precise solutions. These methods use higher order
polynomials, which can easily be increased or decreased within the element, while allowing for discontinuities between
elements. When shocks and discontinuities are present in a simulation, particular attention must be taken to avoid Gibbs
phenomenon within the elements. This phenomenon occurs when steep gradients in the solution are present causing
the solution to have erratic oscillations typically associated with the higher order terms of the integrating polynomial.
These oscillations in turn lead to non-physical solutions such as negative pressures and therefore need to be controlled.
A variety of methods have been developed to mitigate the oscillatory behavior of discontinuous Galerkin methods when
steep gradients are present, a very promising method is the addition of artificial viscosity in order to diminish the effects
of the non-physical oscillations. Adding a viscous term to the conservation equations being solved can inevitably lead to
inaccurate solutions if it is added in excessive amounts. The balance between damping of the non-physical oscillations
and minimizing the amount of artificial viscosity added can if the location of the shocks in the flow field is known.
This intricate balance is achieved by ensuring that the functions used to find the areas of concern are not overlapping
shock regions with smooth regions and when viscosity is added it is important that it is limited to ensure that it will not
completely dissipate the real solution.


identifier: Khadem Moshir, Saeid ORCID: https://orcid.org/0000-0002-3145-7527 <https://orcid.org/0000-0002-3145-7527>  (2021) Stress analysis of straight and initially curved composite tubular beams using an analytical meshless dimensional reduction method.  PhD thesis, Concordia University.

abstract:
Due to high strength to weight ratio of thermoplastic composite structures, their use attracted industrial interests, especially in the aerospace industry. The application of composite curved tubes for landing gear of helicopters instead of aluminum is the subject of interest for the aerospace industry. The focus of the present work is to study mechanical behavior of composite straight and curved composite tubes subjected to the bending loading which is similar to the loading conditions of cross tubes for landing gear of helicopters during landing. The analysis of these structures with a large number of layers may be computationally expensive. The finite element method is widely used for stress analysis of initially curved composite tubes. This method is computationally expensive for design and optimization process. The main objective of the present thesis is to develop an efficient, simple-input method for stress analysis of initially curved and straight composite tubes under four-point bending loadings. To do so, different methodologies for stress analysis of straight and initially curve tubes are introduced. The advantages and disadvantages of the methods are presented. The first part of this thesis focuses on the stress analysis of straight composite cylinders under pure bending moment. The 3D elasticity of Lekhnitskii is employed to carry out the stress analysis of an anisotropic cylinders with many layers. In the second part, an analytical meshless polynomial based method in conjunction with dimensional reduction method are presented to carry out cross-sectional analysis as well as determining strain distribution in straight and curved composite tubes under bending loading (four-point bending loading) in which the effect of shear strains is taken into consideration. In order to obtain the stiffness constants of the cross-section and strains, the powerful mathematical Variational Asymptotic Method (VAM) is employed to decompose a three-dimensional elasticity problem into a two-dimensional cross-sectional analysis and a one-dimensional analysis along the length. The VAM presents Classical and Timoshenko beam models and cross-sectional stiffness matrices. In the Classical beam model cross-sectional stiffness matrix, the effect of shear is not considered. In order to achieve a more precise beam model for the analysis of initially curved and straight tubular beams, the Timoshenko-like beam model and the effect of shear strain is taken into consideration. VABS is a commercial finite element-based software for cross-sectional analysis of composite beams having complex cross-section shape. For the case of simple cross-sections such as rectangular, circular and elliptical shape, the modeling process of VABS can be eliminated by employing meshless method. The presented polynomial meshless dimensional reduction method is employed for tubes with circular and elliptical cross-sections which is the main novelty of this work. In the present work, the utilization of the Pascal polynomials for the cross-sectional analysis of the beams takes advantage of the meshless method compared with the three-dimensional finite element method or VABS. Moreover, a one-dimensional finite element solution is provided for straight and initially curved composite tubes. The presented method for the analysis of initially curved and straight tubes is computationally more efficient and simple-input compared to the 3D finite element method. In addition, it eliminates generating two-dimensional cross-sectional mesh and dividing the cross-section into different segments for straight and curved tubes compared to Variational Asymptotic Beam Sectional Analysis (VABS) software. So, the present method can be more efficient and straightforward in terms of modeling procedure compared to VABS. The parametric study such as determining cross-sectional stiffness constants, strains and displacements for design and optimization will be more straightforward.
The experimental tests are carried out to validate the present method of solution. Test setups for four-point bending test of the straight and initially curved tubes are provided by a teamwork at Concordia Center for Composites (CONCOM). The obtained strains at different spots of the tubes as well as the transverse displacement are compared with the theoretical solution. The effect of lay-up sequence, initial curvature on the mechanical behavior of the composite tubes are studied.


identifier: Tétrault, Alexandre and Gélinas, Yves  (2021) Modelling of natural organic matter affinity for mackinawite, FeS, based on FTIR spectra by partial least squares regression (PLSR).  Masters thesis, Concordia University.

creator:
Tétrault, Alexandre
Gélinas, Yves

abstract: Marine sediments represent the most important sink for natural organic matter (NOM) across geological time spans, in which carbon-containing molecules are sequestered away and can escape remineralization to CO2 by microbial degradation. Strong associations between iron oxide minerals and organic matter reaching the seafloor play a fundamental role in this preservation and have been known for some decades. Despite the importance of this protective mechanism in the balances of the global carbon budget, very little is known about the affinity of NOM for reduced iron species such as mackinawite (FeS) in the anoxic layers of sediment.  In this study, equilibrium partition coefficients (Kd) for three types of NOM (soil leachate, corn leaf and plankton lysate) on FeS were determined through batch sorption experiments.  Attenuated Total Reflectance Fourier Transform Infrared spectra (ATR-FTIR) of the organic matter was then used as model inputs to train a partial least squares regression model (PLSR) to quantitatively predict Kd values based on the FTIR spectra of NOM.  The final model fit the training data with an R2 of 0.97 (n = 17) and the validation data with a Q2 of 0.98 (n = 5) and a RMSEP of 0.036.  Inspection of the PLSR regression coefficients indicate that functional groups characteristic of polysaccharides are the greatest positive predictors of NOM sorption onto FeS at sediment pore water pH.  To our knowledge, this research presents a novel machine-learning approach to the quantitative modelling of NOM sorption to minerals found in marine environments.


identifier: Millichamp, Derek  (2021) Collapse Safety Assessment of Steel Multi-storey Buildings with Friction Sliding Braced Frames and Backup Moment Resisting Frames as a Dual System.  Masters thesis, Concordia University.

abstract:
In the early 1980’s, Concordia University’s library building saw the first application of cross-braced Pall friction dampers (PFD). Although PFDs have evolved and improved, including the friction material used, development of the design procedure has been limited. Using a recently proposed force-based design method and considering detailed computational and modeling techniques, three types of seismic force resisting systems are presented herein: the bare Friction Sliding Braced Frame (FSBF), Friction Sliding Braced Frame with Continuous Columns including gravity columns (FSBF-CC) and Dual FSBF system (D-FSBF). Installing backup MRFs in parallel with a primary FSBF can provide the structure with load path redundancy and elastic-frame action, while taking advantage of the large energy dissipation capacity of PFDs.

The objectives of this research are three-fold: 1) to develop an accurate nonlinear model for PFD that is capable of bearing and failure, 2) to quantify the ductility-related force modification factor, Rd, for the proposed seismic force resisting systems: bare FSBF, FSBF-CC, and D-FSBF and 3) assess fragility and collapse safety of low-rise and middle-rise buildings braced with the proposed seismic force resisting systems subjected to crustal and subduction ground motions.

These objectives are carried out using 2-D numerical models developed in OpenSees for 4- and 8-storey prototype buildings located on Site class C in Vancouver, B.C. A force-based design method was developed in line with NBCC 2015 and CSA/S16-14 standard requirements. Considering the similarity with buckling restrained braced frames (BRBF), design was conducted for RdRo=4 and RdRo=5. All buildings were subjected to short duration crustal and long duration subduction ground motions, and a discussion regarding the slip length demand of PFD was provided.

From nonlinear response history analysis of 4 and 8-storey FSBF buildings (RdR0=4), it was found that the bare FSBF was structurally unstable and reached collapse prior to design level under the ground motion suites. Therefore, using the bare FSBF is not recommended. The 4-storey FSBF-CC building (RdR0=4) prevented collapse at design level, however experienced excessive residual drift, while the 8-storey FSBF-CC building reached collapse at design level under both crustal and subduction ground motions. Thus, the FSBF-CC system can be used only for low-rise buildings, but caution should be taken.

Using the Dual FSBF system composed of FSBF and a backup MRF, designed for an additional 25% base shear and two sets of RdR0 =4 and 5, it resulted that both 4-storey and 8-storey D-FSBF buildings showed sufficient margin of safety under both ground motion suites. Subsequently, when increasing the building height (e.g. the 8-storey building), the ductility-related force modification factor, Rd = 4 is recommended. The Dual FSBF system is recommended to brace low-rise and middle-rise buildings located in subduction zone, as Cascadia subduction zone, where megathrust earthquakes could occur.


identifier: Delpasand Moghadam, Mohammad  (2021) Vibration-based Damage Detection in Laminated Composite Beams Using Spectral Finite Element Method and Genetic Algorithm.  Masters thesis, Concordia University.

abstract: Damage detection requires non-destructive testing of structures. Vibration-based damage detection techniques identify damage based on changes in the vibration features such as natural frequencies and mode shapes. Detecting damage requires solving an inverse problem using an analysis tool that is used as a simulator to produce possible damage cases and an optimization algorithm to find the closest model to the observed vibration features. Capturing some damage cases, such as delamination, is more difficult than others in the way that delamination is revealed in higher modes of vibration. Standard Finite Element Method requires a huge computational effort to obtain natural frequencies and mode shapes. Spectral Finite Element method that benefits from frequency-dependent shape functions, is adopted in this study as the analysis tool to model the dynamic behaviour of laminated composites. A discussion is given on the observations from the output of Spectral Finite Element method and a method is suggested to calculate the complete response of the structure based on the results of Spectral Finite Element analysis. The Wittrick-Willams procedure has been implemented to identify the natural frequencies from the frequency- dependent dynamic stiffness matrix of the system. The effect of delamination on natural frequencies of vibration of delaminated composites are studied. The Genetic Algorithm has been used to develop a damage detection tool that searches for the closest model to the observed frequencies and mode shapes.


identifier: Hutt-Taylor, Kayleigh  (2021) Assessing urban tree taxonomic diversity, composition and structure across public and private green space types: a community-based tree inventory.  Masters thesis, Concordia University.

abstract: The urban forest is a crucial component of the city landscape, providing communities with countless benefits we refer to as ecosystem services. Trees improve urban air quality, decrease city temperatures, provide spaces for recreation and promote mental wellbeing. To properly quantify the benefits the urban forest provides, we require a strong baseline understanding of forest structure, diversity, and composition. To date, fine-scale work considering urban forest diversity has been commonly limited to trees on public land, considering only one or two green space types. However, the governance of green spaces in cities means tree species composition is being influenced by management decisions at various levels, including by institutions, municipalities, and individual landowners responsible for their care. Using a mixed-method approach combining a traditional field-inventory and community science project, I inventoried the urban forest in the residential neighbourhood of Notre-Dame-de-Grȃce, Montreal. I assessed four green space types in the public and private domain: parks, institutions, street rights of way and private yards to quantify how tree diversity, composition and structure varies across multiple land management types at local scales. I additionally considered how patterns of service-traits (traits related to managers preference and ecosystem services) differed across green space types, with implications for the distribution of ecosystem services across the urban landscape.  I found that green space types displayed meaningful differences in both tree diversity and structure. For example, the inclusion of private trees contributed an additional 52 species (30% of total species) not found in the local public tree inventory, and private land was dominated by smaller trees compared to the public domain. I found patterns of richness, size and abundance extend to differences in tree composition and service-traits at local-scales, particularly in the street right-of way and private yards. Composition varied considerably across street blocks; however, blocks were very similar in terms of mean service-based traits. Contrastingly, species composition was similar from yard to yard, however, yards differed significantly in mean service-trait values. Overall, my work emphasizes that public tree inventories are unlikely to be fully representative of urban forest composition and structure, with implications for urban forest management at larger spatial scales.


identifier: Flesher, Sarah  (2021) Ping!: An Exploratory Study of the Relationship between Mental Health Characteristics, IM Usage, and Communication Effectiveness During COVID-19.  PhD thesis, Concordia University.

abstract:
March 2020, the beginning of the coronavirus pandemic, ushered in the immediate use of IM technologies and changed the narrative around the impact of IM usage in the workplace. Rather than debating whether these technologies were increasing productivity and resulting in communication efficiencies, they became a survival mechanism; a way to continue communicating with colleagues without being in-person. Simultaneously, the overall mental health of our workforce began to decline as knowledge workers had to adapt to new work environments, processes and tools in the midst of an unprecedented health crisis. This study concerns itself with these two topics: online communication and mental health; precisely, the relationship between mental health characteristics and the perceived effectiveness of communication through instant message technologies is explored.

The dissertation follows a mixed methods approach and is exploratory in nature. The goal of the study is to understand the impact of mental health characteristics on IM usage and perceived communication effectiveness. Specifically, a comparison is made between employee perception of IM use as an effective means of communication before the pandemic and now. How workers have coped with the changes that come from working remotely and the strategies they have developed to address potential mental health challenges while continuing to work are also examined.

The findings indicate that IM communication tools are effective enough, meaning that, despite their benefits, key flaws negatively impact one’s ability to be an effective communicator. Although overall mental health was not correlated with IM communication effectiveness and has had little impact on one’s ability to use these tools, the pandemic has led to increased feelings of isolation, loneliness, and stress. These factors are exacerbated by the lack of visual cues associated with IM, one’s ability to manage multiple platforms synchronously, the lack of online communication etiquette, and missing governance around online communication that may only come with increased usage and/or time. These conclusions are further analysed and recommendations for organizations and employers are provided.


identifier: Bagley, James Andrew  (2021) Examination of Organic Acid Tolerance in Non-Conventional Yeasts.  Masters thesis, Concordia University.

abstract: Metabolic engineering of yeasts has proven an effective strategy for producing compounds ranging from commodity chemicals to biologics. However, in the case of certain organic acids, there is a toxicity barrier, which prevents commercial production from being viable. To address this problem, we developed a strategy to characterize non-conventional yeasts and used it to search fungal repositories for desirable phenotypes, in our case tolerance to adipic acid, a nylon 6,6 precursor. From publicly accessible yeast collections we selected and screened a collection of 122 strains of yeasts. After finding strains that were tolerant to high concentrations of adipic acid at an industrially relevant pH, suitable antibiotic markers were found and whole genome sequencing and annotation was performed to enable future metabolic engineering efforts in these strains. Annotated strains were examined for evidence of gene expansion in families commonly associated with organic acid tolerance and candidate genes were identified for further research


identifier: PAYAMI, Seyed Alireza  (2021) Design, Modeling and Control of a Magnetostriction-based Force Feedback System for Robot-assisted Cardiovascular Intervention Systems.  Masters thesis, Concordia University.

abstract: Magnetorheological elastomers (MREs), as a class of smart materials, have a property called Magnetostriction means mechanical properties, including deformation of MREs, could be changed in response to an external magnetic field. Because of the controllable deformation, MRE is a suitable candidate for rendering the loss of haptic feedback in Robot-Assisted Cardiovascular (RCI) applications. In the recently-designed such force feedback systems, i.e. TorMag, the effect of matrix shear modulus and filler volume percentage was not studied comprehensively. Tormag also exposed limitations in force range. In the current study, a previously proposed and validated constitutive model of MREs was adopted. Then, twelve MREs with three silicon rubber matrices and four filler volume fractions were fabricated and characterized to improve the limitations mentioned above in Tormag. The average relative error between analytical force range and experiment was 10.2\%, while the maximum force range was 5.29 N (stiffest matrix and 40\% filler), and the minimum range was 1.06 N (softest matrix and 10\% filler). Increasing filler percentage from 10\% to 40\% increased the force feedback range up to 288\%. The state-space analysis of Tormag revealed that this system did not fully cover the required force range and zero force rendering. As an approach, structural optimization of the system is performed using the local and global optimization process. Next, a neural network (NN)-based model as the control framework was proposed and validated to obtain the necessary force for the desired input data. Then, a nearest neighbour search (NNS) method was added to the NN model to find the required magnetic field for a force-displacement profile as input. The proposed neural network accurately predicted the force-displacement behaviour of three types of MREs ($R^2=0.97$, mean-absolute-error=1.26 N). Also, the NN+ NNS model successfully obtained the required magnetic field (mean-absolute error=3.64 mT).


identifier: Rodriguez Ayala, Lluvia Mara  (2022) Sonorous Remnants of the Past: The Phonograph and the Making of Mexican Aural Modernity, 1878-1913.  Masters thesis, Concordia University.

abstract:
Since its invention in 1877, the phonograph produced a torrent of speculation about its mechanism, capable of collecting and preserving the sounds that seemed lost forever. For the members of the Mexico’s industrial and political elites, this novel technology reinforced principles of modernization, cosmopolitanism, and progress that they sought to achieve in the country's capital.
This thesis turns to the reception of the phonograph in Mexico City between 1878 and 1913 by examining how the new recording technology altered the aural texture of Mexico City, in the process transforming both auditory and cultural practices. How did the residents of Mexico City contest and reconfigure the user protocols and presumed meanings that companies from the Global North had developed for the phonograph in the late nineteenth and early-twentieth centuries? What impact did the phonograph have on the reconfiguration of social and spatial listening practices in Mexico City? What, finally, can an emerging Mexican aural modernity tell us about the active adaptation of the talking machine to the social and economic practices of the urban poor between 1870 and 1913?
As this study posits, the development of sound technology in Mexico between 1878 and 1913 did not, by itself, usher in an era of modern aurality. Rather, a Mexican aural modernity emerged from the aural practices and embodied knowledge with which members of the lettered elites, middle- and working-class inhabitants, petty entrepreneurs and musicians approached the phonograph.  The meanings of this new technology were shaped by local ontologies of listening which refined the concept of usage of imported mechanical production of sound in a living act of syncretism with local aural expressions. Ostensibly modern, this emerging twentieth-century Mexican soundscape carried traditional acoustic dimensions; etched into it were the vocalities of indigenous, Afro-descended, and mestizo peoples. Sonorous Remnants of the Past thus contributes to the study of aurality and sound recording in the Global South by critically examining the role of technological transmission and its interaction with social and cultural dynamics that then shaped its innovation, meaning, and use.