identifier: Duval, Kimberly  (2020) When and Why Prediction-Based Appeals Influence Consumer Behavior: The Role of Self-Construal.  PhD thesis, Concordia University.

abstract: Prediction-based marketing prompts consumers to predict their future behavior, typically for socially normative behavior (e.g., voting, recycling, exercising). The prediction increases the likelihood of subsequent norm-consistent action, commonly termed the self-prophecy effect. In this research, I investigate to what extent and why self-construal orientation (independent or interdependent) influences responsiveness to prediction-based advertising in a variety of consumer behavior contexts (i.e., gym attendance, sustainable product choice, monetary donation). I identify that standard prediction-based appeals used in past research (e.g., Will you…?) work effectively for individuals with an independent self-construal but not for individuals with an interdependent self-construal (Study 1 and 2), as the accessible self-concept mitigates the experience of cognitive dissonance (Study 3). I introduce socially anchored prediction-based appeals (e.g., For your loved ones, will you…?) as an effective alternative (Study 4 and 5) and demonstrate the underlying process for different types of prediction appeals relative to self-construal level (Study 4). Moreover, I demonstrate the mediating role of normative beliefs saliency and the impact of past behavior consistency in prediction-based outcomes that lead to downstream consumer behavior. These findings have implications for the effective application of prediction-based marketing in cross-cultural settings to encourage health-related, prosocial, and pro-environmental behaviors.


identifier: Hosseinzadeh, Shadman  (2020) Seismic Fragility Assessment and Resilience of Reinforced Masonry Shear Wall Systems.  PhD thesis, Concordia University.

type: Thesis NonPeerReviewed

abstract:
Reinforced Masonry Shear Walls (RMSWs) are commonly used in low- to high-rise buildings as the lateral load resisting system. There have been several experimental and analytical studies that evaluated the seismic response of RMSW either as a single element (i.e., planar rectangular walls) or as a building consisting of planar walls. However, research on Reinforced Masonry Shear Walls (RMSWs) with end-confined Boundary Elements and flanged shear walls are scarce, especially considering the effects of design parameters on the system’s seismic inelastic response. The end confined RMSWs proved to have a higher level of ductility since they can postpone the reinforcement buckling in compression while increasing the compressive strength of the shear walls’ component at the same time.
The objectives of the current study are to: (i) assess the seismic performance and collapse capacity of the RMSW with end confined Boundary Elements and Flanged shear walls at both structural element, and entire building level, (ii) evaluate the seismic resilience and functionality of the RMSW system when subjected to severe earthquake events, (iii) to quantify and assess the resilience index versus the uncertainty of the studied parameters.
To achieve the first goal, at the structural element level, the RM shear walls were designed with different heights to investigate the effect of the wall’s height on its seismic performance. The impact of utilizing flanged walls was assessed and characterized through new seismic performance standards and assessment approaches. In this respect, a modified macro-modelling approach has been proposed to numerically model and capture the inelastic behaviour of the RM shear walls. The proposed model can capture both flexural and shear deformations. The nonlinear model was first validated against experimental data of RM rectangular and flanged shear walls and walls with masonry boundary elements (MBEs); afterwards, the model has been utilized in simulating RM flanged wall archetypes. Collapse risk evaluation has been conducted by subjecting the wall’s numerical model to various ground motions scaled at different intensity levels. Nonlinear static pushover analysis and incremental dynamic analysis (IDA) has been conducted on numerical models. Quantification of the seismic parameters of the flanged wall system, including period-based ductility, overstrength, and collapse margin ratios, has been conducted to help better understanding the seismic response and collapse capacity of the component. Lastly, the seismic resilience of the archetypes against the expected collapse risk was evaluated, before and after adding flanges and boundary elements to the walls, in terms of functionality curves. Damage levels were considered as performance level functions correlated to the earthquake intensity and were used to estimate total loss and recovery time of the archetypes.
To reach the second objective, the study is extended to investigate the impact of using end-confined masonry boundary elements at the building level by the adoption of such elements for multi-storey RMSW buildings. In this respect, the developed macro-model was updated to take the impact of out-of-plane walls’ shear flexibility into account, after adding an out-of-plane shear spring. The outcome of the test results of a one-third scale two-storey building was used to validate the modelling approach at the system level. Subsequently, the archetype buildings were subjected to multiple ground motion records using Incremental Dynamic Analysis to identify the collapse initiation and derive fragility curves. The results indicate a significant enhancement of the resilience index by using end-confined Masonry Boundary Elements (MBEs).
 To accomplish the third objective, a probabilistic approach was utilized to quantify the seismic resilience index of the RMSW building with MBEs located in a high seismic zone of Canada. The uncertainties associated with the losses and expected recovery time and sensitivity of each parameter were studied and depicted using the resilience index threshold and the Monte Carlo simulation method. The storey shear contribution of in-plane and out-of-plane walls were also quantified for all archetype buildings. The results indicate sufficient seismic resilience of ductile RMSW buildings with MBEs when subjected to the Maximum Credible Earthquake (MCE). The findings of this part are crucial for earthquake mitigation practice and disaster risk reduction plans.


identifier: Tabatabaei, Seyed Moslem  (2020) Narrative Affordances of Scale in VR: Remediating Traditional Iranian Storytelling.  Masters thesis, Concordia University.

abstract: Virtual Reality is turning into a major and more accessible medium to spatial, interactive and linear narrators, aka architects, game designers and filmmakers. This research-creation is conducted with two main objectives: first, to investigate the unique narrative possibilities that VR affords as a result of its specific perceptual cues of scale. Second, to utilize the notion of scale in designing a remediated experience of a traditional screen-based form of storytelling in the Iranian culture known as Pardeh-Khani (literally translated as: reading off curtain/screen). In response to the first objective, possible ways that scale could leverage three distinct forms of immersion in VR were scrutinized under three isolated experiments. Also a broad range of VR and non-VR cases, from cinematic to fully interactive games which revolve around the idea of scale were studied. The key takeaway was that exploiting a dynamic scale of virtual embodiment could lead to spatial experiences, gameplay mechanics and cinematic communications particular to VR. Following the second objective, M.C Escher’s Relativity (1953) became a key inspirational source for designing an impossible architecture which incorporates a malleable scale of embodiment but also hosts the spatiotemporal ritual of Pardeh-Khani. The challenges of and possible solutions for designing the navigational structure of a surreal spatial experience in a room-scale VR are discussed in detail. This research-creation explores the medium-specificities of VR with a multidisciplinary approach from one side. From the other side, it raises the awareness about a marginalized tradition of storytelling through the lens of cutting-edge technology of VR.


identifier: Titov, Andrey  (2020) Comparing Vascular Visualization Techniques with Gamification.  Masters thesis, Concordia University.

abstract:
One of the bottlenecks of visualization research is the lack of volunteers for studies that evaluate new methods and paradigms. However, with the technological advancement in mobile hardware and the availability of online marketplaces, it has become possible to perform user studies using the gamification paradigm. Furthermore, the possibility of implementing volume rendering, a computationally expensive method, on mobile devices opened the door to the use of gamification in the context of medical image visualization studies.

In this thesis, we describe a gamified study that we performed with the goal of comparing several cerebrovascular visualization techniques. The study was implemented in the form of a mobile game, "Connect Brain", that was developed and distributed on both Android and iOS platforms. Connect Brain features two mini-games, one of which asks the player to make decisions about the depth of different vessels, and the second one that has them determine if  two vessels are connected. The gameplay data was sent to a server and analyzed to determine the most effective visualization techniques.

The results of our study confirmed that fog, chroma-depth and pseudo chromdepth are among the most effective depth perception cues, similar to previous studies. However, our results differed for the edge enhancement cue, which we found to be one of the worst in terms of depth perception. The gamification paradigm, which allowed us to collect more data samples from more participants than similar studies, had more similar results to the larger studies. This suggests the importance of having a large number of subjects and trials when evaluating visualization paradigms.

Although gamification presented some challenges, we believe that this technique has great potential for future studies in not only medical image visualization but for the other clinical tasks.


identifier: Fayed, Eslam Mohamed Mahmoud Mohamed  (2020) Influence of Thermal Post-Processing on the Microstructure and Mechanical Behavior of the Additively Manufactured Inconel 718 Superalloy using the Laser Powder Bed Fusion Process.  PhD thesis, Concordia University.

abstract:
In an attempt to improve the performance of the additively manufactured (AM) Inconel 718 (IN718) superalloy, a typical material widely used for turbine engine components in the aerospace and energy industries, the current work studies the effect of thermal post-processing on the microstructure and mechanical behavior of the AM IN718. Additive manufacturing and, in particular, the laser powder bed fusion (LPBF) of IN718 offers several advantages over the conventionally manufactured IN718 (cast and wrought). However, the existence of some inherited manufacturing defects in the as-printed parts presents an obstacle to produce components with specifications that meet the design requirements. Thus, post-heat treatment of LPBF printed IN718 is an essential and integral part of the industrial operations to mitigate these drawbacks.
For this purpose, in the present study, a heat treatment time window, including a wide time range of homogenization (at 1080°C; 1 to 7h) and solution (at 980°C; 15 to 60 min) treatments, is established to study the effects of the treatments time on the microstructure and mechanical properties at room temperature (RT) and at 650°C of the LPBF printed IN718 parts. The results demonstrate that the 1h homogenization treatment is not enough to significantly change the as-printed grain structure, the strong crystallographic texture and to annihilate the primary dislocation tangles. However, a completely recrystallized IN718 material with non-distinct texture and stress relived grains are obtained after 4h. A further increase in the homogenization time to 7h results in grain growth as well as greater and coarser MC carbides. Therefore, the increase in the homogenization time from 1 up to 7h results in a progressive decrease in the mechanical properties at RT and at 650°C. For the solution treatment, the treatment time does not cause a noticeable change in the grain structure and material texture but significantly affects the precipitation amount of δ-phase. The role of the solution time in the improvement of the mechanical properties at 650°C is crucial due to the increase in the grain boundary strength through the pinning effect of δ-phase.
Based on the results obtained at different treatment time, a multi-objective optimization is employed to tune homogenization and solution time and achieve the optimum heat treatments that can fulfill the required mechanical properties and material texture. The results show that, after the conditions which include 2.5 and 4h homogenization treatment at 1080°C followed by 1h solution at 980°C and standard aging treatments (2.5H/1S and 4H/1S), a significant improvement in the mechanical properties at RT and 650°C is observed, compared with the wrought IN718. Furthermore, after the 4H/1S condition, a good balance between the strength and ductility is obtained at RT.
To assess the thermal stability of the obtained optimum heat treatments during the in-service conditions, the as-printed, 2.5H/1S and 4H/1S conditions are subjected to thermal cycling similar to what is encountered in the aircraft turbine engines for long periods up to 3000h. The results reveal that the 4H/1S condition possesses higher thermal stability over the in-service exposure than the as-printed and 2.5H/1S conditions, as a relatively lower strength loss of 3.3% is counted for the 4H/1S condition after 3000h thermal exposure, while for the as printed and 2.5H/1S conditions, strength loss of 7.4 and 5.3%, respectively, are counted. Furthermore, the 4H/1S treatment results in delaying the deterioration of material strength for longer thermal exposure time (after 2000h), whereas the 2.5H/1S treatment results in deterioration of the material strength after only 1000h thermal exposure due to the retarded phase transformation of the metastable γ″ into more stable δ-phase within grains interior in the former treatment.


identifier: Malaki, Milad ORCID: https://orcid.org/0000-0001-6421-9595 <https://orcid.org/0000-0001-6421-9595>  (2020) Engineering design of an adaptive rocking bed for investigating the effects of rocking stimulation sleep.  Masters thesis, Concordia University.

abstract: Despite today’s technological advances, sleep impairments and deprivations in adults and seniors have not yet converged to a deterministic intervention. Recent findings in the new-emerged neuroengineering field reveal a promising nonmedication-based solution as the rocking stimulation effects in optimum settings on sleep. This stimulation accelerates sleep initiation and in general, it will improve the sleep architecture in a healthy population. In this research study, we designed an adaptive Rocking Bed system that replicates this stimulation in a systematic engineering design process. We first developed multiple feasible alternatives and identified the best candidate in a two-step decision-making process. The opted concept was subsequently developed further in the preliminary stage considering system requirements, safety, and ease of fabrication and assembly. According to the system requirements, a desired harmonic linear trajectory with variable excitation frequency and amplitude for the application was considered. By defining the motor motion profile, the proprietary AC servo motor and ACME leadscrew actuator were sized for this application. The design was oriented toward quiet operation and direct drive use. For the motion controller aspect, to ensure attaining a high-quality rocking stimulation, we utilized an AC servo drive with a cascaded PID controller. Thus, a PID motion controller was modeled in Simulink for simulation and tune-up purposes. The developed model showed that the system accurately traces the commanded sinusoidal motion profile for the proposed system with a 7.79:1 inertia ratio. The system was also analyzed in terms of safety of the applied loads on the actuator using the motor sizing verification with Solidworks Motion Analysis (rigid-body dynamics), and structural safety in ANSYS. The analyses confirmed the validity of the designed system. The design was finalized by incorporating some safety measures in the system and the bill of material was generated for the whole system.


identifier: Akbari, Ehsan  (2020) Spatial and Collective Learning through Mobile Sensory Photography and Creative Cartography.  PhD thesis, Concordia University.

abstract:
This dissertation explores how the educational tools of mobile sensory photography and creative cartography can be used in art education settings to encourage youth to attend to their everyday surroundings. Mobile sensory photography utilizes the connectivity of mobile devices to enable learning collectives to create and share photographs of their everyday surroundings. I anchored this process in Sensory Studies as a strategy to engage learners with the everyday places they inhabit. I use creative cartography as an umbrella term to describe a diverse set of practices that use maps to represent subjective, social, collective, political, and spatial experiences. A central question I examine is what kinds of spatial and collective learning occur when integrating these tools in art classrooms. My understanding of spatial and collective learning is rooted in the complementary theoretical frameworks of complexity thinking and spatiality, which regard learning as social, relational, and situated within existing spatio-temporal relations. I used the methodology of Design-Based Research (DBR) to integrate these tools in high school art classrooms.  I worked collaboratively with two art teachers at two different schools in Montreal to design and test a series of educational activities that involved taking sensory photographs of everyday places and sharing these images on social media and online mapping networks. By analyzing student and teacher interviews and their artistic productions, I was able to develop pedagogical strategies and a spatial theoretical framework for using mobile devices to enrich teaching and learning in art classrooms. This research has convinced me of the pertinence of attending to the spatial and temporal dimension of teaching and learning in physical and online spaces, and the symbiotic relationship between photography, the senses, and place-based learning. I also found the particular form of creative cartography that I termed Collective Online Sensory Mapping (COSM) to be a powerful tool for enabling a group of learners to attend to their everyday surroundings, express their identities, and learn about others.
Keywords: Mobile sensory photography, creative cartography, spatiality in education, senses in Art Education


identifier: Zhu, Leixiao  (2020) Using physics-based methods to Model the Deformation of Ice-Hockey Sticks from player shot videos.  Masters thesis, Concordia University.

abstract: In ice-hockey games, the hockey stick is usually deformed significantly when the players hit the puck. Different materials are used to make hockey sticks. Studies have been proposed to find how different hockey sticks and their deformation affect the performance of players. The reconstruction of a hockey stick's deformation during a shot is the key of many of those studies. The goal of this thesis is to model the deformation of the sticks from player shot videos using physics-based models and compare two physics-based methods for their performance on this problem. In this thesis, we propose two physics-based models to deform the stick and we integrate the models into a pipeline for stick reconstruction. The contribution of this thesis is twofold: 1) Integrate the physics-based models to the pipeline including data pre-processing, denoising, and establishing constraints. 2) Adapting, implementing, and comparing two physics-based models. We evaluate the results by overlapping the deformed template with reconstructed point clouds and comparing our results with the data from a MOCAP system.


identifier: Samadi Mollayousefi, Fereshteh  (2020) Engineered Surface Design for Radar Cross Section Reduction.  PhD thesis, Concordia University.

abstract:
Radar cross section (RCS) is the electromagnetic signature of an object and it corresponds to the effective area observable by radar. The frequency, polarization, and incident angle of the impinged radar signal as well as the geometry and composition of the object, are the main factors that affect the RCS. Reducing RCS is a significant subject in stealth technology due to its vast applications in civil and military areas. Nowadays, with the proliferation of detection systems, developing RCS reduction techniques is getting assiduous attention.

The main goal of this research is to develop fast and efficient engineered surfaces design for RCS reduction purposes using artificial intelligence (AI). Specifically, designing engineered surface
within a broad bandwidth and wide oblique incidence stability with the minimum possible RCS in all directions. Toward this end, we implement a practical approach that is based on the concept of destructive interference in the far-field. The general idea of this approach is designing a surface that reflects the impinged wave in-phase and counter-phase concurrently which subsequently cancel out
the reflected waves in the boresight direction. The design procedure includes two steps. The first step is designing at least two reflection type unit-cells with almost 180◦ reflection phase difference. The second step is arranging these unit-cells in a format to achieve field cancellation while satisfying periodic boundary conditions of the unit-cells. In this thesis, we present some approaches both in unit-cell design and arrangement step to develop efficient, low RCS engineered surfaces addressing our objectives.

In the first study, we propose a reflection type linear polarization rotator (PR) unit-cell with a polarization conversion ratio (PCR) above 90% and a very wide bandwidth of around 115%. The proposed PR unit-cell and its mirror features 180◦ reflection phase difference within its PCR
bandwidth. Predefined numbers of the same unit-cells are considered as a super-cell, and binary digits of 0 and 1 are assigned to PR super-cell and its 90◦ rotated one. Using the array theory and binary
codes, an optimization model is developed. Bi-level group search optimization (GSO) algorithm is implemented and solved for the minimum RCS in all directions. Our simulation and measurement
results demonstrate 115% bandwidth for 10 dB normalized RCS reduction.

In the second study, we focus on improving the incident angle stability and RCS reduction of the engineered surface. In this regard, we propose a new type of artificial magnetic conductor (AMC) unit-cell, which is a combination of the conventional metallic patch and perforated dielectric slab. This model provides efficient control of effective permittivity along with metallic patch geometry. The proposed AMC unit-cells (namely as 0 and 1 types) satisfy 180◦ reflection phase
difference characteristics with a wide bandwidth for the oblique incidence up to 60◦. To improve scattering properties of the engineered surface, this time arbitrary numbers of unit-cells are considered for super-cells and optimized along the type selection according to the objective of maximum RCS reduction in all directions. The new arrangement contributes to greater RCS reduction and a more uniform pattern compared to the previous arrangement applied in the first design. Moreover, the monostatic and bistatic RCS reduction are measured as a function of frequency and compared with the simulated ones. Overall, we could achieve a reasonable agreement between simulated and measured RCS reduction results.

In the two aforementioned designs, we implemented optimization algorithms for the fast and efficient arrangement of super-cells. However, the unit-cells are designed through trial and error
process using full-wave (FW) simulators. In our third study, we extend AI techniques in the first design step of engineered surface, i.e., unit-cell design, as well. We develop a methodology for unit-cell design based on state-of-the-art machine learning (ML) algorithms. Toward this purpose, a PR unit-cell model consisting of several rectangular patch segments is presented. The unit-cell inverse design recast as a regression problem and is solved through multiple data-driven algorithms, namely neural network, (NN), deep neural networks (DNNs) with multiple hidden layers, and the support vector regression (SVR). For the proposed PR unit-cell model, the geometrical dimensions of the unit-cell are predicted for the given frequency ranges in the designated radar frequency bands of X, Ku, K, and Ka with a maximum average accuracy of 95.23%. In order to measure the reliability of this approach for practical applications, we measured the resiliency of all our proposed regression models with characterizing adversarial attacks. This addresses the potential reliability concerns
of integrating ML-based models for FW simulators. Finally, we implement the proposed MLbased unit-cell model in designing low RCS engineered surfaces and investigate monostatic and bistatic RCS reduction results. We showed that the normalized 10dB RCS reduction frequency range matches well with the one given in the input vector of our proposed PR unit-cell model.


identifier: Frank, Nelson  (2021) Deep Learning Approaches to Multi-Modal Biomedical Image Segmentation.  Masters thesis, Concordia University.

abstract: Deep learning techniques have been shown to produce state-of-the-art performance in segmenting biomedical images. These techniques, however, are highly dependent on the quantity and quality of available training data, as well as their capacity to represent complex relationships, which is dependent on the size of the network and limited by the computational resources of the machine(s) on which they are trained. In this work, we performed two experiments. First, we explored multi-stream model configurations that can leverage available data from multiple unpaired biomedical imaging modalities to learn a shared representation. Specifically, segmentation of cardiac CT and MRI was done to see if this learns the shared anatomical features and thus performs better than individual models trained on each modality. Second, we compared our full deep learning segmentation pipeline as applied to paired multi-modal brain images against other existing publicly available pipelines. From these experiments, we found that (1) multi-stream architectures can achieve better results in unpaired multi-modal segmentation compared to single-stream models, however, the specific configuration with the best performance is in disagreement with previously published results; and (2) careful adjustment of deep learning pipeline configurations to our specific data set and hardware constraints yields improved segmentation accuracy over publicly available state-of-the-art solutions in paired multi-modal image segmentation.


identifier: Eckert, Isaac M.K. ORCID: https://orcid.org/0000-0002-4384-5041 <https://orcid.org/0000-0002-4384-5041>  (2020) A Single Range-Expanding Species Reshapes Alpine Ecosystems and Their Belowground Diversity.  Masters thesis, Concordia University.

abstract: As a result of rapid environmental change caused by humans, species around the globe are expanding their ranges and spreading into uncharted territories at an unprecedented rate. Range- expansion of foundation species, or any species that plays a disproportionately large role in structuring ecosystems, can have severe impacts on recipient communities and ecosystems. Such species can not only alter biological diversity and ecosystem function, they can also interfere with the fundamental processes underpinning community assembly. However, despite large implications for the integrity and functioning of the world’s ecosystems, the ability of range expanders to alter community assembly processes is largely unknown. Here, we use an ongoing alpine invasion by a single foundation species (Pinus contorta) as a natural experiment to investigate the impacts of range-expansion on belowground community assembly and diversity. We report that abiotic selection exerts an increasingly strong influence as range expansion proceeds through the creation of micro-climatic islands with colder and wetter soils. Later stages of expansion were also associated with a decrease in the relative influence of dispersal and biotic interactions between fungi and their host plants. These changes, in turn, lead to an increase in the richness of fungal pathogens, and a decrease in the richness of symbionts, both locally and regionally. Taken together, these results suggest that range expanding species moving upslope have the potential to create novel ecosystems by rerouting the assembly of resident communities and reshaping biodiversity across scales. As climate change leads to poleward and upslope shifts in the distributions of plants and animals around the world, understanding the ecological processes through which range-expanders reshape native biodiversity can improve our predictions of the threats and challenges facing impacted ecosystems and enable better, more informed, conservation decisions.


identifier: Herzig, Alyssa Jennifer Marion  (2020) Developing Ultra-Short Screening Tools for Depression in Stroke Survivors.  PhD thesis, Concordia University.

abstract: Background: National stroke guidelines recommend that all stroke survivors be screened for depression multiple times following stroke.  However, compliance with screening guidelines is poor and persons with post stroke depression (PSD) remain under diagnosed and undertreated.  Ultra-short PSD screening tools are recommended to increase feasibility of routine screening.  Existing ultra-short depression screening tools were developed for primary care and have not shown sufficient sensitivity for screening PSD relative to gold-standard reference tests.  Objectives: The principal objective was to determine what brief combinations of self-report mood questions can be used in ultra-short screening measures to accurately and feasibly screen for depression in stroke survivors, relative to a gold standard reference test for depression at different times post stroke.   Method: This prospective study included a sample of 121 adults recruited from consecutive hospital admissions.  At five time points within the first year following a stroke, participants were administered the current Major Depressive Episode diagnostic interview of the SCID-I/NP and completed questionnaires containing items assessing mood state, including The Stroke Specific Geriatric Depression Scale, The Mental Health Index, The Stroke Impact Scale version 3.0, and The EuroQOL five dimensions questionnaire.  This author developed and followed a novel protocol for systematically comparing single items and two-item combinations for their abilities to accurately detect diagnoses of major, minor, and any depression according to the SCID-I/NP gold-standard measure.  Results and conclusions: Results indicate that two-item screening tools containing items assessing mood state can accurately screen for depressive disorders and that the accuracy of ultra-short index tests for PSD are time-dependent.  Results are consistent with previous studies suggesting that different screening questions are required at different time points following stroke.  This study concludes that continued development of screening tools can contribute to minimizing the substantial negative impacts and costs of PSD through closing the gap between actual practice and best practice in PSD screening.


identifier: Higgins, Stéphanie  (2020) Application of Artificial Intelligence on Design Strategies to Optimize Urban Wind Energy.  Masters thesis, Concordia University.

abstract: Maximizing urban wind energy capture constitutes a step towards self-sufficient buildings. Optimizing urban wind power requires knowledge of the environmental and building parameters modifying energy capture and tools for predicting urban wind behaviors. This thesis main objective is to build a database to develop artificial intelligence (AI) programs to evaluate different design strategies and optimize urban wind energy. The database includes experimental wind tunnel velocities and turbulence intensities for terrain roughness, channeling effect, typical building shapes and several city configurations for several turbine locations. Wind velocities and turbulence intensities measured at the street-level and rooftop turbines on rectangular, U-shaped, and L-shaped buildings are further investigated with literature CFD results. Through the different combinations of experimental results and literature, a total of over 150 cases are added to the database. A decisional flow chart is developed using the results database and served as a results summary and an aid for programming the artificial intelligence (AI) networks. The elaborated database is implemented in an expert system and an artificial neural network. The AI programs are tested with city configurations models and a real case study, René-Lévesque Boulevard in downtown Montreal. Comparing the testing set to the actual experimental values, the data expert system predicts the modification in wind velocities with 68% - 98%accuracy. The feedforward artificial neural network developed is slightly more accurate than the expert system, showing success rates from 76% to 99%. Thus, AI tools and the decisional flow chart approach may be used for a preliminary assessment of the different design strategies power capture in urban environment.


identifier: Gilker, Sadie  (2021) Belfast’s Sites of Conflict and Structural Violence: An Exploration of the Transformation of Public Spaces through Theatre and Performance.  Masters thesis, Concordia University.

abstract: This interdisciplinary project examines contemporary, everyday, and theatrical performances that represent violence in public space in Belfast, Northern Ireland. Utilizing the fields of Performance Studies, Urban Planning, and History, my thesis explores how theatre and performance can process violence and change perceptions of sites of conflict related to the Northern Irish Troubles (1968-1998). I examine Charabanc Theatre Company’s Somewhere Over the Balcony (1987), Tinderbox Theatre Company’s Convictions (2000), and Black Taxi Tours (2019) to address different time frames in Northern Ireland’s history and assess how performance interacts with violence and public space. The theory of structural violence allows me to examine the Divis Flats, the Crumlin Road Courthouse and sites of memorialization and murals. Structural violence, I argue, is embodied by a built environment and attendant social systems that enact harms on citizens. Combining this analysis with Performance theory provides access to spaces that are located behind sectarian lines to further our knowledge on the urban landscapes in Northern Ireland. This thesis adds to the ongoing narrative of desegregation and reconciliation between the divided communities of Belfast, Northern Ireland by situating theatre and performance as a means of processing the violence of the Troubles and transforming perceptions of public space.


identifier: Chen, Wenxue  (2020) Structural Response of Multi-Story Buildings Subjected to Foundation Differential Settlements.  PhD thesis, Concordia University.

abstract:
Differential settlement between foundation units of a multi-story structure has been responsible for serious damage to buildings, and often catastrophic failure and loss of life. The dynamic changes in the loading conditions of the structure, and the variability of the underlying ground due to environmental changes, are causing the undesirable differential settlement, which is manifested in the form of additional stresses in beams, columns and distortion of the structure elements.
The structural response to the differential settlements depends on the type of the structure (concrete or steel), type of beam-to-column connections (rigid or semi-rigid), the number of floors, height of the floor and the spans of the beams in the building.
Due to the complexity of the problem, and the enormous amount of the governing parameters, research in this field is lagging behind, which further attributed to the lack of communication between structure and geotechnical engineers. Yet, the current design codes of structures do not include these additional stresses. Engineers are dealing with this problem by using empirical formula, recommendations given in the literature, or by increasing the factor of safety of the superstructure.
This study presents experimental and numerical investigations on the problem stated. Experimentally a four-floor aluminum structure was developed in the laboratory. The model was instrumented to measure the stresses and strains induced in beams and columns as a result of the settlement of a center, edge and corner column respectively, which are the critical columns in the structure. Numerically a 3-D finite Element model was developed using the commercial software “ABAQUS”
After being validated with the present experimental results, the numerical model was used to analyze a 9-floor steel structure and to conduct a parametric study. The results are presented in the form of stress distributions in the structure, the role of beam-to-column connections and guideline for the design of these structures.


identifier: Rankin, Ashley  (2020) Improving a Peer Tutor Training Program at an Urban College.  Masters thesis, Concordia University.

abstract:
This thesis equivalent is a theoretical performance improvement project of a peer tutoring program. It focuses on the literature on peer tutor training programs in higher education and provides recommendations for design solutions and evaluation tools based on best practices. The lack of studies on proper training and evaluation within the field of tutoring also lead to a general search on best practices in instructional design that could then be applied within the context of peer tutoring. This would corroborate the decisions of the tutoring programs reviewed in the literature and fill in the gaps, when necessary.
This thesis equivalent originally began with the intention of doing a thorough needs assessment of a peer tutoring program at an urban college and proposing performance improvement interventions and subsequent evaluation tools. Data collection from surveys, focus groups, and observation would have provided valuable information from tutors, tutees, and other stakeholders that would have guided improvements to the program. Issues gaining research ethics approval from the college combined with the Covid-19 pandemic made it apparent that data collection would not be possible within a reasonable timeframe. The proposed data collection tools for a needs assessment were created and included to be used when pursuing data collection becomes feasible again. This study has relied on primary sources to fill in the gaps on what I may have gleaned from the data had I been able to collect.
An analysis based on the literature identified a few major issues with the peer tutoring program. First, there is no current evaluation in place to determine if the training provided to tutors is effective. Second, learning objectives were never discussed or made explicit before the creation of the current training program.
I proposed modifications to the current peer tutoring program based on observations and my findings in the literature. Interventions included making it a recognized tutor certification program, adding training content to include metacognitive skills, self-regulation, and scaffolding. Modifications to the training delivery included more emphasis on situated learning with role-play exercises and observation. Evaluation tools were created to assess the modified peer tutoring program.


identifier: Ranjbar, Sara  (2020) Novel Electro-Integrated Fixed-film Activated Sludge reactor (EIFAS) to enhance nutrients removal from wastewater.  Masters thesis, Concordia University.

abstract:
Novel Electro-Integrated Fixed-film Activated Sludge reactor (EIFAS) to enhance nutrients removal from wastewater
Sara Ranjbar, Master of Applied Science

This study aimed to improve nitrogen removal through developing an Electro-Integrated Fixed-film Activated Sludge reactor. Electrical current controlled redox for both aerobic and anoxic conditions in a single vessel. This complete-mixed reactor ensures the removal of nitrogen and phosphorous. The first phase of this research, which had two phases, focused on ammonia removal from the Integrated Fixed-film Activated Sludge reactor (IFAS) under aerobic conditions with an average dissolved oxygen level of 7 mg/L. Whereas, the second phase was focused on nutrient removal in a novel Electro-Integrated Fixed-film Activated Sludge reactor (EIFAS).  The results of this study showed a promising nitrification process in IFAS with high-efficiency ammonia-nitrogen removal (up to 96% under aerobic conditions) after ten months, although a significant increase in nitrate concentration was recorded. Similarly, the finding from the second phase of this study showed a 75% removal of ammonia-nitrogen with a nitrate-nitrogen concentration of 2.7 mg/L. Furthermore, EIFAS showed a successful removal of orthophosphate and chemical oxygen demand (COD), by 93% and 98% respectively.
This study used a novel EIFAS designed system for a successful wastewater treatment containing high concentrations of ammonia in a single tank. The technology follows sustainable development principles by decreasing footprint and energy consumption.  It can be used in small and medium-sized wastewater treatment plants, upgrading existing facilities in order to prevent eutrophication of receptors.


identifier: Mohammed, Adham  (2020) Large-Scale Modeling and Optimization of Routing, Modulation and Spectrum Assignment Problems in Optical Networks.  Masters thesis, Concordia University.

abstract:
One of the crucial decisions in managing flexible optical fiber networks is the provisioning
of connection requests, known as the Routing and Spectrum Assignment (RSA) problem,
and its extension: Routing, Modulation and Spectrum Assignment (RMSA) problem. Such
problems are becoming more and more challenging everyday with the steadily increasing
demand in optical networking. Therefore, considerable research effort has been exerted in
developing models and algorithms to efficiently solve larger problem instances. Yet, there
still exists a gap between the problem sizes that can be solved thanks to the previous research
efforts and the realistic problem sizes. This work is one step forward towards reducing this
gap.

In this thesis, we propose decomposition models for the RSA and RMSA problems based
on lightpath configurations. The proposed models are Integer Linear Programs (ILPs) with
an exponential number of configuration variables. Therefore, we have developed nested
column generation algorithms to exactly solve both problems. Furthermore, Lagrangian
Relaxation is used to compute valid upper bounds on the Integer Linear Programming
(ILP) optimal objective values, in order to compute a measure of solution quality: the
relative optimality gap.

The proposed algorithms are able to efficiently solve instances with sizes beyond what
has been so far published in literature, and more importantly, with considerably higher
quality, i.e., narrower relative optimality gaps.


identifier: Doma, Aya  (2021) Investigating Thermal Performance of Residential Buildings in Cold Climates.  Masters thesis, Concordia University.

abstract: At least 65% of the existing residential building stock will still be in use by 2050, thus retrofitting existing buildings will be critical to reduce energy consumption. Prioritizing these retrofits typically requires thorough evaluation of the envelope’s thermal performance, and the traditional methods to undergo such evaluation (e.g. energy audits) can be cost prohibitive, especially if it aims to cover hundreds or thousands of buildings. To this end, this study presents a novel data-driven approach to investigate the thermal performance of existing buildings using data collected from smart thermostats. The study focused on more than 60,000 houses across North America and relied on real-time indoor and outdoor temperature measurements at 5-minute intervals over a period of four years. Two grey-box modelling approaches namely, least-squares fitting of 1) decay curves, and 2) numerically integrated thermal energy balance equations were used to estimate a thermal time constant for each house. This time constant represented the time it takes for a house to achieve a new thermal equilibrium in response to changes in its internal and external thermal conditions. The resulting time constant values from both models were used to estimate lower and upper bound effective R-values for the entire envelope of each house. These results were also analysed with respect to ASHRAE climate zones, building-age, building-style, and floor-area. Finally, a classification model was developed to identify the time constant range for houses based on their attributes. The classification model indicated that floor area and ASHRAE climate zone were the most influential factors on time constant values obtained using both methods. By using a large sample size covering thousands of buildings nationwide, results of this research can be used to prioritize retrofits for existing buildings and can provide inputs for urban-scale energy simulations.


identifier: Lamothe, Maxime  (2020) Bridging the Divide Between API Users and API Developers by Mining Public Code Repositories.  PhD thesis, Concordia University.

abstract:
Software application programming interfaces (APIs) are a ubiquitous part of Software Engineering. Their evolution requires constant effort from their developers and users alike. API developers must constantly balance keeping their products modern and attractive whilst preserving their value and backward compatibility. Meanwhile, API users must continually be on the lookout to adapt to changes that could break their applications.

In this thesis, we study existing literature to identify the state-of-the-art in API evolution research. We then use our findings to establish practical and scalable API evolution guidelines and tools to bridge knowledge gaps between API users and API developers. We base these guidelines and tools on public code repositories and use them to perform four empirical studies to further our understanding of API evolution.

To motivate this thesis, we first conduct a systematic literature review of the state-of-the-art in API evolution research. We find that there are a variety of unsolved challenges within the field and that in particular, public code repositories have yet to be fully leveraged to aid both API users and API developers.

We then present three empirical studies that focus on helping API users deal with API knowledge gaps. We find that: (1) even if Android API documentation can help Android API users understand what to migrate from one API version to another, it does not often address how to do so; (2) although Android API migration knowledge is not always present in documentation, automated techniques can be created to mine this knowledge from existing public code repositories and automatically leverage it to help other API users; and (3) API misuse detection approaches can benefit from automatic example generation to reduce their false positive detection rates and improve their usefulness for API users.

Finally, we present an empirical study that uncovers general reasons why API users inquire about API workarounds and the solutions that are generally given to them. Using this information, we develop three API workaround implementation patterns that can be used to detect instances of API workarounds in user code. We find that the knowledge contained within these detected instances of API workarounds can be fed back to API developers as opportunities to improve their APIs. Other API evolution research directions do exist; some are briefly covered in this thesis, for example identifying and using common API usage patterns, leveraging API migration patterns to inform API development, and API migration between programming languages; others still may yet be undiscovered. However, this thesis shows that it is possible to leverage existing knowledge contained in open-source repositories to help API users and API developers alike. This thesis opens the door to future research in the field of API evolution and demonstrates that it is possible to bridge knowledge gaps between API developers and API users for API migration, API misuse detection, and API workarounds usage.


identifier: Shamloo, Shiva  (2020) TportHMM : Predicting the substrate class of transmembrane transport proteins using profile Hidden Markov Models.  Masters thesis, Concordia University.

abstract:
Transporters make up a large proportion of proteins in a cell, and play important roles in metabolism, regulation, and signal transduction by mediating movement of compounds across membranes but they are among the least characterized proteins due to their hydrophobic surfaces and lack of conformational stability. There is a need for tools that predict the substrates which are transported at the level of substrate class and the level of specific substrate.

This work develops a predictor, TportHMM, using profile Hidden Markov Model (HMM) and Multiple Sequence Alignment (MSA). We explore the role of multiple sequence alignment (MSA) algorithms to utilise evolutionary information, specificity-determining site (SDS) algorithms to highlight positional information, and a profile Hidden Markov Model (HMM) classifier to utilise sequence information.

We study the impact of different MSA algorithms (ClustalW, Clustal Omega, MAFFT, MUSCLE, AQUA, T-Coffee and TM-Coffee), and different SDS algorithms (Speer Server, GroupSim, Xdet and TCS). We compare these approaches with the state-of-the-art, TrSSP and TranCEP.


identifier: Chan, Ei Ei  (2020) Analysis of Construction Dispute Cases in Canadian Courts and Lessons Learned for Modular and Off-site Construction Contracts.  Masters thesis, Concordia University.

abstract: Construction projects involve several professionals from various disciplines over the contract duration; contract claims and disputes among various stakeholders are hence inevitable. Construction contracts become more complicated along with the increasing complexity in design, construction process, and construction technology. Recently, Modular and Off-site Construction (MOC) has gained popularity and expanded its global market shares. However, there are yet no standard contracts for MOC to this date. Stakeholders usually adopt pre-drafted standard contracts, originally structured for conventional construction, and modify them based on project requirements. In this respect, there is an urgent need to evaluate such contracts' suitability for MOC projects. This can be done by analyzing the contractual disputes and their root causes through the literature, litigation, and their correlation based on the features of the MOC. This thesis develops a comprehensive framework which consists of (i) developing a model composed of a comprehensive list of contractual dispute causes, as documented in the literature and classifying them; (ii) examining the critical factors by classifying the Canadian court cases to identify the major root causes of litigation disputes based on the proposed model; and (iii) identifying lessons to prevent the dispute causes in the MOC by evaluating the interrelations between the result of case analysis and Canadian standard construction contract documents. The Canadian court system at two levels (of Supreme and Superior Courts) has been scoped, and 191 cases have been selected and analyzed for this study. As a result, the finding of this thesis can help contract drafters/administrators and general contractors recognize common causes of disputes to enhance the contract administration and management in MOC when drafting and administering the contracts in the new projects.


identifier: Wilson, Waylon  (2020) Čá··hu – Is Anyone There: Video Games, Place-Based Knowledge, and the Future Imaginary.  Masters thesis, Concordia University.

abstract: This thesis builds upon concepts of the ‘future imaginary’ as a methodology to consider how digital media can be designed to strengthen human relationships to place as exemplified in the research-creation development of an original Indigenous, Tuscarora video game. The process of developing the video game is examined to discuss how Tuscarora ways of knowing, as a Nation of the Haudenosaunee Confederacy, inform the game making process and adapt the future imaginary to strategize an accountable methodology to create game design that reflects Indigenous knowledge, practice, and place-based teachings. Based in Tuscarora territory, Niagara Falls, this game and thesis seeks to exemplify to other Indigenous nations an accountable strategy to developing Critical Play video games for Indigenous youth that engage them with intergenerational place-based knowledge that gives special attention to inaccessible traditional territories due to impacts of colonization and provides virtual portals to access these locations. This game and project present a future of wellness for all beings who inhabit Indigenous territories, for Indigenous and non-Indigenous residents alike. The game, Čá··hu, is based on Haudenosaunee teachings known as the Thanksgiving Address, which guide the gameplay. Indigenous concepts of humility paired with inspiration from Critical Play are combined to form a method of critical game development that centers Indigenous forms of thinking rather than common Western modes of gameplay and game mechanics.


identifier: Mahato, Prativa ORCID: https://orcid.org/0000-0002-0924-0874 <https://orcid.org/0000-0002-0924-0874>  (2020) Two-Stage (Liquid-Solid) Anaerobic Digestion of High Solid/High Ammonia rich Manures at a Low Temperature adopting Recirculation- Percolation Operational Mode.  Masters thesis, Concordia University.

abstract: Globally, livestock and poultry production leads to total emissions of 7.1 Gigatonnes of Carbon-dioxide (CO2)-equivalent per year, representing 14.5% of all anthropogenic greenhouse gas emissions. Anaerobic digestion (AD) is a sustainable approach to generate methane (CH4) from manure, but the risk of ammonia inhibition and high-solids can limit the AD process. A two-stage (liquid–solid) batch-mode AD biotechnology at a low-temperature (20±1 °C), using an adapted liquid inoculum, was developed to address the limiting factors. This study deals with chicken manure (CM) and dairy cow manure (DM) as feedstock. Furthermore, liquid inoculum recirculation-percolation mode was adopted to replace mechanical mixing. The findings from physio-chemical and biogas analysis showcased the sustainability of this novel biotechnology technique, yielding impressive results at 20±1 °C. Firstly, CM liquid inoculum was adapted to high-ammonia concentrations. Secondly, mono-digestion of CM (TKN: 23-33g/L; TS: 68-72%) was conducted in the aforementioned AD technology. Then, a start-up study on co-digestion of CM+DM (TKN: 13.6 g/L; TS: 48-51%) was conducted for 190 days using same technology. Moreover, to investigate AD process stability, physio-chemical parameters were monitored. The objective of this study was to demonstrate the operational feasibility of the proposed AD biotechnology. Results showed that, although a better SMY (0.52 ± 0.13 L CH4g−1VSfed) was obtained for mono-digestion of CM, co-digesting CM + DM showed a better methane quality and generated comparatively lower FAN. Finally, techno-economic assessment of the aforesaid AD technology, processing 1tonne-CM/day showed that the AD plant obtained revenue after 14 years from the commencement of the project.


identifier: Saraci, Felix  (2020) Exploring RE-MOFs with spn Topology and their Stimuli-Responsive Structural Properties.  Masters thesis, Concordia University.

abstract:
The work described herein explores an emerging class of metal–organic frameworks (MOFs) that are synthesized using rare-earth (RE) metals, known as RE-MOFs. In this work, these RE-MOFs are comprised of RE-hexanuclear clusters and tritopic organic linkers that give rise to a framework with spn topology. This thesis explores the (i) design, synthesis, and characterization of a yttrium (Y(III)) hexanuclear-cluster based RE-MOF, known as CU-45 (CU = Concordia University, experiment 45), (ii) the implementation of neodymium oxide (Nd2O3) precursors as templating agents, and (iii) the design, synthesis, and characterization of terbium and europium (Tb(III) and Eu(III)) MOFs with preliminary exploration of luminescence properties for potential sensing applications.
Chapter 2 explores the synthesis, characterization, and stimuli-responsive structural transformation of CU-45. CU-45, an achiral MOF, is exposed to various external stimuli including pressure, pH, temperature, and solvent, and in each case undergoes a phase transformation to give a chiral, RE-chain based MOF, known as Y-MOF-76. The physical and chemical properties of CU-45 and Y-MOF-76, as well as the underlying mechanism of the stimuli-responsive structural transformation is discussed.
Chapter 3 aims to address and improve the stability of CU-45, first by exploring a phenomenon known as lanthanide templating, which can facilitate the assembly and stabilization of lanthanide clusters. By adding a Nd2O3 precursor template to the CU-45 synthetic mixture, a phase pure MOF with improved crystallinity can be obtained. Furthermore, the effect of incorporating other rare-earth ions in CU-45, including Tb(III)- and mixed-metal Tb(III)/Eu(III)-CU-45, on stability is examined.


identifier: Zamboni, Julia Ghorayeb  (2020) Robot Ludens: Inducing the Semblance of Life in Machines.  PhD thesis, Concordia University.

abstract: As culture and technology move forward, researchers from various fields have continuously developed new ways to create lifelike machines that evoke empathy and engagement with humans. This shared goal drives an enormous effort in the realms of arts, games, and social machines, among others. The present study's core research problem revolves around understanding how non-living devices gain a semblance of life and intelligence. The goal is to identify and examine the expressive components that induce the attribution of life into machines. The research follows the methodological framework of research-creation, integrating theory with creative processes. The theoretical framework's key findings establish the following four design elements for creating lifelike machines: Body, Behavior, Context, and Name. It examines how the articulation of those elements can assign different meanings to devices. In association with the theoretical framework, this study also involves producing two examples of lifelike machines within the realms of art and game design. The first is a robotic art installation called Robot Ludens, exploring possibilities and challenges for creating robots playing alive and playing dead. The other is a drawing game called Pict.io, which tries to simulate camaraderie dynamics between humans and computational players.


identifier: Kliamenakis, Argiro  (2020) The Role of the Moral Identity in Consumption.  PhD thesis, Concordia University.

abstract: In this dissertation, theories on self-perception and self-signaling are leveraged in order to examine the relationship between moral self-signals and the moral identity, and by extension the importance of this relationship in ethical and sustainable consumption. In the first essay, the experience of envy and whether it can influence ethical behaviour is examined—a particularly relevant question given the rise of social media and its conducive role in eliciting this emotion. As such, the first essay demonstrates how the metacognitive appraisal of envy unfavorably alters moral self-perceptions, thereby increasing morally relevant consumption and ethical behavior. Findings from six studies provide empirical support for this effect with implications for consumers and marketers. In the second essay, the relationship between the moral identity and application effectiveness of various cause marketing strategies is investigated. To that end, the second essay contrasts effort-based cause marketing that requires the performance of a prescribed behavior by consumers to generate a donation to the non-profit cause, relative to both purchase-based cause marketing that links donations with sales, and direct donation cause marketing that involves a direct donation from the firm to the cause. Five studies demonstrate that when consumers are driven to reinforce their moral identity—either chronically or due to the drive to restore a tarnished self-image—evaluations of cause marketing with effort-based participation are enhanced. This effect occurs because consumers associate higher levels of moral self-signaling utility from effort-based (relative to purchase-based and direct donation) cause marketing. However, this effect only occurs for cause marketing campaigns in which consumer effort is private. Cause marketing campaigns requiring the public performance of effort are not favored by consumers seeking to reinforce their moral identity, because public effort can be confounded with self-interested, reputation seeking motives. Both essays contribute to our understanding of consumer morality and morally relevant consumption by emphasizing the significance of self-signals that facilitate the formation of individuals’ sense of their moral self, and the role that this self-perception plays in fostering ethical and sustainable consumer behaviour.


identifier: Herrmann, Shaney M.  (2021) Seeping into Stones: Material explorations in deep mapping Ireland.  Masters thesis, Concordia University.

format: text video

abstract:
The goal of this Master of Design thesis is to take a transdisciplinary approach towards fostering a deeper attunement of human individuals of the physical world around them. In particular, my aim is to stimulate a conversation pertaining to contemporary Irish place. Ireland has experienced significant political, social, and physical change over the last two-or-so decades, yet certain stereotypical narratives that have long been perpetuated about the country may still be discerned, even in its own official rhetoric and imagery.
This thesis explores the efficacy of taking design as a point of departure to engage with, and contribute to, an updated conversation about Irish place by visualizing and materializing the variety of narratives that may be teased out of Ireland’s topography and built environment. Using the premise of critical, speculative, and dark design Seeping into Stones—which consists of a series of research-creation projects as well as this thesis—reimagines and re-engages with selected perceptions and narratives about the Irish built and natural environment, and displaces them by contributing and contemplating a series of “deep maps” of specific locations and environments that I visited during my master’s-level research trips. Reaching beyond the discipline of design, the thesis also builds upon my previous academic formation in photography and it moves into the area of literary criticism to focus on the writing of one astute observer of transformations of Irish culture and society, the award-winning author Kevin Barry.
Seeping into Stones contributes additional layers to the collective “deep map” of Ireland as well as another perspective from which to speculate towards a more diverse future.
Keywords: deep mapping, research-creation, critical and dark design, materiality, Irish studies, interdisciplinary, Kevin Barry, photography.


identifier: Rasooli, Armin  (2020) Fabrication, Characterization and Control of a Novel Magnetorheological Elastomer-based Adaptive Tuned Vibration Absorber.  Masters thesis, Concordia University.

abstract:
Semi-active tunable vibration absorbers (SATVAs) have recently received growing interest due to their energy efficiency, simple structure and optimal performance under a wide frequency-bandwidth. SATVAs generally consist of elements with variable stiffness to allow for optimal performance under a wide frequency range compared with their passive analogues which are typically tuned at a particular frequency. Magnetorheological elastomers (MREs) are unique smart materials which can serve as the variable-stiffness elements in SATVAs. MREs are basically the solid state of the well-known magnetorheological (MR) fluids, which in contrast to MR fluids, their stiffness (storage modulus) can be continuously changed rapidly through the application of an external magnetic field.

The present research study is concerned with the modeling, fabrication and control of a novel SATVA based on MRE-filled sandwich structures. To this end, a novel five-layered beam-shape sandwich structure was designed using MREs as core layers, reinforced with thin elastic plates on top, middle and bottom. To provide for a suitable and controllable magnetic field a set of U-shaped electromagnets were also designed. A specific two-node adaptive sandwich beam element has been developed to derive the governing dynamic equations of the MRE-based sandwich beam in the finite element (FE) form. The developed finite element model of the MRE-based sandwich beam together with the developed magnetic finite element of the electromagnets have then been effectively utilized to identify the suitable design parameters for the proposed SATVA to meet the geometrical and mechanical requirements. Experimental tests have been designed to acquire the magnetic permeability and the storage modulus of the fabricated MREs required for the modeling.
Next the proposed SATVA was fabricated and subsequently tested using an electrodynamic shaker to evaluate its vibration performance and also to validate the developed FE models. The results indicate that the fabricated SATVA, provides an approximately 9% shift in the natural frequency. The validated FE models were subsequently utilized to conduct systematic sensitivity analysis to investigate the effect of different design parameters including the thickness of elastic layers and the position of electromagnets.  The experimental results were also used to developed an equivalent lumped mass model for the proposed SATVA. Finally, a phased-based control strategy using the full-state adaptive Kalman filter (AKF) observer has been developed to adaptively tune the natural frequency of the absorber to the varying excitation conditions.  It is expected that the present research dissertation provides an essential guidance for the future development of light-weight adaptive vibration absorbers.


identifier: Parish, Anita  (2020) Mapping Montreal Flaneurs' Stories.  Masters thesis, Concordia University.

title: Mapping Montreal Flaneurs' Stories

abstract:
Although traditionally, the flaneur has been attached to the specific geo-historical context of
nineteenth-century Paris, flaneurs have evolved throughout the twentieth century and continue to
meander in contemporary cities. Flaneurs not only meander; they also tell stories about their
meanderings, including stories about a city, a neighbourhood, a street, a park, a bench and about the
different people and non-human creatures they encounter. Given the detail-oriented trait of the
flaneur's personality and their capacity to act as a connoisseur and a collector of unnoticed, invisible
and neglected city's components, these stories provide a unique perspective on the city, on its
inhabitants and their behaviours. In this project, I investigate flânerie as a critical tool to reflect upon
the relationships between people, objects, and places through the mapping of these stories. My journey
in the world of flanerie starts with the identification of contemporary flaneurs who have been telling
stories about their flaneries, with a particular focus on Montreal. Among the rich material these
flaneurs collected and shared, I selected seven stories from a printed magazine (i.e. the Flaneur
Magazine) dedicated to flaneries along rue Bernard from Outremont to Mile End. To map these
stories, I developed a graphic language dedicated to representing various spatio-temporal and personal
aspects of these stories. This language was inspired by the concept of Inductive Visualization
(Knowles et al. 2015), which allows for the spatial expression of a story based on its content, in
contrast with conventional euclidean cartographic structure. This approach led me to produce The
Flanerie Atlas of Rue Bernard, which corresponds to the creation part of this research-creation project.
Throughout the production of this original atlas, I was able to develop a methodology to map data
from stories and to propose a new (carto)graphic language dedicated to the representation of stories.
This atlas revealed certain particularities of Rue Bernard as captured by flaneurs' stories. It led me to
reflect on the relevance of mobilizing flaneurs' materials to study a park, a street, a neighborhood.
Flaneurs' materials, in this sense, show their potent to reveal people's affective bonds with places.


identifier: Buswa, Tashiina  (2021) "A World Away": Decolonizing Journalism Methods.  Masters thesis, Concordia University.

format: audio text

abstract: This research-creation thesis is an exploration into the possibilities for future Indigenous journalism. With an emphasis on “decolonizing” journalism methods, this project attempts to re-evaluate the sometimes limiting and sterile approach to storytelling that comes with western journalism methodology. By applying Indigenous pedagogy, one can find that both the process and the outcome of telling Indigenous stories through a journalistic lens is much more rewarding and impactful. Prominent theoretical themes of this project included cultural identity and competency – both concepts which are rarely understood in mainstream media. Through the use of personal narrative podcasting, the topic of this project is Indigenous education. The intersection of podcasting and Indigenous storytelling allows for a meaningful auditory experience that is culturally competent. The use of podcasts, a fast-growing genre, is both an intimate and commanding space in which disembodied voices captivate the listener’s immediate attention. This fact was not overlooked during the completion of the project, which attempts to give agency to those who have historically been ignored or misrepresented in traditional media. This type of journalism, guided by Indigenous-informed methodology, can be of great value to future journalists when pursuing stories within Indigenous communities.


identifier: Vahabisani, Azar  (2020) Exploring the Effects of Microalgal Biomass on the Oil Behavior in A Sand-Water System.  Masters thesis, Concordia University.

abstract: This study focused on the impact of microalgal biomass on the oil behavior in a sand-water system. The microalgal biomass was characterized and the interaction between microalgal biomass and oil was analyzed through FTIR. The effects of different conditions including microalgal biomass dose, pH, temperature and salinity on the oil behavior were investigated. A two-level factorial analysis was also used to further explore the interactions of these conditions. The microalgal biomass was found to be the most influential parameter for the residual crude oil on sand. Higher microalgal biomass dose resulted in less residual oil on sand. The remaining oil decreased with increasing solution pH from 4 to 7, and an increase of remaining oil was observed when the pH was further increased above 7. In addition, temperature and salinity could affect the removal of crude oil in the presence of microalgal biomass. Increasing the temperature up to 30 °C could result in less residual oil on sand compared with that at 5 °C. High salinity attributed to more oil removal from contaminated sand was more favorable than that at low salinity. Different mechanisms are related to oil removal and the behaviors of oil in this sand-water system could be influenced by the solution chemistry. The results of this study indicate that the presence of algae in the oiled shoreline can be considered in the comprehensive evaluation of spill risk and prediction of oil fate.


identifier: Sadi, Mohsen  (2020) UAV-based Forest Fire Detection and Localization Using Visual and Thermal Cameras.  Masters thesis, Concordia University.

abstract: In this research, a UAV (unmanned aerial vehicle) system for detecting and locating forest fires is developed. This system uses the information from two cameras: one visual camera and one thermal camera for fire detection and navigation. Two images from these cameras are aligned before they can be used. An alignment process is created and a homography matrix is computed so that it is assured that the two images are aligned and every pixel is the same in both images. By combining data extracted from these cameras, it can verify whether there is no fire or a real fire is happened or a fake fire. A two-degree-of-freedom (2DOF) frame is implemented for testing the tracking and locating capabilities of the UAV. Both cameras are mounted in this frame. This system is based on the concept of image-based thermo-visual servoing (IBTVS). That is, it extracts thermal and visual information of a scene and then it computes the position of a desired object (fire) and commands the servos to move to the desired position. This frame can simulate 2DOF movement of a UAV and can be used to test the developed fire detection algorithms. Finally, a co-simulation system is presented to verify the application of fire detection in a simulated UAV. The experimental tests demonstrate that the developed algorithms can guide the UAV to fly on a predefined path and look for any possible fire. As soon as a fire is detected, the system will alarm and calculate the location of fire and fly the UAV over the fire for further investigations.


identifier: Jess, Raymond  (2020) Situating Ireland: Time, Territory, and Identity in Post-Confederation Irish-Canada.  PhD thesis, Concordia University.

abstract:
Between Canadian Confederation and the founding of the Irish Free State, Canada was the main model of political sovereignty through which British Liberals could imagine a practical form of political devolution for Ireland. This was also a period when Canada wished to populate the western prairies of the country by attracting immigrants from the United Kingdom, and it was hoped that by supporting Home Rule for Ireland, more Irish emigrants would choose Canada as a destination over the United States. But the failure of two Home Rule bills at Westminster would mean that Ireland would increasingly turn towards a cultural nationalist outlook, one that had a greater interest in Canada’s linguistic identity, than its political history.

This thesis will look at how Ireland was situated with regard to three primary co-ordinates of a national imaginary: history, geography, and cultural distinctiveness. I will follow the methodology of the pioneering historian Joep Leerssen whose work on pre-twentieth century Irish-English relations showed how the categories of Ireland and England were constructed as a familiarity of foreignness. While the word Irish has had a long history in English textual discourse, even before the majority of the Irish became anglophone, this thesis will look at the construction of Irishness within the Irish diaspora and the British Empire at a time when the majority of Irish people both at home and abroad had become a literate anglophone population. This thesis seeks to understand how the Irish situated themselves in an anglophone modernity, against an English language history that was never very enamored of Irish cultural distinctiveness.

For many prominent anglophone Canadians, the success of the Canadian model of political sovereignty and the opportunities afforded by settling the Northwest, should have provided the Irish with fruitful routes to transcend their history. But for many francophone Canadians, Ireland was a warning about the dangers of cultural loss, as they battled against the anglicizing influence of the Irish North American Catholic Church. By situating Ireland as a mirror of Canadian politics and culture, both the Irish and the Canadians could better interpret their past and envision their future.


identifier: Boudreau, Charles  (2020) Virtual Machine Migration: Greedy Heuristics and Mathematical Models.  Masters thesis, Concordia University.

abstract:
Live Migration of virtual machines between different physical hosts is an important process for datacenter management, essential for safeguarding hardware integrity and controlling power consumption, among other functions, with no perceptible interruptions for the user of the virtual machine. As the migration operation has a cost in terms of power and service quality degradation, it is of interest to examine how to best conduct multiple live migrations such that the total time needed to complete all planned migrations is minimized. Scheduling of multiple VM migrations may also take into account the risk of bringing the system to a state where all planned migrations cannot be resolved due to deadlocks caused by resource dependencies.

In this work, we propose a set of solutions based on greedy heuristics for the VM migration problem. We have selected four possible criteria to base scheduling decisions on, and we evaluate the total migration time degree of completion of the planned migrations next to a baseline algorithm. Additionally, we propose two decomposed linear programming models intended for column generation solution: a time-based formulation, followed by a precedence-based formulation. We suppose that these decomposed formulations will lead to faster solution times over conventional, “compact” formulations due to their structure permitting the elimination of a large number of variables from explicit consideration when the continuous relaxation is solved with column generation techniques.


identifier: Greco, Brittany  (2020) CRISPR-Cas9 Induced Combinatorial Genome Editing in Saccharomyces cerevisiae.  Masters thesis, Concordia University.

abstract: For decades, Baker’s yeast (Saccharomyces cerevisiae) has served as a tremendous model for biomedical research. Genome-scale engineering in yeast is feasible primarily due to prodigious homology-directed DNA repair, a plethora of genetic tools/selection markers, and simple conversion between haploid and diploid forms. However, with the emergence of yeast as a model eukaryote for systems and synthetic biology research, there is a need for highly efficient and scalable genome engineering strategies. Previously, using CRISPR-Cas9, our laboratory developed a method for one-step, marker-free editing of the yeast genome using Homology Directed Repair (HDR). In the first part of my work, I created CRISPR-Cas9 toolkits targeting several yeast loci and showed specific, efficient and targeted Double-strand Breaks (DSBs) followed by HDR. Next, by combining CRISPR-Cas9, DNA repair via HDR, and yeast mating and sporulation, I demonstrate a highly efficient gene drive (referred to as Cas9-induced Gene Drive or CGD) to perform precise, scar-free, and selection-less conversion of native yeast loci to heterologous engineered loci respectively. To test the efficiency of the gene drive, I convert the functional copy of the Ade2 gene to Ade2 null locus using a heterozygous diploid strain (Ade2 / Δade2::KanMX). First, I show the conversion of the Ade2 to Δade2::KanMX locus is near 100% efficient since the DSB-resistant KanMX copy of the homologous chromosome serves as a highly effective repair template for HDR. Next, I demonstrate the conversion of two or more heterozygous human-yeast loci to become homozygous for human genes at a comparable rate (i.e., ~100%). To show the feasibility and scalability of this method for assembling multi-gene biosynthetic pathways or complexes, I am testing the engineering of the entire carotenoid pathway and the orthologous human proteasome alpha core genes in yeast. Thus, CGD lays the foundation for large-scale combinatorial engineering of the entire heterologous biological processes in budding yeast.


identifier: Koupayi, Kamran  (2020) Separation and Cover Problems in Temporal Graph.  Masters thesis, Concordia University.

abstract:
A graph that changes with time is called a temporal graph. In this work, we focus on temporal graphs whose vertex sets are fixed while edge sets change in discrete time steps. We use n to refer to the number of vertices in the graph and τ to refer to the total number of time steps over which a temporal graph is observed. We refer to non-temporal graphs as static graphs when we wish to emphasize their unchanging nature.

  In this work, we study temporal analogues of the Vertex Separator and Vertex Cover problems from the static world with an emphasis on the Vertex Separator problem. An (s,z)-temporal separator is a set of vertices whose removal disconnects vertex s from vertex z for every time step in a temporal graph. The (s,z)-Temporal Separator problem asks to find the minimum size of an (s,z)-temporal separator for the given temporal graph. The (s,z)-Temporal Separator problem is known to be NP-hard in general, although some special cases (such as bounded treewidth) admit efficient algorithms.

  We introduce a generalization of this problem called (s,z,t)-Temporal Separator problem, where the goal is to find the smallest subset of vertices whose removal eliminates all temporal paths from s to z which take less than t time steps. Observe that setting t = τ captures the (s,z)-Temporal Separator problem as a special case of (s,z,t)-Temporal Separator problem.

  We present a τ-approximation algorithm for (s,z)-Temporal Separator problem, and we convert it to a τ^2-approximation algorithm for (s,z,t)-Temporal Separator problem. We also present an inapproximability lower bound of Ω(ln(n) + ln(τ)) for (s,z,t)-Temporal Separator problem assuming that P ≠ NP.

  We show a polynomial-time reduction from the Discrete Segment Covering problem with bounded-length segments to (s,z,t)-Temporal Separator where the temporal graph has bounded pathwidth.
  Therefore, solving (s,z,t)-Temporal Separator on temporal graph whose underlying graph has bounded pathwidth is more difficult than solving Discrete Segment Covering problem where all segments' lengths are bounded.

  Discrete segment cover is a set of unit-length intervals, which covers at least one of two endpoints of each input segment.

  Lastly, we present a polynomial-time algorithm to find minimum (s,z,t)-temporal separator on temporal graphs whose underlying graph is a series-parallel graph or by removing the source and the terminal it is turned into a tree.

  The second problem of interest is the Activity Timeline problem which is a generalization of a Vertex Cover to the temporal setting. An activity timeline is an assignment of time intervals to vertices. An edge between vertex u and vertex v is covered by an activity timeline φ at time t if one of the time intervals assigned to u or v includes the time t (this is required only if the edge is actually present at time t). In MinTimeline the goal is to find an activity timeline that covers all edges while minimizing the total length of time intervals. This problem is known to be NP-hard. In another problem, called MinTimeLine_m, we are asked to find an activity timeline subject to additional constraints specified by a set of prescribed times {m_v}, one for each vertex v. A valid activity timeline for MinTimeline_m must guarantee that for every vertex v the interval corresponding to v contains m_v. The goal is again to minimize the total length of time intervals. Prior to this work, the best known approximation algorithm for MinTimline_m problem was based on a rather complicated primal-dual linear programming approach and achieved 2 approximation.
  In this work, we present a simple purely combinatorial 2-approximation algorithm for this problem.

  The combinatorial algorithm is inspired by the famous Double Coverage algorithm for the k-Server problem on a line in the area of online algorithms.
  This highlights an interesting cross-over between temporal graph algorithms and online algorithms that might require further investigation. Lastly, we present a polynomial-time algorithm for MinTimeline on temporal graphs whose underlying graphs have bounded treewidth.


identifier: Taghian Alamouti, Shadi  (2020) Exploring Temporal Cycles and Grids.  Masters thesis, Concordia University.

title: Exploring Temporal Cycles and Grids

abstract: A temporal graph is a graph in which the edge set can change from time to time. The temporal graph exploration problem, TEXP, is the problem of computing a foremost exploration schedule for a temporal graph, i.e., a temporal walk that starts at a given start node, visits all nodes of the graph, and has the smallest arrival time.In this work, we consider undirected temporal graphs that are connected at each time step. We present an overview of some known results regarding exploration of temporal cycles and grids, as well as new contributions to the theory of TEXP of cycles and grids. Our results can be grouped into two sets.  The first set of results concerns TEXP of cycles. In particular, we positively resolve the conjecture of Erlebach et al. stating that temporal cycles of size n with constantly many chords can be explored in O(n) time steps. Moreover, we design a polynomial time dynamic programming algorithm for computing an optimal temporal walk for TEXP on cycles from any start node. We implemented this algorithm and performed a limited empirical evaluation, results of which are also reported in this thesis. Our second set of results extends the algorithm of Erlebach et al. for the exploration of 2×n temporal grids to modified temporal grids that allow some neighboring edges to cross each other.


identifier: de Souza Toniolli, Jean Lucas ORCID: https://orcid.org/0000-0001-7507-5355 <https://orcid.org/0000-0001-7507-5355>  (2020) Resource Allocation for Multiple Workflows in Cloud-Fog Computing Systems.  Masters thesis, Concordia University.

abstract: Constant innovations in the Internet of Things (IoT) in latest years have generated large amounts of data, putting pressure on the infrastructure of cloud computing. Fog computing has recently become a popular computing paradigm that can provide computing resources close to the end users and solve multiple issues with the current cloud-only systems. Fog computing helps to reduce transmission latency and monetary cost for cloud resources, while cloud computing helps to fulfill the increasing demands of large-scale compute-intensive offloading applications. Since its introduction, there has been a great number of studies on fog computing, in which devices that are free-of-charge and closer to the user can provide low-latency services to end devices. However, how to schedule workflow applications in the cloud-fog environment to seek the tradeoff between makespan and price is facing enormous challenges. To address such a problem, we present an adaptation of the Path-Clustering Heuristic to the cloud-fog environment for multiple workflows. Firstly, we define the models for workflow execution time and resource cost in fog computing. Afterwards, we describe the algorithms implemented. We validate our proposal by extensive simulation. Experimental results show that our scheduling adaptation achieves better performance while keeping similar costs compared to others.


identifier: Miklin, Alexandra  (2021) Environment-based design enabled scenario analysis for aerospace product development.  Masters thesis, Concordia University.

abstract:
The process of product development is one of the most important and complex activities of an industrial company, especially in the aerospace domain. The requirements of stakeholders play a central role here. Those requirements come from internal and external sources, and further in the process are translated into organizational knowledge (e.g. specifications, etc.). Utilization of this approved knowledge in new programs is very beneficial, and can save resources for design, may reduce the risk of failures, and may ease certification, manufacturing, maintenance and other processes.
The development of such complex systems is an extremely challenging process because of their growing complexity and frequently changing product environment and requirements. Furthermore, the development process affects the amount of information or knowledge (e.g. requirements) to be managed by an organization.
Building on information gained from past projects, this thesis proposes a method to structure the knowledge that was gained. The Environment-Based Design (EBD) methodology is a platform for characterization of this method. Utilizing the EBD tool, a Recursive Object Model (ROM), enables a graphical representation of the knowledge for ontology (components and relationships) that is found within the environment-based analysis. In addition, an example of analysis for the top-level requirement based EBD methodology is provided. This example proposes an opportunity for searching specific requirements by tagging with key words. The results were compared with a model approach based on the Arcadia method, and was found to be effective.


identifier: Mirzai Tavana, Sina  (2020) Thermal Spray Coating of Carbon Reinforcement Composites for Wear and Erosion Resistance Applications.  Masters thesis, Concordia University.

abstract: Polymeric composite materials have been used to manufacture both jet engine fan blades and wind turbine blades. The main considerations in the blades design are efficiency, weight, and durability. The blades must be capable of withstanding solid particles impact with no damage. Polymeric composite does not have a good erosion resistance.  In this thesis, application of thermal spray coatings on polymeric composite materials has been investigated to improve their erosion resistance.  Three different coating materials namely, tungsten carbide-cobalt, martensitic chromium stainless steel, and alumina-titania are chosen because of their excellent abrasion and erosion resistant, good mechanical properties, and relatively low cost. Atmospheric plasma spray is used to deposit the coating on the composite. Composite panels are manufactured using carbon fiber reinforced polymer CFRP using hand layup and autoclave curing. During the layup, a stainless steel mesh is placed on the top of the panel. This metal mesh will protect the composite during coating deposition and serve as an anchor for keeping the coating in place. Different plasma spray processing conditions are tried to have a good coating on the panel. Flatwise tensile tests are performed to measure the adhesion between the composite substrate and coating. It is found that using stainless steel metal mesh makes uniform, high quality coatings with significant adhesion property between composite substrate and coat layer. The solid erosion testing was carried out using air-jet erosion testing (ASTM G76) by hard, angular alumina particles at 30˚, 60˚ and 90˚ impact angle. Different impact angles were measured to demonstrate the erosion regime (ductile or brittle) of each material. In order to determine mechanical properties and microstructure effect, roughness and the hardness of each material have been studied. It is shown that the proposed method of manufacturing can improve significantly the erosion resistance of the polymeric composites.


identifier: Ashraf, Nadeem  (2020) Subarray-Based Multibeam Antenna Frontend for Millimeter-Wave Hybrid Beamforming.  PhD thesis, Concordia University.

abstract:
With the paradigm shift from sub-6 GHz to millimeter-wave (mm-Wave) for wireless communications, beamforming becomes essential for mm-Wave access points to mitigate losses. Due to the small wavelength, a compact circuit could accommodate a large number of antenna elements. This favors the principle of beamforming to achieve high array-gain and spatial resolution through a large-scale N × M array. For such antenna frontends, full-digital beamforming circuitry requires N × M  RF chains, which is unfeasible and energy inefficient. Likewise, a higher-order mm-Wave analog beamforming network is highly lossy to generate N × M beams. Hybrid beamforming addresses this dilemma by partitioning the beamforming between the analog and digital domains appropriately. For this purpose, the antenna frontend needs to be segmented into subarrays, such that the subarray-based analog beamspace patterns are digitally processed rather than processing element patterns individually. Thus, hybrid beamforming requires a suitable subarray-based N × M multibeam antenna frontend.

In this thesis, a study of the subarray antennas is presented for hybrid beamforming operation. A simplified model is considered in which the analog beam-switching is performed in the azimuth plane (H-plane) and the digital beamspace beamforming in the elevation plane (V-plane). This is to reduce the number of RF chains as well as to achieve fine-tuned digital beam-steering in V-plane along with predefined analog switched-beams in H-plane. In this research work, the frequency band of 28 – 32 GHz is considered for prototyping purposes. For practical use at mm-Wave, the microstrip line technology is augmented with the perfect magnetic conductor (PMC) packaging. The fixed-beam and switched-beam subarrays with an order of n × m = 1 × 4, 2 × 2, and 4 × 4 are investigated. A dual-polarized aperture-coupled magneto-electric dipole antenna is designed as a single element with 20% bandwidth, ports' isolation better than 35 dB, cross-polarization less than -25 dB, and gain of 8 dBi. Using this element, a fixed-beam 4 × 4 dual-polarized subarray is designed that maintains a bandwidth of 16.7% at 30 GHz with a maximum gain of 19.3 dBi and symmetrical radiation patterns. The fixed-beam limitation of the 2n × 2m subarray leads to building the efficient switched-beam subarray antennas for hybrid beamforming. For this purpose, a 2 × 2 dual-polarized analog beamforming network is designed for 28-32 GHz. Two identical PMC packaged microstrip line networks, one for each polarization, are designed on a single substrate surface. However, to be processed for beamspace digital beamforming, this topology exhibits physical layout and array factor problems. Thus, further designs are investigated to meet the hybrid beamforming frontend requirements.

To this end, as switched-beam subarrays for hybrid beamforming, two PMC packaged 4 × 4 Butler matrices are presented with a longitudinal layout and a folded layout for the end-fire and broadside radiation characteristics, respectively. The former design achieves a 5 GHz (28-33 GHz) bandwidth with return loss and isolation, both better than 15 dB. At 30 GHz, the insertion loss is 0.8 ± 0.3 dB, and antenna-ports' phase distributions are ±45° and ±135°. E-plane-flared horn antennas terminate the Butler matrix antenna-ports as a linear array. The double-ridge gap waveguide horn antenna is designed to reduce the scan loss within a subarray environment. The H-plane fan-beam switching covers ±42° with a maximum gain of 11.7 and 11.2 dBi for the inner (1R) and outer (2R) radiation beams. The latter novel topology of the folded Butler matrix is laid out for a compact tiled planar antenna frontend to accommodate a beamforming network beneath the antenna array's physical footprints. As compared to the conventional longitudinal layout, the size is reduced by more than 50 %. The PCB aperture-coupled antenna elements are integrated within the PMC packaged environment for a broadside radiation characteristic. The folded Butler matrix and antenna element are designed for a bandwidth of 4 GHz (28-32 GHz). The single antenna element's directivity is 5.22 dBi; whereas, for a 1 × 4 switched-beam subarray antenna, the directivities are 11.1 dBi and 10.6 dBi for 1R and 2R beams, respectively. Using Butler matrices-based 1 × 4 switched-beam subarrays, two types of multibeam antenna frontends with order N × M = 4 × 4 are constructed. Post-processing for the digital beamforming is applied over the subarray-based analog beamspaces. The first hybrid beamforming model maintains a scan range of ± 42o in the H-plane and ± 28o in the V-plane with BV × BH = 3 × 4 = 12 beams. Similarly, the second model maintains a scan range of ± 38o in the H-plane and ± 40o in the V-plane with BV × BH = 4 × 4 = 16 beams. As compared to full-analog two-dimensional (2-D) beamforming, these models are capable of fine-tuned beam-steering in the V-plane because the complex beamforming coefficients are not fixed but calculated digitally. Furthermore, compared to full-digital 2-D beamforming, it reduces the number of active RF chains from N × M to N.