Schulich School of Engineering Research & Publications

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Open Access
Use of GNSS Doppler for Prediction in Kalman Filtering for Smartphone Positioning
(IEEE Journal of Indoor and Seamless Positioning and Navigation, 2023-11-28) Agarwal, Naman; O'Keefe, Kyle
This article demonstrates an alternative approach that uses global navigation satellite system (GNSS) Doppler measurements in a Kalman filter (KF) to improve the accuracy of GNSS smartphone positioning. The proposed method automates the process of estimating the uncertainty of the dynamics model of the system, which is still a challenge for the conventional KF-based GNSS positioning methods that require heuristic tuning. Automation of dynamics model uncertainty estimation also demonstrates notable improvement in GNSS outlier detection or fault detection and exclusion. In addition, this article will perform a quality assessment of the GNSS observations obtained from two Android smartphones and investigate the performance of the proposed method when using GPS L1 + Galileo E1 signals compared to GPS L5 + Galileo E5a signals.
Open Access
Metal-Organic Framework Reinforced Highly Stretchable and Durable Conductive Hydrogel-Based Triboelectric Nanogenerator for Biomotion Sensing and Wearable Human-Machine Interfaces
(Wiley, 2023-07-17) Rahman, Muhammad Toyabur; Rahman, Md Sazzadur; Kumar, Hitendra; Kim, Keekyoung; Kim, Seonghwan
Flexible triboelectric nanogenerators (TENGs) with multifunctional sensing capabilities offer an elegant solution to address the growing energy supply challenges for wearable smart electronics. Herein, a highly stretchable and durable electrode for wearable TENG is developed using ZIF-8 as a reinforcing nanofiller in a hydrogel with LiCl electrolyte. ZIF-8 nanocrystals improve the hydrogel's mechanical properties by forming hydrogen bonds with copolymer chains, resulting in 2.7 times greater stretchability than pure hydrogel. The hydrogel electrode is encapsulated by microstructured silicone layers that act as triboelectric materials and prevent water loss from the hydrogel. Optimized ZIF-8-based hydrogel electrodes enhance the output performance of TENG through the dynamic balance of electric double layers (EDLs) during contact electrification. Thus, the as-fabricated TENG delivers an excellent power density of 3.47 Wm–2, which is 3.2 times higher than pure hydrogel-based TENG. The developed TENG can scavenge biomechanical energy even at subzero temperatures to power small electronics and serve as excellent self-powered pressure sensors for human-machine interfaces (HMIs). The nanocomposite hydrogel-based TENG can also function as a wearable biomotion sensor, detecting body movements with high sensitivity. This study demonstrates the significant potential of utilizing ZIF-8 reinforced hydrogel as an electrode for wearable TENGs in energy harvesting and sensor technology.
Open Access
In situ encapsulation of ZrQ in UiO-66 (Zr-BDC) for pore size control to enhance detection of a nerve agent simulant dimethyl methyl phosphonate (DMMP)
(Wiley, 2022-06-08) Wong, Danny; Kim, Seonghwan; Abuzalat, Osama
Chemical warfare agents are toxic chemicals that require rapid, easy-to-use, sensitive, and selective sensors to countermeasure. Simulants, such as dimethyl methyl phosphonate (DMMP), are used to test the effectiveness of sensors toward nerve agents. Metal organic frameworks (MOFs) offer large surface area and selective accessibility to active sites making them appealing for chemical sensing applications. In this work, we propose a fast, facile, direct synthesis method for manufacturing fluorescent MOFs with high sensitivity and selectivity. Zr-BDC is synthesized with 1, 4-benzenedicarboxylic acid (BDC) as an organic ligand and zirconium (Zr) metal. Fluorescent materials are then encapsulated in a novel and rapid in situ approach with strong solvents. X-ray diffraction, UV–visible spectroscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy are used to verify the successful formation of fluorescent MOFs. Compared to other methods, the gel synthesis method helps to control crystal growth leading to higher BET surface areas of ~1150 m2 g−1 for Zr-BDC and 850 m2 g−1 for ZrQ@Zr-BDC. Titration experiments show the sensitivity of the material to DMMP down to 8.3 nM with a highly linear response. Enhanced fluorescence and occupation of mesopores by ZrQ enable lower limit of detection than those of comparable works in literature. The encapsulation mechanism also prevents substantial defects that would otherwise lead to water adsorption.
Embargo
Object positional uncertainty modelling in 2D viewpoint planning
(Elsevier--Automation in Construction, 2023)
Open Access
Advancing Smart Cities through Novel Social Media Text Analysis: A Case Study of Calgary
(2023 IEEE Symposium Series on Computational Intelligence, 2023-09-15) Mitra Mirshafiee; Dr. Ann Barcomb; Dr. Benjamin Tan
In numerous cities, population expansion and technological advancements necessitate proactive modernization and integration of technology. However, the existing bureaucratic structure often hinders local officials' efforts to effectively address and monitor residents' needs and enhance the city accordingly. Understanding what people find important and useful can be inferred from their posts on social media. Twitter, as one of the most popular social media platforms, provides us with valuable data that, with the right tools and analysis, can provide insights into the performance of urban services and residents' perception of them. In this study, we used the city of Calgary as an exemplar to gather tweets and analyze topics relating to city development, urban planning, and minorities. Natural language processing (NLP) techniques were used and developed to preprocess stored tweets, classify the emotions, and identify the topics present in the dataset to eventually provide a set of topics with the prevalent emotion in that topic. We utilized a variety of methods to analyze the collected data. BERTopic for topic modeling and few-shot learning using Setfit for emotion analysis outperformed the others. Hence, we identify issues related to city development, senior citizens, taxes, and unemployment using these methods, and we demonstrate how delving into these analyses can improve urban planning.
Open Access
Reflections on the 2023 Bonn UN Climate Change Conference: An Engineer's Perspective
(2023-07-20) Demissie, Merkebe Getachew
The reflective process of the 2023 Bonn Climate Change Conference involves examining my initial expectations, reflecting on the conference experience, and identifying key takeaways that significantly impacted my professional development and understanding of climate change. This exercise aims to deepen my knowledge of global developments in climate change mitigation, adaptation, and financing. The conference serves as a powerful platform for raising awareness and promoting change. Additionally, I hope to inspire greater participation in the engineering community, leveraging this conference to increase public awareness about climate change and the vital role engineering plays in addressing these challenges.
Open Access
Direct simulation of stably stratified wall-bounded turbulence using the lattice Boltzmann method
(2023-04-27) Guo, Junwei; Zhou, Qi; Wong, Ron Chik-Kwong
The lattice Boltzmann method (LBM) is employed to simulate stratified plane Couette (SPC) flows in their statistically stationary turbulent state. The aim is to assess the suitability of the LBM for direct simulation of wall-bounded, sheared turbulence under the influence of stable stratification. The SPC flow is generated by two parallel plates moving in opposite directions with velocities ± U w, and the buoyancy is fixed at ± b w at the upper and lower plates, respectively. The Reynolds number Re = U w h / ν, where h is the half-gap height, and ν is the kinematic viscosity, varies from 1000 to 3000. The Richardson number Ri = b w h / U w 2 is set to 0 or 0.01. The LBM results are compared to direct numerical simulations using the conventional pseudo-spectral method, and good agreement is found in various turbulence statistics, such as mean and fluctuation velocity and buoyancy, Reynolds stress, turbulent heat flux, dissipation rate, wall fluxes of momentum and heat, and longitudinal and transverse turbulence spectra. The results from grid-sensitivity tests indicate that the uniform isotropic grid spacing Δ x in LBM needs to be no greater than approximately the near-wall viscous length scale δ ν to achieve adequate resolution of stratified wall-bounded turbulence.
Open Access
Extended-FEM analysis of injection-induced slip on a fault with rate-and-state friction: Insights into parameters that control induced seismicity
(Springer, 2023-03-09) Hosseini, Navid; Priest, Jeffrey; Eaton, David
The extended finite element method (X-FEM) is utilised to simulate the behavior of a heterogeneous fault characterized by rate-state frictional rheology, embedded within a poroelastic medium. The displacement and pore-pressure fields that are discontinuous across the fault are computed using X-FEM, by enriching the standard finite element approximation with additional degrees of freedom for elements intersected by the fault. We investigate a Mw 4.1 injection-induced earthquake in western Canada; this model incorporates depth-varying rate-slip behavior wherein a high-pressure zone due to hydraulic fracturing stimulation intersects the fault within a stable layer, producing aseismic slip that progressively loads an unstable fault region, thereby triggering dynamic rupture. Parametric studies using our numerical approach provide insights into the influence of rate-state parameters on fault activation, as well as hydraulic properties of a damage zone that surrounds the fault. Results confirm that aseismic slip near the injection zone propagates outwards to seismogenic unstable regions of the fault. The coseismic slip profile, seismic moment, and slip latency are determined by the difference a − b for rate-state parameters of the unstable fault regions. Hydraulic diffusivity in the damage zone controls the rate of pore-pressure diffusion along the fault, which affects timing of the initial seismic event and aftershock productivity.
Open Access
Tibial-fibular geometry and density variations associated with elevated bone strain and sex disparities in young active adults
(Elsevier, 2022-05-20) Bruce, Olivia L; Baggaley, Michael; Khassetarash, Arash; Haider, Ifaz T; Edwards, W Brent
Tibial stress fracture is a common injury in runners and military personnel. Elevated bone strain is believed to be associated with the development of stress fractures and is influenced by bone geometry and density. The purpose of this study was to characterize tibial-fibular geometry and density variations in young active adults, and to quantify the influence of these variations on finite element-predicted bone strain. A statistical appearance model characterising tibial-fibular geometry and density was developed from computed tomography scans of 48 young physically active adults. The model was perturbed ±1 and 2 standard deviations along each of the first five principal components to create finite element models. Average male and female finite element models, controlled for scale, were also generated. Muscle and joint forces in running, calculated using inverse dynamics-based static optimization, were applied to the finite element models. The resulting 95th percentile pressure-modified von Mises strain (peak strain) and strained volume (volume of elements above 4000 με) were quantified. Geometry and density variations described by principal components resulted in up to 12.0% differences in peak strain and 95.4% differences in strained volume when compared to the average tibia-fibula model. The average female illustrated 5.5% and 41.3% larger peak strain and strained volume, respectively, when compared to the average male, suggesting that sexual dimorphism in bone geometry may indeed contribute to greater stress fracture risk in females. Our findings identified important features in subject-specific geometry and density associated with elevated bone strain that may have implications for stress fracture risk.
Open Access
A statistical shape model of the tibia-fibula complex: sexual dimorphism and effects of age on reconstruction accuracy from anatomical landmarks
(2021-11-03) Bruce, Olivia L; Baggaley, Michael; Welte, Lauren; Rainbow, Michael J; Edwards, W Brent
A statistical shape model was created for a young adult population and used to predict tibia and fibula geometries from bony landmarks. Reconstruction errors with respect to CT data were quantified and compared to isometric scaling. Shape differences existed between sexes. The statistical shape model estimated tibia-fibula geometries from landmarks with high accuracy (RMSE = 1.51-1.62 mm), improving upon isometric scaling (RMSE = 1.78 mm). Reconstruction errors increased when the model was applied to older adults (RMSE = 2.11-2.17 mm). Improvements in geometric accuracy with shape model reconstruction changed hamstring moment arms 25-35% (1.0-1.3 mm) in young adults.
Open Access
Threshold behavior of local gradient Richardson number in strongly stratified nonequilibrium turbulence
(American Physical Society, 2022-10-20) Zhou, Qi
In this paper we examine the possible self-organization of strongly stratified turbulence around a local critical state by analyzing a data set of a numerically simulated stratified turbulent wake. To facilitate the analysis, the turbulent flow field is decomposed into a“large-scale” flow of horizontal scales greater than the Ozmidov scale, and a “small-scale” flow of scales below O. A local gradient Richardson number, Ri, characterizing the large-scale flow is calculated and then utilized to produce conditional sampling of various turbulence statistics relevant to the local dynamics. While the bulk turbulence is observed to decay by approximately one order of magnitude in terms of the dissipation rate, the median Ri has remained nearly constant due to the self-organization of flow structures under strong stratification; the subsampled Ri distribution peaks around 1/4 for regions in the upper quartile of local dissipation. Regions of small Ri are found to be associated with large dissipation and large net transfer of energy to the small scales. Regions of “back-scatter”of kinetic energy to large scales, where the local eddy viscosity,νe, takes a negative value,are also observed. Occurrence of a large magnitude of both positive and negative νe appears to be most frequent around the critical value of Ri∼1/4, indicating an intense two-way exchange of kinetic energy between the large and small scales around the local critical state. The threshold behavior of Ri underscores the dynamical significance of the critical Ri of 1/4 for locally self-sustained turbulence in a strongly stratified configuration and bears some resemblance to the celebrated self-organized criticality dynamics [Baket al.,Phys.Rev.Lett.59, 381 (1987)].
Open Access
Method of Generating Unique Elementary Circuit Topologies Méthode de génération de topologies de circuits élémentaires uniques
(Institute of Electrical and Electronics Engineers, 2018-01) Shahhosseini, Delaram; Zailer, Eugene; Behjat, Laleh; Belostotski, Leonid
Designing analog circuits with new topologies is often very challenging, as it requires not only circuit design expertise but also an intuition of how various elementary circuits may work when put together to form a larger circuit. In this paper, we present a method of generating all functional elementary circuit topologies. The paper uses combinatorics to ensure that all unique circuit topologies are generated and stored in a database. This database contains 582 two-transistor and 56,280 three-transistor functional and unique elementary circuit topologies. It is envisioned that the circuit topologies stored in the database can save design time and assist designers by both offering previously unknown circuit topologies and providing circuit topologies for further optimizations. To give an example of how this vision can be used in practice, a search for all amplifier circuits was conducted that resulted in 5,177 circuit topologies, some previously unknown, out of 56,862 three-transistor elementary circuit topologies.
Open Access
Planning Delivery-by-Drone Micro-Fulfilment Centres
(2022-07-25) Lamb, Jacob
Delivery drones are a disruptive technology that is spurring logistics system change, such as the adoption of urban micro-fulfilment centres (MFCs). In this paper, we develop and implement a two-stage continuum approximation (CA) model of this disruptive system in a geographic information system (GIS). The model includes common CA techniques at a local level to minimise cost, and then these local solutions are used in a second stage regional location-allocation multiple knapsack problem. We then compare the drone MFC system to a traditional delivery-by-truck system and investigate potential cost or emissions savings by adjusting time-window demand, logistical sprawl, electric truck alternatives, and MFC emissions. Furthermore, we conduct a sensitivity analysis to show that uncertainty in demand and effective storage density both significantly influence the number of MFCs selected and benchmark our model against commercial solvers. This methodology may also be further developed and applied to other new delivery vehicle modes.
Open Access
Protocol for a scoping review of precision technologies for cattle monitoring
(2022-07-20) Besler, Brendon; Mojabi, Pedram; Murphy, James E; Wang, Zefang; Baker, Ryan; Pearson, Jennifer; Fear, Elise
Livestock farming has increased in complexity considerably due to the increased demand for animal products combined with a decreasing number of farmers and ranchers. To meet this challenge, Precision Livestock Farming (PLF) aims to develop fully automated tools that continuously monitor animals, such as cattle. Ineffective cattle management can have significant animal welfare implications, as well as financial consequences for both farmers and the economy because of the size of this substantial industry globally. To our knowledge, no scoping review with explicit published search protocol has broadly examined PLF technologies for both beef and dairy cattle to identify gaps in current research.
Open Access
A collaborative autoethnographic analysis of industry-academia collaboration for software engineering education development
(Canadian Engineering Education Association, 2022-06) Marasco, Emily; Barcomb, Ann; Dwomoh, Gloria; Eguia, Daniel; Jaffary, Abbas; Johnson, Garth; Leonard, Lance; Shupe, Ryan
As engineering educators seek to prepare students for future careers, it can be challenging to keep course materials current with industry practices and knowledge. Students also often experience a disconnect between their studies and perceived relevance to future industry roles. This study examines the potential impact of an industry-academia collaboration on the development and improvement of software engineering education while addressing these issues. A collaborative autoethnographic approach is used to concurrently analyze the experiences of both industry and academic participants in the collaboration. Common themes across the collected personal reflections show that varied benefits were experienced by all stakeholders while contributing to an improved student experience.
Open Access
Evolution of Rayleigh-Taylor instability at the interface between a granular suspension and a clear fluid
(American Institute of Physics, 2022-06-19) Guo, Junwei; Zhou, Qi; Wong, Ron C.-K.
We report the characteristics of Rayleigh-Taylor instabilities (RTI) occurring at the interface between a suspension of granular particles and a clear fluid. The time evolution of these instabilities is studied numerically using coupled lattice Boltzmann and discrete element methods with a focus on the overall growth rate (σ) of the instabilities and their average wave number (k). Special attention is paid to the effects of two parameters, the solid fraction (0.10{less than or equal to}φ{less than or equal to}0.40) of the granular suspension and the solid-to-fluid density ratio (1.5{less than or equal to}R{less than or equal to}2.7). Perturbations at the interface are observed to undergo a period of linear growth, the duration of which decreases with φ and scales with the particle shear time d/w∞, where d is the particle diameter and w∞ is the terminal velocity. For φ>0.10, the transition from linear to nonlinear growth occurs when the characteristic steepness of the perturbations is around 29%. At this transition, the average wave number is approximately 0.67d-1 for φ>0.10 and appears independent of R. For a given φ, the growth rate is found to be inversely proportional to the particle shear time, i.e., σ ∝(d/w∞)-1; at a given R, σ increases monotonically with φ, largely consistent with a linear stability analysis (LSA) in which the granular suspension is approximated as a continuum. These results reveal the relevance of the time scale d/w∞ to the evolution of interfacial granular RTI, highlight the various effects of φ and R on these instabilities, and demonstrate modest applicability of the continuum-based LSA for the particle-laden problem.
Open Access
Combining Multichannel RSSI and Vision with Artificial Neural Networks to Improve BLE Trilateration
(MDPI, 2022-06-07) Naghdi, Sharareh; O'Keefe, Kyle
The demands for accurate positioning and navigation applications in complex indoor environments such as emergency call positioning, fire-fighting services, and rescue operations are increasing continuously. Indoor positioning approaches apply different types of sensors to increase the accuracy of the user’s position. Among these technologies, Bluetooth Low Energy (BLE) appeared as a popular alternative due to its low cost and energy efficiency. However, BLE faces challenges related to Received Signal Strength Indicator (RSSI) fluctuations caused by human body shadowing. This work presents a method to compensate RSSI values by applying Artificial Neural Network (ANN) algorithms to RSSI measurements from three BLE advertising channels and a wearable camera as an additional source of information for the presence or absence of human obstacles. The resulting improved RSSI values are then converted into ranges using path loss models, and trilateration is applied to obtain indoor localization. The proposed artificial system provides significantly better localization solutions than fingerprinting or trilateration using uncorrected RSSI values.
Open Access
Automated Noise-Parameter Measurements of Cryogenic LNAs
(IEEE, 2021-06-25) Sheldon, Alexander; Belostotski, Leonid; Mani, Hamdi; Groppi, Christopher E.; Warnick, Karl F.
This paper addresses the need for measured cryogenic noise parameters. The measurement process is discussed and an analysis of the measurement uncertainty is performed. To verify proper operation of the measurement system, measurements of a 1-to-2-GHz radio-astronomy low-noise amplifier (LNA) at 20, 75, and 296 K are presented. In these measurements, the typical 1$\sigma$ measurement uncertainty in noise temperatures and minimum noise temperatures is < 10%.
Open Access
New method for first-order network design applied to TLS self-calibration networks
(Elsevier, 2021-07-01) Lichti, Derek D; Pexman, Kate; Tredoux, Wynand
Terrestrial laser scanning (TLS) is established as a viable means for precision measurement and the need for systematic error modelling and instrument self-calibration is well recognized. While additional parameter (AP) models and procedures for their estimation from signalized target fields have been developed, the first-order design (FOD) of TLS self-calibration networks remains an active area of research aiming to improve AP quality. The conventional FOD approach of numerical simulation carries a heavy computational burden. This paper reports a new method for TLS self-calibration FOD that avoids the high computational effort and can predict AP precision in closed form. Its basis is a relatively simple analytical model of the distribution of spherical coordinate observations, specifically the elevation angle. The accuracy of predicted AP precision is quantified by comparison of precision estimates from a more complex and detailed observation distribution model and from self-calibration. Results from 25 datasets demonstrate the high accuracy (arc second or better) of the closed-form approach. A new observation distribution model is then developed to optimize the geometric design of TLS self-calibration networks. An ideal observation distribution based on the versine function and a corresponding target field configuration that enhance AP precision are established. Testing was performed on five additional, very dense TLS self-calibration datasets. Each dataset was subsampled so as to replicate the observation distributions corresponding to conventional network design and the proposed design. The results show that up to 55% improvement in AP precision, obtained from self-calibration, can be achieved with the new design and these results agree with versine-distribution model predictions within 14% to 16%.
Open Access
Modelling Extreme Wide-Angle Lens Cameras
(Wiley, 2021-12-01) Lichti, Derek D; Tredoux, Wynand; Maalek, Reza; Helmholz, Petra; Radovanovic, Robert
The use of consumer cameras fitted with extreme wide angle (EWA) lenses for photogrammetric measurement is increasing. Conventional modelling of EWA systems relies on the pinhole camera model and up to five radial lens distortion terms. Aiming to reduce model complexity, this paper reports an investigation into an alternate approach using fisheye lens models for EWA systems, despite them not falling strictly into to the fisheye category. Four fisheye models were tested on four different cameras under laboratory conditions. The self-calibration results show superior model fit for all fisheye models over the pinhole plus radial model in terms of residual RMS. The number radial distortion of terms required for the fisheye models was lower in all cases, so model complexity was reduced. Independent assessment revealed very similar 3D reconstruction accuracy for all models. The results suggest that fisheye modelling is an advantageous alternative for EWA lens systems.