Schulich School of Engineering

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With an annual average of 25 internationally recognized research chairs, more than 160 faculty members and 1,200 graduate students, the Schulich School of Engineering at the University of Calgary is a powerhouse of research and innovation.

Schulich School of Engineering

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Open Access
10-Gb/s 0.13-um CMOS Inductorless Modified-RGC Transimpedance Amplifier
(IEEE, 2015-07-17) Taghavi, Mohammad Hossein; Belostotski, Leonid; Haslett, James W.; Ahmadi, Peyman
This paper presents an inductorless 0.13-um CMOS TIA structure that is a modified version of a regulated cascode (RGC) TIA. An immittance converter is incorporated to reduce power consumption while increasing ransimpedance gain. Measured 3-dB bandwidth is 7 GHz, sufficient for 10-Gb/s operation, in the presence of 250 fF capacitance at the TIA input, representative of typical CMOS photodiode capacitance. The transimpedance gain of the single-stage TIA is 50 dB, and the group-delay variation is less than ±19 ps over the 3-dB bandwidth. The circuit occupies an active area of 180um x 90um and consumes 7 mW from a 1.5-V supply. The measured average input-referred current noise of the TIA is 31 pA/sqrt(Hz). Simulations and analysis show that the proposed single-stage TIA architecture is capable of achieving improvement in the transimpedance limit over a single-stage RGC TIA designed for the same data rate and the same input photodiode capacitance. A comparison of measurement results to published TIAs also demonstrates the competitive performance of the proposed TIA in terms of the TIA transimpendance gain, bandwidth, area, and power consumption.
Open Access
The ABCs of online course syllabi: Anticipate, build on objectives, and collaborate.
(Magna Publications, 2006-05) Jugdev, Kam; Hutchison, Maureen; Lynes, Shelley
Open Access
Accelerating the GMRES solver with block ILU(k) preconditioner on GPUs in reservoir simulation
(Journal of Geology & Geosciences, 2015) Chen, Zhangxing (John); Liu, H.; Yang, B.
This paper studies the parallelization of the restarted GMRES solver, GMRES (m), and the block ILU (k) preconditioner on GPUs used in petroleum reservoir simulations. The difficulty is how to accelerate this preconditioner with a variable block size. In this paper, parallel solution techniques for block triangular systems are proposed, which work for matrices with an arbitrary block size. These techniques also work with an arbitrary level k for the block ILU (k) preconditioner. Numerical experiments show that the GPU-based linear solver GMRES (m) is much faster than its CPU version.
Open Access
Acoustic subsurface-atomic force microscopy: Three-dimensional imaging at the nanoscale
(2021-01) Sharahi, Hossein J.; Janmaleki, Mohsen; Tetard, Laurene; Kim, Seonghwan; Sadeghian, Hamed; Verbiest, Gerard J.
The development of acoustic subsurface atomic force microscopy, which promises three-dimensional imaging with single-digit nanometer resolution by introduction of ultrasound actuations to a conventional atomic force microscope, has come a long way since its inception in the early 1990s. Recent advances provide a quantitative understanding of the different experimentally observed contrast mechanisms, which paves the way for future applications. In this perspective, we first review the different subsurface atomic force microscope modalities: ultrasonic force microscopy, atomic force acoustic microscopy, heterodyne force microscopy, mode-synthesizing atomic force microscopy, and near-field picosecond ultrasonic microscopy. Then, we highlight and resolve a debate existing in the literature on the importance of the chosen ultrasound excitation frequencies with respect to the resonance frequencies of the cantilever and the observed contrast mechanisms. Finally, we discuss remaining open problems in the field and motivate the importance of new actuators, near-field picosecond ultrasonics, and integration with other techniques to achieve multi-functional non-destructive three dimensional imaging at the nanoscale.
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
Antenna Evaluation for Ultra-WidebandMicrowave Imaging
(Hindawi Publishing Corporation, 2010-02-07) Bourqui, Jeremie; Campbell, Mark A.; Williams, Trevor; Fear, Elise C.
Open Access
Antenna-Array Network Model
(IEEE, 2020-03) De Silva, Supun; Okoniewski, Michal; Belostotski, Leonid
An antenna can be modeled as a two-port network using S-parameters. However, having individual antenna S-parameters is not sufficient for modeling an array of antennas as antennas exhibit mutual coupling. This article proposes a network model to represent an antenna array with mutual coupling. Using the proposed model, an N-element antenna array is modeled as a combination of two-port networks representing each element and an N-port network representing mutual coupling. Two techniques to calculate mutual coupling S-parameters are presented: a primary method using numerical solutions and an approximate method using approximate expressions. The proposed model was validated using four monopole arrays having different inter-element spacings, the number of elements, and non-identical antennas.
Open Access
Application and experimental study of cyclic foam stimulation
(RSC (Royal Society of Chemistry) Advances, 2015-08-27) Chen, Zhangxing (John); Zhang, J.; Wu, X.; Han, G.; Wang, J.; Ren, Z.; Zhang, K.
Formation damage is a serious problem in oil and gas industries. Based on common reservoir damage, the conditions and factors resulting in damage were summarized into four categories in this paper. The worldwide advanced technologies applied in reservoir damage treatment are reviewed. For the first time, we propose the concept of injecting nitrogen foam into a formation to treat the damage caused by sand blocking. An application of Cyclic Foam Stimulation is introduced, which enhances productivity significantly. Experimental apparatus for the Cyclic Foam Stimulation was designed, which included a wellbore vessel that could stimulate the effect of sand setting. A reservoir vessel was also designed to supply the foam. Additionally, in order to simulate the formation damage caused by the size and distribution of fine sand, six artificial cores, which were porosity contrastive and sand producing, were prepared based on the technologies of pressure control and PVA membrane wrapping. The experimental results show that the foam has a good discharging effect on sand blockages. Moreover, the effects of the size and distribution of the fine sand on the porosity was studied. It was found that the smaller the size of the grains and the more uniform the grain distribution, the worse the formation porosity. A porosity recovery factor has been defined and the recovery rate of the porosity was also studied. A scientific guide for the application of Cyclic Foam Stimulation can be generated from the studies in this paper.
Open Access
Application of Extended Vortex Theory for Blade Element Analysis of Horizontal-axis Wind Turbines
(Renewable Energy, 2018) Wood, D.H.
Vortex theory is used in blade element analysis (BEA) of wind turbines to account for the finite number of blades, N, usually in terms of Prandtl's “tip loss function”, F. Wood et al. [1] calculated alternative “trailing vorticity functions” using helical vortex theory. F was found to be inaccurate over the entire blade at low tip speed ratio and in error near the hub at any tip speed ratio. Further, the trailing vorticity function is not constrained to be less than unity as is F. Wood & Okulov [2] analyzed the nonlinear terms in the streamtube equations for angular and axial momentum and found an accurate way of including these in BEA. This paper describes the use of the trailing vorticity functions, which can be different in the axial and azimuthal directions, in an otherwise standard blade element analyses. Comparison is made to wind tunnel tests of model rotors and to calculations using F. There is only a small difference in the calculated power and thrust coefficients. The present calculations show higher induced axial velocities in the tip and hub regions and it is suggested that the trailing vorticity functions can be used in situations where F cannot.
Open Access
Application of simplified numerical and analytical methods for rapid analysis in atmospheric entry vehicle design
(AIAA Conference, 2015) Hinman, William; Johansen, Craig; Wilson, Steven
Selected simplified numerical and analytical methods are applied to flow around hypersonic adiabatic blunt bodies. In particular, selected methods that are well defined in the literature, such as the modified Newton’s method, transformed finite difference grid in the shock layer, and the method of characteristics in the supersonic region, are utilized to solve the flow around an adiabatic circular cylinder at Mach 6. The results are compared to results obtained by numerical simulation of the compressible Navier-Stokes equations. The comparison is used to draw conclusions about the applicability and accuracy of these methods as they apply to low Reynolds number, small radius of curvature bodies such as atmospheric entry vehicles. A minor improvement to the results is proposed by the inclusion of an iterative interaction between the boundary layer displacement thickness, and the external inviscid free-stream.
Open Access
Assessment of Different Sensor Configurations for Collaborative Driving in Urban Environments
(Hindawi, 2013-01-07) Petovello, Mark G.; Basnayake, Chaminda; O'Keefe, Kyle; Wei, Phil
Vehicle-to-vehicle relative navigation of a network of vehicles travelling in an urban canyon is assessed using least-squares and Kalman filtering covariance simulation techniques. Between-vehicle differential GPS is compared with differential GPS augmented with between-vehicle ultrawideband range and bearing measurements. The three measurement types are combined using both least-squares and Kalman filtering to estimate the horizontal positions of a network of vehicles travelling in the same direction on a road in a simulated urban canyon. The number of vehicles participating in the network is varied between two and nine while the severity of the urban canyon was varied from 15-to 65-degree elevation mask angles. The effect of each vehicle’s azimuth being known a priori, or unknown is assessed. The resulting relative positions in the network of vehicles are then analysed in terms of horizontal accuracy and statistical reliability of the solution. The addition of both range and bearing measurements provides protection levels on the order of 2 m at almost all times where DGPS alone only rarely has observation redundancy and often exhibits estimated accuracies worse than 200 m. Reliability is further improved when the vehicle azimuth is assumed to be known a priori.
Open Access
Automated calibration of mobile cameras for 3D reconstruction of mechanical pipes
(Wiley, 2021-04-06) Maalek, Reza; Lichti, Derek D
This manuscript provides a new framework for calibration of optical instruments, in particular mobile cameras, using highly-redundant circular black and white target fields. New methods were introduced for (i) matching targets between images; (ii) adjusting the systematic eccentricity error of target centers; and (iii) iteratively improving the calibration solution through a free-network self-calibrating bundle adjustment. It was observed that the proposed target matching effectively matched circular targets in 270 mobile phone images, taken from a calibration laboratory, with robustness to Type II errors. The proposed eccentricity adjustment, which requires only camera projective matrices from two views, behaved synonymous to available closed-form solutions, which require several additional object space target information a priori. Finally, specifically for the case of the mobile devices, the calibration parameters obtained using our framework was found superior compared to in-situ calibration for estimating the 3D reconstructed radius of a mechanical pipe (approximately 45% improvement on average).
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
Biometric Inverse Problems
(Taylor & Francis/CRC Press, 2005-05-05) Svetlana N. Yanushkevich; Adrian Stoica; Vlad P. Shmerko; Denis V. Popel
Traditional methods of biometric analysis are unable to overcome the limitations of existing approaches, mainly due to the lack of standards for input data, privacy concerns involving use and storage of actual biometric data, and unacceptable accuracy. Exploring solutions to inverse problems in biometrics transcends such limits and allows rich analysis of biometric information and systems for improved performance and testing. Although some particular inverse problems appear in the literature, until now there has been no comprehensive reference for these problems. Biometric Inverse Problems provides the first comprehensive treatment of biometric data synthesis and modeling. This groundbreaking reference comprises eight self-contained chapters that cover the principles of biometric inverse problems; basics of data structure design; new automatic synthetic signature, fingerprint, and iris design; synthetic faces and DNA; and new tools for biometrics based on Voronoi diagrams. Based on the authors' vast experience in the field, the book authoritatively examines new approaches and methodologies in both direct and inverse biometrics, providing invaluable analytical and benchmarking tools. The authors include case studies, examples, and implementation codes for practical illustration of the methods. Loaded with approximately 200 figures, 60 problems, 50 MATLAB® code fragments, and 200 examples, Biometric Inverse Problems sets the standard for innovation and authority in biometric data synthesis, modeling, and analysis.
Open Access
Book review: Implementing virtual teams: Guide to organizational and human factors by A Edwards and J R Wilson
(Pergamon, 2004) Jugdev, Kam
Open Access
Capillary forces between two parallel plates connected by a liquid bridge
(Journal of Porous Media, 2015) Chen, Zhangxing (John); Dejam, M.; Hassanzadeh, H.
Liquid flow between porous and nonporous materials plays an important role in many science and engineering applications such as oil recovery from fractured porous media. The capillary continuity between porous matrix blocks via formation of liquid bridges is a key contributor to the gas−oil gravity drainage mechanism in a gas invaded zone of naturally fractured reservoirs, which increases the height of the continuous liquid column in a fractured formation, thereby enhancing the recovery of oil. However, the role of capillary forces information or break-up of liquid bridges between porous matrix blocks remains a controversial topic. In an attempt to improve an understanding of this problem, a force balance is presented for the concave liquid bridges formed between two horizontal parallel plates. The force balance allows development of a simple model that can be used to find a relationship between the net capillary force, contact angle, and liquid bridge volume. Three different regions including: (I) repulsive net capillary force, (II) attractive net capillary force, and (III) nonexistence regions have been identified. Region I is considered as a region of liquid bridge break-up while Region II is considered as a region of liquid bridge formation. The findings improve an understanding of the formation and break-up of the liquid bridges, which is important in oil recovery from naturally fractured reservoirs during a gravity drainage process.
Open Access
Characterization of Signal Quality Monitoring Techniques for Multipath Detection in GNSS Applications
(2017-07-05) Pirsiavash, Ali; Broumandan, Ali; Lachapelle, Gérard
The performance of Signal Quality Monitoring (SQM) techniques under different multipath scenarios is analyzed. First, SQM variation profiles are investigated as critical requirements in evaluating the theoretical performance of SQM metrics. The sensitivity and effectiveness of SQM approaches for multipath detection and mitigation are then defined and analyzed by comparing SQM profiles and multipath error envelopes for different discriminators. Analytical discussions includes two discriminator strategies, namely narrow and high resolution correlator techniques for BPSK(1), and BOC(1,1) signaling schemes. Data analysis is also carried out for static and kinematic scenarios to validate the SQM profiles and examine SQM performance in actual multipath environments. Results show that although SQM is sensitive to medium and long-delay multipath, its effectiveness in mitigating these ranges of multipath errors varies based on tracking strategy and signaling scheme. For short-delay multipath scenarios, the multipath effect on pseudorange measurements remains mostly undetected due to the low sensitivity of SQM metrics.
Open Access
CO2 Gasification of Sugarcane Bagasse Char: Consideration of Pyrolysis Temperature, Silicon and Aluminum Contents, and Potassium Addition for Recirculation of Char
(2020-11-24) Motta, Ingrid Lopes; Arnold, Ross A.; Lopez-Tenllado, Francisco Javier; Filho, Rubens Maciel; Wolf Maciel, Maria Regina; Hill, Josephine M.
In sugarcane bagasse gasification, char recirculation to the gasifier improves the syngas quality and process efficiency. To determine the effect of char properties on the reaction kinetics, in this work, the pregasification pyrolysis temperature, particle size, and catalyst (potassium) loading were varied. Char samples were prepared at 750–900 °C via pyrolysis and gasified isothermally in a thermogravimetric analysis unit at 850 °C with CO2, and gasification data were modeled using the random pore and extended random pore models. Increasing pyrolysis temperatures did not affect the char morphology and surface composition but did reduce the surface area, as determined by N2 adsorption, decreasing initial gasification rates, and the overall fitted rate constants. Reduction of the particle size via ball milling decreased the time required for complete conversion and changed the shape of the rate versus conversion curves from monotonically decreasing to concave down. The char sample prepared via pyrolysis at 900 °C was an exception, having a maximum rate at ∼10% conversion without ball milling. After ball milling of the char sample prepared at 750 °C, there was an accumulation of ash (Al and Si) on the surface of the particles and a reduction in the surface area, consistent with the ash blocking pores—the porosity in these samples increased during the initial stages (up to ∼20% conversion) of gasification. The gasification behavior was generally well modeled by the extended random pore model. Although the addition of KOH (K/Al mass ratio ∼ 0.2–1.25) enhanced the gasification rates, too much K—from the addition of KOH or after 90% conversion—created mass-transfer limitations resulting in lower gasification rates.
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
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.