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
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
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
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
Cooperative Spectrum Sensing Algorithm in Cognitive Radio By Simultaneous Sensing and BER Measurements
(EURASIP Journal on Wireless Communications and Networking, 2016-05-09) Lu, Yingqi; Wang, Donglin; Fattouche, Michel
This paper considers spectrum utilization, the probability of detection in cognitive radio (CR) model based on cooperative spectrum sensing with both simultaneous adaptive sensing and transmission at a transmitting secondary user (TSU), and the bit error rate (BER) detection with variation checking at a receiving user (RSU). In this paper, a novel detecting model is proposed in the being considered scenario for the full-duplex TSU's simultaneous sensing and transmitting. A spectrum sensing scheme with an adaptive sensing window is designed to improve the spectrum utilization with a high SNR. At RSU, the BER variation is used further to detect whether a PU is active or not. Data fusion based on the proposed adaptive sensing scheme and the BER detection is processed for better decision on the spectrum holes. Simulation results show that i) simultaneous spectrum sensing with an adaptive window improves the spectrum utilization compared with a periodical sensing; ii) cooperative spectrum sensing with the BER-assisted detection improves the probability of detection and spectrum utilization compared with the single simultaneous sensing at TSU.
Open Access
Evaluation of Dynamic Time Warp Barycenter Averaging (DBA) for its Potential in Generating a Consensus Nanopore Signal for Genetic and Epigenetic Sequences
(IEEE, 2018-07) Chan, Rachel; Gordon, Paul M. K.; Smith, Michael Richard
Epigenetics is a chemical modification to DNA without changes in the base sequence. While it is known that epigenetic modifications have far reaching implications on how genes are expressed, it is difficult to identify what the modification is or where it can be found. A next-generation method of sequencing called nanopore sequencing may be the solution. Nanopore sequencing runs a voltage bias across the DNA sequence and outputs a unique electric response to each genetic unit. Epigenetic modifications may then be identified by their distinct electric response. In this paper we provide preliminary results of applying dynamic time warp Barycenter Averaging (DBA) to multiple noisy nanopore streams to generate a consensus signal that can be used to identify genetic sequences and their modifications. DBA convergence rates, time complexity, together with qualitative and quantitative metrics to compare the consensus signal with gold standards are evaluated.
Open Access
Evaluation of Tuner-Based Noise-Parameter Extraction Methods for Very Low Noise Amplifiers
(IEEE : New York, New York, 2010-01-13) Belostotski, Leonid; Haslett, James W.
This paper compares the performance of source-tuner noise-parameter extraction methods used to measure noise parameters of low-noise amplifiers that have very low (1 dB) noise figures. The methods discussed are known as the Cold method and the modified Y-factor method (or Hot-Cold method). The paper describes equations used in the extraction algorithms. In a Monte Carlo analysis by randomly adding various sources of uncertainties to "measurements," created with a computer simulation, performances of the noise parameter extraction methods are compared. It is shown that the iterative Cold method and the direct Cold method are the best at extracting Rn and Gamma_opt noise parameters in terms of lowest standard deviation and close proximity of the extracted mean values to the true values. The simplified Cold method, used in a number of commercial systems, has largest systematic offsets in extracted noise parameters while being the quickest to perform. The modified Y-factor method is the slowest to perform due to additional time required for hot measurements. This method is marginally the most accurate to extract F min . These conclusions are also supported with measurement results. This study assembles in one place necessary theoretical background information to serve as a reference for those who are working in the field of noise parameter extraction using tuner-based methods.
Open Access
Evolution Surfaces for Spatiotemporal Visualization of Vortex Features
(2019-09-10) Ferrari, Simon; Hu, Yaoping; Martinuzzi, Robert John
Turbulent fluid flow data is often 4-dimensional (4D), spatially and temporally complex, and requires specific techniques for visualization. Common visualization techniques neglect the temporal aspect of the data, limiting the ability to convey feature motion or offering the user a complicated visualization. To remedy this, we present an approach – evolution surfaces – focused on the spatiotemporal rendering of user-selected flow features (i.e., vortices). By abstracting the spatial representation of these features, the approach renders their spatiotemporal behavior with reduced visual complexity. The behavior of vortex features are presented as surfaces, with textures indicating properties of motion and evolution events (e.g., bifurcation and amalgamation) represented by the surface topology. We evaluated the approach on two datasets generated from empirical measurement and computational simulation (Re = 28000 and Re = 1200 respectively). Our approach’s focus on handling evolution events makes it capable of visualizing higher Reynolds number (Re) flows than other surface-based techniques. This approach has been assessed by fluid dynamicists to assert the validity for flow analysis. Evolution surfaces offer a compact visualization of spatiotemporal vortex behaviors, opening potential avenues for exploration and analysis of fluid flows.
Open Access
A Hybrid RSS/TOA Method for 3D Positioning in an Indoor Environment
(Hindawi Publishing Corporation, 2011-11-21) Tiwari, Smita; Wang, Donglin; Fattouche, Michel; Ghannouchi, Fadhel
Open Access
Identifying Appropriate Dynamic Time Warping, DTW, Metrics to Evaluate the Quality of Vocoder Time-Stretched Speech Phrases
(IEEE, 2018-07) Tanaka, Mai; Smith, Michael Richard
To improve comprehension in a noisy environment, we suggest sending short speech phrases slowed by a phase vocoder directly to seniors’ hearing aids. Dynamic time warping, DTW, metrics for evaluating the speech quality of vocoder modified phrases are compared.
Open Access
Implementation of General Dispersive Anisotropic Materials in Lebedev FDTD
(IEEE, 2018-09-17) Salmasi, Mahbod; Potter, Michael E.; Okoniewski, Michal M.
A variant of the finite-difference time-domain (FDTD) algorithm - the Lebedev FDTD method - is augmented to allow for the simulation of electromagnetic waves in general dispersive anisotropic materials. Distinct dispersions may be applied to each of the principal axes of the anisotropic medium. The method is based on the auxiliary differential equation (ADE) and is simple to implement. Because of the collocated nature of the algorithm, multiterm dispersions necessary in previous implementations are avoided. Lebedev grid has previously been studied in detail by different research groups for simulation of anisotropy. In this work, we specifically focus on extending frequency dispersive materials to this method, and provide multiple examples to demonstrate the accuracy, validity and stability of the method.
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
Multicarrier code for the next-generation GPS
(Springer Open, 2012-05-31) Wang, Donglin; Fattouche, Michel; Ghannouchi, Fadhel
Open Access
A Multilevel Congestion-Based Global Router
(Hindawi Publishing Corporation, 2009-09-02) Rakai, Logan; Behjat, Laleh; Areibi, Shawki; Terlaky, Tamas
Open Access
A New Length-Based Algebraic Multigrid Clustering Algorithm
(Hindawi Publishing Corporation, 2012-02-25) Rakai, Logan; Farshidi, Amin; Behjat, Laleh; Westwick, David
Open Access
A Novel Ranking Method Based on Subjective Probability Theory for Evolutionary Multiobjective Optimization
(Hindawi Publishing Corporation, 2011-07-21) Wei, Shuang; Leung, Henry
Open Access
A Prototype System for Measuring Microwave Frequency Reflections from the Breast
(Hindawi Publishing Corporation, 2012-01-16) Bourqui, Jeremie; Sill, Jeff; Fear, Elise
Open Access
A Replicated Survey of Software Testing Practices in the Canadian Province of Alberta: What has Changed from 2004 to 2009?
(2010) Garousi, Vahid; Varma, Tan
Software organizations have typically de-emphasized the importance of software testing. In an earlier study in 2004, our colleagues reported the results of an Alberta-wide regional survey of software testing techniques in practice. Five years after that first study, the authors felt it is time to replicate the survey and analyze what has changed and what not from 2004 to 2009. This study was conducted during the summer of 2009 by surveying software organizations in the Canadian province of Alberta. The survey results reveal important and interesting findings about software testing Practices in Alberta, and point out what has changed from 2004 to 2009 and what not. Note that although our study is conducted in the province of Alberta, we have compared the results to few international similar studies, such as the ones conducted in the US, Turkey, Hong Kong and Australia, The study should thus be of interest to all testing professionals world-wide. Among the findings are the followings: (1) Almost all companies perform unit and system testing with a slight increase since 2004, (2) Automation of unit, integration and systems tests has increased sharply since 2004, (3) More organization are using observations and expert opinion to conduct usability testing, (4) The choices of test-case generation mechanisms have not changed much from 2004, (5) JUnit and IBM Rational tools are the most widely used test tools, (6) Alberta companies still face approximately the same defect-related economic issues as do companies in other jurisdictions, (7) Alberta software firms have improved their test automation capability since 2004, but there is still some room for improvement, and (8) Compared to 2004, more companies are spending more effort on pre-release testing.
Open Access
Semiautomated Multimodal Breast Image Registration
(Hindawi Publishing Corporation, 2011-10-20) Curtis, Charlotte; Frayne, Richard; Fear, Elise