Department of Computer Science

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Recent Submissions

Now showing 1 - 5 of 41
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    Stainless steel electrochemical capacitive microneedle sensors for multiplexed simultaneous measurement of pH, nitrates, and phosphates
    (2022) Mugo, Samuel; Lu, Weihao; Lemieux, Stephane
    Concerns for agri-food safety and environmental management require development of simple to use and cost- and time effective multiplex sensors for point-of-need (PON) chemical analytics by public end-user. Simultaneous detection of nitrates, phosphates, and pH is of importance in soil and water analysis, agriculture, and food quality assessment. This article demonstrates a suite of stainless steel microneedle electrochemical sensors for multiplexed measurement of pH, nitrate, and phosphate using faradaic capacitance derived from cyclic voltammetry as the mode of detection. The multi-target microneedle sensors were fabricated by layer-by-layer (LbL) assembly in a stainless steel hypodermic microneedle substrate. For nitrate sensing, the stainless steel was coated with carbon nanotube/cellulose nanocrystal (CNT)/CNC) decorated with silver nanoparticles (Ag). For pH measurement, the polyaniline (pANI) was coated onto the CNT/CNC@Ag film, while for phosphate detection, the CNT/CNC/Ag @pANI microneedle was further decorated with ammonium molybdenum tetrahydrate (AMT). The microelectrode platforms were characterized by FTIR, Raman, and microscopic techniques. The nitrate- and phosphate-based microneedle electrochemical sensors had excellent selectivity and sensitivity, with a determined limit of detection (LOD) of 0.008 mM and 0.007 mM, respectively. The pH microneedle sensor was responsive to pH in the linear range of 3–10. The three microneedle sensors yielded repeatable results, with a precision ranging from 4.0 to 7.5% RSD over the concentration ranges tested. The inexpensive (~ 1 $ CAD) microneedle sensors were successfully verified for use in quantification of nitrate, pH, and phosphate in brewed black coffee as a real sample. As such, the microneedle sensors are economical devices and show great promise as robust platforms for PON precision chemical analytics.
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    User testing for serious game design: improving the player experience
    (2022) Shaw, Ross; Sperano, Isabelle; Andruchow, Robert; Cobzas, Dana
    This case study reflects on our use of user testing during a research project in which we designed a serious video game, “Life on the Edge.” The target audience of the game is first-year post-secondary biology students. As we designed the game, user testing was a critical component that allowed us to identify issues. Any issues that interfere with the flow or enjoyment of a video game can be distracting to players. In what follows, we will describe the research design and discuss the processes for testing a serious video game that will allow you to identify game issues successfully. How you recruit participants, test players, and prioritize player feedback is a component of effective user testing and improving your game. With user testing, we were able to identify problems in the game, prioritize them, and address them. By using variable user testing methods, you can adapt to the changing needs of your game project and develop a successful serious video game.
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    Novikov groups are right-orderable
    (2022) Lemieux, Stephane
    Novikov groups were introduced as examples of finitely presented groups with unsolvable conjugacy problem. It was Bokut who showed that each Novikov group has a standard basis and thus a solvable word problem. Further, he showed that for every recursively enumerable degree of unsolvability d there is a Novikov group whose conjugacy problem is of degree d. In the present work, we show that Novikov groups are also right-orderable, thus exhibiting the first known examples of finitely presented right-orderable groups with solvable word problem and unsolvable conjugacy problem.
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    Breach path detection reliability in energy harvesting wireless sensor networks
    (2021) Abougamila, Salwa; Elmorsy, Mohammed; Elmallah, Ehab S.
    In this paper, we consider reliability assessment of energy harvesting wireless sensor networks (EH-WSNs) deployed to guard a geographic area against intruders that can enter and exit the network through a known set of entry-exit perimeter sides. To handle energy fluctuations during different time slots, a node may reduce its transmission power. Using a probabilistic graph model, we formalize a problem denoted EH-BPDREL (for breach path detection reliability). The problem calls for estimating the likelihood that any such intrusion can be detected and reported to a sink node. Due to the hardness of the problem, bounding algorithms are needed. We devise an efficient algorithm to solve a core problem that facilitates the design of various lower bounding algorithms. We obtain numerical results on the use of Monte Carlo simulation to estimate the probabilistic graph parameters, and illustrate the use of our devised algorithm to bound the solutions.
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    Artificial intelligence approaches to build ticket to ride maps
    (2022) Smith, Iain; Anton, Calin
    Fun, as a game trait, is challenging to evaluate. Previous research explores game arc and game refinement to improve the quality of games. Fun, for some players, is having an even chance to win while executing their strategy. To explore this, we build boards for the game Ticket to Ride while optimizing for a given win rate between four AI agents. These agents execute popular strategies human players use: one-step thinking, long route exploitation, route focus, and destination hungry strategies. We create the underlying graph of a map by connecting several planar bipartite graphs. To build the map, we use a multiple phase design, with each phase implementing several simplified Monte Carlo Tree Search components. Within a phase, the components communicate with each other passively. The experiments show that the proposed approach results in improvements over randomly generated graphs and maps.