News and events

  • Joshua Mac Intyre Masters Project Presentation: Thursday, November 27, 11:00 AM

    Joshua Mac Intyre, a Master of Science candidate in the Department of Mathematics and Statistics, will virtually present the Masters Research Project titled Nil Clean Group Rings over Metacyclic Groups on Thursday, November 27, 2025 at 11:00 AM.

    The examination committee includes Supervisor Dr. Yuanlin Li and Supervisory Committee Member Dr. Henryk Fukś.

    Students (both graduate and undergraduate) as well as other members of the Brock Community are invited to attend. A Microsoft Teams link to the meeting can be found here: Join the meeting.

    Keywords: Idempotent; group rings; nilpotent; nil clean; Peirce decomposition; Wedderburn-Artin; Metacyclic groups; Fermat numbers

    Abstract:  A ring is called nil clean if each element can be expressed as the sum of an idempotent and nilpotent. This presentation expounds on our work published in Nil clean group rings over metacyclic groups. We will assume at least an undergraduate understanding of group and ring theory but will provide some preliminary information on nil clean rings, group rings, and metacyclic groups. We will justify our comparison between the nil cleanness of ℤ2G, and any group ring RG, where R is a commutative ring and G is a finite group. This comparison will lead to an analysis of ℤ2G, for G up to an order of 20. Then, when considering a nil clean group ring RG over a metacyclic group G, we were able to reduce to the case where G = < a, b | a^{n} = b^{m} = 1, b^{-1}ab = a^{r} >, with m = 2k, n odd, and the center being trivial. We try to break it down a little further to when n is a prime power, calculating n for each m up to 16, and we verify whether most of these candidate group rings are indeed nil clean. Finally, we discuss the results of our investigation and a connection to Fermat numbers.

  • Mathematics and Statistics Seminar Series, Dr. Bernhard Spangl

    Students, faculty, and staff are invited to attend the upcoming event in the Mathematics and Statistics Seminar Series with speaker Dr. Bernhard Spangl on Tuesday, November 11, from 1:00 PM to 2:00 PM.  The talk is entitled Active learning: blending design of experiments and supervised learning


    Abstract

    In this talk I will focus on two research topics: (i) sample size estimation in balanced ANOVA models and (ii) query-by-committee active learning in regression scenarios. Their common aim is to minimize the sample size.

    First, we consider balanced one-way, two-way, and three-way ANOVA models to test the hypothesis that the fixed factor A has no effect. The other factors are fixed or random. We determine the noncentrality parameter for the exact F-test, describe its minimal value by a sharp lower bound, and thus we can guarantee the worst-case power for the F-test. These results allow us to compute the minimal sample size, i.e. the minimal number of experiments needed. Additionally, we provide a structural result for the minimal sample size that we call “pivot” effect (cf. also Spangl et al., 2021).

    Second, we discuss the problem of active learning in regression scenarios. In active learning, the goal is to provide criteria that the learning algorithm can employ to improve its performance by actively selecting data that are most informative. Active learning is usually thought of as being a sequential process where the training set is augmented one data point at a time. We restrict ourselves to a pool-based sampling scenario and investigate a committee-based approach as query strategy for actively selecting instantiations of the input variables x that should be labelled and incorporated into the training set using a real chemometric data set.

     


    Registration link 

    Mathematics and Statistics Seminar Series: Active learning: blending design of experiments and supervised learning with Dr. Bernhard Spangl – ExperienceBU

  • Srushti Desai Masters Project Presentation: Tuesday, November 4, 11:30 AM

    Srushti Dhavalkumar Desai, a Master of Science candidate in the Department of Mathematics and Statistics, will present the Masters Research Project titled Graph-Theoretical Analysis of Resting-State Functional Connectivity in the Human Brain: Weighted vs. Binary Representations on Tuesday, November 4, 2025 at 11:30 AM.

    The examination committee includes Supervisor Dr. William Marshall and Supervisory Committee Member Dr. Xiaojian Xu.

    Students (both graduate and undergraduate) as well as other members of the Brock Community are invited to attend. If you are interested in the presentation, please contact [email protected] for the room location.

    Keywords: Functional connectivity; resting-state fMRI; graph theory; small-world propensity; weighted networks; binary networks; resilience; ADHD

    Abstract: The brain is always active, even during rest, as different regions continuously interact and exchange information. Understanding these patterns of interaction is essential for exploring how the brain functions as a networked system. When regions exhibit consistent and statistically significant coactivation over time, they are considered functionally connected. Functional Magnetic Resonance Imaging (fMRI) allows researchers to study these connections and construct functional connectivity networks. Graph theory provides a powerful framework for analyzing such networks, where brain regions are represented as nodes and their interactions as edges. Through measures such as small worldness, graph analysis can characterize how efficiently information is processed, reflecting networks that are both highly clustered and globally integrated. However, most graph theoretical metrics were originally designed for binary networks, where connections are treated as either present or absent. Preserving the continuous weights of functional connectivity can provide a more nuanced representation of connection strength and potentially yield deeper insights into brain organization. The present study aimed to determine which representation, binary or weighted, better estimates Small World Propensity (SWP), a measure that quantifies how strongly a network exhibits small world characteristics, and to examine whether SWP is associated with resilience, defined as the capacity to adapt and recover from adversity. Results indicated that weighted graphs performed better for dense networks, while selecting appropriate thresholds improved binary representations for sparse networks. No significant relationship was found between resilience and small worldness within the ADHD group, suggesting that small world organization alone may not account for individual differences in resilience in this dataset.

  • Sambavi Arulnandhy Master Thesis Defence: Tuesday, July 15, 2025 at 9:30 AM

    Sambavi Arulnandhy, a Master of Science candidate in the Department of Mathematics and Statistics, will defend the Statistics thesis titled Enhanced EEG Spectral Decomposition with Applications to Neurodevelopmental Changes in ADHD on Tuesday, July 15, 2025 at 9:30 AM.

    The examination committee includes Chair Melanie Pilkington, Supervisor William Marshall, External Examiner (Brock University) Stephen M. Emrich, and Committee Members Jan Vrbik and S. Ejaz Ahmed.

    Students (both graduate and undergraduate) as well as other members of the Brock Community are invited to attend. If you are interested in the presentation, please contact [email protected] for the room location.

    Keywords: ADHD, Aperiodic Activity, Customized Loss Function, EEG Spectral Decomposition, Modified Specparam

    Abstract:
    Aperiodic activity in electroencephalogram (EEG) signals, typically modeled as a 1/f-like trend in the power spectrum, reflects the brain’s excitation-inhibition balance, and provides valuable insights into neurodevelopment and cognitive function. This thesis focuses on two main goals: (a) to propose algorithmic improvements to EEG spectral decomposition methods; and (b) to apply the most effective method to investigate age- and sex-related differences in aperiodic EEG activity among children with and without Attention-Deficit Hyperactivity Disorder (ADHD). A comparative simulation study evaluated four spectral decomposition algorithms — Better Oscillation Detection Method (BOSC), Irregular Resampling Auto-Spectral Analysis (IRASA), Specparam and modified Specparam — on simulated EEG-like signals. BOSC and IRASA consistently underestimated components in multi-peak contexts. Specparam and modified Specparam demonstrated the highest accuracy with the modified version introducing a customized loss function that penalizes localized spectral dips differently than peaks and uses subgradient descent for adaptive fitting. This led to more stable parameter estimates and reduced mean squared error across simulations. The second objective is addressed in a registered report, applying Specparam to resting-state EEG data from the Healthy Brain Network. This study includes children aged 5-18 years, grouped by sex and ADHD diagnosis. Notably, it aims to address the long-standing underrepresentation of girls in ADHD research by analyzing aperiodic EEG activity in both sexes. The aperiodic estimates will be analyzed as functions of age, sex, and ADHD status, controlling for socioeconomic status, IQ, and the use of psychiatric medications. Statistical hypothesis testing will include Analysis of Variance (ANOVA) or non-parametric equivalents, with adjustments for group imbalance. These contributions enhance EEG spectral analysis techniques and offer insights into sex- and age-related neurodevelopmental differences in ADHD.

  • Yujia Luo Masters Paper Presentation: Monday, July 14, 2025 at 2:30 PM

    Yujia Luo, a Master of Science candidate in the Department of Mathematics and Statistics, will present their STAT 5P99 MRP titled Optimal Design of Progressive Stress Loading Accelerated Life Tests under Progressive Type II Censoring on Monday, July 14, 2025 at 2:30 PM online on Microsoft Teams.

    The examination committee includes supervisor Dr. Xiaojian Xu and Supervisory Committee Member Dr. S. Ejaz Ahmed.

    Students (both graduate and undergraduate) as well as other members of the Brock Community are invited to attend. If you are interested in the presentation, please contact Jesse Larone at [email protected] for a link to the team presentation. Please join with microphones and cameras turned off.

    Keywords: Mean Lifetime Estimation, D-optimality, A-optimality, Exponential distribution, Weibull distribution, Robust design, Relative Efficiency

    Abstract:
    In traditional life testing experiments, it is often difficult to observe failures in highly reliable products due to their long lifespans, especially under normal operating conditions.  Accelerated life tests (ALT) is a widely used strategy to obtain sufficient failure data within a shorter period.

    This project focuses on developing optimal and robust designs for ALT using progressive stress loading plans under progressive Type-II censoring.  The underlying lifetime distributions are assumed to be either exponential or Weibull.  Optimal designs are derived based on three different criteria: c*-optimality, D-optimality, and A-optimality.  The resulting designs demonstrate high efficiency.

    However, these optimal designs are only locally optimal, as they depend on unknown parameters that must be estimated.  To address this uncertainty, we adopt a minimax approach to identify robust stress loading rates that minimize the maximum potential loss.  The resulting minimax designs are shown to be robust over a plausible range of parameter values.

  • FMS Undergraduate Research Symposium 2025 (July 31, 3pm-6pm)

    On behalf of the Faculty of Mathematics and Science (FMS), we are pleased to present to you the information below for the 2025 FMS Undergraduate Research Symposium.


    The FMS Undergraduate Research Symposium is back for 2025! For those unfamiliar, the event will consist of a poster session from undergraduate researchers in FMS at Brock. This event is a great opportunity for undergraduate researchers to share their research with the Brock community and develop valuable skills in their career as scientists. We again will be looking for volunteer judges (senior graduate students, staff, and faculty) and invite all undergraduate researchers in FMS to submit a poster.

    The 2025 FMS Undergraduate Research Symposium will take place on July 31 at 3 pm in the Pond Inlet. Refreshments and snacks will be served. All are invited to attend!

    Student Poster Signup (Deadline July 18)https://forms.gle/2ihaMntrYESgqzgQ6

    Judge Volunteer Signup: https://forms.gle/DxioqJz7RWqTJTbD9

    Check out the webpage for other details.


     

    Categories: Events

  • Remembering Professor Thomas Wolf

    The community at Brock University is saddened to learn of the passing of Thomas Wolf, Professor of Mathematics and Statistics.

    Headshot of Thomas Wolf, Brock University Professor of Mathematics

    Wolf was an inspiration to many — students, staff, and faculty alike.

    In addition to his research interests in differential equations and integrability, computer algebra, general relativity, and combinatorial game theory, Wolf had a passion for the computerization of the game Go and organized the Brock Go Club.  He was also actively engaged in various youth outreach and student initiatives, including the Caribou Contests, a mathematics camp, and serving as a judge in the Niagara Science Fair.

    More details about Wolf and his work can be found in the article in Brock News: Professor Thomas Wolf remembered for sharing his love of math – The Brock News

    The Faculty of Mathematics and Science is planning memorial activities in the Fall. Further details to follow.

    Categories: News

  • Department of Mathematics and Statistics Colloquium: Dr. Basil Nanayakkara

    The Department of Mathematics and Statistics invites students, faculty, and staff to attend the upcoming colloquium with speaker Dr. Basil Nanayakkara on Thursday, May 29, from 2:00 PM to 3:00 PM.  The talk is entitled Limits and co-limits: the categorical viewpoint


    Abstract:


    Registration link:  https://experiencebu.brocku.ca/event/295746

     

    Categories: Events

  • Our Muller Learning Centre in the Newsletters of the International Commission on Mathematical Instruction!

    Congratulations again to our colleague, Professor Emeritus Eric Muller, whose outstanding contributions and commitment in mathematics education were recognized through renaming our Math & Stats Learning Centre after him, and now mentioned in the Newsletter of the International Commission on Mathematical Instruction, published on March 15, 2025:

    Math Learning Centre named after Professor Eric R. Muller

    It may be rather rare nowadays that a university room be named after a person, not in gratitude for a generous financial donation—however important these may be in the life of universities—, but as a tribute to academic excellence and dedication.  Such an event occurred recently at Brock University (Canada), when the Learning Centre of the Department of Mathematics and Statistics became the “Eric Muller Math & Stats Learning Centre”.

     

    Read the full article here.

    Read about Professor Emeritus Eric Muller here.

     

    Categories: News

  • Kamran Asgari Masters Thesis Defence Thursday, January 9th, 9:30 AM

    Kamran Asgari, a Master of Science candidate in the Department of Mathematics and Statistics, will present their Masters Thesis titled Evaluation of Bayesian Networks in Soil Moisture Prediction on Thursday, January 9th, 2025 at 9:30 AM online in-person on campus.

    The examination committee includes supervisors Georgii Nikonov, Chair; Pouria Ramazi, Supervisor; Kelly Biagi, External Examiner (Brock University); and William Marshall and Xiaojian Xu, Committee Members

    Students (both graduate and undergraduate) as well as other members of the Brock Community are invited to attend. If you are interested in attending the presentation, please contact Neil Marshall at [email protected] for the room location.