Publications (20)
The Commuting Graph of a Solvable A-Group
Rachel Carleton, Mark Lewis
Let be a finite group. Recall that an -group is a group whose Sylow subgroups are all abelian. In this paper, we investigate the upper bound on the diameter of the commuting…
Variable Reduction For Quadratic Unconstrained Binary Optimization
Amit Verma, Mark Lewis
Quadratic Unconstrained Binary Optimization models are useful for solving a diverse range of optimization problems. Constraints can be added by incorporating quadratic penalty term…
Negative density-dependent dispersal of the mountain pine beetle in Alberta
Evan C. Johnson, Mark Lewis
Understanding the mountain pine beetle's dispersal patterns is critical for evaluating its threat to Canada's boreal forests. It is generally believed that higher beetle densities…
Material Around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation
Amanda A. Sickafoose, Stephen E. Levine, Amanda S. Bosh +5
A stellar occultation of Gaia DR3 2646598228351156352 by the Centaur (2060) Chiron was observed from the South African Astronomical Observatory on 2018 November 28 UT. Here we pres…
A hypothesis-free bridging of disease dynamics and non-pharmaceutical policies
Xiunan Wang, Hao Wang, Pouria Ramazi +2
Accurate prediction of the number of daily or weekly confirmed cases of COVID-19 is critical to the control of the pandemic. Existing mechanistic models nicely capture the disease…
Efficient QUBO transformation for Higher Degree Pseudo Boolean Functions
Amit Verma, Mark Lewis, Gary Kochenberger
Quadratic Unconstrained Binary Optimization (QUBO) is recognized as a unifying framework for modeling a wide range of problems. Problems can be solved with commercial solvers custo…
Subgroups of Division Rings
Mark Lewis, Murray Schacher
We investigate the finite subgroups that occur in the Hamiltonian quaternion algebra over the real subfield of cyclotomic fields. When possible, we investigate their distribution a…
Liquid marbles as thermally robust droplets: coating-assisted Leidenfrost-like effect
Cedric Aberle, Mark Lewis, Gan Yu +2
The Leidenfrost effect-prolonged evaporation of droplets on a superheated surface-happens only when the surface temperature is above a certain transitional value. Here, we show tha…
Granite Code Models: A Family of Open Foundation Models for Code Intelligence
Mayank Mishra, Matt Stallone, Gaoyuan Zhang +43
Large Language Models (LLMs) trained on code are revolutionizing the software development process. Increasingly, code LLMs are being integrated into software development environmen…
Logical and Inequality Implications for Reducing the Size and Complexity of Quadratic Unconstrained Binary Optimization Problems
Fred Glover, Mark Lewis, Gary Kochenberger
The quadratic unconstrained binary optimization (QUBO) problem arises in diverse optimization applications ranging from Ising spin problems to classical problems in graph theory an…
Constraint Programming to Discover One-Flip Local Optima of Quadratic Unconstrained Binary Optimization Problems
Amit Verma, Mark Lewis
The broad applicability of Quadratic Unconstrained Binary Optimization (QUBO) constitutes a general-purpose modeling framework for combinatorial optimization problems and are a req…
Expansion under climate change: the genetic consequences
Jimmy Garnier, Mark Lewis
Range expansion and range shifts are crucial population responses to climate change. Genetic consequences are not well understood but are clearly coupled to ecological dynamics tha…
Quadratic Unconstrained Binary Optimization Problem Preprocessing: Theory and Empirical Analysis
Mark Lewis, Fred Glover
The Quadratic Unconstrained Binary Optimization problem (QUBO) has become a unifying model for representing a wide range of combinatorial optimization problems, and for linking a v…
QUBO transformation using Eigenvalue Decomposition
Amit Verma, Mark Lewis
Quadratic Unconstrained Binary Optimization (QUBO) is a general-purpose modeling framework for combinatorial optimization problems and is a requirement for quantum annealers. This…
A Characterization of the Prime Graphs of Solvable Groups
Alexander Gruber, Thomas Keller, Mark Lewis +2
Let Ï(G) denote the set of prime divisors of the order of a finite group G. The prime graph of G is the graph with vertex set Ï(G) with edges {p,q} if and only if there exists an…
On impulsive reaction-diffusion models in higher dimensions
Mostafa Fazly, Mark Lewis, Hao Wang
Assume that denotes the density of the population at a point at the beginning of the reproductive season in the th year. We study the following impulsive reaction-d…
From policy to prediction: Forecasting COVID-19 dynamics under imperfect vaccination
Xiunan Wang, Hao Wang, Pouria Ramazi +2
Understanding the joint impact of vaccination and non-pharmaceutical interventions on COVID-19 development is important for making public health decisions that control the pandemic…
Goal Seeking Quadratic Unconstrained Binary Optimization
Amit Verma, Mark Lewis
The Quadratic Unconstrained Binary Optimization (QUBO) modeling and solution framework is a requirement for quantum and digital annealers. However optimality for QUBO problems of a…
Positivity and global existence for nonlocal advection-diffusion models of interacting populations
Valeria Giunta, Thomas Hillen, Mark Lewis +1
In this paper we study a broad class of non-local advection-diffusion models describing the behaviour of an arbitrary number of interacting species, each moving in response to the…
Robust Optimization of Unconstrained Binary Quadratic Problems
Mark Lewis, Gary Kochenberger, John Metcalfe
In this paper we focus on the unconstrained binary quadratic optimization model, maximize x^t Qx, x binary, and consider the problem of identifying optimal solutions that are robus…