Alexander Howse will defend his PhD thesis (September 29, 2017)

posted Aug 29, 2017, 4:32 AM by Hans De Sterck   [ updated Aug 29, 2017, 4:33 AM ]

Waterloo PhD student Alexander Howse will defend his PhD thesis on "Nonlinear Preconditioning Methods for Optimization and Parallel-In-Time Methods for 1D Scalar Hyperbolic Partial Differential Equations" on September 29, 2017.

John Lang defends his PhD thesis (July 8, 2016)

posted Jul 17, 2016, 4:10 PM by Hans De Sterck   [ updated Jul 17, 2016, 4:11 PM ]

Waterloo PhD student John Lang successfully defended his PhD thesis "Mathematical Modelling of Social Factors in Decision Making Processes at the Individual and Population Levels" on July 8, 2016. Congrats, John!

February 2016: Postdoctoral Position, Scalable Solvers for CFD on Adaptive Grids

posted Feb 24, 2016, 6:50 PM by Hans De Sterck

Candidates are sought for a Postdoctoral Research Fellow Position at the School of Mathematical Sciences, Monash University, Melbourne, Australia.

The position focuses on developing novel numerical methods and software for parallel simulation of compressible fluids on adaptive grids. Specific research topics of interest include parallel linear and nonlinear solvers for high-order accurate implicit time integration, and parallel adaptive grid refinement with error estimation. The fellow will be supervised by Professor Hans De Sterck, in a project that involves collaboration with Professor Clinton Groth from the University of Toronto.

We are looking for accomplished candidates with a PhD in applied/computational mathematics, mechanical/aerospace engineering, or computational science, and with specialization in one or more of numerical methods for PDEs (hyperbolic conservation laws), scalable solvers, or computational fluid dynamics.  Experience with parallel programming in C++ is desirable. This is one of two postdoctoral positions in an interdisciplinary project on "Advanced Simulation Methods for the Coupled Solar Interior and Atmosphere". The second postdoctoral fellow will use the advanced simulation techniques developed in the project to address challenging questions in the area of wave propagation in the solar interior and atmosphere.

Monash University is a leading Australian research university that ranks in the top-100 globally. Monash University is located in Melbourne, which is a major cosmopolitan centre and has been named the world's most liveable city for five years in a row. This postdoctoral position is for two years, with an intended start date between June and September 2016 (negotiable). The annual salary is approximately A$80,000.

For more information and to apply online, please visit

The closing date for applications is 31 March 2016.

Please contact with any questions.

Monash Workshop on Numerical PDEs, 15-19 Feb, 2016

posted Jan 30, 2016, 4:28 PM by Hans De Sterck   [ updated Feb 9, 2016, 10:17 PM ]

The schedule is now available for the first "Monash Workshop on Numerical PDEs" that Jerome Droniou and Hans De Sterck are organizing at Monash University's School of Mathematical Sciences on February 15-19 2016.

The program includes 9 exciting invited presentations from international experts in the field, and about 20 contributed presentations.

Our paper on population-level modeling of the smoking epidemic appears in BMC Public Health

posted Dec 24, 2015, 3:26 PM by Hans De Sterck   [ updated Dec 24, 2015, 3:27 PM ]

'The influence of societal individualism on a century of tobacco use: modelling the prevalence of smoking' by 
John Lang, Daniel Abrams, and Hans De Sterck has just appeared in BMC Public Health. [arXiv link] [online version (open access)] We find evidence that adoption and cessation of smoking are influenced by societal individualism/collectivism.

Submitted Paper: A New Line Search Speeds Up LBFGS for Parallel Logistic Regression in Spark

posted Oct 31, 2015, 6:09 AM by Hans De Sterck   [ updated Jan 20, 2016, 1:36 AM ]

Accepted for SIAM Data Mining conference 2016 - We submitted "A polynomial expansion line search for large-scale unconstrained minimization of smooth L2-regularized loss functions, with implementation in Apache Spark" (Hynes and De Sterck). See

Our new line search uses a simple polynomial expansion idea, but for smooth objective functions (like logistic regression) it makes the line search more accurate than commonly used approaches, which decreases the number of iterations required by LBFGS and leads to speed-up in parallel of 30% and more.
Speed-up as a function of accuracy.
(This figure shows speedup as a function of accuracy for some large problems on 16 nodes/256 cores.)

SIAM News Article on "Data Science and How to Teach It"

posted Oct 10, 2015, 9:48 PM by Hans De Sterck   [ updated Oct 10, 2015, 9:49 PM ]

I wrote a SIAM News Article with Chris Johnson on Data Science, and How to Teach It. The data revolution is shaping up to become one of the great new quantitative endeavours of our time, and, as in all quantitative fields, mathematics is poised to play an important role. We make the point that there are important synergies between data science and computational science, which make it clear that educational programs in areas like “computational and data science” or “mathematics of data and computation” hold significant promise for interdisciplinary success.

Submitted Paper: Accelerating Distributed Big Data Recommendation in Spark

posted Sep 3, 2015, 9:55 PM by Hans De Sterck   [ updated Dec 24, 2015, 3:06 PM ]

Best Paper Award at ICPADS 2015! - We submitted "Algorithmic Acceleration of Parallel ALS for Collaborative Filtering: Speeding up Distributed Big Data Recommendation in Spark" (Winlaw, Hynes, Caterini, De Sterck). See

Great teamwork: Anthony did the initial investigations as an undergraduate researcher, Manda did the detailed serial tests, and Mike did the distributed Spark implementation.

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