This is by a large margin the most serious problem and mistake in conference peer review I have seen in my career. Apparently a many people were aware of this and many could find out who their reviewers were. This probably has created a large number of unnecessary enmities.
@iclr-conf.bsky.social
HIIT Open 2025 programming contest has started!
HIIT Open 2025 programming contest coming on Saturday, 45 contestants in 20 teams competing at Aalto University!
open.hiit.fi
New preprint on arXiv: arxiv.org/abs/2510.25254
We propose two novel improvements to MCMC for Bayesian network structures by speeding up the basic moves and pruning less relevant parent sets, both resulting in one to three orders of magnitude improvements in the running time.
HIIT Open 2025 coming on November 8, the registration form is now open! open.hiit.fi
New papers from the HALT community: 2 x SODA 2025, 2 x NeurIPS 2025, 3 x Asiacrypt 2025, and more!
algorithms.fi/publications/
Our follow-up paper to this, "Improving Decision Trees through the Lens of Parameterized Local Search", with Sommer and Sorge, got accepted to NeurIPS '25! We study the parameterized complexity of improving decision trees by modifying multiple internal nodes simultaneously to avoid local optimas.
Most of the presentation slides from Theory Days now available online: algorithms.fi/theory-days-...
Helsinki Algorithms & Theory Days program is now available online: algorithms.fi/theory-days-...
Helsinki Algorithms & Theory Days on 28–29 August, 2025, keynote talk by Andris Ambainis
algorithms.fi/theory-days-...
Preprint now available on arXiv:
arxiv.org/abs/2305.19673
A directed acyclic graph where the labels of the nodes are elements of the universe and their subsets.
In collaboration with Kseniya Rychkova and Mikko Koivisto, our paper "Quantum Speedups for Bayesian Network Structure Learning" was accepted to UAI 2025.
We show the time complexity of classical algorithms for structure learning to be presumably optimal and give better quantum algorithms.
Illustration of two pruning operations: one where the whole subtree is replaced by a leaf and the other where some subtree is raised to replace its parent.
With colleagues from TU Wien—Frank Sommer, Manuel Sorge, and @szeider.bsky.social—our paper "Optimal Decision Tree Pruning Revisited: Algorithms and Complexity" got accepted to ICML. The paper provides a comprehensive study of parameterized complexity of pruning decision trees to reduce overfitting.
The paper is now available in AISTATS'25 proceedings:
proceedings.mlr.press/v258/harviai...
Today's Frontier Friday material here: algorithms.fi/frontier-fri...
Information on HIIT Frontier Friday now here, next meeting: 14 Mar 2025
algorithms.fi/frontier-fri...
Several directed acyclic graphs whose vertices are partitioned into layers, which are used in dynamic programming.
Our paper "On Tractability of Learning Bayesian Networks with Ancestral Constraints" with Pekka Parviainen was accepted to AISTATS'25 🎉
The paper studies parameterized complexity of structure learning for varying constraints when we can say something about the order of any set of nodes larger than k
