Optimization
R. Bardenet,
M. Brendel, B. Kégl, and M. Sebag
Collaborative
hyperparameter tuning
In International Conference on Machine Learning, June 2013.
We simultaneously tune hyperparameters of a given algorithm on several data sets with a surrogate-based ranking and optimization technique.
Ouassim
Ait Elhara, Anne Auger, and Nikolaus Hansen
A median success rule for
non-elitist evolution strategies: Study of feasibility
In Proceedings of the Genetic and Evolutionary Computation Conference,
GECCO. ACM, 2013.
(PDF)
Success rule based step-size adaptation, namely the one-fifth success rule, has shown to be effective for single parent evolution strategies (ES), e.g. the (1+1)-ES. The success rule remains feasible in non-elitist single parent strategies, where the target success rate must be roughly inversely proportional to the population size. This success rule is, however, not easily applicable to multi-parent strategies. In this paper, we introduce the idea of median success adaptation for the step-size, applicable to non-elitist multi-recombinant evolution strategies. In median success adaptation, the median fitness of the population is compared to a fitness from the previous iteration. The comparison fitness is chosen to achieve a target success rate of 1/2, thereby a deviation from the target can be measured robustly in a few iteration steps. As a prerequisite for feasibility of the median success rule, we studied the way the comparison index depends on the search space dimension, the population size, the parent number, the recombination weights and the objective function. The findings are encouraging: the choice of the comparison index appears to be relatively uncritical and experiments on a variety of functions, also in combination with CMA, reveal reasonable behavior.
Youhei
Akimoto, Anne Auger, and Nikolaus Hansen
Convergence of the continuous time trajectories of isotropic evolution
strategies on monotonic cal C2-composite functions
In Carlos A. Coello Coello, Vincenzo Cutello, Kalyanmoy
Deb, Stephanie Forrest, Giuseppe Nicosia, and Mario Pavone, editors, Parallel Problem Solving from Nature - PPSN XII, Volume 7491 of Lecture Notes in Computer Science, pages 42–51. Springer,
2012.
Alexandre Chotard, Anne Auger, and Nikolaus Hansen
Cumulative step-size adaptation on linear functions
In Carlos A. Coello Coello, Vincenzo Cutello, Kalyanmoy
Deb, Stephanie Forrest, Giuseppe Nicosia, and Mario Pavone, editors, Parallel Problem Solving from Nature - PPSN XII, Volume 7491 of Lecture Notes in Computer Science, pages 72–81. Springer,
2012.
L. Arnold, A. Auger, N. Hansen, and
Y. Ollivier
Information-geometric optimization
algorithms: A unifying picture via invariance principles
ArXiv e-prints, June 2011.
We present a canonical way to turn any smooth parametric family of probability distributions on an arbitrary search space into a continuous-time black-box optimization method, the information-geometric optimization (IGO) method. Invariance as a major design principle keeps the number of arbitrary choices to a minimum. The resulting IGO flow, defined as the flow of an ordinary differential equation, conducts a natural gradient ascent using an adaptive, time-dependent transformation of the objective function, and makes no particular assumptions on the objective function to be optimized. The IGO method produces through time discretization explicit IGO algorithms and naturally recovers versions of known algorithms.
J. Bergstra,
R. Bardenet, B. Kégl, and Y. Bengio
Algorithms for
hyper-parameter optimization
In Advances in Neural Information Processing Systems, Volume 24.
The MIT Press, Dec. 2011.
We optimize hyper-parameters using random search and two new greedy sequential methods based on the expected improvement criterion, and compare the methods on tasks of training neural networks and deep belief networks.
Nikolaus
Hansen
Injecting external solutions into
CMA-ES
Technical Report RR-7748, INRIA, October 2011.
(PDF)
Inference
R. Bardenet,
O. Cappé, G. Fort, and B. Kégl
Adaptive MCMC with online relabeling
Bernoulli, 2014.
A. Roodaki,
R. Bardenet, O. Cappé, and B. Kégl
Detection and estimation of high energy physical particles using Monte
Carlo methods
Brest, France, September 2013.
R. Bardenet,
O. Cappé, G. Fort, and B. Kégl
Adaptive
Metropolis with online relabeling
In International Conference on Artificial Intelligence and
Statistics, Volume 22, pages 91–99, Apr. 2012.
We propose a novel adaptive MCMC algorithm named AMOR for efficiently simulating from permutation-invariant targets occurring in, for example, Bayesian analysis of mixture models.
R. Bardenet,
B. Kégl, and G. Fort
Relabelling MCMC algorithms in Bayesian mixture learning
In Snowbird Learning Workshop, 2011.
R. Bardenet and
B. Kégl
An adaptive
Monte-Carlo Markov chain algorithm for inference from mixture
signals
Journal of Physics: Conference Series, 368(1):012044, 2012.
We describe adaptive Metropolis with online relabeling (AMOR) for modeling mixture signals and illustrate the algorithm on a synthetic mixture model inspired by the muonic water Cherenkov signal of the surface detectors in the Pierre Auger Experiment.
Discriminative learning
E. Kaufmann,
O. Cappé, and A. Garivier
On the complexity of best arm identification in multi-armed bandit
models.
E. Kaufmann,
O. Cappé, and A. Garivier
On the complexity of A/B testing
In COLT, Barcelona, Spain, June 2014.
B. Kégl
Correlation-based
construction of neighborhood and edge features
In International Conference on Learning Representations (workshop
track), 2014.
Motivated by an abstract notion of low-level edge detector filters, we propose a simple method of unsupervised feature construction based on pairwise statistics of features. In the first step, we construct neighborhoods of features by regrouping features that correlate. Then we use these subsets as filters to produce new neighborhood features. Next, we connect neighborhood features that correlate, and construct edge features by subtracting the correlated neighborhood features of each other.
R. Busa-Fekete,
B. Kégl, T. Éltető, and Gy. Szarvas
Tune and mix:
learning to rank using ensembles of calibrated multi-class
classifiers
Machine Learning Journal, 93(2):261–292, 2013.
We show that a point-wise ranking approach (based on multi-class classification, calibration, and mixing models) is competitive to more complex pairwise and listwise methods, especially on large sets. Our extensive experimental study is itself an important contribution: we compare most of the existing learning-to-rank techniques on all of the available large-scale benchmark data sets using a standardized implementation of the NDCG score.
B. Szörényi,
R. Busa-Fekete, I. Hegedüs, R. Ormándi, M. Jelasity, and
B. Kégl
Gossip-based distributed stochastic bandit algorithms
In International Conference on Machine Learning, June 2013.
R. Busa-Fekete,
B. Kégl, T. Éltető, and Gy. Szarvas
An apple-to-apple comparison of learning-to-rank algorithms in terms of
Normalized Discounted Cumulative Gain
In ECAI Workshop on Preference Learning, August 2012.
I. Hegedüs,
R. Busa-Fekete, R. Ormándi, M. Jelasity, and B. Kégl
Peer-to-peer multi-class boosting
In International European Conference on Parallel and Distributed
Computing, pages 389–400, June 2012.
D. Benbouzid,
R. Busa-Fekete, and B. Kégl
Fast
classification using sparse decision DAGs
In International Conference on Machine Learning, Volume 29, June
2012.
We build sparse decision DAGs (directed acyclic graphs) from a list of base classifiers using an MDP. Each instance can decide to use or to skip each base classifier, based on the current state of the classifier being built. The algorithm clearly outperforms state-of-the-art cascade detectors. It is also readily applicable for multi-class classification.
D. Benbouzid,
R. Busa-Fekete, N. Casagrande, F.-D. Collin, and B. Kégl
Multiboost: a
multi-purpose boosting package
Journal of Machine Learning Research, 13:549–553, 2012.
The MultiBoost package provides a fast C++ implementation of multi-class/multi-label/multi-task boosting algorithms. It is based on AdaBoost.MH but it also implements popular cascade classifiers and FilterBoost. The package contains common multi-class base learners (stumps, trees, products, Haar filters). Further base learners and strong learners following the boosting paradigm can be easily implemented in a flexible framework.
D. Benbouzid,
R. Busa-Fekete, N. Casagrande, F.-D. Collin, and B. Kégl
Multiboost: the software, 2011.
D. Benbouzid,
R. Busa-Fekete, and B. Kégl
MDDAG:
learning deep decision DAGs in a Markov decision process
setup
In NIPS 2011 Workshop on Deep Learning and Unsupervised Feature
Learning, 2011.
We show how to build sparse decision DAGs (directed acyclic graphs) out of a list of features or base classifiers. The basic idea is to cast the DAG design task as a Markov decision process.
R. Busa-Fekete,
B. Kégl, T. Éltető, and Gy. Szarvas
A robust ranking
methodology based on diverse calibration of AdaBoost
In European Conference on Machine Learning, Volume 22, pages
263–279, 2011.
We show that a simple boosting-based pointwise ensemble approach with a slight listwise touch at the last combination step is competitive to sophisticated (and computationally expensive) ranking techniques.
R. Busa-Fekete,
B. Kégl, T. Éltető, and Gy. Szarvas
Ranking by
calibrated AdaBoost
In Yahoo! Ranking Challenge 2010 (JMLR workshop and conference
proceedings), Volume 14, pages 37–48, 2011.
Our boosting-based pointwise ensemble approach ended up 6th in Track 1 and 11th in Track 2.
Auger
P. Abreu et
al.
Muons in air showers at
the Pierre Auger Observatory: Measurement of atmospheric production
depth
Physical Review Letters D, 90:012012, 2014
Auger Collaboration paper.
The first of two main phyiscs outputs of the project, mainly the work of Diego Garcia Gamez.
B. Kégl and for
the Pierre Auger Collaboration
Measurement of the
muon signal using the temporal and spectral structure of the signals in
surface detectors of the Pierre Auger Observatory
In 33rd International Cosmic Ray Conference (ICRC), 2013.
We measure the muonic signal in surface detectors at a core distance of 1 km for showers of 10 EeV primary energy, using different filtering techniques and a multivariate approach.
D. G. Gamez and for
the Pierre Auger Collaboration
Observations of the
longitudinal development of extensive air showers with the surface detectors
of the Pierre Auger Observatory
In 33rd International Cosmic Ray Conference (ICRC), 2013.
We measure the muonic signal in surface detectors at a core distance of 1 km for showers of 10 EeV primary energy, using different filtering techniques and a multivariate approach.
B. Kégl,
D. Veberič, and D. Garcia Gamez
A
simple estimator of Sμ19(1000)
Technical Report 2012-127, Auger Project Technical Note, 2012.
We develop an estimator for the muon fraction using a parametric function of simple statistics extracted from the FADC signal.
D. Veberič,
B. Kégl, and S. Mićanović
Estimating
muon fraction from individual traces of SD stations
Technical Report 2012-126, Auger Project Technical Note, 2012.
B. Kégl,
R. Busa-Fekete, K. Louedec, R. Bardenet, X. Garrido, I.C. Mariş,
D. Monnier-Ragaigne, S. Dagoret-Campagne, and M. Urban
Reconstructing
Nμ19(1000)
Technical Report 2011-054, Auger Project Technical Note, 2011.
We develop an estimator for the number of muons in an Auger tank given the FADC signal by tuning the jump method with a multivariate approach. Using the tankwise estimator, we reconstruct the lateral distribution function in an empirical Bayes setup that can be intuitively understood as a constrained fit where constraints are estimated from the data.
R. Bardenet,
B. Kégl, and D. Veberič
Single
muon response: The signal model
Technical Report 2010-110, Auger Project Technical Note, 2010.
The lowest part of the comprehensive generative model for the tank signal.