no code implementations • 6 Sep 2024 • Alistair Benford, Per Kristian Lehre
In this paper, we push the scope of runtime analysis to combinatorial games, proving a general upper bound for the number of simulated games needed for UMDA (a type of CoEA) to discover (with high probability) an optimal strategy for an impartial combinatorial game.
no code implementations • 25 Jul 2024 • Per Kristian Lehre, Shishen Lin
On the other hand, the standard $(1,\lambda)$-EA fails to find an $\varepsilon$ approximation to the optimal solution of the \Diagonal problem in polynomial runtime.
no code implementations • 7 May 2024 • Per Kristian Lehre, Shishen Lin
Our drift theorem can be used to prove a strong concentration of the runtime/regret of algorithms in AI.
no code implementations • 26 May 2023 • Zimin Liang, Miqing Li, Per Kristian Lehre
Elitism, which constructs the new population by preserving best solutions out of the old population and newly-generated solutions, has been a default way for population update since its introduction into multi-objective evolutionary algorithms (MOEAs) in the late 1990s.
no code implementations • 30 Jun 2022 • Per Kristian Lehre
Co-evolutionary algorithms have a wide range of applications, such as in hardware design, evolution of strategies for board games, and patching software bugs.
no code implementations • 1 Apr 2020 • Brendan Case, Per Kristian Lehre
The structure of this problem depends on a parameter $k$, which is \emph{a priori} unknown to the algorithm, and which is needed to appropriately set a fixed mutation rate.
no code implementations • 23 Aug 2019 • Duc-Cuong Dang, Anton Eremeev, Per Kristian Lehre
In contrast to this negative result, we also show that for any linear function with polynomially bounded weights, the EA achieves a polynomial expected runtime if the mutation rate is reduced to $\Theta(1/n^2)$ and the population size is sufficiently large.
no code implementations • 29 Jul 2019 • Per Kristian Lehre, Phan Trung Hai Nguyen
More precisely, we show that the UMDA with a parent population size of $\mu=\Omega(\log n)$ has an expected runtime of $e^{\Omega(\mu)}$ on the DLB problem assuming any selective pressure $\frac{\mu}{\lambda} \geq \frac{14}{1000}$, as opposed to the expected runtime of $\mathcal{O}(n\lambda\log \lambda+n^3)$ for the non-elitist $(\mu,\lambda)~\text{EA}$ with $\mu/\lambda\leq 1/e$.
no code implementations • 19 Apr 2019 • Per Kristian Lehre, Phan Trung Hai Nguyen
We perform a rigorous runtime analysis for the Univariate Marginal Distribution Algorithm on the LeadingOnes function, a well-known benchmark function in the theory community of evolutionary computation with a high correlation between decision variables.
no code implementations • 31 Jan 2019 • Per Kristian Lehre, Dirk Sudholt
Our main result is a general performance limit: we prove that on every function every $\lambda$-parallel unary unbiased algorithm needs at least $\Omega(\frac{\lambda n}{\ln \lambda} + n \log n)$ evaluations to find any desired target set of up to exponential size, with an overwhelming probability.
no code implementations • 26 Jul 2018 • Duc-Cuong Dang, Per Kristian Lehre, Phan Trung Hai Nguyen
The facility and generality of our arguments suggest that this is a promising approach to derive bounds on the expected optimisation time of EDAs.
no code implementations • 5 Jun 2018 • Per Kristian Lehre, Phan Trung Hai Nguyen
The Population-Based Incremental Learning (PBIL) algorithm uses a convex combination of the current model and the empirical model to construct the next model, which is then sampled to generate offspring.
no code implementations • 2 Feb 2018 • Per Kristian Lehre, Phan Trung Hai Nguyen
Unlike traditional evolutionary algorithms which produce offspring via genetic operators, Estimation of Distribution Algorithms (EDAs) sample solutions from probabilistic models which are learned from selected individuals.
no code implementations • 4 Sep 2017 • Per Kristian Lehre, Pietro S. Oliveto
This quickly increasing basis of results allows, nowadays, the analysis of sophisticated algorithms such as population-based evolutionary algorithms, ant colony optimisation and artificial immune systems.
no code implementations • 10 Aug 2016 • Duc-Cuong Dang, Tobias Friedrich, Timo Kötzing, Martin S. Krejca, Per Kristian Lehre, Pietro S. Oliveto, Dirk Sudholt, Andrew M. Sutton
This proves a sizeable advantage of all variants of the ($\mu$+1) GA compared to (1+1) EA, which requires time $\Theta(n^k)$.
no code implementations • 12 Jul 2016 • Duc-Cuong Dang, Thomas Jansen, Per Kristian Lehre
It is often claimed that evolutionary algorithms are particularly suitable for dynamic optimisation because a large population can contain different solutions that may be useful in the future.
no code implementations • 17 Jun 2016 • Duc-Cuong Dang, Per Kristian Lehre
Experimental results indicate that self-adaptation, where parameter settings are encoded in the genomes of individuals, can be effective in continuous optimisation.
no code implementations • 7 Dec 2015 • Duc-Cuong Dang, Anton V. Eremeev, Per Kristian Lehre
The paper is devoted to upper bounds on run-time of Non-Elitist Genetic Algorithms until some target subset of solutions is visited for the first time.
no code implementations • 29 Jul 2014 • Dogan Corus, Duc-Cuong Dang, Anton V. Eremeev, Per Kristian Lehre
Finally, we prove that the theorem is nearly optimal for the processes considered.
no code implementations • 9 Jan 2014 • Dogan Corus, Per Kristian Lehre, Frank Neumann, Mojgan Pourhassan
For the generalised minimum spanning tree problem, we analyse the two approaches presented by Hu and Raidl (2012) with respect to the number of clusters that distinguish each other by the chosen representation of possible solutions.
no code implementations • 9 Jul 2013 • Per Kristian Lehre, Carsten Witt
We address this lack by providing a general drift theorem that includes bounds on the upper and lower tail of the hitting time distribution.