no code implementations • 17 Apr 2024 • Sumit Adak, Carsten Witt
A class of metaheuristic techniques called estimation-of-distribution algorithms (EDAs) are employed in optimization as more sophisticated substitutes for traditional strategies like evolutionary algorithms.
no code implementations • 5 Apr 2024 • Martin S. Krejca, Carsten Witt
We propose a new, flexible approach for dynamically maintaining successful mutation rates in evolutionary algorithms using $k$-bit flip mutations.
no code implementations • 3 Jul 2023 • Paul Fischer, Emil Lundt Larsen, Carsten Witt
We consider a simple setting in neuroevolution where an evolutionary algorithm optimizes the weights and activation functions of a simple artificial neural network.
no code implementations • 11 May 2023 • Frank Neumann, Carsten Witt
Pareto optimization using evolutionary multi-objective algorithms has been widely applied to solve constrained submodular optimization problems.
1 code implementation • 21 Apr 2023 • Benjamin Doerr, Taha El Ghazi El Houssaini, Amirhossein Rajabi, Carsten Witt
Even with the optimal temperature (the only parameter of the MA), the MA optimizes most cliff functions less efficiently than simple elitist evolutionary algorithms (EAs), which can only leave the local optimum by generating a superior solution possibly far away.
no code implementations • 18 Apr 2023 • Frank Neumann, Carsten Witt
Evolutionary multi-objective algorithms have successfully been used in the context of Pareto optimization where a given constraint is relaxed into an additional objective.
no code implementations • 11 Aug 2022 • Frank Neumann, Carsten Witt
Linear functions play a key role in the runtime analysis of evolutionary algorithms and studies have provided a wide range of new insights and techniques for analyzing evolutionary computation methods.
no code implementations • 11 Apr 2022 • Frank Neumann, Dirk Sudholt, Carsten Witt
We point out that the cGA faces major difficulties when solving the CLIFF function and investigate its dynamics both experimentally and theoretically around the cliff.
no code implementations • 5 Apr 2022 • Benjamin Doerr, Amirhossein Rajabi, Carsten Witt
We prove that Simulated Annealing with an appropriate cooling schedule computes arbitrarily tight constant-factor approximations to the minimum spanning tree problem in polynomial time.
no code implementations • 13 Sep 2021 • Frank Neumann, Carsten Witt
With this paper, we contribute to the theoretical understanding of evolutionary algorithms for chance constrained optimization.
no code implementations • 9 Apr 2021 • Amirhossein Rajabi, Carsten Witt
In multimodal landscapes with a more complex location of optima of similar gap size, stagnation detection suffers from the fact that the neighborhood size is frequently reset to $1$ without using gap sizes that were promising in the past.
no code implementations • 18 Mar 2021 • Dogan Corus, Andrei Lissovoi, Pietro S. Oliveto, Carsten Witt
On the other hand, we prove that selecting the worst individual as parent leads to efficient global optimisation with overwhelming probability for reasonable population sizes.
no code implementations • 28 Jan 2021 • Amirhossein Rajabi, Carsten Witt
The so-called $SD-(1+1)EA$ introduced by Rajabi and Witt (GECCO 2020) adds stagnation detection to the classical $(1+1)EA$ with standard bit mutation, which flips each bit independently with some mutation rate, and raises the mutation rate when the algorithm is likely to have encountered local optima.
no code implementations • 21 Oct 2020 • Frank Neumann, Mojgan Pourhassan, Carsten Witt
Linear functions have been traditionally studied in this area resulting in tight bounds on the expected optimisation time of simple randomised search algorithms for this class of problems.
no code implementations • 16 Jun 2020 • Amirhossein Rajabi, Carsten Witt
Evolutionary Algorithms (EAs) and other randomized search heuristics are often considered as unbiased algorithms that are invariant with respect to different transformations of the underlying search space.
no code implementations • 12 Jun 2020 • Timo Kötzing, Carsten Witt
Fixed-budget theory is concerned with computing or bounding the fitness value achievable by randomized search heuristics within a given budget of fitness function evaluations.
1 code implementation • 7 Apr 2020 • Amirhossein Rajabi, Carsten Witt
We suggest a mechanism called stagnation detection that can be added as a module to existing evolutionary algorithms (both with and without prior self-adjusting algorithms).
no code implementations • 21 Jun 2019 • Hsien-Kuei Hwang, Carsten Witt
This paper revisits drift analysis for the (1+1) EA on OneMax and obtains that the expected running time $E(T)$, starting from $\lceil n/2\rceil$ one-bits, is determined by the sum of inverse drifts up to logarithmic error terms, more precisely $$\sum_{k=1}^{\lfloor n/2\rfloor}\frac{1}{\Delta(k)} - c_1\log n \le E(T) \le \sum_{k=1}^{\lfloor n/2\rfloor}\frac{1}{\Delta(k)} - c_2\log n,$$ where $\Delta(k)$ is the drift (expected increase of the number of one-bits from the state of $n-k$ ones) and $c_1, c_2 >0$ are explicitly computed constants.
no code implementations • 30 Nov 2018 • Benjamin Doerr, Carsten Witt, Jing Yang
We propose and analyze a self-adaptive version of the $(1,\lambda)$ evolutionary algorithm in which the current mutation rate is part of the individual and thus also subject to mutation.
no code implementations • 14 Jun 2018 • Martin S. Krejca, Carsten Witt
Estimation-of-distribution algorithms (EDAs) are general metaheuristics used in optimization that represent a more recent alternative to classical approaches like evolutionary algorithms.
no code implementations • 7 Apr 2017 • Benjamin Doerr, Christian Gießen, Carsten Witt, Jing Yang
We propose a new way to self-adjust the mutation rate in population-based evolutionary algorithms in discrete search spaces.
no code implementations • 31 Mar 2017 • Carsten Witt
If $\mu\ge c\log n$ for some constant $c>0$ and $\lambda=(1+\Theta(1))\mu$, a general bound $O(\mu n)$ on the expected runtime is obtained.
no code implementations • 14 Jul 2016 • Dirk Sudholt, Carsten Witt
We provide a rigorous runtime analysis concerning the update strength, a vital parameter in probabilistic model-building GAs such as the step size $1/K$ in the compact Genetic Algorithm (cGA) and the evaporation factor $\rho$ in ACO.
no code implementations • 23 Apr 2015 • Frank Neumann, Carsten Witt
Evolutionary algorithms have been frequently used for dynamic optimization problems.
no code implementations • 16 Jul 2013 • Carsten Witt
The fitness-level method, also called the method of f-based partitions, is an intuitive and widely used technique for the running time analysis of randomized search heuristics.
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.