@inproceedings{48863, abstract = {{The novel R package ecr (version 2), short for Evolutionary Computation in R, provides a comprehensive collection of building blocks for constructing powerful evolutionary algorithms for single- and multi-objective continuous and combinatorial optimization problems. It allows to solve standard optimization tasks with few lines of code using a black-box approach. Moreover, rapid prototyping of non-standard ideas is possible via an explicit, white-box approach. This paper describes the design principles of the package and gives some introductory examples on how to use the package in practise.}}, author = {{Bossek, Jakob}}, booktitle = {{Proceedings of the Genetic and Evolutionary Computation Conference Companion}}, isbn = {{978-1-4503-4939-0}}, keywords = {{evolutionary optimization, software-tools}}, pages = {{1187–1193}}, publisher = {{Association for Computing Machinery}}, title = {{{Ecr 2.0: A Modular Framework for Evolutionary Computation in R}}}, doi = {{10.1145/3067695.3082470}}, year = {{2017}}, } @inproceedings{48857, abstract = {{While finding minimum-cost spanning trees (MST) in undirected graphs is solvable in polynomial time, the multi-criteria minimum spanning tree problem (mcMST) is NP-hard. Interestingly, the mcMST problem has not been in focus of evolutionary computation research for a long period of time, although, its relevance for real world problems is easy to see. The available and most notable approaches by Zhou and Gen as well as by Knowles and Corne concentrate on solution encoding and on fairly dated selection mechanisms. In this work, we revisit the mcMST and focus on the mutation operators as exploratory components of evolutionary algorithms neglected so far. We investigate optimal solution characteristics to discuss current mutation strategies, identify shortcomings of these operators, and propose a sub-tree based operator which offers what we term Pareto-beneficial behavior: ensuring convergence and diversity at the same time. The operator is empirically evaluated inside modern standard evolutionary meta-heuristics for multi-criteria optimization and compared to hitherto applied mutation operators in the context of mcMST.}}, author = {{Bossek, Jakob and Grimme, Christian}}, booktitle = {{2017 IEEE Symposium Series on Computational Intelligence (SSCI)}}, keywords = {{Convergence, Encoding, Euclidean distance, Evolutionary computation, Heating systems, Optimization, Standards}}, pages = {{1–8}}, title = {{{A Pareto-Beneficial Sub-Tree Mutation for the Multi-Criteria Minimum Spanning Tree Problem}}}, doi = {{10.1109/SSCI.2017.8285183}}, year = {{2017}}, } @inproceedings{48856, abstract = {{There exist many optimal or heuristic priority rules for machine scheduling problems, which can easily be integrated into single-objective evolutionary algorithms via mutation operators. However, in the multi-objective case, simultaneously applying different priorities for different objectives may cause severe disruptions in the genome and may lead to inferior solutions. In this paper, we combine an existing mutation operator concept with new insights from detailed observation of the structure of solutions for multi-objective machine scheduling problems. This allows the comprehensive integration of priority rules to produce better Pareto-front approximations. We evaluate the extended operator concept compared to standard swap mutation and the stand-alone components of our hybrid scheme, which performs best in all evaluated cases.}}, author = {{Bossek, Jakob and Grimme, Christian}}, booktitle = {{2017 IEEE Symposium Series on Computational Intelligence (SSCI)}}, keywords = {{Evolutionary computation, Processor scheduling, Schedules, Scheduling, Sociology, Standards, Statistics}}, pages = {{1–8}}, title = {{{An Extended Mutation-Based Priority-Rule Integration Concept for Multi-Objective Machine Scheduling}}}, doi = {{10.1109/SSCI.2017.8285224}}, year = {{2017}}, } @article{48864, abstract = {{Bossek, (2017), mcMST: A Toolbox for the Multi-Criteria Minimum Spanning Tree Problem, Journal of Open Source Software, 2(17), 374, doi:10.21105/joss.00374}}, author = {{Bossek, Jakob}}, issn = {{2475-9066}}, journal = {{Journal of Open Source Software}}, number = {{17}}, pages = {{374}}, title = {{{mcMST: A Toolbox for the Multi-Criteria Minimum Spanning Tree Problem}}}, doi = {{10.21105/joss.00374}}, volume = {{2}}, year = {{2017}}, } @article{48865, author = {{Bossek, Jakob}}, issn = {{2073-4859}}, journal = {{The R Journal}}, number = {{1}}, pages = {{103–113}}, title = {{{Smoof: Single- and Multi-Objective Optimization Test Functions}}}, volume = {{9}}, year = {{2017}}, } @article{48837, author = {{Bischl, Bernd and Richter, Jakob and Bossek, Jakob and Horn, Daniel and Thomas, Janek and Lang, Michel}}, journal = {{CoRR}}, title = {{{mlrMBO: A Modular Framework for Model-Based Optimization of Expensive Black-Box Functions}}}, year = {{2017}}, } @inproceedings{46364, abstract = {{Automated algorithm configuration procedures play an increasingly important role in the development and application of algorithms for a wide range of computationally challenging problems. Until very recently, these configuration procedures were limited to optimising a single performance objective, such as the running time or solution quality achieved by the algorithm being configured. However, in many applications there is more than one performance objective of interest. This gives rise to the multi-objective automatic algorithm configuration problem, which involves finding a Pareto set of configurations of a given target algorithm that characterises trade-offs between multiple performance objectives. In this work, we introduce MO-ParamILS, a multi-objective extension of the state-of-the-art single-objective algorithm configuration framework ParamILS, and demonstrate that it produces good results on several challenging bi-objective algorithm configuration scenarios compared to a base-line obtained from using a state-of-the-art single-objective algorithm configurator.}}, author = {{Blot, A and Hoos, H and Jourdan, L and Marmion, M and Trautmann, Heike}}, booktitle = {{LION 2016: Learning and Intelligent Optimization}}, editor = {{et al. Joaquin, Vanschooren}}, pages = {{32–47}}, publisher = {{Springer International Publishing}}, title = {{{MO-ParamILS: A Multi-objective Automatic Algorithm Configuration Framework}}}, doi = {{10.1007/978-3-319-50349-3_3}}, volume = {{10079}}, year = {{2016}}, } @inbook{46363, abstract = {{The averaged Hausdorff distance has been proposed as an indicator for assessing the quality of finitely sized approximations of the Pareto front of a multiobjective problem. Since many set-based, iterative optimization algorithms store their currently best approximation in an internal archive these approximations are also termed archives. In case of two objectives and continuous variables it is known that the best approximations in terms of averaged Hausdorff distance are subsets of the Pareto front if it is concave. If it is linear or circularly concave the points of the best approximation are equally spaced. Here, it is proven that the optimal averaged Hausdorff approximation and the Pareto front have an empty intersection if the Pareto front is circularly convex. But the points of the best approximation are equally spaced and they rapidly approach the Pareto front for increasing size of the approximation.}}, author = {{Rudolph, G and Schütze, O and Trautmann, Heike}}, booktitle = {{Applications of Evolutionary Computation: 19$^th$ European Conference, EvoApplications 2016, Porto, Portugal, March 30 — April 1, 2016, Proceedings, Part II}}, editor = {{Squillero, G and Burelli, P}}, isbn = {{978-3-319-31153-1}}, pages = {{42–55}}, publisher = {{Springer International Publishing}}, title = {{{On the Closest Averaged Hausdorff Archive for a Circularly Convex Pareto Front}}}, doi = {{10.1007/978-3-319-31153-1_4}}, year = {{2016}}, } @inproceedings{46369, abstract = {{This paper formally defines multimodality in multiobjective optimization (MO). We introduce a test-bed in which multimodal MO problems with known properties can be constructed as well as numerical characteristics of the resulting landscape. Gradient- and local search based strategies are compared on exemplary problems together with specific performance indicators in the multimodal MO setting. By this means the foundation for Exploratory Landscape Analysis in MO is provided.}}, author = {{Kerschke, Pascal and Wang, Hao and Preuss, Mike and Grimme, Christian and Deutz, André and Trautmann, Heike and Emmerich, Michael}}, booktitle = {{Proceedings of the 14$^th$ International Conference on Parallel Problem Solving from Nature (PPSN XIV)}}, pages = {{962–972}}, publisher = {{Springer}}, title = {{{Towards Analyzing Multimodality of Multiobjective Landscapes}}}, doi = {{10.1007/978-3-319-45823-6_90}}, year = {{2016}}, } @inproceedings{46367, abstract = {{When selecting the best suited algorithm for an unknown optimization problem, it is useful to possess some a priori knowledge of the problem at hand. In the context of single-objective, continuous optimization problems such knowledge can be retrieved by means of Exploratory Landscape Analysis (ELA), which automatically identifies properties of a landscape, e.g., the so-called funnel structures, based on an initial sample. In this paper, we extract the relevant features (for detecting funnels) out of a large set of landscape features when only given a small initial sample consisting of 50 x D observations, where D is the number of decision space dimensions. This is already in the range of the start population sizes of many evolutionary algorithms. The new Multiple Peaks Model Generator (MPM2) is used for training the classifier, and the approach is then very successfully validated on the Black-Box Optimization Benchmark (BBOB) and a subset of the CEC 2013 niching competition problems.}}, author = {{Kerschke, Pascal and Preuss, Mike and Wessing, Simon and Trautmann, Heike}}, booktitle = {{Proceedings of the 18$^th$ Annual Conference on Genetic and Evolutionary Computation}}, isbn = {{978-1-4503-4206-3}}, pages = {{229–236}}, title = {{{Low-Budget Exploratory Landscape Analysis on Multiple Peaks Models}}}, doi = {{10.1145/2908812.2908845}}, year = {{2016}}, } @article{46371, abstract = {{One main task in evolutionary multiobjective optimization (EMO) is to obtain a suitable finite size approximation of the Pareto front which is the image of the solution set, termed the Pareto set, of a given multiobjective optimization problem. In the technical literature, the characteristic of the desired approximation is commonly expressed by closeness to the Pareto front and a sufficient spread of the solutions obtained. In this paper, we first make an effort to show by theoretical and empirical findings that the recently proposed Averaged Hausdorff (or Δ𝑝-) indicator indeed aims at fulfilling both performance criteria for bi-objective optimization problems. In the second part of this paper, standard EMO algorithms combined with a specialized archiver and a postprocessing step based on the Δ𝑝 indicator are introduced which sufficiently approximate the Δ𝑝-optimal archives and generate solutions evenly spread along the Pareto front.}}, author = {{Rudolph, G and Schütze, O and Grimme, C and Domínguez-Medina, C and Trautmann, Heike}}, journal = {{Computational Optimization and Applications (Comput. Optim. Appl.)}}, number = {{2}}, pages = {{589–618}}, title = {{{Optimal averaged Hausdorff archives for bi-objective problems: theoretical and numerical results}}}, doi = {{10.1007/s10589-015-9815-8}}, volume = {{64}}, year = {{2016}}, } @article{46372, abstract = {{We present a new hybrid evolutionary algorithm for the effective hypervolume approximation of the Pareto front of a given differentiable multi-objective optimization problem. Starting point for the local search (LS) mechanism is a new division of the decision space as we will argue that in each of these regions a different LS strategy seems to be most promising. For the LS in two out of the three regions we will utilize and adapt the Directed Search method which is capable of steering the search into any direction given in objective space and which is thus well suited for the problem at hand. We further on integrate the resulting LS mechanism into SMS-EMOA, a state-of-the-art evolutionary algorithm for hypervolume approximations. Finally, we will present some numerical results on several benchmark problems with two and three objectives indicating the strength and competitiveness of the novel hybrid.}}, author = {{Schütze, O and Sosa, Hernandez VA and Trautmann, Heike and Rudolph, G}}, journal = {{Journal of Heuristics}}, number = {{3}}, pages = {{273–300}}, title = {{{The Hypervolume based Directed Search Method for Multi-Objective Optimization Problems}}}, doi = {{10.1007/s10732-016-9310-0}}, volume = {{22}}, year = {{2016}}, } @inproceedings{46368, abstract = {{Exploratory Landscape Analysis (ELA) aims at understanding characteristics of single-objective continuous (black-box) optimization problems in an automated way. Moreover, the approach provides the basis for constructing algorithm selection models for unseen problem instances. Recently, it has gained increasing attention and numerical features have been designed by various research groups. This paper introduces the R-Package FLACCO which makes all relevant features available in a unified framework together with efficient helper functions. Moreover, a case study which gives perspectives to ELA for multi-objective optimization problems is presented.}}, author = {{Kerschke, Pascal and Trautmann, Heike}}, booktitle = {{Proceedings of the IEEE Congress on Evolutionary Computation (CEC)}}, title = {{{The R-Package FLACCO for Exploratory Landscape Analysis with Applications to Multi-Objective Optimization Problems}}}, doi = {{10.1109/CEC.2016.7748359}}, year = {{2016}}, } @article{46370, abstract = {{This report documents the talks and discussions at the Dagstuhl Seminar 15211 "Theory of Evolutionary Algorithms". This seminar, now in its 8th edition, is the main meeting point of the highly active theory of randomized search heuristics subcommunities in Australia, Asia, North America, and Europe. Topics intensively discussed include rigorous runtime analysis and computational complexity theory for randomised search heuristics, information geometry of randomised search, and synergies between the theory of evolutionary algorithms and theories of natural evolution.}}, author = {{Neumann, F and Trautmann, Heike}}, journal = {{Dagstuhl Reports}}, number = {{5}}, pages = {{78–79}}, title = {{{Working Group Report: Bridging the Gap Between Experiments and Theory Using Feature-Based Run-Time Analysis; Theory of Evolutionary Algorithms (Dagstuhl Seminar 15211)}}}, doi = {{10.4230/DagRep.5.5.57}}, volume = {{5}}, year = {{2016}}, } @inproceedings{48873, abstract = {{Despite the intrinsic hardness of the Traveling Salesperson Problem (TSP) heuristic solvers, e.g., LKH+restart and EAX+restart, are remarkably successful in generating satisfactory or even optimal solutions. However, the reasons for their success are not yet fully understood. Recent approaches take an analytical viewpoint and try to identify instance features, which make an instance hard or easy to solve. We contribute to this area by generating instance sets for couples of TSP algorithms A and B by maximizing/minimizing their performance difference in order to generate instances which are easier to solve for one solver and much harder to solve for the other. This instance set offers the potential to identify key features which allow to distinguish between the problem hardness classes of both algorithms.}}, author = {{Bossek, Jakob and Trautmann, Heike}}, booktitle = {{Learning and Intelligent Optimization}}, editor = {{Festa, Paola and Sellmann, Meinolf and Vanschoren, Joaquin}}, isbn = {{978-3-319-50349-3}}, keywords = {{Algorithm selection, Feature selection, Instance hardness, TSP}}, pages = {{48–59}}, publisher = {{Springer International Publishing}}, title = {{{Evolving Instances for Maximizing Performance Differences of State-of-the-Art Inexact TSP Solvers}}}, doi = {{10.1007/978-3-319-50349-3_4}}, year = {{2016}}, } @inproceedings{46365, abstract = {{Despite the intrinsic hardness of the Traveling Salesperson Problem (TSP) heuristic solvers, e.g., LKH+restart and EAX+restart, are remarkably successful in generating satisfactory or even optimal solutions. However, the reasons for their success are not yet fully understood. Recent approaches take an analytical viewpoint and try to identify instance features, which make an instance hard or easy to solve. We contribute to this area by generating instance sets for couples of TSP algorithms A and B by maximizing/minimizing their performance difference in order to generate instances which are easier to solve for one solver and much harder to solve for the other. This instance set offers the potential to identify key features which allow to distinguish between the problem hardness classes of both algorithms.}}, author = {{Bossek, Jakob and Trautmann, Heike}}, booktitle = {{Learning and Intelligent Optimization}}, editor = {{Festa, P and Sellmann, M and Vanschoren, J}}, isbn = {{978-3-319-50348-6}}, pages = {{48–59}}, publisher = {{Springer International Publishing}}, title = {{{Evolving Instances for Maximizing Performance Differences of State-of-The-Art Inexact TSP Solvers}}}, doi = {{10.1007/978-3-319-50349-3_4}}, volume = {{10079}}, year = {{2016}}, } @inproceedings{46366, abstract = {{State of the Art inexact solvers of the NP-hard Traveling Salesperson Problem (TSP) are known to mostly yield high-quality solutions in reasonable computation times. With the purpose of understanding different levels of instance difficulties, instances for the current State of the Art heuristic TSP solvers LKH+restart and EAX+restart are presented which are evolved using a sophisticated evolutionary algorithm. More specifically, the performance differences of the respective solvers are maximized resulting in instances which are easier to solve for one solver and much more difficult for the other. Focusing on both optimization directions, instance features are identified which characterize both types of instances and increase the understanding of solver performance differences.}}, author = {{Bossek, Jakob and Trautmann, Heike}}, booktitle = {{AI*IA 2016 Advances in Artificial Intelligence}}, editor = {{Adorni, G and Cagnoni, S and Gori, M and Maratea, M}}, isbn = {{978-3-319-49129-5}}, pages = {{3–12}}, publisher = {{Springer}}, title = {{{Understanding Characteristics of Evolved Instances for State-of-the-Art Inexact TSP Solvers with Maximum Performance Difference}}}, doi = {{10.1007/978-3-319-49130-1_1}}, volume = {{10037}}, year = {{2016}}, } @article{52870, author = {{Raket, Lars Lau and Grimme, Britta and Schöner, Gregor and Igel, Christian and Markussen, Bo}}, journal = {{PLoS Computational Biology}}, number = {{9}}, pages = {{e1005092}}, publisher = {{Public Library of Science San Francisco, CA USA}}, title = {{{Separating timing, movement conditions and individual differences in the analysis of human movement}}}, volume = {{12}}, year = {{2016}}, } @inproceedings{46373, abstract = {{The need for automatic methods of topic discovery in the Internet grows exponentially with the amount of available textual information. Nowadays it becomes impossible to manually read even a small part of the information in order to reveal the underlying topics. Social media provide us with a great pool of user generated content, where topic discovery may be extremely useful for businesses, politicians, researchers, and other stakeholders. However, conventional topic discovery methods, which are widely used in large text corpora, face several challenges when they are applied in social media and particularly in Twitter – the most popular microblogging platform. To the best of our knowledge no comprehensive overview of these challenges and of the methods dedicated to address these challenges does exist in IS literature until now. Therefore, this paper provides an overview of these challenges, matching methods and their expected usefulness for social media analytics.}}, author = {{Chinnov, Andrey and Kerschke, Pascal and Meske, Christian and Stieglitz, Stefan and Trautmann, Heike}}, booktitle = {{Proceedings of the 20$^th$ Americas Conference on Information Systems (AMCIS ’15)}}, isbn = {{978-0-9966831-0-4}}, pages = {{1–10}}, title = {{{An Overview of Topic Discovery in Twitter Communication through Social Media Analytics}}}, year = {{2015}}, } @inproceedings{46375, abstract = {{In single-objective optimization different optimization strategies exist depending on the structure and characteristics of the underlying problem. In particular, the presence of so-called funnels in multimodal problems offers the possibility of applying techniques exploiting the global structure of the function. The recently proposed Exploratory Landscape Analysis approach automatically identifies problem characteristics based on a moderately small initial sample of the objective function and proved to be effective for algorithm selection problems in continuous black-box optimization. In this paper, specific features for detecting funnel structures are introduced and combined with the existing ones in order to classify optimization problems regarding the funnel property. The effectiveness of the approach is shown by experiments on specifically generated test instances and validation experiments on standard benchmark problems.}}, author = {{Kerschke, Pascal and Preuss, Mike and Wessing, Simon and Trautmann, Heike}}, booktitle = {{Proceedings of the Genetic and Evolutionary Computation Conference (GECCO ’15)}}, editor = {{Silva, Sara}}, isbn = {{978-1-4503-3472-3}}, pages = {{265–272}}, publisher = {{ACM}}, title = {{{Detecting Funnel Structures by Means of Exploratory Landscape Analysis}}}, doi = {{10.1145/2739480.2754642}}, year = {{2015}}, }