Hans-Paul Schwefel | |
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Born | Berlin | December 4, 1940
Hans-Paul Schwefel (born December 4, 1940) is a German computer scientist and professor emeritus at University of Dortmund (now Dortmund University of Technology), where he held the chair of systems analysis from 1985 until 2006. He is one of the pioneers in evolutionary computation and one of the authors responsible for the evolution strategies (Evolutionsstrategien). His work has helped to understand the dynamics of evolutionary algorithms and to put evolutionary computation on formal grounds.
Schwefel was born in Berlin. He attended the Technische Universität Berlin (TU Berlin) and graduated as an aerospace engineer in 1965 and got his Dr.-Ing. in 1975. While as a student at TU Berlin, he met Ingo Rechenberg in November 1963. Both of them were studying the aero- and space technology and both of them were keen on cybernetics and bionics. Rechenberg was dealing with wall shear stress measurements and Schwefel was responsible for organizing fluid dynamics exercises for other students. Together they were dreaming of a research robot working according to cybernetic principles, but computers became available only later on.
While attending the Hermann Föttinger-Institute for Hydrodynamics (HFI) at TU Berlin, he and Rechenberg began performing experiments upon wings, kinked plates, and other objects related to fluid dynamics. The main objective of those experiments concerned optimizing the shape and/or parameters through mostly small modifications on the real objects, a "technique" they called experimental optimization, in order to reduce the drag, increase the thrust, and so on. Applying classical optimization methods (such as Gauss–Seidel and gradient-based techniques) on such experiments showed that those methods are not well suited to be adopted in experimental optimization, mainly due to noisy measurements and/or multimodality. They realized modifying all the variables at same time via a random manner (e.g., small modifications are more frequent than larger ones). This was the seminal idea to bring to light the first, two membered, evolution strategy, which was initially used on a discrete problem (optimization of a kinked plate in a wind tunnel) and was handled without computers.
Some time later, Schwefel expanded the idea toward evolution strategies to deal with numerical/parametric optimization and, also, has helped to formalize it as it is known nowadays.
Schwefel was one of the initiators of the Parallel Problem Solving from Nature conference series.
In computer science and operations research, a genetic algorithm (GA) is a metaheuristic inspired by the process of natural selection that belongs to the larger class of evolutionary algorithms (EA). Genetic algorithms are commonly used to generate high-quality solutions to optimization and search problems by relying on biologically inspired operators such as mutation, crossover and selection. Some examples of GA applications include optimizing decision trees for better performance, solving sudoku puzzles, hyperparameter optimization, causal inference, etc.
In computational intelligence (CI), an evolutionary algorithm (EA) is a subset of evolutionary computation, a generic population-based metaheuristic optimization algorithm. An EA uses mechanisms inspired by biological evolution, such as reproduction, mutation, recombination, and selection. Candidate solutions to the optimization problem play the role of individuals in a population, and the fitness function determines the quality of the solutions. Evolution of the population then takes place after the repeated application of the above operators.
Technische Universität Berlin is a public research university located in Berlin, Germany. It was the first German university to adopt the name "Technische Universität".
In computer science, evolutionary computation is a family of algorithms for global optimization inspired by biological evolution, and the subfield of artificial intelligence and soft computing studying these algorithms. In technical terms, they are a family of population-based trial and error problem solvers with a metaheuristic or stochastic optimization character.
Mutation is a genetic operator used to maintain genetic diversity of the chromosomes of a population of a genetic or, more generally, an evolutionary algorithm (EA). It is analogous to biological mutation.
In genetic algorithms (GA), or more general, evolutionary algorithms (EA), a chromosome is a set of parameters which define a proposed solution of the problem that the evolutionary algorithm is trying to solve. The set of all solutions, also called individuals according to the biological model, is known as the population. The genome of an individual consists of one, more rarely of several, chromosomes and corresponds to the genetic representation of the task to be solved. A chromosome is composed of a set of genes, where a gene consists of one or more semantically connected parameters, which are often also called decision variables. They determine one or more phenotypic characteristics of the individual or at least have an influence on them. In the basic form of genetic algorithms, the chromosome is represented as a binary string, while in later variants and in EAs in general, a wide variety of other data structures are used.
In computer science and mathematical optimization, a metaheuristic is a higher-level procedure or heuristic designed to find, generate, tune, or select a heuristic that may provide a sufficiently good solution to an optimization problem or a machine learning problem, especially with incomplete or imperfect information or limited computation capacity. Metaheuristics sample a subset of solutions which is otherwise too large to be completely enumerated or otherwise explored. Metaheuristics may make relatively few assumptions about the optimization problem being solved and so may be usable for a variety of problems.
In computer science, an evolution strategy (ES) is an optimization technique based on ideas of evolution. It belongs to the general class of evolutionary computation or artificial evolution methodologies.
In evolutionary algorithms (EA), the term of premature convergence means that a population for an optimization problem converged too early, resulting in being suboptimal. In this context, the parental solutions, through the aid of genetic operators, are not able to generate offspring that are superior to, or outperform, their parents. Premature convergence is a common problem found in evolutionary algorithms in general and genetic algorithms in particular, as it leads to a loss, or convergence of, a large number of alleles, subsequently making it very difficult to search for a specific gene in which the alleles were present. An allele is considered lost if, in a population, a gene is present, where all individuals are sharing the same value for that particular gene. An allele is, as defined by De Jong, considered to be a converged allele, when 95% of a population share the same value for a certain gene.
In computer programming, genetic representation is a way of presenting solutions/individuals in evolutionary computation methods. The term encompasses both the concrete data structures and data types used to realize the genetic material of the candidate solutions in the form of a genome, and the relationships between search space and problem space. In the simplest case, the search space corresponds to the problem space. The choice of problem representation is tied to the choice of genetic operators, both of which have a decisive effect on the efficiency of the optimization. Genetic representation can encode appearance, behavior, physical qualities of individuals. Difference in genetic representations is one of the major criteria drawing a line between known classes of evolutionary computation.
The Gottfried Wilhelm Leibniz Prize, or Leibniz Prize, is awarded by the German Research Foundation to "exceptional scientists and academics for their outstanding achievements in the field of research". Since 1986, up to ten prizes have been awarded annually to individuals or research groups working at a research institution in Germany or at a German research institution abroad. It is considered the most important research award in Germany.
It was observed in evolution strategies that significant progress toward the fitness/objective function's optimum, generally, can only happen in a narrow band of the mutation step size σ. That narrow band is called evolution window.
Ingo Rechenberg was a German researcher and professor in the field of bionics. Rechenberg was a pioneer of the fields of evolutionary computation and artificial evolution. In the 1960s and 1970s he invented a highly influential set of optimization methods known as evolution strategies. His group successfully applied the new algorithms to challenging problems such as aerodynamic wing design. These were the first serious technical applications of artificial evolution, an important subset of the still growing field of bionics.
Wolfgang Siegfried Haack was a German mathematician and aerodynamicist. He in 1941 and William Sears in 1947 independently discovered the Sears–Haack body.
Specialized wind energy software applications aid in the development and operation of wind farms.
Hermann Föttinger was a German engineer and inventor. In the course of his life he submitted over 100 patent applications, but he is most notable for inventing fluid coupling.
In applied mathematics, multimodal optimization deals with optimization tasks that involve finding all or most of the multiple solutions of a problem, as opposed to a single best solution. Evolutionary multimodal optimization is a branch of evolutionary computation, which is closely related to machine learning. Wong provides a short survey, wherein the chapter of Shir and the book of Preuss cover the topic in more detail.
Machine learning control (MLC) is a subfield of machine learning, intelligent control and control theory which solves optimal control problems with methods of machine learning. Key applications are complex nonlinear systems for which linear control theory methods are not applicable.
Parallel Problem Solving from Nature, or PPSN, is a research conference focusing on the topic of natural computing.
The population model of an evolutionary algorithm (EA) describes the structural properties of its population to which its members are subject. A population is the set of all proposed solutions of an EA considered in one iteration, which are also called individuals according to the biological role model. The individuals of a population can generate further individuals as offspring with the help of the genetic operators of the procedure.