МОДИФИКАЦИЯ МЕТАЭВРИСТИЧЕСКОГО МЕТОДА ФЕЙЕРВЕРКОВ ДЛЯ ЗАДАЧ МНОГОКРИТЕРИАЛЬНОЙ ОПТИМИЗАЦИИ НА ОСНОВЕ НЕДОМИНИРУЕМОЙ СОРТИРОВКИ

The article suggests a modification for numerical fireworks method of the single-objective optimization for solving the problem of multiobjective optimization. The method is metaheuristic. It does not guarantee finding the exact solution, but can give a good approximate result. Multiobjective optimization problem is considered with numerical criteria of equal importance. A possible solution to the problem is a vector of real numbers. Each component of the vector of a possible solution belongs to a certain segment. The optimal solution of the problem is considered a Pareto optimal solution. Because the set of Pareto optimal solutions can be infinite; we consider a method for finding an approximation consisting of a finite number of Pareto optimal solutions. The modification is based on the procedure of non-dominated sorting. It is the main procedure for solutions search. Non-dominated sorting is the ranking of decisions based on the values of the numerical vector obtained using the criteria. Solutions are divided into disjoint subsets. The first subset is the Pareto optimal solutions, the second subset is the Pareto optimal solutions if the first subset is not taken into account, and the last subset is the Pareto optimal solutions if the rest subsets are not taken into account. After such a partition, the decision is made to create new solutions. The method was tested on well-known bi-objective optimization problems: ZDT2, LZ01. Structure of the location of Pareto optimal solutions differs for the problems. LZ01 have complex structure of Pareto optimal solutions. In conclusion, the question of future research and the issue of modifying the method for problems with general constraints are discussed.В работе предлагается модификация численного метода фейерверков однокритериальной оптимизации для решения задач многокритериальной оптимизации. Метод относится к метаэвристическим алгоритмам, он не гарантирует нахождения точного решения, но может найти достаточно хорошее приближенное решение. Рассматриваются многокритериальные задачи оптимизации с числовыми критериями, имеющими одинаковую важность. Допустимое решение задачи представляется вектором из действительных чисел, значение каждой компоненты которого принадлежит определенному отрезку. Под оптимальным решением понимается решение, оптимальное по Парето. Так как точных решений, оптимальных по Парето, может быть бесконечно много, рассматривается способ нахождения приближения, состоящего из конечного числа решений, оптимальных по Парето. Модификация основана на процедуре недоминируемой сортировки, которая является основной процедурой для управления процессом поиска приближенного решения. Недоминируемая сортировка – это ранжирование решений на основе значений компонент числового вектора, полученных с помощью вычисления критериев. Каждая компонента соответствует определенному критерию, а множество решений разбивается на непересекающиеся подмножества. Первое подмножество – это решения, оптимальные по Парето, второе подмножество – это решения, оптимальные по Парето, если не учитывать первое подмножество, последнее подмножество – это решения, оптимальные по Парето, если не учитывать все предыдущие подмножества. После такого разбиения принимается решение о генерировании новых допустимых решений. Работа метода протестирована на общеизвестных задачах многокритериальной оптимизации с двумя критериями: ZDT2, LZ01. Задачи отличаются структурой расположения решений, оптимальных по Парето. Так LZ01 имеет достаточно сложную структуру решений, оптимальных по Парето. В заключении обсуждаются вопросы о дальнейшем направлении исследований и о возможности модификации метода для задач многокритериальной оптимизации с произвольными, а не параллелепипедными ограничениями

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Evolution of Scikit-Learn Pipelines with Dynamic Structured Grammatical Evolution

The deployment of Machine Learning (ML) models is a difficult and time-consuming job that comprises a series of sequential and correlated tasks that go from the data pre-processing, and the design and extraction of features, to the choice of the ML algorithm and its parameterisation. The task is even more challenging considering that the design of features is in many cases problem specific, and thus requires domain-expertise. To overcome these limitations Automated Machine Learning (AutoML) methods seek to automate, with few or no human-intervention, the design of pipelines, i.e., automate the selection of the sequence of methods that have to be applied to the raw data. These methods have the potential to enable non-expert users to use ML, and provide expert users with solutions that they would unlikely consider. In particular, this paper describes AutoML-DSGE - a novel grammar-based framework that adapts Dynamic Structured Grammatical Evolution (DSGE) to the evolution of Scikit-Learn classification pipelines. The experimental results include comparing AutoML-DSGE to another grammar-based AutoML framework, Resilient ClassificationPipeline Evolution (RECIPE), and show that the average performance of the classification pipelines generated by AutoML-DSGE is always superior to the average performance of RECIPE; the differences are statistically significant in 3 out of the 10 used datasets.Comment: EvoApps 202

The germinal centre artificial immune system

This thesis deals with the development and evaluation of the Germinal centre artificial immune system (GC-AIS) which is a novel artificial immune system based on advancements in the understanding of the germinal centre reaction of the immune system. The key research questions addressed in this thesis are: can an artificial immune system (AIS) be designed by taking inspiration from recent developments in immunology to tackle multi-objective optimisation problems? How can we incorporate desirable features of the immune system like diversity, parallelism and memory into this proposed AIS? How does the proposed AIS compare with other state of the art techniques in the field of multi-objective optimisation problems? How can we incorporate the learning component of the immune system into the algorithm and investigate the usefulness of memory in dynamic scenarios? The main contributions of the thesis are: • Understanding the behaviour and performance of the proposed GC-AIS on multiobjective optimisation problems and explaining its benefits and drawbacks, by comparing it with simple baseline and state of the art algorithms. • Improving the performance of GC-AIS by incorporating a popular technique from multi-objective optimisation. By overcoming its weaknesses the capability of the improved variant to compete with the state of the art algorithms is evaluated. • Answering key questions on the usefulness of incorporating memory in GC-AIS in a dynamic scenario

学習戦略に基づく学習分類子システムの設計

On Learning Classifier Systems dubbed LCSs a leaning strategy which defines how LCSs cover a state-action space in a problem can be one of the most fundamental options in designing LCSs. There lacks an intensive study of the learning strategy to understand whether and how the learning strategy affects the performance of LCSs. This lack has resulted in the current design methodology of LCS which does not carefully consider the types of learning strategy. The thesis clarifies a need of a design methodology of LCS based on the learning strategy. That is, the thesis shows the learning strategy can be an option that determines the potential performance of LCSs and then claims that LCSs should be designed on the basis of the learning strategy in order to improve the performance of LCSs. First, the thesis empirically claims that the current design methodology of LCS, without the consideration of learning strategy, can be limited to design a proper LCS to solve a problem. This supports the need of design methodology based on the learning strategy. Next, the thesis presents an example of how LCS can be designed on the basis of the learning strategy. The thesis empirically show an adequate learning strategy improving the performance of LCS can be decided depending on a type of problem difficulties such as missing attributes. Then, the thesis draws an inclusive guideline that explains which learning strategy should be used to address which types of problem difficulties. Finally, the thesis further shows, on an application of LCS for a human daily activity recognition problem, the adequate learning strategy according to the guideline effectively improves the performance of the application. The thesis concludes that the learning strategy is the option of the LCS design which determines the potential performance of LCSs. Thus, before designing any type of LCSs including their applications, the learning strategy should be adequately selected at first, because their performance degrades when they employ an inadequate learning strategy to a problem they want to solve. In other words, LCSs should be designed on the basis of the adequate learning strategy.電気通信大学201

Fahrplanbasiertes Energiemanagement in Smart Grids

Die Zunahme dezentraler, volatiler Stromerzeugung im Rahmen der Energiewende führt schon heute zu Engpässen in Stromnetzen. Eine Lösung dieser Probleme verspricht die informationstechnische Vernetzung und Koordination der Erzeuger und Verbraucher in Smart Grids. Diese Arbeit präsentiert einen Energiemanagement-Ansatz, der basierend auf Leistungsprognosen und Flexibilitäten der Akteure spezifische, aggregierte Leistungsprofile approximiert. Hierbei werden Netzrestriktionen berücksichtigt

A model evaluating the number and areas of functional regions

Functional regions are a generalization of changeable social and economic functional interactions in a territory. These regions are increasingly used when analysing economic, social, environmental, and spatial development and when making development-related decisions. In this doctoral dissertation we propose a procedure to evaluate the areas and the number of hierarchical functional regions. The procedure is based on: (a) using Intramax, a hierarchical method to model functional region systems of labour commuting by time intervals, (b) comparison of functional region systems using the index proposed in this dissertation, (c) evaluation of functional regions using selected indicators, and (d) evaluation of the impact of selected socio-economic factors on labour commuting in, and between, functional regions in a spatial interaction model using regression analysis. The procedure of evaluating the systems of hierarchical functional regions was employed for the case study of Slovenia for the period 2000–2011. The study pointed at three characteristic and balanced systems of functional regions, whose area and efficiency, in the light of the proportion of inner flows and homogeneity of employment and housing self-containment, did not significantly change over the period analysed. These are: a system of 5 functional regions with centres in Ljubljana, Maribor, Celje, Koper, and Novo mesto, a system of 7 functional regions with centres in Ljubljana, Maribor, Celje, Koper, Novo mesto, Nova Gorica, and Slovenj Gradec, and a system of 60 functional regions. In the dissertation we tested the assumption that the number and the areas of functional regions could be evaluated according to the socio-economic factors that significantly influence labour commuting. The analysis of the impact of the various factors most often analysed in the literature on labour commuting in, and between, functional regions highlighted four factors whose impacts proved to be statistically significant over the whole period considered and at all hierarchical levels of larger (2–70) functional regions. These factors are: travel time to work, population in origin, population in destination, and the employment rate in destination. The proposed approach allows for continuous monitoring and evaluation of balanced systems of hierarchical functional regions in the territory of Slovenia. The characteristic and balanced systems of 5 and 7 functional regions, respectively, as highlighted in this dissertation, can provide a criterion for deciding about establishing provinces in Slovenia

Quality-driven Multi-objective Optimization of Software Architecture Design: Method, Tool, and Application

Software architecting is a non-trivial and demanding task for software engineers to perform. The architecture is a key enabler for software systems. Besides being crucial for user functionality, the software architecture has deep impact on software qualities such as performance, safety, and cost. In this dissertation, an automated approach for software architecture design is proposed that supports analysis and optimization of multiple quality attributes:First of all, we demonstrate an optimization approach for automated software architecture design. It reports the results of applying our architecture optimization framework to an automotive sub-system that was conducted based on a large-scale real world case study. Moreover, we introduce two novel degrees of freedom which demonstrate how the number of processing nodes and their interconnecting network can be codified to fit into a genetic algorithm. Our studies show that these extra degrees of freedom lead to better overall software architecture optimization. Finally, we propose a new search-based approach for generating a set of optimal software architectural solutions for use in software product lines. Our new approach analyses the commonality of the found optimal solutions and proposes a set of solutions which are suitable for the range of products defined by various feature combinations.Algorithms and the Foundations of Software technolog

Fahrplanbasiertes Energiemanagement in Smart Grids

Die Zunahme dezentraler, volatiler Stromerzeugung im Rahmen der Energiewende führt schon heute zu Engpässen in Stromnetzen. Eine Lösung dieser Probleme verspricht die informationstechnische Vernetzung und Koordination der Erzeuger und Verbraucher in Smart Grids. Diese Arbeit präsentiert einen Energiemanagement-Ansatz, der basierend auf Leistungsprognosen und Flexibilitäten der Akteure spezifische, aggregierte Leistungsprofile approximiert. Hierbei werden Netzrestriktionen berücksichtigt