Search results for "optimointi"

Анализ и оптимизация устойчивости балок на сплошном упругом основании часть II (бесконечные балки) [Analysis and optimization of a beam on elastic fo…

2017

Problems of defining of optimal (against buckling) cross section area distribution for beams interacting with elastic foundation are considered. The stability of limited pinned beams and infinite continuous beams is analyzed. For all beams under consideration, the stability analysis is performed as for constant as for variable distributions of strength beam characteristics. The critical length is determined and the variational statement of beam stability problems is presented for this beam type. For infinite continuous beams, the stability problems are investigated as for constant as for periodic distribution of strength characteristics. In the second case, the analysis of infinite beam can…

On the existence of optimal shapes in contact problems : perfectly plastic bodies

1986

Solving classification problems with multicriteria decision aiding approaches

2007

Iryna Yevseyevan väitöskirjan aiheena on päätöksentekijän avustaminen hänen ratkaistessaan vaativia ja monimutkaisia luokittelutehtäviä. Tällaisia tehtäviä esiintyy erityyppisessä diagnostiikassa, esimerkiksi lääketieteen alalla lääkärin diagnosoidessa potilasta, tekniikan alalla insinöörin määrittäessä koneen rikkoutumisen syytä tai talouden alalla sijoittajan arvioidessa riskejä ennen sijoituspäätöstä.Yevseyevan tutkimat ja kehittämät menetelmät ovat avuksi silloin, kun luokittelupäätökset ovat riippuvaisia päätöksentekijän subjektiivisesta tietämyksestä, intuitiosta ja mieltymyksistä. Esitetyt menetelmät mahdollistavat ongelmakentän määrittelyn ja formalisoinnin, ja lisäksi ne tarjoavat …

Parallel global optimization : structuring populations in differential evolution

2010

On automatic algorithm configuration of vehicle routing problem solvers

2019

Many of the algorithms for solving vehicle routing problems expose parameters that strongly influence the quality of obtained solutions and the performance of the algorithm. Finding good values for these parameters is a tedious task that requires experimentation and experience. Therefore, methods that automate the process of algorithm configuration have received growing attention. In this paper, we present a comprehensive study to critically evaluate and compare the capabilities and suitability of seven state-of-the-art methods in configuring vehicle routing metaheuristics. The configuration target is the solution quality of eight metaheuristics solving two vehicle routing problem variants.…

Interactive data-driven multiobjective optimization of metallurgical properties of microalloyed steels using the DESDEO framework

2023

Solving real-life data-driven multiobjective optimization problems involves many complicated challenges. These challenges include preprocessing the data, modelling the objective functions, getting a meaningful formulation of the problem, and supporting decision makers to find preferred solutions in the existence of conflicting objective functions. In this paper, we tackle the problem of optimizing the composition of microalloyed steels to get good mechanical properties such as yield strength, percentage elongation, and Charpy energy. We formulate a problem with six objective functions based on data available and support two decision makers in finding a solution that satisfies them both. To …

A Multiple Surrogate Assisted Decomposition Based Evolutionary Algorithm for Expensive Multi/Many-Objective Optimization

2019

Many-objective optimization problems (MaOPs) contain four or more conflicting objectives to be optimized. A number of efficient decomposition-based evolutionary algorithms have been developed in the recent years to solve them. However, computationally expensive MaOPs have been scarcely investigated. Typically, surrogate-assisted methods have been used in the literature to tackle computationally expensive problems, but such studies have largely focused on problems with 1–3 objectives. In this paper, we present an approach called hybrid surrogate-assisted many-objective evolutionary algorithm to solve computationally expensive MaOPs. The key features of the approach include: 1) the use of mul…

Desirable properties of performance indicators for assessing interactive evolutionary multiobjective optimization methods

2022

Interactive methods support decision makers in finding the most preferred solution in multiobjective optimization problems. They iteratively incorporate the decision maker's preference information to find the best balance among conflicting objectives. Several interactive methods have been developed in the literature. However, choosing the most suitable interactive method for a given problem can prove challenging and appropriate indicators are needed to compare interactive methods. Some indicators exist for a priori methods, where preferences are provided at the beginning of the solution process. We present some numerical experiments that illustrate why these indicators are not suitable for …

Towards constructing a Pareto front approximation for use in interactive forest management planning

2013

The selection of an appropriate multi-objective forest management plan can be a difficult task due to the vast number of alternatives available to the decision maker (DM). The complexity of the task depends e.g. on how clear the preferences of the DM are. For those DMs who do not have clear preferences, interactive methods of forest planning could assist in clarifying preferences and guiding the selection in an efficient fashion. Interactive planning methods are useful when the DM needs to consider a wide range of efficient solutions quickly. With large forest holdings or with complicated forest management goals, the development of new forest plans can become a rather computationally demand…

Sectoral policies as drivers of forest management and ecosystems services: A case study in Bavaria, Germany

2023

European countries have national sectoral polices to regulate and promote the provision of a wide range of forest ecosystems services (FES). However, potential incoherencies among these policies can negatively affect the efficient provision of FES. In this work, we evaluated the coherence among three national policies from Germany and their ability to effectively provide FES in the future: the Forest Strategy 2020 (FS), the National Strategy on Biological Diversity (BDS), and the German National Policy Strategy on Bioeconomy (BES). Using forest inventory data from the Federal State of Bavaria, we simulated a range of forest management options under three climate trajectories for 100 years i…