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Wyszukujesz frazę "OPTIMIZATION" wg kryterium: Temat


Tytuł:
Structural weight minimization of high speed vehicle-passenger catamaran by genetic algorithm
Autorzy:
Sekulski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/258678.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship structure
optimization
topology optimization
sizing optimization
genetic algorithm
Opis:
Reduction of hull structural weight is the most important aim in the design of many ship types. But the ability of designers to produce optimal designs of ship structures is severely limited by the calculation techniques available for this task. Complete definition of the optimal structural design requires formulation of size-topology-shape-material optimization task unifying optimization problems from four areas and effective solution of the problem. So far a significant progress towards solution of this problem has not been achieved. In other hand in recent years attempts have been made to apply genetic algorithm (GA) optimization techniques to design of ship structures. An objective of the paper was to create a computer code and investigate a possibility of simultaneous optimization of both topology and scantlings of structural elements of large spacial sections of ships using GA. In the paper GA is applied to solve the problem of structural weight minimisation of a high speed vehicle-passenger catamaran with several design variables as dimensions of the plate thickness, longitudinal stiffeners and transverse frames and spacing between longitudinals and transversal members. Results of numerical experiments obtained using the code are presented. They shows that GA can be an efficient optimization tool for simultaneous design of topology and sizing high speed craft structures.
Źródło:
Polish Maritime Research; 2009, 2; 11-23
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bainite transformation time model optimization for Austempered Ductile Iron with the use of heuristic algorithms
Autorzy:
Olejarczyk-Wożeńska, Izabela
Opaliński, Andrzej
Mrzygłód, Barbara
Regulski, Krzysztof
Kurowski, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/29520068.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
heuristic optimization
bainite
ADI
Particle Swarm Optimization
Evolutionary Optimization Algorithm
Opis:
The paper presents the application of heuristic optimization methods in identifying the parameters of a model for bainite transformation time in ADI (Austempered Ductile Iron). Two algorithms were selected for parameter optimization – Particle Swarm Optimization and Evolutionary Optimization Algorithm. The assumption of the optimization process was to obtain the smallest normalized mean square error (objective function) between the time calculated on the basis of the identified parameters and the time derived from the experiment. As part of the research, an analysis was also made in terms of the effectiveness of selected methods, and the best optimization strategies for the problem to be solved were selected on their basis.
Źródło:
Computer Methods in Materials Science; 2022, 22, 3; 125-136
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid optimization process applied to tuning of Dynamic Matrix Control: atudy case with DC motor
Autorzy:
Carvalho, D. F. de
Ganzaroli, C. A.
Couto, L. do
Dias, R. N. H. M.
Calixto, W. P.
Powiązania:
https://bibliotekanauki.pl/articles/136171.pdf
Data publikacji:
2017
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
predictive control
deterministic optimization
heuristic optimization
hybrid optimization
DC motor
Opis:
This paper presents study about Dynamic Matrix Control (DMC) controller applied to speed control of DC motor. DMC controller parameters (prediction horizon, control horizon and damping rate of reference) are obtained through optimization methods employing heuristic, deterministic and hybrid strategies. The use of advanced control technique combined with using of optimization methods aims to achieve highly efficient control, reducing the transient state period and variations in steady state. These methods were applied on a simulation model in order to verify which one provides better control results.
Źródło:
Transactions on Environment and Electrical Engineering; 2017, 2, 2; 24-30
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Composite semi-infinite optimization
Autorzy:
Dentcheva, D.
Ruszczyński, A.
Powiązania:
https://bibliotekanauki.pl/articles/970266.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
semi-infinite optimization
nonsmooth optimization
composite optimization
stochastic programming
stochastic dominance
Opis:
We consider a semi-infinite optimization problem in Banach spaces, where both the objective functional and the constraint operator are compositions of convex nonsmooth mappings and differentiable mappings. We derive necessary optimality conditions for these problems. Finally, we apply these results to non-convex stochastic optimization problems with stochastic dominance constraints, generalizing earlier results.
Źródło:
Control and Cybernetics; 2007, 36, 3; 633-646
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Study of PSO and CMA-ES Algorithms on Black-box Optimization Benchmarks
Autorzy:
Szynkiewicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/307566.pdf
Data publikacji:
2018
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
benchmarking
black-box optimization
CMA-ES
global optimization
PSO
stochastic optimization
Opis:
Numerous practical engineering applications can be formulated as non-convex, non-smooth, multi-modal and ill-conditioned optimization problems. Classical, deterministic algorithms require an enormous computational effort, which tends to fail as the problem size and its complexity increase, which is often the case. On the other hand, stochastic, biologically-inspired techniques, designed for global optimum calculation, frequently prove successful when applied to real life computational problems. While the area of bio-inspired algorithms (BIAs) is still relatively young, it is undergoing continuous, rapid development. Selection and tuning of the appropriate optimization solver for a particular task can be challenging and requires expert knowledge of the methods to be considered. Comparing the performance of viable candidates against a defined test bed environment can help in solving such dilemmas. This paper presents the benchmark results of two biologically inspired algorithms: covariance matrix adaptation evolution strategy (CMA-ES) and two variants of particle swarm optimization (PSO). COCO (COmparing Continuous Optimizers) – a platform for systematic and sound comparisons of real-parameter global optimization solvers was used to evaluate the performance of CMA-ES and PSO methods. Particular attention was paid to the effciency and scalability of both techniques.
Źródło:
Journal of Telecommunications and Information Technology; 2018, 4; 5-17
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hierarchical genetic computation in optimal design
Hierarchiczne obliczenia genetyczne w projektowaniu optymalnym
Autorzy:
Kołodziej, J.
Schaefer, R.
Paszyńska, A.
Powiązania:
https://bibliotekanauki.pl/articles/281989.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
hierarchical genetic optimization
graph encoding
shape optimization
Opis:
The paper presents two examples of genetic hierarchic global optimization methods. They are two different goals of introducing hierarchy into the computational model: to perform the multi-scale search with the adapted accuracy and to better express the structure geometry in the optimal shape design. Results of the formal analysis and simple computational examples are also attached.
Praca przedstawia dwa przykłady hierarchicznych, genetycznych metod optymalizacji. Sklasyfikowano dwa główne powody wprowadzenia hierarchii do modelu obliczeniowego: dla uzyskania wieloskalowego przeszukania z adaptowaną dokładnością oraz dla lepszego odwzorowania kształtu konstrukcji w zadaniach optymalnego projektowania kształtu. Zamieszczono rezultaty formalnej analizy proponowanych strategii oraz proste przykłady obliczeniowe.
Źródło:
Journal of Theoretical and Applied Mechanics; 2004, 42, 3; 519-538
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of influence of calculation precision on the effectiveness of stochastic optimization methods
Autorzy:
Cegielski, M.
Stakhiv, P.
Kozak, Yu.
Powiązania:
https://bibliotekanauki.pl/articles/410742.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
stochastic optimization methods
graphics processors
optimization speed
Opis:
This paper describes the influence of the varying computation precision when performing calculations using the optimizing algorithms. A comparative analysis of the computation speed and obtained result accuracy of the Rastrigin’s direct cone method with adapting of the step length and the angle of the cone's disclosure for varying precision was performed. It is shown that the speed of the optimization algorithm practically does not depend on used computation precision. The difference is observed only in accuracy of the obtained results. The investigation of optimizing algorithms behavior under the presence of noise, in particular due to rounding errors was conducted. It is shown that the optimizing algorithm under research becomes unsuitable after some noise level. Characteristics of the optimization algorithm during calculations with a single precision proved to be better then the characteristics of the algorithm when performing calculations with double precision. The analysis of possibilities of the effective graphics processors (GPU) application in order to conduct optimization was carried out. In particular, the difference in the speed of the GPU when performing calculations with a single and double precision was considered. To ensure the efficiency of calculations based on optimization algorithms, it is recommended to carry out calculations with the use of single precision, and increase the calculation precision in case of impossibility to achieve the desired accuracy of the result. There is considering the significantly higher performance of graphics processors when doing calculations with a single precision in comparison with calculations with double precision it is expedient to use a single calculation precision when graphic processors are used to solve considered problem. Double precision can be used if it is difficult to get sufficiently correct solution by single precision calculations. The results of numerical experiments confirm that the use of lower precision to perform optimization for macromodels creation has a slight influence on the speed of achieving of predetermined optimization accuracy.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2016, 5, 2; 121-126
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydraulic fracturing optimization framework based on PKN and Cinco-Ley methods
Autorzy:
Budzowski, R.
Janiga, D.
Czarnota, R.
Wojnarowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/299213.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
optimization
hydraulic fracturing
nature - inspired optimization algorithms
Opis:
In an era of decreasing number of discoveries of conventional hydrocarbon reservoirs, in the global oil and gas industry we can observe growing interest in unconventional resources. Conducting effective production from this type of reservoirs is associated with carrying out the intensification processes of production, among which hydraulic fracturing is the most popular. Fracturing project design consist of several technological parameters, i.e. the type of fracturing fluid and quantity of proppant, which have a direct impact on the process effectiveness. The actual shape of the fracture is difficult to predict due to the local heterogeneity of the reservoir and the superposition of the phenomena occurring during stimulation treatment. In this paper optimization model was proposed, which allows for selection appropriate parameters of fracturing technology. Developed optimization algorithm is based on two-dimensional PKN fracture model and Cinco-Ley analytical method. Optimization method used in this paper based on nature - inspired algorithms which were compared with gradient method.
Źródło:
AGH Drilling, Oil, Gas; 2017, 34, 1; 157-167
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization as a tool for time reduction in simulation projects
Autorzy:
Gregor, M.
Stefanik, A.
Powiązania:
https://bibliotekanauki.pl/articles/117744.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
simulation
optimization
time reduction
optimization algorithms
application
Opis:
This paper presents the optimization methods appropriate for discrete event simulations of manufacturing systems. The chosen optimization approach was applied in various simulation projects. Given example shows practically how can be utilize optimization in simulation. The paper presents the results of simulation and time reductions achieved through optimisation.
Źródło:
Applied Computer Science; 2006, 2, 1; 135-147
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiobjective optimization of reflector’s shape
Autorzy:
Wandachowicz, K.
Powiązania:
https://bibliotekanauki.pl/articles/97623.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
luminaires
optimization
Opis:
The article presents results of research on the calculation of the shape of a mirror reflector, which ensures the highest possible average illuminance, and uniformity of illuminance. A multiobjective genetic algorithm was used to carry out optimization calculations.
Źródło:
Computer Applications in Electrical Engineering; 2013, 11; 370-379
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graph based discrete optimization in structural dynamics
Autorzy:
Blachowski, B.
Gutkowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/200069.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
discrete structural optimization
combinatorial optimization
structural dynamics
stochastic loading
problem oriented optimization
graphs
Opis:
In this study, a relatively simple method of discrete structural optimization with dynamic loads is presented. It is based on a tree graph, representing discrete values of the structural weight. In practical design, the number of such values may be very large. This is because they are equal to the combination numbers, arising from numbers of structural members and prefabricated elements. The starting point of the method is the weight obtained from continuous optimization, which is assumed to be the lower bound of all possible discrete weights. Applying the graph, it is possible to find a set of weights close to the continuous solution. The smallest of these values, fulfilling constraints, is assumed to be the discrete minimum weight solution. Constraints can be imposed on stresses, displacements and accelerations. The short outline of the method is presented in Sec. 2. The idea of discrete structural optimization by means of graphs. The knowledge needed to apply the method is limited to the FEM and graph representation. The paper is illustrated with two examples. The first one deals with a transmission tower subjected to stochastic wind loading. The second one with a composite floor subjected to deterministic dynamic forces, coming from the synchronized crowd activities, like dance or aerobic.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 1; 91-102
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Loop optimization in managed code environments with expressions evaluated only once
Autorzy:
Piorkowski, A.
Zupnik, M.
Powiązania:
https://bibliotekanauki.pl/articles/1955308.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska
Tematy:
loop optimization
component platforms
compile-time optimization
compilers
Opis:
This paper is concerned with optimizing code execution in virtual machine environments. Code motion is one of the many optimization techniques. We considered a special case of optimization – a loop containing expressions that can be effectively evaluated once. A solution for this case is discussed and two algorithms are proposed. Experimental results for Java VM, MS .NET and Mono are shown here in order to assess the performance of the proposed algorithms.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2010, 14, 4; 397-404
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization problems with convex epigraphs. Application to optimal control
Autorzy:
Kryazhimskii, A. V.
Powiązania:
https://bibliotekanauki.pl/articles/908078.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
równanie nieliniowe
optymalizacja
nonconvex optimization
global optimization methods
Opis:
For a class of infinite-dimensional minimization problems with nonlinear equality constraints, an iterative algorithm for finding global solutions is suggested. A key assumption is the convexity of the "epigraph", a set in the product of the image spaces of the constraint and objective functions. A convexification method involving randomization is used. The algorithm is based on the extremal shift control principle due to N.N. Krasovskii. An application to a problem of optimal control for a bilinear control system is described.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2001, 11, 4; 773-801
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Perturbation algorithm for a minimax regret minimum spanning tree problem
Autorzy:
Makuchowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/406452.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
discrete optimization
robust optimization
perturbation algorithms
minimax regret
Opis:
The problem of finding a robust spanning tree has been analysed. The problem consists of determining a minimum spanning tree of a graph with uncertain edge costs. We should determine a spanning tree that minimizes the difference in costs between the tree selected and the optimal tree. While doing this, all possible realizations of the edge costs should be taken into account. This issue belongs to the class of NP-hard problems. In this paper, an algorithm based on the cost perturbation method and adapted to the analysed problem has been proposed. The paper also contains the results of numerical experiments testing the effectiveness of the proposed algorithm and compares it with algorithms known in the literature. The research is based on a large number of various test examples taken from the literature.
Źródło:
Operations Research and Decisions; 2014, 24, 1; 37-49
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large-scale nonlinear programming algorithm using projection methods
Autorzy:
Białoń, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/729340.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
nonlinear optimization
large scale optimization
projection methods
zigzagging
Opis:
A method for solving large convex optimization problems is presented. Such problems usually contain a big linear part and only a small or medium nonlinear part. The parts are tackled using two specialized (and thus efficient) external solvers: purely nonlinear and large-scale linear with a quadratic goal function. The decomposition uses an alteration of projection methods. The construction of the method is based on the zigzagging phenomenon and yields a non-asymptotic convergence, not dependent on a large dimension of the problem. The method preserves its convergence properties under limitations in complicating sets by geometric cuts. Various aspects and variants of the method are analyzed theoretically and experimentally.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2000, 20, 2; 171-194
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł

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