Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Optimization" wg kryterium: Temat


Tytuł:
Structural weight minimization of high speed vehicle-passenger catamaran by genetic algorithm
Autorzy:
Sekulski, Z.
Tematy:
ship structure
optimization
topology optimization
sizing optimization
genetic algorithm
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:
https://bibliotekanauki.pl/articles/258678.pdf  Link otwiera się w nowym oknie
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.
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
Tematy:
heuristic optimization
bainite
ADI
Particle Swarm Optimization
Evolutionary Optimization Algorithm
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/29520068.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measuring diversity of socio-cognitively inspired ACO search
Autorzy:
Świderska, Ewelina
Lenaerts, Tom
Samson, Dana
Łasisz, Jakub
Byrski, Aleksander
Kisiel-Dorohinicki, Marek
Nowé, Ann
Indurkhya, Bipin
Wydawca:
Springer
Opis:
In our recent research, we implemented an enhancement of Ant Colony Optimization incorporating the socio-cognitive dimension of perspective taking. Our initial results suggested that increasing the diversity of ant population - introducing different pheromones, different species and dedicated inter-species relations - yielded better results. In this paper, we explore the diversity issue by introducing novel diversity measurement strategies for ACO. Based on these strategies we compare both classic ACO and its socio-cognitive variation.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Composite semi-infinite optimization
Autorzy:
Dentcheva, D.
Ruszczyński, A.
Tematy:
semi-infinite optimization
nonsmooth optimization
composite optimization
stochastic programming
stochastic dominance
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Powiązania:
https://bibliotekanauki.pl/articles/970266.pdf  Link otwiera się w nowym oknie
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.
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.
Tematy:
predictive control
deterministic optimization
heuristic optimization
hybrid optimization
DC motor
Pokaż więcej
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Powiązania:
https://bibliotekanauki.pl/articles/136171.pdf  Link otwiera się w nowym oknie
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.
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.
Tematy:
hierarchical genetic optimization
graph encoding
shape optimization
Pokaż więcej
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/281989.pdf  Link otwiera się w nowym oknie
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.
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.
Tematy:
stochastic optimization methods
graphics processors
optimization speed
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Powiązania:
https://bibliotekanauki.pl/articles/410742.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graph based discrete optimization in structural dynamics
Autorzy:
Blachowski, B.
Gutkowski, W.
Tematy:
discrete structural optimization
combinatorial optimization
structural dynamics
stochastic loading
problem oriented optimization
graphs
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/200069.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Study of PSO and CMA-ES Algorithms on Black-box Optimization Benchmarks
Autorzy:
Szynkiewicz, P.
Tematy:
benchmarking
black-box optimization
CMA-ES
global optimization
PSO
stochastic optimization
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/307566.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raport Badawczy = Research Report ; RB/50/2003
Methods review for solving inverse optimization problems
Autorzy:
Gola, Magdalena
Wydawca:
Instytut Badań Systemowych. Polska Akademia Nauk
Systems Research Institute. Polish Academy of Sciences
Powiązania:
Raport Badawczy = Research Report
Opis:
Bibliografia s. 18-20
This paper presents review of methods for solving various inverse combinatorial optimization problems, for example: inverse shortest path problem, inverse spanning tree problem, inverse minimum cut problem, etc., as well as some general methods for solving inverse problems.
20 pages ; 21 cm
20 stron ; 21 cm
Bibliography p. 18-20
Dostawca treści:
RCIN - Repozytorium Cyfrowe Instytutów Naukowych
Książka
Tytuł:
Large-scale nonlinear programming algorithm using projection methods
Autorzy:
Białoń, Paweł
Tematy:
nonlinear optimization
large scale optimization
projection methods
zigzagging
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729340.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A computational study of approximation algorithms for a minmax resource allocation problem
Autorzy:
Przybysławski, B.
Kasperski, A.
Tematy:
discrete optimization
robust optimization
resource allocation
approximation algorithms
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/406619.pdf  Link otwiera się w nowym oknie
Opis:
A basic resource allocation problem with uncertain costs has been discussed. The problem is to minimize the total cost of choosing exactly p items out of n available. The uncertain item costs are specified as a discrete scenario set and the minmax criterion is used to choose a solution. This problem is known to be NP-hard, but several approximation algorithms exist. The aim of this paper is to investigate the quality of the solutions returned by these approximation algorithms. According to the results obtained, the randomized algorithms described are fast and output solutions of good quality, even if the problem size is large.
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.
Tematy:
optimization
hydraulic fracturing
nature - inspired optimization algorithms
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/299213.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization as a tool for time reduction in simulation projects
Autorzy:
Gregor, M.
Stefanik, A.
Tematy:
simulation
optimization
time reduction
optimization algorithms
application
Pokaż więcej
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Powiązania:
https://bibliotekanauki.pl/articles/117744.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bireference Procedure fBIP for Interactive Multicriteria Optimization with Fuzzy Coefficients
Autorzy:
Wojewnik, Piotr
Szapiro, Tomasz
Tematy:
decision support
multicriteria decision making
interactive optimization
fuzzy optimization
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/483325.pdf  Link otwiera się w nowym oknie
Opis:
In the paper an approach to decision making in situations with non-pointlike characterisation and subjective evaluation of the actions is considered. The decision situation is represented mathematically as fuzzy multiobjective linear programming (fMOLP) model, where we apply the reduced fuzzy matrices instead of fuzzy classical numbers. The fMOLP model with reduced parameters is decomposable into the set of point-like models and the point-like models enable effective construction of an optimisation procedure - fBIP, see Wojewnik (2006ab), extending the bireference procedure by Michalowski and Szapiro (1992). The approach is applied to a fuzzy optimization problem in the area of telecommunication services.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Study of Particle Swarm Optimization and Genetic Algorithms for Complex Mathematical Functions
Autorzy:
Valdez, F.
Melin, P.
Tematy:
genetic algorithms
particle swarm optimization (PSO)
hybrid systems
optimization
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Powiązania:
https://bibliotekanauki.pl/articles/384575.pdf  Link otwiera się w nowym oknie
Opis:
The Particle Swarm Optimization (PSO) and the Genetic Algorithms (GA) have been used successfully in solving problems of optimization with continuous and combinatorial search spaces. In this paper the results of the application of PSO and GAs for the optimization of mathematical functions are presented. These two methodologies have been implemented with the goal of making a comparison of their performance in solving complex optimization problems. This paper describes a comparison between a GA and PSO for the optimization of complex mathematical functions.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust Optimization Model for Spatial Land-Use Allocation Problem in Jatinangor Subdistrict, Indonesia
Autorzy:
Romhadhoni, Putri
Chaerani, Diah
Ruchjana, Budi Nurani
Tematy:
Jatinangor Subdistrict
Land-use Allocation
Robust Optimization
Spatial Optimization
Pokaż więcej
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:
https://bibliotekanauki.pl/articles/1031447.pdf  Link otwiera się w nowym oknie
Opis:
Land-use planning become an important thing to do because some types of land-use can have an impact to environment and life quality. Land-use planning is generally an activity that involves the allocation of activities in a particular land. Spatial Optimization can be applied in land-use planning activity. This research aims to make Robust Optimization model for spatial land-use allocation problem in Jatinangor. Optimization model for land-use allocation problem aims to determine the percentage of land-use changes that can maximize comprehensive index and compactness index. In land-use planning, there are several uncertainty factors. Therefore, it’s needed an approach that can handle uncertainty factor, the approach used in this research is Robust Optimization. The result of Robust Optimization Model for land-use allocation problem which is solved by the box uncertainty set approach is a computationally tractable optimization model.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skuteczność nowoczesnych algorytmów optymalizacji czerpiących inspirację z procesów naturalnych
The effectiveness of modern optimization algorithms inspired by natural processes
Autorzy:
Klawikowska, Zuzanna
Puchalski, Bartosz
Tematy:
optymalizacja
algorytmy optymalizacji
benchmark
metaheurystyki
optimization
optimization algorithms
metaheuristics
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Powiązania:
https://bibliotekanauki.pl/articles/1841916.pdf  Link otwiera się w nowym oknie
Opis:
Ze względu na nieistnienie uniwersalnego algorytmu optymalizacji rozwiązującego wszystkie problemy naukowotechniczne opracowywanie nowych i wydajniejszych obliczeniowo algorytmów optymalizacyjnych wciąż jest popularnym zadaniem. Przeglądając literaturę z dziedziny optymalizacji można zauważyć trend tworzenia „wymyślnych” algorytmów opartych na procesach naturalnych. W artykule sprawdzono skuteczność nowopowstałych algorytmów meta-heurystycznych zainspirowanych życiem owadów i zwierząt – czarnych wdów (algorytm BWO) oraz szarego wilka (algorytm GWO). Skuteczność działania wybranych algorytmów porównano z klasycznym algorytmem quasi-Newtonowskim BFGS oraz strategią ewolucyjną CMA-ES, które charakteryzują się solidnym uwarunkowaniem matematycznym. W celach porównawczych wykorzystano 3 wybrane funkcje testowe. W ramach badań sprawdzono również wpływ liczby zmiennych decyzyjnych na czas uzyskiwania rozwiązania.
Due to the lack of a universal optimization algorithm which solves all scientific and technical problems, developing new and more computationally efficient optimization algorithms is still a popular challenge. Reviewing the literature on optimization there is a trend to create "fancy" algorithms based on natural processes. The article examines the effectiveness of newly developed meta-heuristic algorithms inspired by insects and animals - black widows (BWO algorithm) and grey wolf (GWO algorithm). The effectiveness of the selected algorithms was compared with the classical quasi-Newtonian BFGS algorithm and the evolutionary strategy CMA-ES, which are characterized by a solid mathematical background. Three selected benchmark functions were used for comparison purposes. The study also included a test of the influence of the number of design variables on the time complexity.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimum design of non-uniform symmetrical linear antenna arrays using a novel modified invasive weeds optimization
Autorzy:
Kenane, E.
Djahli, F.
Tematy:
invasive weeds optimization
non uniform linear array
optimization
synthesis
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/140370.pdf  Link otwiera się w nowym oknie
Opis:
This paper presents a new modified method for the synthesis of non-uniform linear antenna arrays. Based on the recently developed invasive weeds optimization technique (IWO), the modified invasive weeds optimization method (MIWO) uses the mutation process for the calculation of standard deviation (SD). Since the good choice of SD is particularly important in such algorithm, MIWO uses new values of this parameter to optimize the spacing between the array elements, which can improve the overall efficiency of the classical IWO method in terms of side lobe level (SLL) suppression and nulls control. Numerical examples are presented and compared to the existing array designs found in the literature, such as ant colony optimization (ACO), particle swarm optimization (PSO), and comprehensive learning PSO (CLPSO). Results show that MIWO method can be a good alternative in the design of non-uniform linear antenna array.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emergence of population structure in socio-cognitively inspired ant colony optimization
Autorzy:
Byrski, A.
Świderska, E.
Łasisz, J.
Kisiel-Dorohinicki, M.
Lenaerts, T.
Samson, D.
Indurkhya, B.
Tematy:
ant colony optimization
socio-cognitive systems
discrete optimization
emergence
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/305756.pdf  Link otwiera się w nowym oknie
Opis:
A metaheuristic proposed by us recently, Ant Colony Optimization (ACO) hybridized with socio-cognitive inspirations, turned out to generate interesting results compared to classic ACO. Even though it does not always find better solutions to the considered problems, it usually finds sub-optimal solutions usually. Moreover, instead of a trial-and-error approach to configure the parameters of the ant species in the population, in our approach, the actual structure of the population emerges from predefined species-to-species ant migration strategies. Experimental results of our approach are compared against classic ACO and selected socio-cognitive versions of this algorithm.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Survey on multi-objective based parameter optimization for deep learning
Autorzy:
Chakraborty, Mrittika
Pal, Wreetbhas
Bandyopadhyay, Sanghamitra
Maulik, Ujjwal
Tematy:
deep learning
multi-objective optimization
parameter optimization
neural networks
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/27312917.pdf  Link otwiera się w nowym oknie
Opis:
Deep learning models form one of the most powerful machine learning models for the extraction of important features. Most of the designs of deep neural models, i.e., the initialization of parameters, are still manually tuned. Hence, obtaining a model with high performance is exceedingly time-consuming and occasionally impossible. Optimizing the parameters of the deep networks, therefore, requires improved optimization algorithms with high convergence rates. The single objective-based optimization methods generally used are mostly time-consuming and do not guarantee optimum performance in all cases. Mathematical optimization problems containing multiple objective functions that must be optimized simultaneously fall under the category of multi-objective optimization sometimes referred to as Pareto optimization. Multi-objective optimization problems form one of the alternatives yet useful options for parameter optimization. However, this domain is a bit less explored. In this survey, we focus on exploring the effectiveness of multi-objective optimization strategies for parameter optimization in conjunction with deep neural networks. The case studies used in this study focus on how the two methods are combined to provide valuable insights into the generation of predictions and analysis in multiple applications.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of material distribution for forged automotive components using hybrid optimization techniques
Autorzy:
Sebastjan, Przemysław
Kuś, Wacław
Tematy:
shape optimization
hybrid optimization
genetic algorithms
evolutionary algorithms
gradient algorithms
auto-motive part optimization
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/29520109.pdf  Link otwiera się w nowym oknie
Opis:
The paper deals with the problem of optimal material distribution inside the provided design area. Optimization based on deterministic and stochastic algorithms is used to obtain the best result on the basis of the proposed objective function and constraints. The optimization of the shock absorber is used as an example of the described methods. One of the main difficulties addressed is the manufacturability of the optimized part intended for the forging process. Additionally, nonlinear buckling simulation with the use of the finite element method is used to solve the misuse case of shock absorber compression, where the shape of the optimized part has a key role in the total strength of the automotive damper. All of that, together with the required design precision, creates the nontrivial constrained optimization problem solved using the parametric, implicit geometry representation and a combination of stochastic and deterministic algorithms used with parallel design processing. Two methods of optimization are examined and compared in terms of the total amount of function calls, final design mass, and feasibility of the resultant design. Also, the amount of parameters used for the implicit geometry representation is greatly reduced compared to existing schemes presented in the literature. The problem addressed in this article is strongly inspired by the actual industrial example of the mass minimization process, but it is more focused on the actual manufacturability of the resultant component and admissible solving time. Commercially accessible software combined with authors’ procedures is used to resolve the material distribution task, which makes the proposed method universal and easily adapted to other fields of the optimization of mechanical elements.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Loop optimization in managed code environments with expressions evaluated only once
Autorzy:
Piorkowski, A.
Zupnik, M.
Tematy:
loop optimization
component platforms
compile-time optimization
compilers
Pokaż więcej
Wydawca:
Politechnika Gdańska
Powiązania:
https://bibliotekanauki.pl/articles/1955308.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization problems with convex epigraphs. Application to optimal control
Autorzy:
Kryazhimskii, A. V.
Tematy:
równanie nieliniowe
optymalizacja
nonconvex optimization
global optimization methods
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Powiązania:
https://bibliotekanauki.pl/articles/908078.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Perturbation algorithm for a minimax regret minimum spanning tree problem
Autorzy:
Makuchowski, M.
Tematy:
discrete optimization
robust optimization
perturbation algorithms
minimax regret
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/406452.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiobjective optimization of reflector’s shape
Autorzy:
Wandachowicz, K.
Tematy:
luminaires
optimization
Pokaż więcej
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Powiązania:
https://bibliotekanauki.pl/articles/97623.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid PSO approach for solving non-convex optimization problems
Autorzy:
Ganesan, T.
Vasant, P.
Elamvazuthy, I.
Tematy:
Kuhn-Tucker conditions (KT)
non-convex optimization
particle swarm optimization (PSO)
semi-classical particle swarm optimization (SPSO)
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/229756.pdf  Link otwiera się w nowym oknie
Opis:
The aim of this paper is to propose an improved particle swarm optimization (PSO) procedure for non-convex optimization problems. This approach embeds classical methods which are the Kuhn-Tucker (KT) conditions and the Hessian matrix into the fitness function. This generates a semi-classical PSO algorithm (SPSO). The classical component improves the PSO method in terms of its capacity to search for optimal solutions in non-convex scenarios. In this work, the development and the testing of the refined the SPSO algorithm was carried out. The SPSO algorithm was tested against two engineering design problems which were; ‘optimization of the design of a pressure vessel’ (P1) and the ‘optimization of the design of a tension/compression spring’ (P2). The computational performance of the SPSO algorithm was then compared against the modified particle swarm optimization (PSO) algorithm of previous work on the same engineering problems. Comparative studies and analysis were then carried out based on the optimized results. It was observed that the SPSO provides a better minimum with a higher quality constraint satisfaction as compared to the PSO approach in the previous work.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorytm optymalizacji parametrów eksploatacyjnych środków transportu
An optimization algorithm for exploitation parameters of means of transport
Autorzy:
Wojciechowski, Ł.
Cisowski, T.
Grzegorczyk, P.
Tematy:
eksploatacja pojazdów
optymalizacja
algorytm optymalizacji
exploitation vehicles
optimization
optimization algorithm
Pokaż więcej
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Powiązania:
https://bibliotekanauki.pl/articles/312427.pdf  Link otwiera się w nowym oknie
Opis:
W artykule zaprezentowano algorytm wyznaczania optymalnych parametrów eksploatacyjnych dla środków transportu, oparty na programowaniu dynamicznym. Opisano w nim strukturę oraz zbiory danych algorytmu. Sformułowano i omówiono funkcję oraz podfunkcje celu, dotyczące parametrów eksploatacyjnych pojazdów. Przedstawiono istotę doboru warunków ograniczających jak i możliwości aplikacyjne opracowanego algorytmu.
The paper presents an algorithm for determination of optimal exploitation parameters of means of transport. The algorithm is based on dynamic programming. The paper discusses the structure as well as the data set for the algorithm. The function and subfunctions of the aim concerning exploitation parameters of vehicles were formed. Moreover, the selection of limiting conditions and application possibilities of the developed algorithm were discussed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Joint allocation and transportation problem in supply network optimisation
Autorzy:
Filcek, G.
Tematy:
supply networks
optimization
convex optimization
heuristic algorithms
decision support systems
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/407403.pdf  Link otwiera się w nowym oknie
Opis:
The paper concerns joint allocation and transportation as an optimization problem in selected supply networks. The network consists of a set of suppliers of the raw material, a set of production units and a set of product receivers. The raw material is treated as fast perishing good like vegetables or fruits. The production units are described by time models. In the optimization process, the time of the production and cost of the transportation is taken into account. The objective function is in general non-convex function of raw material allocation and transportation plans of the raw material and the product. To solve the problem considered, exact and heuristic algorithms have been developed and presented. To solve convex problems, solver Lingo developed by Lindo systems is proposed. The idea of a computer decision supported system integrating all presented algorithms is presented as well as four numerical examples illustrating some properties of the assumed supply network model.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Load Balancing Based on Optimization Algorithms: An Overview
Autorzy:
Mbarek, Fatma
Mosorov, Volodymyr
Tematy:
ant colony optimization
honey bee
load balancing
multi-objective optimization
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/308122.pdf  Link otwiera się w nowym oknie
Opis:
Combinatorial optimization challenges are rooted in real-life problems, continuous optimization problems, discrete optimization problems and other significant problems in telecommunications which include, for example, routing, design of communication networks and load balancing. Load balancing applies to distributed systems and is used for managing web clusters. It allows to forward the load between web servers, using several scheduling algorithms. The main motivation for the study is the fact that combinatorial optimization problems can be solved by applying optimization algorithms. These algorithms include ant colony optimization (ACO), honey bee (HB) and multi-objective optimization (MOO). ACO and HB algorithms are inspired by the foraging behavior of ants and bees which use the process to locate and gather food. However, these two algorithms have been suggested to handle optimization problems with a single-objective. In this context, ACO and HB have to be adjusted to multiobjective optimization problems. This paper provides a summary of the surveyed optimization algorithms and discusses the adaptations of these three algorithms. This is pursued by a detailed analysis and a comparison of three major scheduling techniques mentioned above, as well as three other, new algorithms (resulting from the combination of the aforementioned techniques) used to efficiently handle load balancing issues.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The multi-constrained multicast routing improved by hybrid bacteria foraging-particle swarm optimization
Autorzy:
Sahoo, Satya Prakash
Kabat, Manas Ranjan
Tematy:
QoS routing
multicasting
bacteria foraging optimization
particle swarm optimization (PSO)
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/305674.pdf  Link otwiera się w nowym oknie
Opis:
To solve multicast routing under multiple constraints, it is required to generate a multicast tree that ranges from a source to the destinations with minimum cost subject to several constraints. In this paper, PSO has been embedded with BFO to improve the convergence speed and avoid premature convergence that will be used for solving QoS multicast routing problem. The algorithm proposed here generates a set of delay compelled links to every destination present in the multicast group. Then the Bacteria Foraging Algorithm (BFA) selects the paths to all the destinations sensibly from the set of least delay paths to construct a multicast tree. The robustness of the algorithm being proposed had been established through the simulation. The efficiency and effectiveness of the algorithm being proposed was validated through the comparison study with other existing meta-heuristic algorithms. It shows that our proposed algorithm IBF-PSO outperforms its competitive algorithms.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved dolphin swarm optimization algorithm based on information entropy
Autorzy:
Li, Y.
Wang, X.
Tematy:
dolphin swarm optimization
information entropy
convergence
self-adaptive
combinational optimization
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/200085.pdf  Link otwiera się w nowym oknie
Opis:
In order to overcome the shortcomings of the dolphin algorithm, which is prone to falling into local optimum and premature conver-gence, an improved dolphin swarm algorithm, based on the standard dolphin algorithm, was proposed. As a measure of uncertainty, information entropy was used to measure the search stage in the dolphin swarm algorithm. Adaptive step size parameters and dynamic balance factors were introduced to correlate the search step size with the number of iterations and fitness, and to perform adaptive adjustment of the algorithm. Simulation experiments show that, comparing with the basic algorithm and other algorithms, the improved dolphin swarm algorithm is feasible and effective.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Minimized Group Delay FIR Low Pass Filter Design Using Modified Differential Search Algorithm
Autorzy:
Prajapati, Sonelal
Rai, Sanjeev
Tiwari, Manish
Dwivedi, Atul Kumar
Tematy:
differential search optimization algorithm
FIR filter
optimization
small group delay
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/24200750.pdf  Link otwiera się w nowym oknie
Opis:
Designing a finite impulse response (FIR) filter with minimal group delay has proven to be a difficult task. Many research studies have focused on reducing pass band and stop band ripples in FIR filter design, often overlooking the optimization of group delay. While some works have considered group delay reduction, their approaches were not optimal. Consequently, the achievement of an optimal design for a filter with a low group delay value still remains a challenge. In this work, a modified differential search optimization algorithm has been used for the purpose of designing a minimal group delay FIR filter. The results obtained have been compared with the classical techniques and they turned out to be promising.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of robust and reliability based design optimization
Autorzy:
Zabojszcza, Paweł
Radoń, Urszula
Tematy:
deterministic optimization
robust optimization
reliability based design optimization
first order reliability method
Pokaż więcej
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/62645017.pdf  Link otwiera się w nowym oknie
Opis:
This article compares two optimization methods considering random variations in design parameters. One is reliability-based design optimization, which depends on the availability of the joint probability density function. A more practical alternative is robust optimization, which does not require the estimation of failure probability. It accounts for the random response of the structure through definitions of objective functions and constraints, incorporating mean values and response variances. An important element of the algorithm involves approximating unknown responses of the structures and employing efficient statistical moment estimation methods. The kriging method was used in this paper. Additionally, the article evaluates two experimental plan techniques: the classical random sampling plan and the OLH plan.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of tripping velocity profiles on wellbore pressures and dynamic loading of drillstring
Autorzy:
Wang, Z.
Miska, S.
Yu, M.
Takach, N.
Tematy:
trapping velocity
optimization
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/298649.pdf  Link otwiera się w nowym oknie
Opis:
Tripping events are expensive and time-consuming. Thus, minimizing tripping time through choosing optimized tripping velocity becomes urgent. Surge or swab pressures in the wellbore and dynamic loading of drillstring will be generated during tripping. Also, dynamic velocity, which is the velocity at the bottom of drillstring, is different from the input velocity at surface. The effect of tripping velocity profile, i.e., tripping velocity changes with time, on the hook load, downhole pressure changes and drillstring dynamic velocity should be fully studied to achieve the optimization. In this study, the effects of tripping velocity profile on loading of drillstring, dynamic velocity and downhole pressure is investigated using numerical simulation. Bergeron's graphical method and Lubinski's approach are utilized to perform the simulations. Components of drillstring, wellbore depth, drillstring length and mud properties are also included in the simulations. Through the current work, a driller's typical way of changing tripping velocity may not be the best one. Selection of tripping velocity profiles should be adapted to depth: higher velocity, triangular/parabolic profiles in shallow wells and lower velocity, trapezoidal profiles in deep wells. Also, based on simulations, the oscillation magnitude of dynamic velocity can be as high as twice that of velocity at surface.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal design of compressed columns with corrosion taken into account
Autorzy:
Fridman, M. M.
Tematy:
corrosion
optimization
stability
Pokaż więcej
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/279948.pdf  Link otwiera się w nowym oknie
Opis:
This study is devoted to the optimal design of compressed columns with a circular cross section under axial compressive forces and exposed to a corrosive environment. The initial volume of the structure is taken as an optimality parameter. The main constraint is the buckling of a loaded column at the final time of its operation. Gutman-Zaynullin’s exponential stress corrosion model is adopted for the analysis. Analytical and numerical results are derived for optimal variation of the cross-sectional area of the bar along its axis.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Young measures and their applications in micromechanics and optimization. I. Mathematical principles.
Autorzy:
Bielski, W.
Kruglenko, E.
Telega, J. J.
Tematy:
Young measures, optimization
Pokaż więcej
Wydawca:
Polskie Towarzystwo Matematyczne
Powiązania:
https://bibliotekanauki.pl/articles/747902.pdf  Link otwiera się w nowym oknie
Opis:
Artykuł nie zawiera streszczenia
The paper is a review of modern mathematical methods for the analysis of continuous problems of nonlinear mechanics and magnetism. The bibliography contains 175 items. The second part of the paper deals with mechanical problems described by nonconvex density energy functions and with numerical methods to solve such problems.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FTTH Network Optimization
Autorzy:
Nghia Le, H.
Tematy:
cost optimization
development optimization
FTTH
optical technology
telecommunications network
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/308571.pdf  Link otwiera się w nowym oknie
Opis:
Fiber To The Home (FTTH) is the most ambitious among optical technologies applied in the access segment of telecommunications networks. The main issues of deploying FTTH are the device price and the installation cost. Whilst the costs of optical devices are gradually decreasing, the cost of optical cable installation remains challenging. In this paper, the problem of optimization that has practical application for FTTH networks is presented. Because the problem is Non-deterministic polynomial-time hard (NP-hard), an approximation algorithm to solve it is proposed. The author has developed the algorithm in a C# program in order to analyze its performance. The analysis confirms that the algorithm gains near-optimal results with acceptable time consumption. Therefore, the algorithm to be applied in a network design tool for FTTH network planning is proposed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gradient-Based Algorithms in the Brachistochrone Problem Having a Black-Box Represented Mathematical Model
Autorzy:
Dębski, R.
Tematy:
black-box optimization
brachistochrone problem
optimal control
trajectory optimization
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/308956.pdf  Link otwiera się w nowym oknie
Opis:
Trajectory optimization problems with black-box represented objective functions are often solved with the use of some meta-heuristic algorithms. The aim of this paper is to show that gradient-based algorithms, when applied correctly, can be effective for such problems as well. One of the key aspects of successful application is choosing, in the search space, a basis appropriate for the problem. In an experiment to demonstrate this, three simple adaptations of gradient-based algorithms were executed in the forty-dimensional search space to solve the brachistochrone problem having a blackbox represented mathematical model. This experiment was repeated for two different bases spanning the search space. The best of the algorithms, despite its very basic implementation, needed only about 100 iterations to find very accurate solutions. 100 iterations means about 2000 objective functional evaluations (simulations). This corresponds to about 20 iterations of a typical evolutionary algorithm, e.g. ES(μ,l ).
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolutionary algorithms and boundary element method in generalized shape optimization
Algorytmy ewolucyjne i metoda elementów brzegowych w uogólnionej optymalizacji kształtu
Autorzy:
Burczyński, T.
Kokot, G.
Tematy:
evolutionary algorithms
genetic algorithms
generalized shape optimization
topology optimization
Pokaż więcej
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/279253.pdf  Link otwiera się w nowym oknie
Opis:
The coupling of modern, alternative optimization methods such as evolutionary algorithms with the effective tool for analysis of mechanical structures - BEM, gives a new optimization method, which allows one to perform the generalized shape optimization (simultaneous shape and topology optimization) for elastic mechanical structures. This new evolutionary method is free from typical limitations connected with classical optimization methods. In the paper, results of researches on the application of evolutionary methods in the domain of mechanics are presented. Numerical examples for some optimization problems are presented, too.
Połączenie nowoczesnych algorytmów optymalizacji, jakimi są algorytmy ewolucyjne, z metodą elementów brzegowych pozwala opracować alternatywną metodę optymalizacji sprężystych układów mechanicznych w zakresie uogólnionej optymalizacji kształtu (połaczenie optymalizacji kształtu z optymalizacją topologiczną). Metoda ta jest pozbawiona wad związanych z typowymi klasycznymi metodami optymalizacji (ciągłość funkcji celu, wyznaczanie gradientu funkcji itp.), co znacznie rozszerza możliwości jej zastosowań. W artykule przedstawiono proponowaną metodę optymalizacji wraz z przykładami optymalizacji wybranych układów mechanicznych.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topological classes of statically determinate beams with arbitrary number of supports
Klasy topologiczne statycznie wyznaczalnych belek o dowolnej liczbie podpór
Autorzy:
Kozikowska, A.
Tematy:
statically determinate beams
topology optimization
geometry optimization
equivalence classes
Pokaż więcej
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/279355.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents all topologies of statically determinate beams with arbitrary number of pin supports. The geometry of each beam with a fixed topology is optimized by a genetic algorithm, with absolute maximum moment as the objective function. An equality relation between minimum values of this function is defined on the set of all topologies as an equivalence relation. This relation partitions the set of topologies into equivalence classes, called topological classes, for uniform, linear and parabolic gravity loads. An in-depth description of these classes is provided. Exact formulas for optimal locations of supports and hinges are found for the uniform load.
W pracy omówiono wszystkie topologie statycznie wyznaczalnych belek o dowolnej liczbie przegubowych podpór. Geometrię każdej belki o ustalonej topologii zoptymalizowano za pomocą algorytmu genetycznego z bezwzględnie maksymalnym momentem jako funkcją celu. Relację równości minimalnych wartości tej funkcji zdefiniowano na zbiorze wszystkich topologii jako relację równoważności. Na podstawie tej relacji dokonano podziału zbioru topologii na klasy równoważności, zwane klasami topologicznymi, pod równomiernym, linowym i kwadratowym grawitacyjnym obciążeniem. Przedstawiono szczegółową charakterystykę tych klas. Znaleziono ścisłe wzory na optymalne położenie podpór i przegubów belek obciążonych równomiernie.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter estimation of photovoltaic module relied on golden jackal optimization
Autorzy:
Nguyen, Thuan Thanh
Tematy:
golden jackal optimization
henry gas solubility optimization
particle swarm optimization
PV parameter estimation
single diode model
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/27309949.pdf  Link otwiera się w nowym oknie
Opis:
Due to the nonlinear current-voltage (I-V) relationship of the photovoltaic (PV) module, building a precise mathematical model of the PV module is necessary for evaluating and optimizing the PV systems. This paper proposes a method of building PV parameter estimation models based on golden jackal optimization (GJO). GJO is a recently developed algorithm inspired by the idea of the hunting behavior of golden jackals. The explored and exploited searching strategies of GJO are built based on searching for prey as well as harassing and grabbing prey of golden jackals. The performance of GJO is considered on the commercial KC200GT module under various levels of irradiance and temperature. Its performance is compared to well-known particle swarm optimization (PSO), recent Henry gas solubility optimization (HGSO) and some previous methods. The obtained results show that GJO can estimate unknown PV parameters with high precision. Furthermore, GJO can also provide better efficiency than PSO and HGSO in terms of statistical results over several runs. Thus, GJO can be a reliable algorithm for the PV parameter estimation problem under different environmental conditions.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Constraints in allocation of thrusters in a DP simulator
Autorzy:
Zalewski, P.
Tematy:
dynamic positioning
thrust allocation
convex optimization
constrained optimization
DP simulator
thrusters
Pokaż więcej
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Powiązania:
https://bibliotekanauki.pl/articles/135012.pdf  Link otwiera się w nowym oknie
Opis:
Vessels conducting dynamic positioning (DP) operations are usually equipped with thruster configurations that enable the generation of force and torque. Some thrusters in these configurations are deliberately redundant to minimize consequences of thruster failures, enable overactuated control and increase the safety in operation. On such vessels, a thrust allocation system must be used to distribute the control actions determined by the DP controller among the thrusters. The optimal allocation of the thrusters’ settings in DP systems is a problem that can be solved by convex optimization methods depending on the criteria and constraints used. This paper presents a quadratic programming (QP) method, adopted in a DP control model, which is being developed in Maritime University of Szczecin for ship simulation purposes.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Efficiency Analysis of the Parallel Multitransputer Implementation of Two-Level Optimization Algorithms
Autorzy:
Sadecki, J.
Tematy:
automatyka
robotyka
multitransputer systems
parallel optimization algorithms
two-level optimization methods
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Powiązania:
https://bibliotekanauki.pl/articles/908188.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents an approach to improve the efficiency of some two-level optimization algorithms by their implementation in parallel MIMD multiprocessor systems. Diagonal decomposition dynamic programming and parametric optimization methods are considered, and some concepts of their parallelization are discussed. Results regarding the implementation of computations in a parallel multitransputer system are presented. For the analysed problems, the obtained values of speedup are close to the theoretical maximum values.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Function optimization using metaheuristics
Autorzy:
Pilski, M.
Seredyński, F.
Tematy:
particle swarm optimization (PSO)
artificial immune system
genetic algorithm
function optimization
Pokaż więcej
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Powiązania:
https://bibliotekanauki.pl/articles/92887.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents the results of comparison of three metaheuristics that currently exist in the problem of function optimization. The first algorithm is Particle Swarm Optimization (PSO) - the algorithm has recently emerged. The next one is based on a paradigm of Artificial Immune System (AIS). Both algorithms are compared with Genetic Algorithm (GA). The algorithms are applied to optimize a set of functions well known in the area of evolutionary computation. Experimental results show that it is difficult to unambiguously select one best algorithm which outperforms other tested metaheuristics.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvements to Glowworm Swarm Optimization algorithm
Ulepszenia algorytmu Glowworm Swarm Optimization
Autorzy:
Oramus, P.
Tematy:
inteligencja roju
optymalizacja
swarm intelligence
glowworm swarm optimization
multimodal function optimization
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/305567.pdf  Link otwiera się w nowym oknie
Opis:
Glowworm Swarm Optimization algorithm is applied for the simultaneous capture of multiple optima of multimodal functions. The algorithm uses an ensemble of agents, which scan the search space and exchange information concerning a fitness of their current position. The fitness is represented by a level of a luminescent quantity called luciferin. An agent moves in direction of randomly chosen neighbour, which broadcasts higher value of the luciferin. Unfortunately, in the absence of neighbours, the agent does not move at all. This is an unwelcome feature, because it diminishes the performance of the algorithm. Additionally, in the case of parallel processing, this feature can lead to unbalanced loads. This paper presents simple modifications of the original algorithm, which improve performance of the algorithm by limiting situations, in which the agent cannot move. The paper provides results of comparison of an original and modified algorithms calculated for several multimodal test functions.
Algorytm Glowworm Swarm Optimization jest stosowany do równoczesnego odnajdywania wielu optimów funkcji multimodalnych. Algorytm używa zespołu agentów przeszukujących przestrzeń poszukiwań i wymieniających się informacjami o wartości funkcji przystosowania w danym położeniu. Funkcja przystosowania jest reprezentowana przez poziom emitującego światło pigmentu - lucyferyny. Agenci poruszają się w kierunku losowo wybranego sąsiada, który rozgłasza wyższą wartość poziomu lucyferyny. Niestety w przypadku braku sąsiadów agent nie porusza się wcale. Stanowi to niepożądaną cechę algorytmu ograniczającą jego wydajność. W przypadku przetwarzania równoległego cecha ta może prowadzić do niezrównoważenia obciążenia. Praca ta przedstawia proste modyfikacje oryginalnego algorytmu zwiększające jego wydajność poprzez ograniczanie liczby takich sytuacji, w których agent nie może się poruszyć. Przedstawione zostały wyniki porównania pracy oryginalnego i zmodyfikowanych algorytmów dla kilku funkcji testowych.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power system oscillation damping controller design: a novel approach of integrated HHO-PSO algorithm
Autorzy:
Devarapalli, Ramesh
Kumar, Vikash
Tematy:
Harris hawk optimization
power system stabilizers
STATCOM
FACTS
particle swarm optimization
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/1845528.pdf  Link otwiera się w nowym oknie
Opis:
The hybridization of a recently suggested Harris hawk’s optimizer (HHO) with the traditional particle swarm optimization (PSO) has been proposed in this paper. The velocity function update in each iteration of the PSO technique has been adopted to avoid being trapped into local search space with HHO. The performance of the proposed Integrated HHO-PSO (IHHOPSO) is evaluated using 23 benchmark functions and compared with the novel algorithms and hybrid versions of the neighbouring standard algorithms. Statistical analysis with the proposed algorithm is presented, and the effectiveness is shown in the comparison of grey wolf optimization (GWO), Harris hawks optimizer (HHO), barnacles matting optimization (BMO) and hybrid GWO-PSO algorithms. The comparison in convergence characters with the considered set of optimization methods also presented along with the boxplot. The proposed algorithm is further validated via an emerging engineering case study of controller parameter tuning of power system stability enhancement problem. The considered case study tunes the parameters of STATCOM and power system stabilizers (PSS) connected in a sample power network with the proposed IHHOPSO algorithm. A multi-objective function has been considered and different operating conditions has been investigated in this papers which recommends proposed algorithm in an effective damping of power network oscillations.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust optimization of SVM hyperparameters in the classification of bioactive compounds
Autorzy:
Czarnecki, Wojciech
Podlewska, Sabina
Bojarski, Andrzej J.
Opis:
Background: Support Vector Machine has become one of the most popular machine learning tools used in virtual screening campaigns aimed at finding new drug candidates. Although it can be extremely effective in finding new potentially active compounds, its application requires the optimization of the hyperparameters with which the assessment is being run, particularly the C and values. The optimization requirement in turn, establishes the need to develop fast and effective approaches to the optimization procedure, providing the best predictive power of the constructed model. Results: In this study, we investigated the Bayesian and random search optimization of Support Vector Machine hyperparameters for classifying bioactive compounds. The effectiveness of these strategies was compared with the most popular optimization procedures-grid search and heuristic choice. We demonstrated that Bayesian optimization not only provides better, more efficient classification but is also much faster-the number of iterations it required for reaching optimal predictive performance was the lowest out of the all tested optimization methods. Moreover, for the Bayesian approach, the choice of parameters in subsequent iterations is directed and justified; therefore, the results obtained by using it are constantly improved and the range of hyperparameters tested provides the best overall performance of Support Vector Machine. Additionally, we showed that a random search optimization of hyperparameters leads to significantly better performance than grid search and heuristic-based approaches. Conclusions: The Bayesian approach to the optimization of Support Vector Machine parameters was demonstrated to outperform other optimization methods for tasks concerned with the bioactivity assessment of chemical compounds. This strategy not only provides a higher accuracy of classification, but is also much faster and more directed than other approaches for optimization. It appears that, despite its simplicity, random search optimization strategy should be used as a second choice if Bayesian approach application is not feasible.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
The application of different optimization techniques and Artificial Neural Networks (ANN) for coal-consumption forecasting: a case study
Zastosowanie różnych technik optymalizacji i sztucznych sieci neuronowych (SSN) do prognozowania zużycia węgla: studium przypadku
Autorzy:
Seker, Mustafa
Unal Kartal, Neslihan
Karadirek, Selin
Gulludag, Cevdet Bertan
Tematy:
coal consumption
metaheuristic optimization
grey wolf optimization
particle swarm optimization
whale optimization
zużycie węgla
optymalizacja metaheurystyczna
optymalizacja szarego wilka
optymalizacja roju cząstek
optymalizacja wielorybów
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Powiązania:
https://bibliotekanauki.pl/articles/2173847.pdf  Link otwiera się w nowym oknie
Opis:
The demand for energy on a global scale increases day by day. Unlike renewable energy sources, fossil fuels have limited reserves and meet most of the world’s energy needs despite their adverse environmental effects. This study presents a new forecast strategy, including an optimization-based S-curve approach for coal consumption in Turkey. For this approach, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), Grey Wolf Optimization (GWO), and Whale Optimization Algorithm (WOA) are among the meta-heuristic optimization techniques used to determine the optimum parameters of the S-curve. In addition, these algorithms and Artificial Neural Network (ANN) have also been used to estimate coal consumption. In evaluating coal consumption with ANN, energy and economic parameters such as installed capacity, gross generation, net electric consumption, import, export, and population energy are used for input parameters. In ANN modeling, the Feed Forward Multilayer Perceptron Network structure was used, and Levenberg-Marquardt Back Propagation has used to perform network training. S-curves have been calculated using optimization, and their performance in predicting coal consumption has been evaluated statistically. The findings reveal that the optimization-based S-curve approach gives higher accuracy than ANN in solving the presented problem. The statistical results calculated by the GWO have higher accuracy than the PSO, WOA, and GA with R2 = 0.9881, RE = 0.011, RMSE = 1.079, MAE = 1.3584, and STD = 1.5187. The novelty of this study, the presented methodology does not need more input parameters for analysis. Therefore, it can be easily used with high accuracy to estimate coal consumption within other countries with an increasing trend in coal consumption, such as Turkey.
Zapotrzebowanie na energię w skali globalnej rośnie z dnia na dzień. W przeciwieństwie do odnawialnych źródeł energii, paliwa kopalne mają ograniczone rezerwy i zaspokajają większość światowego zapotrzebowania na energię pomimo ich niekorzystnego wpływu na środowisko. Niniejsze opracowanie przedstawia nową strategię prognozowania, w tym oparte na optymalizacji podejście oparte na krzywej S dla zużycia węgla w Turcji. W tym podejściu algorytmy optymalizacji genetycznej (GA) i optymalizacji roju cząstek (PSO), optymalizacja Gray Wolf (GWO) i algorytm optymalizacji wielorybów (WOA) należą do metaheurystycznych technik optymalizacji stosowanych do określenia optymalnych parametrów krzywej S. Ponadto algorytmy te oraz sztuczna sieć neuronowa (SSN) zostały również wykorzystane do oszacowania zużycia węgla. Przy ocenie zużycia węgla za pomocą SSN jako parametry wejściowe wykorzystuje się parametry energetyczne i ekonomiczne, takie jak moc zainstalowana, produkcja brutto, zużycie energii elektrycznej netto, import, eksport i energia ludności. W modelowaniu SSN wykorzystano strukturę Feed Forward Multilayer Perceptron Network, a do uczenia sieci wykorzystano propagację wsteczną Levenberg-Marquardt. Krzywe S zostały obliczone za pomocą optymalizacji, a ich skuteczność w przewidywaniu zużycia węgla została oceniona statystycznie. Wyniki pokazują, że podejście oparte na optymalizacji opartej na krzywej S zapewnia większą dokładność niż SSN w rozwiązaniu przedstawionego problemu. Wyniki statystyczne obliczone przez GWO mają wyższą dokładność niż PSO, WOA i GA z R2 = 0,9881, RE = 0,011, RMSE = 1,079, MAE = 1,3584 i STD = 1,5187. Nowość tego badania, prezentowana metodyka nie wymaga dodatkowych parametrów wejściowych do analizy. Dzięki temu może być z łatwością wykorzystany z dużą dokładnością do oszacowania zużycia węgla w innych krajach o tendencji wzrostowej zużycia węgla, takich jak Turcja.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Benchmarking Procedures for Continuous Optimization Algorithms
Autorzy:
Opara, K.
Arabas, J.
Tematy:
black-box optimization
comparing optimization algorithms
evaluation criteria
parallel computing
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/308400.pdf  Link otwiera się w nowym oknie
Opis:
Reliable comparison of optimization algorithms requires the use of specialized benchmarking procedures. This paper highlights motivations which influence their structure, discusses evaluation criteria of algorithms, typical ways of presenting and interpreting results as well as related statistical procedures. Discussions are based on examples from CEC and BBOB benchmarks. Moreover, attention is drawn to these features of comparison procedures, which make them susceptible to manipulation. In particular, novel application of the weak axiom of revealed preferences to the field of benchmarking shows why it may be misleading to assess algorithms on basis of their ranks for each of test problems. Additionally, an idea is presented of developing massively parallel implementation of benchmarks. Not only would this provide faster computation but also open the door to improving reliability of benchmarking procedures and promoting research into parallel implementations of optimization algorithms.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy losses in big band saw machines – analysis and optimization
Autorzy:
Marinov, Boycho
Tematy:
band saw machine
kinetic energy losses
optimization procedure
optimization solution
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/949943.pdf  Link otwiera się w nowym oknie
Opis:
In this paper, the energy losses in big band saw machines are investigated. These losses are caused by the geometric and angular inaccuracies with which the leading wheels are made. Expressions for calculating the kinetic energy of the mechanical system in the ideal and the real cases are obtained. For this purpose, expressions for calculating the velocities of the centers of the masses in two mutually perpendicular planes are obtained. A dependence for calculation of the kinetic energy losses of the mechanical system in final form is received. Optimization procedure is used to determine the values of the parameters at which these losses have minimum values. The proposed study can be used to minimize energy losses in other classes of woodworking machines.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dobór zespołów projektowych z wykorzystaniem metod stochastycznych
Project team selection using stochastic methods
Autorzy:
Twardochleb, Michał
Tematy:
stochastic optimization
selection of project teams
resource optimization
Monte Carlo
Pokaż więcej
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Powiązania:
https://bibliotekanauki.pl/articles/432408.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents the possibility of application of stochastic methods in supporting the selection of project team members. According to research of M. Belbin an effective collaboration of members of the project team requires 8 team roles (describing the soft skills) in its composition, which will enable the occurrence of the synergy effect. For the purpose of the reasearch, the original software was developed, which uses stochastic methods in the process of assembling teams that meet these criteria. The paper presents the results of experiments based on anonymized surveys conducted among students of different faculties. Teams obtained thorough conducted simulations fulfilled the criterion of completeness of team roles.It was pointed out that the use of stochastic methods in supporting the process of selection of employees in project teams may contribute to improving the efficiency of resource allocation through the appropriate assignation of roles and responsibilities, for example, to avoid a situation where a qualified professional would be attached to the team, wherein his potential would be wasted.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optymalizacja wielopoziomowa i wielokryterialna obiektów budowlanych
Multicriterial and multileveled optimization of buildings
Autorzy:
Gintowt, J.
Tematy:
budynek
optymalizacja wielopoziomowa
optymalizacja wielokryterialna
building
multileveled optimization
multicriterial optimization
Pokaż więcej
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Powiązania:
https://bibliotekanauki.pl/articles/362874.pdf  Link otwiera się w nowym oknie
Opis:
Dla wielu kryteriów zadań optymalizacji podano kryteria matematyczne, ekonomiczne. Dla oceny matematycznej określono warunki i sposób rozwiązania zadań optymalizacji nieliniowej z ograniczeniami, dla oceny ekonomicznej podano niektóre wskaźniki ekonomiczne. Określone zostały parametry stałe, zmienne i dyskretne zadania optymalizacji.
The paper deals with analysis of mathematical and economical criteria. the solution procedure for the nonlinear optimization with bounds are given. For the economic assessment some of the indexes are used. The constant, variable and discrete factors for the optimization are discussed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PROBLEMATYKA WIELOKRYTERIALNEGO WYBORU KOMPETENCJI PRACOWNICZYCH
MULTI-CRITERION SELECTION ISSUES OF EMPLOYEE COMPETENCES
Autorzy:
Piotr, Kuryło
Tematy:
optymalizacja
kryteria optymalizacji
proces produkcyjny
optimization
optimization criteria
production process
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Instytut Inżynierii Bezpieczeństwa i Nauk o Pracy. Polskie Towarzystwo Profesjologiczne.
Powiązania:
https://bibliotekanauki.pl/articles/479197.pdf  Link otwiera się w nowym oknie
Opis:
Praca jest analizą wybranych problemów związanych z wielokryterialną optymalizacja przy wyborze przyszłych kompetencji pracowniczych – profesjonalistów biorących bezpośredni udział w procesach produkcyjnych. W pracy przeanalizowana została także problematyka zwią-zana z realizacją procesów produkcyjnych w funkcji podejmowanych decyzji w zakresie wy-branych zadań produkcyjnych. Omówiona została także problematyka, kryteria oraz metody wielokryterialnej optymalizacji procesów produkcyjnych.
The work is an analysis of selected problems related to multi-criterion optimization in the selec-tion of future professional competencies – professionals directly involved in the production processes. The work also analyzes the issues connected with the realization of production proc-esses as a function of decisions made in the scope of selected production tasks. Problems, crite-ria and methods of multi-criterion optimization of production processes were also discussed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Information management in passenger traffic supporting system design as a multi-criteria discrete optimization task
Autorzy:
Galuszka, A.
Krystek, J.
Swierniak, A.
Lungoci, C.
Grzejszczak, T.
Tematy:
multi objective optimization
discrete static optimization
Pareto solutions
integrated systems
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/229171.pdf  Link otwiera się w nowym oknie
Opis:
This paper presents a concept of an Integrated System of Supporting Information Management in Passenger Traffic (ISSIMPT). The novelty of the system is an integration of six modules: video monitoring, counting passenger flows, dynamic information for passengers, the central processing unit, surveillance center and vehicle diagnostics into one coherent solution. Basing on expert evaluations, we propose to present configuration design problem of the system as a multi-objectives discrete static optimization problem. Then, hybrid method joining properties of weighted sum and ε-constraint methods is applied to solve the problem. Solution selections based on hybrid method, using set of exemplary cases, are shown.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problem strojenia algorytmu optymalizacji rojem cząstek w optymalizacji ciągłej
The problem of tuning the particle swarm optimization algorithm in continuous optimization
Autorzy:
Mrozek, Adam
Badura, Dariusz
Tematy:
Optymalizacja
Optymalizacja rojem cząstek
Strojenie
Optimization
Particle Swarm Optimization
Tuning
Pokaż więcej
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Powiązania:
https://bibliotekanauki.pl/articles/592187.pdf  Link otwiera się w nowym oknie
Opis:
Optymalizacja wybranego zagadnienia, polegająca na znalezieniu analitycznego rozwiązania wyznaczającego ekstremum opisującego to zagadnienie funkcji, jest bardzo często złożona. Analityczne rozwiązanie staje się czasem niemożliwe, szczególnie w przypadku, gdy funkcja jest sformułowana w sposób uwikłany. W wielu przypadkach nie istnieją też metody automatycznego rozwiązywania takich formuł. Do rozwiązywania wielu problemów optymalizacyjnych skutecznym narzędziem okazała się optymalizacja rojem cząstek (ang. Particle Swarm Optimization, PSO). Sam algorytm bywa także stosowany jako część innych niedeterministycznych algorytmów, tworząc konstrukcje hybrydowe. Biorąc pod uwagę skuteczność znajdowania rozwiązania, wśród innych podobnych metod optymalizacji algorytm PSO nie plasuje się na czołowym miejscu. Stąd liczne próby modyfikacji oraz ustalenia najbardziej optymalnych i uniwersalnych parametrów algorytmu PSO. W artykule przedstawiono wyniki badań efektywności podstawowej wersji algorytmu optymalizacji rojem cząstek (PSO) dla problemów ciągłych o różnej skali złożoności. Autorzy podjęli także próbę oceny kosztu strojenia tego algorytmu dla małych problemów.
The optimization of the chosen issue of finding an analytical solution to determine the extreme describing this function is very often complex. An analytical solution is sometimes impossible, especially when the function is formulated in an entangled way. In many cases, there are no methods for automatically solving such formulas. Optimization of the particle swarm (Particle Swarm Optimization, PSO) has proved to be an effective tool for solving many optimization problems. Hence numerous attempts to modify and determine the most optimal and universal parameters of the PSO algorithm. The algorithm itself is also used as a part of other non-deterministic algorithms to create hybrid constructions. The article presents the results of research on the effectiveness of the basic version of the particle swarm optimization algorithm (PSO) for continuous problems of varying complexity scale. The authors also attempted to evaluate the cost of tuning this algorithm for small problems. The carried out computational experiments confirm the hypotheses advanced.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sufficient conditions for the convergence of nonautonomous stochastic search for a global minimum
Autorzy:
Tarłowski, Dawid
Opis:
The majority of stochastic optimization algorithms can be writ- ten in the general form $x_{t+1}= T_{t}\left(x_{t},y_{t}\right)$, where $x_{t}$ is a sequence of points and parameters which are transformed by the algorithm, $T^{_{t}}$ are the methods of the algorithm and $Y_{t}$ represent the randomness of the algorithm. We extend the results of papers [11] and [14] to provide some new general conditions under which the algorithm finds a global minimum with probability one.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Impact of optimization of ALS point cloud on classification
Autorzy:
Błaszczak-Bąk, W.
Sobieraj, A.
Tematy:
optimization
classification
intensity
Pokaż więcej
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Powiązania:
https://bibliotekanauki.pl/articles/298363.pdf  Link otwiera się w nowym oknie
Opis:
Airborne laser scanning (ALS) is one of the LIDAR technologies (Light Detection and Ranging). It provides information about the terrain in form of a point cloud. During measurement is acquired: spatial data (object’s coordinates X, Y, Z) and collateral data such as intensity of reflected signal. The obtained point cloud is typically applied for generating a digital terrain model (DTM) and a digital surface model (DSM). For DTM and DSM generation it is necessary to apply filtration or classification algorithms. They allow to divide a point cloud into object groups (e.g.: terrain points, vegetation, etc.). In this study classification is conducted with one extra parameter–intensity. The obtained point groups were used for digital spatial model generation. Classification is a time and work consuming process, therefore there is a need to reduce the time of ALS point cloud processing. Optimization algorithm enables to decrease the number of points in a dataset. In this study the main goal was to test the impact of optimization on the results of a classification. Studies were conducted in two variants. Variant 1 includes classification of the original point cloud where points are divided in the groups: roofs, asphalt road, tree/bushes, grass. On variant 2 before classification, an optimization algorithm was performed in the original point cloud. Obtained from these two variants object groups were used to generate a spatial model, which was then statistically analyzed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Suppressing Side-Lobes of Linear Phased Array of Micro-Strip Antennas with Simulation-Based Optimization
Autorzy:
Kozieł, S.
Ogurtsov, S.
Bekasiewicz, A.
Tematy:
linear antenna array
micro-strip antenna array
phased antenna array
antenna optimization
antenna array optimization
simulation-based optimization
surrogate model
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/220985.pdf  Link otwiera się w nowym oknie
Opis:
A simulation-based optimization approach to design of phase excitation tapers for linear phased antenna arrays is presented. The design optimization process is accelerated by means of Surrogate-Based Optimization (SBO); it uses a coarse-mesh surrogate of the array element for adjusting the array’s active reflection coefficient responses and a fast surrogate of the antenna array radiation pattern. The primary optimization objective is to minimize side-lobes in the principal plane of the radiation pattern while scanning the main beam. The optimization outcome is a set of element phase excitation tapers versus the scan angle. The design objectives are evaluated at the high fidelity level of description using simulations of the discrete electromagnetic model of the entire array so that the effects of element coupling and other possible interaction within the array structure are accounted for. At the same time, the optimization process is fast due to SBO. Performance and numerical cost of the approach are demonstrated by optimizing a 16-element linear array of microstrip antennas. Experimental verification has been carried out for a manufactured prototype of the optimized array. It demonstrates good agreement between the radiation patterns obtained from simulations and from physical measurements (the latter constructed through superposition of the measured element patterns).
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inverse and direct optimization shape of airfoil using hybrid algorithm Big Bang-Big Crunch and Particle Swarm Optimization
Autorzy:
Masoumi, Heidar
Jalili, Farhad
Tematy:
hybrid optimization algorithm
airfoil
inverse and direct optimization approaches
Euler’s equations
Pokaż więcej
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/281379.pdf  Link otwiera się w nowym oknie
Opis:
In this paper, Big Bang-Big Crunch and Particle Swarm Optimization algorithms are combined and used for the first time to optimize airfoil geometry as a aerodynamic cross section. The optimization process is carried out both in reverse and direct directions. In the reverse approach, the object function is the difference between pressure coefficients of the optimized and target airfoils, which must be minimized. In the direct approach, three objective functions are introduced, the first of which is the drag to lift (D/L) ratio. It is minimized considering four different initial geometries, ultimately, all four geometries converge to the same final geometry. In other cases, maximizing lift the coefficient with the fixed drag coefficient constraint and minimizing the drag coefficient while the lift coefficient is fixed are defined as purposes. The results show that by changing the design parameters of the initial airfoil geometry, the proposed hybrid optimization algorithm as a powerful method satisfies the needs with proper accuracy and finally reaches the desired geometry.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An ant algorithm for the maximum number of 3-cliques in 3-partite graphs
Autorzy:
Schiff, Krzysztof
Tematy:
ant colony optimization
three-partite graph
3-clique
combinatorial optimization
graph theory
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Powiązania:
https://bibliotekanauki.pl/articles/2183443.pdf  Link otwiera się w nowym oknie
Opis:
The problem of finding the maximum number of d- vertices cliques (d = 3) in d-partite graph (d = 3) when graph density q is lower than 1 is an important problem in combinatorial optimization and it is one of many NP-complete problems. For this problem a meta-heuristic algorithm has been developed, namely an ant colony optimization algorithm. In this paper a new development of this ant algorithm and experimental results are presented. The problem of finding the maximum number of 3-vertices cliques can be encountered in computer image analysis, computer vision applications, automation and robotic vision systems. The optimal solution of this problem boils down to finding a set of 3-vertices cliques in a 3-partite graph and this set should have cardinality as high as possible. The elaborated ant colony algorithm can be easily modified for d-dimensional problems, that is for finding the maximum number of d-vertices cliques in a d-partite graph.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raport Badawczy = Research Report ; RB/14/2012
Applications of topological derivative for accelerating the genetic algorithm in shape optimization of coupled models
Autorzy:
Szulc, Katarzyna
Żochowski, Antoni
Novotny, Antonio
Wydawca:
Instytut Badań Systemowych. Polska Akademia Nauk
Systems Research Institute. Polish Academy of Sciences
Powiązania:
Raport Badawczy = Research Report
Opis:
Bibliografia s. 29-32
Bibliography p. 29-32
35 stron ; 21 cm
35 pages ; 21 cm
The paper considers a new variant of the genetic algorithm for finding the location and size of small holes in the domain, in which the coupled linear and non-linear boundary value problems are defined. The linear and non-linear parts are connected by the transmission condition on the common boundary. The expansion of the shape functional for non-linear part and the expansion of Steklov-Poincare operator for linear part are provided in order to determine the form of topological derivative for the coupled model. The value of topological derivative is then used for computing the probability density applied later in generating location of holes by the genetic algorithm.
Dostawca treści:
RCIN - Repozytorium Cyfrowe Instytutów Naukowych
Książka
Tytuł:
Structural analysis of an interregional transport network and assessment of capability for its multi-level optimization
Strukturnyjj analiz mezhregienalnojj transportnojj seti i ocenka vozmozhnosti ejo mnogourovnevojj optimizacii
Autorzy:
Slobodyanyuk, M.
Tararychkin, I.
Nechayev, G.
Tematy:
transport system
infrastructure
optimization
structural analysis
transport network
multilevel optimization
economic activity
Pokaż więcej
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Powiązania:
https://bibliotekanauki.pl/articles/792088.pdf  Link otwiera się w nowym oknie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maximum power point tracking controller for photovoltaic system based on chaos quantum particle swarm optimization – moth-flame optimization hybrid model
Autorzy:
Wang, Zili
Yuan, Weilu
Tematy:
maximum power point tracking
moth-flame optimization
particle swarm optimization
photovoltaic system
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/59111765.pdf  Link otwiera się w nowym oknie
Opis:
To convert photovoltaic arrays to solar energy in a more efficient way, this paper has proposed a maximum power point tracking controller model based on the chaotic quantum particle swarm-mothballing hybrid algorithm. First, the optimization of the particle swarm algorithm is designed to solve defects, such as premature maturity by using the quantum and chaotic strategies. The mothballing algorithm is introduced to help the model find global optimization-seeking more quickly. After that, further optimization was made to operate the tracking model in both offline and real-time parameters. The conductivity increment method and the perturbation observation method were adopted to effectively track the model under different temperatures and light intensities. Finally, the simulation and analysis experiments were carried out on the Simulink platform. The study’s proposed maximum power point tracking controller achieved a steady-state accuracy η2 of 99.84%. In summary, the study has proposed a hybrid intelligent algorithm with extraction of internal parameters. The maximum power point tracker based on the proposed method is proved to be both effective and accurate.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topology optimization of systems governed by variational inequalities
Autorzy:
Myśliński, Andrzej
Tematy:
variational inequality
topology optimization
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729259.pdf  Link otwiera się w nowym oknie
Opis:
This paper deals with the formulation of the necessary optimality condition for a topology optimization problem of an elastic body in unilateral contact with a rigid foundation. In the contact problem of Tresca, a given friction is governed by an elliptic variational inequality of the second order. The optimization problem consists in finding such topology of the domain occupied by the body that the normal contact stress along the contact boundary of the body is minimized. The topological derivative of the cost functional is calculated and a necessary optimality condition is formulated. The calculated topological derivative is also used in the numerical algorithm to find a descent direction by inserting voids in the domain occupied by the body. Numerical examples are provided.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Próby optymalizacjji parametrów energetycznych okien. Część 2 – dotychczas wykonane próby optymalizacji i autorski plan eksperymentu
The trials of optimization of thermal parameters of the windows. Part 2 – the carried out trials of optimization and original experiment’s plan
Autorzy:
Borowska, J.
Tematy:
windows
energy balance
optimization
Pokaż więcej
Wydawca:
ADVSEO
Powiązania:
https://bibliotekanauki.pl/articles/134819.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents trials of optimization of both energetic and technical parameters of windows that were carried out and described in the literature. In addition, the author presented her original plan of the experiment, an ultimate goal of which is the optimization of thermal parameters of windows. As a result of the calculations, there is a possibility of combining different variants of the energy balance for the fragment of the outer wall with a window.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementation of the CQT methodology forbusiness process optimization
Autorzy:
Tupa, J.
Basl, J.
Tematy:
business process
management
optimization
Pokaż więcej
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Powiązania:
https://bibliotekanauki.pl/articles/117898.pdf  Link otwiera się w nowym oknie
Opis:
This contribution deals with business process optimization and management. The aim of this paper is to introduce new CQT methodology for process management and optimization. This new methodology combines known principles and methods for the process management and optimization. The CQT (Cost-Quality- Time) methodology target is the quality improvement, process time and cost reduction as principal process management objectives. The contribution presents also a practical application of the CQT methodology for printed circuit board manufacturing.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization methods modeling and simulation of production systems
Autorzy:
Plinta, D.
Tematy:
modelling
simulation and optimization
Pokaż więcej
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Powiązania:
https://bibliotekanauki.pl/articles/117671.pdf  Link otwiera się w nowym oknie
Opis:
The use of the modelling and simulation method in improving production systems is presented. In the analysed example, two stages were distinguished: creation of the simulation model and optimization. The second stage is illustrated by the practical examples of the use of different optimization methods like the orthogonal plan of Taguchi and fuzzy control. By using simulation connected with optimization, it is possible to check almost all admissible variants of the proposed improvements comparatively quickly in order to evaluate them and to choose the best solution.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors influencing the precision of optimizing the values of definite scalar quantities according to the accepted criteria used in designing heat exchangers
Autorzy:
Łukaszewski, K.
Tematy:
optimization
heat exchangers
design
Pokaż więcej
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Powiązania:
https://bibliotekanauki.pl/articles/244118.pdf  Link otwiera się w nowym oknie
Opis:
The paper outlines the essential factors influencing the precision of optimizing the values of definite scalar quantities according to the criteria that are used in designing heat exchangers. The paper refers to the method of designing heat exchangers of technical power systems in view of the required reliability of these systems described in the work [1]. Optimization is used for the velocity values of the flow of definite fluids through the heat exchanger and for the cooling fluid temperature T2’’ at the output of the definite heat exchanger, as they occur in significant relationships with definite scalar quantities in designing heat exchangers. The paper emphasizes divergences in the results of calculations of the above mentioned optimized values of definite scalar quantities on the example of designing a shell and tube condenser of marine steam turbine. The criterion of optimizing the values of definite scalar quantities is the minimum of total costs min Σ n i=1 Ki τ in the time τ. The time is the set value τ z and constitutes the period, in which the optimization is considered. The paper presents the following factors: time assumption τ z of the period, in which optimization is considered, price assumption of electrical energy KCe consumed in order to pump the cooling water in time τ z, assumption of the values of efficiency τ p of the pump of the cooling water in time τ z, assumption of the values of the friction factor λ str2 of the inside surfaces of the condenser tube in time τ z, at the cooling water flow, the selection of a model of the function determining the Nusselt number Nu2 from the set of models that can be used in a given designing case, price assumption (the selection of a manufacturer) of heat exchanger area KCA of a shell and tube condenser, assumption of the forecasted thickness δos2 of fouling on the heat exchanger area from the side of the flow of the condenser cooling water in time τ z. Finally, the conclusions resulting from the paper’s contents are presented.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Henricis transformation in optimization
Autorzy:
Rhanizar, B.
Tematy:
Henrici's transformation
nonlinear optimization
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Powiązania:
https://bibliotekanauki.pl/articles/1208174.pdf  Link otwiera się w nowym oknie
Opis:
Henrici's transformation is a generalization of Aitken's $Δ^2$-process to the vector case. It has been used for accelerating vector sequences. We use a modified version of Henrici's transformation for solving some unconstrained nonlinear optimization problems. A convergence acceleration result is established and numerical examples are given.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Benchmark Tests on Heuristic Methods in the Darts Game
Autorzy:
Książek, K.
Połap, D.
Woźniak, M.
Tematy:
metaheuristics
optimization
computational intelligence
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/226713.pdf  Link otwiera się w nowym oknie
Opis:
Games are among problems that can be reduced to optimization, for which one of the most universal and productive solving method is a heuristic approach. In this article we present results of benchmark tests on using 5 heuristic methods to solve a physical model of the darts game. Discussion of the scores and conclusions from the research have shown that application of heuristic methods can simulate artificial intelligence as a regular player with very good results.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Testing the integrated package of tools supporting decision making on identification, prediction and optimization of complex technical systems operation, reliability and safety. Part 4. IS&RDSS Application – Exemplary system operation and reliability optimization
Autorzy:
Kołowrocki, K.
Soszyńska-Budny, J.
Xie, M.
Tematy:
reliability
operation process
optimization
Pokaż więcej
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Powiązania:
https://bibliotekanauki.pl/articles/2069544.pdf  Link otwiera się w nowym oknie
Opis:
There is presented the IS&RDSS application to the operation and reliability of an exemplary complex technical system optimization. There are determined, the optimal limit transient probabilities of the exemplary system operation process at the particular operation states maximizing the system lifetime in the reliability states not worse than the critical reliability state and its optimal sojourn times at the particular operation states. There are evaluated the exemplary system optimal unconditional multistate reliability function, the optimal expected values and the standard deviations of its unconditional lifetimes in the reliability state subsets and the optimal mean values of its lifetimes in the particular reliability states are. Moreover, in the case when the system is repairable, its optimal renewal and availability characteristics are found.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of I-section profile design by the finite element method
Autorzy:
Różyło, P.
Tematy:
Abaqus
optimization
numerical analysis
Pokaż więcej
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:
https://bibliotekanauki.pl/articles/103286.pdf  Link otwiera się w nowym oknie
Opis:
This paper discusses the problem of design optimization for an I-section profile. The optimization process was performed using the Abaqus program. The numerical analysis of a strictly static problem was based on the finite element method. The scope of the analysis involved both determination of stresses and displacements in the profile and structure topology optimization. The main focus of the numerical analysis was put on reducing profile volume while maintaining the same load and similar stresses prior to and after optimization. The solution of the optimization problem is just an example of the potential of using this method in combination with the finite element method in the Abaqus environment. Nowadays numerical analysis is the most effective cost-reducing alternative to experimental tests and it enables structure examination by means of a computer.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of optimization of distributed databases in oracle. Part 1
Autorzy:
Barczak, A.
Zacharczuk, D.
Pluta, D.
Tematy:
optimization
distributed databases
Oracle
Pokaż więcej
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Powiązania:
https://bibliotekanauki.pl/articles/92877.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents actions required to tune a distributed database to obtain optimal the performance. Each method and its impact on the performance of a database depending on the environment or configuration is discussed. The last part of the paper describes the stages of the process and data to be collected to obtain positive results.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization System to Minimize Exposure to Occupational Noise
Autorzy:
Reis, Déborah
Miranda, João
Reis, Jorge
Duarte, Marcus
Tematy:
acoustics
noise
optimization
dosimetry
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/2141683.pdf  Link otwiera się w nowym oknie
Opis:
This research deals with the development of an optimization system to minimize employee noise exposure in the work environment. It is known from the literature that continuous exposure to high noise levels can cause heart overload, stress, fatigue, and increase accident numbers at a production line. Thus, it is necessary to develop acoustic solutions at an industrial level that could minimize failures and accident occurrences. The rules that regulate occupational noise exposures allow an assessment of the degrees of exposure and subsequent corrections of working conditions. It is observed that the exposure is necessary for further evaluation and correction. Therefore, this research proposes to simulate occupational noise exposure conditions through mathematical models implemented in C++, using the GUROBI linear optimization package and to act previously to minimize ONIHL (Occupational Noise-Induced Hearing Loss). One of this work results is based on Doses Values, TWA (Time Weighted Average) and Distances Covered, using these three factors simultaneously through the optimization, it obtains a route that minimizes exposure and avoids ONIHL. Although there is a need for balanced doses between employees, to this end, the Designation Problem was implemented. Thus, with the routes obtained by optimization, an efficient allocation task was made for the maintenance crew, resulting in minimized and balanced doses. This model was applied to a real industrial plant that will not be identified, only methodology and results obtained will be presented.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Explanation-driven model stacking
Autorzy:
Bobek, Szymon
Nalepa, Grzegorz
Mozolewski, Maciej
Wydawca:
Springer International Publishing
Opis:
With advances of artificial intelligence (AI), there is a growing need for provisioning of transparency and accountability to AI systems. These properties can be achieved with eXplainable AI (XAI) methods, extensively developed over the last few years with relation for machine learning (ML) models. However, the practical usage of XAI is limited nowadays in most of the cases to the feature engineering phase of the data mining (DM) process. We argue that explainability as a property of a system should be used along with other quality metrics such as accuracy, precision, recall in order to deliver better AI models. In this paper we present a method that allows for weighted ML model stacking and demonstrates its practical use in an illustrative example.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Inne
Tytuł:
System reliability optimization: A fuzzy multi-objective genetic algorithm approach
Optymalizacja niezawodności systemu: metoda rozmytego algorytmu genetycznego do optymalizacji wielokryterialnej
Autorzy:
Mutingi, M.
Tematy:
system reliability optimization
multi-objective optimization
genetic algorithm
fuzzy optimization
redundancy
optymalizacja niezawodności systemu
optymalizacja wielokryterialna
algorytm genetyczny
optymalizacja rozmyta
nadmiarowość
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:
https://bibliotekanauki.pl/articles/300808.pdf  Link otwiera się w nowym oknie
Opis:
System reliability optimization is often faced with imprecise and conflicting goals such as reducing the cost of the system and improving the reliability of the system. The decision making process becomes fuzzy and multi-objective. In this paper, we formulate the problem as a fuzzy multi-objective nonlinear program. A fuzzy multi-objective genetic algorithm approach (FMGA) is proposed for solving the multi-objective decision problem in order to handle the fuzzy goals and constraints. The approach is able flexible and adaptable, allowing for intermediate solutions, leading to high quality solutions. Thus, the approach incorporates the preferences of the decision maker concerning the cost and reliability goals through the use of fuzzy numbers. The utility of the approach is demonstrated on benchmark problems in the literature. Computational results show that the FMGA approach is promising.
Często spotykanym problemem w optymalizacji niezawodności systemu są niedokładnie określone i sprzeczne cele, takie jak zmniejszenie kosztów systemu przy jednoczesnej poprawie jego niezawodności. Proces podejmowania decyzji staje się wtedy rozmyty i wielokryterialny. W niniejszej pracy, sformułowaliśmy ten problem jako rozmyty wielokryterialny program nieliniowy (FMOOP). Zaproponowaliśmy metodę rozmytego wielokryterialnego algorytmu genetycznego (FMGA), która pozwala rozwiązać wielokryterialny problem decyzyjny z uwzględnieniem rozmytych celów i ograniczeń. Podejście to jest uniwersalne, co pozwala na rozwiązania pośrednie, prowadzące do rozwiązań wysokiej jakości. Metoda uwzględnia preferencje decydenta w zakresie celów związanych z kosztami i niezawodnością poprzez wykorzystanie liczb rozmytych. Użyteczność FMGA wykazano na przykładzie wzorcowych problemów z literatury. Wyniki obliczeń wskazują, że podejście FMGA jest obiecujące.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Software Platform for Global Optimization
Autorzy:
Niewiadomska-Szynkiewicz, E.
Marks, M.
Tematy:
global optimization
integrated software systems
nonconvex optimization
numerical libraries
price management
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/308471.pdf  Link otwiera się w nowym oknie
Opis:
This paper addresses issues associated with the global optimization algorithms, which are methods to find optimal solutions for given problems. It focuses on an integrated software environment - global optimization object-oriented library (GOOL), which provides the graphical user interface together with the library of solvers for convex and nonconvex, unconstrained and constrained problems. We describe the design, performance and possible applications of the GOOL system. The practical example - price management problem - is provided to illustrate the effectiveness and range of applications of our software tool.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Necessary optimality conditions for a set valued fractional programming problem in terms of contingent epiderivatives
Autorzy:
Gadhi, A. N.
Idrissi, M. El.
Tematy:
fractional optimization
multi-objective optimization
cone-convex mapping
optimality conditions
subdifferential
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Powiązania:
https://bibliotekanauki.pl/articles/205692.pdf  Link otwiera się w nowym oknie
Opis:
In this paper, we are concerned with a multi-objective fractional extremal programming problem. Using the concept of subdifferential of cone-convex set valued mappings, introduced by Baier and Jahn (1999), together with the convex separation principle, we give necessary optimality conditions. An example illustrating the usefulness of our results is also provided.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Increased Performance of a Hybrid Optimizer for Simulation Based Controller Parameterization
Autorzy:
Neugebauer, R.
Hipp, K.
Hellmich, A.
Schlegel, H.
Tematy:
controller parameterization
simulation based optimization
particle swarm optimization (PSO)
Nelder-Mead
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Powiązania:
https://bibliotekanauki.pl/articles/384707.pdf  Link otwiera się w nowym oknie
Opis:
The controller parameterization is often carried out by applying basic empirical formulas within an integrated automatic design. Hence, the determined settings are often insufficiently verified by the resulting system behavior. In this paper an approach for the controller parameterization by using methods of simulation based optimization is presented. This enables the user to define specific restrictions e.g. the complementary sensitivity function (CSF) to influence the dynamic behavior of the control loop. Furthermore it is possible to choose alternative optimization criteria. A main influence factor for practical offline as well as controller internal optimization methods is the execution time, which can be reduced by applying a hybrid optimization strategy. Thus, the paper presents a performance comparison between the straight global Particle-Swarm-Optimization (PSO) algorithm and the combination of the global PSO with the local optimization algorithm of Nelder-Mead (NM) to a hybrid optimizer (HO) based on examples.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problem of detecting inclusions by topological optimization
Autorzy:
Faye, I.
Ndiaye, M.
Ly, I.
Seck, D.
Tematy:
topological optimization
topological gradient
shape optimization
detection of inclusions
numerical simulations
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/255587.pdf  Link otwiera się w nowym oknie
Opis:
In this paper we propose a new method to detect inclusions. The proposed method is based on shape and topological optimization tools. In fact after presenting the problem, we use topological optimization tools to detect inclusions in the domain. Numerical results are presented.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter optimization of dosator for technique culturs on the quantity intervals, close by to calculation
Parametricheskaja optimizacija dozatora dlja tekhnicheskikh kultur po kolichestvu intervalov, blizkikh k raschetnomu
Autorzy:
Belodedov, V.
Nosko, P.
Boyko, G.
Fil, P.
Mazneva, M.
Tematy:
parameter optimization
dosator
culture technique
calculation
optimization
multifactorial experiment
orthogonal planning
Pokaż więcej
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Powiązania:
https://bibliotekanauki.pl/articles/792300.pdf  Link otwiera się w nowym oknie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power system oscillation damping controller design: a novel approach of integrated HHO-PSO algorithm
Autorzy:
Devarapalli, Ramesh
Kumar, Vikash
Tematy:
Harris hawk optimization
power system stabilizers
STATCOM
FACTS
particle swarm optimization
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/1845539.pdf  Link otwiera się w nowym oknie
Opis:
The hybridization of a recently suggested Harris hawk’s optimizer (HHO) with the traditional particle swarm optimization (PSO) has been proposed in this paper. The velocity function update in each iteration of the PSO technique has been adopted to avoid being trapped into local search space with HHO. The performance of the proposed Integrated HHO-PSO (IHHOPSO) is evaluated using 23 benchmark functions and compared with the novel algorithms and hybrid versions of the neighbouring standard algorithms. Statistical analysis with the proposed algorithm is presented, and the effectiveness is shown in the comparison of grey wolf optimization (GWO), Harris hawks optimizer (HHO), barnacles matting optimization (BMO) and hybrid GWO-PSO algorithms. The comparison in convergence characters with the considered set of optimization methods also presented along with the boxplot. The proposed algorithm is further validated via an emerging engineering case study of controller parameter tuning of power system stability enhancement problem. The considered case study tunes the parameters of STATCOM and power system stabilizers (PSS) connected in a sample power network with the proposed IHHOPSO algorithm. A multi-objective function has been considered and different operating conditions has been investigated in this papers which recommends proposed algorithm in an effective damping of power network oscillations.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of a particle swarm optimization to a physically-based erosion model
Zastosowanie optymalizacji zbioru rozproszonych czasteczek do modelu erozji opartego na podstawach fizycznych
Autorzy:
Santos, C A G
Pinto, L.E.M.
De Macedo Machado Freire, P.K.
Mishra, S.K.
Tematy:
particle swarm optimization
application
erosion model
erosion simulation
run-off
optimization
erosion parameter
Pokaż więcej
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Powiązania:
https://bibliotekanauki.pl/articles/81761.pdf  Link otwiera się w nowym oknie
Opis:
The difficulties involved in calibration of physically based erosion models have been partly attributable to the lack of robust optimization tools. This paper presents the essential concepts and application to optimize channel and plane parameters in an erosion model, with a global optimization method known as Repulsive Particle Swarm (RPS), a variant of Particle Swarm Optimization (PSO) method. The physically-based erosion model that which was chosen is called WESP (watershed erosion simulation program). The optimization technique was tested with the field data collected in an experimental watershed located in a semi-arid region of Brazil. On the basis of these results, the recommended erosion parameter values for a semi-arid region are given, which could serve as an initial estimate for other similar areas.
Trudności w kalibracji modeli erozji opartych na podstawach fizycznych przyczyniły się do braku ogólnych narzędzi optymalizacji. W pracy przedstawiono podstawowe koncepcje i zastosowanie do zoptymalizowania parametrów kanału i płaszczyzny w modelu erozji, globalną metodą optymalizacji znaną jako Repulsive Particle Swarm (RPS), wariantem metody Particle Swarm Optimisation (SPO). Fizycznie uzasadniony model erozji, który został wybrany jest nazywany WESP (watershed erosion simulation program). Technika optymalizacji została wypróbowana na danych terenowych zebranych w zlewni eksperymentalnej zlokalizowanej w umiarkowanie suchym regionie Brazylii. Na podstawie tych wyników przedstawiono wartości rekomendowanego parametru erozji dla umiarkowanie suchego regionu, który może służyć jako początkowe oszacowanie dla podobnych obszarów.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interactive multi-objective optimization for simulated moving bed processes
Autorzy:
Hakanen, J.
Kawajiri, Y.
Miettinen, K.
Biegler, L. T.
Tematy:
multiobjective optimization
interactive methods
Nimbus
interior point optimization
IPOPT
simulated moving bed processes
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Powiązania:
https://bibliotekanauki.pl/articles/970406.pdf  Link otwiera się w nowym oknie
Opis:
In this paper, efficient optimization techniques are used to solve multi-objective optimization problems arising from Simulated Moving Bed (8MB) processes. SMBs are widely used in many industrial separations of chemical products and they are very challenging from the optimization point of view. With the help of interactive multi-objective optimization, several conflicting objectives can be considered simultaneously without making unnecessary simplifications, as it has been done in previous studies. The optimization techniques used are the interactive NIMBUS™ method and the IPOPT optimizer. To demonstrate the usefulness of these techniques, the results of solving an 8MB optimization problem with four objectives are reported.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel generation expansion planning in older power plants : hybrid spotted hyena-particle swarm optimization
Autorzy:
Arun, Kumar A
Suresh, S
Ramkumar, A
Bhuvanesh, A
Tematy:
generation expansion planning
particle swarm optimization
spotted hyena optimization
retirement
recuperation
Tamil Nadu
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:
https://bibliotekanauki.pl/articles/59112941.pdf  Link otwiera się w nowym oknie
Opis:
Due to their lower productivity, lower reliability, and lower economic stability, older power plants are leading to higher carbon emissions. Rather than simply focusing on the retirement and recuperation of power plants, this study focuses on generation expansion planning (GEP). Considering recuperation is economically and environmentally beneficial to power the power generating company. These criteria have made the GEP problem more complex. Hence, the applications of optimization algorithms are required to solve these complex, constrained, and large-scale problems. In this study, an effective hybrid spotted hyena-particle swarm optimization (HSHPSO) algorithm is proposed to handle the GEP problem for the Tamil Nadu power system. This case study addresses the GEP problem for a 7-year planning horizon (2020-2027), as well as a 14-year planning horizon (2020-2034). A significant reduction in total cost and pollution occurs by including retirement and recuperation in GEP. To prove the effectiveness of the proposed HSHPSO technique, it is compared with the existing technologies such as particle swarm optimization (PSO) and differential evolution (DE). Compared to GEP with no recuperation or retirement, the total cost and CO₂ emissions of the GEP have been reduced by 11.07% and 9.48%, respectively. Also, the results demonstrate that the HSHPSO algorithm outperformed other algorithms.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on Energy-Saving Optimization Design of Bridge Crane
Badania dotyczące optymalizacji energooszczędności konstrukcji suwnicy pomostowej
Autorzy:
Yifei, T.
Zhaohui, T.
Wei, Y.
Zhen, Y.
Tematy:
energy-saving design
lightweight design
shape optimization
size optimization
topology optimization
bridge crane
HyperWorks
energooszczędna konstrukcja
lekka konstrukcja
multidyscyplinarna optymalizacja
suwnica pomostowa
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:
https://bibliotekanauki.pl/articles/1366226.pdf  Link otwiera się w nowym oknie
Opis:
Bridge crane is one of the most widely used cranes in our country, which is indispensable equipment for material conveying in the modern production. The security of bridge crane is always focused on when being used. The important indicators of crane performances include strength, stiffness, and crane weight, which mainly depend on the structure design of the bridge crane. So it is of importance to research on energy-saving optimization design by means of finite element analysis, ADMAS and Matlab. In this paper, the framework of energy-saving optimization is proposed. Secondly, taking 50 t – 31.5 m bridge crane as research object, its structure is described and the FE model of the bridge cranes is developed for the finite element analysis. Thirdly, shape optimal mathematical model of the crane is proposed for shape optimization as well as size optimal mathematical model for size optimization and topology optimal mathematical model for topology optimization. Besides, further comprehensive energy-saving optimizations are carried out as well as cross-section optimization. Finally, system-level energy-saving optimization design of bridge crane is further carried out with energy-saving transmission design results feedback to energy-saving optimization design of metal structure. The optimization results show that structural optimization design can reduce total mass of crane greatly by using the finite element analysis and optimization technology premised on the design requirements of cranes such as stiffness, strength and so on, thus energy-saving design can be achieved.
Suwnica pomostowa jest jednym z najczęściej używanych typów suwnic w Chinach i stanowi niezbędne wyposażenie do transportu materiałów w nowoczesnej produkcji. Kluczową kwestią dotyczącą obsługi suwnicy pomostowej jest zawsze bezpieczeństwo. Ważnymi wskaźnikami wydajności suwnicy są m.in. wytrzymałość, sztywność oraz ciężar suwnicy, które zależą głównie od konstrukcji suwnicy. Konieczne są zatem badania nad optymalizacją energooszczędności konstrukcji za pomocą analizy elementów skończonych, ADMAS oraz Matlab. W niniejszej pracy zaproponowano koncepcję optymalizacji energooszczędności. Po drugie, opisano budowę suwnicy pomostowej (50 t – 31.5 m) oraz opracowano model MES suwnicy do analizy metodą elementów skończonych. Po trzecie, przyjmując minimalną pojemność jako funkcję celu, wysokość i szerokość suwnicy jako zmienne projektowe, a naprężenie, energię odkształcenia, modalnych jako ograniczenia, ustalono optymalny model matematyczny kształtu żurawia dla celów optymalizacyjnego projektowania kształtu. Po czwarte, przyjmując minimalny udział objętościowy jako funkcję celu, a grubości płyt jako zmienne projektowe, ustalono optymalny model matematyczny rozmiarów do celów optymalizacyjnego projektowania rozmiarów. Po piąte, przyjmując minimalny udział objętościowy jako funkcję celu, a gęstości materiału każdego z elementów jako zmienne projektowe, ustalono optymalny model matematyczny topologii do celów optymalizacyjnego projektowania topologii. Wreszcie, wykonano multidyscyplinarny energooszczędny projekt optymalizacyjny systemu suwnicy pomostowej, a wyniki energooszczędnego projektowania układu napędu zostały wykorzystane jako informacja zwrotna przy energooszczędnym projektowaniu optymalizacyjnym konstrukcji metalowej. Wyniki optymalizacji pokazują, że optymalizacyjne projektowanie konstrukcji z wykorzystaniem analizy MES oraz technologii optymalizacji opartej na wymogach projektowych dla suwnic, takich jak sztywność, wytrzymałość itd., może znacznie obniżyć całkowitą masę dźwigu, a co za tym idzie zwiększyć jego energooszczędność.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie metod optymalizacji bazujących na prymitywach i wstępnym modelu geometrycznym
Comparision of optimisation methods basing on primitives and initiall geometric models
Autorzy:
Wilk, P.
Kosmol, J.
Tematy:
korpus obrabiarki
optymalizacja
metoda optymalizacji
metoda elementów skończonych
algorytm ewolucyjny
optymalizacja parametryczna
optymalizacja topologiczna
machine tool body
optimization
optimization method
finite element method
evolutionary algorithm
parametric optimization
topology optimization
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Inżynierii Materiałów Polimerowych i Barwników
Powiązania:
https://bibliotekanauki.pl/articles/277922.pdf  Link otwiera się w nowym oknie
Opis:
W artykule przedstawiono porównanie dwóch metod optymalizacji korpusów maszyn. Obie metody wykorzystują zarówno metodę elementów skończonych jak i algorytm ewolucyjny. Pierwsza z nich zakłada, że znany jest model wstępny obiektu i wówczas należy użyć tylko optymalizacji parametrycznej. Natomiast w drugim przypadku, kiedy nie ma żadnych informacji o modelu obiektu należy zastosować zarówno optymalizacje topologiczną jak i parametryczną. Ta druga metoda wykorzystuje prymitywy, jako modele wstępne obiektu. W artykule zamieszczono wyniki porównania obu metod dla wybranego korpusu obrabiarki. Porównaniu podlegały optymalne rozwiązania w postaci: wskaźników sztywności, ich rozrzutu, masy korpusów i częstotliwość drgań własnych. Wyniki tych porównań są dosyć oczywiste: metoda optymalizacji, bazująca na prymitywach daje korzystniejsze efekty niż metoda bazująca na projekcie wstępnym. Dotyczy to w szczególności masy zoptymalizowanego korpusu, która może być nawet o 10 mniejsza.
The paper presents comparison of two optimisation methods of machine frames. Both methods use Finite Element Methods and Evolutionary Algorithm simultanously. The first of the method assumes that the initail model of the body is known and in such situation the parametric optimisation should be applied only. In the second case when one has no information about the object’s model, the Topology optimisation and Parametric optimisation should be applied. The second method uses Prymitives as preliminary model of object. The paper presents results of comparision of both metof applied to an example frame. Such parameters were compared: coefficients of stiffness, dispersion of stiffness, masses od frames, free frequency of vibration. Results of comparision are very obviousness: method of optimisation based on primitives gives better results than method based on initialy project. First of all it concerns on the mass of opimised frame, which may be even 10% smaller.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorytm inspirowany polem walki - połączenie algorytmów numerycznych z ideą roju
Autorzy:
Baumgart, Jan
Sangho, Belco
Tematy:
algorytm optymalizacyjny
inspiracja polem walki
rozwiązanie
optymalizacja
rzeczywiste problemy optymalizacji
optymalizacja funkcji
algorytm numeryczny
optimization algorithms
battlefield inspired inspiration
solution
optimization
real optimization problems
function optimization
numerical algorithm
Pokaż więcej
Wydawca:
Uniwersytet Kazimierza Wielkiego w Bydgoszczy
Powiązania:
https://bibliotekanauki.pl/articles/41206049.pdf  Link otwiera się w nowym oknie
Opis:
Artykuł przedstawia przygotowany algorytm na bazie połączenia idei znanych metod numerycznych z metodami opartymi na idei roju. Algorytm został przygotowany z inspiracji polem walki podczas którego w równych odstępach żołnierze przeczesują siły wroga z różnymi prędkościami zależnie od posiadanego orężu a następnie ograniczają zakres pola bitwy. Zaproponowane rozwiązanie wywodzi się właśnie ze zbliżonych założeń. Głównym założeniem pracy było przedstawienie potencjalnego zysku z połączenia metod optymalizacji oraz porównanie metody mieszanej z metodami bazującymi na idei roju pod względem prędkości działania oraz skuteczności odnajdowania optimum globalnego.Algorytm został porównany z dwoma algorytmami metaheurystycznymi pod kątem dokładności odnalezionych rozwiązań oraz prędkości. Zgodnie z wynikami eksperymentów posiada wydajność podobną w porównaniu z innymi algorytmami oraz daje zadowalające efekty w wykorzystaniu.
he article presents prepared algorithm based on the combination of the ideas of known numericalmethods with methods based on the idea of a swarm. The algorithm was prepared inspired by the battlefield,during which, at equal intervals, soldiers scour enemy forces at different speeds depending on the weapon theyhave, and then limit the scope of the battlefield. The proposed solution is based on similar assumptions. Themain assumption of the work was to present the potential profit from the combination of optimization methodsand to compare the mixed method with methods based on the idea of a swarm in terms of operating speed andthe effectiveness of finding the global optimum. The algorithm was compared with two metaheuristic algorithmsin terms of the accuracy of the solutions found and speed. According to the results of the experiments, it hasa similar performance compared to other algorithms and gives satisfactory results in use.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementation of multithreaded Particle Swarm Optimization algorithm
Implementacja wielowątkowego algorytmu Particle Swarm Optimization
Autorzy:
Rachwał, Szczepan
Opis:
This paper has been written with an intention to introduce the recipent to a problem of optimizing multidimensional functions. It covers a theoretical approach to this issue, defining the concept. The main goal of this paper is to present a version of Particle Swarm Optimization algorithm which has been improved in comparison to the original one. Both the formal definition, as well as a practical usage will be covered. A series of tests on different functions will be performed to target typical issues with Particle Swarm Optimization and their behavior in the proposed multithread algorithm version.A computer program written in Java is an integral part of this paper. It implements the proposed new version of the Particle Swarm Optimization algorithm, to demonstrate this new approach and its strengths.
Niniejsza praca ma na celu przybliżenie tematyki optymalizacji funkcji wielu zmiennych. Głównym jej założeniem jest przedstawienie optymalizacji skomplikowanych funkcji wielowymiarowych za pomocą ulepszonego algorytmu Particle Swarm Optimization. Zostanie zaprezentowana teoretyczna część tego zagadnienia, jak również działanie algorytmu na przykładach. Przybliżone zostaną również konkretne typy funkcji pozwalające zaprezentować mocne i słabe strony Particle Swarm Optimization.Ponadto, integralną częścią pracy jest również program komputerowy napisany w języku Java, w którym zostanie zaimplementowane wspomniane nowe podejście do zagadnienia Particle Swarm Optimization, eliminujące niektóre słabości oryginalnej wersji algorytmu.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Inne
Tytuł:
Fault diagnosis of power transformer based on improved particle swarm optimization OS-ELM
Autorzy:
Li, Yuancheng
Ma, Longqiang
Tematy:
power transformer
fault diagnosis
improved particle swarm optimization
OS-ELM
parameter optimization
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/140428.pdf  Link otwiera się w nowym oknie
Opis:
A transformer is an important part of power transmission and transformation equipment. Once a fault occurs, it may cause a large-scale power outage. The safety of the transformer is related to the safe and stable operation of the power system. Aiming at the problem that the diagnosis result of transformer fault diagnosis method is not ideal and the model is unstable, a transformer fault diagnosis model based on improved particle swarm optimization online sequence extreme learning machine (IPSO-OS-ELM) algorithm is proposed. The improved particle swarmoptimization algorithm is applied to the transformer fault diagnosis model based on the OS-ELM, and the problems of randomly selecting parameters in the hidden layer of the OS-ELM and its network output not stable enough, are solved by optimization. Finally, the effectiveness of the improved fault diagnosis model in improving the accuracy is verified by simulation experiments.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Technique of Optimization for the COCOMO II Model Parameters using Teaching-Learning-Based Optimization Algorithm
Autorzy:
Khuat, T. T.
Le, M. H.
Tematy:
COCOMO II
cost estimation
NASA software
optimization
teaching-learning-based optimization algorithm
Pokaż więcej
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:
https://bibliotekanauki.pl/articles/309064.pdf  Link otwiera się w nowym oknie
Opis:
Software cost estimation is a critical activity in the development life cycle for controlling risks and planning project schedules. Accurate estimation of the cost before the start-up of a project is essential for both the developers and the customers. Therefore, many models were proposed to address this issue, in which COCOMO II has been being widely employed in actual software projects. Good estimation models, such as COCOMO II, can avoid insufficient resources being allocated to a project. However, parameters for estimation formula in this model have not been optimized yet, and so the estimated results are not close to the actual results. In this paper, a novel technique to optimize the coefficients for COCOMO II model by using teaching-learning-based optimization (TLBO) algorithm is proposed. The performance of the model after optimizing parameters was tested on NASA software project dataset. The obtained results indicated that the improvement of parameters provided a better estimation capabilities compared to the original COCOMO II model.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a Predictive PID Controller Using Particle Swarm Optimization
Autorzy:
Mustafa, Norhaida
Hashim, Fazida Hanim
Tematy:
proportional integral derivative controller
particle swarm optimization (PSO) algorithm
optimization
predictive PID
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/1844451.pdf  Link otwiera się w nowym oknie
Opis:
The proportional-integral-derivative (PID) controller is widely used in various industrial applications such as process control, motor drives, magnetic and optical memory, automotive, flight control and instrumentation. PID tuning refers to the generation of PID parameters (Kp, Ki, Kd) to obtain the optimum fitness value for any system. The determination of the PID parameters is essential for any system that relies on it to function in a stable mode. This paper proposes a method in designing a predictive PID controller system using particle swarm optimization (PSO) algorithm for direct current (DC) motor application. Extensive numerical simulations have been done using the Mathwork’s Matlab simulation environment. In order to gain full benefits from the PSO algorithm, the PSO parameters such as inertia weight, iteration number, acceleration constant and particle number need to be carefully adjusted and determined. Therefore, the first investigation of this study is to present a comparative analysis between two important PSO parameters; inertia weight and number of iteration, to assist the predictive PID controller design. Simulation results show that inertia weight of 0.9 and iteration number 100 provide a good fitness achievement with low overshoot and fast rise and settling time. Next, a comparison between the performance of the DC motor with PID-PSO, with PID of gain 1, and without PID were also discussed. From the analysis, it can be concluded that by tuning the PID parameters using PSO method, the best gain in performance may be found. Finally, when comparing between the PID-PSO and its counterpart, the PI-PSO, the PID-PSO controller gives better performance in terms of robustness, low overshoot (0.005%), low minimum rise time (0.2806 seconds) and low settling time (0.4326 seconds).
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation-based sailboat trajectory optimization using on-board heterogeneous computers
Autorzy:
Dębski, R.
Tematy:
black-box optimization
trajectory optimization
dynamic programming
heterogeneous computing
micro HPC platform
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/305745.pdf  Link otwiera się w nowym oknie
Opis:
A dynamic programming-based algorithm adapted to on-board heterogeneous computers for simulation-based trajectory optimization was studied in the context of high-performance sailing. The algorithm can efficiently utilize all OpenCL-capable devices, starting the computation (if necessary, in single precision) on a GPU and finalizing it (if necessary, in double-precision) with the use of a CPU. The serial and parallel versions of the algorithm are presented in detail. Possible extensions of the basic algorithm are also described. The experimental results show that contemporary heterogeneous on-board/mobile computers can be treated as micro HPC platforms. They offer high performance (the OpenCL-capable GPU was found to accelerate the optimization routine 41 fold) while remaining energy and cost efficient. The simulation-based approach has the potential to give very accurate results, as the mathematical model upon which the simulator is based may be as complex as required. The black-box represented performance measure and the use of OpenCL make the presented approach applicable to many trajectory optimization problems.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optymalizacja topologiczna z ograniczeniem naprężeniowym konstrukcji pojazdu
Topology optimization with stress constraint of vehicle structure
Autorzy:
Mrzygłód, M.
Michalik, M.
Tematy:
optymalizacja topologiczna
metoda elementów skończonych
topology optimization
structural optimization
finite element method
Pokaż więcej
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:
https://bibliotekanauki.pl/articles/158216.pdf  Link otwiera się w nowym oknie
Opis:
W artykule przedstawiono propozycje prostego w aplikacji algorytmu optymalizacji topologicznej z ograniczeniem naprężeniowym. Procedura optymalizacyjna została zaimplementowana do programu MES w postaci skryptu. Metodykę optymalizacji topologicznej zilustrowano przykładem optymalizacji konstrukcji pojazdu samochodowego z uwzględnieniem złożonego zestawu obciążeń. Badania optymalizacyjne wykazały dużą efektywność działania proponowanej metodyki zarówno z punktu widzenia obniżenia masy konstrukcji, jak i poprawy jej własności wytrzymałościowych. Zaproponowany algorytm optymalizacyjny dzięki swej prostocie i efektywności powinien znaleźć szerokie zastosowanie w przemyśle.
In the article a simple in application algorithm of topology optimization with stress constraint was presented (see Fig. 1). An optimization procedure in form of a FEM program script was built. The methodology of topology optimization was illustrated by an example of optimization of road vehicle structure subjected to complex load conditions. The optimization investigations shows high efficiency of proposed methodology both, from point of view of mass decreasing, and improvement of durability of the structure(see Fig. 2, 4). Proposed optimization algorithm, thanks to its simplicity and efficiency, should find wide application in industry.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Population diversity maintenance in brain storm optimization algorithm
Autorzy:
Cheng, S.
Shi, Y.
Qin, Q.
Zhang, Q
Bai, R.
Tematy:
brainstorm
optimization algorithm
convergence
divergence
brainstorm optimization
BSO
swarm intelligence
BSO algorithm
Pokaż więcej
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Powiązania:
https://bibliotekanauki.pl/articles/91571.pdf  Link otwiera się w nowym oknie
Opis:
The convergence and divergence are two common phenomena in swarm intelligence. To obtain good search results, the algorithm should have a balance on convergence and divergence. The premature convergence happens partially due to the solutions getting clustered together, and not diverging again. The brain storm optimization (BSO), which is a young and promising algorithm in swarm intelligence, is based on the collective behavior of human being, that is, the brainstorming process. The convergence strategy is utilized in BSO algorithm to exploit search areas may contain good solutions. The new solutions are generated by divergence strategy to explore new search areas. Premature convergence also happens in the BSO algorithm. The solutions get clustered after a few iterations, which indicate that the population diversity decreases quickly during the search. A definition of population diversity in BSO algorithm is introduced in this paper to measure the change of solutions’ distribution. The algorithm’s exploration and exploitation ability can be measured based on the change of population diversity. Different kinds of partial reinitialization strategies are utilized to improve the population diversity in BSO algorithm. The experimental results show that the performance of the BSO is improved by part of solutions re-initialization strategies.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Socio-cognitively inspired ant colony optimization
Autorzy:
Łasisz, Jakub
Indurkhya, Bipin
Lenaerts, Tom
Świderska, Ewelina
Byrski, Aleksander
Samson, Dana
Nowe, Ann
Kisiel-Dorohinicki, Marek
Opis:
Recently we proposed an application of ant colony optimization (ACO) to simulate socio-cognitive features of a population, incorporating perspective-taking ability to generate differently acting ant colonies. Although our main goal was simulation, we took advantage of the fact that the quality of the constructed system was evaluated based on selected traveling salesman problem instances, and the resulting computing system became a metaheuristic, which turned out to be a promising method for solving discrete problems. In this paper, we extend the initial sets of populations driven by different perspective-taking inspirations, seeking both optimal configuration for solving a number of TSP benchmarks, at the same time constituting a tool for analyzing socio-cognitive features of the individuals involved. The proposed algorithms are compared against classic ACO, and are found to prevail in most of the benchmark functions tested.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Grey wolf optimization algorithm for a concurrent real-time optimization problem in game theory
Autorzy:
Ogorzałek, Maciej
Górski, Adam
Opis:
In this paper we present a grey wolf algorithm for a concurrent real time optimization problem in searching for optimal game solving solution. There are many solutions to solve the game. Each solution can demand different optimal values of different parameters. However some ways in which the players try to solve the game do not lead to success. The optimization problem consists of two phases. Each phase Impacts the second one in real time. The first phase is responsible for the optimization parameters choice. The second phase validates the choice and makes the optimization of the parameters. As a optimizing method we chose grey wolf optimization. At the beginning the algorithm generates some number of solutions. The solution which has the value of the parameters the closest to maximum is a position of an alfa wolf. The rest of solutions are, according to the values of the parameters, split to be the positions of beta, delta and omega wolves.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Optymalizacja czasowo-kosztowa w harmonogramowaniu wieloobiektowych przedsięwzięć budowlanych
Optimization when scheduling large object building initiatives
Autorzy:
Podolski, M.
Tematy:
inwestycja budowlana
projekt wieloobiektowy
harmonogramowanie
optymalizacja czasowa
optymalizacja kosztowa
model optymalizacyjny
building investment
multi-object project
scheduling
time optimization
cost optimization
optimization model
Pokaż więcej
Wydawca:
Polski Związek Inżynierów i Techników Budownictwa
Powiązania:
https://bibliotekanauki.pl/articles/163397.pdf  Link otwiera się w nowym oknie
Opis:
W pracy przedstawiono model optymalizacyjny przedsięwzięcia, które jest realizowane w systemie pracy potokowej i polega na wykonaniu wielu obiektów budowlanych. Wykonawca przedsięwzięcia może korzystać z zasobów własnych lub zewnętrznych (podwykonawców). Dodatkowymi parametrami rozważanymi w modelu, oprócz czasów trwania robót, są koszty pracy podwykonawców. W związku z dużą liczbą rozwiązań dopuszczalnych problemu do rozwiązania zadań optymalizacji dyskretnej, zastosowano algorytm poszukiwania z zakazami (tabu search) stosowany w teorii szeregowania zadań. Zaprezentowany model zilustrowano przykładem obliczeniowym.
The work presents a model of optimization of building initiative, which is being realized as a pipeline workflow, and the aim of that initiative is to create multiple buildings. The contractor may use his own resources or resources of the external sub-contractors. Besides that, additional parameters which are being considered by the model, besides the time of the work, include the costs of subcontracting. Due to a large number of the solutions which may be used to solve the tasks of discrete optimization, a search algorithm with prohibitions (taboo search) has been used. This algorithm is used in the theory of ordering the tasks. The presented model has been illustrated with a calculation example.
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies