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Wyszukujesz frazę "convex optimization" wg kryterium: Temat


Tytuł:
Methods of thrust allocation in a DP simulation system of Maritime University of Szczecin
Autorzy:
Zalewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/320729.pdf
Data publikacji:
2016
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
dynamic positioning thrust allocation
convex optimization
Opis:
Vessels conducting dynamic positioning (DP) operations are usually equipped with thruster configurations that enable generation of resultant force and moment in any direction. These configurations are deliberately redundant in order to reduce the consequences of thruster failures and increase the safety. 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 thrusters’ settings in DP systems is a problem that can be solved by several convex optimization methods depending on criteria and constraints used. The paper presents linear programming (LP) and quadratic programming (QP) methods adopted in DP control model which is being developed in Maritime University of Szczecin for ship simulation purposes.
Statki pozycjonowane dynamicznie (DP) mają konfiguracje pędników umożliwiające wytwarzanie wypadkowej siły i momentu w dowolnym kierunku. Konfiguracje te są zazwyczaj nadmiarowe w celu zmniejszenia skutków awarii pojedynczych pędników, a tym samym zwiększenia poziomu bezpieczeństwa wykonywanej pracy. Na takich jednostkach musi być stosowany system alokacji wyliczający i przydzielający nastawy do poszczególnych pędników. Optymalna alokacja nastaw pędników w systemach DP jest problemem, który można rozwiązać, w zależności od zadanych kryteriów i ograniczeń, kilkoma metodami optymalizacji wypukłej. W artykule przedstawiono metody programowania liniowego (LP) i kwadratowego (QP) zastosowane w modelu sterowania DP w symulatorach nawigacyjno-manewrowych Akademii Morskiej w Szczecinie.
Źródło:
Annual of Navigation; 2016, 23; 209-218
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Penalty/barrier path-following in linearly constrained optimization
Autorzy:
Grossmann, Christian
Powiązania:
https://bibliotekanauki.pl/articles/729261.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
penalty/barrier
interior point methods
convex optimization
Opis:
In the present paper rather general penalty/barrier path-following methods (e.g. with p-th power penalties, logarithmic barriers, SUMT, exponential penalties) applied to linearly constrained convex optimization problems are studied. In particular, unlike in previous studies [1,11], here simultaneously different types of penalty/barrier embeddings are included. Together with the assumed 2nd order sufficient optimality conditions this required a significant change in proving the local existence of some continuously differentiable primal and dual path related to these methods. In contrast to standard penalty/barrier investigations in the considered path-following algorithms only one Newton step is applied to the generated auxiliary problems. As a foundation of convergence analysis the radius of convergence of Newton's method depending on the penalty/barrier parameter is estimated. There are established parameter selection rules which guarantee the overall convergence of the considered path-following penalty/barrier techniques.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2000, 20, 1; 7-26
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximation of set-valued functions by single-valued one
Autorzy:
Ginchev, Ivan
Hoffmann, Armin
Powiązania:
https://bibliotekanauki.pl/articles/729538.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Chebyshev approximation
set-valued functions
convex optimization
Opis:
Let $Σ: M → 2^Y\{∅}$ be a set-valued function defined on a Hausdorff compact topological space M and taking values in the normed space (Y,||·||). We deal with the problem of finding the best Chebyshev type approximation of the set-valued function Σ by a single-valued function g from a given closed convex set V ⊂ C(M,Y). In an abstract setting this problem is posed as the extremal problem $sup_{t ∈ M} ρ(g(t), (t)) → inf$, g ∈ V. Here ρ is a functional whose values ρ(q,S) can be interpreted as some distance from the point q to the set S ⊂ Y. In the paper, we are confined to two natural distance functionals ρ = H and ρ = D. H(q,S) is the Hausdorff distance (the excess) from the point q to the set cl S, and D(q,S) is referred to as the oriented distance from the point q to set cl conv S. We prove that both these problems are convex optimization problems. While distinguishing between the so called regular and irregular case problems, in particular the case V = C(M,Y) is studied to show that the solutions in the irregular case are obtained as continuous selections of certain set-valued maps. In the general case, optimality conditions in terms of directional derivatives are obtained of both primal and dual type.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2002, 22, 1; 33-66
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Joint allocation and transportation problem in supply network optimisation
Autorzy:
Filcek, G.
Powiązania:
https://bibliotekanauki.pl/articles/407403.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
supply networks
optimization
convex optimization
heuristic algorithms
decision support systems
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.
Źródło:
Management and Production Engineering Review; 2012, 3, 3; 3-10
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Convex optimization of thrust allocation in a dynamic positioning simulation system
Autorzy:
Zalewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/135112.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
dynamic positioning
thrust allocation
convex optimization
configurations
programming
simulator
Opis:
Vessels conducting dynamic positioning (DP) operations are usually equipped with thruster configurations that enable the generation of resultant force and moment in any direction. These configurations are deliberately redundant in order to reduce the consequences of thruster failures and increase the safety. 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 thrusters’ settings in DP systems is a problem that can be solved by several convex optimization methods depending on criteria and constraints used. The paper presents linear programming (LP) and quadratic programming (QP) methods adopted in the DP control model which is being developed at the Maritime University of Szczecin for ship simulation purposes.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 48 (120); 58-62
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Constraints in allocation of thrusters in a DP simulator
Autorzy:
Zalewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/135012.pdf
Data publikacji:
2017
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
dynamic positioning
thrust allocation
convex optimization
constrained optimization
DP simulator
thrusters
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.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2017, 52 (124); 45-50
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified PSO Based Channel Allocation Scheme for Interference Management in 5G Wireless Mesh Networks
Autorzy:
Benni, Nirmalkumar S.
Manvi, Sunilkumar S.
Powiązania:
https://bibliotekanauki.pl/articles/2142305.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
channel allocation
co-channel interference
convex optimization
multicarrier NOMA
Rayleigh fading
Opis:
Efficient channel management is a challenge that next-generation wireless networks need to meet in order to satisfy increasing bandwidth demand and transmission rate requirements. Non-orthogonal multiple access (NOMA) is one of such efficient channel allocation methods used in 5G backhaul wireless mesh networks. In this paper, we propose a power demand-based channel allocation method for 5G backhaul wireless mesh networks by employing NOMA and considering traffic demands in small cells, thereby improving channel utility. In this scheme, we work with physical layer transmission. The foremost aim is to mutually optimize the uplink/downlink NOMA channel assignment in order to increase user fairness. The approach concerned may be divided into two steps. First, initial channel allocation is performed by employing the traveling salesman problem (TSP), due to its similarity to many-to-many double-side user-channel allocation. Second, the modified particle swarm optimization (PSO) method is applied for allocation updates, by introducing a decreasing coefficient which may have the form of a standard stochastic estimate algorithm. To enhance exploration capacity of modified the PSO, a random velocity is included to optimize the convergence rate and exploration behavior. The performance of the designed scheme is estimated through simulation, taking into account such parameters as through put, spectral efficiency, sum-rate, outage probability, signal to-interference plus noise ratio (SINR), and fairness. The proposed scheme maximizes network capacity and improves fairness between the individual stations. Experimental results show that the proposed technique performs better than existing solutions.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 2; 1--13
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application-oriented experiment design for model predictive control
Autorzy:
Jakowluk, W.
Świercz, M.
Powiązania:
https://bibliotekanauki.pl/articles/201147.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
model predictive control
optimal input design
convex optimization
application-oriented identification
Opis:
The model predictive control (MPC) technique has been widely applied in a large number of industrial plants. Optimal input design should guarantee acceptable model parameter estimates while still providing for low experimental effort. The goal of this work is to investigate an application-oriented identification experiment that satisfies the performance objectives of the implementation of the model. A- and D-optimal input signal design methods for a non-linear liquid two-tank model are presented in this paper. The excitation signal is obtained using a finite impulse response filter (FIR) with respect to the accepted application degradation and the power constraint. The MPC controller is then used to control the liquid levels of the double tank system subject to the reference trajectory. The MPC scheme is built based on the linearized and discretized model of the system to predict the system’s succeeding outputs with reference to the future input signal. The novelty of this model-based method consists in including the experiment cost in input design through the objective function. The proposed framework is illustrated by means of numerical examples, and simulation results are discussed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 883-891
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of descriptor approaches in design of PD observer-based actuator fault estimation
Autorzy:
Filasova, A.
Krokavec, D.
Serbak, V.
Powiązania:
https://bibliotekanauki.pl/articles/229212.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PD observers
actuator fault estimation
descriptor system observation
convex optimization
linear matrix inequalities
Opis:
Stability analysis and design for continuous-time proportional plus derivative state observers is presented in the paper with the goal to establish the system state and actuator fault estimation. Design problem accounts a descriptor principle formulation for non-descriptor systems, guaranteing asymptotic convergence both the state observer error as fault estimate error. Presented in the sense of the second Lyapunov method, an associated structure of linear matrix inequalities is outlined to possess parameter existence of the proposed estimator structure. The obtained design conditions are verified by simulation using a numerical illustrative example.
Źródło:
Archives of Control Sciences; 2015, 25, 1; 51-64
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sub-gradient algorithms for computation of extreme eigenvalues of a real symmetric matrix
Autorzy:
Yassine, A.
Powiązania:
https://bibliotekanauki.pl/articles/205834.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
problem wartości własnej
difference of convex functions
eigenvalue problems
Lagrangian duality
non-convex optimization
sub-gradient algorithms
Opis:
The computation of eigenvalues of a matrix is still of importance from both theoretical and practical points of view. This is a significant problem for numerous industrial and scientific situations, notably in dynamics of structures (e.g. Gerardin, 1984), physics (e.g. Rappaz, 1979), chemistry (e.g. Davidson, 1983), economy (e.g. Morishima, 1971; Neumann, 1946), mathematics (e.g. Golub, 1989; Chatelin, 1983, 1984, 1988). The study of eigenvalue problems remains a delicate task, which generally presents numerical difficulties in relation to its sensivity to roundoff errors that may lead to numerical unstabilities, particularly if the eigenvalues are not well separated. In this paper, new subgradient-algorithms for computation of extreme eigenvalues of a symmetric real matrix are presented. Those algorithms are based on stability of Lagrangian duality for non-convex optimization and on duality in the difference of convex functions. Some experimental results which prove the robustness and efficiency of our algorithms are provided.
Źródło:
Control and Cybernetics; 1998, 27, 3; 387-415
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid PSO approach for solving non-convex optimization problems
Autorzy:
Ganesan, T.
Vasant, P.
Elamvazuthy, I.
Powiązania:
https://bibliotekanauki.pl/articles/229756.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Kuhn-Tucker conditions (KT)
non-convex optimization
particle swarm optimization (PSO)
semi-classical particle swarm optimization (SPSO)
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.
Źródło:
Archives of Control Sciences; 2012, 22, 1; 87-105
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solving Support Vector Machine with Many Examples
Autorzy:
Białoń, P.
Powiązania:
https://bibliotekanauki.pl/articles/308497.pdf
Data publikacji:
2010
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
concept drift
convex optimization
data mining
network failure detection
stream processing
support vector machines
Opis:
Various methods of dealing with linear support vector machine (SVM) problems with a large number of examples are presented and compared. The author believes that some interesting conclusions from this critical analysis applies to many new optimization problems and indicates in which direction the science of optimization will branch in the future. This direction is driven by the automatic collection of large data to be analyzed, and is most visible in telecommunications. A stream SVM approach is proposed, in which the data substantially exceeds the available fast random access memory (RAM) due to a large number of examples. Formally, the use of RAM is constant in the number of examples (though usually it depends on the dimensionality of the examples space). It builds an inexact polynomial model of the problem. Another author's approach is exact. It also uses a constant amount of RAM but also auxiliary disk files, that can be long but are smartly accessed. This approach bases on the cutting plane method, similarly as Joachims' method (which, however, relies on early finishing the optimization).
Źródło:
Journal of Telecommunications and Information Technology; 2010, 3; 65-70
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust H∞ control for a class of uncertain neutral systems with both state and control input time-varying delays via a unified LMI optimization approach
Autorzy:
Chen, J. D.
Yang, C. D.
Lin, K. J.
Lien, C. H.
Powiązania:
https://bibliotekanauki.pl/articles/970609.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
robust H[infinity] control
neutral systems
unified LMI approach
convex optimization approach
delay-dependent criterion
Opis:
The robust H∞ control problem is considered for a class of uncertain neutral system involving both state and control input time-varying delays. The uncertainties under consideration are nonlinear time-varying parameter perturbations. The methodology is based on the Lyapunov functional combined with a unified LMI approach, and a new delay-dependent criterion is proposed to guarantee the stabilization and disturbance attenuation of systems. Moreover, a convex optimization approach is used to solve the robust H∞ control disturbance attenuation problem. Finally, a numerical example is illustrated to show the validity of this paper. The simulation results reveal significant improvement over the recent results.
Źródło:
Control and Cybernetics; 2008, 37, 3; 517-530
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear and Planar Array Pattern Nulling via Compressed Sensing
Autorzy:
Mohammed, Jafar Ramadhan
Thaher, Raad H.
Abdulqader, Ahmed Jameel
Powiązania:
https://bibliotekanauki.pl/articles/1839322.pdf
Data publikacji:
2021
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
compressed sensing
convex optimization
iterative re-weighted l1- norm minimization
linear array
planar array
Opis:
An optimization method based on compressed sensing is proposed for uniformly excited linear or planar antenna arrays to perturb excitation of the minimum number of array elements in such a way that the required number of nulls is obtained. First, the spares theory is relied upon to formulate the problem and then the convex optimization approach is adopted to find the optimum solution. The optimization process is further developed by using iterative re-weighted l1- norm minimization, helping select the least number of the sparse elements and impose the required constraints on the array radiation pattern. Furthermore, the nulls generated are wide enough to cancel a whole specific sidelobe. Simulation results demonstrate the effectiveness of the proposed method and the required nulls are placed with a minimum number of perturbed elements. Thus, in practical implementations of the proposed method, a highly limited number of attenuators and phase shifters is required compared to other, conventional methods.
Źródło:
Journal of Telecommunications and Information Technology; 2021, 3; 50-55
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal training strategies for locally recurrent neural networks
Autorzy:
Patan, K.
Patan, M.
Powiązania:
https://bibliotekanauki.pl/articles/1396735.pdf
Data publikacji:
2011
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
training schedule
neural network
Fisher information matrix
network parameters
optimal experimental design
convex optimization theory
Opis:
The problem of determining an optimal training schedule for locally recurrent neural network is discussed. Specifically, the proper choice of the most informative measurement data guaranteeing the reliable prediction of neural network response is considered. Based on a scalar measure of performance defined on the Fisher information matrix related to the network parameters, the problem was formulated in terms of optimal experimental design. Then, its solution can be readily achieved via adaptation of effective numerical algorithms based on the convex optimization theory. Finally, some illustrative experiments are provided to verify the presented approach.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2011, 1, 2; 103-114
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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