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PL
Omówiono wybrane algorytmy służące do poprawiania jakości sygnałów pomiarowych pola elektromagnetycznego we wnękach rezonansowych akcelerator FLASH. Krótko scharakteryzowano autorskie rozwiązania filtrów o skończonej odpowiedzi impulsowej. Filtry zostały zaimplementowane w środowisku MATLAB/OCTAVE i przeanalizowane z wykorzystaniem rzeczywistych sygnałów zarejestrowanych podczas pracy akceleratora FLASH. We wstępie krótko scharakteryzowano eksperyment FLASH, a w szczególności jego system sterowania wnękami rezonansowymi typu TESLA.
EN
Algorithms used for conditioning signals of EM field in resonance cavities in FLASH experiment are introduced in this thesis. Brief of sketch of FLASH experiment is found in introduction. In particular control system for TESLA resonance cavities. Proposed solutions for finite impulse response filters response are explained. Filters are implemented in Matlab/Octave computational environment. They are analyzed with usage of real signals collected during experiments at FLASH accelerator. In conclusion effectiveness proposed solutions is estimated. Additionally, plans for further improvements of the system are proposed.
EN
This paper is devoted to the application of an Evolutionary Algorithm to the design of Finite Impulse Response filters (FIR). A hybrid algorithm is proposed, which consists of a robust global optimization method (Evolutionary Algorithm - EA) and a good local optimization method (Quasi-Newton - QN). An experimental comparison of the hybrid algorithm against EA and QN alone indicates that EA yields filters with the better amplitude characteristics than QN. Furthermore the hybrid method yields filters with even better amplitude characteristics and in some times, it needs significantly less time than EA alone to reach good solutions.
EN
In the paper, a method for designing two-dimensional finite impulse response linear phase digital filters is presented. The method can be applied for designing filters with both real and complex impulse response. In the method, two approximation criteria are used, i.e., the equiripple error criterion in the passband and the least-squared (LS) error criterion in the stopband. The design problem is solved by means of its transformation into an equivalent bicriterion optimization problem. A column vector Y of filter coefficients is defined and two objective functions X1(Y) and X2(Y) are introduced. The function X1(Y) has the global minimum equal to zero when the amplitude error is equiripple in the passband. The LS error in the stopband is used as the second objective function X2(Y). The bicriterion optimization problem is converted into a single criterion one using the weighted sum strategy. Optionally, a constraint on the maximum permissible error in the passband can also be added and easily incorporated into the optimization problem. The obtained constrained minimization problem is solved using the penalty function algorithm. Unconstrained minimization is performed by means of a conjugate gradient method. Three design examples illustrating the application of the proposed method are given. The results are compared with those obtained using the equiripple and the LS approaches.
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