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Wyszukujesz frazę "Koziel, S." wg kryterium: Autor


Wyświetlanie 1-10 z 10
Tytuł:
Computationally Efficient Two-Objective Optimization of Compact Microwave Couplers through Corrected Domain Patching
Autorzy:
Kozieł, S.
Bekasiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/221065.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computer-aided design
compact circuits
microwave couplers
multi-objective optimization
domain patching
surrogate modelling
response correction
Opis:
Finding an acceptable compromise between various objectives is a necessity in the design of contemporary microwave components and circuits. A primary reason is that most objectives are at least partially conflicting. For compact microwave structures, the design trade-offs are normally related to the circuit size and its electrical performance. In order to obtain comprehensive information about the best possible trade-offs, multi-objective optimization is necessary that leads to identifying a Pareto set. Here, a framework for fast multi-objective design of compact micro-strip couplers is discussed. We use a sequential domain patching (SDP) algorithm for numerically efficient handling of the structure bandwidth and the footprint area. Low cost of the process is ensured by executing SDP at the low-fidelity model level. Due to its bi-objective implementation, SDP cannot control the power split error of the coupler, the value of which may become unacceptably high along the initial Pareto set. Here, we propose a procedure for correction of the S-parameters’ characteristics of Pareto designs. The method exploits gradients of power split and bandwidth estimated using finite differentiation at the patch centres. The gradient data are used to correct the power split ratio while leaving the operational bandwidth of the structure at hand intact. The correction does not affect the computational cost of the design process because perturbations are pre-generated by SDP. The final Pareto set is obtained upon refining the corrected designs to the high-fidelity EM model level. The proposed technique is demonstrated using two compact microstrip rat-race couplers. Experimental validation is also provided.
Źródło:
Metrology and Measurement Systems; 2018, 25, 1; 139-157
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rapid Design Optimization of Multi-Band Antennas by Means of Response Features
Autorzy:
Kozieł, S.
Bekasiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/221503.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
antenna design
antenna measurements
computer-aided design
surrogate modelling
feature-based optimization
Opis:
This work examines the reduced-cost design optimization of dual- and multi-band antennas. The primary challenge is independent yet simultaneous control of the antenna responses at two or more frequency bands. In order to handle this task, a feature-based optimization approach is adopted where the design objectives are formulated on the basis of the coordinates of so-called characteristic points (or response features) of the antenna response. Due to only slightly nonlinear dependence of the feature points on antenna geometry parameters, optimization can be attained at a low computational cost. Our approach is demonstrated using two antenna structures with the optimum designs obtained in just a few dozen of EM simulations of the respective structure.
Źródło:
Metrology and Measurement Systems; 2017, 24, 2; 337-346
0860-8229
Pojawia się w:
Metrology and Measurement Systems
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.
Powiązania:
https://bibliotekanauki.pl/articles/220985.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
linear antenna array
micro-strip antenna array
phased antenna array
antenna optimization
antenna array optimization
simulation-based optimization
surrogate model
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).
Źródło:
Metrology and Measurement Systems; 2016, 23, 2; 193-203
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of positioning error and its impact on high frequency properties of differential signal coupler
Autorzy:
Zmuda, M.
Szczepański, S.
Kozieł, S.
Powiązania:
https://bibliotekanauki.pl/articles/200709.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high speed data transmission monitoring
coupler positioning accuracy
manufacturing of coupling structures
monitoring wysokiej prędkości transmisji danych
dokładność pozycjonowania
produkcja konstrukcji sprzęgła
Opis:
This paper presents the analysis of the effect of differential signal coupler positioning accuracy on its high frequency performance parameters for contact-less high speed chip-to-chip data transmission on PCB application. Our considerations are continuation of the previous works on differential signal coupler concept, design methodology and analysis for high speed data transmission monitoring. The theoretical analysis of possible coupler positioning innaccuracies is extended for representative design cases by simulations carried out using EM simulator. The results reported here confirm that the concept of contactless monitoring of high speed chip-to-chip data transmission in a pair of coupled microstrip lines is of practically usefulness without applying the expensive and precise positioning system.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 2; 549-553
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design Optimization and Trade-Offs of Miniaturized Wideband Antenna for Internet of Things Applications
Autorzy:
ul Haq, M. A.
Kozieł, S.
Powiązania:
https://bibliotekanauki.pl/articles/220987.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compact antennas
internet of things (IoT)
communication devices
numerical optimization
footprint-reduction-oriented design
Opis:
Internet of Things (IoT) will play an important role in modern communication systems. Thousands of devices will talk to each other at the same time. Clearly, smart and efficient hardware will play a vital role in the development of IoT. In this context, the importance of antennas increases due to them being essential parts of communication networks. For IoT applications, a small size with good matching and over a wide frequency range is preferred to ensure reduced size of communication devices. In this paper, we propose a structure and discuss design optimization of a wideband antenna for IoT applications. The antenna consists of a stepped-impedance feed line, a rectangular radiator and a ground plane. The objective is to minimize the antenna footprint by simultaneously adjusting all geometry parameters and to maintain the electrical characteristic of antenna at an acceptable level. The obtained design exhibits dimensions of only 3.7 mm × 11.8 mm and a footprint of 44 mm2, an omnidirectional radiation pattern, and an excellent pattern stability. The proposed antenna can be easily handled within compact communication devices. The simulation results are validated through measurements of the fabricated antenna prototype.
Źródło:
Metrology and Measurement Systems; 2017, 24, 3; 463-471
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rapid antenna design optimization using shape-preserving response prediction
Autorzy:
Kozieł, S.
Ogurtsov, S.
Szczepański, S.
Powiązania:
https://bibliotekanauki.pl/articles/201113.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
antenna design
simulation-driven design
antenna optimization
shape-preserving response prediction
coarse-discretization simulation
Opis:
An approach to rapid optimization of antennas using the shape-preserving response-prediction (SPRP) technique and coarsediscretization electromagnetic (EM) simulations (as a low-fidelity model) is presented. SPRP allows us to estimate the response of the high-fidelity EM antenna model, e.g., its reflection coefficient versus frequency, using the properly selected set of so-called characteristic points of the low-fidelity model response. The low-fidelity model, corrected by means of SPRP, is subsequently used to predict the optimal design. The design process is cost efficient because most operations are performed on the low-fidelity model. Performance of our technique is demonstrated using a dielectric resonator antenna and two planar wideband antenna examples. In all cases, the optimal design is obtained at a cost corresponding to a few high-fidelity simulations of the antenna under design.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 143-149
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The contact-less method of chip-to-chip high speed data transmission monitoring
Autorzy:
Zmuda, M.
Szczepański, S.
Kozieł, S.
Graczyk, S.
Powiązania:
https://bibliotekanauki.pl/articles/202115.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high speed data transmission monitoring
microstrip coupler
connector-less transmission monitoring
time-domain measurement
Opis:
This paper presents a technique of decoupling differential signals transmitted in a pair of microstrip lines on a printed circuit board (PCB), using dedicated coupler for high speed data transmission monitoring in chip-to-chip interconnections. The coupler used for signal probing is overlayed on the pair of microstrip lines under test, and provides a signal to the next blocks of the measurement system without disturbing transmission in the lines. Starting from the basic configuration obtained in the previous work, we describe a procedure of re-designing the coupler for enhanced directivity so that it is suitable for high-speed data transmission monitoring. The new coupler structure has improved topology based on stepped-impedance resonators with geometry parameters adjusted using numerical optimization techniques. The correctness of the design has been confirmed by the time-domain measurements performed for real chip-to-chip communication signals, using a dedicated measurement system based on Xilinx Virtex-6 FPGA Development Kit. The presented technology can be used for reducing the cost of the product diagnostics by eliminating dedicated measurement connectors, run-time system debugging or reverse engineering.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 1; 61-68
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reducing the Impact of Failures in Power Grids on the End Recipients by Means of Grid Structure Sectioning
Ograniczenie oddziaływania skutków awarii w sieciach energetycznych na odbiorcę końcowego za pomocą sekcjonowania struktury sieciowej
Autorzy:
Moskwa, S.
Kozieł, S.
Siłuszyk, M.
Galias, Z.
Powiązania:
https://bibliotekanauki.pl/articles/952957.pdf
Data publikacji:
2018
Wydawca:
ENERGA
Tematy:
niezawodność
sieci dystrybucyjne
optymalizacja
sekcjonowanie
algorytmy ewolucyjne
reliability
distribution power grids
optimization
sectioning
evolutionary algorithms
Opis:
The paper reviews the options to reduce the impact of failure effects in medium voltage distribution grids in terms of the frequency and duration (short, long, very long and catastrophic) of outages of end-consumers’ supply. As the method to reduce the failure effects, the placement in the grid structure of remotely controlled circuit breakers and/or reclosers was adopted, which in the event of a failure allows disconnecting only part of the grid in the failure area. An important element of this method is the selection of the optimal number of these circuit breakers and their optimal location in the grid structure. The paper proposes a method of solving these issues by applying distribution grid reliability models and evolutionary algorithms that allow for optimizing the location of circuit breakers. As the optimization criteria, the ENS, SAIDI and SAIFI indicators were adopted. The analysis was based on an example model of a real distribution grid structure. The model includes the reliability parameters of individual grid sections, distribution nodes, MV/LV switching substations, and the number of recipients connected to a specific substation.
Artykuł obejmuje analizę możliwości ograniczenia oddziaływania skutków awarii w sieciach dystrybucyjnych średnich napięć, w zakresie częstości występowania i czasu trwania przerw (krótkich, długich, bardzo długich i katastrofalnych) w zasilaniu odbiorców końcowych. Jako metodę ograniczenia skutków awarii przyjęto lokalizację w strukturze sieciowej wyłączników zdalnie sterowanych lub reklozerów, które w przypadku awarii pozwolą na odłączenie tylko części sieci lub ciągu zasilania w obszarze występowania awarii. Istotnym elementem tej metody jest optymalny dobór liczby tych wyłączników oraz ich lokalizacja w strukturze sieciowej. Artykuł proponuje metodę rozwiązania tych zagadnień poprzez zastosowanie modeli niezawodnościowych sieci dystrybucyjnych oraz algorytmów ewolucyjnych pozwalających na optymalizację lokalizacji wyłączników. Jako kryteria optymalizacyjne przyjęto wartości wskaźników ENS, SAIDI oraz SAIFI. Analizę przeprowadzono na przykładzie modelu opracowanego na podstawie struktury rzeczywistej sieci dystrybucyjnej. W modelu uwzględniono parametry niezawodnościowe poszczególnych odcinków sieci, węzłów rozdzielczych, stacji rozdzielczych SN/nN oraz liczbę odbiorców przyłączonych do danej stacji.
Źródło:
Acta Energetica; 2018, 4; 23-26
2300-3022
Pojawia się w:
Acta Energetica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Komputerowa weryfikacja układów cyfrowyh CMOS utworzonych z podukładów zasilanych ze źródeł o różnych wartościach napięcia
Computer verification of a cmos digital circuit created by subcircuits supplied by different voltages
Autorzy:
Szcześniak, W.
Kozieł, S.
Jendernalik, W.
Hasse, L.
Szcześniak, P.
Powiązania:
https://bibliotekanauki.pl/articles/267925.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
redukcja poboru mocy
weryfikacja układu
układy CMOS
reduction in power consumption
verification system
CMOS settings
Opis:
W pracy zaprezentowano wyniki komputerowej weryfikacji cyfrowego układu CMOS utworzonego z klastrów Cn-1, Cn-2, …, Ci, … C0, z których każdy jest zasilany odpowiednio malejącymi wartościami napięć Vddn-1 > Vddn-2 > … > Vddi > … > Vdd0 . Zbiór klastrów {Ci} został utworzony przy pomocy algorytmu ECA (Evolutionary Clustering Algorithm) dla potrzeb redukcji mocy pobieranej ze źródła zasilającego. Otrzymane rozwiązanie charakteryzujące się zmniejszeniem zapotrzebowania na moc zasilającą nie powoduje pogorszenia przepustowości zaprojektowanego systemu cyfrowego CMOS.
The paper presents results of a computer simulation of a CMOS digital circuit composed of Cn-1, Cn-2, …, Ci, … C0 clusters. The clusters are supplied with voltages Vddn-1 > Vddn-2 > … > Vddi > … > Vdd0, respectively. Set of clusters {Ci} was created with aid of ECA (Evolutionary Clustering Algorithm) for reduction of power dissipated. The obtained result enables for power reduction without deteriorating the throughput of the designed CMOS circuit, measured as system latency.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2007, 23; 105-108
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anthropometric predispositions for swimming from the perspective of biomechanics
Autorzy:
Rejman, M.
Tyc, Ł.
Kociuba, M.
Bornikowska, A.
Rudnik, D.
Kozieł, S.
Powiązania:
https://bibliotekanauki.pl/articles/306959.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pływanie
profil antropometryczny
biomechanika
swimming
anthropometric profile
biomechanics
Opis:
Early identification of anthropological potential in swimmers is considered important to the recruitment and selection of children and adolescents to perform extensive and strenuous training. The aim of the research was a comparative analysis of the anthropometric parameters and indicators of adult, elite swimmers with people who had never trained for swimming. It was assumed that the specific characteristics of the swimmers’ somatic composition referred to the laws of swimming biomechanics. Methods: Anthropometric measurements were taken in a group of elite male swimmers (N = 28), aged 17–24. The same set of measurements was taken in a homogeneous control group of students of physical education. An anthropometric profile significantly differentiating swimmers from the control group was constructed. Next, a linear forward stepwise discriminant analysis was conducted to investigate which indices can be used to distinguish the two groups. Results: It seems significant that a specific somatic composition trait of swimmers in the form of a relatively long shank was observed, which had not been observed in earlier studies. Additionally, indices of relatively slim hand dimension, and indices describing a “reversed triangle” shape of trunk, were the most powerful discrimination variables between the two examined groups. Conclusion: The results obtained cannot be generalised to the entire population of swimmers, however referring them to the laws of biomechanics of swimming allows for the continuation of research into identifying the prognostic traits desirable for success among young swimmers.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 4; 151-159
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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