PL
 |
EN
Ograniczanie wyników
Czasopisma help
  1. 4 Bulletin of the Polish Academy of Sciences. Technical Sciences
  2. 4 Hydroacoustics
  3. 4 Journal of Science of the gen. Tadeusz Kosciuszko Military Academy of Land Forces
  4. 4 Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki
  5. 3 Computer Science
Więcej...
Autorzy help
  1. 35 Majewski P.
  2. 7 Majewski P
  3. 6 Klusek Z.
  4. 5 Żokowski M.
  5. 4 Baranowski L.
Więcej...
Lata help
  1. 2 2020
  2. 4 2018
  3. 3 2017
  4. 3 2016
  5. 2 2014
Więcej...
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 42

Liczba wyników na stronie
first rewind previous Strona / 3 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 3 next fast forward last
1
Content available The generalized S- and σ-inverse – a comparative case study for right- and left-invertible plants
Majewski P., Hunek W. P.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2020
|
Vol. 68, nr 6
1517--1523
EN
In this paper, an advanced study covering the comparison between two classes of generalized inverses is conducted. Two sets of instances, strictly derived from the recently introduced nonunique S- and σ-inverse, are analyzed, especially in terms of degrees of freedom-oriented interchangeable application in different engineering tasks. Henceforth, the respective collections of right and left inverses can be combined in order to achieve a complex tool for robustification of a plethora of real processes. The great potential of two S- and σ-inverse, in particular in robust control and signal recovery as well as complex optimal tasks, is confirmed in the manuscript and supported by the recently carried out research investigations.
2
Content available Explicit form of the “modified point mass trajectory model” for the use in Fire Control Systems
Baranowski L., Majewski P., Szymonik J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2020
|
Vol. 68, nr 5
1167--1175
EN
The main objective of this article is to obtain equations of motion of the spin–stabilized projectile in the presence of non–constant wind. Introducing models allowing utilization of inhomogeneous wind is dictated by new possibilities created by the use of e.g. lidars in the Fire Control Systems (FCS). Constant feed of wind data can replace meteorological messages, increasing the FCS effectiveness. Article contains results of projectile flight simulations which indicate the positive effect that the derived explicit form of the model has when considering software development for modern Fire Control Systems.
3
Content available remote Sprowadzenie niebezpieczeństwa katastrofy, w szczególności w ruchu drogowym
Majewski G., Majewski P.
Paragraf na Drodze
|
2018
|
Nr 2
5--13
PL
Autorzy dokonują analizy przestępstwa z art. 174 § 1 Kodeksu karnego ze szczególnym uwzględnieniem niebezpieczeństwa katastrofy. Wskazują jedne z najważniejszych orzeczeń Sądu Najwyższego. Omawiają kryteria bezpośredniości niebezpieczeństwa.
EN
The authors analyse the crime under article 174 paragraph 1 of the Penal Code with particular emphasis on the danger of a disaster in road traffic. They indicate one of the most important judgements of the Supreme Court. They discuss the criteria of danger immediacy.
4
Content available remote Miejsce spowodowania i sprawca wypadku drogowego w kontekście art. 177 Kodeksu karnego
Majewski G., Majewski P.
Paragraf na Drodze
|
2018
|
Nr 4
47--57
PL
Autorzy dokonują analizy przestępstwa z art. 177 k.k. ze szczególnym uwzględnieniem miejsca popełnienia przestępstwa. Omawiają pojęcie wypadku oraz ruchu lądowego. Przedstawiają najważniejsze orzeczenia Sądu Najwyższego w tej materii.
EN
The authors analyse the crime under article 177 of the Penal Code with particular emphasis on the place of committing the crime. They indicate one of the most important judgements of the Supreme Court. They discuss the concept of accident and road traffic.
5
Content available Analiza pracy źródła zasilania elektrycznego autobusu miejskiego
Biernacki M., Majewski P.
Maszyny Elektryczne : zeszyty problemowe
|
2018
|
Nr 2 (118)
23--28
PL
W pracy wykonano analizę testów drogowych stosowanych między innymi do badań nowoprojektowanych układów napędowych autobusów miejskich. Został opracowany własny model trasy testowej autobusu na bazie jednego ze znormalizowanych cykli jazdy autobusu w warunkach miejskich oraz rzeczywistych danych zebranych na podstawie wielokrotnego przejazdu jedną z tras obsługiwanych przez komunikację miejską w jednym z największych miast w Polsce, między przystankami krańcowymi. Przeanalizowano pracę zasobników energii elektrycznej pod kątem wymagań odnośnie zasięgu pojazdu (według potrzeb zakładu komunikacji miejskiej i uwzględnieniu aktualnych możliwości technicznych), trwałości i masy źródła energii, czasu potrzebnego na naładowanie źródła po cyklu bądź cyklach jazdy. Ze względów ekonomicznych poza obecnie najczęściej stosowanymi zasobnikami energii typu litowo-jonowego, czy litowo-polimerowego, wzięto pod uwagę inne typy źródeł energii, mniej korzystne z punktu widzenia gromadzenia energii (z uwagi na masę). Celem pracy jest określenie charakteru pracy elektrycznego źródła energii oraz opracowanie wytycznych doboru parametrów źródła energii istotnych z punktu widzenia eksploatacji oraz analiza jego trwałości w zależności od założonych parametrów ruchu pojazdu komunikacji zbiorowej (autobusu) w warunkach miejskich. Ponadto, praca ma na celu zwrócenie uwagi na inne technologie wykonania zasobników energii, niekiedy znacznie tańsze niż obecnie wykorzystywane, a w odpowiednich warunkach możliwe do zastosowania.
EN
The paper involved the analysis of road tests used for the research of newly designed drive systems of city buses. An own model of the bus test route was developed based on one of the standardized bus cycles in urban conditions and real data collected on the basis of multiple journeys by one of the routes, between end stops, served by public transport in one of the largest cities in Poland. The electric energy storages operate have analyzed taking in to account of the vehicle range requirements (according to the needs of the municipal transport plant and taking into account the current technical capabilities), durability and mass of the Energy source, time needed to charge the source after the one cycle or driving cycles. For economic reasons, apart from currently the most commonly used lithium-ion or lithium-polymer type energy storage, other types of Energy sources, less beneficial from the point of view of energy accumulating (mass), have been taken into account. The purpose of this paper is to determine of the electric energy source operating regime and develop guidelines for the selection of parameters of the source which are important from the point of view exploitation and analysis of its durability depending on the assumed parameters of the traffic of the public transport vehicle (bus) in urban conditions. In addition, the this paper purpose is to draw attention to other energy storage technologies, sometimes much cheaper than currently used, and in appropriate conditions possible to apply.
6
Content available 35 mm ammunition’s trajectory model identification based on firing tables
Baranowski L., Gadomski B., Majewski P., Szymonik J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2018
|
Vol. 66, nr 5
635--643
EN
The article presents a procedure designed for identification of projectile’s trajectory model through aerodynamic coefficients estimation. The identification process is based on firing tables artificially prepared (firing tables prepared using mathematical flight model for the projectile instead of trajectories recorded on field tests) with the use of modified point–mass and rigid body trajectory models. All the necessary data, including physical parameters of the projectile and its aerodynamic characteristics are provided. The detailed results of estimation of chosen aerodynamic coefficients are presented in both visual and tabular form. The main purpose of this paper is to establish the minimum number of trajectories (as characterized in firing tables), and the permissible error of initial parameters being passed to the mathematical model that would allow the correct identification of projectile’s trajectory model.
7
Content available remote Badania symulacyjne bezprzewodowej transmisji danych z wykorzystaniem S-inwersji macierzowo-wielomianowej
Hunek W., Majewski P.
Przegląd Elektrotechniczny
|
2017
|
R. 93, nr 3
159--161
PL
W artykule przedstawiono nową metodę perfekcyjnej rekonstrukcji sygnałów używaną w układach transmisji bezprzewodowej MIMO, składających się z nierównej liczby anten nadawczych i odbiorczych. Zaproponowanie nowe rozwiązanie bazuje na rachunku wielomianowomacierzowym, w szczególności na tzw. S-inwersji pewnej niekwadratowej macierzy stowarzyszonej z opisem dynamiki środowiska propagacyjnego. Przeprowadzone w autorskim symulatorze badania wskazują na dużą wartość implementacyjną nowej metody w kontekście poprawy odporności całego procesu odzysku sygnału.
EN
In this paper a new method of perfect signal reconstruction dedicated to MIMO wireless data transmission systems comprising different number of input and output antennas is presented. A new proposed approach based on polynomial matrix calculus, in particular so-called S-inverse of certain nonsquare matrix associated with dynamic description of propagation environment. The simulation studies conducted by means of authors’ tool confirm a big potential of a new method in terms of increasing the robustness of whole signal recovery process.
8
Content available remote Analiza przyczyn drgań i iskrzenia szczotek wirnika turbogeneratora synchronicznego
Biernacki M., Majewski P.
Przegląd Elektrotechniczny
|
2017
|
R. 93, nr 11
21--24
PL
Przedstawiono problem z rzeczywistym układem szczotkowym. Dokonano symulacji przebiegów napięć i prądów w obwodzie statycznego tyrystorowego układu wzbudzenia. Wykonano szereg prac pomiarowych i badawczych oraz zaproponowano rozwiązanie problemu nadmiernych drgań i iskrzenia szczotek, zasilających wirnik turbogeneratora.
EN
This paper introduces to the real brush system problems in the synchronous generator rotor. The current and voltage were simulated and the thyristor excitation system was analyzed. The proposals of the solution of the rotor supplied brush sparking problem are presented.
9
Content available Detection damage in bearing system of jet engine using the vibroacoustic method
Żokowski M., Majewski P., Spychała J.
Acta Mechanica et Automatica
|
2017
|
Vol. 11, no. 3
237--242
EN
The article discusses typical, operational systems for monitoring vibrations of jet engines, which constitute the propulsion of combat aircraft of the Armed Forces of the Republic of Poland. After that, the paper presents the stage of installing vibration measuring sensors in the direct area of one of the jet engine bearings, which is a support system for its rotor. The article discusses results of carried out analyses of data gathered during tests of the engine in the conditions a jet engine test bed. Results of detecting damages to the bearing, using sensors built in the direct area will be presented.
10
Content available Some problems with vibroacoustic method in relation to the transmission gearbox of a military helicopter
Majewski P., Spychała J., Żokowski M.
Zeszyty Naukowe. Transport / Politechnika Śląska
|
2016
|
z. 93
79--90
EN
The article presents the results of a laboratory gear stage with regard to deepening its consumption. In addition, the study looked at the construction of the transmission gearbox of a military helicopter, according to the basic kinematic results of the analysis of vibroacoustic signals, in order to determine the diagnostic criteria for the assessment of the technical condition of a military helicopter’s transmission gearbox.
11
Content available Comparison of explicit and implicit forms of the modified point mass trajectory model
Baranowski L., Gadomski B., Szymonik J., Majewski P.
Journal of Theoretical and Applied Mechanics
|
2016
|
Vol. 54 nr 4
1183--1195
EN
The article compares the results of trajectory computation for a 35 mm projectile using two forms (explicit and implicit) of the modified point-mass trajectory model. All necessary ammunition parameters (aerodynamic coefficients, dimensions, mass etc.) and initial conditions for differential equations are provided. The results of numerical integration (using non-stiff fourth-order Runge-Kutta solver) are presented in form of projectile trajectories projections onto vertical and horizontal planes. Data tables comparing both models in terms of projectile position and velocity in chosen time steps are also attached.
12
Content available Explicit “ballistic M-model”: a refinement of the implicit “modified point mass trajectory model”
Baranowski L., Gadomski B., Majewski P., Szymonik J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2016
|
Vol. 64, nr 1
81--89
EN
Various models of a projectile in a resisting medium are used. Some are very simple, like the “point mass trajectory model”, others, like the “rigid body trajectory model”, are complex and hard to use, especially in Fire Control Systems due to the fact of numeric complexity and an excess of less important corrections. There exist intermediate ones - e.g. the “modified point mass trajectory model”, which unfortunately is given by an implicitly defined differential equation as Sec. 1 discusses. The main objective of this paper is to present a way to reformulate the model obtaining an easy to solve explicit system having a reasonable complexity yet not being parameter-overloaded. The final form of the M-model, after being carefully derived in Sec. 2, is presented in Subsec. 2.5.
13
I/Q modulation in OFDM wireless communication
Majewski P.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2014
|
z. 70
65-66
EN
In this paper some simulation studies concerning I/Q modulation in the OFDM systems (such as WiFi, WiMAX, LTE/LTE-Advanced) are presented.
14
Content available Parameters of echo signals originated from a gas seepage site in the Southern Baltic Sea
Majewski P., Klusek Z.
Hydroacoustics
|
2014
|
Vol. 17
143--150
EN
Gaseous shallow sediment has been recognized in several areas of the Southern Baltic Sea. The most commonly observed manifestation of the gas in the bottom top layer is an acoustic blanking or shadowing resulting from significant attenuation and scattering of acoustic signals in the regions of gas bubble occurrence at the bottom. The main goal of this publication was to examine whether known methods of acoustic echo parameterization generally used to determine the fraction of the surface deposits would be sufficient in determining the extent of the occurrence of gas saturated sediments and areas with periodic gaseous outflows. To this end, a set of an acoustic echo signals recorded in gas seepage regions by using four different frequencies (12, 70, 120 and 200 kHz) was analyzed. To determine the acoustic features of gaseous sediments, based on the shape of the echo envelope, a few statistical parameters, as well as the parameters resulting from a wavelet transform, were calculated. A comparison of the results allowed for a relatively accurate separation of pockmark areas.
15
Signal Perfect Reconstruction Based on Polynomial Matrix Calculation
Majewski P.
Zeszyty Naukowe. Elektryka / Politechnika Opolska
|
2013
|
z. 69
55--56
EN
In this paper, preliminary simulation studies about signal perfect reconstruction, around wireless transmission with non-equal transmit/receive antennas, was presented. The polynomial-matrix equation, in particular Smith factorization based on polynomial S-inverse, has been taking into account .
16
Content available remote Geochemical and acoustic evidence for the occurrence of methane in sediments of the Polish sector of the southern Baltic Sea
Brodecka A., Majewski P, Bolałek J., Klusek Z.
Oceanologia
|
2013
|
No. 55 (4)
951--978
EN
This paper presents the results of geochemical and acoustic investigations of sediments in the Polish sector of the southern Baltic Sea. Its objective was to indicate areas of gas bubble formation and the occurrence of methane. Over 3000 nautical miles of transects were recorded using a variety of hydroacoustic instruments, and five coring points were selected for further analyses of pore waters (CH4, SO4-2, H2S, NH4+, total alkalinity) and sediments (grain size distribution, Corg, Ntot, LOI and WC). Gas turned out to be present at shallow depths in different forms such as recent and buried pockmarks, and gas-saturated sediments (including gas pockets and seepages). It was found that methane was widespread in the sediments of the study area, both in the surface sediments, e.g. in the vicinity of the Hel Peninsula or in the central Gulf of Gdańsk, and in deeper sediment layers, e.g. in the Gdańsk Deep and the Słupsk Furrow. Chemical analysis showed that as a result of the rapid decomposition of organic matter, sulphates were depleted in the top 20 cm layer of sediments and that methane was produced at relatively shallow depths (in some areas even at depths of 20-30 cm bsf) compared to other regions of the Baltic, reaching concentrations of >6 mmol l-1 in the 30-40 cm layer below the sediment surface. The sulphate-methane transition zone (SMTZ) was 4-37 cm thick and was situated in the uppermost 50 cm of the sediments.
17
Content available remote Układ redukcji drgań z zastosowaniem technologii zawieszeń magnetycznych
Spychała J., Żokowski M., Majewski P
Journal of KONBiN
|
2013
|
No. 3-4 (27-28)
31--42
PL
W artykule przedstawiono rozważania, dotyczące budowy układu redukcji drgań z zastosowaniem technologii zawieszeń magnetycznych. Przedstawiono wyniki badań symulacyjnych, numerycznych i eksperymentalnych samołożyskującego się silnika elektrycznego, dla którego z sukcesem zastosowano tego typu rozwiązanie. Pozytywne wyniki badań i testów stały się podstawą do opracowania koncepcji budowy tego typu układu aktywnej redukcji drgań, pełniącego zarazem funkcję podpory dla obiektu technicznego, jakim jest silnik odrzutowy. Defekty łożysk objawiają się ubytkiem lub zniekształceniem ich masy, co w konsekwencji prowadzi do całkowitego zniszczenia łożyska tocznego, a co za tym idzie przekłada się na bezpieczeństwo. W artykule zostanie przedstawiona koncepcja budowy zespołu aktywnego zawieszenia magnetycznego w celu eliminacji z układu łożyskowania klasycznego łożyska tocznego i zastąpienie go łożyskiem magnetycznym.
EN
The article presents considerations concerning the construction of vibration reduction system using magnetic suspension technology. Presents the results of simulation, numerical and experimental the bearing less electric motor, for which successfully used this type of solution. Positive results of research and testing have become the basis for the development of the concept of building this type of active vibration reduction system , at the same time acting as a support for a technical object, which is a jet engine. Bearing failures are manifested by loss or distortion of their mass, which leads to a total destruction of the roller bearing, and thus reflected in the security. The article presents the concept of building active magnetic suspension to eliminate the bearing system of classical rolling bearing and replace it with magnetic bearing
18
Content available Web pages content analysis using browser-based volunteer computing
Turek W., Nawarecki E., Dobrowolski G., Krupa T., Majewski P.
Computer Science
|
2013
|
Vol. 14 (2)
215--230
EN
Existing solutions to the problem of finding valuable information on the Web suffers from several limitations like simplified query languages, out-of-date in- formation or arbitrary results sorting. In this paper a different approach to this problem is described. It is based on the idea of distributed processing of Web pages content. To provide sufficient performance, the idea of browser-based volunteer computing is utilized, which requires the implementation of text processing algorithms in JavaScript. In this paper the architecture of Web pages content analysis system is presented, details concerning the implementation of the system and the text processing algorithms are described and test results are provided.
19
Content available Volunteer computing simulation using repast and mason
Byrski A., Feluś M., Gawlik J., Jasica R., Kobak P., Jankowski G., Nawarecki E., Wroczyński M., Majewski P, Krupa T., Strychalski J.
Computer Science
|
2013
|
Vol. 14 (1)
153--172
EN
Volunteer environments usually consist of a large number of computing nodes, with highly dynamic characteristics, therefore reliable models for a planning of the whole computing are highly desired. An easy to implement approach to modelling and simulation of such environments May employ agent-based universal simulation frameworks, such as RePast or MASON. In the course of the paper the above-mentioned simulation frame Works are adapter to suport simulation of volunteer computing. After giving implementation details, selected results concerning computing time and speedup are given and are compared with the ones obtained from an actual volunteer environment.
20
Content available Comcutejs:a Web browser based platform for large-scale computations
Dębski R., Krupa T., Majewski P
Computer Science
|
2013
|
Vol. 14 (1)
143--152
EN
The paper presents a new, cost effective,volunteer computing based platform. It utilizes volunteers’web browsers as computational nodes. The computational tasks are delegated to the browsers and executed in the background (independently of any user interface scripts) making use of the HTML5 web workers technology. The capabilities of the platform hale been proved by experiments performer in a wide range of numbers of computational nodes (1–400).
first rewind previous Strona / 3 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.