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Wyszukujesz frazę "Lesiak, A." wg kryterium: Autor


Tytuł:
Fault injection stress strategies in dependability analysis
Autorzy:
Sosnowski, J.
Gawkowski, P.
Lesiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/970437.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
iniekcja błędów
modelowanie błędów
oszacowanie detekcji i tolerancji błędów
fault injection
fault modeling
test coverage
fault detection and fault tolerance evaluation
Opis:
The paper deals with the problem of testing computer system's susceptibility to hardware faults by means of software implemented fault injectors. Basing on our experience with fault injection techniques we present various strategies of fault stressing in relevance to fault impact analysis in the function of the application input data profile, fault injection profile in time and space, resource activities etc. We discuss the problem of test result qualification and significance. Fault hardening at the software level is also outlined. The considerations presented are illustrated with numerous experimental results obtained in Windows and Linux environments.
Źródło:
Control and Cybernetics; 2004, 33, 4; 679-699
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carriers Diffusion in GaAs/AlAs Type II Quantum Well
Autorzy:
Lesiak, A.
Chwalisz, B.
Wysmołek, A.
Potemski, M.
Stępniewski, R.
Thierry-Mieg, V.
Powiązania:
https://bibliotekanauki.pl/articles/2044497.pdf
Data publikacji:
2005-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
78.66.Fd
78.67.Hc
75.75.+a
Opis:
The micro-photoluminescence of GaAs/AlAs type II double quantum well structure is presented. The specific band alignment of the investigated system allows obtaining high concentration of long lived carriers. This enables us to study diffusion of carriers and/or indirect excitons. It was found that the carrier flow does not follow the classical diffusion equation and is driven by the potential modification due to the presence of photo created carriers.
Źródło:
Acta Physica Polonica A; 2005, 108, 5; 755-760
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Head Defect Images of Railway Rails in Laser Scatterometry
Ocena obrazów wad szyn kolejowych typu head checking w badaniach metodą skaterometrii laserowej
Autorzy:
Lesiak, P.
Sokołowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/215589.pdf
Data publikacji:
2017
Wydawca:
Instytut Kolejnictwa
Tematy:
railway rails
head checking
laser scatterometry method
similarity functions
distance function
szyny kolejowe
wady head checking
metoda skaterometrii laserowej
funkcje podobieństwa i odległości
Opis:
The images of head checking faults of railway rails have been examined by laser scattering method. The studies used the functions of similarity and distance, both for binary images and multi-level quantized ones. The analysis was performed on the basis of numerical calculations, experimentally determined images of samples of these defects. These type of functions have proven extremely useful in evaluating these faults and can be used to classify them.
Dokonano oceny obrazów wad szyn kolejowych typu head checking, zbadanych metodą skaterometrii laserowej. W badaniach wykorzystano funkcje podobieństwa i odległości, zarówno dla obrazów zbinaryzowanych, jak i skwantowanych wielopoziomowo. Analizę przeprowadzono na podstawie obliczeń numerycznych, wyznaczonych doświadczalnie obrazów próbek tych wad. Funkcje tego typu okazały się niezwykle przydatne w ocenie tych wad i mogą być wykorzystywane do ich klasyfikacji.
Źródło:
Problemy Kolejnictwa; 2017, 177; 37-43
0552-2145
2544-9451
Pojawia się w:
Problemy Kolejnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preprocessing algorithms of vision research damage to concrete railway sleepers
Autorzy:
Lesiak, P.
Sokołowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/215079.pdf
Data publikacji:
2018
Wydawca:
Instytut Kolejnictwa
Tematy:
railway track
concrete sleeper
image processing algorithms
Opis:
The paper presents algorithms for the preprocessing of the visual method of detecting damages of concrete railway sleepers. It starts with acquiring images of the surface of the sleepers, by selecting the recorded frames of the images. Then, the color image is transformed into monochrome, so as to obtain the highest contrast possible. The Kanan and Cottrell algorithms were used for this purpose. A simple way is to segment the damage images of the sleepers, by thresholding, in order to binarize them. However, more elaborate algorithms are recommended. For this purpose, images are denoted using a median filter and further morphological operations to extract the edge of damage. For this purpose, noise is removed from images using a median filter, and morphological operations are carried out, to extract the edge of damage. In addition, texture images of the surface of the sleepers are used, removing them from the visual content. As the criterion for selecting the preprocessing algorithm, the shape of the image histogram and its standard deviation were assumed. Such prepared images form the basis for further assessment of the size of damages (cracks and voids) and classification of concrete sleepers.
Źródło:
Problemy Kolejnictwa; 2018, 180; 93-99
0552-2145
2544-9451
Pojawia się w:
Problemy Kolejnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations of Au Segregation in AuNi Alloys by the Line Shape Analysis of Photoelectron Spectra
Autorzy:
Lesiak, B.
Biliński, A.
Jóźwik}, A.
Powiązania:
https://bibliotekanauki.pl/articles/2046828.pdf
Data publikacji:
2006-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.82.Bg
68.35.Dv
79.60.-i
Opis:
The surface segregation of Au in Au5Ni95 polycrystalline alloy is studied applying the line shape analysis, known as the fuzzy k-nearest neighbour rule, to the selected X-ray photoelectron and X-ray induced Auger spectra. Each line, characterised by the kinetic electron energy exhibited in the particular transition, samples the depth described by the mean escape depth depending on the inelastic mean free path of electron in the investigated material and the geometry of the measurement. The following electron transitions in the electron kinetic energy range 216.6-1486.6 eV are analysed: Au N$\text{}_{5}$N$\text{}_{67}$V, Ni 2p, Ni L$\text{}_{2}$M$\text{}_{23}$M$\text{}_{45}$-Ni L$\text{}_{3}$M$\text{}_{45}$M$\text{}_{45}$, Au 4d, Au 4f and the valence band transitions (overlapping Au 5d6s and Ni 3d4s transitions). The results of the quantitative analysis using the fuzzy k-nearest neighbour rule are compared to the results of quantitative analysis by the multiline approach which applies the Au 4f and Ni 2p photoelectron transitions. Both methods demonstrate Au surface segregation starting at the temperature above 200ºC. The line shape analysis was shown to be applicable for quantification of the surface region with possibility of investigating the in-depth non-uniform concentration profiles.
Źródło:
Acta Physica Polonica A; 2006, 109, 6; 701-714
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cross-correlation function in identifying head checking defects of the railway rails
Funkcja korelacji wzajemnej w identyfikacji wad head checking szyn kolejowych
Autorzy:
Lesiak, P.
Sokołowski, A.
Wlazło, M.
Powiązania:
https://bibliotekanauki.pl/articles/327852.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
cross-correlation
railway rails
defect head checking
laser scatterometry method
korelacja wzajemna
szyny kolejowe
wada head checking
metoda skaterometrii laserowej
Opis:
The cross-correlation function has been applied to the study of the similarity of the two functions. One of these functions is known and represents a defect type HC (Head Checking) in the railway rail. The second function is unknown and based on cross-correlation function of both functions specifies the parameters of the similarities. These functions correspond to defects whose images have been determined using laser scatterometry method. FFT method has been used to calculate these functions.
Zastosowano funkcję korelacji wzajemnej do badania podobieństwa dwóch funkcji. Jedną z tych funkcji jest znana i stanowi opis wzorca wady head checking (HC) w szynie kolejowej. Druga funkcja jest nieznana. Na podstawie funkcji korelacji wzajemnej obu tych funkcji, określa się parametry ich podobieństwa. Funkcje te reprezentują obrazy wyznaczone doświadczalnie, metodą skaterometrii laserowej. W obliczeniach wykorzystano szybką transformatę FFT.
Źródło:
Diagnostyka; 2017, 18, 2; 65-73
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical and experimental investigation of methane-oxygen detonation in a 9 m long tube
Autorzy:
Malik, K.
Żbikowski, M.
Teodorczyk, A.
Lesiak, P.
Powiązania:
https://bibliotekanauki.pl/articles/246813.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
detonation
methane
combustion
simulation
experiment
characteristic cell size
Opis:
Numerical investigation of methane-oxygen detonation parameters was conducted with an OpenFoam code. Custom solver ddtFoam made especially for detonation problems was made use of. It uses the HLLC scheme to resolve the discontinuities and the subgridscale model to improve results on coarse meshes. Combustion model is based on progress variable equation, which contains two source terms. The first is the deflagrative source term and is modelled using the Weller correlation. The second is the detonative source term and it accounts for autoignition effects. Range of analysed gaseous mixture compositions was 20, 33 and 40% of methane in oxygen. The 2D calculation geometry was a 9 m long pipe with diameter 0.17 m. The mesh consisted of 382 500 hexahedral cells with the dimensions of 2x2 mm. Experimental results such as pressure profiles and detonation velocities are presented. Simulations were performed using LES turbulence model (k-equation-eddy-viscosity model) and compared with experimental data. Various dynamic parameters, like for example reaction lengths for methane-oxygen detonations, are estimated from the steady ZND analyses conducted in Cantera and SDToolbox libraries and based on GRI 3.0 kinetic mechanism of methane combustion. These lengths were then used in empirical formulas to obtain the characteristic cell sizes and assessed against experimental data.
Źródło:
Journal of KONES; 2016, 23, 4; 311-318
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Longitudinal Strain Induced Birefringence in Highly Birefringent Fiber for Dynamic Compensation of Polarization Mode Dispersion
Autorzy:
Domański, A. W.
Lesiak, P.
Woliński, T. R.
Powiązania:
https://bibliotekanauki.pl/articles/2035697.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.81.Gs
42.81.Pa
42.25.Ja
42.25.Dd
Opis:
The paper addresses a compensation method of polarization mode dispersion based on longitudinal strain applied to a highly birefringent fiber introduced as apart from optical fiber link. As an introduction a short overview of the polarization mode dispersion compensation methods known up-to-now is done. Dependence of polarization mode dispersion on longitudinal strain is discussed. Some results of experiment with birefringence changes due to longitudinal strain in the bow-tie highly birefringent fiber necessary for dynamic polarization mode dispersion are presented.
Źródło:
Acta Physica Polonica A; 2003, 103, 2-3; 221-227
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mean Escape Depth of Signal Photoelectrons from Amorphous and Polycrystalline Solids
Autorzy:
Tilinin, I. S.
Jabłoński, A.
Lesiak-Orłowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/1931766.pdf
Data publikacji:
1994-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.80.Bm
72.10.Bg
79.60.-i
Opis:
Escape depth of photoelectrons leaving a target without being scattered inelastically was submitted to extensive theoretical analysis. Dependence of the mean escape depth on the X-ray angle of incidence and the electron initial angular distribution inside the sample was considered. The Monte Carlo algorithm was developed basing on a differential elastic scattering cross-section calculated within the partial-wave expansion method and a realistic electron-atom interaction potential. The mean escape depth was evaluated by means of the depth distribution function found analytically by solving a kinetic equation and by the Monte Carlo technique. The agreement between the results obtained from two methods is excellent. Elastic scattering was found to reduce considerably the escape depth. This reduction may reach up to 25% in the case of heavy elements in the practical X-ray photoelectron spectroscopy analysis. It was shown that the mean escape depth expressed in units of the electron transport mean free path is a universal function of the ratio of the inelastic to the transport mean free paths, the asymmetry parameter and the X-ray angle of incidence. A simple explicit expression for this function is proposed.
Źródło:
Acta Physica Polonica A; 1994, 86, 5; 845-852
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Signal Photoelectron Yield Dependence on the X-Ray Angle of Incidence
Autorzy:
Tilinin, I. S.
Jabłoński, A.
Lesiak-Orłowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/1931768.pdf
Data publikacji:
1994-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.80.Bm
72.10.Bg
79.60.-i
Opis:
The photoelectron emission from solids irradiated by X-rays was described by the analytical theory of electron transport and simulated by the Monte Carlo technique. The medium energy electron transport problem is treated by means of a Boltzmann type kinetic equation satisfying appropriate boundary conditions. The solution of the transport equation was obtained in the transport approximation based on the generalized radiative field similarity principle. Simple and reliable formalism was derived for both the differential and the total photoelectron yields. The dependence of the photoelectron yield on the X-ray incidence angle and the "flattening" effect of multiple elastic scattering on the angular distribution of electrons leaving the target are analysed in detail. The photoelectron yields and angular distributions calculated by the Monte Carlo algorithm, based on a realistic differential elastic scattering cross-section, are in good agreement with the results found from analytical theory. It is shown that main characteristics of the photoelectron emission are determined primarily by two parameters: the inelastic and the transport mean free paths.
Źródło:
Acta Physica Polonica A; 1994, 86, 5; 853-859
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sucrose and cytokinin interactions in relation to ethylene and abscisic acid production in the regulation of morphogenesis in pelargonium x hortorum L.H. Bailey in vitro
Autorzy:
Wojtania, A.
Wegrzynowicz-Lesiak, E.
Dziurka, M.
Waligorski, P.
Powiązania:
https://bibliotekanauki.pl/articles/19900.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The aim of the study was to determine the effect of exogenous sucrose and cytokinin on ethylene production and responsiveness in relation to the shoot formation of Pelargonium × hortorum 'Bergpalais' in vitro. Increasing the concentration of sucrose from 15 to 40 g L-1 in medium containing meta-topolin (mT) resulted in a two-fold decrease in the number of shoots and leaves as well as a reduction in ethylene production. The addition of ethylene synthesis inhibitor (AVG) to mT-medium significantly reduced the ethylene production and the shoot growth, but it had no significant influence on the shoot formation. The mT-induced shoot formation was, however, significantly reduced in the presence of ethylene action inhibitor (AgNO3), in a manner dependent on sucrose levels. At the end of the subculture period, increased sucrose concentrations (15–40 g L-1) in the presence of mT and AgNO3 resulted in a 3.7-fold increase in ethylene emission. At the same time, the supply of sucrose caused a 2.8-fold increase in the level of endogenous abscisic acid (ABA). Our results may suggest that the inhibitory effect of high sucrose concentration (30 and 40 g L-1) may depend on its influence on ethylene sensitivity. It also suggests that sucrose-regulation of the shoot formation of Pelargonium in vitro is mediated by ABA.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2015, 57, 1
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Recoil Effect and Surface Excitations on the Inelastic Mean Free Paths of Electrons in Polymers
Autorzy:
Lesiak, B.
Kosiński, A.
Jablonski, A.
Sulyok, A.
Gergely, G.
Tóth, J.
Varga, D.
Powiązania:
https://bibliotekanauki.pl/articles/2046849.pdf
Data publikacji:
2006-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.35.Cd
82.80.Pv
87.16.Ac
Opis:
In this work, the influence of recoil effect and surface excitations on the inelastic mean free paths for polythiophenes is investigated. The inelastic mean free paths of electrons in polythiophenes are measured with the elastic peak electron spectroscopy method using the Ag standard and the electron elastic scattering cross-sections from the database NIST 3.1 in the electron kinetic energy range 200-5000 eV. The Monte Carlo model is applied for evaluating the electron backscattering intensities from the polymers and the Ag standard, as well as for evaluating electrons quasi-elastically backscattered from atoms of different atomic numbers (the recoil effect). The surface excitation corrections are accounted for using the formalism of Chen, with the material parameters for polythiophenes evaluated from the elastic peak electron spectroscopy method. Deviations due to recoil effect and surface excitations to the inelastic mean free paths are compared and discussed. Correction to the inelastic mean free paths due to recoil effect is considerable but is smaller, however, than the correction due to surface excitations. Accounting for recoil effect and surface excitations leads to improvement of the inelastic mean free paths, as compared to the inelastic mean free paths resulting from the predictive formulae of Gries.
Źródło:
Acta Physica Polonica A; 2006, 109, 6; 789-800
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of methyl jasmonate and gums formed in stone fruit trees on in vitro ethylene production by mycelium of Verticillium dahliae and Alternaria alternata
Autorzy:
Wegrzynowicz-Lesiak, E.
Jarecka Boncela, A.
Goraj, J.
Saniewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1980.pdf
Data publikacji:
2013
Wydawca:
Instytut Ogrodnictwa
Tematy:
Verticillium dahliae
Alternaria alternata
mycelium
ethylene production
gum
methyl jasmonate
jasmonic acid
fruit tree
Źródło:
Journal of Horticultural Research; 2013, 21, 2
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarimetric and Bragg Optical Fiber Sensors for Stress Distribution and Temperature Measurements in Composite Materials
Autorzy:
Lesiak, P.
Szeląg, M.
Mileńko, K.
Woliński, T.
Domański, A.
Jędrzejewski, K.
Boczkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1493251.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.81.Gs
42.81.Pa
62.23.Pq
Opis:
Composite structures are made from two or more constituent materials with significantly different physical or chemical properties and they remain separate and distinct in a macroscopic level within the finished structure. This feature allows us for introducing an optical fiber sensors matrix into the composite material. These sensors can demonstrate stress distribution inside a tested material influenced by external tensions. Two types of the optical fiber sensors, placed into one fiber simultaneously, are used as s matrix structure. One of them is based on application of the Bragg grating structure written inside the core of the fiber. Longitudinal stress modifies changes parameters of the Bragg grating and in the same, spectral characteristics of the light transmitted through the fiber. The second one is based on application of highly birefringent fibers which under external stress introduce polarization changes in the output light. These sensors placed into one fiber give a possibility to the measure two external tensions separately.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 698-701
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Angular Orientation of the Embedded Highly Birefringent Fiber on PMD Changes under Axial Stress
Autorzy:
Budaszewski, D.
Lesiak, P.
Plaga, R.
Rajan, G.
Semenova, Y.
Farrell, G.
Boczkowska, A.
Domański, A.
Woliński, T.
Powiązania:
https://bibliotekanauki.pl/articles/1493020.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.81.Gs
42.81.Pa
62.23.Pq
Opis:
In the paper we present results of the research on polarization mode dispersion changes inside the polarimetric optical fiber sensors based on highly birefringent optical fibers embedded into composite materials with different angular orientations of the optical axes. Based on measurements made for different types of highly birefringent optical fiber sensors we have shown that strain sensitivities after lamination process are different in comparison to the data obtained before lamination. Our results indicate that polarization mode dispersion in side-hole highly birefringent fibers under axial stress strongly depends on fiber orientation in the composite material suggesting that orientation of the polarization axes of the highly birefringent fiber can be responsible for behavior of the fiber inside the composite material.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 575-578
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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