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  1. 10 Journal of Telecommunications and Information Technology
  2. 7 Dendrobiology
  3. 7 Elektronika : konstrukcje, technologie, zastosowania
  4. 7 Folia Horticulturae
  5. 7 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
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  1. 4 2023
  2. 3 2022
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  4. 3 2020
  5. 10 2019
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  1. 15 Bogucki J.
  2. 12 Wielowieyska E.
  3. 5 Kolasinski M.
  4. 4 Domagalski J.
  5. 4 Kozaczka E.
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1
Content available The Influence of Meteorological Phenomena on Modern Satellite Systems
100%
Bogucki J. , Jarkowski J. , Wielowieyska E.
Journal of Telecommunications and Information Technology
|
2009
|
tom nr 4
88-94
EN
The areas of attention, described in this paper, extend throughout the modern satellite systems. Future satellite systems are to be planned for the millimeter band, which has greater weather attenuation effects than until now used bands. This paper provides a brief overview of propagation factors on millimeter-band earth-satellite paths and requirements in relation to the need for specific types of propagation data.
2
Łącza satelitarne w zakresie częstotliwości powyżej 20 GHz
100%
Bogucki J. , Wielowieyska E.
Elektronika : konstrukcje, technologie, zastosowania
|
2005
|
tom Vol. 46, nr 5
42-44
PL
Opisano czynniki propagacyjne mające wpływ na niezawodność pracy łączy satelitarnych pracujących w zakresie fal milimetrowych. Przedstawiono przykładowe obliczenia tras satelitarnych z uwzględnieniem wszystkich tych czynników.
EN
Propagation phenomena describing satellite links are described in this paper. Calculation examples of propagation phenomena on satellite - Earth path are presented herewith.
3
Content available Wind farms influence on radiocommunication systems operating in the VHF and UHF bands
100%
Bronk K. , Lipka A. , Niski R. , Wereszko B.
Telekomunikacja i Techniki Informacyjne
|
2015
|
tom nr 1-2
44--56
EN
The following paper discusses several aspects connected with the wind farms’ impact on radiocommunication systems. The first part of this article is filled with the analysis of the ITU-R BT.1893 model, originally created for the analysis of the interaction between the wind turbines and digital TV receivers in the UHF band. A measurement campaign carried out by the authors confirmed that this model is also applicable for the lower, maritime VHF band. Utilizing the software implementation of this model, the authors conducted a thorough simulation analysis of the wind turbines’ influence on radio systems working in both VHF and UHF bands. The results of these simulations are presented and discussed in the second part of the paper.
4
Content available Analytical - diffraction model of V-band propagation for the Radiocommunication Events Management System (REMS)
100%
Mąka M. , Majzner P.
Annual of Navigation
|
2019
|
tom No. 26
127--135
EN
The paper presents an analytical-diffraction propagation model for the needs of the Radiocommunication Events Management System, for coast and ship radio stations in sea area A1. The V-wave propagation in sea area 1 has been analyzed as part of an analysis of ranges of particular radio stations and their ability to establish radio contact. The theoretical basis and assumptions on which the model structure design process is based have been presented. Methods of modelling and presentation of dislocation of particular radio stations and their ranges have been discussed.
5
Content available remote Propagation Technique for Ultrashort Pulses. II: Numerical Methods to Solve the Pulse Propagation Equation
100%
Long V. C. , Viet H. N. , Trippenbach M. , Xuan K. D.
Computational Methods in Science and Technology
|
2008
|
tom Vol. 14, nr 1
14-19
EN
We presented the numerical technique to approximately solve the pulse propagation equation. Two efficient methods for this problem, the Split-Step Fourier and the fourth order Runge-Kutta methods are considered. Their high accuracy are shown by comparison with analytical solutions in some particular situations. Our numerical experiments are implemented for soliton propagation and interacting high order solitons. We also numerically investigate an important technique to create ultrashort pulses, which is known as the pulse compression. It is based on high order soliton propagation in Kerr media when the effect of stimulated Raman scattering is taken into account.
6
Content available remote Propagation Technique for Ultrashort Pulses. I: Propagation Equation for Ultrashort Pulses in a Kerr Medium
100%
Long V. C. , Viet H. N. , Trippenbach M. , Xuan K. D.
Computational Methods in Science and Technology
|
2008
|
tom Vol. 14, nr 1
5-11
EN
In this work we investigated propagation of ultrashort laser pulses in dispersive nonlinear media. We derived a general propagation equation of pulses which includes the linear and nonlinear effects to all orders. We studied in the specific case of Kerr media and obtained an ultrashort pulse propagation equation called a Generalized Nonlinear Schrödinger Equation. The impact of the third order dispersion, the higher-order nonlinear terms self-steepening, and stimulated Raman scattering are explicitly analyzed.
7
Content available remote Propagation Technique for Ultrashort Pulses III: Pulse Splitting of Ultrashort Pulses in a Kerr Medium
100%
Long V. C. , Viet H. N. , Trippenbach M. , Xuan K. D.
Computational Methods in Science and Technology
|
2008
|
tom Vol. 14, nr 1
21-26
EN
Impact of such terms as third order dispersion, self-steepening and stimulated Raman scattering on evolution of ultrashort pulses is considered in detail. Under influence of these effects, pulse did not maintain its initial shape. Pulse splits into constituents, its spectrum also evolving into several bands which are known as optical shock and self-frequency shift phenomena. We concluded that when the input peak power is large enough, dynamics of pulse splitting will be complicated. Our numerical simulations were in good agreement with experimental results.
8
Content available remote Significance of the second dip in the ultra-high energy cosmic ray spectrum
100%
Wibig T.
Open Physics
|
2007
|
tom 5
|
nr 4
528-538
EN
A new feature in the spectrum of ultra high energy cosmic rays (UHECR) has been announced in the paper by Berezinsky, Gazizov and Kachelrieβ. The ratio of the solution of the exact transport equation to its solution in the continuous energy loss limit shows intriguing features which, according to the Authors, are related to the very nature of the energy loss processes of UHECR: the very sharp second dip predicted at 6.3 × 1019 eV can be used as an energy calibration point and also as the UHECR mass indicator for big future cosmic ray experiments. In the present paper we would like to advocate that this statement is an overinterpretation. The second dip is a result of an inappropriate approximation used, and thus it cannot help to understand the nature of UHECR in any way.
9
Content available Closed-form Distribution and Analysis of a Combined Nakagami-lognormal Shadowing and Unshadowing Fading Channel
100%
Singh R. , Rawat M.
Journal of Telecommunications and Information Technology
|
2016
|
tom nr 4
81--87
EN
The realistic wireless channels face combined (time shared) Nakagami-lognormal shadowing and unshadowing fading because of time varying nature of radio channel and mobile user. These channels can be modeled as time-shared sum of multipath-shadowing and unshadowing Rician distributions. These fading create severe problems in long distance wireless systems where multipath fading is superim-posed on shadowing fading (called multipath-shadowing fading). The multipath effect can be modeled using Rayleigh, Rician, Nakagami-m or Weibull distribution and shadowing effect is modeled using lognormal distribution. In this paper, authors present a new closed-form probability distribution function of a Nakagami-lognormal fading channel. Using this result, the closed-form expression of combined Nakagami-lognormal shadowing and unshadowing fading is presented. The obtained closed-form result facilitates to derive the important performance metrics of a communication system such as amount of fading, outage probability, and average channel capacity in closed-form expressions.
10
Content available Propagation in rectangular waveguides with a pseudochiral omega slab
100%
Mazur J. , Dorko K.
Journal of Telecommunications and Information Technology
|
2002
|
tom nr 1
52-55
EN
The transfer matrix approach is applied for analysis of waveguides loaded with a uniaxial pseudochiral omega slab. In particular a pseudochiral parallel plate and rectangular guides are investigated. Based on the numerical analysis the influence of the pseudochirality on propagation characteristics and field distribution are examined. Other feature such as a field displacement phenomenon appearing in the both considered structures due to the pseudochirality is also discussed.
11
Content available The propagation of the waves in the CTO S.A. towing tank
100%
Drzewiecki M.
Polish Maritime Research
|
2018
|
tom S 1
22--28
EN
The paper presents the results of research focused on the wave propagation in the CTO S.A. deepwater towing tank. In the scope of paper, the wavemaker transfer function was determined for regular waves, based on the Biésel Transfer Function and further for irregular waves, based on Hasselman model of nonlinear energy transfer. The phenomena: wave damping, wave breakdown and wave reflection, were measured, analyzed and mathematically modeled. Developed mathematical models allow to calculate the impact of mentioned phenomena on the wave propagation and furthermore to calculate the wave characteristics along the whole measurement area in the CTO S.A. deepwater towing tank, based on wavemaker flap motion control.
12
Content available Wind Farms Influence on Radiocommunication Systems Operating in the VHF and UHF Bands
100%
Bronk K. , Lipka A. , Niski R. , Wereszko B.
Journal of Telecommunications and Information Technology
|
2015
|
tom nr 2
30--43
EN
The following paper discusses several aspects connected with the wind farms’ impact on radiocommunication systems. The first part of this article is filled with the analysis of the ITU-R BT.1893 model, which was originally created for the analysis of the interaction between the wind turbines and digital TV receivers in the UHF band. A measurement campaign carried out by the authors confirmed that this model is also applicable for the lower, maritime VHF band. Utilizing the software implementation of this model, the authors conducted a thorough simulation analysis of the wind turbines’ influence on radio systems working in both VHF and UHF bands. The results of these simulations are presented and discussed in the second part of the paper.
13
Content available Identification of hydro-acoustic waves emitted from floating units during mooring tests
100%
Kozaczka E. , Domagalski J. , Grelowska G. , Gloza I.
Polish Maritime Research
|
2007
|
tom nr 4
40-46
EN
Measurements of hydro-acoustic noise emitted from vessels are a.o. a subject of the tests carried out in the control measurement ranges of the Navy. The measurements are performed both on anchored and floating vessels. Acoustic field of vessels is changing along with their speed changing and is associated with acoustic activity of wave sources installed in vessel’s hull (main engines, electric generating sets, reduction gears, pumps, shaft-lines, piping, ventilating ducts etc) as well as hydro-dynamic sources such as screw propellers and water flow around the hull [5, 7]. Vibration energy generated by the onboard devices is transferred through ship structural elements to water where it propagates in the form of hydro-acoustic waves of a wide frequency band.
14
Content available remote Propagation of a four-beamlets laser array through an apertured optical system
100%
Yuan Y. , Qu J. , Shi J. , Cui Z.
Optica Applicata
|
2010
|
tom Vol. 40, nr 1
155--164
EN
By expanding the hard-aperture function into a finite sum of complex Gaussian functions, an analytical formula for a four-beamlets laser array propagating through an apertured ABCD optical system is derived based on the generalized Collins formula. As a numerical example, the on-axis irradiance of a four-beamlets laser array focused by a squarely apertured bifocal thin lens is studied, and it is found that the focused irradiance is closely related to the parameters of the optical system and the laser array. Our formula provides a convenient way for studying the paraxial propagation of a four-beamlets laser array through an apertured ABCD optical system.
15
New possibilities of electromagnetic logging in anisotropic and heterogeneous rock medium
100%
Gawin A. , Gawin H.
Acta Geophysica Polonica
|
2000
|
tom Vol. 48, nr 4
489-521
EN
This paper, being a continuation of the earlier works by the author, presents new possibilities of electromagnetic logging in anisotropic and heterogeneous rocks. The theoretical background for (among other things) the azimuth-radial electromagnetic logging with wave and geometrical shaping - of the field is described. It is assumed that the medium at the outside of boreholes - the zone contaminated by mud filtrate and uninvated zone - is heterogeneous and anisotropic. In general, we treat the specific conductivity tensor s, the electric permittivity tensor e, and the magnetic permeability tensor m, as functions C1 of the point. An influence of anisotropy of electric properties is much simpler. In the case of monochromatic fields, a uniform wave tensor can be employed. An assumption that also magnetic permeability is a tensor helps us to introduce a uniform tensor according to the classical theory. These difficulties are avoided, at last in the formal operation with equations, if the approach to the problem is relativistic.
16
Content available Reliability of line-of-sight radio-relay systems
100%
Bogucki J. , Wielowieyska E.
Journal of Telecommunications and Information Technology
|
2006
|
tom nr 1
87-92
EN
The modern radio transmission systems are specifically designed for catching principally two main objectives: on one side to provide a radio solution for long distance where large configurations are required to fulfil the high capacity transmissions needs, on the other side to guarantee link quality as high as possible. The availability of a radio-relay system is dependent upon many factors and particularly upon: the reliability of equipment and propagation conditions. The article describes the wave propagation and equipment that determine the performance of a radio-relay path. National Institute of Telecommunications (NIT) carried out research on propagation phenomena on terrestrial path and exemplary results are described herewith. The availability of radio equipment based on the mean time between failures for equipment modules is presented too.
17
Content available Identification of hydroacoustic wave sources of ship in motion
100%
Kozaczka E. , Domagalski J.
Polish Maritime Research
|
2010
|
tom nr 4
64-71
EN
This paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In the publication results of identification tests of underwater noise generated by a ship in motion, are presented.
18
Tłumienie dodatkowe w łączu satelitarnym
100%
Bogucki J. , Wielowieyska E.
Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
|
1998
|
tom nr 1
48-51
PL
Określono podstawowe zależności opisujące łącze satelitarne. Omówiono badania propagacyjne prowadzone w Instytucie Łączności na trasach satelitarnych. Przedstawiono wyniki tych badań z trasy Łucz 1 - IŁ w Miedzeszynie.
EN
Formulas describing satellite links are presented in this paper. Propagation phenomena on satellite - Earth path were carried out by Institute of Telecommunications and their results are described herewith.
19
Content available remote Propagation of EEG activity during continuous attention test
100%
Kuś R. , Blinowska K. J. , Kamiński M. , Basińska-Starzycka A.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2005
|
tom Vol. 53, nr 3
217-222
EN
The propagation of EEG activity during the Continuous Attention Test (CAT) was determined by means of Short-time Directed Transfer Function (SDTF). SDTF supplied the information on the direction, spectral content and time evolution of the propagating EEG activity. The differences in propagation for target and non-target conditions were found mainly in the frontal structures of the brain.
20
Content available The spread of the regional intellectual capital: the case of the Russian Federation
100%
Markhaichuk M. , Zhuckovskaya I.
Oeconomia Copernicana
|
2019
|
tom 10
|
nr 1
89-111
EN
Research background: The positive relationship between the availability of intellectual capital and the ability of the state, region or firm to develop economically stimulates an increase in the intellectual capital. In order to manage intellectual capital, it is necessary to have a clear idea of its availability, capacity, features, growth reserves, as well as concentration in certain territories and ability to spread. Many studies are devoted to the measurement of intellectual capital, its diffusion and impact on the economic efficiency of the organization, region, and nation. However, in the case of the Russian Federation there is a gap in the study of the spread of intellectual capital over the country. Purpose of the article: The purpose of the article is to evaluate intellectual capital in the federal districts of the Russian Federation and to model the spread of intellectual capital. Methods: Data on 8 Russian federal districts for the 2017 year from Unified Inter-departmental Information and Statistical System (EMISS) of the Russian Federation were taken as a basis for the research. Based on three-component model (human capital, structural capital, and relational capital), we formed a set of indicators for assessing regional intellectual capital, relevant to the Russian Federation. This allowed us to evaluate the integrated indicators of intellectual capital in federal districts and to determine the probability of intellectual capital spreading from each federal district to neighboring federal districts. We used percolation theory methods to model the spread of intellectual capital. Findings & Value added: The study contributes to the Russian regional knowledge on intellectual capital. Intellectual capital in the Russian Federation is disproportionately distributed, concentrating closer to the capital, and has a lower level in remote territories. It spreads unevenly, flowing from the Central Federal District to neighboring federal districts, however, other federal districts develop almost in isolation.
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