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Wyświetlanie 1-15 z 22
Tytuł:
Proposed Methodology for the Annoyance Penalty of Amplitude Modulated Wind Turbine Noise
Autorzy:
Makarewicz, Rufin
Powiązania:
https://bibliotekanauki.pl/articles/2141682.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
annoyance
wind turbine noise
amplitude modulation.
Opis:
Amplitude modulation increases the annoyance caused by wind turbine noise. One gets the improved annoyance when a penalty is added to the measured or calculated time-average sound level. The amplitude modulated wind turbine noise consists of pulses. Each of them could be characterized by the short time-average sound level and the modulation depth. The latter determines the pulse penalty. This paper shows how to calculate the improved annoyance of amplitude modulated wind turbine noise, when the short time-average sound level and the penalty for each pulse are known. A special case of identical pulses is discussed. The proposed methodology needs to be tested by research.
Źródło:
Archives of Acoustics; 2022, 47, 1; 125-128
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decreasing of error probability in telecommunication access networks by using amplitude modulation of many components
Autorzy:
Klymash, M.
Gorbatyy, I.
Powiązania:
https://bibliotekanauki.pl/articles/411412.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
telecommunication access network
data transmission
bit error rate
quadrature amplitude modulation
amplitude modulation of many components
Opis:
The paper addresses the research of data transmission technologies in telecommunication access networks. These networks are characterized by limited bandwidth and are suitable for high speed data transmission. Particular attention is paid on the data transmission technologies in telecommunication access networks based on symmetrical telecommunication lines. Paper proposes the method of adaptive data transmission in telecommunication access networks using amplitude modulation of many components. The results of mathematical modeling are presented, which allows estimating the bit error rate decrease in telecommunication access networks using this method.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2014, 3, 1; 55-60
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resource allocation in MIMO systems specific to radio communication
Autorzy:
Ghaderi, Bahar
Parhizgar, Naser
Powiązania:
https://bibliotekanauki.pl/articles/140794.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spatial modulation
multi quadrature amplitude modulation
modulation
Huffman coding
MIMO systems
Opis:
The performance of the multi-input multi-output (MIMO) systems can be improved by spatial modulation. By using spatial modulation, the transmitter can select the best transmit antenna based on the channel variations using channel state information (CSI). Also, the modulation helps the transmitter to select the best modulation level such that the system has the best performance in all situations. Hence, in this paper, two issues are considered including spatial modulation and information modulation selection. For the spatial modulation, an optimal solution for obtaining the probability of selecting antenna is calculated and then Huffman coding is used such that the transmitter can select the best transmit antenna to maximize the channel capacity. For the information modulation, a multi quadrature amplitude modulation (MQAM) strategy is used. In this modulation, the modulation size is changed based on the channel state variations; therefore, the best modulation index is used for transmitting data in all channel situations. In simulation results, the optimal method is compared with Huffman mapping. In addition, the effect of modulation on channel capacity and a bit error rate (BER) is shown.
Źródło:
Archives of Electrical Engineering; 2019, 68, 1; 91-100
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission Perspective on the Mechanism of Coarse and Fine Crackle Sounds
Autorzy:
Lu, Bing-Yuh
Hsueh, Meng-Lun
Wu, Huey-Dong
Powiązania:
https://bibliotekanauki.pl/articles/1953484.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
crackles
computer simulation
lung sound
respiration
amplitude modulation
frequency modulation
Opis:
The possibility of a normal distribution indicates that few particles are in the same phase during a breath and their reflections can be observed on the chest wall, then a few explosive waves with relatively large power occurr occasionally. Therefore, the one-cycle sine wave which is simulated as a single burst of the explosive effect phenomenon penetrates through the chest wall and was analysed to explore the reason of the crackle sounds. The results explain the differences between the definitions of crackle proposed by Sovijärvi et al. (2000a). The crackles in the lungs were synthesised by a computer simulation. When the coarse crackles occur, the results indicate that higher burst frequency carriers (greater than 100 Hz) directly penetrate the bandpass filter to simulate the chest wall. The simulated coarse crackle sounds were low pitched, with a high amplitude and long duration. The total duration was greater than 10 ms. However, for a lower frequency carrier (approximately 50 Hz), the fundamental frequency component was filtered out. Therefore, the second harmonic component of the lower frequency carrier, i.e., the fine crackle, penetrated the chest wall. Consequently, it is very possible that the normal lung sounds may contain many crackle-shaped waves with very small amplitudes because of the filtering effects of the chest wall, environment noises, electric devices, stethoscopes, and human ears, the small crackles disappear in the auscultations. In addition, our study pointed out that some unknown crackles of the very low frequency under the bandwidth of the human ears cannot penetrate the airways and be detected by medical doctors. Therefore, it might be necessary to focus advanced electronic instrumentation on them in order to analyse their possible characteristics for diagnosis and treatment of the respiration system.
Źródło:
Archives of Acoustics; 2021, 46, 2; 289-300
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Usefulness of Measurement on a Board at Ground Level for Assessing the Noise Level from a Wind Turbine
Autorzy:
Wszołek, Tadeusz
Pawlik, Paweł
Mleczko, Dominik
Chronowska, Jagna
Powiązania:
https://bibliotekanauki.pl/articles/176301.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
wind turbine noise
amplitude modulation
acoustical measurements
environmental acoustics
Opis:
The specific working conditions of the wind turbine in strong wind cause a number of problems in the measurement of noise indicators used in its short and long-term assessment. The wind is a natural working environment of the turbine, but it also affects the measurement system, moreover, it can be a secondary source of other sounds that interfere with the measurement. One of the effective methods of eliminating the direct impact of wind on the measurement system is placing the microphone on the measurement board at ground level. However, the obtained result can not be directly compared with the admissible values, as it has to be converted to a result at a height of 4 m. The results of previous studies show that this relation depends, inter alia, on the speed and direction of the wind. The paper contains the results of measurements on the measurement board, according to EN 61400-11:2013, and at a height of 4 m above ground made simultaneously in three points around the 2 MW turbine at various instantaneous speeds and changing wind directions. Analysis of the impact of measuring point location on the measurement result of noise indicators and the occurrence of additional features affecting the relationship between the values measured on the board and at the height of 4 m, and especially the tonality, amplitude modulation and content of low frequency content, was made.
Źródło:
Archives of Acoustics; 2020, 45, 1; 165-175
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trellis Coded 4-ary PAM using Distance-Preserving Mapping
Autorzy:
Shongwe, T.
Powiązania:
https://bibliotekanauki.pl/articles/226278.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
distance-preserving mappings
hamming distance
euclidean distance
pulse amplitude modulation
Opis:
A trellis coded 4-ary Pulse Amplitude Modulation (4-PAM) is presented, where the encoding algorithm is derived from Distance Preserving Mapping (DPM) algorithm. In this work, we modify the DPM algorithm for 4-PAM and obtain a new construction for mapping binary sequences to permutation sequences, where the permutation sequences are obtained by permuting symbols of a 4-PAM constellation. The resulting codebook of permutation sequences formed this way are termed mappings. We also present several metrics for assessing the performance of the mappings from our construction, and we show that a metric called the Sum of Product of Distances (SOPD) is the best metric to use when judging the performance of the mappings. Finally, performance results are presented, where the mappings from our construction are compared against each other and also against the conventional mappings in the literature.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 4; 527-533
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Permutation Coding with Injections for Modified PAM System
Autorzy:
Ogunyanda, Opeyemi O.
Shongwe, Thokozani
Swart, Theo G.
Powiązania:
https://bibliotekanauki.pl/articles/226518.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
injection
permutation codes
power line communications
pulse amplitude modulation
jitter
Opis:
Arriving at a good combination of coding and modulation schemes that can achieve good error correction constitutes a challenge in digital communication systems. In this work, we explore the combination of permutation coding (PC) and pulse amplitude modulation (PAM) for mitigating channel errors in the presence of background noise and jitter. Since PAM is characterised with bi-polar constellations, Euclidean distance is a good choice for predicting the performance of such coded modulation setup. In order to address certain challenges facing PCs, we therefore introduce injections in the coding system, together with a modified form of PAM system. This modification entails constraining the PAM constellations to the size of the codeword’s symbol. The results obtained demonstrate the strength of the modified coded PAM system over the conventional PC coded PAM system.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 3; 399-404
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise Annoyance Caused by Amplitude Modulated Sounds Resembling the Main Characteristics of Temporal Wind Turbine Noise
Autorzy:
Hafke-Dys, H.
Preis, A.
Kaczmarek, T.
Biniakowski, A.
Kleka, P.
Powiązania:
https://bibliotekanauki.pl/articles/177437.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wind turbines amplitude modulation
noise annoyance
modulacja amplitudy turbin wiatrowych
uciążliwości hałasu
Opis:
Annoyance ratings for artificially created noises, resembling the main characteristics of temporal wind turbine noise, were studied by means of a listening experiment involving 21 participants with normal hearing. Three types of stimuli were examined: broadband noise (−4 dB/octave), noise generated by moving cars, and narrowband noise. All stimuli had the sound level fluctuations typical for wind turbine noise. The magnitude of the sound level fluctuations was measured in a quantitative way, by using the characteristics of amplitude modulated sound: modulation rate and modulation depth. Our aim was to examine how the modulation rate and the modulation depth influence the noise annoyance assessment of broadband and narrowband amplitude modulated noises. Three different modulation rates, 1, 2 and 4 Hz, and sound level fluctuations (a measure of the modulation depth), 3, 6, 9 dB, were applied to each type of stimuli (with exception of noise generated by the moving cars) and investigated. The participants in the listening experiment were presented with sound stimuli in laboratory conditions and asked to rate their annoyance on a numerical scale. The results have shown a significant difference between the investigated conditions. The effect was particularly strong between the annoyance judgments of different types of noise (narrow and broadband), and modulated versus unmodulated noises. Temporal fluctuations occurring in wind turbine noise are very pertinent to the perception of annoyance and could be responsible for its being a relatively annoying noise source. The obtained results were discussed and compared to the typical modulation rates and level changes that occur in recordings of real wind turbine noise.
Źródło:
Archives of Acoustics; 2016, 41, 2; 221-232
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of DVB-S2 Standard Using Signal-Code Constructions Based on Amplitude Modulation of Many Components
Autorzy:
Horbatyi, Ivan
Yashchyshyn, Yevhen
Powiązania:
https://bibliotekanauki.pl/articles/227156.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DVB-S2 standard
frequency efficiency
energy efficiency
amplitude modulation of many components
Opis:
It is proposed to modernize the DVB-S2 standard by using AMMC (amplitude modulation of many components) signals instead of 8PSK (8-phase shift keying) and APSK (amplitude-phase shift keying) signals, and to modernize the DVB-S2 standard equipment by using the AMMC modulator and AMMC demodulator. Usage of AMMC makes it possible to reduce the symbol error rate in communication channel up to 52 times. The satellite digital video broadcast systems that apply signal-code constructions based on AMMC are characterized by a higher energy efficiency from 1 to 2.6 dB compared with signal-code constructions based on 8PSK and APSK.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 315-320
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural condition evaluation of prestressed concrete structures based on vibroacoustic monitoring
Ocena stanu technicznego betonowych konstrukcji sprężonych na podstawie monitoringu wibroakustycznego
Autorzy:
Radkowski, S.
Gałęzia, A.
Mączak, J.
Szczurowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/328826.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
diagnostyka techniczna
struktura wstępnie sprężona
modulacja amplitudowa
technical diagnostics
presstresed structures
amplitude modulation
Opis:
Analysis of the phenomenon of modulation of vibroacoustic signal's parameters, especially the amplitude and the frequency structure of the envelope which is directly associated with the occurrence of group velocity, may prove to be an effective tool for diagnosing the technical condition of pre-stressed structures. This scope of work and the examination of the influence of local defects and of the environmental impact was the main research task during COST Action 534 project duration. An issue that is particularly interesting and that calls for additional analyses and experiments will be the development and adaptation of effective de-modulation algorithms.
Analiza zjawiska modulacji wibroakustycznych parametrów sygnału, a w szczególności amplitudy i struktury częstościowej obwiedni, która jest bezpośrednio związana ze zjawiskiem prędkości grupowej, może być efektywnym narzędziem w diagnozowaniu stanu technicznego struktur sprężonych. Ten zakres pracy, jak również badanie wpływu występowania miejscowych wad było głównym zadaniem kończącej się Akcji COST 534. Zadaniem, szczególnie interesującym i wymagającym dalszych analiz i eksperymentów, jest rozwój i adaptacja użytecznych algorytmów demodulacji.
Źródło:
Diagnostyka; 2007, 4(44); 105-112
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the FPAA to Sample Input Signal for Laboratory Exercise: Pulse Amplitude Modulation
Autorzy:
Grzechca, Damian
Chruszczyk, Lukas
Powiązania:
https://bibliotekanauki.pl/articles/227335.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
field programmable analog array (FPAA)
signal processing
pulse amplitude modulation (PAM)
student laboratory
Opis:
This paper presents exemplary exercise on the fundamentals of signal processing course which is offered for second year bachelor level students. Application of Field Programmable Analog Array (FPAA) for pulse amplitude modulation (PAM) exercise is described with signal processing laboratory. There are presented two methods for implementing PAM modulation and demodulation technique in FPAA module. Example configuration files are available form Authors’ web site.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 1; 25-28
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research of the AMWG algorithm for assessing amplitude modulation in wind turbine noise
Autorzy:
Czapla, Marcjanna
Wszołek, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/24202008.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
wind turbine noise
amplitude modulation
modulation depth
modulation frequency
hałas turbin wiatrowych
modulacja amplitudy
głębokość modulacji
częstotliwość modulacji
Opis:
The operation of a wind turbine (WT) is characterized by fluctuations in sound pressure amplitude associated with the passage of the propeller blade through the tower. Amplitude Modulation (AM) is one of the factors that contributes to the increased annoyance of wind turbine noise. The phenomenon of AM is currently the subject of research in many research centers around the world in the context of a parametric assessment of its impact on annoyance. Despite the development of many methods to measure the AM of a WT noise, there is no commonly accepted method. This paper discusses the most crucial factors that stimulate the phenomenon of AM and the implementation in the MATLAB environment of the algorithm to find the frequency and depth of AM proposed by the Amplitude Modulation Working Group (AMWG). The results of verification of the developed algorithm as well as the measurement results of the frequency and depth of modulation for two measurement samples of a 2 MW wind turbine are presented.
Źródło:
Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022317
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MultiDot - nowa idea rastrowania AM
MultiDot - the new AM screening concept
Autorzy:
Kunstetter, A.
Powiązania:
https://bibliotekanauki.pl/articles/128482.pdf
Data publikacji:
2018
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Przemysłu Poligraficznego
Tematy:
raster
farba
przyrost punktu rastrowego
modulowanie amplitudowe
system MultiDot
paint
amplitude modulation
MultiDot system
Opis:
Screening technology let reproduce continuous tone images using bilevel printing method (as f.e. offset). Some properties of human eye allows the correct reception of the continuous tone image. One have to remember, that tonal value (caused by surface covered by printing elements only) existing on the printing plateis not the same as the one present on the printout. In offset printing technology the difference between tonal value on the printing plate and on the printout is provoked by two different phenomenons: one is the DotGain, while the other is caused by driving the ink out by dampening solution. The DotGaineffecthas 3 mainreasons: – spilling out of the ink on the printedsurface, – deformation of transfer medium (f.e. offset blanket) – present only when indirect printing technology is in use – “shadow” of the printing inklayer, ... and iswelldefined and known. The mutual (the ink and the water/dampening solution) influence is very difficult to predict using mathematic formulas. We can observe, that (because of the DotGain effect) there are some areas not covered by ink, but absorbing the light as they would be – so it can be a base for some ink saving – if the effect would be used properly. However the FM screening has significant DotGain effect (so ink saving should be noticeable), it demonstrates lot of disadvantages: less print stability, unevenly flat areas and many, many others. To fulfill some expectations the new AM screening was developed (and patented). It was named MultiDot and is based on multi-cluster principle, where – what’s important – single clusters have different size and shape. Optimal shape and tonal function caused, that newly developed screening concept let the user receive stable, rich in details and Moire free images with significant ink-saving capabilities. The other aspect of using MultiDot screening structure is to prevent prints against illegal copying and allowing the user to confirm (or deny) the authenticity of certain printouts or goods – this functionality is called MultiDot Security and will be a subject of another article.
Źródło:
Acta Poligraphica; 2018, 11; 23-29
2299-9981
Pojawia się w:
Acta Poligraphica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Soft-Output STBC Decoder for Aeronautical Telemetry
Autorzy:
Louёt, Yves
Othman, Rami
Skrzypczak, Alexandre
Powiązania:
https://bibliotekanauki.pl/articles/309130.pdf
Data publikacji:
2020
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
continuous-phase modulation
CPM
pulse amplitude modulation
PAM
shaped offset quadrature phase shift keying
SOQPSK
space-time block coding
STBC
ternary symbol
Opis:
Alamouti encoding is a well-known space time block encoding technique used to improve the received signal quality in Rayleigh fading channels. In aeronautical telemetry, this encoding technique is applied to shaped offset quadrature phase shift keying tier generation (SOQPSK-TG) modulation in order to handle the two-antenna issue. It is provided for in telemetry-related IRIG standards. In this paper, we propose a unique decoding architecture for Alamouti-encoded SOQPSK-TG signals, taking advantage of pulse amplitude modulation decomposition with soft and hard outputs. We exploit this result to obtain a Viterbi algorithm (VA) for hard decoding and a soft output Viterbi algorithm (SOVA) for soft and hard decoding, with a twofold benefit: operation using one trellis structure, unlike decoders that are based on the 8-waveforms cross-correlated trellis-coded quadrature modulation (XTCQM) approximation, and very attractive bit error rate performance, as well as a complexity trade-off.
Źródło:
Journal of Telecommunications and Information Technology; 2020, 1; 13-20
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radio Photonic Systems for Measurement of Instantaneous Radio Frequency with Amplitude-phase Modulation of Optical Carrier
Autorzy:
Morozov, O. G.
Nasybullin, A. R.
Vedenkin, D. A.
Agliullin, T. A.
Powiązania:
https://bibliotekanauki.pl/articles/958054.pdf
Data publikacji:
2016
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
amplitude-phase modulation
transformation
fiber Bragg grating (FBG)
instantaneous frequency
radio photonics
Opis:
In this article questions related to the development instantaneous radio frequency measurement system based on application in them original ways of the amplitude-phase modulation transformation of single-frequency optical carrier by a radio signal in symmetric two-frequency and measuring “frequency-amplitude” transformation in fiber Bragg grating with special profile are considered. Such systems have broad prospects for use in telecommunications, military systems and for environmental monitoring.
Źródło:
Journal of Telecommunications and Information Technology; 2016, 2; 103-107
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
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