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Tytuł:
GIS-based technic for roadside-slope stability assessment: an bivariate approach for A1 East-West highway, North Algeria
Autorzy:
Dahoua, L.
Yakovitch, S. V.
Hadji, R. H.
Powiązania:
https://bibliotekanauki.pl/articles/89034.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
landslide susceptibility
frequency ratio
bivariate statistics
mountain
geotechnic
Opis:
This paper presents a GIS-based method for landslide susceptibility (LS) assessment using slope-movement inventory and field data. The study has been carried out along A1-Highway (A1-H) in Hanif region as this road section is threated by several types of mass wasting. This hilly zone is known by their landslides sensitive terrains in the North of Algeria. The terrain data are collected from a Géologic map, satellite imageries, digital elevation model, rainfall data, field suveys and ancillary data. In this paper Frequency Ratios (FR) based on bivariate statistical method are evaluated by comparing the observed landslides to their controlling factors. The product of the linear summation of the FR values was a landslide susceptibility index (LSI) map. It was categorized using the natural breaks classification method. The resultant LS zonation map delineates the area into five hierarchic zones. The results confirms that the angle of the slope, plays the most role in wasting especially in road sides. The LS can be used for preliminary land use planning and hazard mitigation purpose. By means of this map the current route of the A1-H can be improved to cross less susceptibles zones.
Źródło:
Mining Science; 2017, 24; 117-127
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of Flood-Hazard-Mapping Model Using Random Forest and Frequency Ratio in Sumedang Regency, West Java, Indonesia
Autorzy:
Ismanto, Rido Dwi
Fitriana, Hana Listi
Manalu, Johanes
Purboyo, Alvian Aji
Prasasti, Indah
Powiązania:
https://bibliotekanauki.pl/articles/27314279.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
flood-susceptibility assessment
random forest
frequency ratio
Sumedang
remote sensing
Opis:
Flooding, often triggered by heavy rainfall, is a common natural disaster in Indonesia, and is the third most common type of disaster in Sumedang Regency. Hence, flood-susceptibility mapping is essential for flood management. The primary challenge in this lies in the complex, non-linear relationships between indices and risk levels. To address this, the application of random forest (RF) and frequency ratio (FR) methods has been explored. Ten flood-conditioning factors were determined from the references: the distance from a river, elevation, geology, geomorphology, lithology, land use/land cover, rainfall, slope, soil type, and topographic wetness index (TWI). The 35 flood locations from the flood-inventory map were selected, and the remaining 18 flood locations were used for justifying the outcomes. The flooded areas from the RF model were 28.39%; the rest (71.61%) were non-flooded areas. Also, the flooded areas from the FR method were 8.02%, and the non-flooded areas were 91.98%. The AUC for both methods was a similar value – 83.0%. This result is quite accurate and can be used by policymakers to prevent and manage future flooding in the Sumedang area. These results can also be used as materials for updating existing flood-susceptibility maps.
Źródło:
Geomatics and Environmental Engineering; 2023, 17, 6; 129--157
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Landslide susceptibility assessment in Constantine region (NE Algeria) by means of statistical models
Autorzy:
Manchar, N.
Benabbas, C.
Hadji, R.
Bouaicha, F.
Grecu, F.
Powiązania:
https://bibliotekanauki.pl/articles/178256.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
geographic information system
probabilistic methods
information value
weight of evidence
frequency ratio
Opis:
The purpose of the present study was to compare the prediction performances of three statistical methods, namely, information value (IV), weight of evidence (WoE) and frequency ratio (FR), for landslide susceptibility mapping (LSM) at the east of Constantine region. A detailed landslide inventory of the study area with a total of 81 landslide locations was compiled from aerial photographs, satellite images and field surveys. This landslide inventory was randomly split into a testing dataset (70%) for training the models, and the remaining (30%) was used for validation purpose. Nine landslide-related factors such as slope gradient, slope aspect, elevation, distance to streams, lithology, distance to lineaments, precipitation, Normalized Difference Vegetation Index (NDVI) and stream density were used in the landslide susceptibility analyses. The inventory was adopted to analyse the spatial relationship between these landslide factors and landslide occurrences. Based on IV, WoE and FR approaches, three landslide susceptibility zonation maps were categorized, namely, “very high, high, moderate, low, and very low”. The results were compared and validated by computing area under the receiver operating characteristic (ROC) curve (AUC). From the statistics, it is noted that prediction scores of the FR, IV and WoE models are relatively similar with 73.32%, 73.95% and 79.07%, respectively. However, the map, obtained using the WoE technique, was experienced to be more suitable for the study area. Based on the results, the produced LSM can serve as a reference for planning and decision-making regarding the general use of the land.
Źródło:
Studia Geotechnica et Mechanica; 2018, 40, 3; 208-219
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric analysis of the whole loading process of translation-torsion coupled vibration characteristics of the multi-layer bi-directional eccentric frame structure
Autorzy:
Kuang, Yuping
Liu, Yanshan
Powiązania:
https://bibliotekanauki.pl/articles/2104768.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
eccentric structure
translation-torsion coupled
vibration characteristics
eccentricity
uncoupled torsion to lateral frequency ratio
Opis:
Earthquake investigations confirm that irregular structures suffer more damage than their symmetric counterparts. The vibration mode of irregular structures is affected by the cou- pling of lateral and torsional vibration characteristics. The analysis of the lateral-torsional coupling effect is mainly limited to unidirectional eccentric structure or single-layer eccentric design. To fill this gap, this paper presents a parametric study of the whole loading pro- cess, exploring lateral-torsional coupling vibration characteristics of multi-layer bi-directional eccentric structures. The performed nonlinear static analysis revealed that the natural fre- quency of eccentric frames with different layers exhibited a general pattern with a three-stage evolution from elastic to elastic-plastic stages. Accordingly, three different elastic-plastic de- velopment stages of parametric analysis were defined. The effects of the uncoupled torsion-to- -lateral frequency ratios Ω and stiffness eccentricities on the translation-torsion coupled vi- bration characteristics in the above three stages were simulated via self-compiled programs on the MATLAB platform. The results obtained show that the range of Ω controlling the vibration characteristics was related to the eccentricities. Therefore, it was proposed to set different limit values of Ω in designing and analyzing the structures with different bi- directional eccentric degrees. At Ω = 1.1 ∼ 1.2, the coupling effect between bi-directional eccentricities led to transformation between the first- and second-order vibration modes, while the direction with the lowest lateral stiffness could not be directly judged as the structure first-order principal vibration direction. In the third stage, when the bi-directional eccentricities reached or even exceeded 0.3, the second and third modes transformed into each other.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 479--494
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large amplitude free vibration analysis of tapered Timoshenko beams using coupled displacement field method
Autorzy:
Rajesh, K.
Saheb, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/265957.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wibracje
belka Timoshenki
parametry stożka
współczynnik smukłości
large amplitude vibrations
coupled displacement field method
tapered Timoshenko beams
taper ratio
slenderness ratio
frequency ratio
Opis:
Tapered beams are more efficient compared to uniform beams as they provide a better distribution of mass and strength and also meet special functional requirements in many engineering applications. In this paper, the linear and non-linear fundamental frequency parameter values of the tapered Timoshenko beams are evaluated by using the coupled displacement field (CDF) method and closed form expressions are derived in terms of frequency ratio as a function of slenderness ratio, taper ratio and maximum amplitude ratio for hinged-hinged and clamped-clamped beam boundary conditions. The effectiveness of the CDF method is brought out through the solution of the large amplitude free vibrations, in terms of fundamental frequency of tapered Timoshenko beams with axially immovable ends. The results obtained by the present CDF method are validated with the existing literature wherever possible.
Źródło:
International Journal of Applied Mechanics and Engineering; 2018, 23, 3; 673-688
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue and Corrosion Fatigue of 18Ni Maraging Steel
Autorzy:
Yongmei, Zhu
Junjie, Chen
Wenxian, Tang
Weicheng, Cui
Xiaorong, Wang
Fang, Wang
Baoji, Yin
Powiązania:
https://bibliotekanauki.pl/articles/2049667.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
corrosion fatigue
18Ni (250)
loading frequency
stress ratio
3.5%NaCl solution
Opis:
This study focused on the fatigue and corrosion fatigue of maraging steel 18Ni (250). The 18Ni (250) samples were tested for axial fatigue in air and 3.5% NaCl solution. The effects of loading frequency and stress ratio on the fatigue strength of 18Ni (250) were studied. in air, the loading frequency was 10 Hz, and the stress ratio was 0.5. however, three loading methods were used in the 3.5% NaCl solution: (i) the loading frequency of 1 Hz and stress ratio of 0.5; (ii) the loading frequency of 1 Hz and stress ratio 0.1, and (iii) the loading frequency 5 Hz and stress ratio 0.5. The corrosion fatigue strength of samples in the 3.5% NaCl solution was 63.3% lower than that of the samples in air. The fractures in the samples were observed after the test.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 2; 381-390
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue and Corrosion Fatigue of 18Ni Maraging Steel
Autorzy:
Yongmei, Zhu
Junjie, Chen
Wenxian, Tang
Weicheng, Cui
Xiaorong, Wang
Fang, Wang
Baoji, Yin
Powiązania:
https://bibliotekanauki.pl/articles/2049558.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
corrosion fatigue
18Ni (250)
loading frequency
stress ratio
3.5%NaCl solution
Opis:
This study focused on the fatigue and corrosion fatigue of maraging steel 18Ni (250). The 18Ni (250) samples were tested for axial fatigue in air and 3.5% NaCl solution. The effects of loading frequency and stress ratio on the fatigue strength of 18Ni (250) were studied. In air, the loading frequency was 10 Hz, and the stress ratio was 0.5. However, three loading methods were used in the 3.5% NaCl solution: (i) the loading frequency of 1 Hz and stress ratio of 0.5; (ii) the loading frequency of 1 Hz and stress ratio 0.1, and (iii) the loading frequency 5 Hz and stress ratio 0.5. The corrosion fatigue strength of samples in the 3.5% NaCl solution was 63.3% lower than that of the samples in air. The fractures in the samples were observed after the test.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 321-330
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of interval damping ratio under uncertain load in power system
Autorzy:
Xing, J.
Chen, C.
Wu, P.
Powiązania:
https://bibliotekanauki.pl/articles/201058.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power system
low frequency oscillation
interval load
interval damping ratio
successive linear programming method
Opis:
The problem of small-signal stability considering load uncertainty in power system is investigated. Firstly, this paper shows attempts to create a nonlinear optimization model for solving the upper and lower limits of the oscillation mode’s damping ratio under an interval load. Then, the effective successive linear programming (SLP) method is proposed to solve this problem. By using this method, the interval damping ratio and corresponding load states at its interval limits are obtained. Calculation results can be used to evaluate the influence of load variation on a certain mode and give useful information for improvement. Finally, the proposed method is validated on two test systems.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 151-158
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ARL-Wavelet-BPF optimization using PSO algorithm for bearing fault diagnosis
Autorzy:
Ahsan, Muhammad
Bismor, Dariusz
Manzoor, Muhammad Arslan
Powiązania:
https://bibliotekanauki.pl/articles/27322619.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
signal-to-noise ratio
asymmetric real Laplace wavelet
bandpass filter
particle swarm optimization
spectral kurtosis
fault frequency
Opis:
Rotating element bearings are the backbone of every rotating machine. Vibration signals measured from these bearings are used to diagnose the health of the machine, but when the signal-to-noise ratio is low, it is challenging to diagnose the fault frequency. In this paper, a new method is proposed to enhance the signal-to-noise ratio by applying the Asymmetric Real Laplace wavelet Bandpass Filter (ARL-wavelet-BPF). The Gaussian function of the ARL-wavelet represents an excellent BPF with smooth edges which helps to minimize the ripple effects. The bandwidth and center frequency of the ARL-wavelet-BPF are optimized using the Particle Swarm Optimization (PSO) algorithm. Spectral kurtosis (SK) of the envelope spectrum is employed as a fitness function for the PSO algorithm which helps to track the periodic spikes generated by the fault frequency in the vibration signal. To validate the performance of the ARL-wavelet-BPF, different vibration signals with low signal-to-noise ratio are used and faults are diagnosed.
Źródło:
Archives of Control Sciences; 2023, 33, 3; 589--606
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of DFT-S-OFDM waveform for Li-Fi systems
Autorzy:
Hussin, S.
Shalaby, E. Mansour
Powiązania:
https://bibliotekanauki.pl/articles/2063891.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
light-fidelity
visible light communications
orthogonal frequency division multiplexing
discrete Fourier transform spread
peak-to-average power ratio
Opis:
In this paper, the effect of an indoor visible light communication channel is studied. Moreover, the analysis of the received power distribution of the photodiode in the line of sight and the first reflection of the channel without line of sight with several parameters is simulated. Two different waveforms are explained in detail. Orthogonal frequency division multiplexing has been widely adopted in radio frequency and optical communication systems. One of the most important disadvantages of the orthogonal frequency division multiplexing signal is the high peak-to-average power ratio. Therefore, it is important to minimize the peak-to-average power ratio in the visible light communication systems more than in radio-frequency wireless applications. In the visible light communication systems, the high peak-to-average power ratio produces a high DC bias which reduces power efficiency of the system. A discrete Fourier transform spread orthogonal frequency division multiplexing is proposed to be used in wireless communication systems; its ability to minimize peak-to-average power ratio has been tested. The analysis of two different subcarrier allocation methods for the discrete Fourier transform-spread subcarriers, as well as the examination of two distinct subcarrier allocation strategies, distributed and localized mapping, are investigated and studied. The effects of an accurate new sub-band mapping for the localized discrete Fourier transform spread orthogonal frequency division multiplexing scheme are presented in this paper. The light-fidelity system performance of the orthogonal frequency division multiplexing and discrete Fourier transform spread orthogonal frequency division multiplexing with different sub-mapping techniques are simulated with Matlab™. A system performance size of bit error rate and peak-to-average power ratio are obtained, as well.
Źródło:
Opto-Electronics Review; 2021, 29, 4; 167--174
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance evaluation of UFMC-based VLC systems using a modified SLM technique
Autorzy:
Mansour Shalaby, E.
Dessouky, M.
Hussin, S.
Powiązania:
https://bibliotekanauki.pl/articles/1818194.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
universal filtered multi-carrier
orthogonal frequency division
multiplexing
peak-to-average power ratio
selected-mapping
discrete Hartley transform precoding
Opis:
Universal filtered multi-carrier (UFMC) is being studied as the favourable waveforms supporting the visible light communication broadcasting systems. However, the UFMC system faces a serious performance degradation on the transmitter side due to its high peak-to-average power ratio (PAPR). High PAPR of the signal is an analytical intention parameter for mobile networks, and it is necessary to minimize it as much as possible. This paper focuses on the PAPR reduction of the UFMC scheme. An efficient hybrid method of the PAPR reduction has been proposed and analysed through the Matlab™ simulation. The proposed hybrid scheme consists of a mixture of the selected-mapping method and the discrete Hartley transform precoding for a UFMC system (SLM-DHT-P-UFMC). The simulation results show that the proposed hybrid system has a better PAPR reduction performance compared to traditional SLM-UFMC and DHT-P-UFMC systems. Hence, LM-DHT-P-UFMC is considered to be the suggested scheme in visible light communication broadcasting systems.
Źródło:
Opto-Electronics Review; 2021, 29, 3; 85--90
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance evaluation of UFMC-based VLC systems using a modified SLM technique
Autorzy:
Mansour Shalaby, E.
Dessouky, M.
Hussin, S.
Powiązania:
https://bibliotekanauki.pl/articles/1818201.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
universal filtered multi-carrier
orthogonal frequency division
multiplexing
peak-to-average power ratio
selected-mapping
discrete Hartley transform precoding
Opis:
Universal filtered multi-carrier (UFMC) is being studied as the favourable waveforms supporting the visible light communication broadcasting systems. However, the UFMC system faces a serious performance degradation on the transmitter side due to its high peak-to-average power ratio (PAPR). High PAPR of the signal is an analytical intention parameter for mobile networks, and it is necessary to minimize it as much as possible. This paper focuses on the PAPR reduction of the UFMC scheme. An efficient hybrid method of the PAPR reduction has been proposed and analysed through the Matlab™ simulation. The proposed hybrid scheme consists of a mixture of the selected-mapping method and the discrete Hartley transform precoding for a UFMC system (SLM-DHT-P-UFMC). The simulation results show that the proposed hybrid system has a better PAPR reduction performance compared to traditional SLM-UFMC and DHT-P-UFMC systems. Hence, LM-DHT-P-UFMC is considered to be the suggested scheme in visible light communication broadcasting systems.
Źródło:
Opto-Electronics Review; 2021, 29, 3; 85--90
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise effect on parameters of quiet sonar with code modulation
Autorzy:
Salamon, Roman
Marszal, Jacek
Jedel, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/24201997.pdf
Data publikacji:
2023
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
silent sonar
maximum length sequence
signal-to-noise ratio
frequency modulation
cichy sonar
sekwencje o maksymalnej długości
stosunek sygnału do szumu
modulacja częstotliwości
Opis:
Earlier publications of the paper authors have shown that the use of code keying mixed with the CW FM sound signal allows the significant reduction in the distance measurement error, compared to classic silent CW FM sonar. In addition to the code modulation parameters, the magnitude of this error is influenced by the received input acoustic noise. The article shows the dependence of the input signal-to-noise ratio and the sound signal parameters on the target distance measurement error and the detection conditions, such as the output signal-to-noise ratio and the side lobe level. The results of the analysis were compared to the same parameters of the CW FM silent sonar without code modulation.
Źródło:
Vibrations in Physical Systems; 2023, 34, 1; art. no. 2023109
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakterystyka dynamiczna mostu drogowego wykonanego z polimerowych kompozytów włóknistych FRP
Dynamic characterisation of road bridge made of fibre reinforced polymer composites
Autorzy:
Siwowski, T.
Rajchel, M.
Kaleta, D.
Powiązania:
https://bibliotekanauki.pl/articles/105158.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
współczynnik dynamiczny
częstość drgań własnych
współczynnik tłumienia
przęsło mostu
kompozyt FRP
badania mostu
dynamic coefficient
natural frequency
damping ratio
bridge superstructure
FRP composite
bridge test
Opis:
Przęsło kompozytowe mostu drogowego ma zazwyczaj wysoki stosunek obciążeń ruchomych do stałych (ciężaru własnego), co czyni je znacznie bardziej wrażliwym na oddziaływanie poruszających się pojazdów niż mosty konwencjonalne ze stali i betonu. To m.in. powoduje, że charakterystyka dynamiczna przęseł mostów kompozytowych jest obecnie jednym z najważniejszych aspektów, koniecznych do analizy w procesie projektowania, budowy i eksploatacji mostów kompozytowych. W badaniach dynamicznych obiektu mostowego jego charakterystykę otrzymuje się zazwyczaj z bezpośredniego pomiaru przyśpieszeń, odkształceń lub przemieszczeń określonych punktów konstrukcji, wymuszonych w czasie rzeczywistym przez poruszające się po nim z różną prędkością pojazdy. Ta metoda została zastosowana również w badaniach pierwszego polskiego mostu drogowego, którego zarówno dźwigary główne jak i płytę pomostu wykonano z kompozytów FRP. Na podstawie pomiarów przemieszczeń wybranych punktów przęsła pod wpływem obciążenia przejeżdżającymi pojazdami wyznaczono podstawowe charakterystyki dynamiczne mostu: współczynniki dynamiczne, częstości drgań własnych oraz współczynnik tłumienia. Otrzymane wartości potwierdziły właściwe parametry dynamiczne mostu kompozytowego w świetle wymagań stawianych drogowym obiektom mostowym w Polsce.
In the first decade of XXI century the new structural material, fibre reinforced polymer composites (FRP), promulgate remarkably in bridge engineering. FRP composite bridge superstructure characterizes usually the high live load / dead load ratio, which makes FRP bridges more sensitive to moving vehicles than conventional bridges. Therefore the dynamic characterization of FRP superstructure has become recently one the most important issues in its design, construction and maintenance. Dynamic characterization of a bridge is usually identified by direct measurement of accelerations, strains or displacements in relevant structural points, induced by moving vehicles with various velocities. This method has been applied in the dynamic test of the first Polish allcomposite bridge. On the basis of displacements measurement in relevant points of the FRP superstructure during bridge loading the basic dynamic parameters have been identified: dynamic coefficients, natural frequencies and damping ratio. The values established during the test confirmed the FRP composite bridge has the adequate dynamic characterization according to the Polish requirements for road bridges.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2017, 64, 2/I; 227-238
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of a high-speed hybrid OAM-OFDM-MDM multiplexed coherent FSO system under desert conditions
Autorzy:
Sinha, Shivaji
Kumar, Chakresh
Powiązania:
https://bibliotekanauki.pl/articles/27310107.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
atmospheric attenuation
bit error rate
BER
orbital angular momentum
OAM
optical signal-to-noise ratio
OSNR
orthogonal frequency division multiplexing
OFDM
quadrature amplitude modulation
QAM
transmission range
Opis:
To meet the needs of future wireless optical networks, this paper introduces a high-speed, hybrid multiplexed, coherent free-space optical (FSO) communication system that integrates an orbital angular momentum (OAM) multiplexed signal with an orthogonal frequency division multiplexing (OFDM) technique. Two independent QAM polarized beams, each carrying in-phase and quadrature (I/Q) phase 16-QAM-OFDM modulated data, are combined using mode division multiplexing (MDM) to increase the capacity of the proposed system. The reason of choosing OFDM is its capability to support higher data rate, and mitigating intersymbol interference (ISI). The signal is detected using a coherent detection-based digital signal processing (DSP) algorithm at the receiver end. The proposed hybrid FSO system is evaluated in low and heavy dust environments using bit error rate (BER), link distance, optical signal-to-noise ratio (OSNR), and received optical power performance matrices. The simulation results demonstrate the successful transmission of a 120 Gb/s single carrier over the longest link ranges of 1.5 and 0.40 km, respectively, under low and heavy dust weather environments below the signal degradation threshold value (forward error correction (FEC) limit) of BER 2.2 × 10–3 in strong turbulent conditions.
Źródło:
Optica Applicata; 2023, 53, 3; 431--445
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 17

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