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Wyszukujesz frazę "Abed, H. S." wg kryterium: Autor


Wyświetlanie 1-2 z 2
Tytuł:
Implementation of Selected Spectrum Sensing Systems for Cognitive Radio Networks using FPGA Platform
Autorzy:
Abdullah, H. N.
Abed, H. S.
Powiązania:
https://bibliotekanauki.pl/articles/958080.pdf
Data publikacji:
2018
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
cognitive radio
energy consumption
energy detection
FPGA
Opis:
The energy efficient spectrum sensing method is very important in cognitive radio (CR), since high power drain may limit its implementation in mobile applications. The spectrum sensing feature consumes more energy than other functional blocks, as it depends on continuous detection of the presence or absence of the primary user (PU). In this paper, we proposed two methods to reduce energy consumption of the spectrum sensing feature. The first is of a single stage variety with a reduced number of sensed samples. The other uses two stages. The first stage performs coarse sensing for many subchannels, and the best subchannel is forwarded for fine sensing in the second stage. The performance of the proposed methods is evaluated in AWGN channel and compared with the existing approach. The proposed methods are simulated using Matlab and ModelSim and are then hardware implemented using the Altera Cyclone II FPGA board. Simulation results show that the proposed methods offer an improvement in energy consumption with an acceptable reduction in the probability of detection. At Eb/N0 Eb/N0 Eb/N0 of 0 dB, the energy consumption is reduced by 50% and 72% in the first and second proposed method, respectively, compared to the traditional method (100% sensing).
Źródło:
Journal of Telecommunications and Information Technology; 2018, 4; 81-87
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rare-earth and trace elements of the lower Cambrian–Lower Cretaceous siliciclastic succession of NE Gondwana in Jordan : from provenance to metasomatism
Autorzy:
Amireh, Belal S.
Saffarini, Ghazi A.
Amaireh, Mazen N.
Jarrar, Chaleb H.
Abed, Abdulkader A.
Powiązania:
https://bibliotekanauki.pl/articles/2134835.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Jordan
NE Gondwana
rare-earth and trace elements
fractionation
provenance proxies
Arabian-Nubian Shield
siliciclastics
Opis:
The present bulk-rock geochemical study aims to answer some questions concerning the distribution and variability of trace elements (TEs) and rare earth elements (REEs) in the lower Cambrian–Lower Cretaceous sandstones and mudstones of NE Gondwana in Jordan. The study proved that the REE and the TE distribution patterns in both detrital and authigenic, light and heavy minerals are controlled principally by the source-rock provenance, followed by an interplay of many factors: chemical weathering, recycling, hydraulic sorting, locally low-temperature, hydrothermal metasomatism, depositional environment and redox conditions, and diagenesis. On the basis of specific trace elements, trace-element ratios, and petrographic proxies, the provenance is constrained to be mainly felsic-, rarely mafic granitoids of the Arabian-Nubian Shield, and less commonly, recycled Palaeozoic and Mesozoic siliciclastic strata. REEs are hosted mainly in zircon, Ti-bearing minerals, and partly in clay minerals. They were depleted by both chemical weathering and recycling; nevertheless, they were enriched by subsequent hydraulic sorting and low-temperature, hydrothermal metasomatism. Chemical weathering initially depleted zirconium. However, this was counteracted by subsequent enrichment through recycling, hydraulic sorting, and low-temperature, hydrothermal metasomatism. The fractionation of the other TEs, due to these sedimentological factors during the genesis of subarkosic arenites, quartz arenites and mudstones, is discussed and some conclusions are derived. The Eu negative anomaly was enhanced significantly by recycling and low-temperature, hydrothermal metasomatism. Scandium abundance increased with decreasing grain size from coarse sand to the mud fraction. The recorded REE and TE fractionation might also apply to siliciclastics in similar, geological environments.
Źródło:
Annales Societatis Geologorum Poloniae; 2022, 92, 2; 109--158
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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