Browsing by Author "El Shafie, Ahmed"
Now showing items 21-28 of 28
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Security-Enhanced SC-FDMA Transmissions Using Temporal Artificial-Noise and Secret Key Aided Schemes
Marzban, Mohamed F.; El Shafie, Ahmed; Al-Dhahir, Naofal; Hamila, Ridha ( Institute of Electrical and Electronics Engineers Inc. , 2019 , Article)We investigate the physical-layer security of uplink single-carrier frequency-division multiple-access (SC-FDMA) systems. Multiple users, Alices, send confidential messages to a common legitimate base-station, Bob, in the ... -
Spectrum-aggregating cognitive multi-antenna user with multiple primary users
El Shafie, Ahmed; Khattab, Tamer ( Institute of Electrical and Electronics Engineers Inc. , 2014 , Conference Paper)We investigate a cognitive radio scenario involving a single cognitive transmitter equipped with K antennas sharing the spectrum with M primary users (PUs) transmitting over orthogonal bands. Each terminal has a queue to ... -
Synthesis and Application of Cobalt Oxide (Co3O4)-Impregnated Olive Stones Biochar for the Removal of Rifampicin and Tigecycline: Multivariate Controlled Performance
El-Shafie, Ahmed S.; Ahsan, Insharah; Radhwani, Mohamed; Al-Khangi, Mohammed Ali; El-Azazy, Marwa ( MDPI , 2022 , Article)Cobalt oxide (Co3O4) nanoparticles supported on olive stone biochar (OSBC) was used as an efficient sorbent for rifampicin (RIFM) and tigecycline (TIGC) from wastewater. Thermal stabilities, morphologies, textures, and ... -
Throughput maximization via adjusting packet size of a buffered cognitive radio user
El Shafie, Ahmed; Khattab, Tamer ( Institute of Electrical and Electronics Engineers Inc. , 2014 , Conference Paper)In this paper, we investigate a cognitive scenario with one secondary user and one primary user. Users are assumed to be buffered terminals. Each user has certain arrival rate with certain packet size. We propose a scheme ... -
Throughput of a cooperative energy harvesting secondary user in cognitive radio networks
El Shafie, Ahmed; Khattab, Tamer ( Wiley Blackwell , 2016 , Article)This paper investigates the maximum throughput of a rechargeable secondary user (SU) sharing the spectrum with a primary user (PU). The SU is assumed to be an energy harvesting node, which harvests energy packets from the ... -
Transmit and receive cooperative cognition: Protocol design and stability analysis
El Shafie, Ahmed; El-Keyi, Amr; Khattab, Tamer; Nafie, Mohamed ( IEEE Computer Society , 2013 , Conference Paper)In this paper, we investigate the stability of a cooperative cognitive system. We propose a cooperative secondary transmitter-receiver system (CSTR), where, the secondary transmitter (ST) and the secondary receiver (SR) ... -
Utilization of 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) for spectrochemical determination of L-ornithine: A multivariate optimization-assisted approach
Aly, Hend; El-Shafie, Ahmed S.; El-Azazy, Marwa ( Royal Society of Chemistry , 2019 , Article)A simple and highly sensitive univariate calibration strategy based on ultraviolet-visible (UV-Vis) absorption spectroscopy and assisted by multivariate screening and optimization was utilized for the determination of ... -
Wiretap TDMA Networks with Energy-Harvesting Rechargeable-Battery Buffered Sources
El Shafie, Ahmed; Al-dhahir, Naofal; Ding, Zhiguo; Duong, Trung Q.; Hamila, Ridha ( IEEE , 2019 , Article)We investigate the physical-layer security of an uplink wireless time-division multiple-access channel with energy-harvesting source nodes. We consider a set of source nodes equipped with rechargeable batteries and information ...