Ahmed S. Mansour

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OBJECTIVE The purpose of this study was to test the retention of metal copings fabricated to fit on the one-groove, one flat-sided solid titanium abutment using six different cements. MATERIALS AND METHODS Ten hollow screw 3.8 mm ITI implants were mounted in acrylic resin blocks. A solid titanium abutment was placed on each implant and torqued at 35 Ncm.(More)
This paper considers a three-receiver broadcast channel with degraded message sets and message cognition. The model consists of a common message for all three receivers, a private common message for only two receivers and two additional private messages for these two receivers, such that each receiver is only interested in one message, while being fully(More)
We study the transmission of a common message and three confidential messages over a broadcast channel with two legitimate receivers and an eavesdropper. Each legitimate receiver is interested in decoding two of the three confidential messages, while having the third one as side information. In order to measure the ignorance of the eavesdropper about the(More)
We study secure communication in which two confidential messages are transmitted over a broadcast channel to two legitimate receivers, while keeping an eavesdropper ignorant. Each legitimate receiver is interested in decoding one confidential message, while having the other one as side information. In order to measure the secrecy of the communication, we(More)
A series of pyrazolo[1,5-a]pyrimidine, triazolo[1,5-a]pyrimidine, and pyrimido[1,2-a]benzimidazole ring systems incorporating phenylsulfonyl moiety were synthesized via the reaction of 3-(N,N-dimethylamino)-1-aryl-2-(phenylsulfonyl)prop-2-en-1-one derivatives 2a,b with appropriate nitrogen nucleophiles. The analgesic and anti-inflammatory activities of the(More)
We study secure communication in which a transmitter wants to send confidential messages to an arbitrary number of receivers in the presence of an external eavesdropper. We consider two classes of Gaussian channels: the Gaussian single-input single-output (SISO) multi-receiver wiretap channel and the degraded Gaussian multiple-input multiple-output (MIMO)(More)
In this paper, secure communication over a broadcast channel with multiple legitimate receivers and an external eavesdropper is investigated. Two different secrecy measures are considered. The first criterion is a conservative one known as joint secrecy, where the mutual leakage of all confidential messages must be small. The second criterion is a less(More)
The Upper Cretaceous was a period when reefs and reef mounds were abundant in many parts of the world (JAMES, 1983). One of the most remarkable features of the Cretaceous carbonate platforms in tropical and subtropical environments of the Tethyan realm, was the development of facies complexes dominated by rudists, with or without associated corals (MASSE &(More)
We study a secure communication scenario in which the channel is under two classes of attacks at the same time: a passive eavesdropper and an active jammer. This scenario is modelled using the arbitrarily varying wiretap channel (AVWC), in which the channel varies from one channel use to the other. It has been shown that in general reliable communication(More)