American University in Cairo

About: American University in Cairo is a education organization based out in Cairo, Egypt. It is known for research contribution in the topics: Population & Context (language use). The organization has 2472 authors who have published 5339 publications receiving 73741 citations.

Noncoherent Backscatter Communications Over Ambient OFDM Signals

Abstract: In recent years, ambient backscatter communications have gained a lot of interests as a promising enabling technology for the Internet-of-Things and green communications. In ambient backscatter communication systems, ultra-low power devices are able to transmit information by backscattering ambient radio-frequency signals generated by legacy communication systems such as Wi-Fi and cellular networks. This paper is concerned with ambient backscatter communications over legacy orthogonal frequency division multiplexing (OFDM) signals. We propose a backscatter modulation scheme that allows backscattering devices to take advantage of the spectrum structure of ambient OFDM symbols to transmit information. The proposed modulation scheme allows both binary and higher-order modulation using noncoherent energy detection. We investigate the detector design and analyze the error performance of the proposed scheme. We provide an exact expression for the error probability for the binary case, whereas accurate approximate expressions for the error probability are derived for the $M$ -ary case. We corroborate our analysis using Monte–Carlo simulation and investigate the effects of varying the OFDM symbol size, maximum channel delay spread, and the number of receive antennas on the error performance. Our numerical results show that the proposed technique outperforms other techniques available in this paper for backscatter communication over ambient OFDM signals in different scenarios.

Arab Citizen Journalism in Action: Challenging Mainstream Media, Authorities and Media Laws

Abstract: Arab citizens have adopted the blogging technology of the internet to create a venue for alternate viewpoints in a manner similar to their global counterparts. Initially a handful of bloggers, writing mostly in English and reflecting a Western flavour in their content, initiated the Arab blogosphere. They have since been joined by thousands of Arabic blogs. Their impact has been noted, whether directly on politics and media or in their ability to enable civil society by providing instant networking and expanding the space for freedom of expression. They have also created an unexpected challenge to their governments, causing inconsistent reactions. This article analyzes the region’s laws, regulations and the methods used to govern those nationals who choose to join the growing number of global citizen journalists, and how they often learn to defy those rules. The primary focus has been the case of Egypt’s blogs due to their influential role in the regional blogosphere.

KP-Miner: Participation in SemEval-2

Abstract: This paper briefly describes the KP-Miner system which is a system developed for the extraction of keyphrases from English and Arabic documents, irrespective of their nature. The paper also outlines the performance of the system in the "Automatic Keyphrase Extraction from Scientific Articles" task which is part of SemEval-2.

Compliance with International Accounting Standards in a national context: some empirical evidence from the Cairo and Alexandria Stock Exchanges

Abstract: The contribution of this paper is to provide evidence, from a sample of 281 listed companies, about Egyptian convergence to international accounting. We construct indices to measure both disclosure and measurement/presentation convergence, and the impacts of education and training, tax, and three company characteristics on compliance. Compliance, which is low, is associated with the volume of trading in company stocks, but not with industry sector or legal status. The findings suggest weak enforcement, and a need for education and training of accountants, and the removal of adverse tax implications for companies if increased convergence is to be achieved.