Hard Decision Cooperative Spectrum Sensing Based on Estimating the Noise Uncertainty Factor

Spectrum Sensing (SS) is one of the most challenging issues in Cognitive Radio (CR) systems. Cooperative Spectrum Sensing (CSS) is proposed to enhance the detection reliability of a Primary User (PU) in fading environments. In this paper, we propose a hard decision based CSS algorithm using energy detection with taking into account the noise uncertainty effect. In the proposed algorithm, two dynamic thresholds are toggled based on predicting the current PU activity, which can be successfully expected using a simple successive averaging process with time. Also, their values are evaluated using an estimated value of the noise uncertainty factor. These dynamic thresholds are used to compensate the noise uncertainty effect and increase (decrease) the probability of detection (false alarm), respectively. Theoretical analysis is performed on the proposed algorithm to deduce its enhanced false alarm and detection probabilities compared to the conventional hard decision CSS. Moreover, simulation analysis is used to confirm the theoretical claims and prove the high performance of the proposed scheme compared to the conventional CSS using different fusion rules.Comment: 5 pages, 4 figures, IEEE International Conference on Computer Engineering and Systems (ICCES 2015). arXiv admin note: text overlap with arXiv:1505.0558

Postmodern Analysis of New Preachers of Islam in Egypt: A Cultural Study of Mustafa Hosni's Digital Media Platforms

In recent years, Arab academia inspected the phenomenon of new preachers of Islam, especially in Egypt, predicted on such notions as new liberalism, self-help, and salvation. This study contributes to the scholarship by examining the postmodern characteristics of Mustafa Hosni’s discourse, as appears in his new media materials. Drawing upon insights from media cultural studies, the paper examines the mini-narratives of a tolerant, non-violent Muslim discourse as opposed to the customarily hostile Muslim meta-narratives. Further, the study analyses all sorts of pastiche that render Hosni’s discourse hybrid, glocal, and coexistent. It uses qualitative discourse analysis to shed light on the nexus between forms of religious discourse and the logic of media consumption in Muslim late neo-liberal capitalism

A tutorial system for studying chromatography techniques

The goal of this project is to use the Generic Tutorial System for the Sciences (GTSS) tools to develop a prototype interactive chromatography simulation with the Chrom-Quiz system. This will demonstrate Chrom-Quiz/chromatography integration as a teaching system

Social Semiotics for Social Media Visuals: A Framework for Analysis and Interpretation

The social semiotics approach examines the meaning-making process in order to demonstrate how meaning is constructed in social actions and contexts. The rising interest of researchers in social media and its widespread use in society have both highlighted new challenges for data analysis. Social semiotics can provide a deep understanding of the visual grammar of the social media meaning-making process by assuming that this process is considered a social practice. The main objective of this chapter is to guide researchers and enable them to use the social semiotic approach as a research tool for the analysis of visuals in the social media environment. The chapter introduces the key elements, principles, assumptions, and rules of using the social semiotics approach in the analysis, understanding, and interpretations of social media visuals and how to explore the role played by visual elements in the meaning-making process in a social media within a specific social context

Performance analysis of modified asymmetrically-clipped optical orthogonal frequency-division multiplexing systems

A modification to the Asymmetrically-Clipped Optical Orthogonal Frequency-Division Multiplexing (ACO-OFDM) technique is proposed through unipolar encoding. A performance analysis of the Bit Error Rate (BER) is developed and Monte Carlo simulations are carried out to verify the analysis. Results are compared to that of the corresponding ACO-OFDM system under the same bit energy and transmission rate; an improvement of 1 dB is obtained at a BER of 10-4. In addition, the performance of the proposed system in the presence of atmospheric turbulence is investigated using single-input multiple-output (SIMO) configuration and its performance under that environment is compared to that of ACO-OFDM. Energy improvements of 4 dB and 2.2 dB are obtained at a BER of 10-4 for SIMO systems of 1 and 2 photodetectors at the receiver for the case of strong turbulence, respectively

Integrating identity-based cryptography in IMS service authentication

Nowadays, the IP Multimedia Subsystem (IMS) is a promising research field. Many ongoing works related to the security and the performances of its employment are presented to the research community. Although, the security and data privacy aspects are very important in the IMS global objectives, they observe little attention so far. Secure access to multimedia services is based on SIP and HTTP digest on top of IMS architecture. The standard deploys AKA-MD5 for the terminal authentication. The third Generation Partnership Project (3GPP) provided Generic Bootstrapping Architecture (GBA) to authenticate the subscriber before accessing multimedia services over HTTP. In this paper, we propose a new IMS Service Authentication scheme using Identity Based cryptography (IBC). This new scheme will lead to better performances when there are simultaneous authentication requests using Identity-based Batch Verification. We analyzed the security of our new protocol and we presented a performance evaluation of its cryptographic operationsComment: 13Page

Improving visual SLAM accuracy through deliberate camera oscillations

Visual Simultaneous Localization And Mapping, (VSLAM) algorithms exploit the observation of scene naturally-existing distinct features to infer the camera motion and build a map of a static environment. There is an increasing interest towards building efficient VSLAM algorithms mainly from computational perspectives; however, there may be insufficient clues to solve for SLAM parameters efficiently. In this paper, deliberate camera oscillations are superimposed on the camera main motion (robot motion), mostly in a lateral direction to give sufficient physical clues for the solution. Filtering methods exploit correlation to infer the motion parameters, and since oscillation introduces more local changes, it can enhance the estimation by correlation. Simulation results are presented showing the effects of oscillation parameters on visual SLAM performance in different motion scenarios. The results showed significant improvement of accuracy for oscillating camera over the steady camera case, and in several cases errors are reduced to less than half its value. These simulation results can be the basis to design a real experimental system