Analysis of cyclic prefix length effect on ISI limitation in OFDM system over a Rayleigh-fading multipath

In this work, the influence of the cyclic prefix on the performance of the OFDM system is studied. We worked out an OFDM transceiver using a 16 QAM modulation scheme, a comparison of the BER for various lengths of the cyclic prefix has been achieved, and the influence of the noise introduced in the channel has been highlighted, for both a Gaussian and Rayleigh noise. The simulation was carried out on MATLAB where the curves of the BER for various lengths of the cyclic prefix are given and compared. We also adopted as a metric the QAM constellation to show the dispersion of the carriers as a consequence of the transmission channel, the mitigation of this effect by the CP is noticeable

G-Shaped Antenna Mounted On USB Dongle Optimized For MIMO Applications Under WLAN 5.2/5.8/5.9

In this study, we used a G-shaped antenna due to its ease of integration into the overall design. The basic structure was adapted from a model proposed by W.-C. Liu. Then, we integrated it into a USB dongle, then added another antenna element to use it for MIMO applications in WLAN networks. A neutralization line is added between these two antenna elements to increase insulation

Analytical model for life time in wirless sensor networks

Numerous analytical models have been proposed to evaluate the performance of wireless sensor networks, therefore, analytical models providing a clear understanding of the fundamental limitations of different systems, as well as a convenient way to review their performance and optimize their parameters are necessary. In this paper, we propose an analytical framework model that defines the performance of a sensor network, with an emphasis on an analytic model that is based on the lifetime, the offered traffic, and the maximum number of retransmissions Kmax

Big Data at the service of teaching and scientific research within the UAE

With the emergence of the digital world, data access has become an action as quick and direct that many questions arise about the reliability and value of information. However, the data returned by the online search engines are based on an open and massive environment, which include data of any type, which come from different sources of information. Indeed, in the field of education and especially when using online search, the learner is left with a set of heterogeneous information that does not exist in an orderly format and are not easy to consume. This aspect of data variety represents the second V in the design of the Big Data phenomenon. With the aim to support learners in their search for information, it is proposed to design a specialized structuring tool to combine process and classify the variety of these massive data so they can provide the best result to the learner. The present article deals with the descriptive study of the current state of using online search by UAE's students, and the proposal to explore new methods and approaches through experimentation of our solution for open and massive data environment, in order to enhance learning and scientific research in the UAE

Rapid detection of diabetic retinopathy in retinal images: a new approach using transfer learning and synthetic minority over-sampling technique

The challenge of early detection of diabetic retinopathy (DR), a leading cause of vision loss in working-age individuals in developed nations, was addressed in this study. Current manual analysis of digital color fundus photographs by clinicians, although thorough, suffers from slow result turnaround, delaying necessary treatment. To expedite detection and improve treatment timeliness, a novel automated detection system for DR was developed. This system utilized convolutional neural networks. Visual geometry group 16-layer network (VGG16), a pre-trained deep learning model, for feature extraction from retinal images and the synthetic minority over-sampling technique (SMOTE) to handle class imbalance in the dataset. The system was designed to classify images into five categories: normal, mild DR, moderate DR, severe DR, and proliferative DR (PDR). Assessment of the system using the Kaggle diabetic retinopathy dataset resulted in a promising 93.94% accuracy during the training phase and 88.19% during validation. These results highlight the system's potential to enhance DR diagnosis speed and efficiency, leading to improved patient outcomes. The study concluded that automation and artificial intelligence (AI) could play a significant role in timely and efficient disease detection and management

Securing information systems through increasing software quality

it is very obvious that we are living during the last decades an era of information, where the one who controls it makes his hands on an enormous power. One of the most known forms of the use of information is through information systems. These Systems tend to collect, process and produce information from raw data. These information systems take many forms and play a major role in the success of not only individuals and organizations but even whole governments. Consequently, information systems are open for continuous attacks and threats that may damage the quality of information that they are producing. For this reason, we are discussing in this paper the different aspects and criteria for considering a good information system, particularly from a security point of view. Then we focus our efforts on increasing information security inside information systems through proving the existence of the relationship between software quality and information systems’ security. Finally we discuss how software quality can be increased in order to secure information systems from deficiencies

Ensuring Data Integrity for Big Data Security in a Cloud-Based System

after its emergence, the web 2.0 has affected all areas of new technology. A large number of original concepts and innovative applications continue to appear every day, such as social networks, blogs, etc, which has crowded the web by a large amount of data, variable and characterized by an impressive creation speed. We call them big data and which we can consider as a very rich and interesting basis for decision-making. Cloud computing is considered as a fast-growing technology which is increasingly becoming an important tool, especially in the business field. The relationship between big data and cloud computing is not novel, many organizations, especially enterprises opted for this combination to support the data processing and management since the cloud computing constitutes a very useful tool to process data as large data sets. However, when we speak about decision support databases, in particular the data warehouse which constitutes the company's gold mine, a large number of enterprises prefer, for safety reasons, to keep it at hand and under control. To resolve this problematic, we propose in this paper a model that allows us to exploit the benefits of the cloud computing, ensuring the data integrity and consequently the big data security in the cloud

Analysis on the effects of the human body on the performance of wearable textile antenna in substrate integrated waveguide technology

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A wearable textile circular ring slot antenna based on a substrate integrated waveguide cavity is presented. In this paper, the focus is on studying and understanding the technical behavior of the SIW textile antenna when located near the human body. Thus, based on the electrical properties of conductive material and the dielectric characteristics of the Felt substrate, a 5.5GHz electro-textile antenna was designed. The proposed antennas are simulated in free space, while the performance of antenna is investigated for on-body condition. The simulated impedance bandwidths of the proposed antenna in free space and on phantom are 120MHz and 110MHz at 5.5GHz respectively. The efficiencies of the antenna at 5.5GHz are 95.8% in free space, and 91.6% on phantom, respectively, meanwhile the gains of that are 8.64dB and 9.35dB, respectively.Peer ReviewedPostprint (author's final draft

Very Thin Dielectric Resonator Antenna For Wireless Communications

In this paper, a very thin rectangular dielectric resonator antenna (Al2O3, εr = 9.8) is presented. A strip connected to a probe is used as feed mechanism. Moreover, at the dielectric resonator antenna back and top faces we have placed parasite strips to excite new resonances. The proposed antenna exhibit compact dimensions (0.9 x 8 x 7 mm3), very wide band (50.89%), good performances and a maximum gain of about 10.86 dBi. The dielectric resonator antenna performances is simulated on Ansoft HFSS and CST microwave studio