Distributed applications are nowadays seen in abundance due to the performance enhancements they introduce. One common architecture used for such applications is the peertopeer architecture. In a peertopeer system, multiple independent hosts cooperate together to perform a particular task without the need for a centralized server. There are several examples of distributed applications? one of which is a chat application that will be presented in this paper.
Cloud computing adoption is increasing to cover massive services on the internet including social media applications.Users prefer to perform all their tasks on portable smart devices rather than using their computers. As the number of the smarts devices is increasing rapidly over the world, guidelines for performing cloud forensics should be developed to allow investigators to identify and locate the useful artifacts from cloud applications installed on the smart devices. In this research, the Snapchat was examined on Android platform and a set of proposed guidelines were presented to identify, locate, and analyze the useful artifacts that can be recovered from smart devices. These artifacts hold a detailed information about the suspect device which includes location, contacts, and activities data. The examination and testing process was conducted by performing multiple activities and taking multiple physical images for the test device then identifying the changes among them from the entire image
Visible light communications (VLC) systems are expected to provide remarkably high speed indoor communications and support ubiquitous connectivity. The key limitation in VLC systems is the narrow modulation bandwidth of the light sources. Nonorthogonal multiple access (NOMA) has been recently proposed for enhancing the spectral efficiency of indoor downlink VLC systems. In this paper, we evaluate the biterrorrate (BER) performance of NOMAVLC where we derive a novel closedform BER expression that explicitly takes cancellation errors and interference terms into account. The obtained analytical results are corroborated by respective results from extensive Monte Carlo simulations and are used to provide useful insights on the performance of NOMAVLC systems.
Nanosized devices operating inside the human body open up new prospects in the healthcare domain. In vivo wireless nanosensor networks (iWNSNs) will result in a plethora of applications ranging from intrabody healthmonitoring to drugdelivery systems. With the development of miniature plasmonic signal sources, antennas and detectors, wireless communications among intrabody nanodevices will expectedly be enabled in the Terahertz Band (0.110 THz). In this paper, a rigorous channel model for intrabody communication in iWNSNs is developed. The total path loss is computed by taking into account the combined effect of the spreading of the propagating wave, molecular absorption from human tissues, as well as scattering from both small and large body particles. The overall attenuation model of intrabody THz propagation facilitates the accurate design and practical deployment of iWNSNs.
Cognitive radio (CR) networks offer a great advantage to secondary users (SUs) by allowing them to exploit the unused spectrum of primary users (PUs) on an opportunistic basis. However, it is more challenging to deliver video services over dynamic CR channels that are available to SUs not only intermittently but with all the challenges of wireless channels. In this paper, two video streaming schemes that integrate channel allocation and scheduling algorithms with adaptive modulation and scalable source coding techniques are devised to adapt to the variations in the channel conditions and the dynamics of the SUs playback buffers. This in turn resulted in efficient usage of the available CR resources as demonstrated in the achieved PSNR of the reconstructed video streams with no interruptions in the playback process.
Precoding is a spectrally efficient approach to improve the immunity of orthogonal frequency division multiplexing (OFDM) systems in frequencyselective multipath fading channels. However, the performance of precoded OFDM (POFDM) is usually evaluated under the assumption of perfect channel estimation and synchronization conditions. Therefore, the aim of this work is to evaluate the performance of POFDM in the presence of carrier frequency offset (CFO). The considered precoding in this work is based on the WalshHadamard transform (WHT). We observe that the signaltointerference plus noise ratio (SINR) of POFDM substantially changes based on the subcarrier index, which is not the case for conventional OFDM systems.
This paper addresses the impact of art exhibitions based in Dubai, particularly on tourism. Today, there is a growing demand towards the Emirate of Dubai as a cultural destination that could play an essential role in improving and generating creative sustainability in MENA and the Gulf region. The primary intent is to discuss the existed validity of the art movement in the city, as a practical approach, in motivating and developing creative entrepreneurship. As a descriptive case study, this paper reflects also the interpretation of artdisplaying and creative resources in Dubai in order to maintain the role of communication within a "reallife" context for the purpose of circulating the region's creative and cultural values.
This study aimed at exploring the perceived and the actual written feedback preferences of EFL students and teachers in the UAE. To achieve this aim a convergent parallel mixedmethod research design was employed. Teachers of cycle 3 (n=67) and eleventh grade students (n=116) in public schools participated in this study. Results of the study revealed that there were more similarities than variations among the teachers and students' feedback preferences. Moreover, there were some variations among teachers' perceived preferences and their actual practices of feedback provision. Furthermore, the students' preferences aligned with their teachers actual practices. Additionally, when interviewed, teachers revealed some factors that affect the use of feedback, such as schools' orientations regarding feedback, students' proficiency and the nature of tasks and objectives. Students viewed direct correction as viable option for them but it is not necessary needed with easy and simple tasks errors.
As a critical branch of Social Sustainability studies, human dimensions of the urban spaces in national housing neighborhoods of Dubai is studied in this paper, by focusing on the role of "Neighborhood Centers". In another word, considering the role of the neighborhood centers, the way a neighborhood can treat the social life and wellbeing of its residents is discussed. The discussion is followed by an investigation aiming to figure out the extent to which the Dubai's development trend approaches the social viability and liveliness of neighborhoods, and the city's social sustainability and life quality standards in general. For this purpose, a conceptual framework consists of the principles reflecting the social sustainability condition within urban spaces is prepared. Accordingly, a set of indicators are set based on which the physical and spatial attributes and characteristics of the neighborhood and its center is observed and studied, and therefore evaluated from this perspective.
Over the last decades the scientific community has invested a lot of effort in studying and explaining photocatalytic processes. One of its many uses is the rather unselective oxidation of different organic compounds present in effluents. In our study we have used 0.8% nitrogen doped TiO2 as catalyst that when activated by irradiation promotes the formation of highly oxidative radicals. One of the main features of this process is the ability to remove even trace amounts of pollutants, being extremely interesting the possibility of using photocalysis as a secondary treatment, using the effluent of a biological process as an input for the photocatalytic process. This paper studies the photocatalytic treatment of an effluent of an eMBR system under visible radiation. The photocatalytic treatment of untreated grey water under visible radiation is also targeted. In both cases the reactivity is tested in the presence of oxygen and ozone.
