Ahmed Wathik Naji

The effect of weather on free space optics communication (FSO) under tropical weather conditions and a proposed setup for measurement

Free Space Optics communications (FSO) has attracted a lot of attention for a variety of applications in telecommunications field. The unlicensed, higher speed, broader and unlimited bandwidth, low cost solutions, and shortest deployment time frame are some of the drive to deploy FSO. However, weather attenuation has a big impact on the transmission line of FSO. There are a lot of studies and experiments have been done on FSO in the temperate climate region where the attenuation due to snow and fog are the two major problems in the deployment of FSO. However, there are no comprehensive study is done for the deployment of FSO in the tropical climate region where the rain and haze are present throughout the year. The objective of this paper is to produce analysis result of the different weather attenuations that have effect on FSO link. The parameters are attenuation due to geometric, molecular, atmospheric, rain, haze, and scintillation. The parameters are used to evaluate link availability of the FSO link. The result of the evaluation can provide more knowledge on the feasibility of FSO deployment under tropical weather condition especially for a long range link.

Development of an Arabic text-to-speech system

Research on Text-to-speech technology has received the interest of professional researchers in many languages which is a consequence of wide range of applications where Text-To-Speech is implemented. However, Arabic language, spoken by millions of people as an official language in 24 different countries, gained less attention compared with other languages despite the fact that it has a religious value for more than 1.6 billion Muslim worldwide. These facts exhibit the need for a high quality, small size, and completely free Arabic TTS with the ability of future improvements. The vowelized written text of Arabic language carries the pronunciation rules with limited exceptions, so rule-based system with an exception dictionary for words that fail with those letter-to-phoneme rules may be a much more reasonable approach. This paper is a development of a rule-based text- to- speech Hybrid synthesis system which is a combination formant and concatenation techniques with acceptable naturalness. The simulation results of the system shows good quality in handling word, phrase, and sentence level compared to other available Arabic TTS systems. The accuracy of the overall system is 96%. Further improvements need to be done for stressed syllable position and intonation.

Approved Undetectable-Antivirus Steganography for Multimedia Information in PE-File

The strength of the information hiding science is due to the non-existence of standard algorithms to be used in hiding secret messages. Also there is randomness in hiding methods such as combining several media (covers) with different methods to pass a secret message. In addition, there are no formal methods to be followed to discover the hidden data. For this reason, the task of this paper becomes difficult. In this paper a new method is suggested to hide a file in .EXE file undetectable antivirus system. The aims of this paper is to study the different types of steganography systems, design and implementation of steganography system which embeds information in an .EXE files and proposed system to be undetectable with anti virus softwares and making it imperceptible by any anti-virus software, for the reason that the antivirus programmed consider one of software used to find information hiding inside secret cover file.

Investigating of rain attenuation impact on Free Space Optics propagation in tropical region

Free Space Optics (FSO) is an emerging technology in the area where higher speed and larger bandwidth is required. Technologically, FSO is similar to communication using fiber optic cables. Since the two technologies are similar, they share the same advantages such as higher speed, unlimited bandwidth and protocol independent. However, in term of cost and time for deployment, the cost to deploy FSO is cheaper and the deployment time is shorter since no cable is needed for FSO so the time and cost is reduce significantly. Although FSO has all the advantages of the best quality as communication medium, local weather condition is the drawback of FSO link performance. The aim of this paper is to investigate on this limitation with the focus on atmospheric attenuation on the propagation of FSO signal. General atmospheric attenuation will be discussed and the focus will be on rain. The motivation of this is to develop attenuation model that best represent tropical weather condition.

Effects of rain intensity variation on rain attenuation prediction for Free Space Optics (FSO) links

Free Space Optics (FSO) link have capabilities of providing optical communications similar to fiber optics based communications. However, the operational status of an FSO link is highly weather dependent which hampered the FSO link with feasibility issue. Among the major effect on FSO links under local weather condition is due to attenuation of heavy rainfall. Attenuation due to rainfall can restrict the path length of communication systems at frequencies above 10 GHz. The studies on the effect of rain intensity variation have been proposed by many models based on the radio wave propagation at centimeter or millimeter wavelength. Among the models are Lin Model, Moupfouma Model, Assis Model, Dissanayake and Allnutt Model, ITU Model, Abdulrahman Model and Silva Mello Model. The objective of this research to investigate the effect of rain intensity variation on the rain attenuation prediction for FSO links.

Gateway placement optimisation problem for mobile multicast design in Wireless Mesh Networks

The provision for addressing multiple destinations in group multimedia application delivery over Wireless Mesh Networks (WMN) can be achieved efficiently via multicasting while considering the mobility of Mesh Clients (MC). One of the prominent components of WMN is the Internet Gateway (IGW) which provides wired bridge connection between the backbone network and the Internet. In addition, its cost is significant therefore its placement is one of the main determinants of the overall performance and deployment cost of WMN. This current work explores IGW placement or deployment optimisation for the purpose of incorporation of multicasting and mobility management. Thus, the main focus in this work centres on investigating IGW placement optimisation with the intent of extracting the design issues to answer questions on the appropriateness of the problem formulation and modeling techniques for the optimisation problem. Furthermore, the paper develops the sketch of modeling and formulation of IGW placement problem with the objective of optimising IGW placement while cost of multicast tree and mobility are optimised. This formulation is different from existing works which considers only geographic positioning, load-balancing and interference-based placement. This novel formulation will serve as the basis for IGW placement and selection algorithm to address IGW deployment problem in a mobile multicast WMN architecture.

Stego-Analysis Chain, Session One Investigations on Steganography Weakness vs Stego-Analysis System for Multimedia File

This paper give an overview on hidden data in a different carrier, in particular the paper overview different technique for steganography and giving a brief explain about each one, in order to implements stego-analysis system, this paper highlight the weak on the hidden data technique (disadvantage, weak point, type of attacker, stage of attacking the massage, ..etc). This paper also appoint the name of attackers on the data hidden and the passable way they follow for against that data, the review have gone through the Characterization of Steganography Systems, it also disscuse many features on this area, which it may somehow give proper idea about immplement some stego-analysis systems.

A low-cost first-order sigma-delta converter design and analysis

This paper presents the design and analysis of an interface circuit for MEMS or biomedical sensor applications. This circuitry performs the function of an analog-to-digital converter. A first-order 1-bit sigma-delta (Σ-Δ) analog-to-digital converter is designed and simulated using Silterra 0.13μm CMOS process technology with power supply of 1.2V through Cadence. Then the circuit simulation results are transferred to MATLAB, in order to get the frequency domain power spectral density (PSD). The simulation results on noise and error analysis are compared with those from a traditional analog-to-digital converter to prove that sigma-delta is performing better in the case of weak signals acquisition.

Stego-Analysis Chain, Session Two Novel Approach of Stego-Analysis System for Image File

Stenography systems has too many approaches, it has a lot of applications and different ways, too many type of attackers have been tried to attacked the information that already embed in the carrier, however there is not yet a real stego- analysis system offered, the goal of this chain is to have too many investigations on the stego analysis systems, this paper will focus on the image file, the earlier tests showing that we may use the histogram habits to classify the image in to image carried data hidden and original image, the study will focus in to two main idea, the first idea, on the colour image, the colour start become grouping parallel with the increasing of the data hidden and the second feature on the gray level image, the histogram in the original image was pure without colours, after the embedding method has been applied there are many colour start to appears as shown down in the histogram, we will try through this paper to offer a new stego-analysis system though study the habits of the histogram.

Modeling and characterization of all possible triple pass EDFA configurations

The main purpose of designing multi-stage erbium-doped fiber amplifiers (EDFAs) is to achieve higher gain and lower noise figure for long haul optical communication. Among the multi-stage EDFAs, triple pass EDFAs were chosen in this research. This paper presents all possible triple pass EDFA configurations. The well-established one-stage mathematical models were modified to design two-stage and three-stage triple pass EDFAs. Performances of all the configurations were analyzed with pump power ratio and signal power. Optimum length and Optimum pump power ratio were also determined for each and every configuration. From the performance analysis, best triple pass EDFA was recommended for practical design.