This chapter contains sections titled: Introduction Overview of Multicarrier CDMA Systems Channel Model Performance of MC-CDMA System Performance of Overlapping Multicarrier DS-CDMA Systems Performance of Multicarrier DS-CDMA-I Systems Performance of AMC DS-CDMA Systems Performance of SFH/MC DS-CDMA Systems Chapter Summary and Conclusion 
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Overview of Multicarrier CDMA

Passive optical networks (PONs) are currently evolving into next-generation PONs (NG-PONs) which aim at achieving higher data rates, wavelength channel counts, number of optical network units (ONUs), and extended coverage compared to their conventional counterparts. Due to the increased number of stages and ONUs, NG-PONs face significant challenges to provide the same level of survivability like conventional PONs without exceeding the budget constraints of cost-sensitive access networks. Toward this end, partial optical protection, in combination with interconnecting a subset of ONUs through a wireless mesh network (WMN) front-end, are promising solutions to render NG-PONs survivable in a cost-effective manner. In this paper, we present a probabilistic analysis of the survivability of NG-PONs and hybrid fiber-wireless (FiWi) access networks, taking both optical and wireless protection into account. In addition, we propose different selection schemes to wirelessly upgrade a subset of ONUs, and investigate their performance for a wide range of fiber link failure scenarios and different NG-PON topologies.

Survivability Analysis of Next-Generation Passive Optical Networks and Fiber-Wireless Access Networks

Sun, oven (50 and 70 °C) and microwave oven (210 and 700 W) drying of onion slices were carried out to monitor the drying kinetics and quality degradation of the product. Page, “Modified Page” and “Midilli and Kucuk” models exhibited high coefficient of determination (R2) values, ranging between 0.994 and 0.999. The calculated effective diffusivity (Deff) values (m2/s) of onion slices for the sun, oven 50 °C and oven 70 °C, microwave 210 W and microwave 700 W drying process were 8.339 × 10−10, 7.468 × 10−10, 1.554 × 10−9, 4.009 × 10−8 and 4.869 × 10−8, respectively. Fresh and dried onion slices had high amounts of K (696.82–16357.55 mg/kg), Ca (69.64–340.03 mg/kg), Na (37.72–1895.43 mg/kg), Mg (3.31–964.77 mg/kg) and P (46.47–3384.07 mg/kg) minerals. The highest mineral values were determined in oven dried samples. Sun (L∗ 58.00 ± 4.83, a∗ 0.27 ± 0.10, b∗ 14.36 ± 2.40) and microwave oven drying (210 W) (L∗ 54.78 ± 7.54, a∗ −0.71 ± 0.09, b∗ 13.17 ± 1.05) revealed better colour values in the dried products. The phenolic contents of microwave oven dried samples (1664.39 ± 134.12 and 1623.59 ± 140.02 for 210 W and 700 W, respectively) were higher than those of the other dried onion slices.

Study the effect of sun, oven and microwave drying on quality of onion slices

Free space optical communication

Corneal manifestations of ocular demodex infestation

Synthesis of arbitrarily shaped radiation patterns using linear antenna arrays has a significant importance in many applications. Many attempts based on analytical schemes are exerted for this purpose. However, these analytical methods are developed for specific problems, and usually synthesis of the radiation pattern is subject to only one restriction. On the other hand, optimization algorithms are utilized for more general problems. However, these algorithms require more computational time. In this letter, a new hybrid technique for synthesizing arbitrary-shaped radiation pattern using a linear array is developed. The algorithm is based on a combination between the method of moments (MoM) and the genetic algorithm (GA). The proposed algorithm is applied to synthesis of both symmetric and asymmetric radiation pattern distributions with minimum number of elements. Excellent agreement is obtained by comparison to other analytical and optimization techniques.

Optimum Design of Linear Antenna Arrays Using a Hybrid MoM/GA Algorithm

To enhance security and robustness of digital audio watermarking algorithms, this paper presents an algorithm based on mean-quantization in Discrete Wavelet Transform (DWT) domain. A binary image is used as a watermark, and is encrypted with chaotic encryption with secret key. This approach is based on the embedding of an encrypted watermark in the low frequency components using a two wavelet functions with adaptation to the frame size. The reason for embedding the watermark in the low frequency components is that these components' energy is high enough to embed the watermark in such a way that the watermark is inaudible; therefore, it should not alter the audible content and should not be easy to remove. The algorithm has a good security because only the authorized can detect the copyright information embedded to the host audio signal. The watermark can be blindly extracted without knowledge of the original signal. To evaluate the performance of the presented audio watermarking method, objective quality tests including bit error rate (BER), normalized cross correlation(NCC), peak-signal to noise ratio (PSNR) are conducted for the watermark and Signal-to-Noise Ratio(SNR) for audio signals. The tests' results show that the approach maintains high audio quality, and yields a high recovery rate after attacks by commonly used audio data manipulations such as noise addition, amplitude modification, low-pass filtering, re-quantization, re-sampling, cropping, cutting, and compression. Simulation results show that our approach not only makes sure robustness against common attacks, but it also further improves systemic security and robustness against malicious attack.

Secure and robust high quality DWT domain audio watermarking algorithm with binary image

Stool and urine analysis of 150 cases of phlyctenular eye disease, revealed that 115 (76.67%) were positive for intestinal parasites. The most prevalent parasites were Hymenolepis nana (49.56%) followed by Ascaris lumbricoides (27.82%). Eosinophilia (5-10%) was detected in 90 phlycten cases (60%), 80 of them (88.8%) had parasitic infection. Since H. nana can produce a type of tissue hypersensitivity, phlyctenular eye disease may be partly referred to such an infection.

The role of parasitic infection in the aetiology of phlyctenular eye disease.

Digital watermarking technology is concerned with solving the problem of copyright protection, data authentication, content identification, distribution, and duplication of the digital media due to the great developments in computers and Internet technology Recently, protection of digital audio signals has attracted the attention of researchers This paper proposes a new audio watermarking scheme based on discrete wavelet transform (DWT), singular value decomposition (SVD), and quantization index modulation (QIM) with a synchronization code embedded with two encrypted watermark images or logos inserted into a stereo audio signal In this algorithm, the original audio signal is split into blocks, and each block is decomposed with a two-level DWT, and then the approximate low-frequency sub-band coefficients are decomposed by SVD transform to obtain a diagonal matrix The prepared watermarking and synchronization code bit stream is embedded into the diagonal matrix using QIM After that, we perform inverse singular value decomposition (ISVD) and inverse discrete wavelet transform (IDWT) to obtain the watermarked audio signal The watermark can be blindly extracted without knowledge of the original audio signal Experimental results show that the transparency and imperceptibility of the proposed algorithm is satisfied, and that robustness is strong against popular audio signal processing attacks High watermarking payload is achieved through the proposed scheme

High payload multi-channel dual audio watermarking algorithm based on discrete wavelet transform and singular value decomposition

https://iopscience.iop.org/article/10.1088/1742-6596/1447/1/012053/pdf

Mohamed E. Nasr

Papers

Optimum Design of Linear Antenna Arrays Using a Hybrid MoM/GA Algorithm

Secure and robust high quality DWT domain audio watermarking algorithm with binary image

The role of parasitic infection in the aetiology of phlyctenular eye disease.

High payload multi-channel dual audio watermarking algorithm based on discrete wavelet transform and singular value decomposition

Secure Image Encryption Scheme Based on DNA and New Multi Chaotic Map