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The rapid development in the field of topological physics rises from condensed matter promises a new phenomenon of waves-matter interaction in a topological photonic system. These topologically protected photonics structural systems are insulators in bulk but a conductor at the outer surfaces. In electromagnetics, 2-D topological protected metasurfaces are observed by engineering a multilayered structure with a strong magnetoelectric coupling [1] or using a lumped element circuit model [2] where a Chiral one-way edge state is produced in a time-reversal symmetry system. Topological edge modes in such a system are confined along the interface between the trivial and nontrivial cladding having different spin Chern number (i.e., geometrical phase accumulation of the wavenumber in the momentum space). These gapless edge modes are immune to backscattering from a sharp corner and imperfection in the fabrication. Recent research in the field of photonic topological insulator metasurfaces shows an outstanding property, such as a highly robust EM waveguide implemented on a single substrate [3] . This structure constructed from a dielectric material sandwich between two thin dual metallic layers exhibits a topologically protected mode.

The most important challenge in the analog integrated fitter design is the selecting the proper values of the filter components, and particularly the realization of the big value of the inductor in the applications that required low frequencies such as biomedical (medical) applications. This paper analyze and design integrated active low pass filter of Chebyshev third and fifth order based on the concept of Frequency Dependent Negative Resistance (FDNR) as substitutional to inductors. The design parameters of this filter has been optimized using genetic algorithm by selecting the optimum component speared of the filter. The genetic algorithm (GA) technique using MATLAB is applied to obtain the optimum component spreads and a significant reduction in component spreads are obtained, R Spread ≈ 86, and C Spread ≈ 2. Advance Design system simulator program (ADS) is used to verify that the obtained optimum parameters satisfy the specified filter performance. It is also shown that this technique is useful as the required filter order increased that leads to increase the component spread.

An ultrathin antenna of thickness nearly 100th of the wavelength is presented, which is capable of providing small-scale beam steering. The antenna is inspired by concepts used in high impedance surfaces (HISs) A linear array antenna comprised of periodic dogbone-shaped elements mounted on top of a grounded substrate with multiple feeds is analyzed to obtain beam scanning and large gain bandwidth, despite the ultrathin thickness. Beam steering is observed when one port at the time is excited among multiple ports distributed along the length of the array. When multiple ports are excited simultaneously, a significantly larger gain bandwidth is observed even from this ultra-low-profile configuration. A maximum gain of 5.7 dBi is achieved along with a 3 dB gain bandwidth over a wide frequency range from 19.2 GHz to 25.2 GHz (27%).

This paper demonstrates the use of a 2-D sparse array feeding as a primary excitation source of a wideband planar Fabry-Perot Cavity (FPC) antenna for gain enhancement. The antenna is constructed from a thick partially reflective surface (PRS) mounted on top of an air-filled cavity. The antenna is fed by a 2×2 array of magnetic dipoles (slots) located on the ground plane. A proper choice of the array interelement distance gives a maximum gain of 18.1 dB and a 3 dB gain-bandwidth of 36.4%, which is remarkable for an FPC antenna. Results show a significant enhancement in the broadside gain by employing sparse array feeding with 2.7 times improvement in the gain-bandwidth product as compared to the conventional single element excitation source.

An ultrathin antenna based on a curved high impedance surface (HIS) is designed, which has wide beamscanning capability if the leaky wave is excited by proper selection of the feed location. The HIS-inspired curved printed antenna exploits the leaky wave properties of a linear arrangement of dogbone-shaped copper patches over a curved ground plane. By selecting the excitation port along the array demonstrates a beamscanning capability ranging from $\mathbf{-34^{\circ}}$ to $\mathbf{+34^{\circ}}$ . The curved HIS-based antenna exhibits a rather wide 3dB gain bandwidth. The thickness is in the order of a hundredth of a wavelength.

This paper presents a technique for obtaining wide gain-bandwidth from an ultrathin leaky wave-based high impedance surface (HIS) antenna. By properly selecting multiple feed locations over a linear dogbone-shaped patch array antenna, its gain bandwidth is maximized. Dogbone-shaped patches distributed along the surface of the grounded substrate are able to support a leaky wave. The HIS made of dogbone-shaped patches is directly used as radiator. Different feed locations are investigated and a wide gain-bandwidth of 5.8 GHz or 29.89% is observed with the use of multipoint excitation.

A wideband planar Fabry-Perot cavity (FPC) antenna formed by an electrically thick partially reflective surface (PRS) with overlapping radiating apertures operating at different frequencies is investigated. Recent techniques for FPC wideband operation allow the reuse of the same FPC at multiple frequencies, where each frequency has its own feed. The distance between two adjacent feeds is in the order of 1.2 wavelength.

Radiation characteristics of wideband Fabry-Perot cavity (FPC) antennas formed by a cavity covered by thick partially reflective surfaces (PRSs) are shown analytically and verified numerically. Thick PRSs are designed and optimized to exhibit a reflection phase with positive slope with a non-Foster-like response in the antenna operational bandwidth. By satisfying the antenna resonance condition over a wide frequency band, a wide radiated-power bandwidth is obtained. A more general and direct relation between the thick-PRS's reflection coefficient and the radially propagating leaky-wave inside the cavity structure is reported. In addition, a leaky-wave based power intensity formula is studied and verified numerically using PRSs formed by stacks of metal-dielectric layers.

Wide band planar Fabry-Perot cavity (FPC) antennas formed by an electrically thick partially reflective surface (PRS) composed of multiple metal/dielectric layers are investigated. These multiple metal and dielectric layers have been optimized to satisfy the FPC resonance condition at multiple frequencies, and hence, a larger antenna gain-bandwidth is achieved. The periodic metallic screen impedance is approximated based on its geometrical parameters and implemented as a shunt admittance in the transverse equivalent network (TEN). Two wideband FPC antennas with a single and double dielectric layers with metallic grids patterned at the bottom are designed and verified with a full-wave simulation result, with the double layer PRS leading to a wider band than the single layer one. In addition, the dispersion relation of the leaky-waves shows a quasi-oscillatory behavior versus frequency around the maximum radiated power bands.

A 2D periodic leaky wave antenna produces a narrow and highly directive beam at broadside. This structure is optimized and implemented in the microwave regime and also the optical regime. The antenna radiation characteristics as well as the modal properties of the 2D periodic leaky wave structure have been studied. The 2D periodic leaky wave antenna (LWA) for microwave frequencies is then further optimized in the shape of a cross to eliminate grating lobes.

In this research, we propose the use of Firefly algorithm for the extraction of summaries of single Arabic documents. The proposed approach is compared with two evolutionary approaches that use genetic algorithms and harmony search. The EASC Corpus and the ROUGE toolkit are used for the evaluation of the proposed approach. Experimental results showed that the proposed approach achieved competitive and even higher ROUGE scores in comparison with the two state-of-the-art approaches.

In this paper, an extremely thin planar antenna comprising only a high impedance surface (HIS) layer as the main radiator has been proposed. By eliminating the need of the dipole on top of the HIS, the proposed structure is formed with an extremely thin grounded dielectric layer covered by a patterned sheet of dogbone-shaped metal patches. This HIS antenna has been designed and optimized on a thin substrate with a thickness of 1/100 of the wavelength at the operating frequency, 900MHz. The proposed antenna is constructed from a 6 × 6 unit-cells where the performance is being analyzed and compared with an array of 2 × 2 rectangular patches designed to operate at the same frequency band. Despite the very thin substrate, the antenna radiates with a broadside gain of 13 dBi and a gain-bandwidth of 23.14 %.

Automated Text Summarization (ATS) systems are very significant in many fields in Natural Language Processing (NLP). ATS generates a shorter version of the source text that contains most of the relevant information in the original text which can help users to find the required information they are looking for saving time and resources. Text summarization can be classified according to different criteria. One of these criteria is the number of input documents. Text summarization tasks can be classified into single-document and multi-document summarization. In single-document summarization, the summary of only one document needs to be extracted, while multi-document summarization requires a collection of documents to be extracted.

A broadband single-layer Fabry-Perot Cavity antenna formed by a thin metallic frequency-selective-surface over a grounded non-uniform dielectric slab having a radial variation in the permittivity is designed. The performance of the proposed design is investigated using full-wave simulations.

Evaluating and scoring essay questions is an exhausting, time consuming process and require a lot of effort. So, applying automated tools is essentially required to tackle these drawbacks. In this study, we propose an automated scoring approach for short answers to Arabic essay questions. The scoring process is based on the similarity between the student's answer and model answer, cosine similarity measure is used for this purpose. Cosine similarity is a heuristic evolutionary measure that has succeeded to solve text to text similarity problems. Word root and synonyms for each keyword in the student's answer and the model answer are used in order to achieve accurate results. Experimental results showed that the proposed approach achieved competitive scores in comparison with other approaches.

Steganography is the science of embedding the secret messages inside other medium files in a way that hides the existence of the secret message at all. Steganography can be applied to text, audio, image, and video file types. In this study, we propose a new steganography approach for digital images in which the RGB coloring model was used. The efficiency of the proposed approach has been tested and evaluated. The experimental results show that the proposed approach produce high-quality stego images that resist against visual and statistical attacks.

In this work, for the first time, a set of two-and three-dimensional (3D) analysis techniques are combined to clarify the nature of resistive switching (RS) in state-of-the-art TiO2-based vacancy modulated conductive oxide (VMCO) memory. (1) A non-filamentary switching mechanism is observed. (2) The role of oxygen incorporation and motion in the TiO2 is demonstrated. (3) The oxygen profile inside scaled cells is measured and a RS-model based on the modulation of oxygen inside the stack is proposed. In addition, we perform the tomographic analysis of fully-fabricated devices with Scalpel SPM, thus probing in 3D the entire stack and the contribution of TiO2 grain boundaries (GBs) to the switching operations. Finally, devices failed by breakdown (BD) during cycling are characterized, identifying the formation of parasitic filaments as root-cause of the failure.

A V-band Fabry-Perot Cavity antenna, formed by a thick partially-reflective surface, is proposed with a wideband 3 dB gain bandwidth. The radiation performance of the proposed antenna is investigated based on full-wave simulation results showing a maximum gain of 19.3 dBi and a 3 dB gain bandwidth of more than 5.2 GHz at the center frequency of 60 GHz.