212 results on '"El-Sayed"'
Search Results
2. Double Etch Method for the Fabrication of Nanophotonic Devices from Van der Waals Materials
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Schaeper, Otto Cranwell, Spencer, Lesley, Scognamiglio, Dominic, El-Sayed, Waleed, Whitefield, Benjamin, Horder, Jake, Coste, Nathan, Barclay, Paul, Toth, Milos, Zalogina, Anastasiia, and Aharonovich, Igor
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Physics - Optics ,Physics - Applied Physics - Abstract
The integration of van der Waals (vdW) materials into photonic devices has laid out a foundation for many new quantum and optoelectronic applications. Despite tremendous progress in the nanofabrication of photonic building blocks from vdW crystals, there are still limitations, specifically with large-area devices and masking. Here, we focus on hexagonal boron nitride (hBN) as a vdW material and present a double etch method that overcomes problems associated with methods that employ metallic films and resist-based films for masking. Efficacy of the developed protocol is demonstrated by designing and fabricating a set of functional photonic components including waveguides, ring resonators and photonic crystal cavities. The functionality of the fabricated structures is demonstrated through optical characterization over several key spectral ranges. These include the near-infrared and blue ranges, where the hBN boron vacancy (VB-) spin defects and the coherent B center quantum emitters emit, respectively. The double etch method enables fabrication of high-quality factor optical cavities and constitutes a promising pathway toward on-chip integration of vdW materials., Comment: 10 pages, 4 figures
- Published
- 2024
3. Search for dark matter in the framework of Einstein-Cartan gravity at the International Linear Collider (ILC)
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Taha, Hossam, El-dahshan, El-sayed A., and Elgammal, S.
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High Energy Physics - Phenomenology - Abstract
This paper investigates the possibility of Dark Matter (DM) fermions production alongside a gauge boson (A$^{\prime}$) using a model based on Einstein-Cartan gravity in an electron-positron linear collider, such as the ILC, that operates at a center-of-mass energy $\sqrt{s} = 500$ GeV with a detector's integrated luminosity of 1000 fb$^{-1}$. We used the WHIZARD package as the event generator to simulate the $ e^{+} e^{-}$ interactions that lead to the production of di-muon pairs and missing transverse energy. We specifically are performing this study on a low mass dark gauge boson, M$_{A^\prime}$= 10 GeV, that can subsequently decay into a muon pair (A$^\prime\rightarrow \mu^{+}\mu^{-})$ while aiming to set upper limits on the free parameters' masses of the model, such as the torsion field (ST), if evidence for physics beyond the standard model is not found.
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- 2024
4. Investigating a new neutral heavy gauge boson within the mono-Z$^{\prime}$ portal via simulated pp collisions at $\sqrt{s}$ = 14 TeV at the HL-LHC
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H., Ali Muhammad H., El-dahshan, El-sayed A., and Elgammal, S.
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High Energy Physics - Phenomenology - Abstract
In this study, we aim to explore the potential for generating events related to dark matter (DM) in conjunction with a neutral heavy gauge boson (Z$^{\prime}$) decaying leptonically during proton-proton collisions at the Large Hadron Collider (LHC). These collisions occur at a center-of-mass energy of $\sqrt{s}$ = 14 TeV, with a high integrated luminosity equivalent to 1000 fb$^{-1}$. Our analysis involves interpreting the outcomes through Monte Carlo simulation of the effective field theory (EFT) framework. If no new physics is detected, we establish constraints on various parameters within the EFT context, such as the scenario cutoff scale ($\Lambda$) and the Z$^{\prime}$ mass.
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- 2024
5. The Ethics of Advanced AI Assistants
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Gabriel, Iason, Manzini, Arianna, Keeling, Geoff, Hendricks, Lisa Anne, Rieser, Verena, Iqbal, Hasan, Tomašev, Nenad, Ktena, Ira, Kenton, Zachary, Rodriguez, Mikel, El-Sayed, Seliem, Brown, Sasha, Akbulut, Canfer, Trask, Andrew, Hughes, Edward, Bergman, A. Stevie, Shelby, Renee, Marchal, Nahema, Griffin, Conor, Mateos-Garcia, Juan, Weidinger, Laura, Street, Winnie, Lange, Benjamin, Ingerman, Alex, Lentz, Alison, Enger, Reed, Barakat, Andrew, Krakovna, Victoria, Siy, John Oliver, Kurth-Nelson, Zeb, McCroskery, Amanda, Bolina, Vijay, Law, Harry, Shanahan, Murray, Alberts, Lize, Balle, Borja, de Haas, Sarah, Ibitoye, Yetunde, Dafoe, Allan, Goldberg, Beth, Krier, Sébastien, Reese, Alexander, Witherspoon, Sims, Hawkins, Will, Rauh, Maribeth, Wallace, Don, Franklin, Matija, Goldstein, Josh A., Lehman, Joel, Klenk, Michael, Vallor, Shannon, Biles, Courtney, Morris, Meredith Ringel, King, Helen, Arcas, Blaise Agüera y, Isaac, William, and Manyika, James
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Computer Science - Computers and Society - Abstract
This paper focuses on the opportunities and the ethical and societal risks posed by advanced AI assistants. We define advanced AI assistants as artificial agents with natural language interfaces, whose function is to plan and execute sequences of actions on behalf of a user, across one or more domains, in line with the user's expectations. The paper starts by considering the technology itself, providing an overview of AI assistants, their technical foundations and potential range of applications. It then explores questions around AI value alignment, well-being, safety and malicious uses. Extending the circle of inquiry further, we next consider the relationship between advanced AI assistants and individual users in more detail, exploring topics such as manipulation and persuasion, anthropomorphism, appropriate relationships, trust and privacy. With this analysis in place, we consider the deployment of advanced assistants at a societal scale, focusing on cooperation, equity and access, misinformation, economic impact, the environment and how best to evaluate advanced AI assistants. Finally, we conclude by providing a range of recommendations for researchers, developers, policymakers and public stakeholders.
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- 2024
6. A Mechanism-Based Approach to Mitigating Harms from Persuasive Generative AI
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El-Sayed, Seliem, Akbulut, Canfer, McCroskery, Amanda, Keeling, Geoff, Kenton, Zachary, Jalan, Zaria, Marchal, Nahema, Manzini, Arianna, Shevlane, Toby, Vallor, Shannon, Susser, Daniel, Franklin, Matija, Bridgers, Sophie, Law, Harry, Rahtz, Matthew, Shanahan, Murray, Tessler, Michael Henry, Douillard, Arthur, Everitt, Tom, and Brown, Sasha
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Computer Science - Computers and Society ,Computer Science - Artificial Intelligence - Abstract
Recent generative AI systems have demonstrated more advanced persuasive capabilities and are increasingly permeating areas of life where they can influence decision-making. Generative AI presents a new risk profile of persuasion due the opportunity for reciprocal exchange and prolonged interactions. This has led to growing concerns about harms from AI persuasion and how they can be mitigated, highlighting the need for a systematic study of AI persuasion. The current definitions of AI persuasion are unclear and related harms are insufficiently studied. Existing harm mitigation approaches prioritise harms from the outcome of persuasion over harms from the process of persuasion. In this paper, we lay the groundwork for the systematic study of AI persuasion. We first put forward definitions of persuasive generative AI. We distinguish between rationally persuasive generative AI, which relies on providing relevant facts, sound reasoning, or other forms of trustworthy evidence, and manipulative generative AI, which relies on taking advantage of cognitive biases and heuristics or misrepresenting information. We also put forward a map of harms from AI persuasion, including definitions and examples of economic, physical, environmental, psychological, sociocultural, political, privacy, and autonomy harm. We then introduce a map of mechanisms that contribute to harmful persuasion. Lastly, we provide an overview of approaches that can be used to mitigate against process harms of persuasion, including prompt engineering for manipulation classification and red teaming. Future work will operationalise these mitigations and study the interaction between different types of mechanisms of persuasion.
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- 2024
7. Evaluating Frontier Models for Dangerous Capabilities
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Phuong, Mary, Aitchison, Matthew, Catt, Elliot, Cogan, Sarah, Kaskasoli, Alexandre, Krakovna, Victoria, Lindner, David, Rahtz, Matthew, Assael, Yannis, Hodkinson, Sarah, Howard, Heidi, Lieberum, Tom, Kumar, Ramana, Raad, Maria Abi, Webson, Albert, Ho, Lewis, Lin, Sharon, Farquhar, Sebastian, Hutter, Marcus, Deletang, Gregoire, Ruoss, Anian, El-Sayed, Seliem, Brown, Sasha, Dragan, Anca, Shah, Rohin, Dafoe, Allan, and Shevlane, Toby
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Computer Science - Machine Learning - Abstract
To understand the risks posed by a new AI system, we must understand what it can and cannot do. Building on prior work, we introduce a programme of new "dangerous capability" evaluations and pilot them on Gemini 1.0 models. Our evaluations cover four areas: (1) persuasion and deception; (2) cyber-security; (3) self-proliferation; and (4) self-reasoning. We do not find evidence of strong dangerous capabilities in the models we evaluated, but we flag early warning signs. Our goal is to help advance a rigorous science of dangerous capability evaluation, in preparation for future models.
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- 2024
8. The illusion of artificial inclusion
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Agnew, William, Bergman, A. Stevie, Chien, Jennifer, Díaz, Mark, El-Sayed, Seliem, Pittman, Jaylen, Mohamed, Shakir, and McKee, Kevin R.
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Computer Science - Computers and Society - Abstract
Human participants play a central role in the development of modern artificial intelligence (AI) technology, in psychological science, and in user research. Recent advances in generative AI have attracted growing interest to the possibility of replacing human participants in these domains with AI surrogates. We survey several such "substitution proposals" to better understand the arguments for and against substituting human participants with modern generative AI. Our scoping review indicates that the recent wave of these proposals is motivated by goals such as reducing the costs of research and development work and increasing the diversity of collected data. However, these proposals ignore and ultimately conflict with foundational values of work with human participants: representation, inclusion, and understanding. This paper critically examines the principles and goals underlying human participation to help chart out paths for future work that truly centers and empowers participants., Comment: Proceedings of the CHI Conference on Human Factors in Computing Systems (CHI 2024)
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- 2024
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9. Advancements in Generative AI: A Comprehensive Review of GANs, GPT, Autoencoders, Diffusion Model, and Transformers
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Bengesi, Staphord, El-Sayed, Hoda, Sarker, Md Kamruzzaman, Houkpati, Yao, Irungu, John, and Oladunni, Timothy
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence - Abstract
The launch of ChatGPT has garnered global attention, marking a significant milestone in the field of Generative Artificial Intelligence. While Generative AI has been in effect for the past decade, the introduction of ChatGPT has ignited a new wave of research and innovation in the AI domain. This surge in interest has led to the development and release of numerous cutting-edge tools, such as Bard, Stable Diffusion, DALL-E, Make-A-Video, Runway ML, and Jukebox, among others. These tools exhibit remarkable capabilities, encompassing tasks ranging from text generation and music composition, image creation, video production, code generation, and even scientific work. They are built upon various state-of-the-art models, including Stable Diffusion, transformer models like GPT-3 (recent GPT-4), variational autoencoders, and generative adversarial networks. This advancement in Generative AI presents a wealth of exciting opportunities and, simultaneously, unprecedented challenges. Throughout this paper, we have explored these state-of-the-art models, the diverse array of tasks they can accomplish, the challenges they pose, and the promising future of Generative Artificial Intelligence.
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- 2023
10. Clinical Study to Evaluate the Possible Efficacy and Safety of Levocetirizine in Patients With Diabetic Kidney Disease
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Sahar El-Haggar, Prof Clinical pharmacy Department- Tanta University, Osama Mohamed Hassan Ibrahim , Prof Clinical pharmacy Department- Tanta University, Maryam Ali Ali El Sayed Rizk Clinical pharmacy Department- Tanta University, and Mostafa Bahaa, Teaching Assistant
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- 2024
11. Entanglement Between Stochastic Atomic Motion and Three-Level Atom
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Salah, Ahmed, El-Sayed, M. A., and Wahab, N. H. Abdel
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Quantum Physics ,Physics - Optics - Abstract
In this paper, we are interested in studying entropy and dynamics entanglement between a single time dependent three-level atom interacting with one-mode cavity field when the atomic motion is taken into account. An exact analytical solution for the wave function is given by using Schr\"odinger equation for a specific initial condition. The field entropy of this system is investigated in the non-resonant case. The influences of the detuning parameters and atomic motion on the entanglement degree are examined. We show that both of the detuning parameters and atomic motion play important roles in the evolution of von Neumann entropy and atomic populations. Finally, conclusion and some features are given.
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- 2022
12. Modeling the Initial Stages of Si(100) Thermal Oxidation: An Ab-initio Approach
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Cvitkovich, Lukas, Waldhör, Dominic, El-Sayed, Al-Moatassem, Jech, Markus, Wilhelmer, Christoph, and Grasser, Tibor
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Condensed Matter - Materials Science - Abstract
Silicon together with its native oxide SiO$_2$ was recognized as an outstanding material system for the semiconductor industry in the 1950s. In state-of-the-art device technology, SiO$_2$ is widely used as an insulator in combination with high-$k$ dielectrics such as HfO$_2$, demanding fabrication of ultra-thin interfacial layers. The classical standard model derived by Deal and Grove accurately describes the oxidation of Si in a progressed stage, however, strongly underestimates growth rates for thin oxide layers. Recent studies report a variety of oxidation mechanisms during the growth of oxide films in the range of \SI{10}{\angstrom} with various details still under debate. This paper presents a first-principles based approach to theoretically assess the thermal oxidation process of the technologically relevant Si(100) surfaceduring this initial stage. Our investigations range from the chemisorption of single O$_2$ molecules onto the $p(2\times2)$ reconstructed Si surface to oxidized Si surface layers with a thickness of up to \SI{20}{\angstrom}. The initially observed enhanced growth rate is assigned to barrierless O$_2$ chemisorption events upon which the oxygen molecule dissociate. We present strong evidence for an immediate amorphization of the oxide layer from the onset of oxidation. Surface reactions dominate until the surface is saturated with oxygen and separated from the Si substrate by a \SI{5}{\angstrom} transition region. The saturated surface becomes inert to dissociative reactions and enables the diffusion of molecular oxygen to the \interface interface as assumed within the Deal-Grove model. Further oxidation of the Si substrate is then provided by O$_2$ dissociations at the interface due to the same charge transfer process responsible for the chemisorption at the surface., Comment: 12 pages, 8 figures
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- 2022
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13. Stochastic geometric modelling and simulation of cellular systems for coverage probability characterization
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Nassar, Hamed, Taher, Gehad, and El-Hady, El-Sayed
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Computer Science - Networking and Internet Architecture ,Computer Science - Performance - Abstract
Stochastic geometry (SG) has been successfully used as a modelling tool for cellular networks to characterize the coverage probability in both the downlink (DL) and uplink (UL) systems, under the assumption that the base stations (BS) are deployed as a Poisson point process. In the present article, we extend this use and provide further results for interference limited and Rayleigh fading networks, culminating in a multifaceted contribution. First, we compactly model the two systems at once, allowing parallels to be drawn and contrast to be created. Also, for DL we manage to obtain two closed form expressions for two special cases. Moreover, for UL, notorious for being difficult, we develop a clever approximation that overcomes the difficulty, yielding excellent results. Additionally, we present two efficient Monte Carlo simulation algorithms, designed primarily to validate the models, but can be of great use for SG modelling of communications systems in general. Finally, we prove two theorems at odds with popular belief in cellular communications research. Specifically, we prove that under the SG model, the coverage probability in both DL and UL is independent of BS density. Based on this revelation, a plethora of results in the literature have to be re-examined to rid them of a parameter that has been proven superfluous., Comment: 32 pages, 4 figures
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- 2021
14. Electrically driven programmable phase-change meta-switch reaching 80% efficiency
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Abdollahramezani, Sajjad, Hemmatyar, Omid, Taghinejad, Mohammad, Taghinejad, Hossein, Krasnok, Alex, Eftekhar, Ali A., Teichrib, Christian, Deshmukh, Sanchit, El-Sayed, Mostafa, Pop, Eric, Wuttig, Matthias, Alu, Andrea, Cai, Wenshan, and Adibi, Ali
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Physics - Optics ,Physics - Applied Physics - Abstract
Despite recent advances in active metaoptics, wide dynamic range combined with high-speed reconfigurable solutions is still elusive. Phase-change materials (PCMs) offer a compelling platform for metasurface optical elements, owing to the large index contrast and fast yet stable phase transition properties. Here, we experimentally demonstrate an in situ electrically-driven reprogrammable metasurface by harnessing the unique properties of a phase-change chalcogenide alloy, Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST), in order to realize fast, non-volatile, reversible, multilevel, and pronounced optical modulation in the near-infrared spectral range. Co-optimized through a multiphysics analysis, we integrate an efficient heterostructure resistive microheater that indirectly heats and transforms the embedded GST film without compromising the optical performance of the metasurface even after several reversible phase transitions. A hybrid plasmonic-PCM meta-switch with a record electrical modulation of the reflectance over eleven-fold (an absolute reflectance contrast reaching 80%), unprecedented quasi-continuous spectral tuning over 250 nm, and switching speed that can potentially reach a few kHz is presented. Our work represents a significant step towards the development of fully integrable dynamic metasurfaces and their potential for beamforming applications.
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- 2021
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15. Dynamic hybrid metasurfaces
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Abdollahramezani, Sajjad, Hemmatyar, Omid, Taghinejad, Mohammad, Taghinejad, Hossein, Kiarashinejad, Yashar, Zandehshahvar, Mohammadreza, Fan, Tianren, Deshmukh, Sanchit, Eftekhar, Ali A., Cai, Wenshan, Pop, Eric, El-Sayed, Mostafa, and Adibi, Ali
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Physics - Optics ,Physics - Applied Physics - Abstract
Efficient hybrid plasmonic-photonic metasurfaces that simultaneously take advantage of the potential of both pure metallic and all-dielectric nanoantennas are identified as an emerging technology in flat optics. Nevertheless, post-fabrication tunable hybrid metasurfaces are still elusive. Here, we present a reconfigurable hybrid metasurface platform by incorporating the phase-change material Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) into metal-dielectric meta-atoms for active and non-volatile tuning of properties of light. We systematically design a reduced-dimension meta-atom, which selectively controls the fundamental hybrid plasmonic-photonic resonances of the metasurface via the dynamic change of optical constants of GST without compromising the scattering efficiency. As a proof-of-concept, we experimentally demonstrate miniaturized tunable metasurfaces that control the amplitude and phase of incident light necessary for high-contrast optical switching and anomalous to specular beam deflection, respectively. Finally, we leverage a deep learning-based approach to present an intuitive low-dimensional visualization of the enhanced range of response reconfiguration enabled by the addition of GST. Our findings further substantiate dynamically tunable hybrid metasurfaces as promising candidates for the development of small-footprint energy harvesting, imaging, and optical signal processing devices.
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- 2020
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16. Quasinormal mode theory of elastic Purcell factors and Fano resonances of optomechanical beams
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El-Sayed, Al-Waleed and Hughes, Stephen
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Physics - Optics ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We introduce a quasinormal mode theory of mechanical open-cavity modes for optomechanical resonators, and demonstrate the importance of using a generalized (complex) effective mode volume and the phase of the quasinormal mode. We first generalize and fix the normal mode theories of the elastic Purcell factor, and then show a striking example of coupled quasinormal modes yielding a pronounced Fano resonance. Our theory is exemplified and confirmed by full three-dimensional calculations on optomechanical beams, but the general findings apply to a wide range of mechanical cavity modes. This quasinormal mechanical mode formalism, when also coupled with a quasinormal theory of optical cavities, offers a unified framework for describing a wide range of optomechanical structures where dissipation is an inherent part of the resonator modes., Comment: 11 pages, 7 figures
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- 2020
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17. A Parallel Hybrid Technique for Multi-Noise Removal from Grayscale Medical Images
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Youssef, Nora, Mahmoud, Abeer M., and El-Horbaty, El-Sayed M.
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Computer Science - Computer Vision and Pattern Recognition - Abstract
Medical imaging is the technique used to create images of the human body or parts of it for clinical purposes. Medical images always have large sizes and they are commonly corrupted by single or multiple noise type at the same time, due to various reasons, these two reasons are the triggers for moving toward parallel image processing to find alternatives of image de-noising techniques. This paper presents a parallel hybrid filter implementation for gray scale medical image de-noising. The hybridization is between adaptive median and wiener filters. Parallelization is implemented on the adaptive median filter to overcome the latency of neighborhood operation, parfor implicit parallelism powered by MatLab 2013a is used. The implementation is tested on an image of 2.5 MB size, which is divided into 2, 4 and 8 partitions; a comparison between the proposed implementation and sequential implementation is given, in terms of time. Thus, each case has the best time when assigned to number of threads equal to the number of its partitions. Moreover, Speed up and efficiency are calculated for the algorithm and they show a measured enhancement.
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- 2020
18. Gray s decomposition on doubly warped product manifolds and applications
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El-Sayed, Hoda K., Mantica, Carlo Alberto, Shenawy, Sameh, and Syied, Noha
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Mathematics - Differential Geometry ,Mathematical Physics ,53C21, Secondary 53C50, 53C80 - Abstract
A. Gray presented an interesting $O\left( n\right) $ invariant decomposition of the covariant derivative of the Ricci tensor. Manifolds whose Ricci tensor satisfies the defining property of each orthogonal class are called Einstein-like manifolds. In the present paper, we answered the following question: Under what condition(s), does a factor manifold $M_{i},i=1,2$ of a doubly warped product manifold $M=_{f_{2}}M_{1}\times _{f_{1}}M_{2}$ lie in the same Einstein-like class of $M$? By imposing sufficient and necessary conditions on the warping functions, an inheritance property of each class is proved. As an application, Einstein-like doubly warped product space-times of type $\mathcal{A},$ $\mathcal{B}$ or $\mathcal{P}$ are considered.
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- 2019
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19. Time Delay Estimation, Using Correlation Approaches Applied to Seismic Time Picking
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Yahia, Ashraf H., El-Dahshan, El-Sayed, and Guirguis, Albert K.
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Physics - Computational Physics ,Physics - Geophysics - Abstract
In wave propagation theories, many problems of multi-sensor systems utilize time delay in their solution in signal processing. This technique finds great utility in seismic exploration and static correction (low-velocity weathering), which compensates the difference in elevations of the surveyed land. Traditionally, cross-correlation approaches; such as phase delay, coherence ratio and higher order, for instance, bispectral techniques are the preferred methods of time delay estimation. In this work, we study the reliability of these approaches for estimating the time delay and proposed an interactive algorithm, which used the estimated time delay for automatically obtaining the first break times of seismic data signals; this is considered an essential step in static correlation stage. Here we show that the phase delay and coherence ratio are almost equivalent to the higher order (bispectral) correlation technique and take a computational time less than the higher order (bispectral) correlation, so is recommended to use., Comment: 10 pages, 4 figure, 6th International Conference of Applied Geophysics. Cairo: Journal of Applied Geophysics
- Published
- 2018
20. Large Enhancement of Circular Dichroism Using an Embossed Chiral Metamaterial
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Mousavi, S. Hamed Shams, Panikkanvalappil, Sajanlal R., El-Sayed, Mostafa A., Eftekhar, Ali A., and Adibi, Ali
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Physics - Optics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Materials Science - Abstract
In the close vicinity of a chiral nanostructure, the circular dichroism of a biomolecule could be greatly enhanced, due to the interaction with the local superchiral fields. Modest enhancement of optical activity using a planar metamaterial, with some chiral properties, and achiral nanoparticles has been previously reported. A more substantial chirality enhancement can be achieved in the local filed of a chiral nanostructure with a three-dimensional arrangement. Using an embossed chiral nanostructure designed for chiroptical sensing, we measure the circular dichroism spectra of two biomolecules, Chlorophylls A and B, at the molecular level, using a simple polarization resolved reflection measurement. This experiment is the first realization of the on-resonance surface-enhanced circular dichroism, achieved by matching the chiral resonances of a strongly chiral metamaterial with that of a chiral molecule, resulting in an unprecedentedly large differential CD spectrum from a monolayer of a chiral material.
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- 2016
21. Innovative Method for enhancing Key generation and management in the AES-algorithm
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Mohammad, Omer K. Jasim, Abbas, Safia, El-Horbaty, El-Sayed M., and Salem, Abdel-Badeeh M.
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Computer Science - Cryptography and Security - Abstract
With the extraordinary maturity of data exchange in network environments and increasing the attackers capabilities, information security has become the most important process for data storage and communication. In order to provide such information security the confidentiality, data integrity, and data origin authentication must be verified based on cryptographic encryption algorithms. This paper presents a development of the advanced encryption standard (AES) algorithm, which is considered as the most eminent symmetric encryption algorithm. The development focuses on the generation of the integration between the developed AES based S-Boxes, and the specific selected secret key generated from the quantum key distribution., Comment: 7 pages, 10 figures. arXiv admin note: text overlap with arXiv:1503.04796
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- 2015
22. Evolution of an Emerging Symmetric Quantum Cryptographic Algorithm
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Jasim, Omer K., Abbas, Safia, Horbaty, El-Sayed M., and Salem, Abdel-Badeeh M.
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Computer Science - Cryptography and Security - Abstract
With the rapid evolution of data exchange in network environments, information security has been the most important process for data storage and communication. In order to provide such information security, the confidentiality, data integrity, and data origin authentication must be verified based on cryptographic encryption algorithms. This paper presents a new emerging trend of modern symmetric encryption algorithm by development of the advanced encryption standard (AES) algorithm. The new development focuses on the integration between Quantum Key Distribution (QKD) and an enhanced version of AES. A new quantum symmetric encryption algorithm, which is abbreviated as Quantum-AES (QAES), is the output of such integration. QAES depends on generation of dynamic quantum S-Boxes (DQS-Boxes) based quantum cipher key, instead of the ordinary used static S-Boxes. Furthermore, QAES exploits the specific selected secret key generated from the QKD cipher using two different modes (online and off-line).
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- 2015
23. A Simulation Modeling Approach for Optimization of Storage Space Allocation in Container Terminal
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Said, Gamal Abd El-Nasser A. and El-Horbaty, El-Sayed M.
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Computer Science - Other Computer Science - Abstract
Container handling problems at container terminals are NP-hard problems. This paper presents an approach using discrete-event simulation modeling to optimize solution for storage space allocation problem, taking into account all various interrelated container terminal handling activities. The proposed approach is applied on a real case study data of container terminal at Alexandria port. The computational results show the effectiveness of the proposed model for optimization of storage space allocation in container terminal where 54% reduction in containers handling time in port is achieved., Comment: International Journal of Computer, Information, Systems and Control Engineering Vol:9 No:1, 2015
- Published
- 2015
24. A New Trend of Pseudo Random Number Generation using QKD
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Jasim, Omer K., Abbas, Safia, El-Horbaty, El-Sayed M., and Salem, Abdel-Badeeh M.
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Computer Science - Cryptography and Security - Abstract
Random Numbers determine the security level of cryptographic applications as they are used to generate padding schemes in the encryption/decryption process as well as used to generate cryptographic keys. This paper utilizes the QKD to generate a random quantum bit rely on BB84 protocol, using the NIST and DIEHARD randomness test algorithms to test and evaluate the randomness rates for key generation. The results show that the bits generated using QKD are truly random, which in turn, overcomes the distance limitation (associated with QKD) issue, its well-known challenges with the sending/ receiving data process between different communication parties, Comment: 5 pages, 5 figures, 1 table, International Journal of Computer Applications, 2014
- Published
- 2014
25. Simulation and optimization of container terminal operations: a case study
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Said, Gamal Abd El-Nasser A., Mahmoud, Abeer M., and El-Horbaty, El-Sayed M.
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Computer Science - Other Computer Science - Abstract
Container terminals are facing a set of interrelated problems. Container handling problems at container terminals are NP-hard problems. The docking time of container ships at the port must be optimized. In this paper we have built a simulation model that integrates all the activities of a container terminal. The proposed approach is applied on a real case study data of container terminal at El-Dekheilla port. The results show that the proposed approach reduced the ship turnaround time in port where 51% reduction in ship service time (loading/unloading) in port is achieved., Comment: 10 pages, 3 figures
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- 2014
26. Solving container terminals problems using computer-based modeling
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Said, Gamal Abd El-Nasser A., Mahmoud, Abeer M., and El-Horbaty, El-Sayed M.
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Computer Science - Other Computer Science - Abstract
This paper addresses the applications of different techniques for solving container terminals problems. We have built a simulation model that can be used to analyze the performance of container terminal operations. The proposed approach is intended to be applied for a real case study in Alexandria Container Terminal (ACT) at Alexandria port. The implementation of our approach shows that a proposed model increases the efficiency of Alexandria container terminal at Alexandria port., Comment: 11 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1407.6257
- Published
- 2014
27. A Comparative Study of Meta-heuristic Algorithms for Solving Quadratic Assignment Problem
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Said, Gamal Abd El-Nasser A., Mahmoud, Abeer M., and El-Horbaty, El-Sayed M.
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Computer Science - Artificial Intelligence ,Computer Science - Neural and Evolutionary Computing - Abstract
Quadratic Assignment Problem (QAP) is an NP-hard combinatorial optimization problem, therefore, solving the QAP requires applying one or more of the meta-heuristic algorithms. This paper presents a comparative study between Meta-heuristic algorithms: Genetic Algorithm, Tabu Search, and Simulated annealing for solving a real-life (QAP) and analyze their performance in terms of both runtime efficiency and solution quality. The results show that Genetic Algorithm has a better solution quality while Tabu Search has a faster execution time in comparison with other Meta-heuristic algorithms for solving QAP., Comment: 6 pages, 3 figures
- Published
- 2014
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28. Study of Neural Network Algorithm for Straight-Line Drawings of Planar Graphs
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El-Sayed, Mohamed A., Abdel-Khalek, S., and Amin, Hanan H.
- Subjects
Computer Science - Computational Geometry ,Computer Science - Neural and Evolutionary Computing - Abstract
Graph drawing addresses the problem of finding a layout of a graph that satisfies given aesthetic and understandability objectives. The most important objective in graph drawing is minimization of the number of crossings in the drawing, as the aesthetics and readability of graph drawings depend on the number of edge crossings. VLSI layouts with fewer crossings are more easily realizable and consequently cheaper. A straight-line drawing of a planar graph G of n vertices is a drawing of G such that each edge is drawn as a straight-line segment without edge crossings. However, a problem with current graph layout methods which are capable of producing satisfactory results for a wide range of graphs is that they often put an extremely high demand on computational resources. This paper introduces a new layout method, which nicely draws internally convex of planar graph that consumes only little computational resources and does not need any heavy duty preprocessing. Here, we use two methods: The first is self organizing map known from unsupervised neural networks which is known as (SOM) and the second method is Inverse Self Organized Map (ISOM).
- Published
- 2014
29. Study of Efficient Technique Based On 2D Tsallis Entropy For Image Thresholding
- Author
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El-Sayed, Mohamed A., Abdel-Khalek, S., and Abdel-Aziz, Eman
- Subjects
Computer Science - Computer Vision and Pattern Recognition ,68U10 - Abstract
Thresholding is an important task in image processing. It is a main tool in pattern recognition, image segmentation, edge detection and scene analysis. In this paper, we present a new thresholding technique based on two-dimensional Tsallis entropy. The two-dimensional Tsallis entropy was obtained from the twodimensional histogram which was determined by using the gray value of the pixels and the local average gray value of the pixels, the work it was applied a generalized entropy formalism that represents a recent development in statistical mechanics. The effectiveness of the proposed method is demonstrated by using examples from the real-world and synthetic images. The performance evaluation of the proposed technique in terms of the quality of the thresholded images are presented. Experimental results demonstrate that the proposed method achieve better result than the Shannon method.
- Published
- 2014
30. An Identification System Using Eye Detection Based On Wavelets And Neural Networks
- Author
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El-Sayed, Mohamed A. and Khafagy, Mohamed A.
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
The randomness and uniqueness of human eye patterns is a major breakthrough in the search for quicker, easier and highly reliable forms of automatic human identification. It is being used extensively in security solutions. This includes access control to physical facilities, security systems and information databases, Suspect tracking, surveillance and intrusion detection and by various Intelligence agencies through out the world. We use the advantage of human eye uniqueness to identify people and approve its validity as a biometric. . Eye detection involves first extracting the eye from a digital face image, and then encoding the unique patterns of the eye in such a way that they can be compared with pre-registered eye patterns. The eye detection system consists of an automatic segmentation system that is based on the wavelet transform, and then the Wavelet analysis is used as a pre-processor for a back propagation neural network with conjugate gradient learning. The inputs to the neural network are the wavelet maxima neighborhood coefficients of face images at a particular scale. The output of the neural network is the classification of the input into an eye or non-eye region. An accuracy of 90% is observed for identifying test images under different conditions included in training stage., Comment: Mohamed A. El-Sayed and Mohamed A. Khafagy, An Identification System Using Eye Detection Based On Wavelets And Neural Networks. International Journal Of Computer And Information Technology. Vol. 1, No. 2, pp. 43-48, 2012. arXiv admin note: text overlap with arXiv:1205.5097 by other authors without attribution
- Published
- 2014
31. Future of Surgery: Technology Enhanced Surgical Training: Report of the FOS:TEST Commission
- Author
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Adebayo, Oliver, primary, Aldoori, Joanna, additional, Allum, William, additional, Aruparayil, Noel, additional, Badran, Abdul, additional, Winter Beatty, Jasmine, additional, Bhatia, Sanchita, additional, Bolton, William, additional, Giwa-Brown, Lolade, additional, Burke, Josh, additional, Carr, Harry J, additional, Chae, Yeonwoo, additional, Clements, Joshua, additional, El-Sayed, Charlotte, additional, Foster, William, additional, Gall, Tamara, additional, George, Manish, additional, Guest, Francesca, additional, Haq, Makinah, additional, Hardie, John, additional, Harris, Matthew, additional, Harvey, Neil, additional, Hoyle, Antonia, additional, Jalal, Arif Hanafi Bin, additional, Jesudian, Gnararaj, additional, Jiwa, Natasha, additional, Kalra, Neeraj, additional, Kapur, Karan, additional, Kawka, Michal, additional, Kazzazi, Fawz, additional, Keates, Natasha, additional, Kennion, Oliver, additional, King, Martin, additional, Lam, Angela, additional, Lemma, Gedeon, additional, Lim, Jun Wei, additional, Longman, Patrick, additional, Mikhail, Mark, additional, Mohammed, Walid, additional, Nasher, Omar, additional, Ngai, Victoria, additional, Okocha, Michael, additional, Pandit, Anand, additional, Pegna, Victoria, additional, Rehman, Haroon, additional, Toale, Conor, additional, Walker, Eleanor, additional, Wellington, Jack, additional, Wicks, Catherine, additional, Birchall, Martin, additional, Brennan, Peter, additional, Harji, Deena, additional, Irune, Ekpemi, additional, Janakan, Gnananandan, additional, Jayne, David, additional, McDermott, Frank D, additional, McMenamin, Paul, additional, Munsch, Chris, additional, Payne, Steve, additional, Peter, Mark, additional, Plastow, Ricci, additional, Smail, Hassiba, additional, Theodoreli-Riga, Celia, additional, Robson, Andrew, additional, Culmer, Peter, additional, Mallender, Jacque, additional, and Price, Richard, additional
- Published
- 2022
- Full Text
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32. Helwan University Project Developing Primary School Pupils' Abilities and Skills at Some Egyptian Underprivileged Areas (Slums). (Field Study)
- Author
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El-Tayeb, Mahmoud N., El Nashar, Moham, Zeid, Mai M., El-Sayed, Magda, Ramadan, Mohamed A., Hamdi, Safia M., El-Affy, Nabila, Ebeid, Amina K., El-Marasi, Sonia S., and Abou-Elmahty, Maher
- Abstract
Through directing concerted efforts and educational services of seven Faculties of Helwan University towards socially underprivileged pupils in slum areas (EL-Marg area in big Cairo) this research project had two main aims: firstly, modifying a set of arbitrary behaviors of those pupils, in a trial to develop some behavior skills associated with positive social values (character building); Secondly, developing their loyalty values and attitude towards studying. This was done by using various educational activities through all school subjects as well as involving pupils in practicing different activities in sports, music, art, family economics, and social work that support and sharpen their skills as well as other learning outcomes and build their characters in an integrated and civilized manner. This was within the frame of the "100 Schools National Development Project" under the auspices of Egypt's First Lady/ Suzanne Mubarak. The seven faculties presented an integrated educational program based on a variety of learning and instructional activities that are suitable for the pupils' age group (6:12 years old). This field study of the project was implemented in one primary school in El-Marg educational zone over the full academic year (2009/2010). The project made use of pre-diagnostic, intervene and post measurement tests. Data was collected through four main tools: attitude towards studying measure, loyalty measure, behavior problems measure, and physical Ability test as both pre- and post-intervention measurement tools. Collected data is illustrated through tables and graphs throughout the paper followed by narrative analysis. Results indicated that there were significant modifications in the pupils' behaviors, as they became able to behave in a well civilized manner with their colleagues, teachers and other adults in the school also they became more motivated and engaged in the learning process. Moreover, results assured that incorporating integrated learning activities into daily school schedule improved pupils' self esteem, loyalty, and positive attitude towards school. The project team recommends continuation of this research project and the dissemination of its aims in many schools of different Egyptian governorates through the Egyptian universities to serve pupils living in slums. Two appendixes are included: (1) The loyalty photographical measure; and (2) The situation based copy of the loyalty measure. (Contains 11 tables.)
- Published
- 2010
33. Changes in adsorption heights upon self-assembly of bicomponent supramolecular networks
- Author
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Goiri, Elizabeth, Matena, Manfred, El-Sayed, Afaf, Lobo-Checa, Jorge, Borghetti, Patrizia, Rogero, Celia, Detlefs, Blanka, Duvernay, Julien, Ortega, J. Enrique, and de Oteyza, Dimas G.
- Subjects
Condensed Matter - Materials Science - Abstract
Codeposition of two molecular species [CuPc (donor) and PFP (acceptor)] on noble metal (111) surfaces leads to the self-assembly of an ordered mixed layer with maximized donor-acceptor contact area. The main driving force behind this arrangement is assumed to be the intermolecular C-F...H-C hydrogen-bond interactions. Such interactions would be maximized for a coplanar molecular arrangement. However, precise measurement of molecule-substrate distances in the molecular mixture reveals significantly larger adsorption heights for PFP than for CuPc. Most surprisingly, instead of leveling to increase hydrogen bond interactions, the height difference is enhanced in mixed layers as compared to the heights found in single component CuPc and PFP layers, resulting in an overall reduced interaction with the underlying substrate. The influence of the increased height of PFP on the interface dipole is investigated through work function measurements.
- Published
- 2013
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34. Understanding Charge Transfer in Donor-Acceptor/Metal Systems: A Combined Theoretical and Experimental Study
- Author
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Cabellos, J. L., Mowbray, D. J., Goiri, E., El-Sayed, A., Floreano, L., de Oteyza, D. G., Rogero, C., Ortega, J. E., and Rubio, A.
- Subjects
Condensed Matter - Materials Science - Abstract
We develop an effective potential approach for assessing the flow of charge within a two-dimensional donor-acceptor/metal network based on core-level shifts. To do so, we perform both density functional theory (DFT) calculations and x-ray photoemission spectroscopy (XPS) measurements of the core-level shifts for three different monolayers adsorbed on a Ag substrate. Specifically, we consider perfluorinated pentacene (PFP), copper phthalocyanine (CuPc) and their 1:1 mixture (PFP+CuPc) adsorbed on Ag(111)., Comment: 12 pages, 10 figures
- Published
- 2013
- Full Text
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35. The Effectiveness of Reflection in Developing Students' Oracy in English at the Faculties of Tourism and Hospitality
- Author
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Zayed, Jihan El-Sayed Ahm
- Abstract
This study aimed at determining the effectiveness of using reflection in developing Tourism and Hospitality students' oracy in English. Two modes of reflection (i.e., "active reflection" and "proactive reflection") were used for developing two aspects of oracy: language awareness of some features of spoken language (i.e., "phonology," "vocabulary," "grammar," and "pragmatics") and some oral performance criteria (i.e., "active listening," "turn-taking," "questioning," "responding," and "overall performance quality"). To investigate the problem of the study, two sections from third-year, Tourism students--Faculty of Tourism and Hospitality, Suez Canal University--were randomly assigned to be either the experimental group (EG) or the control group (CG). Both groups studied six spoken texts; the former had the chance to practice reflection with its two modes while the latter had not that chance. They were pre-tested and post-tested on their oracy. A "t" test for independent samples demonstrated that there was a statistically significant difference between the mean score of the EG and that of the CG on the post OT favoring the EG in language awareness including vocabulary, grammar, and pragmatics and oral performance including "active listening," "turn-taking," "questioning," "responding," and "overall performance quality." Therefore, it was concluded that using reflection is effective in developing Tourism and Hospitality students' oracy in English. The following are appended: (1) Pilot Study; (2) Manuscript Submitted for Validation; (3) Oracy Test (OT); (4) A Scoring Rubric (SR) for Part II of the OT; (5) Spoken Journal (SJ); (6) Student Questionnaire (SQ); (7) Sessions Plans; and (8) Jury Members. An Arabic summary is included.
- Published
- 2009
36. Analysis of Reactivity Induced Accident for Control Rods Ejection with Loss of Cooling
- Author
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Saad, Hend Mohammed El Sayed, Mansour, Hesham Mohammed Mohammed, and Wahab, Moustafa Aziz Abd El
- Subjects
Nuclear Theory - Abstract
Understanding of the time-dependent behavior of the neutron population in nuclear reactor in response to either a planned or unplanned change in the reactor conditions, is a great importance to the safe and reliable operation of the reactor. In the present work, the point kinetics equations are solved numerically using stiffness confinement method (SCM). The solution is applied to the kinetics equations in the presence of different types of reactivities and is compared with different analytical solutions. This method is also used to analyze reactivity induced accidents in two reactors. The first reactor is fueled by uranium and the second is fueled by plutonium. This analysis presents the effect of negative temperature feedback with the addition positive reactivity of control rods to overcome the occurrence of control rod ejection accident and damaging of the reactor. Both power and temperature pulse following the reactivity- initiated accidents are calculated. The results are compared with previous works and satisfactory agreement is found., Comment: 11 pages,4 figures
- Published
- 2013
37. Building a health care data warehouse for cancer diseases
- Author
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Sheta, Osama El-Sayed and Eldeen, Ahmed Nour
- Subjects
Computer Science - Databases - Abstract
This paper presents architecture for health care data warehouse specific to cancer diseases which could be used by executive managers, doctors, physicians and other health professionals to support the healthcare process. The data today existing in multi-sources with different formats makes it necessary to have some techniques for data integration. Executive managers need access to Information so that decision makers can react in real time to changing needs. Information is one of the most factors to an organization success that executive managers or physicians would need to base their decisions on, during decision making. A health care data warehouse is therefore necessary to integrate the different data sources into a central data repository and analysis this data., Comment: 8 pages,4 figures
- Published
- 2012
- Full Text
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38. New Edge Detection Technique based on the Shannon Entropy in Gray Level Images
- Author
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El-Sayed, Mohamed A. and Hafeez, Tarek Abd-El
- Subjects
Computer Science - Computer Vision and Pattern Recognition ,94A17, 68U10, 94A08 - Abstract
Edge detection is an important field in image processing. Edges characterize object boundaries and are therefore useful for segmentation, registration, feature extraction, and identification of objects in a scene. In this paper, an approach utilizing an improvement of Baljit and Amar method which uses Shannon entropy other than the evaluation of derivatives of the image in detecting edges in gray level images has been proposed. The proposed method can reduce the CPU time required for the edge detection process and the quality of the edge detector of the output images is robust. A standard test images, the real-world and synthetic images are used to compare the results of the proposed edge detector with the Baljit and Amar edge detector method. In order to validate the results, the run time of the proposed method and the pervious method are presented. It has been observed that the proposed edge detector works effectively for different gray scale digital images. The performance evaluation of the proposed technique in terms of the measured CPU time and the quality of edge detector method are presented. Experimental results demonstrate that the proposed method achieve better result than the relevant classic method.
- Published
- 2012
39. A New Algorithm Based Entropic Threshold for Edge Detection in Images
- Author
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El-Sayed, Mohamed A.
- Subjects
Computer Science - Computer Vision and Pattern Recognition ,94A17, 68U10, 94A08 - Abstract
Edge detection is one of the most critical tasks in automatic image analysis. There exists no universal edge detection method which works well under all conditions. This paper shows the new approach based on the one of the most efficient techniques for edge detection, which is entropy-based thresholding. The main advantages of the proposed method are its robustness and its flexibility. We present experimental results for this method, and compare results of the algorithm against several leading edge detection methods, such as Canny, LOG, and Sobel. Experimental results demonstrate that the proposed method achieves better result than some classic methods and the quality of the edge detector of the output images is robust and decrease the computation time.
- Published
- 2012
40. Performance of the Google Desktop, Arabic Google Desktop and Peer to Peer Application in Arabic Language
- Author
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Hajjar, Abd El Salam Al, Ismail, Anis, Hajjar, Mohammad, and El-Sayed, Mazen
- Subjects
Computer Science - Information Retrieval - Abstract
The Arabic language is a complex language; it is different from Western languages especially at the morphological and spelling variations. Indeed, the performance of information retrieval systems in the Arabic language is still a problem. For this reason, we are interested in studying the performance of the most famous search engine, which is a Google Desktop, while searching in Arabic language documents. Then, we propose an update to the Google Desktop to take into consideration in search the Arabic words that have the same root. After that, we evaluate the performance of the Google Desktop in this context. Also, we are interested in evaluation the performance of peer-to-peer application in two ways. The first one uses a simple indexation that indexes Arabic documents without taking in consideration the root of words. The second way takes in consideration the roots in the indexation of Arabic documents. This evaluation is done by using a corpus of ten thousand documents and one hundred different queries., Comment: 15 pages, 4 figures
- Published
- 2012
41. Energy Levels, Transition Probabilities and Electron-Impact Excitations Of Ge-Like Pr, Nd, Pm, Sm and Eu ions
- Author
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Nagy, O. and El_Sayed, Fatma
- Subjects
Physics - Atomic Physics - Abstract
Energies, wavelengths, transition probabilities, and oscillator strengths have been calculated for the 4s24p2-4s4p3, 4s24p2-4s24p4d and 4s4p3-4p4 allowed transitions in heavy Ge-like ions with Z=59-63. The fully relativistic Multiconfiguration Dirac-Fock (MCDF) method taking into account both the correlations within the n=4 complex and the quantum electrodynamic (QED) effects have been used in the calculations. MCDFGME code is used to calculate electron impact excitation cross sections for the 4s24p2-4s4p3 and 4s24p2-4s24p4d transitions with plane-wave Born approximation. The results of Pr XXVIII, Nd XXIX, Pm XXX, Sm XXXI and Eu XXXII are compared with HFR method results., Comment: 6 pages, 5 figures, 16 tables
- Published
- 2010
42. On applications of Ulam-Hyers stability in biology and economics
- Author
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Ahmed, E., El-Sayed, A. M. A., El-Saka, H. A. A., and Ashry, Gehan A.
- Subjects
Nonlinear Sciences - Chaotic Dynamics ,Quantitative Biology - Other Quantitative Biology - Abstract
We argue that Ulam-Hyers stability concept is quite significant in realistic problems in numerical analysis, biology and economics. A generalization to nonlinear systems is proposed and applied to the logistic equation (both differential and difference), SIS epidemic model, Cournot model in economics and a reaction diffusion equation. To the best of our knowledge this is the first time Ulam-Hyers stability is considered from the applications point of view., Comment: 6 pages, 0 figures
- Published
- 2010
43. The Effectiveness of the Dramatic Activities in the Development of the Oral Performance Skills of Prep Students in English
- Author
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Zayed, Jihan El-Sayed Ahm
- Abstract
The goal of this study was to determine the effect of using some dramatic activities on developing the oral performance skills of second year prep school students in English. The dramatic activities included storytelling, story-acting, pantomime, puppetry, role-playing, reader's theater and choral reading. The oral performance skills were "pronunciation", "vocabulary", "word-formation", "grammar" and language functions. To investigate the problem of the study, the experimental design was adopted. Seventy-eight girls of second year prep students in two classes from Sammanoud Prep School for Girls were chosen as the subjects of the study. The two classes were randomly assigned to either the experimental or the control group. The experimental group was taught the first term units including stories of Hello! 4 using the dramatic activities. On the other hand, the control group studied these units as recommended by the Ministry of Education. The two groups were pretested and posttested on their oral performance skills. For investigating the differences between the mean scores of the experimental group and those of the control group on the oral performance pre- and post-test, the t-test for independent samples was applied. The results demonstrated that there were statistically significant differences between the mean score of the experimental group and those of the control group on the oral performance post-test favoring the experimental group in the oral performance in general and in the skills of "pronunciation", "word-formation", "grammar" and "language functions". Based upon these findings and in the light of the t-values of the pre- and post-testing for each skill of both the experimental and control groups, it was concluded that using the dramatic activities is highly effective in developing the oral performance skills of second year prep students in English.
- Published
- 2003
44. Ethernet Networks: Current Trends and Tools
- Author
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El-Sayed, Abdulqader M.
- Subjects
Computer Science - Networking and Internet Architecture - Abstract
Ethernet topology discovery has gained increasing interest in the recent years. This trend is motivated mostly by increasing number of carrier Ethernet networks as well as the size of these networks, and consequently the increasing sales of these networks. To manage these networks efficiently, detailed and accurate knowledge of their topology is needed. Knowledge of a network's entities and the physical connections between them can be useful in various prospective. Administrators can use topology information for network planning and fault detecting. Topology information can also be used during protocol and routing algorithm development, for performance prediction and as a basis for accurate network simulations. From a network security perspective, threat detection, network monitoring, network access control and forensic investigations can benefit from accurate network topology information. In this paper, we analyze market trends and investigate current tools available for both research and commercial purposes., Comment: Proceedings of IEEE International Conference on Advanced Information Networking and Applications, 8 pages
- Published
- 2009
45. On stability, persistence and Hopf bifurcation of fractional order dynamical system
- Author
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El-Saka, Hala, Ahmed, E., Shehata, M. I., and -El-Sayed, A. M. A.
- Subjects
Nonlinear Sciences - Cellular Automata and Lattice Gases ,Nonlinear Sciences - Chaotic Dynamics - Abstract
This is a preliminary study for bifurcation in fractional order dynamical systems. Stability, persistence and hopf bifurcation are studied. Some studies are also done for functional equations., Comment: 6 pages
- Published
- 2008
46. Strong Electromagnetic Waves Propagation in an Electron-Positron-Ion Plasma
- Author
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Ashry, Magdy Yassin EL and Shalaan, EL Sayed Ibrahim
- Subjects
Physics - Plasma Physics - Abstract
The main purpose of this work is the investigation of the influence of electron-positron-ion on the electrostatic wakefields that are driven by intense, short electromagnetic wave packets in a three component unmagnetized plasma. The equations that describes the driven electrostatic wakefield are given in the form of system of nonlinear differential equations. The solution of that system was carried out numerically and the results are displayed graphically., Comment: 11 pages, Latex, 4 figures
- Published
- 2002
47. Time Resolved Optical Studies on The Plasmonic Field Enhancement of Bacteriorhodopsin Proton Photo-current: Final Technical Report Covering Aug 31, 2015–Aug 31, 2016
- Author
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El-Sayed, Mostafa A., primary
- Published
- 2016
- Full Text
- View/download PDF
48. Development of Targeted Nanobubbles for Ultrasound Imaging and Ablation of Metastatic Prostate Cancer Lesions
- Author
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El-Sayed, Mohamed E., primary
- Published
- 2014
- Full Text
- View/download PDF
49. Enhancing livelihood opportunities for young women in rural Upper Egypt: The Neqdar Nesharek Program
- Author
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Ramadan, Nada, primary, Abdel-Tawab, Nahla, additional, El Sayed, Khaled, additional, and Roushdy, Rania, additional
- Published
- 2014
- Full Text
- View/download PDF
50. Heavy Ion Transient Characterization of a Photobit Hardened-by-Design Active Pixel Sensor Array
- Author
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Marshall, Paul W, Byers, Wheaton B, Conger, Christopher, Eid, El-Sayed, Gee, George, Jones, Michael R, Marshall, Cheryl J, Reed, Robert, Pickel, Jim, and Kniffin, Scott
- Subjects
Electronics And Electrical Engineering - Abstract
This paper presents heavy ion data on the single event transient (SET) response of a Photobit active pixel sensor (APS) four quadrant test chip with different radiation tolerant designs in a standard 0.35 micron CMOS process. The physical design techniques of enclosed geometry and P-channel guard rings are used to design the four N-type active photodiode pixels as described in a previous paper. Argon transient measurements on the 256 x 256 chip array as a function of incident angle show a significant variation in the amount of charge collected as well as the charge spreading dependent on the pixel type. The results are correlated with processing and design information provided by Photobit. In addition, there is a large degree of statistical variability between individual ion strikes. No latch-up is observed up to an LET of 106 MeV/mg/sq cm.
- Published
- 2002
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