1,721,454 research outputs found
Elsayed Mohamed
No full textHyperdimensional Time Theory (HTT)
Abstract
The Hyperdimensional Time Theory (HTT) proposes that the flow of time is inversely proportional to the
number of spatial dimensions within a cosmic system. According to HTT, universes or regions with higher
dimensional frameworks allow for higher maximum achievable speeds, approaching or even reaching the
speed of light, while simultaneously experiencing a significant reduction in temporal flow. This model
suggests that the universal speed limit observed in our three-dimensional space is indirect evidence of hidden
dimensional constraints. Mathematical models are developed to describe this coupling between dimensions,
time, and speed. Moreover, a practical experimental framework is proposed, involving ultra-precise
measurements of light speed and time dilation variations across different gravitational environments, aiming to
detect the influence of higher dimensions on our observable universe
POST-OCCUPANCY EVALUATION FOR RESIDENTIAL BUILDINGS IN THE EU (Case Study: Italy-Finland)
No full textBuilding retrofitting is generally considered a better alternative to demolition when it
comes to upgrading and improving buildings' performance since constructing
buildings from scratch emits much more embodied carbon. Retrofitting options and
solutions are based on research studies conducted in laboratories, simulation
programs, and the most current technologies. Architects and engineers tend to use
the available techniques, tools, and materials universally across a range of buildings,
climate zones and occupants, but other factors, including building location,
orientation, area, design, occupant behaviour, etc., may have a significant impact on
building performance. When these other factors are ignored, building refurbishment
may fail to meet occupants' needs and comfort. This may result in unexpected
performance that is neither desirable nor necessary regarding energy consumption,
indoor environment quality, occupant satisfaction, and indoor health and well-being
conditions.
Residential buildings with a wide range of types; detached, semi-detached, terraced
houses and flats of different ages representing different types of inefficient
construction in terms of energy demand with varying user occupancy patterns and
activities provide a challenge for the energy manager. The need to study and
evaluate the performance of residential buildings is because there is a lack of
evidence about how advanced systems can be used for upgrading residential
buildings, as well as a discrepancy, observed between actual and predicted solutions
for current retrofitted buildings in the European Union.
The research utilizes post-occupancy evaluation (POE) of retrofitted residential
buildings as a technique that can assist in evaluating buildings’ indoor environmental
quality (IEQ) performance, people’s satisfaction with IEQ, and their health and well-
being conditions. This study aims to achieve its objective through a literature review
of the topic, in addition to two field studies conducted in Italy and Finland
Towards Multimodal Cognitive Architecture for Human-Robot Shared Perception
No full textFor many years, robots have been used in specific repetitive tasks, especially in industrial contexts. However, in recent years, robots start to be deployed in interactive and collaborative contexts with humans. The cognitive capabilities of robots are one of the main open challenges for effective interactions. Shared Perception is one of the important skills that are important for effective collaboration. In robotics, shared perception was studied from the human perspective (how to enable shared perception in an interaction with a robot). In the cognitive architectures side of research shared perception was never studied except for some skills that are important to enable shared perception (perspective talking, gaze understanding, and gaze following). Therefore, my research firstly bases five general required skills for robotics in shared perception which are Having a common representation, Expressing effective communication, Spatiotemporal coordination, Affective modulation mechanism, and Understanding the other. Indeed, it is a complex skill and requires more than a Ph.D. to cover all concepts. Therefore, the main research activities were building cognitive architectures that try to address different concepts within the first three skills. The main aim is to build cognitive architectures that take the robots one step towards shared perception cognitive architecture. The architectures are built sequentially and based on each other. The approach to building these architectures has four characteristics Biological inspiration, Multi-modality more specifically audio and vision, Generalization (Not targeting a specific task), and Attention-based (Starting with state-of-the-art attention models and building upwards to include higher cognitive capabilities). Following this, the Ph.D. has three main research questions as the following:
1. How can we integrate state-of-the-art vision and audio models to allow the robot to jointly attend to the environment with a human partner? Is the behavior of the robot effectively received by the human partner? and What is the mutual influence between the robot and the human partner during the interaction using this architecture?
2. How can this integrated audio-visual attention architecture be used by the robot to understand a complex audio-visual environment? How can uncertainty be handled? How can the robot actively perceive the environment?
3. Can this perception architecture be generalized to different robots and applied to a complex task that requires coordination with another agent?
Each question of these three questions is related to one or more skills within the first three required skills from the mentioned five skills above. Trying to address these questions, I designed a series of architectures that are implemented cumulatively and showed how different cognitive blocks can be integrated to improve the perception capabilities of the robot, dealing with uncertainty, and noise in general conditions. The validation of these architectures was done using multiple robotic platforms (iCub, Pepper robot, and Essex agricultural robot) in different conditions with the robot only, with the existence of a human partner, with another robotic agent, and in a real-world application.
Further, I did some research activities related to improving the auditory modality. This was due to the outcomes of the experiments where audio processing was the main bottleneck process in the system. The improvements were building a developmental pipeline for audio. I used this pipeline to create an alternative model for audio localization that achieved very promising results. The second activity in auditory improvements was exploring alternative learning processes other than deep learning models that are more lightweight and suitable for robotic applications. Although the proposed architectures don’t address all the required skills of shared perception, they address some points in that direction and also some open challenges in the field of cognitive architecture. More specifically, mutual influence in human-robot interaction scenarios, cross-modal interaction, and general unified perception modeling. The last integrated proposed architecture is a solid base for the development of a shared perception cognitive architecture for robots. Finally, this work opens multiple research lines in the future. The future development research lines can be divided into three main categories which are Integrating other cognitive components, Improving the individual modalities, and Applications, and Modeling the impairments
Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics
No full textZidan, Islam Mohammad, El-Saiedy, Elsayed Mohamed Ahmed K., Abou-Elella, Gomaa Mohamed, Hassan, Mourad Fahmy (2022): Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics. Persian Journal of Acarology 11 (4): 731-752, DOI: 10.22073/pja.v11i4.7621
DDPG Performance in THz Communications over Cascaded RISs: A Machine Learning Solution to the Over-Determined System
Full text linkTHz technology is considered a key element in 6G wireless communication because it provides ultra-high bandwidths, considerable capacities, and significant gains. However, wireless systems operating at high frequencies are faced with uncertainty and highly dynamic channels. Reflecting intelligent surfaces (RISs) can increase the range of the THz communication links and boost the rate at the receiver. In contrast to the existing literature, we investigate the scenario of multiple access multi-hop (cascaded) RISs uplink THz networks in a correlated channel environment. We show that our inspected cascaded RIS system is over-determined and that the rate maximization optimization problem is non-convex. To this end, we derive a closed-form expression of the received power and derive an analytical solution based on pseudo-inverse to obtain optimum RISs' phase shifts that maximize the received signal power and hence increase the rate. In addition, we utilize deep reinforcement learning (DRL), which is capable of solving non-convex optimization problems, to obtain the optimum cascaded RISs' phase shifts at the receiver taking into account the situation of the spatially correlated channels. Simulation results demonstrate that the DRL algorithm achieves higher rates than the mathematical sub-optimal method and the case of randomized phases
Figure 2 in Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics
No full textFigure 2. Schematic diagram of the experiment's plantation and IPM methodology, C.n: Cydnoseius negevi, A.s: Amblyseius swirskii, and P.p Phytoseiulus persimilis. (Photo credits: Dr. Zidan has created this diagram on www.biorender.com).Published as part of Zidan, Islam Mohammad, El-Saiedy, Elsayed Mohamed Ahmed K., Abou-Elella, Gomaa Mohamed & Hassan, Mourad Fahmy, 2022, Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics, pp. 731-752 in Persian Journal of Acarology 11 (4) on page 734, DOI: 10.22073/pja.v11i4.76217, http://zenodo.org/record/744759
Figure 1 in Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics
No full textFigure 1. Google Earth map photography of the experimental locations (pointed with pin) – i) Om Sabir, Kom Hamada, El Beheira Governorate (30° 29' 50.6" N, 30° 46' 18.8" E), and ii) Kom Oshim, Fayoum Governorate (29° 34' 40.9" N, 30° 55' 38.3" E).Published as part of Zidan, Islam Mohammad, El-Saiedy, Elsayed Mohamed Ahmed K., Abou-Elella, Gomaa Mohamed & Hassan, Mourad Fahmy, 2022, Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics, pp. 731-752 in Persian Journal of Acarology 11 (4) on page 733, DOI: 10.22073/pja.v11i4.76217, http://zenodo.org/record/744759
Economic growth and development in Egypt
Full text linkThesis(Master) -- KDI School: Master of Public Policy, 2020This research is to measure the degree of significance of different aspects of the economy to determine what factors affect the economic growth performance in Egypt. Time series analysis will be used to identify the impact of different economic factors on economic development performance in Egypt over the period 1985-2015. Ordinary Least Square technique will be applied in this paper. The first step was testing the stationarity of data using Augmented Dickey-Fuller unit root test to avoid spurious regression results. The results of the analysis showed that all factors are stationary at first difference. After that, the regression model was tested, and the results revealed that foreign direct investment has an insignificant effect on GDP per capita in Egypt while government consumption expenditures, contributing family workers and secondary school enrollment rate can affect GDP per capita positively and significantly. The results also showed a negative and significant Impact of conditions of trade and household consumption expenditures on economic evolution and dilation in Egypt. The policy implications based on the results of the test suggest more focus on the allocation and quality of foreign direct investment in different sections in Egypt. Additionally, government consumption expenditures would be beneficial for economic growth in particular spending on national defense and security. Moreover, promoting exports is a necessity to enhance trade conditions and reduce its adverse effect on economic boom or prosperity. Households consumption expenditure is required to be reduced to save more money for longterm investment. The study also suggested that government could facilitate the regulations to operate the family business. Finally, enhancing education quality is essential for economic development through providing better technologies and teaching methods.CHAPTER I: INTRODUCTION
Chapter II: LITERATURE REVIEW
Chapter III: HISTORICAL OVERVIEW OF EGYPTIAN ECONOMIC GROWTH
Chapter V: POLICY IMPLICATIONS AND RECOMMENDATIONS
Chapter VI: ConclusionmasterpublishedAhmed Elsayed Mohamed Morsy ERAK
Sensor cromo-fluorógeno selectivo para la detección de Cu2 + en solución acuosa
No full text[EN] A simple chemosensor consisted of an Imidazole derivative (N,N-dimethyl-4-(4,5-di(thiophen-2-yl)-1H-imidazol-2-yl)benzenamine) was synthesized and characterized. The chemosensor 1 showed a selective colorimetric sensing ability for Cu2+ by changing colour from pale yellow to red in aqueous solutions facilitating naked eye detection of Cu2+. The UV/Vis titration in aqueous solutions (MeCN: H2O, 1:1 (v/v), pH 7.4) showed high sensitivity towards Cu2+ with a limit of detection of 4.4 μM which is lower than WHO acceptable limits (31.5 μM) in drinking water. Additionally, the fluorescence of chemosensor 1 in MeCN : H2O 1:1 (v/v) solutions (1.0 × 10-5 mol dm-3) at pH 7.4 is quenched in the presence of Cu2+.[ES] Un quimiosensor simple consistente en un derivado de imidazol (N, N-dimetil-4- (4,5-di (tiofen-2-il) -1H-imidazol-2-il) bencenamina) fue sintetizado y caracterizado. Este quimiosensor mostró una capacidad de detección colorimétrica selectiva para Cu2 + cambiando el color de amarillo pálido a rojo en soluciones acuosas que facilitan la detección de Cu2 + a simple vista. La valoración UV / Vis en soluciones acuosas (MeCN: H2O, 1: 1 (v / v), pH 7,4) mostró una alta sensibilidad hacia Cu2 + con un límite de detección de 4,4 μM que es inferior a los límites aceptados por la OMS (31,5 μM) para agua potable. Además, la fluorescencia de este quimiosensor en soluciones de MeCN: H _ {2} O 1: 1 (v / v) (1,0 x 10-5 mol dm - 3) a pH 7,4 se extingue en presencia de Cu2 +.Essam Elsayed Mohamed Okda, H. (2017). Sensor cromo-fluorógeno selectivo para la detección de Cu2 + en solución acuosa. Universitat Politècnica de València. https://riunet.upv.es/handle/10251/78183TFG
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