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Ground motion spatial variability effects on seismic response control of cable-stayed bridges

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Earthquake Engineering and Engineering Vibration 2011年第1期10卷 37-49页

作者： shehata E. Abdel Raheem Toshiro Hayashikawa Uwe Dorka Civil Engineering Department Faculty of Engineering Assiut University Bridge and Structural Design Engineering Hokkaido University Steel & Composite Structures Kassel Universitt

The spatial variability of input ground motion at supporting foundations plays a key role in the structural response of cable-stayed bridges （CSBs）; therefore, spatial variation effects should be included in the analysis and design of effective vibration control systems. The control of CSBs represents a challenging and unique problem, with many complexities in modeling, control design and implementation, since the control system should be designed not only to mitigate the dynamic component of the structural response but also to counteract the effects of the pseudo-static component of the response. The spatial variability effects on the feasibility and efficiency of seismic control systems for the vibration control of CSBs are investigated in this paper. The assumption of uniform earthquake motion along the entire bridge may result in quantitative and qualitative differences in seismic response as compared with those produced by uniform motion at all supports. A systematic comparison of passive and active system performance in reducing the structural responses is performed, focusing on the effect of the spatially varying earthquake ground motion on the seismic response of a benchmark CSB model with different control strategies, and demonstrates the importance of accounting for the spatial variability of excitations.

关键词： cable-stayed bridge vibration control earthquake spatial variation seismic design semi-active control

A Practical Study of Intelligent Image-Based Mobile Robot for Tracking Colored objects

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Computers, Materials & Continua 2024年第8期80卷 2181-2197页

作者： Mofadal Alymani Mohamed Esmail Karar Hazem Ibrahim shehata College of Computing and Information Technology Shaqra UniversityShaqra11961Saudi Arabia Faculty of Electronic Engineering Menoufia UniversityMenouf32952Egypt Faculty of Engineering Zagazig UniversityZagazig44519Egypt

object tracking is one of the major tasks for mobile robots in many real-world ***,artificial intelligence and automatic control techniques play an important role in enhancing the performance of mobile robot *** contrast to previous simulation studies,this paper presents a new intelligent mobile robot for accomplishing multi-tasks by tracking red-green-blue(RGB)colored objects in a real experimental ***,a practical smart controller is developed based on adaptive fuzzy logic and custom proportional-integral-derivative(PID)schemes to achieve accurate tracking results,considering robot command delay and tolerance *** design of developed controllers implies some motion rules to mimic the knowledge of experienced *** scenarios of three colored object combinations have been successfully tested and evaluated by using the developed controlled image-based robot *** PID control failed to handle some tracking scenarios in this *** proposed adaptive fuzzy PID control achieved the best accurate results with the minimum average final error of 13.8 cm to reach the colored targets,while our designed custom PID control is efficient in saving both average time and traveling distance of 6.6 s and 14.3 cm,*** promising results demonstrate the feasibility of applying our developed image-based robotic system in a colored object-tracking environment to reduce human workloads.

关键词： Mobile robot autonomous systems fuzzy logic control real-time image processing

Developed Fall Detection of Elderly Patients in Internet of Healthcare Things

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Computers, Materials & Continua 2023年第8期76卷 1689-1700页

作者： omar Reyad Hazem Ibrahim shehata Mohamed Esmail Karar College of Computing and Information Technology Shaqra UniversityP.O.Box 33Shaqra11961Saudi Arabia Faculty of Computers and Artificial Intelligence Sohag UniversitySohag82524Egypt Faculty of Engineering Zagazig UniversityZagazig44519Egypt Faculty of Electronic Engineering Menoufia UniversityMenouf32952Egypt

Falling is among the most harmful events older adults may *** the continuous growth of the aging population in many societies,developing effective fall detection mechanisms empowered by machine learning technologies and easily integrable with existing healthcare systems becomes *** paper presents a new healthcare Internet of Health Things(IoHT)architecture built around an ensemble machine learning-based fall detection system(FDS)for older *** to deep neural networks,the ensemble multi-stage random forest model allows the extraction of an optimal subset of fall detection features with minimal *** number of cascaded random forest stages is automatically *** study uses a public dataset of fall detection samples called SmartFall to validate the developed fall detection *** SmartFall dataset is collected based on the acquired measurements of the three-axis accelerometer in a *** scenario in this dataset is classified and labeled as a fall or a *** comparison to the three machine learning models—K-nearest neighbors(KNN),decision tree(DT),and standard random forest(SRF),the proposed ensemble classifier outperformed the other models and achieved 98.4%*** developed healthcare IoHT framework can be realized for detecting fall accidents of older people by taking security and privacy concerns into account in future work.

关键词： Elderly population fall detection wireless sensor networks Internet of health things ensemble machine learning

Finite element modeling assumptions impact on seismic response demands of MRF-buildings

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Earthquake Engineering and Engineering Vibration 2018年第4期17卷 821-834页

作者： shehata E Abdel Raheem Ahmed K Abdel Zaher Ahmed MA Taha Civil Engineering Department Engineering College Taibah University Civil Engineering Department Faculty of Engineering Assiut University

Recent seismic events have raised concerns over the safety and vulnerability of reinforced concrete moment resisting frame ＂RC-MRF＂ buildings. The seismic response of such buildings is greatly dependent on the computational tools used and the inherent assumptions in the modelling process. Thus, it is essential to investigate the sensitivity of the response demands to the corresponding modelling assumption. Many parameters and assumptions are justified to generate effective structural finite element（FE） models of buildings to simulate lateral behaviour and evaluate seismic design demands. As such, the present study focuses on the development of reliable FE models with various levels of refinement. The effects of the FE modelling assumptions on the seismic response demands on the design of buildings are investigated. the predictive ability of a FE model is tied to the accuracy of numerical analysis; a numerical analysis is performed for a series of symmetric buildings in active seismic zones. The results of the seismic response demands are presented in a comparative format to confirm drift and strength limits requirements. A proposed model is formulated based on a simplified modeling approach, where the most refined model is used to calibrate the simplified model.

关键词： RC-MRF buildings design codes provisions seismic design finite element modeling modeling assumptions response demands

Geochemistry of an Alaskan-type mafic-ultramafic complex in Eastern Desert, Egypt:New insights and constraints on the Neoproterozoic island arc magmatism

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Geoscience Frontiers 2019年第3期10卷 941-955页

作者： Shehta E.Abdallah shehata Ali Mohamed A.obeid Geology Department Faculty of Science Zagazig University Geology Department Faculty of Science Minia University Geology Department Faculty of Science Fayoum University Faculty of Petroleum and Mining Sciences Alexandria University (Matrouh Branch)

Mikbi intrusion(MI) is a part of the Neoproterozoic Nubian Shield located along the NE-SW trending major fracture zones prevailing southern Eastern Desert of Egypt. In this study, we present for the first time detailed mineralogical and bulk-rock geochemical data to infer some constraints on the parental magma genesis and to understand the tectonic processes contributed to MI formation. Lithologically, it is composed of fresh peridotite, clinopyroxenite, hornblendite, anorthosite, gabbronorite, pyroxene amphibole gabbro, amphibole gabbro and diorite. All rocks have low Th/La ratios(mostly ositive Zr and Th anomalies excluding significant crustal contamination. They show very low concentrations of Nb, Ta, Zr and Hf together with sub-chondritic ratios of Nb/Ta(2-15) and Zr/Hf(19-35),suggesting that their mantle source was depleted by earlier melting extraction event. The oxygen fugacity(logfo_2) estimated from diorite biotite is around the nickel-nickel oxide buffer(NNo) indicating crystallization from a relatively oxidized magma. Amphiboles in the studied mafic-ultramafic rocks indicate relative oxygen fugacity(i.e. ΔNNo; nickel-nickel oxide) of 0.28-3 and were in equilibrium mostly with 3.77-8.24 wt.% H_2 o_(melt)(i.e. water content in the melt), consistent with the typical values of subduction-related magmas. Moreover, pressure estimates(0.53-6.79 kbar) indicate polybaric crystallization and suggest that the magma chamber(s) was located at relatively shallow crustal levels. The enrichment in LILE(e.g., Cs, Ba, K and Sr) and the depletion in HFSE(e.g., Th and Nb) relative to primitive mantle are consistent with island arc signature. The olivine, pyroxene and amphibole compositions also reflect arc affinity. These inferences suggest that their primary magma was derived from partial melting of a mantle source that formerly metasomatized in a subduction zone setting. Clinopyroxene and bulkrock data are consistent with orogenic tholeiitic affinity. Conse

关键词： Alaskan-type complex Neoproterozoic Arc magmatism Eastern desert Egypt

Deep Forest-Based Fall Detection in Internet of Medical Things Environment

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Computer Systems Science & Engineering 2023年第6期45卷 2377-2389页

作者： Mohamed Esmail Karar omar Reyad Hazem Ibrahim shehata College of Computing and Information Technology Shaqra UniversityP.O.Box 33Shaqra11961Saudi Arabia Department of Industrial Electronics and Control Engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Computer Science Department Faculty of Computers and Artificial IntelligenceSohag UniversitySohag82524Egypt Department of Computer and Systems Engineering Faculty of EngineeringZagazig UniversityZagazig44519Egypt

This article introduces a new medical internet of things(IoT)framework for intelligent fall detection system of senior people based on our proposed deep forest *** cascade multi-layer structure of deep forest classifier allows to generate new features at each level with minimal hyperparameters compared to deep neural ***,the optimal number of the deep forest layers is automatically estimated based on the early stopping criteria of validation accuracy value at each generated *** suggested forest classifier was successfully tested and evaluated using a public SmartFall dataset,which is acquired from three-axis accelerometer in a *** includes 92781 training samples and 91025 testing samples with two labeled classes,namely non-fall and *** results of our deep forest classifier demonstrated a superior performance with the best accuracy score of 98.0%compared to three machine learning models,i.e.,K-nearest neighbors,decision trees and traditional random forest,and two deep learning models,which are dense neural networks and convolutional neural *** considering security and privacy aspects in the future work,our proposed medical IoT framework for fall detection of old people is valid for real-time healthcare application deployment.

关键词： Elderly population fall detection wireless sensor networks internet of medical things deep forest

Robust design and analysis for opto-mechanical two array laser warning system

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Defence Technology（防务技术） 2023年第9期27卷 46-52页

作者： Mazhar Tayel Mohamed shehata Mohamed Mabrouk Abdlarhman Adel Mohamed Shady Shokry Mostafa Alshershby Faculty of Engineering Alexandria UniversityAlexandriaEgypt Egyptian Air Defense Collage AlexandriaEgypt Laser and optoelectronics Department Technical Research CenterEgypt

In the past three decades,laser warning systems(LWS)have emerged in great importance,as the development of laser-guided weapons,such as airborne Hellfire missiles,has increased,posing an imminent threat to vital areas and *** laser warning station(LWS)can detect,classify,identify,and give alarm from laser threat at a very short time with high ***,the designers of this system must take into account the detectability and field of view to cover the area to be *** main contribution in this research is an analytical design of LWS that consists of 24 detector elements,distributed in two arrays(2×12)***,calculating the best distance between the detectors according to the laser beam spot *** addition,enhancement laser warring sensor detection capability and detection performance FoV between the detectors to increase coverage area up to 360°.Moreover,decreasing dead zone area between the laser detectors *** calculations and illustrations made to reach the best systematic design.

关键词： LWS Field of view Detector elements

Stiffness increase of red blood cells during storage

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Microsystems & Nanoengineering 2018年第1期4卷 484-489页

作者： Zhensong Xu Yi Zheng Xian Wang Nadine shehata Chen Wang Yu Sun Department of Mechanical and Industrial Engineering University of TorontoTorontoONCanada M5S 3G8 Department of Mechanical Engineering University of MichiganAnn ArborMI48109USA Department of Medicine University of TorontoTorontoONCanada M5G 1X5 Department of Pathology and Laboratory Medicine Mount Sinai HospitalTorontoONCanada M5G 1X5 Department of Laboratory Medicine and Pathobiology University of TorontoTorontoONCanada M5G 1X5 Institute of Biomaterials and Biomedical Engineering University of TorontoTorontoONCanada M5S 3G8 Department of Electrical and Computer Engineering University of TorontoTorontoONCanada M5S 3G8

In transfusion medicine,the deformability of stored red blood cells(RBCs)changes during storage in blood *** RBC deformability can reduce the transfusion efficiency or intensify transfusion complications,such as *** paper reports the microfluidic mechanical measurement of stored RBCs under the physiological deformation mode(that is,folding).Instead of using phenomenological metrics of deformation or elongation indices(DI or EI),the effective stiffness of RBCs,a flow velocityindependent parameter,is defined and used for the first time to evaluate the mechanical degradation of RBCs during *** RBCs and RBCs stored up to 6 weeks(42 days)in the blood bank were measured,revealing that the effective stiffness of RBCs increases over the storage *** stored for 1 week started to show significantly higher stiffness than fresh RBCs,and stored RBC stiffness degraded faster during the last 3 weeks than during the first 3 ***,the results indicate that the time points of the effective stiffness increase coincide well with the degradation patterns of S-nitrosothiols(SNo)and adenosine triphosphate(ATP)in RBC storage lesions.

关键词： red blood cell effective stiffness deformability storage lesions microfluidics

Middle East respiratory syndrome coronavirus： a comprehensive review

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Frontiers of Medicine 2016年第2期10卷 120-136页

作者： Mahmoud M. shehata Mokhtar R. Gomaa Mohamed A. Ali Ghazi Kayali Center of Scientific Excellence for Influenza Viruses National Research Centre Giza Egypt Department of Infectious Diseases St. Jude Children's Research Hospital Memphis TN 38105 USA

The Middle East respiratory syndrome eoronavirus was first identified in 2012 and has since then remained uncontrolled. Cases have been mostly reported in the Middle East, however travel-associated cases and outbreaks have also occurred. Nosocomial and zoonotic transmission of the virus appear to he the most important routes. The infection is severe and highly fatal thus necessitating rapid and efficacious interventions. Here, we performed a comprehensive review of published literature and summarized the epidemiology of the virus. In addition, we summarized the virological aspects of the infection and reviewed the animal models used as well as vaccination and antiviral tested against it.

关键词： MERS coronavirus review