检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

评估偏头痛患者的耳蜗和听觉通路

评估偏头痛患者的耳蜗和听觉通路

Evaluating the inelastic displacement ratios of moment-resisting steel frames designed according to the Egyptian code

中国中西医结合学会眩晕病专业委员会第二次学术大会暨河南省中西医结合学会眩晕病专业委员会第三次学术大会暨眩晕高峰论坛

作者： Sherifa Ahmad Hamed Ahmed hamdy youssef Amal Mohammad Elattar Department of Neurology and Psychiatry Assiut University Hospital Department of Ear Nose and ThroatAudiology UnitAssiut University Hospital

目的:本研究旨在确定偏头痛患者耳蜗及外周和中枢性听觉通路的功能。材料和方法:评估了58例偏头痛患者和40例健康受试者使用常规诊断听力测量以及瞬态诱发耳声发射(TOAE),畸变产物耳声发射(DPOAE)和听觉脑干反应(ABR)在高和低重复率频...

目的:本研究旨在确定偏头痛患者耳蜗及外周和中枢性听觉通路的功能。材料和方法:评估了58例偏头痛患者和40例健康受试者使用常规诊断听力测量以及瞬态诱发耳声发射(TOAE),畸变产物耳声发射(DPOAE)和听觉脑干反应(ABR)在高和低重复率频率。结果:近三分之二的偏头痛患者有一个或多个异常电生理检测。与对照组相比,患者报告在1 kHz频率(右:P=0.0003;左:P=0.002),3 kHz(右:P=0.025)

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2019年第1期18卷 159-170页

作者： hamdy Abou-Elfath Structural Engineering Department Faculty of Engineering Alexandria University

Seismic codes estimate the maximum displacements of building structures under the design-basis earthquakes by amplifying the elastic displacements under the reduced seismic design forces with a deflection amplification factor(DAF). The value of DAF is often estimated as ρ× R, where R is the force reduction factor and ρ is the inelastic displacement ratio that accounts for the inelastic action of the structure according to the definition presented by FEMA P695. The purpose of this study is to estimate the ρ-ratio of moment resisting steel frames(MRSFs) designed according to the Egyptian code. This is achieved by conducting a series of elastic and inelastic time-history analyses by two sets of earthquakes on four MRSFs designed according to the Egyptian code and having 2, 4, 8 and 12 stories. The earthquakes are scaled to produce maximum story drift ratios(MSDRs) of 1.0%, 1.5%, 2.0% and 2.5%. The mean values of the ρ-ratio are calculated based on the displacement responses of the investigated frames. The results obtained in this study indicate that the consideration of ρ for both the roof drift ratios(RDRs) and the MSDRs equal to 1.0 is a reasonable estimation for MRSFs designed according to the Egyptian code.

关键词： steel frame story drift inelastic analysis earthquake deflection amplification factor

State Observer Based Dynamic Fuzzy Logic System for a Class of SISO Nonlinear Systems

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2013年第2期10卷 118-124页

作者： Mohamed hamdy Department of Industrial Electronics and Control Engineering Faculty of Electronic Engineering Menofia University

This paper presents an observer based dynamic fuzzy logic system （DFLS） scheme for a class of unknown single-input single-output （SISO） nonlinear dynamic systems with external disturbances. The proposed approach does not need the availability of the state variables. Within this scheme, the DFLS is employed to identify the unknown nonlinear dynamic system. The control law and parameter adaptation laws of the DFLS are derived based on Lyapunov synthesis approach. The control law is robustfied in H∞ sense to attenuate external disturbance, model uncertainties, and fuzzy approximation errors. It is shown that under appropriate assumptions, it guarantees the boundedness of all the signals in the closed-loop system and the asymptotic convergence to zero of tracking errors. The proposed method is applied to an inverted pendulum system to verify the effectiveness of the proposed algorithms.

关键词： Single-input single-output (SISO) nonlinear system dynamic fuzzy logic system (DFLS) observer Lyapunov synthesis approach stability analysis.

Inelastic displacement ratio of low-to mid-rise BRBFs designed under variable levels of seismicity

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2023年第3期22卷 763-775页

作者： hamdy Abou-Elfath Mostafa Ramadan Faculty of Engineering Alexandria UniversityAlexandria 21544Egypt

Buckling-restrained braces(BRBs)have shown their capability to provide building structures with stiffness,strength,and *** the seismic drifts of buckling-restrained braced frames(BRBFs)is an important design step to control structural and non-structural *** current practice of seismic design,the estimation of seismic drifts of BRBFs is performed by using empirical calculations that are independent upon either the type of the structural system or the design level of *** these empirical calculations,the seismic drifts are estimated by amplifying the reduced elastic drifts obtained under design lateral loading with a displacement amplification factor(DAF).The value of DAF is considered equal to the product of the response modification factor R and the inelastic displacement ratioρ.The goal of the current research is to assess the value ofρfor low-to mid-rise BRBFs designed under low and high levels of *** goal has been achieved by conducting a series of elastic and inelastic time-history analyses pertaining to an ensemble of earthquake records on 3-,6-and 9-story *** results indicate that theρ-ratio increases with an increase in design seismic intensity and an increase in experienced *** range ofρfor low seismicity designs ranges from 0.63 to 0.9,while for high seismicity designs this range stretches from 0.83 to *** has been found that the consideration of a generalρ-ratio of 1.0 is a reasonable estimation for the design of the BRBFs considered in this study.

关键词： displacement amplification factor inelastic displacement ratio seismicity buckling-restrained brace seismic drift seismic design

Theoretical-period characteristics of frame buildings designed under variable levels of seismicity and allowable-drift

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2020年第3期19卷 669-681页

作者： hamdy Abou-Elfath Emad Elhout Structural Engineering Department Faculty of EngineeringAlexandria UniversityAlexandria 21544Egypt Higher Institute of Engineering and Technology King-MarriottAlexandriaEgypt

Period equations provided by seismic codes are generally derived by calibration with recorded period data of buildings located in high seismicity *** period-equations do not account for either the design level of seismicity or the permissible limit of lateral *** designed under high level of seismicity are expected to display higher stiffness and shorter periods than buildings designed under low-to-medium seismicity *** addition,buildings designed with high level of permissible lateral-drift are expected to display lower stiffness and longer periods than buildings designed with low level of permissible *** this study,the theoretical fundamental-periods of an ensemble of regular reinforced concrete(RC)and steel moment-resisting frame(MRF)buildings having 3-,6-,9-and 12-stories and designed with various levels of seismicity and permissible lateral-drift are *** obtained outcome indicates the sensitivity of the MRF theoretical-periods to the design seismicity and the permissible *** results also indicate the need for modifying the current period equations to realistically account for the variations in the design seismicity and allowable lateral-drift of MRF buildings.

关键词： concrete frame stiffness

Comparative Study of Different Decoupling Schemes for TITO Binary Distillation Column via PI Controller

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 869-877页

作者： Mohamed hamdy Abdalhady Ramadan Belal Abozalam Industrial Electronics and Control Engineering Department Faculty of Electronic EngineeringMenoufia UniversityMenouf-23952Egypt Badr Petroleum Company(BAPETCO) CairoEgypt

This paper presents a comparative study of different decoupling control schemes for a two-input, two-output(TITO) binary distillation column via proportional-integral(PI)controller. The key idea behind this paper is designing two novel fuzzy decoupling schemes that depend on human knowledge,instead of the system mathematical model used in conventional decoupling schemes. Based on conventional and inverted decoupling schemes, fuzzy and inverted fuzzy decoupling schemes are developed. The control effect is compared using simulation results for the proposed two schemes with conventional decoupling and inverted decoupling. The proposed fuzzy decoupling schemes are easy to realize and simple to design, besides they have a good decoupling capability. Two methods are used to prove asymptotic stability of each loop and the entire closed-loop system by applying the proposed fuzzy decoupling-based PI *** Wood and Berry model of a binary distillation column is used to illustrate the applicability of the proposed schemes.

关键词： Binary distillation column conventional decoupling fuzzy decoupling proportional-integral(PI) controller stability analysis

Observer-based Adaptive Fuzzy Control for a Class of Nonlinear Time-delay Systems

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2013年第4期10卷 275-280页

作者： Hassan A. Yousef Mohamed hamdy Department of Electrical and Computer Engineering College of Engineering Sultan Qaboos University Department of Industrial Electronics and Control Engineering Faculty of Electronic Engineering Menofia University

An observer-based adaptive fuzzy control is presented for a class of nonlinear systems with unknown time delays. The state observer is first designed, and then the controller is designed via the adaptive fuzzy control method based on the observed states. Both the designed observer and controller are independent of time delays. Using an appropriate Lyapunov-Krasovskii functional, the uncertainty of the unknown time delay is compensated, and then the fuzzy logic system in Mamdani type is utilized to approximate the unknown nonlinear functions. Based on the Lyapunov stability theory, the constructed observer-based controller and the closed-loop system are proved to be asymptotically stable. The designed control law is independent of the time delays and has a simple form with only one adaptive parameter vector, which is to be updated on-line. Simulation results are presented to demonstrate the effectiveness of the proposed approach.

关键词： Observer adaptive fuzzy control nonlinear systems time delay stability.

Partially Deep-Learning Encryption Technique

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第2期74卷 4277-4291页

作者： hamdy M.Mousa Faculty of Computers and Information Menoufia UniversityMenoufia32511Egypt

The biggest problem facing the world is information security in the digital *** protection and integrity are hot topics at all times,so many techniques have been introduced to transmit and store data *** increase in computing power is increasing the number of security breaches and attacks at a higher rate than before on ***,a number of existing security systems are at risk of *** paper proposes an encryption technique called Partial Deep-Learning Encryption Technique(PD-LET)to achieve data ***-LET includes several stages for encoding and decoding digital *** preprocessing,convolution layer of standard deep learning algorithm,zigzag transformation,image partitioning,and encryption key are the main stages of ***,the proposed technique converts digital data into the corresponding matrix and then applies encryption stages to *** implementation of encrypting stages is frequently *** collaboration between deep learning and zigzag transformation techniques provides the best output result and transfers the original data into a completely undefined image which makes the proposed technique efficient and secure via data ***,its implementation phases are continuously changed during the encryption phase,which makes the data encryption technique more immune to some future attacks because breaking this technique needs to know all the information about the encryption *** security analysis of the obtained results shows that it is computationally impractical to break the proposed technique due to the large size and diversity of keys and PD-LET has achieved a reliable security system.

关键词： Encryption technique deep learning security zigzag transformation image partitioning

Effect of reperfusion strategy on QT dispersion in patients with acute myocardial infarction:Impact on in-hospital arrhythmia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Cardiology 2023年第3期15卷 106-115页

作者： Mohamed Aboel-Kassem F Abdelmegid Mohamed M Bakr hamdy Shams-Eddin Amr A youssef Ahmed Abdel-Galeel Department of Cardiovascular Medicine Assiut University Heart HospitalAssiut UniversityAssiut 71526Egypt Department of Cardiology Sohag Heart and GIT CenterSohag 85264Egypt Department of Cardiology Assiut Police HospitalAssiut 71526Egypt Department of Cardiology Qena General HospitalQena 92354Egypt

BACKGROUND Myocardial ischemia and ST-elevation myocardial infarction(STEMI)increase QT dispersion(QTD)and corrected QT dispersion(QTcD),and are also associated with ventricular *** To evaluate the effects of reperfusion strategy[primary percutaneous coronary intervention(PPCI)or fibrinolytic therapy]on QTD and QTcD in STEMI patients and assess the impact of the chosen strategy on the occurrence of in-hospital *** This prospective,observational,multicenter study included 240 patients admitted with STEMI who were treated with either PPCI(group I)or fibrinolytic therapy(group II).QTD and QTcD were measured on admission and 24 hr after reperfusion,and patients were observed to detect in-hospital *** There were significant reductions in QTD and QTcD from admission to 24 hr in both group I and group II *** and QTcD were found to be shorter in group I patients at 24 hr than those in group II(53±19 msec vs 60±18 msec,P=0.005 and 60±21 msec vs 69+22 msec,P=0.003,respectively).The occurrence of in-hospital arrhythmia was significantly more frequent in group II than in group I(25 patients,20.8%vs 8 patients,6.7%,P=0.001).Furthermore,QTD and QTcD were higher in patients with in-hospital arrhythmia than those without(P=0.001 and P=0.02,respectively).CONCLUSION In STEMI patients,PPCI and fibrinolytic therapy effectively reduced QTD and QTcD,with a higher observed reduction using *** was associated with a lower incidence of in-hospital arrhythmia than fibrinolytic *** addition,QTD and QTcD were shorter in patients not experiencing in-hospital arrhythmia than those with arrhythmia.

关键词： Arrhythmia QT dispersion ST-segment elevation myocardial infarction Reperfusion Primary percutaneous coronary intervention Fibrinolytic therapy