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Active control of an aircraft tail subject to harmonic excitation

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Acta Mechanica Sinica 2007年第4期23卷 451-462页

作者： M.Eissa H.S.Bauomy y.a.amer Department of Engineering Mathematics Faculty of Electronic EngineeringMenouf 32952Egypt Department of Mathematics Faculty of ScienceZagazig UniversityZagazigEgypt

Vibration of structures is often an undesirable phenomena and should be avoided or controlled. There are two techniques to control the vibration of a system, that is, active and passive control techniques. In this paper, a negative feedback velocity is applied to a dynamical system, which is represented by two coupled second order nonlinear differential equations having both quadratic and cubic nonlinearties. The system describes the vibration of an aircraft tail. The system is subjected to multi-external excitation forces. The method of multiple time scale perturbation is applied to solve the nonlinear differential equations and obtain approximate solutions up to third order of accuracy. The stability of the system is investigated applying frequency response equations. The effects of the different parameters are studied numerically. Various resonance cases are investigated. A comparison is made with the available published work.

关键词： Active vibration control Stability Response curves Aircraft tail

Solving Fractional Integro-Differential Equations by Using Sumudu Transform Method and Hermite Spectral Collocation Method

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Computers, Materials & Continua 2018年第2期54卷 161-180页

作者： y.a.amer A.M.S.Mahdy E.S.M.youssef Department of Mathematics Faculty of Science44519Zagazig UniversityEgypt Department of Mathematics and Statistics Faculty of ScienceTaif UniversitySaudi Arabia

In this paper we are looking forward to finding the approximate analytical solutions for fractional integro-differential equations by using Sumudu transform method and Hermite spectral collocation *** fractional derivatives are described in the Caputo *** applications related to Sumudu transform method and Hermite spectral collocation method have been developed for differential equations to the extent of access to approximate analytical solutions of fractional integro-differential equations.

关键词： Caputo derivative integro-differential equations hermite polynomials sumudu transform

Position and Velocity Time Delay for Suppression Vibrations of a Hybrid Rayleigh-Van der Pol-Duffing Oscillator

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Sound & Vibration 2020年第3期54卷 149-161页

作者： y.a.amer A.T.El-Sayed M.N.Abd El-Salam Mathematics Department Science FacultyZagazig UniversityZagazigEgypt Basic Sciences Department Modern Academy for Engineering and TechnologyCairoEgypt Basic Sciences Department Higher Technological Institute10th of Ramadan CityEgypt

In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing *** system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external *** applied the multiple scales method to get the solution from first *** and numerically,we studied the system before and after adding time delay feedback at the primary resonance case(ffi!).We used MATLAB program to simulate the efficacy of different parameters and the time delay on the main system.

关键词： Position time delay feedback velocity time delay feedback multiple scales method resonance cases

A Suitable Active Control for Suppression the Vibrations of a Cantilever Beam

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Sound & Vibration 2022年第2期56卷 89-104页

作者： y.a.amer A.T.EL-Sayed M.N.Abd EL-Salam Mathematics Department Science FacultyZagazig UniversityZagazigEgypt Basic Sciences Department Modern Academy for Engineering and TechnologyCairoEgypt Basic Sciences Department Higher Technological Institute10th of Ramadan CityEgypt

In our consideration,a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried *** four types are the linear velocity feedback control,the cubic velocity feedback control,the non-linear saturation controller(NSC)and the positive position feedback(PPF)*** suitable type is the PPF controller for suppression the vibrations of the cantilever *** approximate solution obtained up to the first approximation by using the multiple scale *** PPF controller effectiveness is studied on the *** used frequency-response equations to investigate the stability of a cantilever *** notified that,there is a good agreement between the analytical solution and the numerical solution.

关键词： Cantilever beam cubic velocity feedback control linear velocity feedback control non-linear saturation controller(NSC) positive position feedback(PPF)controller

Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov Igor y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

Optimal Coordination of Transportable Power Sources and Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 189-201页

作者： Zhao Shi yan Xu Dunjian Xie Shiwei Xie amer M.y.M.Ghias Nanyang Technological University Singapore the School of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108China

This paper proposes a new method for service restoration of distribution network with the support of transportable power sources(TPSs)and repair crews(RCs).Firstly,a coupling model of distribution networks and vehicle routing of TPSs and RCs is proposed,where the TPSs serve as emergency power supply sources,and the RCs are used to repair the faulted *** the uncertainty of traffic congestion,the probability distribution of the travel time spent on each road is derived based on the Nesterov user equilibrium model,and a two-stage stochastic program is formulated to determine the optimal routings of TPSs and *** efficiently solve the proposed stochastic mixed-integer linear program(MILP),a two-phase scenario reduction method is then developed to scale down the problem size,and an adaptive progressive hedging algorithm is used for an efficient *** effectiveness of the proposed methods and algorithms has been illustrated in a modified IEEE 33-bus system.

关键词： Service restoration distribution network traffic uncertainty transportable power source repair crew stochastic program

Eczema herpeticum vs dermatitis herpetiformis as a clue of dedicator of cytokinesis 8 deficiency diagnosis:A case report

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World Journal of Clinical Cases 2022年第29期10卷 10735-10741页

作者： amer Alshengeti Department of Pediatrics College of MedicineTaibah UniversityDepartment of Infection prevention and controlPrince Mohammad Bin Abdulaziz HospitalNational Guard Health AffairsAl-Madinah 41491Saudi Arabia

BACKGROUND Dedicator of cytokinesis 8(DOCK 8) deficiency,also known as autosomal recessive hyper immunoglobulin E(IgE) syndrome,is a combined immunodeficiency disease that was first recognized in *** is caused by genetic alterations(mutations or deletions) in the DOCK 8 gene and is characterized by multiple allergies,elevated IgE levels,and susceptibility to viral and bacterial *** diagnosis is critical to optimize the success of stem cell *** SUMMARy This study reports the case of a pediatric patient with DOCK 8 deficiency who had negative genetic testing using multiplex primary immunodeficiency(PID) panel and whole-exome sequencing(WES) with a next-generation sequencing *** presented with chronic diarrhea and was managed as celiac disease based on previous negative workup for immunodeficiency and duodenal *** developed a generalized vesicular rash which was thought to be dermatitis herpetiformis associated with celiac ***,it turned out to be Eczema herpeticum based on positive herpes simplex virus from blood and *** diagnosis was re-evaluated after the child was found to have multiple viral,bacterial,and parasitic co-infections(herpes simplex virus,cytomegalovirus,Epstein-Barr virus,Salmonella,and cryptosporidiosis).Re-evaluation with target gene testing with copy number variation(CNV) analysis and Multiplex Ligation Probe Amplification(MLPA) showed a large homozygous deletion in the DOCK 8 gene,confirming the diagnosis of DOCK 8 *** Targeted gene testing with CNV analysis might detect deletions that can be missed by WES for diagnosing patients with PID.

关键词： Immunoglobulin E Whole-exome sequencing Infections Dedicator of cytokinesis 8 Case report

Application of machine learning algorithms to predict tubing pressure in intermittent gas lift wells

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Petroleum Research 2022年第2期7卷 246-252页

作者： Nagham amer Sami Department of Petroleum Engineering Faculty of Earth ScienceUniversity of Miskolc3515MiskolcHungary

Tubing pressure at gas injection depth in intermittent wells is one of the most critical parameters for production engineers to evaluate the performance of the ***,monitoring of the tubing pressure is not usually carried out in real *** has been realized that the generally used correlations are not effective enough due to complexity of the intermittent process which involve many parameters and assumptions to develop such *** focus of this study is to utilize machine learning(ML)algorithms to develop a model that can accurately predict tubing pressure in artificial intermittent gas lift *** algorithms built on the field data provide a solution that is easy to use and universally applicable to the complex *** non-linear regression ML methods are employed in this study,namely,Decision Tree-regression(DT),Random Forest-regression(RF)and K Nearest Neighbors-regression(KNN).All the tubing pressures obtained from ML models were compared with the actual values to ensure the effectiveness of the *** developed models show that it can predict the pressure with more than 99.9%*** is an interesting result,as such outcome accuracy has not been reported usually in the open literature.

关键词： Machine learning Artificial intelligence Intermittent gas lift Tubing pressure Random forest Decision tree KNN

Binary Representation of Polar Bear Algorithm for Feature Selection

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Computer Systems Science & Engineering 2022年第11期43卷 767-783页

作者： amer Mirkhan NumanÇelebi Sakarya University Computer Engineering DepartmentSakaryaTurkey Sakarya University Information Systems Engineering DepartmentSakaryaTurkey

In most of the scientific research feature selection is a challenge for *** all available features is not an option as it usually complicates the research and leads to performance drop when dealing with large *** the other hand,ignoring some features can compromise the data *** the rough set theory presents a good technique to identify the redundant features which can be dismissed without losing any valuable information,however,exploring all possible combinations of features will end with NP-hard *** this research we propose adopting a heuristic algorithm to solve this problem,Polar Bear Optimization PBO is a metaheuristic algorithm provides an effective technique for solving such kind of optimization *** other heuristic algorithms it proposes a dynamic mechanism for birth and death which allows keep investing in promising solutions and keep dismissing hopeless *** evaluate its efficiency,we applied our proposed model on several datasets and measured the quality of the obtained minimal feature set to prove that redundant data was removed without data loss.

关键词： Optimization rough set feature selection heuristic algorithms