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中国临床解剖学杂志 2003年第4期21卷 F003-F003页

作者： m. hamid C. Fallet-Bianco V. Delmas O. Plaisant 李鉴轶傅群武

Axial response and material efficiency of tapered helical piles

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Journal of Rock mechanics and Geotechnical Engineering 2021年第1期13卷 176-187页

作者： hamid mortazavi Bak Amir m.Halabian hamid Hashemolhosseini mohammadali Rowshanzamir Department of Civil Engineering Isfahan University of TechnologyIsfahan84156-83111Iran

Different techniques have been proposed to increase the bearing capacity of open-ended *** helices to the shaft and tapering the pile shaft could be used simultaneously to enhance the static and dynamic behaviors of these *** paper subjects the bearing capacity,stiffness,frictional behavior,and material efficiency of the tapered helical piles to *** helical piles are introduced herein as an alternative option to improve the material efficiency of hollow *** on the Taguchi method,a series of experiments was designed and *** axial responses of tapered helical piles are also investigated using finite element *** results derived from loadedisplacement curves and strain gages are used to characterize the axial compression responses of tapered helical *** effects of tapered angle,helices diameter and helices distance are examined using dimensionless parameters,and the degree of contribution of these factors is calculated on each of the enumerated variables *** results show that the shaft friction resistance of tapered helical piles increases continuously with the pile head ***,the effect of tapered wall on the shaft friction resistance is more tangible at low stress *** results showed that the relative material efficiency factor of the optimum pile could be 2.5 times that of unoptimized pile with a similar quantity of material.

关键词： Tapered helical pile Axial response Bearing capacity Shaft resistance Initial tangent stiffness Relative material efficiency Taguchi method

Experimental and theoretical investigations of the lateral vibrations of an unbalanced Jeffcott rotor

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Frontiers of Structural and Civil Engineering 2020年第4期14卷 1024-1032页

作者： Ali ALSALEH hamid mSEDIGHI Hassen mOUAKAD Saudi Arabian Oil Company(ARAmCO) Dhahran 31311Saudi Arabia mechanical Engineering Deparment Faculty of EngineeringShahid Chamran University of AhvazAhvaz 61357-43337Iran Drilling Center of Excellence and Research Shahid Chamran University of AhvazAhvaz 61357-43337Iran mechanical and Industrial Engineering Deparment Sultan Qaboos UniversinAI Khoudh MuscatOman

The current work experimentally explores and then theoretically examines the lateral vibrations of an unbalanced Jeffcott rotor-system working at several unbalance *** this end,three conditions of eccentric masses are considered by using a Bently Nevada RK-4 rotor *** of the steady-state as well as the startup data at rigid and flexible rotor states are captured by conducting a setup that mimics the vibration monitoring industrial *** linear governing equation of the considered rotor is extracted by adopting the Lagrange method on the basis of rigid rotor assumptions to theoretically predict the lateral *** dynamic features of the rotor system such as the linearized bearing induced stiffness are exclusively acquired from startup *** is demonstrated that,with an error of less than 5%,the proposed two-degrees-of-freedom model can predict the flexural vibrations at rigid *** at flexible condition,it fails to accurately predict the dynamic *** contrast to the other works where nonlinear mathematical models with some complexities are proposed to mathematically model the real systems,the present study illustrates the applicability of employing simple models to predict the dynamic response of a real rotor-system with an acceptable accuracy.

关键词： rotor-dynamics Jeffcott rotor lateral vibrations Lagrange method system-equivalent stfess sleeve bearings il film induced stiffness

DYNAmIC PULL-IN INSTABILITY OF DOUBLE-SIDED ACTUATED NANO-TORSIONAL SWITCHES

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Acta mechanica Solida Sinica 2015年第1期28卷 91-101页

作者： hamid m.Sedighi Kourosh H.Shirazi Department of mechanical Engineering Shahid Chamran University

A nonlinear frequency-amplitude relation is developed to investigate the vibrational amplitude effect on the dynamic pull-in instability of double-sided-actuated nano-torsional switches. The governing equation of a nano-electro-mechanical system pre-deformed by an electric field contains the quintic nonlinear term. The influences of basic parameters on the pull-in instability and natural frequency are investigated using a powerful analytical approach called the homotopy perturbation method. It is demonstrated that two terms in series expansion are sufficient to produce an acceptable solution. The numerical results obtained have verified the soundness of the asymptotic procedure. The phase portraits of the double-sided nano-torsionalactuator exhibit periodic, homoclinic and heteroclinic orbits.

关键词： homotopy perturbation method frequency-amplitude relationship double-sidedactuated nano-switch dynamic pull-in instability homoclinic orbit heteroclinic orbit

Gravitomagnetic Effects on Collective Plasma Oscillations in Compact Stars

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Communications in Theoretical Physics 2006年第3期45卷 568-572页

作者： Babur m. mirza hamid Saleem Depaxtment of mathematics Quaid-i-Azam University Islamabaci 45320 Pakistan PINSTECH Nilore Islamabad Pakistan COmSATS Institute of Information Technology Islamabad Pakistan

The effects of gravitomagnetic force on plasma oscillations are investigated using the kinetic theory of homogeneous electrically neutral plasma in the absence of external electric or magnetic field. The random phase assumption is employed neglecting the thermal motion of the electrons with respect to a fixed ion background. It is found that the gravitomagnetic force reduces the characteristic frequency of the plasma thus enhancing the refractive index of the medium. The estimates for the predicted effects are given for a typical white dwarf, pulsar, and neutron star.

关键词： gravitomagnetism compact stars plasma osillations

Role of higher levels of post-challenge antibodies in protective vaccination against Leishmania tropica infection of BALB/c mice

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Asian Pacific Journal of Tropical Biomedicine 2020年第12期10卷 532-539页

作者： mosayeb Rostamian hamid m.Niknam Infectious Diseases Research Center Health InstituteKermanshah University of Medical SciencesKermanshahIran Immunology Department Pasteur Institute of Iran69 Pasteur AvenueTehran 13169-43551Iran

Objective:To study the role of antibodies in protection against Leishmania tropica(***)infection in the experimental model of BALB/c ***:BALB/c mice were vaccinated against *** by soluble Leishmania antigen or recombinant *** stress-inducible protein-1(LtSTI1)of ***,and against Leishmania major(***)by soluble Leishmania *** lipid A was used as an *** ***-or ***-vaccinated mice were challenged by *** or ***,*** levels of anti-Leishmania antibodies(IgG1 and IgG2 a)were determined after vaccination and after ***:All vaccinated groups caused a higher antibody response in comparison with the control *** ***-vaccinated group showed lower IgG1 response than the control group after the ***,in ***-vaccinated mice,the levels of antibodies were higher than the control ***,the group receiving rLtSTI1 and monophosphoryl lipid A showed higher levels of antibodies than those of the rLtSTI1 *** vaccinated mice,antibody responses against *** remained high until 16 weeks after the ***:The higher levels of post-challenge antibodies are associated with protective vaccination against *** infection of BALB/c *** findings provide new insight into the association of antibody with vaccine-induced protective immunity against *** *** studies are needed to clarify the role of antibody in protection against ***.

关键词： Leishmania tropica Vaccination Antibody IgG1 IgG2a

饲料中添加发酵豆粕对岩鱼生长性能、身体组成、抗氧化酶活性和抗病性能的影响

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饲料博览 2016年第7期26卷 54-54页

作者： Sang m L hamid m A Kyung H Chang

试验研究用发酵豆粕鱼料(FSm)代替常规鱼料(Fm)对幼鱼期和生长期岩鱼(又名许氏鲆鲉)生长性能、身体组成、抗氧化酶活性和抗病能力的影响。FSm含量分别为0、8%、16%、24%和32%的等氮(51%)和等热量(mJ·kg^(-1))鱼料代替Fm蛋白质含量约0、... 详细信息

试验研究用发酵豆粕鱼料(FSm)代替常规鱼料(Fm)对幼鱼期和生长期岩鱼(又名许氏鲆鲉)生长性能、身体组成、抗氧化酶活性和抗病能力的影响。FSm含量分别为0、8%、16%、24%和32%的等氮(51%)和等热量(mJ·kg^(-1))鱼料代替Fm蛋白质含量约0、10%、20%、30%和40%的鱼料(分别为FSm0组、FSm8组、FSm16组、FSm24组和FSm32组)。每组鱼料分别饲喂3组幼生期岩鱼(1.2±0.04 g;EXPⅠ组)和3组生长期岩鱼(148.2±2.9 g;EXPⅡ组),2次·d^(-1),共8周。与FSm0组、FSm8组和FSm16组相比,饲喂FSm32组幼生期岩鱼的体增重(WG)显著降低。FSm16组、FSm24组和FSm32组的饲料效率(FE)和岩鱼蛋白质功效比值(PER)显著低于FSm0组和FSm8组。FSm24组的日采食量(DFI)显著低于FSm0组和FSm8组。但生长期岩鱼的生长性能和饲料利用率未表现出显著改变。FSm32组幼生期岩鱼的内脏指数(VSI)显著低于其他各组。FSm替代Fm量达到40%,对幼生期和生长期岩鱼的整个身体和肌肉指标、氨基酸组成均无显著影响。与对照组相比,鱼料中含有FSm的生长期岩鱼的血清抗氧化酶活性显著提高。腹腔注射迟钝爱德华菌后存活的幼生期岩鱼不受饲料变化的影响。试验结果表明,FSm是一种成功的Fm替代品,幼生期岩鱼鱼料中替代量可达10%,生长期岩鱼料中替代量达40%时,对其生长性能仍无不良影响。

关键词：发酵豆粕抗氧化酶活性岩鱼许氏平鲉生长性能

Effects of fixed and dynamic mesh methods on simulation of stepped planing craft

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Journal of Ocean Engineering and Science 2019年第1期4卷 33-48页

作者： m.mehdi Doustdar hamid Kazemi Department of mechanical Engineering Imam Hossein UniversityTehranIran

In the present study,we investigate the effects of fixed and dynamic mesh methods on CFD simulation of stepped planing *** this accomplishment,three different body forms of without step,one step,and two step Cougar planing crafts are ***-dimensional CFD analysis is conducted using finite volume method(FVm).Volume of fluid(VOF)model is used for free surface *** mesh technique(dynamic mesh)and fixed mesh method are conducted by STAR CCm and ANSYS CFX CFD toolboxes,*** results of total hydrodynamic resistance and dynamic trim angle are compared against our measured experimental data to assess the performance and accuracy of considered mesh *** more details,pressure distributions,wave patterns and streamlines around the hull models are also *** on our CFD results,dynamic mesh method is more accurate and precise to simulate the stepped planing crafts compared to fixed mesh ***,computational cost for dynamic mesh method is significantly greater than the fixed mesh *** also found that the porpoising phenomenon is only detectable using dynamic mesh method in simulation of stepped Cougar planing craft.©2018 Shanghai Jiaotong *** by Elsevier B.V.

关键词： CFD Dynamic mesh method Fixed mesh method Stepped planing craft.

Specific wave profiles and closed-form soliton solutions for generalized nonlinear wave equation in(3+1)-dimensions with gas bubbles in hydrodynamics and fluids

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Journal of Ocean Engineering and Science 2023年第1期8卷 91-102页

作者： Sachin Kumar Ihsanullah hamid m.A.Abdou Department of mathematics Faculty of Mathematical SciencesUniversity of DelhiDelhi 110007India Department of mathematics College of SciencesUniversity of BishaP.O.Box 344Bisha 61922Saudi Arabia Physics Department Faculty of ScienceMansoura UniversityMansoura 35516Egypt

Nonlinear evolution equations(NLEEs)are frequently employed to determine the fundamental principles of natural *** equations are studied extensively in nonlinear sciences,ocean physics,fluid dynamics,plasma physics,scientific applications,and marine *** generalized exponen-tial rational function(GERF)technique is used in this article to seek several closed-form wave solutions and the evolving dynamics of different wave profiles to the generalized nonlinear wave equation in(3+1)dimensions,which explains several more nonlinear phenomena in liquids,including gas bubbles.A large number of closed-form wave solutions are generated,including trigonometric function solutions,hyper-bolic trigonometric function solutions,and exponential rational functional *** the dynamics of distinct solitary waves,a variety of soliton solutions are obtained,including single soliton,multi-wave structure soliton,kink-type soliton,combo singular soliton,and singularity-form wave *** de-termined solutions have never previously been *** dynamical wave structures of some analyt-ical solutions are graphically demonstrated using three-dimensional graphics by providing suitable values to free *** technique can also be used to obtain the soliton solutions of other well-known equations in engineering physics,fluid dynamics,and other fields of nonlinear sciences.

关键词： Closed-form solutions Dynamical wave patterns Analytic solutions Nonlinear wave equation GERF method Solitary waves Solitons

Optimized Generative Adversarial Networks for Adversarial Sample Generation

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Computers, materials & Continua 2022年第8期72卷 3877-3897页

作者： Daniyal m.Alghazzawi Syed hamid Hasan Surbhi Bhatia Faculty of Computing and Information Technology King Abdulaziz UniversityJeddah21589Saudi Arabia Department of Information Systems College of Computer Sciences and Information TechnologyKing Faisal UniversitySaudi Arabia

Detecting the anomalous entity in real-time network traffic is a popular area of research in recent *** few researches have focused on creating malware that fools the intrusion detection system and this paper focuses on this *** are using Deep Convolutional Generative Adversarial Networks(DCGAN)to trick the malware classifier to believe it is a normal *** this work,a new dataset is created to fool the Artificial Intelligence(AI)based malware detectors,and it consists of different types of attacks such as Denial of Service(DoS),scan 11,scan 44,botnet,spam,User Datagram Portal(UDP)scan,and ssh *** discriminator used in the DCGAN discriminates two different attack classes(anomaly and synthetic)and one normal *** model collapse,instability,and vanishing gradient issues associated with the DCGAN are overcome using the proposed hybrid Aquila optimizer-based mine blast harmony search algorithm(AO-mBHS).This algorithm helps the generator to create realistic malware samples to be undetected by the *** performance of the proposed methodology is evaluated using different performance metrics such as training time,detection rate,F-Score,loss function,Accuracy,False alarm rate,*** superiority of the hybrid AO-mBHS based DCGAN model is noticed when the detection rate is changed to 0 after the retraining method to make the defensive technique hard to be noticed by the malware detection *** support vector machines(SVm)is used as the malicious traffic detection application and its True positive rate(TPR)goes from 80%to 0%after retraining the proposed model which shows the efficiency of the proposed model in hiding the samples.

关键词： Aquila optimizer convolutional generative adversarial networks mine blast harmony search algorithm network traffic dataset adversarial artificial intelligence techniques