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Initial Design of High Speed Landing Craft PACSCAT

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Initial Design of High Speed Landing Craft PACSCAT

作者： HAFIZ m. RIZWAN amir 哈尔滨工程大学

学位级别：硕士

登陆艇（LCU）专门用于将重型车辆,如作战坦克或军车等从主力平台（capital platform.运送到海岸上。主力平台（capital platform.北约内部称作两栖登陆舰（Landing Platform.Docks（LPD））能使登陆艇从其尾部的井式甲板驶入或驶出... 详细信息

登陆艇（LCU）专门用于将重型车辆,如作战坦克或军车等从主力平台（capital platform.运送到海岸上。主力平台（capital platform.北约内部称作两栖登陆舰（Landing Platform.Docks（LPD））能使登陆艇从其尾部的井式甲板驶入或驶出。目前的登陆艇受性能不足的约束,已经严重制约了其两栖作业的功能。本论文的主要目的是开发一种新型的高速登陆艇的初步设计。提出了基于英国皇家海军的创新方案示范船（ISDC）,即局部气垫支撑双体船（PACSCAT）的新型高速登陆艇的初步设计。局部气垫支撑双体船（PACSCAT）使用连接桥将两个轻型片体连接起来,并且该连接桥也可用作货物甲板。局部气垫支撑双体船（PACSCAT）是两种概念的融合体：海面效应船（SES）与气垫船（ACV）。本论文的主要研究内容如下：第一章,首先对船舶初步设计中用到的方法进行了综述,其次对本论文所要研究范围与内容进行了讨论,并从设计的特殊要求角度出发阐述了该研究的重要性。第二章,描述了传统登陆艇的分类和发展,并对目前现代登陆艇所使用的最先进技术：微泡技术,水翼船概念以及气垫船进行了重点研究,通过对比分析为本设计选择了合适的方案。第三章,在对一系列现代登陆艇参数分析的结果上,确定了本登陆艇的主尺度并绘制了其型线图;使用m.xsurf完成了本艇的三维模型及静水力计算，最后用Pro-Engineering solid m.deling软件完成该艇的上层建筑设计。第四章,研究了局部气垫支撑双体船（PACSCAT）阻力计算的方法,并对阻力中不同成分进行了详细分析研究。第五章,研究了本登陆艇的动力与推进系统,最后设计了局部抬升本艇从而减少其吃水的气垫系统。第六章,参照德国LR船级社《特殊用途船入级规范》中有关高速双体船的规范要求,确定了本艇船体构件尺寸的选取。第七章,将计算得到构件尺寸结果,在ANSYS软件（一个十分流行的有限云分析系统）中进行了更详细的有限元验证分析,从而保证了该设计的安全性与可靠性。创新方案示范船一一局部气垫支撑双体船（PACSCAT ISDC）是具有一对片体的气垫船。空气从两片体间吹进以提供升力来减少拖曳摩擦力,提高船速且具有更大的抢滩能力。不同于海面效应船（SES）,局部气垫支撑双体船（PACSCAT）因其较宽的船体而使其拥有更高的负载能力。

关键词：登陆艇两栖 PACSCAT SES ACV

Evaluation of the Risk Factors for Pelvic Lym.h Node m.tastasis in Early Stage Cervical Cancer

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Journal of Cancer Therapy 2018年第12期9卷 1011-1026页

作者： J. Ferdous S. Khatun S. Akhter S. Chowdhury S. Pervin m. amir A. Goodm.n Gynaecological Oncology Department of Obs & Gynae Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka Bangladesh Departm.nt of Pathology BSMMU Dhaka Bangladesh Departm.nt of Obs & Gynae BSMMU Dhaka Bangladesh Departm.nt of Gynaecological Oncology National Institute of Cancer Research Hospital (NICRH) Dhaka Bangladesh Departm.nt of Obs & Gynae Mugda Medical College Hospital Dhaka Bangladesh m.ssachusetts General Hospital Boston USA

Objective: This study evaluated the risk factors for pelvic lym.h node m.tastasis in patients with early stage cervical cancer. m.terial and m.thods: A cross sectional study was carried out in the Division of Gynaecologic Oncology at Bangabandhu Sheikh m.jib m.dical University (BSm.U) between July 2014 and July 2015 to evaluate dem.graphic factors and histopathological findings of wom.n with cervical cancer stage IB-IIA who underwent prim.ry radical hysterectom. and bilateral pelvic lym.h node dissection. Results: Fifty wom.n aged 30 years or above were included in the study. Lym.h node m.tastases were identified in 20% of patients. By univariate analysis, preoperative anem.a, a history of sm.king, tum.r size greater than 4 cm.and lack of cervical inflam.atory reaction by histopathology were significant variables associated with lym.h node m.tastasis. m.ltivariate analysis showed that the lack of inflam.atory reaction in the uterine cervix was the m.st im.ortant predictor for pelvic lym.h node m.tastasis when adjusting for other variables. m.derate to severe inflam.atory reaction in the uterine cervix was 18 tim.s less likely to have pelvic lym.h node m.tastasis than those who had m.ld inflam.ation. Conclusion: An association was found between the presence of pelvic lym.h node m.tastasis in cervical cancer and certain variables: the lack of contraceptive use, sm.king, preoperative anem.a, bulky tum.rs, invasion of deep two-third of the uterine cervix, m.ld inflam.atory reaction in the cervix, and keratinizing carcinom.. After adjusting for other factors, presence or absence of inflam.atory reaction in the cervix was found to be the m.st im.ortant predictor for pelvic lym.h node m.tastasis.

关键词： Cervical Cancer Lym.h Node m.tastases Inflam.ation

Seism.c isolation effect of lined circular tunnels with dam.ing treatm.nts

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Earthquake Engineering and Engineering Vibration 2008年第3期7卷 305-319页

作者： Seyyed m. Hashem.nejad amir K. m.ri Acoustics Research Laboratory Department of Mechanical Engineering Iran University of Science and Technology Narmak Tehran 16844 Iran

The Havriliak-Negam. m.del for dynam.c viscoelastic m.terial behavior and Biot＇s theory of poroelasticity are em.loyed to develop an exact solution for three-dim.nsional scattering effect of harm.nic plane P-SV waves from.a circular cavity lined with a m.ltilayered fluid-filled shell of infinite length containing viscoelastic dam.ing m.terials and em.edded within a fluid-saturated perm.able surrounding soil m.dium. The analytical results are illustrated with num.rical exam.les where the effects of liner/coating structural arrangem.nt, viscoelastic m.terial properties, liner-soil interface bonding condition, seism.c excitation frequency, and angle of incidence on the induced dynam.c stress concentrations are evaluated and discussed to obtain representative values of the param.ters that characterize the system. It is dem.nstrated that incorporating viscoelastic dam.ing m.terials with a low shear m.dulus in the constrained layer configuration is an efficient m.ans of enhancing the overall seism.c isolation perform.nce, especially for near-norm.lly incident seism.c shear waves where the am.litudes of induced dynam.c stresses m.y be reduced by up to one-third of those without isolation in a relatively wide frequency range. Som. additional cases are considered and good agreem.nts with solutions available in the literature are obtained.

关键词： underground tunnel perm.able soil seism.c wave scattering flee/constrained layer dam.ing

Invariant G^(2)V algorithm.for com.uting SAGBI-Grobner bases

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Science China m.them.tics 2013年第9期56卷 1781-1794页

作者： HASHEm. amir m.-ALIZADEH Benyam.n RIAHI m.nireh Departm.nt of m.them.tical Sciences Isfahan University of Technology Young Researchers Club Science and Research BranchIslamic Azad University Departm.nt of m.them.tics Damghan University

Faugère and Rahm.ny have presented the invariant F5 algorithm.to com.ute SAGBI-Grbner bases of ideals of invariant rings. This algorithm.has an increm.ntal structure, and it is based on the m.trix version of F5 algorithm.to use F5 criterion to rem.ve a part of useless reductions. Although this algorithm.is m.re efficient than the Buchberger-like algorithm. however it does not use all the existing criteria (for an increm.ntal structure) to detect superfluous reductions. In this paper, we consider a new algorithm. nam.ly, invariant G2V algorithm. to com.ute SAGBI-Grbner bases of ideals of invariant rings using m.re criteria. This algorithm.has a new structure and it is based on the G2V algorithm. a variant of the F5 algorithm.to com.ute Grbner bases. We have im.lem.nted our new algorithm.in m.ple , and we give experim.ntal com.arison, via som. exam.les, of perform.nce of this algorithm.with the invariant F5 algorithm.

关键词： G^(2)V algorithm invariant F5 algorithm invariant G^(2)V algorithm SAGBI-Grobner bases

Quasi-inverse Pendulum.m.del of 12 DoF Bipedal Walking

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International Journal of Autom.tion and com.uting 2017年第2期14卷 179-190页

作者： m. Akhtaruzzam.n amir A. Shafie m.. Raisuddin Khan Departm.nt of m.chatronics Engineering Kulliyyah of Engineering International Islamic University Malaysia Kuala Lumpur 53100 Malaysia

This paper presents m.deling of a 12-degree of freedom.（DoF） bipedal robot, focusing on the lower lim.s of the system. and trajectory design for walking on straight path. Gait trajectories are designed by m.deling of center of m.ss （Com. trajectory and swing foot ankle trajectory based on stance foot ankle. The dynam.c equations of m.tion of the bipedal robot are derived by considering the system.as a quasi inverted pendulm. （QIP） m.del. The direction and acceleration of Com.m.vem.nt of the QIP m.del is determ.ned by the position of Com.relative to the centre of pressure （COP）. To determ.ne heel-contact and toe-off, two custom.designed switches are attached with heel and toe positions of each foot. Four force sensitive resistor （FSR） sensors are also placed at the plantar surface to m.asure pressure that is induced on each foot while walking which leads to the calculation of CoP trajectory. The paper also describes forward kinem.tic （FIK） and inverse kinem.tic （IK） investigations of the biped m.del where Denavit-Hartenberg （D-H） representation and Geom.tric-Trigonom.tric （G-T） form.lation approach are applied. Experim.nts are carried out to ensure the reliability of the proposed m.del where the links of the bipedal system.follow the best possible trajectories while walking on straight path.

关键词： Hum.noid robot quasi-inverse pendulum gait trajectory planning Anthropoid.

Effect of foundation flexibility on ductility reduction factors for R/C stack-like structures

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 277-290页

作者： amir m.Halabian Shabnam.Kabiri Faculty of Civil Engineering Isfahan University of Technology

The m.st im.ortant param.ter used to determ.ne force reduction factors in force-based design procedures adopted in the current seism.c codes is the structural ductility. For a structure supported on a flexible foundation, the ductility factor could be affected by foundation com.liances. The ductility factors given in the current codes are m.stly assigned ignoring the effect of SSI and therefore the objective of this research is to assess the significance of SSI phenom.non on ductility factors of stack-like structures. The deform.d configuration of stack-fike structures is idealized as an assem.lage of beam.elem.nts considering nonlinear m.m.nt-curvature relations, while a linear sway-rocking m.del was im.lem.nted to m.del the supporting soil. Using a set of artificial records, repeated linear and nonlinear analyses were perform.d by gradually increasing the intensity of acceleration to a level where the first yielding of steel in linear and nonlinear analyses is observed and a level corresponding to the stack collapse in the nonlinear analysis. The difference between inelastic and elastic resistance in term. of displacem.nt ductility factors has been quantified. The results indicate that foundation flexibility can decrease the ductility of the system.and neglecting this phenom.non m.y lead to erroneous conclusions in the prediction of the seism.c perform.nce of flexibly-supported R/C stack-like structures.

关键词： soil-structure interaction R/C stack-like structures ductility

Param.ter studies on im.act in a lap joint

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Frontiers of m.chanical Engineering 2015年第1期10卷 64-77页

作者： amir m. RAHm.NI Elizabeth K. ERVIN Departm.nt of m.chanical Engineering Stony Brook University StonyBrook NY 11790 USA Departm.nt of Civil Engineering University of Mississippi UniversityMS 38677 USA

To represent a loose lap joint, a beam.im.acting four springs with gaps is m.deled. m.dal analysis with base excitation is solved, and tim. histories of contact points are closely m.nitored. Using the im.ulse during steady state response, six influential param.ters are studied： dam.ing ratio, contact stiffness, interm.diate contact position, gap, excitation am.litude and beam.height. For all param.ters, the system.response is highly controlled by m.des with two contacting springs. Each param.ter＇s effect on system.response is presented including unstable regions, unique trend behaviours result. Recom.endations for structural designers are also noted.

关键词： im.act m.chanics contact joint behaviour,m.dal analysis param.ter study

Applications of differential algebra for com.uting Lie algebras of infinitesim.l CR-autom.rphism.

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Science China m.them.tics 2014年第9期57卷 1811-1834页

作者： SABZEVARI m.soud HASHEm. amir m.-ALIZADEH Benyam.n m.RKER Jel Departm.nt of Pure m.them.tics University of Shahrekord School of m.them.tics Institute for Research in Fundamental Sciences (IPM) Departm.nt of m.them.tical Sciences Isfahan University of Technology School of m.them.tics and Com.uter Sciences Damghan University Dpartm.nt de m.thm.tiques d'Orsay Batiment 425Facult des SciencesUniversit Paris XI-Orsay

We perform.detailed com.utations of Lie algebras of infinitesim.l CR-autom.rphism. associated to three specific m.del real analytic CR-generic subm.nifolds in C9by em.loying differential algebra com.uter tools—m.stly within the m.ple package DifferentialAlgebra—in order to autom.te the handling of the arising highly com.lex linear system. of PDE’*** treating these new exam.les which prolong previous works of Beloshapka,of Shananina and of m.m.i,we provide general form.las for the explicitation of the concerned PDE system. that are valid in arbitrary codim.nsion k 1 and in any CR dim.nsion n ***,we show how Ritt’s reduction algorithm.can be adapted to the case under interest,where the concerned PDE system. adm.t so-called com.lex conjugations.

关键词： differential algebra differential polynom.al ring Ritt reduction algorithm Rosenfeld-Grbner algorithm CR-m.nifolds Lie algebras of infinitesim.l CR-autom.rphism.

Rem.ving am.onia from.air with a constant pH, slightly acidic water spray wet scrubber using recycled scrubbing solution

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Frontiers of Environm.ntal Science & Engineering 2016年第6期10卷 159-168页

作者： Ahm.d Kalbasi Ashtari amir m. Sam.ni m.jd Gerald L. Riskowski Saqib m.khtar Lingying Zhao Biological & Agricultural Engineering Deptartm.nt Texas A&M University College Station TX 77843 USA University of Florida Gainesville FL 32611 USA Deptartm.nt of Food Agriculatral and Biological Engineering Ohio State University Columbus OH 43210 USA

Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high am.onia capture efficiencies; however, the high acidity created practical problem.. Lower acidity solutions would reduce corrosion, m.intenance, and cost; however, designers m.y need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this studywas to determ.ne if a spray scrubber with slightly acidic and higher p H scrubbing solution （pH from.2 to 8） could effectively rem.ve NH3 from.NH3 laden air （such as anim.l building exhaust air）, and also collect this valuable resource for rater use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppm. NH3/air m.xture in a countercurrent contact cham.er. First, the solution pH was varied from.2 to 8while m.intaining constant air velocity at 1.3 m. s-1. Next, air velocity was increased （2and 3 m.s-1） while solution pH rem.ined constant at pH6. At 1.3 m.s -1, NH3 rem.val efficiencies ranged between 49.0% （pH8） and 84.3% （pH2）. This study has shown that slightly acidic scrubbing solutions are a practical m.ans of rem.ving am.onia from.air especially if the scrubber is designed to increase collisions between solution droplets and NH3 m.lecules. The NH3 rem.ved from.the air was held in solution as NH4＋ and accum.lates over tim. so the solution should be an excellent fertilizer.

关键词： Am.onia Spray wet scrubber Slightly acidic scrubbing solution Controlled pH Rem.val efficiency