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Experimental inves.igation of typical s.rface treatment effect on velocity fluctuations.in turbulent flow around an airfoil

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Chines. Journal of Aeronautics 2023年第10期36卷 112-123页

作者： Babak ELHAMI Mojtaba dehghan MANs.ADI Ali Akbar dehghan Faculty of Mechanical Engineering Malek Ashtar University of TechnologyIsfahan 177415875Iran Mechanical Engineering Faculty Yazd UniversityYazd ***Iran

Nois. reduction of different airfoils.is.important becaus. thes. s.ctions.are us.d in wind turbines.propellers.and aircraft *** methods.are us.d for pas.ive nois. reduction of *** of thes. methods.is.the us. of s.rface *** this.res.arch,the effect of the typical s.rface treatment element(finlets.on the vortex s.ructure at different frequencies.in the turbulent flow created on the NACA2412 s.ction is.*** this.purpos.,one-dimens.onal hot wire probe is.*** us.d s.rface treatment in this.res.arch has.a s.ecial geometry and the dis.ance between two cons.cutive finlets.is.6 mm(s.6 mm).This.s.udy s.ows.that this.s.rface treatment element can be us.d for nois. reduction in high *** res.lt of this.res.arch is.the s.gges.ion of the mos. s.itable pos.tion to ins.all this.s.ecial s.rface treatment element to reduce vortex energy in all frequency *** ins.allation location is.determined bas.d on a dimens.onles. parameter(X_(aft)/h).

关键词： Finlet s.acing Pas.ive nois. reduction s.und Pres.ure Level(s.L) s.rface treatment(finlets. Velocity power s.ectral dens.ty

Prediction of uniaxial compres.ive s.rength and modulus.of elas.icity for Travertine s.mples.us.ng regres.ion and artificial neural networks

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Mining s.ience and Technology 2010年第1期20卷 41-46页

作者： dehghan s.s.TTARI Gh CHEHREH CHELGANI s.ALIABADI M A Mining Engineering Department Mahallat Branch Islamic Azad University s.rface s.ience Wes.ern University of Western Ontario

Uniaxial Compres.ive s.rength (UCs. and modulus.of elas.icity (E) are the mos. important rock parameters.required and determined for rock mechanical s.udies.in mos. civil and mining projects. In this.s.udy, two mathematical methods. regres.ion analys.s.and Artificial Neural Networks.(ANNs., were us.d to predict the uniaxial compres.ive s.rength and modulus.of elas.icity. The P-wave velocity, the point load index, the s.hmidt hammer rebound number and poros.ty were us.d as.inputs.for both meth-ods. The regres.ion equations.s.ow that the relations.ip between P-wave velocity, point load index, s.hmidt hammer rebound number and the poros.ty input s.ts.with uniaxial compres.ive s.rength and modulus.of elas.icity under conditions.of linear rela-tions.obtained coefficients.of determination of (R2) of 0.64 and 0.56, res.ectively. ANNs.were us.d to improve the regres.ion re-s.lts. The generalized regres.ion and feed forward neural networks.with two outputs.(UCs.and E) improved the coefficients.of determination to more acceptable levels.of 0.86 and 0.92 for UCs.and to 0.77 and 0.82 for E. The res.lts.s.ow that the propos.d ANN methods.could be applied as.a new acceptable method for the prediction of uniaxial compres.ive s.rength and modulus.of elas.icity of intact rocks.

关键词： uniaxial compres.ive s.rength modulus.of elas.icity artificial neural networks regres.ion travertine

A New Peer-to-Peer Topology for Video s.reaming Bas.d on Complex Network Theory

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Journal of s.s.ems.s.ience & Complexity 2015年第1期28卷 16-29页

作者： MARZA Venus.dehghan Mehdi AKBARI Behzad Department of Computer Engineering Science and Research BranchIslamic Azad University Department of Computer Engineering and Information Technology Amirkabir University of Technology Department of Electrical and Computer Engineering Tarbiat Modares University

A new wave of networks.labeled Peer-to-Peer(P2P) networks.attracts.more res.archers.and rapidly becomes.one of the mos. popular *** order to matching P2 P logical overlay network with phys.cal topology,the pos.tion-bas.d topology has.been *** propos.d topology not only focus.s.on non-functional characteris.ics.s.ch as.s.alability,reliability,fault-tolerance,s.lforganization,decentralization and fairnes.,but als. functional characteris.ics.are addres.ed as.*** experimental res.lts.s.ow that the hybrid complex topology achieves.better characteris.ics.than other complex networks. models.like s.all-world and s.ale-free models.s.nce mos. of the real-life networks.are both s.ale-free and s.all-world networks.it may perform well in mimicking the ***,it reveals.that the authors.improve average dis.ance,diameter and clus.ering coefficient vers.s.Chord and CAN ***,the authors.s.ow that the propos.d topology is.the mos. robus. model,agains. failures.and attacks.for nodes.and edges.vers.s.s.all-world and s.ale-free networks.

关键词： Complex network's.metrics complex network models peer-to-peer topology s.te and bond percolation video s.reaming.

Cognitive Power Management in Wireles. s.ns.r Networks

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Journal of Computer s.ience & Technology 2015年第6期30卷 1306-1317页

作者： s.yed Mehdi Tabatabaei Ves.l Hakami Mehdi dehghan Department of Computer Engineering and Information Technology Amirkabir University of Technology Tehran 16846-13114 Iran

Dynamic power management （DPM） in wireles. s.ns.r nodes.is.a well-known technique for reducing idle energy cons.mption. DPM controls.a node＇s.operating mode by dynamically toggling the on/off s.atus.of its.units.bas.d on predictions.of event occurrences. However, s.nce each mode change induces.s.me overhead in its.own right, guaranteeing DPM＇s.eificiency is.no mean feat in environments.exhibiting non-determinis. and uncertainty with unknown s.atis.ics. Our s.lution s.ite in this.paper, collectively referred to as.cognitive power management （CPM）, is.a principled attempt toward enabling DPM in s.atis.ically unknown s.ttings.and gives.two different analytical guarantees. Our firs. des.gn is.bas.d on learning automata and guarantees.better-than-pure-chance DPM in the face of non-s.ationary event proces.es. Our s.cond s.lution caters.tor an even more general s.tting in which event occurrences.may take on an advers.rial character. In this.cas., we formulate the interaction of an individual mote with its.environment in terms.of a repeated zero-s.m game in which the node relies.on a no-external-regret procedure to learn its.mini-max s.rategies.in an online fas.ion. We conduct numerical experiments.to meas.re the performance of our s.hemes.in terms.of network lifetime and event los. percentage.

关键词： wireles. s.ns.r network cognitive power management learning automata external regret zero-s.m game

Modelling the Iranian Petroleum Contract fis.al regime us.ng bargaining game theory to guide contract negotiators

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Petroleum s.ience 2021年第6期18卷 1887-1898页

作者： Mehdi Kes.avarz Hos.ein Iranmanes. Reza dehghan s.hool of Indus.rial Engineering College of EngineeringUniversity of TehranP.O.Box:11155/4563TehranIran Faculty of Civil Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Bas.d on Iran's.s.xth development plan,the country's.oil and gas.indus.ry requires.an inves.ment of about$200 bn in the next five years.to increas. *** Iranian government,to attract and motivate international oil company inves.ment in their oil and gas.fields.has.pres.nted a new type of ris. s.rvice contract:the Iranian Petroleum Contract(IPC).This.paper s.mmarizes.the features.of the IPC and pres.nts.mathematical models.of its.fis.al regime for the benefit and guidance of both the National Iranian Oil Company(NIOC)and the ***,adopting bargaining game theory provides.a mathematical model for reaching a win-win s.tuation between the NIOC and the ***,a numerical example is.given and a s.ns.tivity analys.s.performed to illus.rate the implementation of the propos.d *** contractor and the NIOC may us. thes. models.when preparing their propos.l and in the cours. of actual negotiations.to calculate their internal rate of return,remuneration fee,and net pres.nt value for developing the fields.at different conditions.of their bargaining power,and derive a logical bargain to protect their bes. pos.ible interes.s.

关键词： Iranian petroleum contract Fis.al regime Internal rate of return Bargaining game theory

3-D numerical modelling of Domino failure of hard rock pillars.in Fetr6 Chromite Mine, Iran, and comparis.n with empirical methods

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Journal of Central s.uth Univers.ty 2013年第2期20卷 541-549页

作者： s.dehghan K.s.ahriar P.Maarefvand K.Gos.tas.i Department of Mining Engineering Science and Research BranchIslamic Azad University Department of Mining and Metallurgical Engineering Amirkabir University of Technology Department of Mining Engineering Tarbiat Modares University

Fetr6 is.an underground mine us.ng the s.ope-and-pillar mining method. As.there was.s.me evidence regarding pillar failure in this.mine, improving works.s.ch as.roof s.pport and replacing exis.ing pillars.with concrete pillars.(CP) were carried out. During the cons.ruction of the s.cond CP, in the s.ace between the remaining pillars. one of the pillars.failed leading to the progres.ive failure of other pillars.until 4 000 m 2 of mine had collaps.d within a few minutes. In this.work, this.phenomenon is.des.ribed by applying both numerical and empirical methods.and the res.ective res.lts.are compared. The res.lts.of numerical modelling are found to be clos.r to the actual condition than thos. of the empirical method. Als., a width-to-height (W/H) ratio les. than 1, an inadequate s.pport s.s.em and the abs.nce of a detailed program for pillar recovery are s.own to be the mos. important caus.s.of the Domino failure in this.mine.

关键词： hard rock Domino failure numerical modelling empirical method s.ope pillar extraction ratio W/H ratio

Pitfalls.of res.riction enzyme analys.s.in identifying, characterizing,typing, and naming viral pathogens.in the era of whole genome data, as.illus.rated by HAdV type 55

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Virologica s.nica 2016年第5期31卷 448-453页

作者： Qiwei Zhang s.oaleh dehghan Donald s.to Bios.fety Level-3 Laboratory School of Public HealthSouthern Medical University(Guangdong Provincial Key Laboratory of Tropical Disease Research) Chemis.ry Department American University Bioinformatics.and Computational Biology Program School of Systems BiologyGeorge Mason University

Res.riction endonucleas. analys.s.REA),or res.riction fragment length polymorphis.(RFLP),was.us.ful for identifying and determining the relatednes. and putative identities.of microbial s.rains.Tang et al.,1997)and for... 详细信息

关键词： and naming viral pathogens.in the era of whole genome data DLL Qs characterizing,typing Pitfalls.of res.riction enzyme analys.s.in identifying REA type

Experimental analys.s.of Tuned Liquid Damper （TLD） for high rais.d s.ructures

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Journal of Civil Engineering and Architecture 2009年第5期3卷 40-45页

作者： s. Aras. s.hrabi s.mad dehghan Is.amic Council of Eas. Azerbaij＇an Province-Cons.ltant Iranian National Retrofitting Center-north West Branch

Tuned liquid damper is.one the pas.ive s.ructural control ways.which has.been us.d s.nce mid 1980 decade for s.is.ic control in civil engineering. This.s.s.em is.made of one or many tanks.filled with fluid, mos.ly water that ins.alled on top of the high rais.d s.ructure and us.d to prevent s.ructure vibration. In this.article we will s.ow how to make s.is.ic table contain TLD s.s.em and analys.s.the res.lt of us.ng this.s.s.em in our s.ructure. Res.lts.imply that when frequency ratio approaches.1 this.s.s.em can perform its.bes. in both dis.ipate energy and increas.ng s.ructural damping. And als. res.lts.of thes. s.rial experiments.are proved compatible with Hunzer linear theory behavior.

关键词： TLD s.is.ic table s.ructural s.s.em Hunzer linear behavior

Elas.odynamic s.lution for plane-s.rain res.ons. of functionally graded thick hollow cylinders.by analytical method

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Applied Mathematics.and Mechanics.Englis. Edition) 2011年第2期32卷 189-202页

作者： M.NIKKHAH F.HONARVAR E.dehghan Faculty of Mechanical Engineering K.N.Toosi University of Technology

An elas.odynamic s.lution for plane-s.rain res.ons. of functionally graded thick hollow cylinders.s.bjected to uniformly-dis.ributed dynamic pres.ures.at boundary s.rfaces.is.pres.nted. The material properties. except Pois.on＇s.ratio, are as.umed to vary through the thicknes. according to a power law function. To achieve an exact s.lution, the dynamic radial dis.lacement is.divided into two quas.-s.atic and dynamic parts. and for each part, an analytical s.lution is.derived. The quas.-s.atic s.lution is.obtained by means.of Euler＇s.equation, and the dynamic s.lution is.derived us.ng the method of the s.paration of variables.and the orthogonal expans.on technique. The radial dis.lacement and s.res. dis.ributions.are plotted for various.functionally graded material （FGM） hollow cylinders.under different dynamic loads. and the advantages.of the pres.nted method are dis.us.ed. The propos.d analytical s.lution is.s.itable for analyzing various.arrangements.of hollow FGM cylinders.with arbitrary thicknes. and arbitrary initial conditions. which are s.bjected to arbitrary forms.of dynamic pres.ures.dis.ributed uniformly on their boundary s.rfaces.

关键词： functionally graded material elas.odynamic s.lution hollow cylinder,power law function