基于频散特性的杆中超声波传播仿真

针对超声实时在线检测中缓冲杆应用的局限性,以无限长杆的频散特性为理论基础,利用有限长杆的端面边界条件,分别以应力关系和应变关系为系统函数,建立了超声波在有限长杆中传播的系统模型。通过在杆端面施加激励,借助系统传输模型,获取回波信号,并与实验进行对比,验证该方法的正确性。同时得出了超声波在有限长杆中传播产生的多次回波的重复周期与杆半径之间成正比的关系。     

Decentralized Bezout Identity and a Parametrization of Decentralized Controllers for Singular Systems

1　 IntroductionConsider a singular decentralized control system of the formEx(t) =Ax(t) ∑Ni=1Biui(t)yi =Cix(t) ,i∈ N ={ 1 ,2 ,… ,N}(1 )where x(t)∈ Rn is the state vector,ui(t)∈ Rmi and yi(t)∈ Rpi are respectively the localcontrol input and measure outputvectors of the ith control channel.The matrix E may besingular,i.e.,rank(E) 相似文献   

The Optimum Model and Its Decision Support System of Coal Quality Balance

1　 Coal Quality Balance and Its Significance[1]Coal quality balance is to make a comprehensive plan concerning excavation steps and coalamount disposition of different coal seams based upon the natural coal-preservation stateand its relation with mining engineering in the three dimensional space so as to have thequality of coal excavated from different districts blended and coordinated the greatestextent possible and ensure the coal quality uniformity and stability,thus raise economicand soc…     

Study on the Investment Behavior under Transaction Cost in Futures Market

1　IntroductionAfter10yearsdevelopment,thestockmarketsofchinaarewaitingtoseestock-indexfu-turesinthenewcentury.Itisofgreatimportantforbothsmallinvestorsandlargeinvest-menthousestoadjusttheirbehaviorincasetheyenterintomarketswithnewinstruments.Inrecentyears,speculatingwithfutureswasdiscussedinsomepapers[1～4],andtheresultsachievedroutinelyholdtheassumptionsasnotransactioncosts(TC),nodifferentbetweenborrowingandlandingrates,andalltradingprofitsbeingsubjecttothesametaxrate.Themainproblemisthatne…     

Primary Structural and Quantitative Analysis of Infeasible Solution to Job shop Scheduling Problem

1　IntroductionTheJobShopSchedulingProblemisawell-knownNP-hardproblem,whichattractslotsofmathematiciansallovertheworldspendingmuchtimeandenergyinthisfield.Uptonowtherearemanyefficientheuristicalgorithms,whichhadalreadybeendeveloped,buttheinfeasiblesolutioncertainlypossessesthemajorityofsearchspacewhichhasinfluencedtheefficiencyofthesealgorithms.Atthemoment,noonehasbeenfoundtobededicatingtothequantitativeanalysisoftheinfeasiblesolutionproblem.InthispaperthestructureofinfeasiblesolutiontoJSS…     

Macro-economic Model and Its H_∞ Control Strategies for Liaoning Province

1　ＩｎｔｒｏｄｕｃｔｉｏｎＣｏｎｓｉｄｅｒａｂｌｅｒｅｓｅａｒｃｈｅｓｈａｖｅｂｅｅｎｍａｄｅｏｎｍａｃｒｏｅｃｏｎｏｍｉｃｍｏｄｅｌｓｔｉｌｌｎｏｗ .Ｐｏｌｉｃｙｍａｋｅｒｓｕｓｕ ａｌｌｙｐｒｅｄｉｃｔａｎｄａｎａｌｙｚｅｅｃｏｎｏｍｉｃｓｉｔｕａｔｉｏｎ ,ｍａｋｅｅｃｏｎｏｍｉｃｄｅｃｉｓｉｏｎｓｂａｓｅｄｏｎｔｈｅｓｅｍｏｄｅｌｓ[1] .Ｔｅｃｈｎｉｑｕｅｓｕｓｅｄｉｎｄｅｃｉｓｉｏｎｐｒｏｂｌｅｍａｎｄｒｉｓｋｍａｎａｇｅｍｅｎｔｕｓｕａｌｌｙａｒｅｏｐｔｉｍａｌｒｅｇｕｌａｔｏｒｔｈｅ…     

The System Dynamics (SD) is used for researching on battle simulation

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎ 1 95 6 ,ｔｈｅＳｙｓｔｅｍＤｙｎａｍｉｃｓ (ＳＤ)ｗａｓｓｅｔｕｐｂｙＰｒｏｆｅｓｓｏｒＪａｙ .Ｗ .Ｆｏｒｒｅｓｔｅｒ,ｗｈｏｗｏｒｋｅｄｉｎＡｍｅｒｉｃａＭａｓｓａｃｈｕｓｅｔｔｓＩｎｓｔｉｔｕｔｅｏｆｔｅｃｈｎｏｌｏｇｙ .ＡｎｄＳＤｗａｓｄｅｎｏｍｉｎａｔｅｄａｓ″ｓｔｒａｔｅｇｉｃａｎｄｓｔｒａｔａｇｅｍｌａｂｏｒａｔｏｒｙ″ .ＳＤｕｎｄｅｒｓｔａｎｄ ,ｔｈａｔｓｙｓｔｅｍａｔｉｃａｃｔｉｏｎｍｏｄｅａｎｄｍａｉｎｐｅｃｕｌｉａｒｉｔｙｇｏｖｅｒｎｂｙｉｔ′ｓ…     

悬崖上的玫瑰园

<正>几片玫瑰花瓣飘到了艾茵村的坎儿井中。这是一种具有典型的阿曼风格的水渠。玫瑰花瓣随着水渠中的水流漂荡,绕过一片片种植着玫瑰花的土地。正是因为有了这些植物,阿卡达尔才远近驰名。要知道,阿卡达尔直译过来便是"绿山"。继续漂流的花瓣迅速绕过种满了石榴树、桃树、杏树的园子。最后,花瓣在重力的作用下逐渐消失不见了。几千年来,在阿卡达尔村得益于     

《大数据百科全书》术语特点及收录与处理原则

大数据发展日新月异,新的应用需求和实践问题层出不穷,社会各界越来越重视大数据的基础研究。百科全书作为知识门类的概述性著作,是开展和推动基础研究的重要载体。作为大数据知识传播的工具,《大数据百科全书》不仅要有实用与新颖兼备的知识内容,并且还应具备准确严谨与通畅易懂的专业化语言文字表达。其中,术语是《大数据百科全书》不可或缺的有机组成部分,文章总结大数据领域的术语特点,并以此提出《大数据百科全书》术语方面的收录和处理原则。     

美国人重拾家庭影院梦

在美国富裕群体中,家庭影院的普及率较高.金融危机迫使美国人暂时放弃这一爱好.如今,随着美国经济逐渐复苏,家庭影院又一次受到追捧.不过,在家里享受极致观影体验的花费确实不菲.