简介:D·B·库珀是世界航空史上大名鼎鼎的传奇人物,而他这个知名度的得来并不是因为他对航空科技做出过什么贡献,更不是因为他有多么高超的飞行技艺,而是因为他制造了航空史上第一个劫机案.同时,该案也是唯一至今未破的劫机案。劫机案已经过去四十多年。作为劫机犯,库珀本来应该是臭名昭著的。但是在时间的发酵下。公众对他最初的痛恨早已烟消云散。而他在劫机过程中,从精心策划到顺利实施,再到成功逃脱。反倒使他拥有了无数粉丝。四十多年中。数以千计的人声称自己就是库珀,但是经联邦调查局一一确认,没有一个人是真正的库珀,这更增加了库珀的神秘性和公众的热情。
简介:Athree-dimensionalrigidbodyontheshapeofaparallelepipedismodelledinordertorockonasideoravertexofthebase,inordertoevaluatetheseismicresponseofrigidblockslyingonahorizontalsupport.Thecenterofmassofthebodyisconsideredaseccentricwithrespecttoitsgeometriccenter.Asseismicinput,threeItalianrecordedaccelerograms,withdifferentspectralcontent,areused.Thestudyismainlyconductedtohighlightthedifferencesbetweentheseismicresponseof2Dand3Dmodelsofrigidblocks,withtheaimtounderstandif,insomecases,theuseofthe3Dmodelofrigidblockisrequiredtoobtainsaferresults.Infact,theoutcomesshowthatinsomerangesofthegeometricalandmechanicalparametersthatcharacterizetheexcitationandthebody,atwo-dimensionalmodel,whichisnotabletoconsiderthe3Drockingonavertex,canprovideunsaferesults.Inparticular,itisfoundthattheoverturningprocessofthethree-dimensionalblockcanoccurunderexcitationswhicharelowerthanthosewhichoverturnacorrespondingtwo-dimensionalblock.
简介:Thehumanvisionsystemcanreconstructa3Dobjecteasilyfromsingle2Dlinedrawingsevenifthehiddenlinesoftheobjectareinvisible.Now,therearemanymethodshaveemulatedthisability,butwhenthehiddenlinesoftheobjectareinvisible,thesemethodscannotreconstructacomplete3Dobject.Therefore,weputforwardanewalgorithmtosettlethishardproblem.Ourapproachconsistsoftwosteps:(1)infertheinvisibleverticesandedgestocompletethelinedrawing,(2)proposeavertex-basedoptimizationmethodtoreconstructa3Dobject.
简介:Totesttheaccuracyofanewfingerprintscanner,researcherstypicallyrunmillionsofknownfingerprintimagesthroughthesystem'smatchingsoftware.Butthistestingprocedurecan'tquitemimicrealoperatingconditions,asa2-Dimagefedintoaprogramisfundamentallydifferentthana3-Dfingerpressedtoasensor.
简介:2014年大年初一,投资5亿、耗时3年制作的《西游记之大闹天宫》一经公映,便在圈内外引发热议。作为一部几乎全特效视觉大片,应该说《大闹天宫》在技术上代表了华语电影工业的最高水准,IMAX、3D、CG全上阵,震撼的3D效果、逼真的特效,让处于中国人想象中的神话王国跃然银幕之上。自2010年《阿凡达》在全球掀起3D狂潮后,世界影坛都将3D视为电影革新的生力军,而后伪3D、后期转制3D等兴盛,让3D技术蒙上了一丝阴影。如今,《大闹天宫》则让3D在华语电影圈再次扬眉吐气。本期话题聚焦3D技术,让三位电影业内专家揭开电影技术的神秘面纱,走进神奇的3D世界。