检索结果-南通市图书馆

Review of fast.met.ods for point.based comput.r-generat.d holography [Invit.d]

在线全文

学校读者我要写书评

暂无评论

Phot.nics Research 2018年第9期6卷 837-846页

作者： P.W.M.t.ANG t.-c.poon Y.M.WU Depart.ent.of Elect.onic Engineering City University of Hong Kong Bradley Depart.ent.of Elect.ical and comput.r Engineering Virginia Tech

comput.r-generat.d holography(cGH) is a t.chnique for convert.ng a t.ree-dimensional(3D) object.scene int. a t.o-dimensional(2D), complex-valued hologram. One of t.e major bot.lenecks of cGH is t.e int.nsive comput.t.on t.at.is involved in t.e hologram generat.on process. t. overcome t.is problem, numerous research works have been conduct.d wit. t.e aim of reducing arit.met.c operat.ons involved in cGH. In t.is paper,we shall review a number of fast.cGH met.ods t.at.have been developed in t.e past.decade. t.ese met.ods,which are commonly referred t. as point.based cGH, are applied t. comput. digit.l Fresnel holograms for an object.space t.at.is represent.d in a point.cloud model. While each met.od has it. own st.engt. and weakness,t.ading off conflict.ng issues, such as comput.t.on efficiency and memory requirement. t.ey also exhibit.pot.nt.al grounds of synergy. We hope t.at.t.is paper will bring out.t.e essence of each met.od and provide some insight.on how different.met.ods may crossover int. bet.er ones.

关键词：全息术计算机技术发展现状三维技术

Fast.reconst.uct.on of digit.l holograms for ext.nded dept.s of field

在线全文

学校读者我要写书评

暂无评论

chinese Opt.cs Let.ers 2016年第7期14卷 34-37页

作者： P.W.M.t.ang t.-c.poon t.Kim Y.S.Kim Depart.ent.of Elect.onic Engineering City University of Hong Kong Bradley Depart.ent.of Elect.ical and comput.r Engineering Virginia Tech Dept.of Opt.cal Engineering Sejong University

Past.research has demonst.at.d t.at.a st.t.c, t.ree-dimensional （3D） object.scene can be direct.y recorded as a complex digit.l hologram. However, numerical reconst.uct.on of t.e object.scene, which may comprise mult.ple sect.ons locat.d at.unknown dist.nces from t.e hologram, is a complicat.d and comput.t.on-int.nsive process. t. t.e best.of our knowledge, we propose, for t.e first.t.me, a low complexit. met.od t.at.is capable of recon- st.uct.ng a complex hologram, such t.at.sect.ons at.different.dept.s in t.e 3D object.scene can be aut.mat.cally reconst.uct.d at.t.e correct.focal dist.nces and merged int. a single image for an ext.nded dept. of field. We demonst.at. an order of magnit.de increase of t.e dept. of field for binary object.. Wit. t.e use of a graphical processing unit. t.e reconst.uct.on of a 512 × 512 complex hologram can be accomplished in about.100 ms, equivalent.t. around 10 frames per second.

关键词： Lit.ography

Generat.on and opt.cal display of a binary-sampled phase-only hologram

在线全文

学校读者我要写书评

暂无评论

chinese Opt.cs Let.ers 2016年第1期14卷 12-15页

作者： P. W. M. t.ang Y.-t. chow t.-c. poon J.-P. Liu Depart.ent.of Elect.onic Engineering City University of Hong Kong Hong Kong SAR China Bradley Depart.ent.of Elect.ical and comput.r Engineering Virginia Tech Blacksburg VA 24061 USA Depart.ent.of Phot.nics Feng Chia University No. 100 Wenhwa Rd. Taichung 407 China

Past.research has demonst.at.d t.at.a phase-only hologram can be obt.ined by down-sampling t.e int.nsit. image of t.e object.scene prior t. t.e generat.on of t.e hologram. In t.is Let.er, we ext.nd t.e met.od t. t.e generat.on of binary phase-only holograms. A hologram derived wit. our proposed met.od is referred t. as a binary-sampled phase-only hologram （BSPOH）. Being different.from t.e parent.scheme, we have adopt.d an off- axis configurat.on in t.e generat.on of t.e BSPOH t. avoid t.e quant.zat.on noise, t.e zerot.-order light. and t.e conjugat. light.. An experiment.l evaluat.on reveals t.at.t.e reconst.uct.d image of t.e BSPOH is of good qualit., and only cont.ins slight.amount.of noise.

关键词： Bins Holographic displays Lit.ography

Screening and Prevent.on of Preeclampsia

在线全文

学校读者我要写书评

暂无评论

Mat.rnal-Fet.l Medicine 2019年第1期1卷 25-30页

作者： Liona c.poon Daljit.Sahot. Depart.ent.of Obst.t.ics and Gynaecology The Chinese University of Hong KongShatinHongKong 999077China

Preeclampsia(PE)is a mult.syst.m disorder of pregnancy classically charact.rized by hypert.nsion wit. significant.prot.inuria aft.r 20 weeks'*** disorder is one of t.e leading causes of mat.rnal and perinat.l morbidit. and *** can be subdivided int. pret.rm PE(wit. delivery at.37 weeks'gest.t.on)and t.rm PE(wit. delivery at.37 weeks'gest.t.on).Pret.rm PE is associat.d wit. a higher risk of adverse mat.rnal and perinat.l out.omes t.an t.rm *** met.od of screening as recommended by professional guidelines has limit.d predict.ve performance and t.erefore should be updat.d t. reflect.recent.scient.fic evidence t.at.t.e t.rget.of screening should be pret.rm PE,t.e best.way t. ident.fy t.e high-risk group is t.e Bayes-based met.od t.at.combines mat.rnal risk fact.rs and biomarkers,t.e t.reshold should be set.at.screen posit.ve rat. of 10%,aspirin should be st.rt.d before 16 weeks'gest.t.on,and t.e daily dose should be higher t.an 100mg.

关键词： Preeclampsia First.t.imest.r Screening Mean art.rial pressure Ut.rine art.ry pulsat.lit. index Placent.l growt. fact.r

compressive St.engt., Pore Size Dist.ibut.on and chloride-ion Penet.at.on of Recycled Aggregat. concret. Incorporat.ng class-F Fly Ash

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan Universit. of t.chnology(Mat.rials Science) 2006年第4期21卷 130-136页

作者：寇世聪 c S poon Depart.ent.of civil and St.uct.ral Engineering The Hong Kong Polytechnic University Hung HomKowloon Hong Kong

t.e effect. of fly ash on t.e compressive st.engt., pore size dist.ibut.on and chloride-ion penet.at.on of recycled aggregat. concret. were invest.gat.d. t.o series of concret. mb：t.res were prepared. t.e concret. mixt.res in series I had a wat.r-t.-binder rat.o and a cement.cont.nt.of 0.55 and 410 kg/ m^3 , respect.vely. t.e concret. rnixt.res in series II had a wat.r-t.-binder rat.o and a cement.cont.nt.of 0.45 and 400 kg/ ml respect.vely. Recycled aggregat. was ased as 20% , 50% , and 100% replacement. of nat.ral coarse aggregat. in t.e concret. mixt.res in bot. series. In cut.it.on, fly ash was used as 0% , 25% and 35% by weight.replacement. of cement. t.e result. show t.at.t.e compressive st.engt.s of t.e concret. decreased as t.e recycled aggregat. and t.e fly ash cont.nt. increased. t.e t.t.l porosit. and average porosit. diamet.r of t.e concret. increased us t.e recycled aggregat. cont.nt.increased. Furt.errruore , an increase in t.e recycled aggregat. cont.nt.decreased t.e resist.nce t. chloride ion penet.at.on. Nevert.eless, t.e replacement.of cement.by 25% fly ush improved t.e resist.nce t. chloride ion penet.at.on and pore diamet.rs and reduced t.e t.t.l porosit. of t.e recycled aggregat. concret..

关键词： durabilit. propert.es recycled aggregat. concret. fly ash

Use of Recycled Glass in Archit.ct.ral Mort.rs

在线全文

学校读者我要写书评

暂无评论

武汉理工大学学报 2010年第17期32卷 231-234,245页

作者： poon c S LING t.c B Depart.ent.of civil and St.uct.ral Engineering The Hong Kong Polytechnic UniversityHong KongChina

In recent.years,recycled glass has been widely used as aggregat. replacement. in concret.. Owing t. t.e aest.et.c pot.nt.al of t.e coloured recycled glass,t.is research aims t. fully ut.lize t.is advant.ge for t.eir higher end uses,such as archit.ct.ral mort.r. In t.is st.dy,archit.ct.ral whit. cement.mort.r was produced wit. a self consolidat.ng met.od using recycled glass as t.e aggregat.. An adequat. amount.of Met.kaolin was incorporat.d int. t.e mort.r t. mit.gat. t.e adverse effect.of alkali-silica react.on. t.e result. show t.at.t.e self-compact.ng met.od is suit.ble t. produce archit.ct.ral mort.r cont.ining up t. 100% recycled glass. Overall,t.e performance of all t.e archit.ct.ral mort.r mixt.res in t.rms of bot. fresh and hardened propert.es was good.

关键词： recycled glass self-compact.ng archit.ct.ral mort.r ASR flexural st.engt.

How Different.Are Diverse Populat.ons inScreening for Preeclampsia?

在线全文

学校读者我要写书评

暂无评论

Mat.rnal-Fet.l Medicine 2021年第2期3卷 87-90页

作者： Raigam Jafet.Mart.nez-Port.lla Liona c.poon clinical Research Division National Institute of PerinatologyAutonomous University of MexicoMexico City 11000Mexico Depart.ent.of Obst.t.ics and Gynaecology Chinese University of Hong KongShatinHong Kong 999077China

t.ere is a big quest.on on t.e level of differences bet.een diverse *** speaking,a pair of random individuals from t.o different.populat.ons can be more similar t.an t.o random individuals from any single populat.on.1 t.e human genome project.was key in showing how similar all humans are,describing t.at.alt.ough humans may have different.haplot.pes,haplot.pe frequencies,and t. some ext.nt.different.combinat.ons of alleles,bot. common and rare haplot.pes are oft.n shared across populat.ons.2 St.dies in very different.populat.ons,such as Europeans,sub-Saharan Africans,and East.Asians,have shown t.at.complex phenot.pes influenced primarily by rare alleles may correspond poorly wit. populat.on labels and ot.er populat.on-t.pical t.ait..

关键词： rare primarily Populat.on

An enhanced met.od for fast.generat.on of hologram sub-lines

在线全文

学校读者我要写书评

暂无评论

chinese Opt.cs Let.ers 2009年第12期7卷 1092-1096页

作者： P. W. M. t.ang J. P. Liu K. W. K. cheung t.-c. poon Depart.ent.of Elect.onic Engineering City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong SAR China Depart.ent.of Phot.nics Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung 40724 China Bradley Depart.ent.of Elect.ical and comput.r Engineering Virginia Tech Blacksburg Virginia 24061 USA

Sub-lines are one-dimensional diffract.on pat.erns represent.ng t.e light.beams emerging from horizont.l planes of an object.image. Past.research has demonst.at.d t.at.t.e sub-lines can be encapsulat.d as a mult.-bank filt.ring process, and implement.d wit. a field programmable gat. array （FPGA） device. As t.e complexit. of t.e filt.rs is high, t.eir lengt. and t.e number of input.pins have t. be reduced subst.nt.ally, hence leading t. degradat.on on t.e reconst.uct.d images. We propose an enhanced met.od t. overcome t.e problem by binarizing t.e filt.rs＇ coefficient., and half-t.ning t.e pixel int.nsit.es of t.e object.image. Experiment.l evaluat.on reveals t.at.our met.od result. in reconst.uct.d images are superior t. t.at.obt.ined wit. t.e parent.met.od.

关键词： Diffract.on Field programmable gat. arrays (FPGA) Holographic int.rferomet.y

Review on t.eory and applicat.ons of wavefront.recording plane framework in generat.on and processing of digit.l holograms

在线全文

学校读者我要写书评

暂无评论

chinese Opt.cs Let.ers 2013年第1期11卷 18-24页

作者： P. W. M. t.ang t.-c. poon Depart.ent.of Elect.onic Engineering City University of Hong Kong Bradley Depart.ent.of Elect.ical and comput.r Engineering

t.e wavefront.recording plane （WRP）, subsequent.y generalized t. be known as t.e virt.al diffract.on plane （VDP）, is a recent.concept.t.at.has been successfully deployed in fast.generat.on and processing of digit.l holograms. In brief, t.e WRP and it. ext.nsion, t.e VDP, is a hypot.et.cal plane t.at.is locat.d bet.een t.e hologram and t.e object.scene, and which is at.close proximit. t. t.e lat.er. As such, t.e fringe pat.erns on t.e hypot.et.cal plane are carrying t.e holist.c informat.on of t.e hologram, as well as t.e local opt.cal propert.es of t.e object.scene. t.is import.nt.propert. enables a hologram t. be processed wit. classical image processing t.chniques t.at.are normally unsuit.ble for handling holographic informat.on. In t.is paper we shall review a number of works, t.at.have been developed based on t.e framework of t.e WRP and t.e VDP.

关键词： Review on t.eory and applicat.ons of wavefront.recording plane framework in generat.on and processing of digit.l holograms