简介：Large-scaleMIMO(multiple-inputmultiple-output)systemswithnumerouslow-powerantennascanprovidebetterperformanceintermsofspectrumefficiency,powersavingandlinkreliabilitythanconventionalMIMO.Forlarge-scaleMIMO,thereareseveraltechnicalissuesthatneedtobepracticallyaddressed(e.g.,pilotpatterndesignandlow-powertransmissiondesign)andtheoreticallyaddressed(e.g.,capacitybound,channelestimation,andpowerallocationstrategies).Inthispaper,weanalyzethesumrateupperboundoflarge-scaleMIMO,investigateitskeytechnologiesincludingchannelestimation,downlinkprecoding,anduplinkdetection.Wealsopresentsomeperspectivesconcerningnewchannelmodelingapproaches,advanceduserschedulingalgorithms,etc.

简介：随机的地震倒置是geostatistics和从地震记录，井木头，和geostatistics把信息集成到表面下的模型的以后的概率密度功能(PDF)的地震倒置技术的联合。Markov链蒙特卡罗(MCMC)方法被用来取样以后的PDF，表面下的模型特征能被分析推断一套以后的PDF样品。在这份报纸，我们首先介绍随机的地震倒置理论，讨论并且分析四个关键参数：地震数据signal-to-noise比率(S/N)，variogram，以后的PDF样品数字，和井密度，并且建议这些参数的最佳选择。分析结果证明地震数据S/N调整在地震数据的影响之间的妥协，倒置上的geostatistics结果，variogram控制倒置结果的光滑，以后的PDF样品数字决定统计特征的可靠性源于样品，并且很好，密度影响倒置无常。最后，在随机的地震倒置之间的比较和确定的模型基于地震倒置显示随机的地震倒置能提供表面下的特性的更可靠的信息。

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简介：Inordertoovercomethepoorlocalsearchabilityofgeneticalgorithm,resultinginthebasicgeneticalgorithmistime-consuming,andlowsearchabilityinthelateevolutionary,weusethegraycodinginsteadofbinarycodingatthebeginningofthecoding;weusemulti-pointcrossovertoreplacetheoriginalsingle-pointcrossoveroperation.Finally,theexperimentshowsthattheimprovedgeneticalgorithmnotonlyhasastrongsearchcapability,butalsothestabilityhasbeeneffectivelyimproved.

简介：DriftmarkedChina-Japantiesinmostpartofthe1990s,accompaniedwithwildswings.Thelastdecadeofthe20thcenturywitnessedthecommemorationofthe20thanniversary(1972-1992)ofdiplomaticnormalization,the50thanniversary(1945-1995)ofthevictoryoftheWarofResistanceAgainstJapaneseAggression,thefuroroverthe"NoWardecision"inJapan,andtheshockwavesfromthereorientationofJapan-U.S.relationshipin1996andtherevisionoftheguidelines

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简介：AbstractMandibular condylar fractures are among the most common facial fractures and some of the most difficult to manage. Opinions about the management of mandibular condylar fractures differ among surgeons. With the implementation of new technology, an increased understanding of fracture management, and better functional and morphological outcomes reported in the literature, open reduction and internal fixation is becoming many surgeons’ preferred choice for the treatment of condylar fractures. Because surgical treatment of such fractures is complex, certain factors must be considered to achieve satisfactory outcomes. In this article, we summarise six key points in the management of mandibular condylar fractures: virtual evaluation of condylar fracture, a suitable surgical approach, good reduction, stable internal fixation, repair of the articular disc, and restoration of the mandibular arch width. We believe that these points will help to improve the prognosis of mandibular condyle fractures.

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简介：Densechromiumsesquioxiderefractorieshavewidelybeenusedinthekilnsformakingalkai-freeandanti-alkaliglassfibersduetotheirexcellentre-sistancetomoltenglasses.Densificationsofchromiumsesquioxideduringsinteringcanbeblockedbyevaporationofchromiumtrioxidederivedfromoxidationathightemperature,Inthispaperthemech-anismofsinteringchromiumoxideandtheprocess-ingtechniqueformakingdensechromiumsesquiox-iderefractoriesarediscussed.Aprocessinlaboratoryscaleformakingdensechromiumsesquioxidebricksisdemonstrated.

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简介：IntroductiontoHECHarbinElectricMachineryCompanyLimited(HEC)isapivotalcompanythatproduceslargeelectricmachineryandaccessorialcontrolequipmentinChina.ThehydrounitsmadebyHEChaveaccounted

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简介：10月26日至27日,'中国重载铁路技术交流暨大秦重载铁路运营三十周年论坛'在太原举行。论坛全面总结和展示了我国铁路重载领域发展的技术成果,共同谋划了中国重载铁路发展的新方向,加强国内外同行业的技术交流与合作,推动中国重载铁路技术创新,为调整运输结构、提高铁路货运量、打好污染防治攻坚战提供技术支撑。

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简介：由北京强都科技开发有限公司生产的工业用多极重载连接器，是吸取国外先进的技术，采用优质的工业原料及严格的生产工艺制造的。该产品采用金属外壳、银铜触点，具有开断容易、导通率好、插拔方便、接驳正确率高以及抗震动和防水功能好的特点，适于对环境要求高及检修难度大、频繁插拔的情况，可用于机床、电气控制、开关柜、纺织机械、电梯、机车制造业、电力设备、冶金、仪表、工业自动化等行业。

简介：摘要：文章主要论述重载铁路维护维修策略需求分析，提出了重载铁路养护维修策略。旨在对重载铁路养护维修决策制定与执行起到一定的借鉴与指导作用。

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简介：Invideoinformationretrieval,keyframeextractionhasbeenrecognizedasoneoftheimportantresearchissues.Althoughmuchprogresshasbeenmade,theexistingapproachesareeithercomputationallyexpensiveorineffectiveincapturingsalientvisualcontent.Inthispaper,wefirstdiscusstheimportanceofkeyframeextractionandthenbrieflyreviewandevaluatetheexistingapproaches.Toovercometheshortcomingeoftheexistingapproaches,weintroduceanewalgorithmforkeyframeextractionbasedonunsupervisedclustring.Meanwhile,weprovideafeedbackchaintoadjustthegranularityoftheextractionresult.Theproposedalgorithmisbothcomputationallysimpleandabletocapturethevisualcontent.Theefficiencyandeffectivenessarevalidatedbylargeamountofreal-worldvideos.