简介:Thedamagetothemasonry-infilledreinforcedconcrete(RC)framebuildingsinCharikot,thecapitalcityofDolakhadistrictinNepal,duringthe2015April-to-MayNepalearthquakesequenceisreported.Mostofthesebuildingswerebuiltbytheownerswithlittlegovernmentalinspectionsregardingtheirstructuraldesignorconstructionalquality.Althoughtheygenerallyperformedbetterthanotherstructuralsystemssuchasstone-masonryhouses,theRCframessustainedextensivedamagerangingfromcrackingofinfilltocompletecollapse.Inparticular,eightofthe72inspectedRCframesalongsideanuphillstreetcollapsedindifferentways.Inadditiontotheun-engineerednatureoftheseRCframes,theircollapsecouldalsobeattributedtomultipletechnicalreasonsincludingtheeffectofterrain,thepoundingbetweenadjacentbuildingsandtheaccumulativedamageintheearthquakesequence.
简介:Background:Neighborhoodbuiltenvironmentmayprofoundlyinfluencechildren’sphysicalactivity(PA)andbodyweight.ThisstudysystematicallyreviewedscientificevidenceregardingtheimpactofbuiltenvironmentonPAandobesityamongchildrenandadolescentsinChina.Methods:AkeywordandreferencesearchwasconductedinActiveLivingResearch,CochraneLibrary,PubMed,andWebofScience.Studiesthatmetallofthefollowingcriteriawereincludedinthereview:(1)studydesigns-experimentalstudies,observationalstudies,andqualitativestudies;(2)studysubjects-Chinesechildrenand/oradolescentsaged≤17years;(3)exposures-neighborhoodbuiltenvironment;(4)outcomes-PAand/orbodyweightstatus;(5)articletype-peer-reviewedpublications;(6)timewindowofsearch-fromtheinceptionofanelectronicbibliographicdatabasetoMay31,2018;(7)country-China;and(8)language-articleswritteninEnglish.Results:Atotalof20studies,including16cross-sectionalstudies,3longitudinalstudies,and1descriptivestudy,metthepredeterminedselectioncriteriaandwereincludedinthereview.Atotalof13studiesadoptedsubjectivebuiltenvironmentmeasuresreportedbyparentsand/orchildren,2adoptedobjectivemeasures(e.g.,geographicalinformationsystem,fieldobservations),and5adoptedbothobjectiveandsubjectivemeasures.PAbehaviorsincludedPA,physicalinactivity,sedentarybehavior,active/passivecommutingfrom/toschool,andparkvisits.Amongthe16studiesthatprovidedsomequantitativeestimatesoftheinfluenceofbuiltenvironmentonPAandbodyweightstatus,allreportedastatisticallysignificantrelationshipintheexpecteddirection.Availabilityandaccessibilityinproximitytogreenspaces,parks,recreationalfacilities,andsidewalkswerefoundtobeassociatedwithincreasedPAlevels,reducedsedentarybehaviors,and/oractivecommutingamongChinesechildrenandadolescents.Incontrast,theabsenceofbikelanesandlivinginhigherdensityresidentialareaswer
简介:Variousindexstructureshaverecentlybeenproposedtofacilitatehigh-dimensionalKNNqueries,amongwhichthetechniquesofapproximatevectorpresentationandone-dimensional(1D)transformationcanbreakthecurseofdimensionality.Basedonthetwotechniquesabove,anovelhigh-dimensionalindexisproposed,calledBit-codeandDistancebasedindex(BD).BDisbasedonaspecialpartitioningstrategywhichisoptimizedforhigh-dimensionaldata.Bythedefinitionsofbitcodeandtransformationfunction,ahigh-dimensionalvectorcanbefirstapproximatelyrepresentedandthentransformedintoa1Dvector,thekeymanagedbyaB+-tree.AnewKNNsearchalgorithmisalsoproposedthatexploitsthebitcodeanddistancetoprunethesearchspacemoreeffectively.ResultsofextensiveexperimentsusingbothsyntheticandrealdatademonstratedthatBDout-performstheexistingindexstructuresforKNNsearchinhigh-dimensionalspaces.
简介:在环境保护观念普及化的今天,国际投资协定(BIT)将环境问题纳入规范之列,已成犬势所趋。美国正是在此背景下在其新版BIT中强化了环境保护。强化主要表现为用语、款项变化和内容增加,但却因专门环境条款用语仍极富弹性、缺乏法律责任规定和没有争议解决的法律机制作为实施保障,而表现出很强的政策属性,其法律意义因而打折。然而,因为一系列“强化”反映出向法律性质的靠近,法律意义并非阚如。对于美国来说,这种从政策性向法律性过渡的选择是现实需要与摆脱两难处境的折衷做法。正在与美国加紧谈判BIT的中国,应该在了解其内容、性质和发展趋势基础上,积极参与这类国际规则的制订过程。
简介:Inthispaper,weproposeoptimumandsub-optimumresourceallocationandopportunisticschedulingsolutionsfororthogonalfrequencydivisionmultipleaccess(OFDMA)-basedmulticellularsystems.Theapplicability,complexity,andperformanceoftheproposedalgorithmsareanalyzedandnumericallyevaluated.Intheinitialsetup,thefractionalfrequencyreuse(FFR)techniqueforinter-cellinterferencecancellationisappliedtoclassifytheusersintotwogroups,namelyinteriorandexteriorusers.Adaptivemodulationisthenemployedaccordingtothechannelstateinformation(CSI)ofeachusertomeetthesymbolerrorrate(SER)requirement.Therethen,wedevelopsubcarrier-and-bitallocationmethod,whichmaximizesthetotalsystemthroughputsubjecttotheconstraintsthateachuserhasaminimumdataraterequirement.Thealgorithmtoachievetheoptimumsolutionrequireshighcomputationalcomplexitywhichhindersitfrompracticability.Towardthisend,weproposeasuboptimummethodwiththecomplexityextensivelyreducedtotheorderofO(NK),whereNandKdenotethetotalnumberofsubcarriersandusers,respectively.Numericalresultsshowthattheproposedalgorithmapproachestheoptimumsolution,yetitenjoysthefeaturesofsimplicity,dynamiccellconfiguration,adaptivesubcarrier-and-bitallocation,andspectralefficiency.IndexTermsAdaptivemodulation,fractionalfrequencyreuse,multiusersubcarrier-and-bitallocation,opportunisticscheduling,orthogonalfrequencydivisionmultipleaccess.
简介:OnJuly24.2013.alow-EcoatedglassprojectofXianyangCo.,Ltd.ofTaiwanglassGroupwithadailycapacityof1.2thousandtonswasstartedtobebuilt,meanwhileafloatglassproductionlinewasputintoproduction.ThefloatglasslinewithCNY1.5billionofinvestmentwasbuiltinJuly.2008.TotalinvestmentofphaseIofthelow-EcoatedglassprojectwasCNYone
简介:摘要现阶段,科学技术的发展迅速,饮食健康的重要性逐渐在日常生活中凸显出来,因此人们下厨亲自做饭的几率便越来越高,但烹饪过程中产生的油烟,对人体的肺部以及免疫系统都会产生较大的危害。因此,吸油烟机作为保障人们免受油烟侵害的首要厨房电器,对于人们生活品质的提升起着至关重要的作用,在调查当中显示,吸油烟机最受消费者关注的三个指标便是吸烟效果,空气性能以及噪声。其中,空气性能与噪声之间属于负相关指标,空气性能的提升势必会带来噪声的提高。因此,如果能在保障吸油烟机现有空气性能的基础上降低其运行时产生的噪声,将对吸油烟机产品整体性能的提升以及推动行业发展有着极为重大的意义。
简介:摘要:为保证静止煤采样机所采煤样具有代表性,采样机需每两年进行一次性能试验,且需不定期进行内部质量控制。在内部质量控制中,参比煤样的采取是试验的一个难点。本文提出一种操作简单且代表性更强的方法代替人工钻孔法进行参比样的采取,通过t检验法进行采样机偏倚的判定。经过试验发现该采样机因螺旋钻叶片磨损较为严重,采取的煤样存在偏倚,更换螺旋钻后采样机性能恢复正常。