简介：~~

简介：

简介：

简介：~~

简介：体积变化是影响木材处理的一个无常元素。我们学习了优秀缺点在传统的木材处理引起并且建立了一条优化途径的木头的体积变化，用一个柔韧的优化方法。我们使用了生产学习在板厚度和原料日志之间的关系的可接受的板的全部的数字，用控制改进板的输出，减少副产品的数量，并且降低生产费用的板体积的变化的一个启发式的搜索算法。柔韧的优化方法能有效地在木材处理控制体积变化的影响，远及增长处理的可能的使用减少切的废物并且增加利润，最大化木材的利用比率，在处理阻止废物，栽培树种类的生产类型并且节省森林资源。

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简介：BPandRBFneuralnetworktopredictforeststockvolumewerestudied,butthestudyinevaluatingbothnetworks’applicationeffectswasnotconducted.Inordertofindahigherforecastprecision,morestrongapplicativemethod,thecomprehensiveanalysisandevaluationonthetwomethodswerecarriedoutinthepracticalapplication.Bythecorrelationanalysis,crowndensity,shady-slopeandsunny-slope,TM1,TM2,TM3,TM5,TM7,NDVI,TM,(4-3),TM4/3wereselectedasinputvariables,andtheforestvolumeofMiyunCountyasoutputvariables,RBFandBPneuralnetworkmodelsforforecastingtheforestvolumewereestablished.Andtheneuralnetworktrainingsteplength,trainingtime,predictionaccuracyandtheapplicabilitymodelofthetwomethodswerecomprehensivelyanalyzed.TheresultsshowthattheRBFneuralnetworkmodelissuperiortotheBPneuralnetworkmodel.

简介：我们在北伊朗的多山的森林里根据包含的山腰材料(土壤或岩石)和山腰坡度的类型调查了邻近小量的道路的树看台的损坏的分发和频率。80个阴谋的一个总数系统地并且随机被取样记录损坏的树(弯曲，压碎并且伤害)由在道路的边的山腰坡度和材料的班。树在岩石斜坡伤害并且压碎比在有黏土的混合的山腰显著地大(p?45%是比在有斜坡坡度的山腰上更经常的2，8.5和2.3次<15%为分别地弯曲，压碎并且伤害。类型和最经常的损坏改变的损坏分发是树伤害(p?

简介：Background:Volumeandtaperequationsareessentialforobtainingestimatesoftotalandmerchantablestemvolume.Taperfunctionsprovideadvantagestomerchantablevolumeequationsbecausetheyestimatediameterinsideoroutsidebarkatspecificheightsonthestem,enablingtheestimationoftotalandmerchantablestemvolume,volumeofindividuallogs,andaheightatagivendiameter.Methods:Usingdatacollectedfrom1218trees(1093Douglas-fir(Pseudotsugamenziesii(Mirbel)Franco)and125westernhemlock(Tsugaheterophylla)),weevaluatedtheperformanceofonesimplepolynomialfunctionandfourvariable-exponenttaperfunctionsinpredictingupperstemdiameter.SampletreeswerecollectedfromdifferentpartsofthestatesofOregon,Washington,andCalifornia.Wecomparedinside-barkvolumeestimatesobtainedfromtheselectedtaperequationwithestimatesobtainedfromasimplelogarithmicvolumeequationforthedataobtainedinthisstudyandtheequationsusedbytheForestInventoryandAnalysisprograminthePacificNorthwest(FIA-PNW)inthestateofCaliforniaandwesternhalfofthestatesofOregonandWashington.Results:Variableexponenttaperequationsweregenerallybetterthanthesimplepolynomialtaperequations.TheFIA-PNWvolumeequationsperformedfairlywellbutvolumeequationswithfewerparametersfittedinthisstudyprovidedcomparableresults.TheRMSEobtainedfromtaper-basedvolumeestimateswerealsocomparablewiththeRMSEoftheFIA-PNWvolumeequationsforDouglas-firandwesternhemlocktreesrespectively.Conclusions:ThetaperequationsfittedinthisstudyprovideaddedbenefittotheusersovertheFIA-PNWvolumeequationsbyenablingtheuserstopredictdiameteratanyheight,heighttoagivendiameter,andmerchantablevolumeinadditiontocubicvolumeincludingtopandstump(CVTS)ofDouglas-firandwesternhemlocktreesinthePacificNorthwest.ThefindingsofthisstudyalsogivemoreconfidencetotheusersofFIA-PNWvolumeequations.