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Developing kNN forest data imputation for Catalonia

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Journal of Forestry Research 2024年第4期35卷 142-155页

作者： timo Pukkala Núria Aquilué Ariadna Just Jordi Corbera Antoni Trasobares Forest Science and Technology Centre of Catalonia(CTFC) Crta.de St.Llorençde MorunysKm 225280 SolsonaSpain Cartographic and Geological Institute of Catalonia(ICGC) 08038 BarcelonaSpain

The combined use of LiDAR(Light Detection And Ranging)scanning and field inventories can provide spatially continuous wall-to-wall information on forest *** information can be used in many ways in forest mapping,scenario analyses,and forest manage-ment *** study aimed to find the optimal way to obtain continuous forest data for Catalonia when using kNN imputation(kNN stands for“k nearest neighbors”).In this method,data are imputed to a certain location from k field-measured sample plots,which are the most similar to the location in terms of LiDAR metrics and topographic *** multidimensional Euclidean distance was used as the similarity *** study tested two different methods to optimize the distance *** first method optimized,in the first step,the set of LiDAR and topographic variables used in the measure,as well as the transformations of these *** weights of the selected variables were optimized in the second *** other method optimized the variable set as well as their transformations and weights in one single *** two-step method that first finds the variables and their transfor-mations and subsequently optimizes their weights resulted in the best imputation *** the study area,the use of three to five nearest neighbors was *** and latitude turned out to be the most important variables when assessing the similarity of two locations of Catalan forests in the context of kNN data *** optimal distance measure always included both LiDAR metrics and topographic *** study showed that the optimal similarity measure may be different for different ***,it was suggested that kNN data imputation should always be started with the optimization of the measure that is used to select the k nearest neighbors.

关键词： Forest inventory Differential evolution Simulated annealing LiDAR

Two decades of fire activity over the PEEX domain:a look from space,with contribution from models and ground-based measurements

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Big Earth Data 2024年第2期8卷 350-396页

作者： Larisa Sogacheva timo H.Virtanen Anu-Maija Sundström Pekka Kolmonen Mikhail Sofiev Hanna K.Lappalainen Antti Arola Finnish Meteorological Institute Climate Research ProgrammeHelsinkiFinland Finnish Meteorological Institute Space and Earth Observation CentreHelsinkiFinland Institute for Atmospheric and Earth System Research/Physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland

It has been suggested that forest fires will become more frequent/intense with changing climate,which would increase aerosol/gas emissions into the atmosphere.A better under-standing of the relations between meteorological conditions,fires,and fire emissions will help estimate the climate response via forest *** this study,we use ERA5 meteor-ological products,including temperature,precipitation,and soil moisture,to explain the frequency of forest fires and the amount of radiant energy released per time unit by burning vegetation(fire radiative power,FRP).We explore the relation-ships between satellite-retrieved fire products and aerosol properties(aerosol optical depth,AOD),carbon monoxide(CO),formaldehyde(HCHO),and nitrogen dioxide(NO_(2))con-centrations over the PEEX domain,which covers different vegetation zones(***/grasslands,forest,arctic tun-dra)of Pan-Eurasia and *** analyse the concentrations of black carbon and absorbing organic carbon using groundbased AErosol RObotic *** analysis covers the months of May to August from 2002 to *** show posi-tive temperature trends in the Northern zone(>65°N)in June and August(1.56°C and 0.64°C,respectively);all statistically significant trends for precipitation and soil moisture are *** can explain increased fire activity in Siberia over the recent years(2019-2022).Over the whole PEEX domain,FC and FRP trends remain insignificant or negative;a decrease in AOD may address those negative *** show that intrasummer variations exist for cropland/grassland fires,which occur most often in May and August,while Siberian forest fires occur more often in July and *** show that CO concentration has been gradually decreasing in the last two decades in May and *** trends are negative in May,June,and over summer for all regions,in July in Europe,China,the Southern zone(<55°N),and the PEEX *** trends are not significant in all ***_(2)trends are positive in May and

关键词： PEEX wild fires satellite trend enhancement ratios

单木造材优化嵌入传统林分经营优化中的红松人工林精准经营模式

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东北林业大学学报 2024年第2期52卷 13-20页

作者：徐颖蒋博金星姬 timo Pukkala 东北林业大学哈尔滨150040 东芬兰大学芬兰•约恩苏

以黑龙江省红松(Pinus koraiensis Siebold et Zuccarini)人工林主要分布区域的标准幼龄林(初植密度2500、3300株/hm~2,地位指数12、14、16 m)为研究对象,利用韦布尔(Weibull)函数预测株数保存率为85%时不同立地指数的红松人工林在10 a... 详细信息

以黑龙江省红松(Pinus koraiensis Siebold et Zuccarini)人工林主要分布区域的标准幼龄林(初植密度2500、3300株/hm~2,地位指数12、14、16 m)为研究对象,利用韦布尔(Weibull)函数预测株数保存率为85%时不同立地指数的红松人工林在10 a时的直径分布;依据红松人工林幼龄标准林分数据,利用人工红松单木-林分基础模型和球果模型构建的林分模拟器对标准林分进行生长模拟,在传统经营优化模式中嵌套单木造材优化,构建单木造材优化嵌入传统林分经营优化中的红松人工林精准经营模式(简称“精准林分经营优化模式”);以木材和球果总净现值最大为目标,对比精准林分经营优化模式、传统林分经营优化模式的差异,分析造材优化对林分经营优化结果、林分经营措施的影响。结果表明:在约束间伐强度和固定下层伐的条件时,与传统经营优化模式相比,精准林分经营优化模式使总经济效益提升6.5%~9.1%。立地条件越好,精准林分经营优化模式对木材净现值增长率、年均木材产量、主伐时林分平均胸径的增量影响越显著,而对年均球果产量、球果净现值增长率的增量影响较小。在同一立地条件时,与传统林分经营优化模式相比,精准林分经营优化模式提升木材净现值增长率对林分初植密度更敏感。

关键词：红松人工林经营模式造材优化净现值

顾及边缘的多时相SAR图像半监督建筑区提取

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西南交通大学学报 2024年第5期59卷 1225-1234页

作者：陈帅霖杨文李恒超 TAPETE Deodato BALZ timo 武汉大学电子信息学院湖北武汉430072 西南交通大学信息科学与技术学院四川成都611756 意大利航天局(ASI) 罗马00133 武汉大学测绘遥感信息工程国家重点实验室湖北武汉430079

针对合成孔径雷达(synthetic aperture radar,SAR)图像中建筑区域难以辨识与标注的问题,提出一种结合改进的伪标签技术和边缘增强策略的半监督建筑区提取新方法.首先,引入同一位置、不同时相的SAR图像作为自然数据增强手段,并通过多个... 详细信息

针对合成孔径雷达(synthetic aperture radar,SAR)图像中建筑区域难以辨识与标注的问题,提出一种结合改进的伪标签技术和边缘增强策略的半监督建筑区提取新方法.首先,引入同一位置、不同时相的SAR图像作为自然数据增强手段,并通过多个不同时相图像的预测结果投票确定伪标签;其次,设计一种边缘增强辅助模块,通过特征图变形以修正建筑区主体特征,辅以跳跃连接改进边缘特征,并针对主体和边缘特征进行分离式监督;此外,构建一个包含2种传感器和2个城市区域的多时相SAR图像建筑区提取数据集,含1 000幅带标注图像和800组无标注时序图像,并基于该数据集进行实验验证.实验表明,在所构建测试集上,基线方法使用全量数据训练后交并比(intersection over union,IoU)为63.43%,而所提方法在使用10%和全量数据时IoU分别为63.46%和68.24%,仅利用10%的标注数据即可达到基线方法使用全量标注数据训练的精度.

关键词：建筑区提取合成孔径雷达半监督学习边缘提取

应用优化建模法构建红松人工林单木直径生长模型

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东北林业大学学报 2024年第5期52卷 63-69,74页

作者：吕洁童茜坪金星姬 timo Pukkala 东北林业大学哈尔滨150040 东芬兰大学

为了提高不完备数据集下红松人工林直径生长模型的预测精度,以1980—2022年黑龙江省75块红松林不同复测间隔期的样地数据(林木胸径、竞争因子和立地等),利用优化建模法构建红松人工林单木直径生长模型,采用单纯形优化算法寻求模拟和实... 详细信息

为了提高不完备数据集下红松人工林直径生长模型的预测精度,以1980—2022年黑龙江省75块红松林不同复测间隔期的样地数据(林木胸径、竞争因子和立地等),利用优化建模法构建红松人工林单木直径生长模型,采用单纯形优化算法寻求模拟和实测直径分布差异最小下的模型参数,并利用自举法对模型进行检验。结果表明:优化建模法损失函数的初始参数a=1、b=0.003、c1=c2=1.5时,预测期末林分断面积偏差为0.02 m^(2)·hm^(-2),显著优于由传统归回建模法的精度(林分断面积偏差为0.44 m^(2)·hm^(-2));结合实测数据与视图分析,验证了优化建模法的优势和可靠性,揭示了优化法损失函数与传统回归法构建的直径生长模型之间的差异。因此,优化法损失函数构建的红松人工林生长模型在模拟自然生长中表现优越,为制定科学的森林经营方案提供了技术支持。

关键词：红松人工林单木生长模型单纯形优化方法自举法

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符合人体工程学的提升吊具

现代制造 2024年第2期 24-27页

作者： timo Gans 不详

平稳地吊起40 kg的截止阀,有条不紊地完成各种复杂外形零部件的吊运:在Aliaxs德国公司的帮助下,Schnalz公司研发生产的Jumboflex真空管吊具的足迹几乎遍布德国各地,可与真空管吊具配套使用的各种辅具使生产实践中的真空吊具如虎添翼。

关键词：人体工程学截止阀吊具真空管复杂外形德国

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塑料机械设备的优化潜力

现代制造 2024年第2期 32-33页

作者： timo Gans 不详

网络化的液压系统有许多优点,例如提高了能源利用效率和经济性。因此,越来越多的塑料加工设备生产厂家们也意识到了这一点,并正在从模拟技术转移到数字化、网络化解决方案中,他们都将从液压技术和数字化技术中受益匪浅。为了灵活地满足... 详细信息

网络化的液压系统有许多优点,例如提高了能源利用效率和经济性。因此,越来越多的塑料加工设备生产厂家们也意识到了这一点,并正在从模拟技术转移到数字化、网络化解决方案中,他们都将从液压技术和数字化技术中受益匪浅。为了灵活地满足不同要求,目前的塑料生产设备都已采用了易于更换的模块化液压驱动、混合驱动和电力驱动机构。但在大功率的塑料生产设备中,液压驱动技术凭借其很高的功率密度和坚固耐用性能有着明显的优势。

关键词：塑料机械电力驱动能源利用效率液压驱动数字化技术混合驱动液压技术液压系统

泥炭仍旧是最重要的基质材料——访凯吉拉-BVB首席执行官佩卡坦尼拉

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中国花卉园艺 2024年第9期 24-26页

作者：晓白(译) timo Taulavuori 不详

凯吉拉(Kekkila)品牌于1924年诞生在芬兰,当时的主营业务是肥料。1952年,他们成为芬兰第一家将盆栽土装袋销售给家庭园艺用户的企业。同年,他们推出通用水溶性肥料“凯吉拉粉(Kekkila’sPink)”,至今仍受到花园爱好者和专业种植者的喜爱... 详细信息

凯吉拉(Kekkila)品牌于1924年诞生在芬兰,当时的主营业务是肥料。1952年,他们成为芬兰第一家将盆栽土装袋销售给家庭园艺用户的企业。同年,他们推出通用水溶性肥料“凯吉拉粉(Kekkila’sPink)”,至今仍受到花园爱好者和专业种植者的喜爱。20世纪50年代,凯吉拉进入了快速发展阶段,除了花园用基质,在公共园林景观用混合基质领域也取得了一定成就。

关键词：园林景观家庭园艺水溶性肥料混合基质基质材料首席执行官吉拉盆栽土

Improved guidelines for any-aged forestry

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Journal of Forestry Research 2022年第5期33卷 1443-1457页

作者： timo Pukkala University of Eastern Finland P.O.Box 11180101 JoensuuFinland

Any-aged forest management (AAF) is a means to reduce clear-felling without compromising profitability or timber production. The concept of AAF is to choose between clear-felling or thinning one harvest at a time based on what is better at that time in terms of the management objectives for the forest. No permanent choice is made between rotation forest management (RFM) and continuous cover forestry (CCF). Optimized AAF is never less profitable than RFM or CCF because all cutting types of both RMF and CCF are also allowed in AAF. This study developed a new set of guidelines for managing boreal forest stands under AAF when the forest landowner maximizes economic profitability. The first part of the guidelines indicates whether the stand should be cut or left to grow. This advice is based on stand basal area, mean tree diameter, minimum allowable post-thinning basal area, site productivity, and discount rate. If the optimal decision is harvesting, the second instruction determines whether the harvest should be clear-felling or thinning. In the case of thinning, the remaining two steps determine the optimal harvest rate in different diameter classes. The guidelines were developed using two different modeling approaches, regression analysis, and optimization, and applied to two Finnish forest holdings, one representing the southern boreal zone and the other the northern parts of the boreal zone. The results show that AAF improves profitability compared to current Finnish management instructions for RFM. The use of clear-felling also decreased the lower the minimum acceptable post-thinning basal area of the stand.

关键词： Management optimization Silvicultural system Differential evolution