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基于粒子索引排序算法的kd-tree缓存优化问题研究
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作者 张挺 林震寰 +2 位作者 杨丁颖 王宗锴 陈轶凡 《工程科学与技术》 北大核心 2026年第1期313-323,共11页
在使用kd-tree进行大规模随机粒子近邻搜索时,可能出现计算域内索引值相近的粒子在空间上距离较远而导致kd-tree搜索路径在短时间内产生较大差异等问题,使得节点数据的访问效率降低,最终影响kd-tree近邻搜索的效率。为解决该问题,本文... 在使用kd-tree进行大规模随机粒子近邻搜索时,可能出现计算域内索引值相近的粒子在空间上距离较远而导致kd-tree搜索路径在短时间内产生较大差异等问题,使得节点数据的访问效率降低,最终影响kd-tree近邻搜索的效率。为解决该问题,本文引入了主成分分析中最大离散度降维的思想,采用平均绝对差作为离散度衡量指标,提出了基于平均绝对差粒子索引值排序的缓存优化策略MAD-index-sort,通过计算粒子集群平均绝对差最大的维度来实现数据降维,进而完成粒子的索引值重排序,并应用具有自动终止准则的ATC-kd-tree进行近邻搜索。为验证MADindex-sort缓存优化策略的可行性,设计了不同维度和离散度对照组进行近邻搜索效率对比实验。结果表明,MADindex-sort能根据粒子集群的离散度自动改变排序方向,具有更强的适应性,相较于未排序的情况性能最高可提升30.3%。 展开更多
关键词 KD-tree 粒子近邻搜索 缓存优化 粒子索引值排序
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Combined Fault Tree Analysis and Bayesian Network for Reliability Assessment of Marine Internal Combustion Engine
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作者 Ivana Jovanović Çağlar Karatuğ +1 位作者 Maja Perčić Nikola Vladimir 《哈尔滨工程大学学报(英文版)》 2026年第1期239-258,共20页
This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for ... This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels. 展开更多
关键词 Fault tree analysis Bayesian network RELIABILITY REDUNDANCY Internal combustion engine
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基于CART决策树算法的成绩管理预警系统的设计与实现
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作者 温林燕 赵育祺 +1 位作者 高庆儒 王金恒 《电脑编程技巧与维护》 2026年第1期64-68,共5页
在日常教学管理中,部分学生在学习过程中出现成绩波动,但往往难以及时被发现和干预,尝试构建一套具备预测能力的成绩预警系统。以某高校“数据库原理及应用课程设计”课程平台上54名学生的在线学习数据为基础,采集了包括课程完成率、视... 在日常教学管理中,部分学生在学习过程中出现成绩波动,但往往难以及时被发现和干预,尝试构建一套具备预测能力的成绩预警系统。以某高校“数据库原理及应用课程设计”课程平台上54名学生的在线学习数据为基础,采集了包括课程完成率、视频学习进度、章节学习次数等6项行为特征,利用CART(分类与回归树)算法进行建模与风险分类。在系统实现方面,后端采用Spring Boot构建服务接口,并通过ProcessBuilder方式调用本地Python模型;前端基于Vue开发交互界面,支持学生输入行为数据并实时返回预测等级。为避免模型过拟合,在训练阶段引入剪枝操作,并对输入特征进行了归一化预处理。系统部署后,在测试数据集上达到了55%左右的预测准确率,能初步辅助教师发现成绩下滑趋势。尽管该系统仍存在进一步优化空间,但是其在教学实践中已展现出一定的应用潜力,尤其适用于早期识别潜在风险学生并辅助开展个性化教学干预。 展开更多
关键词 cart算法 成绩预警系统 Spring Boot框架 Vue框架 教育信息化
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基因编辑在肿瘤相关动物模型构建和CART治疗中的应用
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作者 李大力 朱一凡 国昊哲 《中国科学基金》 北大核心 2025年第1期144-152,共9页
基于第373期双清论坛“临床问题驱动的肿瘤研究新范式”会议内容,本文列举了基因编辑相关技术的发展历程和基本原理、肿瘤相关动物模型的构建以及基因编辑对这一领域所发挥的促进作用,并概述了其在嵌合抗原受体T细胞疗法(CART)治疗中的... 基于第373期双清论坛“临床问题驱动的肿瘤研究新范式”会议内容,本文列举了基因编辑相关技术的发展历程和基本原理、肿瘤相关动物模型的构建以及基因编辑对这一领域所发挥的促进作用,并概述了其在嵌合抗原受体T细胞疗法(CART)治疗中的应用。基因编辑技术自20世纪90年代起历经多次革新,从早期的巨型核酸酶、锌指核酸酶(ZFN)和转录激活因子样效应核酸酶(TALEN),逐步发展为以CRISPR-Cas系统为核心的各类编辑工具。通过CRISPR系统可以实现自发性肿瘤动物模型的构建和肿瘤治疗靶点的筛选。另外,基因编辑技术显著推动了CART疗法的优化,通过敲除特定基因,能够增强CART疗法的安全性、有效性和通用性。综上,基因编辑技术在肿瘤模型构建及治疗领域具有广阔的应用前景。 展开更多
关键词 基因编辑 肿瘤 动物模型 cart
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基于成长型CART的综合能源系统安全调度方法研究 被引量:1
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作者 李鑫 庞超 王智爽 《传感器与微系统》 北大核心 2025年第2期53-56,共4页
随着天然气网络与电网耦合性的逐步提高,电力和天然气综合能源系统的运行更易受到多重因素的影响。提出了一种基于成长型分类与回归树(CART)的电力和天然气综合能源系统安全调度方法。首先,构建了基于成长型分类与回归树的安全域划分模... 随着天然气网络与电网耦合性的逐步提高,电力和天然气综合能源系统的运行更易受到多重因素的影响。提出了一种基于成长型分类与回归树(CART)的电力和天然气综合能源系统安全调度方法。首先,构建了基于成长型分类与回归树的安全域划分模型,根据CART确定安全域和可控变量边界;其次,提出了电-气综合能源系统的安全调度策略,构建了基于安全约束的功率流和天然气流优化模型,CART规则用于描述安全域的约束,对最优发电量和产气量进行预防性调整;最后,本文以15节点天然气网络和IEEE118节点电网测试系统为例,验证了所提出的安全调度方法在恢复安全运行方面的效果。 展开更多
关键词 综合能源系统 安全调度 成长型分类与回归树 安全域
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A New Approach to Predict Financial Failure: Classification and Regression Trees (CART) 被引量:1
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作者 Ayse Guel Yllgoer UEmit Dogrul Guelhan Orekici Temel 《Journal of Modern Accounting and Auditing》 2011年第4期329-339,共11页
The increase of competition, economic recession and financial crises has increased business failure and depending on this the researchers have attempted to develop new approaches which can yield more correct and more ... The increase of competition, economic recession and financial crises has increased business failure and depending on this the researchers have attempted to develop new approaches which can yield more correct and more reliable results. The classification and regression tree (CART) is one of the new modeling techniques which is developed for this purpose. In this study, the classification and regression trees method is explained and tested the power of the financial failure prediction. CART is applied for the data of industry companies which is trade in Istanbul Stock Exchange (ISE) between 1997-2007. As a result of this study, it has been observed that, CART has a high predicting power of financial failure one, two and three years prior to failure, and profitability ratios being the most important ratios in the prediction of failure. 展开更多
关键词 business failure financial distress PREDICTION classification and regression trees cart
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A retinal blood vessel extraction algorithm based on CART decision tree and improved AdaBoost
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作者 DIWU Peng-peng HU Ya-qi 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第1期61-68,共8页
This paper presents a supervised learning algorithm for retinal vascular segmentation based on classification and regression tree (CART) algorithm and improved adptive bosting (AdaBoost). Local binary patterns (LBP) t... This paper presents a supervised learning algorithm for retinal vascular segmentation based on classification and regression tree (CART) algorithm and improved adptive bosting (AdaBoost). Local binary patterns (LBP) texture features and local features are extracted by extracting,reversing,dilating and enhancing the green components of retinal images to construct a 17-dimensional feature vector. A dataset is constructed by using the feature vector and the data manually marked by the experts. The feature is used to generate CART binary tree for nodes,where CART binary tree is as the AdaBoost weak classifier,and AdaBoost is improved by adding some re-judgment functions to form a strong classifier. The proposed algorithm is simulated on the digital retinal images for vessel extraction (DRIVE). The experimental results show that the proposed algorithm has higher segmentation accuracy for blood vessels,and the result basically contains complete blood vessel details. Moreover,the segmented blood vessel tree has good connectivity,which basically reflects the distribution trend of blood vessels. Compared with the traditional AdaBoost classification algorithm and the support vector machine (SVM) based classification algorithm,the proposed algorithm has higher average accuracy and reliability index,which is similar to the segmentation results of the state-of-the-art segmentation algorithm. 展开更多
关键词 classification and regression tree (cart) improved adptive boosting (AdaBoost) retinal blood vessel local binary pattern (LBP) texture
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列线图与CART决策树模型对膝关节置换术后急性疼痛风险预测中的效能比较 被引量:1
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作者 马超 韩影 程旻桦 《新疆医科大学学报》 2025年第2期195-202,共8页
目的分别构建预测膝关节置换术(TKA)后急性疼痛(APP)风险的列线图与分类与回归树(CART)决策树模型,并比较两种模型在对TKA后APP风险预测中的预测效能。方法以274例膝关节骨性关节炎(KOA)患者为研究对象,均于2018年3月至2024年4月在本院... 目的分别构建预测膝关节置换术(TKA)后急性疼痛(APP)风险的列线图与分类与回归树(CART)决策树模型,并比较两种模型在对TKA后APP风险预测中的预测效能。方法以274例膝关节骨性关节炎(KOA)患者为研究对象,均于2018年3月至2024年4月在本院进行TKA治疗,根据术后是否发生APP将患者分为APP组(n=98)和非APP组(n=176),对两组患者进行单因素分析。根据单因素分析结果进行Logistic回归分析TKA后APP的危险因素,根据危险因素绘制列线图模型;根据单因素分析结果进行CART决策树模型建立。绘制两种模型的受试者工作特征(ROC)曲线并对两种模型的预测效能进行DeLong检验。结果单因素分析结果显示,两组患者在年龄、体质指数(BMI)、糖尿病、西安大略和麦克马斯特大学骨关节炎指数(WOMAC)、术前疼痛灾难化量表(PCS)评分、术前视觉模拟评分(VAS)、止血带使用时间、神经阻滞、术后使用镇痛泵方面比较差异具有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,BMI≥25 kg/m^(2)、糖尿病、PCS评分≥27分、VAS评分≥5分、术后未使用镇痛泵为TKA后APP的独立危险因素(P<0.05)。基于多因素Logistic回归结果采用R软件绘制列线图模型。将单因素分析中差异具有统计学意义的相关因素纳入CART决策树模型,最终模型筛选出5个特征,包括BMI≥25 kg/m^(2)、糖尿病、WOMAC≥48分、术前使用神经阻滞、未使用术后镇痛泵。绘制两种模型的ROC曲线,结果显示列线图模型和CART决策树模型的AUC分别为0.858和0.911,灵敏度分别为81.88%和86.34%,特异度分别为82.91%和87.62%,阳性预测值分别为75.43%和80.69%,阴性预测值分别为82.94%和89.27%,预测准确率分别为83.31%和89.75%。两种模型AUC值相比差异具有统计学意义(Z=9.864,P<0.001)。结论两种模型均对TKA后APP风险具有较好的预测效能,CART决策树预测效能优于列线图模型。 展开更多
关键词 膝关节置换术 术后急性疼痛 预测效能 列线图模型 cart决策树模型
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基于SQL数据库和KD-Tree算法的船体型线匹配方法 被引量:1
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作者 余恺 马宁 +1 位作者 史琪琪 孙利 《舰船科学技术》 北大核心 2025年第11期8-14,共7页
为提高船舶初步设计效率,提出一种基于SQL数据库和KD-Tree算法的船舶型线快速匹配方法。针对船舶数据繁多复杂的问题,利用SQL语言保存、分类和提取船舶设计过程中的型线数据和特征线数据,提高了数据的存储和利用效率。针对船体复杂曲面... 为提高船舶初步设计效率,提出一种基于SQL数据库和KD-Tree算法的船舶型线快速匹配方法。针对船舶数据繁多复杂的问题,利用SQL语言保存、分类和提取船舶设计过程中的型线数据和特征线数据,提高了数据的存储和利用效率。针对船体复杂曲面的匹配问题,采取基于特征线描述船体特征,并求解特征线B样条控制点的方法保存船体的曲面特征数据。针对高维度变量的匹配问题,在不同大小的测试集中采用KD-Tree结构保存数据并采用最邻近搜索算法,能将船体型线的搜索匹配速度提高34.31%~84.16%。该方法对提高船舶初步设计效率提供有益的借鉴和帮助。 展开更多
关键词 船体设计 SQL数据库 KD-tree算法 船舶特征线
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Urban tree species classification based on multispectral airborne LiDAR 被引量:1
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作者 HU Pei-Lun CHEN Yu-Wei +3 位作者 Mohammad Imangholiloo Markus Holopainen WANG Yi-Cheng Juha Hyyppä 《红外与毫米波学报》 北大核心 2025年第2期211-216,共6页
Urban tree species provide various essential ecosystem services in cities,such as regulating urban temperatures,reducing noise,capturing carbon,and mitigating the urban heat island effect.The quality of these services... Urban tree species provide various essential ecosystem services in cities,such as regulating urban temperatures,reducing noise,capturing carbon,and mitigating the urban heat island effect.The quality of these services is influenced by species diversity,tree health,and the distribution and the composition of trees.Traditionally,data on urban trees has been collected through field surveys and manual interpretation of remote sensing images.In this study,we evaluated the effectiveness of multispectral airborne laser scanning(ALS)data in classifying 24 common urban roadside tree species in Espoo,Finland.Tree crown structure information,intensity features,and spectral data were used for classification.Eight different machine learning algorithms were tested,with the extra trees(ET)algorithm performing the best,achieving an overall accuracy of 71.7%using multispectral LiDAR data.This result highlights that integrating structural and spectral information within a single framework can improve the classification accuracy.Future research will focus on identifying the most important features for species classification and developing algorithms with greater efficiency and accuracy. 展开更多
关键词 multispectral airborne LiDAR machine learning tree species classification
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基于Extra Trees模型的咪唑类离子液体植物毒性预测及SHAP值分析
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作者 茹雨璇 曹雨希西 +2 位作者 胡肖肖 邵云海 马琳 《宝鸡文理学院学报(自然科学版)》 2025年第3期17-22,44,共7页
目的构建一种高效可行的机器学习模型用于咪唑类离子液体对植物的毒性预测,为绿色、低毒性离子液体的开发提供理论支持和新思路。方法收集200余个咪唑类离子液体对植物的毒性实验数据集,基于SMILES字符串提取分子描述符,构建了一个Extra... 目的构建一种高效可行的机器学习模型用于咪唑类离子液体对植物的毒性预测,为绿色、低毒性离子液体的开发提供理论支持和新思路。方法收集200余个咪唑类离子液体对植物的毒性实验数据集,基于SMILES字符串提取分子描述符,构建了一个Extra Trees预测模型。模型的性能通过决定系数(R^(2))、均方根误差(RMSE)等指标进行评估,并采用SHapley Additive exPlanations(SHAP)值分析预测结果,以量化特征值对毒性预测的贡献程度。结果Extra Trees模型在测试集上显示出良好的预测性能(R^(2)=0.944,RMSE=0.351)。SHAP分析揭示了分子中非极性基团、支链/环状结构、分子量等物理化学性质及分子结构对植物毒性的影响。结论构建的Extra Trees模型能够快速准确地预测咪唑离子液体的植物毒性,具有较好的泛化能力和鲁棒性,可为环境风险评估及绿色离子液体的设计开发提供科学依据。 展开更多
关键词 咪唑离子液体 机器学习 Extra trees模型 植物毒性
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Establishment of an efficient Agrobacterium rhizogenes-mediated hairy root transformation method for subtropical fruit trees 被引量:1
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作者 Mao Yin Yonghua Jiang +4 位作者 Yingjie Wen Fachao Shi Hua Huang Qian Yan Hailun Liu 《Horticultural Plant Journal》 2025年第4期1699-1702,共4页
Agrobacterium tumefaciens-mediated transformation has been widely adopted for plant genetic engineering and the study of gene function(Krenek et al.,2015).This method is prevalent in the genetic transformation of herb... Agrobacterium tumefaciens-mediated transformation has been widely adopted for plant genetic engineering and the study of gene function(Krenek et al.,2015).This method is prevalent in the genetic transformation of herbaceous plants,with notable applications in species such as Arabidopsis(Yin et al.,2024),soybean(Zhang et al.,2024),rice(Zhang et al.,2020),and Chinese cabbage(Li et al.,2021).However,its application in fruit trees is limited.This is primarily due to their long growth cycles and lack of rapid,efficient,and stable transgenic systems,which severely hinders foundational research involving plant genetic transformation(Mei et al.,2024).Furthermore,for subtropical fruit trees,the presence of recalcitrant seeds adds an extra layer of difficulty to genetic transformation(Umarani et al.,2015),as most methods rely on seed germination as a basis for transformation. 展开更多
关键词 study gene function krenek plant genetic engineering hairy root transformation fruit trees agrobacterium rhizogenes subtropical fruit trees genetic transformation chinese cabbage li
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Possibilities of native endophytic fungi as entomopathogenic biocontrol agents at a local scale:the case of deciduous and non-deciduous Mediterranean forest trees 被引量:1
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作者 Álvaro Benito-Delgado Sergio Diez-Hermano Julio Javier Diez 《Journal of Forestry Research》 2025年第3期224-236,共13页
Tree endophytic fungi play an important role in reducing insect herbivory,either by repelling them or kill-ing them directly.Identifying which fungi show such activ-ity could lead to new environmentally friendly pesti... Tree endophytic fungi play an important role in reducing insect herbivory,either by repelling them or kill-ing them directly.Identifying which fungi show such activ-ity could lead to new environmentally friendly pesticides.In this study,the Mediterranean basin climate conditions are projected to harshen in the next decades,will increase vulnerability of tree species to pest invasions.Endophytic fungi were isolated from wood and leaves of Quercus pyr-enaica,Q.ilex and Q.suber and tested for virulence against adults of the mealworm beetle,Tenebrio molitor L.using a direct contact method.Only 3 of 111 sporulating isolates had entomopathogenic activity,all identified as Lecanicillium lecanii.The pathogenicity of L.lecanii on T.molitor resulted in a median lethal time(TL50)of 14-16 d.Compared with commercial products,L.lecanii caused faster insect death than the nematode Steinernema carpocapsae and nuclear polyhedrosis virus(no effect on T.molitor survival),and slower than Beauveria bassiana(TL50=5),Beauveria pseu-dobassiana(TL50=8d)and Bacillus thuriengensis(80%mortality first day after inoculation).Mortality was also accelerated under water stress,reducing TL50 by an addi-tional 33%.Remarkably,water stress alone had a comparable effect on mortality to that of L.lecanii isolates.This study confirms T.molitor as a good model insect for pathogenicity testing and agrees with management policies proposed in the EU Green Deal. 展开更多
关键词 BIOCONTROL PESTICIDE tree pest Native fungi Climate change
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基于Adaboost和Decision Tree的地层岩性预测研究
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作者 杨春曦 肖文梁 +2 位作者 徐亚军 郝梓宇 鲍挺 《地下空间与工程学报》 北大核心 2025年第S2期634-642,650,共10页
本文旨在研究基于Adaboost和Decision Tree算法的地层岩性预测方法,通过对气井的地层岩性实测数据进行分析,筛选出深度、地层电阻率等九种关键地球物理参数,利用上述机器学习算法构建气井地层岩性预测模型。在模型构建过程中,为解决Adab... 本文旨在研究基于Adaboost和Decision Tree算法的地层岩性预测方法,通过对气井的地层岩性实测数据进行分析,筛选出深度、地层电阻率等九种关键地球物理参数,利用上述机器学习算法构建气井地层岩性预测模型。在模型构建过程中,为解决Adaboost SAMME和Decision Tree算法参数选取和优化难点,利用交叉验证法筛选出最优参数组合。结果表明:Adaboost SAMME算法在岩性和地层岩性预测方面表现优异,准确率高达96%以上,相对而言,Decision Tree算法准确率稍低,为87%;模型预测准确率随训练集比例的增大而增加,原始数据随机化处理可以提高模型预测准确率;主成分分析(PCA)效果明显优于奇异值分解(SVD)。研究成果可为地下空间与能源工程钻井的地层岩性预测提供参考。 展开更多
关键词 地层岩性预测 机器学习 ADABOOST Decision tree
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Rapid springtime leaf osmotic adjustment,but low late-seasonal and interannual variation in leaf turgor loss points in three temperate tree species 被引量:1
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作者 Norbert Kunert 《Journal of Forestry Research》 2025年第4期31-40,共10页
Leaf turgor loss point has been recognized as an important plant physiological trait explaining a species’drought tolerance( π_(tlp)).Less is known about the variation of π_(tlp) in time and how seasonal or interan... Leaf turgor loss point has been recognized as an important plant physiological trait explaining a species’drought tolerance( π_(tlp)).Less is known about the variation of π_(tlp) in time and how seasonal or interannual differences in water availability are affecting π_(tlp) as a static trait.I monitored the seasonal variation of π_(tlp) during a drought year starting in early spring with juvenile leaves and assessed the interannual variation in π_(tlp) of fully matured leaves among years with diverting water availability for three temperate broad-leaved tree species.The largest seasonal changes in π_(tlp) occurred during leaf unfolding until leaves were fully developed and matured.After leaves matured,no significant changes occurred for the rest of the vegetation period.Interannual variation that could be related to water availability was only present in one of the three tree species.The results suggest that the investigated species have a rapid period of osmotic adjustment early in the growing season followed by a period of relative stability,when π_(tlp) can be considered as a static trait. 展开更多
关键词 Drought Leaf drought tolerance traits tree mortality Turgor loss point
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基于CART的钓鱼网站检测识别研究 被引量:1
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作者 宋珂 《信息记录材料》 2025年第7期31-34,共4页
钓鱼网站成为当前网络安全的重要威胁之一,钓鱼网站凭借其伪装合法站点窃取敏感信息的特性,已然成为危及个人隐私与网络生态安全的关键风险源。本研究利用分类与回归树(CART)算法构建了一个决策树模型,并与逻辑回归模型相结合,对安全套... 钓鱼网站成为当前网络安全的重要威胁之一,钓鱼网站凭借其伪装合法站点窃取敏感信息的特性,已然成为危及个人隐私与网络生态安全的关键风险源。本研究利用分类与回归树(CART)算法构建了一个决策树模型,并与逻辑回归模型相结合,对安全套接层(SSL)证书状态、统一资源定位符(URL)的锚文本以及域名前后缀等网络特征进行分析。实验结果显示:该混合模型能够自动高效地识别钓鱼网站,最终达到了76.9%的准确率。 展开更多
关键词 钓鱼网站监测 分类与回归树(cart)算法 决策树
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基于i-Tree模型的北京10条绿道木本植物的生态效益评估 被引量:1
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作者 王希 徐敏 王美仙 《园林》 2025年第5期106-113,共8页
植物是发挥绿道生态功能的重要载体,量化植物的生态效益不仅能更直观地表现绿道的生态价值,而且可以为未来建设或更新绿道植物景观时选择高生态效益植物提供数据支撑,进而做出更加科学的决策。调查北京10条绿道木本植物的应用情况,运用i... 植物是发挥绿道生态功能的重要载体,量化植物的生态效益不仅能更直观地表现绿道的生态价值,而且可以为未来建设或更新绿道植物景观时选择高生态效益植物提供数据支撑,进而做出更加科学的决策。调查北京10条绿道木本植物的应用情况,运用i-Tree模型量化绿道以及单种本本植物在吸收CO_(2)、净化空气、截留雨水、节能4方面的生态效益,并探索绿道和植物特征与生态效益之间的关系。研究结果表明:北京10条绿道植物群落的稳定性较高,且种数分布比较均匀,生长状态稳定,有利于生态结构稳定性的维持以及生态效益的发挥;10条绿道共产生节能效益(672.82万元)>净化空气效益(135.73万元)>截留雨水效益(124.57万元)>吸收CO_(2)效益(16.68万元);乔木的单株生态效益高于灌木,高生态效益乔木有桑、胡桃、悬铃木、毛白杨、美国皂荚、刺槐、鹅掌楸、黑杨、臭椿、黑松;灌木有野茉莉、胡枝子、贴梗海棠、黄栌、平枝栒子、迎春、金银忍冬、欧洲荚蒾、暴马丁香、锦带花;株高高于6 m、胸径(地径)大于20 cm、冠幅大于4 m的木本植物生态效益较高;适当延长绿道长度、增加木本植物数量、丰富植物群落配置层次,可以提高绿道的生态效益。 展开更多
关键词 北京市绿道 木本植物 生态效益 i-tree模型 生态系统服务价值评估
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Intelligent sequential multi-impulse collision avoidance method for non-cooperative spacecraft based on an improved search tree algorithm 被引量:1
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作者 Xuyang CAO Xin NING +4 位作者 Zheng WANG Suyi LIU Fei CHENG Wenlong LI Xiaobin LIAN 《Chinese Journal of Aeronautics》 2025年第4期378-393,共16页
The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making co... The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making collision avoidance significantly more challenging than that for space debris.Much existing research focuses on the continuous thrust model,whereas the impulsive maneuver model is more appropriate for long-duration and long-distance avoidance missions.Additionally,it is important to minimize the impact on the original mission while avoiding noncooperative targets.On the other hand,the existing avoidance algorithms are computationally complex and time-consuming especially with the limited computing capability of the on-board computer,posing challenges for practical engineering applications.To conquer these difficulties,this paper makes the following key contributions:(A)a turn-based(sequential decision-making)limited-area impulsive collision avoidance model considering the time delay of precision orbit determination is established for the first time;(B)a novel Selection Probability Learning Adaptive Search-depth Search Tree(SPL-ASST)algorithm is proposed for non-cooperative target avoidance,which improves the decision-making efficiency by introducing an adaptive-search-depth mechanism and a neural network into the traditional Monte Carlo Tree Search(MCTS).Numerical simulations confirm the effectiveness and efficiency of the proposed method. 展开更多
关键词 Non-cooperative target Collision avoidance Limited motion area Impulsive maneuver model Search tree algorithm Neural networks
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基于自适应理论和CART算法的电极片表面缺陷智能检测模型构建
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作者 汤淑芳 龙鹰 +1 位作者 阮威 彭梅 《自动化与仪器仪表》 2025年第2期18-23,共6页
针对传统电极片表面缺陷检测精度低、检测效率不高的问题,提出构建一个基于自适应理论和CART算法的电极片表面缺陷智能检测模型。首先,采用基于灰度直方图重建的自适应阈值分割算法GHR-AT对电极片表面图像缺陷进行分割处理;然后通过遗... 针对传统电极片表面缺陷检测精度低、检测效率不高的问题,提出构建一个基于自适应理论和CART算法的电极片表面缺陷智能检测模型。首先,采用基于灰度直方图重建的自适应阈值分割算法GHR-AT对电极片表面图像缺陷进行分割处理;然后通过遗传算法(Genetic Algorithm, GA)对分类回归树算法(Classification And Regression Tree, CART)进行优化,即利用GA算法代替二分法找到最优分裂点,以避免陷入局部最优问题,提升缺陷检测精度;最后将分割后的电极片表面缺陷输入至GA-CART算法中进行缺陷检测。实验结果表明,本模型对电极片表面图像缺陷检测精确率和召回率分别取值为97.84%和96.33%,相较于Faster R-CNN模型、SSD模型和Yolov5模型明显更高,且本模型的缺陷检测时长仅为7.62 ms,比另外三种模型分别低了10.05 ms、17.49 ms和23.84 ms。综合分析可知,本模型能够实现电极片表面缺陷的快速准确检测,检测效率显著提升,具备一定有效性和时效性。 展开更多
关键词 自适应阈值分割 cart分类 遗传算法 电极片 缺陷检测
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Unveiling urbanization effects on trees outside forests along the urban-rural gradient in megacity Bengaluru
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作者 Tao Jiang Maximilian Freudenberg +3 位作者 Christoph Kleinn V.P.Tewari B.N.Diwakara Nils Nolke 《Forest Ecosystems》 2025年第1期56-65,共10页
Rapid urbanization has caused significant changes along the urban-rural gradient,leading to a variety of landscapes that are mainly shaped by human activities.This dynamic interplay also influences the distribution an... Rapid urbanization has caused significant changes along the urban-rural gradient,leading to a variety of landscapes that are mainly shaped by human activities.This dynamic interplay also influences the distribution and characteristics of trees outside forests(TOF).Understanding the pattern of these trees will support informed decision-making in urban planning,in conservation strategies,and altogether in sustainable land management practices in the urban context.In this study,we employed a deep learning-based object detection model and high resolution satellite imagery to identify 1.3 million trees with bounding boxes within a 250 km^(2)research transect spanning the urban-rural gradient of Bengaluru,a megacity in Southern India.Additionally,we developed an allometric equation to estimate diameter at breast height(DBH)from the tree crown diameter(CD)derived from the detected bounding boxes.Our study focused on analyzing variations in tree density and tree size along this gradient.The findings revealed distinct patterns:the urban domain displayed larger tree crown diameters(mean:8.87 m)and DBH(mean:43.78 cm)but having relatively low tree density(32 trees per hectare).Furthermore,with increasing distance from the city center,tree density increased,while the mean tree crown diameter and mean tree basal area decreased,showing clear differences of tree density and size between the urban and rural domains in Bengaluru.This study offers an efficient methodology that helps generating instructive insights into the dynamics of TOF along the urban-rural gradient.This may inform urban planning and management strategies for enhancing green infrastructure and biodiversity conservation in rapidly urbanizing cities like Bengaluru. 展开更多
关键词 Individual tree detection URBANIZATION tree density tree crown diameter
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