Results 31 to 40 of about 367,240 (203)

Logistic回归和支持向量机在电缆老化状态评估中的应用与比较

open access: yesGaoya dianqi, 2023
电缆老化状态评估主要有物理模型和统计模型两大类,物理模型一般用于电缆个体老化评估,但难以用于在线评估,统计模型一般用于电缆整体老化评估,无法评估个体状态。为建立电缆运行数据与电缆老化状态之间的关联关系,在线评估电缆个体老化状态,文中提出了基于机器学习的电缆老化状态评估方法,建立了Logistic回归和支持向量机这两种机器学习模型,采用十折交叉验证对模型准确率进行了评估,同时计算了模型的F1-Score。结果表明支持向量机采用多项式核时的总体样本准确率平均值为96%,高于Logistic回归 ...
谭笑   +5 more
doaj  

A link between increased temperature and avian body condition in a logged tropical forest

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract The combined effects of anthropogenic disturbances, such as logging and climate change, remain poorly understood; yet, they are the main threats to tropical biodiversity. Most tropical African countries lack long‐term climate data, so climate impacts on biodiversity cannot be assessed.
Moreen Uwimbabazi   +7 more
wiley   +1 more source

Differences in characteristics between naturalized threatened plants and other threatened plants

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract Many non‐native plant species introduced by humans have become naturalized. At the same time many species are threatened in their native range. However, the number of plant species threatened in their native range that are naturalized elsewhere remains unknown.
Weihan Zhao   +10 more
wiley   +1 more source

Functional homogenization of terrestrial mammals outside protected areas in the Hengduan Mountains, China

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract Despite the crucial role of human impacts on biodiversity loss, many assessments of this loss focus on single metrics, such as species richness, and overlook the multidimensional effects of human activities. Because of its importance to ecosystem functioning, we investigated the functional diversity of medium‐ and large‐sized mammal ...
Xueyou Li   +8 more
wiley   +1 more source

贵州大沙河国家级自然保护区生态环境保护成效评估

open access: yes, 2023
对自然保护区在维持生物多样性和保障生态系统服务功能等方面的综合成效进行重点评估,能科学直观地反映自然保护区的保护成效,有利于促进自然保护区生态环境质量不断提升。采用量化分析生态环境变化等级,结合专家打分,判定生态环境状况等级对贵州大沙河国家级自然保护区生态环境保护成效进行评估。结果表明:贵州大沙河国家级自然保护区生态环境变化评分(EC)为71.63分,评估等级变好(65≤EC<85);生态环境状况评分(ES)为93.87分,等级为Ⅰ级(ES≥85);综合判定保护区生态环境保护成效评估结果为优 ...
李乔明   +4 more
core   +1 more source

Geographic risks to functional groups of mammals and birds from habitat loss in Mexico

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract There is a need to quantify the impact of habitat loss due to anthropogenic factors on different aspects of biodiversity, such as functional trait diversity represented by functional groups (FGs). We developed a metric to assess the weighted risk of loss of habitat for 33 FGs of mammals and 36 FGs of birds in Mexico based on potential ...
Fernando Mayani‐Parás   +4 more
wiley   +1 more source

海洋溢油生态损害的简易评估和综合评估方法 [PDF]

open access: yes, 2012
通过对海洋生态系统服务的讨论,结合生态学及经济学的评估方法,提出对不同规模溢油事故的区别性评估方法体系:简易评估和综合评估.中小型溢油选用公式化的简易评估法,大型溢油污染事故则建议从生物资源、海洋生境、环境容量、景观文化开展综合评估,并分别提出相应的评估方法.简易评估在美国佛罗里达公式的基础上,进行了适于我国国情的修改,该方法对信息量的要求小,简单易行,其推算的赔偿范围符合以往的索赔案例,可在今后的中小型溢油中推广实践并不断完善.综合评估中,对生物资源的评估,实现了非经济物种的价值化 ...
杨寅, 韩大雄, 王海燕, 黄浩
core   +1 more source

基于Relief特征量优化及SOM网络的断路器操作机构状态评估

open access: yesGaoya dianqi, 2017
为提高断路器操作机构状态评估的效率及准确性,文中提出了采用Relief优化方法对分合闸线圈电流特征向量进行优化及SOM网络对线圈电流样本进行分类的高压断路器操作机构状态评估方法。仿真研究结果表明:基于Relief的分合闸线圈电流特征向量优化方法和SOM网络分类方法的操作机构状态评估能够实现操作机构状态的准确评估,同时采用优化后的电流特征向量数据进行状态评估减小了运算量和缩短了运算时间,提高了断路器机构状态评估的效率。
张浩   +7 more
doaj  

Scenarios and strategies for future‐proofing ecosystem management under climatic novelty

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract Climate change is driving unprecedented declines in dominant, habitat‐forming foundation species across marine and terrestrial ecosystems globally. As climatic novelty becomes the norm, ecosystem reassembly will become increasingly common. Predicting and understanding these transitions, and their implications for future ecosystem functioning ...
Lauren T. Toth   +14 more
wiley   +1 more source

生态系统服务的价值评估方法研究

open access: yes, 2008
在综合分析国内外生态系统服务功能分类和估价研究基础上,对价值评估方法进行了汇总.目前对生态系统服务进行估价的方法可概括为4大类:实际市场评估技术、替代市场评估技术、模拟市场评估技术以及新近提出的空间-能值分析技术.由于生态系统服务本身的复杂性和交叉性,不同研究人员采用不同的研究方法得出的评价结果间对比性很低,缺少一个统一、规范 ...
周可法, 孙莉, 秦艳芳
core  

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