In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribut...In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.展开更多
由于年代久远和自然因素等影响,许多古代壁画表面存在着不同程度的损坏,精准地检测这些破损区域对于保护文化遗产具有重要研究价值。然而,现有的方法在古代壁画的破损检测中存在检测不全,对微小细节的破损区域检测不准确等问题。针对以...由于年代久远和自然因素等影响,许多古代壁画表面存在着不同程度的损坏,精准地检测这些破损区域对于保护文化遗产具有重要研究价值。然而,现有的方法在古代壁画的破损检测中存在检测不全,对微小细节的破损区域检测不准确等问题。针对以上问题,提出基于嵌套U型结构网络的壁画破损区域检测方法U2-DUANet,该方法采用了一种新的深度监督聚合模块,能够更有效地融合侧边输出的细节信息。提出了一种像素级上下文及通道注意力(pixel-wise contextual and channel attention,PCCA)机制,来选择性地关注每个像素上的信息上下文特征以及通道信息,更精确地捕捉图像的重要特征,提高模型的准确性。自主创建了一个古代破损壁画图像的数据集,并对其破损区域进行了人工标注。在壁画数据集上的实验结果表明,U2-DUANet相比于U-Net,在精确率和F-measure上分别提升了10.5个百分点和8.2个百分点,并且具有更好的鲁棒性和泛化能力。展开更多
随着分布式能源(distributed energy resource,DER)广泛接入配电网以及电力市场环境的开放,DER有机会参与电力市场竞标并获得收益。为此,建立考虑光伏发电不确定性的DER聚合商参与电力市场竞标的鲁棒双层规划模型,并分析其策略性竞标行...随着分布式能源(distributed energy resource,DER)广泛接入配电网以及电力市场环境的开放,DER有机会参与电力市场竞标并获得收益。为此,建立考虑光伏发电不确定性的DER聚合商参与电力市场竞标的鲁棒双层规划模型,并分析其策略性竞标行为。该模型的上层问题是两阶段鲁棒优化问题,第1阶段以最大化DER聚合商收益为目标确定其竞标量,第2阶段以最小化光伏发电出力最恶劣场景下弃光惩罚成本为目标对配电网安全性进行校核,并且还考虑配电网的离散控制特性。该模型的下层问题是日前电能量市场出清问题,首先采用Karush-Kuhn-Tucker条件替代将鲁棒双层规划模型转化为两阶段鲁棒优化问题,再采用嵌套列与约束生成算法求解,最后在修改的IEEE 30节点系统和IEEE 18节点配电网构成的输配联合系统上进行仿真分析,验证所提方法的有效性。展开更多
文摘In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.
文摘由于年代久远和自然因素等影响,许多古代壁画表面存在着不同程度的损坏,精准地检测这些破损区域对于保护文化遗产具有重要研究价值。然而,现有的方法在古代壁画的破损检测中存在检测不全,对微小细节的破损区域检测不准确等问题。针对以上问题,提出基于嵌套U型结构网络的壁画破损区域检测方法U2-DUANet,该方法采用了一种新的深度监督聚合模块,能够更有效地融合侧边输出的细节信息。提出了一种像素级上下文及通道注意力(pixel-wise contextual and channel attention,PCCA)机制,来选择性地关注每个像素上的信息上下文特征以及通道信息,更精确地捕捉图像的重要特征,提高模型的准确性。自主创建了一个古代破损壁画图像的数据集,并对其破损区域进行了人工标注。在壁画数据集上的实验结果表明,U2-DUANet相比于U-Net,在精确率和F-measure上分别提升了10.5个百分点和8.2个百分点,并且具有更好的鲁棒性和泛化能力。
文摘随着分布式能源(distributed energy resource,DER)广泛接入配电网以及电力市场环境的开放,DER有机会参与电力市场竞标并获得收益。为此,建立考虑光伏发电不确定性的DER聚合商参与电力市场竞标的鲁棒双层规划模型,并分析其策略性竞标行为。该模型的上层问题是两阶段鲁棒优化问题,第1阶段以最大化DER聚合商收益为目标确定其竞标量,第2阶段以最小化光伏发电出力最恶劣场景下弃光惩罚成本为目标对配电网安全性进行校核,并且还考虑配电网的离散控制特性。该模型的下层问题是日前电能量市场出清问题,首先采用Karush-Kuhn-Tucker条件替代将鲁棒双层规划模型转化为两阶段鲁棒优化问题,再采用嵌套列与约束生成算法求解,最后在修改的IEEE 30节点系统和IEEE 18节点配电网构成的输配联合系统上进行仿真分析,验证所提方法的有效性。
