Rapidly and accurately assessing the geometric characteristics of coarse aggregate particles is crucial for ensuring pavement performance in highway engineering.This article introduces an innovative system for the thr...Rapidly and accurately assessing the geometric characteristics of coarse aggregate particles is crucial for ensuring pavement performance in highway engineering.This article introduces an innovative system for the three-dimensional(3D)surface reconstruction of coarse aggregate particles using occlusion-free multi-view imaging.The system captures synchronized images of particles in free fall,employing a matte sphere and a nonlinear optimization approach to estimate the camera projection matrices.A pre-trained segmentation model is utilized to eliminate the background of the images.The Shape from Silhouettes(SfS)algorithm is then applied to generate 3D voxel data,followed by the Marching Cubes algorithm to construct the 3D surface contour.Validation against standard parts and diverse coarse aggregate particles confirms the method's high accuracy,with an average measurement precision of 0.434 mm and a significant increase in scanning and reconstruction efficiency.展开更多
为充分挖掘电力负荷历史数据的潜在特征,提高短期负荷预测模型的预测精度,提出了一种由改进残差网络(ResNetPlus)、注意力机制(Attention mechanism,AM)和双向长短期记忆网络(Bi-directional long short-term memory,Bi-LSTM)结合而成...为充分挖掘电力负荷历史数据的潜在特征,提高短期负荷预测模型的预测精度,提出了一种由改进残差网络(ResNetPlus)、注意力机制(Attention mechanism,AM)和双向长短期记忆网络(Bi-directional long short-term memory,Bi-LSTM)结合而成的残差AM-Bi-LSTM预测模型。该模型将历史负荷、温度和所预测日期的特征作为输入,在Bi-LSTM模型基础上,引入多层改进残差网络提取输入数据的隐藏特征,有效克服了网络隐藏层数加深导致的网络退化问题,使模型的反向传播能力大幅提升;加入注意力机制,分析网络中输入信息与当前负荷的相关性并突出重要信息的影响,从而提高模型的速度与准确率;使用Snapshot策略集成收敛于不同局部极小值的多个模型,以提升模型的准确率和鲁棒性。最后,使用美国ISO-NE数据集进行模拟预测,测试结果表明:所提模型的平均预测精度达到98.27%;在连续的12个月中采用该模型的平均预测精度相比于LSTM模型提高了2.87%;在不同季节下采用该模型的平均预测精度相比于AM-Bi-LSTM和ResNetPlus模型分别提高了1.05%和1.16%。说明所提模型相较于对比模型具有较高的准确率、鲁棒性以及泛化能力。展开更多
基金Supported by the Key R&D Projects in Shaanxi Province(2022JBGS3-08)。
文摘Rapidly and accurately assessing the geometric characteristics of coarse aggregate particles is crucial for ensuring pavement performance in highway engineering.This article introduces an innovative system for the three-dimensional(3D)surface reconstruction of coarse aggregate particles using occlusion-free multi-view imaging.The system captures synchronized images of particles in free fall,employing a matte sphere and a nonlinear optimization approach to estimate the camera projection matrices.A pre-trained segmentation model is utilized to eliminate the background of the images.The Shape from Silhouettes(SfS)algorithm is then applied to generate 3D voxel data,followed by the Marching Cubes algorithm to construct the 3D surface contour.Validation against standard parts and diverse coarse aggregate particles confirms the method's high accuracy,with an average measurement precision of 0.434 mm and a significant increase in scanning and reconstruction efficiency.
文摘为充分挖掘电力负荷历史数据的潜在特征,提高短期负荷预测模型的预测精度,提出了一种由改进残差网络(ResNetPlus)、注意力机制(Attention mechanism,AM)和双向长短期记忆网络(Bi-directional long short-term memory,Bi-LSTM)结合而成的残差AM-Bi-LSTM预测模型。该模型将历史负荷、温度和所预测日期的特征作为输入,在Bi-LSTM模型基础上,引入多层改进残差网络提取输入数据的隐藏特征,有效克服了网络隐藏层数加深导致的网络退化问题,使模型的反向传播能力大幅提升;加入注意力机制,分析网络中输入信息与当前负荷的相关性并突出重要信息的影响,从而提高模型的速度与准确率;使用Snapshot策略集成收敛于不同局部极小值的多个模型,以提升模型的准确率和鲁棒性。最后,使用美国ISO-NE数据集进行模拟预测,测试结果表明:所提模型的平均预测精度达到98.27%;在连续的12个月中采用该模型的平均预测精度相比于LSTM模型提高了2.87%;在不同季节下采用该模型的平均预测精度相比于AM-Bi-LSTM和ResNetPlus模型分别提高了1.05%和1.16%。说明所提模型相较于对比模型具有较高的准确率、鲁棒性以及泛化能力。
