基于图像信息的辅助,提高从非结构化文本中识别命名实体的准确率,可以有效缓解社交媒体场景中因短文本语义信息不全而产生歧义,图片多却不能发挥作用的问题.尽管现有的研究通常采用跨模态注意力机制合并文本和图像的语义表示,但是大多...基于图像信息的辅助,提高从非结构化文本中识别命名实体的准确率,可以有效缓解社交媒体场景中因短文本语义信息不全而产生歧义,图片多却不能发挥作用的问题.尽管现有的研究通常采用跨模态注意力机制合并文本和图像的语义表示,但是大多不能建立一个一致的表示来融合两种模态之间的语义信息,且图像中的冗余信息往往会影响多模态实体识别(Multimodal Name Entity Recognition,MNER)的性能.为了解决这些问题,本文提出了一种基于异构图模型的MNER方法,可以有效利用文本和图像之间的交互信息.具体地,首先,构建了一个基于BERT-BiLSTM-CRF的实体识别模型,识别出文本中可能存在的实体;其次,以文本中可能存在的实体作为两个模态之间的桥梁,设计了一个由Token、实体和视觉对象组成的异构图网络,并定义了两种边来表示相互间的语义关系;最后,基于文本和图像组成的异构图,设计了一种多模态融合模型(MHGT),从而减轻了图像噪声的负面影响.在两个通用的MNER数据集上的实验结果表明,本文提出的多模态实体识别方法在Twitter2015和Twitter2017上分别获得了75.26%和86.51%的F1值,优于基线模型的性能.展开更多
The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modell...The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modelling of this superalloy is established and the processing maps at different strains are constructed.The results show that the Q value is in the range of 751.22−878.29 kJ/mol.At a temperature of 1060°C,strain rate of 0.001 s^(−1),and strain of 0.65,the m value of GH4586 superalloy reaches a maximum of 0.42.The optimal processing parameter of GH4586 superalloy is at a deformation temperature of 1050°C and a strain rate of 0.001 s^(−1).The domains of flow instability notably expand with increasing strain during high temperature deformation of GH4586 superalloy.展开更多
The hot deformation behaviors of Cr5 steel were investigated.The hot compression tests were conducted in the temperature range of 900-1150 °C under strain rates of 0.01,0.1 and 1 s^(-1).The constitutive equation ...The hot deformation behaviors of Cr5 steel were investigated.The hot compression tests were conducted in the temperature range of 900-1150 °C under strain rates of 0.01,0.1 and 1 s^(-1).The constitutive equation and material constants(Q,n,α ln A) are obtained according to the hyperbolic sine function and Zener-Hollomon parameter.Besides,dynamic recrystallization(DRX) grain size model and critical strain model are acquired.The processing maps with the strain of 0.1,0.3 and 0.5 are obtained on the basis of dynamic materials model.It has been observed that DRX occurs at high temperature and low strain rate.According to the processing map,the safety region exists in the temperature range of 920-1150 °C with strain rate of 0.01-0.20 s^(-1).展开更多
文摘基于图像信息的辅助,提高从非结构化文本中识别命名实体的准确率,可以有效缓解社交媒体场景中因短文本语义信息不全而产生歧义,图片多却不能发挥作用的问题.尽管现有的研究通常采用跨模态注意力机制合并文本和图像的语义表示,但是大多不能建立一个一致的表示来融合两种模态之间的语义信息,且图像中的冗余信息往往会影响多模态实体识别(Multimodal Name Entity Recognition,MNER)的性能.为了解决这些问题,本文提出了一种基于异构图模型的MNER方法,可以有效利用文本和图像之间的交互信息.具体地,首先,构建了一个基于BERT-BiLSTM-CRF的实体识别模型,识别出文本中可能存在的实体;其次,以文本中可能存在的实体作为两个模态之间的桥梁,设计了一个由Token、实体和视觉对象组成的异构图网络,并定义了两种边来表示相互间的语义关系;最后,基于文本和图像组成的异构图,设计了一种多模态融合模型(MHGT),从而减轻了图像噪声的负面影响.在两个通用的MNER数据集上的实验结果表明,本文提出的多模态实体识别方法在Twitter2015和Twitter2017上分别获得了75.26%和86.51%的F1值,优于基线模型的性能.
基金Project(2020JC-17)supported by the Science Fund for Distinguished Young Scholars from Shaanxi Province,ChinaProject(51705425)+4 种基金supported by the National Natural Science Foundation of ChinaProject(2019-QZ-04)supported by the Research Fund of the State Key Laboratory of Solidification Processing(NWPU),ChinaProjects(3102019PY007,3102019MS0403)supported by the Fundamental Research Funds for the Central Universities,China。
文摘The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modelling of this superalloy is established and the processing maps at different strains are constructed.The results show that the Q value is in the range of 751.22−878.29 kJ/mol.At a temperature of 1060°C,strain rate of 0.001 s^(−1),and strain of 0.65,the m value of GH4586 superalloy reaches a maximum of 0.42.The optimal processing parameter of GH4586 superalloy is at a deformation temperature of 1050°C and a strain rate of 0.001 s^(−1).The domains of flow instability notably expand with increasing strain during high temperature deformation of GH4586 superalloy.
基金Project(51322405)supported by the National Natural Science Foundation of China
文摘The hot deformation behaviors of Cr5 steel were investigated.The hot compression tests were conducted in the temperature range of 900-1150 °C under strain rates of 0.01,0.1 and 1 s^(-1).The constitutive equation and material constants(Q,n,α ln A) are obtained according to the hyperbolic sine function and Zener-Hollomon parameter.Besides,dynamic recrystallization(DRX) grain size model and critical strain model are acquired.The processing maps with the strain of 0.1,0.3 and 0.5 are obtained on the basis of dynamic materials model.It has been observed that DRX occurs at high temperature and low strain rate.According to the processing map,the safety region exists in the temperature range of 920-1150 °C with strain rate of 0.01-0.20 s^(-1).
