基于改进EfficientNetV2网络的脑肿瘤分类方法

针对脑肿瘤磁共振图像分类问题中过拟合及分类准确率较低的问题,提出一种基于改进EfficientNetV2网络的脑肿瘤分类方法.该方法在EfficientNetV2网络中引入坐标注意力机制,该注意力机制将同时从垂直和水平两个方向获取脑肿瘤的特征信息,精准识别脑肿瘤的病灶特征,从而帮助模型更全面、准确地定位和识别病灶区域信息,有效抑制背景信息对检测结果的影响,使模型分类精度更高,解决了因获取特征信息不足导致分类精度低的问题.为进一步提升分类准确率,引入Hard-Swish激活函数,该激活函数不仅可以提升脑肿瘤分类网络模型的运算速度,也可有效提高分类精度.同时,改进后的模型搭配了Dropout层和归一化层,可更好抑制过拟合的发生,加快模型收敛速度,提高模型的鲁棒性,且分类精度有明显提升.实验结果表明,改进后的模型在验证集中获得了98.4%的分类准确率,通过对比实验和消融实验验证了改进后的模型在脑肿瘤分类任务中的有效性.     

改进型DeepLabV3+的糖尿病眼底病变分割

针对糖尿病视网膜眼底病变多类分割难及小病灶识别率低的问题,提出一种融合注意力机制与改进型DeepLabV3+的糖尿病视网膜眼底病变多类病症分割方法．该方法首先通过使用MobileNetV2网络提取病灶特征,减少参数量并提高算法训练速度;接着通过优化空洞空间卷积金字塔池化中的空洞卷积层数与空洞率,以提高捕获小病灶特征的能力;然后基于DeepLabV3+网络模型进行改进,借助坐标注意力机制感知病灶方向和位置信息,从而提高识别精度;最后采用FGADR和IDRiD数据集分别训练和测试所提出的模型．实验结果表明：所提出方法的平均交并比(MIoU)指标为73.75%,具有较高的分割精度,验证了模型有效性．     

基于多头注意力机制的磷酸化位点预测模型

计算预测蛋白质磷酸化位点的方法常用于位点识别的初筛阶段。为了提升位点初筛的准确率,本文提出一个深度学习模型MAPhos。该模型首先运用氨基酸向量与位置向量的和表示每一个氨基酸残基;随后使用双向GRU循环神经网络捕获各氨基酸残基的特征;接着引入多头注意力机制计算各注意力头的子上下文向量,并将它们连接起来构成肽段的上下文向量;最后通过一个全连接神经网络进行非线性变换和结果预测。真实数据集上的实验结果表明,MAPhos模型预测磷酸化位点在AUC值、灵敏度、正确率、精度和F₁分数统计度量上胜过基于特征提取的模型和基于卷积神经网络的模型,同时与基于卷积神经网络的模型相比具有更好的可解释性,这证明了MAPhos模型更加适用于磷酸化位点识别任务的初筛阶段。     

基于双阶段注意力机制的大坝变形深度学习预测模型

为提升大坝结构变形预测精度，采用完全自适应噪声集合经验模态分解(CEEMDAN)法将变形实测序列解耦为一系列具有不同时频特征的本征模态函数，使用小波阈值消噪对高频分量平稳化处理后进行重构，利用基于双阶段注意力机制的长短期记忆网络(DA-LSTM)模型对重构变形序列进行预测。实例验证结果表明，联合CEEMDAN算法和小波阈值消噪方法能够有效识别并清洗实测数据中的异常值，提升了测值对大坝运行性态的表征能力，同时DA-LSTM模型可以充分挖掘大坝变形的滞后性和增强网络的可解释性，据此构建的变形预测模型具有优良的稳健性。     

基于注意力模型的卷积循环神经网络城市声音识别

环境声音识别（Eenvironment Ssound Rrecognition ,ESR）在基于情景感知和辅助技术等领域发挥着重要作用。卷积神经网络（CNN）和循环神经网络（RNN）作为两种最具代表性的特征提取方法,在语音和音乐信号处理方面都取得显著效果,然而二者都存在一定缺点,CNN无法有效提取时间特征,RNN在提取空间特征上也存在明显劣势。为了有效的提取并利用时间特征和空间特征,提出一种新模型,利用时间分布卷积神经网络（CNN）从梅尔频谱图中提取城市环境声音特征,然后应用双向长短时记忆网络（BiLSTM）从CNN输出中获取时间信息,最后在BRNN的输出序列上实施注意力机制,从而关注到与城市环境声音最相关的特征进而做出分类判断,注意力机制既提高了分类准确性,又增强了模型的可解释性。实验结果表明,在Urbansound8K数据集中,该模型可获得80.2%的分类准确率,这优于以前在同一数据集的报告结果     

融入注意力机制的时间激励与聚集行为识别模型

视频行为识别通常应用短区间动作特征和长区间视频聚集特征进行时序建模.而这种时序建模方式在特征提取过程中,将不同时序区间的动作特征同等看待,忽略了关键通道信息和重要动作内容,不能达到理想的行为识别效果.注意力机制能够重点关注目标区间,在提取时间激励与聚集行为特征基础上融入通道-空间注意力模块.该模型分别通过通道和空间模块改变时序动作的特征分布,通道注意力关注关键通道信息是“哪些”,空间注意力机制关注重要视频内容在“哪里”,突出关键通道信息和重要内容等特征,提高了行为识别的识别率.同时在数据集Something-Something 1,UCF101和HMDB51对模型进行实验,融入通道-空间注意力模块的时间激励与聚集行为识别模型能够有效提高行为识别率.     

基于句法结构的神经网络复述识别模型

为解决已有复述语义计算方法未考虑句法结构的问题, 提出基于句法结构的神经网络复述识别模型, 设计基于树结构的神经网络模型进行语义组合计算, 使得语义表示从词语级扩展到短语级。进一步地, 提出基于短语级语义表示的句法树对齐机制, 利用跨句子注意力机制提取特征。最后, 设计自注意力机制来增强语义表示, 从而捕获全局上下文信息。在公开英语复述识别数据集Quora上进行评测, 实验结果显示, 复述识别性能得到改进, 达到89.3%的精度, 证明了提出的基于句法结构的语义组合计算方法以及基于短语级语义表示的跨句子注意力机制和自注意力机制在改进复述识别性能方面的有效性。     

基于改进ResNet网络的猫狗图像识别

动物种类的识别一直是图像识别领域的重点,为了更好地对图像中动物进行识别、帮助社会对家庭宠物的管理,本论述提出一种基于ACNet模块和CBAM注意力机制模块而改进的ACResNet18模型用来识别猫狗种类,通过非对称卷积快增强网络模型的核骨架,实现更有效的特征提取,引入CBAM注意力机制加强网络识别精度,能够更精确地对图像中猫狗进行识别和分类。本次实验使用Kaggle竞赛中的猫狗数据集进行图像识别,并通过对比实验,验证了相比于原模型,改进后的模型准确率有明显提升,最终提高了模型在图像分类上的精确度和鲁棒性,证实了该模型的可靠性。     

融合多尺度注意力和双向LSTM的行人重识别

将深度学习应用于行人重识别领域,嵌入多尺度注意力融合模块至神经网络中进行多尺度特征提取和表示,可有效提升注意力机制对深度学习网络的识别性能。提出了一种基于SE block的多尺度通道注意力融合模块,并结合ResNet50卷积神经网络提取特征;然后通过双向LSTM网络进一步提取特征序列上下文信息,在提高模型对图像重要特征的提取能力的同时,降低对图像冗余特征的关注度;最后使用级联难采样三元组损失函数和交叉熵损失函数共同训练网络模型,使样本能够在高维特征空间中实现聚类,进一步提升模型识别准确性。所提出算法在Market1501数据集和CUHK03数据集分别进行实验,并在同等条件下和其他注意力模块算法进行比较。为进一步验证各模块作用,对算法进行消融实验,以验证各模块的有效性,实验结果表明,所提出方法可有效应用于行人重识别     

基于CXANet-YOLO的火焰检测方法

快速准确的火焰检测对于降低火灾危害具有重要意义，为了加强模型的火焰特征提取能力以及解决特征图尺寸不平衡的问题，利用XSepConv (Extremely Separated Convolution)、大卷积核、Mish激活函数等构建CXANet-block(ConvolutionExtremelyAttentionNetwork)作为YOLOv5的骨干网络，引入CBAM (ConvolutionBlockAttention Module)注意力机制，提出一种基于CXANet-YOLO的火焰检测方法，通过增加通道注意力和空间注意力来提高检测性能.在自建火焰数据集上进行训练，提升模型的鲁棒性和泛化能力.实验结果表明，CXANet-YOLO模型比基准模型YOLOv5在火焰检测上具有更高的检测精度和检测速度，准确率提高了8.2%，检测速度每秒提升25帧.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with