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基于KMeans-EDA算法的非均衡评论情感分类研究

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山东理工大学学报（自然科学版） 2024年第4期38卷 45-52页

作者：郭卡安徽外国语学院信息与数学学院安徽合肥231200

学习者真实的评价是反映在线课程优缺点的重要指标,快速准确地获得其反馈,对于在线课程的优化极为重要。为深入挖掘学习者的在线学习行为,继而为在线教学提供有效的数据基础,爬取了中国大学MOOC平台的课程评论文本,基于Bert模型的结构,... 详细信息

学习者真实的评价是反映在线课程优缺点的重要指标,快速准确地获得其反馈,对于在线课程的优化极为重要。为深入挖掘学习者的在线学习行为,继而为在线教学提供有效的数据基础,爬取了中国大学MOOC平台的课程评论文本,基于Bert模型的结构,建立了基于自注意力文本表征的机器学习模型,能够实现对评论文本的精确情感分类,从而获得学习者内隐的情感状态。由于爬取数据中负面评论较少,故设计了KMeans-EDA自适应均衡采样训练策略,解决了训练过程中模型偏向多数类的问题,提升了模型对负面评论的识别能力。实验结果表明,该策略可以将模型对评论文本的f1-score值从0.6902提升到0.7399。

关键词：在线课程评论文本文本情感分类预训练特征表示非均衡训练

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Spatial analysis of vegetation cover response to climate trends in Khakassia(South Siberia)

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Journal of Mountain Science 2023年第10期20卷 2869-2884页

作者： im Sergei Institute of Natural Sciences and mathematics Khakassian State University named after N.F.KatanovAbakan 655000Russia V.N.Sukachev Institute of forest Krasnoyarsk Science Centre of the Siberian Branch of Russian Academy of ScienceKrasnoyarsk 660036Russia Institute of Ecology and Geography Siberian Federal UniversityKrasnoyarsk 660041Russia Institute of Space Research and High Technologies Reshetnev Siberian State University of Science and TechnologyKrasnoyarsk660014Russia

An analysis of the changes in vegetation cover on the territory of the Republic of Khakassia in 2000–2021 due to climatic trends was carried out based on the MODIS *** changes in vegetation cover were estimated based on trends in Normalized Difference Vegetation Index(NDVI)and Enhanced Vegetation Index(EVI).In general,in the 21st century,an increase in the biomass of vegetation cover is *** trends were observed in 16%–22%of the territory,and negative only in 1%–3%.for about 20%of the analyzed territory,a significant influence of climate on the changes in vegetation cover was *** most pronounced negative impact on vegetation cover was caused by summer air and soil temperatures,spring temperature,and summer winds,and the positive impact was caused by summer precipitation and soil *** response of the vegetation cover to climate was non-uniform concerning the ***,a significant correlation with the amount of precipitation was observed for~20%–35%of vegetation growing below 600 m above sea level and for less than 5%above this *** negative effect of summer temperatures on plants prevailed mainly at an elevation below~1400 m above sea *** climate change is likely to lead to significant degradation of vegetation in the steppe and foreststeppe in Khakassia in the coming decades.

关键词： Khakassia South Siberia Vegetation cover Climate trends Remote sensing MODIS NDVI EVI Relief

TS-Aug架构的半监督自训练情感分类算法

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南京师范大学学报（工程技术版） 2024年第1期24卷 45-52页

作者：郭卡王芳安徽外国语学院信息与数学学院安徽合肥231200

网络教学资源的普及使得资源评价的文本数据规模逐步增大.传统的有监督学习文本分类对标注数据的依赖度较高,需要足够的数据量和高质量数据才能得到良好的结果.在网络教学资源的评价文本工作中,由于标注数据难以获取且质量参差不齐,使... 详细信息

网络教学资源的普及使得资源评价的文本数据规模逐步增大.传统的有监督学习文本分类对标注数据的依赖度较高,需要足够的数据量和高质量数据才能得到良好的结果.在网络教学资源的评价文本工作中,由于标注数据难以获取且质量参差不齐,使得这一任务的难度越来越高.针对这一困难,提出一种TS-Aug半监督自训练方案,通过添加无标签数据并进行伪标签训练,能在强力数据增广的作用下大幅扩充样本集,解决数据增广中的过拟合风险.首先利用标注数据和弱增广策略进行初始化监督训练,然后利用无标注数据和强增广策略进行半监督训练,最后使用标注数据进行微调监督训练.在自建的在线课程评论数据中,能将分类f 1-Score从0.88提升至0.95,表明TS-Aug半监督自训练方案在文本分类任务中具有较好的应用前景.

关键词：少样本学习半监督训练数据增广情感分类

Residential building performance analysis at near extreme weather conditions in Hong Kong through a thermal-comfort-based strategy

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Building Simulation 2023年第1期16卷 13-25页

作者： K.f.fong C.K.Lee Kevin ka-Lun Lau Edward Yan Yung Ng Division of Building Science and Technology College of EngineeringCity University of Hong KongHong KongChina Department of Civil Engineering and Natural Resources Lulea University of TechnologySweden School of Architecture The Chinese University of Hong KongHong KongChina

The precise building performance assessment of residential housings in subtropical regions is usually more difficult than that for the commercial premises due to the much more complicated behavior of the occupants with regard to the change in indoor *** conventional use of a fixed schedule for window opening,clothing insulation and cooling equipment operation cannot reflect the real situation when the occupants respond to the change in thermal comfort,thus affecting the appropriateness of the assessment *** rectify the situation,a new modeling strategy in which the modification of the various operation schedules was based on the calculated thermal comfort(TC),was developed in this *** this new TC-based strategy,the realistic building performances under different cooling provision scenarios applied to a high-rise residential building under the near extreme weather conditions were investigated and *** was found that sole provision of ventilation fans could not meet the zone thermal comfort by over 68%of the time,and air-conditioning was *** optimal use of ventilation fans for cooling could only help reduce the total cooling energy demand by less than 12%at best which could only be realistically evaluated by adopting the present *** studies were conducted which revealed that some design factors could offer opportunities for reducing the total cooling energy under the near extreme weather conditions.

关键词： predicted mean vote thermal comfort ventilation potential building performance simulation residential housings

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利用择形分子筛异构化亚甲基二苯胺

Chinese Journal of Catalysis 2024年第7期62卷 124-130页

作者： Sam Van Minnebruggen ka Yan Cheung Trees De Baerdemaeker Niels Van Velthoven matthias Degelin Galahad O’Rourke Hiroto Toyoda Andree Iemhoff imke Muller Andrei-Nicolae Parvulescu Torsten mattke Jens ferbitz 吴勤明肖丰收 Toshiyuki Yokoi Nils Bottke Dirk De Vos 巴斯夫股份有限公司膜分离、吸附、催化和光谱学可持续解决方案中心(cmaCS) 比利时巴斯夫股份有限公司研究组德国东京工业大学纳米空间催化研究所横滨日本浙江大学化学系浙江杭州310028

亚甲基二苯胺(MDA)被广泛用作生产聚氨酯和聚异氰脲酸酯的中间体.然而,当前MDA的生产工艺在控制(4,4’/(2,4’+2,2’))异构体比例方面还存在局限.其中,4,4’-MDA被认为是最有价值的异构体.尽管2,4'-MDA在市场上也有一定的需求,但如果能... 详细信息

亚甲基二苯胺(MDA)被广泛用作生产聚氨酯和聚异氰脲酸酯的中间体.然而,当前MDA的生产工艺在控制(4,4’/(2,4’+2,2’))异构体比例方面还存在局限.其中,4,4’-MDA被认为是最有价值的异构体.尽管2,4'-MDA在市场上也有一定的需求,但如果能将其有效地转化为4,4'-MDA,将能显著提升其附加值.本文在使用苯胺的条件下,利用β分子筛等催化剂,通过双分子机制,可以选择性地将2,4'-MDA异构化为4,4'-MDA.尽管实验显示,多种酸性沸石具有较高的异构化活性,但MCM-68(具有MSE拓扑结构)的催化性能尤为出色,它不仅展现出高异构化活性,而且具有很好的选择性.MCM-68主要催化2,4'-MDA异构化为4,4'-MDA,而2,2'-MDA和低聚物的形成则可以忽略不计.本文还深入探讨了该择形作用的原因,并详细研究了酸位置在MSE分子筛孔道限制中的关键作用.

关键词：铝分布多相催化异构化亚甲基二苯胺聚氨酯择形

复合因素急性应激诱导肠道屏障功能障碍及其作用机制研究

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陆军军医大学学报 2024年第1期46卷 73-83页

作者：林启运候鹏飞郎和东张钧陈卡易龙糜漫天陆军军医大学(第三军医大学)军事预防医学系军队营养与食品安全研究中心重庆市医学营养研究中心重庆市营养与健康重点实验室重庆400038

目的研究复合因素急性应激对肠道屏障功能的影响,并探索相关作用机制。方法20只7~8周龄的雄性C57BL/6小鼠(体质量20~22 g),用随机数表法分为对照(CON)组和模型(MOD)组,n=10。MOD组小鼠于24 h内先后给予4 h休息、15 h的睡眠剥夺、3 h的噪... 详细信息

目的研究复合因素急性应激对肠道屏障功能的影响,并探索相关作用机制。方法20只7~8周龄的雄性C57BL/6小鼠(体质量20~22 g),用随机数表法分为对照(CON)组和模型(MOD)组,n=10。MOD组小鼠于24 h内先后给予4 h休息、15 h的睡眠剥夺、3 h的噪音(120 dB)/闪光(2000±500 lx)和2 h的强迫游泳运动(水温26±1℃、水深45 cm),建立复合因素急性应激模型;CON组小鼠置于恒温恒湿、正常昼夜节律的无噪音环境中不做任何处理。MOD组小鼠强迫游泳运动结束后,将小鼠麻醉采血,颈椎脱臼处死并取材。通过免疫酶联吸附实验试剂盒检测血清肠损伤标志物,HE染色法检测结肠组织形态变化,PAS染色检测肠道杯状细胞数目,免疫荧光、免疫组化和RT-qPCR法检测结肠组织屏障功能和炎症因子相关蛋白及基因表达,16S rRNA技术分析小鼠肠道菌群变化。结果与CON组比较,MOD组小鼠血清肠道损伤标志物脂多糖(Lipopolysaccharide,LPS)、肠脂肪酸结合蛋白(Intestinal fatty acid binding protein,I-fABP)、连蛋白(Zonulin)明显升高(Pf_Erysipelotrichaceae)属、孪生球菌(Gemella)属、丹毒丝菌(Erysipelotrichaceae)属显著减少(Pfactor,TNf-α)、白细胞介素6(interleukin-6,IL-6)以及活性氧(reactive oxygen species,ROS)水平均显著增加(P<0.05)。结论复合因素急性应激显著诱导小鼠肠道损伤和肠屏障功能障碍。

关键词：复合因素急性应激肠道屏障机械屏障化学屏障微生物屏障

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基于多层感知分类器的皮革图像缺陷识别研究

中国皮革 2024年第8期53卷 40-46页

作者：马静陕西国防工业职业技术学院陕西西安710300

针对传统皮革图像缺陷识别准确率和识别效率不高的问题,提出一种改进多层感知分类器的皮革图像缺陷识别方法。首先,以多层感知分类器作为基础网络模型,对其结构进行优化,并选择适宜的激活函数、分类器和权值与偏置更新方法;然后,搭建一... 详细信息

针对传统皮革图像缺陷识别准确率和识别效率不高的问题,提出一种改进多层感知分类器的皮革图像缺陷识别方法。首先,以多层感知分类器作为基础网络模型,对其结构进行优化,并选择适宜的激活函数、分类器和权值与偏置更新方法;然后,搭建一个基于改进多层感知分类器的皮革图像缺陷识别模型;最后,提出一套皮革缺陷图像数据集构建方案,通过滑窗裁剪、样本标注、图像增广等获得4类皮革缺陷图像样本,并将该数据集输入至搭建缺陷识别模型中进行缺陷识别。试验结果表明,本模型对孔洞缺陷、划痕缺陷、针眼缺陷和无缺陷4种故障样本的平均精确率、召回率、准确率和f1值分别为96.97%、96.52%、94.99%和96.14,且本模型进行缺陷识别所用时长仅为3.56 s。相较于经典卷积神经网络VGG16、残差网络ResNet10和支持向量机SVM,本模型对皮革图像不同样本的故障识别准确率更高,识别时间更短。由此说明,本模型能够提升皮革图像缺陷识别准确率和效率,模型性能具备优越性和有效性。

关键词：多层感知分类器皮革图像图像增广权值与偏置更新缺陷识别

非高斯环境下基于最大相关熵的平滑估计器设计

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控制理论与应用 2024年第5期41卷 941-949页

作者：马海平刘婷孙圣溢费敏锐绍兴文理学院电子工程系浙江绍兴312000 上海大学机电工程与自动化学院上海200444

针对kalman平滑估计器在非高斯噪声环境下性能衰退问题,本文提出了一种基于最大相关熵准则作为最优估计标准的平滑估计方法,将其应用于固定滞后问题的状态估计,称之为固定滞后最大相关熵平滑估计器(fLMCS).首先,使用矩阵变换,给出最大... 详细信息

针对kalman平滑估计器在非高斯噪声环境下性能衰退问题,本文提出了一种基于最大相关熵准则作为最优估计标准的平滑估计方法,将其应用于固定滞后问题的状态估计,称之为固定滞后最大相关熵平滑估计器(fLMCS).首先,使用矩阵变换,给出最大相关熵kalman滤波器的另一种形式;然后,以此为基础,通过引入新的状态变量来增广系统,并推导出所提平滑估计器的在线迭代方程;进一步比较平滑前后状态估计误差协方差,从理论上分析算法性能改进效果;最后,通过算例仿真验证所提平滑估计器在非高斯噪声干扰下的有效性和优越性.

关键词：平滑估计 kalman滤波最大相关熵准则固定滞后非高斯环境

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TRPC5 is essential in endothelium-dependent contraction of aorta from diet-induced obese mice

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fundamental Research 2022年第3期2卷 429-436页

作者： Yifei Zhu Sheng Wang Yuan Chu ka Zhang Xin Wen Lei feng fan Yu Xin ma Wuxi School of Medicine Jiangnan UniversityWuxi 214000China

The role of the Ca^(2+)-permeable ion channel TRPC5 in regulating vasocontraction in obesity is poorly ***,we investigated whether TRPC5 contributes to vascular dysfunction in obesity by promoting endothelium-dependent contraction via activation of cytosolic phospholipase A2(cPLA_(2))in the aortic endothelial cells of obese ***-induced endothelium-dependent relaxation and contraction in the aorta were measured us-ing wire ***_(2)activity was measured by the fluorogenic PLA_(2)substrate Bis-BODIPY^(TM)fL C_(11)-*** intracellular Ca^(2+)level in response to acetylcholine was measured by fluo-4 ***-derived contracting factors were assessed by enzyme ***-induced obesity(DIO)attenuated endothelium-dependent vasodilation,enhanced endothelium-dependent contraction(EDC),and increased the expression of TRPC5 in the mouse *** of TRPC5 promoted EDC in the wild-type mouse aorta,whereas pharma-cological inhibition and genetic knockout of TRPC5 decreased EDC in the DIO mouse ***,cPLA_(2)phosphorylation and activity were higher in aortic endothelial cells from DIO mice,and this was attenuated by inhibition and knockout of *** 2(COX-2)expression was increased in DIO mouse endothe-lium and was decreased by a TRPC5 inhibitor and knockout of *** of prostaglandins f_(2α(PGf_(2α)and E 2(PGE 2)was involved in TRPC5-regulated EDC in DIO *** study demonstrated that TRPC5 contributes to endothelial and vascular dysfunction and is involved in EDC through activation of cPLA_(2)and enhanced COX-2-PGf_(2α)/PGE_(2)levels in DIO mice.

关键词： Transient receptor potential channel canonical family member 5(TRPC5) Endothelium-dependent contraction Vascular function Diet-induced obesity