针对传统方法提取文本特征向量存在语义缺失,以及有些文本情感识别任务涉及多分类问题,提出一种新的基于BERT(bidirectional encoder representations from transformers)和动态集成选择的多分类文本情感识别策略。首先,采用BERT对文本...针对传统方法提取文本特征向量存在语义缺失,以及有些文本情感识别任务涉及多分类问题,提出一种新的基于BERT(bidirectional encoder representations from transformers)和动态集成选择的多分类文本情感识别策略。首先,采用BERT对文本进行向量化处理,针对多分类文本情感识别任务采用OVO分解策略拆分成多个二分类子任务;其次,针对每个子任务采用动态集成选择策略构建分类器集成模型;最后,基于聚合策略获得最终的预测结果。采用公开的影评数据集对所提出的方法进行实证分析。结果表明:(1)相较于传统的TF-IDF与Word2Vec方法,基于BERT模型的词向量化处理有助于提高文本情感识别精度;(2)针对多分类情感识别任务中的每个子问题,采用动态集成选择策略可以有效提高识别效果;(3)本文建立的预测模型性能比其他现有情感识别模型具有显著优势。展开更多
Ceria nano discs were synthesized by the stepwise thermal decomposition strategy of the oxalate precursor. A series of Ce（1-x）CuxO2（x = 0, 0.02, 0.1, 0.2 and 0.3） nano sized oxide systems were prepared through the...Ceria nano discs were synthesized by the stepwise thermal decomposition strategy of the oxalate precursor. A series of Ce（1-x）CuxO2（x = 0, 0.02, 0.1, 0.2 and 0.3） nano sized oxide systems were prepared through thermal decomposition route. Kinetic characterization of formation of solid solution was made by isoconversional strategy under non-isothermal condition. Introduction of various reactant molar ratios of Cu2＋：Ce4＋ has a pivotal role in the creation of new oxygen vacancies, decomposition strategy,particle size and shape. Cu2＋ doping（x = 0.02 and 0.1） damages the disc shaped morphology of ceria.Homogeneous distribution of Cu2＋ on the oxalate precursor has a significant role in the catalyzing activity for the destruction of oxalate bond to oxide. 2 mol% doped Cu2＋ promotes breaking of oxalate bonds in nitrogen atmosphere. In vitro cell viability assay illustrates enhanced toxicity to cancer cells with 10 mol% Cu2＋ doped ceria.展开更多
文摘针对传统方法提取文本特征向量存在语义缺失,以及有些文本情感识别任务涉及多分类问题,提出一种新的基于BERT(bidirectional encoder representations from transformers)和动态集成选择的多分类文本情感识别策略。首先,采用BERT对文本进行向量化处理,针对多分类文本情感识别任务采用OVO分解策略拆分成多个二分类子任务;其次,针对每个子任务采用动态集成选择策略构建分类器集成模型;最后,基于聚合策略获得最终的预测结果。采用公开的影评数据集对所提出的方法进行实证分析。结果表明:(1)相较于传统的TF-IDF与Word2Vec方法,基于BERT模型的词向量化处理有助于提高文本情感识别精度;(2)针对多分类情感识别任务中的每个子问题,采用动态集成选择策略可以有效提高识别效果;(3)本文建立的预测模型性能比其他现有情感识别模型具有显著优势。
文摘Ceria nano discs were synthesized by the stepwise thermal decomposition strategy of the oxalate precursor. A series of Ce（1-x）CuxO2（x = 0, 0.02, 0.1, 0.2 and 0.3） nano sized oxide systems were prepared through thermal decomposition route. Kinetic characterization of formation of solid solution was made by isoconversional strategy under non-isothermal condition. Introduction of various reactant molar ratios of Cu2＋：Ce4＋ has a pivotal role in the creation of new oxygen vacancies, decomposition strategy,particle size and shape. Cu2＋ doping（x = 0.02 and 0.1） damages the disc shaped morphology of ceria.Homogeneous distribution of Cu2＋ on the oxalate precursor has a significant role in the catalyzing activity for the destruction of oxalate bond to oxide. 2 mol% doped Cu2＋ promotes breaking of oxalate bonds in nitrogen atmosphere. In vitro cell viability assay illustrates enhanced toxicity to cancer cells with 10 mol% Cu2＋ doped ceria.
