中文微博情感分类的简单多标签排序算法

针对中文微博文本情感分类中每个样本最多只有两种有序情感标签的情形,提出了一种简单的多标签排序算法——TSMLR,该算法采用两步学习和两步分类的策略,通过学习情感标签之间的主次关系,对微博文本的情感进行分类并对情感标签进行排序。首先,将一个多标签排序问题转化为八个多类单标签分类问题,分别对主要情感标签和次要情感标签进行学习;然后,利用得到的分类模型对微博表达的情感进行两步分类,首先给出主要情感标签,再给出次要情感标签。通过在NLP&CC2014的中文微博文本情感分析评测数据集上进行实验,与校准标签排序方法(CLR)相比,TSMLR方法的准确度和平均精度分别提高了8.59%和9.28%,1-错误率相应下降了9.77%,而且TSMLR所需的训练时间相对较少。实验结果表明:TSMLR对标签之间顺序关系的学习能够有效提高对中文微博情感分类的准确率。     

Three naive Bayes approaches for discrimination-free classification

In this paper, we investigate how to modify the naive Bayes classifier in order to perform classification that is restricted to be independent with respect to a given sensitive attribute. Such independency restrictions occur naturally when the decision process leading to the labels in the data-set was biased; e.g., due to gender or racial discrimination. This setting is motivated by many cases in which there exist laws that disallow a decision that is partly based on discrimination. Naive application of machine learning techniques would result in huge fines for companies. We present three approaches for making the naive Bayes classifier discrimination-free: (i) modifying the probability of the decision being positive, (ii) training one model for every sensitive attribute value and balancing them, and (iii) adding a latent variable to the Bayesian model that represents the unbiased label and optimizing the model parameters for likelihood using expectation maximization. We present experiments for the three approaches on both artificial and real-life data.     

Feature selection for multi-label naive Bayes classification

In multi-label learning, the training set is made up of instances each associated with a set of labels, and the task is to predict the label sets of unseen instances. In this paper, this learning problem is addressed by using a method called Mlnb which adapts the traditional naive Bayes classifiers to deal with multi-label instances. Feature selection mechanisms are incorporated into Mlnb to improve its performance. Firstly, feature extraction techniques based on principal component analysis are applied to remove irrelevant and redundant features. After that, feature subset selection techniques based on genetic algorithms are used to choose the most appropriate subset of features for prediction. Experiments on synthetic and real-world data show that Mlnb achieves comparable performance to other well-established multi-label learning algorithms.     

Attention based hierarchical LSTM network for context-aware microblog sentiment classification

World Wide Web - Analyzing sentiment polarities of microblog has become a hot research topic for both academic and industrial communities. Most of the existing algorithms regard each microblog as...     

基于机器学习的中文微博情感分类实证研究

使用三种机器学习算法、三种特征选取算法以及三种特征项权重计算方法对微博进行了情感分类的实证研究。实验结果表明,针对不同的特征权重计算方法,支持向量机(SVM)和贝叶斯分类算法(Nave Bayes)各有优势,信息增益(IG)特征选取方法相比于其他的方法效果明显要好。综合考虑三种因素,采用SVM和IG,以及TF-IDF(Term Frequency-Inverse Document Frequency)作为特征项权重,三者结合对微博的情感分类效果最好。针对电影领域,比较了微博评论和普通评论之间分类模型的通用性,实验结果表明情感分类性能依赖于评论的风格。     

微博情感分析综述

随着微博用户数量的快速增长,微博中所携带的一些情感和观点对社会的影响越来越大,尤其是一些涉及到公众人身安全的负面情绪,可能会影响到社会的稳定,因此进行微博情感分析意义重大。微博情感分析的内容包括微博语料的获取、微博语料的预处理和情感分析方法等,常用的情感分析方法有基于情感词典的方法、基于机器学习的方法和基于深度学习的方法。随着注意力机制在NLP领域的广泛使用,很多研究者开始将注意力机制融合到深度学习模型中进行情感分析,这使得情感分析的准确率得到了很大的提升。谷歌提出的BERT模型本质上也是基于注意力机制实现的,BERT模型在情感分析领域取得了突破性的进展。     

面向短文本情感分类的端到端对抗变分贝叶斯方法

针对文本情感分析中文本过短而导致的分类准确度低的问题,结合对抗学习和变分推断提出一种端到端的短文本情感分类模型。首先,使用谱规范化技术解决了判别器在训练过程中的震荡问题;然后,添加额外的分类模型来指导推断模型的更新;其次,使用对抗变分贝叶斯（AVB）模型提取短文本的主题特征;最后,使用三次注意力机制来融合主题特征与预训练词向量特征进行分类。通过在一个产品评论和两个微博数据集上的实验结果证明,所提模型较基于自注意力的双向长短期记忆网络（BiLSTM-SA）在分类准确度上分别提高了2.9、2.2和8.4个百分点。由此可见,该模型适用于挖掘社交短文本中的情感和观点信息,对舆情发现、用户反馈、质量监督和其他相关领域具有重要的意义。     

面向短文本情感分类的端到端对抗变分贝叶斯方法

针对文本情感分析中文本过短而导致的分类准确度低的问题，结合对抗学习和变分推断提出一种端到端的短文本情感分类模型。首先，使用谱规范化技术解决了判别器在训练过程中的震荡问题；然后，添加额外的分类模型来指导推断模型的更新；其次，使用对抗变分贝叶斯（AVB）模型提取短文本的主题特征；最后，使用三次注意力机制来融合主题特征与预训练词向量特征进行分类。通过在一个产品评论和两个微博数据集上的实验结果证明，所提模型较基于自注意力的双向长短期记忆网络（BiLSTM-SA）在分类准确度上分别提高了2.9、2.2和8.4个百分点。由此可见，该模型适用于挖掘社交短文本中的情感和观点信息，对舆情发现、用户反馈、质量监督和其他相关领域具有重要的意义。     

Privacy-preserving naive Bayes classification on distributed data via semi-trusted mixers

Distributed data mining applications, such as those dealing with health care, finance, counter-terrorism and homeland defense, use sensitive data from distributed databases held by different parties. This comes into direct conflict with an individual's need and right to privacy. It is thus of great importance to develop adequate security techniques for protecting privacy of individual values used for data mining.     

Effective naive Bayes nearest neighbor based image classification on GPU

Non-parametric classifier, Naive Bayes nearest neighbor, is designed with no training phase, and its performance outperforms many well-trained learning-based image classifiers. Unfortunately, despite its high accuracy, it suffers from great computational pressure from distance computations in space of local feature. This paper explores accelerating strategies from perspectives of both algorithm design and software development. Our approach integrates space decomposition capability of Product quantization (PQ) and parallel accelerating capability of underlying computational platform, Graphics processing unit (GPU). PQ is exploited to compress the indexed local features and prune the search space. GPU is used to ease most of computational pressure by processing the tasks in parallel. To achieve good parallel efficiency, a new sequential classification process is first designed and decomposed into independent components with high parallelism. Effective parallelization techniques are then presented to make use of computational resources. Parallel heap array is built to accelerate the process of feature quantization. Distance table lookup is built to speed up the process of feature search. Comparative experiments on UIUC-Sport dataset demonstrate that our integrated solution outperforms other implementations significantly on Core-quad Intel Core i7 950 CPU and GPU of NVIDIA Geforce GTX460. Scalability experiment on 80 million tiny images database shows that our approach still performs well when large-scale image database is explored.     

Constrained domain maximum likelihood estimation for naive Bayes text classification

The naive Bayes assumption in text classification has the advantage of greatly simplifying maximum likelihood estimation of unknown class-conditional word occurrence probabilities. However, these estimates are usually modified by application of a heuristic parameter smoothing technique to avoid (over-fitted) null estimates. In this work, we advocate the reduction of the parameter domain instead of parameter smoothing. This leads to a constrained domain maximum likelihood estimation problem for which we provide an iterative algorithm that solves it optimally.     

Ontology-based sentiment analysis of twitter posts

The emergence of Web 2.0 has drastically altered the way users perceive the Internet, by improving information sharing, collaboration and interoperability. Micro-blogging is one of the most popular Web 2.0 applications and related services, like Twitter, have evolved into a practical means for sharing opinions on almost all aspects of everyday life. Consequently, micro-blogging web sites have since become rich data sources for opinion mining and sentiment analysis. Towards this direction, text-based sentiment classifiers often prove inefficient, since tweets typically do not consist of representative and syntactically consistent words, due to the imposed character limit. This paper proposes the deployment of original ontology-based techniques towards a more efficient sentiment analysis of Twitter posts. The novelty of the proposed approach is that posts are not simply characterized by a sentiment score, as is the case with machine learning-based classifiers, but instead receive a sentiment grade for each distinct notion in the post. Overall, our proposed architecture results in a more detailed analysis of post opinions regarding a specific topic.     

基于朴素贝叶斯分类的居民出行起讫点识别方法

针对手机信令数据存在的精度不高、时间间隔大、信号"乒乓切换"等问题,提出一种基于朴素贝叶斯分类（NBC）的方法来利用手机定位数据识别居民出行起讫点（OD）。首先,利用80位志愿者连续1个月记录的出行活动数据,依据职住距离分类统计移动和停留状态下的条件概率分布;其次,建立用于表征用户移动停留状态的两个特征参数指标：方向夹角和最小覆盖圆直径;最后,依据NBC原理计算用户的移动或停留状态概率,将连续两个以上为移动状态的过程集聚为出行OD。利用厦门市移动的手机定位数据的分析结果表明：所提方法得到的人均出行次数的平均绝对百分比误差（MAPE）误差为7.79%,具备较高的精度,出行OD的分析结果可以较好地反映真实出行规律。     

基于词语相关度的微博新情感词自动识别

针对微博中新情感词的识别问题,提出了一种基于词语相关度的微博新情感词自动识别方法。首先,对于分词软件把一个新词错分成几个词的问题,利用组合思想将相邻词进行合并作为新词的候选词;其次,为了充分利用词语上下文的语义信息,采用神经网络训练语料获得候选新词的空间表示向量;最后,利用已有的情感词典作为指导,融合基于词表集合的关联度排序和最大关联度排序算法,在候选词上筛选,获得最终的情感新词。在COAE2014(第六届中文倾向性分析评测)任务3语料上,提出的融合算法与点互信息(PMI)、增强互信息(EMI)、多词表达距离(MED)、新词语概率(NWP)以及基于词向量的新词识别方法相比,准确率至少提高了22%,说明该方法自动识别微博新情感词效果优于其他五种方法。     

基于动态主题情感混合模型的微博主题情感演化分析方法

针对现有模型无法进行微博主题情感演化分析的问题,提出一种基于主题情感混合模型(TSCM)和情感周期性理论的主题情感演化模型——动态主题情感混合模型(DTSCM)。DTSCM通过捕获不同时间片中微博消息集的主题和情感,追踪不同时间片内主题与情感的变化趋势,获得主题情感演化图,从而实现主题和情感的演化分析。真实微博数据集上的实验结果表明,与当前优秀代表算法JST(Joint Sentiment/Topic)、S-LDA(Sentiment-Latent Dirichlet Allocation)和DPLDA(Dependency Phrases-Latent Dirichlet Allocation)相比,该方法的情感分类准确率分别提高了3.01%、4.33%和8.75%,并且可以获得主题情感演化图。这表明该方法具有更高的情感分类准确率并且可以进行微博主题情感演化分析,为舆情分析等应用提供了较好的帮助。     

Bayesian model averaging of naive Bayes for clustering.

This paper considers a Bayesian model-averaging (MA) approach to learn an unsupervised naive Bayes classification model. By using the expectation model-averaging (EMA) algorithm, which is proposed in this paper, a unique naive Bayes model that approximates an MA over selective naive Bayes structures is obtained. This algorithm allows to obtain the parameters for the approximate MA clustering model in the same time complexity needed to learn the maximum-likelihood model with the expectation-maximization algorithm. On the other hand, the proposed method can also be regarded as an approach to an unsupervised feature subset selection due to the fact that the model obtained by the EMA algorithm incorporates information on how dependent every predictive variable is on the cluster variable.     

Gender classification of microblog text based on authorial style

Information Systems and e-Business Management - Gender profiling of unstructured text data has several applications in areas such as marketing, advertising, legal investigation, and recommender...     

Ensemble of feature sets and classification algorithms for sentiment classification

In this paper, we make a comparative study of the effectiveness of ensemble technique for sentiment classification. The ensemble framework is applied to sentiment classification tasks, with the aim of efficiently integrating different feature sets and classification algorithms to synthesize a more accurate classification procedure. First, two types of feature sets are designed for sentiment classification, namely the part-of-speech based feature sets and the word-relation based feature sets. Second, three well-known text classification algorithms, namely na?¨ve Bayes, maximum entropy and support vector machines, are employed as base-classifiers for each of the feature sets. Third, three types of ensemble methods, namely the fixed combination, weighted combination and meta-classifier combination, are evaluated for three ensemble strategies. A wide range of comparative experiments are conducted on five widely-used datasets in sentiment classification. Finally, some in-depth discussion is presented and conclusions are drawn about the effectiveness of ensemble technique for sentiment classification.     

维吾尔语情感分类算法

情感分类是一项具有实用价值的分类技术。目前英语和汉语的情感分类的研究比较多,而针对维吾尔语的研究较少。以n-gram模型作为不同的文本表示特征,以互信息、信息增益、CHI统计量和文档频率作为不同的特征选择方法,选择不同的特征数量,以Naǐve Bayes、ME（最大熵）和SVM（支持向量机）作为不同的文本分类方法,分别进行了维吾尔语情感分类实验,并对实验结果进行了比较,结果表明：采用UniGrams特征表示方法、在5 000个特征数量和合适的特征选择函数,ME和SVM对维吾尔语情感分类能取得较好的效果。