Automatic Irony Detection using Feature Fusion and Ensemble Classifier

With the advent of micro-blogging sites, users are pioneer in expressing their sentiments and emotions on global issues through text. Automatic detection and classification of sentiments like sarcastic or ironic content in microblogging reviews is a challenging task. It requires a system that manages some kind of knowledge to interpret the sentiment expressed in text. The available approaches are quite limited in their capabilities and scope to detect ironic utterances present in the text. In this regards, the paper propose feature fusion to provide knowledge to the system by alternative sets of features obtained using linguistic and content based text features. The proposed work extracts five sets of linguistic features and fuses with features selected using two stages of a feature selection method. In order to demonstrate the effectiveness of the proposed method, we conduct extensive experimentation by selecting different feature subsets. The performances of the proposed method are evaluated using Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), Decision Tree (DT) and ensemble classifiers. The experimental result shows the proposed approach significantly out-performs the conventional methods

Segmentation et indexation d'objets complexes dans les images de bandes dessinées

In this thesis, we review, highlight and illustrate the challenges related to comic book image analysis in order to give to the reader a good overview about the last research progress in this field and the current issues. We propose three different approaches for comic book image analysis that are composed by several processing. The first approach is called "sequential'' because the image content is described in an intuitive way, from simple to complex elements using previously extracted elements to guide further processing. Simple elements such as panel text and balloon are extracted first, followed by the balloon tail and then the comic character position in the panel. The second approach addresses independent information extraction to recover the main drawback of the first approach : error propagation. This second method is called “independent” because it is composed by several specific extractors for each elements of the image without any dependence between them. Extra processing such as balloon type classification and text recognition are also covered. The third approach introduces a knowledge-driven and scalable system of comics image understanding. This system called “expert system” is composed by an inference engine and two models, one for comics domain and another one for image processing, stored in an ontology. This expert system combines the benefits of the two first approaches and enables high level semantic description such as the reading order of panels and text, the relations between the speech balloons and their speakers and the comic character identification.Dans ce manuscrit de thèse, nous détaillons et illustrons les différents défis scientifiques liés à l'analyse automatique d'images de bandes dessinées, de manière à donner au lecteur tous les éléments concernant les dernières avancées scientifiques en la matière ainsi que les verrous scientifiques actuels. Nous proposons trois approches pour l'analyse d'image de bandes dessinées. La première approche est dite "séquentielle'' car le contenu de l'image est décrit progressivement et de manière intuitive. Dans cette approche, les extractions se succèdent, en commençant par les plus simples comme les cases, le texte et les bulles qui servent ensuite à guider l'extraction d'éléments plus complexes tels que la queue des bulles et les personnages au sein des cases. La seconde approche propose des extractions indépendantes les unes des autres de manière à éviter la propagation d'erreur due aux traitements successifs. D'autres éléments tels que la classification du type de bulle et la reconnaissance de texte y sont aussi abordés. La troisième approche introduit un système fondé sur une base de connaissance a priori du contenu des images de bandes dessinées. Ce système permet de construire une description sémantique de l'image, dirigée par les modèles de connaissances. Il combine les avantages des deux approches précédentes et permet une description sémantique de haut niveau pouvant inclure des informations telles que l'ordre de lecture, la sémantique des bulles, les relations entre les bulles et leurs locuteurs ainsi que les interactions entre les personnages

EmoCNN: Encoding Emotional Expression from Text to Word Vector and Classifying Emotions—A Case Study in Thai Social Network Conversation

We present EmoCNN, a collection of specially-trained word embedding layer and convolutional neural network model for the classification of conversational texts into 4 types of emotion. This model is part of a chatbot for depression evaluation. The difficulty in classifying emotion from conversational text is that most word embeddings are trained with emotionally-neutral corpus such as Wikipedia or news articles, where emotional words do not appear very often or at all, and the language style is formal writing. We trained a new word embedding based on the word2vec architecture in an unsupervised manner and then fine-tuned it on soft-labelled data. The data was obtained from mining Twitter using emotion keywords. We show that this emotion word embedding can differentiate between words which have the same polarity and words which have opposite polarity, as well as find similar words with the same polarity, while the standard word embedding cannot. We then used this new embedding as the first layer of EmoCNN that classifies conversational text into the 4 emotions. EmoCNN achieved macro-averaged f1-score of 0.76 over the test set. We compared EmoCNN against three different models: a shallow fully-connected neural network, fine-tuning RoBERTa, and ULMFit. These got the best macro-averaged f1-score of 0.5556, 0.6402 and 0.7386 respectively

Atribuição de autoria em micro-mensagens

Orientadores: Ariadne Maria Brito Rizzoni Carvalho, Anderson de Rezende RochaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação CientíficaResumo: Com o crescimento continuo do uso de midias sociais, a atribuição de autoria tem um papel imortante na prevenção dos crimes cibernéticos e na análise de rastros online deixados por assediadores, \textit{bullies}, ladrões de identidade entre outros. Nesta dissertação, nós propusemos um método para atribuição de autoria que é de cem a mil vezes mais rápido que o estado da arte. Nós também obtivemos uma acurácia 65\% na classificação de 50 autores. O método proposto se baseia numa representação de caracteristicas escalável utilizando os padrões das mensagens dos micro-blogs, e também nos utilizamos de um classificador de padrões customizado para lidar com grandes quantidades de dados e alta dimensionalidade. Por fim, nós discutimos a redução do espaço de busca na análise de centenas de suspeitos online e milões de micro mensagens online, o que torna essa abordagem valiosa para forense digital e aplicação das leisAbstract: With the ever-growing use of social media, authorship attribution plays an important role in avoiding cybercrime, and helping the analysis of online trails left behind by cyber pranks, stalkers, bullies, identity thieves and alike. In this dissertation, we propose a method for authorship attribution in micro blogs with efficiency one hundred to a thousand times faster than state-of-the-art counterparts. We also achieved a accuracy of 65% when classifying texts from 50 authors. The method relies on a powerful and scalable feature representation approach taking advantage of user patterns on micro-blog messages, and also on a custom-tailored pattern classifier adapted to deal with big data and high-dimensional data. Finally, we discuss search space reduction when analysing hundreds of online suspects and millions of online micro messages, which makes this approach invaluable for digital forensics and law enforcementMestradoCiência da ComputaçãoMestre em Ciência da Computaçã

Evaluation of potential Spanish text markers on social posts asfeatures for polarity classification

This work describes the identification and evaluation process of potential text markers for sen-timent analysis. Evaluation of the markers and its use as part of the feature extraction processfrom plain text that is needed for sentiment analysis is presented. Evaluation of text markerobtained as a result of systematic analysis from a corpus over a second one allowed us to iden-tify that emphasized positive words are strong indicators for positive text. The second corpusallowed us to evaluate the relation between the polarity of emphasized words and the text theyappear in. Evaluation of the markers for polarity detection task in combination with a polarizeddictionary produced polarity classification average precision of 56% using only three markers.This are promising results compared to the top 69% obtained using more features and specializeddictionaries for the same taskUniversidad de Costa Rica/[]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[]/MICITT/Costa RicaUCR::Vicerrectoría de Docencia::Ingeniería::Facultad de Ingeniería::Escuela de Ciencias de la Computación e InformáticaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ingeniería::Centro de Investigaciones en Tecnologías de Información y Comunicación (CITIC)UCR::Vicerrectoría de Docencia::Artes y Letras::Facultad de Letras::Escuela de Filología, Lingüística y Literatur

Analyzing Granger causality in climate data with time series classification methods

Attribution studies in climate science aim for scientifically ascertaining the influence of climatic variations on natural or anthropogenic factors. Many of those studies adopt the concept of Granger causality to infer statistical cause-effect relationships, while utilizing traditional autoregressive models. In this article, we investigate the potential of state-of-the-art time series classification techniques to enhance causal inference in climate science. We conduct a comparative experimental study of different types of algorithms on a large test suite that comprises a unique collection of datasets from the area of climate-vegetation dynamics. The results indicate that specialized time series classification methods are able to improve existing inference procedures. Substantial differences are observed among the methods that were tested

Multilingual sentiment analysis in social media.

252 p.This thesis addresses the task of analysing sentiment in messages coming from social media. The ultimate goal was to develop a Sentiment Analysis system for Basque. However, because of the socio-linguistic reality of the Basque language a tool providing only analysis for Basque would not be enough for a real world application. Thus, we set out to develop a multilingual system, including Basque, English, French and Spanish.The thesis addresses the following challenges to build such a system:- Analysing methods for creating Sentiment lexicons, suitable for less resourced languages.- Analysis of social media (specifically Twitter): Tweets pose several challenges in order to understand and extract opinions from such messages. Language identification and microtext normalization are addressed.- Research the state of the art in polarity classification, and develop a supervised classifier that is tested against well known social media benchmarks.- Develop a social media monitor capable of analysing sentiment with respect to specific events, products or organizations