Bogdan Dumitru


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Exploring Optimism and Pessimism in Twitter Using Deep Learning
Cornelia Caragea | Liviu P. Dinu | Bogdan Dumitru
Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing

Identifying optimistic and pessimistic viewpoints and users from Twitter is useful for providing better social support to those who need such support, and for minimizing the negative influence among users and maximizing the spread of positive attitudes and ideas. In this paper, we explore a range of deep learning models to predict optimism and pessimism in Twitter at both tweet and user level and show that these models substantially outperform traditional machine learning classifiers used in prior work. In addition, we show evidence that a sentiment classifier would not be sufficient for accurately predicting optimism and pessimism in Twitter. Last, we study the verb tense usage as well as the presence of polarity words in optimistic and pessimistic tweets.

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ALB at SemEval-2018 Task 10: A System for Capturing Discriminative Attributes
Bogdan Dumitru | Alina Maria Ciobanu | Liviu P. Dinu
Proceedings of the 12th International Workshop on Semantic Evaluation

Semantic difference detection attempts to capture whether a word is a discriminative attribute between two other words. For example, the discriminative feature red characterizes the first word from the (apple, banana) pair, but not the second. Modeling semantic difference is essential for language understanding systems, as it provides useful information for identifying particular aspects of word senses. This paper describes our system implementation (the ALB system of the NLP@Unibuc team) for the 10th task of the SemEval 2018 workshop, “Capturing Discriminative Attributes”. We propose a method for semantic difference detection that uses an SVM classifier with features based on co-occurrence counts and shallow semantic parsing, achieving 0.63 F1 score in the competition.


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On the stylistic evolution from communism to democracy: Solomon Marcus study case
Anca Dinu | Liviu P. Dinu | Bogdan Dumitru
Proceedings of the International Conference Recent Advances in Natural Language Processing, RANLP 2017

In this article we propose a stylistic analysis of Solomon Marcus’ non-scientific published texts, gathered in six volumes, aiming to uncover some of his quantitative and qualitative fingerprints. Moreover, we compare and cluster two distinct periods of time in his writing style: 22 years of communist regime (1967-1989) and 27 years of democracy (1990-2016). The distributional analysis of Marcus’ text reveals that the passing from the communist regime period to democracy is sharply marked by two complementary changes in Marcus’ writing: in the pre-democracy period, the communist norms of writing style demanded on the one hand long phrases, long words and clichés, and on the other hand, a short list of preferred “official” topics; in democracy tendency was towards shorten phrases and words while approaching a broader area of topics.