Phishing is a type of fraud attempt in which the attacker, usually by e-mail, pretends to be a trusted person or entity in order to obtain sensitive information from a target. Most recent phishing detection researches have focused on obtaining highly distinctive features from the metadata and text of these e-mails. The obtained attributes are then used to feed classification algorithms in order to determine whether they are phishing or legitimate messages. In this paper, it is proposed an approach based on machine learning to detect phishing e-mail attacks. The methods that compose this approach are performed through a feature engineering process based on natural language processing, lemmatization, topics modeling, improved learning techniques for resampling and cross-validation, and hyperparameters configuration. The first proposed method uses all the features obtained from the Document-Term Matrix (DTM) in the classification algorithms. The second one uses Latent Dirichlet Allocation (LDA) as an operation to deal with the problems of the ''curse of dimensionality'', the sparsity, and the text context portion included in the obtained representation. The proposed approach reached marks with an F1-measure of 99.95% success rate using the XGBoost algorithm. It outperforms state-of-the-art phishing detection researches for an accredited data set, in applications based only on the body of the e-mails, without using other e-mail features such as its header, IP information or number of links in the text.INDEX TERMS Feature engineering, feature extraction, natural language processing, phishing detection, topics modeling, XGBoost.

ResumoObjetivo. Este artigo pretende apresentar o conceito de Gamificação como uma alternativa multimodal para a educação, considerando ser uma iniciativa relativamente recente. É um fenômeno em fase inicial, carente de maiores estudos e discussões, mas não por isso menos interessante, porquanto propõe uma nova abordagem para a educação e muitos outros segmentos do conhecimento humano contemporâneo. Método.A pesquisa mostra que na Educação de Nível Superior, como em outras áreas, o seu uso ainda é incipiente, pois a polêmica que envolve o tema ainda é considerável, no entanto, vem conjugar esforços com outras propostas de mesma envergadura, na tentativa de sublimar alguns dos problemas de aprendizagem dos indivíduos, levando-os ao engajamento e motivação no ambiente educacional. Não se trata de uma revolução, ou proposta de abandono de conceitos e procedimentos pré-existentes, mas uma tentativa de compor com o que já existe e de aproveitar os benefícios da evolução por que passa a humanidade para que a aprendizagem se torne cada vez mais natural aos olhos dos indivíduos.Resultados. Desafios terão que ser transpostos, podendo ser de natureza tecnológica, financeira, procedimental, educacional ou estrutural, com maiores estudos e pesquisas e avaliação dos resultados pode-se avaliar se a iniciativa é consistente e se veio para ficar. Palavras-chaveAprendizagem; educação; gamificação; multimodalidade; tecnologia educacional Gamification: a new multimodal approach to education AbstractObjective. This article intends to present the concept of Gamification as a multimodal alternative for education, considering it a relatively recent initiative. It is a phenomenon still in its infancy, lacking in more studies and discussions, but not les s interesting, since it proposes a new approach to education and many other segments of contemporary human knowledge.Method. The research shows that in Higher Education, as in other areas, its use is still incipient, because the controversy surrounding the theme is still considerable, however, it joins efforts with other proposals of the same magnitude, in an attempt to sublimate some of the learning problems of the individuals, leading them to the engagement and motivation in the educational environment. It is not a revolution, or a proposal to abandon pre-existing concepts and procedures, but an attempt to compose with what already exists and to take advantage of the benefits of evolution through which humanity passes, so that learning becomes increasingly more natural in the eyes of individuals.Results. Challenges will have to be transposed, and may be of a technological, financial, procedural, educational or structural nature. With more studies, research, and evaluation of the results, it is possible to evaluate if the initiative is consistent and if it has come to stay.

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O Brasil está em processo de convergência de sua contabilidade pública em relação aos padrões internacionais desenvolvidos pela Federação Internacional dos Contadores (Ifac). A implementação de sistemas de informação contábil é geralmente realizada por meio das abordagens top-down ou bottomup. Assim, este estudo tem por objetivos: 1) identificar a abordagem adotada pelo governo federal brasileiro; 2) descrever o modelo de implementação do sistema de informação contábil público no Brasil; e 3) mapear o fluxo de informações e atores envolvidos no processo de convergência. A abordagem qualitativa foi adotada utilizando a pesquisa documental e análise de conteúdo de documentos disponíveis para operacionalizar a pesquisa. Foi identificado que o Brasil utiliza a abordagem middleup-down, que favorece a interação entre múltiplos atores no processo, diferentemente da abordagem top-down, que segue o modelo internacional divulgado. P a l a v r a s -c h a v e : sistema de informação; Federação Internacional dos Contadores; contabilidade pública internacional; abordagem top-down; abordagem bottom-up. Convergencia brasileña con los estándares internacionales de contabilidad pública vis-à-vis las estrategias top-down y bottom-upBrasil pasa por un proceso de convergencia de su contabilidad pública con relación a los estándares internacionales desarrollados por la Federación Internacional de Contadores (Ifac). La implementación de sistemas de información contable es realizada generalmente por medio de los abordajes top-down o bottom-up. Así, este estudio tiene como objetivos: 1) identificar el abordaje adoptado por el gobierno federal brasileño; 2) describir el modelo de implementación del sistema de información contable pública en Brasil; y 3) mapear el flujo de informaciones y los actores involucrados en el proceso de Artigo recebido em 29 dez. 2012 e aceito em 11 nov. 2013. convergencia. El abordaje cualitativo fue adoptado utilizando la investigación documental y el análisis de contenido de documentos disponibles para poner en operación la investigación. Se identificó que Brasil utiliza el abordaje middle-up-down, que favorece la interacción entre múltiples actores en el proceso, diferentemente del abordaje top-down, que sigue el modelo internacional divulgado. P a l a b r a s c l a v e : sistema de información; Federación Internacional de Contadores; contabilidad pública internacional; abordaje top-down; abordaje bottom-up. Brazilian convergence with the international standards of public accounting vis-à-vis the topdown and bottom-up strategiesBrazil is undergoing a convergence process of its public accounting with regard to the international standards developed by the International Federation of Accountants (Ifac). The implementation of accounting information systems is usually conducted by means of the top-down or bottom-up approaches. Thus, this study aims to: 1) identify the approach adopted by the Brazilian federal government; 2) describe the implementation model of the public accounting information system in Brazil; a...

This article reports the findings of an empirical study about Automated Text Clustering applied to scientific articles and newspaper texts in Brazilian Portuguese, the objective was to find the most effective computational method able to cluster the input of texts in their original groups. The study covered four experiments, each experiment had four procedures: 1. Corpus Selections (a set of texts is selected for clustering), 2. Word Class Selections (Nouns, Verbs and Adjectives are chosen from each text by using specific algorithms), 3. Filtering Algorithms (a set of terms is selected from the results of the preview stage, a semantic weight is also inserted for each term and an index is generated for each text), 4. Clustering Algorithms (the clustering algorithms Simple K-Means, sIB and EM are applied to the indexes). After those procedures, clustering correctness and clustering time statistical results were collected. The sIB clustering algorithm is the best choice for both scientific and newspaper corpus, under the condition that the sIB clustering algorithm asks for the number of clusters as input before running (for the newspaper corpus, 68.9% correctness in 1 minute and for the scientific corpus, 77.8% correctness in 1 minute). The EM clustering algorithm additionally guesses the number of clusters without user intervention, but its best case is less than 53% correctness. Considering the experiments carried out, the results of human text classification and automated clustering are distant; it was also observed that the clustering correctness results vary according to the number of input texts and their topics.