Statistical Audit via Gaussian Mixture Models in Business Intelligence Systems

A Business Intelligence (BI) System employs tools from several areas of knowledge for the collection, integration and analysis of data to improve business decision making. The Brazilian Ministry of Planning, Budget and Management (MP) uses a BI System designed with the University of Bras´ılia to ascertain irregularities on the payroll of the Brazilian federal government, performing audit trails on selected items and fields of the payroll database. This current auditing approach is entirely deterministic, since the audit trails look for previously known signatures of irregularities which are composed by means of an ontological method used to represent auditors concept maps. In this work, we propose to incorporate a statistical filter in this existing BI system in order to increase its performance in terms of processing speed and overall system responsiveness. The proposed statistical filter is based on a generative Gaussian Mixture Model (GMM) whose goal is to provide a complete stochastic model of the process, specially the latent probability density function of the generative mixture, and use that model to filter the most probable payrolls. Inserting this statistical filter as a pre-processing stage preceding the deterministic auditing showed to be effective in reducing the amount of data to be analyzed by the audit trails, despite the penalty fee intrinsically associated with stochastic models due to the false negative outcomes that are not further processed. In our approach, gains obtained with the proposed pre-processing stage overcome impacts from false negative outcomes

On the Electronic Structure of a Recently Synthesized Graphene-like BCN Monolayer from bis-BN Cyclohexane: A DFT Study

Since the rising of graphene, boron nitride monolayers have been deeply studied due to their structural similarity with the former. A hexagonal graphene-like boron-carbon-nitrogen (h-BCN) monolayer was synthesized recently using bis-BN cyclohexane (B2N2C2H12) as a precursor molecule. Herein, we investigated the electronic and structural properties of this novel BCN material, in the presence of single-atom (boron, carbon, or nitrogen) vacancies, by employing density functional theory calculations. The stability of these vacancy-endowed structures is verified from cohesion energy calculations. Results showed that a carbon atom vacancy strongly distorts the lattice leading to breaking on its planarity and bond reconstructions. The single-atom vacancies induce the appearance of flat midgap states. A significant degree of charge localization takes place in the vicinity of these defects. It was observed a spontaneous magnetization only for the boron-vacancy case, with a magnetic dipole moment about 0.87 mu_B. Our calculations predicted a direct electronic bandgap value of about 1.14 eV, which is in good agreement with the experimental one. Importantly, this bandgap value is intermediate between gapless graphene and insulating h-BN.Comment: 9 pages, 4 figure

Data security and trading framework for smart grids in neighborhood area networks

Due to the drastic increase of electricity prosumers, i.e., energy consumers that are also producers, smart grids have become a key solution for electricity infrastructure. In smart grids, one of the most crucial requirements is the privacy of the final users. The vast majority of the literature addresses the privacy issue by providing ways of hiding user’s electricity consumption. However, open issues in the literature related to the privacy of the electricity producers still remain. In this paper, we propose a framework that preserves the secrecy of prosumers’ identities and provides protection against the traffic analysis attack in a competitive market for energy trade in a Neighborhood Area Network (NAN). In addition, the amount of bidders and of successful bids are hidden from malicious attackers by our framework. Due to the need for small data throughput for the bidders, the communication links of our framework are based on a proprietary communication system. Still, in terms of data security, we adopt the Advanced Encryption Standard (AES) 128bit with Exclusive-OR (XOR) keys due to their reduced computational complexity, allowing fast processing. Our framework outperforms the state-of-the-art solutions in terms of privacy protection and trading flexibility in a prosumer-to-prosumer design

Electronic and Structural Properties of Janus SMoSe/MoX2_2 (X=S,Se) In-plane Heterojunctions: A DFT Study

The electronic and structural properties of Janus MoSSe/MoX$_2$ (X=S,Se) in-plane heterojunctions, endowed with single-atom vacancies, were studied using density functional theory calculations. The stability of these structures was verified from cohesion energy calculations. Results showed that single-atom vacancies induce the appearance of flat midgap states, and a substantial amount of charge is localized in the vicinity of these defects. As a consequence, these heterojunctions presented an intrinsic dipole moment. No bond reconstructions were noted by removing an atom from the lattice, regardless of its chemical species. Our calculations predicted indirect electronic bandgap values between 1.6-1.7 eV.Comment: 10 pages, 5 Figure

DESAFIOS E APRENDIZADOS DAS AÇÕES DE EDUCAÇÃO AMBIENTAL NA OCUPAÇÃO VISTA ALEGRE DO JUÁ, SANTARÉM, PARÁ

O recorrente aumento das zonas urbanas e a redução das áreas arborizadas acarretam baixa qualidade aos ambientes de convivência social. A educação ambiental entra como ferramenta auxiliadora de criação e manutenção dessas áreas. Com objetivo de contribuir para a qualidade ambiental em uma zona de ocupação irregular no município de Santarém, Pará, desenvolveu-se um trabalho de arborização, atrelando ações educativas, associando preservação e educação. Procedeu-se com a atividades de produção de mudas e plantio de espécies arbóreas, junto a práticas educacionais voltadas a educação ambiental, como discussão de temáticas ambientais. Foram desenvolvidas atividades de contação de histórias, construção de maquetes e desenhos, além de práticas de produção de mudas, compostagem, plantio e cuidados com as espécies arbóreas. Ocorreu contribuição significativa para com as crianças e jovens, na formação de uma consciência crítica, incentivando-as a agir de maneira mais ativa dentro do contexto abordado. Palavras-chave: Educação ambiental; produção de mudas; compostagem; consciência ecológica

The relationship between genetic risk variants with brain structure and function in bipolar disorder: A systematic review of genetic-neuroimaging studies

Genetic-neuroimaging paradigms could provide insights regarding the pathophysiology of bipolar disorder (BD). Nevertheless, findings have been inconsistent across studies. A systematic review of gene-imaging studies involving individuals with BD was conducted across electronic major databases from inception until January 9th, 2017. Forty-four studies met eligibility criteria (N=2122 BD participants). Twenty-six gene variants were investigated across candidate gene studies and 4 studies used a genome-wide association approach. Replicated evidence (i.e. in >2 studies) suggests that individuals with BD carrying the BDNF Val66Met risk allele could have reduced hippocampal volumes compared to non-carriers. This review underscores the potential of gene-neuroimaging paradigms to provide mechanistic insights for BD. However, this systematic review found a single replicated finding. Suggestions to improve the reproducibility of this emerging field are provided, including the adoption of a trans-diagnostic approac

Early improvement of psychotic symptoms with lithium monotherapy as a predictor of later response in mania

Although lithium has been the first line agent in the treatment of bipolar disorder (BD), few studies have evaluated lithium's efficacy in mania with psychosis and its association with later response. Furthermore, given the widespread concern about antipsychotic side effects, answering a question about whether lithium alone can manage to treat both psychotic and non-psychotic mania seems a very relevant one. The present study addresses the antipsychotic efficacy of lithium monotherapy in acute mania and early improvement of psychotic symptoms as a predictor of later response of manic symptoms. Forty-six patients presenting a manic episode (32 with psychotic features and 14 subjects without psychotic features) were treated for 4 weeks with lithium monotherapy and evaluated weekly using the Young Mania Rating Scale (YMRS). Subjects with rapid cycling, substance abuse/dependence, or mixed episodes were excluded. The overall antimanic efficacy of lithium in psychosis vs. non-psychosis groups was evaluated. In addition, early improvement of psychotic symptoms and its prediction of subsequent response (>50% decrease in total YMRS scores) or remission were evaluated. Lithium showed a similar efficacy in both psychosis and non-psychosis mania. Early improvement of psychotic symptoms was associated with clinical response and remission at endpoint. (C) 2012 Elsevier Ltd. All rights reserved.Stanley Medical Research Institute [03T-356