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TubeSpam: filtragem automática de comentários indesejados postados no YouTube
(Universidade Federal de São Carlos, 2017-02-03) Alberto, Túlio Casagrande; Almeida, Tiago Agostinho de; https://lattes.cnpq.br/5368680512020633; https://lattes.cnpq.br/0353538405905082
YouTube has become an important video sharing platform. Several users regularly produce video content and make this task their main livelihood. However, such success is also drawing the attention of malicious users propagating undesired comments and videos, looking for self-promotion or disseminating malicious links which may have malwares and viruses. Since YouTube offers limited tools for blocking spam, the volume of such messages is shockingly increasing and harming users and channels owners. In addition to the problem being naturally online, comment spam filtering on YouTube is different than the traditional email spam filtering, since the messages are very short and often rife with spelling errors, slangs, symbols and abbreviations. This manuscript presents a performance evaluation of traditional online classification methods, aided by lexical normalization and semantic indexing techniques when applied to automatic filter YouTube comment spam. It was also evaluated the performance of MDLText, a promising text classification method based on the minimum description length principle. The statistical analysis of the results indicates that MDLText, Passive-Aggressive, Naïve Bayes, MDL and Online Gradient Descent obtained statistically equivalent performances. The results also indicate that the lexical normalization and semantic indexing techniques are effective to be applied to the problem. Based on the results, it is proposed and designed TubeSpam, an online tool to automatic filter undesired comments posted on YouTube.
Proposta de um modelo para a gestão da qualidade na cadeia da produção da cana-de-açúcar no estado de São Paulo
(Universidade Federal de São Carlos, 2017-02-03) Palota, Paulo Henrique; Martins, Manoel Fernando; https://lattes.cnpq.br/3921504261628850; https://lattes.cnpq.br/9058966903654835
The sugarcane generates income for the country through the exportation of sugar, ethanol and more recently through energy cogeneration. The globalization and the fact that the prices of the main sugarcane products are linked to commodities exchange and futures, the sugarcane agricultural industry needs to be competitive in each of the chain agents that comprise it. In this context, the quality of sugarcane is of great importance for the sugarcane chain to be competitive. Total Recoverable Sugar (TRS), which is the main quality requirement of sugarcane as it represents the amount of sugar present in sugarcane, fell by around 10% between the years 2009 and 2015. Other quality requirements for sugarcane as mineral and vegetable impurities increased 18.8% and 42.86% between 2008 and 2013, respectively. These factors justify a model for Quality Management of sugarcane. The main objective of this work is to propose a model for the management of quality in the sugarcane production chain that adds value to it. This model is based on the concepts of integration and Supply Chain Quality Management theory in Chain Supply and Supply Chain Quality Coordination in Agro-Food Production. An empirical investigation of multiple cases is carried out in the main agents of the sugarcane production chain in order to identify the deficiencies and the virtues in light of these theories so that they can provide subsidies for the proposal of the model. The results of this research show that, in most cases, there is no integration between the segments of the chain links of sugarcane both upstream and downstream. The model is evaluated by industry experts. This evaluation demonstrated that the model is capable and sufficient in terms of information to meet the needs of its application, has terms of easy understanding to users and is flexible the characteristics of users. In addition to contain elements necessary for quality coordination, contributing to the improvement and preservation of the quality in the product and to reduce costs and losses in the stages of this production chain.
Análise das respostas ventilatórias, metabólicas e do controle autonômico cardiovascular durante testes de resistência muscular inspiratória e de determinação da pressão inspiratória crítica
(Universidade Federal de São Carlos, 2017-02-03) Minatel, Vinicius; Catai, Aparecida Maria; https://lattes.cnpq.br/5801652590531684; https://lattes.cnpq.br/2451652025356071
Respiratory muscle weakness has a strong relationship with autonomic cardiovascular control dysfunction and exercise limitation. For this reason, inspiratory muscle training programs (IMT) have been applied to improve respiratory muscle strength/endurance, exercise performance and autonomic cardiovascular control. However, the optimal IMT intensity to induce a better systemic response has not been defined yet. Therefore, we developed our First Study, that aimed to identify the inspiratory critical pressure (PThC) using the critical power model in healthy men, evaluate the ventilatory and metabolic responses at the PThC and identify the predictors variables of PThC and propose an equation to obtain it. The participants of the study (n=79) underwent the PThC protocol, which consisted of a progressive inspiratory threshold-loading test to set the sustained maximal inspiratory load (PThMAX). In a subsequent visit was carried out a constant load inspiratory exercise protocol (95%, 100% and 105%PThMAX). Both tests were performed until task failure using a linear inspiratory load resistor connected in series to a gas exchange analysis system. The inspiratory endurance time for each load was used to calculate the PThC, and the resulting value was tested using a constant load protocol performed in a different day from previous tests. Results showed that PThC was influenced by age and weight (R=0.66, R2=0.43, p<0.001) and corresponded to 90.9±4.9%PTHMAX. Moreover, PThMAX (R=0.96; R2=0.92, p<0.001) was the main determinant in the proposed equation. Additionally, we observed an inadequate ventilatory response, reduced inspiratory muscle efficiency and increased perceived effort at the end of inspiratory endurance exercise at PThC. Furthermore, the equation developed in the present study will allow to determine the PThC in a single visit, which is fundamental for the implementation of an IMT program using this load in future studies. As for the autonomic cardiovascular control, there is no consensus on the effects of IMT on the autonomic nervous system (ANS) responses. This is due to the fact that no studies were performed to evaluate the cardiovascular responses during high-intensity inspiratory endurance exercise, nor to evaluate autonomic cardiac control through non-linear methods. Therefore, our Second Study aim was to evaluate the effect of high-intensity inspiratory endurance exercise on heart rate variability (HRV) using linear and non-linear approaches. The healthy young participants of this study (n=20) performed different high-intensity inspiratory endurance exercises (80%, 95%, 100%PThMAX and PThc), which consisted in constant load tests until task failure. Moreover, the heart rate dynamics baseline (WITHOUT mouthpiece, WITH mouthpiece and SHAM) was collected in sitting position. The results of this study showed that symbolic analysis identified a more pronounced increase in sympathetic modulation (0V%) when severe exercise intensity loads were applied (95% and 100%PThMAX) (p<0.001). Increased sympathetic modulation was associated with an increase in metabolic demand (VO2) and changes in the respiratory pattern (Ti/Ttot) (p<0.001). As observed, breathing pattern has a great impact on the dynamics of autonomic cardiac control; however, the use of an inspiratory resistance load may potentiate changes in cardiovascular dynamics. Thus, the aim of our Third Study was to characterize the baroreflex sensitivity (BRS) behavior during high-intensity inspiratory endurance exercise using the sequence method (αSEQ), transfer function spectral analysis (αFT(BF)) and the closed loop model (αCL). The participants and the experimental protocol were the same reported in the Second Study. Results 3 showed that there is a decrease in BRS during high-intensity inspiratory endurance exercise when compared to rest conditions (p<0.001), and that all the methods applied in this study were efficient for BRS characterization. However, αFT(BF) was the most effective index to quantify the effects of inspiratory load on the autonomic cardiovascular control evaluated by BRS. Conclusions: the results of the present thesis showed that the concept of critical power can be applied to the inspiratory muscles to determine the PThC, which marks the transition between intense and severe inspiratory exercise. In addition, acute ventilatory, metabolic and autonomic cardiovascular control responses (HRV and BRS) observed during acute high-intensity inspiratory endurance exercise allow us to extend the PThC use to assess inspiratory muscle performance and to prescribe a high-intensity IMT program until PThC in populations like that studied in this thesis.