No abstract

Abstract-The ability to filter improper content from multimedia sources based on visual content has important applications, since text-based filters are clearly insufficient against erroneous and/or malicious associations between text and actual content. In this paper, we investigate a method for detection of nudity in videos based on a bag-of-visual-features representation for frames and an associated voting scheme.Bag-of-Visual-Features (BoVF) approaches have been successfully applied to object recognition and scene classification, showing robustness to occlusion and also to the several kinds of variations that normally curse object detection methods. To the best of our knowledge, only two proposals in the literature use BoVF for nude detection in still images, and no other attempt has been made at applying BoVF for videos. Nevertheless, the results of our experiments show that this approach is indeed able to provide good recognition rates for nudity even at the frame level and with a relatively low sampling ratio. Also, the proposed voting scheme significantly enhances the recognition rates for video segments, achieving, in the best case, a value of 93.2% of correct classification, using a sampling ratio of 1/15 frames. Finally, a visual analysis of some particular cases indicates possible sources of misclassifications.

This study tested the ecological apparency hypothesis in the community of Barroquinha, in the municipality of Lagoa, Paraíba State, Brazil. We used the Use Value (UV) by testing the information obtained through three types of calculations: UV general , UV current , and UV potential . The botanical sampling was conducted in two areas of the community (Preserved -A1; Degraded -A2), and interviews were carried out with 66 people, who signed a Free and Transparent Consent form, required by the Research Ethics Committee. The Spearman's correlation test was performed to relate phytosociological data to ethnobotanical data. We used the Pearson Correlation to test the correlation between genders and the Use Values (UVs). Fifteen useful species were recorded in A1 and 16 species in A2. Positive correlations were found in both areas between species and the phytosociological data: in A1 between UV current with basal area and dominance (p < 0.05) and in A2 between UV general and UV current with all parameters (p < 0.05). Only the forage category showed a positive correlation in A1 between UV potential and density and frequency (p < 0.05). In A2, the fuel category was correlated with UV current and basal area and dominance (p < 0.05). There was positive correlation between UV general /UV current , UV general /UV potential , UV current /UV potential (p < 0.0001). Men and women considered the same species as the most important (p < 0.0001). According to the results of this study, we can conclude that ecological apparency best explains the relationship between use and availability of species used for timber.

BackgroundThis study aimed to investigate the local botanical knowledge of native food plants in three rural communities, located in the semiarid region of Paraíba State, Brazil, verifying possibilities of differences of knowledge among communities and between men and women.MethodsSemi-structured interviews about native plant knowledge and use were conducted with all householders in each community, totaling 117 informants. The species similarity among the communities of Pau D’Arco, Várzea Alegre, and Barroquinha was compared with Jaccard index, and the use value index (UVgeneral, UVcurrent, UVpotential) was used to determine the most important species. The Kruskal-Wallis test was used to compare the use values among communities and genders. The consensus factor among the informants was calculated according to the uses cited, and the Wilcoxon test was used to compare the use values between men and women.ResultsWe recorded 9 species belonging to 8 genera and 8 families in Várzea Alegre; 10 species, 9 genera, and 9 families in Barroquinha; and 7 species, 7 genera and 7 families in Pau D’Arco. Spondias tuberosa Arruda (Anacardiaceae) in Várzea Alegre, Spondias sp. (Anacardiaceae) in Barroquinha, and Ximenia americana L. (Olacaceae) in Pau D’Arco were the most prominent species. Preparation methods are slightly different in the three communities, and there is low similarity about species use among the communities. Regarding gender, the analysis of use value among the communities evidenced significant differences only for UVgeneral among women, specifically between Barroquinha and Pau D’Arco. For men and women within each community, there is a difference only for UVpotential in Barroquinha.ConclusionThis study showed that the residents of the three rural communities have limited knowledge of native food plants found in their communities, but they know where to find them, which parts they may use and how to consume them. The fact is that men know plants that are more distant from the residences and women know those that are next to them.

No abstract