On the r−r-stability of spacelike hypersurfaces

In this paper we study the strong stability of spacelike hypersurfaces with constant $r$-th mean curvature in Generalized Robertson-Walker spacetimes of constant sectional curvature. In particular, we treat the case in which the ambient spacetime is the de Sitter space

Automatic Face Recognition System Based on Local Fourier-Bessel Features

We present an automatic face verification system inspired by known properties of biological systems. In the proposed algorithm the whole image is converted from the spatial to polar frequency domain by a Fourier-Bessel Transform (FBT). Using the whole image is compared to the case where only face image regions (local analysis) are considered. The resulting representations are embedded in a dissimilarity space, where each image is represented by its distance to all the other images, and a Pseudo-Fisher discriminator is built. Verification test results on the FERET database showed that the local-based algorithm outperforms the global-FBT version. The local-FBT algorithm performed as state-of-the-art methods under different testing conditions, indicating that the proposed system is highly robust for expression, age, and illumination variations. We also evaluated the performance of the proposed system under strong occlusion conditions and found that it is highly robust for up to 50% of face occlusion. Finally, we automated completely the verification system by implementing face and eye detection algorithms. Under this condition, the local approach was only slightly superior to the global approach.Comment: 2005, Brazilian Symposium on Computer Graphics and Image Processing, 18 (SIBGRAPI

Thermodynamic, Dynamic and Structural Anomalies for Shoulder-like potentials

Using molecular dynamic simulations we study a family of continuous core-softened potentials consisting of a hard core, a shoulder at closest distances and an attractive well at further distance. The repulsive shoulder and the well distances represent two length scales. We show that if the first scale, the shoulder, is repulsive or has a small well, the potential has a region in the pressure-temperature phase diagram with density, diffusion and structural anomalies. However, if the closest scale becomes a deep attractive well the regions in the pressure-temperature phase diagram where the three anomalies are present shrink and disappear. This result enables us to predict by the shape of the core-softened potential if anomalies would or would not be present

Causas de variação do peso de vacas da raça Canchim criadas em regime de pastagens.

O objetivo do trabalho foi estimar os efeitos de fatores genético e ambientais no peso de vacas da raça Canchim, criadas em regime de pastagens na EMBRAPA-UEPAE, São Carlos, SP

Fatores que influenciam os pesos de bezerros Canchim ao nascimento e a desmama.

Foram analisados os pesos ao nascimento a desmama de 1.404 bezerros Canchim, filhos de touros e nascidos durante o período de 1971 a 1979. Os pesos a desmama foram ajustados para 270 dias pelo ganho médio diário do nascimento e pela regressão do peso observado em função da idade da desmama