Review of Person Re-identification Techniques

Person re-identification across different surveillance cameras with disjoint fields of view has become one of the most interesting and challenging subjects in the area of intelligent video surveillance. Although several methods have been developed and proposed, certain limitations and unresolved issues remain. In all of the existing re-identification approaches, feature vectors are extracted from segmented still images or video frames. Different similarity or dissimilarity measures have been applied to these vectors. Some methods have used simple constant metrics, whereas others have utilised models to obtain optimised metrics. Some have created models based on local colour or texture information, and others have built models based on the gait of people. In general, the main objective of all these approaches is to achieve a higher-accuracy rate and lowercomputational costs. This study summarises several developments in recent literature and discusses the various available methods used in person re-identification. Specifically, their advantages and disadvantages are mentioned and compared.Comment: Published 201

Adubos verdes e seus efeitos no rendimento da cana-de-açúcar em sistema de plantio direto.

O objetivo deste trabalho foi avaliar adubos verdes e seus efeitos no rendimento da cana-de-açúcar em sistema de plantio direto (SPD). O trabalho foi realizado em Campos dos Goytacazes (RJ), no período de dezembro de 2003 a julho de 2005. O delineamento experimental foi em blocos casualizados, com quatro repetições. Os tratamentos foram: feijão-de-porco (Canavalia ensiformis), mucuna-preta(Mucuna aterrimum), crotalária (Crotalária juncea) em plantio direto e vegetação espontânea em preparo convencional (testemunha). Com crotalária aos 35 dias após emergência (DAE) houve maior taxa de cobertura do solo – 87% – e, aos 92 DAE produziu 17.852 kg ha-1 de matéria seca, respectivamente, 41%, 78% e 407% superior ao feijão-de-porco, mucuna e vegetação espontânea, além de superá-las em acúmulos de K, Mg, S, Zn e Fe. O feijão-de-porco e a mucuna proporcionaram o maior teor de N na parte aérea. Com feijão-de-porco, os teores de P e Ca foram maiores que a crotalária e a mucuna. Com vegetação espontânea, o maior teor de K foi na parte aérea. As leguminosas acumularam maiores quantidades de N e Cu do que a vegetação espontânea. A crotalária e o feijão-de-porco acumularam 66% a mais de P na parte área que a mucuna. O SPD utilizando a adubação verde contribuiu significativamente para a maior produtividade de cana-de-açúcar, 135.863 kg ha-1, sendo 37% superior ao PC com a vegetação espontânea

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

We present the results of searches for dipolar-type anisotropies in different energy ranges above $2.5\times 10^{17}$ eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% $C.L.$ for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.Comment: 28 pages, 11 figure