A bank of unscented Kalman filters for multimodal human perception with mobile service robots

A new generation of mobile service robots could be ready soon to operate in human environments if they can robustly estimate position and identity of surrounding people. Researchers in this field face a number of challenging problems, among which sensor uncertainties and real-time constraints. In this paper, we propose a novel and efficient solution for simultaneous tracking and recognition of people within the observation range of a mobile robot. Multisensor techniques for legs and face detection are fused in a robust probabilistic framework to height, clothes and face recognition algorithms. The system is based on an efficient bank of Unscented Kalman Filters that keeps a multi-hypothesis estimate of the person being tracked, including the case where the latter is unknown to the robot. Several experiments with real mobile robots are presented to validate the proposed approach. They show that our solutions can improve the robot's perception and recognition of humans, providing a useful contribution for the future application of service robotics

Observational Search for PeV-EeV Tau Neutrino from GRB081203A

We report the first observational search for tau neutrinos from gamma ray bursts (GRBs) using one of the Ashra light collectors. The earth-skimming tau-neutrino technique of imaging Cherenkov tau showers was applied as a detection method. We set stringent upper limits on the tau-neutrino fluence in PeV-EeV region for 3780 s (between 2.83 and 1.78 hours before) and another 3780 s (between 21.2 and 22.2 hours after) surrounding GRB081203A triggered by the Swift satellite. This first search for PeV-EeV tau neutrino complements other experiments in energy range and methodology, and suggests the prologue of "multi-particle astronomy" with a precise determination of time and location.Comment: 13 pages, 4 figure

On the Mean Convergence Time of Multi-parent Genetic Algorithms Without Selection

Abstract. This paper investigates genetic drift in multi-parent genetic algorithms (MPGAs). An exact model based on Markov chains is pro-posed to formulate the variation of gene frequency. This model iden-tifies the correlation between the adopted number of parents and the mean convergence time. Moreover, it reveals the pairwise equivalence phenomenon in the number of parents and indicates the acceleration of genetic drift in MPGAs. The good fit between theoretical and experi-mental results further verifies the capability of this model.

Ordered nanopore boring in silicon: Metal-assisted etching using a self-aligned block copolymer Au nanoparticle template and gravity accelerated etching

Metal-assisted etching into Si (1 0 0) surfaces can be performed in a highly defined and regular arrangement using self-organized patterns of single-size gold catalyst particles that are block polymer templated on Si surfaces. We show that small size catalyst particles (diameter ≈10 nm) can be forced to maintain straight etch tracks perpendicular to the surface using adequate centrifugal gravity force. This allows the creation of highly ordered uniform and synchronized pore boring into the substrate with single pore diameters in the 10 nm range

Biologia reprodutiva do peixe-donzela, Stegastes fuscus Cuvier, em arrecifes rochosos no nordeste do Brasil

A biologia reprodutiva do peixe-donzela, Stegastes fuscus Cuvier, 1830 (Perciforemes, Pomacentridae), foi estudada nos arrecifes rochosos da praia de Búzios, Nísia Floresta, Rio Grande do Norte, Brasil. Os peixes foram coletados mensalmente, medidos, pesados, dissecados, as gônadas foram removidas, pesadas e examinadas para identificação do sexo. Avaliação macroscópica dos estádios de maturação gonadal foi realizada. Um total de 549 exemplares foi capturado durante o período de outubro de 2004 a setembro de 2005. Foi registrada uma maior freqüência de fêmeas (78%), em relação aos machos (22%). Foi observado que 50% da população das fêmeas e dos machos iniciaram o processo de maturação gonadal com comprimento de 6,2 cm e 7,0 cm, respectivamente. Em relação à fecundidade absoluta, o número de ovócitos vitelogênicos variou entre 1790 a 14780, com média de 6832. A análise da relação gonadossomática para ambos os sexos indicou que o período de fevereiro a agosto de 2005 foi associado a um longo período de repouso gonadal. Os peixes foram considerados aptos à reprodução a partir de janeiro e em setembro-outubro com dois picos de desova registrados nesses meses, com desova do tipo parcelada. Cinco estádios de maturação gonadal foram identificados através de análises macroscópicas das gônadas: imaturo, em maturação, maduro, esgotado e repouso.<br>Reproductive biology of the damselfish, Stegastes fuscus Cuvier, 1830 (Perciformes: Pomacentridae), was studied in the coastal rocky reefs of Búzios Beach, Nísia Floresta, Rio Grande do Norte, Brazil. The fish were captured on a monthly basis, and were measured, weighed, dissected and the gonads were removed, weighed and examined in order to separate males and females. Macroscopic characterization of the stages of gonadal maturation was carried out. A total of 549 samples were captured from October 2004 to September 2005. A higher frequency of females (78%) was registered in relation to males (22%). It was observed that 50% of the population of females and males initiated gonadal maturation with a body size of 6.2 cm and 7.0 cm respectively. In relation to absolute fecundity, the number of vitelogenic oocytes ranged from 1790 to 14780, with mean of 6832. The analysis of gonadosomatic relation indicated that the period of February to August was associated to a long phase of gonadal resting in males and females. Two peaks of partial spawning were registered during January and September-October. Five stages of gonadal maturation were identified through macroscopic analysis: immature, in maturation, mature, spent and resting