Indoor localization and navigation for blind persons using visual landmarks and a GIS

In an unfamiliar environment we spot and explore all available information which might guide us to a desired location. This largely unconscious processing is done by our trained sensory a nd cognitive systems. These recognize and memorize sets of landmarks which allow us to create a mental map of the envi ronment, and this map enables us to navigate by exploiting very few but the most important landmarks stored in our memory. We present a system which integrates a geographic information system of a building with visu al landmarks for localizing the user in the building and for tracing and validating a route for the user's navigation. Hence, the developed system complements the white cane for improving the user's autonomy during indoor navigation. Although de signed for visually impaired persons, the system can be used by any person for wayfinding in a complex building

Analyzing Trails in Complex Networks

Even more interesting than the intricate organization of complex networks are the dynamical behavior of systems which such structures underly. Among the many types of dynamics, one particularly interesting category involves the evolution of trails left by moving agents progressing through random walks and dilating processes in a complex network. The emergence of trails is present in many dynamical process, such as pedestrian traffic, information flow and metabolic pathways. Important problems related with trails include the reconstruction of the trail and the identification of its source, when complete knowledge of the trail is missing. In addition, the following of trails in multi-agent systems represent a particularly interesting situation related to pedestrian dynamics and swarming intelligence. The present work addresses these three issues while taking into account permanent and transient marks left in the visited nodes. Different topologies are considered for trail reconstruction and trail source identification, including four complex networks models and four real networks, namely the Internet, the US airlines network, an email network and the scientific collaboration network of complex network researchers. Our results show that the topology of the network influence in trail reconstruction, source identification and agent dynamics.Comment: 10 pages, 16 figures. A working manuscript, comments and criticisms welcome

Competição de variedades de macaxeira (Manihot esculenta, L.) para agricultura familiar, no Município de Salvaterra, Marajó - Pa.

Edição dos Anais do XIII Congresso Brasileiro de Mandioca; VII Workshop sobre Tecnologia em Agroindústrias de Tuberosas Tropicais, Botucatu, 2009. Disponível também on-line

Resposta da mandioca (Manihot esculenta, L.), variedade Poti, à doses de N, P, K no Município de Salvaterra, Marajó - Pará.

Edição dos Anais do XIII Congresso Brasileiro de Mandioca; VII Workshop sobre Tecnologia em Agroindústrias de Tuberosas Tropicais, Botucatu, 2009. Disponível também on-line