32 resultados para disaster
Resumo:
Launched with considerable fanfare in 1969, the Committee on the Challenges of Modern Society (CCMS) was supposed to bring new life to NATO by both re-energising public support and engaging with a variety of themes, issues and partners well beyond the alliance’s traditional scope. The first aim of this article is to go beyond the careful media operation that surrounded the launch of the CCMS and to examine the scepticism and resistance of some European partners, particularly the British. The second aim is to demonstrate that NATO started to think in terms of crisis management, disaster relief and environmental disasters well before 1989. The sheer military strength of the alliance and of its partners did remain central – and notably came back to the forefront in 1979 – but the alliance did start to see itself as a geopolitical player and to consider engagement beyond its strictly defined geographical area as early as 1969.
Resumo:
Wireless Sensor Networks (WSNs) have been an exciting topic in recent years. The services offered by a WSN can be classified into three major categories: monitoring, alerting, and information on demand. WSNs have been used for a variety of applications related to the environment (agriculture, water and forest fire detection), the military, buildings, health (elderly people and home monitoring), disaster relief, and area or industrial monitoring. In most WSNs tasks like processing the sensed data, making decisions and generating emergency messages are carried out by a remote server, hence the need for efficient means of transferring data across the network. Because of the range of applications and types of WSN there is a need for different kinds of MAC and routing protocols in order to guarantee delivery of data from the source nodes to the server (or sink). In order to minimize energy consumption and increase performance in areas such as reliability of data delivery, extensive research has been conducted and documented in the literature on designing energy efficient protocols for each individual layer. The most common way to conserve energy in WSNs involves using the MAC layer to put the transceiver and the processor of the sensor node into a low power, sleep state when they are not being used. Hence the energy wasted due to collisions, overhearing and idle listening is reduced. As a result of this strategy for saving energy, the routing protocols need new solutions that take into account the sleep state of some nodes, and which also enable the lifetime of the entire network to be increased by distributing energy usage between nodes over time. This could mean that a combined MAC and routing protocol could significantly improve WSNs because the interaction between the MAC and network layers lets nodes be active at the same time in order to deal with data transmission. In the research presented in this thesis, a cross-layer protocol based on MAC and routing protocols was designed in order to improve the capability of WSNs for a range of different applications. Simulation results, based on a range of realistic scenarios, show that these new protocols improve WSNs by reducing their energy consumption as well as enabling them to support mobile nodes, where necessary. A number of conference and journal papers have been published to disseminate these results for a range of applications.