Analysis of detection performance in spectrum sensing optimisation for long sensing periods

Spectrum sensing optimisation techniques maximise the efficiency of spectrum sensing while satisfying a number of constraints. Many optimisation models consider the possibility of the primary user changing activity state during the secondary user's transmission period. However, most ignore the possibility of activity change during the sensing period. The observed primary user signal during sensing can exhibit a duty cycle which has been shown to severely degrade detection performance. This paper shows that (a) the probability of state change during sensing cannot be neglected and (b) the true detection performance obtained when incorporating the duty cycle of the primary user signal can deviate significantly from the results expected with the assumption of no such duty cycle.

The source of the good faith obligation in the performance and enforcement of commercial contracts

There are many issues associated with good faith that will ultimately confront the Australian High Court and a number of these have been well canvassed. However, one significant issue has attracted relatively little comment. To date, a number of Australian courts (lower in the judicial hierarchy) have been prepared to hold directly, tacitly accept or assume (without making a final determination) that good faith is implied (as a matter of law) in the performance and enforcement of a very broad class of contract, namely commercial contracts per se. This broad approach is demonstrated in decisions from the Federal Court, the New South Wales Court of Appeal, the Supreme Courts of Victoria and Western Australia and has crept into pleadings in commercial matters in Queensland

Remote monitoring of outdoor performance of low scale dye sensitized solar cells for nanosensors nodes

This is the first outdoor test of small-scale dye sensitized solar cells (DSC) powering a stand-alone nanosensor node. A solar cell test station (SCTS) has been developed using standard DSC to power a gas nanosensor, a radio transmitter, and the control electronics (CE) for battery charging. The station is remotely monitored through wired (Ethernet cable) or wireless connection (radio transmitter) in order to evaluate in real time the performance of the solar cells and devices under different weather conditions. The 408 cm2 active surface module produces enough energy to power a gas nanosensor and a radio transmitter during the day and part of the night. Also, by using a programmable load we keep the system working on the maximum power point (MPP) quantifying the total energy generated and stored in a battery. These experiments provide useful data for future outdoor applications such as nanosensor networks.