124 resultados para Access

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper details a researcher's experience of gaining access to three statutory social work agencies in order to conduct a study examining how social workers respond to family support cases and how parents and carers experience the intervention of social workers in these cases. The stages in gaining access are outlined, the gate-keepers involved at each stage are identified and some of the difficulties encountered are highlighted and discussed. The paper concludes that researchers need to give greater priority to access considerations and that social work agencies need to give greater priority to co-operation with researchers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Wireless enabled portable devices must operate with the highest possible energy efficiency while still maintaining a minimum level and quality of service to meet the user's expectations. The authors analyse the performance of a new pointer-based medium access control protocol that was designed to significantly improve the energy efficiency of user terminals in wireless local area networks. The new protocol, pointer controlled slot allocation and resynchronisation protocol (PCSAR), is based on the existing IEEE 802.11 point coordination function (PCF) standard. PCSAR reduces energy consumption by removing the need for power saving stations to remain awake and listen to the channel. Using OPNET, simulations were performed under symmetric channel loading conditions to compare the performance of PCSAR with the infrastructure power saving mode of IEEE 802.11, PCF-PS. The simulation results demonstrate a significant improvement in energy efficiency without significant reduction in performance when using PCSAR. For a wireless network consisting of an access point and 8 stations in power saving mode, the energy saving was up to 31% while using PCSAR instead of PCF-PS, depending upon frame error rate and load. The results also show that PCSAR offers significantly reduced uplink access delay over PCF-PS while modestly improving uplink throughput.