953 resultados para road safety application
Resumo:
Nowadays, road safety and traffic congestion are major concerns worldwide. This is why research on vehicular communication is very vital. In static scenarios vehicles behave typically like in an office network where nodes transmit without moving and with no defined position. This paper analyses the impact of context information on existing popular rate adaptation algorithms. Our simulation was done in MATLAB by observing the impact of context information on these algorithms. Simulation was performed for both static and mobile cases.Our simulations are based on IEEE 802.11p wireless standard. For static scenarios vehicles do not move and without defined positions, while for the mobile case, vehicles are mobile with uniformly selected speed and randomized positions. Network performance are analysed using context information. Our results show that in mobility when context information is used, the system performance can be improved for all three rate adaptation algorithms. That can be explained by that with range checking, when many vehicles are out of communication range, less vehicles contend for network resources, thereby increasing the network performances. © 2013 IEEE.
Resumo:
Wireless-communication technology can be used to improve road safety and to provide Internet access inside vehicles. This paper proposes a cross-layer protocol called coordinated external peer communication (CEPEC) for Internet-access services and peer communications for vehicular networks. We assume that IEEE 802.16 base stations (BS) are installed along highways and that the same air interface is equipped in vehicles. Certain vehicles locating outside of the limited coverage of their nearest BSs can still get access to the Internet via a multihop route to their BSs. For Internet-access services, the objective of CEPEC is to increase the end-to-end throughput while providing a fairness guarantee in bandwidth usage among road segments. To achieve this goal, the road is logically partitioned into segments of equal length. A relaying head is selected in each segment that performs both local-packet collecting and aggregated packets relaying. The simulation results have shown that the proposed CEPEC protocol provides higher throughput with guaranteed fairness in multihop data delivery in vehicular networks when compared with the purely IEEE 802.16-based protocol.
Resumo:
This paper reports on a work-in-progress project on the management of patient knowledge in a UK general hospital. Greater involvement of patients is generally seen as crucial to the effective provision of healthcare in the future. However, this presents many challenges, especially in the light of the ageing population in most developed countries and the consequent increasing demand for healthcare. In the UK, there have been many attempts to increase patient involvement by the systematisation of patient feedback, but typically they have not been open to academic scrutiny or formal evaluation, nor have they used any knowledge management principles. The theoretical foundations for this project come first from service management and thence from customer knowledge management. Service management stresses the importance of the customer perspective. Healthcare clearly meets the definitions of a service even though it may also include some tangible elements such as surgery and provision of medication. Although regarding hospital patients purely as "customers" is a viewpoint that needs to be used with care, application of the theory offers potential benefits in healthcare. The two main elements we propose to use from the theory are the type of customer knowledge and its relationship to attributes of the quality of the service provided. The project is concerned with investigating various knowledge management systems (KMS) that are currently in use (or proposed) to systematise patient feedback in an NHS Trust hospital, to manage knowledge from and to a lesser extent about patients. The study is a mixed methods (quantitative and qualitative) action research investigation intended to answer the following three research questions: • How can a KMS be used as a mechanism to capture and evaluate patient experiences to provoke patient service change • How can the KMS assist in providing a mechanism for systematising patient engagement? • How can patient feedback be used to stimulate improvements in care, quality and safety?