A Secure Group Communication Architecture for a Swarm of Autonomous Unmanned Aerial Vehicles

This thesis investigates the application of a secure group communication architecture to a swarm of autonomous unmanned aerial vehicles (UAVs). A multicast secure group communication architecture for the low earth orbit (LEO) satellite environment is evaluated to determine if it can be effectively adapted to a swarm of UAVs and provide secure, scalable, and efficient communications. The performance of the proposed security architecture is evaluated with two other commonly used architectures using a discrete event computer simulation developed using MatLab. Performance is evaluated in terms of the scalability and efficiency of the group key distribution and management scheme when the swarm size, swarm mobility, multicast group join and departure rates are varied. The metrics include the total keys distributed over the simulation period, the average number of times an individual UAV must rekey, the average bandwidth used to rekey the swarm, and the average percentage of battery consumed by a UAV to rekey over the simulation period. The proposed security architecture can successfully be applied to a swarm of autonomous UAVs using current technology. The proposed architecture is more efficient and scalable than the other tested and commonly-used architectures. Over all the tested configurations, the proposed architecture distributes 55.2 – 94.8% fewer keys, rekeys 59.0 - 94.9% less often per UAV, uses 55.2 - 87.9% less bandwidth to rekey, and reduces the battery consumption by 16.9 – 85.4%

Working with interpreters: the challenges of introducing Option Grid patient decision aids

Objective We aimed to observe how an Option GridTM decision aid for clinical encounters might be used where an interpreter is present, and to assess the impact of its use on shared decision making. Methods Data were available from three clinical consultations between patient, clinician (a physiotherapist), and interpreter about knee osteoarthritis. Clinicians were trained in the use of an Option Grid decision aid and the tool was used. Consultations were audio-recorded, transcribed, and translated by independent translators into English. Results Analysis revealed the difficulties with introducing a written decision aid into an interpreted consultation. The extra discussion needed between the clinician and interpreter around the principles and purpose of shared decision making and instructions regarding the Option Grid decision aid proved challenging and difficult to manage. Discussion of treatment options while using an Option Grid decision aid was predominantly done between clinician and interpreter. The patient appeared to have little involvement in discussion of treatment options. Conclusion Patients were not active participants within the discussion. Further work needs to be done on how shared decision making can be achieved within interpreted consultations. Practice Implications Option Grid decision aids are not being used as intended in interpreted consultations

The Newgate novels and drama of the 1830s

SIGLEAvailable from British Library Document Supply Centre- DSC:DXN056759 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Sumario e ideas para la conclusión del Encuentro del Grupo de Investigación de Paisaje (Landscape Research Group).

Sheffield, Reino Unido, 19-20 de noviembre de 2007.Hemos conseguido un admirable resultado en poco más de veinticuatro horas. El que haya podido hacerse tanto recorrido en tan corto tiempo es mérito de los organizadores de este excelente acontecimiento (en particular, Paul Selman y Gareth Roberts), de los patrocinadores que le dieron su generoso apoyo, y de todos ustedes que acudieron aquí para compartir experiencia y conocimiento..

The influence of environmental factors on the generalisability of public health research evidence: physical activity as a worked example

BACKGROUND: It is rare that decisions about investing in public health interventions in a city, town or other location can be informed by research generated in that specific place. It is therefore necessary to base decisions on evidence generated elsewhere and to make inferences about the extent to which this evidence is generalisable to the place of interest. In this paper we discuss the issues involved in making such inferences, using physical activity as an example. We discuss the ways in which elements of the structural, physical, social and/or cultural environment (environmental factors [EFs]) can shape physical activity (PA) and also how EFs may influence the effectiveness of interventions that aim to promote PA. We then highlight the ways in which EFs may impact on the generalisability of different types of evidence. DISCUSSION: We present a framework for thinking about the influence of EFs when assessing the generalisability of evidence from the location in which the evidence was generated (place A) to the location to which the evidence is to be applied (place B). The framework relates to similarities and differences between place A and place B with respect to: a) the distributions of EFs; b) the causal pathways through which EFs or interventions are thought to exert their effect on PA and c) the ways in which EFs interact with each other. We suggest, using examples, how this scheme can be used by public health professionals who are designing, executing, reporting and synthesising research on PA; or designing/implementing interventions. SUMMARY: Our analysis and scheme, although developed for physical activity, may potentially be adapted and applied to other evidence and interventions which are likely to be sensitive to influence by elements of the structural, physical, social and/or cultural environment such as the epidemiology of obesity and healthy weight promotion

A Secure Group Communication Architecture for Autonomous Unmanned Aerial Vehicle

This paper investigates the application of a secure group communication architecture to a swarm of autonomous unmanned aerial vehicles (UAVs). A multicast secure group communication architecture for the low earth orbit (LEO) satellite environment is evaluated to determine if it can be effectively adapted to a swarm of UAVs and provide secure, scalable, and efficient communications. The performance of the proposed security architecture is evaluated with two other commonly used architectures using a discrete event computer simulation developed using MATLAB. Performance is evaluated in terms of the scalability and efficiency of the group key distribution and management scheme when the swarm size, swarm mobility, multicast group join and departure rates are varied. The metrics include the total keys distributed over the simulation period, the average number of times an individual UAV must rekey, the average bandwidth used to rekey the swarm, and the average percentage of battery consumed by a UAV to rekey over the simulation period. The proposed security architecture can successfully be applied to a swarm of autonomous UAVs using current technology. The proposed architecture is more efficient and scalable than the other tested and commonly used architectures. Over all the tested configurations, the proposed architecture distributes 55.2–94.8% fewer keys, rekeys 59.0–94.9% less often per UAV, uses 55.2–87.9% less bandwidth to rekey, and reduces the battery consumption by 16.9–85.4%

Coarse-grained meandering distributive fluvial system of the Basal Cedar mountain formation, U.S.A.

Funding Information: We thank the following for reviews of this manuscript: Associate Editor Tobi Payenberg, Matt Joeckel, two anonymous reviewers, and John Southard. This work was funded by the SAFARI group. We are deeply grateful to Joe Phillips, Sean Kelly, James Mullins, Ryan King, and Jostein Myking Kjærefjord for help in the field.Peer reviewedPostprin