Time for Cloud? Design and implementation of a time-based cloud resource management system

The current pay-per-use model adopted by public cloud service providers has influenced the perception on how a cloud should provide its resources to end-users, i.e. on-demand and access to an unlimited amount of resources. However, not all clouds are equal. While such provisioning models work for well-endowed public clouds, they may not always work well in private clouds with limited budget and resources such as research and education clouds. Private clouds also stand to be impacted greatly by issues such as user resource hogging and the misuse of resources for nefarious activities. These problems are usually caused by challenges such as (1) limited physical servers/ budget, (2) growing number of users and (3) the inability to gracefully and automatically relinquish resources from inactive users. Currently, cloud resource management frameworks used for private cloud setups, such as OpenStack and CloudStack, only uses the pay-per-use model as the basis when provisioning resources to users. In this paper, we propose OpenStack Café, a novel methodology adopting the concepts of 'time' and booking systems' to manage resources of private clouds. By allowing users to book resources over specific time-slots, our proposed solution can efficiently and automatically help administrators manage users' access to resource, addressing the issue of resource hogging and gracefully relinquish resources back to the pool in resource-constrained private cloud setups. Work is currently in progress to adopt Café into OpenStack as a feature, and results of our prototype show promises. We also present some insights to lessons learnt during the design and implementation of our proposed methodology in this paper

Probable Innocence Revisited

International audienceOften we wish to ensure that the identity of the user performing a certain action is maintained secret. This property is called anonymity. Examples of situations in which we may wish to provide anonymity include: publishing on the web, retrieving information from the web, sending a message, etc. Many protocols have been designed for this purpose, for example, Crowds [15], Onion Routing [23], the Free Haven [7], Web MIX [1] and Freenet [4]

Using predicted patterns of 3D prey distribution to map king penguin foraging habitat

FUNDING The at-sea data collection and 50% of CLG’s Ph.D. studentship was provided by the Swiss Polar Institute as a grant ‘Unlocking the Secrets of the False Bottom’ to ASB. The School of Biology, University of St Andrews, funded the other 50% of CLG’s studentship. Work at South Georgia was supported by the Natural Environment Research Council’s Collaborative Antarctic Science Scheme (CASS-129), a grant from the TransAntarctic Association grant to RBS, and a British Antarctic Survey Collaborative Gearing Scheme grant to RBS and ASB. ASB and RP were supported in part by UKRI/NERC under grant NE/R012679/1. ACKNOWLEDGMENTS We thank the staff at the British Antarctic Survey base at King Edward Point (South Georgia), Quark Expeditions and the crew and staff of the Ocean Endeavour and the FPV Pharos South Georgia for their help with the fieldwork logistics. We also thank the Swiss Polar Institute and the ACE foundation for funding our ACE project, and all our colleagues who assisted with acoustic data collection at sea: Matteo Bernasconi, Inigo Everson, and Joshua Lawrence. We thank Yves Cherel for fruitful discussion on the role of prey patches for king penguins in the Kerguelen region. We also thank C. Ribout and the Centre for Biological Studies of Chizé for conducting the sexing analyses of the birdsPeer reviewedPublisher PD

Probabilistic Anonymity

The concept of anonymity comes into play in a wide range of situations, varying from voting and anonymous donations to postings on bulletin boards and sending mails. A formal definition of this concept has been given in literature in terms of nondeterminism. In this paper, we investigate a notion of anonymity based on probability theory, and we we discuss the relation with the nondeterministic one. We then formulate this definition in terms of observables for processes in the probabilistic $pi$-calculus, and propose a method to verify automatically the anonymity property. We illustrate the method by using the example of the dining cryptographers

Pećnjaci Garić grada

Funding: This work was supported by the EU Horizon 2020 project, Team-Play (https://www.teamplay-h2020.eu), grant number 779882, and UK EPSRC Discovery, grant number EP/P020631/1.Energy, Time and Security (ETS) properties of programs are becoming increasingly prioritised by developers, especially where applications are running on ETS sensitive systems, such as embedded devices or the Internet of Things. Moreover, developers currently lack tools and language properties to allow them to reason about ETS. In this paper, we introduce a new contract specification frame-work, called Drive, which allows a developer to reason about ETS or other non-functional properties of their programs as first-class properties of the language. Furthermore, we introduce a contract specification language, allowing developers to reason about these first-class ETS properties by expressing contracts that are proved correct by an underlying formal type system. Finally, we show our contract framework over a number of representable examples, demonstrating provable worst-case ETS properties.Postprin

Effects of Ving Tsun Chinese martial art training on musculoskeletal health, balance performance, and self-efficacy in community-dwelling older adults

[Purpose] The aim of this study was to investigate the effects of Ving Tsun (VT) Chinese martial art training on radial bone strength, upper- and lower-limb muscular strength, shoulder joint mobility, balance performance, and self-efficacy in elderly participants. [Subjects and Methods] Twelve seniors voluntarily joined the VT training group, and twenty-seven seniors voluntarily joined the control group. The VT group received VT training for three months, while the control group received no training. The bone strength of the distal radius was assessed using an ultrasound bone sonometer. Muscular strength in the limbs was evaluated using a Jamar handgrip dynamometer and the five times sit-to-stand test. Shoulder joint mobility was examined using a goniometer. Balance performance and self-efficacy were evaluated using the Berg Balance Scale and the Chinese version of the Activities-specific Balance Confidence Scale, respectively. [Results] The results revealed a nonsignificant group-by-time interaction effect, group effect, and time effect for all outcome variables. However, general trends of maintenance or improvement in all outcome parameters were observed to a greater extent in the VT group than in the control group. [Conclusion] VT training might be a potential fall-prevention exercise that can be used to maintain general physique, balance, and confidence in the elderly population. A further randomized controlled trial is needed to confirm this postulation

Gazette de Bayonne, de Biarritz et du Pays basque

30 mars 19351935/03/30 (A44,N8246).Appartient à l’ensemble documentaire : Aquit