8,253 research outputs found
Design and Experimental Evaluation of a Route Optimisation Solution for NEMO
An important requirement for Internet protocol (IP)
networks to achieve the aim of ubiquitous connectivity is network
mobility (NEMO). With NEMO support we can provide Internet
access from mobile platforms, such as public transportation vehicles,
to normal nodes that do not need to implement any special
mobility protocol. The NEMO basic support protocol has been
proposed in the IETF as a first solution to this problem, but this
solution has severe performance limitations. This paper presents
MIRON: Mobile IPv6 route optimization for NEMO, an approach
to the problem of NEMO support that overcomes the limitations
of the basic solution by combining two different modes of operation:
a Proxy-MR and an address delegation with built-in routing
mechanisms. This paper describes the design and rationale of the
solution, with an experimental validation and performance evaluation
based on an implementation.Publicad
Nuclear Fusion via Triple Collisions in Solar Plasma
We consider several nuclear fusion reactions that take place at the center of
the sun, which are omitted in the standard pp-chain model. More specifically
the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei
in triple collisions involving electrons are estimated within the framework of
the adiabatic approximation. These rates are compared with those of the
corresponding binary fusion reactions.Comment: 3 pages, latex (RevTex), no figure
Crypton: CRYptographic Prefixes for Route Optimization in NEMO
Proceedings of: 2010 IEEE International Conference on Communications (ICC 2010), 23-27 May, 2010, Cape Town, South AfricaThe aviation community is in the process of designing the next generation Aeronautical Telecommunications
Network (ATN), based on Internet standards, to provide airground
communications for the aircraft. Support for mobile
networks in the current Internet architecture is provided by
the NEtwork Mobility (NEMO) protocol. As currently defined,
NEMO Basic Support protocol lacks of Route Optimization
support which is an essential requirement for its adoption as
part of the next generation ATN. This paper presents a novel
security tool, the Crypto Prefixes, and their application to the
Route Optimization in Nemo (CRYPTRON). The Crypto Prefixes
are IPv6 prefixes with embedded cryptographic information that
enable the Mobile Network Prefix proof-of ownership without
any centralized trust infrastructure. In CRYPTRON, the Crypto
Prefixes are used to protect the establishment of the bindings on
the Correspondent Nodes for the whole Mobile Network PrefixEuropean Community's Seventh Framework ProgramPublicad
Toric Calabi-Yau Fourfolds, Duality Between N=1 Theories and Divisors that Contribute to the Superpotential
We study issues related to F-theory on Calabi-Yau fourfolds and its duality to heterotic theory for Calabi-Yau threefolds. We discuss principally fourfolds that are described by reflexive polyhedra and show how to read off some of the data for the heterotic theory from the polyhedron. We give a procedure for constructing examples with given gauge groups and describe some of these examples in detail. Interesting features arise when the local pieces are fitted into a global manifold. An important issue is how to compute the superpotential explicitly. Witten has shown that the condition for a divisor to contribute to the superpotential is that it have arithmetic genus 1. Divisors associated with the short roots of non-simply laced gauge groups do not always satisfy this condition while the divisors associated to all other roots do. For such a `dissident' divisor we distinguish cases for which the arithmetic genus is greater than unity corresponding to an X that is not general in moduli (in the toric case this corresponds to the existence of non-toric parameters). In these cases the `dissident' divisor D does not remain an effective divisor for general complex structure. If however the arithmetic genus is less than or equal to 0, then the divisor is general in moduli and there is a genuine instability
Experimental stone tool replication at the Early Stone Age site of Sterkfontein, Gauteng, South Africa
Transverse Dynamics at RHIC
Studies of , transverse momentum spectra and anisotropy flow from
nuclear collisions at RHIC indicate early thermalization and strong collective
expansion. We propose a systematic study of the anisotropy parameter and
the transverse momentum distributions of and in order to extract information on partonic collective flow.Comment: 4 pages, 3 figures; presented at Quark Matter 2002, Nantes, France,
July 18-24, 2002. Proceedings to be published in Nucl. Phys.
Exploring the behavioural drivers of veterinary surgeon antibiotic prescribing: a qualitative study of companion animal veterinary surgeons in the UK
Background:
Multi-drug resistant bacteria are an increasing concern in both human and veterinary medicine. Inappropriate prescribing and use of antibiotics within veterinary medicine may be a contributory factor to antimicrobial resistance (AMR). The âOne Healthâ Initiative aims to work across species and environments to reduce AMR, however; little is currently known about the factors which influence antibiotic prescribing among veterinary surgeons in companion animal practice.
This paper reports on qualitative data analysis of interviews with veterinary surgeons whose practice partially or wholly focuses on companion animals (N =â16). The objective of the research was to explore the drivers of companion animal veterinary surgeonsâ antibiotic prescribing behaviours. The veterinary surgeons interviewed were all practising within the UK (England (n =â4), Scotland (n =â11), Northern Ireland (n =â1)). A behavioural thematic analysis of the data was undertaken, which identified barriers and facilitators to specific prescribing-related behaviours.
Results:
Five components of prescribing behaviours were identified: 1) confirming clinical need for antibiotics; 2) responding to clients; 3) confirming diagnosis; 4) determining dose, duration and type of antibiotic; and 5) preventing infection around surgery (with attendant appropriate and inappropriate antibiotic prescribing behaviours). Barriers to appropriate prescribing identified include: business, diagnostic, fear, habitual practice and pharmaceutical factors. Facilitators include: AMR awareness, infection prevention, professional learning and regulation and government factors.
Conclusion:
This paper uses a behavioural lens to examine drivers which are an influence on veterinary surgeonsâ prescribing behaviours. The paper contributes new understandings about factors which influence antibiotic prescribing behaviours among companion animal veterinary surgeons. This analysis provides evidence to inform future interventions, which are focused on changing prescribing behaviours, in order to address the pressing public health concern of AMR
Within You / Without You: Biotechnology, Ontology, and Ethics
As Implantable Cardioverter Defibrillators (ICDs) have become more common, ethical issues have arisen regarding the deactivation of these devices. Goldstein et al., have shown that both patients and cardiologists consider ICD deactivation to be different from the discontinuation of other life-sustaining treatments. It cannot be argued ethically that ICDs raise new questions about the distinction between withholding and withdrawing treatment, and neither the fact that they are used intermittently, nor the duration of therapy, nor the mere fact that they are located inside the body can be considered unique to these devices and morally decisive. However, frequent allusions to the fact that they are located inside the body might provide a clue about what bothers patients and physicians. As technology progresses, some interventions seem to become a part of the patient as a unified whole person, completely replacing body parts and lost physiological functions rather than merely substituting for impaired structure and function. If a life-sustaining intervention can be considered a âreplacementââa part of the patient as a unified whole personâthen it seems that deactivation is better classified as a case of killing rather than a case of forgoing a life-sustaining treatment. ICDs are not a âreplacementâ therapy in this sense. The deactivation of an ICD is best classified, under the proper conditions, as the forgoing of an extraordinary means of care. As technology becomes more sophisticated, however, and new interventions come to be best classified as âreplacementsâ (a heart transplant would be a good example), âdiscontinuingâ these interventions should be much more morally troubling for those clinicians who oppose euthanasia and assisted suicide
Analytical Characterization of Failure Recovery in REAP
This paper characterizes analytically the performance of REAchability Protocol (REAP), a network layer
end-to-end recovery protocol for IPv6. REAP was developed by the IETF SHIM6 Working Group as part
of its multihoming solution. The behavior of REAP is governed by a small number of parameters: three
timers, a simple characterization of the application traffic, and the communication delay. The key figure
of merit of REAP performance is the time to recover from a path failure as seen by the upper layers, figure
that cannot be trivially obtained, despite the apparent simplicity of this reachability protocol. In this
paper we provide upper bounds for the recovery time of REAP for different deployment scenarios, applying
these analytical results to two interesting case studies, TCP and VoIP traffic.European CommunityÂŽs Seventh Framework ProgramPublicad
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