6,298 research outputs found
The Capillary Pumped Loop Flight Experiment (CAPL): A pathfinder for EOS
The CAPL shuttle flight experiment will provide microgravity verification of the prototype capillary pumped loop (CPL) thermal control system for EOS. The design of the experiment is discussed with particular emphasis on the new technology areas in ammonia two-phase reservior design and heat pipe heat exchanger development. The thermal and hydrodynamic analysis techniques and results are also presented, including pressure losses, fluid flow, and non-orbit heat rejection capability. CAPL experiment results will be presented after the flight, presently planned for 1993
Ultrasoft NLL Running of the Nonrelativistic O(v) QCD Quark Potential
Using the nonrelativistic effective field theory vNRQCD, we determine the
contribution to the next-to-leading logarithmic (NLL) running of the effective
quark-antiquark potential at order v (1/mk) from diagrams with one potential
and two ultrasoft loops, v being the velocity of the quarks in the c.m. frame.
The results are numerically important and complete the description of ultrasoft
next-to-next-to-leading logarithmic (NNLL) order effects in heavy quark pair
production and annihilation close to threshold.Comment: 25 pages, 7 figures, 3 tables; minor modifications, typos corrected,
references added, footnote adde
Challenge-response trust assessment model for personal space IoT
© 2016 IEEE. Internet of Things (IoT) embraces the interconnection of identifiable devices that are capable of providing services through their cooperation. The cooperation among devices in such an IoT environment often requires reliable and trusted participating members in order to provide useful services to the end user. Consequently, an IoT environment or space needs to evaluate the trust levels of all devices in contact before admitting them as members of the space. Existing trust evaluation models are based on resources such as historical observations or recommendations information to evaluate the trust level of a device. However, these methods fail if there is no existing trust resource. This paper introduces a specific IoT environment called personal space IoT and proposes a novel trust evaluation model that performs a challenge-response trust assessment to evaluate the trust level of a device before allowing it to participate in the space. This novel challenge-response trust assessment model does not require the historical observation or previous encounter with the device or any existing trusted recommendation. The proposed challenge-response trust assessment model provides a reliable trust resource that can be used along with other resources such as direct trust, recommendation trust to get a comprehensive trust opinion on a specific device. It can also be considered as a new method for evaluating the trust value on a device
Initial trust establishment for personal space IoT systems
© 2017 IEEE. Increasingly, trust has played a crucial role in the security of an IoT system from its inception to the end of its lifecycle. A device has to earn some level of trust even before it is authenticated for admission to the system. Furthermore, once the device is admitted to the system, it may behave maliciously over time; hence its behavior must be evaluated constantly in the form of trust to ensure the integrity of the system. Currently, no mechanism exists to establish an initial trust on a device, without prior knowledge, before its admission to an IoT system. Even when trust is applicable, trust evaluation models require direct/indirect observations over time, historical data on past encounters, or third party recommendations. However, this type of past data is not available in the first encounter between the system and the device. The question is how to establish whether a device can be trusted to a level that merits further evaluation for admission into a mobile and dynamic IoT system when it encounters the system for the first time? This paper addresses this challenge by proposing a challenge-response method and a trust assessment model to establish, without prior knowledge, the initial trust that a device places on another in a mobile and dynamic environment called personal space IoT. The initial trust is established before further interaction can take place and under the assumption that only a limited window of time is available for the trust assessment. The paper describes and evaluates the proposed model theoretically and by simulation. It also describes a practical scheme for realizing the proposed solution
The Sharing Economy and Collaborative Finance: the Case of P2p Lending in Vietnam
Peer-to-peer Online Lending (P2PO) has received increasing attention over the last years, not only because of its disruptive nature and its disintermediation of nearly all major banking functions, but also because of its rapid growth and expanding breadth of services. This model offers a new way of investing in addition to investing in traditional channels such as banking or financial company. The transaction process is done online, the personal information and terms of mobilization are completely transparent and secure in the best way. The strong development of P2PO also raises a number of issues that require careful attention to promote positive and to limit negative aspects. The research aims to highlight particular aspects of this new business model and to analyze the opportunities and risks for lenders and borrowers in Viet Nam. The research combines qualitative analysis and data survey to serve descriptive statistics about P2PO in Viet Nam. The research show the potential of online peer lending is enormous but the regulators will restrict the Sharing economy model in general and P2PO lending in particula
MAGIC sensitivity to millisecond-duration optical pulses
The MAGIC telescopes are a system of two Imaging Atmospheric Cherenkov
Telescopes (IACTs) designed to observe very high energy (VHE) gamma rays above
~50 GeV. However, as IACTs are sensitive to Cherenkov light in the UV/blue and
use photo-detectors with a time response well below the ms scale, MAGIC is also
able to perform simultaneous optical observations. Through an alternative
system installed in the central PMT of MAGIC II camera, the so-called central
pixel, MAGIC is sensitive to short (1ms - 1s) optical pulses. Periodic signals
from the Crab pulsar are regularly monitored. Here we report for the first time
the experimental determination of the sensitivity of the central pixel to
isolated 1-10 ms long optical pulses. The result of this study is relevant for
searches of fast transients such as Fast Radio Bursts (FRBs).Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC
2017), Bexco, Busan, Korea (arXiv:1708.05153
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