2,554 research outputs found
Overview in Big Data Analysis of the Japanese Defense System: Ambiguous Adjustment to a Strategic Environment Change
Taiwan and Japan are both maritime countries. The natural resources in the territory are quite limited. Due to this inherent limitation, both Taiwan and Japan rely on trade to safeguard their own economic interests. Therefore, defending the maritime traffic lines and ensuring maritime interests are important missions of the Taiwan and Japan defense systems. The recent increasingly harsh international situation in the Asia-Pacific region has seriously affected the security and stability of the surrounding areas. Invisible also poses many challenges to Taiwan’s maritime rights and interests, so it is a reflection on Taiwan’s future development by understanding the Japanese defense system
Low-energy electronic recoil in xenon detectors by solar neutrinos
Low-energy electronic recoil caused by solar neutrinos in multi-ton xenon
detectors is an important subject not only because it is a source of the
irreducible background for direct searches of weakly-interacting massive
particles (WIMPs), but also because it provides a viable way to measure the
solar and neutrinos at the precision level of current
standard solar model predictions. In this work we perform
many-body calculations for the structure, photoionization, and
neutrino-ionization of xenon. It is found that the atomic binding effect yields
a sizable suppression to the neutrino-electron scattering cross section at low
recoil energies. Compared with the previous calculation based on the free
electron picture, our calculated event rate of electronic recoil in the same
detector configuration is reduced by about . We present in this paper the
electronic recoil rate spectrum in the energy window of 100 eV - 30 keV with
the standard per ton per year normalization for xenon detectors, and discuss
its implication for low energy solar neutrino detection (as the signal) and
WIMP search (as a source of background).Comment: 12 pages, 3 figure
Atomic ionization by sterile-to-active neutrino conversion and constraints on dark matter sterile neutrinos with germanium detectors
The transition magnetic moment of a sterile-to-active neutrino conversion
gives rise to not only radiative decay of a sterile neutrino, but also its
non-standard interaction (NSI) with matter. For sterile neutrinos of keV-mass
as dark matter candidates, their decay signals are actively searched for in
cosmic X-ray spectra. In this work, we consider the NSI that leads to atomic
ionization, which can be detected by direct dark matter experiments. It is
found that this inelastic scattering process for a nonrelativistic sterile
neutrino has a pronounced enhancement in the differential cross section at
energy transfer about half of its mass, manifesting experimentally as peaks in
the measurable energy spectra. The enhancement effects gradually smear out as
the sterile neutrino becomes relativistic. Using data taken with germanium
detectors that have fine energy resolution in keV and sub-keV regimes,
constraints on sterile neutrino mass and its transition magnetic moment are
derived and compared with those from astrophysical observations
A Two Energy Gap Preformed-Pair Scenario For the Cuprates: Implications for Angle-Resolved Photoemission Spectroscopy
We show how, within a preformed pair scenario for the cuprate pseudogap, the
nodal and antinodal responses in angle resolved photoemission spectroscopy
necessarily have very different temperature dependences. We examine the
behavior and the contrasting dependences for a range of temperatures both
below and above . Our calculations are based on a fully microscopic
-matrix approach for addressing pairing correlations in a regime where the
attraction is stronger than BCS and the coherence length is anomalously short.
Previously, the distinct nodal and anti-nodal responses have provided strong
support for the "two-gap scenario" of the cuprates in which the pseudogap
competes with superconductivity. Instead, our theory supports a picture in
which the pseudogap derives from pairing correlations, identifying the two gap
components with non-condensed and condensed pairs. It leads to reasonably good
agreement with a range of different experiments in the moderately underdoped
regime and we emphasize that here there is no explicit curve fitting. Ours is a
microscopic rather than a phenomenological theory. We briefly address the more
heavily underdoped regime in which the behavior is more complex.Comment: 12 pages; 10 figure
Virtual Machines Performance Modeling with Support Vector Regressions
Virtualization is a key technology in cloudcomputing to render on-demand provisioning of virtual services.Xen, an open source paravirtualized virtual machine monitor(hypervisor), has been adopted by many leading data centersof the world today. A scheduler in Xen handles CPU resourcessharing among virtual machines hosted on the same physicalsystem. This study is focused on a scheduler in the currentXen release - the Credit scheduler. Credit uses two parameters(weight and cap) to fine tune CPU resources sharing. Previousstudies have shown that these two parameters can impact variousperformance measures of virtual machines hosted on Xen. In thisstudy, we present a holistic procedure to establish performancemodels of virtual machines. Empirical data of two commonly usedmeasures, namely calculation power and network throughput,were collected by simulations under various settings of weightand cap. We then employed a powerful machine learning tool(multi-kernel support vector regression) to learn performancemodels from the empirical data. These models were evaluatedsatisfactorily by using established procedures in machinelearning
Ultrasound-Guided Glenohumeral Joint Injection Using the Posterior Approach
Injection treatment to the glenohumeral joint is often needed to treat shoulder problems such as adhesive capsulitis. This can be done through blind palpation technique and fluoroscopic or musculoskeletal ultrasound guidance. In recent years, ultrasound has been proven to increase the accuracy of needle placement into the glenohumeral joint. Ultrasound is radiation free and offers real-time images in performing needle-guided injection procedures. Glenohumeral joint injection can be done using the anterior rotator interval approach or the posterior approach technique. Both techniques are generally well tolerated by the patients. However, it was shown that the posterior injection technique offers an easier and a more effective approach to the glenohumeral joint with less extravasation rate as compared with the anterior approach. The posterior approach also avoids the potential risk of accidental puncture or injection into the axillary neurovascular structures. A linear transducer of 5–12 MHz is usually used. This technique is often applied to inject corticosteroid for the treatment of frozen shoulder or contrast medium for computed tomography or magnetic resonance shoulder arthrography
- …