10,705 research outputs found
Outage-based ergodic link adaptation for fading channels with delayed CSIT
Link adaptation in which the transmission data rate is dynamically adjusted
according to channel variation is often used to deal with time-varying nature
of wireless channel. When channel state information at the transmitter (CSIT)
is delayed by more than channel coherence time due to feedback delay, however,
the effect of link adaptation can possibly be taken away if this delay is not
taken into account. One way to deal with such delay is to predict current
channel quality given available observation, but this would inevitably result
in prediction error. In this paper, an algorithm with different view point is
proposed. By using conditional cdf of current channel given observation, outage
probability can be computed for each value of transmission rate . By
assuming that the transmission block error rate (BLER) is dominated by outage
probability, the expected throughput can also be computed, and can be
determined to maximize it. The proposed scheme is designed to be optimal if
channel has ergodicity, and it is shown to considerably outperform conventional
schemes in certain Rayleigh fading channel model
Side-View Operando Optical Microscopy Analysis of a Graphite Anode to Study Its Kinetic Hysteresis
Operando analyses have provided several breakthroughs in the construction of high-performance materials and devices, including energy storage systems. However, despite the advances in electrode engineering, the formidable issues of lithium intercalation and deintercalation kinetics cannot be investigated by using planar observations. This study concerns side-view operando observation by optical microscopy of a graphite anode based on its color changes during electrochemical lithiation. Since the graphite color varies according to the optical energy gap during lithiation and delithiation, this technique can be used to study the corresponding charge-discharge kinetics. In addition, the cell configuration uses liquid electrolytes similar to commercial cells, allowing practical application. Furthermore, this side-view observation has shown that microscale spatial variations in rate and composition control the insertion and deinsertion, revealing the kinetics throughout the whole electrode. The results of this study could enhance the fundamental understanding of the kinetics of battery materials
Forbidden Channels and SIMP Dark Matter
In this review, we focus on dark matter production from thermal freeze-out
with forbidden channels and SIMP processes. We show that forbidden channels can
be dominant to produce dark matter depending on the dark photon and / or dark
Higgs mass compared to SIMP.Comment: 5 pages, Prepared for the proceedings of the 13th International
Conference on Gravitation, 3-7 July 201
On thermal production of self-interacting dark matter
We consider thermal production mechanisms of self-interacting dark matter in
models with gauged symmetry. A complex scalar dark matter is stabilized
by the , that is the remnant of a local dark . Light dark matter
with large self-interaction can be produced from thermal freeze-out in the
presence of SM-annihilation, SIMP and/or forbidden channels. We show that dark
photon and/or dark Higgs should be relatively light for unitarity and then
assist the thermal freeze-out. We identify the constraints on the parameter
space of dark matter self-interaction and mass in cases that one or some of the
channels are important in determining the relic density.Comment: 26 pages, 11 figures, Version to appear in Journal of High Energy
Physic
Anti-neuroinflammatory Effects of Ethanol Extract of Inula helenium L (Compositae)
Purpose: To evaluate the in vitro antioxidant and anti- neuroinflammatory activities of Inula helenium extract (IHE) against lipopolysaccharide (LPS)-induced production of nitric oxide (NO) by primary microglial cells.Methods: Cell viability was estimated by 3-(4, 5-dimethylthiazol-2- yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay. Antioxidant activity was evaluated using 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. LPS-stimulated BV-2 microglia were used to study the expression and production of inflammatory mediators, including NO, inducible NO synthase (iNOS)and Interukin-6 (IL-6).Results: Pretreatment with IHE prior to LPS treatment significantly inhibited excessive production of NO (p < 0.001 at 20, 40, 80 and 100 μg/mL) in a dose-dependent manner, and was associated with downregulation of expression of inducible nitric oxide synthase (iNOS). IHE also suppressed the LPSinduced increase in IL-6 level (p < 0.01 at 40 and 80 μg/mL) in BV-2 cells. The antioxidant activity exhibited by IHE might play a critical role in ameliorating neuroinflammatory processes in LPSstimulated BV-2 microglial cells.Conclusion: IHE may be beneficial in preventing and treating neurodegenerative and oxidative stressrelated diseases.Keywords: Inula helenium, DPPH, Neurodegenerative diseases, Anti inflammatory, Anti-oxidant, Microglial cel
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