83 research outputs found
Enabling smartphone-based HD video chats by cooperative transmissions in CRNs
Smartphones have been equipped with the cameras that can shoot HD videos, and the video chat apps such as Skype are becoming popular. We can, therefore, intuitively predict the trend that users are expecting to enjoy HD video chats via utilizing their smartphones. Most of the current Internet services, however, cannot support the live HD video transmissions because of their low uplink rate. In order to overcome this limit, we propose to offload the uplink transmissions to cooperative users via cognitive radio networks. Specifically, we first divide the video stream into several substreams according to the H.264/SVC standard and the cooperative users’ uplink rates. Then, the cooperative users are selected by employing our proposed optimal multiple stopping method. Finally, the substreams are assigned to the selected cooperative users by a 0-1 Knapsack-based allocation algorithm. The simulation results demonstrate that our proposed scheme can successfully support 720P HD video chats
Observation of Rydberg moir\'e excitons
Rydberg excitons, the solid-state counterparts of Rydberg atoms, have sparked
considerable interest in harnessing their quantum application potentials,
whereas a major challenge is realizing their spatial confinement and
manipulation. Lately, the rise of two-dimensional moir\'e superlattices with
highly tunable periodic potentials provides a possible pathway. Here, we
experimentally demonstrate this capability through the observation of Rydberg
moir\'e excitons (XRM), which are moir\'e trapped Rydberg excitons in monolayer
semiconductor WSe2 adjacent to twisted bilayer graphene. In the strong coupling
regime, the XRM manifest as multiple energy splittings, pronounced redshift,
and narrowed linewidth in the reflectance spectra, highlighting their
charge-transfer character where electron-hole separation is enforced by the
strongly asymmetric interlayer Coulomb interactions. Our findings pave the way
for pursuing novel physics and quantum technology exploitation based on the
excitonic Rydberg states.Comment: 24 pages, including 4 figures and 6 supplementary figure
Characterization of the response of IHEP-IME LGAD with shallow carbon to Gamma Irradiation
Low Gain Avalanche Detectors (LGAD), as part of High-Granularity Timing
Detector (HGTD), is crucial to reducing pileup in the upgrading to HL-LHC. Many
studies have been done on the bulk damages of the LGAD. However, there's no
study about the surface radiation hardness of the LGAD sensors with carbon
implanted. The IHEP-IME LGAD version 3 with the shallow carbon and different
interpad separations were irradiated up to 2 MGy by gamma irradiation. The
performance of the IHEP-IME LGAD version 3 before and after irradiation had
been tested, such as the leakage current, break-down voltage, capacitance,
V, and inter-pad resistance. The results showed that apart from minor
fluctuations in some samples, no significant changes concerning inter-pad
separation were observed before and after irradiation. Leakage current and
break-down voltage increase after irradiation, which is considered due to
surface passivation; the overall inter-pad resistance are larger than $10^9\
\Omega_{gl}$ after irradiation. All parameters meet the
requirements of HGTD, and the results indicated that IHEP-IME LGAD v3 has
excellent anti-irradiation performance
Leakage current simulations of Low Gain Avalanche Diode with improved Radiation Damage Modeling
We report precise TCAD simulations of IHEP-IME-v1 Low Gain Avalanche Diode
(LGAD) calibrated by secondary ion mass spectroscopy (SIMS). Our setup allows
us to evaluate the leakage current, capacitance, and breakdown voltage of LGAD,
which agree with measurements' results before irradiation. And we propose an
improved LGAD Radiation Damage Model (LRDM) which combines local acceptor
removal with global deep energy levels. The LRDM is applied to the IHEP-IME-v1
LGAD and able to predict the leakage current well at -30 C after an
irradiation fluence of . The
charge collection efficiency (CCE) is under development
Replication Data for: Effects of Lactobacillus reuteri on early feeding tolerance and infection prevention in preterm infants
Preterm infants have not well-developed organs, immature gastrointestinal tract, delayed colonization of intestinal flora and poor immunity. In this study, the effects of Lactobacillus reuteri DSM 17938 on daily reflux, the maximum feeding amount, weight gain, hospital stay, nosocomial infection and neonatal necrotizing enterocolitis were surveyed, and we elucidated its roles in early feeding tolerance, growth and infection prevention of preterm infants
Anisotropic Picone identities and anisotropic Hardy inequalities
Abstract In this paper, we derive an anisotropic Picone identity for the anisotropic Laplacian, which contains some known Picone identities. As applications, a Sturmian comparison principle to the anisotropic elliptic equation and an anisotropic Hardy type inequality are shown
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