In multi-channel cognitive radio networks, it is important to investigate the sensing-throughput tradeoff from cross-layer perspective. Jointly considering imperfect spectrum sensing in physical layer and multi-channe...
详细信息
In multi-channel cognitive radio networks, it is important to investigate the sensing-throughput tradeoff from cross-layer perspective. Jointly considering imperfect spectrum sensing in physical layer and multi-channel access contention in MAC layer, we reformulate this tradeoff via taking the interference probability, rather than the detection probability, as the optimization constraint. And we further obtain the optimal sensing duration and detection threshold depending on the number of available channels to maximize the secondary throughput under the interference probability constraint. Numerical results show that the proposed cross-layer method can improve the secondary throughput performance significantly.
Arbitrary power splitting ratio is obtained by an 1-to-2 asymmetric multimode interference splitter. The dimension of the multimode section is less than 1.5μm × 3μm while the excess loss is lower than 0.15 dB.
ISBN:
(纸本)9781479922833
Arbitrary power splitting ratio is obtained by an 1-to-2 asymmetric multimode interference splitter. The dimension of the multimode section is less than 1.5μm × 3μm while the excess loss is lower than 0.15 dB.
Pancreatic beta-cell plays a central role in the body blood homeostasis by systematically activating glucose uptake after food intake. Diabetes arises when beta-cells are unable to meet insulin demand in the body, eit...
详细信息
Pancreatic beta-cell plays a central role in the body blood homeostasis by systematically activating glucose uptake after food intake. Diabetes arises when beta-cells are unable to meet insulin demand in the body, either due to a decrease in beta-cell mass or deterioration of beta-cell function [1]. A potential strategy is to generate massive functional beta-cells in vitro from stem cells before transplantation into patients to correct the glucose intolerance. Despite recent progresses, generation of fully functional pancreatic beta-cells in vitro is still not accomplished, which is due to the little understanding of functional maturation of pancreatic beta-cells during development in vivo. To address this question, we aim to study the functional maturation of islet beta-cells of transgenic zebrafish at different development stages in vivo. To achieve this goal, we have updated our previous two-photon three-axis digital scanned light-sheet microscopy(2P3A-DSLM)[3] in the following aspects: 1) two individual high-power femtosecond lasers with two fast Pockels cells for intensity modulation to compensate for the inhomogeneous excitation along the tunable acoustic grin(TAG) scanning range, 2) a system to scan the lightsheet in three dimensions 3) a three-axis movable sample stage coupled with a fast piezo-Z on the emission objective to collect three dimensional fluorescence signals rapidly. 4) an EMCCD cameras and a channel-split device to enable simultaneous dual-color detection of weak fluorescence *** further generated a ins:Rcamp1.07 transgenic zebrafish line, which could be used to monitor glucose-evoked Ca2+ oscillation in pancreatic beta-cells in vivo. Using this fish line, we show an important role of blood circulation per se in promoting insulin-positive cells into glucose responding, insulin-secreting matured beta-cells in vivo.
Silicon Mach-Zehnder modulators were used in IM-DD advanced optical communications. 6.25 Gbaud Nyquist-16, 32 and 64-Quadrature Amplitude Modulation optical signals were generated. 160 km transmission of 100 Gb/s WDM ...
详细信息
A tapered silica photonic crystal fiber was designed and fabricated to generate more than one octave spanning supercontinuum (from 550 nm to 1400 nm at -30 dB level), by an input pulse of 40 fs 200 pJ directly from an...
详细信息
We propose a dynamic wavelength and time slot assignment scheme for TWDM-PON based on inter-ONU priority rating. Simulation results show that the time delay and packet loss ratio are reduced compared with conventional...
详细信息
A wideband tunable dual loop Optoelectronic Oscillator based on a single-bandpass microwave photonic filter and a recirculating delay line is proposed and experimentally demonstrated. A tunable frequency range from 10...
详细信息
Platooning, the idea of cars autonomously following their leaders to form a road train, has huge potentials to improve traffic flow efficiency and, most importantly, road traffic safety. Wireless communication is a fu...
详细信息
HTTP Adaptive Streaming (HAS) is employed by more and more video streaming services in the Internet. It allows to adapt the downloaded video quality to the current network conditions, and thus, avoids stalling (i.e., ...
详细信息
暂无评论