Predictive Resource Allocation in mmWave Systems with Rotation Detection

Millimeter wave (MmWave) has been regarded as a promising technology to support high-capacity communications in 5G era. However, its high-layer performance such as latency and packet drop rate in the long term highly depends on resource allocation because mmWave channel suffers significant fluctuation with rotating users due to mmWave sparse channel property and limited field-of-view (FoV) of antenna arrays. In this paper, downlink transmission scheduling considering rotation of user equipments (UE) and limited antenna FoV in an mmWave system is optimized via a novel approximate Markov decision process (MDP) method. Specifically, we consider the joint downlink UE selection and power allocation in a number of frames where future orientations of rotating UEs can be predicted via embedded motion sensors. The problem is formulated as a finite-horizon MDP with non-stationary state transition probabilities. A novel low-complexity solution framework is proposed via one iteration step over a base policy whose average future cost can be predicted with analytical expressions. It is demonstrated by simulations that compared with existing benchmarks, the proposed scheme can schedule the downlink transmission and suppress the packet drop rate efficiently in non-stationary mmWave links.Comment: 7 pages, 5 figures. Paper accepted for publication in IEEE International Conference on Communications, 202

Face-to-face intercrossed ZnO nanorod arrays with extensive NR-NR homojunctions for a highly sensitive and self-powered ultraviolet photodetector

Abstract(#br)A self-powering ultraviolet photodetector (UVPD) that effectively utilizes UV energy in an easy-to-implement way is an attractive alternative for the UV optical sensing and communication. Here we report a novel self-powered UVPD based on a face-to-face hybrid ZnO nanorod arrays (ZNRAs) nanostructure. Large-area free-standing ZNRAs have been grown on indium tin oxide (ITO) conductive glass and Ti substrates through a hydrothermal method. Different geometric dimension of ZNRAs/ITO and ZNRAs/Ti structures were designed to pair hybrid each other for achieving the optimum photoelectric performance. Experimentally, it is found that the optimum UVPD based on face-to-face hybrid ITO/ l -ZNRAs/ l -ZNRAs/Ti structure exhibits an enhancement of ‘1+1>2’ in photoelectric conversion without applying any external DC voltage when compared with single-face ZNRAs-based UVPDs, and the optimum UVPD demonstrates a responsivity of 2.45 mA W −1 and on/off current ratio of 6.6 × 10 5 under a UV irradiation of 3.06 μW cm −2 as well as a high durability with a cyclic balance of no less than 93.5% in a 4250-s on/off irradiation. The generation of self-power and the high photoelectric performance of face-to-face hybrid ZNRAs-based UVPDs are associated to the Schottky junctions in ITO/ZnO interface as well as the extensive ZnO nanorod-nanorod homojunction

Survival Dynamics and Colonization of Exogenous Probiotic Bacteria Bacillus subtilis in Aquaculture Water and Intestine of Zebra Fish (Danio rerio)

Adaptability of probiotic bacteria is an important trait for the survival and colonization in water or fish intestine and the performance of their bio-control function. Bacillus is a widely used genus of probiotic bacteria in aquaculture. However, its survival dynamics and effect on water or fish intestine is still unclear. In this study, we assessed the survival dynamics of exogenous Bacillus subtilis Bst51 and its effect on the microbial community structure in water and fish intestine by using green fluorescent protein (GFP) labeling and bacteriological methods. Results showed that GFP labeling was an efficient method for detection of the survival of B. subtilis in the water column and fish intestine. Our results showed that when administered only once, the concentration of Bst51 in water declined to one-tenth of the original concentration and reached a stable state after 24 h. This confirmed that Bst51 strain was able to survive and colonize in aquaculture water with concentrations higher than 103 CFU (Colony Forming Units)/mL. The concentration of Bst51 cells in zebra fish intestine decreased slightly and remained constant at around 5×106 CFU/g after only one treatment. The results confirmed that if Bst51 cells have a concentration of over 109 CFU/mL they can survive and colonize in zebra fish intestine

Speed and Heading Control of an Unmanned Surface Vehicle Based on State Error PCH Principle

This paper proposes a novel nonlinear control scheme based on energy-shaping (ES) principle and state error port-controlled Hamiltonian (PCH) systems for unmanned surface vehicles (USV) system. The PCH model of three degrees of freedom for USV kinetics system is established. By the ES principle, interconnection assignment and damping injection method is applied to the speed and heading control of the closed-loop USV system to realize an overall stability of control mechanism. Simulation results show that the validity and stability of control algorithm can be satisfied with the performance in speed and heading tracking of which the high simplification and portability make it applicable to the various region

Fabrications of <i>L</i>-Band LiNbO₃-Based SAW Resonators for Aerospace Applications

High frequency surface acoustic wave (SAW) technology offers many opportunities for aerospace applications in passive wireless sensing and communication. This paper presents the design, simulation, fabrication, and test of an L-band SAW resonator based on 128&#176; Y-X LiNbO3 substrate. The design parameters of SAW resonator were optimized by the finite element (FEM) method and the coupling-of-mode (COM) theory. Electron-beam lithography (EBL) technology was used to fabricate the submicron-scale of interdigital transducers (IDTs) and grating reflectors. The effects of some key EBL processes (e.g., the use of electron beam resist, the choice of metal deposition methods, the charge-accumulation effect, and the proximity-effect) on the fabrication precision of SAW devices were discussed. Experimentally, the LiNbO3-based SAW resonators fabricated using improved EBL technology exhibits a Rayleigh wave resonance peaks at 1.55 GHz with return loss about &#8722;12 dB, and quality factor Q is 517. Based on this SAW resonator, the temperature and strain sensing tests were performed, respectively. The experimental results exhibit a well linear dependence of temperature/strain on frequency-shift, with a temperature sensitivity of 125.4 kHz/&#176;C and a strain sensitivity of &#8722;831 Hz/&#956;&#949;, respectively

Novel Antioxidant Peptides from Crassostrea Hongkongensis Improve Photo-Oxidation in UV-Induced HaCaT Cells

Enzymatic hydrolysates from Oysters (OAH) display multiple biological activities. Previously, a 3~5 KDa oyster ultrafiltration component (OUP) showed a high property of preventing skin oxidation. Subsequently, we identified specific peptides with such activity. OUP was fractionated stepwise by Sephadex-G25 and RP-HPLC, and active fractions were screened using UV-irradiated HaCaT cells. The most active fractions (OP5-3) were analyzed by LC-MS/MS and a total of 17 peptides were identified. Results from mass spectrometry showed that OP5-3 consisted of peptides with a molecular weight range of 841.51&ndash;1786.92 Da. Six of these peptides were synthesized for validating the activity of resisting skin oxidation in the same cell model. All six peptides showed varying degrees of antioxidant activity, while pretreatment of HaCaT cells with AIVAEVNEAAK alleviated UV cytotoxicity, inhibited metalloproteinase 1 (MMP-1) expression, and showed the highest activity to resist UV-induced skin photo-oxidation among these peptides. In addition, results from molecular docking analysis of MMP-1 with AIVAEVNEAAK showed that AIVAEVNEAAK suppresses its enzymatic activity by directly interacting with MMP-1 and thus exhibit anti-photoaging activity