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Resilient tightly coupled INS/UWB integration method for indoor UAV navigation under challenging scenarios

Defence Technology（防务技术） 2023年第4期22卷 185-196页

作者： Qian Meng Yang Song sheng-ying Li Yuan Zhuang Key Laboratory of Micro-Inertial Instrument and Advanced Navigation Technology Southeast UniversityNanjing210096China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina

Based on the high positioning accuracy,low cost and low-power consumption,the ultra-wide-band(UWB)is an ideal solution for indoor unmanned aerial vehicle(UAV)localization and ***,the UWB signals are easy to be blocked or reflected by obstacles such as walls and furniture.A resilient tightly-coupled inertial navigation system(INS)/UWB integration is proposed and implemented for indoor UAV navigation in this paper.A factor graph optimization(FGO)method enhanced by resilient stochastic model is established to cope with the indoor challenging *** deal with the impact of UWB non-line-of-sight(NLOS)signals and noise uncertainty,the conventional neural net-works(CNNs)are introduced into the stochastic modelling to improve the resilience and reliability of the *** on the status that the UWB features are limited,a‘two-phase'CNNs structure was designed and implemented:one for signal classification and the other one for measurement noise *** proposed resilient FGO method is tested on flighting UAV platform under actual indoor challenging *** to classical FGO method,the overall positioning errors can be decreased from about 0.60 m to centimeter-level under signal block and reflection *** superiority of resilient FGO which effectively verified in constrained environment is pretty important for positioning accuracy and integrity for indoor navigation task.

关键词： Unmanned aerial vehicle(UAV) Resilient navigation Indoor positioning Factor graph optimization Ultra-wide band(UWB)

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5G基站自适应天馈系统设计与建模

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重庆大学学报 2023年第4期46卷 89-96页

作者：沈煜航王晟电子科技大学信息与通信工程学院成都611731

为了提供一个各方面更优的全自动天面自适应调整方案,在降低维护成本的同时实现更优覆盖效果,从5G天面的信号辐射方向调整方法入手,对5G基站自适应天馈系统的智能调节系统设计关键技术进行研究,提出对基于深度强化学习的基站天面自适应... 详细信息

为了提供一个各方面更优的全自动天面自适应调整方案,在降低维护成本的同时实现更优覆盖效果,从5G天面的信号辐射方向调整方法入手,对5G基站自适应天馈系统的智能调节系统设计关键技术进行研究,提出对基于深度强化学习的基站天面自适应调节策略。基于此设计了5G基站自适应天馈系统,可以使用电信公司RSRP信号覆盖地图作为数据源,获取当前状态的观测值并自动分析数据,对天面进行自动调整。在虚拟环境下,对基于强化学习的系统进行了模拟搭建与仿真训练,结果符合预期。

关键词： 5G基站强化学习天馈系统自适应调整系统设计仿真分析

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Difference between static and dynamic angle of repose of uniform sediment grains

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International Journal of Sediment Research 2017年第2期32卷 149-154页

作者： Nian-sheng Cheng Kuifeng Zhao School of Civil and Environmental Engineering Nanyang Technological University

In the investigation of sediment transport,it is necessary to differentiate various definitions of angle of repose(AoR) available in the *** static AoR,composed of upper and lower angle of slope,forms just before and after slope instability,while the dynamic AoR can be observed when sediment grains are moving continuously down an inclined *** the present study,a series of laboratory experiments was conducted to measure static and dynamic angle of repose for uniform natural sediments with median diameter of 0.28-4.38 *** results show that the different slope angles have different *** upper and dynamic AoR increase slightly with increasing grain diameter,while the lower AoR is not sensitive to changes in sediment size and may assume a constant *** average of the upper and lower AoR is equivalent to the dynamic AoR,and the difference between them increases with increasing grain *** present study suggests that the different angles of repose should be treated with caution when applying in investigations of bedload transport,dune migration and local scour development.

关键词： Angle of repose Avalanche Sediment transport

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A naked-eye colorimetric sensor for chloroform

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Chinese Chemical Letters 2019年第4期30卷 895-898页

作者： Kai sheng Haifeng Lu Anbang Sun Yanmin wang Yuantao Liu Feng Chen Wenchao Bian Yang Li Rui Kuang Di Sun School of Aeronautics Shandong Jiaotong University School of Chemistry and Chemical Engineering Shandong University School of Transportation and Civil Engineering Shandong Jiaotong University

A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chromism. SP shows colorless solution when dissolved in most solvents initially but changes to blue color in chloroform under UV irradiation(λ = 365 nm) within 5 s. The luminescence spectra of SP in halogenated solvent show a large bathochromic shift(> 100 nm) with 60-fold enhanced emission intensity compared to that in halogen-free solvents. It is also worth mentioning that the photoinduced reaction between SP molecule and the halogenated solvents occurred. Based on the detailed NMR, fluorescence and mass spectra, the possible radical reaction mechanism was *** from the majority of solvatochromic sensors that based on the polarity of solvents for detection of halogenated solvents, our sensor system worked in a special

关键词： Colorimetric sensor Luminscence Halogenated solvents detection

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300mm口径W波段辐射计偏馈反射面天线设计

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红外与毫米波学报 2013年第6期32卷 545-549页

作者：彭树生吴礼李向芹南京理工大学电光学院上海航天技术研究院第八〇四研究所

为W波段辐射计设计了一副口径为300 mm偏馈反射面天线,天线要求的工作频率为94.5 GHz,副瓣电平低于-25 dB,交叉极化电平低于-30 dB,半功率波束宽度优于1°.采用较小偏置角以改善偏置天线的交叉极化特性,采用焦面场匹配法和模比法设计了... 详细信息

为W波段辐射计设计了一副口径为300 mm偏馈反射面天线,天线要求的工作频率为94.5 GHz,副瓣电平低于-25 dB,交叉极化电平低于-30 dB,半功率波束宽度优于1°.采用较小偏置角以改善偏置天线的交叉极化特性,采用焦面场匹配法和模比法设计了匹配馈源,通过仿真优化设计,得到良好的波瓣等化电平和驻波比.测量结果表明,测量值与理论值吻合,满足辐射计的指标要求.

关键词： W波段偏馈反射面天线匹配馈源模比法

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Numerical simulations of propeller cavitation flows based on OpenFOAM

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Journal of Hydrodynamics 2020年第6期32卷 1071-1079页

作者： Min-sheng Zhao Wei-wen Zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

In order to study the cavitation and hydrodynamic characteristics of propeller under uniform and non-uniform flows,numerical investigations are performed using interPhaseChangeDyMFoam in the open source computational fluid dynamics(CFD)software platform OpenFOAM with Schnerr-Sauer cavitation *** simulation results can be used as a reference to evaluate the working ability of a propeller in case of actual navigation.A new grid encryption method is adopted in the research to better capture the existence of vortex cavitation at the propeller *** method of function input is carried out in the study to simulate the condition of non-uniform flow and reduce the calculation *** unsteady dynamics are predicted by the Reynolds-averaged Navier-Stokes(RANS)method with a modified shear stress transport(SST)k−ωturbulence *** numerical results of the propeller such as cavitation shape and pressure distribution under uniform and non-uniform flow are analyzed and compared with each other.

关键词： OpenFOAM E779A propeller cavitation non uniform flow

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Weak-force sensing with squeezed optomechanics

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Science China(Physics,Mechanics & Astronomy) 2020年第2期63卷 71-81页

作者： Wen Zhao sheng-Dian Zhang Adam Miranowicz Hui Jing Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China College of Physics and Materials Science Henan Normal UniversityXinxiang 453007China Faculty of Physics Adam Mickiewicz UniversityPozna´n 61-614Poland

We investigate quantum-squeezing-enhanced weak-force sensing via a nonlinear optomechanical resonator containing a movable mechanical mirror and an optical parametric amplifier(OPA). Herein, we determined that tuning the OPA parameters can considerably suppress quantum noise and substantially enhance force sensitivity, enabling the device to extensively surpass the standard quantum limit. This indicates that under realistic experimental conditions, we can achieve ultrahigh-precision quantum force sensing by harnessing nonlinear optomechanical devices.

关键词： weak-force sensing squeezing optomechanics

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Pointwise Pseudo-Orbit Tracing Property and Chaos

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Journal of Mathematical Research and Exposition 2008年第2期28卷 413-420页

作者： wang Qun YANG Run sheng Department of Information Technology Communication University of China＇s Nanjing Jiangsu 211172 China College of Mathematics and Computer Science Nanjing Normal University Jiangsu 210097 China

In this article, we discuss the relationship between pointwise pseudo-orbit tracing property and chaotic properties such as topological mixing. When f has pointwise pseudo-orbit tracing property, we give some equal co... 详细信息

关键词： tracing property chaos mixing uniform positive entropy completely positive entropy.

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DFT Study on Intermolecular Cleavage Reaction of N-(2-Hydroxyphenyl)-phthalamic Acid

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Chemical Research in Chinese Universities 2008年第6期24卷 790-792页

作者： ZHAO Chu-feng TANG Ming-sheng wang Hong-ming WEI Dong-hui ZHAO Jing ZHANG Shou-ren CAO Shu-xia Department of Chemistry Zhengzhou University Zhengzhou 450052 P. R. China

The reaction mechanisms of intermolecular cleavage reaction of N-（2-hydroxyphenyl）-phthalamic acid were studied via the density functional theory（DFT）. All geometries of the reactant, transition states, and products were optimized at the B3LYP/6-31G（d, p） level. Vibration analysis was carried out to confirm its identity as transitions＇ structure, and the intrinsic reaction coordinate method（IRC） was used to search the minimum energy path. Two possible reaction channels are reported in this article. The calculated results indicate that O-cyclization reaction channel has the lower activation barrier, and therefore, it occurs more easier than the other.

关键词： Intermolecular decomposition reaction Density functional theory(DFT) O-Cyclization N-Cyclization N-(2-Hydroxyphenyl)-phthalamic acid

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Power Adjusting Algorithm： A New Cross-Layer Power Saving Mechanism for Mobile Ad-Hoc Networks

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Journal of Computer Science & Technology 2013年第1期28卷 42-53页

作者： Jin-Tao Meng Jian-Rui Yuan sheng-Zhong Feng Lian-sheng Tan Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Central South University Changsha 410083 China School of Information Science and Engineering Central China Normal University Wuhan 430079 China

Power saving is one of the key issues in Mobile Ad-Hoc Networks （MANETs）. It can be realized in Medium Access Control （MAC） layer and network layer. However, previous attentions were mainly paid to MAC layer or network layer with the aim of improving the channel utilization by adopting variable-range transmission power control. In this paper we focus on the power saving in both MAC layer and network layer, and propose a Power Adjusting Algorithm （PAA）. In the presence of host＇s mobility, PAA is designed to conserve energy by adjusting the transmission power to maintain the route＇s connectivity and restarting the route discovery periodically to find a new route with better energy efficiency dynamically. After analyzing the operations of PAA, we find that the length of route discovery restarting period is a critical argument which will affect power saving, and an energy consumption model is abstracted to find the optimal value of the restarting period by analyzing the energy consumption of this algorithm. PAA can handle the mobility of MANET by adjusting the transmission power and in the meantime save energy by restarting route discovery periodically to balance the energy consumption on route discovery and packet delivering. Simulation results show that, PAA saves nearly 40% energy compared with Dynamic Source Routing protocol when the maximum speed of mobile hosts is larger than 8 m/s.

关键词： mobile ad-hoc networks mobility control power control power efficiency

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