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A Recursive DRL-Based Resource Allocation Method for Multibeam Satellite Communication Systems

Chinese Journal of Electronics 2024年第5期33卷 1286-1295页

作者： Haowei MENG Ning XIN Hao qin Di ZHAO State Key Laboratory of Integrated Services Networks Xidian University China Academy of Space Technology Institute of Telecommunication Satellite

Optimization-based radio resource management(RRM) has shown significant performance gains on high-throughput satellites(HTSs). However, as the number of allocable on-board resources increases, traditional RRM is difficult to apply in real satellite systems due to its intense computational complexity. Deep reinforcement learning(DRL) is a promising solution for the resource allocation problem due to its model-free advantages. Nevertheless, the action space faced by DRL increases exponentially with the increase of communication scale, which leads to an excessive exploration cost of the algorithm. In this paper, we propose a recursive frequency resource allocation algorithm based on long-short term memory(LSTM) and proximal policy optimization(PPO), called PPO-RA-LOOP,where RA means resource allocation and LOOP means the algorithm outputs actions in a recursive manner. Specifically, the PPO algorithm uses LSTM network to recursively generate sub-actions about frequency resource allocation for each beam, which significantly cuts down the action space. In addition, the LSTM-based recursive architecture allows PPO to better allocate the next frequency resource by using the generated sub-actions information as a prior knowledge, which reduces the complexity of the neural network. The simulation results show that PPO-RA-LOOP achieved higher spectral efficiency and system satisfaction compared with other frequency allocation algorithms.

关键词： High-throughput satellites Proximal policy optimization Deep reinforcement learning Long-short term memory High-throughput satellites Proximal policy optimization Deep reinforcement learning Long-short term memory OPTIMIZATION POWER

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Consistent and Accurate TDOA Localization in Dynamic NLOS Environments via Prior Information Independent Estimation

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China Communications 2024年第9期21卷 198-210页

作者： Luo Mei Long Yu Xiong Youzhi qin Shuang Key Laboratory of Wireless Sensor Network in University of Sichuan Province College of Physics and Electronic EngineeringSichuan Normal UniversityChengdu 610101China

In the time-difference-of-arrival(TDOA)localization,robust least squares(LS)problems solved by mathematical programming were proven to be superior in mitigating the effects of non-line-of-sight(NLOS)***,the existing algorithms still suffer from two disadvantages:1)The algorithms strongly depend on prior information;2)The approaches do not satisfy the mean square error(MSE)optimal criterion of the measurement *** tackle the troubles,we first formulate an MSE minimization model for measurement noise by taking the source and the NLOS biases as *** obtain stable solutions,we introduce a penalty function to avoid abnormal *** further tackle the nonconvex locating problem with semidefinite relaxation ***,we incorporate mixed constraints and variable information to improve the estimation *** and experiments show that the proposed method achieves consistent performance and good accuracy in dynamic NLOS environments.

关键词： mathematical programming NLOS mitigation robust least squares TDOA

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SAR regional all-azimuth observation orbit design for target 3D reconstruction

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Journal of Systems Engineering and Electronics 2024年第3期35卷 609-618页

作者： WANG Yanan ZHOU Chaowei LIU Aifang MAO qin Beijing Institute of Tracking and Communication Technology Beijing 100094China Nanjing Research Institute of Electronics Technology Nanjing 210012China Shanghai Aerospace Electronic Technology Institute Shanghai 201109China

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

关键词： synthetic aperture radar(SAR) orbit design all-azimuth observation(AAO) three-dimensional(3D)reconstruction successive coverage

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Physics-data coupling-driven method to predict the penetration depth into concrete targets

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 184-192页

作者： Shuai qin Hao Liu Jianhui Wang Qiang Zhao Lei Zhang Institute of Defense Engineering AMSLuoyang 471000China Harbin Engineering University Harbin 150001China

The projectile penetration process into concrete target is a nonlinear complex *** the increase ofexperiment data,the data-driven paradigm has exhibited a new feasible method to solve such complex ***,due to poor quality of experimental data,the traditional machine learning(ML)methods,whichare driven only by experimental data,have poor generalization capabilities and limited prediction ***,this study intends to exhibit a ML method fusing the prior knowledge with experiment *** newML method can constrain the fitting to experimental data,improve the generalization ability and the predic-tion *** results show that integrating domain prior knowledge can effectively improve theperformance of the prediction model for penetration depth into concrete targets.

关键词： Penetration into concrete Artificial neural networks Prior knowledge fusion Prediction model

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Cavity-enhanced metrology in an atomic spin-1 Bose−Einstein condensate

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Frontiers of physics 2024年第3期19卷 185-196页

作者： Renfei Zheng Jieli qin Bing Chen Xingdong Zhao Lu Zhou School of Physics Hefei University of TechnologyHefei 230009China State Key Laboratory of Precision Spectroscopy Department of PhysicsSchool of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China School of Physics and Materials Science Guangzhou University230 Wai Huan Xi RoadGuangzhou Higher Education Mega CenterGuangzhou 510006China Department of Physics Henan Normal UniversityXinxiang 453007China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Atom interferometer has been proven to be a powerful tool for precision metrology. Here we propose a cavity-aided nonlinear atom interferometer, based on the quasi-periodic spin mixing dynamics of an atomic spin-1 Bose−Einstein condensate trapped in an optical cavity. We unravel that the phase sensitivity can be greatly enhanced with the cavity-mediated nonlinear interaction. The influence of encoding phase, splitting time and recombining time on phase sensitivity are carefully studied. In addition, we demonstrate a dynamical phase transition in the system. Around the criticality, a small cavity light field variation can arouse a strong response of the atomic condensate, which can serve as a new resource for enhanced sensing. This work provides a robust protocol for cavity-enhanced metrology.

关键词： nonlinear atom interferometer spin-1 Bose−Einstein condensate spin-mixing dynamics quantum Fisher information parameter estimation

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Integrated bound-state-in-the-continuum photon-pair source

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Photonics Research 2024年第6期12卷 1322-1327页

作者： FAN YE YUE qin CHENFEI CUI XIANKAI SUN HON KI TSANG Department of Electronic Engineering The Chinese University of Hong KongHong KongChina

Integrated photon-pair sources based on spontaneous parametric down conversion(SPDC)in novel high-χ^((2))materials are used in quantum photonic systems for quantum information processing,quantum metrology,and quantum ***,the need for extensive fabrication process development and optimization of dry-etching processes significantly impedes the rapid exploration of different material platforms for low-loss quantum photonic ***,bound states in the continuum(BICs)have emerged as a promising approach for realizing ultralow-loss integrated photonic circuits without requiring an etching *** realizations of BIC photonic circuits have,however,been limited primarily to the classical ***,we explore the BIC phenomena in the quantum regime and show that the etchless BIC platform is suitable for use in integrated entangled photon-pair sources based on the SPDC process in high-χ^((2))*** lithium niobate as an example,we demonstrate photon-pair generation at telecommunication wavelengths,attaining a maximum internal generation rate of 3.46 MHz,a coincidence-to-accidental ratio of 5773,and an experimental two‐photon interference visibility of 94%.Our results demonstrate that the BIC platform can be used for quantum photonic circuits,and this will enable the rapid exploration of different emergingχ^((2))materials for possible use in integrated quantum photonics in the future.

关键词： process quantum continuum

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Supported Atomically Dispersed Pd Catalyzed Direct Alkoxylation and Allylic Alkylation

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Chinese Journal of Chemistry 2024年第7期42卷 719-724页

作者： Ruixuan qin Ziwen Chen qingyuan Wu Nanfeng Zheng Pengxin Liu New Cornerstone Science Laboratory State Key Laboratory for Physical Chemistry of Solid SurfacesCollaborative Innovation Center of Chemistry for Energy Materialsand National&Local Joint Engineering Research Center of Preparation Technology of NanomaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamenFujian 361005China Innovation Laboratry for Scences and Technoogies of Energy Materials of Fujan Province(IKKM) Xiamen Fujian 361102China School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China Fujian Key Laboratory of Rare-earth Functional Materials Fujian Shanhai Collaborative Innovation Center of Rare-earth Functional MaterialsLongyanFujian 366300China

A new approach to allylic alkylation is realized using an atomically dispersed palladium catalyst(Pd1/TiO2-EG).Unlike conventional methods that require derivation of substrates and utilization of additives,this method allows for direct allylic alkylation from allylic alcohols,producing H2O as the sole *** catalyst's high efficiency is attributed to the local hydrogen bonding at the or-ganic-inorganic interface(Pd-EG interface),facilitating hydroxyl group activation forη3π-allyl complex *** system demonstrates successful direct C—O and C—C coupling reactions with high selectivity,requiring no *** study highlights the potential of supported atomically dispersed catalysts for greener and more efficient catalysis,meanwhile,offers unique insights into the distinct behavior of atomically dispersed catalysts in comparison to homogeneous or nanoparticle-based catalysts.

关键词： Atomically dispersed catalyst Alkylation C—C coupling Organic-inorganic Interface Hydrogen bond Tsuji-Trost reaction Green catalysis

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Nano-effect enhanced cooperative luminescence of Yb^(3+) clusters in bulk materials

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Journal of Rare Earths 2024年第3期42卷 473-478,I0002页

作者： Daguang Li Jiahao Cui Yanhui Dong Hao Cui Dan Zhao Weiping qin State Key Laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun130012China

In order to improve the multi-ion cooperative transition, we proposed and exploited a novel nanoscale effect, namely the nanoshell effect in bulk materials. Based on the effect, an optimal material structure was designed by coating the surfaces of Ca F_(2):Yb^(3+)micron size particles with ZrO_(2). An about 2 times higher intensity of cooperative luminescence is observed upon laser excitation at 980 nm. Dynamical analysis exhibits that the novel effect plays a key role in improving the performance of cooperative transitions. Our results also suggest that the nanoshell effect in bulk materials is likely to be significant in some special cases, which have not been reported yet in the literature.

关键词： Yb^(3+)cluster ZrO_(2) Nanoshell Enhancement Cooperative luminescence Rare earths

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甲型H1N1流感病毒感染年轻和老年C57BL/6小鼠诱导肺组织CD8^(+)T细胞特异性免疫应答的比较研究

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中国实验动物学报 2021年第4期29卷 461-466页

作者：刘洋王超任晓楠李顺秦波音杨华周晓辉复旦大学附属公共卫生临床中心上海201508

目的比较甲型H1N1流感病毒PR8毒株感染老年和年轻C57BL/6小鼠诱导肺组织CD8^(+)T细胞特异性免疫应答的能力。方法使用490 PFU的PR8病毒分别滴鼻感染年轻(3月龄)和老年(24月龄)C57BL/6小鼠,连续14 d每日记录其体重变化及死亡情况。在感... 详细信息

目的比较甲型H1N1流感病毒PR8毒株感染老年和年轻C57BL/6小鼠诱导肺组织CD8^(+)T细胞特异性免疫应答的能力。方法使用490 PFU的PR8病毒分别滴鼻感染年轻(3月龄)和老年(24月龄)C57BL/6小鼠,连续14 d每日记录其体重变化及死亡情况。在感染后第8天分离小鼠肺组织细胞,使用流式细胞术(fluorescence-activated cell sorting,FACS)技术检测病毒抗原特异性CD8^(+)T细胞数量及功能:MHC-I表位肽四聚体法(tetramer staining)染色流感特异性CD8^(+)T细胞,细胞内细胞因子染色法(intracellular cytokine staining,ICS)检测CD8^(+)T细胞经流感病毒特异性肽刺激后分泌细胞因子水平包括TNF-α、IFN-γ、IL-2以及与CD8^(+)T细胞杀伤功能有关的颗粒酶B(Granzyme B)的水平。结果相同量的PR8流感病毒感染小鼠后,老年小鼠体重下降更多,死亡率显著高于年轻小鼠(P<0.01)。另一方面,老年组小鼠诱生的病毒特异性CD8^(+)T细胞比例显著低于年轻组;同时,老年组CD8^(+)T细胞活化后分泌细胞因子TNF-α、IFN-γ、IL-2的水平显著低于年轻组;此外,老年组CD8^(+)T细胞表达granzyme B的水平同样显著低于年轻组。结论PR8流感病毒感染老年和年轻C57BL/6小鼠后,老年小鼠肺组织诱导产生的特异性CD8^(+)T细胞的数量减少且功能降低。结果表明:与年轻小鼠相比,老年小鼠肺组织CD8^(+)T细胞特异性免疫应答功能受损。

关键词：甲型流感病毒病毒特异性CD8^(+)T细胞免疫应答

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Multiscale modeling of gas-induced fracturing in anisotropic clayey rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2091-2110页

作者： Jianxiong Yang Jianfeng Liu Zhengyuan qin Xuhai Tang Houquan Zhang State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610042China School of Resources and Safety Engineering Wuhan Institute of TechnologyWuhan430073China School of Civil Engineering Wuhan UniversityWuhan430072China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China

In the context of repositories for nuclear waste,understanding the behavior of gas migration through clayey rocks with inherent anisotropy is crucial for assessing the safety of geological disposal *** primary mechanism for gas breakthrough is the opening of micro-fractures due to high gas *** occurs at gas pressures lower than the combined strength of the rock and its minimum principal stress under external loading *** investigate the mechanism of microscale mode-I ruptures,it is essential to incorporate a multiscale approach that includes subcritical microcracks in the modeling *** this contribution,we derive the model from microstructures that contain periodically distributed microcracks within a porous *** damage evolution law is coupled with the macroscopic poroelastic system by employing the asymptotic homogenization method and considering the inherent hydro-mechanical(HM)anisotropy at the *** resulting permeability change induced by fracture opening is implicitly integrated into the gas flow *** examples are presented to validate the developed model step by *** analysis of local macroscopic response is undertaken to underscore the influence of factors such as strain rate,initial damage,and applied stress,on the gas migration *** examples of direct tension tests are used to demonstrate the model’s efficacy in describing localized failure ***,the simulation results for preferential gas flow reveal the robustness of the two-scale model in explicitly depicting gas-induced fracturing in anisotropic clayey *** model successfully captures the common behaviors observed in laboratory experiments,such as a sudden drop in gas injection pressure,rapid build-up of downstream gas pressure,and steady-state gas flow following gas breakthrough.

关键词： Deep geological repositories Mode-I microcracks Time-dependent damage Fracturing process Anisotropic rock

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