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Joint UAV trajectory and communication design with heterogeneous multi-agent reinforcement learning

Science China(Information Sciences) 2024年第3期67卷 225-245页

作者： Xuanhan ZHOU jun xiong Haitao ZHAO Xiaoran LIU Baoquan REN Xiaochen ZHANG Jibo WEI Hao YIN College of Electronic Science and Technology National University of Defense Technology Systems Engineering Institute Academy of Military Sciences PLA

Unmanned aerial vehicles(UAVs) are recognized as effective means for delivering emergency communication services when terrestrial infrastructures are unavailable. This paper investigates a multiUAV-assisted communication system, where we jointly optimize UAVs’ trajectories, user association, and ground users(GUs)’ transmit power to maximize a defined fairness-weighted throughput metric. Owing to the dynamic nature of UAVs, this problem has to be solved in real time. However, the problem’s non-convex and combinatorial attributes pose challenges for conventional optimization-based algorithms, particularly in scenarios without central controllers. To address this issue, we propose a multi-agent deep reinforcement learning(MADRL) approach to provide distributed and online solutions. In contrast to previous MADRLbased methods considering only UAV agents, we model UAVs and GUs as heterogeneous agents sharing a common objective. Specifically, UAVs are tasked with optimizing their trajectories, while GUs are responsible for selecting a UAV for association and determining a transmit power level. To learn policies for these heterogeneous agents, we design a heterogeneous coordinated QMIX(HC-QMIX) algorithm to train local Q-networks in a centralized manner. With these well-trained local Q-networks, UAVs and GUs can make individual decisions based on their local observations. Extensive simulation results demonstrate that the proposed algorithm outperforms state-of-the-art benchmarks in terms of total throughput and system fairness.

关键词： unmanned aerial vehicle (UAV) trajectory design resource allocation multi-agent deep reinforcement learning (MADRL) heterogeneous agents

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Incidence,Risk Factors,and Prognosis of Patients with Hepatocellular Carcinoma and Brain Metastases

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Current Medical Science 2024年第1期44卷 180-186页

作者： Jin-cheng FENG Ying HE Georgios Polychronidis Jian XIN Shen YOU jun xiong Department of Liver Transplantation Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Key Laboratory of Transplant Engineering and Immunology Laboratory of Liver TransplantationFrontiers Science Center for Disease-Related Molecular NetworkWest China HospitalSichuan UniversityChengdu 610041China Department of General Visceral and Transplant SurgeryUniversity of HeidelbergIm Neuenheimer Feld 110Heidelberg 69120Germany Department of Hepatobiliary and Pancreatic Surgery Fujian Provincial HospitalFuzhou 350001China

Objective Brain metastases significantly impact the clinical course of patients with hepatocellular carcinoma(HCC).This study aimed to examine the age-related incidence,demographics,and survival of patients with HCC and brain *** Data of HCC patients from 2010 to 2015 in the Surveillance,Epidemiology,and End Results(SEER)Registry were screened for the presence of brain *** were stratified by age and *** logistic and Cox regression analyses were used to identify factors associated with brain metastases and those with overall survival(OS)and liver cancer-specific survival(CSS),*** A total of 141 HCC patients presenting with brain metastases were identified,accounting for 0.35% of all HCC patients and 2.37% of patients with metastatic *** all HCC patients,the incidence rate was the highest among patients aged 30-49 years old(0.47%).Ethnicity was not associated with the presence of brain metastases at the time of HCC ***,African-American patients presented with a significantly lower disease-specific survival[median time:1 month;interquartile range(IQR):0-3.0 months].Initial lung or bone metastasis was independently associated with an increased risk of the presence of brain metastases[odds ratio(OR):12.62,95% confidence interval(CI):8.40-18.97]but was not associated with a worse OS or CSS among those with brain *** This study identified the age-related incidence and risk factors of brain metastases in HCC *** results may contribute to the consideration of brain screening among patients with initial metastatic HCC with lung or bone metastases,and influence the counseling of this patient population regarding their prognosis.

关键词： brain metastases hepatocellular carcinoma age-related incidence cancer-specific survival overall survival

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Phase field modeling of grain stability of nanocrystalline alloys by explicitly incorporating mismatch strain

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Rare Metals 2024年第7期43卷 3370-3382页

作者： Min Zhou Hong-Hui Wu Yuan Wu Hui Wang xiong-jun Liu Sui-He Jiang Xiao-Bin Zhang Zhao-Ping Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083Cnina Institute for Carbon Neutrality University of Science and TechnologyBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Ab st ra ct Nanocrystalline materials exhibit unique properties due to their extremely high grain boundary(GB) ***,this high-density characteristic induces grain coarsening at elevated temperatures,thereby limiting the widespread application of nanocrystalline *** experimental observations revealed that GB segregation and second-phase pinning effectively hinder GB migration,thereby improving the stability of nanocry stalline *** this study,a mouified phase-field model that integrates mismatch strain,solute segregation and precipitation was developed to evaluate the influence of lattice misfit on the thermal stability of nanocrystalline *** simulation results indicated that introducing a suitable mismatch strain can effectively enhance the microstructural stability of nanocrystalline *** synergizing precipitation with an appropriate lattice misfit,the formation of second-phase particles in the bulk grains can be suppressed,thereby facilitating solute segregation/precipitation at the *** concentrated solute segregation and precipitation at the GBs effectively hinders grain migration,thereby preventing grain *** findings provide a new perspective on the design and regulation of nanocrystalline alloys with enhanced thermal stability.

关键词： Phase field model Mismatch strain Second-phase precipitation Grain boundary segregation Nanocrystalline alloys

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The Violent Redemption Theme in A Good Man is Hard to Find

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Journal of Literature and Art Studies 2024年第8期14卷 684-688页

作者： xiong jun-yu Wuhan Institute of Technology WuhanChina

Flannery O’Connor is one of the representative figures of American Southern *** recognized as the most outstanding writer of the American South after Faulkner,she has great influence in the literary *** works are always shrouded in a strange and grotesque atmosphere and full of death as well as religious *** protagonists are a series of American Southern freaks struggling with the crisis of spiritual *** protagonists of her novel A Good Man is Hard to Find are a hypocritical believer in the world of sinners and a lost man suffering in the midst of real sin,thus O’Connor uses the highest form of violence-death to bring ultimate redemption to *** people’s conception,violence and redemption are often opposite to each other,but O’Connor uses bloody and violent plots to explore the theme of religious salvation,integrating and unifying the two contrary concepts to form her unique and profound violent redemption writing.

关键词： O’Connor A Good Man is Hard to Find violent redemption

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Demethylase-assisted site-specific detection of N^(1)-methyladenosine in RNA

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Chinese Chemical Letters 2024年第5期35卷 397-401页

作者： jun xiong Ke-Ke Chen Neng-Bin Xie Wei Chen Wen-Xuan Shao Tong-Tong Ji Si-Yu Yu Yu-Qi Feng Bi-Feng Yuan College of Chemistry and Molecular Sciences Research Center of Public HealthRenmin Hospital of Wuhan UniversitySchool of Public HealthWuhan UniversityWuhan 430071China Department of Laboratory Medicine Zhongnan Hospital of Wuhan UniversityWuhan UniversityWuhan 430071China

The dynamic RNA modifications have been viewed as new posttranscriptional regulator in modulating gene expression as well as in a broad range of physiological processes.N^(1)-methyladenosine(m^(1)A)is one of the most prevalent modifications existing in multiple types of ***-depth investigation of the functions of m^(1)A requires the site-specific assessment of m^(1)A stoichiometry in ***,we established a demethylase-assisted method(DA-m^(1)A)for the site-specific detection and quantification of m^(1)A in RNA.N^(1)-methyl group in m^(1)A could result in the stalling of reverse transcription at m^(1)A site,thus producing the truncated *** AlkB is a demethylase that can demethylate m^(1)A to produce adenine in RNA,thus generating full-length cDNA from AlkB-treated *** of the produced amounts of full-length cDNA by quantitative real-time PCR can achieve the site-specific detection and quantification of m^(1)A in *** the DA-m^(1)A method,we examined and successfully confirmed the previously well-characterized m^(1)A sites in various types of RNAs with low false positive *** addition,we found that the level of m^(1)A was significantly decreased at the bromodomain containing 2(BRD2)mRNA position 1674 and CST telomere replication complex component 1(CTC1)mRNA position 5643 in human hepatocellular carcinoma *** results suggest that these two m^(1)A sites in mRNA may be involved in liver *** together,the DA-m^(1)A method is simple and enables the rapid,cost-effective,and site-specific detection and quantification of m^(1)A in RNA,which provides a valuable tool to decipher the functions of m^(1)A in human diseases.

关键词： N^(1)-methyladenosine RNA modification AlkB demethylase RNA epigenetics Quantitative real-time PCR Hepatocellular carcinoma

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Backward scattering of laser plasma interactions from hundreds-of-joules broadband laser on thick target

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Matter and Radiation at Extremes 2024年第1期9卷 5-14页

作者： Peipei Wang Honghai An Zhiheng Fang jun xiong Zhiyong Xie Chen Wang Zhiyu He Guo Jia Ruirong Wang Shu Zheng Lan Xia Wei Feng Haitao Shi Wei Wang Jinren Sun Yanqi Gao Sizu Fu Shanghai Institute of Laser Plasma CAEPShanghai 201899People’s Republic of China

The use of broadband laser technology is a novel approach for inhibiting processes related to laser plasma interactions(LPIs).In this study,several preliminary experiments into broadband-laser-driven LPIs are carried out using a newly established hundreds-of-joules broadband second-harmonic-generation laser *** direct comparison with LPI results for a traditional narrowband laser,the actual LPI-suppression effect of the broadband laser is *** broadband laser had a clear suppressive effect on both back-stimulated Raman scattering and back-stimulated Brillouin scattering at laser intensities below 1×10^(15) W cm^(−2).An abnormal hot-electron phenomenon is also investigated,using targets of different thicknesses.

关键词： scattering laser hundreds

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核心概念统整下的数与运算一致性教学探索

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教学与管理 2024年第5期 55-59页

作者：熊淑君重庆市长寿区教师发展中心

培养学生核心素养是新一轮课程改革的重要目标。小学数学数与运算主题是培养学生核心素养的重要知识载体。小学阶段数与运算一致地表现为计数单位及个数多少的表达。以核心概念统领数与运算的教学,帮助学生建立计数单位的概念,建立数与... 详细信息

培养学生核心素养是新一轮课程改革的重要目标。小学数学数与运算主题是培养学生核心素养的重要知识载体。小学阶段数与运算一致地表现为计数单位及个数多少的表达。以核心概念统领数与运算的教学,帮助学生建立计数单位的概念,建立数与运算的认知结构;紧扣核心概念设计基本问题,实施一致性教学,帮助学生用结构化的知识形成结构化的思维和方法,是数与运算一致性教学的一般路径。

关键词：核心概念数与运算一致性计数单位

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基于测序技术的核糖核酸修饰定位分析方法研究进展

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色谱 2024年第7期42卷 632-645页

作者：熊军冯甜袁必锋武汉大学公共卫生学院湖北武汉430071

迄今为止,已在核糖核酸(RNA)中发现了170多种不同的化学修饰,这些修饰分布在各种类型的RNA中,包括信使RNA(mRNA)、核糖体RNA(rRNA)、转运RNA(tRNA)和小核RNA(snRNA)等。RNA修饰在广泛的生物过程中发挥着至关重要的作用,如调节基因表达... 详细信息

迄今为止,已在核糖核酸(RNA)中发现了170多种不同的化学修饰,这些修饰分布在各种类型的RNA中,包括信使RNA(mRNA)、核糖体RNA(rRNA)、转运RNA(tRNA)和小核RNA(snRNA)等。RNA修饰在广泛的生物过程中发挥着至关重要的作用,如调节基因表达、维持RNA稳定性和促进蛋白质翻译等。RNA修饰构成了基因表达调控的新层面,即“表观转录组”。RNA修饰以及相关修饰酶(writer)、去修饰酶(eraser)和修饰识别蛋白(reader)的发现,为研究RNA修饰的动态调控及生理功能提供了重要依据。随着RNA修饰检测技术的发展,RNA表观转录组学研究进入了单碱基分辨率、多层面、全覆盖的发展阶段。这些覆盖全转录组的分析方法有助于发现新的RNA修饰位点,对于阐明表观转录组学的分子调控机制、探索RNA修饰的疾病关联及临床应用具有重要意义。根据处理方式及测序原理的差异,现有的RNA修饰测序技术可以分为直接高通量测序、抗体富集测序、酶辅助测序、化学辅助测序、代谢标记测序和纳米孔测序。这些方法伴随着RNA修饰功能的研究大大拓展了人们对表观转录组学的认识。在这篇综述中,我们总结了近年来有关RNA修饰检测技术的进展,重点聚焦于不同方法的基本原理、优势和局限性。针对不同类型的RNA修饰,探讨测序分析方法,对未来新型RNA修饰定位技术的开发具有指导意义,有助于在全转录组范围内研究RNA修饰的功能。

关键词：表观转录组学核糖核酸修饰定位分析高通量测序单碱基分辨率

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Machine learning for parameters diagnosis of spark discharge by electro-acoustic signal

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Plasma Science and Technology 2024年第8期26卷 64-72页

作者：熊俊卢诗宇刘晓明周文俊查晓明裴学凯 State Key Laboratory of Power Grid Environmental Protection School of Electrical Engineering and AutomationWuhan UniversityWuhan 430072People’s Republic of China State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of TechnologyTianjin 300131People’s Republic of China

Discharge plasma parameter measurement is a key focus in low-temperature plasma *** diagnostics often require costly equipment,whereas electro-acoustic signals provide a rich,non-invasive,and less complex source of discharge *** study harnesses machine learning to decode these *** establishes links between electro-acoustic signals and gas discharge parameters,such as power and distance,thus streamlining the prediction *** building a spark discharge platform to collect electro-acoustic signals and implementing a series of acoustic signal processing techniques,the Mel-Frequency Cepstral Coefficients(MFCCs)of the acoustic signals are extracted to construct the *** machine learning models(Linear Regression,k-Nearest Neighbors,and Random Forest)are introduced and applied to the predictors to achieve real-time rapid diagnostic measurement of typical spark discharge power and discharge *** models display impressive performance in prediction precision and fitting *** them,the k-Nearest Neighbors model shows the best performance on discharge power prediction with the lowest mean square error(MSE=0.00571)and the highest R-squared value(R^(2)=0.93877).The experimental results show that the relationship between the electro-acoustic signal and the gas discharge power and distance can be effectively constructed based on the machine learning algorithm,which provides a new idea and basis for the online monitoring and real-time diagnosis of plasma parameters.

关键词： discharge plasma plasma real-time diagnosis electro-acoustic signal machine learning acoustic signature

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空中无人集群时滞置信传播协同导航算法

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导航与控制 2024年第1期23卷 14-23+13页

作者：王婕熊智王融陈明星熊骏南京航空航天大学自动化学院安徽工程大学南京邮电大学

空中无人集群协同导航系统依赖于载体间的信息传输，信息传输时间导致相对导航观测出现时滞。针对传统置信传播算法消息传递时未考虑观测时滞的问题，提出了一种空中无人集群时滞置信传播协同导航算法。首先根据置信传播中相对测距信息... 详细信息

空中无人集群协同导航系统依赖于载体间的信息传输，信息传输时间导致相对导航观测出现时滞。针对传统置信传播算法消息传递时未考虑观测时滞的问题，提出了一种空中无人集群时滞置信传播协同导航算法。首先根据置信传播中相对测距信息轮播出现的时滞量建立时滞功能节点误差模型，再通过卫星伪距一阶泰勒展开项与导航卫星运动速度的数量级变化推算伪距值，并利用时滞置信传播算法完成所有无人飞行器的后验概率估计。仿真结果表明，无人飞行器定位精度在60 m/s的情况下最高提升了32.70%,在100 m/s的情况下最高提升了48.01%,满足了中高速飞行状态下的定位需求，有效地改善了传统置信传播算法的协同导航性能。

关键词：协同导航置信传播空中无人集群观测时滞图模型

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