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一种基于迁移学习的多任务制导算法

兵工学报 2024年第6期45卷 1787-1798页

作者：罗皓文何绍溟亢有为北京理工大学宇航学院北京100081 北京理工大学无人机自主控制技术北京市重点实验室北京100081 上海机电工程研究所上海201109

针对典型的飞行器制导任务,利用深度学习算法可以有效地拟合导弹飞行状态与制导指令之间的函数关系。然而当制导任务发生变化时,其二者之间的映射关系也会随之改变,从而导致在当前环境下预训练好的模型无法直接作用于新环境,重新训练制... 详细信息

针对典型的飞行器制导任务,利用深度学习算法可以有效地拟合导弹飞行状态与制导指令之间的函数关系。然而当制导任务发生变化时,其二者之间的映射关系也会随之改变,从而导致在当前环境下预训练好的模型无法直接作用于新环境,重新训练制导模型需要大量的弹道数据和巨额的时间成本。为解决上述问题,基于迁移学习的思想引入域对抗神经网络,提出基于迁移学习的多任务制导算法。以1个含有大量标签数据的源域任务辅助2个含有极少量标签数据的目标域任务进行迁移学习,从而克服预训练与在线控制之间的环境差异。使用特征提取器和域判别器提取出对任务环境不敏感的关键特征,使神经网络学习到各个任务所共享的底层信息;为提高预测精度,分别设计针对不同任务的偏置加速度预测器。数值仿真结果表明:基于迁移学习的多任务制导算法实现了导弹在不同任务中的加速度指令预测。

关键词：多约束制导计算制导深度学习迁移学习偏置比例导引

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Optimal three-dimensional impact time guidance with seeker’s field-of-view constraint

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Chinese Journal of Aeronautics 2021年第2期34卷 240-251页

作者： shaoming he Chang-Hun LEE Hyo-Sang SHIN Antonios TSOURDOS School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Department of Aerospace Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea School of Aerospace Transport and ManufacturingCranfield UniversityCranfiehMK43 OALUnited Kingdom

This paper proposes a new three-dimensional optimal guidance law for impact time control with seeker’s Field-of-View(FOV) constraint to intercept a stationary target. The proposed guidance law is devised in conjunction with the concept of biased Proportional Navigation Guidance(PNG). The guidance law developed leverages a nonlinear function to ensure the boundedness of velocity lead angle to cater to the seeker’s FOV limit. It is proven that the impact time error is nullified in a finite-time under the proposed method. Additionally, the optimality of the biased command is theoretically analyzed. Numerical simulations confirm the superiority of the proposed method and validate the analytic findings.

关键词： Applied optimal control Field-of-view constraint Impact time control Missile guidance Optimal error dynamics

A unified formulation of optimal guidance-to-collision law for accelerating and decelerating targets

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Chinese Journal of Aeronautics 2022年第7期35卷 40-54页

作者： Young-Won KIM Boseok KIM Chang-Hun LEE shaoming he Department of Aerospace Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

This paper provides a unified formulation of optimal guidance-to-collision law for a target with an arbitrary acceleration or *** collision course for general target acceleration or deceleration is first determined from the engagement geometry in conjunction with the nonlinear engagement kinematics in the proposed *** heading error defined in the collision course is then adopted as a variable to be nullified for accomplishing the intercept *** proposed guidance law is derived based on the heading error dynamics and the optimal error dynamics to ensure optimality and finite-time *** illustrative examples,the proposed guidance command for a constant target acceleration and a target deceleration in the form of a quadratic function of speed are ***,the time-to-go prediction method is suggested for implementing the proposed *** characteristics of the proposed guidance command are analytically investigated to provide insight into the proposed *** key benefits of the proposed method lie in not producing unnecessary guidance commands near a target compared to other methods and ensuring optimality in guidance command even in the nonlinear engagement ***,numerical simulations are performed to validate the proposed method and to show our findings.

关键词： Guidance-to-collision law Optimal guidance Optimal error dynamics Target acceleration or deceleration Unified formulation

Reservoir Regulation for Control of an Ancient Landslide Reactivated by Water Level Fluctuations in heishui River,China

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Journal of Earth Science 2020年第6期31卷 1058-1067页

作者： Jian Guo Mo Xu Qiang Zhang Xianxuan Xiao Shishu Zhang shaoming he State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China PowerChina Chengdu Engineering Corporation Limited Chengdu 610072China

Due to the complex geological processes of Qinghai-Tibet Plateau,numerous deposits,especially the large-scale ancient landslide deposits,are characteristic features of the valleys incised in southwestern *** water level fluctuations since 2011 in Maoergai Reservoir,China,registered the reactivation of Xierguazi ancient landslide,and presented a significant risk to neighboring *** on detailed field survey and drilling exploration,the landslide was divided into Zone A and Zone B,and other characterizations of landslide were studied as *** precisely measure the extent of landslide displacement during filling and drawdown stage,surface displacement monitoring system was deployed on the *** monitoring analyses data reveal that reservoir fluctuation is the dominant factor influencing landslide displacement,especially during drawdown ***,a future sliding is anticipated in Zone A,while a creep had already existed in Zone B.A reservoir regulation was then established using the lead-lag correlation between reservoir fluctuation and landslide displacement and landslide stability *** the end,the follow-up deformation monitoring demonstrates that the reservoir regulation controlled the landslide *** control by reservoir regulation in Maoergai can serve as a case study for other settlements involved in similar construction activities.

关键词： ancient landslide reactivation reservoir regulation displacement monitoring correlation analysis

Numerical and analytical studies on the coupling effects of unloading and cutterhead vibration on tunnel face in dry sandy ground

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Underground Space 2024年第5期18卷 256-272页

作者： Junzuo he shaoming Liao Mengbo Liu Motoi Iwanami Yanqing Men Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of Road and Traffic Engineering Ministry of EducationTongji UniversityShanghai 200092China Department of Civil and Environmental Engineering Waseda UniversityTokyo 169-0072Japan Jinan Rail Transit Group Co. Ltd.Jinan 250014China

When tunnelling in difficult ground conditions,shield machine would inevitably produce significant ground loss and vibration,which may disturb the ground ahead of the tunnel *** this paper,discrete element models calibrated by model tests were established to investigate the response of tunnel face under the coupling effects of unloading and cutterhead *** results show that the friction angle reduction under cyclic loading and vibration attenuation in the sandy ground are significant and can be estimated by the fitted exponential *** cutterhead vibration,the tunnel face stability is undermined and the limit support pressure(LSP)increases to 1.4 times as that in the static case with the growth of frequency and ***,the loosening zone becomes wider and the arching effect is weakened with the reduction of peak horizontal stress and the increase of vertical stress above the *** on the numerical results,a pseudo-static method was introduced into the limit equilibrium analysis of the wedge-prism model for calculating the LSP under *** an error rate less than 5.2%,the proposed analytical method is well *** analytical calculation reveals that the LSP would increase with the growth of vibration amplitude,vibration frequency and covered depth but decrease with the increase of friction *** study can not only lay a solid foundation for the further investigation of ground loss,ground water and soft-hard heterogeneous ground under cutterhead vibration,but also provide meaningful references for the control of environmental disturbance in practice.

关键词： Cutterhead vibration Tunnel face stability Discrete element method Pseudo-static method

A mixed Nash equilibrium solution for visibility-based pursuit-evasion game with multiple obstacles

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Science China(Information Sciences) 2024年第9期67卷 330-332页

作者： shaoming BU Li LIANG Youqing WANG College of Information Science and Technology Beijing University of Chemical Technology

This study primarily investigates a visibility-based pursuitevasion game with multiple obstacles. The pursuer aims to maintain surveillance over the evader as long as possible, while the evader's objective is to escape the pursuer's surveillance as quickly as possible. We use the explicit strategy method to analyze the winning conditions and optimal strategy of the player in the case of corner obstacles and propose a 'Present-Future-Past'(PFP) loop structure to extend the strategy to the case of multiple obstacles.

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浅谈地铁车站空调负荷特性

暖通空调 2007年第8期37卷 125-127,120页

作者：何绍明广州市地铁设计研究院

介绍了地铁车站空调负荷的计算方法。以广州典型地铁车站的设计数据为例,经分析得出了地铁车站空调负荷的主要控制因素是车站客流量和新风负荷的结论。

关键词：地铁空调负荷屏蔽门逐时负荷

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某餐饮娱乐楼空调方案比选

暖通空调 2005年第9期35卷 93-95页

作者：何绍明广州地铁设计研究院

介绍了建筑物的概况和对空调系统的使用要求,比较分析了三种空调方案的初投资及运行费,得到了适合该建筑的空调方案。

关键词：空调方案螺杆式冷水机组 VRV空调系统空气源热泵机组比选娱乐餐饮空调系统建筑物运行费

Plant-based dietary patterns and risk of esophageal cancer:A prospective cohort study spanning 17 years

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Chinese Journal of Cancer Research 2024年第1期36卷 36-45页

作者： Xiaorui Zhang Feifan he Jiayue Li Ru Chen Xinqing Li Li Li Fen Liu shaoming Wang Wenqiang Wei Department of Epidemiology and health Statistics School of Public HealthBeijing Municipal Key Laboratory of Clinical EpidemiologyCapital Medical UniversityBeijing 100069China National Central Cancer Registry office National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of Cancer Epidemiology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China

Objective: Plant-based diets have multiple health benefits for cancers;however, little is known about the association between plant-based dietary patterns and esophageal cancer(EC).This study presents an investigation of the prospective associations among three predefined indices of plant-based dietary patterns and the risk of ***: We performed endoscopic screening for 15,709 participants aged 40-69 years from two high-risk areas of China from January 2005 to December 2009 and followed the cohort until December 31, 2022. The overall plant-based diet index(PDI), healthful plant-based diet index(h PDI), and unhealthful plant-based diet index(u PDI), were calculated using survey responses to assess dietary patterns. We applied Cox proportional hazard regression to estimate the multivariable hazard ratios(HRs) and 95% confidence intervals(95% CIs) of EC across 3plant-based diet indices and further stratified the analysis by ***: The final study sample included 15,184 participants in the cohort. During a follow-up of 219,365person-years, 176 patients with EC were identified. When the highest quartile was compared with the lowest quartile, the pooled multivariable-adjusted HR of EC was 0.50(95% CI, 0.32-0.77) for h PDI. In addition, the HR per 10-point increase in the h PDI score was 0.42(95% CI, 0.27-0.66) for ECs. Conversely, u PDI was positively associated with the risk of EC, and the HR was 1.80(95% CI, 1.16-2.82). The HR per 10-point increase in the u PDI score was 1.90(95% CI, 1.26-2.88) for ECs. The associations between these scores and the risk of EC were consistent in most subgroups. These results remained robust in sensitivity ***: A healthy plant-based dietary pattern was associated with a reduced risk of EC. Emphasizing the healthiness and quality of plant-based diets may be important for preventing the development of EC.

关键词： Esophageal cancer diet dietary pattern epidemiology nutrition prospective cohort study