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Chinese Journal of Aeronautics 2022年第6期35卷 226-239页

作者： Guanlin LI ming yang Songyan WANG Tao CHAO Control and Simulation Center Harbin Institute of TechnologyHarbin 150001China

This paper deals with the problem of guidance law design for the single moving mass controlled reentry vehicle when impact angle constraints and maneuvering target are taken into *** specifically,a modified rolling guidance law is proposed with the interactive virtual target and the landing point prediction ***,considering the fact that the roll channel can be controlled directly,the relative motion between the single moving mass controlled reentry vehicle and the target is described by the error angle between the relative velocity and the ***,a nonlinear error angle command is given to reduce the rotation *** satisfy impact angle constraints,an interactive virtual target is presented and the‘‘S”formed velocity of the virtual target is given to abate the error angle tracking difficulty at the final stage of the reentry ***,the landing point prediction strategy is employed and the motion variation trend is also taken into *** the maneuvering target is replaced with the predicted landing point,the error angle tracking difficulty caused by the target velocity decreases,which is helpful to meet impact angle constraints and improve guidance accuracy at the same ***,the finite-time rolling guidance law is proposed and proved via Lyapunov stability *** with the existing method,lower-speed rotation,smaller missing distance and less impact angle errors are obtained,which can be demonstrated by numerical simulations.

关键词： Reentry vehicles Guidance law Impact angle Maneuvering target Finite-time convergence

Linear-quadratic and norm-bounded differential game combined guidance strategy against active defense aircraft in three-player engagement

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Chinese Journal of Aeronautics 2023年第8期36卷 331-350页

作者： Tao CHAO Xintao WANG Songyan WANG ming yang Control and Simulation Center Harbin Institute of TechnologyHarbin 150080China

A new type of guidance strategy, combining linear quadratic and norm-bounded game theory, is proposed for the scenario of an attacker against active defense aircraft in three-player engagement. The problem involves three players, an attacker, a defender and a target. The differential game theory and the solution of Hamiltonian equation are utilized to obtain the combined guidance strategy for each player with arbitrary-order dynamics. The game process is divided into4 phases, C1-C4, according to the switching time. The linear quadratic differential game guidance scheme is employed to reduce the fuel cost in the game parts of C1 and C3. The norm-bounded game guidance strategy is adopted to satisfy the constraint of control input in the game stages C2 and C4. Furthermore, zero-effort miss distance is introduced to meet the constraints of game space and defender’s killing radius in the guidance strategy, which guarantees that the attacker is able to avoid the interception of the defender and hit the target with lower fuel cost and maximum acceleration. And it is proved that the proposed guidance strategy satisfies the Nash equilibrium condition. Finally, the feasibility and superiority of combined guidance strategy are respectively illustrated by nonlinear numerical simulation and verified by comparing with linear quadratic and norm-bounded differential game guidance strategies.

关键词： Activedefense aircraft Acceleration Energy optimization Game theory Three-player engagement

Bayesian Network Based Imprecise Probability Estimation Method for Wind Power Ramp Events

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Journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1510-1519页

作者： Yuanchun Zhao Wenli Zhu ming yang Mengxia Wang Key Laboratory of Power System Intelligent Dispatch and Control Shandong University State Grid Jinan Power Company

Although wind power ramp events(WPREs)are relatively scarce,they can inevitably deteriorate the stability of power system operation and bring risks to the trading of electricity *** this paper,an imprecise conditional probability estimation method for WPREs is proposed based on the Bayesian network(BN)*** method uses the maximum weight spanning tree(MWST)and greedy search(GS)to build a BN that has the highest fitting degree with the observed ***,an extended imprecise Dirichlet model(IDM)is developed to estimate the parameters of the BN,which quantificationally reflect the ambiguous dependencies among the random ramp event and various meteorological *** BN is then applied to predict the interval probability of each possible ramp state under the given meteorological conditions,which is expected to cover the target probability at a specified confidence *** proposed method can quantify the uncertainty of the probabilistic ramp event ***,by using the extracted dependencies and Bayesian rules,the method can simplify the conditional probability estimation and perform reliable prediction even with scarce *** results on a real wind farm with three-year operation data illustrate the effectiveness of the proposed method.

关键词： Bayesian network(BN) conditional probability imprecise Dirichlet model(IDM) imprecise probability wind power ramp events

Dynamic Simulation of a Novel Solar Polygeneration System for Heat, Power and Fresh Water Production based on Solar Thermal Power Tower Plant

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Journal of Thermal Science 2020年第2期29卷 378-392页

作者： LI Xing WANG Zhifeng yang ming YUAN Guofeng Key Laboratory of Solar Thermal Energy and Photovoltaic System Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Engineering Research Center of Solar Thermal Power Beijing 100190China

A novel solar polygeneration system for heat, power and fresh water production with absorption heat pump(AHP) and humidification-dehumidification(HDH) desalination system was proposed for high-efficiency utilization of solar energy. A case study of the proposed system was investigated based on 1 MW solar thermal power(STP) tower plant located in Beijing. Depending on mathematical modeling of the proposed system, corresponding modules were developed in TRNSYS. Meanwhile, control and operation strategies were fully studied with principal of solar energy cascade utilization. The thermodynamic performance of the proposed system was dynamically simulated at one minute intervals in a typical day. It was found that solar energy utilization level was improved with the help of solar thermal storage system and continuous heating in different operation modes met well with flexible heating loads from 93.76 kW to 169.49 kW. During AHP operation period, its Coefficient of Performance(COP) varied from 1.39 to 1.73 due to recoverable condensate heat restricted by heating demand. Meanwhile, fresh water production of HDH increased from 352.05 kg/h to 416.62 kg/h with Gained Output Ratio(GOR) increase from 2.48 to 2.67. Compared with original STP tower plant, maximum power generation efficiency was increased from 18.66% to 19.22% with power from 1169.69 kW to 1204.44 kW.

关键词： polygeneration solar thermal power dynamic simulation absorption heat pump humidification-dehumidification

Robust spline-line energy management guidance algorithm with multiple constraints and uncertainties for solid rocket ascending

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Chinese Journal of Aeronautics 2022年第2期35卷 214-234页

作者： Songyan WANG Fei LIU Tao CHAO ming yang Control and Simulation Center Harbin Institute of TechnologyHarbin 150001China

For the solid rocket with depletion shutdown system,effective energy management is significant to meet terminal constraints by exhausting excess *** traditional energy management algorithms cannot satisfy the altitude constraint and path constraints are not sufficiently *** velocity adjustment capability of these algorithms is limited and the uncertainties are not *** on the on-line programming of velocity capability curve,Spline-Line Energy Management(SLEM)guidance algorithm is *** introduces lateral maneuvers to further consume the available velocity on the basis of longitudinal energy *** expressing the constraints as several algebraic equations,the closed-loop guidance problem is converted to solving a system of nonlinear equations about the curve parameters in real *** advantage is that the altitude constraint can be satisfied *** overload and control variable change rate and amplitude constraints are also considered during the flight by constructing the feasible boundary of velocity capability *** improve the robustness,it is further extended by estimating the actual *** effectiveness and advantages of SLEM are demonstrated by simulations and comparisons with other energy management *** results show that the proposed approach can satisfy multiple constraints with high precision under the condition of uncertainties.

关键词： Ascent guidance Energy management Multiple constraints Solid rockets Uncertainty Velocity capability curve

土地利用变化对非点源污染负荷的影响研究——以鉴江流域化州站控制区域为例

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节水灌溉 2025年第1期 51-60,67页

作者：郑李杰沈帅杨明杰王浩东李彤皖江工学院水利工程学院安徽马鞍山243031

土地利用类型的不同对流域非点源污染负荷的影响较大。为探究土地利用变化对非点源污染负荷的影响,以鉴江流域化州站控制区域为研究对象,利用SWAT模型进行模拟研究,通过对3种土地利用情景下氮、磷污染负荷变化的模拟分析,揭示其不同情... 详细信息

土地利用类型的不同对流域非点源污染负荷的影响较大。为探究土地利用变化对非点源污染负荷的影响,以鉴江流域化州站控制区域为研究对象,利用SWAT模型进行模拟研究,通过对3种土地利用情景下氮、磷污染负荷变化的模拟分析,揭示其不同情景下流域氮、磷的时空分布特征。结果表明:①径流、总氮和总磷在率定期、验证期的R2大于0.6、NSE大于0.5、PBIAS小于25%,可以较好地模拟流域径流、总氮和总磷过程。②和其他情景相比,情景二流域中总氮、总磷的负荷强度最低,其年均负荷量分别为16451.42 t、4642.72 t,且年内负荷强度与降雨量密切相关,说明其农业用地是控制流域非点源污染的关键区域,雨季是控制的关键时期。③在该地区未来的土地利用规划中,应尽量少占用林地,同时通过调整种植结构和防护措施的实施来减少农业用地氮、磷的输出。该研究可为土地利用和污染物控制提供研究思路,为保护和改善流域水环境和水质提供理论支持。

关键词：鉴江流域 SWAT模型土地利用非点源污染时空分布

Zero chiral bulk modes in 3D Weyl metamaterials

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Science Bulletin 2019年第12期64卷 799-801页

作者： yang ming Cheng-Wei Qiu School of Physics and Electronic Engineering Changshu Institute of TechnologySuzhou 215000China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore

In the Weyl semimetals, a special type of one-way chiral zero mode (CZM) can be supported if a strong magnetic field is applied. The corresponding CZM is related to the zero-order Landau level for relativistic particles in Dirac or Weyl systems. This special energy level can lead to chiral anomaly, which describes the phenomenon of breaking the conservation of chirality [1]. Under the action of an effective magnetic field, the zeroth Landau mode can be expected to propagate only in the chiral direction according to the chirality (left-handed or right-handed) of the Weyl points and the magnetic field direction. Distinguished from the topological insulators, such a one-way propagation mode is a bulk state rather than a surface state or edge state that travels along the interface. Recently, the discovery of Dirac or Weyl degeneracies in the electronic and photonic systems brings opportunities for experimental detection of the chiral zeroth Landau levels [2,3]. Notwithstanding, the chiral Landau level in the 3D photonic system has not been observed yet.

关键词： chiral zero mode(CZM) chirality topological insulators

Detection of Safety Helmet-Wearing Based on the YOLO_CA Model

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Computers, Materials & Continua 2023年第12期77卷 3349-3366页

作者： Xiaoqin Wu Songrong Qian ming yang State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025China

Safety helmets can reduce head injuries from object impacts and lower the probability of safety accidents,as well as being of great significance to construction ***,for a variety of reasons,construction workers nowadays may not strictly enforce the rules of wearing safety *** order to strengthen the safety of construction site,the traditional practice is to manage it through methods such as regular inspections by safety officers,but the cost is high and the effect is *** the popularization and application of construction site video monitoring,manual video monitoring has been realized for management,but the monitors need to be on duty at all times,and thus are prone to ***,this study establishes a lightweight model YOLO_CA based on YOLOv5 for the automatic detection of construction workers’helmet wearing,which overcomes the shortcomings of the current manual monitoring methods that are inefficient and *** coordinate attention(CA)addition to the YOLOv5 backbone strengthens detection accuracy in complex scenes by extracting critical information and suppressing non-critical *** parameter compression with deeply separable convolution(DWConv).In addition,to improve the feature representation speed,we swap out C3 with a Ghost module,which decreases the floating-point operations needed for feature channel fusion,and CIOU_Loss was substituted with EIOU_Loss to enhance the algorithm’s localization ***,the original model needs to be improved so as to enhance the detection of safety *** experimental results show that the YOLO_CA model achieves good results in all indicators compared with the mainstream *** with the original model,the mAP value of the optimized model increased by 1.13%,GFLOPs cut down by 17.5%,and there is a 6.84%decrease in the total model parameters,furthermore,the weight size cuts down by 4.26%,FPS increased by 39.58%,and the detection effect and model size of

关键词： Safety helmet CA YOLOv5 ghost module

Rotation Profiles of Solar-like Stars with Magnetic Fields

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Chinese Journal of Astronomy and Astrophysics 2008年第6期8卷 677-685页

作者： Wu-ming yang Shao-Lan Bi Department of Physics and Chemistry Henan Polytechnic University Jiaozuo 454000 China Department of Astronomy Beijing Normal University Beijing 100875 China National Astronomical Observatories/Yunnan Observatoryl Chinese Academy of Sciences Kunming 650011 China

We investigate the rotation profile of solar-like stars with magnetic fields. A diffu- sion coefficient of magnetic angular momentum transport is deduced. Rotating stellar models with different mass incorporating the coefficient are computed to give the rotation profiles. The total angular momentum of a solar model with only hydrodynamic instabilities is about 13 times larger than that of the Sun at the age of the Sun, and this model can not reproduce quasi-solid rotation in the radiative region. However, the solar model with magnetic fields not only can reproduce an almost uniform rotation in the radiative region, but also a total angular momentum that is consistent with the helioseismic result at the 3 tr level at the age of the Sun. The rotation of solar-like stars with magnetic fields is almost uniform in the radiative region, but for models of 1.2-1.5 MG, there is an obvious transition region between the convective core and the radiative region, where angular velocity has a sharp radial gradient, which is different from the rotation profile of the Sun and of massive stars with magnetic fields. The change of angular velocity in the transition region increases with increasing age and mass.

关键词： stars evolution stars: rotation stars: magnetic fields

B(LF,ω～2 )-refinability of inverse limits

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Applied Mathematics(A Journal of Chinese Universities) 2010年第4期25卷 496-502页

作者： XIONG Zhao-hui yang ming-quan Department of Mathematics Zhejiang Sci-Tech University Hangzhou 310018 China Department of Mathematics Jiaxing College Jiaxing 314001 China

Let X be the limit of an inverse system {Xα, παβ, ∧} and and let λ be the cardinal number of A. Assume that each projection πα ： X → Xα is an open and onto map and X is A-paracompact. We prove that if each Xα is B（LF, ω^2）-refinable （hereditarily B（LF, ω^2）- refinable）, then X is B（LF, ω^2）-refinable （hereditarily B（LF,ω ^2）-refinable）. Furthermore, we show that B（LF, ω^2）-refinable spaces can be preserved inversely undcr closed maps.

关键词： Inverse limit B(LF ω^2)-refinability hereditary B(LF,ω ^2)-refinability.