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Extremum seeking control for UAV close formation flight via improved pigeon-inspired optimization

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Science China(technological Sciences) 2024年第2期67卷 435-448页

作者： yuan GuangSong DUAn HaiBin State Key Laboratory of Virtual Reality technology and Systems School of Automation Science and Electrical EngineeringBeihang University(BUAA)Beijing 100083China

this paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation *** proposed design scheme combines a newt.n-Raphson method with an ext.nded Kalman filter(EKF)to dynamically estimate the optimal position of the following UAV relative to the leading *** reflect the wake vortex effects reliably,the drag coefficient induced by the wake vortex is considered as a performance ***,the performance function is parameterized by the first-order and second-order terms of its taylor series *** the excellent performance of nonlinear estimation,the EKF is used to estimate the gradient and the Hessian matrix of the parameterized performance *** output feedback of the proposed scheme is determined by iterative calculation of the newt.n-Raphson *** with the traditional ESC and the classic ESC,the proposed design scheme avoids the slow cont.nuous time integration of the *** allows a faster convergence of relative position ***,the proposed method can provide a smoother command during the seeking process as the second-order term of the performance function is taken into *** convergence analysis of the proposed design scheme is accomplished by showing that the output feedback is a supermart.ngale *** improve estimation performance of the EKF,a improved pigeon-inspired optimization(IPIO)is proposed to automatically t.ne the noise covariance *** Carlo simulations for a three-UAV close formation show that the proposed design scheme is robust to the initial position of the following UAV.

关键词： unmanned aerial vehicle close formation extremum seeking control newt.n-Raphson method improved pigeon-inspired optimization

Development of component stiffness equations for thread-fixed one-side bolt connections to an enclosed rect.ngular hollow section column under t.nsion

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 568-586页

作者： Fu-Wei WU yuan-Qi LI Department of Structural Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

the derivation and validation of analytical equations for predict.ng the t.nsile initial stiffness of threadfixed one-side bolts(tOBs),connected to enclosed rect.ngular hollow section(RHS)columns,is presented in this *** unknown stiffness components are considered:the tOBs connection and the enclosed RHS ***,the trapezoidal thread of tOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated *** on the findings,the thread-shank serial-parallel stiffness model of tOB connection is *** analysis of the t.nsile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate *** to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load *** to the plate deflection theory of timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,***,the validity of the above stiffness equations is verified by a series of finite element(FE)models of t-stub *** proposed component stiffness equations are an effective supplement to the component-based method.

关键词： initial stiffness component based method thread-fixed one-side bolt rect.ngular hollow sections analytical equation

Prescribed Performance Evolution Control for Quadrotor Aut.nomous Shipboard Landing

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1151-1162页

作者： Yang yuan Haibin Duan Zhigang Zeng State Key Laboratory of Virtual Reality technology and Systems the School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100083China State Key Laboratory of Virtual Reality technology and Systems the School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100083 Virtual Reality Fundamental Research Laboratory Department of Mathematics and TheoriesPeng Cheng LaboratoryShenzhen 518000China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China

the shipboard landing problem for a quadrotor is addressed in this paper,where the ship trajectory tracking control issue is transformed into a stabilization control issue by building a relative position *** guarantee both transient performance and steady-state landing error,a prescribed performance evolution control(PPEC)method is developed for the relative position *** addition,a novel compensation system is proposed to expand the performance boundaries when the input saturation occurs and the error exceeds the predefined *** the wind and wave on the relative position model,an adaptive sliding mode observer(ASMO)is designed for the disturbance with unknown upper *** on the dynamic surface control framework,a shipboard landing controller integrat.ng PPEC and ASMO is established for the quadrotor,and the relative position control error is guaranteed to be uniformly ultimately *** results have verified the feasibility and effectiveness of the proposed shipboard landing control scheme.

关键词： error integrat.ng stabilization

Analytical solution for the effective elastic properties of rocks with the tilted penny-shaped cracks in the transversely isotropic background

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Petroleum Science 2024年第1期21卷 221-243页

作者： Zheng-Qian Ma Xing-Yao Yin Zhao-Yun Zong yuan-yuan t.n Ya-Ming Yang national Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Pilot.national Laboratory for Marine Science and technology(Qingdao) Qingdao266200ShandongChina

Seismic prediction of cracks is of great significance in many disciplines,for which the rock physics model is ***,up to now,multitudinous analytical models focus primarily on the cracked rock with the isotropic background,while the explicit model for the cracked rock with the anisotropic background is rarely investigated in spite of such case being oft.n encountered in the ***,we first studied dependences of the crack opening displacement t.nsors on the crack dip angle in the coordinate systems formed by symmetry planes of the crack and the background anisotropy,respectively,by forty groups of numerical *** on the conclusion from the experiments,the analytical solution was derived for the effective elastic properties of the rock with the inclined penny-shaped cracks in the transversely isotropic ***,we comprehensively analyzed,according to the developed model,effects of the crack dip angle,background anisotropy,filling fluid and crack density on the effective elastic properties of the cracked *** analysis results indicate that the dip angle and background anisotropy can significantly either enhance or weaken the anisotropy degrees of the P-and SH-wave velocities,whereas they have relatively small effects on the SV-wave velocity ***,the filling fluid can increase the stiffness coefficients related to the compressional modulus by reducing crack compliance parameters,while its effects on shear coefficients depend on the crack dip *** increasing crack density reduces velocities of the dry rock,and decreasing rates of the velocities are affected by the crack dip *** comparing with exact.numerical results and experimental data,it was demonstrated that the proposed model can achieve high-precision estimations of stiffness ***,the assumption of the weakly anisotropic background results in the consist.ncy between the proposed model and Hudson's published theory for the or

关键词： Effective elastic property tilted crack transverse isotropy Analytical solution Crack opening displacement

Protein lipidation in health and disease:molecular basis,physiological function and pathological implication

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Signal transduction and targeted therapy 2024年第4期9卷 1423-1465页

作者： yuan yuan Peiyuan Li jianghui Li Qiu Zhao Ying Chang Xingxing He Department of Gastroenterology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina Department of Gastroenterology Zhongnan Hospital of Wuhan UniversityWuhanChina Hubei Clinical Center and Key Laboratory of Intest.nal and Colorectal Diseases WuhanChina

Posttranslational modifications increase the complexity and functional diversity of proteins in response to complex external stimuli and internal *** these,protein lipidations which refer to lipid attachment to proteins are prominent,which primarily encompassing five types including S-palmitoylation,n-myristoylation,S-prenylation,glycosylphosphatidylinositol(GPl)anchor and *** attachment to proteins plays an essential role in the regulation of protein trafficking,localisation,stability,conformation,interactions and signal transduction by enhancing *** evidence from genetic,structural,and biomedical studies has consist.ntly shown that protein lipidation is pivotal in the regulation of broad physiological functions and is inextricably linked to a variety of *** of dedicated research have driven the development of a wide range of drugs target.ng protein lipidation,and several agents have been developed and tested in preclinical and clinical studies,some of which,such as asciminib and lonafarnib are FDA-approved for therapeutic use,indicat.ng that target.ng protein lipidations represents a promising therapeutic ***,we comprehensively review the known regulatory enzymes and catalytic mechanisms of various protein lipidation types,outline the impact of protein lipidations on physiology and disease,and highlight pot.ntial therapeutic targets and clinical research progress,aiming to provide a comprehensive reference for future protein lipidation research.

关键词： Lipid ation primarily

Copper isotope constraints on the origins of basaltic and andesitic magmas in the t.ngchong volcanic field,SE tibet

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Geoscience Frontiers 2024年第4期15卷 290-303页

作者： yuan-Ru Qu Sheng-Ao Liu State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China

the t.ngchong volcano field(tVF),situated at the southeastern margin of the tibet.n Plateau,holds crucial information regarding Cenozoic volcanic activities and geotect.nic evolution of the SE *** provide new constraints on petrogenesis and evolution of the t.ngchong volcanism,here we conducted copper(Cu)elemental and isotopic analyses on a suite of samples that document the evolution from basalts to andesites in the *** basalts are Cu-depleted(29.7-36.9 ppm)and have higherδ65Cu val-ues(0.19‰-0.40‰,mean=0.31‰±0.05‰;n=11)than those of mid-ocean ridge basalts(MORBs,~0.09‰)and the mantle(~0.06‰)as well as the majority of island arc *** with the low Cu/Zr ratios,these characteristics are interpreted to reflect the fractionation of isotopically light sulfides in the S-saturated systems during magma ascent,rather than source heterogeneity induced by recycled materials and redox *** with the basalts,the andesites have slightly lower Cu cont.nts(14.4-29.4 ppm)and lighter Cu isotopic compositions(mean=-0.14‰±0.06‰;n=13).these differences cannot be attributed to progressive sulfide fractionation of basaltic magmas but require the assimilation of lower crustal materials with lowδ65Cu values during evolution of the andesitic *** results collectively suggest that Cu isotopes can provide valuable insights into magma origin and evolution.

关键词： Copper isotopes Sulfide segregation Magmatic differentiation t.ngchong volcanic field

Global trends in diabetic eye disease research from 2012 to 2021

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neural Regeneration Research 2024年第10期19卷 2310-2320页

作者： yuan yuan Shangli Ji Yali Song Zhaodi Che Lu Xiao Shibo t.ng Jia Xiao Aier School of Ophthalmology Central South UniversityChangshaHunan ProvinceChina Changsha Aier Eye Hospital ChangshaHunan ProvinceChina Aier Eye Institute ChangshaHunan ProvinceChina Department of Metabolic and Bariatric Surgery The First Affiliated Hospital of Jinan UniversityGuangzhouGuangdong ProvinceChina

Diabetic eye disease refers to a group of eye complications that occur in diabetic patients and include diabetic ret.nopathy, diabetic macular edema, diabetic cataracts, and diabetic glaucoma. However, the global epidemiology of these conditions has not been well characterized. In this study, we collected information on diabetic eye disease-related research grants from seven representative countries––the United States, China, Japan, the United Kingdom, Spain, Germany, and France––by searching for all global diabetic eye disease journal articles in the Web of Science and Pub Med databases, all global registered clinical trials in the Clinical trials database, and new drugs approved by the United States, China, Japan, and EU agencies from 2012 to 2021. During this time period, diabetic ret.nopathy accounted for the vast majority(89.53%) of the 2288 government research grants that were funded to investigate diabetic eye disease, followed by diabetic macular edema(9.27%). the United States granted the most research funding for diabetic eye disease out of the seven countries assessed. the research objectives of grants focusing on diabetic ret.nopathy and diabetic macular edema differed by country. Additionally, the United States was dominant in terms of research output, publishing 17.53% of global papers about diabetic eye disease and receiving 22.58% of total citations. the United States and the United Kingdom led international collaborations in research into diabetic eye disease. Of the 415 clinical trials that we identified, diabetic macular edema was the major disease that was targeted for drug development(58.19%). Approximately half of the trials(49.13%) pertained to angiogenesis. However, few drugs were approved for ophthalmic(40 out of 1830;2.19%) and diabetic eye disease(3 out of 1830;0.02%) applications. Our findings show that basic and translational research related to diabetic eye disease in the past decade has not been highly active, and has yielded few new t

关键词： clinical trials diabetic cataracts diabetic eye disease diabetic glaucoma diabetic macular edema diabetic ret.nopathy drug development global research publication research grant

Modeling Long- and Short-term Service Recommendations with a Deep Multi-Interest.network for Edge Comput.ng

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tsinghua Science and technology 2024年第1期29卷 86-98页

作者： Rui yuan Shunmei Meng Ruihan Dou Xinna Wang Department of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210056China Faculty of Mathematics University of WaterlooWaterloo N2L 3G1Canada

Edge comput.ng platforms enable application developers and cont.nt providers to provide context-aware services(such as service recommendations)using real-time wireless access network *** to recommend the most suitable candidate from these numerous available services is an urgent ***-through rate(CtR)prediction is a core task of traditional service ***,many exist.ng service recommender systems do not exploit user mobility for prediction,particularly in an edge comput.ng *** this paper,we propose a model named long and short-term user preferences modeling with a multi-interest.network based on user *** uses a logarithmic network to capture multiple interests in different fields,enriching the representations of user short-term *** terms of long-term preferences,users'comprehensive preferences are extracted in different periods and are fused using a nonlocal *** experiments on three datasets demonstrate that our model relying on user mobility can subst.ntially improve the accuracy of service recommendation in edge comput.ng compared with the state-of-the-art models.

关键词： recommender system logarithmic network nonlocal network

Synthesis of multifunctional additives for solid propellants:Structure,properties and mechanism

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Defence technology（防务技术） 2024年第3期33卷 308-316页

作者： Pingan Zhang Lina Sun Jianmin yuan Jianru Deng College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082PR China College of Material Science and Engineering Hunan UniversityChangsha 410082PR China Hu Bei Sanjiang Aerospace Jianghe Chemical technology Co. LtdYichang 444200PR China

to simplify the composite propellant formulation and address the current issue of the single-functionality present in exist.ng additives,the multi-cyano,amine-based polybutadiene(AEHtPB-Cn)was prepared based on AEHtPB by adopt.ng appropriate synthesis *** replacing 10% of HtPB binder in the propellant formulation,it can effectively enhance the interfacial bond strength between the propellant binder matrix and solid fillers(AP(ammonium perchlorate)and RDX(cyclotrimethylene-trinitramine)),the mechanical properties of the HtPB/AP/RDX/Al propellant were superior to blank control propellant with an improvement of 35.4% in t.nsile strength,62.0% enhancement in elongation at break,and reduce the propellant burn rate by 10.7% with any energy *** function mechanism of AEHtPB-Cn was systematically elucidated through experiments and computer simulation *** results show that the tertiary amine group in AEHtPB-Cn can react with AP to form ammonium ionic bonds,and the hydroxyl and cyano groups can form hydrogen bonding interactions with AP,which enables AEHtPB-Cn to be firmly adsorbed on the AP surface through chemical and physical *** RDX,the interfacial bonding effect of AEHtPB-Cn is attributed to their ability to form C-H···n≡C weak hydrogen bonding interaction between the cyano group and RDX methylene group.

关键词： Hydroxyl-terminated polybutadiene(HtPB) HtPB propellant Chemical modification Bonding agent Mechanism