检索结果-南通市图书馆

A reduced-order-model-based multiple-in multiple-out gust alleviation control law design method in transonic flow

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2014年第2期57卷 368-378页

作者： chen Gang WANG xian LI YueMing State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace Xi'an Jiaotong University

Gust alleviation is very important to a large flexible aircraft.A nonlinear low-order aerodynamic state space model is required to model the nonlinear aeroelastic responses due to *** on the proper orthogonal decomposition method,a reduced order modeling of gust loads was *** then the open-loop and closed-loop reduced order state space model for the transonic aeroelastic system was *** static output feed back control scheme was used to design a simple multiple-in multiple-out(MIMO)gust alleviation control *** control law was demonstrated with the Goland+wing model with four control *** simulation results of different discrete gusts show the capability and good performance of the designed MIMO controller in transonic gust alleviation.

关键词： transonic gust alleviation reduced order model proper orthogonal decomposition static output feed back

ruin Probability and Joint Distributions of Some Actuarial Random Vectors in the Compound Pascal Model

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2011年第1期27卷 63-74页

作者： xian-min Geng Shu-chen Wan College of Science Nanjing University of Aeronautics & Astronautics Nanjing 210016 China

The compound negative binomial model, introduced in this paper, is a discrete time version. We discuss the Markov properties of the surplus process, and study the ruin probability and the joint distributions of actuarial random vectors in this model. By the strong Markov property and the mass function of a defective renewal sequence, we obtain the explicit expressions of the ruin probability, the finite-horizon ruin probability, the joint distributions of T, U（T - 1）, ｜U（T）｜ and inf U（n）（i.e., the time of ruin, the surplus immediately before ruin, the deficit at ruin and maximal deficit from ruin to recovery） and the distributions of some actuarial random vectors.

关键词： Compound negative binomial model ruin probability Sequence of up-crossing zero points,Ultimately leaving deficit time Joint distributions

A Finite-Dimensional Completely Integrable System Associated with Boussinesq Hierarchy

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第12期52卷 1081-1086页

作者： chen Lan-Xin ZHANG Jun-xian China University of Mining and Technology Beijing 100083 China Shijiazhuang University Shijiazhuang 050035 China

In this paper, a new completely integrable system related to the complex spectral problem -φ xx＋（i/4）wpx＋（i/4）（wp）x＋（1/4）vφ=iλφxand the constrained flows of the Boussinesq equations axe generated. According to the viewpoint of Hamiltonian mechanics, the Euler-Lagrange equations and the Legendre transformations, a reasonable Jacobi-Ostrogradsky coordinate system is obtained. Moreover, by means of the constrained conditions between the potentiaJ u, v and the eigenfunction φ, the involutive representations of the solutions for the Boussinesq equation hieraxchy axe given.

关键词： eigenvalue problem constraint flow symplectic manifold completely integrability involutive representation

Two Dimensional Indecomposable Modules over Infinite Dimensional Hereditary Path Algebras

在线全文

学校读者我要写书评

暂无评论

Communications in Mathematical Research 2015年第2期31卷 171-179页

作者： Hou ru-chen Wang Guo-hui cheng Zhi Du xian-kun School of Mathematics and Information Science Yantai University Yantai Research Institution China Agricultural University College of Mathematics and Computer Science Anhui Normal University

Non-isomorphic two dimensional indecomposable modules over infinite dimensional hereditary path algebras are described. We infer that none of them can be determined by their dimension vectors.

关键词： infinite dimensional hereditary path algebra path algebra quiver rep-resentation indecomposable module

在线全文

学校读者我要写书评

暂无评论

混合微电网参数识别方法研究

自动化仪表 2025年第1期46卷 26-30,35页

作者：孟贤陈曦张晓波华北电力大学经济与管理学院北京102206 国家电网有限公司物资部北京100032 北京国电通网络技术有限公司供应链管理业务事业部北京100070

针对现有混合微电网参数识别时精度低的问题,提出了一种改进人工兔群优化(ARO)算法的混合微电网参数识别方法。以最小化输出的实际值和估计值的计算误差为目标函数,建立了混合光伏-固体氧化物燃料电池(PV-SOFC)优化模型。提出了一种基... 详细信息

针对现有混合微电网参数识别时精度低的问题,提出了一种改进人工兔群优化(ARO)算法的混合微电网参数识别方法。以最小化输出的实际值和估计值的计算误差为目标函数,建立了混合光伏-固体氧化物燃料电池(PV-SOFC)优化模型。提出了一种基于改进ARO算法的PV-SPFC参数识别模型,应用迂回觅食搜索、随机躲避、能量收缩策略加快搜索效率并跳出局部极值。试验结果表明,与灰狼优化(GWO)算法和人工蜂群(ABC)算法相比,改进ARO算法具有更优质的解和更稳定的收敛过程。所提方法可为混合微电网数字孪生模型的建立提供支撑。

关键词：电力系统混合微电网数字孪生参数识别灰狼优化人工兔群优化人工蜂群

Markov Jump Processes in Estimating Sharing of Identity by Descent

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2021年第1期37卷 183-191页

作者： xian chen Wei GUO Xu-min NI School of Mathematical Sciences Xiamen UniversityXiamen 361005China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044China

Identity by descent(IBD)sharing is a very important genomic feature in population genetics which can be used to reconstruct recent demographic *** this paper we provide a framework to estimate IBD sharing for a demographic model called two-population model with *** adopt the structured coalescent theory and use a continuous-time Markov jump process{X(t),t≥0}to describe the genealogical process in such *** we apply Kolmogorov backward equation to calculate the distribution of coalescence time and develop a formula for estimating the IBD *** simulation studies show that our method to estimate IBD sharing for this demographic model is robust and accurate.

关键词： IBD sharing structured coalescent theory Markov jump process Kolmogorov backward equation

Pricing and Inventory Control Strategy for a Periodic-Review Energy Buy-Back System

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2016年第4期29卷 1018-1033页

作者： ZHANG Jihong chen Hongqiao DING Xiaosong LI xian International Business School Beijing Foreign Studies University Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences DECIDE Research Group Department of Computer and Systems Sciences Stockholm University

Along with the rapid development of economics and enhancement of industrialization, the power demand keeps rising and frequently creates mismatch between demand and supply in *** provides miscellaneous energy buy-back programs with great opportunities. Such programs, when activated, offer certain amount of financial compensations to participants for reducing their energy consumption during peak time. They aim at encouraging participants to shift their electricity usage from peak to non-peak time, and thereby release the demand pressure during peak time. This paper considers a periodic-review joint pricing and inventory decision model under an energy buy-back program over finite planning horizons, in which the compensation levels, setup cost and additive random demand function are incorporated. The objective is to maximize a manufacturer's expected total *** using Veinott's conditions, it is shown that the manufacturer's optimal decision is a state dependent(s, S, P) policy under a peak market condition, or partly an(s, S, A, P) policy under the normal market condition.

关键词： Additive demand function energy buy-back program joint pricing and inventory control Veinott's conditions.

Lower bound of local quantum uncertainty for high-dimensional bipartite quantum systems

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2019年第9期62卷 34-40页

作者： ShuHao Wang Hui Li xian Lu Bin chen State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China School of Science Tianjin University of TechnologyTianjin 300191China Institute of Software Chinese Academy of SciencesBeijing 100080China

Quantum correlations are of fundamental importance in quantum phenomena and studies related to quantum information processing. The measurement of quantum correlations is a central challenge. A recently proposed measure of quantum correlations,local quantum uncertainty(LQU), satisfies all the physical requirements as a measure of quantum correlations. This study derives a closed-form lower bound of the LQU for arbitrary-dimensional bipartite quantum states using operator relaxation. We also compared the lower bound with the optimized LQU for several typical sets of quantum states. The results show that the lower bound is near to the optimized LQU for three-dimensional bipartite quantum systems.

关键词： quantum correlations local quantum uncertainty bipartite quantum systems

Corrosion behavior and failure mechanism of SiC whisker and c-AlPO_(4) particle-modified novel tri-layer Yb_(2)Si_(2)O_(7)/mullite/SiC coating in burner rig tests

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2022年第12期11卷 1901-1917页

作者： Pengju chen Peng XIAO xian TANG Yang LI School of Nuclear Science and Technology University of South ChinaHengyang 421001China Powder Metallurgy Research Institute Central South UniversityChangsha 410083China National Key Laboratory of Science and Technology on High-strength Structural Materials Central South UniversityChangsha 410083China

The corrosion behavior of environmental barrier coatings(EBCs)directly affects the service life and stability of ceramic matrix composite(CMC)structural parts in the *** silicon carbide(SiC)whisker toughening phase and c-AlPO_(4) bonding phase are firstly used to improve the service life of novel tri-layer Yb_(2)Si_(2)O_(7)/mullite/SiC EBCs in the burner rig *** formation of penetrating cracks in Yb_(2)Si_(2)O_(7)/mullite/SiC coating caused the failure of coating at 1673 *** SiC whiskers in mullite middle coating significantly inhibited the formation of penetrating cracks in Yb_(2)Si_(2)O_(7)/mullite/SiC coating,and efficiently prevented the oxidation of carbon fiber reinforced silicon carbide(C_(f)/SiC)samples for 360-min thermal cycles(24 times)with a weight loss of 6.19×10^(−3) g·cm^(−2).Although c-AlPO_(4) particles further improved the service life of SiC_(w)-mullite(SM)coating,the overflow of PO_(x) gas aggravated the formation and expansion of cracks in the Yb_(2)Si_(2)O_(7) outer coating,and caused the service life of overall Yb_(2)Si_(2)O_(7)/c-AlPO_(4)-SiC_(w)-mullite(ASM)/SiC coating to be slightly lower than that of Yb_(2)Si_(2)O_(7)/SM/SiC *** study guides the design of modified tri-layer EBCs with long service life in high-temperature and high-speed gas environment.

关键词： Yb_(2)Si_(2)O_(7) mullite tri-layer sol-gel burner rig test