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Dual smoothing ionospheric gradient monitoring algorithm for dual-frequency BDS GBAS

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Chinese Journal of Aeronautics 2020年第12期33卷 3395-3404页

作者： Zhipeng WANG Yu YIN Dan SONG Kun FANG Qiang LI Xiao LI National Key Laboratory of CNS/ATM School of Electronic and Information EngineeringBeihang UniversityBeijing 100083China Beijing Hualong Tong Science and Technology Co LtdBeijing 100084China

In this study,a Dual Smoothing Ionospheric Gradient Monitor Algorithm(DSIGMA)was developed for Code-Carrier Divergence(CCD)faults of dual-frequency Ground-Based Augmentation Systems(GBAS)based on the Bei Dou Navigation Satellite System(BDS).Divergence-Free(DF)combinations of the signals were used to form test statistics for a dualfrequency ***,the single-frequency DSIGMA was reviewed,which supports the GBAS approach service type D(GAST-D)for protection against the effect of large ionospheric *** single-frequency DSIGMA was used to create a novel input scheme for the dual-frequency DSIGMA by introducing DF *** steady states of the test statistics were also *** monitors were characterized using BDS measurement data,whereby standard deviations of 0.0432 and 0.0639 m for the proposed two test statistics were used to calculate the monitor *** extensive simulation was designed to assess the monitor performance by comparing the Probability of Missed Detection(PMD)according to the differential error with the range domain PMD limits under different fault *** results showed that the proposed algorithm has a higher integrity performance than the single-frequency *** minimum detectable divergence with the same missed probability is less than 50%that of GAST-D.

关键词： Approach Augmentation Integrity Ionosphere-monitoring Satellite navigation Smoothing algorithms steady state Threshold

Liquid Jet Impingement Heat Transfer with or without Boiling

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Journal of Thermal Science 1993年第1期2卷 32-49页

作者： C.F.Ma T.Gomi 等 DepartmentofThermalScienceandEngineering BeijingPolytechnicUniversityBeijing100022China Departmento

The purpose of this paper is to summarize the important studies in the area of impingement heat transfer with or without phase change, with emphasis on the research conducted at Beijing Polytechnic University mainly with circular jets. Heat transfer characteristics of single phase jets are discussed in detail. Comment is presented on boiling heat transfer of impinging jets for steady and transient states. Some special colling configurations of two-phase jets are also introduced.

关键词： impingement heat transfer single phase phase change steady state transient state.

BIFURCATION ANALYSIS OF A MITOTIC MODEL OF FROG EGGS

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Applied Mathematics and Mechanics(English Edition) 2003年第3期24卷 284-297页

作者：吕金虎张子范张锁春 Institute of Systems Science Academy of Mathematics and System SciencesChinese Academy of Sciences Institute of Applied Mathematics Academy of Mathematics and System SciencesChinese Academy of Sciences

The mitotic model of frog eggs established by Borisuk and Tyson is qualitatively *** existence and stability of its steady states are further ***,the bifurcation of above model is further investigated by using theoretical analysis and numerical simulations. At the same time, the numerical results of Tyson are verified by theoretical analysis.

关键词： mitosis steady state periodic solution supercritical bifurcation subcritical bifurcation

STABILITY OF A PREDATOR-PREY SYSTEM WITH PREY TAXIS IN A GENERAL CLASS OF FUNCTIONAL RESPONSES

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Acta Mathematica Scientia 2016年第1期36卷 62-72页

作者： M.YOUSEFNEZHAD S.A.MOHAMMADI Department of Mathematical Sciences Sharif University of Technology Tehran Iran Department of Mathematics College of Sciences Yasouj University Yasouj 75918-71934 Iran

In this paper, a diffusive predator-prey system with general functional responses and prey-tactic sensitivities is studied. Providing such generality, we construct a Lyapunov function and we show that the positive constant steady state is locally and globally asymptotically stable. With an eye on the biological interpretations, a numerical simulation is performed to illustrate the feasibility of the analytical findings.

关键词： predator-prey global stability steady state Lyapunov function

Elastodynamic analysis at an interface of viscous fluid/thermoelastic micropolar honeycomb medium due to inclined load

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Applied Mathematics and Mechanics(English Edition) 2009年第3期30卷 353-364页

作者： Rajneesh Kumar Rajani Rani Gupta Li-qun CHEN Department of Mathematics Kurukshetra University Kurukshetra 136119 India 不详

In this paper, the effect of angle inclination at the interface of a viscous fluid and thermoelastic micropolar honeycomb solid due to inclined load is investigated. The inclined load is assumed to be a linear combination of normal load and tangential load. Laplace transform with respect to time variable and Fourier transform with respect to space variable are applied to solve the problem. Expressions of stresses, temperature distribution, and pressures in the transformed domain are obtained by introducing potential functions. The numerical inversion technique is used to obtain the solution in the physical domain. The frequency domain expressions for steady state are also obtained with appropriate change of variables. Graphic representations due to the response of different sources and changes of angle inclination are shown. Some particular cases are also discussed.

关键词： viscous fluid thermoelastic micropolar honeycomb material inclined load time harmonic steady state

A RepairableGeoX/G/1 Retrial Queue with Bernoulli Feedback and Impatient Customers

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Acta Mathematicae Applicatae Sinica 2014年第1期30卷 205-222页

作者： Shan GAO Zai-ming LIU Department of Mathematics Fuyang Normal College School of Mathematics and Statistics Central South University

Abstract This paper deals with a discrete-time batch arrival retrial queue with the server subject to starting *** from standard batch arrival retrial queues with starting failures,we assume that each customer after service either immediately returns to the orbit for another service with probabilityθor leaves the system forever with probability 1θ（0≤θ〈1）.On the other hand,if the server is started unsuccessfully by a customer（external or repeated）,the server is sent to repair immediately and the customer either joins the orbit with probability q or leaves the system forever with probability 1 q（0≤q〈1）.Firstly,we introduce an embedded Markov chain and obtain the necessary and sufcient condition for ergodicity of this embedded Markov ***,we derive the steady-state joint distribution of the server state and the number of customers in the system/orbit at arbitrary *** also derive a stochastic decomposition *** the special case of individual arrivals,we develop recursive formulae for calculating the steady-state distribution of the orbit ***,we investigate the relation between our discrete-time system and its continuous ***,some numerical examples show the influence of the parameters on the mean orbit size.

关键词： discrete-time queue retrial queue starting failure steady state Bernoulli feedback

Output Rate of Atomic Four-Wave Mixing in Two-Component Bose-Einstein Condensate

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Communications in Theoretical Physics 2004年第5期41卷 695-698页

作者： LI Jia-Hua~1 LI Wei-Bing~1 PENG Ju-Cun~2 1 Department of Physics,Huazhong University of Science and Technology,Wuhan 430074,China2 Department of Physics,Xiaogan Normal University,Xiaogan 432100,China Department of Physics Huazhong University of Science and Technology Wuhan 430074 China Department of Physics Xiaogan Normal University Xiaogan 432100 China

In this letter,following the proposal of Heurich et al.[***.A63(2001)033605],we analyze anddiscuss output rate of atomic four-wave mixing in the two-component Bose-Einstein condensate under the condition ofthe steady *** results show that the magnitude of the signal beam increases with the increase of the intensityof the probe beam,up to a saturated value,then it decreases as the probe beam *** influence of theinteraction range on the signal beam is also *** particular,it is worth while pointing out that in contrast tothe previous solutions,our obtained analytical solutions are of very simple and explicit forms,which open the door forfurther investigating the related physical mechanisms.

关键词： atomic four-wave mixing steady state Bose-Einstein condensate

An Efficient Nonlinear Multigrid Solver for the Simulation of Rarefied Gas Cavity Flow

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Communications in Computational Physics 2023年第7期34卷 357-391页

作者： Zhicheng Hu Guanghan Li School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106China

We study efficient simulation of steady state for multi-dimensional rarefied gas flow,which is modeled by the Boltzmann equation with BGK-type collision term.A nonlinear multigrid solver is proposed to resolve the efficiency issue by the following *** unified framework of numerical regularized moment method is first adopted to derive the high-quality discretization of the underlying problem.A fast sweeping iteration is introduced to solve the derived discrete problem more efficiently than the usual time-integration scheme on a single level *** it as the smoother,the nonlinear multigrid solver is then established to significantly improve the convergence *** OpenMP-based parallelization is applied in the implementation to further accelerate the *** experiments for two lid-driven cavity flows and a bottom-heated cavity flow are carried out to investigate the performance of the resulting nonlinear multigrid *** results show the wonderful efficiency and robustness of the solver for both first-and second-order spatial discretization.

关键词： Boltzmann equation moment method multigrid rarefied gas flow steady state

Effects of combined drug therapy on HIV-1 infection dynamics

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International Journal of Biomathematics 2016年第5期9卷 1-23页

作者： Deepmala Kamboj M. D. Sharma MLN College Yamuna Nagar Haryana India Department of Mathematics Kurukshetra University India

Infection of human immunodeficiency virus （HIV） is determined through the decay of healthy CD44- T-cells in a well-mixed compartment, such as a bloodstream. A mathe- matical model is considered to illustrate the effects of combined drug therapy, i.e. reverse transcription plus protease inhibitor, on viral growth and T-cell population dynamics. This model is used to explain the existence and stability of infected and uninfected steady states in HIV growth. An analytical technique, called variational iteration method （VIM）, is used to solve the mathematical model. This method is modified to obtain the rapidly convergent successive approximations of the exact solution. These approximations are obtained without any restrictions or the transformations that may change the physical behavior of the problem. Numerical simulations are computed and exhibited to illustrate the effects of proposed drug therapy on the growth or decay of infection.

关键词： HIV infection CD4+ T-cells steady state stability iteration method efficacy.