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An Improved, Downscaled, Fine Model for Simulation of Daily Weather States 被引量:1
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作者 江志红 丁裕国 +1 位作者 郑春雨 陈威霖 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第6期1357-1366,共10页
In this study,changes in daily weather states were treated as a complex Markov chain process,based on a continuous-time watershed model(soil water assessment tool,SWAT) developed by the Agricultural Research Service... In this study,changes in daily weather states were treated as a complex Markov chain process,based on a continuous-time watershed model(soil water assessment tool,SWAT) developed by the Agricultural Research Service at the U.S.Department of Agriculture(USDA-ARS).A finer classification using total cloud amount for dry states was adopted,and dry days were classified into three states:clear,cloudy,and overcast(rain free).Multistate transition models for dry-and wet-day series were constructed to comprehensively downscale the simulation of regional daily climatic states.The results show that the finer,improved,downscaled model overcame the oversimplified treatment of a two-weather state model and is free of the shortcomings of a multistate model that neglects finer classification of dry days(i.e.,finer classification was applied only to wet days).As a result,overall simulation of weather states based on the SWAT greatly improved,and the improvement in simulating daily temperature and radiation was especially significant. 展开更多
关键词 stochastic simulation daily weather state series Markov chain state vector.
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State vector evolution localized over the edges of a square tight-binding lattice
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作者 何良明 石端文 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第3期1214-1220,共7页
We study thc time evolution of a state vector in a square tight-binding lattice, focusing on its evolution localized over the system surfaces. In this tight-binding lattice, the energy of atomic orbital centred at sur... We study thc time evolution of a state vector in a square tight-binding lattice, focusing on its evolution localized over the system surfaces. In this tight-binding lattice, the energy of atomic orbital centred at surface site is different from that at the interior (bulky) site by an energy shift U. It is shown that for the state vector initially localized on a surface, there exists an exponential law (y = ae^x/b + Y0) determined by the absolute value of the energy shift, |U|, which describes the transition of the state evolving on the square tight-binding lattice, from delocalized over the whole lattice to localized over the surfaces. 展开更多
关键词 Anderson localization surface states state vector evolution
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State Vectors—A New Method for Seismicity Analysis
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作者 YinXiangchu YuHuaizhong ZhangYongxian 《Earthquake Research in China》 2004年第3期263-270,共8页
The concept of state vector stems from statistical physics, where it is usually used to describe the evolution of a continuum field in its way of coarse-graining. In this paper, the state vector is employed to depict ... The concept of state vector stems from statistical physics, where it is usually used to describe the evolution of a continuum field in its way of coarse-graining. In this paper, the state vector is employed to depict the evolution of seismicity quantitatively, and some interesting results are presented. The authors investigated some famous earthquake cases (e.g., the Haicheng earthquake, the Tangshan earthquake, the west Kunlun Mountains earthquake, etc.) and found that the state vectors evidently change prior to the occurrence of large earthquakes. Thus it is believed that the state vector can be used as a kind of precursor to predict large earthquakes. 展开更多
关键词 State vector SEISMICITY Earthquake prediction
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Dynamics of Quantum State and Effective Hamiltonian with Vector Differential Form of Motion Method
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作者 Long Xiong Wei-Feng Zhuang Ming Gong 《Chinese Physics Letters》 SCIE EI CAS CSCD 2022年第7期36-40,共5页
Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective H... Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective Hamiltonian using various methods has gained great interest. We consider a vector differential equation of motion to derive the effective Hamiltonian for any periodically driven two-level system, and the dynamics of the spin vector are an evolution under the Bloch sphere. Here, we investigate the properties of this equation and show that a sudden change of the effective Hamiltonian is expected. Furthermore, we present several exact relations, whose expressions are independent of the different starting points. Moreover, we deduce the effective Hamiltonian from the high-frequency limit, which approximately equals the results in previous studies. Our results show that the vector differential equation of motion is not affected by a convergence problem, and thus, can be used to numerically investigate the effective models in any periodic modulating system. Finally, we anticipate that the proposed method can be applied to experimental platforms that require time-periodic modulation, such as ultracold atoms and optical lattices. 展开更多
关键词 Dynamics of Quantum State and Effective Hamiltonian with vector Differential Form of Motion Method HAMILTONIAN vector QUANTUM
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On Utility Maximization with Random Interval Payoffs 被引量:2
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作者 YOU Su-rong PENG Yu-zheng ZHAO Fei-fei 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第3期424-431,共8页
This article discusses the problem of utility maximization in a market with random-interval payoffs without short-selling prohibition. A novel expected utility model is given to measure an investor's subjective vi... This article discusses the problem of utility maximization in a market with random-interval payoffs without short-selling prohibition. A novel expected utility model is given to measure an investor's subjective view toward random interval wealth. Some techniques are proposed to transfer a complex programming involving interval numbers into a simple non-linear programming. Under the existence of the optimal strategy, relations between the optimal strategy and assets' prices are discussed. Some properties of the maximal utility function with respect to the endowment are given. 展开更多
关键词 random interval payoff acceptable state price vector expected utility optimal strategy
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Dynamic Response of Truss Adaptive Structures 被引量:1
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作者 ZHANG Lianwen XIA Renwei HUANG Hai 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第6期849-855,共7页
It is pointed out that the damping matrix deduced by active members in the finite element vibration equation of a truss adaptive structure generally can not be decoupled, which leads to the difficulty in the process o... It is pointed out that the damping matrix deduced by active members in the finite element vibration equation of a truss adaptive structure generally can not be decoupled, which leads to the difficulty in the process of modal analysis by classical superposition method. This paper focuses on the computational method of the dynamic response for truss adaptive structures. Firstly, a new technique of state vector approach is applied to study the dynamic response of truss adaptive structures. It can make the coeffic lent matrix of first derivative of state vector a symmetric positive definite matrix, and particularly a diagonal matrix provided that mass matrix is derived by lumped method, so the coefficient matrix of the first derivative of state vector can be exactly decomposed by CHOLESKY method. In this case, the proposed technique not only improves the calculation accuracy, but also saves the computing time. Based on the procedure mentioned above, the mathematical formulation for the system response of truss adaptive structures is systematically derived in theory. Thirdly, by using FORTRAN language, a program system for computing dynamic response of truss adaptive structures is developed. Fourthly, a typical 18 bar space truss adaptive structure has been chosen as test numerical examples to show the feasibility and effectiveness of the proposed method. Finally, some good suggestions, such as how to choose complex mode shapes practically in determining the dynamic response are also given. The new approach can be extended to calculate the dynamic response of general adaptive structures. 展开更多
关键词 truss adaptive structure dynamic response active member complex modal analysis state vector approach
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Exact Solutions of Two Coupled Harmonic Oscillators Related to the Sp(4,R) Lie Algebra 被引量:1
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作者 PANFeng DAILian-Rong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第6期661-664,共4页
Exact solutions of the eigenvalue problem of two coupled harmonic oscillators related to the Sp(4, R) Lie algebra are derived by using an algebraic method. It is found that the energy spectrum of the system is determi... Exact solutions of the eigenvalue problem of two coupled harmonic oscillators related to the Sp(4, R) Lie algebra are derived by using an algebraic method. It is found that the energy spectrum of the system is determined by one-boson excitation energies built on a vector coherent state of Sp(4, R) U(2). 展开更多
关键词 coupled harmonic oscillators Sp(4 R) Lie algebra vector coherent states
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Wavelet transform for Fresnel-transformed mother wavelets
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作者 刘述光 陈俊华 范洪义 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第12期57-62,共6页
In this paper, we propose the so-called continuous Fresnel-wavelet combinatorial transform which means that the mother wavelet undergoes the Fresnel transformation. This motivation can let the mother-wavelet-state its... In this paper, we propose the so-called continuous Fresnel-wavelet combinatorial transform which means that the mother wavelet undergoes the Fresnel transformation. This motivation can let the mother-wavelet-state itself vary from |ψ〉 to Ftr, s |ψ〉, except for variation within the family of dilations and translations. The Parseval's equality, admissibility condition and inverse transform of this continuous Fresnel-wavelet combinatorial transform are analysed. By taking certain parameters and using the admissibility condition of this continuous Fresnel-wavelet combinatorial transform, we obtain some mother wavelets. A comparison between the newly found mother wavelets is presented. 展开更多
关键词 wavelet transform fresnel transformation quantum state vector
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Combined forecast method of HMM and LS-SVM about electronic equipment state based on MAGA 被引量:1
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作者 Jianzhong Zhao Jianqiu Deng +1 位作者 Wen Ye Xiaofeng Lü 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第3期730-738,共9页
For the deficiency that the traditional single forecast methods could not forecast electronic equipment states, a combined forecast method based on the hidden Markov model(HMM) and least square support vector machin... For the deficiency that the traditional single forecast methods could not forecast electronic equipment states, a combined forecast method based on the hidden Markov model(HMM) and least square support vector machine(LS-SVM) is presented. The multi-agent genetic algorithm(MAGA) is used to estimate parameters of HMM to overcome the problem that the Baum-Welch algorithm is easy to fall into local optimal solution. The state condition probability is introduced into the HMM modeling process to reduce the effect of uncertain factors. MAGA is used to estimate parameters of LS-SVM. Moreover, pruning algorithms are used to estimate parameters to get the sparse approximation of LS-SVM so as to increase the ranging performance. On the basis of these, the combined forecast model of electronic equipment states is established. The example results show the superiority of the combined forecast model in terms of forecast precision,calculation speed and stability. 展开更多
关键词 parameter estimation hidden Markov model(HMM) least square support vector machine(LS-SVM) multi-agent genetic algorithm(MAGA) state forecast
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A Combined Heterotic String and Kähler Manifold Elucidation of Ordinary Energy,Dark Matter,Olbers’s Paradox and Pure Dark Energy Density of the Cosmos
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作者 Mohamed S.El Naschie 《Journal of Modern Physics》 2017年第7期1101-1118,共18页
We utilize the topological-geometrical structure imposed by the Heterotic superstring theory on spacetime in conjunction with the K3 K&auml;hler manifold to explain the mysterious nature of dark matter and its cou... We utilize the topological-geometrical structure imposed by the Heterotic superstring theory on spacetime in conjunction with the K3 K&auml;hler manifold to explain the mysterious nature of dark matter and its coupling to the pure dark energy density of the cosmos. The analogous situations in the case of a Kerr black hole as well as the redundant components of the Riemannian tensor are pointed out and the final result was found to be in complete agreement with all previous theoretical ones as well as all recent accurate measurements and cosmic observations. We conclude by commenting briefly on the Cantorian model of Zitterbewegung and the connection between Olbers’s paradox and dark energy. 展开更多
关键词 Heterotic Strings K3 Kahler Manifold Dark Matter Pure Heterotic Dark Energy Einstein’s Relativity Accelerated Cosmic Expansion Negative Gravity Fractal Spacetime E-Infinity Theory Kerr Black Holes Geometry Kaluza-Klein Theory Dvoretzky’s Theorem Empty Set Zero Set Connes Noncommutative Geometry ‘tHooft Renormalon STATE vector Reduction Density Matrix ‘tHooft Fractal Spacetime Transfinite Cellular Automata Interpretation of Quantum Mechanics ZITTERBEWEGUNG Olbers’s Dark Sky Paradox
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Multi-sensor Data Fusion for Wheelchair Position Estimation with Unscented Kalman Filter 被引量:5
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作者 Derradji Nada Mounir Bousbia-Salah Maamar Bettayeb 《International Journal of Automation and computing》 EI CSCD 2018年第2期207-217,共11页
This paper investigates the problem of estimation of the wheelchair position in indoor environments with noisy mea- surements. The measuring system is based on two odometers placed on the axis of the wheels combined w... This paper investigates the problem of estimation of the wheelchair position in indoor environments with noisy mea- surements. The measuring system is based on two odometers placed on the axis of the wheels combined with a magnetic compass to determine the position and orientation. Determination of displacements is implemented by an accelerometer. Data coming from sensors are combined and used as inputs to unscented Kalman filter (UKF). Two data fusion architectures: measurement fusion (MF) and state vector fusion (SVF) are proposed to merge the available measurements. Comparative studies of these two architectures show that the MF architecture provides states estimation with relatively less uncertainty compared to SVF. However, odometers measurements determine the position with relatively high uncertainty followed by the accelerometer measurements. Therefore, fusion in the navigation system is needed. The obtained simulation results show the effectiveness of proposed architectures. 展开更多
关键词 Data fusion unscented Kalman filter (UKF) measurement fusion (MF) NAVIGATION state vector fusion (SVF) wheelchair.
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AN IMPROVED ALGORITHM FOR SOLVING ALL D-MPS IN MULTI-STATE NETWORKS 被引量:1
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《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2017年第6期711-731,共21页
Reliability is a desirable performance indicator of many real-world systems to measure the quality level. One general method for evaluating multi-state reliability is using d-minimal paths (d-MPs). However, being an... Reliability is a desirable performance indicator of many real-world systems to measure the quality level. One general method for evaluating multi-state reliability is using d-minimal paths (d-MPs). However, being an NP-hard problem, searching for all d-MPs is a rather challenging task. This paper proposes an improved algorithm to solve the d-MP problem. To reduce the search space of d-MPs, a concept of lower capacity bound is introduced into the d-MP problem, and an effective technique is developed to fred lower capacity bounds. Meanwhile, the fast enumeration method which is a recent improvement to the traditional enunaeration method is employed to solve d-MPs. In addition, by introducing the operation of transforming undirected edges into directed edges, the proposed algorithm is applicable to solving both directed networks and undirected networks. Through numerical experiments, it is found that the proposed algorithm holds a distinct advantage over the existing methods in solving all d-MPs. 展开更多
关键词 RELIABILITY multi-state network d-minimal paths state vector
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Guided Wave Propagation in Multilayered Two-dimensional Quasicrystal Plates with Imperfect Interfaces
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作者 Xin Feng Liangliang Zhang +2 位作者 Zhiming Hu Han Zhang Yang Gao 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2022年第4期694-704,共11页
An analytical solution of the guided wave propagation in a multilayered twodimensional decagonal quasicrystal plate with imperfect interfaces is derived.According to the elastodynamic equations of quasicrystals(QCs),t... An analytical solution of the guided wave propagation in a multilayered twodimensional decagonal quasicrystal plate with imperfect interfaces is derived.According to the elastodynamic equations of quasicrystals(QCs),the wave propagating problem in the plate is converted into a linear control system by employing the state-vector approach,from which the general solutions of the extended displacements and stresses can be obtained,These solutions along the thickness direction are utilized to derive the propagator matrix which connects the physical variables on the lower and upper interfaces of each layer.The special spring model,which describes the discontinuity of the physical quantities across the interface,is introduced into the propagator relationship of the multilayered structure.The total propagator matrix can be used to propagate the solutions in each interface and each layer about the multilayered plate.In addition,the traction-free boundary condition on the top and bottom surfaces of the laminate is considered to obtain the dispersion equation of wave propagation,Finally,typical numerical examples are presented to illustrate the marked influences of stacking sequence and interface coeficients on the dispersion curves and displacement mode shapes of the QC laminates. 展开更多
关键词 Two-dimensional QC materials Wave propagation Dispersion curve State vector approach Propagator matrix Imperfect interface
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Isotopic Effects on Stereodynamics of the C^+ + H_2→CH^+ + H Reaction
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作者 郭璐 杨云帆 +2 位作者 范晓星 马凤才 李永庆 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第5期549-553,共5页
The effects of isotope substitution on stereodynamic properties for the reactions C^+ + H_2/HD/HT →CH^+ + H/D/T have been studied applying a quasi classical trajectory method occurring on the new ground state CH_2^+ ... The effects of isotope substitution on stereodynamic properties for the reactions C^+ + H_2/HD/HT →CH^+ + H/D/T have been studied applying a quasi classical trajectory method occurring on the new ground state CH_2^+ potential energy surface [J. Chem. Phys. 142(2015) 124302]. In the center of mass coordinates applying the quasi classical trajectory method to investigate the orientation and the alignment of the product molecule. Differential cross section and three angle distribution functions P(θ_r), P(ф_r), P(θ_r, ф_r) on the potential energy surface that fixed the collision energy with a value is 40 kcal/mol have been studied. The isotope effect becomes more and more important with the reagent molecules H_2 changing into HD and HT. P(θ_r, ф_r) as the joint probability density function of both polar angles θ_r and ф_r, which can illustrate more detailed dynamics information. The isotope effect is obvious influence on the properties of stereodynamics in the reactions of C^+ + H_2/HD/HT → CH^+ + H/D/T. 展开更多
关键词 isotope effect quasi classical trajectory vector correlation stereodynamic ground state CH2+ potential energy surface
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