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Calculation of Klinkenberg permeability, slip factor and turbulence factor of core plugs via nonlinear regression

JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 2009年第3-4期67卷 159-167页

作者： Pazos, Fernando A. Bhaya, Amit Martins Compan, Andre Luiz Univ Fed Rio de Janeiro Dept Elect Engn PEE COPPE BR-21945970 Rio De Janeiro Brazil TRA PDP CENPES Petrobras Res Ctr Rio De Janeiro Brazil

Published methods to determine the Klinkenberg permeability, Klinkenberg slip factor and Forchheimer turbulence factor of core plugs can exhibit considerable *** presented a technique based on gas pressure decay measurements during the transient state, where, with a single run, an algorithm can calculate the parameters with precision. However, this paper shows that Jones' method is based on a linear regression to find a fixed point of a nonlinear error function, and is presented without theoretical justification or convergence conditions. This paper proposes a simple algorithm, based on nonlinear regression, to calculate the unknown parameters, and has the advantage of theoretical justification as well as weaker requirements for convergence. In addition, a strategy to calculate the unknown physical parameters when the measurements are noisy is presented. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Klinkenberg permeability Klinkenberg slip factor Forchheimer turbulence factor core plugs nonlinear regression transient state permeameter iterative algorithm convergence gas pressure decay measurements

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An iterative Stabilized Scheme for Unsteady Incompressible Viscous Flow

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Journal of Shanghai Jiaotong university(Science) 2009年第4期14卷 404-409页

作者：包艳周岱李华峰 School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University

An efficient iterative algorithm is presented for the numerical solution of viscous incompressible Navier-Stokes equations based on Taylor-Galerkin like split and pressure correction method in this paper. Taylor-Hood element is introduced to overcome the numerical difficulties arising from the fluid incompressibility. In order to confirm the properties of the algorithm, the numerical simulation on plane Poisseuille flow problem and lid- driven cavity flow problem with different Reynolds numbers is presented. The numerical results indicate that the proposed iterative version can be effectively applied to the simulation of viscous incompressible flows. Moreover, the proposed iterative version has a better overall performance in maximum time step size allowed, under comparable convergence rate, stability and accuracy, than other tested versions in numerical solutions of the plane PoisseuiUe flow with different Reynolds numbers ranging from low to high viscosities.

关键词： Taylor-Galerkin scheme viscous incompressible flow pressure correction method iterative algorithm Reynolds number

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Structure-Preserving Stabilization for Hamiltonian System and its Applications in Solar Sail

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2009年第3期32卷 997-1004页

作者： Xu, Ming Xu, Shijie Beijing Univ Aeronaut & Astronaut Sch Astronaut Beijing 100083 Peoples R China

A structure-preserving controller is constructed to stabilize a hyperbolic Hamiltonian system. Bounded orbits for the planar solar sail three-body problem are generated by means of the controller. The invariant (stable, unstable, and center) manifolds of the equilibrium are used to stabilize a Hamiltonian system of 2 degrees of freedom using only position feedback. It is proved that the poles of the system can be assigned to any position on the imaginary axis by choosing the manifolds' gains properly. A new type of quasi-periodic orbit referred to as a stable Lissajous orbit is obtained. The orbit will degenerate to a periodic orbit in the case of resonance between modes and suitable initial values (Lyapunov orbit). Using the controller to solve the solar sail three-body problem yields a stable Lissajous orbit, which is quite different from the classical Lissajous orbit. We show that the sail equilibrium can be stabilized, and moreover that the orbit is bounded. The allocation law of the controller is also studied, which verifies that the controller is realizable.

关键词： Solar Sail Earth iterative algorithm Lagrange Points Astrodynamics Nonlinear Control Lyapunov Stability Spacecraft Orbits Fuel Consumption Libration Points

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A resource allocation method based on competitiveness equilibrium for manufacturing grid

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2009年第9-10期41卷 997-1002页

作者： Shi, Shengyou Yang, Haicheng Liu, Haibin Hou, Junjie China Aerosp Engn Consultat Ctr Beijing 100048 Peoples R China China Aerosp Sci & Technology Corp Beijing 100048 Peoples R China

Optimal resource configuration is a critical issue for manufacturing grids. Economics is introduced for establishing a manufacturing grid resource marketplace and allocating resources based on market equilibrium and resource consumers' utilities. Firstly, the resource allocation architecture is constructed based on the total framework of the manufacturing grid. Secondly, the economic environment of resource allocation is defined based on the characteristics of marketplace competitiveness, in which the feasible and Pareto optimization conditions of resource allocation are given. The competitive equilibrium of Pareto optimization is defined, in which resource owners may gain most economic profits, resource consumers gain maximal utilities and the market equilibrium was achieved. Finally, an iterative algorithm is introduced for the resource equilibrium price. The test results indicated that a resource price could be converged at its equilibrium price rapidly, and actual resources allocation result could be approximate to the equilibrium state.

关键词： Grid Manufacturing grid Resource allocation Competitive equilibrium iterative algorithm

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Trajectory Shaping of Projectiles Through Cross-Entropy-Minimization-Based Search

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2009年第1期32卷 300-304页

作者： Lehevin, Nicolas Wong, Franklin Rabbath, Camille Alain Numer Technol Inc Quebec City PQ G3J 1X5 Canada Def Res & Dev Canada Valcartier Quebec City PQ G3J 1X5 Canada

A trajectory shaping solution for projectiles over the entire flight was obtained using a cross-entropy-minimization-based search (CEMBS). This trajectory shaping solution provided a lateral-acceleration time or waypoint trajectory, which can be tracked by the projectile by appropriate guidance-law and autopilot before launch. The solution generated a finite-in-time sequence of lateral-acceleration or waypoint commands, which further produced a sample set to perform simulations of the guided projectile. It was observed that the near-optimal trajectory-shaping solution can be computed in very short time for a given target set. The CEMBS method for trajectory shaping was developed in this solution and a 3-degree-of-freedom model was used for flight dynamics of the projectile. Trajectory solution generated a sequence of commands for guided projectile to achieve a set of target constraints.

关键词： Guided Projectiles Entropy iterative algorithm Flight Path Angle Guidance Laws Closed Loop System Monte Carlo Simulation Precision Guided Munition Probability Distribution Autopilot

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A Multi-baseline Data Fusion algorithm for Distributed Satellites SAR Interferometry by Combining iterative and Maximum-Likelihood Methods

A Multi-baseline Data Fusion Algorithm for Distributed Satel...

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2009 2nd Asian-Pacific Conference on Synthetic Aperture Radar（APSAR2009）

作者： Shi Xiaojin,Zhang Yunhua Center for Space Science and Applied Research,Chinese Academy of Sciences,Beijing,China

In distributed satellites interferometric SAR(InSAR) system,short baselines usually make higher height ambiguity but the interferometric phase can be unwrapped much more easily,while the long baselines usually cause more complicated phase unwrapping problems but have less height ***'s of obvious significance if we can combine the data from baselines of different *** this paper,a multi-baseline InSAR data fusion method based on iterative and maximum-likelihood methods is proposed to combine the information from different baselines and obtain more accurate digital elevation model(DEM)compared with single *** simulation shows that the proposed algorithm is more effective and accurate than iterative or maximum-likelihood method in multi-baseline InSAR system,and it is especially appropriate for the rugged terrain height retrieving or processing highly ambiguous data,for which commonly used phase unwrapping algorithms may fail.

关键词： InSAR Multi-baseline Data Fusion iterative algorithm Maximum-likelihood algorithm Phase Unwrapping

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Optimal portfolio of safety-first models

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JOURNAL OF STATISTICAL PLANNING AND INFERENCE 2009年第9期139卷 2952-2962页

作者： Ding, Yuanyao Zhang, Bo Renmin Univ China Ctr Appl Stat Beijing 100872 Peoples R China Ningbo Univ Fac Business Ningbo 315211 Zhejiang Peoples R China

The purpose of this article is to study Kataoka's safety-first (KSF) model, which is a representative of safety-first models of most popular models in portfolio selection of modern finance. We obtain conditions that guarantee that the KSF model has a finite optimal solution without normality assumption. When short-sell is allowed, we provide an explicit analytical solution of the KSF model in two cases. When short-sell is not allowed, we propose an iterating algorithm for finding the optimal portfolios of the KSF model. We also investigate a KSF model with constraint of mean return and obtain the explicit analytical expression of the optimal portfolio. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Safety-first criterion KSF model Mean return constraint Analytical solution iterative algorithm

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STRONG CONVERGENCE THEOREMS OF k-STRICT PSEUDO-CONTRACTIONS IN HILBERT SPACES

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CZECHOSLOVAK MATHEMATICAL JOURNAL 2009年第3期59卷 695-706页

作者： Qin, Xiaolong Kang, Shin Min Shang, Meijuan Gyeongsang Natl Univ Dept Math Chinju 660701 South Korea Gyeongsang Natl Univ RINS Chinju 660701 South Korea Shijiazhuang Univ Dept Math Shijiazhuang 050035 Peoples R China

Let K be a nonempty closed convex subset of a real Hilbert space H such that K +/- K subset of K, T : K -> H a k-strict pseudo-contraction for some 0 = 1, where S : K -> H is defined by Sx = kx + (1 - k)Tx, P-K ... 详细信息

Let K be a nonempty closed convex subset of a real Hilbert space H such that K +/- K subset of K, T : K -> H a k-strict pseudo-contraction for some 0 <= k < 1 such that F(T) = {x is an element of K: x = Tx} not equal empty set. Consider the following iterative algorithm given by for all x(1) is an element of K, x(n+1) = alpha(n)gamma f(x(n)) + beta(n)x(n) + ((1 - beta(n))I - alpha(n)A)P(K)Sx(n), n >= 1, where S : K -> H is defined by Sx = kx + (1 - k)Tx, P-K is the metric projection of H onto K, A is a strongly positive linear bounded self-adjoint operator, f is a contraction. It is proved that the sequence {x(n)} generated by the above iterative algorithm converges strongly to a fixed point of T, which solves a variational inequality related to the linear operator A. Our results improve and extend the results announced by many others.

关键词： Hilbert space nonexpansive mapping strict pseudo-contraction iterative algorithm fixed point

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Determination of integer solutions of a system of simultaneous Pell equations

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MATHEMATICAL NOTES 2009年第3-4期86卷 556-566页

作者： Nesterenko, A. Yu. Moscow MV Lomonosov State Univ Moscow Russia

We describe an algorithm for finding integer solutions of a system of simultaneous Pell equations whose effective estimates can be obtained using the theory of linear forms in the logarithms of algebraic numbers. We use Matveev's estimate for forms in three logarithms. To decrease the resulting estimate, we use an iterative algorithm. At the end of the paper, results of the practical implementation of the proposed algorithm are given.

关键词： simultaneous Pell equations Diophantine equation linear and quadratic forms continued fraction iterative algorithm quadratic field algebraic number quadratic irrationality

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SVD-based model for mine quasi-geoid establishment

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Procedia Earth and Planetary Science 2009年第1期1卷 1212-1219页

作者： Xu, Chang-hui Qin, Zhen School of Environment Science and Spatial Informatics China University of Mining and Technology Xuzhou 221116 China Jiangsu Key Laboratory of Resources and Environmental Information Engineering Xuzhou 221116 China

Existing rank-defect free network adjustment is to some extent adaptable for singular problems with additional conditions but not responsible for abnormal adjustment including singular and ill-conditioned situations in the establishment of mine quasi-geoid. To avoid additional conditions, a new singular value decomposition (SVD)-based pseudoinverse solution is introduced, which needs only two steps for calculation. The coefficient matrix was transformed into bidiagonal matrix with full orthogonal decomposition, and the accomplishment was carried out by iterative algorithm of implicit symmetric QR decomposition. To evaluate the effects and stability, we compared the result using least squares for full rank including ill-conditioned and singular with that using SVD. Meanwhile, both inside precision and outside precision were used to assess the efficiency of these methods. Based on analyzing two situations with or without coordinates constants, the three methods have the same effect if there is no any constant; however, if there are some constants, only the SVD method can have a right result. © 2009.

关键词： Singular value decomposition Mining Bidiagonal Coefficient matrix Defect free networks Height anomaly If there are Ill conditioned problems Ill conditioned iterative algorithm Least Square matrix Orthogonal decomposition Pseudo inverse solution Q R decomposition singular and ill conditioned problems Singular problem SVD method

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