Galaxies with supermassive binary black holes: (I) a possible model for the centers of core galaxies     

Ing-Guey Jiang  Li-Chin Yeh 《Astrophysics and Space Science》2014,349(2):881-893

The dynamics of galactic systems with central binary black holes is studied. The model is a modification from the restricted three body problem, in which a galactic potential is added as an external potential. Considering the case with an equal mass binary black holes, the conditions of existence of equilibrium points, including Lagrange Points and additional new equilibrium points, i.e. Jiang-Yeh Points, are investigated. A critical mass is discovered to be fundamentally important. That is, Jiang-Yeh Points exist if and only if the galactic mass is larger than the critical mass. The stability analysis is performed for all equilibrium points. The results that Jiang-Yeh Points are unstable could lead to the core formation in the centers of galaxies.  相似文献   

A GALERKIN FINITE-ELEMENT PROGRAM FOR SIMULATING UNSATURATED FLOW IN POROUS MEDIA   总被引：1，自引：0，他引：1  

R. Khaleel  T.-C. Yeh 《Ground water》1985,23(1):90-96

Abstract. A fully documented Galerkin finite-element FORTRAN program is presented for solving the one-dimensional, transient flow equation in unsaturated porous media. Material balance error summaries are presented to demonstrate accuracy of the numerical scheme. Comparison of our simulated results with other existing numerical solutions using the Galerkin scheme provided excellent agreement.  相似文献   

On the Chermnykh-Like Problems: I. the Mass Parameter μ = 0.5     

Ing-Guey Jiang  Li-Chin Yeh 《Astrophysics and Space Science》2006,305(4):341-348

Following Papadakis (2005)'s numerical exploration of the Chermnykh's problem, we here study a Chermnykh-like problem motivated by the astrophysical applications. We find that both the equilibrium points and solution curves become quite different from the ones of the classical planar restricted three-body problem. In addition to the usual Lagrangian points, there are new equilibrium points in our system. We also calculate the Lyapunov Exponents for some example orbits. We conclude that it seems there are more chaotic orbits for the system when there is a belt to interact with.  相似文献   

A STARTING POINT          下载免费PDF全文

Ye Duzheng 《Acta Meteorologica Sinica》1987,1(1):123-123

Acta Meteorologica Sinica (AMS) is an academic quarterly journal sponsored by the Chinese Meteorological Society(CMS). Sixty-one years have elapsed since it started publication in Chinese in 19253.As a first-rate advanced academic journal,it has played an important role in meteorological circles and has continually given impetus to the advances of atmospheric sciences.  相似文献   

On the Chermnykh-Like Problems: II. The Equilibrium Points     

Li-Chin Yeh  Ing-Guey Jiang 《Astrophysics and Space Science》2006,306(4):189-200

Motivated by Papadakis (2005a, b), we study a Chermnykh-like problem, in which an additional gravitational potential from the belt is included. In addition to the usual five equilibrium points (three collinear and two triangular points), there are some new equilibrium points for this system. We studied the conditions for the existence of these new equilibrium points both analytically and numerically.  相似文献   

A novel analytical solution for constant‐head test in a patchy aquifer     

Shaw‐Yang Yang  Hund‐Der Yeh 《国际地质力学数值与分析法杂志》2006,30(12):1213-1230

A mathematical model describing the hydraulic head distribution for a constant‐head test performed in a well situated at the centre of a patchy aquifer is presented. The analytical solution for the mathematical model is derived by the Laplace transforms and the Bromwich integral method. The solution for the hydraulic head has been shown to satisfy the governing equations, related boundary conditions, and continuity requirements for the hydraulic head and flow rate at the interface of the patch and outer regions. An efficient numerical approach is proposed to evaluate the solution, which has an integral covering an integration range from zero to infinity and an integrand consisting the product and square of the Bessel functions. This solution can be used to produce the curves of dimensionless hydraulic head against dimensionless time for investigating the effect of the contrast of formation properties on the dimensionless hydraulic head distribution. Define the ratio of outer‐region transmissivity to patch‐region transmissivity as α. The dimensionless hydraulic head for α=0.1 case is about 2.72 times to that for α=10 case at dimensionless large time (e.g. τ?10⁶) when the dimensionless distance (ρ) equals 10. The results indicate that the hydraulic head distribution highly depends on the hydraulic properties of two‐zone formations. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

The drag-induced resonant capture for Kuiper Belt objects     

Ing-Guey Jiang  Li-Chin Yeh 《Monthly notices of the Royal Astronomical Society》2004,355(4):L29-L32

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Three-dimensional analyses of the sliding surface distribution in the Huangtupo No. 1 riverside sliding mass in the Three Gorges Reservoir area of China     

Jinge Wang  Aijun Su  Qingbing Liu  Wei Xiang  Hsin-Fu Yeh  Chengren Xiong  Zongxing Zou  Cheng Zhong  Junqi Liu  Shen Cao 《Landslides》2018,15(7):1425-1435

The Huangtupo landslide is one of the largest and most destructive landslides still deforming in the Three Gorges area of China. In recent years, most studies on this landslide have been based on the data obtained from an investigation conducted in 2001. To further elucidate the geological structure and evolution of the landslide, we began building a field test site in the area of the sliding mass with the fastest deformation velocity in 2009. A group of tunnels with a total length of 1.1 km has been excavated, and nine boreholes with depths between 76.8 and 127.1 m have been drilled into the sliding body. Additionally, relative monitoring devices, such as borehole inclinometers and crack meters, have been installed. Based on the findings of the previous investigation and the latest tunneling, drilling, and monitoring data, a spatial distribution model of the sliding surfaces of the Huangtupo No. 1 riverside sliding mass has been established using the discrete smooth interpolation (DSI) method. Significant differences are revealed between the previous proposed sliding surface and the latest monitoring data. We propose that the Huangtupo No. 1 sliding mass has two sliding surfaces. Thus, the sliding mass can be further divided into two secondary sliding bodies, which are named the No. 1-1 (east) and No. 1-2 (west) sliding masses. The No. 1-1 sliding mass slid first, and the material along the western boundary slid later, producing the No. 1-2 sliding body, which has a smaller volume and shallower depth. The areas, volumes, and thicknesses of each sliding body have been calculated using a digital 3D model.  相似文献   

Integration of neural networks and cellular automata for urban planning     

Anthony Yeh  Li Xia 《地球空间信息科学学报》2013,16(1):6-13

This paper presents a new type of cellular automata (CA) model for the simulation of alternative land development using neural networks for urban planning. CA models can be regarded as a planning tool because they can generate alternative urban growth. Alternative development patterns can be formed by using different sets of parameter values in CA simulation. A critical issue is how to define parameter values for realistic and idealized simulation. This paper demonstrates that neural netowrks can simplify CA models but generate more plausible results. The simulation is based on a simple three-layer network with an output neuron to generate conversion probability. No transition rules are required for the simulation. Parameter values are automatically obtained from the training of network by using satellite remote sensing data. Original training data can be assessed and modified according to planning objectives. Alternative urban patterns can be easily formulated by using the modified training data sets rather than changing the model.  相似文献   

Spatial interpolation using MLP–RBFN hybrid networks     

I-Cheng Yeh  Yau-Hwang Kuo 《International journal of geographical information science》2013,27(10):1884-1901

It is easy for a multi-layered perception (MLP) to fit a stratified spatial interpolation pattern whose form is close to open surface; while it is easy for a radial basis function network (RBFN) to fit a pocket (radial) spatial interpolation pattern whose form is close to closed surface. However, in the real world, the spatial interpolation pattern may consist of stratified and pocket patterns. Neither MLP nor RBFN can fit the pattern easily. To combine their advantages to fit the complex hybrid spatial interpolation patterns, in this article we propose a novel neural network, MLP–RBFN hybrid network (MRHN), whose hidden layer contains sigmoid and Gaussian units at the same time. Although there are two kinds of processing units in MRHN, in this study we used the principle of minimizing the error sum of squares to derive the supervised learning rules for all the network parameters. This research took rainfall distribution in Taiwan as a case study. The results show that (1) the prediction error of the testing dataset outside the training dataset demonstrated that MRHN was the most accurate among the three networks, RBFN was the next best, and MLP was the worst; (2) the MLP model seriously underestimated the values of high observed rainfall; (3) over-learning may be a serious shortcoming of using RBFN in spatial interpolation applications; (4) MRHN may have better generalization learning capacity than RBFN in spatial interpolation applications.  相似文献