基于模糊多目标遗传算法的飞行器模拟件结构参数优化

空间飞行器模拟件的设计是一个具有约束的多目标多准则优化问题。本文在建立空间飞行器模拟件参数优化的数学模型的基础上,将模糊多目标决策理论用于飞行器模拟件的结构参数优化,提出了一种新的模糊评价指数。结构参数优化的结果已经用于某试验系统。

金川矿山岩体移动规律及竖井变形、破坏机理研究

The Jinchuan Nickel Mine is the largest underground mine with cut-and-fill mining in China. It is very difficult to be exploited for very low safety stability of rock mass caused by complex geological conditions, developed faults, cracked rock mass and high stress. In this paper, the laws of rock mass movement、mechanics of shaft deformation and destroy were analyzed based on the collection of date, the detailed field engineering investigations, ground movement monitoring by GPS, theoretical analysis and numerical simulation. According to the GPS monitoring result of ground surface movement, there are different ground movement characteristics among the three Mine area of Jinchuan Nickel Mine. In No. 2 Mine area, the ground movement funnel with apparent asymmetry is developing, the influence scope is larger in the up faulted block than in the down faulted block, and the centre of ground movement is moving along the up faulted block direction with increasing depth of mining. Moreover, the tunnels in the corresponding area with the centre of ground movement are damaged seriously. In Longshou Mine area, the ground movement funnel is also developing, but the moving path and the nonlinear characters are more sophisticated because of the long-term effects of open excavating and the effects of underground mining together. In No. 3 Mine area, the underground mining impact on surface is not serious for the time of mining activity is not for long, but the ground movement funnel is also forming now. The underground mining has caused widespread land subsidence in Jinchuan Nickel Mine area, but the phenomena of surface raise appeared in some partial areas of Longshou Mine area and No. 3 Mine area. Analysis proved that the reason for the open pit bottom raise is the slope deformation activation caused by the excavation from open pit into underground mine; and that the raise of surface in No.3 Mine area is caused by the effect of elastic foundation due to underground mining. Although the GPS Monitoring results show the amount of subsidence is increasing constantly, the subsidence rate has a descending tendency with fluctuation in Jinchuan No. 2 Mine area. The subsidence rate curve is a time function and exists an extreme point, the rate increasing before extreme point and decreasing after the extreme point ,but the scale of decreasing rate will be very small after the rate decreasing up to a certain degree, moreover, the characteristics is different among different areas, which have some relation with the distance to the mining section and the dip of the ore body. ArcView is GIS software, which we adopted as a development platform, and made secondary development by its development language “avenue”, through which we developed a ground movement analysis and forecast System for Jinchuan Nickel Mine, which contain three modules : management of ground movement information; analysis and evaluation of ground movement; and ground movement forecast. In the module of evaluation, using the technique of MATLAB6.5 program with VB6.0, the system can achieve the ANN prediction model for GPS monitoring data, data preparation results analysis and model integrated was realized by Avenue programming. Finally, the author analyzed the mechanical of deformation and destroy of the No. 14 shaft, and its repair and artificial-support effectiveness also given detailed demonstration in various aspect. The result showed that the reason for the destroy of No. 14 shaft is underground mining, and being the case, the destroy of the shaft also has its special features, which mainly contains forked stress contour for mining steep ore and fault effect caused by mining activities. The repair and artificial-support played some restrictions on the rock mass movement and deformation, but did not show a strong or marked effect. With the increasing of mining depth and large-scale, the closure rock of the shaft will still deformed, even be destroyed.

超参数控制下的波阻抗约束反演

The seismic survey is the most effective geophysical method during exploration and development of oil/gas. As a main means in processing and interpreting seismic data, impedance inversion takes up a special position in seismic survey. This is because the impedance parameter is a ligament which connects seismic data with well-logging and geological information, while it is also essential in predicting reservoir properties and sand-body. In fact, the result of traditional impedance inversion is not ideal. This is because the mathematical inverse problem of impedance is poor-pose so that the inverse result has instability and multi-result, so it is necessary to introduce regularization. Most simple regularizations are presented in existent literature, there is a premise that the image(or model) is globally smooth. In fact, as an actual geological model, it not only has made of smooth region but also be separated by the obvious edge, the edge is very important attribute of geological model. It's difficult to preserve these characteristics of the model and to avoid an edge too smooth to clear. Thereby, in this paper, we propose a impedance inverse method controlled by hyperparameters with edge-preserving regularization, the inverse convergence speed and result would be improved. In order to preserve the edge, the potential function of regularization should satisfy nine conditions such as basic assumptions edge preservation and convergence assumptions etc. Eventually, a model with clear background and edge-abnormity can be acquired. The several potential functions and the corresponding weight functions are presented in this paper. The potential functionφLφHL andφGM can meet the need of inverse precision by calculating the models. For the local constant planar and quadric models, we respectively present the neighborhood system of Markov random field corresponding to the regularization term. We linearity nonlinear regularization by using half-quadratic regularization, it not only preserve the edge, and but also simplify the inversion, and can use some linear methods. We introduced two regularization parameters (or hyperparameters) λ2 and δ in the regularization term. λ2 is used to balance the influence between the data term and the transcendental term; δ is a calibrating parameter used to adjust the gradient value at the discontinuous position(or formation interface). Meanwhile, in the inverse procedure, it is important to select the initial value of hyperparameters and to change hyperparameters, these will then have influence on convergence speed and inverse effect. In this paper, we roughly give the initial value of hyperparameters by using a trend- curve of φ-(λ2, δ) and by a method of calculating the upper limit value of hyperparameters. At one time, we change hyperparameters by using a certain coefficient or Maximum Likelihood method, this can be simultaneously fulfilled with the inverse procedure. Actually, we used the Fast Simulated Annealing algorithm in the inverse procedure. This method overcame restrictions from the local extremum without depending on the initial value, and got a global optimal result. Meanwhile, we expound in detail the convergence condition of FSA, the metropolis receiving probability form Metropolis-Hasting, the thermal procession based on the Gibbs sample and other methods integrated with FSA. These content can help us to understand and improve FSA. Through calculating in the theoretic model and applying it to the field data, it is proved that the impedance inverse method in this paper has the advantage of high precision practicability and obvious effect.