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A new scheme of target discrimination in SAR images, consisted of frames, models and algorithms, is proposed. Under such a scheme, a global frame, combining orderly the algorithm based on feature extraction and that based on knowledge, is then proposed. Moreover, in the method of target discrimination based on feature extraction, a "loose-coupling" model is given. The existing features are chosen and three new features about the contrast are given under the "loose-coupling". Meanwhile, an algorithm of feature selection based on Genetic Algorithm is also modified to solve the problem that the existing algorithm can not evaluate the goodness-of-features comprehensively. The weighted quadratic distance discriminator is designed to improve the performance of target discrimination. Finally, a method based on the knowledge of target groups to remove clutter false alarms is also given.

提出了一种目标鉴别的新方案，该方案包括目标鉴别的框架、模型以及算法；提出了基于特征选取鉴别和基于编队提取鉴别"序贯"连接相结合的目标鉴别框架；在基于特征选取进行目标鉴别的方法中，提出了目标鉴别的"松耦合"模型；提出了"松耦合"模型下目标鉴别的特征提取方法，包括已有特征的筛选和3个新的对比度特征的提出；改进了一种基于GA的特征选择方法，克服了已有方法对特征优劣评价不全面的问题；设计了加权二次距离鉴别器，提高了鉴别的性能；研究了基于目标编队知识进行进一步杂波虚警剔除的方法。

In addition, by utilizing Jacobi two square numbers theorem and Lagrange four square numbers theorem and some theta function identities, we also prove the known results of number theory: two triangular number theorem, four triangular number theorem, and the number of representations of a positive integer by various quadratic forms in terms of divisor functions

包括Jacobi二平方数定理，Lagrange四平方数定理等，然后利用这些结果结合几个theta函数恒等式，我们获得了把任意一个正整数表示成两个三角数或四个三角数的和以及其他的二次形式的方法数，这些方法数都是用因子函数来表示的。

The dynamic measuring method of alignment parameters based on the Satisfaction Criterion Model is presented in this paper. Using the quadratic regression crosscut combination method to organize the experiment, the mapping relationship between side force of slippage and camber angle and toe-in of the testing vehicles is obtained by regressing the experiment data. In this experiment, side force and slippage are testing objects, camber and toe-in value are testing factors.

本文提出了基于满意准则数学模型的车轮定位参数智能化动态测量方法，运用二次回归正交组合设计方法组织和安排试验，以车轮外倾角和前束值作为试验因素，侧向力和侧滑量作为试验目标，通过对试验数据的回归处理得到了试验车辆的侧滑量或侧滑量同车轮外倾角以及前束值之间的映射关系。

An optimization design scheme is crucial for torpedo, however, there has been no any such method recognized so far. This paper presents a method for torpedo lineshape optimization design based on the iSIGHT. In this method, the optimization strategies of simulated annealing algorithm and continuous quadratic planning method are adopted, and the fluid analysis software Fluent is integrated to calculate the fluid parameters of torpedo body lineshape. The comparison of the optimization results obtained by both the presented and the traditional methods shows that the torpedo lineshape optimization method based on the iSIGHT is satisfactory and feasible.

寻找最优设计方案是鱼雷设计的重中之重，针对目前鱼雷优化设计领域还没有一套公认的优化设计方法这一现状，提出了一套基于iSIGHT的工程设计优化方法，将这款商业软件应用于鱼雷线形优化设计中，采用了模拟退火算法+连续二次规划法的优化策略，集成流体分析软件Fluent对雷体线形的流体参数进行了计算，并与传统优化方法结果相比较，结果表明，基于iSIGHT的优化设计方法在鱼雷线形优化设计中是可行的，能够得到令设计人员满意的鱼雷线形优化方案。

The nonlinear dynamic system with quadratic and cubic nonlinearities is obtained by applying mathematical transformation to the equation.

基於Karman方程的动态比拟，运用Galerkin法，选用合适的正交函数将控制薄板振动的偏微分方程离散化为常微分方程，得到一带有平方和立方非线性的参数激励和外激励联合作用的非线性动力学系统。

Show that the coefficient a of the quadratic term changes sign at the BCS transition point, while b and c are positive.

证明系数a的四次项在BCS跃迁点上变号，而b及 c 均是正的。

In this paper,we give a sufficient and necessary condition for the level surface s with respect to non-degenerate quadratic functions by the usage of the Hessian metric and of a transversal vector field.

本文利用Hessian度量和横截向量场，给出了非退化二次函数的水平曲面的一个充要条件。

The trigonometric polynomial curves retain the main superiority of the quadratic Bézier curves.

给出了二次三角多项式形式的Bézier曲线，基函数由一组带形状参数的二次三角多项式组成。

Necessary and sufficient conditions for equalities between a 2 y′y and minimum norm quadratic unbiased estimator of variance under the general linear model, where a 2 is a known positive number, are derived.

给出了一般线性模型下方差的最小范数二次无偏估计相等的充要条件，并且当高斯马尔可夫估计与最小二乘估计相等时，获得了一个相对简单的条件，最后给出此条件应用于抽样调查的一个例子。

In this paper, using the method of the Lagrangian dual, an unconstraint but nondifferentiable optimal problem in input space is proposed as the dual of the quadratic programm...

证明了该分片二次函数的极小点对应原二次规划的ε最优解，而用此极小点可直接算出支持向量和最优超平面。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。