Such methods are generally decreasing method , such as , feasible direction methods , constrained variable metric methods , etc . another class is sub - problems method , which approximates the optimal solution by solving a series of simple sub - problems , such as penalty function methods , trust region methods , and successive quadratic programming sub - problems , etc . the same property of two classes of methods is that they determine whether the next iterative point is " good " or " bad " by comparing the objective function value or merit function value at the current point and next iterative point 另一类叫做子问题算法，这种算法是通过一系列简单子问题的解来逼近原问题的最优解，如罚函数法、信赖域算法、逐步二次规划算法等。这两类算法的一个共同特点是，通过比较当前点和下一个迭代点的目标函数值或评价函数值来确定迭代点的“优”或“劣” ，若迭代点比当前点“优”则该迭代点可以被接受，否则须继续搜索或调整子问题。
To make it clear , the article use and analyze numerical value cases from bellmum and zadeh . finally in order to work out the value function in all forms and the expected value of optimization in all aspects easily , we take down all the problem existing in multi - stage stochastic decision processes . the solution of optimum is formed and multi - stage stochastic decision tree - table is introduced 为说明问题，本文利用bellman和zadeh [ 1 ]的数值例，应用两种方法进行分析，最后为了更方便的解出对所有形式的评价函数，及其期望值的最优化解对各种进行的发展，把经过多阶段概率决策过程的问题记述下来，构成一个最优解的统一图表，引入了多段概率决策树表。
As core searching algorithm , genetic algorithm is applied to generate software structural test case . to achieve higher performance , such issues as coding strategy , evaluation function construction and instrumentation are discussed in detail . in particular , much emphasis is put on how to improve the genetic algorithm operator which has a significant influence on the algorithm efficiency 该技术采用遗传算法作为核心搜索算法来生成软件结构测试用例，其中讨论了编码策略、评价函数构造及插装等问题的解决方案，并重点说明了如何对遗传算子进行改进，使算法在解决本问题时更加有效。
In order to solve current problems in autofocus field , this dissertation fulfilled some important theoretical studies , such as autofocus theories and methods , focus measures , focus algorithms and focus framing technologies . furthermore , we have designed and construct two autofocus systems based on pc and dsp respectively . funded by the financial aids for cadre college teachers of the education ministry , this dissertation achieved a numbers of outcomes 本文结合教育部高校骨干教师计划“ ccd成像频谱分析与对焦算法研究” ，针对现有对焦方法存在的问题，主要就自动对焦理论与方法、对焦评价函数及算法、对焦窗口的智能规划等理论问题进行深入研究，并设计制作了基于计算机和dsp的自动对焦系统样机。
Via numeric sample analysis , it is found that evaluation functions are constructed by weighing principal components for pca . however , evaluation functions can be quite different when there are more than three principal components and characteristic vectors other than first one are chosen in different directions . for spca , variance contribution can be greater than 90 % by selecting just one principle component 将谱主成分分析应用于多指标评价系统中，通过数值例子分析：主成分分析是通过对各个主成分加权构造评价函数，当主成分个数不小三个时，从第二个特征向量开始，对方向的不同选取，可导致评价函数的极大差异：而用谱主成分分析，能做到只取一个谱主成分就可使方差贡献率大于90 。
This paper takes the sum of the square of gray difference as the criteria of evaluation function which image is or not focused and takes an effective searching way of autofocusing based on threshold value and curve fitting . this way enhances effectively speed and precision of autofocusing 在自动聚焦过程中，本论文采用了图像的灰度差分的平方和作为焦距评价函数，解决了自动聚焦过程中是否正确聚焦的判断问题；提出了一种行之有效的基于阈值和曲线拟合的自动聚焦搜索方式，使聚焦速度和精度都得到了很大的提高。
In course of auto - focusing , the paper takes the sum of the square of gray difference as focal distance evaluation function to decided that image is in focus or not quickly and put forward an effective auto - focus searching way based on threshold value and curve fitting . these improve speed and precision of auto - focusing 在自动聚焦过程中，论文采用了图象的灰度差分的绝对值之和的平方作为焦距评价函数，解决了是否正确聚焦的快速判断问题；采用了一种行之有效的基于阈值和曲线拟合的自动聚焦搜索方式，使聚焦速度和精度都得到了很大的提高。
