When user defined functions ( udfs ) are involved in the join predicate , the algorithms for the computation of relational joins can not be used directly . in the paper , the restricting transformation function r , is defined , which can restrict some variable ' s values . without scanning the entire relation , performance of join algorithm can be improved greatly 当连接条件中包含用户自定义的复杂函数时，原有的连接算法不能直接应用于该连接运算，为此，本文提出了限定变换函数t _ r概念，来限定连接谓词中某些变元的取值范围，从而避免对整个关系的扫描，达到提高连接算法性能的目的。
According to the basic mathematical model of the oil / water two - phase profile interpretation based on temperature and flowmeter logs , a similar idea to that of " first getting the retrieve function then the original function " is employed to solve the model . the recursive arithmetic suitable to computer programming has been presented , which make the profile technique available in practical production 本文根据利用流量、温度信息确定油水两相产出剖面的基本数学模型，提出了一种类似于函数论中常常用到的一种求形式复杂函数的办法对模型进行了求解，从这一思想出发，给出了适合计算机程序实现的递推求解算法，并且编制程序对算法进行了实现。
Svm is a kind of universal learning algorithm , which developed from statistical learning theory , that is , small sample learning theory proposed by vapnik . it can represent complicated functions especially in high dimensions , which can avoid the trouble of the dimension tragedy that happened in general algorithm . it also will not affect the system performance by using original data of the array for the eigenvector directly 支持向量机是由vapnik等人提出的小样本统计理论? ?统计学习理论发展而来的一种新的通用学习算法，特别在高维空间中表示复杂函数，避免了常规算法“维数灾难”等麻烦问题，可直接用阵列原始数据作为特征向量而不影响系统性能。
Abstract : by introducing chaos state to genetic algorithm , this paper proposed a novel optimization algorithm named chaos genetic algorithm . its major measures are chaos initialization and chaos carrier wave of best fitness in population both based on the ergodicity , stochastic property and regularity of chaos . simulation results of typical complex function optimization show that chaos genetic algorithm improves the convergence and reduces the computing time greatly 文摘:将混沌融入遗传算法提出了混沌遗传算法，该方法利用混沌运动的随机性、遍历性、对初始条件的敏感性特性进行群体的混沌初始化和最优个体的混沌变尺度载波寻优.典型复杂函数优化的仿真结果表明该方法较遗传算法具有更快的收敛速度和更小的计算量，是复杂函数优化的有效手段
In this article , a comparison between basic genetic algorithms and optimal elitist model niche genetic algorithms is made and it illustrates that the optimization has greatly optimized the previous sectional solutions and has speeded up the algorithm convergence and the rate of convergence 摘要探讨了基于稳态复制策略的二进制小生境遗传算法，并把其应用于复杂函数优化问题中，通过与基于最优保存策略的基本遗传算法进行比较，说明改进算法可以极大克服遗传算法未成熟收敛问题以及极易陷入局部解问题，提高了算法收敛性能和收敛速度。
