最小二乘分段多项式拟合及其计算机程序

本文运用数理统计的原理,阐述了对平面离散数据进行最小二乘分段多项式拟合的数学模型和方法,估计了拟合曲线的误差,并编制了相应的通用FORTPAN计算程序,能对平面离散数据构成的单值函数曲线和多值函数曲线(在自变量x单调变化的转折点,函数连续而不光滑)进行分段多项式拟合,并能通过适当地选择曲线分界节点、各段多项式次数和各分界节点处连续的导数的阶数,满足很多实际问题的需要和所提出的精度要求。     

计算机编程语言的演变

回顾了计算机语言发展的主要脉络,并对计算机语言的发展前景进行了展望。     

ANSYS三维模型导入MAR的方法及

MARC和ANSYS是2个没有直接接口的优秀通用有限元软件，为充分利用2个软件各自的优势，有时需要进行模型互导，即利用ANSYS的APDL和FORTRAN95语言，将ANSYS的模型导入MARC中进行计算。     

A computer‐assisted method for CEC estimation and quality control in a routine soil‐test operation

Abstract

Cation‐exchange capacity (CEC) of 30 Alabama soils was estimated by two different methods based or routine soil‐test results consisting of soil‐water pH, Adams‐Evans buffer pH, and Mehlich‐1 extractable cations (K, Mg, and Ca), which were obtained automatically by a computerized data acquisition system. In one method, CEC was calculated by solving a quadratic equation involving soil‐water and buffer pH's; in the other, CEC was estimated as the summation of extractable cations and exchangeable acidity. The two estimated CEC's agreed well with each other and also had the same magnitude as CEC determined by the normal NaOAc, pH 8.2 method. By averaging the two calculated values, an even closer estimation of the measured CEC was found. These calculations and comparisons can be accomplished quickly and efficiently by a minicomputer via a simple FORTRAN program.

In addition, a discrepancy between the two estimated CEC's would indicate possible errors in analytical determinations and/or the inadequacy of the soil testing procedures. Therefore, an additional means for quality control in a routine soil‐test operation can be obtained by comparing the two CEC values.     

平键联结的计算机辅助设计(CAD)

用FORTRAN77计算机高级语言编写了平键联结的计算机辅助设计(CAD)程序。它由一个主程序和五个子程序(SS、Sa、Sb、Sc、Sd)组成。SS为主子程序,调用其它四个分子程序,实现整个设计过程。本程序使平键联结设计周期缩短,设计质量提高。