Cubic Bézier approximation of a digitized curve

In this paper we present an efficient technique for piecewise cubic Bézier approximation of digitized curve. An adaptive breakpoint detection method divides a digital curve into a number of segments and each segment is approximated by a cubic Bézier curve so that the approximation error is minimized. Initial approximated Bézier control points for each of the segments are obtained by interpolation technique i.e. by the reverse recursion of De Castaljau's algorithm. Two methods, two-dimensional logarithmic search algorithm (TDLSA) and an evolutionary search algorithm (ESA), are introduced to find the best-fit Bézier control points from the approximate interpolated control points. ESA based refinement is proved to be better experimentally. Experimental results show that Bézier approximation of a digitized curve is much more accurate and uses less number of points compared to other approximation techniques.     

JDZ-1型固态存储雨量器降水量误差成因分析

对JDZ-1型固态存储雨量器与虹吸自记雨量计平行观测资料进行了系统分析,分析了两者存在误差的影响因素。对JDZ-1型固态存储雨量器在北方地区使用过程中存在的问题提出了解决方法,以保证和提高JDZ-1型固态存储雨量器资料质量。     

Solid Modeling Error : Analysis and Compensation

ＳｏｌｉｄＭｏｄｅｌｉｎｇＥｒｏｒ：ＡｎａｌｙｓｉｓａｎｄＣｏｍｐｅｎｓａｔｉｏｎ①ＸｕＺｈｉｇａｎｇＨｕａｎｇＫｅｚｈｅｎｇＡｉＸｉｎｇＳｈａｎＬｉａｎｙｅＣｏｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎｇ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉ...     

经纬仪竖盘检测新方法及综合检验仪

本文提出一种检定经纬仪竖直盘测角误差的新方法．该方法精度高，稳定性好，能直接与国家角度标准溯源．由它组成的“经纬仪综合检验仪”可以检测ＪＪＧ４１４—９４光学经纬仪检定规程中所有的项目及细分误差，其总不确定度为０．４″．被测仪器包括各种类型及精度的光学经纬仪、电子经纬仪、水准仪等．     

干涉式光纤陀螺系统Serrodyne调制误差分析

本文首先针对实现闭环光纤陀螺系统相位零化技术的Ｓｅｒｒｏｄｙｎｅ调制理论进行了详细分析，通过对实际Ｓｅｒｒｏｄｙｎｅ调制分析得出因回扫时间的延迟产生周期性反对称毛刺是导致调制失真的因素，运用 Ｆｏｕｒｉｅｒ Ａｎｇｉｅｒ Ｂｅｓｓｅｌ级数对误差信号各次谐波分解得出低次谐波分量在误差信号中占主导作用，并提出减小调制误差的方法。     

A stability classification method and its application to pipelined solution of linear recurrences

A new method of classification for numerical stability of parallel algorithms is proposed based on the theoretical foundation of forward error analysis. It partitions the algorithms according to their asymptotic stability—a measure introduced to relate the limiting behavior of the stability to the size of the problem. Using this method, the stability aspect of the pipelined solution technique for first-order and second-order linear recurrences—the core of a tridiagonal linear equation solver—is studied. In particular, it shows that the pipelined solution method of the first-order linear recurrences has the same degree of stability as the commonly used sequential evaluation algorithms. The stability problems of sequential and pipelined solution methods of the second-order linear recurrences are also studied.     

快速钨铼热电偶的测温误差

本文用热电偶误差计算的通用方法（极限误差表达法）分析了构成快速钨铼热电偶测温误差的因素，从量的角度探讨了各因素对总的误差的影响，对如何认识快速钨铼热电偶的测温精度，提出了可供参考的观点。     

EXL能谱仪薄样品X线的定量分析

研究了Link公司能谱仪中RTS软件（薄膜定量分析软件）可靠性及适用性。实验结果表明：RTS软件定量分析结果误差较小。但对C、N、O等轻元素定量分析，试样厚度小于1500以下时，结果才比较可靠。     

光盘的出错率分析和研究

本文通过对光存储系统出错特性的分析，研究了一些描述出错特性的主要参数，并且给出了描述出错特性的Ｇｉｌｂｅｒｔ模型及其改进型模型。     

Error handling in a parallel LR substring parser

Parallel parsing is currently receiving attention but there is little discussion about the adaptation of sequential error handling techniques to these parallel algorithms. We describe a noncorrecting error handler implemented with a parallel LR substring parser. The parser used is a parallel version of Cormack's LR substring parser. The applicability of noncorrecting error handling for parallel parsing is discussed. The error information provided for a standard set of 118 erroneous Pascal programs is analysed. The programs are run on the sequential LR substring parser.