摆脱母语干扰,提高英语写作水平

大学生英语写作暴露出的诸多问题中,相当一部分语言错误是由于母语干扰产生的。因此,摆脱母语干扰对提高大学生英语写作水平起着举足轻重的作用。     

模糊控制器的一种在线插值算法

普通模糊控制器引入在线插值算法,改善了普通模糊控制器的稳态性能,消除了普通模糊控制器的调节死区.     

Discovering the Laws of Sampling

That the sample mean and variance are “good” estimates of the corresponding population parameters is easily accepted as “obvious” by students, but the concept of standard error of the mean is often found to be quite a hurdle. That this standard error decreases inversely as the square-root of the sample size, and the mysterious appearance of the Normal distribution, are often taken as magical and incomprehensible effects, and non-mathematical students can often be turned away from further understanding. This article describes a program which provides an experimental framework in which the student can rapidly develop an intuition for the basic properties of sampling.     

渐开线圆柱齿轮精度的计算机辅助设计

该文介绍渐开线圆柱齿轮精度的计算机辅助设计及计算的有关问题，对提高齿轮精度设计的准确度及其合理性有一定的实际指导意义。     

Visible region extraction from a sequence of rational Bézier surfaces

A method for computing the visible regions of free-form surfaces is proposed in this paper. Our work is focused on accurately calculating the visible regions of the sequenced rational Bézier surfaces forming a solid model and having coincident edges but no inner-intersection among them. The proposed method calculates the silhouettes of the surfaces without tessellating them into triangle meshes commonly used in previous methods so that arbitrary precision can be obtained. The computed silhouettes of visible surfaces are projected onto a plane orthogonal to the parallel light. Then their spatial relationship is applied to calculate the boundaries of mutual-occlusion regions. As the connectivity of the surfaces on the solid model is taken into account, a surface clustering technique is also employed and the mutual-occlusion calculation is accelerated. Experimental results showed that our method is efficient and robust, and can also handle complex shapes with arbitrary precision. Project supported by the National Basic Research Program (973) of China (No. 2002CB312106) and the National Natural Science Foundation of China (Nos. 60533070, and 60403047). The third author was supported by the project sponsored by a Foundation for the Author of National Excellent Doctoral Dissertation of China (No. 200342) and a Program for New Century Excellent Talents in University (No. NCET-04-0088), China     

一类积微分方程自由边界问题解的误差估计

讨论带跳扩散模型下美式期权价格及最佳实施边界当执行日期趋于无穷大时的误差估计。在相应的基本假设下,美式期权的定价模型是一个抛物积微分方程自由边界问题,而永久美式期权的定价模型是一个积微分方程自由边界问题。利用抛物型偏微分方程的极值原理,得到了带跳扩散模型下美式期权价格及最佳实施边界的误差估计。     

A NEW ALGORITHM FOR FAST HIDDEN SURFACE REMOVAL OF COMPLEX OBJECTS

ＡＮＥＷＡＬＧＯＲＩＴＨＭＦＯＲＦＡＳＴＨＩＤＤＥＮＳＵＲＦＡＣＥＲＥＭＯＶＡＬＯＦＣＯＭＰＬＥＸＯＢＪＥＣＴＳＦｕＹｕｑｉｎｇ（富煜清）；ＨｕａｎｇＪｉｎｆａ（黄金法）；ＬｉｎＦｅｎｇ（林峰）（ＤｅｐａｒｔｎｉｅｎｔｏｆＲａｄｉｏＥｎｓｉｎｅｅｒｉ...     

费歇判别法在乳房癌诊断中的应用

研究了乳房肿瘤的分类问题，通过对500个已知肿瘤性质(良性或恶性)细胞核的显微图像的10个量化特征进行统计分析，利用费歇判别法，建立了费歇判别模型，给出了判别准则，对未知乳房肿瘤性质的病例进行了成功的诊断；最后对变量进行了合理的缩减．本方法具有良好的实用性和操作性．     

折线型坡面时土压力的近似计算

针对折线形坡面，通过经典库仑土压力理论，对挡土墙的土压力作出近似的计算。