A divine surprise: The golden mean and the round-oil error

This article deals with an example of the systematic round-off error that can be encountered in numerical computations. The example is based on the recursion relation used for calculating higher powers of the golden mean. In the process, the link between the golden mean and the Fibonacci sequence also becomes apparent.     

运用逻辑知识提高阅读理解正确率

讨论了学生在英语阅读理解中的难项--推断题,分析了造成这一现象的原因,并提出了运用逻辑知识,提高阅读理解率的一些具体办法.     

高精度时钟系统的设计

近几年来，随着科学技术的进步和时代的发展，人们对时间精度提出了越来越高的要求，特别是在国防、科研及电力、铁道、交通、航海等方面，所以，研制高精度时钟系统已越来越重要。现用Motorola公司的GT-on-core GPS接收模块来制作高精度时钟系统。     

人事档案中出生时间和参加工作时间准确性刍议

本文指出了目前人事档案存在出生时间和参加工作时间互不一致的现象 ,及其此现象对组织人事工作的正常进行造成被动 ,并影响职工的个人利益 ,同时提出为避免这种现象的出现而采取的措施及对既成现象的应对办法。     

Classifying Data Sets Using Support Vector Machines Based on Geometric Distance

Support vector machines (SVMs) are not as favored for large-scale data mining as for pattern recognition and machine learning because the training complexity of SVMs is highly dependent on the size of data set. This paper presents a geometric distance-based SVM (GDB-SVM). It takes the distance between a point and classified hyperplane as classification rule, and is designed on the basis of theoretical analysis and geometric intuition. Experimental code is derived from LibSVM with Microsoft Visual C 6.0 as system of translating and editing. Four predicted results of five of GDB-SVM are better than those of the method of one against all (OAA). Three predicted results of five of GDB-SVM are better than those of the method of one against one (OAO). Experiments on real data sets show that GDB-SVM is not only superior to the methods of OAA and OAO, but highly scalable for large data sets while generating high classification accuracy.     

对络合滴定中滴定速度的探讨

该文选择络合滴定法,在不同滴定速度下对水硬度进行了实验测定,并就滴定结果对滴定速度的影响进行了分析和讨论．     

几种高精度差分格式的比较试验

具体比较了三种含基架网点少的高精度格式：紧致平方守恒格式、特征保形格式和特征Ｈｅｒｍｉｔｅ插值格式．实例表明前两种格式计算效果较好,第三种格式有明显位相差．     

求解泊松方程的高精度紧致差分方法

基于Kreiss[1]所建立的紧致差分逼近公式,提出一种数值求解二维泊极方程的高精度紧致差分方法．该方法是矩形网络下九结点差分近似,其推导过程简单,且具有四阶精度．最后给出了误差估计和数值结果．     

图像分割算法在零件图像测量中的应用研究

通过分析图像测量系统的组成,说明了图像分割算法在零件图像测量中的重要地位,综合阐述了目前常用的图像分割算法的特点。针对零件图像测量的实际应用情况,提出了一种新的图像分割算法,实现了对目标边缘的准确检测。在此基础上设计了边缘检测的亚像素细分算法,对目标边缘进行亚像素精确定位,并用实例说明了本算法的可行性。     

Validity of Self-Reported Pedometer Steps per Day in College Students

The purpose of this article was to examine the validity of self-reported pedometer steps/day. Forty-seven participants were provided a New Lifestyles NL-2000 (NL-2000; Lees Summit, MO, USA) pedometer and a physical activity (PA) diary for 3 weeks, but not informed of the data-storing capabilities. For weeks 2 and 3, each participant was given a step goal of 3,000 steps/day above week 1 average. A 2 × 3 repeated measures analysis of variance (ANOVA) was used to examine differences between reported steps/day. Bland–Altman plots assessed the mean bias and limits of agreement between reporting methods. Mean self-reported and NL-2000 steps/day were 9,264 ± 3,555 and 8,971 ± 3,590 steps/day (n = 26, p > .05). Mean biases were 216 ± 1,753 (week 1), –506 ± 1,355 (week 2), and –590 ± 1,360 (week 3) steps/day. Negative mean bias values indicate higher self-reported steps/day. Mean steps/day were similar between recording methods, but large differences were observed among individuals, suggesting self-reported steps/day may be valid for PA research at the population level, but not the individual level.