基于ECDSA的校园CA设计

利用校园网络可以实现校园内信息与资源的共享和网上交易，由于电子信息本身可更改，且交易时无需面对面进行，这使得假冒身份、抵赖所发送的电子信息成为可能，基于椭圆曲线数字签名算法(ECDSA)有着密钥长度小、计算负载少、节省带宽等特性，提出了一种校园CA设计，为校园网络的进一步应用，提供了安全通信机制。     

用数理统计方法建立钢的淬透性曲线模型

利用统计学中的Ｌｏｇｉｓｔｉｃ数理模型，经过适当改造后可以建立起主要钢种的淬透性曲线的数学模型，并且具有较同的拟合性，误差较小，结合此种方法，通过少量的实测点就可以作出一般钢种的淬透性曲线。此种方法在实践上对于机械零件热处理的自动化，在理论上对探索钢的物理冶金机理，可能具有较大的意义。     

一对相同非圆齿轮传动节曲线的设计方法

提供了一对相同非圆齿轮传动节曲线的设计方法，对初始节曲线的获得、节曲线光滑性的改善以及节曲线的外凸设计等作了较为详细的讨论，并以实例加以说明。     

极化曲线在电有机合成中的应用

本文以电解氧化2,5-二甲基呋喃和对丙烯基苯甲醚为实例,阐明如何分析所测得的极化曲线,怎样从极化曲线来确定有关的实验条件。实验证明,这是一种快速而有效的方法。     

丙氨酸ESR剂量计的剂量特性

使用JES FEIXG ESR谱仪测量用γ-射线和电子束辐照过的丙氨酸的剂量响应曲线,研究其零剂量特性、探测下限、线性范围、饱和区域以及辐照和保存时环境条件的影响,并从微剂量学的角度研究其剂量响应,给出D_(37)特征剂量.     

方型Koch曲线的定义,分维及性质

文中定义了基本方型Koch曲线和方型Koch曲线,计算了它们的分维(相似性维数),证明了方型Koch曲线的分维集在区间〔1,2〕中稠密。这样就可用方型Koch曲线来研究和描述任意分形曲线的某些性质(如曲线的复杂程度)。     

The impact on the performance of growth curve models of changes in parameter re-estimation period and other factors

A simulation model of a real electricity supply undertaking was used to provide a financial performance measure for growth curve forecasting models. The impact on financial performance was determined when changes were made in (1) the method of estimating the model parameters, (2) the period between re-estimations, (3) the growth curve fitted and (4) the amount of smoothing of the demand time-series. The response to variation of the parameter review period was found to behave surprisingly, in that it exhibited different signs for two different estimation methods. Changes in re-estimation period explained somewhat more of the variation in performance than did a change in growth curve. Correcting the demand series for conditions which were known to be abnormal improved performance.     

柴达木盆地西部地区第三系碎屑岩粒度概率累积曲线特征

在岩心观察的基础上,利用主要取心井的粒度分析资料,对柴达木盆地西部地区第三系碎屑岩主要沉积环境的粒度概率曲线进行了研究。研究表明,该地区发育的沉积相有扇三角洲、冲积平原、三角洲、湖泊、湖底扇,每一种沉积相又分为几种沉积亚相类型;该地区碎屑岩的粒度概率累积曲线特征主要包括:“上拱弧形”式、一段式、两段式、三段式、多段式、复杂两段式和复杂三段式、“低斜多段”式、“高斜多跳一悬”式和“高斜多跳一悬夹过渡”式、“高斜多跳”式、“宽缓上拱”式等,每种沉积亚相类型对应其独特的粒度概率累积曲线特征。该研究成果可为新探区的沉积环境判断提供参考。     

Fitting of growth curves over time when the data are obtained from a single realization

This paper focuses on the general problem of forecasting the maximum value of a time series which by the nature of the data must approach an asymptotic value. Examples of such series include the growth of organisms, the concentration of a chemical reagent during a reaction occurring over time or the amount of a fossil fuel resource which has been discovered or produced as a function of time. The approach taken below differs from the usual models for this type of data in that it assumes that an unobserved time series is actually driving the process, and that the observed data series is a function of the unobserved process. In the case of fossil fuels the unobserved series might be a measure of the exploratory drilling, the number of production days in a given time period or even the amount of fiscal resources devoted to exploratory activities. A maximum likelihood method is developed for estimating the parameters of the process, especially the maximum S, and the covariance structure of the estimators is developed. The methodology is illustrated on an example of oil production. Finally, methods are developed for forecasting the data into the near future.     

公路平曲线参数对车辆轨迹和速度的影响规律

为得到弯道几何参数对切弯时车辆轨迹和速度的影响,构建了切弯效用的量测指标———曲中速度增量和曲中轨迹半径增量,然后用"公路-驾驶人-车辆"仿真系统模拟了跟弯和切弯2种模式下的弯道行驶过程,得到了弯道转角、半径、路幅宽度、弯道长度与切弯效用之间的关系曲线,结果表明:①切弯效用在转角ΔA=20°时最大,然后随着ΔA增加而迅速衰减.②对于低于10°的小转角弯道,即使是跟弯行驶,轨迹半径仍大于弯道半径,只有ΔA>20°时,轨迹半径才会与弯道半径一致.③存在一个临界转角ΔA0C,当ΔA<ΔA0C时,路宽的增加才会提高切弯效用.④转角一定的情况下,切弯效用随弯道半径的增加而衰减,并且转角越大,衰减越迅速.⑤对于30m半径的急弯,不管路宽和转角取何值,切弯都可以提高通过速度.⑥切弯效用随弯道长度的增加而减小,弯道长度超过临界值时,切弯效用为零.