log-normal distribution

In the long term growth rate of housing values obey log-normal distribution .

长期来看住房价值增长率服从对数正态分布。

The packing density of log-normal distribution is more than one of normal distribution at the same coefficient of uniformity .

采用均匀系数来比较这两个不同分布时，相同的均匀系数下，对数正态分布的堆积密度要大于正态分布函数，这主要是对数正态分布下存在更多的半径较小的球体。

An Approximate Method of Estimating the Parameters of Three-Parameter Log-Normal Distribution

一种估算三参数log-normal分布参数的近似方法

For all test fuels , the particle number and size distribution show unimodal or bimodal log-normal distribution .

柴油机排气颗粒数量的尺寸分布呈现单峰或双峰对数分布。

Therefore , a Log-Normal distribution Reliability model ( LOGNR ) is developed to assess the link travel time reliability . 3 .

在此基础上，建立了路段行程时间可靠性评价的对数正态分布可靠性模型（LOGNR）。

The three-parameter log-normal distribution is widely used in the reliability engineering , but there are some difficulties in estimation of its distribution parameters .

三参数（log－normal）分布在可靠性工程中有广泛应用，但其分布参数的估计较为困难。

The model is built on no-arbitrage constraints , and assumes that the forward LIBOR obey log-normal distribution .

该模型建立在无套利约束之上，并且假设远期LIBOR服从对数正态分布。

The results show that the probability distribution characteristic of the vertical permeability coefficient in fissured rock zone is much close to the log-normal distribution .

结果表明，同正态分布和均匀分布相比，裂隙岩体地区的垂向渗透系数更接近对数正态分布。

This thesis introduces parameter CFAR method , and implements radar CFAR detection under Rayleigh distribution , Weibull distribution , Log-normal distribution sea clutter .

本文对参量型的恒虚警率方法进行介绍，分别在瑞利分布、韦布尔分布、对数正态分布的海杂波下实现恒虚警率检测。

Log-series and log-normal distribution models could well fit to the species-abundance distribution of soil animals communities , but broken-stick model cannot .

对数级数分布模型和对数正态分布模型能较好地拟合土壤动物群落物种-多度分布格局，形成富集种少，稀有种多的格局。

His paper points out a mistake of reference [ 1 ] , and discuss the parameter estimates of the progressive accelerated life tests under log-normal distribution .

本文指出文献〔1〕中一个错误，讨论了寿命分布为对数正态分布时序进应力加速寿命试验下，参数的点估计和区间估计。

Under the hypotheses of log-normal distribution of system prior reliability , confidence lower-bound of system reliability can be obtained by taking full advantage of component test information and system configuration .

在系统可靠性验前为对数正态分布的假设之下，充分利用单元的试验信息和系统的构型，得到了系统可靠性的置信下限。

One can see from results that crack growth size under the certain load cycles and crack growth rate under the certain stress intensity factor range can be fitted with the log-normal distribution .

结果表明，一定载荷循环次数下的裂纹扩展尺寸和一定应力强度因子变程下的裂纹扩展速率较好地服从对数正态分布。

The measured size distribution of desert aerosol are characterized by 3-modes , which can be fitted very well by the sum of three log-normal distribution functions .

实测粒度谱呈三峰型结构，能用三对数正态分布函数和来拟合。

Present the approximate maximum likelihood estimate of the parameters under multicomponent data with a single-parameter exponential , two-parameter exponential , two-parameter Weibull or two-parameter log-normal distribution .

给出了单参数指数、两参数指数、两参数Weibull及两参数对数正态分布型产品在基于分组型数据下参数的近似极大似然估计。

To summarize two-dimensional non-normal joint distribution in use , such as Bivariate Weibull Distribution , Bivariate Log-normal Distribution , Bivariate Gumbel Distribution , and Bivariate Gamma Distribution .

归纳总结了已经出现的非正态二维联合概率分布模型，如二维威布尔分布、二维对数正态分布、二维冈贝尔分布及二维伽玛分布等。

In this paper , parameter CFAR method of treatment , respectively , of the Rayleigh distribution , the log-normal distribution , Weibull distribution , K distribution data points sea clutter histogram with the theoretical value .

本文采用参量法的恒虚警处理方法，分别研究了瑞利分布、对数-正态分布、韦布尔分布、K分布海杂波数据直方图与理论值。

The results show that the anisotropy of grain boundary energy and mobility induce grain size inhomogeneous , grain shape irregular , grain growth exponent decreasing , grain size distribution deviating from log-normal distribution .

结果表明：各向异性晶界能和晶界迁移率使晶粒尺寸不均匀、形状不规则，降低了晶粒长大指数，晶粒尺寸分布偏离对数正态分布；

Ne water peak eluted from organic support 402 ( a kind of porous polymer beads , made at Shanghai ReagentPlant ) at 144 ℃ was fitted well with log-normal distribution function .

由高分子多孔小球（有机担体402）填充柱流出的水的色谱峰，用对数正态分布函数拟合得较好。

The length distribution of liquid slug liquid slug can be depicted by log-normal distribution at three locations of the pipe such as 25D , 55D , 100D .

实验得到管路25D，55D，以及100D处液弹长度分布均可以用对数正态分布函数来描述。

Through statistical data and simulation results we found that both the first response time and fighting time accord with log-normal distribution law and the probability of occurrence of the burned area with the first response time has the power function relationship .

通过统计数据和模拟实验可以发现消防响应第一出动时间和战斗时间都符合对数正态分布规律，并且在第一出动时间下过火面积的发生概率有幂函数的关系。

In the extruded fibers , the dispersed phase distributes in PP matrix phase as sphere with the typical " sea-island " structure , the histogram of droplets diameter distribution is in fine with log-normal distribution .

挤出丝中，PS分散相呈球形分布于基体相PP中，呈典型的海-岛结构，分散相液滴直径呈对数正态分布。

Based on the assumption that prices of stocks follow log-normal distribution , and their volatility is constant , considering pricing European option problems with transaction costs are proportional to stocks ′ value and discrete stochastic dividends of stocks .

在股票价格服从对数正态分布，波动率为常数的假设下，考虑了有与股票价格成比例的交易费和股票的离散随机分红时的期权定价问题。

The results indicate that the distribution of liquid slug lengths can be well fitted by log-normal distribution , and the fluctuation of liquid slug lengths is characterized with chaotic vibration which are sensitively dependent on initial conditions .

结果表明，水平管道段塞流的液塞长度符合对数正态分布，其波动是对初始条件敏感的混沌振荡，遵循分形统计规律，且具有持久性。

At the same time the disturbance of the community structure of macrobenthos in each station has been analysed by using the log-normal distribution of individuals among species , and the result shows that about 60 % stations have been disturbed .

同时，用种内个体对数-正态分布法对各调查站位大型底栖生物群落结构受扰动的程度进行了分析，结果有60%的站位底栖生物群落已受到中度的扰动。

Some fatigue test data of crankshaft were listed and statistical regression analyses were conducted in normal distribution , log-normal distribution and the Weibull distribution respectively . By the results , reasonableness comparison of each distribution for crankshaft fatigue test data was made .

以曲轴弯曲疲劳试验的实测数据为例，进行了正态分布、对数正态分布、威布尔分布下的数据统计回归分析，并对比分析了各种分布在曲轴失效数据的合理性。

Presently , most study on light scattering from smoke particles are focused on single aggregate . In fact , the smoke has a similar fractal structure . The number of primary particles approximately obeys log-normal distribution , and aggregates are in random orientation .

目前烟颗粒光散射特征的研究多针对单个凝团，实际上烟雾是具有近似分形结构、基本颗粒数N近似服从对数正态分布、空间随机取向的烟颗粒群。

Secondly , this thesis thoroughly presents the methods of modeling of clutter , analyzing the different statistical model in amplitude and power spectrum , and producing two clutter sequences which separately obey Rayleigh distribution and Log-Normal distribution by Zero Memory Nonlinearity ( ZMNL ) method .

然后，文章详细论述了杂波建模仿真方法，分析了服从不同幅度和功率谱统计特性的杂波模型，并采用ZMNL法产生了瑞利分布和对数正态分布杂波序列。

Based on the data of the listed enterprises in China from 2001 to 2004 , the paper finds that financial ratios of listed enterprise reflecting short-term debt paying ability follow log-normal distribution , and financial ratios of listed enterprises reflecting long-term debt paying ability follow normal distribution .

通过对上海证券交易所2004年上市公司年报的4个财务比率指标的统计分析，发现表征短期偿债能力的财务比率指标服从对数正态分布，表征长期偿债能力的财务指标服从正态分布。

The corresponding descriptive statistical indices of the snails including median , 95 % confidence interval ( 95 % CI ) and aggregation index were calculated . Finally , the negative binomial distribution , log-normal distribution , exponential distribution and Weibull distribution were fitted to the data of Oncomelania hupensis .

计算4块滩地的中位数、95%可信区间（95%CI）等描述性统计指标，并分别用负二项分布、对数正态分布、指数分布和Weibull分布拟合钉螺数据以分析钉螺的分布规律。