共查询到18条相似文献，搜索用时 640 毫秒
1.
成都地面风速年极值的4种分布函数拟合结果的比较 总被引：4，自引：0，他引：4
分别用Webukk分布，Gumbel分布，Pearson Ⅲ分布和对数正态分布拟合成都1993－1997年间地面风速年极大值的渐近分布，其结果表明Gumbel分布和对数正态分布拟合效果最好。 相似文献
2.
利用重庆1951—1996年间地面气温年极大值的记录，分别用韦伯分布、耿贝尔分布、皮尔逊Ⅲ型分布和对数正态分布进行拟合试验，通过统计推断比较，得出重庆地面气温年极大值遵循的渐进分布为韦伯分布和耿贝尔分布。 相似文献
3.
降水量的发生概率是天气预报及旱涝灾害等灾害风险评估的重要组成部分,希望通过对宜宾市季度降水量分布函数的研究,为当地的防灾减灾及农业生产提供一定的科学依据.利用四川省宜宾市1960～2010年51年的降水量数据资料,分别应用正态分布、对数正态分布、伽马分布和皮尔逊-Ⅲ分布函数对该地区的降水分布特征进行研究.在此基础上,利用最小离差平方和准则进行4种分布函数的拟合优度检验.结果表明:4种分布函数均能拟合宜宾季度降水量分布;伽马分布、正态分布、对数正态分布及P-Ⅲ分布分别为宜宾市春、夏、秋、冬各季降水量的最优拟合分布函数. 相似文献
4.
降水量的发生概率是天气预报及旱涝灾害等灾害风险评估的重要组成部分,希望通过对宜宾市季度降水量分布函数的研究,为当地的防灾减灾及农业生产提供一定的科学依据.利用四川省宜宾市1960～2010年51年的降水量数据资料,分别应用正态分布、对数正态分布、伽马分布和皮尔逊-Ⅲ分布函数对该地区的降水分布特征进行研究.在此基础上,利用最小离差平方和准则进行4种分布函数的拟合优度检验.结果表明:4种分布函数均能拟合宜宾季度降水量分布;伽马分布、正态分布、对数正态分布及P-Ⅲ分布分别为宜宾市春、夏、秋、冬各季降水量的最优拟合分布函数. 相似文献
5.
利用１９３３～１９９２年期间成都地面最高气温和地面最大风速年极值的记录，通过统计推断，找出了成都地面最高气温年极值和地面最大风速年极值遵循的渐近分布——Ｗｅｉｂｕｌ分布和Ｇｕｍｂｅｌ分布，并讨论了它们的参数估计方法。 相似文献
6.
利用成都１９３３～１９９２年间的地面最低气温年极值记录，采用韦伯分布和耿贝尔分布，分别对其进行了渐近分布拟合。通过统计推断，找出了成都地面最低气温年极值所遵循的最佳渐近分布——韦伯分布。 相似文献
7.
强降水的GP分布拟合 总被引：1，自引：0，他引：1
邹波 《成都信息工程学院学报》2002,17(2):101-104
根据极值理论中处于重要地位的GP分布模型，讨论了模型中的形状参数、位置参数及尺度参数的算法，并将其用于拟合呈偏斜状态的月和日降水量资料中强降水部分，得到强降水发生的直观年数。 相似文献
8.
周世健 《地球科学与环境学报》1996,(4)
根据截尾均值、平尾均值的定义和截尾正态分布，本文得到了这两种均值都是最或然估计量．并导出了它们的影响函数，用来表征估值的抗差性，最后对效率问题作了一些讨论。 相似文献
9.
区域化探中多数元素含量的概率分布服从或接近对数正态分布。在对数正态分布情况下,将标准离差与平均值的对数比值作为变异系数是不科学的。文章提出了类似参数新的计算方法和解释思路。 相似文献
10.
分析了现行求更新函数解析所存在的不足之处,探讨采用蒙特卡洛模拟法求机器在常用寿命分布情况下的更新函数,并以对数正态分布为例介绍其应用过程。 相似文献
11.
人口数据空间化表达与应用 总被引：13，自引：0，他引：13
人口数据空间化是“数字地球”的重要研究内容。本文在介绍人口空间分布研究的基础上,从人口分布影响因子、土地利用等空间数据的应用、构建间接的人口指标、人口数据空间化建模以及城市人口数据空间化五个方面,回顾了人口数据空间化研究的最新进展,并简要阐述了面插值的概念及其对人口数据空间化研究的意义。在总结前人相关研究的基础上,本文以福建省为研究区,在栅格数据模型的支持下,通过多源信息融合,从乡镇行政区划的尺度上对人口数据空间化模拟进行了尝试。 相似文献
12.
Bioaerosols were collected by using a six-stage bioaerosols sampler from September 2007 to August 2008 in the coastal region of Qingdao, China. The terrestrial and marine microbes(including bacteria and fungi) were analyzed in order to understand the distribution features of bioaerosols. The results show that the average monthly concentrations of terrestrial bacteria, marine bacteria, terrestrial fungi and marine fungi are in the ranges of 80–615 CFU m-3, 91–468 CFU m-3, 76–647 CFU m-3 and 231–1959 CFU m-3, respectively. The concentrations of terrestrial bacteria, marine bacteria, terrestrial fungi, marine fungi and total microbes are the highest in each microbial category during fall, high in spring, and the lowest in the summer and winter. The bacterial particles are coarse in spring, autumn and winter. The sizes of fungal particle present the log-normal distribution in all the seasons. 相似文献
13.
重庆地面最高气温与最大风速年极值的渐近分布 总被引：3，自引：0，他引：3
利用重庆1951-1990年间地面最高气温和1956-1990年间地面最大风速年极值的记录,采用韦伯分布和耿贝尔分布分别对其渐近分布进行拟合.通过统计推断,找出重庆地面最高气温和地面最大风速年极值遵循的最佳渐近分布--韦伯分布. 相似文献
14.
Population density in Guangzhou City is characterized by a main single center and considerable differences throughout the
8 districts and 112 neighborhoods and towns. Historically, population density in Guangzhou City rose sharply, and population
distribution was mainly influenced by the attraction of the port. After the founding of the People’s Republic of China (PRC),
a series of large-sized factories were built in suburban areas, which drew in a large amount of population from the areas
outside of Guangzhou. A small part of this population lived in the suburban areas while most resided within the city centre.
As the natural increase rate of population was very high, the population density of both the city centre and suburban areas
rose, the former rose at higher rates. Since reform and the opening up to the outside world, Chinese economy has grown quickly,
the total population of Guangzhou has also increased quickly. Meanwhile, changes in population density within the city is
becoming more and more obvious. Population density in the city centre is falling and in city periphery is rising. From the
analysis of the population density model, it is found that population distribution of Guangzhou is in the process of transition
from an early stage to a mature stage. Population decline within the centre city of Guangzhou City, which reflects a prosperous
economy of the city, is significantly different from the recession of in the western countries. 相似文献
15.
利用重庆 1951-1996 年间 46 年地面气温年极小值的记录,采用韦伯分布和耿贝尔分布分别进行拟合试验.通过统计推断和对比,找出重庆地面最低气温年极值遵循的最佳渐近分布--韦伯分布. 相似文献
16.
Ｉ．ＰＯＰＵＬＡＴＩＯＮＤＩＳＴＲＩＢＵＴＩＯＮＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＢｙｔｈｅｅｎｄｏｆ１９９４,ｔｈｅｐｏｐｕｌａｔｉｏｎｏｆＧｕａｎｇｚｈｏｕＣｉｔｙｈａｄｉｎｃｒｅａｓｅｄｔｏ３．８０３ｍｉｌｉｏｎ,ａｐｏｐｕｌａｔｉｏｎｓｉｚｅｒａ... 相似文献
17.
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18.
P. J. HARRISON K. FURUYA P. M. GLIBERT J. H. W. LEE D. M. ANDERSON R. GOWEN A. R. AL-AZRI A. Y. T. HO 《中国海洋湖沼学报》2011,29(4):807-831
The dinoflagellate Noctiluca scintillans is one of the most important and abundant red tide organisms and it is distributed world-wide. It occurs in two forms. Red Noctiluca is heterotrophic and fills the role of one of the microzooplankton grazers in the foodweb. In contrast, green Noctiluca contains a photosynthetic symbiont Pedinomonas noctilucae (a prasinophyte), but it also feeds on other plankton when the food supply is abundant. In this review, we document the global distribution of these two forms and include the first maps of their global distribution. Red Noctiluca occurs widely in the temperate to sub-tropical coastal regions of the world. It occurs over a wide temperature range of about 10°C to 25°C and at higher salinities (generally not in estuaries). It is particularly abundant in high productivity areas such as upwelling or eutrophic areas where diatoms dominate since they are its preferred food source. Green Noctiluca is much more restricted to a temperature range of 25°C-30°C and mainly occurs in tropical waters of Southeast Asia, Bay of Bengal (east coast of India), in the eastern, western and northern Arabian Sea, the Red Sea, and recently it has become very abundant in the Gulf of Oman. Red and green Noctiluca do overlap in their distribution in the eastern, northern and western Arabian Sea with a seasonal shift from green Noctiluca in the cooler winter convective mixing, higher productivity season, to red Noctiluca in the more oligotrophic warmer summer season. 相似文献