一类指数混合分布族的结果

在统计分析中,多元t分布是一种重要的分布以及指数分布族也是一种重要的分布族。模仿从多元正态分布得到多元t分布的过程,把指数分布族pθ与gamma分布进行混合,得到一种新的分布族,称为指数混合分布族pθ,并讨论了参数函数在指数混合分布族pθ下的无偏性以及讨论指数分布族pθ和指数混合分布族pθ有相同的完全统计量和充分统计量。     

二元威布尔分布形状参数相等的检验

将二元威布尔分布转化为二元极值分布，威布尔分布形状参数相等的检验转化为极值分布尺度参数相等的检验，给出了当相关参数θ=0.2,0.5,0.8,1时，检验统计量的模拟分位和统计量的功效，然后就独立情况与基于简单线无偏估计（GLUE）和最佳线性无偏估计（BLUE）给出的统计量进行比较，最后给出一个实例。     

具有部分缺失数据的两个拉普拉斯分布总体参数的估计与检验

本文研究样本不能完全观测时拉普拉斯分布总体参数的估计问题及相关假设检验问题.讨论了估计量的大样本性质,建立了相关检验的检验统计量,同时给出了检验统计量的极限分布.     

均匀分布U(θ_1,θ_2)的参数估计及优效性研究

讨论均匀分布U(θ_1,θ_2)中参数θ_1,θ_2的估计问题,给出了最大次序统计量和最小次序统计量的分布函数和联合分布函数,并讨论了最大次序统计量和最小次序统计量的数字特征以及这些统计量的优效性.     

柯西分布族对数似然方程根的大样本性质

文章针对一类具体的分布族———柯西分布族中参数θ,证明了存在θ的一个强相合且最好渐近正态估计^θ,它以概率1当样本量n充分大时是对数似然方程的根。     

几种分布族中参数之待估函数可估性的判定

考虑总体是ξ的分布族{F（x,θ）,θ∈},其中θ=（θ_1,θ_2,…,θ_h）是待估计的 未知参数, 设g（θ）是参数θ的实值待估函数,从总体ξ中抽取i.i.d.样本（ξ_1,ξ_2,…,ξ_n）,如果存在统计量g（ξ_1,ξ_2,…,ξ_n）:R~((n))→,使得     

极值分布的方差分析检验

本文考虑位置参数和尺度参数未知时极值分布的拟合优度检验。所提统计量W_G类似于Shapiro和Wilk(1965)的正态性检验W,对n=3(1)25给出了W_G的系数表及分布的分位点表,还将W_G与Cramer-Von Mises型统计量A~2,W~2,U~2作了检验功效比较,指出W_G是关于极值分布拟合优度检验的较好统计量。     

响应变量缺失情形下非线性EV模型的估计

考虑了响应变量随机缺失情形下的非线性EV模型.通过利用核实数据,构造了响应变量均值θ的调整的经验对数似然比统计量.证明了所构造的经验对数似然比统计量渐近于标准χ2分布,所得结果可以用来构造未知参数的大样本置信区间.     

负二项分布参数的UMVU估计及其渐近有效性

通过讨论负二项分布族的充分完备统计量 ,可给出未知参数θ的一致最小方差无偏估计 ,并通过Cramer Rao不等式及其无偏估计下界的讨论 ,证明了θ的惟一的UMVU估计是渐近有效估计     

几种非正态总体未知参数的贝叶斯假设检验问题

利用贝叶斯统计思想总结了两种常见的假设检验方法,在此基础上针对双边检验H0∶θ=θ0,H1∶θ≠θ0,提出了构造参数θ的否定域,即求出参数θ的置信概率为1-α的最大后验区间D,区域Θ-D为参数θ的否定域.检验θ是否在否定域内,若在就否定H0.研究了四类非正态总体几何分布、负二项分布、威布尔分布和瑞利分布的未知参数的贝叶斯假设检验,并给出了相应的否定域.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to