利用AR(p)模型的抗差最小二乘估计预报城市地铁隧道工程变形监测数据

变形监测数据由于受多种因素的影响,观测值的精度会有所不同,观测值中也会出现异常值。选择观测值残差平方的倒数作为观测值的权矩阵,利用加权最小二乘法进行预测,能提高观测值预测的精度,并应用抗差估计对含有粗差的观测值进行预报,能有效提高观测值预报的精度。某城市地铁隧道工程地表沉降预报的实验数据证明加权最小二乘估计和抗差最小二乘法的合理性、有效性和可行性。     

随机模型对GPS网平差结果的影响

指出根据观测数据对随机模型验后估计的意义，介绍随机模型验后估计的理论和方法及GPS基线网平差的数学模型，研究用方差分量估计与非负估计方法对不同时段不同分区的方差协方差矩阵进行估计，以评定基线观测值的质量，同时研究它对参数估计的影响，算例的计算结果表明，方差分量估计正确与否对GPS网平差结果的影响可达6mm。因此，在GPS网平差中，合理估计方差分量并定权对改善平差结果具有积极意义。     

线性回归模型的抗差泛最小二乘估计

首次用抗差泛最小二乘法考虑线性回归模型，得到了抗差泛最小二乘估计；然后，研究了该估计的影响函数和渐近方差-协方差矩阵；最后，用算例说明了抗差泛最小二乘估计具有抗差性，优于传统的最小二乘估计及作提出的泛最小二乘估计。     

稳健估计的两种粗差探测方法

在测量数据服从正态分布的情况下,最小二乘估计具有最优化统计性质,它是应用最广泛的一种估计方法.针对测量数据由于过失误差而偏离正态分布,最小二乘估计并没有抵抗异常值的能力,需要寻求具备抗粗差能力的估计理论和方法,对测量数据中的粗差进行判别和剔除,使其不影响测量结果.使用了两种粗差检验的方法对观测数据中存在的粗差进行检验,分别是选权迭代法和数据探测法,并利用水准网数据验证了它们抵抗粗差的效果,表明选权迭代法中IGG法更容易实现粗差的探测与定位.     

Kalman滤波质量控制的一种改进算法

探讨了Kalman滤波中观测粗差和状态方程异常的处理问题,分析了以往处理方法,如Sage自适应滤波法、两步假设检验法及抗差自适应Kalman滤波法等的优点和不足,提出一种改进算法,一方面用拟准检定法检测观测方程中的粗差,另一方面再用Sage自适应方法实时估计状态噪声方差阵,减免状态方程异常对参数估计的影响.通过一个星载GPS低轨卫星定轨算例,验证这种思路是可行的.     

基于奇异值分解法的抗差总体最小二乘

在最小二乘平差中,认为只有观测向量中存在误差,因此当有粗差存在时,也只需要考虑观测向量中的粗差,采用抗差最小二乘可达到剔除粗差的目的。而总体最小二乘同时顾及了系数矩阵和观测向量中的误差,这就要求抗差总体最小二乘同时考虑系数矩阵和观测向量中的粗差。为了同时对粗差进行探测和定位,在加权总体最小二乘奇异值分解法的基础上,提出了一种总体最小二乘抗差估计,最后通过2个算例证明了本文提出方法的有效性和可行性。     

基于不同等价权函数的抗差粒子滤波对比研究

粒子滤波与其他非线性滤波相比,具有更好代表性,因而在实际中得到广泛应用。在状态空间中寻找随机样本来对概率密度函数进行近似,以样本均值代替积分运算,来获得最小方差状态估计。在此过程中,含粗差的观测值对赋权产生干扰影响粒子滤波效果。在已有抗差粒子滤波的基础上,讨论了基于不同权函数的抗差粒子滤波。模拟计算并对数据分析表明,IGGⅢ抗差粒子滤波提高了粒子滤波的鲁棒性。     

基于选权迭代最小二乘的地表移动盆地 边界角量参数估计

在厚松散层矿区,利用常规地表移动观测站变形观测成果无法估计松散层、岩层的边界角和移动角参数,针对此问题,文章提出了一种基于选权迭代最小二乘的地表移动盆地边界角量参数估计模型。首先将地质采矿条件相似的观测站归为一类(作为基础数据),然后以综合移动角和综合边界角为观测值,推导了以岩层移动角、岩层边界角、松散层移动角及松散层边界角为参数的观测方程,考虑到综合移动角和综合边界角中可能存在粗差,引入Hampel法和IGG法2种选权的方法,通过多次迭代求取参数最优值,并对求参结果进行精度评价。基于该模型利用Matlab软件开发了参数估计程序。顾桥矿、顾北矿的工程应用结果表明,Hampel法的参数估计精度优于4°,IGG法参数估计精度优于1°。基于IGG法选权迭代最小二乘估计的顾桥矿、顾北矿地表移动盆地边界角量参数分别为:φ_0=48.02°,φ=64.47°,β_0=48.19°,β=69.18°,γ_0=48.20°,γ=70.01°,δ_0=35.32°,δ=49.92°。     

相关观测的抗差估计

相关观测可以通过正交分解转成独立观测，用三角分解将相关观测变换成等权独立观测，再运用Ｈｕｂｅｒ 法进行抗差估计，形成相关独立法。经实例计算，此方法具有很好的抗差性。     

新型抗差Kalman滤波及其在GPS动态导航中的应用

目前,抗差Kalman滤波一般采用独立等价权形式,观测值相关时等价权的确定是一个难题.从抗差估计的原始定义出发,首先直接对观测残差进行限制,然后利用观测残差与状态预报值残差的关系对状态预报值残差进行限制,这样可同时消除观测模型误差和状态模型误差的影响.此外,本方法无需考虑观测值是独立的还是相关的.最后给出了算例,结果表明,该方法是切实可行的.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-