Practical Maximum Pseudolikelihood for Spatial Point Patterns(with Discussion)

This paper describes a technique for computing approximate maximum pseudolikelihood estimates of the parameters of a spatial point process. The method is an extension of Berman & Turner's (1992) device for maximizing the likelihoods of inhomogeneous spatial Poisson processes. For a very wide class of spatial point process models the likelihood is intractable, while the pseudolikelihood is known explicitly, except for the computation of an integral over the sampling region. Approximation of this integral by a finite sum in a special way yields an approximate pseudolikelihood which is formally equivalent to the (weighted) likelihood of a loglinear model with Poisson responses. This can be maximized using standard statistical software for generalized linear or additive models, provided the conditional intensity of the process takes an 'exponential family' form. Using this approach a wide variety of spatial point process models of Gibbs type can be fitted rapidly, incorporating spatial trends, interaction between points, dependence on spatial covariates, and mark information.     

Differential equation models for statistical functions

Differential equations have been used in statistics to define functions such as probability densities. But the idea of using differential equation formulations of stochastic models has a much wider scope. The author gives several examples, including simultaneous estimation of a regression model and residual density, monotone smoothing, specification of a link function, differential equation models of data, and smoothing over complicated multidimensional domains. This paper aims to stimulate interest in this approach to functional estimation problems, rather than provide carefully worked out methods.     

Bayes linear analysis for graphical models: The geometric approach to local computation and interpretive graphics

This paper concerns the geometric treatment of graphical models using Bayes linear methods. We introduce Bayes linear separation as a second order generalised conditional independence relation, and Bayes linear graphical models are constructed using this property. A system of interpretive and diagnostic shadings are given, which summarise the analysis over the associated moral graph. Principles of local computation are outlined for the graphical models, and an algorithm for implementing such computation over the junction tree is described. The approach is illustrated with two examples. The first concerns sales forecasting using a multivariate dynamic linear model. The second concerns inference for the error variance matrices of the model for sales, and illustrates the generality of our geometric approach by treating the matrices directly as random objects. The examples are implemented using a freely available set of object-oriented programming tools for Bayes linear local computation and graphical diagnostic display.     

基于平均余命的中国养老金个人账户缴费率研究

平均余命是影响个人账户缴费率的重要因素之一。在退休人口平均余命逐步延长的趋势下,现行缴费率下的个人账户养老金积累额不能满足退休人口平均余命期间的支付需求,不能保障基本生活需要。如果不能及时依据平均余命适当调整个人账户缴费率,退休人口将面临因长寿风险而陷入生活贫困的境遇。本文测算了平均余命提高条件下中国2000~2050年个人账户缴费率的上限值与下限值范围,分析了职工个人缴纳养老保险费的经济承受能力,并提出了若干建议。     

外语教师队伍建设要重视造就学者型教师

外语教师队伍建设要从改变教师的传统教育理念,加强专业理论知识学习,提高教师的反思意识,研究教师的发展模式等方面入手,引导培养青年教师向学者型教师发展。     

文化图式缺省和冲突与文化翻译

认知心理学图式理论为文化翻译研究提供了新的理论指导,提出文化翻译即源语和的语的文化图式间的转换这一观点。文化图式缺省和冲突是文化翻译的主要障碍,同时应对缺省和冲突的文化图式翻译模式进行探讨。     

网络依赖行为研究及其干预模型的理论构建

通过对西安交通大学3557名大学生网络依赖行为的研究,从情绪、情感因素、心理应激与心理压力、社会性分离等层面,分析大学生网络依赖行为及其心理成因,探讨网络依赖行为的理论解释及综合心理干预因素,并就网络依赖行为的心理干预模型构建,提出心理-社会-家庭-学校多维系统的干预模型理论.     

浅析绵阳城市内部人口迁居特征及机制

试图通过绵阳城市内部人口迁居的研究,来说明我国中等城市内部人口迁居的一般理论和方法。在绵阳城区选择五个典型社区进行问卷调查,在详细问卷调查基础上总结出绵阳城市内部人口迁居的迁移性、迁移方向性、迁移距离和迁移空间类型等特征;浅析了迁居机制及变化,并据此提出绵阳城市居住空间结构调整的相关建议。此建议对于我国中等城市居住空间结构的调整具有借鉴意义。     

中国股票市场的信息反应曲线和股票价格波动的非对称性

股票价格波动对于市场信息的反应过程具有非对称性。通过利用多种非对称性GARCH 模型,描述和检验了沪市股票日收益率序列的条件波动性,并通过对股票市场信息影响曲线的分析,发现沪市股票价格波动中存在显著的非对称性反应。这说明股市波动对于不同的政策干预和信息冲击具有不同程度的反应,“利好消息”对股市的刺激作用仍然需要其他市场干预的配合才能发挥出来。     

关于弱化缓冲算子的研究

通过对缓冲算子的研究,构造了几何平均弱化缓冲算子GAWBO、加权平均弱化缓冲算子WAWBO、加权几何平均弱化缓冲算子WGAWBO等若干个具有普遍意义的实用弱化算子,并研究了其特性及各种弱化缓冲算子之间的内在关系,从而使序列前一部分增长(衰减)速度过快,而后一部分增长(衰减)速度过缓的冲击扰动系统数据序列在建模预测过程中常常出现的定量预测结果与定性分析结论不符的问题得到有效解决。