Detecting long‐run relationships in regional house prices in the UK

Recent developments in the analysis of cointegration in the presence of asymmetric adjustment are extended and applied to data on regional house prices in the UK. This extension is found to have a dramatic impact upon the results derived. In contrast to recent studies employing standard methods, allowance for the possibility of asymmetric behaviour results in the detection of a large number of long‐run relationships between house prices in different regions. A consistent pattern of asymmetric adjustment is observed, with reversion to equilibrium occurring more rapidly (slowly) when house prices in the South of England decrease (increase) relative to other regions. While the results derived support the existence of a ripple effect underlying the observed movements in regional house prices, the extent of cointegration uncovered casts doubt upon the recently proposed notion of weak segmentation in the UK housing market.     

Least squares, preliminary test and Stein-type estimation in general vector AR(p) models

In the general vector autoregressive process AR ( p ), multivariate least square estimation (LSE)/maximum likelihood estimation (MLE) of a subset of the parameters is considered when the complementary subset is suspected to be redundant. This may be viewed as a special case of linear constraints of autoregressive parameters. We incorporate this nonsample information in the estimation process and propose preliminary test and Stein-type estimators for the target subset of parameters. Under local alternatives their asymptotic properties are investigated and compared with those of unrestricted and restricted LSE. The dominance picture of the estimators is presented.     

Estimating Systematic Risk Using Time Varying Distributions

This article proposes a dynamic vector GARCH model for the estimation of time-varying betas. The model allows the conditional variances and the conditional covariance between individual portfolio returns and market portfolio returns to respond asymmetrically to past innovations depending on their sign. Covariances tend to be higher during market declines. There is substantial time variation in betas but the evidence on beta asymmetry is mixed. Specifically, in 50% of the cases betas are higher during market declines and for the remaining 50% the opposite is true. A time series analysis of estimated time varying betas reveals that they follow stationary mean-reverting processes. The average degree of persistence is approximately four days. It is also found that the static market model overstates non-market or, unsystematic risk by more than 10%. On the basis of an array of diagnostics it is confirmed that the vector GARCH model provides a richer framework for the analysis of the dynamics of systematic risk.     

有限长铁芯实心转子感应电机的运算电抗

本文在考虑铁心有效长度的情况下,以实心转子感应电机的简化模型为基础,推出了这种电机运算电抗的表达式。     

On Social Statement Spaces

In this fundamental draft we shall introduce the concept of social propositional spaces as a general notion of social science and in particular language, logic and methodology. This should help us bridge an old gap between extension and cognition, or said in more specific words, between space as conceived in mathematics or physics and space as is brought in by social location, by the meaning of predicates, their explanation and logic. ¹ We shall not rely on the idea of factor analysis where some “main components” are fit into the data. Because the notion of euclidean normalization and orthogonality, in this context, is a bit artificial. We first show how combinatorial manifolds of statements can be represented in finite vector spaces over the Galois field F₂. This space which we denote as logic statement space can be spanned by generators of alternating codes. In this way the old concepts of truth tables and interaction attributes can be linked to informatics and in particular code theory and geometry. Extending the logic statement space onto a real vector space by mapping units of the finite rings onto units of the real rings we obtain logistic statement spaces. It turns out that vectors in logistic statement spaces represent cross-tables of logits connected with logistic regression analysis. As a completion of the theory we show that the logit is the first derivative of entropy with respect to probability.     

基于向量误差修正模型的城市产业集聚效应分析——以天津市为例

本文利用向量误差修正模型研究城市产业集聚效应。以天津市为例对城市产业集聚形成的增长极、竞争优势、空间聚集与扩散、要素转移和结构调整效应进行了实证检验,结果显示天津市产业集聚形成的五种效应存在且正在发挥作用,一定程度上提高了资源配置效率,扩大了规模经济的竞争优势,并加速了要素转移和结构调整步伐。     

基于支持向量回归的现代气象雷达寿命预测

为了准确地预测气象雷达使用寿命, 提高气象雷达运行可靠性、安全性和可维护性, 提出了一种新的基于多元回归的气象雷达使用寿命预测框架。在该框架内,采用了支持向量 回归(SVR)方法来求解气象雷达使用寿命的多元回归问题;提出了基于SVR的气象雷达特征参 数选择FSSSVR（Feature Subset Selection SVR）算法去掉冗余和无效的特征参数。实验结 果表明,基于SVR方法的预测算法能够准确地预测气象雷达的使用寿命,能够为雷达全寿命 周期管理提供参考依据。     

卫星稀疏信道中频谱空穴的新型检测算法

面对宽带移动卫星通信中信道占用呈现的稀疏状态和时而存在的稀疏干扰,以低速率 采样和运算是简化设备的必要途径。针对宽带频谱范围内稀疏信道信号和干扰信号的检测, 提出了一种用于直接估计频谱空穴的压缩采样算法,以低速率对信号进行采样,通过相 关向量机进行迭代优化,给出检测估计值。该算法基于最大似然贝叶斯估计,具有良好的抗 噪性能,同时能够降低设备复杂度。仿真结果表明,其抗噪性能明显好于CVX方法而略逊于理 想情况,而前端随机序列的相关性是影响检测性能的重要因素。     

健康险赔付与医院收入长期联动效应分析——基于VAR和VEC模型的实证

近年来我国健康险发展较快,但其高赔付率成了进一步发展的"瓶颈",这主要源于医险市场中的道德风险。本文运用计量经济学方法,对保险赔付和医院收入的关系进行了实证分析。结论:医院医疗收入、门诊收入和住院收入是导致保险赔付上升的原因,健康险赔付对医院收入的影响作用不显著,健康险业务的健康发展离不开医方的紧密协作。建议:保险公司需重视与医院和医生的合作,突出合作重点、改革合作方式和革新合作内容。     

我国国际资本流动：直接投资 与非直接投资影响因素的比较研究

本文基于向量误差修正模型对1982-2010年期间我国直接投资类、间接投资类（含其他投资）、错误与遗漏及投资收益类三种类型国际资本流动的影响因素进行了实证研究。实证检验结果表明：在长期,我国三类国际资本流动与人民币对美元的实际汇率升贴水年率之间为负向变动关系,与中美利差、中美通胀之差、我国实际经济增长及人民币对美元的实际汇率预期之间为正向变动关系;在短期,三类国际资本流动与上述影响因素之间关系并非一致;实际经济增长是我国直接投资类国际资本流动的主要原因,人民币对美元的实际汇率预期是我国非直接投资国际资本流动的主要原因。