On the Validity of the Markov Interpretation of Path Diagrams of Gaussian Structural Equations Systems with Correlated Errors

Pearl's d -separation concept and the ensuing Markov property is applied to graphs which may have, between each two different vertices i and j , any subset of { i ← j , i → j , i ↔ j } as edges. The class of graphs so obtained is closed under marginalization. Furthermore, the approach permits a direct proof of this theorem: "The distribution of a multivariate normal random vector satisfying a system of linear simultaneous equations is Markov w.r.t. the path diagram of the linear system".     

The Additive Risk Model for Estimation of Effect of Haplotype Match in BMT Studies

Abstract. In this article we consider a problem from bone marrow transplant (BMT) studies where there is interest on assessing the effect of haplotype match for donor and patient on the overall survival. The BMT study we consider is based on donors and patients that are genotype matched, and this therefore leads to a missing data problem. We show how Aalen's additive risk model can be applied in this setting with the benefit that the time‐varying haplomatch effect can be easily studied. This problem has not been considered before, and the standard approach where one would use the expected‐maximization (EM) algorithm cannot be applied for this model because the likelihood is hard to evaluate without additional assumptions. We suggest an approach based on multivariate estimating equations that are solved using a recursive structure. This approach leads to an estimator where the large sample properties can be developed using product‐integration theory. Small sample properties are investigated using simulations in a setting that mimics the motivating haplomatch problem.     

Simultaneous Credible Bands for Latent Gaussian Models

Abstract. Deterministic Bayesian inference for latent Gaussian models has recently become available using integrated nested Laplace approximations (INLA). Applying the INLA‐methodology, marginal estimates for elements of the latent field can be computed efficiently, providing relevant summary statistics like posterior means, variances and pointwise credible intervals. In this article, we extend the use of INLA to joint inference and present an algorithm to derive analytical simultaneous credible bands for subsets of the latent field. The algorithm is based on approximating the joint distribution of the subsets by multivariate Gaussian mixtures. Additionally, we present a saddlepoint approximation to compute Bayesian contour probabilities, representing the posterior support of fixed parameter vectors of interest. We perform a simulation study and apply the given methods to two real examples.     

An IV Model of Quantile Treatment Effects

The ability of quantile regression models to characterize the heterogeneous impact of variables on different points of an outcome distribution makes them appealing in many economic applications. However, in observational studies, the variables of interest (e.g., education, prices) are often endogenous, making conventional quantile regression inconsistent and hence inappropriate for recovering the causal effects of these variables on the quantiles of economic outcomes. In order to address this problem, we develop a model of quantile treatment effects (QTE) in the presence of endogeneity and obtain conditions for identification of the QTE without functional form assumptions. The principal feature of the model is the imposition of conditions that restrict the evolution of ranks across treatment states. This feature allows us to overcome the endogeneity problem and recover the true QTE through the use of instrumental variables. The proposed model can also be equivalently viewed as a structural simultaneous equation model with nonadditive errors, where QTE can be interpreted as the structural quantile effects (SQE).     

非线性常微分方程的Lie级数解法及其计算机代数实现

Ｌｉｅ级数是常微分方程的以初始条件为系数的幂级数解,它适于微分方程的性态的研究,并易于说明其对初始条件敏感的混沌性,在此利用Ｍａｔｈｅｍａｔｉｃａ繁育地此问题予以实现,给出产生ＯＤＥｓ的近似解析解的方法。     

Happy Spouses,Happy Parents? Family Relationships Among Finnish and Dutch Dual Earners

In this study links between spousal and parent‐child relationships among Finnish (n = 157 couples) and Dutch (n = 276 couples) dual earners with young children were examined using paired questionnaire data. Variable‐oriented analyses (structural equation modeling with a multigroup procedure) supported the spillover hypothesis, as higher levels of satisfaction in the spousal relationship were related to higher quality in the parent‐child relationship and lower parental role restrictions. These connections did not differ by gender or country. With family typological analyses (mixture modeling), 4 family types were identified: families with satisfying relationships (73.4% of the families), families with unsatisfying parent‐child relationships (13.4%), and families with either dissatisfied men (6.0%) or dissatisfied women (7.2%).     

三阶中立型分布时滞微分方程的振动定理

研究了一类三阶中立型分布时滞微分方程的振动性.利用广义Riccati变换和积分平均技巧,建立了保证此方程一切解振动或者收敛到零的若干新的充分条件.     

基于结构方程建模的区域科技创新能力评价

现有区域科技创新能力评价方法大多忽视了指标体系中各因素之间可能存在的相关关系和层级差异。结构方程建模能够过滤误差、同时考察不同层级变量间的直接作用与间接作用,找出变量间存在的内在结构关系,在分析区域科技创新能力评价指标体系各种变量间多种关系方面具有可行性和必要性。应用SEM时除了要注意选取恰当指标、构建合适模型以外,还应注意对样本容量、缺失数据的处理和信度效度的检验。     

话语标记语在同声传译顺译中的作用

针对同声传译顺译研究的现状,引用了语言学中的一个重要概念,即作为话语联络成分的话语标记语（discourse marker）,阐述了其对话语意义理解的指向作用。通过分析话语标记语的含义与特征在同声传译中的重要作用,指出话语标记语在顺句驱动时所起到的语义提示作用。实践证明,话语标记语的研究有利于把握同声传译顺译的基本规律,对同声传译训练大有裨益。     

跨部门集成创新中产品开发柔性作用的实证研究

在Liker,Collins和Hull研究的基础上,引入制造柔性变量,构建了设计柔性和制造柔性为外生潜变量、设计．制造集成为中介变量、新产品绩效为结果变量的结构方程模型;采用23个新产品开发项目、208份有效问卷调查数据,对结构方程模型进行实证检验。验证结果证明,设计与制造部门能通过设计柔性、制造柔性的匹配实现有效集成。