中国现阶段环境约束下的适度经济增长率研究——基于废气排放量视角的分析

经济发展与环境污染的关系历来都是一对不可回避的矛盾,也是学术界研究的热点,国内外大多数学者都在考察人均GDP与环境污染的库兹涅茨曲线,但对于环境与经济增长率的关系却很少有人研究。首先建立环境变量与经济增长率关系的变参数状态空间模型,并将建立的状态空间模型转化成线性规划中的决策方程,之后应用参数区间估计和集合论两种方法,通过约束相应的变量及变量的系数来估计中国现阶段环境约束下的适度经济增长率。     

Asymptotics of the Finite-time Ruin Probability for the Sparre Andersen Risk Model Perturbed by an Inflated Stationary Chi-process

In this article, we consider the Sparre Andersen risk model that is perturbed by an inflated chi-process with non-negative random inflator R. Under some conditions on the perturbation and the random inflator, which allow for both small and large fluctuations, exact asymptotic behaviour of the finite-time ruin probability is obtained when initial reserve tends to infinity.     

基于顾客社区的创新模式研究——以Cspace顾客社区为例

以价值共创理论为基础，对企业如何通过顾客社区与顾客共同开展创新活动问题进行深入研究。首先，基于价值共创理论和价值链模型，构建顾客社区创新模式的理论框架；其次，通过对现有顾客社区的研究成果加以分类解析，提出顾客社区创新模式的理论命题；第三，以Cspace及旗下顾客社区为研究对象，对命题加以验证；最后，总结基于顾客社区的企业创新模式的价值链模型。     

一种榫卯连接方钢管组装框架模型的荷载 位移曲线试验研究

提出一种榫卯连接方钢管组装框架结构。对两个方向的平面框架模型进行受力性能试验。介绍试验概况，给出框架模型的竖向荷载与挠度和水平荷载与水平侧移曲线，这些曲线介于刚节点框架和铰节点框架之间，属于半刚性节点框架的范畴。     

Exponential tilt models for two-group comparison with censored data

We study application of the Exponential Tilt Model (ETM) to compare survival distributions in two groups. The ETM assumes a parametric form for the density ratio of the two distributions. It accommodates a broad array of parametric models such as the log-normal and gamma models and can be sufficiently flexible to allow for crossing hazard and crossing survival functions. We develop a nonparametric likelihood approach to estimate ETM parameters in the presence of censoring and establish related asymptotic results. We compare the ETM to the Proportional Hazards Model (PHM) in simulation studies. When the proportional hazards assumption is not satisfied but the ETM assumption is, the ETM has better power for testing the hypothesis of no difference between the two groups. And, importantly, when the ETM relation is not satisfied but the PHM assumption is, the ETM can still have power reasonably close to that of the PHM. Application of the ETM is illustrated by a gastrointestinal tumor study.     

Simultaneous confidence band for the difference of segmented linear models

Consider comparing between two treatments a response variable, whose expectation depends on the value of a continuous covariate in some nonlinear fashion. We fit separate segmented linear models to each treatment to approximate the nonlinear relationship. For this setting, we provide a simultaneous confidence band for the difference between treatments of the expected value functions. The treatments are said to differ significantly on intervals of the covariate where the simultaneous confidence band does not contain zero. We consider segmented linear models where the locations of the changepoints are both known and unknown. The band is obtained from asymptotic results.     

Bayesian predictive densities based on latent information priors

Construction methods for prior densities are investigated from a predictive viewpoint. Predictive densities for future observables are constructed by using observed data. The simultaneous distribution of future observables and observed data is assumed to belong to a parametric submodel of a multinomial model. Future observables and data are possibly dependent. The discrepancy of a predictive density to the true conditional density of future observables given observed data is evaluated by the Kullback-Leibler divergence. It is proved that limits of Bayesian predictive densities form an essentially complete class. Latent information priors are defined as priors maximizing the conditional mutual information between the parameter and the future observables given the observed data. Minimax predictive densities are constructed as limits of Bayesian predictive densities based on prior sequences converging to the latent information priors.     

Covariate Selection for the Semiparametric Additive Risk Model

Abstract.  This paper considers covariate selection for the additive hazards model. This model is particularly simple to study theoretically and its practical implementation has several major advantages to the similar methodology for the proportional hazards model. One complication compared with the proportional model is, however, that there is no simple likelihood to work with. We here study a least squares criterion with desirable properties and show how this criterion can be interpreted as a prediction error. Given this criterion, we define ridge and Lasso estimators as well as an adaptive Lasso and study their large sample properties for the situation where the number of covariates p is smaller than the number of observations. We also show that the adaptive Lasso has the oracle property. In many practical situations, it is more relevant to tackle the situation with large p compared with the number of observations. We do this by studying the properties of the so-called Dantzig selector in the setting of the additive risk model. Specifically, we establish a bound on how close the solution is to a true sparse signal in the case where the number of covariates is large. In a simulation study, we also compare the Dantzig and adaptive Lasso for a moderate to small number of covariates. The methods are applied to a breast cancer data set with gene expression recordings and to the primary biliary cirrhosis clinical data.     

论澳大利亚任务型翻译教学

澳大利亚极具潜力的翻译市场,使澳洲高校形成了完整而规范的专业翻译教学体系。个案分析表明,澳大利亚翻译教学主要基于任务型教学模式,这一模式的特点以学生为中心,开发其自主学习和研究翻译的能力。此外,在课程设置上,澳大利亚翻译教学重视理论和实践的并重。     

探析《街头日记》所展现的教育模式

电影《街头日记》是根据美国加州长滩市高中英语教师——艾琳·格鲁威尔的真实人生经历改编而成。本文以影片中所展现的艾琳老师的教学实践为基础,结合电影的具体片段,旨在探讨艾琳老师的以学生为中心的教育模式。