论信息时代高等学校创新型教师队伍建设

建设创新型国家,要求我国高等学校必须实施创新教育。创新型教师是高等学校实施创新教育的关键。创新型教师必须具备创新理念、创新思维和创新能力等素质。创新型教师素质的培养和形成,不仅需要教师个人的努力,还需要学校制定各项制度措施来实现。     

食品安检专业开设动物病理学课程的改革与探索

本文从专业现状及教学中存在的问题,对食品安检专业开设动物病理学课程的教学改革相关问题进行阐述,为全面培养高素质的食品安检专业人才提供经验。     

应用现代教育技术提高教育教学质量

现代教育技术朝着智能化、多媒化、网络化的方向发展,具有教学信息资源和信息渠道多元化、课堂教学开放化、教学手段智能化以及教学过程情景化等特点。而课堂教学现代化是提高教学质量的有效途径,通过合理应用现代教育技术手段,使教学效果达到最优化。     

我国森林资源境外开发对策研究

森林资源境外开发是森林资源三大供给体系的重要组成部分,是指运用相关理论,采取一定的方式与手段与本国以外的国家、地区、企业发生的一些具体的林业经济关系。文章分析了我国林业利用国外森林资源战略目标及实现条件,研究并提出一系列措施。     

虚拟社区中的人际互动

网络的特殊性改变了传统的人际互动模式,形成了一个新的人际交往空间———虚拟社区。人们在其中依靠化名的身份建立起类似于现实社会中的人际互动。虚拟社区能够满足人们在现实生活中所不能完全得到满足的心理需求。     

Classification with minimum ambiguity under distribution heterogeneity

The traditional classification is based on the assumption that distribution of indicator variable X in one class is homogeneous. However, when data in one class comes from heterogeneous distribution, the likelihood ratio of two classes is not unique. In this paper, we construct the classification via an ambiguity criterion for the case of distribution heterogeneity of X in a single class. The separated historical data in each situation are used to estimate the thresholds respectively. The final boundary is chosen as the maximum and minimum thresholds from all situations. Our approach obtains the minimum ambiguity with a high classification accuracy allowing for a precise decision. In addition, nonparametric estimation of the classification region and theoretical properties are derived. Simulation study and real data analysis are reported to demonstrate the effectiveness of our method.     

Graphical representation of survival curves in the presence of time-dependent categorical covariates with application to liver transplantation

Graphical representation of survival curves is often used to illustrate associations between exposures and time-to-event outcomes. However, when exposures are time-dependent, calculation of survival probabilities is not straightforward. Our aim was to develop a method to estimate time-dependent survival probabilities and represent them graphically. Cox models with time-dependent indicators to represent state changes were fitted, and survival probabilities were plotted using pre-specified times of state changes. Time-varying hazard ratios for the state change were also explored. The method was applied to data from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Survival curves showing a ‘split’ at a pre-specified time t allow for the qualitative comparison of survival probabilities between patients with similar baseline covariates who do and do not experience a state change at time t. Time since state change interactions can be visually represented to reflect changing hazard ratios over time. A2ALL study results showed differences in survival probabilities among those who did not receive a transplant, received a living donor transplant, and received a deceased donor transplant. These graphical representations of survival curves with time-dependent indicators improve upon previous methods and allow for clinically meaningful interpretation.     

Cox regression of clustered event times with covariates missing not at random

Motivated by a recent tuberculosis (TB) study, this paper is concerned with covariates missing not at random (MNAR) and models the potential intracluster correlation by a frailty. We consider the regression analysis of right‐censored event times from clustered subjects under a Cox proportional hazards frailty model and present the semiparametric maximum likelihood estimator (SPMLE) of the model parameters. An easy‐to‐implement pseudo‐SPMLE is then proposed to accommodate more realistic situations using readily available supplementary information on the missing covariates. Algorithms are provided to compute the estimators and their consistent variance estimators. We demonstrate that both the SPMLE and the pseudo‐SPMLE are consistent and asymptotically normal by the arguments based on the theory of modern empirical processes. The proposed approach is examined numerically via simulation and illustrated with an analysis of the motivating TB study data.     

Semiparametric Bayesian analysis for longitudinal mixed effects models with non-normal AR(1) errors

Statistics and Computing - This paper studies Bayesian inference on longitudinal mixed effects models with non-normal AR(1) errors. We model the nonparametric zero-mean noise in the autoregression...     

中国货币当局资产负债表结构与货币政策调控方式转变

货币当局资产负债表是分析央行行为与货币政策执行情况的一个重要报表。我国货币当局资产负债表科目随着经济金融结构的演变经历了多次调整,本文梳理了我国货币当局资产负债表结构及其演变过程,重新编制1999-2018年的年度可比货币当局资产负债表,通过解析各科目余额及其结构的动态变化特征,揭示统计数据背后的经济逻辑与政策实践、以及重要资产负债科目间的勾稽关系。研究发现：外汇占款和对其他存款性公司的债权是我国货币当局投放基础货币的主要渠道。过去20年中,两种渠道此消彼长反映出我国基础货币投放方式和货币政策调控方式的两次重要转变与创新。在外汇占款大幅增长时期,货币当局曾通过频繁提高法定存款准备金率和发行央行票据回笼过剩流动性。随着国际收支顺差收窄和国内经济由高速增长向高质量发展转变,公开市场操作和创新型再贷款工具将成为货币当局主动投放基础货币的重要渠道。