Towards Uniformly Efficient Trend Estimation Under Weak/Strong Correlation and Non‐stationary Volatility

In this paper, we consider the deterministic trend model where the error process is allowed to be weakly or strongly correlated and subject to non‐stationary volatility. Extant estimators of the trend coefficient are analysed. We find that under heteroskedasticity, the Cochrane–Orcutt‐type estimator (with some initial condition) could be less efficient than Ordinary Least Squares (OLS) when the process is highly persistent, whereas it is asymptotically equivalent to OLS when the process is less persistent. An efficient non‐parametrically weighted Cochrane–Orcutt‐type estimator is then proposed. The efficiency is uniform over weak or strong serial correlation and non‐stationary volatility of unknown form. The feasible estimator relies on non‐parametric estimation of the volatility function, and the asymptotic theory is provided. We use the data‐dependent smoothing bandwidth that can automatically adjust for the strength of non‐stationarity in volatilities. The implementation does not require pretesting persistence of the process or specification of non‐stationary volatility. Finite‐sample evaluation via simulations and an empirical application demonstrates the good performance of proposed estimators.     

四川地区农民持续增收的制约因素分析

根据四川省统计局的历年数据,本文分析了四川省农民收入增长的规律：改革来,四川农民收入总量上呈现逐年增长、增幅减缓的特征;四川农民收入水平在全国的排位下降。宏观经济分析表明,影响农民收入持续增长的主要有外部因素如制度障碍、农业投入不足、农资价格上涨等,内部因素如生产结构不合理、基础设施脆弱和农民素质不高等方面。因此,要构建农民增收的长效机制必须突破制度障碍。     

论当前的物欲型犯罪

当前的物欲型犯罪有其经济根源和直接原因 ,其动机、行为方式及侵害对象具有一些带规律性的特点 ;犯罪人在市场经济中的地位 ,决定了其犯罪动机和行为方式。尤其少部分身居高位、掌握实权的领导干部或国有企业负责人对个人财富、权力的不当追求 ,导致权钱交易、化公为私 ,造成国有财产的大量流失。这种犯罪不断发生的重要原因是 ,国有财产所有者虚位 ;应从源头上遏制此类犯罪的蔓延     

反馈型振荡器起振条件的新研究

阐述了目前被广泛应用的对于反馈型振荡器的分析方法在描述起振条件和稳定条件时存在严重的逻辑缺陷。提出了一种普适的起振条件判据,推导出两组具体而又具有实际指导意义的起振条件判据,阐明了不存在“频率稳定条件”的理由。     

脱贫成效精准:脱贫户获得感测度及其影响因素

从脱贫户获得感维度检验中国脱贫的实践效应。通过对广东省48 村1 518 已脱贫农户的调查研究,发现其家庭人均年收入持续增长且比已知脱贫收入线显著偏高,产业扶贫对收入增长的作用显著;脱贫户基于家庭劳动力人数、老人数和学生子女数等客观需求,多数自觉获得了体现客观机会获得的脱贫政策福利;脱贫户拥有较高的获得感,并没因调查个体的人口特征而存在差异,其显著地与客观需求呈负相关,与客观获得呈正相关,需求既定时客观获得增加,则获得感会显著提升,这意味着新时代基于需求-获得-满足的精准扶贫逻辑具有实践效应。在客观获得确定而需求增加时,获得感会显著偏低,收入的影响作用最大。因此,后脱贫时代需要继续推进乡村产业发展,加强对劳动力的职业技能培训和乡村教育扶持力度,从外部基础、成人主体内在动力和代际发展潜力来保障和提升脱贫成效的持续性。     

高铜对育肥猪生产效果的影响

将30头30±2kg的育肥猪(长白×内江)随机分成试验组和对照组。对照组采用个体户原用添加剂,试验组采用自配高铜添加剂。结果表明:对照组日增重341.67g,料肉比4.0:1试验组日增重364.67g,料肉比3.7:1。两组日增重差异显著(P<0.05)。     

利用数控增益放大器提高A/D转换器的分辨率

文章介绍利用数控增益放大器LH0086大幅度提高A／D转换器分辨率的方法,可将8位A／D转换器的分辨率提高到接近16位A／D的水平,适用于高速数据系采集系统,给出了相应的硬件原理图和软件框图。     

Bayesian adaptive dose‐escalation designs for simultaneously estimating the optimal and maximum safe dose based on safety and efficacy

The main purpose of dose‐escalation trials is to identify the dose(s) that is/are safe and efficacious for further investigations in later studies. In this paper, we introduce dose‐escalation designs that incorporate both the dose‐limiting events and dose‐limiting toxicities (DLTs) and indicative responses of efficacy into the procedure. A flexible nonparametric model is used for modelling the continuous efficacy responses while a logistic model is used for the binary DLTs. Escalation decisions are based on the combination of the probabilities of DLTs and expected efficacy through a gain function. On the basis of this setup, we then introduce 2 types of Bayesian adaptive dose‐escalation strategies. The first type of procedures, called “single objective,” aims to identify and recommend a single dose, either the maximum tolerated dose, the highest dose that is considered as safe, or the optimal dose, a safe dose that gives optimum benefit risk. The second type, called “dual objective,” aims to jointly estimate both the maximum tolerated dose and the optimal dose accurately. The recommended doses obtained under these dose‐escalation procedures provide information about the safety and efficacy profile of the novel drug to facilitate later studies. We evaluate different strategies via simulations based on an example constructed from a real trial on patients with type 2 diabetes, and the use of stopping rules is assessed. We find that the nonparametric model estimates the efficacy responses well for different underlying true shapes. The dual‐objective designs give better results in terms of identifying the 2 real target doses compared to the single‐objective designs.     

结构优化对我国农产品出口竞争力的影响

应用产业组织理论,揭示结构优化对农产品国际竞争力的作用机理。以RCA衡量农产品出口竞争力并建立多元回归模型,在有效分离工资、土地灌溉面积和汇率等因素后,实证研究发现技术结构对农产品出口竞争力有显著正向影响。当前经济背景下,提升农产品出口竞争力的政策思路,需从传统的要素禀赋优势转移到结构优化的轨道上来。优化农产品出口结构,政府需加大对高附加值农产品在生产、流通、出口等环节的支持力度,营造寡占的农产品市场结构,鼓励和扶持创意农业的发展。