A PANIC Attack on Unit Roots and Cointegration

This paper develops a new methodology that makes use of the factor structure of large dimensional panels to understand the nature of nonstationarity in the data. We refer to it as PANIC—Panel Analysis of Nonstationarity in Idiosyncratic and Common components. PANIC can detect whether the nonstationarity in a series is pervasive, or variable‐specific, or both. It can determine the number of independent stochastic trends driving the common factors. PANIC also permits valid pooling of individual statistics and thus panel tests can be constructed. A distinctive feature of PANIC is that it tests the unobserved components of the data instead of the observed series. The key to PANIC is consistent estimation of the space spanned by the unobserved common factors and the idiosyncratic errors without knowing a priori whether these are stationary or integrated processes. We provide a rigorous theory for estimation and inference and show that the tests have good finite sample properties.     

论林语堂小说的感觉叙事

一般来说,情感与思想是小说中事件的起点和落脚点,也是事件发展的原动力,感觉只是陪衬、背景和氛围。可在林语堂的小说叙事中,感觉往往成为事件的缘起、转折点和终点。感觉不仅是事件过程的“决定者”,还是事件意义的“赋予者”。在他所谓的重大事件——“生死”与“丧失”里,人的感觉被发现和释放出来,并实现生命的升华。林语堂的感觉叙事生动复杂又变幻多姿,它们好像按照某种自然程序进行,事先无法做出预测。它不是群体理性的表现,而是人物复杂个性的展示,从而可以淋漓尽致地诠释新文学的个性解放主题,也赓续和创新了中西叙事传统,弥补和纠正了新文学甚至世界现代文学的某些偏误。     

连铸准沸腾钢生产技术的发展

介绍了连铸准沸腾钢生产技术的发展现状,提出了我国钢厂连铸生产中采用准沸腾钢生产技术的有关建议.     

总量函数与精确指数的关系研究

一、问题的提出指数是一个古老且为大家熟悉的经济分析方法。在复杂经济系统中,对于不同商品的总体,在数量上往往是不能直接加总的,要综合测定其变动程度,只有通过引进一个同度量因素,使之过渡到可以直接加总的综合指标,而后进行不同区域间或不同时期的对比,来测定...     

关于对时序模型定阶方法的研究

目前时序模型的理论研究和应用都十分活跃,在所有利用时序模型进行时间序列分析与预测模型当中,以移动平均ＭＡ（ｑ）,自回归ＡＲ（ｐ）和混合自回归移动平均ＡＲＭＡ（Ｐ,Ｑ）模型为最常用,而建立时序模型最为关键的、也比较困难的是确定模型的阶数。本文是对国内外各种文献中的时序模型定阶方法进行系统的归纳分类整理、比较分析、优劣评价及其适用条件与场合的研究。　　一、基于相关分析确定模型阶数的方法　　１利用样本自相关函数ρｋ和样本偏自相关函数φｋｋ的截尾性来判定模型的阶数ＢｏｘＪｅｎｋｉｎｓ提出使用样本…     

历史唯物主义的解放意蕴

作为关于无产阶级解放的条件的学说,马克思的历史唯物主义揭示和批判了资本主义社会个人受非神圣形象———资本统治的异化生存状况,主张通过实际的反对和消灭现存状况的现实运动,来推翻资本主义社会物统治人的颠倒的社会关系,进而把人的世界和人的关系还给人自己,最终使人获得一切感觉和特性的彻底解放,但这一解放需要经过一个漫长的历史过程。     

由"被动城市化"到"主动城市化"——兼论城乡经济社会一体化的演进

城市化要经历"被动城市化"和"主动城市化"两个阶段.本文认为,随着工业化对城市化带动作用的弱化和城市自生发展能力的不断增强,中国当前正处于由"被动城市化"阶段向"主动城市化"转变的阶段."主动城市化"是"后改革时代"深化改革的必然要求,它将推动中国经济发展方式的转型与社会主义和谐社会的构建,并以农民工市民化为突破口,促进城乡经济社会一体化新格局的形成.     

新农村建设中山西省城郊农民教育问题研究

加强城郊农民教育是城郊新农村建设的重要途径和必然要求,有利于促进城郊农民的增收,有利于实现城郊农民的市民化,培养有文化、懂技术、会经营、善管理、完全融入城市社会之中的新型农民。但是,在新农村建设中,山西省城郊农民的教育存在着农民文化素质较低、教育内容方法针对性较差、教育投入保障不力等问题。对此,应建立健全城郊农民职业教育培训工作机制,注重职业教育内容的实用性与教育形式的灵活性。     

Determining the Number of Factors in Approximate Factor Models

In this paper we develop some econometric theory for factor models of large dimensions. The focus is the determination of the number of factors (r), which is an unresolved issue in the rapidly growing literature on multifactor models. We first establish the convergence rate for the factor estimates that will allow for consistent estimation of r. We then propose some panel criteria and show that the number of factors can be consistently estimated using the criteria. The theory is developed under the framework of large cross‐sections (N) and large time dimensions (T). No restriction is imposed on the relation between N and T. Simulations show that the proposed criteria have good finite sample properties in many configurations of the panel data encountered in practice.     

Quantitative microbiological risk assessment of nontyphoidal Salmonella in ground pork in households in Chengdu,China

Foodborne disease caused by nontyphoidal Salmonella (NTS) is one of the most important food safety issues worldwide. The objectives of this study were to carry out microbial monitoring on the prevalence of NTS in commercial ground pork, investigate consumption patterns, and conduct a quantitative microbiological risk assessment (QMRA) that considers cross-contamination to determine the risk caused by consuming ground pork and ready-to-eat food contaminated during food handling in the kitchen in Chengdu, China. The food pathway of ground pork was simplified and assumed to be several units according to the actual situation and our survey data, which were collected from our research or references and substituted into the QMRA model for simulation. The results showed that the prevalence of NTS in ground pork purchased in Chengdu was 69.64% (95% confidence interval [CI], 60.2–78.0), with a mean contamination level of −0.164 log CFU/g. After general cooking, NTS in ground pork could be eliminated (contamination level of zero). The estimated probability of causing salmonellosis per day was 9.43E-06 (95% CI: 8.82E-06–1.00E-05), while the estimated salmonellosis cases per million people per year were 3442 (95% CI: 3218–3666). According to the sensitivity analysis, the occurrence of cross-contamination was the most important factor affecting the probability of salmonellosis. To reduce the risk of salmonellosis caused by NTS through ground pork consumption, reasonable hygiene prevention and control measures should be adopted during food preparation to reduce cross-contamination. This study provides valuable information for household cooking and food safety management in China.