应急监测在处置突发性环境污染事故中面临挑战的思考

针对环境监测部门在处置突发性环境污染事故中承担的任务,提出了应急监测软件支持系统建设内容、目前应着力解决的问题及能力建设的思路与对策。目的是使监测部门从基础信息、技术装备、能力培养和资金渠道等方面全面满足环境应急监测的需要。为有关部门采取控制污染措施、减轻污染危害赢得宝贵时间和及时准确的技术信息支持,以最大限度地减少污染造成的损失和危害。     

民族隐秘文化浅析

对于什么是民族文化,目前可以说论述颇多。但是,对于什么是民族隐秘文化,应该说至今还没有多少人能够论及,以至于我们在此之前想找一个较为完整的定义都不能如愿。因此,本文的目的就是从现代汉语中“隐秘”一词的含义入手,通过对民族文化中“显性文化”和“隐性文化”的区分,以期能对“民族隐秘文化”的含义和内容进行界定。     

Two-Group Classification Using Neural Networks*

Artificial neural networks are new methods for classification. We investigate two important issues in building neural network models; network architecture and size of training samples. Experiments were designed and carried out on two-group classification problems to find answers to these model building questions. The first experiment deals with selection of architecture and sample size for different classification problems. Results show that choice of architecture and choice of sample size depend on the objective: to maximize the classification rate of training samples, or to maximize the generalizability of neural networks. The second experiment compares neural network models with classical models such as linear discriminant analysis and quadratic discriminant analysis, and nonparametric methods such as k-nearest-neighbor and linear programming. Results show that neural networks are comparable to, if not better than, these other methods in terms of classification rates in the training samples but not in the test samples.     

从认识论到生存论: 走进怀疑论研究的生存论视野

怀疑论作为“一种有教养的意识”,凝聚着众多思想流派及其思想家的智慧。在认识论的视野中,人们从怀疑论在人类认识及科学发展中的积极作用和产生根源两方面为怀疑论存在的合理性作了充分的论证,但是人类的日常生活、科学存在及科学成功发展的事实与理性逻辑的同一性却在实际上坚定地消解了怀疑论存在的一切合理性,从而使在认识论视野中为怀疑论存在的合理性所作的一切努力成为徒劳。而怀疑论存在的事实本身及其对人类社会发展的巨大影响却昭示着怀疑论存在的合理性,这就迫使我们为怀疑论存在的合理性的辩护必须超越认识论的视野,以人之存在及古代希腊怀疑论的生存论本质为基础,实现向怀疑论研究的生存论视野转换。     

Australia’s national urban policy: The smart cities agenda in perspective

The Australian Government's attempts at national urban policy have been sporadic and inconsistent, under the constraints of constitutional, financial, ideological and political factors. This paper concerns the recent resurgence of national urban policy under the rubric of “smart cities” adopted by the Turnbull Government and carried on by the incumbent Morrison Government. It investigates how this round of smart cities agenda articulates with Australia's political tradition of national urban policy to seek continuity and change, through comparing historical policies, unpacking major smart cities programmes, identifying explanatory factors and critically commenting on its innovation and legacy. Drawing upon these analyses, this paper argues that understanding the smart cities agenda needs to move beyond the political, ideological “to-and-fro” pendulum to national urban policy observed in history. Rather, it resonates with a globalised policy norm established upon the city-based global integration and competition, driven by an imperative of transitioning to a knowledge economy and pursuing innovation capacity. It is too early to judge whether the smart cities agenda will bring changes to Australian cities in the way it wishes, since it involves long-term infrastructure investment and urban development projects. However, a comprehensive and consistent national urban policy to govern the Australian system of cities and towns has not been established yet.     

银行关系型业务经济学解释及其启示

与银行交易型业务以及资本市场的直接融资相区别,银行关系型业务与客户有着特殊、密切的关系。本文立足于现代金融中介理论对银行关系型业务展开分析,并在此基础上提出对我国商业银行业务经营管理的指导建议。     

官督商办企业:由传统向近代企业制度演进的过渡性组织形态

从19世纪70年代起,官督商办企业在近代中国活跃了30余年。然而,这种组织形式并没有作为独立的组织制度存在,而是近代工业企业由传统的手工作坊向现代的股份制公司制度发育的过程,是一种过渡型“准企业”组织形式。本文试图从官督商办企业创建的起因、运行方式及发展结果三个方面来阐述和解答这个问题。     

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.     

Conditional design of the EWMA median chart with estimated parameters

The exponentially weighted moving average (EWMA) chart is often designed assuming the process parameters are known. In practice, the parameters are rarely known and need to be estimated from Phase I samples. Different Phase I samples are used when practitioners construct their own control chart's limits, which leads to the “Phase I between-practitioners” variability in the in-control average run length (ARL) of control charts. The standard deviation of the ARL (SDARL) is a good alternative to quantify this variability in control charts. Based on the SDARL metric, the performance of the EWMA median chart with estimated parameters is investigated in this paper. Some recommendations are given based on the SDARL metric. The results show that the EWMA median chart requires a much larger amount of Phase I data in order to reduce the variation in the in-control ARL up to a reasonable level. Due to the limitation of the amount of the Phase I data, the suggested EWMA median chart is designed with the bootstrap method which provides a good balance between the in-control and out-of-control ARL values.     

Sex differences in the development of mild cognitive impairment and probable Alzheimer’s disease as predicted by hippocampal volume or white matter hyperintensities

This study examined biological sex differences in the development of mild cognitive impairment (MCI) and probable Alzheimer’s disease (AD) development as predicted by changes in the hippocampus or white matter hyperintensities. A secondary data analysis of the National Alzheimer’s Coordinating Center Uniform Data Set was conducted. We selected samples of participants with normal cognition at baseline who progressed to MCI (n = 483) and those who progressed to probable AD (n = 211) to determine if hippocampal volume or white matter hyperintensities (WMH) at baseline predicted progression to probable AD or MCI and whether the rate of progression differed between men and women. The survival analyses indicated that changes in hippocampal volumes affected the progression to probable AD (HR = 0.535, 95% CI [0.300–0.953]) only among women. White men had an increased rate of progression to AD (HR = 4.396, CI [1.012–19.08]; HR = 4.665, 95% CI [1.072–20.29]) compared to men in other race and ethnic groups. Among women, increases in hippocampal volume ratio led to decreased rates of progressing to MCI (HR = 0.386, 95% CI [0.166–0.901]). Increased WMH among men led to faster progression to MCI (HR = 1.048. 95% CI [1.011–1.086]). Women and men who were older at baseline were more likely to progress to MCI. In addition, results from longitudinal analyses showed that women with a higher CDR global score, older age at baseline, or more disinhibition symptoms experienced higher odds of MCI development. Changes in hippocampal volumes affect the progression to or odds of probable AD (and MCI) more so among women than men, while changes in WMH affected the progression to MCI only among men.