Designing and integrating composite networks for monitoring multivariate gaussian pollution fields

Networks of ambient monitoring stations are used to monitor environmental pollution fields such as those for acid rain and air pollution. Such stations provide regular measurements of pollutant concentrations. The networks are established for a variety of purposes at various times so often several stations measuring different subsets of pollutant concentrations can be found in compact geographical regions. The problem of statistically combining these disparate information sources into a single 'network' then arises. Capitalizing on the efficiencies so achieved can then lead to the secondary problem of extending this network. The subject of this paper is a set of 31 air pollution monitoring stations in southern Ontario. Each of these regularly measures a particular subset of ionic sulphate, sulphite, nitrite and ozone. However, this subset varies from station to station. For example only two stations measure all four. Some measure just one. We describe a Bayesian framework for integrating the measurements of these stations to yield a spatial predictive distribution for unmonitored sites and unmeasured concentrations at existing stations. Furthermore we show how this network can be extended by using an entropy maximization criterion. The methods assume that the multivariate response field being measured has a joint Gaussian distribution conditional on its mean and covariance function. A conjugate prior is used for these parameters, some of its hyperparameters being fitted empirically.     

Hard thresholding regression

In this paper, we propose the hard thresholding regression (HTR) for estimating high‐dimensional sparse linear regression models. HTR uses a two‐stage convex algorithm to approximate the ?₀‐penalized regression: The first stage calculates a coarse initial estimator, and the second stage identifies the oracle estimator by borrowing information from the first one. Theoretically, the HTR estimator achieves the strong oracle property over a wide range of regularization parameters. Numerical examples and a real data example lend further support to our proposed methodology.     

高维大数据基因网络中的社区发现——以NC方法为例

从大量基因中识别出致病基因是大数据下的一个十分重要的高维统计问题。基因间网络结构的存在使得对于致病基因的识别已从单个基因识别扩展到基因模块识别。从基因网络中挖掘出基因模块就是所谓的社区发现（或节点聚类）问题。绝大多数社区发现方法仅利用网络结构信息,而忽略节点本身的信息。Newman和Clauset于2016年提出了一个将二者有机结合的基于统计推断的社区发现方法（简称为NC方法）。本文以NC方法为案例,介绍统计方法在实际基因网络中的应用和取得的成果,并从统计学角度提出了改进措施。通过对NC方法的分析可以看出对于以基因网络为代表的非结构化数据,统计思想和原理在数据分析中仍然处于核心地位。而相应的统计方法则需要针对数据的特点及关心的问题进行相应的调整和优化。     

网络社区发现算法在流动表建模中的设计与应用

代际流动表可以统计子代与其父代社会地位配对数据的交互频数,反映了社会资源占有的优劣势在父子两代人之间的比较。对财富、阶级、特权等社会基本特征演变的实证考察,均依赖于代际流动表的量化分析。对数线性模型是流动表建模分析的基本工具,通过对列联表单元格频数进行拟合,可以识别流动表行分类与列分类之间的强弱交互效应,刻画父子社会地位间的交互结构。本文利用复杂网络社区发现算法分析父子社会地位的关联结构,针对简约对数线性模型拟合精度不够的问题,提出一种新的建模思路：利用社区发现算法对简约对数线性模型的残差列联表进行关联关系挖掘,将发现的社区效应作为附加参数约束引入原对数线性模型,以改善数据的拟合情况。由于该方法只在原简约对数线性模型中增加了一个参数约束,因此仍可以保证建模结果的简洁性及理论意义,同时社区效应补充了原对数线性模型对经验数据结构的解读。论文用此方法对来源于中国综合社会调查数据的经验代际职业流动表进行建模分析,较好地解释了子代职业阶层与父代职业阶层间的关联模式。     

REAL EXCHANGE RATE,MONETARY POLICY,AND THE U.S. ECONOMY: EVIDENCE FROM A FAVAR MODEL

This paper examines the effects of exchange rate depreciation to the U.S. economy in a factor‐augmented vector autoregression model using monthly data of 148 variables for the post–Bretton Woods period of 1973–2017. Exchange rate shock is identified to reflect exogenous disturbances to the foreign exchange market, and movements in exchange rate that are not accounted for by changes in the U.S. monetary policy. We find that depreciation is expansionary and inflationary to the broad U.S. economy, the current account improves over time conforming to the J‐curve theory, and monetary policy is leaning against the wind. (JEL E3, E5, F31, F32, F41)     

Impact of metabolic status on the association of serum vitamin D with hypogonadism and lower urinary tract symptoms/benign prostatic hyperplasia

Objective: The objective of this study is to investigate the impact of metabolic status on associations of serum vitamin D with hypogonadism and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH).

Patients and methods: A total of 612 men underwent physical examination, biochemical/hormonal blood testing, and transrectal prostate ultrasound. Moreover, the subjects filled out standard questionnaires for identification and grading of LUTS and hypogonadism symptoms. Parameters were statistically compared with independent t-tests and correlation analyses.

Results: Vitamin D levels positively correlated with total testosterone (TT) but not with prostate volume or International Prostate Symptom Score (IPSS). Patients with metabolic syndrome had significantly lower vitamin D levels, which were not correlated with TT, prostate volume, or IPSS. However, vitamin D was positively correlated with TT, and negatively correlated with prostate volume and quality-of-life IPSS in subjects without metabolic syndrome.

Conclusion: The clinical usefulness of vitamin D for treatment of hypogonadism or LUTS/BPH varies according to metabolic status.     

适度提高养老保险农民缴费档次的可行性分析

通过对不同经济发展程度地区农民参保情况的调查,发现目前农民在选择养老保险缴费时往往选择最低标准和档次的缴费。通过分析,认为城乡居民基本养老保险制度设计缺乏长远考虑、制度执行过程注重眼前利益、农民更倾向传统养老方式以及存在盲从心理等是城乡居民基本养老保险农民低档次缴费的原因。在对农民养老需求与缴费能力进行分析的基础上,认为当前可以适度提高农民缴费档次,通过采取更具有激励性的缴费政策、规范制度执行等措施来促进农民选择更高的缴费档次。     

The reproductive health indices and sex hormone levels in middle-aged and elderly Chinese men

Objective: The aim of this study was to analyze the age-related recession trajectory of reproductive health indices in middle-aged and elderly Chinese men.

Methods: A population-based cross-sectional study was conducted in Jiashan County, Zhejiang in 2012. Healthy men between 40 and 80 years of age were considered eligible for the study. Physical examination and the sex hormones were measured. The subjects were assessed based on the 5-item version of the International Index of Erectile Function (IIEF-5) for Erectile Dysfunction (ED), and Aging Males’ Symptoms (AMS) scale for Symptomatic Late-Onset Hypogonadism (SLOH).

Results: TG showed a decrease at age 60 years. Testis volume and TT did not show significant difference among the four age groups; cFT began to decrease at age 50 years and Bio-T decreased faster at age 50 years. SHBG and LH increased faster at age 50 and 70 years, respectively. IIEF5 score decrease faster at age 60 years. AMS scores increased faster at age 70 years. With the increase in age, the symptoms of ED and SLOH became severer.

Conclusion: Different indices on reproductive health of men showed turning points at different ages. At first, androgenic sex hormones decreased faster, and then erectile dysfunction got severer, and the last overall male syndromes declined.     

社会参与对中老年消费的影响及作用机制研究

本文基于中国健康与养老追踪调查（CHARLS）2018年数据,利用工具变量法及倾向得分匹配方法实证分析社会参与和中老年消费之间的关系,并采用中介效应模型研究社会参与影响中老年消费的作用机制。研究发现：社会参与对中老年总消费、日常性消费、发展性消费、享受性消费均有正向影响,其中对享受性消费的促进作用最为明显。社会参与能通过影响认知能力、投资与缓解信贷约束间接影响中老年消费,且三者的作用机制存在差异;社会参与对中等收入群体、城市消费群体、中年消费群体的影响更大。因此,未来应创造相应条件鼓励中老年人积极进行社会参与,加大对中老年人学习信息技术、参与老年教育的引导和支持力度。同时,加速适老化社交型产品和服务的开发,以有效发挥社会参与对中老年消费的拉动作用。     

论司法中的程序公正

司法公正包括实体公正和程序公正两个方面,其中程序公正是司法公正的核心。罗尔斯将程序正义区分为纯粹的程序正义、完善的程序正义和不完善的程序正义三种类型。根据罗尔斯的程序正义理论,程序公正可以被视为纯粹的程序正义。程序公正的衡量标准包括法官中立、当事人平等、程序公开、司法效率这四方面的基本原则。