Approximation of the Bivariate Renewal Function

Recently, Kambo and his co-researchers (2012) proposed a method of approximation for evaluating the one-dimensional renewal function based on the first three moments. Their method is simple and elegant, which gives exact values for well-known distributions. In this article, we propose an analogous method for the evaluation of bivariate renewal function based on the first two moments of the variables and their joint moment. The proposed method yields exact results for certain widely used bivariate distributions like bivariate exponential distribution, bivariate Weibull distributions, and bivariate Pareto distributions. An illustrative example in the form of a two-dimensional warranty problem is considered and comparisons of our method are made with the results of other models.     

巴渝古崖居的空间分布与景观特征

巴渝古崖居的分布与地理、地质、交通等诸多因素有关，以成渝交通要道、长江干流和支流为线，串起沿途各个点，由线成面，呈现出渝西、渝东北两头集中、整体北多南少的分布特征。巴渝古崖居大多开凿于明清晚期，这一时期巴渝许多地区战乱频繁、匪患猖獗。古崖居的集中分布与这些地区相吻合，从侧面印证了巴渝古崖居的空间分布特征。巴渝古崖居的广泛开凿体现了古人高超的建筑艺术以及社会历史文化的变迁。     

How do countries choose their monetary policy frameworks?

This paper investigates the determinants of countries’ choices of monetary policy framework. A brief narrative focused on groupings of countries motivates an econometric analysis which draws on previous work on the determinants of exchange rate regimes, bringing in standard factors as well as the trade networks of potential anchor currency blocs and the financial market depth that are emphasised in the narrative. The model turns out to be able to predict three quarters of countries’ choices, and there is no obvious systematic pattern in the errors. The results have important implications for how countries should choose their monetary policy frameworks.     

明清时期长江中下游地区的土地利用

我国明清时期长江中下游地区的土地利用状况是自汉、唐以来人地关系日益尖锐的结果。文章在分析了当时土地利用方式的基础上 ,进一步对形成土地集约化经营趋势日趋明显的原因进行了论述 ,并从明清时期的土地利用得出启示 :我国土地资源的开发利用必须走可持续发展之路     

上海辐射与苏南地区思想观念嬗变的动因分析

从上海辐射的角度考察苏南地区思想观念嬗变的主要原因 ,有经济基础、文化教育和科学知识三个方面。上海买办地位的转变 ,说明经济基础在观念变迁中的重要作用 ,由此导致上海和苏南地区人们的思想观念向重商重利转变。随着近代教育在上海成为时尚 ,苏南地区的近代教育也日渐兴起 ,新式学堂具有重视传播科学知识和培养创新精神、注重塑造民族精神、宣传男女平等等特征 ,有助于苏南地区思想观念的变革。上海开埠后 ,介绍西方科学知识的书籍首先从这一窗口流向内地 ,苏南地区作为桥头堡而得其先 ,在译介中发挥了重要作用。     

论重庆弱势群体的救助方略

在今天社会大变革、政府大转型之时,对弱势群体给予特殊的就业援助,对稳定社会具有重要的现实意义。为此,详实地分析了重庆市弱势群体的类型,以及市政府采取的及时有效的救援措施,并提出了一些相应对策。     

长江三峡人文地理研究的回顾与展望

以文献法为主要研究方法,利用网络资源检索出的相关专业论文,选取了其中的150多篇为研究基础,并参考了部分专著,在回顾以长江三峡为特定区域的人文地理研究的历史进程的基础上进行了综合评述。重点分析、总结了1990年代以来的主要研究特点,并在此基础上就长江三峡人文地理研究的未来趋向进行了展望。     

论华中抗日根据地基层政权的民主选举—以乡选为中心的考察

为从根本上改造基层政权,中国共产党领导下的华中抗日根据地广泛开展了一场轰轰烈烈的民主选举运动。根据地颁布了一系列法令、条例,使选举规范化;人民群众在实践中也充分发挥智慧创造了适合自己的选举方式。选举体现了广泛性、平等性、真实性的特点。这一运动使基层政权性质彻底改变,为争取抗战乃至整个新民主主义革命的胜利提供了重要保证。     

Assessing accuracy of a continuous screening test in the presence of verification bias

Summary.  In studies to assess the accuracy of a screening test, often definitive disease assessment is too invasive or expensive to be ascertained on all the study subjects. Although it may be more ethical or cost effective to ascertain the true disease status with a higher rate in study subjects where the screening test or additional information is suggestive of disease, estimates of accuracy can be biased in a study with such a design. This bias is known as verification bias. Verification bias correction methods that accommodate screening tests with binary or ordinal responses have been developed; however, no verification bias correction methods exist for tests with continuous results. We propose and compare imputation and reweighting bias-corrected estimators of true and false positive rates, receiver operating characteristic curves and area under the receiver operating characteristic curve for continuous tests. Distribution theory and simulation studies are used to compare the proposed estimators with respect to bias, relative efficiency and robustness to model misspecification. The bias correction estimators proposed are applied to data from a study of screening tests for neonatal hearing loss.     

抗战前重庆近代报业情况研究 --以《商务日报》为例

20世纪初,随着资产阶级革命运动的兴起,国内报刊活动空前活跃.重庆近代报业也伴随时代风潮产生、发展起来.作为新兴媒介,同这一特殊历史时期的国家一样,经历了种种风云变幻、艰难屈辱,却最终顽强坚韧地壮大起来.以重庆当时土生土长、在本地刊行时间最长的<商务日报>为样本,分析研究近代重庆地方报业的发展情况及特点.