论公共品需求曲线的推导

传统的公共品需求理论并没有考虑公共品需求曲线的具体推导.事实上,由于和私人品性质的不同,公共品需求曲线的推导也与私人品需求曲线的推导不同,并且要复杂得多.因此,必须在充分考虑偏好表露、偏好甄别、偏好表露激励、偏好传导和预算约束等环节的影响后,运用基本的经济学方法,才能够大致描绘出一条一般的公共品需求曲线.     

从辩证逻辑视角看微积分

在当今科学哲学界,虽然辩证法派属于少数派,但作者却愿意加入这一行列。作者立足于数学上公认的事实材料,用辩证逻辑的流动范畴的眼光来分析微积分主要的基本概念的辩证本性,并且对微积分与代数、代数与算术之间的关系,和辩证逻辑与形式逻辑之间的关系,进行对应与类比,从而在辩证思维的语境中揭示了数学中所隐含的辩证逻辑内涵。     

论危险犯的“危险后中止”

危险犯中危险状态具备后,行为人又自动消除该状态的,学界在该情形的定性上存在危险犯既遂说、危险犯中止说和实害犯中止说之争。犯罪停止形态是一种犯罪因主客观原因停止下来,或者犯罪虽然尚未停止,但是行为人的行为成立犯罪既遂已经为不可逆转的既定事实的情况下形成的犯罪形态,各犯罪停止形态之间不能相互转化。而实害犯只有是否成立的问题,不存在停止形态的划分。在上述理论基础上,应认为危险犯中止说更具合理性。     

Nonparametric covariate adjustment for receiver operating characteristic curves

The accuracy of a diagnostic test is typically characterized using the receiver operating characteristic (ROC) curve. Summarizing indexes such as the area under the ROC curve (AUC) are used to compare different tests as well as to measure the difference between two populations. Often additional information is available on some of the covariates which are known to influence the accuracy of such measures. The authors propose nonparametric methods for covariate adjustment of the AUC. Models with normal errors and possibly non‐normal errors are discussed and analyzed separately. Nonparametric regression is used for estimating mean and variance functions in both scenarios. In the model that relaxes the assumption of normality, the authors propose a covariate‐adjusted Mann–Whitney estimator for AUC estimation which effectively uses available data to construct working samples at any covariate value of interest and is computationally efficient for implementation. This provides a generalization of the Mann–Whitney approach for comparing two populations by taking covariate effects into account. The authors derive asymptotic properties for the AUC estimators in both settings, including asymptotic normality, optimal strong uniform convergence rates and mean squared error (MSE) consistency. The MSE of the AUC estimators was also assessed in smaller samples by simulation. Data from an agricultural study were used to illustrate the methods of analysis. The Canadian Journal of Statistics 38:27–46; 2010 © 2009 Statistical Society of Canada     

Optimal Composite Markers for Time‐Dependent Receiver Operating Characteristic Curves with Censored Survival Data

Abstract. To increase the predictive abilities of several plasma biomarkers on the coronary artery disease (CAD)‐related vital statuses over time, our research interest mainly focuses on seeking combinations of these biomarkers with the highest time‐dependent receiver operating characteristic curves. An extended generalized linear model (EGLM) with time‐varying coefficients and an unknown bivariate link function is used to characterize the conditional distribution of time to CAD‐related death. Based on censored survival data, two non‐parametric procedures are proposed to estimate the optimal composite markers, linear predictors in the EGLM model. Estimation methods for the classification accuracies of the optimal composite markers are also proposed. In the article we establish theoretical results of the estimators and examine the corresponding finite‐sample properties through a series of simulations with different sample sizes, censoring rates and censoring mechanisms. Our optimization procedures and estimators are further shown to be useful through an application to a prospective cohort study of patients undergoing angiography.     

Smoothed empirical likelihood confidence intervals for the relative distribution with left‐truncated and right‐censored data

The study of differences among groups is an interesting statistical topic in many applied fields. It is very common in this context to have data that are subject to mechanisms of loss of information, such as censoring and truncation. In the setting of a two‐sample problem with data subject to left truncation and right censoring, we develop an empirical likelihood method to do inference for the relative distribution. We obtain a nonparametric generalization of Wilks' theorem and construct nonparametric pointwise confidence intervals for the relative distribution. Finally, we analyse the coverage probability and length of these confidence intervals through a simulation study and illustrate their use with a real data set on gastric cancer. The Canadian Journal of Statistics 38: 453–473; 2010 © 2010 Statistical Society of Canada     

Relationship between the weighted distributions and some inequality measures

In this paper, we study the relationships between the weighted distributions and the parent distributions in the context of Lorenz curve, Lorenz ordering and inequality measures. These relationships depend on the nature of the weight functions and give rise to interesting connections. The properties of weighted distributions for general weight functions are also investigated. It is shown how to derive and to determine characterizations related to Lorenz curve and other inequality measures for the cases weight functions are increasing or decreasing. Some of the results are applied for special cases of the weighted distributions. We represent the reliability measures of weighted distributions by the inequality measures to obtain some results. Length-biased and equilibrium distributions have been discussed as weighted distributions in the reliability context by concentration curves. We also review and extend the problem of stochastic orderings and aging classes under weighting. Finally, the relationships between the weighted distribution and transformations are discussed.     

“微笑曲线”视角下中国客车制造行业竞争战略及其优化

为了深入研究 “微笑曲线”在中国客车制造行业的应用价值,从客车制造行业价值链的各个环节入手,通过对产业链上、中、下游各环节附加值的分析,从理论知识层面制定出中国客车制造行业竞争战略优化方案,并且在解读“微笑曲线”模型以及对现阶段中国客车制造企业竞争策略剖析的基础上,进一步提出中国客车制造行业“微笑曲线”。研究表明,中国客车制造行业通过自主创新和技术引进构建企业核心竞争力,在采取外包中游制造业的同时,拓展下游品牌销售,可以确保持续性的附加价值和永续性的经营价值,以实现中国客车制造行业的转型和升级。