张家界旅游城镇化响应动力仿真分析

在旅游城镇化响应动力系统中，旅游资源禀赋、经济发展水平、旅游需求和交通通达性等动力因素，通过因果反馈关系，推动城镇化对旅游产业成长的响应。以张家界2005—2018年相关统计数据为基础，构建系统仿真分析模型，选取仿真区间为2005—2030年。模型系统结构共划分为三个子系统，分别是人口子系统、经济子系统和旅游子系统，在仿真期间，各子系统及其要素均呈现出增长趋势，但增长幅度和发展趋势有所差异。在不同情景模式下，经济水平和旅游业发展增长幅度存在差异，通过对比三种情景模式得出，为促进旅游业发展，需要加强基础设施建设，增加旅游投资，同时也应加强旅游宣传。     

Listeria monocytogenes Dose Response Revisited—Incorporating Adjustments for Variability in Strain Virulence and Host Susceptibility

Evaluations of Listeria monocytogenes dose‐response relationships are crucially important for risk assessment and risk management, but are complicated by considerable variability across population subgroups and L. monocytogenes strains. Despite difficulties associated with the collection of adequate data from outbreak investigations or sporadic cases, the limitations of currently available animal models, and the inability to conduct human volunteer studies, some of the available data now allow refinements of the well‐established exponential L. monocytogenes dose response to more adequately represent extremely susceptible population subgroups and highly virulent L. monocytogenes strains. Here, a model incorporating adjustments for variability in L. monocytogenes strain virulence and host susceptibility was derived for 11 population subgroups with similar underlying comorbidities using data from multiple sources, including human surveillance and food survey data. In light of the unique inherent properties of L. monocytogenes dose response, a lognormal‐Poisson dose‐response model was chosen, and proved able to reconcile dose‐response relationships developed based on surveillance data with outbreak data. This model was compared to a classical beta‐Poisson dose‐response model, which was insufficiently flexible for modeling the specific case of L. monocytogenes dose‐response relationships, especially in outbreak situations. Overall, the modeling results suggest that most listeriosis cases are linked to the ingestion of food contaminated with medium to high concentrations of L. monocytogenes. While additional data are needed to refine the derived model and to better characterize and quantify the variability in L. monocytogenes strain virulence and individual host susceptibility, the framework derived here represents a promising approach to more adequately characterize the risk of listeriosis in highly susceptible population subgroups.     

网络云端服务提供者侵犯著作权罪的刑法应对——刑法实质解释论之运用

网络云端服务提供者侵犯著作权罪具有犯罪主体新颖、犯罪方式独特、犯罪情节复杂的特点。刑法学界关于网络服务提供者是否需承担刑事责任问题以及网络中立帮助行为是否成立帮助犯问题未能达成共识，使得网络云端服务提供者侵犯著作权罪的认定面临着理论上的困境。我国关于侵犯著作权罪的刑事法律规范大多形成于网络云端技术诞生之前，网络云端技术的出现给网络侵犯著作权罪的认定带来了新问题。在侵犯著作权罪刑法规则尚未作出更新性应对之前，应当积极发挥司法的自我适应功能，对于网络云端服务提供者侵犯著作权的行为，可以基于实质解释论的立场，在不违背罪行法定原则的前提下，对“复制发行”、“以营利为目的”、“犯罪主观”等犯罪构成要件进行扩大解释。     

Optional randomized response technique in two-phase sampling

Two-phase optional randomized response (TORR) technique has been proposed. The proposed randomized response (RR) performs much better in general than the existing RR techniques. Theoretical and numerical illustrations identified conditions of superiority of the proposed TORR over the existing comparable optional randomized response (ORR) techniques.     

Adjusted Kuk's model using two non sensitive characteristics unrelated to the sensitive characteristic

In this paper, we adjust the Kuk (1990 Kuk, A.Y.C. (1990). Asking sensitive questions indirectly. Biometrika 77(2):436–438.[Crossref], [Web of Science ®] , [Google Scholar]) model for both protection and efficiency by making use of proportions of two non sensitive characteristics which are unrelated to the main sensitive characteristic of interest. Various situations, where the proportions of the two non sensitive characteristics in the population of interest are known and that when these proportions are unknown, have been investigated. We compared the adjusted model and Kuk's model through a simulation study from both the protection and efficiency points of view.     

Use of scrambled response model in estimating the finite population mean in presence of non response when coefficient of variation is known

We propose an estimator for the finite population mean utilizing known coefficient of variation of the study character in case of quantitative sensitive variable considering a randomization mechanism on the second call that provides privacy protection to the respondents to get truthful information. We also propose generalized ratio- and regression-type estimators under two-phase sampling scheme. The conditions under which the proposed estimators are more efficient than the relevant estimators under scrambled response model have been obtained. An empirical study is carried out to evaluate performances of the estimators.     

投资者关注与IPO首日超额收益——基于双边随机前沿分析的新视角

细分IPO一级市场和二级市场投资者关注指标,从一、二级市场两个维度考察投资者关注对IPO首日超额收益的影响.基于2012年～ 2015年间138只创业板IPO新股样本进行研究,采用双边随机前沿模型的检验结果表明,一级市场上股票发行定价明显偏高,新股定价前一级市场投资者关注加剧了发行价格超出内在价值的程度,由此导致较低的定价效率.隐性市盈率上限的窗口指导抑制了一级市场定价泡沫,从而在一定程度上提高了我国新股发行定价效率.进一步研究发现,一级市场定价泡沫越大的新股在上市首日产生的超额收益越高,同时二级市场投资者关注对IPO首日超额收益也具有显著的正向影响.     

An efficient new randomized response model

This paper addresses the problem of estimating the population proportion π of a sensitive group. We have suggested a randomized response (RR) model that is more efficient than the one envisaged by Gjestvang and Singh ([2006), A new randomized response model, Journal of Royal Statistcal Socity, B, (3), 523–530].     

Robust first-order rotatable lifetime improvement experimental designs

Experimental designs are widely used in predicting the optimal operating conditions of the process parameters in lifetime improvement experiments. The most commonly observed lifetime distributions are log-normal, exponential, gamma and Weibull. In the present article, invariant robust first-order rotatable designs are derived for autocorrelated lifetime responses having log-normal, exponential, gamma and Weibull distributions. In the process, robust first-order D-optimal and rotatable conditions have been derived under these situations. For these lifetime distributions with correlated errors, it is shown that robust first-order D-optimal designs are always robust rotatable but the converse is not true. Moreover, it is observed that robust first-order D-optimal and rotatable designs depend on the respective error variance–covariance structure but are independent from these considered lifetime response distributions.     

Bayesian estimation of the multidimensional graded response model with nonignorable missing data

A Bayesian approach is developed for analysing item response models with nonignorable missing data. The relevant model for the observed data is estimated concurrently in conjunction with the item response model for the missing-data process. Since the approach is fully Bayesian, it can be easily generalized to more complicated and realistic models, such as those models with covariates. Furthermore, the proposed approach is illustrated with item response data modelled as the multidimensional graded response models. Finally, a simulation study is conducted to assess the extent to which the bias caused by ignoring the missing-data mechanism can be reduced.