我国人工智能产业人才政策的量化分析、前沿动态与"十四五"展望

创新型人才是实现我国人工智能产业关键核心技术突破的重要抓手.通过量化分析和知识图谱聚类等方法,对我国人工智能产业人才政策和文献进行量化评估和可视化分析.结果表明,我国人工智能产业人才政策总体偏向于社会人才引进,人才自主培养较为薄弱,人才质量与产业发展速度不相适配.同时,我国人工智能人才的顶层设计、培养模式是学术界和产业界研究与关注的热点."十四五"时期,我国应该在基础研究等方面弥补人才短板,引培并举,用好人才评价激励的"指挥棒".     

先锋诗歌“反语义”写作研究——以杨黎为个案

在对早期非非形而上学追求主题的继承下,杨黎颠倒了文化语言系统中能指和所指的主从关系,通过对语义的取消或抑制,突出了对能指声音和语言的"逻辑形式"的清晰呈现,从而导致了相对于以"内容"为诗歌本体的传统诗学观念的不同的诗歌本体追求。在杨黎那里,诗歌写作完全变成了诗人一种对语言的体验。作为先锋诗歌反语义写作的典型代表,杨黎的诗学探索为中国新诗提供了宝贵的经验,但也直接导致了诗人与读者的隔阂。     

中国城乡居民口粮消费差距估算——基于中国健康与营养调查数据

利用中国健康与营养调查数据,并结合食物成分表和人口统计年鉴的数据,可以估算城乡居民自1997年到2009年部分年份的口粮消费量.在估算时,需要考虑居民在外就餐的情况,并需解决同一类食物下不同种食物不能直接加总和不同特征人群之间食物消费不能直接加总的问题.根据估算结果,自1997年到2009年城乡居民的口粮消费量都出现了下降的趋势,并且农村居民的年人均口粮消费量在最近几年都是比城镇居民只高20公斤至24公斤(按成品粮计算),二者的口粮消费结构差异也不是很明显,据此可以认为城乡居民基本生活水平差距并没有因其收入差距的拉大而拉大.     

零售商资金约束时的供应链协调问题研究

在一般随机需求的情况下,根据报童模型可以得出最优订货量,但是这是在企业有足够资金的条件下才能实现的,但现实往往并非如此。当零售商没有足够资金进行最优订货时,不但会影响自身的收益,也会损害整条供应链的利益,此时零售商可以选择贷款。本文是基于报童模型的在零售商资金约束时的供应链协调问题研究,分析内容分为以下三种情况:(1)零售商无融资服务下的供应链协调问题研究;(2)供应链中核心制造商提供商业信用时的供应链协调问题研究(内部融资);(3)供应链中核心制造商担保下零售商外部融资时的供应链协调问题研究。最后得出,零售商在资金约束时贷款可以提高供应链的收益,并且集中决策有利于供应链整体的最优化。     

Normal tests for unit roots based on instrumental variable estimators

For estimating unit roots of autoregressive processes, we introduce a new instrumental variable (IV) method which discounts large values of regressors corresponding to the unit roots. Based on the IV estimator, we propose new unit root tests whose limiting null distributions are standard normal. Observation at time t is adjusted for mean recursively by the sample mean of observations up to the time t. The powers of the proposed tests are better than those of the Dickey–Fuller tests and are comparable to those of the tests based on the weighted symmetric estimator, which are known to have the best power against stationary alternatives.     

Citizen‐agency versus state‐agency at the frontline in prisons and probation services: A systematic literature review

Street‐level bureaucrats play a key role in the delivery of public services to the citizens with whom they interact. Using the Preferred Reporting Items for Systematic Review and Meta‐Analyses approach, we rely on a street‐level perspective to report a systematic review of 46 studies about officer–offender interactions in prisons and probation services. In doing so, we examine how correctional officers articulate state‐agency – whereby they focus on the implementation of rules and policies – and citizen‐agency – whereby their decisions regarding offenders are based on judgements of offenders' worth. Our results provide evidence that frontline work in prisons and probation services stems from a mix of citizen‐ and state‐agencies in which the former is prioritized over the latter: when rule enforcement allows it, correctional officers often make discretionary decisions based on professional judgements rooted in professional norms. In this respect, the managerial and actuarial approach to risk management and public protection involved by contemporary correctional reforms comes with new role expectations that conflict with correctional officers' rehabilitative ideals. At the same time, the literature provides many instances of officers coping with workload in order to meet policy objectives and organizational demands while maintaining satisfactory working conditions. In other words, there is an increasingly elaborate and fragile articulation of state‐ and citizen‐agencies at the frontline, in prisons and probations services. We conclude with some implications and an agenda for future research.     

A Goodness-of-Fit Test for Logistic Regression Models in Stratified Case-Control Studies via Empirical Likelihood

In the literature, there were only a few reports on goodness-of-fit tests on logistic regression models specifically derived for case-control studies. In this article, we propose a goodness-of-fit test for logistic regression models in stratified case-control studies using an empirical likelihood approach. The proposed statistic is an alternative to the statistic G _o , recently proposed by Arbigast and Lin (2005 Arbigast , P. G. , Lin , D. Y. ( 2005 ). Model-checking techniques for stratified case-control studies . Statist. Med. 24 : 229 – 247 . [Google Scholar]). Simulation results show that the proposed statistic is often slightly more powerful than G _o , although their performances are always close to each other. Moreover, implementation of our method is easy since the usual stratified logistic regression procedures in many statistical softwares can be employed. Some asymptotic results and application of the proposed statistic to two real datasets are also presented.     

Maximum likelihood estimation for arma models in the presence of ARMA errors

An ARMA(p, q) process observed with an ARMA(c, d) error has an ARMA (p + c, k) representation with k = max(c + q, p + d) whose parameters satisfy some nonlinear constraints. Identification of the model is discussed. We develop Newton-Raphson estimators for the ARMA(p + c, k) process which take advantage of the information contained in the nonlinear restrictions. Explicit expressions for the derivatives of the restrictions are derived.