Penalized contrast estimator for adaptive density deconvolution

The authors consider the problem of estimating the density g of independent and identically distributed variables X_I, from a sample Z₁,… Z_n such that Z_I = X_I + σ? for i = 1,…, n, and E is noise independent of X, with σ? having a known distribution. They present a model selection procedure allowing one to construct an adaptive estimator of g and to find nonasymptotic risk bounds. The estimator achieves the minimax rate of convergence, in most cases where lower bounds are available. A simulation study gives an illustration of the good practical performance of the method.     

周代的生态观

周代非常重视保护自然资源,颁布了严厉的禁采禁捕法令,由各种专职官员负责实施。公元前780年三川流域发生大震灾,西周的自然生态和社会生态遭到毁灭性的破坏。太史伯阳父依据当时的生态危机和政治危机,参考夏、商灭亡的历史经验,预言了西周10年内必将灭亡。《礼记.月令》记述了周代一系列的禁采禁捕法令,以及气象异常与水、旱、风、疫等灾害的关联。这些关联,当是先民长期经验的总结,应予足够的重视,并值得学者深入研究,或可从中发现某些规律,作为现代短期灾害预测的参考。     

关于一集类圆柱投影的探讨

本文所要探讨的是一集类圆柱投影。它不同于伪圆柱投影,而属于标准线型投影族的一个新类型;其中包含着两个新型的等面积投影。     

Managers' attitudes about firm responsibilities

A mail survey was conducted in order to investigate whether the importance a manager attaches to corporate ethical and legal responsibilities varies according to personality characteristics, demographic variables, or the perceived moral climates in the manager's firm. Respondents were middle- and lower-level managers in 112 for-profit businesses located throughout the United States. As expected, attitudes about corporate ethical responsibility were significantly related to (1) the individual's capacity for empathy and (2) a perceived caring climate in the firm; attitudes about corporate legal responsibility were significantly related to (1) the individual's hierarchical position and (2) an organizational climate perceived to be supportive of law.Data collection for this research was subsidized by the Old Dominion University Research Foundation and the ODU College of Business and Public Administration Bureau of Research.     

江汉平原农业气候灾害及减灾对策探讨

本文运用灾害学的原理,分析了江汉平原主要农业气候灾害及成因机制,并对减灾对策作了探讨.     

农民对气候变化认知及适应的差异性分析——基于山东省部分地区的实证调研

气候变化已成为国际社会公认的事实,作为落实国家气候战略的微观主体,农民对气候变化的认知及适应行为对应对气候变化至关重要。通过在山东省部分地区的实地调研和问卷调查,运用SPSS软件,赋值分析了农民对气候变化认知及适应的得分概况,并从性别、政治面貌、婚姻状况、教育水平、家庭条件以及农业生产年限等方面分析了农民对气候变化认知及适应的群体差异,最后从农民气候认知与适应的相关性、认知与适应的得分差异以及认知与适应的群体差异等方面提出应对策略。     

数字经济、人工智能制造与劳动力错配

文章基于2013—2019年中国30个省份的面板数据,先运用模拟退火优化投影寻踪模型测算中国数字经济发展指数,再采用双向固定效应模型和广义空间两阶段最小二乘法验证数字经济和人工智能制造对劳动力资源错配的影响效应。结果表明,2013—2019年我国数字经济发展水平整体呈现稳中有进的趋势,年均增速为11.8%。尽管数字经济发展先行区主要位于东部沿海地区,但近年来西部地区各省份年均增速较高,已形成"东部领跑,西部追赶"的空间分异格局。数字经济能显著缓解劳动力错配,人工智能制造在其中发挥着重要的中介作用,这一结论经过稳健性检验后依然成立。     

中国农业碳排放研究回顾、评述与展望

发展低碳农业,提高农业应对气候变化的能力,是促进农业可持续发展的重要途径。在回顾我国农业碳排放问题研究的基础上,对其主要论点进行了归纳与简要述评,指出了当前研究存在的一些不足:以实证定量研究为主,缺少理论分析与概念阐述;测算体系未完全形成,测算结果差异较大;研究视野带有局限性,经济学思想植入不够;对策建议多空泛而谈,缺少针对性与可行性验证。进而,提出了今后4个值得探讨的研究视角:科学整合现有测算体系,编制中国农业碳排放数据库;广泛引入经济学理论与方法,多视角探讨农业碳排放与农业发展间的关系;强化农户碳行为方式研究,注重微观层面的制度设计与优化;理论联系实际,宏微观有机结合,构建差异化的农业碳减排政策体系。     

关于中亚干燥地带的水缺乏和地区农业的开发现状

干燥沙漠地带的“水问题”是了解本地区的社会、经济及历史的最重要的方法之一。本文从这个入口着手。考察了中亚地区农业的开发现状、水缺乏、水资源的分配等问题。由于丝绸之路干燥地区的水缺乏及水资源分配等难题会引起矛盾和纷争 ,但 2 1世纪可持续的农业开发区域是消除这一地区不安定因素的一个途径。     

Upper Bound for p-Value of the Test of Multivariate Normal Ordered Mean Vectors Against all Alternatives

Consider the problem of testing the isotonic of several p-variate normal mean vectors against all alternatives. It is difficult to compute the exact p-value for this problem of testing with the classical method when the covariance matrices are completely unknown. In the present paper, a test statistic is proposed for this problem of testing. A reformulation of the test statistic is given based on the orthogonal projections on the closed convex cones and then the upper bound for p-value of the test statistic is computed.