A fast splitting procedure for classification trees

This paper provides a faster method to find the best split at each node when using the CART methodology. The predictability index is proposed as a splitting rule for growing the same classification tree as CART does when using the Gini index of heterogeneity as an impurity measure. A theorem is introduced to show a new property of the index : the for a given predictor has a value not lower than the for any split generated by the predictor. This property is used to make a substantial saving in the time required to generate a classification tree. Three simulation studies are presented in order to show the computational gain in terms of both the number of splits analysed at each node and the CPU time. The proposed splitting algorithm can prove computational efficiency in real data sets as shown in an example.     

经济收敛理论与检验方法研究综述

在大量文献研究的基础上,对收敛问题的产生及收敛概念的发展作了全面概括,并对绝对收敛、条件收敛、俱乐部收敛和σ收敛作了深入辨析,对各种识别方法作了全面归纳。归纳了对世界大多数国家和地区数据所作识别的结果。还从收敛理论与传统理论的冲突与协调方面作了深入分析。最后对近年收敛研究的深化与扩展研究的趋势作了概括。     

基于顾客网络评价的乡村民宿服务质量分析 ——以武夷山南源岭村民宿为例

以武夷山南源岭乡村民宿作为研究对象,选取携程旅行网的顾客评价数据为样本,利用ROST CM 6内容挖掘软件,进 行评论信息提取,建立3项一级指标和13项二级指标,并将点评内容与民宿服务质量测评指标相对应,分析武夷山南源岭乡村 民宿服务质量。最后,针对服务质量的不足提出升级民宿硬件设施设备、加强民宿经营者培训等意见和建议。     

政策工具视角的中国装配式建筑政策文本量化研究

为了更科学地进行政策分析和研究,评测已有装配式建筑政策体系完善与否,从政策工具的视角,将基本政策工具、装配式建筑驱动主体和产业价值链组合成一个三维研究框架.利用该框架,运用内容分析法对中国现有13份中央政府级装配式建筑政策文本中采用的政策工具进行计量和分析.得出环境型和供给型政策工具过溢,针对企业和科研机构的政策工具缺失,装配式建筑产业价值链维度的政策工具滞后于其价值实现环节等结论,并为完善装配式建筑政策体系提出建议.     

国家义务构造论的功能主义建构

国家义务是保障公民权利不可或缺的工具。确定国家义务内容主要诉诸基本权利功能、人权保障和规范主义3种路径。但以上路径过于强调国家义务内容的组成,从而带来理论层级设计混乱、语词选择不一、内部逻辑不明、理论功能不完善、整体性建构缺失等弊端。欲解决以上诸问题,层级化、递进式的国家义务构造理论为可行方案。其中,自由权向社会权的转向决定其实质内容,需求层次理论形塑内部层级结构,而融贯体系化和系统构造论则提供外部理论支持。功能主义系统论和内容理论的积淀最终建构了以尊重、保护和给付为基本要素的“二元三层次多位阶”的国家义务构造论。     

零部件进口对中国制造业技术进步的影响

在中国制造业转型时期,零部件进口对促进我国技术进步至关重要,将出口品国内技术含量作为衡量技术进步的标准,对零部件进口与中国制造业技术进步的关系进行量化分析。研究结果表明:扩大零部件进口规模对技术进步有正向影响,但发挥作用存在一定时滞,且在高技术行业中促进作用尤为显著;扩大零部件进口种类能显著促进技术进步,主要体现在低技术行业;外商直接投资、人均资本和研发投入均对技术进步有正向影响,但对不同技术层次行业的影响程度存在差异。     

Asymptotic behaviour of proportions of observations in random regions determined by central order statistics from stationary processes

In this paper, we show that proportions of observations that fall into a random region determined by a given Borel set and a central order statistic converge almost surely, provided that the corresponding population quantile is unique. We also describe three types of possible asymptotic behaviour of these proportions in the case of non-unique population quantile. As an application of our findings we establish limiting properties of numbers of ties with a central order statistics in a discrete sample. Our results are derived not only for independent and identically distributed observations but more generally for strictly stationary and ergodic sequences of random variables.     

‘We fight for all living things’: countering misconceptions about the radical animal liberation movement

This qualitative content analysis of online documents compiled from the North American Animal Liberation Front (ALF), Earth Liberation Kollective (ELK) and Grassroots Ontario Animal Liberation (GOAL) network websites and Facebook pages explores how activism within the Radical Animal Liberation Movement (RALM) intersects with other social movements. While most literature to date traces the RALM’s (dis)junctures with other forms of social justice activism through analyses of their broad ideological assumptions, or the views of renowned RALM scholars, this research provides authentic insights into the voices of Canadian, American and Mexican activists as they are represented in documents they author themselves. Like activists in anarchistic, anti-capitalist, immigrant rights, Indigenous, prison abolition, prisoner support and radical feminist movements, those in the RALM critique capitalism, colonialism, hierarchy, racism, sexism, state power and the prison industrial complex. Our research calls into question the existing narratives that depict the RALM as an extremist, single-issue movement oblivious to all other forms of social inequality, injustice, marginalization and oppression. Rather, RALM activists are building alliances with other radical social movements to achieve the common goal of ending both human and animal suffering and exploitation.     

人工智能与制造业融合:基本内涵、发展态势与内在逻辑——兼论成都人工智能与制造业融合的探索与实践

人工智能是新一轮科技革命和产业变革的重要驱动力量,人工智能与制造业融合将推动制造业加快转型升级。基于对人工智能与制造业融合的内涵、态势的分析,阐明了人工智能与制造业融合功能区的内在逻辑和分类方式,结合成都的基础条件,对人工智能与制造业融合功能区进行了分类,并借鉴国内先进经验,从加强人工智能技术和产品供给、分类推进制造业智能化、增强基础设施支撑、打造产业融合生态体系四个方面提出建议。