Interpoint Distance Test of Homogeneity for Multivariate Mixture Models

Finite mixtures offer a rich class of distributions for modelling of a variety of random phenomena in numerous fields of study. Using the sample interpoint distances (IPDs), we propose the IPD‐test statistic for testing the hypothesis of homogeneity of mixture of multivariate power series distribution or multivariate normal distribution. We derive the distribution of the IPDs that are drawn from a finite mixture of the multivariate power series distribution and multivariate normal distribution. Based on the empirical distribution of the IPDs, we construct a bootstrap test of homogeneity for other multivariate finite mixture models. The IPD test is applied to mixture models for matrix‐valued distributions and a test of homogeneity for Wishart mixture is presented. Numerical comparisons show that IPD test has accurate type I errors and is more powerful in most multivariate cases than the expectation–maximization (EM) test and modified likelihood ratio test.     

非常规战争与战争形态的演变

进入21世纪以来,非常规战争成为国际社会关注的焦点。在理论谱系上,学术界已经对非常规战争的内在本质、基本特征和行为模式进行了深入研究,提出了一些富有创见的理论。在这些研究的基础上,作者认为非常规战争所呈现出的形态及其战略战术与以往相比有了重要变化,凸显了克劳塞维茨式战争逻辑之外的一面,即战争中的弱者通过非常规方式增强自我力量、通过非常规方式向国家行为体施加成本来战胜强者的隐性逻辑。基于这种隐性逻辑,从非国家行为体的视角重新审视战争,可以发现非常规战争中的作战方式已经使得战争形态发生了四点巨大变化:战争的形态越来越不清晰、战争的胜负之分变得模糊、战争正变得越来越扁平化以及战争伦理受到侵蚀。当前的大国竞争并不会削弱非常规战争的地位,在某种程度上甚至会凸显其独特战略意义。因此,探究非常规战争的隐性逻辑,既有助于我们理解战争形态的变化,也有利于国家行为体据此调整相关战略战术。     

推动国有企业廉洁文化建设,以文化自信坚定理想信念

习近平总书记在党的十九大报告中指出:“没有高度的文化自信,没有文化繁荣兴盛,就没有中华民族伟大复兴。”廉洁文化建设是反腐倡廉工作的重要内容,是一项长期的、艰巨的、复杂的系统工程。论文结合福建省三钢(集团)有限责任公司在开展廉洁文化建设工作中的工作实践,对廉洁文化在企业发展中的重要意义、存在的问题及有效运用进行了分析与探讨,对推进廉洁文化进国企具有较为积极的指导意义。     

Marx 200: The Abiding Relevance of the Labour Theory of Value

ABSTRACT

Marxist political economy is alive and well, and not just because of the habitual turn to Marx in response to any crisis of capitalism. Both through Capital and through the continuing evolution of Marxism, Marxist political economy offers valuable insights that can illuminate the modalities of social and economic reproduction and the relationships between (different aspects of) the economic and the non-economic. Marxism’s presence has been felt through its own internal debates and debates with other approaches to political economy, and even through its influence on those reacting against Marxism. The key to the continuing relevance and analytical strengths of Marxist political economy lies in its capacity to provide a framework of analysis for unifying disparate insights into and critiques of the contradictions of capitalism across the social sciences. The instrument for forging that unity is Marx’s theory of value, the potential of which is examined and illustrated with reference to the Sraffian critique and two key concepts in Marxian political economy: the value of labour power and financialisation. They are explored in the light of the processes of commodification, commodity form and commodity calculation.     

线性文化遗产的特征及其对旅游利用模式的影响——基于《世界遗产名录》的统计分析

线性文化遗产是一种特殊的遗产类型,随着人们对遗产完整性不断深入的理解以及遗产活化利用理念的发展,线性文化遗产旅游的重要性日益显现。因此,树立线性文化遗产意识,把握线性文化遗产特征,是推进线性文化遗产旅游利用和可持续发展的重要问题。本文以《世界遗产名录》中收录的线性文化遗产为基础数据,对线性文化遗产的类别与列入标准、资源组合模式和核心区与缓冲区等典型特征进行深入分析,并从旅游空间演化和旅游活化路径两方面总结其对旅游利用模式的影响,以期为线性文化遗产旅游的可持续发展提供科学参考。研究结果表明,线性文化遗产旅游空间结构发展过程遵循“增长极”演化规律,并在遗产文化分层上表现出不同的利用方式和活化路径。     

Parking futures: Preparing European cities for the advent of automated vehicles

The introduction of automated vehicles (AVs) is a virtual certainty. Much less certain is the timing of their introduction and how rapid the transition to full automation will be. Various governments are already working to facilitate this shift by, for example, amending and elaborating regulations to support the introduction of AVs, or supporting tests in different urban environments. Meanwhile, urban and regional planners and decision-makers are still grappling with the uncertainties and differing opinions about the possible impacts of AVs on land-use changes and location choices, particularly in relation to the space available for vehicles, both moving (i.e. roadspace) and stationary (i.e. parking space). This paper uses a backcasting approach to identify critical policy decisions and measures to be taken before the implementation of AVs, so as to achieve a more desirable, attractive and high-quality city. These policy measures primarily relate to the reuse and reallocation of parking and roadspace. Two strategic decisions are found to be essential to meet the major goals of sustainable and liveable cities: a clear commitment to a shared mobility and the delimitation of Core Attractive Mixed-use Spaces (CAMS). In order to deliver these desired urbanisation patterns, a set of three policy paths, involving eight policy packages, is proposed for the next 20–30 years. This article provides urban and regional decision-makers with examples of interventions that can be implemented beyond and during the implementation of AVs.     

A hybrid information approach to predict corporate credit risk

This study proposes a hybrid information approach to predict corporate credit risk. In contrast to the previous literature that debates which credit risk model is the best, we pool information from a diverse set of structural and reduced‐form models to produce a model combination based on credit risk prediction. Compared with each single model, the pooled strategies yield consistently lower average risk prediction errors over time. We also find that while the reduced‐form models contribute more in the pooled strategies for speculative‐grade names and longer maturities, the structural models have higher weights for shorter maturities and investment grade names.     

“城市双修”理念下屋顶农场景观设计研究——以郑州58中学教学楼为例

“城市双修”的提出,促进了屋顶绿化的发展。将农业活动引入到校园建筑屋顶空间,增加城市的绿化率和人居空间环境的归属感,发挥积极的社会作用。通过实际案例对屋顶农场的概念、建设要求、设计及意义进行分析和说明。屋顶农场的建设,增加了学生们与大自然的亲密接触,丰富了课外活动,引导了学生们的自主学习和创新能力,还解决了生活中师生对部分食品的需求。通过案例研究,以期对城市建筑屋顶农场的推广有一定的促进作用。     

空中庭院与半围合式住宅感知密度的关联性研究——以广州万科峯境为例

在半围合式城市住宅中,感知密度是居住体验的重要环节。空中庭院能够缓解高密度环境中的拥挤感,优化其空间形态,是改善环境感知的建构基础。使用虚拟现实技术进行密度感知实验,能探讨与空中庭院形态相关的视觉因素——可视性和绿视率对环境感知密度的影响。将广州万科峯境作为原型建立15组以可视性与绿视率为变量的实验模型,通过采集受试者对不同环境感知密度的主观评价,反映实验样本的空间特征,进而分析主观评价与客观量化之间的关联机制。分析结果表明：半围合式城市住宅空中庭院的可视性与绿视率是影响居住环境感知密度的重要因素;呈线状分布的、具有视觉层次性的空中庭院更受大众青睐。     

2035年中国的城镇化率与城市群主体空间形态

城镇化是2035年基本实现社会主义现代化的重要引擎,城市群是城镇化的主要空间形态。本文按照“是多少”“主体在哪里”的逻辑顺序,依次研究2035年中国的城镇化率和城市群主体空间形态。在简要回顾城镇化历程的基础上,通过多模型筛选,预测2035年中国的城镇化率将达到73.41%~74.53%,并通过与相关研究比照、与八大发达经济体进行对标研究,对预测结果进行验证。城市群主体空间形态由具有较大首位城市、较强吸引力、紧密经济社会联系、承载未来主导产业和有效促进国家战略格局形成的核心城市群构成,是国家未来国土空间结构的大骨架。为此,从首位城市人口规模、城市人口流动方向、城市群内部经济社会联系、未来主导产业空间分布和国家战略政策影响等五个方面构建分析框架,并依托路径依赖理论预测2035年中国城市群主体空间形态将由京津冀、长三角、粤港澳大湾区、成渝、长江中游五大城市群构成。