The correlation coefficient and problems of inference in recreation research

Correlation analysis frequently has been used for the investigation of leisure research questions. This paper illustrates the problem of “unequal weighting of cases” which is present in the use of correlation analysis. It further illustrates how this problem can mislead researchers when they make substantive inferences about leisure.     

中国自然保护地体系建设——红线管控、旅游发展与文化表征

建立以国家公园为主体的自然保护地体系,是贯彻习近平生态文明思想的重大举措,是党的十九大提出的重大改革任务。有效协调自然保护地保护与开发的功能定位是实现“生态保护、绿色发展、改善民生”三效合一目标的难点与重点。本文围绕如何有效发挥自然保护地生态系统服务功能这一问题框架,系统分析中国自然保护地在生态保护红线划定、旅游发展与文化要素表征3个方面存在的问题与障碍因素,通过政策梳理、学理辨析、国内外对比等研究方法提出以上三方面问题的破题策略。本文认为要建设与国际接轨、具有中国特色的自然保护地体系,需要运用“可接受的改变极限”思想开展红线划定与管控,因地制策、因时制宜、持续监测;需要加大游憩机会谱的研究及应用实践,实现生态保护与旅游发展相得益彰;需要重视自然保护地内文化景观的提炼识别及其表征、传播,重视国家公园文化认同意义表达。     

基于2DPCA和稀疏表示的目标跟踪算法

针对现有的目标跟踪算法难以适应由光照、遮挡以及姿态变化引起的目标外观变化的问题,提出了一种基于二维主成分分析（2DPCA）和稀疏表示的目标跟踪算法。该算法采用2DPCA方法和稀疏表示建立目标外观模型,降低了目标模板的维数,并通过引入增量子空间更新方法对目标模板进行在线更新,降低了算法对存储空间的要求,提高了目标外观描述的准确性。仿真实验表明,在目标出现较大形变、部分遮挡和光照变化的情况下,该算法仍能保持较高的跟踪精度,具有较强的鲁棒性。     

基于框架表示法的工程项目案例知识表示研究

知识管理系统是当今研究热点之一。对一个知识管理系统而言,如何选择一种合适的知识表示方式至关重要。在建筑工程领域,对于工程项目案例知识的表示问题,由于案例知识的复杂性,一直都是一个难点。论文利用框架表示法善于表示结构性知识的特点,提出了一种有效的表示方法。通过继承把工程项目案例知识的层次关系表现出来,建立了工程项目案例知识二层框架结构。     

Recovering Sociology from the Trash Heap: Of Waste Politics and the Spatialization of Local Representation in Lagos

This article excavates the debate that unfolded during the 1980s between Jacques Rancière and Pierre Bourdieu to shed light on the theoretical divide that still cuts across the field of urban studies today. Looking at contemporary Rancièrian scholarship through a Bourdieusian lens, it points to their main theoretical shortcomings and reasserts the value of relational, field‐based and empirically grounded approaches to urban politics. At the same time, this article engages seriously Rancière's critique of Bourdieu's failure to account for space in order to question the territoriality inherent to the notion of field. We put this theoretical discussion to the test of Lagos's garbage. Drawing on an ethnographic study conducted in Lagos from 2015 to 2016, we propose analyzing the process of spatialization of the field of local representation by looking at the ways solid waste—here conceived as a political opportunity—is mobilized by different actors. We argue that the deployment of a waste infrastructure in Lagos is congruent with a relative disinvestment in practices of territorial control that reshapes the structure of local representation, reconfiguring the ‘stage’ on which politics is played out in the Nigerian metropolis.     

CONTINUOUS PREFERENCE ORDERINGS REPRESENTABLE BY UTILITY FUNCTIONS

This paper surveys the conditions under which it is possible to represent a continuous preference ordering using utility functions. We start with a historical perspective on the notions of utility and preferences, continue by defining the mathematical concepts employed in this literature, and then list several key contributions to the topic of representability. These contributions concern both the preference orderings and the spaces where they are defined. For any continuous preference ordering, we show the need for separability and the sufficiency of connectedness and separability, or second countability, of the space where it is defined. We emphasize the need for separability by showing that in any nonseparable metric space, there are continuous preference orderings without utility representation. However, by reinforcing connectedness, we show that countably boundedness of the preference ordering is a necessary and sufficient condition for the existence of a (continuous) utility representation. Finally, we discuss the special case of strictly monotonic preferences.     

A utility representation theorem with weaker continuity condition

We prove that a mixture continuous preference relation has a utility representation if its domain is a convex subset of a finite dimensional vector space. Our condition on the domain of a preference relation is stronger than Eilenberg (1941) and Debreu (1959, 1964), but our condition on the continuity of a preference relation is strictly weaker than the usual continuity assumed by them.     

低房价房地产开发项目桩基方案优化价值分析

软土地区低房价商品房的开发可行性,很大程度上取决于桩基设计方案。文中以一个小高层商品房的桩基方案优选为对象,基于价值分析法,在桩基工程功能和成本分析的基础上,提出桩基设计方案的价值评价指标,并用于该项目评价,结果与传统对比分析法一致。表明:1)价值分析法适用于桩基方案优选,而且与传统的对比分析法相比,用定量的数据说话,更准确、科学;2)所提出的价值评价指标对该项目是正确适用的。此外,还对该工程其它的桩基设计方案以及价值评价指标的通用公式进行了简要探讨,供进一步研究和同类工程参考。     

European and Asian resistance to the use of the American case method in management training: possible cultural and systemic incongruencies

In this contribution to the use of the Harvard-style case-style method in the training of managers, a transfer problem is identified. This is manifested in the difficulties presented for many non-American students in the use of traditional case-studies. As a result, an example of a revised case method is proposed which offers more educational flexibility and better acceptability.     

Bayesian time series analysis of periodic behaviour and spectral structure

Analysis, model selection and forecasting in univariate time series models can be routinely carried out for models in which the model order is relatively small. Under an ARMA assumption, classical estimation, model selection and forecasting can be routinely implemented with the Box–Jenkins time domain representation. However, this approach becomes at best prohibitive and at worst impossible when the model order is high. In particular, the standard assumption of stationarity imposes constraints on the parameter space that are increasingly complex. One solution within the pure AR domain is the latent root factorization in which the characteristic polynomial of the AR model is factorized in the complex domain, and where inference questions of interest and their solution are expressed in terms of the implied (reciprocal) complex roots; by allowing for unit roots, this factorization can identify any sustained periodic components. In this paper, as an alternative to identifying periodic behaviour, we concentrate on frequency domain inference and parameterize the spectrum in terms of the reciprocal roots, and, in addition, incorporate Gegenbauer components. We discuss a Bayesian solution to the various inference problems associated with model selection involving a Markov chain Monte Carlo (MCMC) analysis. One key development presented is a new approach to forecasting that utilizes a Metropolis step to obtain predictions in the time domain even though inference is being carried out in the frequency domain. This approach provides a more complete Bayesian solution to forecasting for ARMA models than the traditional approach that truncates the infinite AR representation, and extends naturally to Gegenbauer ARMA and fractionally differenced models.