Sampling from spatial databases

This paper deals with techniques for obtaining random point samples from spatial databases. We seek random points from a continuous domain (usually ²) which satisfy a spatial predicate that is represented in the database as a collection of polygons. Several applications of spatial sampling (e.g. environmental monitoring, agronomy, forestry, etc) are described. Sampling problems are characterized in terms of two key parameters: coverage (selectivity), and expected stabbing number (overlap). We discuss two fundamental approaches to sampling with spatial predicates, depending on whether we sample first or evaluate the predicate first. The approaches are described in the context of both quadtrees and R-trees, detailing the sample first, acceptance/rejection tree, and partial area tree algorithms. A sequential algorithm, the one-pass spatial reservoir algorithm is also described. The relative performance of the various sampling algorithms is compared and choice of preferred algorithms is suggested. We conclude with a short discussion of possible extensions.     

电信产业投入产出模型的应用研究

本文以全国价值型投入产出表中独立出来的电信产业投入产出表为基础,探讨投入产出模型方法在我国电信产业中的应用,主要介绍了电信产业投入产出模型的开发背景、模块层次结构及其应用分析。     

At the threshold of retirement: From all-absorbing relations to self-actualization

To investigate the complexities of the retirement process, the present article draws on a case study of Eva, a Swedish woman who “awakened” from all-absorbing relations. It considers the ways in which retirement can enable liberation from patriarchal kinship structures and embodied values of respectability. The aim is to illuminate how deep, embodied values can become conscious and explicit during precarious life situations and transitional phases. The relation between the Swedish welfare state, an I-we balance, and gender equity values are illuminated. These analytical dimensions support the analysis by providing insights into the ways in which individuals embody and use cultural and social structures when they aim to manage unpredictability and to create change toward self-actualization.     

Occupy the government: Analyzing presidential and congressional discursive response to movement repression

I examine the role of Occupy Wall Street in shifting presidential and congressional discourse on economic fairness and inequality. Using data from 4646 presidential speeches and 1256 congressional records from 2009 to 2015, I test different mechanisms, including repression, media coverage, public opinion, and presidential agenda-setting by applying a novel combination of web scraping, natural language processing, and time series models. I suggest that movement success can be measured in its ability to shape discursive opportunity structures, and I argue that the role of the president should be at the forefront of social movements research. Ultimately, I demonstrate (1) that the repression of Occupy protesters not only predicts media coverage but also increases discursive opportunities through President Obama and Congress, (2) that media coverage of Occupy predicts presidential discourse, (3) that the president's rhetorical shift increases congressional response, and (4) that this change persists after the movement faltered.     

The myth of price convergence under economic integration: A proposed explanation for the difference in food prices across European countries

Conventional globalization theory states that regional economic integration will precede price standardization across participating countries due to the increased buying power of large retail groups and parallel imports. The resulting price corridor should merely reflect differences in logistic costs and short-term, local competitive actions. Yet, this study uses panel data from 25 European countries to examine how hefty food and beverage price differentials between regions remained constant over the last decade. Income, store productivity, and market concentration all contribute to the explanation for regional price differences. These findings suggest that, contrary to straight-line globalization theory, large European retailers’ decisions can influence price convergence and maintain important price dispersion between economically integrated countries. We provide recommendations to enhance market integration.     

In search of message design best practices: The Silver Anvil Award winners archive

We investigated specific award-winning public relations efforts to derive best practices that bridge industry practices with academic research and pedagogy. The data for this project were the winning entries for the annual Public Relations Society of America's (PRSA) Silver Anvil Award, which is considered the top award recognizing excellence in public relations. We found, however, that the archive of award winners does not provide sufficiently definitive information about what defines any public relations discourse genre or why any genre as used is “excellent.” This archival research provides us with a key rationale for employing rhetorical, narrative, and linguistic theories prospectively to guide public relations message design and planning, theories which hitherto have been used to judge campaigns post hoc or retrospectively.     

Mobilising diasporas for justice. Opportunity structures and the presencing of a violent past

ABSTRACT

This article investigates how the global dominance of the transitional justice (TJ) discourse and practice – and the controversies and conflicts that arise around TJ – have come to make up an important context for diaspora mobilisation. The article looks at the increasingly globalised mechanisms and norms of transitional justice as a set of opportunity structures – political, legal and discursive – which shape diaspora mobilisation. Diaspora engagement in commemoration, truth-seeking and legal justice in relation to atrocities in Rwanda and Sri Lanka is studied. The article shows that in relation to Rwanda, state dominance and divides are largely replicated in the diasporic space, while the Sri Lankan case provides examples of how Tamil diaspora engagement have been able to reverse power dynamics around TJ. Combining opportunity structures with the concept of ‘past presencing’, the article shows how diaspora groups appropriate and strategise in relation to the dominant norms and practices of TJ, and how in doing so the past is performed and experienced in ways which are both personally and politically meaningful.     

Narrative persuasion,identification, attitudes,and trustworthiness in crisis communication

The purpose of this study is to test the effects of narratives in crisis communication. This research assesses how organizations benefit from using stories in their media responses, relative to sharing nonnarrative information. The theory of crisis response narratives (Heath, 2004) holds that ethical narratives are effective because they enhance trustworthiness, attitudes toward the spokesperson, and identification with the spokesperson. Normative crisis communication theory exhorts disclosing truthful information rather than spinning. In an online experiment, participants (N = 365) watched a news interview in which a scandalized company’s spokesperson responded to a journalist’s questions with (a) ethical narratives, (b) unethical (spin) narratives, or (c) nonnarrative information. Multiple mediator modeling assessed identification with the spokesperson, attitudes toward the spokesperson, and perceived trustworthiness of the spokesperson. Results indicate ethical narratives are more effective than unethical narratives. However, nonnarrative information most effectively enhances trustworthiness and bolsters identification.     

开发立体化教材和网络课堂，构建新型教学模式

教学信息化的最基本要素是教学资源数字化和网络化,开发立体化教材和网络课堂是教学资源数字化和网络化的具体实现形式,有助于构建新型教学模式。     

论我国买方市场条件下经济结构的战略性调整

在我国当前特殊的经济环境下形成的买方市场,不同于西方发达国家的买方市场,具有典型的经济过剩特征。它的出现标志着我国经济发展到了一个关键阶段,经济结构的调整已经十分突出地摆在了我们面前,加大经济结构调整的力度是加快我国经济发展的关键一环。