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.     

网络时代的适时财务监控与公司治理

网络技术应用的普及使传统财务监控的变革已成为公司治理和财务管理的热点话题,本文简要揭示新概念——适时财务监控与公司治理的关系,剖析了公司不同管理层次的适时财务监控的实时需求,从公司治理的基本需要对公司价值流再造、公司信息系统变革和适时财务监控机制重构等三个方面进行了初步研究,为网络适时财务监控在公司治理实务中的应用提供了一个基本框架。     

Gaining Competitive Advantages in Higher Education: Analyzing the Gap between Expectations and Perceptions of Service Quality

The research findings have provided several implications for higher educational institutions, managers, and leaders of decision-making processes throughout the world. Service quality, customer satisfaction, and behavioral intentions are global issues that affect all organizations, large or small, profit or non-profit, global or local. We are all influenced or discouraged, satisfied or dissatisfied with positive loyalty behavioral intentions or negative complaining reactions, propelled by the level of service quality received. This revised version was published online in July 2006 with corrections to the Cover Date.     

Forest Fire Risk Management and Public Participation in Changing Socioenvironmental Conditions: A Case Study in a Mediterranean Region

Under current conditions of accelerated socioenvironmental change in the Mediterranean forested landscapes, fire is one of the most critical and difficult risks to tackle within the region. This article summarizes the lessons learned from a project based on the participatory integration of qualitative local stakeholders' knowledge with expert GIS fire simulations carried out in the County of El Bages, Catalonia, Spain. First, in this article, a theoretical model--the forest fire circle--is presented in order to explain the reasons for the rise in the damage and frequency of forest fires in this Mediterranean area. Second, it describes the methodology developed and the stages followed during the project. Results show that: (1) the advocacy of old forest reactive management paradigm assumptions and practices based on uncontrolled forest succession can put vast wooded areas of the Mediterranean basin at critical risk; and (2) forest fire management approaches that ignore the crucial role of long-term prevention and local capacity building strategies have failed. In the final section, the content and the specific dimensions of the old reactive paradigm that has characterized forest fire risk management in Catalonia are discussed and contrasted with the possibly emerging preventative paradigm.     

制造企业服务业务扩展及其认知因素研究

制造企业的竞争越来越激烈,几乎所有的企业都要面对快速反应多变市场和应对价格压力的要求,面对越来越小的产品利润空间和越来越复杂的客户需求,本文从对工业服务管理文献分析和制造企业的调查研究入手,揭示了制造企业从纯粹的产品生产者向客户支持方案提供者发展的转移趋势.通过对瑞士和德国30多家机器和设备制造企业进行的调查研究,说明了服务业务对制造企业在开发财务、营销和战略机会上的重要作用,并对转移过程中服务业务的扩展过程进行了总结.结合具体企业实践,本文对制约制造企业扩展服务业务中在管理动机上的认知因素进行了分析和研究.结合中国加入WTO后,中国制造企业将全面融入国际竞争的背景,本文期望对中国制造企业的发展和竞争地位的提高提供理论和实践上的指导.     

Consumer trust in B2C e-Commerce and the importance of social presence: experiments in e-Products and e-Services

Reducing social uncertainty—understanding, predicting, and controlling the behavior of other people—is a central motivating force of human behavior. When rules and customs are not sufficient, people rely on trust and familiarity as primary mechanisms to reduce social uncertainty. The relative paucity of regulations and customs on the Internet makes consumer familiarity and trust especially important in the case of e-Commerce. Yet the lack of an interpersonal exchange and the one-time nature of the typical business transaction on the Internet make this kind of consumer trust unique, because trust relates to other people and is nourished through interactions with them.This study validates a four-dimensional scale of trust in the context of e-Products and revalidates it in the context of e-Services. The study then shows the influence of social presence on these dimensions of this trust, especially benevolence, and its ultimate contribution to online purchase intentions.     

高校青年志愿服务的发展路径探析——基于AGIL系统模型

高校青年志愿服务是社会志愿服务中重要的组成部分。高校青年志愿服务事业由四个子系统承担着相应的功能:资源系统发挥适应功能;高校志愿服务组织发挥目标达成功能;共青团发挥整合功能;育人系统发挥模式维持功能。在目前的高校志愿服务工作中,各项功能存在发挥不到位的问题。以AGIL理论分析模型为框架,可以从四个方面促进高校青年志愿服务提供路径支撑:资源系统做好社会化发展、高校志愿服务组织做好项目化管理、共青团做好枢纽化整合、育人系统做好价值化引领,从而发挥有机整体的作用。     

县级政府、供应链管理与农产品上行关系研究

基于中国13省87个电子商务进农村示范县的调研材料,分析政府项目驱动下农产品上行问题。实践表明,政策利好为县域农产品电商发展提供了试错空间,“S2B2C”的供应链管理模式对农产品上行的推动作用明显。但是,多数县级政府未能认识到供应链管理之于农产品上行的作用,普遍存在政府治理方式滞后、公共服务网络不健全、农产品区域公用品牌缺乏、冷链等基础设施投入不足等问题。因此,为有效推动农产品上行,政府应进一步推动“公私合作”、构建一体化的公共服务、注重品牌营销、优化产品供应链管理。     

企业用户云服务技术选择行为

如何选择最佳云服务方案,是企业决定采纳云服务之后所面临的一个重要决策。为了解决云服务技术选择问题,从业务流程的视角出发,以模块化系统理论为基础,提出一个流程模块化、IT可拆解性及安全风险如何影响云服务技术选择的研究模型。采用问卷调查和计量经济学的普通最小二乘法OLS进行实证分析。研究结果表明:流程模块化和IT可拆解性对云服务技术选择的抽象程度有显著的正向影响,即流程模块化程度IT可拆解性越高的企业,越倾向于选择抽象程度高的云服务,如软件即服务SaaS;而流程模块化程度和IT可拆解性越低的企业,越倾向于选择抽象程度低的云服务,如基础设施即服务IaaS。同时,安全风险会正向调节流程模块化和IT可拆解性对云服务技术选择的抽象程度的影响。     

That's My Art: A Case Study on Children's Views of Cultural Policy

How do children experience a participatory TV cultural policy project and, related to that, which views do they share on cultural policy matters? These questions guided a case study on a TV show aired on the Flemish children's public service channel, which staged children as cultural experts. Although the programme was presented as a participatory project, we found that the children's views were minimally involved in the production process. The children also expressed concerns about how (their) art and cultural practices were represented. Yet, from a cultural policy perspective, the children accepted adults’ authority in art and cultural matters.