Evaluating the Effects of Geographic Contexts on Individual Accessibility: A Multilevel Approach1

Centrality within a city and neighborhood characteristics have often been used as indicators of access to employment and services in statements about urban form and accessibility, but there are reasons to question the appropriateness of doing so. This paper evaluates the importance of geographic context within the urban environment (both location within cities as well as neighborhoods characteristics) for individuals in Portland, Oregon. Because conventional accessibility measures cannot incorporate individual characteristics, space-time individual accessibility measures were used with multilevel modeling to isolate the effects of individual level variations from that of geographical context. The results show that the influence of context on individual accessibility is weak, as accessibility tends to reflect individual and household characteristics rather than the local urban environment. Accessibility cannot be determined from location within cities, or from land uses around an individual's home, implying that the use of urban design to influence accessibility is inappropriate.     

From cave geomorphology to Palaeolithic human behaviour: speleogenesis,palaeoenvironmental changes and archaeological insight in the Atxurra-Armiña cave (northern Iberian Peninsula)

A detailed geomorphological study was performed in the Atxurra-Armiña cave system (northern Iberian Peninsula) to decode landscape evolution, palaeoenvironmental changes and human use of a cave within an Inner Archaeological Context. The results show an average incision rate of the river of <0.083 mm a^–1 for at least the last 419 ka, with interruptions due to sedimentary inputs. Moreover, allostratigraphic units comprising fluviokarstic deposits at the base and flowstone formation at the top have been shown to be climatically controlled, formed either during glacial–interglacial cycles or during interstadial cycles. Finally, when the cave was used by humans in the Late Magdalenian, the lower entrance was closed, and they must therefore have entered the cave through the upper entrance. To reach the sectors selected to decorate the panels, they probably travelled from the upper cave level, as the current crawlway was wider than today, according to our U/Th dating. Once these visitors reached the panels, the floor in the main gallery would have been around 15 cm lower than at present. However, the morphology of the conduit was similar; this has significant implications for understanding and interpreting the human use of the cave during the Palaeolithic.     

探讨企业级GIS平台"GE Smallworld核心空间技术"

GIS平台已经经历了面向个人、项目和企业的三大变革。以GE Smallworld为代表的面向企业的GIS是这一变革中的一个标志。从GE Smallworld里产生的一些重要的概念、技术已经成为工业界的标准和追求目标,例如版本管理、无缝数据存储和长事务管理等。这些技术为企业级GIS奠定了坚实的基础。本文将重点介绍企业级GIS平台的特点,并向读者展示GE Smallworld企业级的系统结构和功能。     

一种顾及上下文的高光谱遥感图像端元提取方法

端元提取技术是混合像元分解中重要的步骤之一,传统的端元提取方法仅考虑了像元的光谱信息。本文将数学形态学算子扩展到高光谱空间,并应用到端元提取技术中,可以顾及像元的上下文信息。利用AVIRIS高光谱仿真数据对算法进行了实验验证,结果表明本文算法具有较强的抗噪能力和较高的可靠性。在此基础上,结合徐州地区的EO-1 Hyperion高光谱遥感图像,使用本文算法进行了端元提取应用研究,将实验结果与纯净像元指数、顶点成分分析方法做了对比分析和精度评价,证明本文算法是一种可靠的高光谱遥感图像端元提取技术。     

可持续生计分析研究综述

可持续生计分析框架是围绕可持续发展而提出的一种新的研究工具,是一种旨在分析社会和物质环境之间多维复杂关系的框架。通过对可持续生计研究中的国外进展的系统阐述和理论总结,较为清晰和全面地把握了可持续生计分析框架的发展轨迹和重要成果,重点阐明了可持续生计分析框架中的脆弱性背景、生计资本、生计战略和生计输出、结构和过程的转变等组分以及它们之间的相互关系,显示出人们如何利用大量的资本、权利和可能的策略去追求某种生计出路的途径。并在此基础上,讨论了可持续生计分析框架在规划确认和设计、规划新的项目和检查评估现有发展活动中的应用;这些研究在扶贫领域具有较强的参照和指导意义。     

论旅游区的文脉

文脉是旅游区的文化主题和文化精神,是旅游区实体形象的文化补充,是旅游形象的内在文化精神。赋予旅游区独特鲜明的文化主题和文化精神,形成内在的文化脉络,不仅能提升旅游产品的品位,而且能以差别性的文化特征与其他旅游区识别,从而能在日益涌现的旅游产品中脱颖而出。文脉是旅游区的重要质量因子．根据产品质量管理原理,对文脉的规划和构造应遵循以下一些原则：文脉是游客可以理解的;文脉需要有历史继承性;文脉要体现旅游区特定的功能;文脉是符合现代美的;文脉要求旅游区的整体配合;文脉是全局的;文脉是需要改进的;文脉指导旅游区营销形象。     

普适计算与普适GIS

介绍了普适计算及其研究现状，讨论了GIS发展与普适计算相结合的必要性，阐述了普适GIS的研究内容。     

带有区域分裂自适应细化过程的SAR海冰图像分割

受海冰自身特性、成像系统特性和环境因素的影响,合成孔径雷达SAR海冰图像具有非平稳、尺度依赖的空间结构,现有的单马尔可夫随机场MRF模型分割方法只能较好地适应非平稳性,对海冰场景的多尺度结构考虑仍然是全局的。为此,本文提出了一种区域分裂过程与二叉树分层结构自适应更新相结合的单MRF图像分割方法。首先利用单MRF模型的全局迭代权值完成初始区域合并,同时以二叉树形式保护合并过程的记录。所设计的分层合并算法可保证二叉树结构的节点数与场景中的对象尺度具有正相关性。随后的细化分裂并不产生新的区域,只是返回到初始配置。依据场景中不同区域对象的尺度,自适应地调整空间语境模型中的尺度权值,实现区域更新。实验表明,该方法有效提高了带有多尺度结构SAR海冰场景的分割精度。     

语篇、语境与中国古典哲学概念的英译

从语篇分析和语境角度探讨中国典籍中的一些概念的翻译,汉译英时对原文概念内涵与外延的理解应注意原文语篇意旨。译例证明:通过语篇分析和对语境的考虑,选择适当的译语表达源语概念是成功解决像《论语》和《庄子》这类中国古籍中概念翻译问题的有效途径。     

语境、修辞与高级英语教学

英语专业高年级学生掌握语言学修辞知识、语境知识,对理解课文内容及内涵具有重要的作用。教师应变传统的"表面释义型"教学模式为"深层理解型"教学模式,通过相关修辞学、语境学的知识传授,引导学生挖掘、领略名家作品之丰富内涵,真正达到强化教学效果,提高学生运用语言能力的目的。