世博交通保障方案编制过程与思考

回顾世博交通保障方案的编制过程,分析不同阶段的规划实施难点,从实践角度探讨建成区城市更新开发交通规划与实施问题。     

Rust,Dust and Bust: Planning Issues Arising from Replacement of Public Infrastructure

Recent reports by the South Australian Parliamentary Public Accounts Committee on the cost and timing of replacement of the State's major public infrastructure are analyzed. From them three implications are drawn from which three general conclusions concerning urban policy are derived.     

波河平原城市的分布形态和历史的种子

在探索意大利波河平原城市发展历史的基础上,试图在重要的历史时期中找出那些对城市发展产生过影响的事件,并通过案例的研究找出这些历史的种子在今天城市结构中的痕迹。以此作为未来对波河平原和珠江三角洲进行比较研究的开篇。     

生态约束下的西南山地城镇规划策略与实践探索

在生态文明背景下,西南山地城镇 面临守住生态和发展两条底线的要求。基于 对西南地区资源环境特征的认识,结合在重 庆、贵州等地的规划实践,探讨生态约束下的 西南山地城镇规划策略,提出以生态约束为 前提、以可持续发展目标为导向、以空间用途 管制和规划布局优化为核心的规划框架,并 从用地条件和生态环境状况评价,“生态— 产业”、“生态—人口”、“生态—城镇”协同 发展,以及生态空间管控和城镇建设布局等 方面提出对策建议。     

西方视角的中国城市公共空间研究

自1990年代初以来,西方的城市研究学者对中国城市的公共空间给予了越来越多的关注。来自城市规划、城市地理、城市经济、社会学、建筑学等多学科、多领域的研究成果得以互相交叉、补充,勾勒出了一幅中国城市公共空间演变的大致图蒂。该图景立足于西方的研究视角,将中国的城市公共空间发展划分为5个阶段：早期传统城市公共空间、晚期传统城市公共空间、通商口岸与民国时期的城市公共空间、计划经济时代的城市公共空间、市场经济时代的城市公共空间。在各个阶段,影响城市发展的社会、政治和经济因素皆不相同,由此形成了在物质形态和公共用途上都迥然不同的城市公共空间环境。归纳起来,西方的研究成果表达了贯穿整个演变的3个重要变化：从“强权政治”到“商业社会”、从“控制”到“脱离”、从“封闭的墙”到“开放的街道”。     

An efficient approach to important bloggers discovery

Popularity of blogs and the amount of information in the blogosphere increase so fast that it is difficult for Internet users to search the information they care about. Compared with conventional webs, links in the blogosphere are more abundant and conversations between bloggers are more frequent. This paper proposes a method of ranking bloggers based on link analysis, which can exemplify the characteristics of blogs, and reduce the influence of link spamming. This method can also bring convenience to users to read blogs, and it can supply a new methodology for information retrieval in the blogosphere. To ensure the reliability of the ranking results, some evaluation indicators of the important bloggers are proposed, and the grading results of bloggers using the proposed method is compared with that using other indicators. At last, correlation analysis is used to verify the consistency between the proposed method and the evaluation indicators.     

Recombinant Landscapes in the American City

How are urban actors, such as landscape designers, community groups, developers and local politicians, actively restructuring their environments to meet the challenges of the American city in the new global context? Grahame Shane outlines the approaches to landscape that have been emerging since the mid-20th century and are set to recombine urban assemblages whether they are located in historic city centres, postindustrial waterfronts or suburban sprawl. Copyright © 2007 John Wiley & Sons, Ltd.     

粒子滤波理论及其在目标跟踪中的应用

非线性估计领域的经典算法是扩展Kalman滤波（EKF）,它采用了Taylor展开的线性变换来近似非线性模型,因而存在计算量大、实时性差、估计精度低等缺点。而粒子滤波采用一些带有权值的随机样本（粒子）来表示所需要的后验概率密度,而不是采用传统的线性变换,从而得到基于物理模型的近似最优数值解,具有精度高、收敛速度快等特点。对经典的纯方位跟踪问题进行了仿真。仿真结果表明,粒子滤波器的跟踪性能要远优于EKF的性能。