我国大都市人居环境优化模式初探

为了清楚认识大都市居住生活环境质量,研究分析了大都市居住活动的空间分布规律,在此基础上提出大都市人居环境优化发展理念和规划设计建议,从而营造出良好的大都市居住环境景观。     

The Story of An Intersection,or How Early Chicago Became an Urban Laboratory

This essay unravels the history of Chicago as an urban laboratory and the way crisis was utilised and even staged in order to project alternative scenarios. It centres on a single photograph of an intersection from 1909, which shows the location saturated with a shocking amount of traffic brought to a standstill. To make visible what commonly remained hidden (the flows and intensities of urban movement), city officials had administered an urban experiment that suspended police presence and regulation in an effort to test if the metropolis could still self-regulate. Using the city as a stage for experimentation that at times pushed it to the brink of collapse, Chicago’s officials perceived their town as an urban test-bed. Injecting this reading into our established historiography reconfigures some of its most prominent narratives: from Sullivan’s Kindergarten Chats, and Burnham and Bennett’s Plan for the city, to the Chicago school of sociology.     

大城市老年人的空间分布模式与发展趋势研究——以北京、上海、广州、武汉为例

选取了北京、上海、广州、武汉,运用GIS技术对大城市老年人的空间分布模式展开研究,提炼了老年人的社会空间类型,分析了大城市老年人的空间发展趋势.随着我国人口老龄化快速发展,大城市老年人的郊区化趋势加快,老年人社会空间分异加剧.大城市老年人的空间分布具有共性特征,呈现为老年人从城市中心向外扩散,逐渐递减至边缘区,以此为节点向远郊区增长扩散并在局部区域形成增长极.     

上海国际文化大都市发展规划战略探索

文化繁荣是促进城市加速转型的重要软实力。着重从城市规划视角来探索上海构建国际文化大都市的发展战略,重点聚焦在文化的空间性和规划的策略应对上,在借鉴世界城市制订文化战略的基础上,从文化产业、文化设施和文化遗存3个层面来探索文化繁荣助力创新转型的发展战略。     

大城市发展都市型工业的国际经验及其对南京的启示

从工业空间布局等方面归纳了发达国家大城市发展都市型工业的成熟经验,结合南京都市型工业的发展现状和特征,针对性地提出了加快南京都市型工业的发展思路。     

A Bayesian framework for accelerated reliability growth testing with multiple sources of uncertainty

Reliability growth tests are often used for achieving a target reliability for complex systems via multiple test‐fix stages with limited testing resources. Such tests can be sped up via accelerated life testing (ALT) where test units are exposed to harsher‐than‐normal conditions. In this paper, a Bayesian framework is proposed to analyze ALT data in reliability growth. In particular, a complex system with components that have multiple competing failure modes is considered, and the time to failure of each failure mode is assumed to follow a Weibull distribution. We also assume that the accelerated condition has a fixed time scaling effect on each of the failure modes. In addition, a corrective action with fixed ineffectiveness can be performed at the end of each stage to reduce the occurrence of each failure mode. Under the Bayesian framework, a general model is developed to handle uncertainty on all model parameters, and several special cases with some parameters being known are also studied. A simulation study is conducted to assess the performance of the proposed models in estimating the final reliability of the system and to study the effects of unbiased and biased prior knowledge on the system‐level reliability estimates.     

基于数据融合的定位解算算法

为了获得更加准确的估计位置,对一种基于数据融合的定位解算算法进行了研究,在将模拟退火算法与经典的泰勒级数展开法和Chan氏算法进行性能比较的基础上,将模拟退火算法与上述两种经典的位置解算算法相结合,通过构造多算法协同定位模型,并基于该模型设计了融合定位算法,对传统定位解算算法进行改进,提出了一种基于数据融合的定位解算算法.仿真结果表明,融合算法的定位精度优于非融合算法且运算量较小.     

对新一轮大城市总体规划编制的若干思考

在大城市转型发展时期,新一轮大城市总体规划编制成为近期学界讨论的热点.新一轮的北京和上海总体规划编制工作在近年相继开始筹备和运作.笔者就在参加上海市城市总体规划编制前期工作中的所思所想进行归纳总结,指出在新一轮大城市总体规划编制的四个新背景下,大城市转型发展面临着五个新问题与发展趋势,包括从增长主义转向人本主义,从微增长转向零增长,从城郊二元地区转向新城市化地区,从工作圈到生活圈,从邻避到无处邻避.应对这些新的发展趋势,新一轮大城市总体规划编制需突出发展目标的战略性、空间治理的整体性、内容的综合性、过程的公众参与性以及成果表达的政策性,并就二次开发、三线划定、区域协调三大关键性问题提出相应对策.     

基于边介数的大城市公交网络优化模型

为解决大城市公交网络优化设计问题,提出一种考虑交通拥堵的网络优化模型．首先分析最短路策略在大城市应用的弊端和造成交通拥堵的原因,在研究复杂网络理论的基础上,基于边介数提出绕行策略．通过扩展边介数,定义有效边介数和有效路径,提出基于边介数的大城市公交网络优化模型,并设计了实现算法．以长春市路网为例,求解β．结果表明,随着β的变化,平均出行距离先减小后增大,在β=0时最短;平均出行速度先基本稳定后急剧增大．β=0.1时,居民平均出行时间最短,网络效率最高,这时优化模型可快速减少由于交通拥挤造成的网络效率损失．     

Verification Approach of Metropolis Design Framework for Embedded Systems

In this paper, we focus on the verification approach of Metropolis, an integrated design framework for heterogeneous embedded systems. The verification approach is based on the formal properties specified in Linear Temporal Logic (LTL) or Logic of Constraints (LOC). Designs may be refined due to synthesis or be abstracted for verification. An automatic abstraction propagation algorithm is used to simplify the design for specific properties. A user-defined starting point may also be used with automatic propagation. Two main verification techniques are implemented in Metropolis the formal verification utilizing the model checker Spin and the simulation trace checking with automatic generated checkers. Translation algorithms from specification models to verification models, as well as algorithms of generated checkers are discussed. We use several case studies to demonstrate our approach for verification of system level designs at multiple levels of abstraction.