浅谈城市交通旅游图的编制

随着人们生活水平的日益提高,对旅游的需求不断增加,对旅游地图的品质也有更高要求。分析城市交通旅游地图的概念和特点,对城市交通旅游地图的基本内容、符号、比例尺、开本大小以及整饰设计等方面进行论述,提出一种较实用的旅游地图设计方法。     

公路山地灾害的自组织临界性及工程应用探讨

为了解公路山地灾害的共性,从整体上认识其规律性信息,根据自组织临界性理论,用两种沙堆模型作为公路山地灾害的概化模型,通过试验研究了其动力学行为,结果均呈现自组织临界性。并进一步结合滑坡、崩塌和泥石流山地灾害实例的相关观测信息进行了分析,皆表明了幂律和自组织临界性是许多公路山地灾害的共性。最后,在幂律分布特征下,说明了公路山地灾害暴发规模的极值分布的极限收敛于Ⅰ型渐进分布,并以云南蒋家沟泥石流为例,介绍了自组织临界性理论在公路山地灾害防治工程中的应用。     

分形元胞自动机在自组织临界性中的应用

基于元胞自动机分形模型，探讨了散粒体自组织临界性（SOC）的机制．不同级配散粒体单面坡的已有试验表明，散粒体的SOC与非均匀系数有关．应用分形理论计算了沙堆颗粒级配的分维数，结果表明，呈现SOC的沙堆，颗粒级配具有分形特征．进而假设：若大尺度非均匀沙系统的组构特征具有分形特性，系统也能呈现SOC．为解释此假设，建立了既能表征非均匀系数又具有分形组构特征的元胞自动机沙堆模型．数值模拟表明，元胞排列方式服从分形时，沙堆模型呈现SOC，而等间隔排列的模型不呈现SOC，结果与假设一致．最后对SOC的判据进行了讨论，认为系统组构特征具有分形特性是大尺度非均匀沙系统呈现SOC的必要条件．     

临界状态下沙堆大规模坍塌的机制

基于自组织临界性的概念，探讨了散粒体系统的动态特性．通过单面坡沙堆实验，发现颗粒非均匀系数为2．85的沙堆呈现自组织临界性，而由均匀沙构成的沙堆大规模坍塌呈现准周期分布．提出了沙堆具有散粒层和摩阻层典型的二元结构．实验表明，非均匀颗粒的沙堆，在临界状态发生的大规模坍塌基本上只发生在散粒层；而均匀沙堆发生的大规模坍塌影响到摩阻层．认为颗粒的均匀性影响系统在临界状态下的动力学行为特征，均匀性不同的沙堆，在临界状态下发生的大规模坍塌具有散粒层坍塌和深层坍塌2种不同形式．     

The analysis of motor vehicle crash clusters using the vector quantization technique

In this paper, a powerful tool for analyzing motor vehicle data based on the vector quantization (VQ) technique is demonstrated. The technique uses an approximation of a probability density function for a stochastic vector without assuming an “a priori” distribution. A self‐organizing map (SOM) is used to transform accident data from an N‐dimensional space into a two‐dimensional plane. The SOM retains all the original data yet provides an effective visual tool for describing patterns such as the frequency at which a particular category of events occurs. This enables new relationships to be identified. Accident data from three cities in Italy (Turin, Milan, and Legnano) are used to illustrate the usefulness of the technique. Crashes are aggregated and clustered crashes by type, severity, and along other dimensions. The paper includes discussion as to how this method can be utilized to further improve safety analysis. Copyright © 2010 John Wiley & Sons, Ltd.     

������������֯������Ⱥ�Ľ�ͨ��Ԥ��

为了提高城市交通流预测神经网络方法的快速动态学习能力,提出了一种生长自组织神经网络群,将复杂的神经网络个体分解为多个训练简单的神经网络群组,并利用设计的动态生长自组织算法来避免神经网络在学习新知识的时候对已有知识造成破坏,同时保持整个群工作的高效稳定,规模不过度扩张.该神经网络群尝试解决神经网络的一次性学习问题,具有动态知识增殖学习能力和更强的错误自修复能力及系统适应灵活性.仿真结果表明,这一方法能够更精确地实现函数逼近和城市交通流自适应动态预测,适用于需要不断快速动态学习的复杂系统.     

胸中的航海图——郁永河《裨海纪游》手绘“宇内形势图”（示意图）研究

康熙三十六年（1697）郁永河到台湾采硫,记沿途所见等成《裨海纪游》一书.该书有一节“宇内形势”,记述郁永河对渡台海船的火长等航海人员的访谈,并附有手绘“宇内形势图”一帧.该图实为一航海图,航海人员凭经验绘出明清时期东西洋的大部分航线,与《东西洋航海图》 （the SeldenMap）契合,与古代航海文献亦能相照应.该图对古航海图、航海文献及古航海术的研究多有裨益.     

清初屈大均笔下的来粤西洋商船

本文以屈大均《广东新语》卷18《舟语》“洋舶”条的记载为重点,对照牛津版《技术史》关于17世纪欧洲船舶的相关记载,论述明末清初（约17世纪）来粤的西洋商船.通过中西方史料的对比和互补,辅以西方相关绘画,重点分析这一时期来粤西洋商船的载货量、造船材料、桅杆、航海技术及船上生活,并就屈氏所意识到的海防危机略作评论.     

基于自组织临界性理论的船舶电力系统脆性分析

该文建立了船舶电力系统的自组织临界性脆性模型,对船舶电力系统进行脆性分析,通过考察潮流动态来研究脆性发生的机理。该模型分为快动态过程和慢动态过程,前者为基于改进的直流潮流模型的船舶电力系统脆性模型算法,后者为船舶电力系统节点负荷和线路容量增长算法。仿真结果表明,船舶电力系统的脆性故障规模与发生次数在曲线的尾部都具有幂律特性,船舶电力系统脆性具有自组织临界性;同时,过载参数会影响船舶电力系统脆性的自组织临界性。     

Do modes of transportation and GPS affect cognitive maps of Londoners?

Legibility has long been recognized as an important factor in creating a good image of a city in individuals’ minds. This image is perceived to assist people in understanding the city, finding their way, and recalling the city. The quality of the image affects individuals’ abilities in way-finding. This is especially important for cosmopolitan and global cities such as London in order to preserve resources and time, manage travel costs, limit pollution (air or noise) and enhance these cities as places to live, work and visit. This research examines the cognitive maps of London drawn by a sample of its residents to discover how different modes of transportation and GPS usage could affect individuals’ urban images. Such research is useful for town planners, local government departments, and urban and transport planners because of the way it considers the legibility of London as and provides a tool to study individuals’ urban images. 101 participants were recruited with at least a two-year residency from both genders (38.6% females and 61.4% males) with the average age of 33.88 and S.D. = 10.63. The results suggest car use has a positive correlation with seeing London in city scale and GPS usage has a negative correlation. Whilst recent studies have shown that there are differences between active travel modes (e.g., walking, bicycle riding or driving a car) and passive modes (e.g., as a passenger taking a bus, train or taxi), this study indicates that GPS usage also influences cognitive maps, with a negative correlation found between GPS usage and drawing maps on a city scale. Other significant associations were found for the car drivers with a positive relation with the number of roads mentioned on the maps, seeing London in city scale and having a two-dimensional façade image of the city in mind.