美国城市道路分级方法及启示

介绍了美国城市道路分级的原理和方法。分级原理为:解析道路在出行路径中不同的功能层级,定义机动性和可达性两项定性指标用以描述道路功能属性。具体分级为主干路、次干路、集散路和地方路。对美国和我国城市道路分级方法进行了类比,阐述并分析存在的指标差异。最后,对当前我国城市道路规划设计实践中与道路分级相关的若干问题进行了梳理,提出了观点和建议,并对机动性、可达性评价指标在道路规划设计中的运用,以及准快速路标准在中等规模城市的应用进行了总结。     

A validation measure for computational scheduler activity-based transportation models based on sequence alignment methods

In recent decades, activity-based transportation models have gained growing attention, due to their strong foundation in behavioral theory and ability to model the response of individuals to travel demand management policies. Hence, researchers have become increasingly interested in analyzing and predicting individuals’ decisions about activity participation. This paper investigates the reliability and uncertainty of computational process activity-based models. The design of the scheduling process model is experimented with by introducing an alternative decision sequence. The results provide additional information to better understand the process model’s reliability and behavior. Furthermore, the findings show that the current sequence of decision steps in the process model in ALBATROSS achieves satisfactory work activity schedules. Finally, the study concludes that using a decision tree model achieves a better performance than using diverse data mining approaches.     

Resilience of Touristic Island Beaches Under Sea Level Rise: A Methodological Framework

This contribution addresses the need for a simple model for managers to employ when planning strategies for the management of touristic beaches under sea level rise. A methodological framework was developed and tested in two Aegean archipelago islands (Lesvos and Rhodes, Greece). The scheme can represent the status of touristic island beaches, based on easily obtained variables/indicators and projections of beach erosion/retreat under different scenarios of mean sea level rise (MSLR) and extreme events. Information on beach geomorphological characteristics, environmental setting, water quality, management, and services (such as those used in the “Blue Flag” classification) was collated/collected and beach erosion/retreat due to CV & C was estimated through suitable ensembles of cross-shore (1-D) morphodynamic models. A Strength-Weaknesses-Opportunities-Threats (SWOT) framework was employed to assist in the selection of indicators and multicriteria analysis used to optimize indicator weights and rank beaches according to their sustainability under sea level rise. Implementation of the framework at the two islands has shown that: the majority of Lesvos and Rhodes beaches (82% of a total of 217 beaches and 58% of a total of 97 beaches, respectively) can be classified as beaches with no, or minimal, human interference, suggesting that under environmentally sound coastal management further touristic development might be afforded; there could be very significant effects of the sea level rise on the carrying and buffering capacities of the most developed (“Blue Flag”) beaches, with some expected even under conservative projections to be completely eroded by 2100, unless technical adaptation measures are taken; and using the proposed framework, touristic beaches can be rapidly ranked in terms of their resilience to sea level rise and their development potential, allowing prioritization of effective management responses.     

基于多层次注意力机制的交通节点分类

不同交通节点对交通需求和对交通状况的贡献不均衡,在进行道路修建、交通设施设置的时候需要考虑交通节点的交通需求,因此在城市中对交通节点进行分类,有助于交通规划的实施.本文构建基于多层注意力机制的深度网络学习模型,对交通图的节点进行嵌入分类.该模型由2层神经网络组成,第1层通过多层注意力计算节点的低维嵌入,第2层将第1层的...     

基于小波变换和线性判别分析的人脸识别方法

提出了将人脸图像的小波分解和线性判别分析结合以达到人脸识别的方法.首先对人脸图像作小波分解,并将分解后的低频系数进行线性判别分析进一步降低人脸特征向量的维数,最后利用最近邻分类器进行分类识别.实验表明,该方法的正确识别率高于传统的特征脸识别方法.     

城市化进程中公路与城市道路关系研究——以上海市嘉定区道路系统为例

城市化进程的加快,要求公路越来越多的承担起城市道路的功能.针对其中存在的道路等级与土地功能不适应、路网级配不合理、公路断面不能满足城市自行车、行人、公共交通需求等问题,提出了新的道路等级分类体系,以功能为划分标准整合了公路与城市道路.并以县区为单位,按照密集区与稀疏区的划分,规定了道路建设模式与路网规划要求.     

土石混合料的结构分类

根据不同含石量下土石混合料在同一工艺下的压实特性,以含石量为指标,以干密度为判据．对其进行结构分类,给出以含石量为指标的分类界限,对于实际工程碎石土压实工艺的合理选择具有重要意义,同时可为进一步研究土石混合料的压实特性打下基础。     

Classification of underwater still objects based on multi-field features and SVM

A Support Vector Machine is used as a classifier to the automatic detection and recognition of underwater still objects. Discrimination between the objects can be transferred into different projection spaces by the process of multi-field feature extraction. The multi-field feature vector includes time-domain, spectral, time-frequency distribution and bi-spectral features. Underwater target recognition can be considered as a problem of small sample recognition. SVM algorithm is appropriate to this kind of problems because of its outstanding generalizability. The SVM is contrasted with a Gaussian classifier and a k-nearest classifier in some experiments using real data of lake or sea trial. The experimental results indicate that SVM is better than the others two.     

基于状态流的自动驾驶超车控制

在自动驾驶中,交通规则是安全和避免事故发生的保证。现在高级驾驶员发生的交通事故数量有逐渐上升的趋势。然而,交通规则中的逻辑往往由法律文本抽象地表达。文章用状态流实现了上述逻辑。首先采用二值分类法对驾驶员的数据进行处理,判断超车条件。然后建立地图数据库,连接Matlab获取交通规则许可。其中双目摄像头用于获取车辆与障碍物的距离。结果表明,上述逻辑适用于超车场景,并可推广到其他交通规则。     

公路养护工程分类探讨

针对现有的公路养护工程分类几乎割裂了与养护工程造价管理联系的问题,结合公路养护市场化需求,根据高速公路、普通公路和农村公路特点对它们的养护工程进行了重新分类研究。研究结果为:高速公路养护工程应划分为日常保洁、小修保养、恢复更新、专项工程和改建工程5类;普通公路和技术等级为三级或者三级以上的农村公路养护工程应划分为小修保养、中修、大修和改建工程4类;四级以及等外的农村公路养护工程应划分为小修保养、恢复更新和改建工程3类。经过在广东省试用后,该分类方法利于形成不同类别养护工程完整的造价管理体系,便于有针对性地进行养护工程造价管理和招投标管理,从而有利于全面推进公路养护市场化。