Spreading Patterns of Malicious Information on Single‐Lane Platooned Traffic in a Connected Environment

The connected vehicle can be easily attacked by cyber threats due to its communication through the wireless network in an open‐access environment. But very few studies have paid attention to the spreading of malicious information such as denial of service, message delay/replay, and eavesdropping generated by cyberattacks. To this end, this article introduces an analytical model, named vehicular malicious information propagation (VMIP), which integrates a classical epidemic model through two‐layer system structure, in which the upper layer describes the malicious information spreading and the lower describes the traffic flow dynamics. The proposed VMIP model is designated for platooned (one‐lane, particularly) traffic. Numerical experiments show the proposed model can efficiently describe the interactions between traffic dynamics and malicious information spreading; and the information propagation highly depends on traffic flow patterns. This article is expected to contribute to a better understanding of the impacts of cyberattacks on traffic and lays a foundation for future development of control strategies on mitigating the disastrous effects of cyberattacks.     

Long-term performance assessment of the Telegraph Road Bridge using a permanent wireless monitoring system and automated statistical process control analytics

The purpose of this study is to advance wireless sensing technology for permanent installation in operational highway bridges for long-term automated health assessment. The work advances the design of a solar-powered wireless sensor network architecture that can be permanently deployed in harsh winter climates where limited solar energy and cold temperatures are normal operational conditions. To demonstrate the performance of the solar-powered wireless sensor network, it is installed on the multi-steel girder bridge carrying northbound I-275 traffic over Telegraph Road (Monroe, Michigan) in 2011; a unique design feature of the bridge is the use of pin and hanger connections to support the bridge main span. A dense network of strain gauges, accelerometers and thermometers are installed to acquire bridge responses of interest to the bridge manager including responses that would be affected by long-term bridge deterioration. The wireless monitoring system collects sensor data on a daily schedule and communicates the data to the Internet where it is stored in a curated data repository. Bridge response data in the repository are autonomously processed to extract truck load events using machine learning, compensate for environmental variations using nonlinear regression and to quantitatively assess anomalous bridge performance using statistical process control.     

Evaluation of Information Applications of a Self‐Organizing Distributed Traffic Information System for a Large‐Scale Real‐World Traffic Network

Abstract: This article presents an evaluation of the system performance of a proposed self‐organizing, distributed traffic information system based on vehicle‐to‐vehicle information‐sharing architecture. Using microsimulation, several information applications derived from this system are analyzed relative to the effectiveness and efficiency of the system to estimate traffic conditions along each individual path in the network, to identify possible incidents in the traffic network, and to provide rerouting strategies for vehicles to escape congested spots in the network. A subset of vehicles in the traffic network is equipped with specific intervehicle communication devices capable of autonomous traffic surveillance, peer‐to‐peer information sharing, and self‐data processing. A self‐organizing traffic information overlay on the existing vehicular roadway network assists their independent evaluation of route information, detection of traffic incidents, and dynamic rerouting in the network based both on historical information stored in an in‐vehicle database and on real‐time information disseminated through intervehicle communications. A path‐based microsimulation model is developed for these information applications and the proposed distributed traffic information system is tested in a large‐scale real‐world network. Based on simulation study results, potential benefits both for travelers with such equipment as well as for the traffic system as a whole are demonstrated.     

Graph‐Based Modeling of Information Flow Evolution and Propagation under V2V Communications‐Based Advanced Traveler Information Systems

A vehicle equipped with a vehicle‐to‐vehicle (V2V) communications capability can continuously update its knowledge on traffic conditions using its own experience and anonymously obtained travel experience data from other such equipped vehicles without any central coordination. In such a V2V communications‐based advanced traveler information system (ATIS), the dynamics of traffic flow and intervehicle communication lead to the time‐dependent vehicle knowledge on the traffic network conditions. In this context, this study proposes a graph‐based multilayer network framework to model the V2V‐based ATIS as a complex system which is composed of three coupled network layers: a physical traffic flow network, and virtual intervehicle communication and information flow networks. To determine the occurrence of V2V communication, the intervehicle communication layer is first constructed using the time‐dependent locations of vehicles in the traffic flow layer and intervehicle communication‐related constraints. Then an information flow network is constructed based on events in the traffic and intervehicle communication networks. The graph structure of this information flow network enables the efficient tracking of the time‐dependent vehicle knowledge of the traffic network conditions using a simple graph‐based reverse search algorithm and the storage of the information flow network as a single graph database. Further, the proposed framework provides a retrospective modeling capability to articulate explicitly how information flow evolves and propagates. These capabilities are critical to develop strategies for the rapid flow of useful information and traffic routing to enhance network performance. It also serves as a basic building block for the design of V2V‐based route guidance strategies to manage traffic conditions in congested networks. Synthetic experiments are used to compare the graph‐based approach to a simulation‐based approach, and illustrate both memory usage and computational time efficiencies.     

空间句法及其在城市交通研究领域的应用

空间句法提供了一套量化描述空间结构的方法,开拓了一个理解复杂城市交通系统的崭新视角。文章阐述了空间句法的创立背景、核心理论和模型构建方法;详细介绍了空间句法在轨道交通枢纽TOD开发评价、行人步行交通研究、城市空间路网结构合理性分析等城市交通研究方向上的应用,对其在城市交通规划领域的应用前景进行展望。     

Author Index to Volume 18

Abstract:   Route guidance system (RGS) is considered as a low-cost alternative for reducing congestion by providing real-time information to drivers to redistribute traffic in space and time so as to use roadway networks more efficiently. This article focuses on the behavioral component, one of the three components (the other two being dynamic traffic component and information supply strategy component) of a practical RGS developed through a 4-year project at the University of Delaware. Development of the behavioral model is based on the premise that different drivers perceive and behave differently in response to the information provided. Understanding the behavior of RGS-equipped drivers' acceptance or nonacceptance of provided information is essential for understanding the reliability of the system. Backpropagation neural network with its ability to map complex input–output relationships has been used to structure the model. This model was tested on two networks under both recurring and nonrecurring congestion. A comparative analysis of the measures of effectiveness revealed that the performance of the developed RGS is significantly better than the performance under existing non-RGS conditions.     

县级道路管理无线视频监控方案

描述了根据公安交警部门对城市道路交通管理的要求,采用适合要求的无线视频网络对道路交通进行管理的监控方案,对其优势和特点进行了总结,并在实践过程中取得了良好效果,以推广该视频监控的应用.     

Towards an autonomous real-time tracking system of near-miss accidents on construction sites

It has been widely accepted that reported accidents on construction sites are just the tip of the iceberg representing the safety challenge because a very large number of near-miss accidents exist and constitute the portion of under-water surface. Undoubtedly, near-miss accidents provide insights into possible accidents and provide a great opportunity to further improve safety margins. It is possible to significantly improve the safety performance by learning from previous near-miss accidents and tracking near-miss accidents in real time leading to taking appropriate action before a potential up-coming accident. However, little research has been done in both autonomous data requirement analysis of near-miss accidents and technological solutions to track near-miss accidents based on real-time information on construction sites. The objective of this paper is to analyze and verify the autonomous information requirement of near-miss accidents and investigate the feasibility and performance of using a Zigbee RFID sensor network to fulfil these requirements. First, the autonomous data requirement of near-miss accidents is systematically analyzed based on typical historical accident cases. Then, considering the features of construction sites and characteristics of near-miss accidents, an autonomous real-time tracking system of near-miss accidents (ARTTS-NMA) on construction sites is proposed, which employs ultrasonic for outdoor and indoor real-time location tracking, adopts sensors for environment surveillance, RFID for access control as well as storage of safety information about workers, equipment and materials, and wireless sensor networks for data transmission. All system components are integrated into a Zigbee RFID sensor network architecture that features a relatively low cost and fast implementation with a pure wireless network backbone. The demonstration system based on the hybrid RFID sensor network architecture is fully working in a laboratory environment and for safety reasons we have chosen to evaluate it in a warehouse, which is considered as the main scenario of a construction site containing both multi-storey structure and open area, to evaluate the complexity of implementation.     

城市扩张情景模拟下绿地生态网络 构建与优化研究——以南京市部分区域 为例

绿地生态网络对维护城市生态结构稳定有极其重要的作用,其网络结构与城市发展、扩张及结构演化在时空层面有动态的耦合关系。现阶段绿地生态网络构建多处于一种静态的构建与优化思路中,忽视了城市化过程中自然与城市间的动态变化。从风景园林学视角出发,以南京市部分区域为例,通过多期遥感数据,基于CA-Markov模型模拟城市未来发展情景,并在过去、现在和未来各时期用地分类基础上,对城市动态扩张演变下的绿地空间与其所形成的生态网络进行研究,以期构建适用现在、面向未来的绿地生态网络,将丰富城市绿地生态网络研究新思路,并为中国风景园林建设和绿地系统规划提供技术支撑。     

基于Android系统开发的秦皇岛规划移动办公平台解决方案

采用4G无线通信技术、移动GIS技术,以先进的移动终端设备为载体,基于Android系统采用MVP架构设计,开发了秦皇岛规划移动办公App,实现了用户随时随地、远程异地移动办公,提高了工作效率。     

地铁无线视频传输系统设计

摘要地铁无线视频传输系统是提供车辆与车站、控制中心之间的视频传输通道的系统是负责提供电视监控系统、旅客信息系统的车地之间的无线传输通道。本文主要以无线视频传输系统在某地铁的实际应用为例,对该系统的系统架构,传输系统网络、车地无线双向实时传输系统、车载局域网、车辆段和停车场等部分的设计进行了介绍。     

Understanding occupancy pattern and improving building energy efficiency through Wi-Fi based indoor positioning

Detailed visualisation and data analysis of occupancy patterns including spatial distribution and temporal variations are of great importance to delivering energy efficient and productive buildings. An experimental study comprising 24-h monitoring over 30 full days was conducted in a university library building.Occupancy profiles have been monitored and analysis has been carried out. Central to this monitoring study is the Wi-Fi based indoor positioning system based on the measured Wi-Fi devices' number and locations and data mining methods. Distinct from traditional occupancy and energy studies,more detailed informationrelated to the indoor positions and number of occupants has offered a better understanding of building user behaviour. The implication of the occupancy patterns for energy( e. g. lighting and other building services) efficiency is assessed,assisted with data from lighting sensors where needed. It is found occupancy patterns change dramatically with time. Also,the energy waste patterns have been identified through the method of data association rule mining. If the identified energy waste is removed,the total energy consumption can be reduced by 26. 1%. The indoor positioning information also has implications for optimizing space use,opening hours as well as staff deployment. The work could be extended to more rooms with diverse functions,other seasons and other types of non-domestic buildings for a more comprehensive understanding of building user behaviour and energy efficiency.     

商业中心区地下空间发展机制及城市设计方法

商业中心区功能高度复合、空间高度集聚,其发展要求建立舒适的全步行系统、空间垂直发展。地下空间的立体化发展机制是利用地下交通空间带动“地下商业、休闲、娱乐”功能发展,增强城市空间之间的联系使之达到功能混合、空间集聚、交通网络化的目的。商业中心区地下空间城市设计的关键在TOD模式导向下以轨道交通为“发展轴”,与其他区域或中心联系;以轨道站点为“发展源”、地下步行网络为“发展流”、地下车库为“发展块”,将机动车交通全部放入地下,构建片区化、网络化、立体化、简洁化的地下空间形态,建立轨道影响区内的全步行系统及立体步道网络串联公共空间、娱乐空间、商业空间,促进商业中心区的立体集约化发展。     

高校交往空间设计研究

对我国高校交往空间基本状况进行了阐述,从原则和内容两个方面提出交往空间适应性设计需要注意的关键环节,并从整体规划、步行交通系统、空间系统设计出发,分析了高校交往空间的适应性设计方式,指出了当前我国高校校园交往空间设计的基本思路。     

Mapping to Cells: A Simple Method to Extract Traffic Dynamics from Probe Vehicle Data

In the era of big data, mining data instead of collecting data are a new challenge for researchers and engineers. In the field of transportation, extracting traffic dynamics from widely existing probe vehicle data is meaningful both in theory and practice. Therefore, this article proposes a simple mapping‐to‐cells method to construct a spatiotemporal traffic diagram for a freeway network. The method partitions a network region into small square cells and represents a real network inside the region by using the cells. After determining the traffic flow direction pertaining to each cell, the spatiotemporal traffic diagram colored according to traffic speed can be well constructed. By taking the urban freeway in Beijing, China, as a case study, the mapping‐to‐cells method is validated, and the advantages of the method are demonstrated. The method is simple because it is completely based on the data themselves and without the aid of any additional tool such as Geographic Information System software or a digital map. The method is efficient because it is based on discrete space‐space and time‐space homogeneous cells that allow us to match the probe data through basic operations of arithmetic. The method helps us understand more about traffic congestion from the probe data, and then aids in carrying out various transportation researches and applications.     

论城市绿地系统的组成与分类

在分析一般城市绿地分类方法的同时提出新的分类法，进一步阐明了城市绿地系统的组成与分类的原则及依据。并对不同类型城市绿地的含义内容和空间属性作了论述。     

东海企业总部经济区整体交通组织分析

介绍了东海企业总部经济区在地块高强度开发的情况下,从满足企业总部经济区建设需要的交通出发,基于区域总体布局,利用其他相关总部经济区的成功经验,提出合理的交通组织规划。着重介绍了5项建议:建立轨交与普通公交为主的公交体系;加大路网密度;局部形成步行交通网络;严格控制停车位总量;形成地下停车系统。交通组织分析将为企业总部经济区项目建设提供设计条件的依据。     

浅谈新时代铁路交通建筑的空间营造

结合当前大型铁路旅客站房的发展趋势和对空间的多功能需求,对新时代铁路交通建筑的空间营造进行了探讨,分别从现代化交通枢纽的构建、空间的易识别性、空间尺度、照明设计等方面阐述了铁路交通建筑的空间设计,以指导实践。     

Mobile Agent Computing Paradigm for Building a Flexible Structural Health Monitoring Sensor Network

Abstract: Wireless structural health monitoring research has drawn great attention in recent years from various research groups. While sensor network approach is a feasible solution for structural health monitoring, the design of wireless sensor networks presents a number of challenges, such as adaptability and the limited communication bandwidth. To address these challenges, we explore the mobile agent approach to enhance the flexibility and reduce raw data transmission in wireless structural health monitoring sensor networks. An integrated wireless sensor network consisting of a mobile agent‐based network middleware and distributed high computational power sensor nodes is developed. These embedded computer‐based high computational power sensor nodes include Linux operating system, integrate with open source numerical libraries, and connect to multimodality sensors to support both active and passive sensing. The mobile agent middleware is built on a mobile agent system called Mobile‐C. The mobile agent middleware allows a sensor network moving computational programs to the data source. With mobile agent middleware, a sensor network is able to adopt newly developed diagnosis algorithms and make adjustment in response to operational or task changes. The presented mobile agent approach has been validated for structural damage diagnosis using a scaled steel bridge.     

Intelligent wireless web services for construction—A review of the enabling technologies

The vision of intelligent wireless web services, as discussed in this paper centres on the need to provide mobile construction workers highly specific data and services on an as-needed basis, with flexibility of use for the user. With the emergence of high speed wireless networks, such as Wi-Fi, Bluetooth and 3G, and parallel advancements in Internet based technologies such as the Semantic Web, Web Services, Agent based technologies and Context Awareness, the realisation of the vision of the intelligent wireless web has become a possibility. The paper presents a state-of-the-art review of the enabling technologies and discusses how, by exploiting the convergence and synergy between different technologies, it has become possible to deliver intelligent wireless web support to mobile construction workers.