Neural navigation interfaces for Information Retrieval: Are they more than an appealing idea?

Neural networks have recently been proposed for the construction of navigation interfaces for Information Retrieval systems. In this paper, we give an overview of some current research in this area. Most of the cited approaches use (variants) of the well-known Kohonen network. The Kohonen network implements a topology-preserving dimensionality-reducing mapping, which can be applied for information visualization. We identify a number of problems in the application of Kohonen networks for Information Retrieval, most notably scalability, reliability and retrieval effectiveness. To solve these problems we propose to use the Growing Cell Structures network, a variant of the Kohonen network which shows a more flexible adaptation to the domain structure.This network was tested on two standard test-collections, using a combined recall and precision measure, and compared to traditional IR methods such as the Vector Space Model and various clustering algorithms. The network performs at a competitive level of effectiveness, and is suitable for visualization purposes. However, the incremental training procedures for the networks result in a reliability problem, and the approach is computationally intensive. Also, the utility of the resulting maps for navigation will need further improvement.     

Speed and Accuracy Tradeoff for LiDAR Data Based Road Boundary Detection

Road boundary detection is essential for autonomous vehicle localization and decision-making, especially under GPS signal loss and lane discontinuities. For road boundary detection in structural environments, obstacle occlusions and large road curvature are two significant challenges. However, an effective and fast solution for these problems has remained elusive. To solve these problems, a speed and accuracy tradeoff method for LiDAR-based road boundary detection in structured environments is proposed. The proposed method consists of three main stages: 1) a multi-feature based method is applied to extract feature points; 2) a road-segmentation-line-based method is proposed for classifying left and right feature points; 3) an iterative Gaussian Process Regression (GPR) is employed for filtering out false points and extracting boundary points. To demonstrate the effectiveness of the proposed method, KITTI datasets is used for comprehensive experiments, and the performance of our approach is tested under different road conditions. Comprehensive experiments show the road-segmentation-line-based method can classify left, and right feature points on structured curved roads, and the proposed iterative Gaussian Process Regression can extract road boundary points on varied road shapes and traffic conditions. Meanwhile, the proposed road boundary detection method can achieve real-time performance with an average of 70.5 ms per frame.      

基于IPv6的城市车载网移动协议

提出了一种基于IPv6的城市车载网移动切换协议。本协议提出了城市车载网络体系结构, 车辆节点在移动过程中由家乡地址唯一标志, 无须转交地址, 因此节省了转交地址配置时间和代价, 从而缩短了移动切换时间, 降低了移动切换代价。车辆节点无须参与移动切换过程, 从而避免了由于车辆节点高速行驶引起丢包而增加移动切换代价和延迟的情况。仿真数据结果表明该方案的性能更好。     

基于GPS终端的实时路况信息采集方法研究

浮动车的实时路况信息采集存在采集内容复杂、信息不准确等问题.为此,提出一种基于GPS终端的实时路况信息采集方法.采用面向简化路网模型的采集方法,只考虑路段行程时间与路段中途停车时间,将GPS终端替代服务器负责采集内容和地图匹配.实验结果表明,与传统的基于服务器端采集方法相比,该方法能使采集内容更简单,采集信息更准确,可减轻服务器端的高负荷,便于采集信息的传输.     

区分服务网络中带宽利用的公平性

为了解决DiffServ网络中带宽利用的不公平性 ,该文提出了一种自适应的数据包标记算法AFM(AdaptiveFairMarker) .与现有的标记算法相比 ,它有两个显著的不同 :( 1)增加了一种带宽估计机制 ,对网络中可使用的带宽进行动态估计 ,并将所估计的带宽以按比例的方式公平地分配给各个汇聚流 ;( 2 )对TCP协议作了一个微小而又非常有效的改进 ,在控制TCP拥塞窗口的同时尽量避免TCP协议的AIMD机制 .该文通过仿真试验对算法进行了验证 ,结果证实AFM算法比其它几种算法具有更好的公平性     

车辆视觉导航系统中的实时道路检测

提出了一种新的道路检测算法。该算法中首先采用基于线段的区域增长法将采集到的实际道路边缘图像分割成道路区域和非道路区域,使下一步搜索道路标志的区域限定在道路区域;然后恢复道路标志并根据其特征定位道路标志线;最后采用数据拟合的方法找出道路轨迹线。在复杂路况下可以准确、快速估算出车道的延伸方向,实现车辆的防偏预报。、     

行驶车辆磁感应检测及智能道路传感系统

智能运输系统的前提条件之一是实现道路行驶车辆自动检测与交通信息实时采集。详细分析了磁感应式行驶车辆检测工作原理,建立了道路交通流信息计算模型,完成了基于DSP技术的智能检测系统设计与实现,采取了软硬件综合技术来对付现场各种干扰与噪声信号。对试验结果进行了分析,实际测试表明:系统性能稳定可靠。     

Naturalistic study of the risky situations faced by novice riders

This article sets out to identify the typical risky situations experienced by novice motorcyclists in the real world just after licensing. The procedure consists of a follow-up of six novices during their first two months of riding with their own motorbike instrumented with cameras. The novices completed logbooks on a daily basis in order to identify the risky situations they encountered, and were given face-to-face interviews to identify the context and their shortcomings during the reported events. Data show a large number of road configurations considered as risky by the riders (248 occurrences), especially during the first two weeks. The results revealed that a lack of hazard perception skills contributed to the majority of these incidents. These situations were grouped together to form clusters of typical incident scenarios on the basis of their similarities. The most frequent scenario corresponds to a lane change in dense traffic (15% of all incidents). The discussion shows how this has enhanced our understanding of novice riders’ behaviour and how the findings can improve training and licensing. Lastly, the main methodological limitations of the study and some guidelines for improving future naturalistic riding studies are presented.

Practitioner Summary:

This article aims to identify the risky situations of novice motorcyclists in real roads. Two hundred forty-eight events were recorded and 13 incident scenarios identified. Results revealed that a lack of hazard perception contributed to the majority of these events. The most frequent scenario corresponds to a lane change in dense traffic.     

Long‐Range Forecasting Highway Construction Costs

In the process of decision making for design and execution of highway construction projects, long‐range cost forecasting is one of the most significant and complicated problems. This paper describes the development of a model that enables the user to make long‐range cost projections, taking into consideration general characteristics of the highway construction industry, as well as pertinent local conditions. The model presented uses conventional statistical methods to represent the main categories of typical jobs in the highway construction industry. From these categories, a composite model is created by assigning different weights to the input elements costs and then choosing a series of indicators to predict price trends for each separate element of the composite model. Use of this model reveals that bid volume in a certain area is a factor that has significant influence upon cost forecasts. This paper is accompanied by a case study based on actual data from highway construction projects performed for the Florida Department of Transportation in the years 1968–1981.     

Les groupes frigorifiques pour le transport routier à longue distance. Historique et évolutionRefrigeration units for long distance road transport. History and development

The big truck or trailer fitted with a refrigeration unit is a familiar feature of the highway traffic. But 50 years ago the transport of perishable food-stuffs over long distances by road was almost unknown. The development of the truck and trailer industry and the efforts of refrigeration engineers created rapid progress mostly using standard commercial refrigeration units fitted with petrol-driven engines and special controls suited to road traffic. Though there were some early European patents it was in the USA that the first practical units were produced on an industrial basis.The second world war brought a rapid development of mechanically refrigerated road transport since many railroads were destroyed and supplies had to go by road. After the war European industry started building its own models and by the 60's several manufacturers offered refrigeration appliances more or less comparable to US models. Most were still powered by gasoline engines but diesel powered units appeared soon, owning to the important price advantage of diesel fuel. US manufacturers also switched to diesel powered units, due mainly to the new piggy-back transportation mode combining rail and road transport.The increasing size of trucks and trailers, together with the need for lower temperatures by the frozen food industry, and the recent development of paletizing of the load are responsible for the steady increase of refrigeration road transport.