WCDMA系统中无线接入网建模的研究

本文主要讨论了第三代移动通信WCDMA系统无线接入网（RAN）建模中的几个关键模型的建立，包括典型业务模型和多小区模型，同时在分析WCDMA系统无线接入网结构的基础上，建立了WCDMA系统多业务、多小区的仿真平台，并对这种多业务、多小区情况下的系统容量进行了探讨。     

航管应答机BIT单元的研究与实现

本文详细介绍了航管应答机ＢＩＴ单元的方案构思，并着重对实现方法进行了具体分析。     

Assessing the Influence of Traffic Impact Assessments on Land Use Development and Decision Making

Rapid urbanisation and land use planning in cities and countries worldwide have an impact on traffic related risks to society as a whole. Strategic planning decisions made during land use development approvals can affect the performance of transport infrastructure significantly impacting on community safety. One major contributor to the decision-making process is Traffic Impact Assessment （TIA） undertaken prior to development approval. The content of each TIA process differs according to the type of development and its geographical location. The paper presents a brief overview of the strategic decision-making process adopted in Australia in land use development approvals. Using a selected case study area, the importance of the TIAs to the decision-making process is demonstrated. Further, the paper presents the observed differences between the facts presented in TIAs completed by four different consultants and the influence of the new development in the community safety. Traffic records after the new development indicate that the accidents have almost doubled after the new development. It is noted that the current TIA process requires significant changes to ensure that the influence of the land use development decisions are captured correctly to ensure informed strategic decision-making. A set of recommendations to overcome the shortcomings of existing planning and TIA designing process is presented.     

基于流数据挖掘的网络流量异常检测及分析研究

网络流量异常检测及分析是网络及安全管理领域的重要研究内容。本文探讨了网络流量异常的种类、网络流量异常检测的方法,分析了基于传统检测方法在网络流量异常检测应用中存在的问题。并重点对基于流数据模型的网络流量异常检测进行了研究,综述了已有流数据挖掘研究方法在网络流量异常检测中的研究进展。最后,本文对现有研究工作存在的问题及未来的研究方向进行了探讨。     

基于径向基神经网络的铁路短期客流预测

在分析径向基神经网络原理和铁路客流时序特征的基础上,建立基于径向基神经网络的铁路短期客流预测模型,通过径向基神经网络把客运量的年规律、周规律等时间属性有机结合,有效解决客流数据的复杂性和非线性问题。以T15次列车为例进行硬座席别的客运量预测结果表明,径向基神经网络预测模型对铁路短期客流的预测效果较好。     

Measuring the impact of traffic flow management on interarrival duration: An application of autoregressive conditional duration

The Federal Aviation Administration has several tools in its arsenal to manage traffic flows. However, it is very difficult to assess with certainty the impact of traffic flow management procedures such as Time-Based Flow Management (TBFM) or Traffic Management Initiatives (TMI) on airport performance because operational data are not readily available to analysts. This study uses the case of Fort Lauderdale–Hollywood International Airport (FLL) where traffic flow management procedures have been implemented to manage a reduction of airport capacity due to runway constructions. Based on an Autoregressive Conditional Duration (ACD) model, the analysis shows that the use of traffic flow management procedures contributed to reducing the volatility of interarrival duration whether separation relies on time-metering (TBFM) or distance between aircraft (TMI). The lessons learned from this case study may have important implications for airports whose available capacity is severely constrained.     

Transition through subsystem innovation? The case of traffic management

This article analyzes traffic management as an example of infrastructure operation and assesses to what extent the transition approach as developed by Rotmans, Geels, and others is helpful in providing insight and contributes to the transition of the mobility system. Based on a conceptual framework which draws on the work of Luhmann and Critical Systems Thinking (CST), two cases of traffic management innovation in the Netherlands are analyzed. From this it becomes clear that traffic management is more than the optimization of the current mobility system. Rather than being a technical exercise, traffic management has to deal with substantial uncertainty which results from political dynamics and interactions between traffic management and other parts of the larger mobility system. The cases show that, in dealing with these uncertainties, actors may start to explore broader system definitions. Thus, a transition of the car-dependent mobility system is shown to be strongly emergent, which questions overly linear projections formulated by transition researchers as well as practitioners.     

Carpooling and driver responses to fuel price changes: Evidence from traffic flows in Los Angeles

We examine carpooling and driver responses to fuel price changes. Using a simple theoretical model, we show that traffic flows in mainline lanes unambiguously decrease when fuel prices increase, and this effect is stronger when the presence of a carpool lane provides a substitute to driving alone. In contrast, in carpool (HOV) lanes flow can either increase or decrease. These predictions are tested using 8 years of traffic flow data for 1700 locations in Los Angeles. In our preferred specification, the mean elasticity of flow with respect to fuel price is 0.136 for HOV lanes. For a 10% increase in fuel price this implies 10 additional carpools per hour, $8.8 million per year in additional congestion costs for carpoolers and $11.3 million lower costs for mainline drivers. For mainline lanes, flow elasticities are −0.083 and −0.050 for highways with and without an HOV lane. These estimates imply that the mean highway with an HOV lane experiences a 30% larger decrease in hourly flow compared to the mean highway without an HOV lane. Flows in HOV lanes show an immediate decrease following a price increase but respond positively to price increases over time, which suggests time is an important input to carpool formation.     

铁路枢纽参与大都市区城市综合交通运输系统的整合研究

结合铁路的供给特性和我国城市化进程及由此产生的对交通运输方式的需求特点,论文提出铁路业应在其枢纽所在大都市区全面参与到城市综合交通运输系统中来。据此,文中对铁路参与大都市区综合交通运输系统的整合进行了详细的概念界定、数学描述和流程分析,并对成都铁路枢纽参与成都大都市区的交通运输进行了实例探讨。     

道路安全评价方法

为了准确地进行道路交通安全评价,在分析国内外道路交通安全现状的基础上,对影响道路交通安全的影响因素进行了分析。道路交通安全措施的评价研究在欧美一些国家已开展多年,其研究成果为欧美发达国家各国政府制定道路交通安全政策,指导道路交通实际安全工作提供了科学依据。文中通过对道路交通安全措施评价概念的阐述,介绍了国外常用的几种评价方法,并对我国开展道路交通安全措施研究提出了建议。