中国城市乘用车实际行驶工况的研究

分析了中国3个典型城市(北京、上海和广州)车辆行驶的速度、怠速、最大速度、加速度以及行程等特征及其分布特征;结合交通特性研究了车辆行驶运动学水平。研究表明,现行采用ECE15工况与实际行驶工况相比,车辆燃油消耗被低估约10%;覆盖的车辆工况范围远远小于实际行驶工况,不适用于车辆设计开发要求。     

How to assess sustainability of suppliers in volume discount context? A new data envelopment analysis approach

In this paper, we reformulate conventional data envelopment analysis (DEA) models and propose a novel method for evaluating sustainability of suppliers in the presence of interval volume discount offers, fuzzy data, and ordinal data. To this end, we convert all data into interval data. To convert fuzzy data into interval data, we use nearest weighted interval approximation by applying weighting function and we convert each ordinal data into interval one. Then, using enhanced Russell model, interval efficiencies are obtained. After that, using preference degree approach, we rank suppliers. Finally, a case study is presented to illustrate our proposed approach.     

Adaptive data dissemination for time-constrained messages in dynamic vehicular networks

With the advent of emerging wireless communication technologies, tremendous efforts have been put on promoting the safety and efficiency of transportation services by developing innovative applications. In particular, there has been significant interest in accessing information stored at RSUs (Roadside Units). The unique characteristics in vehicular networks, such as dynamic traffic factors including vehicle arrival rate, dwell time and data access patterns, bring us new challenges on data dissemination. This work dedicates to the investigation of timely and adaptive data dissemination in the dynamically changing traffic environment. Firstly, we derive an analytical model to explore and examine the effects of the dynamic traffic factors. In light of the theoretical results, an on-line scheduling algorithm is proposed for adaptive data dissemination. Finally, we evaluate performance of the new algorithm in a variety of circumstances. The simulation results demonstrate satisfactory performance of the proposed algorithm.     

基于数据分类的高速铁路运营事故预测方法

高速铁路运营事故预测方法是度量铁路安全管理水平的重要指标.为提高高速铁路的安全运营水平,引入工业数据分类方法,分析反向传播(BP)神经网络和灰色模型在高速铁路安全运营事故预测过程中的适应性.首先,运用事故次数、事故联动系数、月均事故率3个参数对高速铁路安全运营水平进行度量;然后,根据工业数据分类方法判别高速铁路运营事故数据属于块状型,据此建立反向传播(BP)神经网络运营事故预测模型;针对运营事故数据具有波动大的特点,利用均值聚类方法建立K-GM(1,3)预测模型.以近年来高速铁路运营事故数据为样本对模型进行训练和分析,结果表明:BP神经网络、K-GM(1,3)、GM(1,3)预测模型的预测误差分别为8.92%,13.68%,345.25%,BP神经网络在高速铁路安全运营事故预测过程中的适应性要优于灰度模型.     

地下管线测漏仪中数据的采集和预处理

在对管线渗漏信号进行分析的基础上 ,利用DSP芯片TMS32 0VC5 40 2和模数转换器CS5 36 0实现了数据的高精度采集。同时设计了基于渗漏信号特征的数字滤波器 ,对采集后的信号进行有效预处理。     

基于B/S模式的机车信号检测数据分析系统

结合当今比较流行的计算机技术,研究了一种新型的基于浏览器/服务器（Browser/Server,简称B/S）模式的机车信号检测数据分析系统,给出了系统设计原理和实现方法.     

深圳地铁一期工程FALKO简述

根据深圳地铁一期工程采用的信号系统设备技术特点，对ATS子系统中运行时刻表编辑系统（FALKO）的数据组成、控制流程、系统功能作了初步介绍。     

Quality control of ocean temperature and salinity profiles — Historical and real-time data

A new automated quality control system for oceanic temperature and temperature–salinity profiles is presented. Substantial development was needed for some of the quality control algorithms although the checks were based on documented procedures used elsewhere where appropriate. A new automated ship track check was developed: the results of an undetected position error can be very damaging to ocean analyses. Also important is a check against a gridded background, this can be a climatology but near the surface it is advantageous to use an estimate that is evolving over time. Bayesian probability theory is used in the background check and the associated check against nearby observations (buddy check). The system was used to process archive data for 1956–2004. As a by-product monthly model-free objective analyses for this period were produced. Versions of the system are used for near-real time ocean analysis and for initialising both short-range ocean forecasts and seasonal atmosphere–ocean forecasts. The main features of the oceanic observing systems are presented along with quality control statistics, examples of errors that can occur and some additional problematic cases.     

基于数据融合的单目标船避碰评估系统

建立了一个用于对单目标船避碰操作进行评估的系统。介绍了基于数据融合技术的系统三级处理模型,并重点讨论了基于数据关联的船舶航迹提取,基于坐标转换和几何模型的船舶运动参数计算,基于多测量周期数据融合的船舶操纵识别,和基于知识的碰撞危险、避碰阶段及会遇态势的判定等模块。同时给出了系统的工作流程图,最后通过实例说明系统运行的有效性。     

国内船用VDR型式认可检验

介绍了国内船用VDR型式认可的技术要求和试验方法,为VDR制造商申请产品型式认可提供技术指导,并为验船师在检验过程中起到参考作用。