浅埋偏压隧道洞口段加固方案计算分析

采用虚拟内力计算方法,以FLAC2D为计算工具,对洞冲里隧道的浅埋偏压段拟采用的加固方法进行了计算分析。结果表明：采用侧向管棚治理洞口段偏压无论整体沉降、结构受力均优于正面管棚的加固方法。在随后的监控量测的数据分析中也证明了该加固方案的有效性。     

Understanding the role of the forecast-maker in overestimation forecasts of policy impacts: The case of Travel Demand Management policies

Forecasting the impacts of a proposed policy is an important component of the transportation planning and decision making process. Although scientific tools are often used in transportation forecasts, biases and, more specifically, overestimations of the expected impact are often observed. This study explores the correlations between forecast-maker’s characteristics and forecast bias creation and reduction. The study examines two transport-related policies aiming at the reduction of car use: telecommuting and carsharing. Both are Travel Demand Management (TDM) policies, which attract much attention from transport experts. We tested the extent to which the forecast-maker’s beliefs about the policy at stake affected the forecast bias. We found that attitudes and beliefs associates not only with overestimation bias but also with its reduction over time. We also tested the extent to which the forecast-maker’s affiliation, the performing institute and the publication type were correlated with the biases of the forecast and with the forecaster attitudes and beliefs. These characteristics are intuitively used by the forecast user as tools to assess the ‘objectivity’ of the forecast, but our analysis found no association between these characteristics and the forecast bias.     

云台山公路隧道浅埋偏压段施工技术

针对云台山隧道洞口段浅埋偏压破碎围岩的实际情况,为提高围岩强度,保证其稳定性,改善隧道成拱的作用,提出了采用偏压挡土墙、地表小导管预注浆等技术处理措施。综合分析表明:注浆处理后,围岩完整程度和强度明显提高,采用偏压挡土墙后,保证了洞顶覆盖体稳定性,洞内围岩变形量较小,初期支护及二衬整体受力特征得到了很大改善,小导管预注浆等处理措施效果显著。     

带偏差单元BP神经网络土体灌浆压力预测

灌浆压力是土体灌浆加固的重要参数。基于神经网络非线性映射特性,分析土体灌浆压力主要影响因素,建立符合一般工程判断和决策思维的BP网络预测模型,并引入偏差单元对其结构进行改进,实现了快速收敛,较高精度得出灌浆预测压力的具体数值。预测结果与室内灌浆试验压力对比表明,带偏差单元BP神经网络的土体灌浆压力预测结果具有较高准确性和一定的实用意义。     

一种基于合作目标的机动雷达误差配准技术

针对机动平台传感器非协同误差配准技术实施难度大和配准效果差的问题,对基于合作目标的协同误差配准技术进行了研究。首先根据传感器对合作目标的地球直角坐标系量测方程,建立了系统误差的估计模型,然后根据建立的系统误差估计模型,利用传感器获得的量测和目标通过数据链上报的导航信息,采用最大似然估计技术,对系统误差进行估计。仿真结果表明：该系统误差估计模型可得到系统误差的有效估计,并对目标的导航误差具有强鲁棒性,因此该算法具有一定的工程应用前景。     

Quantitative analysis of probe data characteristics: Coverage,speed bias and congestion detection precision

Abstract

In recent years, there has been a growing desire for the use of probe vehicle technology for congestion detection and general infrastructure performance assessment. Unlike costly traditional data collection by loop detectors, wide area detection using probe-based traffic data is significantly different in terms of the nature of data collection, measurement technique, coverage, pricing, and so on. Although many researches have studied probe-based data, there remains critical questions such as data coverage and penetration over time, or the influential factors in the accuracy of probe data. This research studied probe-sourced data from INRIX, to profoundly explore some of these questions. First, to explore coverage and penetration, INRIX real-time data was illustrated temporally over the entire state of Iowa, demonstrating the growth in real-time data over a 4-year timespan. Furthermore, the availability of INRIX real-time and historical data based on type of road and time of day, were explored. Second, a comparison was made with Wavetronix smart sensors, commonly used sensors in traffic management, to explore INRIX’s speed data quality. A statistical analysis on the behavior of INRIX speed bias, identified some of the influential factors in defining the magnitude of speed bias. Finally, the accuracy and reliability of INRIX for congestion detection purposes was investigated based on the road segment characteristics and the congestion type. Overall, this work sheds light onto some of the less explored aspects of INRIX probe-based data to help traffic managers and decision makers in better understanding this source of data and any resultant analyses.     

硅微陀螺仪数字化温度补偿系统的实现

分析了温度影响陀螺零偏的机理,由温度实验得出硅微陀螺仪零偏与温度呈较复杂的非线性关系;根据实验数据拟合出零偏与温度在三个温度段内的数学表达式;设计了相应的温度补偿系统,该系统以新华龙C8051F363单片机为核心,根据实时测量的温度值经由拟合的多项式计算出各温度下的补偿值,将陀螺原始信号减去补偿值即可得到补偿后的陀螺信号.经温控实验测定,在-40℃-80℃的范围内,补偿后陀螺零偏随温度变化的趋势项基本被消除,且陀螺零偏减小了一个数量级,补偿效果明显.     

大南山隧道浅埋偏压地段加固施工技术

在隧道工程施工中,隧道经常穿越浅埋偏压地段,以山西平定至阳曲高速公路大南山隧道为例,介绍大南山隧道浅埋偏压地段加固施工技术。     

锚泊船走锚过程的仿真研究

本文采用MMG建模的思想,在锚泊船偏荡运动的基础之上,建立了锚泊船走锚运动数学模型,研究了走锚后船舶的运动姿态;对风中锚泊船偏荡运动中船舶走锚数学模型的建立进行了初步探索,为今后进行更为完善的锚泊船走锚运动过程的仿真研究提供了借鉴。     

Mean shift registration algorithm for dissimilar sensors

The mean shift registration (MSR) algorithm is proposed to accurately estimate the biases for multiple dissimilar sensors. The new algorithm is a batch optimization procedure. The maximum likelihood estimator is used to estimate the target states, and then the mean shift algorithm is implemented to estimate the sensor biases. Monte Carlo simulations show that the MSR algorithm has significant improvement in performance with reducing the standard deviation and mean of sensor biased estimation error compared with the maximum likelihood registration algorithm. The quantitative analysis and the qualitative analysis show that the MSR algorithm has less computation than the maximum likelihood registration method.