RTK高程精度的探讨

通过实例分析了RTK技术在控制测量中高程的应用,并提出提高高程观测精度的措施。     

提高探地雷达超前地质预报精度的方法研究

研究目的：在对复杂多变地质条件下的地下隧洞进行施工时，进一步提高喀斯特岩溶多变地质中地质超前预报的精度，使施工顺利开展。 研究方法：通过对黔桂铁路扩能改造工程隧道群施工中应用探地雷达技术对掌子面前方不良地质体的预测预报实践探索，围绕关键技术问题展开研究。 研究结果：结合现场实际提出了改良优化检测方法与工艺、建立预报及预警体系、多种预测分析相互核检滤差、引入数码影像三维预测等综合预报方法的见解并通过实践检验。 研究结论：该方法有效提高了探地雷达在喀斯特岩溶地质中对不良地质体探测预报的精确度和分析描述的准确性。     

基于多元线性回归的船体补偿量优化

为提高船体精度补偿设计的准确性,提高船舶总装工序的原始坡口保留率,以某型在建海洋工程产品的建造数据为例,通过多元线性回归理论,给出一种补偿量的优化计算方法,得出精度补偿的预测计算公式,并编写相应的计算程序。该方法适用性强,可计算各类型分段在不同工序的补偿值,优化船舶建造补偿系统。     

基于云模糊理论的图像纹理分割

为了处理图像纹理的模糊性和随机性,基于云模糊理论提出了纹理特征矢量云模型,并成功地应用于纹理图像分割.该方法在对纹理统计描述符模糊化处理后,逆向生成纹理特征矢量云.矢量云模型的数字特征能够很好地表达纹理的模糊性和随机性,据此通过云距离计算及纹理特征矢量云生长,完成对图像纹理的分割.实验结果表明,该方法较经典的ISODATA算法和K-means簇算法的分割精度高,并且迭代收敛速度快.     

Construction of a stochastic model of track geometry irregularities and validation through experimental measurements of dynamic loading

This paper describes the construction of a stochastic model of urban railway track geometry irregularities, based on experimental data. The considered irregularities are track gauge, superelevation, horizontal and vertical curvatures. They are modelled as random fields whose statistical properties are extracted from a large set of on-track measurements of the geometry of an urban railway network. About 300–1000 terms are used in the Karhunen–Loève/Polynomial Chaos expansions to represent the random fields with appropriate accuracy. The construction of the random fields is then validated by comparing on-track measurements of the contact forces and numerical dynamics simulations for different operational conditions (train velocity and car load) and horizontal layouts (alignment, curve). The dynamics simulations are performed both with and without randomly generated geometrical irregularities for the track. The power spectrum densities obtained from the dynamics simulations with the model of geometrical irregularities compare extremely well with those obtained from the experimental contact forces. Without irregularities, the spectrum is 10–50?dB too low.     

DTM在高速公路设计中的精度验证及应用分析

介绍数字地面模型(DTM,简称数模)的理论、类型,并结合省内高速公路中数模的使用情况,对利用数模采集数据与利用传统测量方法(GPS、全站仪等)采集数据的方法、结果进行针对性比较验证,分析得出现行数模技术在高速公路勘察设计中的应用范围,使用注意事项及数模本身存在的问题。     

船舶舱室噪声预报的方法

对船舶舱室噪声预报的各种方法进行了较详细的阐述,并结合某型实船介绍了以统计能量法进行舱室噪声预报及改进设计研究的方法,可为今后船舶开发提供相关参考依据.     

基于统计能量法的轻型客车降噪处理

针对某轻型客车噪声较大的问题，尝试使用统计能量法进行能量流分析．找出对车内噪声贡献较大的部位，并采取较为经济的措施，得到良好的降噪效果。     

Computational precision of traffic equilibria sensitivities in automatic network design and road pricing

Recent studies demonstrate the importance of computational precision of user equilibrium traffic assignment solutions for scenario comparisons. When traffic assignment is hierarchically embedded in a model for network design and/or road pricing, not only the precision of the solution itself becomes more important, but also the precision of its derivatives with respect to the design parameters should be considered.The main purpose of this paper is to present a method for precise computations of equilibrium derivatives. Numerical experiments are used for two evaluations: (1) precision of computed equilibrium derivatives for a medium-size network (Anaheim); and (2) the impact of precise derivatives on capacity-expansion solution quality for a small network (Sioux Falls).     

一种高速模数转换模块的设计与实现

在模数转换中,存在着速度和精度的相互限制,为了满足高速采样下的高精度要求,研制了一种基于高速、高精度、宽输入带宽模数转换器AD7762的数据采集模块,并总结了数采模块的接口、去耦电路、低噪声电压参考源、时钟及时序等设计经验。