CRTSII型双块式无砟轨道施工技术与病害处治技术探讨

在郑西客运专线CRTSII型双块式无砟轨道施工中,采用了德国技术旭普林机械施工和人工轨排施工方法。针对两种施工方法的施工工艺、关键技术及后期运营效果进行了技术性总结,并针对施工过程和后期运营存在的常见病害提出处治措施。     

基于人工鱼优化的MP超声微弱信号提取方法研究

强噪声背景下微弱信号的提取一直是超声信号处理领域研究的一个难题,传统的信号处理方法难以准确提取弱缺陷信号,稀疏分解方法为提高超声弱缺陷的检出率开辟一条新途径,但计算量大是困扰其应用的一个主要因素。本文提出一种人工鱼群优化匹配追踪的快速算法。人工鱼是一种新型智能优化算法,具有并行寻优、全局收敛性好,对初值不敏感的特点。利用本文算法在重建信号质量不变的情况下,提高稀疏分解在冗余字典中原子匹配的速度和精度,满足信号处理实时性要求。采用与超声信号最优匹配的Gabor函数,经伸缩和平移生成过完备原子库,提高对超声信号的表达能力。通过仿真分析和实际检测铸钢试件,表明该方法能够有效地检测出强噪声背景下的弱信号。     

地铁盾构法隧道孤石工程分类及处理对策

分析国内常见孤石工程问题,弱化地质成因,依据工程特征将孤石分为3类,即残积层孤石、沉积层孤石和人工填石。在孤石分类的基础上,从勘察、盾构机选型和具体工程处理措施出发论述不同种类的孤石的处理对策。     

人工智能技术在城市智能交通系统中的应用

城市化的快速发展能为人们的日常出行提供便利。但是与此同时,交通方面的问题也变得越发严重,传统的交通管理模式和交通系统已经无法满足时代的实际要求。在全新的时代背景下,城市交通必须要朝着智能化的方向进行转变,积极引入先进的人工智能技术,针对当前存在的问题进行具有针对性的解决,这样才能有效解决一系列交通问题。我国在发展过程中一直都十分注重可持续发展,并且致力于从多方面和多角度来贯彻可持续发展的理念,将人工智能技术充分运用在智能交通系统中,符合我国所提倡的可持续发展理念,不仅能够推动城市得到快速的发展,同时也能有效缓解严重的交通问题。     

Artificial Reefs as Restoration Tools: A Case Study on the West Florida Shelf

Artificial reefs are one of a number of tools that should be considered by scientists and managers when planning coastal zone restoration and/or mitigation projects. In this article, the details of one project from the West Florida Shelf are presented. Two types of artificial reefs were used to mitigate pipeline construction impacts on natural hardbottom ledges in the eastern Gulf of Mexico. The project's primary objective was to avoid the paradigm of building artificial reefs as fish attraction devices, and to instead implement a design that would mimic, not augment, natural hardbottom conditions. Fish assemblage parameters (species richness and commercial fish abundances) were compared between the artificial habitats and natural hardbottom reference sites. Results indicate that species richness trends are similar among artificial and natural reefs, while certain commercial fish abundances are significantly higher on the artificial reefs. Recommendations for future restoration/mitigation projects using artificial reefs are discussed.     

Effects of closed trawl fishery areas on some elasmobranch species in the Cantabrian Sea

This study examines the effects of certain closed areas to the trawl fishery on some Rajidae species and small-spotted catshark in the southern area of the Bay of Biscay. The results are based on abundance index (number/haul) and catch length composition obtained from a series of bottom trawl surveys carried out in the area (1993–2005). Abundance trends are similar considering or not closed areas, but with much lower values excluding closed areas. The length distributions revealed that in some of the species like Scyliorhinus canicula the larger specimens were the most affected by this decrease in number. Finally, the effects and consequences of one of these marine protected areas (MPAs), an artificial reef were examined in more detail for all the fishes and invertebrates. The analysis of the yield series showed an increase in total biomass after the placement of the reefs not only for S. canicula and rays but also teleosts fishes like Pagellus acarne, Trachurus trachurus, Mullus surmuletus and Trachinus draco and particularly invertebrates (sea urchins). On the contrary, the main target species of the trawl fishery (hake, monkfish and megrim among others) did not increase.     

人工计数法应用于城市区域性路网交通量统计

介绍了运用人工计数方法来统计区域性路网的交通量大小,对重庆市两路口区域路网进行了交通量统计和数据处理;并通过数据进行分析,掌握了两路口区域的交通流量特点。实践证明该方法具有可操作性。     

基于神经网络的汽车制动系可靠性分析

以某轻型客车制动系统为例进行可靠性分析,利用威布尔过程对这些数据进行了拟合,用人工神经网络方法进行参数估计,计算所获得分布的参数值,绘制出可靠度曲线。     

基于神经网络算法的高速公路基本路段线圈检测器布设间距研究

为研究高速公路交通事件检测算法及线圈检测器布设间距,设计了高速公路基本路段的人工神经网络事件检测算法,并研究基本路段检测器布设间距在200～700m不同情况下的事件检测效果。利用VISSIM4.2软件仿真获得数据,并在Matlab人工神经网络工具箱中计算,验证了所设计事件检测算法的有效性,得出基本路段线圈检测器的合理布设间距。     

支持向量机在路段行程时间预测中的应用研究

主要探讨支持向量机理论在路段行程时间预测中的应用。具体的方法是,首先将研究路段根据路段交通状态和车辆检测器设置情况进行分段,然后以前几个时段的各个小路段的交通流量、平均速度和车道占有率和整个路段的行程时间为输入,以下一时段的整个路段的行程时间为输出,选取高斯径向基函数作为核函数,建立了基于支持向量机的路段行程时间预测模型,从而探讨支持向量机在路段行程时间预测中的应用效果。最后,利用交通仿真软件的模拟数据进行验证,并与BP神经网络计算结果比较,计算结果的对比表明本文提出的方法预测效果更好。