集装箱码头计算机模拟模型概况

简要介绍了计算机模拟技术以及它在港口工程方面的应用。特别是针对几家国外咨询公司开发的集装箱码头的模拟模型，分别讨论了它们的特点和应用范围。最后结合例子，介绍了一航院CTSS模型的概况。     

汽车防抱死制动系统H_∞控制与PID控制的比较研究

控制方法是汽车防抱死制动系统的核心技术。为了提高ABS系统的鲁棒性能,在建立汽车防抱死制动系统数学模型的基础上,设计了H∞控制器,在Matlab/Simulink平台上对基于H∞控制器的ABS系统进行了动态仿真,并与基于传统PID控制器的ABS系统进行对比。通过对仿真结果进行比较发现,PID控制和H∞控制都能使ABS系统获得较好的制动性能;H∞控制响应迅速、具有优秀的稳定性和鲁棒性,总体控制效果优于PID控制。     

Optimal development of alternative fuel station networks considering node capacity restrictions

A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is the use of alternative fuel vehicles (AFV). As global GHG emission standards have been in place for passenger cars for several years, infrastructure modelling for new AFV is an established topic. However, as the regulatory focus shifts towards heavy-duty vehicles (HDV), the market diffusion of AFV-HDV will increase as will planning the relevant AFV infrastructure for HDV. Existing modelling approaches need to be adapted, because the energy demand per individual refill increases significantly for HDV and there are regulatory as well as technical limitations for alternative fuel station (AFS) capacities at the same time. While the current research takes capacity restrictions for single stations into account, capacity limits for locations (i.e. nodes) – the places where refuelling stations are built such as highway entries, exits or intersections – are not yet considered. We extend existing models in this respect and introduce an optimal development for AFS considering (station) location capacity restrictions. The proposed method is applied to a case study of a potential fuel cell heavy-duty vehicle AFS network. We find that the location capacity limit has a major impact on the number of stations required, station utilization and station portfolio variety.     

脐血胰岛素样生长因子-2和印记基因H19与胎儿生长受限的关系

目的探讨脐血胰岛素样生长因子-2(IGF-2)和H19印记状态与胎儿生长受限(FGR)的关系。方法采用放射免疫法测定42例FGR孕妇(研究组)和晚期正常妊娠妇女30例(对照组)脐血中IGF-2水平,同时采用逆转录多聚酶链反应(RT-PCR)技术,检测胎盘组织中H19基因印记状态。结果①研究组脐血IGF-2水平为(1.52±0.20)μg/L,明显低于对照组的(1.97±0.21)μg/L(P<0.05)。②研究组中杂合子20例,其中9例双等位基因表达;对照组中杂合子14例,均为单等位基因表达;研究组H19基因印记丢失明显高于对照组(P<0.05)。③研究组H19双等位基因表达的病例脐血IGF-2水平均明显低于H19杂合性丢失和H19单等位基因表达病例(P<0.05);H19杂合性丢失和H19单等位基因表达病例脐血IGF-2水平无显著性差异。结论妊娠晚期IGF-2减低是导致FGR发生的原因之一;H19基因印记丢失下调IGF-2基因间接影响胎儿生长发育。     

一种可伸缩的预测性快速运动向量搜索算法

基于钻石搜索的特点，提出了搜索距的概念．通过对不同搜索距的检测点特性的研究，并吸收了PMVFAST算法中“见好就收”的思想和初始预测候选运动向量集的概念，提出了一种新的可伸缩的预测性十字方块快速运动搜索算法，该算法以检测点的块失真特性统计为基础，制定出精确可控的可适应搜索准则．大量模型实验表明：该算法能获得更好的视频质量，同时，拥有良好的搜索速度伸缩性，在允许图象质量有0．05dB降低时，搜索速度能提高1．5-2．5倍．     

Fast Mode Decision Method Based on Historical Information for H.264/AVC

Mode decision based on rate-distortion optimization algorithm brings high compression efficiency to H.264/AVC. However, heavy computation load is also added to the encoder at the same time. In order to reduce the computation burden of mode decision, this paper presented a fast mode decision method based on mode information of the previously coded frame. Moreover, all coding modes were activated when scene change occurs and a scheme to detect scene change was proposed. The simulation results show that compared to the original encoder, the proposed method achieves a reduction of over 38% encoding time and keeps almost the same PSNR and bitrate for a wide range of quantization parameter.     

Error Robust H. 264 Video Transmission Schemes Based on Multi-frame

Multi-frame coding is supported by the emerging H. 264. It is important for the enhancement of both coding efficiency and error robustness. In this paper, error resilient schemes for H. 264 based on multi frame were investigated. Error robust H. 264 video transmission schemes were introduced for the applications with and without a feedback channel. The experimental results demonstrate the effectiveness of the proposed schemes.     

基于多传感器的列车里程计定位误差检测及校正方法

城市轨道交通列车运行过程中,轮对空转/滑行和车轮磨损是造成车载里程计测速测距误差的主要原因,因此里程计定位误差的检测和校正主要是对列车空转/滑行和车轮磨损的检测和误差校正。通过城市轨道交通列车定位需求分析以及传感器定位特性分析,在列车里程计基础上引入多普勒雷达,采用二者构建车载组合定位系统。基于H!滤波理论实现两种传感器量测信息的融合处理,得到列车定位参数的最优估计,在此基础上,利用空转/滑行和车轮磨损检测方法完成相关检测并对误差进行校正。仿真试验结果验证了本方法的有效性,达到了模型的预期设计目的,提高了车载定位系统的自主定位能力。     

透水框架护岸模型试验

透水框架护岸是将透水框架铺设在岸坡坡面上,利用透水框架的减速促淤机理来防护岸坡。本试验开展了四面六边透水框架和扭双工字型透水框架铺设在岸坡坡面上的试验研究,对其护岸效果、减速促於机理进行分析,了解透水框架护岸的优缺点,分析透水框架护岸的应用部位。     

一种新型可移动吊臂式清障车

在消化吸收国外产品先进技术的基础上,自主创新研制出一种吊臂既能旋转又能向后移动的清障车,在该车设计上应用了一些新技术,如软轴操纵机构,下沉式H型前支腿和四节伸缩式后支腿。