提速改线工程路基施工质量控制

介绍为达到铁路提速要求,改线工程和改善设备状态是关键。施工必须统一思想,明确目标,加强管理,严格标准,控制质量,特别对改移较大的曲线地段路基工程,采取多种措施、优质、出色地完成了施工任务。     

路堤荷载下管桩复合地基设计理论的试验研究

介绍了管桩复合地基在某高速公路软基试验工程中的应用,并简单分析了其加固效果,进而结合已有的研究成果,提出了一套路堤下刚性桩复合地基的设计理论。通过工程实践表明,该设计理论具有在工程实践中推广运用的价值。     

连续刚构桥的群桩基础计算模型研究

群桩基础是连续刚构最常用的基础形式之一，分析探讨了群桩基础的几种建模方法，给出了建模思路和参数取值。结合苏通大桥辅航道桥预应力混凝土连续刚构的工程需要，提出了考虑群桩基础与上部结构共同工作的计算模型，并将计算结果与不考虑桩基的模型计算结果进行了对比分析，计算方法对类似工程有直接参考价值。     

计算机仿真研究平整度指标与路面状态的定量关系

参照平整度测量仪的结构及原理,用MATLAB科学计算语言对平整度的测量过程进行了模拟仿真,分析平整度指标与路面状态参数之间的定量关系,并阐述了此项研究对提出新的摊铺机自动找平系统的控制方式,提高路面平整度具有的实际意义与可行性.     

船载动中通卫星天线系统的应用

本文介绍了船载动中通卫星通信天线系统在实船上的应用,希望为船舶行业设计者提供一定参考。     

Development and calibration of a long-distance passenger traffic assignment model

This paper studies the assignment of long-distance passenger traffic on a highway corridor network. First, we propose a traditional model for the long-distance traffic assignment considering interactions with local commuter traffic. It addresses the effect of local networks on highway corridors. An iterative algorithm is developed to solve for the exact solution. Then, to address the potential computational issues that arise therein, a decomposition method is proposed by introducing a new concept of corridor elasticity. An assignment procedure for long-distance passenger traffic is developed accordingly. Numerical tests show that the proposed decomposition method makes significant improvements in computational performance at a small loss of optimality. This decomposition method well approximates the exact assignment from the traditional formulation, especially when the highway corridors are near-saturation. The proposed decomposition method appears practical for application.     

车用摇枕铸钢件浇冒口切割打磨自动化系统的设计

铸钢件毛坯浇冒口切割及打磨时存在噪音大、弧光强烈、粉尘污染严重,增加了人工操作时的劳动强度,并严重影响操作人员的身体健康。本文针对这些问题,拟以铁路车辆摇枕铸钢件浇冒口切割及打磨为例,提出了单工位打磨、流水线式多工位合作的打磨清理方案,设计了自动化打磨单元,实现机械化、自动化操作,既提高了铸件打磨清理的质量和生产率,又大大改善了工人操作条件,减轻了工人的劳动强度,达到了“以机代人”的目的,对铸钢件实现绿色化乃至智能化生产具有重要意义。     

海洋平台海洋平台常用流量计的选型分析

文章主要介绍了海洋平台常用流量计的原理和特点,结合海洋平台的特点叙述了流量计选型时的注意事项,并给出了海洋平台常用流量计的选型原则和计算方法,为海洋平台选出最合适的流量计提供了一种方案。     

海上风电大直径单桩基础固有频率影响因素的数值分析

针对海上风电整机结构其低阶固有频率的控制问题,基于有限元分析技术开展小直径桩土相互作用的数值模拟分析,与试验结果、API规范计算结果进行对比,验证了数值模型的适用性,分析大直径单桩结构桩内土芯、冲刷深度、表层土置换措施对整机固有频率的影响,结果表明,基于有限元实体单元计算所得一、二阶整机固有频率要明显大于传统p-y方法计算结果;桩内土芯对一、二阶整机固有频率影响很小;在一定范围内,随着泥面冲刷深度的增加,一、二阶固有频率降低不明显,认为传统p-y方法对于大直径单桩的适用性有待研究;在实际工程设计中,桩内土芯的影响可忽略;对于大直径单桩,在一定范围内可以忽略冲刷的影响。     

Automatic outer surface extraction of femoral head in CT images

Computer-aided hip surgery planning and implant design applications require accurate segmentation of femoral head and proximal acetabulum. An accurate outer surface extraction of femoral head using marching cubes algorithm remains challenging due to deformed shapes and extremely narrow inter-bone regions. In this paper, we present an automatic and fast approach for segmentation of femoral head and proximal acetabulum which leads to accurate and compact representation of femoral head using marching cubes algorithm. At first, valley-emphasized images are constructed from original images so that valleys stand out in high relief. Otsu’s multiple thresholding technique is applied to seperate the images into bone and non-bone classes. Region growing method and threedimensional (3D) morphological operations are performed to fill holes in the bone. In the reclassification process, the bone regions are further segmented, and the boundaries of the bone regions are further refined based on Bayes decision rule. Finally, marching cubes algorithm is applied to reconstruct a 3D model and extract the outer surface of femoral head and proximal acetabulum. Experimental results show that this method is an accurate segmentation technique for femoral head and proximal acetabulum and it can be applied as a tool in medical practice.