悬臂浇筑连续梁施工技术探讨

近年来随着悬臂浇筑预应力混凝土连续梁桥在我国快速发展,对设计和施工各方面提出了很高的要求.文中根据多座预应力连续梁悬臂浇筑施工的实践经验,总结了悬臂浇筑临时锚固、合龙段施工及线形控制等方面的关键技术.     

Wind pressure distribution and wind-induced dynamic response for spatial groined latticed vaults

The wind pressure distribution and wind-induced vibration responses of long-span spatial groined latticed vaults (SGLVs) were numerically simulated, which always are ones of the most important problems in the structural wind resistance design. Incompressible visco-fluid model was introduced, and the standard k-εtwo equation model and semi-implicit method for pressure linked equation (SIMPLE) were used to describe the flow turbulence. Furthermore, the structural dynamic equation was set up, which is solved by Newmark-β method. And several sort of wind-induced vibration coefficients such as the wind-induced vibration coefficient corresponding to the nodal displacement responses and wind loads were suggested. In the numerical simulation where the SGLV consisting of the cylindrical sectors with different curved surface was chosen as the example,the influence on the relative wind pressure distribution and structural wind-induced vibration responses of the closed or open SGLV caused by such parameters as the number of cylindrical sectors, structural curvature and the ratio of rise to span was investigated. Finally, some useful conclusions on the local wind pressure distribution on the structural surface and the wind-induced vibration coefficients of SGLV were developed.     

Joint distortion model for progressive image transmission using error correcting arithmetic codes

A novel joint source channel distortion model was proposed, which can essentially estimate the average distortion in progressive image transmission. To improve the precision of the model, the redundancy generated by a forbidden symbol in the arithmetic codes is used to distinguish the quantization distortion and the channel distortion, all the coefficients from the first error one to the end of the sequence are set to be a value within the variance range of the coefficients instead of zero, then the error propagation coming from the entropy coding can be essentially estimated, which is disregarded in the most conventional joint source channel coding （JSCC） systems. The precision of the model in terms of average peak-signal-to-noise has been improved about 0.5 dB compared to classical works. An efficient unequal error protection system based on the model is developed, and can be used in the wireless communication systems.     

公路建设环境保护与绿色施工

对公路建设施工造成的环境污染及其危害性进行了分析,提出切实可行的文明施工、防止污染、新科技环保等综合措施,坚持可持续发展的科学发展观,发展文明施工、绿色施工。     

利用NI Multisim软件的MCU模块进行《单片机》课程仿真实训及教学的研究

本文分析了单片机教学及实训中易出现的问题,阐述了利用Multisim10的MCU模块进行计算机仿真教学和实训的思路和方法.     

煤系地层公路高切坡稳定性评价

在山区修建公路不可避免地需要进行高切深挖,往往会形成大量的高切坡,边坡岩体原有应力平衡被打破,为高切坡的失稳创造了地质条件。以两巫公路(巫山及巫溪)K 90+310~K 90+370段煤系高切坡为研究对象,利用赤平极射投影法、有限元ANSYS法对高切坡整体和局部稳定性做出了评价。研究表明,坡体主控结构面对岩质高切坡的整体稳定性起控制作用;煤夹层对岩质高切坡的局部稳定性起控制作用。建议采用锚杆喷射混凝土-挂网来加固坡体整体,用锚索-格构梁和劈裂注浆联合法来加固坡体局部。     

贵阳市公交线两规划方法研究

贵阳是山地城市,城市路网、交通结构与居民出行方式特殊,公交的服务水平、现状存在问题及发展方案有别于其他城市,故传统的公交线网规划方法在贵阳存在一定的局限性.本文通过分析当前运用广泛的层次规划法,结合贵阳公交的现状及发展趋势,在满足居民出行需求的基础上,提出了基于公交客流的线网规划方法.     

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应用整数规划研究航运集装箱路径选择问题,并将重箱和空箱统一在一个系统中研究。在本文模型中,以集装箱运输总利润最大化为目标函数,利润是重箱运输利润减去重、空箱运输成本。约束条件考虑到满足空集装箱需求和重集装箱需求、航线运输能力限制及空箱供给数量等。应用LINGO9.0求解模型,并通过数值仿真来证明不同参数影响下的调运策略。本文旨在为船公司提供合理的航运集装箱运输方案,从而降低船公司的集装箱运输成本,实现船公司集装箱运输效益最大化。     

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提出了一种应用于智能交通监控系统的运动目标识别和跟踪方法。针对帧间差分提取运动目标的缺陷与不足,提出了一种基于冗余小波变换的运动目标识别算法,即直接在冗余小波变换域提取运动区域,从而检测出运动目标。对于检测出来的运动目标,本文对mean-shift算法进行了改进,采用自适应mean-shift算法,对目标进行跟踪。实验结果表明,本文提出的算法可以有效地提取运动目标,即使目标与背景具有较高的相似度,也可以较准确的提取出前景运动信息,效果要好于传统的帧差法;跟踪目标准确度高,不受目标大小变化的影响。本算法具较高的实用价值和应用前景。     

矿山法海底隧道废水排水系统设计实践

以青岛胶州湾海底隧道工程为依托,对废水系统排水能力的确定、废水提升方案的选择及废水泵房优化设计等方面进行分析,探讨矿山法海底隧道废水排水系统的主要关键技术。主要结论如下： 1）废水排水能力确定的关键在于隧道的结构渗漏水的定量,常规的水下隧道的结构渗漏水量数据不一定适用于海底隧道,必须实际测量后确定; 2）废水提升方案关系到排水的经济性和安全性,核心在于选取安全可靠的水泵类型; 3）废水泵房优化主要从废水池有效容积、结构设计及设备检修等方面进行展开分析; 4）矿山法海底隧道废水排水系统的设计,必须从隧道实际情况出发,综合考虑各类影响因素,以达到安全、经济的设计目标。