高速公路交通流的分形维数与相空间重构预测

对成渝高速公路短时交通流通过计算不同时间尺度下Hurst指数而等到其相应的分形维数,结果表明,时间间隔越短的交通流,其分形维数越大,结构越复杂.由于时间间隔越短的交通流随机性大和复杂的结构,所以预测也就越困难.提出了一种新的基于相空间重构和移动平均相结合的预测方法——移动平均最近邻域法,从理论与实际数据两方面分析和验证了该方法对短时交通流预测的有效性.     

多锤头碎石化技术在旧砼路面改造中的应用

结合所参与的一条试验路,通过沉降、弯沉、回弹模量等多个检测指标,以及采用面波和雷达等先进的检测仪器,论证评价了多锤头破碎技术.对多锤头破碎技术在旧砼路面改造破碎过程中的应用进行了全面深入的探讨,为旧砼路面的改造提供了有力的科研、设计及施工依据.     

移动荷载作用下连续粘弹性基础支承无限长梁的有限元分析

把无限长梁、连续粘弹性基础和移动荷载视为一个系统，并将该系统进行有限单元离散，梁单元的弯曲形函数采用Hermitian三次方插值函数，利用弹性系统动力学总势能不变值原理，得到单元的刚度矩阵、质量矩阵、阻尼矩阵和节点荷载列阵，建立该系统的振动方程组；再用Wilsonθ法求解该振动方程组，得到梁中点的位移时程曲线。举例分析了基础的粘弹性特性和梁的抗弯刚度对梁动力响应的影响。计算结果表明：增大基础的弹性系数、阻尼系数和梁的抗弯刚度都有利于减小梁的动力响应。     

多车场车辆优化调度模型及算法

针对多车场满载运输问题的特征，提出了多车场车辆优化调度的数学模型，设计了求解该问题的启发式算法，应用结果表明，该算法是可行的。     

多发性骨髓瘤48例误诊分析

48例多发性骨髓瘤入院时误诊为骨骼。肾脏、肝脏.造血和神经系统等疾病,而本身被漏诊,漏、误诊率66.7%。临床分析表明,40岁以上病人如有:进行性骨痛;原因不明的贫血或红细胞缗钱现象;血沉明显增快或高球蛋白血症;反复感染,持续性蛋白尿或不伴高血压的肾衰;扁平骨肿块;脊髓压迫或神经根受损等情况时,应疑及本病,需进一步检查明确诊断。     

ANALYSIS OF SPECTRAL PHASE ENCODING OCDMA SYSTEM WITH PSEUDORANDOM CODING

Introduction　　In a spectral phase encoding optical code- divi-sion multiple- access ( SPE- OCDMA) system,thesuccess of system operation depends on the effec-tive suppression of multiple- access interference( MAI) ,which is achieved primarily through pseu-dorandom coding[1～ 3 ] .In Ref.[1 ],SPE- OCDMAsystems with pseudorandom coding were firstlydiscussed,but the authors ( J.A.Salehi et al.)modeled the MAI as Gaussian random process andanalyzed the system performance under the as-su…     

多发性骨髓瘤预后因素的COX模型分析

为探讨影响多发性骨髓瘤患者生存的危险因素，用ＣＯＸ模型对７１例多发性骨髓瘤患者的１５项临床及实验室指标进行了单、多因素回归，结果筛选出两项显著性指标，即血肌酐及尿素氮水平升高是影响骨髓瘤预后的危险因素。并进一步分析了骨髓瘤肾功损害与诸因素的关系，发现骨髓瘤所造成的继发性损害如贫血、感染、高血钙、尿ＢＪＰ（本一周蛋白）均与肾功能不全有关，提示可用肾功能损害程度综合反映骨髓瘤患者的生存预后。     

Numerical simulation of aerodynamic performance of a couple multiple units high-speed train

In order to determine the effect of the coupling region on train aerodynamic performance, and how the coupling region affects aerodynamic performance of the couple multiple units trains when they both run and pass each other in open air, the entrance of two such trains into a tunnel and their passing each other in the tunnel was simulated in Fluent 14.0. The numerical algorithm employed in this study was verified by the data of scaled and full-scale train tests, and the difference lies within an acceptable range. The results demonstrate that the distribution of aerodynamic forces on the train cars is altered by the coupling region; however, the coupling region has marginal effect on the drag and lateral force on the whole train under crosswind, and the lateral force on the train cars is more sensitive to couple multiple units compared to the other two force coefficients. It is also determined that the component of the coupling region increases the fluctuation of aerodynamic coefficients for each train car under crosswind. Affected by the coupling region, a positive pressure pulse was introduced in the alternating pressure produced by trains passing by each other in the open air, and the amplitude of the alternating pressure was decreased by the coupling region. The amplitude of the alternating pressure on the train or on the tunnel was significantly decreased by the coupling region of the train. This phenomenon did not alter the distribution law of pressure on the train and tunnel; moreover, the effect of the coupling region on trains passing by each other in the tunnel is stronger than that on a single train passing through the tunnel.     

基于ABAQUS的盾构切刀群模拟切削研究

为了解决复合式土压平衡盾构(earth pressure balance)在实际施工时常出现刀盘结饼、刀箱堵塞等工程问题,从刀群切削效果角度研究刀盘刀具布置的合理性,采用切刀群和滚刀群的动态切削模拟方法,提出土体质量变化和刀盘受载的评价指标,得到以下结论:软土地质下切刀群存在内偏角时的切削效果明显好于无内偏角的情况;掘进地层地质较软时宜采用小切刀切削重叠量,地质较硬时宜采用大切刀切削重叠量。刀群布置的研究过程为实际工程问题的解决提供了方法,数值仿真结果为复合式土压平衡盾构刀盘刀群的组合设计提供了参考。     

动车组牵引传动三电平逆变器SVPWM控制

提出了适用于高速动车组牵引传动中三电平逆变器控制的空间矢量脉宽调制(SVPWM)控制策略.动车组起动和低速阶段要求转矩脉动小,采用恒定最大开关频率控制的三电平异步调制策略;高速时,要求逆变器在低开关频率下的良好谐波性能,在中高速和高速分别采用4脉冲和2脉冲同步调制策略.仿真结果与实测动车组牵引电机电压波形进行了对比,证实了SVPWM控制策略的有效性.