基于灰色关联分析的铁路工程项目投资方案研究

铁路建设投资额较大,对投资方的资金要求较高,如何决策不仅影响项目的可行性,也直接关系到投资方的投资决策.本文站在铁路投资方角度,利用灰色关联分析法对影响铁路投资估算额度的项目技术标准、工程地质条件、桥隧比、所经地区经济发展程度、材料价格水平等特征进行分析,建立了项目决策与投资估算的灰色关联度分析模型.通过该分析模型,投...     

长江干线中下游航道枯水位变异特性研究*

为深入认识长江中下游枯水情势发生的复杂变化,采用水文变异诊断系统对宜昌、沙市、汉口、大通等重要控制站点的枯水位进行分月变异特性研究。结果表明：宜昌站枯水期发生中、强的变异;沙市站发生强、巨的变异,变异程度最强;汉口站发生纯随机（无变异）至强变异;大通站发生纯随机（无变异）至中变异;各站点10—11月均发生向下的变异,与2003年相比,2021年汛后宜昌、沙市、汉口站水位（流量）分别下降了0.76 m（6 000 m3s）、2.82 m（7 000 m3s）、1.66 m（1万m3s）,大通站则未发生明显变化,其对航运的潜在影响需加强分析。     

上海内河货运量的组合预测

内河航运是综合交通运输系统中不可缺少的运输方式,存在着很大的潜在优势.定量地把握未来内河运输的发展趋势,具有重大的现实意义.通过利用时间序列模型、logistic曲线与自回归模型等,对2010-2015年的上海内河货运量进行预测.在此基础上,对不同模型赋予不同的权重,建立了组合预测模型.研究表明:未来上海内河货运量将持续稳定地增长.为提高预测的精度,有必要综合地使用多个预测方法.     

区域最佳及区域准最佳序列偶的研究

随着最佳信号的广泛应用,只用一个序列来形成最佳信号限制了最佳信号的存在空间,两个序列组成的序列偶成为研究热点。根据有关序列偶及零／低相关区域序列的概念,定义新的序列形式,即区域（或准）最佳自相关序列偶。给出并证明了相应的变换性质．最后论证了此类信号的存在．     

红外序列图像帧间匹配算法研究

文章在现有单帧图像检测算法的基础上,提出了一种可同步跟踪运动目标的帧间匹配算法。算法采取对相邻两帧间像素点匹配,匹配过程与当前两帧外的其余帧无关,把匹配结果兴趣区域像素点对应的另一个全零矩阵位置值赋为1,顺利输入检测后的单帧图像,执行匹配操作,实时形成目标运动轨迹。该算法结构简单、存储量少、计算速度快,硬件平台要就低,可有效地完成对多个目标、交叉目标、迎头目标的检测与跟踪。根据仿真和实拍照片的试验,证实了算法理论上的优点,有较高的应用价值。     

静水压力作用下环肋圆柱壳自由振动基频的数值拟合公式

圆柱壳是航空、宇航飞行器和海洋工程中大量采用的结构形式,它的动态特性一直受到广泛的研究.本文基于Flugge经典壳体理论和正交各向异性方法,求解了静水压力作用下薄膜简支边界环肋圆柱壳的自由振动基频,给出了基频的最低包络面.采用序列二次规划方法(SQP),对基频进行数值拟合,给出了回归公式及其误差分布,大部分拟合点的相对误差都在±10%以内.本文提出的公式具有较高的精度,可为实际设计提供参考.     

基于图像序列区域混沌特征的海面舰船目标检测算法

为了检测复杂海面背景中的舰船目标,提出了一种基于图像序列区域混沌特征的目标检测新算法,算法利用小数据量法计算图像序列区域的最大Lyapunov指数,分析运动目标存在时背景信号混沌特征的变化,并利用混沌特征的变化差别检测淹没在混沌背景信号中的目标信号,最后对100帧图像进行了目标检测.计算结果表明:新算法检测率为100%,虚警率为5%,检测结果优于利用统计分析方法的结果.     

SMO算法在邮件过滤中的应用

针对传统的支持向量机(SVM)算法在速度方面的缺陷,本文提出将序列最小优化(SMO)算法引人到垃圾邮件过滤系统中,实验结果证明,该模型训练时间快,过滤效果好.     

Genotypic diagnosis of long QT syndrome by analysis of candidate genes

Objective To diagnose 6 LQTS families by genetic analysis. Methods A total aof 6 LQTS pedigrees with 43 family members were brought together for genetic diagnosis by using short-sequence tandem-repeat (SIR) markers or sequencing. Genomic DNA was extracted from blood samples by standard procedure. STR markers or KCNQ1, KCNH2 and SCN5A were amplified. The haplotype analysis for LQTS was performed. If the family got the negative haplotype analysis, the sequencing was performed. Results LQTS patients were always linkaged with the SCNSA gene in family 1. KCNH2 was linkaged with the disease in family 2 to 5.21 gene carriers were identified from these 5 families. A mutation (A561V-KCNH2) was only found in the proband of family 6 and an SNP (G1691A) was found in all the members of the family. Conclusion Genetic diagnosis can not only improve presymptomatic diagnosis,bnt also provide the basis for personal therapy and research on disease-causing mutations.     

Construction of expression vector for NT4-ADNF-9 fusion gene

Objective To construct the prokaryotic expression vector bearing fusion gene NT4-ADNF-9 and lay foundation for further study on genetic therapy of neuraseusory deafness. Methods By means of asymmetrical prince/ template, double stranded eDNA of activity dependent neurotrophic factor-9 (ADNF-9) was obtained, which included restriction enzymes sites on the two extremities. ADNF-9 eDNA was ligated to the signal and leader peptides of nenrotrophin 4 (NT4), and the fusion gene was named NT4-ADNF-9. Then it was suheluned into prokaryotic expression vector pBV220, and called pBV220/ NT4-ADNF-9. Results Evidences of DNA sequence analysis and restrtction enzymes digestion showed that we recombined ADNF-9 eDNA to the 3'terminal of the signal and leader peptides of NT4, and the fusion gene was subcluned into pBV220 successfully. Bioactivity of the products was proved that it could support the cell survival and neurite growth in the primary cultures of dorsal root ganglia (DRG) of embryonic day-8 cbicken neurons as compared to the control. Conclusion Prokaryotic expression vector pBV220/NT4-ADNF-9 can be constructed successfully and the bioactivtty is satisfactory.