首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   133篇
  免费   3篇
公路运输   12篇
综合类   24篇
水路运输   43篇
铁路运输   27篇
综合运输   30篇
  2022年   2篇
  2021年   3篇
  2020年   4篇
  2019年   2篇
  2018年   4篇
  2017年   2篇
  2016年   2篇
  2015年   7篇
  2014年   7篇
  2013年   11篇
  2012年   10篇
  2011年   6篇
  2010年   5篇
  2009年   10篇
  2008年   6篇
  2007年   16篇
  2006年   9篇
  2005年   7篇
  2004年   6篇
  2003年   10篇
  2002年   1篇
  2001年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
排序方式: 共有136条查询结果,搜索用时 552 毫秒
81.
2007年8月上旬,南通航运职业技术学院出国(境)考察团对新加坡南洋理工学院等国际知名学府进行了考察。考察的主题是办学理念、办学特色、管理经验以及产学研结合、科技创新与成果转化等方面。通过考察,考察团对新加坡南洋理工学院先进的办学理念、创新的办学特色、高效的管理运行机制印象深刻,并深受启发,认为其对我国高等职业院校发展办学特色、提高人才培养工作水平有许多可资借鉴之处。  相似文献   
82.
随着信息化的发展,智能驾驶技术应用前景广阔。轨迹跟踪控制作为智能驾驶技术中的一环,受到越来越多的关注。文章介绍了智能汽车的运动学以及动力学模型,详细阐述了目前常用的几种跟踪控制方法的理论推导,分析了其各自的适用场景及优缺点。从而可知,无论哪一种控制方法都有其弊端,建模方法以及行驶速度的不同,都会影响控制效果。因此,需要结合实际情况进行改进,使智能汽车的控制更有适用性。  相似文献   
83.
获取道砟颗粒廓形是研究有砟轨道道床力学性能及开展仿真分析的基础。针对传统图像处理中利用边缘检测算法获得道砟二维廓形信息的不足,提出追踪提取算法。采用数码相机和计算机技术搭建图像采集平台,通过颜色空间转化、二值化处理、边界追踪和数据优化等步骤实现了道砟二维廓形的提取。算法特点在于,提取的道砟颗粒二维廓形数据为有序的点列,廓形曲线连续且闭合良好,检测出来的边缘是单像素宽,通过使用游标卡尺测量证明实际廓形的最大粒径在考虑测量误差及精度的条件下二者数值基本相同。同时,基于前期学者对棱角指数的算法对本文提取廓形进行相应计算并与实测值比较,数值基本吻合,从而说明本算法在一定误差及精度条件下的有效性与可靠性。  相似文献   
84.
In this paper we describe commuting trends in the Netherlands in the past decade and examine the influence of urban form and travel accessibility on commuting journeys over time on the basis of data from the Dutch National Travel Survey. Exploratory analysis is performed to identify changes in commuting participation, departure time, commuting time, commuting distance and the modal split. Regression analysis and choice models are used to examine the influence of the built environment on commuting parameters over time. The results indicate that urban form has consistently influenced the parameters of commuting journey in the Netherlands in the last 10 years. However, the trend of the influence is unique for each commuting model. Some influences have become less significant in the last decade and some have become stronger.
Kees MaatEmail:
  相似文献   
85.
Policymakers often seek to increase the visibility of plug-in electric vehicle (PEV) chargers in public locations in effort to build familiarity and interest in PEVs. However, it is not clear if the visibility of public charging stations actually has an impact on PEV demand. The purposes of the present study are to (1) assess the current levels of visibility for public PEV charging infrastructure within Canada and (2) identify whether or not a statistically significant relationship exists between consumer awareness of public charging infrastructure and interest in purchasing a PEV. We use data collected from a sample of 1739 Canadian new-vehicle buyers in 2013. About 18% of Canadian respondents have seen at least one public charger, while the proportion is highest in British Columbia (31%). We find a significant bivariate relationship between public charger awareness and PEV interest. However, when controlling for multiple explanatory variables in regression analyses, the relationship is weak or non-existent. While perceived existence of at least one charger exhibits no significant relationship with PEV interest, perceived existence of multiple chargers can have a weak but significant relationship. Thus, public charger awareness is not a strong predictor of PEV interest; other variables are more important, such as the availability of level 1 (110/120-volt) charging at home.  相似文献   
86.
Recent years saw a continuing shift in labour force composition, e.g. greater participation of women and a prominent rise in part-time workers. There are as yet relatively few recent studies that examine systematically the influences on the travel of employed adults from such perspectives, particularly regarding possible transport disadvantages of the fastest growing segments of workers. A robust analysis requires systematic data on a wide range of explanatory variables and multiple travel outcomes including accessibility, mobility and trip frequency for different trip purposes. The UK NTS data does meet the majority of this demanding data requirement, but its full use has so far been hampered by methodological difficulties. To overcome complex endogeneity problems, we develop novel, integrated structural equation models (SEMs) to uncover the influences of latent land use characteristics, indirect influences on car ownership, interactions among trip purposes as well as residents’ self-selection and spatial sorting. This general-purpose method provides a new, systematic decomposition of the influences on travel outcomes, where the effects of each variable can be examined in turn with robust error terms. The new insights underline two direct policy implications. First, it highlights the contributions of land use planning and urban design in restraining travel demand in the 2000s, and their increasing influence over the decade. Secondly, it shows that there may still be a large mobility disadvantage among the fastest growing segments of workers, particularly in dense urban areas. This research further investigates trend breaking influences before and after 2007 through grouped SEM models, as a test of the methodology for producing regular and timely updates regarding the main influences on personal travel from a system level.  相似文献   
87.
介绍了法国、德国铁路GSM-R通信系统考察情况,以及一点体会,提出建议,希望能起到抛砖引玉的作用.  相似文献   
88.
数字化直接序列扩频接收机设计与实现   总被引:1,自引:0,他引:1  
沈锋  黄平  徐定杰 《中国航海》2006,(4):51-53,77
介绍了一种数字化DS/BPSK导航接收机设计方案与实现。该接收机采用了基于FPGA的硬件设计,结合数字信号处理算法完成信号的捕获、跟踪、位置解算。捕获采用大步进串行捕获方案,采用Tong算法判决策略,伪码跟踪采用全数字超前-滞后跟踪环(DDLL),载波跟踪采用全数字Costas环(DPLL)。最后对这种设计方案进行了试验。  相似文献   
89.
基于自组织神经网络的多目标跟踪方法   总被引:2,自引:0,他引:2  
本文陈述了多维Kohonen网络和网络的学习算法,提出了一种使用多维Kohonen网络求解多目标跟踪问题的神经网络方法。仿真结果表明Kohonen网络能够用于求解多目标跟踪问题,克服了传统方法的组合爆炸问题,提高了跟踪速度和精度。  相似文献   
90.
对持续3个月的ISM规则世界性大检查作认真分析,对船舶管理缺陷、船舶滞留、安全文化及防污染问题提出看法及改进措施。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号