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   66篇
  免费   2篇
公路运输   10篇
综合类   17篇
水路运输   14篇
铁路运输   20篇
综合运输   7篇
  2023年   1篇
  2022年   2篇
  2021年   1篇
  2019年   1篇
  2018年   1篇
  2017年   3篇
  2016年   3篇
  2015年   6篇
  2014年   5篇
  2013年   5篇
  2012年   6篇
  2011年   6篇
  2010年   2篇
  2009年   5篇
  2008年   4篇
  2007年   4篇
  2006年   5篇
  2005年   2篇
  2004年   1篇
  2000年   1篇
  1998年   1篇
  1997年   2篇
  1994年   1篇
排序方式: 共有68条查询结果,搜索用时 31 毫秒
31.
公共交通出行者ATIS信息选择行为对ATIS实际实施效果存在显著影响。本文以大连市公共交通出行信息需求专项调查为基础,通过因子分析方法提取并定义ATIS信息因子,对公共交通相关ATIS信息进行合理分类,同时引入公共交通出行者年龄、职业、先进通讯技术使用情况等个人特征变量,建立公共交通出行者ATIS信息选择Binary Logit 模型,对公共交通出行者ATIS信息选择行为影响因素进行研究。研究结果显示公共交通出行者个人特征与ATIS信息内容特性对公共交通出行者ATIS信息选择行为存在不同程度的影响,城市交通信息服务系统的建设与运营应进一步面向公共交通出行者实现“以人为本”。  相似文献   
32.
提出了一种基于血流图与双树复数小波域傅里叶变换的红外人脸识别方法.首先利用血流模型把温谱图转换成血流图,然后将人脸血流图进行一级双树复数小波分解,保留分解后的4个低频子带并分别进行傅里叶变换,得到每个低频子带的特征矩阵,分别计算4个子带的欧氏距离并进行简单的加法融合,再用三阶近邻分类器得到最终的识别结果.为了减小算法的时间复杂度,我们对血流模型进行简化.实验结果表明,本文所提的方法有较好的识别结果.而简化的血流图相比原模型的识别率没有明显的下降,甚至某些情况下还稍高于血流模型,说明本文的方法是有效的.  相似文献   
33.
Urban transit is a complex system that contains both electrical and mechanical entities; therefore, it is necessary to construct a maintenance system for ensuring safety during high-speed driving. Expert systems are computer programs that use numerical or non-numerical domain-specific knowledge to solve problems. This research aims to develop an expert system that diagnoses the causes of failures quickly and displays measures to correct them. For the development of this expert system, the standardization of a failure code classification and the creation of a Bill of Materials (BOM) were first performed. Through the analysis of both failure history and maintenance manuals, a knowledge base has been constructed. Also, for retrieving the procedure of failure diagnosis and repair linking with the knowledge base, we have built a Rule-Based Reasoning (RRB) engine with a pattern matching technique and a Case-Based Reasoning (CBR) engine with a similar search method. Finally, this system has been developed as web based in order to maximize accessibility.  相似文献   
34.
详细介绍了故障树分析法的特点、常用符号以及分析步骤,并以S195型柴油机为例提出了对工程机械的可靠性采用故障树分析的新思路。  相似文献   
35.
Most studies that address the integration of cycling and public transport (PT) focus on developed countries and deal with multi-modal bicycle-train trips. Little is known about the integration of cycling and other main modes such as bus and metro, especially in developing countries, where entirely different socio-economic and trip making conditions prevail. The aim of this study is to model the propensity of current PT users to shift to the bicycle in access trips to bus stops, train and metro stations in Rio de Janeiro, Brazil. Interviews were conducted to collect data on the socio-economic characteristics of the interviewee, trip and spatial characteristics and self-reported barriers and motivators for bicycle use. Two binary logit models were estimated to predict the main factors affecting the propensity to use a bicycle as feeder mode to PT. The results show that socio-economic characteristics as well as barriers and motivators are important factors to explain propensity for bike and ride. The barriers’ model reveals that personal constraints, living too close to the PT boarding point, current parking conditions and public safety play a role. For the motivators’ model, changing home location, owning a bicycle, implementation of cycle ways and improvement in parking conditions are explanatory. Policy recommendations are formulated to increase bicycle ownership and improve cycling infrastructure.  相似文献   
36.
In this paper, a person-delay-based optimization method is proposed for an intelligent TSP logic that enables bus/signal cooperation and coordination among consecutive signals under the Connected Vehicle environment. This TSP logic, called TSPCV-C, provides a method to secure the mobility benefit generated by the intelligent TSP logic along a corridor so that the bus delay saved at an upstream intersection is not wasted at downstream intersections. The problem is formulated as a Binary Mixed Integer Linear Program (BMILP) which is solved by standard branch-and-bound method. Minimizing per person delay has been adopted as the criterion for the model. The TSPCV-C is also designed to be conditional. That is, TSP is granted only when the bus is behind schedule and the grant of TSP causes no extra total person delay.The logic developed in this research is evaluated using both analytical and microscopic traffic simulation approaches. Both analytical tests and simulation evaluations compared four scenarios: without TSP (NTSP), conventional TSP (CTSP), TSP with Connected Vehicle (TSPCV), and Coordinated TSP with Connected Vehicle (TSPCV-C). The measures of effectiveness used include bus delay and total travel time of all travelers. The performance of TSPCV-C is compared against conventional TSP (CTSP) under four congestion levels and five intersection spacing cases. The results show that the TSPCV-C greatly reduces bus delay at signalized intersection for all congestion levels and spacing cases considered. Although the TSPCV is not as efficient as TSPCV-C, it still demonstrates sizable improvement over CTSP. An analysis on the intersection spacing cases reveals that, as long as the intersections are not too closely spaced, TSPCV can produce a delay reduction up to 59%. Nevertheless, the mechanism of TSPCV-C is recommended for intersections that are spaced less than 0.5 mile away. Simulation based evaluation results show that the TSPCV-C logic reduces the bus delay between 55% and 75% compared to the conventional TSP. The range of improvement corresponding to the four different v/c ratios tested, which are 0.5, 0.7, 0.9 and 1.0, respectively. No statistically significant negative effects are observed except when the v/c ratio equals 1.0.  相似文献   
37.
为减少无信控人行横道处多类型冲突及其带来的交通安全问题,本文采用交通冲突指标和回归分析模型研究交通冲突的严重程度和影响因素。提出考虑驾驶员视野障碍影响的冲突指标(TTZ),结合后侵入时间(PET)和安全减速度(DST)冲突指标,量化交通冲突的严重程度;通过计算的冲突指标值,利用模糊C-均值聚类方法识别严重冲突和非严重冲突;将严重冲突和非严重冲突作为因变量,建立基于二元Logit模型的多类型交通冲突严重程度预测模型。结果表明,相较于单次冲突,多重威胁冲突的严重程度更高,其中,多重威胁冲突是严重冲突的占比为57.9%,单次冲突是严重冲突的占比为27.7%。相较于行人,非机动车的严重程度更高,其中,非机动车-机动车冲突是严重冲突的占比为45.7%,行人-机动车冲突是严重冲突的占比为35.4%。关于影响因素,机动车数量、过街等待时间、过街速度及侧面车辆合法屈服行为等因素对多重威胁冲突的严重程度具有显著影响;机动车数量、过街等待时间、过街速度及前方车辆屈服行为等因素对单次冲突的严重程度具有显著影响。  相似文献   
38.
计算机联锁进路搜索算法的分析与研究   总被引:3,自引:0,他引:3  
简述了计算机联锁系统中站场型数据结构的建立方法,通过深入研究站场型数据结构形状与二叉树的相似性,结合在实际搜索进路过程中总结的经验,提出了一种基于站场型数据结构的新的进路搜索算法。该算法是结合了二叉树、四叉链表和高度原则的新的进路搜索算法。详细论述了这种算法,并给出了完整的描述。  相似文献   
39.
柯军  向阳 《船舶》2007,(3):61-63
"三缆定位"为绞吸式挖泥船的定位方式之一,比起"钢桩定位"方式,它更适合大挖深、大风浪等恶劣工况,但其原理上更复杂,对技术要求更高."三缆定位"主要通过绞吸式挖泥船尾部的三根定位钢缆来给船舶定位.众所周知,绞吸挖泥船的施工精度,主要由船舶的定位精度来决定,所以,一个准确高效的"三缆定位"算法将是系统设计的核心.通过对"三缆定位"控制原理及过程的描述,最终实现了绞吸式挖泥船的"三缆定位".  相似文献   
40.
船舶火灾是海难事故的主要原因之一,机舱火灾在船舶火灾中占有很大比例。文章利用事件树分析法对机舱火灾事故编制事件树,由此得出事故链,并在此基础上提出预防和控制船舶机舱火灾事故的措施。  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