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261.
出行前停车诱导系统中两阶段停车选择方法 总被引:3,自引:0,他引:3
为了同时解决机动车辆出行过程中停与行的问题,减少车辆巡泊产生的无效交通,提高出行效率,提出了服务于出行前停车诱导系统的两阶段停车选择方法.第一阶段是以停车场距目的地的步行距离、停车设施类型、有效停车泊位数、停车费用等4项指标对候选停车场进行初选;第二阶段为组合选择过程,以步行距离最短、停放可行性最高、停放成本最低、停放安全性最高、驾车至停车场行驶时间最短为优化目标,采用基于模糊偏好的多目标决策模型,为用户提供各候选停车场的决策排序.该方法求解效率高,且充分考虑驾车者意愿,适用于出行前的停车诱导系统. 相似文献
262.
The intention of this paper has been to raise some doubts about the extent to which the control of congestion is understood, not as an engineering problem, but as a socio‐economic one concerned with making the most appropriate use of scarce resources. Despite some doubts, it seems that the basic theory, as applied to a highly simplified situation, is technically correct. What is much less clear, however, is the extent to which the acceptance of this analysis as a basis for policy making in the real world is justified. Even if, qualitatively, its implications are correct, there are significant quantitative uncertainties. Given that governments, local and national, are still pouring considerable sums of money, both through subsidies and investment, into the relief of congestion, it is desirable to change this state of affairs. There seems to be ample scope for the transport economist, the transport planner and the transport engineer to contribute to a debate which has a long and, in places, distinguished pedigree, but where the outcome is as yet considerably outstripped by the importance and complexity of the problems which must be solved. 相似文献
263.
This paper presents a framework to evaluate the logistics performance of intermodal freight transportation. Fuzzy set techniques are applied to assess the logistics performance within the decision process of freight operators. Using a fuzzy‐based approach, fuzzy‐AHP is applied to assess the criteria by different judgment procedures. Consequently, fuzzy‐MCDM is used to assess operators' perception of the logistics performance via proper assignment of numerical scores. The subjective judgments for hierarchical criteria are transformed into fuzzy degrees of score. The methodology provides an alternative approach to facilitate the importance of a set of performance criteria. It can also entail use of improved corresponding parameters to develop a better freight transport system. 相似文献
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With the approach of introducing the conceptions of mental account and mental budgeting into the process of travelers’ route choice, we try to identify why the usages of tolled roads are often overestimated. Assuming that every traveler sets a mental account for his/her travel to keep track of their expense and keep out-of-pocket spending under control, it addresses these questions such that “How much money can I spend on the travel?” and “What if I spend too much?”. Route tolls that exceed the budget are much more unacceptable compared to those within budget due to the non-fungibility of money between different accounts. A simple network with two nodes and two routes is analyzed firstly, the analytical solutions are obtained and the optimal road tolls supporting the user equilibrium as a system optimum are also derived. The proposed model is then extended to a generalized network. The multiclass user equilibrium conditions with travel mental budgeting are formulated into an equivalent variational inequality (VI) problem and an equivalent minimization problem. Through analyses with numerical examples, it is found that the main reason that the usages of high tolled roads are often overestimated is due to the fact that travelers with low and moderate out-of-pocket travel budget perceive a much higher travel cost than their actual cost on the high tolled roads. 相似文献
268.
本文分析了按常规土工试验方法制备试样测定盐渍土基本性质指标所存在的问题,探讨了盐渍土主要是硫酸盐盐渍土的土样制备方法。 相似文献
269.
为提高白车身轻量化设计效率,提出了一种试验设计与PSI决策相结合的轻量化设计策略.首先对白车身基本静-动态性能和正撞安全性能进行有限元分析,并通过车辆正撞试验验证有限元模型的准确性.然后采用贡献度分析对白车身前端结构进行设计变量筛选.接着通过试验设计获得白车身前端结构轻量化备选解.最后采用PSI法对众多备选解进行多目标... 相似文献
270.
动力吸振器被广泛用于船舶、飞机和汽车等工业领域。在结构振动控制中,为了最大限度地发挥吸振器的耗能减振作用,需要寻找吸振器的最优参数,即最优频率比、最优阻尼比和最优质量比,使得结构在不同的频率激励下获得最好的减振效果。文章将基于进化算法的多目标优化技术与多属性决策方法联合运用,针对主系统存在阻尼的减振系统,研究了动力吸振器的优化和决策问题。对于多目标优化问题,采用改进的非支配解排序的多目标进化算法(NSGAII),求出Pareto最优解,由这些Pareto最优解构成决策矩阵,使用客观赋权的信息熵方法对最优解的属性进行权值计算,然后用逼近理想解的排序方法(TOPSIS)进行多属性决策(MADM)研究,对Pareto最优解给出排序。文中给出了4个设计参数、3个目标函数的动力吸振器优化设计算例。 相似文献