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21.
应用随机后悔最小化理论与随机效用最大化理论,分别建立RRM-MNL模型和RUM-MNL模型研究了出行方式选择行为。在模型参数、拟合优度方面对2个模型进行了比较,应用直接弹性分析了在交通管理措施评价方面的区别,并通过城际出行方式中的飞机、火车、长途汽车、小汽车4种出行方式数据进行实际验证。分析结果表明:相比于RUM-MNL模型,RRM-MNL模型能够描述在多属性方案选择过程中的部分补偿性决策行为和折衷效应,能更真实地反映实际出行行为选择过程;等待时间、出行时间和出行费用对飞机、火车和长途汽车3种出行方式的选择概率都具有弹性;在RRM-MNL模型中,等待时间对3种方式的弹性值分别较RUM-MNL模型的低7.30%、13.14%和7.70%。可见,对于同一属性变量,出行者具有不同的选择偏好,会表现出不同的选择行为。  相似文献   
22.
This paper presents an integrated design procedure for determination of structural arrangement and scantlings for the complete structure of small high-speed craft. The purpose of the procedure is to serve as a tool in the preliminary design stage where it enables generation of weight minimized designs with very limited effort. The design procedure is applied in a material concept study for a high-speed patrol craft. The various concepts include single skin and sandwich composites, aluminum and steel. It is demonstrated that the mass of the aluminum hull structure can be reduced from the original 11.7 tonnes to 9.6 tonnes through application of the presented design procedure. The most weight efficient material concept is a carbon-fiber foam-cored sandwich with a structural mass of 4.8 tonnes, which is about 50% less than the refined aluminum version. Through simple hydromechanic analysis, potential for fuel and CO2 emission reductions of 8% for the refined aluminum version and 27% for the carbon-fiber sandwich version in relation to the original craft are indicated.  相似文献   
23.
鉴于应急疏散者出行决策的后悔规避心理,以政府公交车、自有私家车和借用私家车三类疏散交通方式选择问题为例,选取平均运行时间、运行时间不确定性、平均等待时间和预期感知服务水平等属性变量,分别构建了基于随机后悔最小化和效用最大化的多项Logit 模型.以应急疏散意向行为调查数据为基础,表明后悔模型的模型拟合度优于效用模型,对属性变量间关系的刻画更符合实际.进一步通过弹性计算和敏感性分析,揭示出平均运行时间这一属性最为敏感.研究表明,应急疏散者是后悔规避的,其决策行为试图将后悔感知最小化,而非预期效用最大化,从随机后悔视角描述疏散决策行为更为准确.  相似文献   
24.
交通需求管理和控制与时间因素密切相关,对出行时耗的研究是出行行为分析的重要内容. 本文提出了用于出行时间分析的持续时间模型,讨论了通勤者日出行时间投入随出行者及其家庭社会经济属性、活动和出行特征变化的连续分布规律. 模型用已投入出行时间约束下出行结束的条件概率更准确地描述了出行的动态过程,从对活动与出行之间派生和竞争关系的分析,部分地反映了通勤者的时间分配行为. 分析表明,出行时间最小化的行为假设对大多数通勤者成立. 本研究为出行时耗的定量研究提供了更准确有效的分析工具,对于准确把握通勤者时间分配行为有重要意义.  相似文献   
25.
The bunker price fluctuations in recent years have severely threatened the stability of liner shipping companies’ operations. As an efficient countermeasure, the swap contract is widely adopted throughout the liner shipping industry to hedge the procurement risk resulting from the bunker price fluctuation. This paper looks at the short-term liner shipping bunker procurement problem with swap contracts (BPPSC), aiming to optimally plan the amount of bunker purchased from the spot market and the amount hedged by the swap contract for several months ahead. This BPPSC is first formulated as a bunker procurement cost mean-variance minimization (MVM) model, and is subsequently solved using a tangible two-step approach developed in this study. In the first step, the movements of the swap contract price and the spot market price of the bunker are described using a calibrated multivariate generalized autoregressive conditional heteroskedasticity (mGARCH) time series model. In the second step, the MVM model is approximated and solved by a price scenario tree constructed from the mGARCH time series model. A numerical example shows that the risk hedging strategy obtained can simultaneously control the bunker procurement cost as well as the procurement risk from price fluctuations. This article is a revised and expanded version of the abridged eight-page paper entitled ‘Optimal hedging for liner bunker procurement’ presented at ‘2015 International Conference on Logistics and Maritime Systems (LOGMS 2015)’, Hong Kong, 27–29 August 2015.  相似文献   
26.
针对某新型双电机行星耦合插电式混合动力汽车(PHEV)中发动机在起停及怠速运行状态下会导致油耗增加的问题,基于等效燃油消耗最小能量管理策略,加入发动机起停优化控制模块,以进一步改善整车燃油经济性.建立了整车动力学和传动模型并加入发动机起停优化控制模块,对ECMS能量管理策略输出的发动机及电机最优目标转矩进行重新优化分配...  相似文献   
27.
This paper develops new methodological insights on Random Regret Minimization (RRM) models. It starts by showing that the classical RRM model is not scale-invariant, and that – as a result – the degree of regret minimization behavior imposed by the classical RRM model depends crucially on the sizes of the estimated taste parameters in combination with the distribution of attribute-values in the data. Motivated by this insight, this paper makes three methodological contributions: (1) it clarifies how the estimated taste parameters and the decision rule are related to one another; (2) it introduces the notion of “profundity of regret”, and presents a formal measure of this concept; and (3) it proposes two new family members of random regret minimization models: the μRRM model, and the Pure-RRM model. These new methodological insights are illustrated by re-analyzing 10 datasets which have been used to compare linear-additive RUM and classical RRM models in recently published papers. Our re-analyses reveal that the degree of regret minimizing behavior imposed by the classical RRM model is generally very limited. This insight explains the small differences in model fit that have previously been reported in the literature between the classical RRM model and the linear-additive RUM model. Furthermore, we find that on 4 out of 10 datasets the μRRM model improves model fit very substantially as compared to the RUM and the classical RRM model.  相似文献   
28.
基于支持向量机的船舶航向广义预测控制研究   总被引:1,自引:1,他引:0  
船舶的动态性能具有大惯性、大时滞、非线性等特点,采用基于结构风险最小化原则的神经网络———支持向量机(SVM),充分发挥其可以任意逼近非线性模型的良好特性对船舶模型进行有效辨识,以此作为广义预测控制(GPC)算法中的预测模型,并加以相应的GPC算法达到保持航向的目的。仿真结果表明:SVM学习速度快,在小样本情况下具有良好的非线性建模和泛化能力;基于SVM的GPC算法在航向保持方面具有很好的控制性能。  相似文献   
29.
30.
以最小化时间表长为目标函数,对具有学习效果的两机流水车间调度问题进行研究.由于工序加工时间引入了学习效果,传统的Johnson法则和NEH启发式算法不再适用.针对该问题的NP-hard特性,提出了JNEH和MNEH两种求解问题的多项式启发式算法.计算机数据实验证明了新的启发式算法求解问题的可行性和有效性;表明了JNEH启发式算法和MNEH启发式算法对小规模问题求解的精度更高、稳定性更好;同时证明MNEH启发式算法对求解大规模问题具有比传统算法更好的寻优性能和鲁棒性.  相似文献   
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