In this research,optimization models for air freight forwarders that considers renting air containers and assigning cargos to containers are proposed with the objective to minimize total operating cost.The transportat...In this research,optimization models for air freight forwarders that considers renting air containers and assigning cargos to containers are proposed with the objective to minimize total operating cost.The transportation network consists of an intermediate hub which is used for unloading and sorting cargos before the delivery to destinations.The models provide operational decision at both regions and hub.The proposed models are formulated based on the cargo demand information provided by the forwarders’customers.The models are applicable for air freight forwarders to plan their bookings with airlines with either regular shipment or irregular demand of cargos during peak season.The proposed models take into account constraints related to weight and volume limits of containers and also on constraints related to available containers.The computational results show that the proposed models can be used for practical air cargo planning.A two-phase method is also proposed in order to generate solutions for large instance data sets.The obtained results from the paper also suggest new research directions in this field.展开更多
针对轮毂直驱电动汽车簧下质量较大和电动机不平衡电磁力的问题,进行了轮毂直驱空气悬架(hub direct drive air suspension,HDD-AS)系统垂向动力学特性分析.构建了轮毂电动机与带附加气室空气悬架耦合模型,当轮毂直驱空气悬架系统在路...针对轮毂直驱电动汽车簧下质量较大和电动机不平衡电磁力的问题,进行了轮毂直驱空气悬架(hub direct drive air suspension,HDD-AS)系统垂向动力学特性分析.构建了轮毂电动机与带附加气室空气悬架耦合模型,当轮毂直驱空气悬架系统在路面随机激励与电动机不平衡电磁力耦合作用下,附加气室容积和阻尼系数改变时,分析了电动机偏心距、电动机不平衡电磁力、簧上质量加速度、悬架动行程、轮胎动载荷和簧下质量加速度均方根值的变化规律,研究了附加气室容积和阻尼系数变化对电动机偏心距、簧上质量加速度、悬架动行程、轮胎动载荷和簧下质量加速度的频域影响.结果表明:附加气室容积和阻尼系数的变化对轮毂直驱空气悬架系统悬架性能和轮毂电动机振动具有较大的影响.展开更多
基金This work was supported by an SIIT Young Researcher Grant under Contract No.SIIT 2015-YRG01。
文摘In this research,optimization models for air freight forwarders that considers renting air containers and assigning cargos to containers are proposed with the objective to minimize total operating cost.The transportation network consists of an intermediate hub which is used for unloading and sorting cargos before the delivery to destinations.The models provide operational decision at both regions and hub.The proposed models are formulated based on the cargo demand information provided by the forwarders’customers.The models are applicable for air freight forwarders to plan their bookings with airlines with either regular shipment or irregular demand of cargos during peak season.The proposed models take into account constraints related to weight and volume limits of containers and also on constraints related to available containers.The computational results show that the proposed models can be used for practical air cargo planning.A two-phase method is also proposed in order to generate solutions for large instance data sets.The obtained results from the paper also suggest new research directions in this field.
文摘针对轮毂直驱电动汽车簧下质量较大和电动机不平衡电磁力的问题,进行了轮毂直驱空气悬架(hub direct drive air suspension,HDD-AS)系统垂向动力学特性分析.构建了轮毂电动机与带附加气室空气悬架耦合模型,当轮毂直驱空气悬架系统在路面随机激励与电动机不平衡电磁力耦合作用下,附加气室容积和阻尼系数改变时,分析了电动机偏心距、电动机不平衡电磁力、簧上质量加速度、悬架动行程、轮胎动载荷和簧下质量加速度均方根值的变化规律,研究了附加气室容积和阻尼系数变化对电动机偏心距、簧上质量加速度、悬架动行程、轮胎动载荷和簧下质量加速度的频域影响.结果表明:附加气室容积和阻尼系数的变化对轮毂直驱空气悬架系统悬架性能和轮毂电动机振动具有较大的影响.
