质量体积双约束下车辆装载与配送路径联合优化研究

目的针对质量与体积共同限制的配送路径问题,综合考虑订单不可拆分、货物的体积等约束,构建包含路径最短和装载率最高双目标的车辆装载与配送路径联合优化模型。方法在车辆路径优化模型的求解方面,首先利用聚类算法对配送区域进行划分,然后通过车辆的载质量判断是否能进行站点货物的配送,最后利用遗传算法求得最优路径。在三维装载模型的求解上使用贪心算法和基于块的启发式算法,解决了货物的装箱问题。结果基于某公司具体实例对模型与算法的可行性进行了验证,优化后配送的车辆减少了1辆,配送距离减少了154.247 km,平均装载率达到了93.89%,节省了企业的配送成本。结论所构建的模型以及求解的算法可以提高装载率和配送效率,为解决车辆装载与配送路径联合优化问题提供理论依据。

生态系统理论视角下“虚拟养老院”服务聚合研究

作为实现我国养老服务发展的重要途径,“虚拟养老院”是养老服务体系下的新型养老模式。文章在生态系统理论视角下,阐明了“虚拟养老院”的内涵与本质特征,构建了以文化政策、制度保障、价值主张、内部激励、信息对称和技术摄入为影响因素的“虚拟养老院”服务聚合结构框架,在宏观、中观和微观层面分别提出了“虚拟养老院”服务聚合主体组成和各主体行为逻辑,从自动力和它动力两个方面探析了“虚拟养老院”服务聚合的驱动力,从而实现“虚拟养老院”的精细化管理,以期促进养老服务健康可持续发展。

Simulation Study on Influence of Rake Angle in Gear Skiving Processes

Gear skiving is a promising gear cutting technology that can achieve a multiple faster internal gear cutting process than that of gear shaping. However,the kinematic system complicates skiving process,resulting in severe crater wear due to the intense variation of local cutting features. In particular,the negative rake angle near the cut-out is recognized as influential factor affecting the cutter wear progress,which needs the sophisticated simulation approach to elucidate the underlying cutting mechanism. In this research,the influence of the rake angle,e.g. top and side nominal rake angles of the cutter,is studied to further understand its role in the gear skiving process,for seeking the possibility of skiving process improvement by calculating the effective rake angle. As a result,the top and side rake angles of the cutter can both increase the effective rake angle when compared with the case of the none-rake angle,leading to an enhanced skiving process. This work provides fundamental knowledge of the rake angle for the gear skiving research,contributing to the optimization on the cutter parameters by considering the effective rake angle.