Strategic outsourcing under technology spillovers

We study a supply chain in which an original equipment manufacturer (OEM) and a contract manufacturer (CM) compete in the finished goods market. The OEM can decide whether to outsource the intermediate good, a critical component for producing the finished good, from the CM or make in‐house production. Technology transition improves the CM's production efficiency, and it can take two different forms: a direct technology transfer from the OEM to the CM or technology spillovers through outsourcing from the OEM to the CM. We document the possibility of strategic outsourcing, that is, the CM supplies the intermediate good to the OEM when she is less efficient than the OEM's in‐house production. We find that technology spillovers can strengthen the incentive for strategic outsourcing. Furthermore, compared with direct technology transfers, outsourcing coupled with technology spillovers may generate more technology transition. Outsourcing is a particularly appropriate channel for implicit collusion when the OEM is not very efficient with the production of the intermediate good. Our results suggest that ex post competition on the finished goods can create room for ex ante collaboration and provide some implications on the OEM's outsourcing strategies when facing a competitive CM.© 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 501–514, 2014     

基于Hurst指数的油罐声发射信号分析

由油罐声发射检测直接得出油罐底板状态等级的评价研究工作有待完善。提出一种基于Hurst指数理论分析声发射信号幅值最大值分布的评价方法。从Hurst指数分形理论出发,结合声发射信号参数处理方法,给出研究条件假设,分析现场油罐声发射信号结果,并与开罐检测的底板状况加以对比分析。研究发现,相同检测条件,同种类型油罐底板状态等级与Hurst指数呈相反的关系。     

LEACH—DRT算法中基于神经网络的数据预测算法

为了保证无线传感器网络中数据的完整性,针对基于LEACH路由协议的动态轮时间算法存在的问题,提出一种基于人工神经网络的数据预测算法。该动态轮时间算法中,部分簇因调整后的轮时间不足以完成数据的采集而丢失数据。数据预测算法结合传感器节点数据具有时空相关性的特点,将时空延迟算子引入神经网络模型,并通过建立的神经网络模型对数据进行预测。仿真时采用伯克利英特尔实验室的传感器数据,通过Mafl软件对模型进行测试并分析仿真结果。实验结果表明：该算法对连续多个数据的预测效果理想,预测误差始终保持在较低水平。     

Joint inventory and pricing decisions for perishable products with two‐period lifetime

We consider a periodic review model over a finite horizon for a perishable product with fixed lifetime equal to two review periods. The excess demand in a period is backlogged. The optimal replenishment and demand management (using price) decisions for such a product depend on the relative order of consumption of fresh and old units. We obtain insights on the structure of these decisions when the order of consumption is first‐in, first‐out and last‐in, first‐out. For the FIFO system, we also obtain bounds on both the optimal replenishment quantity as well as expected demand. We compare the FIFO system to two widely analyzed inventory systems that correspond to nonperishable and one‐period lifetime products to understand if demand management would modify our understanding of the relationship among the three systems. In a counterintuitive result, we find that it is more likely that bigger orders are placed in the FIFO system than for a nonperishable product when demand is managed. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

精密加工过程切削用量和表面粗糙度关系的模糊化处理方法

在金属切削原理中,用切削用量可以估计理论表面粗糙度。由于切削过程的复杂性,实际加工表面粗糙度和理论表面粗糙度有较大差距。本文采用模糊模式识别方法,对切削用量和表面粗糙度的关系进行了实验研究。本人介绍的理论方法、实现技术路线和实验结果,为以后开展ＦＭＳ或ＣＩＭＳ中智能化质量监控技术的进一步研究打下了基础。     

阶比谱分析与汽车起动电机故障的实时诊断

本文主要论述阶比谱分析方法及其在汽车起动电机故障实时诊断中的应用。首先阐述了阶比谱分析的原理以及阶比采样中混迭与泄漏的产生及其抑制方法,然后讨论了如何在起动电机运行过程短、升速快的情况下获取感兴趣的噪声信号,进而采用阶比谱分析方法从信号中提取故障特征信息,最后利用阀值判别法起动电机的故障进行实时诊断。     

一个功能较强的等离子体电磁波粒子模拟程序

本文发展了一个功能较强的1 2/2D 等离子体粒子模拟程序。文中就一维情况,论述了等离子体粒子模拟的原理、方法和计算机编程中的处理技巧。最后讨论了电磁模拟的应用。     

15cm×15cm 磁悬挂天平系统(MSBS)的电磁场分析与计算

本文采用二维电磁场有限元法及磁路的简化计算法对15cm×15cm磁悬挂天平系统（MSBS）的阻力线圈间距、磁场的分布情况进行了分析计算,并与测试结果进行了分析比较,给出了15cm×15cm磁悬挂天平系统（MSBS）的结构方案。     

氦原子1S, 3S, 1P, 3P态的电子关联计算

本文从二次量子化公式出发,选取广义Laguerre多项式乘以γ~lcxp(-alγ)作为单电子径向函数完全集,这里a_l是依赖于轨道角动量l的变分参数,用组态相互作用方法计算了氨原子~1S,~3S,~1P,~3P态的能量和波函数。当组态限于主量子数n≤4,计算的能量相对精度约为99.9%;当组态限于%≤6,能量相对精度约为99.99%;而Hartree Fock方法的能量相对精度约为99%,利用原子波函数计算了一些原子参数,其结果与其他作者的结果符合很好。     

一阶与二阶常微分方程系统的隐式和半隐式解法

本文对于非定常问题在经Galerkin半离散化所得到的一阶及二阶常微分方程系统分别提出了具有二级精度的隐式和牛隐式求解方案,并从数学上严格证明了这两个数值方案均是无条件稳定的;另对于正定对称矩阵,通过应用近似求逆法大大地减少了计算工作量;最后提供了两个简单算例,证明本方法是行之有效的。