Banach空间中集值测度的表示定理

本文提出了用向量测度及概率测度生成集值测度的方法,推广了文[1]的结果,并给出了有界闭凸集值测度由一族等比向量测度生成的充要条件。     

An adaptive forecasting algorithm and inventory policy for products with short life cycles

Products with short life cycles are becoming increasingly common in many industries, such as the personal computer (PC) and mobile phone industries. Traditional forecasting methods and inventory policies can be inappropriate for forecasting demand and managing inventory for a product with a short life cycle because they usually do not take into account the characteristics of the product life cycle. This can result in inaccurate forecasts, high inventory cost, and low service levels. Besides, many forecasting methods require a significant demand history, which is available only after the product has been sold for some time. In this paper, we present an adaptive forecasting algorithm with two characteristics. First, it uses structural knowledge on the product life cycle to model the demand. Second, it combines knowledge on the demand that is available prior to the launch of the product with actual demand data that become available after the introduction of the product to generate and update demand forecasts. Based on the forecasting algorithm, we develop an optimal inventory policy. Since the optimal inventory policy is computationally expensive, we propose three heuristics and show in a numerical study that one of the heuristics generates near‐optimal solutions. The evaluation of our approach is based on demand data from a leading PC manufacturer in the United States, where the forecasting algorithm has been implemented. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

Optimal pricing for a short life‐cycle product when customer price‐sensitivity varies over time

Technology products often experience a life‐cycle demand pattern that resembles a diffusion process, with weak demand in the beginning and the end of the life cycle and high demand intensity in between. The customer price‐sensitivity also changes over the life cycle of the product. We study the prespecified pricing decision for a product that exhibits such demand characteristics. In particular, we determine the optimal set of discrete prices and the times to switch from one price to another, when a limited number of price changes are allowed. Our study shows that the optimal prices and switching times show interesting patterns that depend on the product's demand pattern and the change in the customers' price sensitivity over the life cycle of the product. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012     

基于模糊商空间理论的产品粒化过程分析

模块形成与划分是展开模块化设计及大规模定制生产的关键环节。为了进一步扩展产品模块化的定量分析手段,提出了一种基于模糊商空间理论的产品粒化方法。通过引入粒度计算,将基于相关性分析的产品模块化过程转化为基于粒度计算的产品粒化过程,并应用模糊商空间理论对其进行了分析,给出了基于归一化距离和综合模糊相似关系的产品粒度空间构建方法,建立了基于两阶段优化算法的最佳产品粒层确定流程,进而得到了最优模块划分方案,最后以某堆垛机货叉机构为例对该方法进行了有效性验证。此方法为产品模块聚类与优化提供了一种新的数值分析和评价手段,应用结果表明该方法具有一定的可行性和合理性,能够有效指导产品模块化过程的实施。     

基于GA-SVDD的轴承性能退化评估

为解决因机械设备轴承损伤导致机械故障而无法正常工作的问题,提出了一种基于GA-SVDD的轴承性能退化定量评估方法。该方法采用遗传算法优化选择特征参量,并建立SVDD超球体模型,运用SVDD距离评估轴承的性能退化程度。实验分析表明：该方法能够有效地对轴承性能退化过程的细节进行描述,实现对待测样本退化程度的定量评估。     

基于AdaBoost-SVM算法的某火炮炮闩技术状态评估

针对现役装备技术状态评估多依赖于手工拆卸的现状,提出一种基于AdaBoost-SVM模式识别算法的在线技术状态评估方法。利用人工后坐在线检测设备对炮闩装置技术状态参数进行检测,在对检测数据进行相关性分析特征提取的基础上,引入支持向量机模式识别方法,建立炮闩装置技术状态评估模型。通过将评估模型与Ada-Boost算法相结合,每次迭代都根据测试精度对分类错误的样本点和各分量分类器的权重重新赋值,在下一次迭代中形成新的分量分类器以优化分类结果,最终将各分量分类器依其权重综合完成评估。实例分析结果验证了评估模型的正确性和有效性。     

猎雷具定位水中悬浮目标的方法

猎雷具的前视声纳在发现锚雷时,无法解算其位置坐标,从而使猎雷具无法准确、安全地消灭锚雷,影响了猎雷具的作战效能,因此利用目标在声纳波束中的临界状态,结合单位波束的方向性特点,提出了对水中悬浮目标进行定位的方法,并根据实际作战环境,对计算结果进行了修正,完善了解算模型。     

面向SDR应用的向量存储器的设计与优化

针对面向SDR应用的SIMD数字信号处理器高带宽数据访存需求,提出并实现了一种新型的向量存储结构.该向量存储器由16路向量存储块构成,每路采用两组多体低位地址交叉编址存储结构,减少了访存体冲突,充分利用多存储体带宽,以较小的功耗代价实现并行访问多个向量数据.在此基础上,还设计了一种向量访存重整理单元,使向量存储器可灵活支持多路SIMD结构向量处理单元的非对齐访问,实现了其对向量存储器的共享.测试结果表明,该向量存储器能有效减少或消除向量处理单元之间的数据混洗操作,加速相关应用算法.     

面向装备健康管理的可测性指标研究

可测性指标是开展可测性设计、验证和评估的依据.针对传统可测性指标主要用于故障可检测性和故障可隔离性水平评价,不能全面反映面向装备健康管理可测性水平的问题,在定性分析装备健康管理对可测性的本质需求基础上,从全域和瞬态角度提出了五个可测性指标以定量描述面向装备健康管理的可测性水平;并基于故障模式状态矢量给出了可测性指标的分析计算流程.最后以某装备柴油机的机体子系统为案例详细说明了可测性指标的计算过程,应用结果表明所提指标具有一定的可行性和合理性,可以有效指导面向装备健康管理的可测性优化设计.     

支持向量机的OTHR多频特征目标分类识别法

针对低信噪比下多频法在天波超视距雷达(Over-The-Horizon Radar,OTHR)目标分类识别中分类精度不高的缺点,充分利用雷达量测的一些先验信息,将基于支持向量机(Support Vector Machine,SVM)的多分类器引入多频法中,提出了一种基于SVM的OTHR多频特征目标分类识别方法。仿真结果表明,利用较少的3个频率点,在信噪比较低的条件下可获得较好的分类识别效果,说明了该方法在OTHR目标分类识别中的有效性和可行性。