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161.
This paper develops a methodology for measuring the capital value of military assets in monetary terms. We distinguish between two military capital measures. One measure, called the value of military capital (services) summarizes the value of military defense assets during a particular year. A comparison of the capital‐services value of U.S. and Soviet tactical combat aircraft is provided for the period 1970–1984. One feature of the capital‐services measure that makes it particularly interesting is that its size can be compared with such military expenditures as operating and support. While these latter expenditures reflect the readiness of a defense establishment, the relevant capital‐services measure reflects force structure and modernization. A second measure, called the value of military capital (wealth), summarizes the military benefits obtained from defense assets over the remainder of their service lives. This measure depreciates the capital as it ages, and is useful for comparing military wealth with other types of wealth in the economy. We provide this measure for the U.S. military capital stock for 1925–1984. 相似文献
162.
The defense‐growth nexus is investigated empirically using time series data for the US and allowing the effect of defense spending on growth to be non‐linear. Using recently developed econometric methods involving threshold regressions, evidence of a level‐dependent effect of military expenditure on GDP growth is found: the positive externality effect of defense spending prevails for relatively lower levels of defense spending (with respect to the history of defense spending in the US) and reverts its influence for higher levels. 相似文献
163.
This article studies operations sequencing for a multi‐stage production inventory system with lead times under predictable (deterministic) yield losses and random demand. We consider various cases with either full or partial release of work‐in‐process inventories, for either pre‐operation or post‐operation cost structures, and under either the total discounted or average cost criteria. We derive necessary and sufficient criteria for the optimal sequence of operations in all cases. While the criteria differ in their specific forms, they all lead to the same principal: those operations with (1) lower yields, (2) lower processing costs, (3) longer lead times, and (4) lower inventory holding costs should be placed higher upstream in the system.Copyright © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 144–154, 2014 相似文献
164.
The costs of many economic activities such as production, purchasing, distribution, and inventory exhibit economies of scale under which the average unit cost decreases as the total volume of the activity increases. In this paper, we consider an economic lot‐sizing problem with general economies of scale cost functions. Our model is applicable to both nonperishable and perishable products. For perishable products, the deterioration rate and inventory carrying cost in each period depend on the age of the inventory. Realizing that the problem is NP‐hard, we analyze the effectiveness of easily implementable policies. We show that the cost of the best Consecutive‐Cover‐Ordering (CCO) policy, which can be found in polynomial time, is guaranteed to be no more than (4 + 5)/7 ≈ 1.52 times the optimal cost. In addition, if the ordering cost function does not change from period to period, the cost of the best CCO policy is no more than 1.5 times the optimal cost. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献
165.
为了研究不确定性能参数对固体推进剂药柱结构分析的影响 ,将非概率凸集合理论模型和粘弹性有限元相结合 ,以增量法处理遗传积分 ,利用摄动法预测其响应量区间 ,发展了一种适合药柱特点的不确定性方法。将其和随机结构分析进行对比 ,表明两种方法之间有一定的联系。 相似文献
166.
在分段数为1和2时,现有有限元模型的一阶谐振频率比一维分布参数模型的一阶谐振频率低许多,因而其适用的频率范围较低,计算精度较差。本文提出了一种改进的小分段数有限元模型,通过修正流体管道的并联导纳使分段数为1和2时的有限元模型的一阶谐振频率与一维分布参数模型一致,从而提高了其使用的频率范围和计算精度。利用单根管道阀门关闭的水击问题的仿真计算对改进模型的效果进行了验证。在分段数为2时,原有的有限元模型的计算结果与分布参数模型的计算结果相差较大,而改进后的模型的计算结果与分布参数模型的计算结果基本一致。 相似文献
167.
168.
攻击型航空综合体作战效能分析的模型构成 总被引:2,自引:0,他引:2
给出了航空综合体及其作战效能的基本概念,并根据攻击型航空综合体作战特点及作战过程,阐述了对其作战效能进行分析时所需要建立的数学模型及各自应具有的主要功能 相似文献
169.
根据院校教材的需求特点及自印教材的费用发生特点,研究提出了3种适合于院校自印教材印量决策的随机库存模型.所提出的模型实用性强,对节省院校教材保障经费将起到直接的作用. 相似文献
170.
分析了备件库存管理所对应的库存控制策略及其有关的因素,以费用为目标函数、不缺备件概率为约束条件,运用概率论及库存论原理建立了备件库存限量的决策摸型。 相似文献