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811.
排队论用于C^3I系统作战指挥周期与管理效能研究 总被引:1,自引:0,他引:1
未来高科技战争,信息万变,对作战时间的要求越来越高,如何缩短作战指挥周期一直是C3I系统效能研究的课题之一.本文从现代作战对时间的需求出发,运用排队论的方法,对影响C3I系统效能的系统反应时间进行分析,提出一种缩短作战指挥周期提高管理效能的方法,在实践中具有指导意义. 相似文献
812.
813.
提出了一种基于码相扩展扩频信号集上的TTCM直接序列扩频系统方案,通过将Turbo编码与扩频映射相结合,使得信号之间的最小欧氏距离增加,从而在不增加发射功率、不减小信息速率、不改变调制方式的前提下提高了系统的误码率性能.仿真结果表明,基于码相扩展的TTCM直序扩频系统可以比单纯直序扩频多获得1~3dB的编码增益,同时对载波初相估计误差和相位噪声的敏感程度并不增加. 相似文献
814.
815.
加固液晶显示器自动温控技术 总被引:1,自引:0,他引:1
随着电子技术的发展,液晶显示器在军、民品中的应用越来越广泛,已逐渐替代了CRT显示器成为了显示领域的主流产品。介绍了液晶显示器加固过程中的温控原理,通过CPLD/FPGA编程的方法实现了低温加热的自动控制,拓宽了液晶显示器低温工作范围。 相似文献
816.
We consider the coordination problem between a vendor and a buyer operating under generalized replenishment costs that include fixed costs as well as stepwise freight costs. We study the stochastic demand, single‐period setting where the buyer must decide on the order quantity to satisfy random demand for a single item with a short product life cycle. The full order for the cycle is placed before the cycle begins and no additional orders are accepted by the vendor. Due to the nonrecurring nature of the problem, the vendor's replenishment quantity is determined by the buyer's order quantity. Consequently, by using an appropriate pricing schedule to influence the buyer's ordering behavior, there is an opportunity for the vendor to achieve substantial savings from transportation expenses, which are represented in the generalized replenishment cost function. For the problem of interest, we prove that the vendor's expected profit is not increasing in buyer's order quantity. Therefore, unlike the earlier work in the area, it is not necessarily profitable for the vendor to encourage larger order quantities. Using this nontraditional result, we demonstrate that the concept of economies of scale may or may not work by identifying the cases where the vendor can increase his/her profits either by increasing or decreasing the buyer's order quantity. We prove useful properties of the expected profit functions in the centralized and decentralized models of the problem, and we utilize these properties to develop alternative incentive schemes for win–win solutions. Our analysis allows us to quantify the value of coordination and, hence, to identify additional opportunities for the vendor to improve his/her profits by potentially turning a nonprofitable transaction into a profitable one through the use of an appropriate tariff schedule or a vendor‐managed delivery contract. We demonstrate that financial gain associated with these opportunities is truly tangible under a vendor‐managed delivery arrangement that potentially improves the centralized solution. Although we take the viewpoint of supply chain coordination and our goal is to provide insights about the effect of transportation considerations on the channel coordination objective and contractual agreements, the paper also contributes to the literature by analyzing and developing efficient approaches for solving the centralized problem with stepwise freight costs in the single‐period setting. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
817.
818.
采用纳米电刷镀技术在钢基体表面制备了n-Al2O3/Ni-P复合刷镀层,研究了复合刷镀液中纳米颗粒含量、刷镀电压和刷镀笔移动速度对复合刷镀层中P和Al2O3含量的影响.优化后的工艺参数范围为刷镀液中n-Al2O3颗粒含量20~30 g/L、刷镀电压8~12 V、刷镀笔移动速度5~10 m/min.制备的n-Al2O3/Ni-P复合刷镀层组织致密,含有纳米颗粒和非晶相. 相似文献
819.
We consider a two‐stage supply chain, in which multi‐items are shipped from a manufacturing facility or a central warehouse to a downstream retailer that faces deterministic external demand for each of the items over a finite planning horizon. The items are shipped through identical capacitated vehicles, each incurring a fixed cost per trip. In addition, there exist item‐dependent variable shipping costs and inventory holding costs at the retailer for items stored at the end of the period; these costs are constant over time. The sum of all costs must be minimized while satisfying the external demand without backlogging. In this paper we develop a search algorithm to solve the problem optimally. Our search algorithm, although exponential in the worst case, is very efficient empirically due to new properties of the optimal solution that we found, which allow us to restrict the number of solutions examined. Second, we perform a computational study that compares the empirical running time of our search methods to other available exact solution methods to the problem. Finally, we characterize the conditions under which each of the solution methods is likely to be faster than the others and suggest efficient heuristic solutions that we recommend using when the problem is large in all dimensions. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006. 相似文献
820.