Inventory control and periodic price discounting campaigns

This paper develops an inventory model that determines replenishment strategies for buyers facing situations in which sellers offer price‐discounting campaigns at random times as a way to drive sales or clear excess inventory. Specifically, the model deals with the inventory of a single item that is maintained to meet a constant demand over time. The item can be purchased at two different prices denoted high and low. We assume that the low price goes into effect at random points in time following an exponential distribution and lasts for a random length of time following another exponential distribution. We highlight a replenishment strategy that will lead to the lowest inventory holding and ordering costs possible. This strategy is to replenish inventory only when current levels are below a certain threshold when the low price is offered and the replenishment is to a higher order‐up‐to level than the one currently in use when inventory depletes to zero and the price is high. Our analysis provides new insight into the behavior of the optimal replenishment strategy in response to changes in the ratio of purchase prices together with changes in the ratio of the duration of a low‐price period to that of a high‐price period. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007.     

2015 and the survival of the Nigerian State

Nigeria is currently faced with serious domestic challenges. While the state is not officially at war, it is standing on the precipice, especially with the eruption of violence occasioned by the emergence of the Boko Haram sect and the tenuous peace in the Niger Delta. With the 2015 general elections on the horizon, fears of further violence and disintegration are rife, more so because of the debate over who occupies the Presidential Villa at Abuja. President Goodluck Jonathan, a southerner, seems poised for a comeback even amidst the vociferous challenge posed by the political elites of northern Nigeria. This article looks at the different scenarios that might play out in 2015. It analyses the challenges of the survival of the Nigerian state, and makes some policy recommendations that Nigeria and its people need to put into place in order to ensure its survival beyond 2015.     

武器装备体系能力多视图模型研究

针对武器装备体系能力概念抽象、关系复杂特点导致建模困难、重用性差、语义不一致等诸多问题,提出了一种基于本体的能力多视图模型构建方法,建立了6个能力视图的元模型.该方法首先明确能力领域问题,确定武器装备体系能力领域核心本体及构建原则,然后采用形式化方法描述本体,建立核心本体的关系模型,最后面向能力视图内容建立元模型,通过...     

多次点火固体火箭发动机在面空导弹上的应用研究

论述了多次点火固体火箭发动机的多次点火的最佳控制,具体研究了两次点火固体火箭发动机的参数对飞行性能的影响,对两次点火固体火箭发动机结合弹道同时最佳化问题给出了仿真结果.     

Changing the paradigm: Simulation,now a method of first resort

Decades ago, simulation was famously characterized as a “method of last resort,” to which analysts should turn only “when all else fails.” In those intervening decades, the technologies supporting simulation—computing hardware, simulation‐modeling paradigms, simulation software, design‐and‐analysis methods—have all advanced dramatically. We offer an updated view that simulation is now a very appealing option for modeling and analysis. When applied properly, simulation can provide fully as much insight, with as much precision as desired, as can exact analytical methods that are based on more restrictive assumptions. The fundamental advantage of simulation is that it can tolerate far less restrictive modeling assumptions, leading to an underlying model that is more reflective of reality and thus more valid, leading to better decisions. Published 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 293–303, 2015     

一个多Agent系统合作模型

从多Agent系统的组成结构出发,综述合作问题的理论机制,提出了采用多Agent系统模型来求解逻辑推理问题的方法,根据各Agent自身意图,相互合作以达成群体目标。     

高级程序设计语言综述

为读者选择语言提供了总体思路,给出了高级语言的发展的趋势。