Equitable bandwidth allocation in content distribution networks

Applications for content distribution over networks, such as Video‐on‐Demand (VOD), are expected to grow significantly over time. Effective bandwidth allocation schemes that can be repeatedly executed must be deployed since new programs are often installed at various servers while other are deleted. We present a model for bandwidth allocation in a content distribution network that consists of multiple trees, where the root of each tree has a server that broadcasts multiple programs throughout the tree. Each network link has limited capacity and may be used by one or more of these trees. The model is formulated as an equitable resource allocation problem with a lexicographic maximin objective function that attempts to provide equitable service performance for all requested programs at the various nodes. The constraints include link capacity constraints and tree‐like ordering constraints imposed on each of the programs. We present an algorithm that provides an equitable solution in polynomial time for certain performance functions. At each iteration, the algorithm solves single‐link maximin optimization problems while relaxing the ordering constraints. The algorithm selects a bottleneck link, fixes various variables at their lexicographic optimal solution while enforcing the ordering constraints, and proceeds with the next iteration. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

Revenue management with aircraft reassignment flexibility

A well‐studied problem in airline revenue management is the optimal allocation of seat inventory among different fare‐classes, given a capacity for the flight and a demand distribution for each class. In practice, capacity on a flight does not have to be fixed; airlines can exercise some flexibility on the supply side by swapping aircraft of different capacities between flights as partial booking information is gathered. This provides the airline with the capability to more effectively match their supply and demand. In this paper, we study the seat inventory control problem considering the aircraft swapping option. For theoretical and practical purposes, we restrict our attention to the class of booking limit policies. Our analytical results demonstrate that booking limits considering the swapping option can be considerably different from those under fixed capacity. We also show that principles on the relationship between the optimal booking limits and demand characteristics (size and risk) developed for the fixed‐capacity problem no longer hold when swapping is an option. We develop new principles and insights on how demand characteristics affect the optimal booking limits under the swapping possibility. We also develop an easy to implement heuristic for determining the booking limits under the swapping option and show, through a numerical study, that the heuristic generates revenues close to those under the optimal booking limits. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

基于并行工程的装备作战需求论证方法

提出了一种基于并行工程的系统化、规范化的装备作战需求论证方法.论述了该方法的特点及理论框架,详细研究了装备作战需求分析中模糊质量功能配置的构建,以及基于并行工程的装备作战需求论证的全过程.最后结合实例,说明了模糊质量功能配置模型的正确性以及论证方法的可行性.     

基于备件需求预测的两步法理论?

在对备件需求时间序列研究的基础上,结合指数平滑法和Croston法的特点,分析了指数平滑法与两步法的原理,通过对指数平滑法和两步法方差的研究,得到两步法是指数平滑法的一般形式的结论,为两步法的进一步研究提供一定的理论支撑。     

基于能力的装备型号体系结构开发方法

为适应装备型号需求生成的复杂性,必须开发面向作战能力应用的装备型号体系结构模型。按照装备型号需求生成工程化思想,建立了结构化的装备型号体系结构开发流程,并对每个环节进行了系统分析。装备型号作战体系结构和系统体系结构开发流程都划分为8个环节,为作战活动分析、系统功能分析提供了可追溯、可验证的模块化开发模式。装备型号体系结构关联开发流程分为4个环节,实现了作战能力对系统实体的关联关系,确保了系统需求对作战需求的支持,提高了装备型号需求成果的系统性和正确性。     

摧毁固定目标的空袭兵器需求量算法研究

在反空袭作战中,预先对敌空袭兵器的出动量的有效判断程度,关系到我防空兵器的兵力需求论证与战斗部署。以往这方面的研究成果中,定性多于定量,为提高准确性,加强定量研究有很大的必要。由于影响作战的因素很多,且需求量的计算分为多个方面,不可能一一作出研究。分析了敌空袭固定目标时兵力选择所依据的因素,分别用排队论与Lanchester方程理论进行了数学建模。     

A general strategic capacity planning model under demand uncertainty

Capacity planning decisions affect a significant portion of future revenue. In equipment intensive industries, these decisions usually need to be made in the presence of both highly volatile demand and long capacity installation lead times. For a multiple product case, we present a continuous‐time capacity planning model that addresses problems of realistic size and complexity found in current practice. Each product requires specific operations that can be performed by one or more tool groups. We consider a number of capacity allocation policies. We allow tool retirements in addition to purchases because the stochastic demand forecast for each product can be decreasing. We present a cluster‐based heuristic algorithm that can incorporate both variance reduction techniques from the simulation literature and the principles of a generalized maximum flow algorithm from the network optimization literature. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

What you should know about queueing models to set staffing requirements in service systems

One traditional application of queueing models is to help set staffing requirements in service systems, but the way to do so is not entirely straightforward, largely because demand in service systems typically varies greatly by the time of day. This article discusses ways—old and new—to cope with that time‐varying demand. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

The strategic effects of a merger upon supplier interactions

We consider how a merger between two naturally differentiated dealers affects their interactions with a common supplier and identify conditions under which the merger can increase or decrease the combined net worth of the two firms. Among other things, we find that the attractiveness of merging depends upon the extent to which end demand can be stimulated by either an upstream supplier or the dealers. Specifically, the greater the supplier's ability to invest in stimulating end demand, the more likely it is that the naturally differentiated firms will be better off operating independently than merging. On the other hand, if the greatest opportunities for stimulating demand are through the service that is provided by the dealers, then merging their operations will be more attractive. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

当代先进生产力特点及其对社会要求

生产力有先进与否之分 ,某一时代的先进生产力是在该时代起 (或将起 )核心或主导作用的生产力。当代先进生产力是以生物技术、信息技术、纳米技术等为代表的高新技术。不同的生产力有不同的特点并因而对社会生活有不同的要求 ,当代先进生产力也是一样。明确当代先进生产力的特点及其对社会生活的要求 ,就可以使我们方向明确地、切实地践行中国共产党“始终代表中国先进生产力的发展要求”这“第一要务” ,从而推动社会整体的发展与进步 ,并真正实现“中国最广大人民的根本利益”。