Optimal timing of switches between product sales for sports and entertainment tickets

Like airlines and hotels, sports teams and entertainment venues can benefit from revenue management efforts for their ticket sales. Teams and entertainment venues usually offer bundles of tickets early in their selling horizon and put single‐event tickets on sale at a later date; these organizations must determine the best time to offer individual tickets because both types of ticket sales consume the same fixed inventory. We model the optimal a priori timing decision for a seller with a fixed number of identical tickets to switch from selling the tickets as fixed bundles to individual tickets to maximize the revenue realized before the start of the performance season. We assume that bundle and single‐ticket customers each arrive according to independent, nonhomogeneous Markovian death processes with a linear death rate that can vary over time and that the benefit from selling a ticket in a package is higher than from selling the ticket individually. We characterize the circumstances in which it is optimal for the seller to practice mixed bundling and when the seller should only sell bundles or individual tickets, and we establish comparative statics for the optimal timing decision for the special case of constant customer arrival rates. We extend our analytical results to find the optimal time for offering two groups of tickets with high and low demand. Finally, we apply the timing model to a data set obtained from the sports industry. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

基于运载能力评估的固体运载火箭推力向量控制方案比较

从对运载能力影响角度开展固体运载火箭发动机推力向量控制系统比较分析研究。设计了三种采用不同发动机推力向量控制系统的多级固体运载火箭方案,将增广乘子法与共轭方向法相结合,对固体运载火箭上升段弹道进行了优化设计,给出运载能力评估结果。研究表明,起飞质量均为50 000kg,目标轨道均为300km太阳同步轨道时,采用栅格舵和侧喷流作为推力向量控制系统方案,比采用燃气舵和侧喷流作为推力向量控制系统方案,运载能力提高70kg,比各级固体发动机全部采用摆动喷管控制方案,运载能力提高115kg,为固体运载火箭总体方案论证提供理论依据。     

The effects of customer rebates and retailer incentives on a manufacturer's profits and sales

In some industries such as automotive, production costs are largely fixed and therefore maximizing revenue is the main objective. Manufacturers use promotions directed to the end customers and/or retailers in their distribution channels to increase sales and market share. We study a game theoretical model to examine the impact of “retailer incentive” and “customer rebate” promotions on the manufacturer's pricing and the retailer's ordering/sales decisions. The main tradeoff is that customer rebates are given to every customer, while the use of retailer incentives is controlled by the retailer. We consider several models with different demand characteristics and information asymmetry between the manufacturer and a price discriminating retailer, and we determine which promotion would benefit the manufacturer under which market conditions. When demand is deterministic, we find that retailer incentives increase the manufacturer's profits (and sales) while customer rebates do not unless they lead to market expansion. When the uncertainty in demand (“market potential”) is high, a customer rebate can be more profitable than the retailer incentive for the manufacturer. With numerical examples, we provide additional insights on the profit gains by the right choice of promotion.© 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

高校科研团队科技创新能力评价研究

科技创新能力是体现高校综合办学实力的核心指标。以科研团队为视角对高校科技创新能力的评价问题进行了研究,分析了高校团队科技创新能力的要素构成、结构特征,在此基础上从人员队伍、条件基础、文化环境、科技投入、科技产出5个方面出发定义了一个可扩展的团队科技创新能力评价指标模型;提出了基于多属性决策的科技创新能力评价方法,为科研团队绩效管理提供了方法支撑。     

Route optimization for multiple searchers

We consider a discrete time‐and‐space route‐optimization problem across a finite time horizon in which multiple searchers seek to detect one or more probabilistically moving targets. This article formulates a novel convex mixed‐integer nonlinear program for this problem that generalizes earlier models to situations with multiple targets, searcher deconfliction, and target‐ and location‐dependent search effectiveness. We present two solution approaches, one based on the cutting‐plane method and the other on linearization. These approaches result in the first practical exact algorithms for solving this important problem, which arises broadly in military, rescue, law enforcement, and border patrol operations. The cutting‐plane approach solves many realistically sized problem instances in a few minutes, while existing branch‐and‐bound algorithms fail. A specialized cut improves solution time by 50[percnt] in difficult problem instances. The approach based on linearization, which is applicable in important special cases, may further reduce solution time with one or two orders of magnitude. The solution time for the cutting‐plane approach tends to remain constant as the number of searchers grows. In part, then, we overcome the difficulty that earlier solution methods have with many searchers. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

返回舱垂直着陆过程动力学研究

在考虑着陆场地面弹塑性特点的情况下,建立了返回舱垂直着陆过程的弹塑性接触模型。数值分析结果表明,返回舱的着陆过程与地面土壤的物理性质有很大关系,在相同的弹性模量下,土壤的极限应力越大,则着陆过载最大值就越大,着陆过程中的能量损失就越小,返回舱的"跳跃"现象越明显。     

基于复杂网络的联合作战指挥体系研究

以作战指挥理论需求为牵引,从复杂网络的角度对联合作战指挥体系问题进行网络抽象,将指挥体系中的指挥机构作为网络的节点,将指挥关系作为网络的边,按照指挥体系历史发展的规律,从简单到复杂,分别构建了传统层级纵长树状型的指挥体系网络模型,在树状模型基础上,增加了横向联系但依然具有层级结构的信息共享改进型的指挥体系网络模型,以及...     

针对官兵能力个体差异做好部队训练工作

正确认识能力的多样性及个体差异,有利于增强部队训练工作的科学性,提高战斗力。由于“能力”理解的多样性,对部队训练能力的认识也具有多个层面的涵义。个体在部队训练中体现出发展水平、结构、表现时间以及性别的差异。正确认识这些差异需要走出认知上的误区,做好“两头人”的工作,充分发挥“三互小组”的作用以及制定不同阶段的具体目标等。     

When the Going Gets Tough… Monitoring Missions and a Changing Conflict Environment in Sri Lanka, 2002–2008

This article analyzes how the conflict environment in which a civilian monitoring mission is deployed influences the monitors' assessment of the operation. It draws on unique empirical material from the experience of the Sri Lanka Monitoring Mission (SLMM), deployed to oversee a ceasefire agreement in Sri Lanka 2002–2008. With material from a survey and in-depth interviews, experiences of the monitors are analyzed and changes over time are traced in relation to the monitors' assessment of the mandate and organizational set-up of the mission. The study points to the difficulty of monitoring missions to address escalation during an ongoing peace process. Its function is dependent on the goodwill of the parties. In essence, monitoring missions have the potential to strengthen peace when there is momentum in favor of progress, but when relations between the parties turn sour and the conflict escalates a civilian monitoring mission basically loses its potential. During the final stages of the war, which saw a very large number of civilian casualties, the war-torn areas were closed to international observers. Moreover, international pressure for a short-term ceasefire to alleviate the humanitarian situation was dismissed by the Sri Lankan government, which also saw the backing of several important actors, not the least China.     

Explaining US and British performance in complex expeditionary operations: The civil-military dimension

A nation's structure and culture of civil-military relations are important and largely overlooked factors in explaining the performance of armed forces involved in complex expeditionary operations. The US model of ‘Huntingtonian’, divided civil-military structures and poor interagency cooperation, makes the US military less suited for complex expeditionary operations. British civil-military relations involve a Defence Ministry that conscientiously integrates military and civilian personnel, as well as extensive interagency cooperation and coordination. This ‘Janowitzean’, integrated form of civil-military relations makes the British military more likely to provide for the planning and implementation of comprehensive campaigns that employ and coordinate all instruments of power available to the state, as well as troops in the field displaying the flexibility and cultural and political understanding that are necessary in complex expeditionary operations.