Cost of Equity in Homeland Security Resource Allocation in the Face of a Strategic Attacker

Hundreds of billions of dollars have been spent in homeland security since September 11, 2001. Many mathematical models have been developed to study strategic interactions between governments (defenders) and terrorists (attackers). However, few studies have considered the tradeoff between equity and efficiency in homeland security resource allocation. In this article, we fill this gap by developing a novel model in which a government allocates defensive resources among multiple potential targets, while reserving a portion of defensive resources (represented by the equity coefficient) for equal distribution (according to geographical areas, population, density, etc.). Such a way to model equity is one of many alternatives, but was directly inspired by homeland security resource allocation practice. The government is faced with a strategic terrorist (adaptive adversary) whose attack probabilities are endogenously determined in the model. We study the effect of the equity coefficient on the optimal defensive resource allocations and the corresponding expected loss. We find that the cost of equity (in terms of increased expected loss) increases convexly in the equity coefficient. Furthermore, such cost is lower when: (a) government uses per‐valuation equity; (b) the cost‐effectiveness coefficient of defense increases; and (c) the total defense budget increases. Our model, results, and insights could be used to assist policy making.     

平均干扰下的无线传感器网络高效能传输研究

传输功率的调整是当前无线传感器网络进行低功耗优化设计的主要手段之一,但较低的传输功率却又很难保证连通性(因外围节点干扰引入的随机性),较大的传输功率不仅增加能耗而且会对邻近通信节点带来干扰,如果简单地在网络中进行传输功率调整,极易造成相邻通信子网传输功率的相互攀升,从而极大地降低了传输效能。该文从干扰模型分析出发,给出了基于平均干扰下的最优传输功率计算方法,考虑到网络环境的时变性,将该优化传输功率与自适应速率控制机制结合以提高传输效能。仿真结果表明,相比于MCP协议和Basic协议,基于平均干扰下的优化传输功率机制在单比特能耗及平均吞吐率上能够得到更好的性能折中。     

谈如何创造语言学习的最佳情感条件

情感因素是语言学习过程中不可忽视的因素之一,为学习者创造语言学习的最佳情感条件也就显得尤为重要。目前我国英语教学现状不够理想的重要原因之一,就是由于过于重视认知能力的培养,而忽视情感方面的发展。因此,研究情感因素在英语教学中的影响,合理适时地在教学中运用情感策略调控情感因素,从而为学习者创造语言学习的最佳情感条件有着重要的现实意义。     

UWB脉冲正交综合优化设计算法

从提高频谱利用率和满足FCC辐射掩模规定的角度出发,采用频域反推和时域正交综合相结合的设计方法,利用扁长椭球波函数(PSWF)来生成脉冲基。在此基础上,应用基于有限项PSWF脉冲基的正交综合来优化设计UWB成形脉冲。仿真结果表明该算法设计的脉冲不仅能很好地满足FCC辐射掩模的要求,而且具有较好的频谱利用率。     

现场总线控制系统信息通道结构分析与优化设计

分析了现场总线控制系统的典型拓扑结构及信息通道结构的能通性、可靠性和经济性，并采用广义自适应遗传算法对信息结构进行了优化设计，从而为现场总线控制系统的结构设计和分析提供了一种新方法。     

基于柔性战略观的企业财务战略管理机制创新研究

柔性战略观下的企业财务战略管理是企业战略管理的重要内容,它直接关系到企业战略管理的决策效率。文章以柔性战略观为导向,遵循利益相关者合作逻辑,以企业财权有效配置为路径,对企业财务战略有效实施机理进行了研究。揭示了柔性战略观下企业财务战略的特征,剖析了其连续一体化的生成机理,提出了共同互动管理和相机治理管理相结合的有效实施机制,以此确保企业财务战略目标的实现。     

半刚性沥青路面结构组合优化设计研究

针对目前半刚性基层沥青路面早期破坏严重的问题，采取柔化基层的方法优化路面结构组合设计，一方面这样并不会降低路面的结构承载力，另一方面基层模量与沥青面层模量的合理匹配，使面层内的剪应力和层底拉应力均控制在较低的应力水平，避免早期损坏的发生。同时，采用一种全新的抗剪性能评价方法——单轴贯入试验方法，进行沥青混合料抗剪性能评价，并铺筑了试验路，结果表明该设计具有良好的路用性能。提出的设计理念及试验方法、材料级配，对于国内类似工程必然具有重要的指导意义，同时也为我国道路设计理论的发展提供有益的借鉴。     

论科技资源向科技资本的转变

我国科技资源一直存在着利用效率低的问题,原因之一在于忽视了资源的资本属性。特别强调了科技资本的概念,指出了科技资源向科技资本转化的必要性,剖析了转化过程中存在的各种障碍,并就转化过程中的不同阶段针对性地提出了解决手段和措施。     

核岛内外设备的维修策略及最佳维修周期模型

研究了核电站核岛内外设备的不同维修策略、维修周期。建立了不同维修方法下的费用最小模型及可用度最大模型，为设备的合理维修给出了理论基础。     

A RANDOMIZED LONGITUDINAL PLAY-THE-WINNER DESIGN FOR REPEATED BINARY DATA

In some clinical trials with two treatment arms, the patients enter the study at different times and are then allocated to one of two treatment groups. It is important for ethical reasons that there is greater probability of allocating a patient to the group that has displayed more favourable responses up to the patient's entry time. There are many adaptive designs in the literature to meet this ethical constraint, but most have a single binary response. Often the binary response is longitudinal in nature, being observed repeatedly over different monitoring times. This paper develops a randomized longitudinal play‐the‐winner design for such binary responses which meets the ethical constraint. Some performance characteristics of this design have been studied. It has been implemented in a trial of pulsed electro‐magnetic field therapy with rheumatoid arthritis patients.