集合线对对数周期偶极子天线的影响

主要研究了对数周期偶极子天线.基于Pocklington积分方程和全域基函数,采用矩量法结合网络理论建立了天线算法模型;使用该模型计算了在天线阵和集合线共同作用下天线的辐射方向图,得出了集合线在不同频段上对天线辐射性能的影响,并通过截短延长线长度改善了天线低频段的辐射特性,增强了天线轴向方向性.     

A theory of war economies

This article presents a proposed theory of how war economies are formed and maintained, as well as an integrated policy framework to guide the dismantling of war economies emanating from the proposed theory. Additionally, six potential areas for future research pertaining to the dismantling of war economies are also presented.     

Strategic defense and attack for series and parallel reliability systems: reply 1 to comment 1

Kovenock and Roberson's [2011] comment provides initial work which has the potential, when suitably extended, to advance the research frontier. Kovenock and Roberson's paper consists of three sections. The first section is an interesting introduction. The second section, titled ‘Model and Main Result,’ provides no contribution beyond Hausken [2008a]. It consists of Equations (1)–(10) which are equivalent to equations developed by Hausken, and Equation (11) which is equivalent to the utility requirements u???0 and U???0 provided after Equation (17) in Hausken. The third section provides interesting ideas about mixed-strategy equilibria that can be extended in future research.     

模糊推理在软件维护性评估和预测中的应用

摘要：在基于活动的质量模型维护性分析方法基础上,对贝叶斯方法进行了扩展,将模糊推理技术与现有的贝叶斯方法进行比较,开发了一个基于模糊推理的系统来对软件维护性进行量化评估和预测,描述了模糊技术在维护性评估和预测准确度方面的优势．     

基于Bayes理论的固有可用度定时截尾试验方案

为解决小子样条件下进行产品固有可用度试验验证的问题,基于Bayes理论,提出了一种固有可用度定时截尾试验方案．该试验方案在假设故障间隔时间和修复时间均服从指数分布的前提下,将现场试验分为同时进行的可靠性和维修性定时截尾试验2个部分,要求在利用验前试验信息的基础上,使本次试验获得的验后分布还可以作为下一次现场试验的验前分布,提高了试验数据的利用率,具有较好的经济效益．     

Countering the effects of IED systems in Afghanistan: an integral approach

The current approach to countering the threat of improvised explosive devices (IEDs) in Afghanistan has met with limited success. The relative lack of success may be in part because the current approach is not holistic and discounts the social systems that foster the IEDs. Insurgents are using IEDs as a tool to further their strategic aims, but the coalition and to a lesser extent the Government of the Islamic Republic of Afghanistan (GIRoA) are attacking the IEDs as if they are an end in and of themselves. Combining network disruption with information change maximizes the opportunities for mitigating the IED threat. More specifically, to mitigate the IED threat requires disrupting the social and economic systems associated with IEDs, and at the same time providing alternative economic opportunities and improving rule of law and governance at the local level. In other words, counter-IED (C-IED) must be Counter-Insurgency (COIN) centric to be successful. This paper reviews the current state of C-IED efforts, identifies five main problems with the current approach, and suggests changes to reduce or mitigate the IED threat in Afghanistan.     

Nonparametric bayesian lifetime data analysis using dirichlet process lognormal mixture model

We propose a nonparametric Bayesian lifetime data analysis method using the Dirichlet process mixture model with a lognormal kernel. A simulation‐based algorithm that implements the Gibbs sampling is developed to fit the Dirichlet process lognormal mixture (DPLNM) model using rightly censored failure time data. Five examples are used to illustrate the proposed method, and the DPLNM model is compared to the Dirichlet process Weibull mixture (DPWM) model. Results indicate that the DPLNM model is capable of estimating different lifetime distributions. The DPLNM model outperforms the DPWM model in all the examples, and the DPLNM model shows promising potential to be applied to analyze failure time data when an appropriate parametric model for the data cannot be specified. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

建构主义视角下强化大学生信仰教育的对策探析

建构主义学习理论在强化大学生信仰教育方面有着重要的指导作用。夺文简要分析了夫掌生信仰教育存在的问题,探讨了建构主义学习理论对于强化大学生信仰教育的重要意义,并以建构主义卷习理论隽指导,从“以学生为中心”、“情景创设”、“协作学习”、“利用各种资源”四个方面提出了强化对策,以期提高大学生信仰教育水平,实现大学思想政治教育的功能。     

Market entry strategy in the presence of market spillovers and efficiency differentiation

Firms form various alliances or use brand extensions to enter new markets in order to improve their operational efficiency and create a positive spillover. However, they do not always know the implications of these strategies for market entry and multimarket competition because the sale of products in one market can have negative spillover effects on product sales in other markets. We present an analytical framework to examine whether and how (i.e., by choosing alliance entry or independent entry) competing firms should enter a market in a situation where market spillovers occur when a firm enters a spillover-producing market to sell products that may increase or decrease the consumers' willingness to pay for products in the primary market. Our analysis shows that the operational efficiency (or quality differentiation ability) of firms in a spillover-producing market varies, and hence, the impact of market spillovers differs for firms. We identify the key factors, such as bargaining power, brand value difference in the primary market, and the extent of efficiencies and spillovers, that determine the firms benefitting from the different entry strategies. Specifically, we show that firms would be more willing to choose an alliance strategy to enter a spillover-producing market if the negative spillover is small and alliance efficiency is high. In contrast, if an alliance entry is not favored, the firms' relative operational efficiency is crucial for them to decide whether to enter the market independently under moderate spillover conditions. Finally, we show the implications of market entry strategies for managers.