一个 C1 单调保形插值三次样条的构造

本文利用三次Bernstein多项式构造了一种C~1单调保形插值三次样条函数。该方法除计算简单外,还能应用于外形设计中且能灵活地调节外形曲线。     

Country survey IV: Pakistan

This paper examines the role of the military in Pakistan, particularly in regard to civil‐military relations and defence industrialisation. Pakistan's military expenditure is relatively high, but apart from investment multipliers, little of this spending filters through to the civil sector. Pakistan's defence‐industrial strategy centres on rebuild and Chinese technological collaboration. However, while this ‘capital‐saving’ approach has merit, the strategy has thus far failed to stimulate broader civil development linkages. A conclusion of this paper is that Pakistan is failing to maximise the strategic dual‐use benefits of integrating civil‐military activity.     

双极化天线的通信信号检测方法

在详细分析与探讨信号防御性能的基础上,对利用边界扫描的大区域通信信号电路体系进行了探讨,提出以TD-SCDMA网络为基础的双极化天线通信信号检测系统。通信信号检测过程中,用嵌入式处理器LPC2148结合四阶累积量的切片检测出TD-SCDMA信号,并通过估计获得TD-SCDMA信号的采样率,经过二次谱算法的运算,获得谱峰间的距离来估计出OVSE码的周期参数。以标准验证芯片为中心,针对相同类型的混合信号电路组建验证电路,最终完成对验证模块DOT4MBST及验证电路的检测验证。测试结果表明,提出的双极化天线的通信信号检测系统能够在错综复杂环境中,对通信信号进行精确的采集,且鲁棒性强。     

新型频率选择表面加载双极化超宽带紧耦合阵列天线

为使紧耦合阵列天线在超宽频带内实现电磁性能更佳、辐射性能更稳定的目的,提出一种新型条形频率选择表面宽角阻抗匹配层加载的双极化超宽带紧耦合阵列天线。通过高频仿真软件CST周期边界条件对阵列单元截断并进行研究分析。掌握阵元阻抗和辐射等电磁性能后,优化设计并加工出一个6×6单元的阵列天线进行实际测量。测量结果表明,该天线在2~12 GHz的频带内驻波比均小于3,驻波比带宽为10 GHz。带内辐射特性稳定,主瓣电磁能量集中,交叉极化小。工作频带内,最大增益可以达到13 dBi。该阵列天线可应用于超宽带相控阵天线领域中。     

双高速摄像机交汇的高旋弹丸位姿估计算法及误差分析

为了测量高旋弹丸在炮口处的各种信息,基于双高速摄像机交汇的测量方法,提出了一种新的弹丸位姿估计方法.对总攻角函数进行了误差建模与分析,结果表明两台高速摄像机的光轴应相互垂直,且应选择光轴远离攻角平面的高速摄像机所对应的测量函数计算总攻角,此时测量误差最小.以靶场实验的方式对攻角函数的误差分析结论和位姿估计算法进行验证....     

双重系统加密研究: 获得完全安全的IBE及其扩展

双重系统加密技术首先由Waters提出,是用于构造完仝安全的基于身份的加密(IBE)及其扩展方案的有力方法.针对完全安全方案的构造,研究了双重系统加密技术并提出了一个完全安仝方案的通用构造方法,即将一个利用双重系统加密的IBE方案与一个普通的方案相结合,得到一个新的可以利用双重系统加密证明安全的方案.在通用构造的基础上提出了一个实例,该实例是一个基于层级身份的加密( HIBE)方案,具有常密文长度.该方案比Waters提出的双重系统加密HIBE方案更高效,并且在判定BDH假设和判定线性假设下证明是完全安全的.     

射频/红外复合制导半实物仿真技术的发展

射频 /红外双模复合制导技术的不断发展引发了对射频 /红外双模复合制导仿真工具的迫切需求。国外从 20世纪 80年代末就开始了射频 /红外半实物仿真系统的研究。分析了美国海军空战中心等 4个单位的射频 /红外半实物仿真系统及其发展过程、技术特点。     

Fashion products with asymmetric sales horizons

In this study, we explore an inventory model for a wholesaler who sells a fashion product through two channels with asymmetric sales horizons. The wholesaler can improve profitability by employing joint procurement and inventory reallocation as a recourse action in response to the dynamics of sales. In this research, a simple stochastic programming model is analyzed to specify the properties of the optimal inventory decisions. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

The Dao of foreign policy: Understanding China’s dual strategy in the South China Sea

In the South China Sea, China neither implements power-maximizing policy nor engages a peaceful approach. Instead, China implements both coercion and cooperation in pursuing its strategic interest in the disputed area. How can we explain China’s paradoxical behavior? This article claims that the best way to explain China’s policy in the South China Sea is to understand the character of dualism in China’s strategic culture. Following constructivist theory that stresses culture, this article argues that Chinese duality approach in the South China Sea is rooted in the philosophy of Daoism. The symbol of Yin-Yang depicts Chinese assertive as well as cooperative behavior in dealing with the South China Sea dispute. Although from a normative perspective Daoism recognizes pacifism and non-violent behavior, the most important feature of Daoism is the assumption that reality consists of two opposing elements that are mutually embedded.     

Excess procurement strategies by a dominant buyer under constrained supply

Supply chains are often characterized by the presence of a dominant buyer purchasing from a supplier with limited capacity. We study such a situation where a single supplier sells capacity to an established and more powerful buyer and also to a relatively less powerful buyer. The more powerful buyer enjoys the first right to book her capacity requirements at supplier's end, and then the common supplier fulfills the requirement of the less powerful buyer. We find that when the supplier's capacity is either too low (below the lower threshold) or too high (above the higher threshold), there is no excess procurement as compared to the case when supplier has infinite capacity. When the supplier's capacity is between these two thresholds, the more powerful buyer purchases an excess amount in comparison to the infinite capacity case.