重型鱼雷的机动搜索及机动搜索弹道架构

针对潜射重型鱼雷在技术性能上的大幅提高和智能化作战的需要,在提出并分析鱼雷机动搜索概念和机动搜索时机的基础上,研究了远程重型鱼雷实现机动搜索在弥补发射平台目标定位误差、鱼雷发射后目标的有意机动和适应点对域攻击战法转变等作战环节中的必要性,构建了重型鱼雷机动搜索弹道的技术框架.     

大学英语分级教学模式下的学习策略培养

大学英语分级教学模式下对学生的学习策略培养非常重要。教师在整个教学过程当中,要研究和掌握学生的语言学习习得过程,研究其学习特点,认知风格,心理特征,加强对学生学习策略的培养和指导,帮助学生积极参与、探索、建构和使用学习策略,为学生掌握学习策略提供条件与平台,使学生自觉运用学习策略自我管理、自我调控、自我评估学习过程和学习效果,不断提高自主学习的能力。     

基于支持向量机的功率变换器开关管开路故障诊断

提出一种基于支持向量机的功率变换器开关管开路故障诊断方法。利用支持向量机建立分类模型,模型以相电流功率谱为输入量,7种故障状态为输出量,选用高斯核,使用基于二叉树分类器的分类算法。将诊断结果与基于BP神经网络的诊断结果进行比较,结果表明基于支持向量机的分类器在功率变换器开关管开路故障诊断中具有更高的准确率和更好的泛化能力。     

基于声矢量阵的宽带波束域高分辨方位估计

宽带信号波束域处理是实现水下目标高分辨方位估计的重要途径,它相对阵元域具有运算量小、分辨信噪比门限低以及角度分辨力高的优点。声矢量阵单个阵元能同时测量声场中的声压量和3个正交的质点振速分量,相对于声压阵,它能获取更多的声场信息。因此通过均匀声矢量阵运用MUSIC算法对宽带信号源波束域DOA估计进行了研究,改善了对弱相干信号源的方位分辨和估计性能,实验所获得的仿真结果表明了该方法具有较高的参考价值。     

Natural gas storage valuation and optimization: A real options application

In this article, we present an algorithm for the valuation and optimal operation of natural gas storage facilities. Real options theory is used to derive nonlinear partial‐integro‐differential equations (PIDEs), the solution of which give both valuation and optimal operating strategies for these facilities. The equations are designed to incorporate a wide class of spot price models that can exhibit the same time‐dependent, mean‐reverting dynamics, and price spikes as those observed in most energy markets. Particular attention is paid to the operational characteristics of real storage units. These characteristics include working gas capacities, variable deliverability and injection rates, and cycling limitations. We illustrate the model with a numerical example of a salt cavern storage facility that clearly shows how a gas storage facility is like a financial straddle with both put and call properties. Depending on the amount of gas in storage the relative influence of the put and call components vary. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

Designing and pricing menus of extended warranty contracts

Extended warranties provide “piece of mind” to a consumer in that product failures which occur after the base warranty expires are rectified at little or no cost. They also provide an additional source of revenue for manufacturers or third‐party providers, such as retailers or insurance providers, and help cultivate consumer loyalty. In this article, we analyze a number of extended warranty contracts which differ in design, including restrictions on deferrals and renewals. With the use of dynamic programming, we compute the optimal strategy for a consumer with perfect information and determine the optimal pricing policy for the provider given the consumer's risk characterization. We also provide insight into when different contracts should be issued. Finally, we illustrate how profits can be dramatically increased by offering menus of warranty contracts, as opposed to stand alone contracts, with the use of integer programming. Surprisingly, risk‐taking consumers provide the greatest benefit to offering menus. These insights can help a company develop a comprehensive warranty planning strategy for given products or product lines. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

基于多线程的CABAC并行编码方法

CABAC(Context based Adaptive Binary Arithmetic Coding)是H.264/AVC主要档次以上配置中推荐采用的熵编码方法.相比其他的熵编码方法,CABAC能够节省编码码率,但其计算串行性强,不能较好适应片上多核环境.针对这一问题提出了基于多线程的CABAC并行编码方法.大量实验统计表明,该方法负载划分较为均衡,对序列熵编码的单独加速比最高可达1.78.     

面向普适计算应用的构件定义语言UCDL

普适计算的适应性特征对于软件重用的要求决定了构件模型是目前普适计算软件体系结构的理想选择.在面向普适计算的自适应软件平台UbiStar的研究过程中,为了准确地对普适应用中构件的外部特征进行抽象描述,参考了CORBA构件模型使用IDL3和CIDL对构件进行特征抽象的方法,结合UbiStar普适计算平台的特点与需求,提出了一种适用于普适计算环境的构件定义语言UCDL,并且给出了一个应用示例.     

一种基于0-1整数规划的全局数据分布优化方法

数据分布是影响并行程序在分布主存多处理机上执行性能的重要因素.针对分布主存多处理机中的数据分布问题,提出了一种基于0-1整数规划、利用数据变换技术进行有效数据分布的方法.该方法通过数据变换技术改变数据的存储布局,以使得数据能被有效地分布,并且该方法还利用数据分布图描述程序被并行的情况及其所含数组被访问的情况,并将全局数据分布优化问题转换为求解数据分布图中最优路径的问题,从而可用0-1整数规划求解最优路径问题.该方法能对多个嵌套循环中具有仿射数组下标的任意维数组进行有效的数据分布,并且也能使嵌套循环的并行度尽可能地大.另外,该方法也考虑了偏移常量的对准问题,从而能使数据通信量尽量地小.实验结果验证了该方法的有效性.