定子磁钢轨道拼接错位对动圈式永磁直线电机性能的影响

陆基车载无人机电磁弹射器是一种新型的弹射起飞装置。为了实现高机动性,提出双边动圈式永磁直流直线电机和定子磁钢轨道分段拼接结构方案。为了评估定子磁钢轨道拼接可能对电机性能的影响,建立了永磁直线电机模型。利用有限元分析软件,分析研究了轨道分段拼接上下错位、左右错位以及倾斜错位可能造成的影响,根据分析结果给出了磁钢轨道拼接错位所允许的偏移范围大小。     

美国网络安全人才培养机制

加强网络安全人才队伍建设已经成为世界主要国家抢占网络空间制高点的战略举措。近年来的研究表明,美国通过发布专门的网络安全人才培养国家战略,设立专门的网络安全人才培养卓越中心,开发专门的网络安全人才培养在线资源,形成了一套较为成熟的惠及全民的网安全人才培养机制。     

Optimizing disaster relief: Real-time operational and tactical decision support

We introduce a real-time decision support system which uses optimization methods, simulation, and the judgement of the decision maker for operational assignment of units to tasks and for tactical allocation of units to task requirements. The system, named ARES for the Greek god of war, accommodates a high degree of detail in the logistics of unit movements during operations, yet separates the assignment and allocation activities in a fashion which naturally accommodates human intervention and judgement—ARES is designed to assist the decision maker, not to replace him. ARES is demonstrated with a hypothetical scenario constructed for 14 Engineering Battalions of the Hellenic Army which are assigned 20 tasks employing 25 resource types in repairing major damage to public works following a great earthquake. (This hypothetical data was prepared prior to the earthquake in Kalamata near Athens on 13 September, 1986, and exhibits uncanny, but coincidental, resemblance to that real situation.) ARES is designed for use in real time, and quick data preparation is aided by the provision from published sources of standard data for many foreseeable tasks; this data can be quickly accessed via visual icons on a computer screen and customized for the actual work at hand. © 1993 John Wiley & Sons, Inc.     

Real-time task scheduling with overheads considered

n periodic tasks are to be processed by a single machine, where each task i has a maximum request rate or periodicity F_i, a processing time E_i, a deadline D_i, relative to each request of task i, a task-request interrupt overhead I_i, and a task-independent scheduling overhead S. Two scheduling strategies are considered for sequencing the execution of an arbitrary arrangement of task requests in time: the preemptive and the nonpreemptive earliest-deadline algorithms. Necessary and sufficient conditions are derived for establishing whether a given set of tasks can be scheduled by each scheduling strategy. The conditions are given in the form of limited simulations of a small number of well-defined task-request arrangements. If all simulations succeed, the schedule is feasible for the given set of tasks. If any simulation fails, the schedule is infeasible. While interrupt handling and scheduling overheads can be handled by such simulations, context switching overhead resulting from preemption cannot. A counterexample illustrates how the simulations fail to uncover unschedulable task sets when context switching overhead is considered.     

基于二代小波的三维虚拟人脸的LOD简化模型研究

针对三维虚拟人脸数据量大的问题,结合曲面多分辨率细分模型,首次提出了具有C2连续光滑的对称性双正交三次B样条小波的快速提升构造方案。算法通过引入 s-lift和w-lift算子,根据B样条的两尺度及小波二阶消失矩关系构造了l和h滤波器。定义了一个与顶点角标无关的提升运算以得到一个平面张量积形式的B样条小波函数,从而将提升构造算法推广到二维,研究了三维人脸网格曲面的张量积小波变换LOD控制算法。对误差计算进行了定义和分析,并对三维人脸的LOD小波控制算法进行了优化。结果表明:二代小波LOD模型压缩率高,人脸曲面失真度小。     

An analytical evaluation of optimal solution value estimation procedures

The estimation of optimal solution values for large-scale optimization problems is studied. Optimal solution value estimators provide information about the deviation between the optimal solution and the heuristic solution. Some estimation techniques combine heuristic solutions with randomly generated solutions. In particular, we examine a class of jacknife-based estimators which incorporate any heuristic solution value with the two best randomly generated solution values. The primary contribution of this article is that we provide a framework to analytically evaluate a class of optimal solution value estimators. We present closed-form results on the relationship of heuristic performance, sample size, and the estimation errors for the case where the feasible solutions are uniformly distributed. In addition, we show how to compute the estimation errors for distributions other than uniform given a specific sample size. We use a triangular and an exponential distribution as examples of other distributions. A second major contribution of this article is that, to a large extent, our analytical results confirm previous computational results. In particular, the best estimator depends on how good the heuristic is, but seems to be independent of the underlying distribution of solution values. Furthermore, there is essentially an inverse relationship between the heuristic performance and the performance of any estimator. © 1994 John Wiley & Sons, Inc.     

基于态势信息融合体系的军用计划识别关键技术研究

文章阐述了C2、态势信息融合体系及计划识别之间的联系,并根据计划识别理论的发展应用情况,指出了军用与经典计划识别之间的区别与联系以及亟待解决的关键技术,提出了军用多Agent计划识别构成模型,并探讨了相关动态不确定性集成建模、推理方法在军用计划识别问题上的应用。     

海上补给计算机仿真训练系统框架设计研究

在分析海上补给仿真训练系统的用户需求的基础上,确定了海上补给仿真训练系统应该具备的功能,在此基础上对系统的组成、体系设计进行深入的研究。     

地空导弹旅(团)指挥控制系统坐标变换模型

在以往的人工或半自动化指挥中所采用的方格坐标已不能适应自动化指挥控制的需求,根据地面防空武器坐标系的设置方法,提出适合地空导弹旅(团)自动化指挥控制系统的坐标方案,主要包括:地心直角坐标系、地理坐标系、站心地平直角坐标系.根据实际应用需要,给出了不同坐标间的转换模型,经过仿真计算和实际应用,验证了模型的正确性,坐标转换精度满足系统要求,已在某新型地空导弹武器装备中得到应用.     

一类基于模型的仿射代数不变量

3D目标的标识别已逐渐成为计算机视觉领域的热点问题.在研究了传统的基于几何不变量和基于3D/2D约束关系两种识别方法的基础上,提出了1类新的空间几何结构模型,并计算出了这类模型3D仿射不变量和其对应的2D仿射不变量之间的约束关系.利用这种关系,可以在目标的姿态和摄像机的参数均未知的情况下,有效利用单幅图像来识别3D目标.