三维抛物化N-S方程全隐格式矢通量分裂求解

采用全隐格式的矢通量分裂算法,在通用曲线坐标系内求解三维无因次抛物化强守恒型N-S(Navier-Stokes)方程.所建立的计算程序,可计算较为复杂边界的三维流场,如求解亚、跨、超音速共存的流场,分区模拟内外流共存流动及其混合剪切尾流.给出了一轴对称亚跨超音速喷管内流场的计算结果,包括计算网格,流矢分布,压力、温度和马赫数等值线分布.也给出了一喷管内外流及其混合尾流的计算结果,包括计算网格,流矢分布,无因次压力、密度和温度等值线分布.     

基于模糊神经网络的异步电机速度控制系统

针对矢量控制异步电动机，利用模糊神经网络控制理论．提出了一种教师值指导和隶属函数自调整的模糊神经网络控制器。详细描述了模糊神经网络控制器和教师值控制器的设计过程，采用了隶属函数参数在线调节的办法，推导了隶属函数参数调整的公式和算法，研究了以转矩电流Iqs为目标函数和系统输出转速ω为目标函数的情况下的系统转速响应，分析了系统转动惯量J、粘滞摩擦系数B和转矩系数Kt变化情况下系统的性能，仿真结果表明该控制器具有速度响应快、鲁棒性较强等优点。     

GPS／MAP实现智能低空突防

低空突防在现代战争中起着十分重要的作用，并向着智能和自主式的方向发展，本文研究了采用全球定位系统（ＧＰＳ）和电子数字地图（ＭＡＰ）实现智能低空突防的几个关键问题。文中首先研究了智能低空突防的定义，给出了采用ＧＰＳ和ＭＡＰ实现智能低突防的总体方案和工作原理，其次研究了电子数字地图的设计，包括电子数字地图的功能设计，数据库设计及软，硬件设计要求等。再次，研究了ＭＡＰ与ＧＰＳ及自动飞行控制系统（ＡＦＣＳ     

旋转矢量航姿算法的一种新的表达式

传统的旋转矢量航姿算法一般采用陀螺的角增量输出来构造积分算法，本文将光纤陀螺输出的角速率信号再引入航姿计算，提出一种新的航姿算法表达式，并分析了此算法在圆锥运动输入下的误差。与传统的旋转矢量法比较，新算法具有较高的精度，为改进旋转矢量算法提供了一种新的思路。     

高速矢量处理器DSP24

介绍一种高性能的矢量处理器 DSP2 4 / MMU2 4。该芯片组不仅具有优异的处理性能 ,而且数据吞吐率很高 ,编程方便。通过合理地设计电路图和 PCB板 ,可以将该处理芯片方便地设计成多种不同处理性能的处理机 ,以满足不同处理领域的要求。     

Use of principal component analysis in the identification of the spatial pattern of an ionospheric total electron content anomalies after China’s May 12, 2008, M = 7.9 Wenchuan earthquake

This paper uses principal component analysis (PCA) to determine the spatial pattern of total electron content (TEC) anomalies in the ionosphere post the China’s Wenchuan Earthquake of 12 May, 2008 (UTC) (M_w = 7.9). PCA and image processing are applied to the global ionospheric map (GIM) with transforms conducted for the time period 08:00–10:00 UT on 12 May 2008. Results show that at a height of approximately 200 km the anomaly is widespread and less intense; however, it becomes more localized with height reaching maximum intensity and localization at an altitude of 300 km. The spatial distribution is remarkably similar to that reported for a TEC anomaly previously identified as a precursor anomaly on May 9, 2008 for the same time period. Potential causes of the results are discussed with emphasis given to vertical acoustic gravity waves based on the spatial pattern identified.     

Unsteady aerodynamic modeling at high angles of attack using support vector machines

Accurate aerodynamic models are the basis of flight simulation and control law design.Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determination and parameter estimation due to little understanding of the flow mechanism.Support vector machines(SVMs)based on statistical learning theory provide a novel tool for nonlinear system modeling.The work presented here examines the feasibility of applying SVMs to high angle-of-attack unsteady aerodynamic modeling field.Mainly,after a review of SVMs,several issues associated with unsteady aerodynamic modeling by use of SVMs are discussed in detail,such as selection of input variables,selection of output variables and determination of SVM parameters.The least squares SVM(LS-SVM)models are set up from certain dynamic wind tunnel test data of a delta wing and an aircraft configuration,and then used to predict the aerodynamic responses in other tests.The predictions are in good agreement with the test data,which indicates the satisfying learning and generalization performance of LS-SVMs.     

SketchMapia: Qualitative Representations for the Alignment of Sketch and Metric Maps

More and more private citizens collect and publish environmental data via web-based geographic information systems. These systems face two challenges: The user interface must be intuitive and the processing of geographic information must account for cognitive impact. We propose to use sketch maps as the medium for interaction, because they reflect a person's spatial knowledge. Information from sketch maps is distorted, schematized, incomplete, and generalized and metric maps are not. This article employs qualitative representations for the alignment of sketch and metric maps. We suggest a set of cognitively oriented aspects in sketch maps stably computed by people and evaluate qualitative representations to formalize these aspects. This allows us to align and integrate geographic information from sketch maps.     

风洞试验模型表面的荧光油膜路径运动速度测量

风洞试验模型在气流脉动作用下小幅振动，导致光流法从荧光油膜时序图像中解得的荧光油膜路径运动速度含有模型运动速度，降低了荧光油膜全局摩阻测量准度。为此，提出试验模型表面的荧光油膜路径运动速度测量方法，将模型表面的背景纹理（如人工网格线或其他典型特征）作为基准，利用图像相关法离散匹配，获得相邻时序图像中背景纹理的（几何位姿）映射矩阵；基于模型运动的连续性，推导了映射矩阵的全局优化方程，并结合光流法，实现了模型振动与其表面荧光油膜路径运动的解耦。Oseen涡对的荧光油膜路径运动速度场仿真试验结果表明：在给定的平移旋转条件下，本文方法的计算结果（沿Oseen涡核连线分布的测量速度）与理论值的最大相对误差为4.1%，较无平移旋转条件下的光流计算结果最大相对误差仅增加0.6%。2 m量级高速风洞某空腔试验与机翼试验的荧光油膜路径运动速度测量结果进一步显示：本文方法测得的流动现象正确，能得到定量、清晰的表面摩擦应力线图谱与油膜路径运动速度场，较传统方法优势明显，工程应用价值大。     

基于D-S证据理论的GPS/MM组合系统车辆定位算法

根据分段、特征提取等地图匹配关键技术探讨了地图匹配的一般原理,提出了基于D-S证据推理理论的GPS(Global Positioning System)/MM(Map Matching)组合算法,提高了GPS单点定位精度.仿真结果和跑车实验验证结果表明上述方法是行之有效的.地图匹配算法不增加系统的硬件成本,对目前广泛应用的车载GPS导航定位系统是一个有效的解决方案.