基于R2V和AutoCAD的树木年代学方法及其在冀北山地的初步应用

综合应用AbleSoftwareR2V的矢量化功能和AutoCAD的测量功能,提出一种新的树木年轮测量方法,并用此方法测定了冀北山地广为分布的白榆地径年轮宽度,进而用来尝试过去气候序列的重建。结果表明:5—9月平均气温和总降雨量与年轮指数成正相关,相关系数分别为0·597(α<0·05)、0·695(α<0·05)。以此为基础,建立了5—9月平均气温、总降雨量的转换方程,重建了冀北山地1940—1955年共16年5—9月平均气温和总降雨量。

A Statistical Parameter Analysis and SVM Based Fault Diagnosis Strategy for Dynamically Tuned Gyroscopes

Gyro's fault diagnosis plays a critical role in inertia navigation systems for higher reliability and precision. A new fault diagnosis strategy based on the statistical parameter analysis (SPA) and support vector machine (SVM) classification model was proposed for dynamically tuned gyroscopes (DTG). The SPA, a kind of time domain analysis approach, was introduced to compute a set of statistical parameters of vibration signal as the state features of DTG, with which the SVM model, a novel learning machine based on statistical learning theory (SLT), was applied and constructed to train and identify the working state of DTG. The experimental results verify that the proposed diagnostic strategy can simply and effectively extract the state features of DTG, and it outperforms the radial-basis function (RBF) neural network based diagnostic method and can more reliably and accurately diagnose the working state of DTG.