系统观思维的兴起及其对传统思维方式的变革

随着系统科学的兴起,其方法论思想引起人类思维方式的又一次飞跃,即系统思维方式的形成。系统观的思维方式要求以非线性的、非决定的、整体的角度认识世界,从关系和过程中把握世界,从而区别于以还原主义为基础的决定论的思维方式。     

基于梯度矢量流snake与多尺度分析的血管内超声图像轮廓提取

提取血管内超声(IVUS)图像的血管内腔轮廓对冠状动脉疾病的诊断有积极意义。本文提出了一种基于梯度矢量流(GVF)snake与多尺度分析的轮廓提取新方法。针对传统GVF snake的轮廓初始化、抑制噪声和伪像干扰两个难点,本文方法在如下两个方面进行了改进:第一,利用序列图像的特性产生时间方差图并得到初始轮廓,从而实现轮廓提取过程的全自动化;第二,引入多尺度分析,使GVF snake在离散小波变换得到的多尺度图中形变,从而增强了算法的鲁棒性。对仿真图像和实际IVUS图像的实验表明,该方法在轮廓提取的精度方面优于传统的GVF snake方法。     

增量调制DFT的硬件实现

作者在文献[1,2]中提出过一种基于 DM(LDM 和 ADM)序列的 DFT 实现方法,与常规的 PCM 处理方法相比较,它不需要使用模数变换器和乘法器,从而简化了硬件设备量,降低了成本,而其信噪比与 PCM 处理结果相一致。本文在笔者以前研究的模拟分析基础上用硬件实现基于 DM的 DFT 实时处理。文中采用 ROM 来存贮各个系数值。本法具有速度快、硬件结构简单的特点,但由于ROM 存取速度的限制,目前还只能用于对语音、地震等信号的处理。     

Wavelet Regression Technique for Streamflow Prediction

In order to explain many secret events of natural phenomena, analyzing non-stationary series is generally an attractive issue for various research areas. The wavelet transform technique, which has been widely used last two decades, gives better results than former techniques for the analysis of earth science phenomena and for feature detection of real measurements. In this study, a new technique is offered for streamflow modeling by using the discrete wavelet transform. This new technique depends on the feature detection characteristic of the wavelet transform. The model was applied to two geographical locations with different climates. The results were compared with energy variation and error values of models. The new technique offers a good advantage through a physical interpretation. This technique is applied to streamflow regression models, because they are simple and widely used in practical applications. However, one can apply this technique to other models.     

小波变换在轴承故障声发射信号降噪中的应用

噪声消除是小波变换最成功的应用之一，其基本思想是将信号的小波变换系数通过阈值处理，然后进行小波重构得到降躁的信号。根据故障轴承声发射信号的脉冲特性选取Morlet小波．以“小波熵最小”原则确定Morlet小波的波形参数，然后进行连续小波变换。采用软阈值方法处理小波东数，通过小波重构得到降噪后的故障声发射信号，噪声得到了很好的抑制，故障脉冲特征明显增强。采用实验数据，通过与离散小波变换的比较，得到了用连续小波变换可以有效降低噪声、提取故障声发射信号特征的结论。     

基于图像内容可恢复的脆弱水印技术

提出了一种用于图像内容认证和保护的脆弱数字图像水印算法,该算法不仅可以检测定位出图像中内容的篡改,而且可以恢复被篡改的图像内容。算法用小波变换提取出图像的低频部分作为水印,然后再用RS纠错编码技术对水印进行编码,再利用置乱技术及加密技术将校验码处理后植入图像的最低有效位。实验结果证明该算法是比较有效的脆弱水印算法。     

Massively parallel computing: a statistical application

Massively parallel computing is a computing environment with thousands of subprocessors. It requires some special programming methods, but is well suited to certain imaging problems. One such statistical example is discussed in this paper. In addition there are other natural statistical problems for which this technology is well suited. This paper describes our experience, as statisticians, with a massively parallel computer in a problem of image correlation spectroscopy. Even with this computing environment some direct computations would still take in the order of a year to finish. It is shown that some of the algorithms of interest can be made parallel.     

Homogeneity testing in a Weibull mixture model

The mixed Weibull distribution provides a flexible model to analyze random durations in a possibly heterogeneous population. To test for homogeneity against unobserved heterogeneity in a Weibull mixture model, a dispersion score test and a goodness-of-fit test are investigated. The empirical power of these tests is assessed and compared on a broad range of alternatives. It comes out that the dispersion score test, as it is based on a Weibull-to-exponential transformation, often breaks down. A simple new procedure is introduced for Weibull mixtures in scale, which combines the dispersion score test and the goodness-of-fit test. The new test is compared with several known procedures and shown to have a good overall power. To detect mixtures in shape and scale, a goodness-of-fit test is recommended. This research has been partially sponsored by a grant of the Deutsche Forschungsgemeinschaft. We thank Lars Haferkamp for computational assistance and Wilfried Seidel and a referee for their remarks on alternative test procedures.     

浅谈高等院校思想政治工作的创新思维

“建设社会主义核心价值体系，增强社会主义意识形态的吸引力和凝聚力”，“切实把社会主义核心价值体系融入国民教育和精神文明建设全过程，转化为人民的自觉追求”，是中国共产党当前和今后的一项重要任务。要达到“融入”和“转化”的目的，必须加强和改进思想政治教育工作，牢牢把握“适时、求是、默化、适度、守正、出新”十二字要义，以创新的思维，推动工作的创新。