小波提升算法在JPEG2000可逆变换中的应用与实现

离散小波变换是图像处理和压缩技术的基础，而基于提升方法的离散小波变换是当今业界研究的热点之一。在分析二维图像的小波变换的基础上，研究小波提升算法、其特点及其实施方法，探讨该算法在JPEG2000中可逆小波变换上的实现，给出该算法的C语言实现，并进行了分析。     

机车仿真器视景系统中的图象处理

为了满足视景仿真中空间分辨率的要求，将传统的几何变换和小波变换相结合，提出了一种改进的图象放大算法。该算法能够在不丢失高频信息的条件下放大图象，使得放大后的图象画面清晰，细节丰富。为了叠加信号灯，提出了基于模式识别的区域连接增长算法，该算法能够自动跟踪信号灯的位置和大小。     

基于匹配追踪和Radon变换的LFM信号宽带时延-时间伸缩声成像方法

分析了宽带延展目标的时延-时间伸缩效应，及其导致的回波信号在时域和频率域的特性．针对LFM信号的时频分布特点，利用匹配追踪和Radon变换，提出了一种提取LFM信号在时一频域分布特性参数的时延一时间伸缩声成像方法，有效避免了利用WVD时产生的交叉项影响．通过计算机仿真与实验验证，表明该方法是有效的．     

Fault detection of vehicle suspension system using wavelet analysis

This paper presents a method based on continuous wavelet transform to detect the faults of vehicle suspension systems. The Morlet wavelet functions are employed to approach the natural frequencies of the system and the frequency components of the signal with relative maximum energy. To evaluate our method, we use a full vehicle dynamic model which has been simulated in ADAMS/CAR and validated by laboratory test results. The suspension faults have been considered due to the damage of shock absorbers (dampers) and upper damper bushings (UDBs) and assumed as the decrease in damping force and loose joints, respectively. In this paper, the incapability of the spectral analysis by using fast Fourier transform in analysis of the signals is revealed through applying the inputs that include transient characteristics and then wavelet transform employed to achieve more proper results. A swept frequency is applied as an input to the wheels that simulates the road irregularities. After detection of faulty sections of the system using signal energy distribution, the defects of damper and UDBs are distinguished from each other through observing the changes of natural frequencies and corresponding energy amplitudes.     

某港重力式墩台压顶方块开裂原因分析

通过对某港重力式墩台压顶方块开裂原因的分析,阐述了一种罕见的支撑状态改变引起墩台上构件破损的因素。     

小波变换用于列车振动信号消噪的研究

小波变换的重要应用之一就是用于信号的消噪。通常从列车上采集的振动信号都混有大量的噪声 ,现采用非线性小波阈值法对信号进行消噪 ,并利用阈值处理后的小波系数重建信号 ,从而得到有用的信号波形。实验结果表明该方法能有效的去除噪声 ,可靠性高 ,特别适用于信号中混有白噪声的情况     

基于 Keystone 变换的俯冲加速运动 SAR 成像算法

俯冲加速条件下的SAR成像算法是当前SAR成像领域中一个热门研究课题。受到加速度的影响,其距离方程不再是单纯的双曲线形式,从而导致无法根据驻定相位原理求得俯冲加速SAR回波的二维频谱解析表达式。因此,传统SAR频域成像算法不再适用于俯冲加速SAR成像。论文从SAR距离徙动特性着手,利用Keystone变换实现对俯冲加速SAR的线性徙动校正,从而实现距离向和方位向的二维解耦合,得到最终的SAR聚焦图像。     

暗河地区高填路堤筋墙方式拓宽重载动力响应模型试验

利用重载动力响应模型试验装置,对路堤下伏溶洞的变形破坏机理与稳定性进行了深入分析,归纳出路基下不同部位变形破坏特征,分析了暗河漏斗地区高填路堤的稳定性。得出了路基路面在不同荷载作用下相应产生变形,传递到路面下各结构层并引起相应沉降变形,最终导致了路面塌陷和坡脚的破坏,确定暗河地区高填路堤筋墙方式拓宽,为暗河地区高填路堤整治方案奠定了基础。     

公路货运抽样调查数据自动采集系统应用措施研究

公路货运抽样调查数据自动采集系统是利用科学技术进行数据自动采集与传输,并能避开人为干扰因素.具有很好的推广应用价值.     

A High-performance Low Cost Inverse Integer Transform Architecture for AVS Video Standard

A high-performance, low cost inverse integer transform architecture for advanced video standard (AVS) video coding standard was presented. An 8×8 inverse integer transform is required in AVS video system which is compute-intensive. A hardware transform is inevitable to compute the transform for the real-time ap-plication. Compared with the 4×4 transform for H.264/AVC, the 8×8 integer transform is much more complex and the coefficient in the inverse transform matrix Ts is not inerratic as that in H.264/AVC. Dividing the Ts into matrix S8 and R8, the proposed architecture is implemented with the adders and the specific CSA-trees instead of multipliers, which are area and time consuming. The architecture obtains the data processing rate up to 8 pixels per-cycle at a low cost of area. Synthesized to TSMC 0.18 μm COMS process, the architecture attains the operating frequency of 300 MHz at cost of 34 252 gates with a 2-stage pipeline scheme. A reusable scheme is also introduced for the area optimization, which results in the operating frequency of 143 MHz at cost of only 19 758 gates.