磁流变智能液场致微结构变化的Monte Carlo模拟

从磁流变液中存在的各种相互作用势出发，对Ｎ＝１００个球形羰基铁颗粒均匀分布于一正方形二维体系之中的物理模型，利用ＭｏｎｔｅＣａｒｌｏ方法和Ｍｅｔｒｏｐｌｉｓ算法着重计算了磁流变智能液的场致微结构变化。计算结果表明，磁流变液（ＭＲＦ）的流变效应在外磁场中的变化是由于其ＭＲＦ中磁性颗粒的成链团簇有序化所致。这与磁流变液在外磁场中熵的下降和对ＭＲＦ的光学显微镜观察结果是一致的。     

Bayesian object extraction from uncalibrated image pairs

This paper proposes a region-based algorithm for the extraction of foreground objects in uncalibrated images or video sequences. At the initialization step, a pair of images are overly segmented based on color and texture. Then, several dominant transforms that represent the relationship between two images are found, and each pixel is transformed by these transformations. By considering transform parameters and using the proposed area-ratio test, each pixel is assigned to a background or an object. We consider the resulting binary image as a binary random field, from which the likelihood of being foreground is computed for each initial segment. Using the likelihood model for each segment and the a priori assumption on the smoothness of labels, Bayesian approach is applied to label the segments. Experiments on various images and videos show promising results that the objects are clearly extracted.     

一种新的两分类器融合的空谱联合高光谱分类方法

本文提出一种两分类器融合的高光谱空谱联合分类方法,首先利用子空间多项式逻辑回归在图像的特征子空间中分类,得到满概率图;根据满概率将每个像元分至概率最大的两个最可信类别,并在原始空间中构建最可信类别字典,利用稀疏解混对每个像元在最可信类别字典下进行稀疏表示,得到稀疏概率图;最后将满概率图和稀疏概率图线性融合,并利用边缘保持的马尔可夫正则项挖掘图像空间信息,得到具有边缘保持的空谱分类模型.实验表明,提出的两分类器融合方法即使在训练样本较少时也比现有方法得到更好的分类结果.     

基于MRF的高性能二进制LDPC码译码算法

二进制LDPC码译码改进算法主要是提升硬判决性能或者降低软判决计算复杂度。本文应用高斯-马尔可夫随机场(Markov Random Field,MRF)模型实现信源参数估计,对信道译码端接收的比特序列进行对数似然比修正,在译码时加入信源的残留冗余信息来增加译码器的纠错能力。信源估计修正系数自适应可变,是由误码率参数调控。在计算复杂度不变的情况下,基于MRF的LDPC码译码算法有效提高了译码性能,降低误比特率     

Toward Accurate Road Detection in Challenging Environments Using 3D Point Clouds

In this paper, we propose a novel method for road recognition using 3D point clouds based on a Markov random field (MRF) framework in unstructured and complex road environments. The proposed method is focused on finding a solution for an analysis of traversable regions in challenging environments without considering an assumption that has been applied in many past studies; that is, that the surface of a road is ideally flat. The main contributions of this research are as follows: (a) guidelines for the best selection of the gradient value, the average height, the normal vectors, and the intensity value and (b) how to mathematically transform a road recognition problem into a classification problem that is based on MRF modeling in spatial and visual contexts. In our experiments, we used numerous scans acquired by an HDL‐64E sensor mounted on an experimental vehicle. The results show that the proposed method is more robust and reliable than a conventional approach based on a quantity evaluation with ground truth data for a variety of challenging environments.     

MRF154在短波固态线性功放中的应用

介绍了一种新型的大功率场效应管MRF154的技术参数和特点，给出了由MRF154组成的一款推挽式高频功率放大器的具体电路，并对该电路进行 详细分析，同时对实际应用中的有关工艺问题和散热问题作了说明。     

Multi-Feature Based Bayesian Segmentation of Cerebrovascular from Time-of-flight Magnetic Resonance Angiography

Vessel analysis in medical images is important both for diagnostic and intervention planning purposes, especially, a three-dimensional representation of vasculature can be extremely important in image-guided neurosurgery and pre-surgical planning. In this paper, a Bayesian approach is proposed to aggregating geometric shape and intensity features for whole cerebrovascular tree extraction from Time-of-flight Magnetic resonance angiography （TOF-MRA）, while most of the current segmentation methods solely deal with the latter. In this method, we first utilige scale space analysis to get shape feature of blood vessels, then both shape and speed features are incorporated into a Bayesian segmentation framework. Maximum a posterior （MAP） method is used to estimate the posterior probabilities of vessel and background for classi- fication. The experimental results show that the proposed method can obtain a better quality of segmentation than those sole feature utilized methods.     

磁流变液效应对远端流场的扰动

研究了磁流变效应对远离磁极的流道中流动的扰动问题。通过双腔型结构器件的动态力学响应以及混合流模式的流动分析,揭示了当磁流变液离开磁极后,由于剩磁的影响,磁极后方的管道中的流动将受影响,主要表现在流过管道的介质的体积比浓度将发生显著变化。     

基于马尔可夫随机场的SAR目标切片图像分割方法

SAR目标切片图像分割是基于SAR图像目标识别的一个重要步骤。文中通过利用马尔可夫随机场模型 ,引入图像象素的局部结构信息 ,有效实现了SAR目标切片图像的高精度分割。通过对SAR目标切片图像进行统计分析 ,精确选择了分割算法的迭代初值 ,极大提高了算法的计算效率。和其它分割算法相比 ,文中算法在分割速度和精度上均有较大提高