基于非刚性配准的交互式医学图像序列分割

提出了一种新的交互式医学图像序列分割算法,该算法将非刚性配准技术和解剖先验知识相结合把图像分割问题转化为图像配准问题。首先采用Demons算法进行图像配准,用光流法计算瞬时位移,设计了一个新的停止准则使其能自适应地确定迭代次数,并将它在金字塔型的多尺度框架下实现。然后用配准得到的形变域对已精确分割的图像进行形变就能自动地获得未分割目标图像的分割结果。扩展上述过程就可实现整个图像序列分割。试验结果表明该算法用户干预少、分割速度快、分割结果准确。     

基于蔡氏电路混沌系统的图像加密方法

鉴于低维混沌加密存在密钥空间相对较小的局限性,基于三维蔡氏电路混沌系统的图像空域置乱加密方法可避免该局限性.利用产生的混沌序列,经过预处理生成置乱索引矩阵用于图像加密.该方案密钥敏感性高,可实现多幅图像的并行加密,是一种具有较高的安全性,加密效率高,且易于实现的图像加密算法.     

Variational Segmentation of Image Sequences Using Region-Based Active Contours and Deformable Shape Priors

In this paper we address the problem of segmentation in image sequences using region-based active contours and level set methods. We propose a novel method for variational segmentation of image sequences containing nonrigid, moving objects. The method is based on the classical Chan-Vese model augmented with a novel frame-to-frame interaction term, which allow us to update the segmentation result from one image frame to the next using the previous segmentation result as a shape prior. The interaction term is constructed to be pose-invariant and to allow moderate deformations in shape. It is expected to handle the appearance of occlusions which otherwise can make segmentation fail. The performance of the model is illustrated with experiments on synthetic and real image sequences.     

线性复杂度可控的新型密钥流生成器

本文利用布尔函数的真值表,给出了一类全新的密钥流生成器.它具有实现简单和所产生的密钥流,可根据不同的需求,调节其线性复杂度等优点.此外,利用该新思想还得到了一个求2~n 长序列线性复杂度的快速算法.     

一些有趣数列及其组合恒等式

研究了一些有趣数列的性质，同时给出了一些组合恒等式。     

Parallel allocation of attention prior to the execution of saccade sequences.

In a series of 5 experiments, the allocation of attention prior to the execution of saccade sequences was examined by using a dual-task paradigm. In the primary task, participants were required to execute a sequence of 2 endogenous saccades. The secondary task was a forced-choice letter identification task. During the programming of the saccade sequences, letters were briefly presented at the saccade goals and at no-saccade locations. The results showed that performance was better for letters presented at any of the saccade goals than for letters presented at any of the no-saccade locations. The results support a spatial model that assumes that prior to the execution of a saccade sequence, attention is allocated in parallel to all saccade goals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

装配规划中基于割集的装配顺序生成方法

针对装配规划提出一种新的装配零件关系的描述方法，该方法应用改进的关联图－优先约束关联图，描述装配零件间的连接关系、优先关系及约束关系。在生成产品装配顺序时，充分地把装配优先关系与割集法副合到装配顺序搜索中，有效地生成产品所有满足装配条件的装配顺序，为装配规划提供参考的装配工艺路径。     

一种基于匹配滤波的红外小目标检测系统

低信噪比条件下的小目标检测问题一直是近些年来国内外学者研究的一个热门课题。目前,围绕这一课题已经发展了许多有实际意义的检测算法和处理机体系结构。本文在总结前人研究成果的基础上,针对复杂背景红外图像的统计特性,提出了一种基于组合式空间匹配滤波器的运动小目标检测方法。     

A generalized model for Kalman filtering of motion information in video compression

In this paper, we tackle the problem of motion estimation in video compression. Since Full Search Algorithms (FSA) present the disadvantage of adding a high computational burden to the encoder, fast search techniques have been used in conjunction with predictive filtering, in such a way to guarantee an acceptable quality with an affordable complexity. The aim of this work is to propose a novel framework for Kalman filtering of motion information in compressed video sequences. The merits of our new framework are twofold: First, using an appropriate formulation of the system equations, several shortcomings inherent with former models in the literature are greatly counteracted. Secondly, it is constructed using a generalized structure in such a way to enclose a large variety of prediction models. Therefore, it can adapt to different types of motion activities in video sequences, without the need for a different formulation in each prediction model, as was the case in previous studies. Furthermore, we propose an adaptive motion compensation technique that permits an additional improvement to the decoded video quality. Our framework permits a considerable gain in the average performance compared to previous models and even to the FSA technique.     

一种新的混沌伪随机序列生成方法*

针对单混沌系统因计算机有限精度效应产生的混沌退化问题,提出了一种多级混沌映射交替变参数的伪随机序列产生方法。该方法基于一维Logistic映射和二维Henon映射,用交错变参的Logistic映射的混沌迭代值的汉明重量来控制Henon映射输出的混沌迭代分量。生成序列通过仿真表明,符合Golomb三个随机性公设要求及局部随机性统计检验要求,可作为密钥流序列应用到加密体制中。