基于星凸形随机超曲面模型多扩展目标多伯努利滤波器

针对复杂不确定性环境下具有不规则形状的多扩展目标跟踪问题, 提出了一种基于星凸形随机超曲面模型(Star-convex RHM)的多扩展目标多伯努利滤波算法.首先, 在有限集统计(Finite set statistics, FISST)理论框架下, 采用多伯努利随机有限集(MBer-RFS)和泊松RFS (Possion-RFS)分别描述多扩展目标的状态和观测, 并给出扩展目标势均衡多目标多伯努利(ET-CBMeMBer)滤波器.其次, 利用RHM去描述任意星凸形扩展目标的量测源分布, 提出了容积卡尔曼高斯混合星凸形多扩展目标多伯努利滤波器.此外, 本文给出了一种多扩展目标不规则形状估计性能的评价指标.最后, 通过多扩展目标和具有形状突变的多群目标的跟踪仿真实验验证了本文方法的有效性.     

机动多目标跟踪中的传感器控制策略的研究

针对机动多目标跟踪中的传感器控制问题, 本文提出一种基于信息论的多模型多伯努利滤波器的控制方案. 首先, 基于随机有限集(Random finite set, RFS)方法给出信息论下的传感器控制的一般方法; 其次, 本文给出多模型势均衡多目标多伯努利滤波器的序贯蒙特卡罗实现形式. 此外, 提出一种目标导向的多伯努利概率密度的粒子采样方法, 并借助该方法近似多目标概率密度, 继而利用Bhattacharyya 距离求解最终的控制方案. 典型机动多目标跟踪问题的仿真应用验证了本文传感器控制方法的有效性.     

高斯过程回归模型多扩展目标多伯努利滤波器

针对复杂不确定性环境下不规则形状的多扩展目标跟踪问题, 本文提出了一种基于高斯过程回归(GPR) 模型的多扩展目标多伯努利(GPR–ETCBMeMBer)滤波算法. 首先, 在利用有限集统计理论(FISST)将多扩展目标的 状态集与量测集分别建模为多伯努利随机有限集(MBer RFS) 和泊松随机有限集(Poisson RFS) 的基础上, 通过 GPR方法建立多扩展目标随机超曲面的跟踪滤波模型. 然后, 基于容积卡尔曼滤波器(CKF)详细推导并提出GPR多 扩展目标多伯努利滤波算法的高斯混合(GM)实现. 最后, 通过构造对星凸形多扩展目标和多群目标跟踪的仿真实 验验证了本文所提算法的有效性.     

Rao-Blackwellized粒子势均衡多目标多伯努利滤波器

由于多伯努利滤波器直接近似递推了多目标状态的后验概率密度,使得多目标跟踪问题在基于随机有限集理论框架下的求解及目标状态的估计显得更为直观.本文针对一个状态可分解(线性/非线性)的状态空间模型,分析基于Rao-Blackwell定理的滤波估计方法,结合噪声的去相关构造线性状态的滤波方程.文中详细推导并提出Rao-Blackwellized粒子势均衡多目标多伯努利滤波器的一般实现形式,包括给出多伯努利非线性状态粒子滤波的实现形式,并结合非线性滤波结果给出多伯努利线性状态的递推滤波公式.本文提出的滤波器实现方法能够在更低维的状态空间上进行采样,滤波器的整体跟踪性能得到提高.多目标跟踪的仿真实验结果验证了该算法的有效性.     

多扩展目标跟踪中基于加权最优子模式分配距离的传感器管理方法

针对多扩展目标跟踪优化中的传感器管理问题,本文基于随机有限集(RFS)提出一种基于加权最优子模式分配(W–OSPA)距离的传感器管理方法.首先,在部分可观测马尔可夫决策过程(POMDP)理论框架下,给出基于逆威沙特椭圆分布假设的多扩展目标跟踪传感器管理的基本方法.其次,利用W–OSPA距离求解多扩展目标后验分布的离差,以离差最小化获得最优化的多扩展目标状态估计设计传感器管理策略.最后,通过推导给出的离差数值求解方法进行最优传感器管理方案的决策.仿真实验基于OSPA距离评价验证了所提传感器管理方法相对于其他算法对多扩展目标的质心运动状态和椭圆形状都有更好的估计效果.     

面向非线性MTT的多模型泊松多伯努利混合滤波算法

在多目标跟踪(Multi-target Tracking, MTT)的非线性特性与低检测概率情况下,针对多伯努利滤波算法的高斯混合(Gaussian Mixture, GM)实现难以精确估计目标的势与运动状态的实际问题,本文提出了一种适用于非线性系统的泊松多伯努利混合滤波(Poisson Multi-Bernoulli Mixture Filter, PMBM)算法.首先,推导出多模型泊松多伯努利混合滤波的高斯混合(GM Multi-model PMBM,GM-MM-PMBM)实现过程.然后,分别对GM-MM-PMBM的伯努利高斯分量进行预测与更新,实现了基于非线性系统的MTT.为提升系统稳定性,基于平方根协方差矩阵推导出GM-MM-PMBM均方根容积卡尔曼滤波算法的实现过程.最后,仿真实验综合验证了本文算法的跟踪性能.     

多目标跟踪中多传感器分布式控制策略

分布式传感器网络技术在复杂的多目标跟踪系统中发挥了极其重要的作用.本文针对多传感器多目标跟踪中的分布式传感器控制问题,提出了基于信息论的多传感器控制策略.首先,本文利用随机有限集(RFS)建模,给出了多传感器多伯努利滤波器,并通过一组参数化的多伯努利过程来近似多传感器多伯努利密度.进一步的,通过多伯努利滤波器的序贯蒙特卡罗实现,设计采样方案对多伯努利密度进行粒子采样,用一组带有权值的粒子集近似多目标状态空间分布.随后,借助巴氏距离(Bhattacharyya distance)作为传感器控制的评价函数用于多个传感器的独立并行控制方案的决策制定.作为另外一个重要内容,本文提出了一种基于多目标战术重要性评估的多传感器控制策略.该控制方案旨在评估多目标战术重要性的基础上对威胁度最大的目标进行优先跟踪.最后,仿真实验验证了所提算法的有效性.     

基于变分贝叶斯势均衡多目标多伯努利滤波的 多扩展目标跟踪算法

由于传统多扩展目标跟踪算法在量测噪声协方差未知情况下跟踪性能急剧下降,本文提出一种基于变分贝叶斯的势均衡多目标多伯努利滤波(VB--CBMe MBer)跟踪算法,并给出了高斯混合实现.该算法在未知量测噪声协方差的情况下,将量测看成随机分布在扩展目标上的量测产生点所产生,利用变分贝叶斯方法近似地求出各量测产生点状态和量测噪声协方差的联合概率密度,并给出其递归形式以估计量测产生点,继而将得到的量测产生点状态进行聚类得到扩展目标的状态.仿真实验表明,所提算法可以自适应地跟踪未知数目、未知量测噪声协方差的多扩展目标.其跟踪精度与传统的CBMe MBer跟踪算法相比,有明显提高.     

基于GLMB滤波和Gibbs采样的多扩展目标有限混合建模与跟踪算法

本文针对杂波条件下多扩展目标的状态估计, 目标个数估计, 扩展目标形状估计问题, 提出了一种基于标签随机有限集(Labelled random finite sets, L-RFS)框架下多扩展目标跟踪学习算法, 该学习算法主要包括两方面:多扩展目标动态建模和多扩展目标的跟踪估计.首先, 结合广义标签多伯努利滤波器(Generalized labelled multi-Bernoulli, GLMB)建立了扩展目标的量测有限混合模型(Finite mixture models, FMM), 利用Gibbs采样和贝叶斯信息准则(Bayesian information criterion, BIC)准则推导出有限混合模型的参数来对多扩展目标形状进行学习, 然后采用等效量测方法来替代扩展目标产生的量测, 对扩展目标形状采用椭圆逼近建模, 实现扩展目标形状与状态的估计.仿真实验表明本文所给的方法能够有效跟踪多扩展目标, 并且在目标个数估计方面优于CBMeMBer算法.此外, 与标签多伯努利滤波(LMB)计算比较表明: GLMB和LMB算法滤波估计精度接近, 二者精度高于CBMeMBer算法.     

基于星凸RHM的扩展目标SMC-PHD滤波

针对扩展目标跟踪过程中存在的外形拟合和非线性的问题,提出一种基于星凸随机超曲面模型(RHM)的扩展目标序贯蒙特卡洛概率假设密度滤波(SMC-PHD)算法。该算法运用星凸RHM对扩展目标量测源建模,在SMC-PHD的框架下,推导出非线性滤波算法的量测似然表达式和更新方程,实现扩展目标跟踪。仿真结果证明,文中所提算法的跟踪性能较其他滤波对于目标扩散程度和质心估计均有提高。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。