多智能体系统协作及控制机理和基本问题分析

首先介绍智能体的概念，并从协作、协调一致性，理性原理及冲突等方面，较为全面而深化入地分析阐述了多智能体系统协从航控制的机理和基本问题。     

Constraint-Based Verification of Parameterized Cache Coherence Protocols

We propose a new method for the parameterized verification of formal specifications of cache coherence protocols. The goal of parameterized verification is to establish system properties for an arbitrary number of caches. In order to achieve this purpose we define abstractions that allow us to reduce the original parameterized verification problem to a control state reachability problem for a system with integer data variables. Specifically, the methodology we propose consists of the following steps. We first define an abstraction in which we only keep track of the number of caches in a given state during the execution of a protocol. Then, we use linear arithmetic constraints to symbolically represent infinite sets of global states of the resulting abstract protocol. For reasons of efficiency, we relax the constraint operations by interpreting constraints over real numbers. Finally, we check parameterized safety properties of abstract protocols using symbolic backward reachability, a strategy that allows us to obtain sufficient conditions for termination for an interesting class of protocols. The latter problem can be solved by using the infinite-state model checker HyTech: Henzinger, Ho, and Wong-Toi, A model checker for hybrid systems, Proc. of the 9th International Conference on Computer Aided Verification (CAV'97), Lecture Notes in Computer Science, Springer, Haifa, Israel, 1997, Vol. 1254, pp. 460–463. HyTech handles linear arithmetic constraints using the polyhedra library of Halbwachs and Proy, Verification of real-time systems using linear relation analysis, Formal Methods in System Design, Vol. 11, No. 2, pp. 157–185, 1997. By using this methodology, we have automatically validated parameterized versions of widely implemented write-invalidate and write-update cache coherence protocols like Synapse, MESI, MOESI, Berkeley, Illinois, Firefly and Dragon (Handy, The Cache Memory Book, Academic Press, 1993). With this application, we have shown that symbolic model checking tools like HyTech, originally designed for the verification of hybrid systems, can be applied successfully to new classes of infinite-state systems of practical interest.     

An evaluation of dimension reduction techniques for one-class classification

Dimension reduction (DR) is important in the processing of data in domains such as multimedia or bioinformatics because such data can be of very high dimension. Dimension reduction in a supervised learning context is a well posed problem in that there is a clear objective of discovering a reduced representation of the data where the classes are well separated. By contrast DR in an unsupervised context is ill posed in that the overall objective is less clear. Nevertheless successful unsupervised DR techniques such as principal component analysis (PCA) exist—PCA has the pragmatic objective of transforming the data into a reduced number of dimensions that still captures most of the variation in the data. While one-class classification falls somewhere between the supervised and unsupervised learning categories, supervised DR techniques appear not to be applicable at all for one-class classification because of the absence of a second class label in the training data. In this paper we evaluate the use of a number of up-to-date unsupervised DR techniques for one-class classification and we show that techniques based on cluster coherence and locality preservation are effective.     

Store Atomicity for Transactional Memory

We extend the notion of Store Atomicity [Arvind and Jan-Willem Maessen. Memory model = instruction reordering + store atomicity. In ISCA '06: Proceedings of the 33rd annual International Symposium on Computer Architecture, 2006] to a system with atomic transactional memory. This gives a fine-grained graph-based framework for defining and reasoning about transactional memory consistency. The memory model is defined in terms of thread-local Instruction Reordering axioms and Store Atomicity, which describes inter-thread communication via memory. A memory model with Store Atomicity is serializable: there is a unique global interleaving of all operations which respects the reordering rules and serializes all the operations in a transaction together. We extend Store Atomicity to capture this ordering requirement by requiring dependencies which cross a transaction boundary to point in to the initiating instruction or out from the committing instruction. We sketch a weaker definition of transactional serialization which accounts for the ability to interleave transactional operations which touch disjoint memory. We give a procedure for enumerating the behaviors of a transactional program—noting that a safe enumeration procedure permits only one transaction to read from memory at a time. We show that more realistic models of transactional execution require speculative execution. We define the conditions under which speculation must be rolled back, and give criteria to identify which instructions must be rolled back in these cases.     

基于ROI分割和相干映射的裸手字母手势识别

提出了实时条件下裸手单目的手部定位和跟踪算法。结合改进的差分法提出了实用的手部约束条件，从每帧图像中提取手部图像，确定感兴趣区域（ROI，region of interesting），得到较为满意的手部分割结果，再对手部图像特征进行深入分析和提取，利用改进的相干映射算法（VCM，vector coherence mapping）进行跟踪，针对手的运动增加了约束，保证了顽健性。在这个基础上，提出了时间相关的运动预测模型，满足了实时性的要求，保证前后分析结果的一致性。实验结果证明，在不同光照和复杂背景下系统有最高达99％的识别率，与已有的系统相比，性能显著提高。     

英语翻译中目标语篇局部连贯重构刍议

文章从局部连贯和整体连贯出发,通过调整衔接手段的方式来解决译文的局部连贯;译文中的局部连贯应服务于译文的整体连贯。旨在使目标语篇和源语篇同样达到连贯。     

星载分布式SAR干涉信号分析

星载分布式合成孔径雷达(SAR)具有双站和斜视的特点,本文分析了在这种情况下干涉信号的一些特征:(1)干涉信号相位与成像处理间的关系;(2)考虑地形情况下,干涉信号相位差及其相干性;(3)考虑配准误差时干涉信号相位差及其相干性。仿真分析了一系统干涉信号相干性随地形、基线及配准误差的变化。     

基于PDE的一致增强性扩散方法研究及其应用

针对具有线性纹理特征的图像,对基于偏微分方程的一致增强性扩散去噪方法进行了研究,详细分析了它的扩散去噪过程和纹理结构的保护及增强,设计出具体的算法步骤.在此基础上,针对线性结构图像序列,给出了三维一致增强性扩散模型.在选择合适的扩散参数情况下,一致增强性扩散算法不但使具有线性结构图像的信噪比有明显的提高,而且可以很好的保护和增强线性结构,具有广泛的应用领域.     

基于spikes-LFP相关性的相位同步化研究

神经系统的信息处理过程依赖于一种基本的神经机制-相位同步化.已往的研究表明单个神经元的spike与LFP构成同步化时会对应一个精确的相位,该相位能够对进一步处理信息以及与时间相关的可塑性产生影响.本文基于这项研究,提出了一种新颖的研究同步化现象的方法.运用该方法探索局部场电位(LFP)与神经元动作电位发放(Spikes)之间的相关性,该方法不仅能够保证数据分析的可靠性,而且在使用方面更简单、更具普遍性.     

一种基于离散小波基的压缩传感测量矩阵优化方法

测量矩阵优化是压缩传感理论(CS)研究的重要内容,基于离散小波基,提出一种测量矩阵优化算法.根据离散小波变换的系数分布特点,构建优化矩阵来对原测量矩阵系数进行调整,提高了采样效率,同时降低了测量矩阵列向量的相干性.理论分析和实验验证表明,该优化算法对压缩传感中常用测量矩阵进行优化后,其重建效果都有所提高,特别是在低采样率的条件下,优化效果明显.经过验证,优化后的测量矩阵满足有限等距特性(RIP).