Active contours driven by local image fitting energy

A new region-based active contour model that embeds the image local information is proposed in this paper. By introducing the local image fitting (LIF) energy to extract the local image information, our model is able to segment images with intensity inhomogeneities. Moreover, a novel method based on Gaussian filtering for variational level set is proposed to regularize the level set function. It can not only ensure the smoothness of the level set function, but also eliminate the requirement of re-initialization, which is very computationally expensive. Experiments show that the proposed method achieves similar results to the LBF (local binary fitting) energy model but it is much more computationally efficient. In addition, our approach maintains the sub-pixel accuracy and boundary regularization properties.     

服务本体驱动的构件协同模型

设计构件协同的关键在于向构件提供一种可观测的交互模式,众多协同模型虽然对此问题有所考虑,但并未将其抽象到通用级别。采用描述逻辑对构件服务予以概念化而构成服务本体,并将其作为构件可观测的基准,在软件体系结构的抽象级别上利用服务本体扩展了软件体系结构连接件。基于上述基本思路,设计了协同介质的基本结构并规范了基于脚本语言的协同规则,提出了一种通用的构件协同模型。     

双目标推动下群体行为的元胞自动机模拟

采用元胞自动机对自推动粒子改进模型进行模拟,在此基础上分别探讨无目标与双目标群体行为的演化特征。无目标条件下群体行为的元胞模拟结果显示低密度环境下大部分个体处于动态均衡,高密度环境下大部分个体处于静态均衡,中等密度下两种均衡均存在。基于双目标吸引力的群体行为模拟结果显示当智能体的理性程度较低时系统演化能够产生一定的集聚效应,处于吸引源以外的智能体与吸引源保持一定距离并呈湍流式运动,而当智能体具备小概率全局理性判断能力时,群体行为的演化结果为大部分智能体都聚集在吸引源附近。     

MDA的设想与实现

模型驱动体系结构(MDA)提出了一种利用模型进行软件开发的方法,它将模型作为软件开发过程的关键,MDA的基本思想是将模型区分为平台独立模型(platform independent model)和平台相关模型(platform specific model),通过不同抽象层次模型之间的转换完成软件开发过程。介绍了MDA的设想,包括MDA的基本概念,基于MDA的开发过程,讨论了实现MDA所涉及的几个重要问题。     

基于局部熵的主动轮廓模型

针对传统C-V模型对灰度分布不均匀图像分割效果不理想的问题,研究了一种基于局部熵的主动轮廓模型.首先,算法将局部熵的概念引入到C-V模型中,通过核函数获得局部区域的不均匀信息,来构建局部熵能量函数;其次,采用变分水平集的方法,最小化局部熵能量泛函,得到水平集的梯度下降流,根据梯度下降流不断更新水平集,获得目标轮廓图;最后,对4组灰度严重不均匀的图像进行仿真实验,并将本文算法与LBF方法和LGDF方法进行对比.实验结果表明,与LBF方法和LGDF方法相比,本文算法实现了灰度不均匀的图像的精确分割.     

基于人眼视觉感知驱动的井下图像增强算法

为解决传统的对比度增强方法在对井下图像进行处理时不能兼顾压缩动态范围、调整亮度以及增强图像对比度等问题,提出一种基于人眼视觉感知特性的井下图像对比度增强算法。首先根据人眼亮度掩蔽特性对图像进行区域划分,然后基于非线性亮度映射模型,对图像的不同区域进行不同尺度的非线性调整,最后再将亮度调整后的不同区域组合成新的图像。实验结果表明,该方法能有效增强井下低照度图像的对比度,提升图像的视觉效果。     

Dynamic multi-objective optimization based on membrane computing for control of time-varying unstable plants

Dynamic multi-objective optimization is a current hot topic. This paper discusses several issues that has not been reported in the static multi-objective optimization literature such as the loss of non-dominated solutions, the emergence of the false non-dominated solutions and the necessity for an online decision-making mechanism. Then, a dynamic multi-objective optimization algorithm is developed, which is inspired by membrane computing. A novel membrane control strategy is proposed in this article and is applied to the optimal control of a time-varying unstable plant. Experimental results clearly illustrate that the control strategy based on the dynamic multi-objective optimization algorithm is highly effective with a short rise time and a small overshoot.     

质子交换膜燃料电池风机控制技术研究

该文首先研究了质子交换膜燃料电池(PEMFC)风机的性能,分析了PEMFC的工作温度对其性能的影响,并给出了控制PEMFC风机的数学模型。然后,对高电压、大电流运算放大器OPA548进行了详细的介绍,设计了用OPA548控制PEMFC风机工作电压的硬件电路,最后,对使用OPA548时应注意的事项进行了讨论。     

融合局部和全局高斯概率信息的图像分割模型

在现有的活动轮廓中,LBF模型、LIF模型和LGDF模型是著名的基于区域的模型。虽然能分割灰度不均匀的图像,但对活动轮廓的初始化和噪声较为敏感。针对该问题,提出一种融合全高斯和局部高斯概率信息的活动轮廓模型。首先由全局高斯模型的全局灰度拟合力和局部高斯模型的局部灰度拟合力的一个线性组合来构造水平集演化力,然后引入这两个拟合力的动态权重以达到该模型的灵活性,实验结果表明,该模型能分割灰度不均的图像,且允许灵活的轮廓初始化,抗噪声性强。     

Analysis of membrane microdomain-associated proteins in the insular cortex of post-mortem human brain

Membrane microdomains (MM) are membrane rafts within the cell membrane enriched in cholesterol and glycosphingolipids that have been implicated in the trafficking and sorting of membrane proteins, secretory and endocytotic pathways, and signal transduction. To date, MM have not been characterised in the human brain. We reason that by identifying MM in the normal human cortex, we may better understand the molecular mechanisms of human brain dysfunction. To characterize the protein composition of MM in the human brain, we have carried out a comprehensive proteomic analysis of detergent resistant membranes (DRMs) associated proteins derived from human postmortem insular cortex using 1-DE separation prior to LC coupled to MS/MS or GeLC-MS/MS. Eighty five proteins were identified including 57 unique to human brain cortex DRMs (by comparison with DRM proteins reported in other cell types). High levels of signal transduction, cell adhesion, cell transport and cell trafficking proteins were identified including synaptic proteins such as synapsin II and synaptic vesicle membrane protein, mitochondrial proteins such as ATPase subunits and metabolic enzymes such as malate dehydrogenase. This data will facilitate our understanding of protein expression changes within membranes in candidate brain regions in human brain diseases such as schizophrenia, bipolar disorder and other psychiatric and neurodegenerative disorders.     

模拟进化优化方法及其应用：遗传算法

在本世纪六十年代中期,美国、德国等国家的一些科学家开始研究用模仿生物和人类进化的方法求解复杂的优化问题的方法,这里我们统称之为模拟进化优化方法(optimi:ation method by simulatedevolution)。但这些方法在六十年代和七十年代并未受到普遍的重视,一是因为当时这些方法还不成熟,二是当时计算机发展水平低,容量小,计算速度慢,这些方法又需要较大的计算量,难以实际应用。但在这期间有一些科学家一直在进行不懈的努力.代表性人物之一为美国的著名科学家J.H.Holland,他和他的学生甲直在对他所提出的一种模拟进化优化方法—遗传算法(Genetic Algorithm,GA)进行理论研究并开拓其应用领域。八十年代初期,伴随着人工神经元网络理论和机器学习理论的发展以及计算机容量和计算速度的不断提高,遗传算法的研究也越来越受到重视而逐步成熟起来,并日益受到各学科研究人员的普遍重视。自八十年代中期开始,这种方法除了在人工智能领域。     

A rewriting logic framework for operational semantics of membrane systems

Existing results in membrane computing refer mainly to P systems’ characterization of Turing computability, also to some polynomial solutions to NP-complete problems by using an exponential workspace created in a “biological way”. In this paper we define an operational semantics of a basic class of P systems, and give two implementations of the operational semantics using rewriting logic. We present some results regarding these implementations, including two operational correspondence results, and discuss why these implementations are relevant in order to take advantage of good features of both structural operational semantics and rewriting logic.     

结合统计和梯度信息的高效活动轮廓模型

提出一种由统计和梯度信息驱动的活动轮廓模型。该模型有效利用梯度信息使演化轮廓线快速精确地定位到物体的边缘;同时,由局部统计信息和全局统计信息构造符号压力函数,减少噪声对轮廓线演化的影响。另外,模型利用局部统计信息能够有效处理灰度分布不均的图像,全局信息的利用避免了演化轮廓线陷入局部最小,因此,该模型可以任意设置初始轮廓线。最后通过高斯卷积核对水平集函数规则化,避免了传统模型中计算代价高昂的重新初始化和规则化。实验结果表明,提出的模型不仅能够在任意初始轮廓下精确有效地分割灰度分布均匀的图像和不均匀的图像,而且对噪声具有较好的鲁棒性。     

基于功能的构件演化模型的应用研究

基于构件的软件架构技术是软件工程领域中新兴的软件设计技术,其中构件演化理论成为目前软件工程理论研究的热点问题。本文从构件的功能出发建立了基于功能的构件演化模型,分析了该模型的性质,并通过该模型建立了构件演化的判断条件和演化后软件系统的可达性判断方法。     

状态和数据双因素驱动的决策支持系统模型复合方法

针对决策支持系统（DSS）模型复合工程中存在着单一因素驱动方法适用范围窄、效率低以及多因素驱动方法缺乏对算法或子模型层次的逻辑关系的描述、黑盒抽象程度低等不足,提出了状态和数据双因素共同驱动的模型复合方法。该方法首先定义工作流过程模型,将DSS子模型生成为一个可移植的、逻辑独立的工作流活动,该活动内部包含了模型的求解算法,对外提供了参数接口;其次根据活动执行的依赖关系,制定相应的事件-条件-动作（ECA）规则来动态地绑定它们之间的复合关系;最后将规则转换为网络活动图,并借助自定义工作流平台进行复合。实验过程表明,该方法能解决一般性模型复合问题,具备较好的通用性及可扩展性。     

差分进化算法的性能分析及其动力学模型参数估计

差分进化算法以遗传算法为基础,在算法中引入扰动矢量,利用个体间的距离和方向等信息进行搜索,克服遗传算法容易“早熟”的缺陷。此外,差分进化算法收敛性及鲁棒性好,控制变量需要得不多,简单易用。分析差分进化算法的寻优性能,并将它应用于铯一铷一钒系低温硫酸催化剂中,SO2氧化反应的参数估计,证明利用差分进化算法得到的模型更加精确。     

突触噪声作用下的IF阈值神经元模型的随机共振

基于带阈值的积分放电模型研究了神经元在突触递质噪声和周期信号驱动下的随机共振现象.利用平均法得到系统输出幅值增益的精确表达式,考察了输出幅值增益与信号频率、噪声强度、相关时间及非对称度的关系.发现输出幅值增益随着这些参量的演化曲线在一定条件下呈非单调的,这些都表明在突触递质噪声和周期信号驱动下的神经发放确实存在随机共振现象.     

The response of grandstands driven by filtered Gaussian white noise processes

This paper presents a semi-analytical estimate of the response of a grandstand occupied by an active crowd and by a passive crowd. Filtered Gaussian white noise processes are used to approximate the loading terms representing an active crowd. Lumped biodynamic models with a single degree of freedom are included to reflect passive spectators occupying the structure. The response is described in terms of the first two moments, employing the Itô formula and the state augmentation method for the stationary time domain solution. The quality of the approximation is compared on the basis of three examples of varying complexity using Monte Carlo simulation based on a synthetic generator available in the literature. For comparative purposes, there is also a brief review of frequency domain estimates.