Dissipative control systems synthesis with full state feedback

In this paper we present a general framework for synthesizing state feedback controllers to achieve any desired closed loop dissipative behavior. Special cases include positive real andH _∞ controller synthesis. We show that the solution to this dissipative controller synthesis problem is equivalent to the existence of a solution to a partial differential inequality (nonlinear systems case) or an algebraic Riccati inequality (linear systems case). Stability results can be obtained under appropriate detectability assumptions, and a generalization of the strict bounded real lemma is given. We also present an application of the results to a robust stabilization problem. This work was supported by the Cooperative Research Centre for Robert and Adaptive Systems (CRASys), Australia.     

Displacement Following of Hidden Objects in a Video Sequence

In a video sequence, computing the motion of an object requires the continuity of the apparent velocity field. This property does not hold when the object is hidden by an occlusion during its motion. The minimization of an energy functional leads to a simple algorithm which allows the recovery of the most likely trajectory of the occluded object from optical flow data at the border of the occlusion. Optical flow used for developing our method is an improvement on any variational technique of computing it. This improvement is based on a multichannel segmentation.     

基于数学形态滤波器抑制局部放电窄带周期性干扰的研究

变压器局部放电在线检测的关键技术之一是有效抑制现场强烈的电磁干扰。文中引入非线性数学形态学变换，基于最小均方(LMS)算法构造了一种结构元素自适应的形态开、闭组合形态滤波器，很好地解决了局部放电在线检测的窄带周期性干扰问题。仿真表明该方法对窄带周期性干扰的噪声抑制比(NNR)大于60dB，而现场实际测量的噪声抑制比超过20dB。数学形态滤波器为电力变压器局部放电在线检测提供了一种新的干扰抑制方法。     

Integrated condition monitoring and control of fed-batch fermentation processes

This paper investigates the benefits that the partial least squares (PLS) modelling approach offers engineers involved in the operation of fed-batch fermentation processes. It is shown that models developed using PLS can be used to provide accurate inference of quality variables that are difficult to measure on-line, such as biomass concentration. It is further shown that this model can be used to provide fault detection and isolation capabilities and that it can be integrated within a standard model predictive control framework to regulate the growth of biomass within the fermenter. This model predictive controller is shown to provide its own monitoring capabilities that can be used to identify faults within the process and also within the controller itself. Finally it is demonstrated that the performance of the controller can be maintained in the presence of fault conditions within the process.     

多级实时数据库的安全性策略

实时数据库根本目标就是使满足截止时间的事物数量为最大,因而,管理和支持优先考虑时间的事务处理是非常重要的。然而,随着实时计算的迅速发展,安全成了许多实时应用另一个必须考虑的问题。因此,在多级实时数据库系统中,提出一种结合实时性和安全性的方法是非常必要的。本文陈述了实时系统设计者应该考虑的实时性和安全性,描述了一种规范语言允许设计者在适当的级别设定数据库的重要属性以支持部分安全并探讨了一种自适应方法以达此目的。     

增强现实中基于自然特征的实时跟踪方法

在增强现实系统的复杂场景中,对目标的实时跟踪受到场景中诸多因素的制约,导致实时跟踪方法效率低且不准确,为此提出一种基于自然特征的实时跟踪方法。设计了一种螺旋分割模型,对捕获的图像进行螺旋分割,利用SURF算法在分割子块中提取特征点,并进行匹配。在对目标进行跟踪定位时,利用前一帧来预测当前帧目标出现的位置,以减少SURF算法的扫描区域,加速系统运算效率。实验中分别对场景光线强弱、视点和仿射变化以及目标被部分遮挡等不同情况进行测试,该方法均表现出较高的跟踪效率。     

Nicotinamide Mononucleotide Protects against Retinal Dysfunction in a Murine Model of Carotid Artery Occlusion

Cardiovascular abnormality-mediated retinal ischemia causes severe visual impairment. Retinal ischemia is involved in enormous pathological processes including oxidative stress, reactive gliosis, and retinal functional deficits. Thus, maintaining retinal function by modulating those pathological processes may prevent or protect against vision loss. Over the decades, nicotinamide mononucleotide (NMN), a crucial nicotinamide adenine dinucleotide (NAD⁺) intermediate, has been nominated as a promising therapeutic target in retinal diseases. Nonetheless, a protective effect of NMN has not been examined in cardiovascular diseases-induced retinal ischemia. In our study, we aimed to investigate its promising effect of NMN in the ischemic retina of a murine model of carotid artery occlusion. After surgical unilateral common carotid artery occlusion (UCCAO) in adult male C57BL/6 mice, NMN (500 mg/kg/day) was intraperitoneally injected to mice every day until the end of experiments. Electroretinography and biomolecular assays were utilized to measure ocular functional and further molecular alterations in the retina. We found that UCCAO-induced retinal dysfunction was suppressed, pathological gliosis was reduced, retinal NAD⁺ levels were preserved, and the expression of an antioxidant molecule (nuclear factor erythroid-2-related factor 2; Nrf2) was upregulated by consecutive administration of NMN. Our present outcomes first suggest a promising NMN therapy for the suppression of cardiovascular diseases-mediated retinal ischemic dysfunction.     

混合高斯模型结合五帧差分的运动目标检测

在复杂背景下,光照变化、目标短暂遮挡以及背景运动等因素会导致运动目标检测精度较低.提出一种结合改进混合高斯模型和改进五帧差分的运动目标检测算法,首先在混合高斯模型中加入自适应学习率以及背景学习速率更新策略有效解决传统背景更新速率恒定而出现的残影现象;然后利用改进的五帧差分法克服运动目标短暂遮挡问题,并加入光照阈值判别因...     

多窗口目标跟踪算法

目标在复杂环境下运动,特征会受到光照、摄像机角度等因素影响,并且目标可能会被自身其他部分或者场景物体遮挡,为此,提出一种多窗口概念的视频目标跟踪算法,基本思想就是将目标用多个不同的窗口表示,每一个窗口对应一个跟踪器.这些窗口之间可以存在重叠,也可以包含被跟踪目标上下文信息,如在人脸跟踪中,有些跟踪窗口可以包含颈部信息、上衣颜色信息.然后利用这些窗口之间的位置关系以及在后继跟踪过程中的相似度来估计目标的真实位置.通过实验可以看出,提出的多窗口均值移动跟踪算法可以提高系统在遮挡、光照变化等复杂条件下的跟踪性能.     

位移场估计法在交通管理中的应用研究

智能交通系统中，车辆的行驶速度是重要的参数之一，为了快速获得车辆的行驶速度，提出了一种基于位移场的运动场估计计算法，该方法首先构造一个基于图象灰度的指标函数，再通过变分法中的欧拉方程分析和偏微分方程的数值解法，即可得到序列图象间的位移场；然后利用帧间位移场、帧间时间差、摄像机与车辆间的距离等参数相结合可计算出车辆的行驶速度，实验结果表明，与块匹配法相比，该方法不仅可得到更好的位移场，而且可快速获得车辆的行驶速度。