一类非自治时滞微分系统有界解的收敛性

研究一类非自治时滞微分系统有界解的渐近性态,且给出系统的有界解收敛于其平衡态的结果。     

A New delay control method for real-time flows

This paper presents a novel control algorithm to decrease the worst-case delay bound for high rate homogeneous and heterogeneous real-time flows when the network traffic load becomes heavy. The algorithm is adaptive based on the instantaneous network situations. It employs a generalized form of traditional (σ,ρ) regulator called the generalized (σ,ρ,λ) regulator that operates like the (σ,ρ) regulator under the normal network traffic load situation, but provides more regulations for the heavy network traffic load situation. For a set of real-time flows, we can show that D _rg ≤D _g where D _rg and D _g are the worst-case delay bounds with the (σ,ρ,λ) regulator and the (σ,ρ) regulator respectively. More specifically, we have developed a set of formulas to set the parameters for the new regulator so as to reduce the worst-case delay bounds for the real-time flows. We can prove that there exists a threshold input rate ρ^* such that D _rg = D _g for ρ≤ρ^* and D _rg < D _g for ρ > ρ^*. When the average input rate of real-time flows is very high, the generalized regulator can effectively control the delay. The extensive experiment data match our theoretical results. The part of this paper has been appeared in The 23 ^rd IEEE International Conference on Distributed Computing Systems, 2003. The work is supported by CityU strategic grant Nos: 7001777 and 7001709 and CityU ARP Project No. 9610027. H. Wang was partially supported by National Natural Science Foundation of China (10471088, 60572126) and CityU strategic grant no. 7001709. Wanqing Tu is now with Department of Computer Science, The Hong Kong University of Science and Technology. Clear Water Bay, New Territories, Kowloon, Hong Kong.     

一类带有时滞的神经网络一致稳定性判别法

讨论带有时滞神经网络一致稳定性的问题,给出了状态函数与输出函数关于平衡点一致稳定、全局一致渐近稳定性等价性定理及判别方法。     

实现千兆防火墙的关键技术及其发展前景

针对目前国内很多"号称"具有千兆防火墙的技术局面,阐述了真正的千兆防火墙所要达到的性能要求,详细地分析了实现千兆防火墙的关键技术,展望了防火墙包过滤技术、体系结构和系统管理3方面的发展趋势.     

The assessment of tumour response to treatment

Summary.  A parsimonious model for treated tumours is developed as a continuation of our previous work on regrowth curve theory. The statistical model belongs to the family of marginal non-linear models since the only linear parameters of the model are tumour specific and random facilitating parameter estimation. An important feature of the model is that it enables the estimation of the fraction of cancer cells surviving the treatment in vivo having easy-to-obtain longitudinal measurements of tumour volume. We compare several methods of estimation, including Lindstrom–Bates, iterated reweighted least squares and maximum likelihood. The last two methods are computed via the total estimating equations approach and variance least squares. The theory is illustrated with a photodynamic tumour therapy example.     

积分微分系统的鲁棒稳定化

研究了具有时滞的积分微分系统的鲁棒稳定化问题，利用不等式分析技巧，给出了具有不确定系统的鲁捧全局一致渐近稳定性的判别准则，举例说明了文中结果的优越性。     

误差补偿和时滞辨识预测控制算法

通过神经网络辨别出非线性系统的滞后时间,并采用误差补偿手段对神经网络进行修正,控制系统的反馈取自不带时滞的非线性神经网络的输出,采用预测控制策略改善整个系统的控制性能。仿真实验表明该方法具有较快的响应速度和较强的自适应性与鲁棒性,能有效克服延迟和干扰给控制品质带来的不利影响,取得了良好的控制性能。     

关于Bellman問題

本文首先研究了常时滞线性方程与变时滞线性方程解之间的一致性问题,然后作为特殊情况,解决了Bellman于1965年提出的一个问题。     

数字多声束形成技术

医用超声诊断设备中存在两种声束形成技术。近年来在少数几个高档设备中使用了数字声束形成技术。正交分解是获得复包络信号的幅度和相位的关键，而数字延迟是数字电子聚焦所必须的。文中介绍了数字多声束形成的原理及应用。     

Dynamic sampling plans in on-line control charts

Three simple dynamic sampling plans for detecting the change point are investigated in the discrete-time case. The first is a two-rate sampling CUSUM procedure. The second is a two-rate sampling Shiryayev-Roberts procedure. The third is a periodic sequential testing procedure. Two problems are discussed. First, simple design methods are provided for practical use. Second, a comparison between the three plans is made in the continuous-time case, which shows that by properly choosing the design parameters, the three plans can be made equally efficient in certain senses.