Finite-time stability and stabilization for stochastic markov jump systems with mode-dependent time delays

This paper is concerned with the problems of finite-time stability and stabilization for stochastic Markov systems with mode-dependent time-delays. In order to reduce conservatism, a mode-dependent approach is utilized. Based on the derived stability conditions, state-feedback controller and observer-based controller are designed, respectively. A new N-mode algorithm is given to obtain the maximum value of time-delay. Finally, an example is used to show the merit of the proposed results.     

煤机整体拉移在高普工作面跳压回采中的成功实践

介绍了皖北煤电集团公司祁东煤矿高普工作面遇落差2.5m以上断层跳采时,采用采煤机、转载机、运输机(三块溜槽为一组)整体拉移,快速完成工作面收作、安装任务的成功经验,对类似地质条件下高普工作面的跳压搬家回采具有一定的借鉴作用。     

Loss behavior in space priority queue with batch Markovian arrival process — discrete-time case

This paper applies matrix-analytic approach to the examination of the loss behavior of a space priority queue. In addition to the evaluation of the long-term high-priority and low-priority packet loss probabilities, we examine the bursty nature of packet losses by means of conditional statistics with respect to critical and non-critical periods that occur in an alternating manner. The critical period corresponds to having more than a certain number of packets in the buffer; non-critical corresponds to the opposite. Hence there is a threshold buffer level that splits the state space into two. By such a state-space decomposition, two hypothesized Markov chains are devised to describe the alternating renewal process. The distributions of various absorbing times in the two hypothesized Markov chains are derived to compute the average durations of the two periods and the conditional high-priority packet loss probability encountered during a critical period. These performance measures greatly assist the space priority mechanism for determining a proper threshold. The overall complexity of computing these performance measures is of the order O(K²m₁³m₂³), where K is the buffer capacity, and m₁ and m₂ are the numbers of phases of the underlying Markovian structures for the high-priority and low-priority packet arrival processes, respectively. Thus the results obtained are computationally tractable and numerical results show that, by choosing a proper threshold, a space priority queue not only can maintain the quality of service for the high-priority traffic but also can provide the near-optimum utilization of the capacity for the low-priority traffic.     

The Problem of On-Line Forecasting of Stochastic Characteristics of Markovian Parametric Systems

A two-stage numerical analytical method for forecasting stochastic characteristics of a Markovian dynamic system described by an evolutionary equation is developed in the paper within the framework of the projective-parametric theory. The solution continuously depends on a vector of real parameters that determine system operation conditions.     

Influence of Correlations between Measurement Errors on the Systematic Error of an Empirical Dependence

A method of estimating the systematic error of a model is developed and its introduction into a physical experiment is proposed for the case of correlated measurements of unequal accuracy. Algorithms for calculating the confidence limits of the systematic error of the model are obtained and investigated theoretically and their efficiency is demonstrated.     

Scaled consensus for MASs with compound noises over Markovian switched topologies

This article aims to address the stochastic scaled consensus issue in almost surely and mean square sense of stochastic multiagent systems (SMASs) with compound noises in a Markovian switching setting. At first, based on stochastic approximation technique and nearest-neighbor interaction rules, the stochastic scaled consensus controller is built for SMASs in presence of multiplicative and additive noise by designing a time-varying gain. Meanwhile, some consensus criterions of SMASs are addressed if the union of the graph and time-varying gain fulfill some mild requirements. Furthermore, the scaled consensus means that the agents' state variables tend to a prescribed proportion rather than the common value, so this behavior can be seen as non-convergent behavior. The difference with most of excellent literatures is that the coexistence of noncooperative behavior and multiplicative noise generates that it is not easy to transform the multiplicative noise term into the form of an error equation, which means that the Lyapunov methods cannot be directly utilized in our article. To cope with this, we first demonstrate the boundedness for each agent's state, and hence the convergence can be achieved. Finally, in order to reveal the efficiency of our proposed protocol, the corresponding example is given in the simulation part.     

大型圆筒混合机筒体制造工艺设计分析与论证

圆筒混合机的制造成功是大型机械设备国产化的新成果。混合机筒体的制造质量,直接关系整台设备运行的稳定性和使用寿命,是该设备制造技术重点、难点及核心。本文在分析这种超大型筒体结构特征及其关键制造技术的基础上,阐述了筒体的分段组合制造工艺方案的合理性,并详细论述了关系筒体强度和使用寿命各筒节焊接工艺的措施及关系筒体整体制造质量各关键筒节的制造工艺、工艺施工中的关键技术措施。通过筒体制造精度的检测结果验证了确保筒体最终制造质量的筒体组焊工艺、工艺装备及其调整、齿圈架法兰精整加工工艺设计是成功的。     

Approximate solutions for heavily loaded Markov-modulated queues

The existing exact solutions for Markov-modulated queues are computationally intensive and prone to numerical problems when the number of states of the Markovian environment becomes large. To address this problem, a simple geometric approximation is proposed. It uses the dominant eigenvalue of the characteristic matrix polynomial, together with the associated left eigenvector. That approximation is shown to be asymptotically exact in heavy traffic. In other cases, its accuracy is examined numerically.     

Savart — Masson effect in granular media

The paper describes experimental results for the Savart — Masson effect in a perfect granular medium under shearing. The relationships between displacement jumps, forces, gravitation load and the medium state are determined, and the dynamics of individual jumps is analyzed. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 13–18, November–December, 2008.     

Delay-dependent stability analysis for Markovian jump systems with interval time-varying-delays

This paper proposes improved stochastic stability conditions for Markovian jump systems with interval time-varying delays. In terms of linear matrix inequalities (LMIs), less conservative delay-range-dependent stability conditions for Markovian jump systems are proposed by constructing a different Lyapunov-Krasovskii function. The resulting criteria have advantages over some previous ones in that they involve fewer matrix variables but have less conservatism. Numerical examples are provided to demonstrate the efficiency and reduced conservatism of the results in this paper.