372 research outputs found
Distributed filtering of networked dynamic systems with non-gaussian noises over sensor networks: A survey
summary:Sensor networks are regarded as a promising technology in the field of information perception and processing owing to the ease of deployment, cost-effectiveness, flexibility, as well as reliability. The information exchange among sensors inevitably suffers from various network-induced phenomena caused by the limited resource utilization and complex application scenarios, and thus is required to be governed by suitable resource-saving communication mechanisms. It is also noteworthy that noises in system dynamics and sensor measurements are ubiquitous and in general unknown but can be bounded, rather than follow specific Gaussian distributions as assumed in Kalman-type filtering. Particular attention of this paper is paid to a survey of recent advances in distributed filtering of networked dynamic systems with non-Gaussian noises over sensor networks. First, two types of widely employed structures of distributed filters are reviewed, the corresponding analysis is systematically addressed, and some interesting results are provided. The inherent purpose of adding consensus terms into the distributed filters is profoundly disclosed. Then, some representative models characterizing various network-induced phenomena are reviewed and their corresponding analytical strategies are exhibited in detail. Furthermore, recent results on distributed filtering with non-Gaussian noises are sorted out in accordance with different network-induced phenomena and system models. Another emphasis is laid on recent developments of distributed filtering with various communication scheduling, which are summarized based on the inherent characteristics of their dynamic behavior associated with mathematical models. Finally, the state-of-the-art of distributed filtering and challenging issues, ranging from scalability, security to applications, are raised to guide possible future research
Survival Analysis of a Nonautonomous Logistic Model with Stochastic Perturbation
Taking white noise into account, a stochastic nonautonomous logistic model is proposed and investigated. Sufficient conditions for extinction, nonpersistence in the mean, weak persistence, stochastic permanence, and global asymptotic stability are established. Moreover, the threshold between weak persistence and extinction is obtained. Finally, we introduce some numerical simulink graphics to illustrate our main results
Stability and bifurcation of numerical discretization Nicholson blowflies equation with delay
A kind of discrete system according to Nicholson's blowflies
equation with a finite delay is obtained by the Euler forward
method, and the dynamics of this discrete system are investigated.
Applying the theory of normal form and center manifold, we not
only discuss the linear stability of the equilibrium and the
existence of the local Hopf bifurcations, but also give the
explicit algorithm for determining the direction of bifurcation
and stability of the periodic solution of bifurcation
Stability and Stabilization of Impulsive Stochastic Delay Differential Equations
We consider the stability and stabilization of impulsive stochastic delay differential equations (ISDDEs). Using the Lyapunov-Razumikhin method, we obtain the sufficient conditions to guarantee the pth moment exponential stability of ISDDEs. Then the almost sure exponential stability is considered and the sufficient conditions of the almost sure exponential stability are obtained. Moreover, the stabilization problem of ISDDEs is studied and the criterion on impulsive stabilization of ISDDEs is established. At last, examples are presented to illustrate the correctness of our results
Comparison of the Effectiveness of Pars Plana Vitrectomy with and without Internal Limiting Membrane Peeling for Idiopathic Retinal Membrane Removal: A Meta-Analysis
We conducted a meta-analysis of published retrospective studies and compared the effectiveness of pars plana vitrectomy with and without internal limiting membrane (ILM) peeling for idiopathic epiretinal membrane (IERM). The results revealed that patients in the IERM+ILM peeling group had better BCVA after surgery within 12 months than those in IERM peeling group. But patients in the IERM peeling group showed better BCVA in the 18th month. More retrospective studies or randomized controlled trials are required to investigate and compare the long-term effect of IERM removal with and without ILM peeling
Optimization of Inner Dumping Uncovered Height with Partially Covered End Wall in Adjacent Surface Coal Mining Districts
In order to analyze the relationships of inner dumping with covered end wall in adjacent surface coal mining districts, a trough-shaped uncovered end wall model was put forward. A mathematical model concerning uncovered end wall height (UEWH) was established based on minimum cost method. The inner dump capacity was considered regarding its effect on UEWH. Besides, a comprehensive model was established for calculating optimal UEWH in inner dumping with partially covered end wall mode and a shifting distance optimization model based on cost compensation method for building a provisional haulage system to connect inner dump. As for case study in Huolinhe number 1 surface coal mine, research results show that optimal UEWH was 225 m between North Pit and South Pit whereas in number 3 mining district of North Open-Pit Mine it was 23.50 m when making its transition from cross mining to mining along strike. Nevertheless, due to limited inner dump capacity, inner dump height in South and North mining districts shall be appropriately increased and closed pits from earlier period shall be fully utilized to make room for inner dumping with partially uncovered end walls
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