The impact of PMU measurement delays and a heterogenous communication network on a linear state estimator

Author(s):  
Markos Asprou ◽  
Elias Kyriakides ◽  
Ana-Maria Dumitrescu ◽  
Mihaela Albu
1990 ◽  
Vol 112 (4) ◽  
pp. 774-781 ◽  
Author(s):  
R. J. Chang

A practical technique to derive a discrete-time linear state estimator for estimating the states of a nonlinearizable stochastic system involving both state-dependent and external noises through a linear noisy measurement system is presented. The present technique for synthesizing a discrete-time linear state estimator is first to construct an equivalent reference linear model for the nonlinearizable system such that the equivalent model will provide the same stationary covariance response as that of the nonlinear system. From the linear continuous model, a discrete-time state estimator can be directly derived from the corresponding discrete-time model. The synthesizing technique and filtering performance are illustrated and simulated by selecting linear, linearizable, and nonlinearizable systems with state-dependent noise.


Author(s):  
Pradeep Lall ◽  
Hao Zhang ◽  
Lynn Davis

The reliability consideration of LED products includes both luminous flux drop and color shift. Previous research either talks about luminous maintenance or color shift, because luminous flux degradation usually takes very long time to observe. In this paper, the impact of a VOC (volatile organic compound) contaminated luminous flux and color stability are examined. As a result, both luminous degradation and color shift had been recorded in a short time. Test samples are white, phosphor-converted, high-power LED packages. Absolute radiant flux is measured with integrating sphere system to calculate the luminous flux. Luminous flux degradation and color shift distance were plotted versus aging time to show the degradation pattern. A prognostic health management (PHM) method based on the state variables and state estimator have been proposed in this paper. In this PHM framework, unscented kalman filter (UKF) was deployed as the carrier of all states. During the estimation process, third order dynamic transfer function was used to implement the PHM framework. Both of the luminous flux and color shift distance have been used as the state variable with the same PHM framework to exam the robustness of the method. Predicted remaining useful life is calculated at every measurement point to compare with the tested remaining useful life. The result shows that state estimator can be used as the method for the PHM of LED degradation with respect to both luminous flux and color shift distance. The prediction of remaining useful life of LED package, made by the states estimator and data driven approach, falls in the acceptable error-bounds (20%) after a short training of the estimator.


Author(s):  
Dženan Brigić

The transformation of hunter-gatherer society, who lived as nomads for a  very long time, largely influenced the development of road communication. These communities now established permanent settlements, especially in arable lands, and had a somewhat lifestyle than before. The cultivation of grains  and domestication of animals meant that people had no more need for migration and the search for better locations, instead they started setting up their  homes in the proximity to other community members, thereby forming the  first Neolithic settlements. By forming the settlements appeared the need to  establish a communication with other communities in the territory of present-day Balkans and wider, usually for the purpose of trade of certain goods,  which had a direct impact on the road communication development that laid  foundations for the development of the roads in the Roman period. Several  such settlements are known in the territory of present-day Bosnia that maintained continuity and tradition as well as road communications from the  Neolithic period up to the Roman period, i.e. Roman governor Publius Cornelius Dolabella, under whose governorship the widest road communication  network was built in the territory of the province of Dalmatia.     


2004 ◽  
Vol 2004 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Magdi S. Mahmoud ◽  
Peng Shi

This paper develops a result on the design of robust steady-state estimator for a class of uncertain discrete-time systems with Markovian jump parameters. This result extends the steady-state Kalman filter to the case of norm-bounded time-varying uncertainties in the state and measurement equations as well as jumping parameters. We derive a linear state estimator such that the estimation-error covariance is guaranteed to lie within a certain bound for all admissible uncertainties. The solution is given in terms of a family of linear matrix inequalities (LMIs). A numerical example is included to illustrate the theory.


Author(s):  
Vinaya Chakati ◽  
Madhurima Pore ◽  
Ayan Banerjee ◽  
Anamitra Pal ◽  
Sandeep K.S. Gupta

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