Kaiserslautern, Techn. Univ., Diss., 2003. / Computerdatei im Fernzugriff.

Kaiserslautern, Techn. University, Diss., 2003.

Universiẗat, Diss., 2002--Jena.

Doctor of Philosophy / Department of Electrical and Computer Engineering / Balasubramaniam Natarajan / Stochastic hybrid system (SHS) is a class of dynamical systems that experience interaction of both discrete mode and continuous dynamics with uncertainty. State estimation for SHS has attracted research interests for decades with Kalman filter based solutions dominating the area. Mode-based Kalman filter is an extended version of the traditional Kalman filter for SHS. In general, as Kalman filter is unbiased for non-hybrid system estimation, prior research efforts primarily focus on the behavior of error covariance. In SHS state estimate, mode mismatch errors could result in a bias in the mode-based Kalman filter and have impacts on the continuous state estimation quality. The relationship between mode mismatch errors and estimation stability is an open problem that this dissertation attempts to address. Specifically, the probabilistic model of mode mismatch errors can be independent and identically distributed (i.i.d.), correlated across different modes and correlated across time. The proposed approach builds on the idea of modeling the bias evolution as a transformed system. The statistical convergence of the bias dynamics is then mapped to the stability of the transformed system. For each specific model of the mode mismatch error, the system matrix of the transformed system varies which results in challenges for the stability analysis. For the first time, the dissertation derives convergence conditions that provide tolerance regions for the mode mismatch error for three mode mismatch situations. The convergence conditions are derived based on generalized spectral radius theorem, Lyapunov theorem, Schur stability of a matrix polytope and interval matrix method. This research is fundamental in nature and its application is widespread. For example, the spatially and timely correlated mode mismatch errors can effectively capture cyber-attacks and communication link impairments in a cyber-physical system. Therefore, the theory and techniques developed in this dissertation can be used to analyze topology errors in any networked system such as smart grid, smart home, transportation, flight management system etc. The main results provide new insights on the fidelity in discrete state knowledge needed to maintain the performance of a mode-based Kalman filter and provide guidance on design of estimation strategies for SHS.

No description available.

The efficacy of low frequency dosing, and application of the insect growth regulator pyriproxyfen, for the control of sewage filter flies, was assessed. The low dosing frequency trials targeted primarily Sylvicola fenestralis, but also the chironomids Limnophyes minimus and Metriocnemus hygropetricus. The trials of pyriproxyfen targeted Psychoda altemata. Three trials, assessing the effect of a range of dosing frequencies (20 down to 6 doses h-1), on filters with 50mm and 75mm slag media were undertaken. Retention time studies demonstrated that an increased surge or pulse of the applied sewage passed rapidly through the filter when the dosing frequency was reduced below 10, and at or below 12 doses h-1, for filters with 50mm and 75mm media, respectively. A significant (P < 0.05) increase in the wash-out of S. fenestralis egg masses, and a highly significant (P < 0.01) reduction in S.fenestralis larval numbers and adult emergence was recorded, in filters with a dosing frequency below 10, and at or below 12 doses h-1, for filters with 50mm and 75mm media. S. fenestralis populations were positively correlated (P < 0.05) with dosing frequency and retention. Surface film accumulation was not appreciably reduced, but accumulation deeper into the filters was altered. Chironomid populations were significantly (P < 0.05) increased in filters with a reduced dosing frequency. Low frequency dosing did not effect the nondipteran fauna, or the long-term BOD purification efficiency of the filters. Two trials, assessing the efficacy of pyriproxyfen were undertaken. In the first, pyriproxyfen was applied as an aqueous suspension, at a concentration of 0.5mg 1-1. Significant (P < 0.05) reductions in the emergence of P. altemata adults were achieved for 22 days. Reductions ranged from 19% to 77%. In the second trial pyriproxyfen was applied as the granular formulation, Sumilarv®, at a dose rate of 77.4 g m-2 of filter area. Significant (P < 0.05) reductions in adult emergence were achieved for 28 days. Control ranged from 35% to 92%. No adverse effects on the non-dipteran filter fauna, the purification efficiency I or the invertebrates in the river receiving the works effluent, were detected.

This study is based on applying a non-linear mapping method, here the unscented Kalman filter; to estimate and optimize data rate resulting from the arrival rate having a Poisson distribution in an orthogonal frequency division multiplexing (OFDM) transmission system. OFDM is an emerging multi-carrier modulation scheme. With the growing need for quality of service in wireless communications, it is highly necessary to optimize resources in such a way that the overall performance of the system models should rise while keeping in mind the objective to achieve high data rate and efficient spectral methods in the near future. In this study, the results from the OFDM-TDMA transmission system have been used to apply cross-layer optimization between layers so as to treat different resources between layers simultaneously. The main controller manages the transmission of data between layers using the multicarrier modulation techniques. The unscented Kalman filter is used here to perform nonlinear mapping by estimating and optimizing the data rate, which result from the arrival rate having a Poisson distribution.

This master thesis deals with the problematics of CT filters and focuses on Gm – C filter. Three linearisation techniques are listed and compared in terms of linear input range, distortion and retuning. In the practical part – second - order low – pass filter is designed and its tuning capabilities are examined.

No description available.

With the advent of wireless sensor technologies becoming more and more common-place in wearable devices and smartphones, indoor localization is becoming a heavily researched topic. One such application for this topic is in the medical field where wireless sensor devices that are capable of monitoring patient vitals and giving accurate location estimations allow for a less intrusive environment for nursing home patients. This project explores the usage of using received signal strength indication (RSSI) in conjunction with an inertial navigation system (INS) to provide location estimations without the use of GPS in a Particle Filter with a small development microcontroller and base station. The paper goes over the topics used in this thesis and the results.