Temporal redundancy methods using risk-sensitive filtering andparameter estimation to detect failures in neutronic sensors duringreactor start-up and steady-state operation

In this paper, simple linear single-input-single output models of the reactor-regulating system have been considered, and risk-sensitive filtering and risk-sensitive parameter-estimation techniques have been used to obtain temporal-redundancy relations. While a risk-sensitive filter is used to provide a temporally redundant measurement of reactivity from an analytically redundant process parameter during a reactor start-up, a risk-sensitive parameter estimation technique is used to obtain temporally redundant measurements during steady state operation     

Cellular automata studies of mixing in chaotic flows

Results of cellular automata based studies of mixing in a square cavity are presented. Two periodic models are considered: one in which two walls move in opposite directions one at a time and the other in which they act simultaneously but alternate the directions of motion. Both flows are found to be chaotic and the Poincare sections and Lyapunov exponents are determined. The morphology of mixing is different in the two cases.     

A mixed norm performance measure for the design of multiratefilterbanks

A mixed norm performance measure is presented to design the synthesis filters of a multirate filterbank. The mixed norm performance measure is based on the energy as well as the peak value of the error signal. Mathematically, the performance measure minimizes the l₂ -norm of the error signal subject to the l_∞-norm of the error being bounded by some positive value v (this imposes a bound on the peak value of the error signal). The design problem is shown to be that of a mixed ℋ₂/ℋ_∞ optimization problem. The theory of linear matrix inequalities (LMIs) offers a tractable solution to such multiobjective synthesis problems. The synthesis filters designed with the new performance measure are compared with those obtained by similar induced norm minimization techniques in terms of degree of reconstruction, order of the synthesis filters, SNR, and aliasing distortion