Neural networks have shown good results for detecting a certain pattern in a given image. In this paper, faster neural networks for pattern detection are presented. Such processors are designed based on cross correlation in the frequency domain between the input matrix and the input weights of neural networks. This approach is developed to reduce the computation steps required by these faster neural networks for the searching process. The principle of divide and conquer strategy is applied through matrix decomposition. Each matrix is divided into submatrices small in size, and then each one is tested separately by using a single faster neural processor. Furthermore, faster pattern detection is obtained by using parallel processing techniques to test the resulting submatrices at the same time, employing the same number of faster neural networks. In contrast to faster neural networks, the speed-up ratio is increased with the size of the input matrix when using faster neural networks and matrix decomposition. Moreover, the problem of local submatrix normalization in the frequency domain is solved. The effect of matrix normalization on the speed-up ratio of pattern detection is discussed. Simulation results show that local submatrix normalization through weight normalization is faster than submatrix normalization in the spatial domain. The overall speed-up ratio of the detection process is increased as the normalization of weights is done offline.
An original Nyquist-based frequency domain robust decentralized controller (DC) design technique for robust stability and guaranteed nominal performance is proposed, applicable for continuous-time uncertain systems described by a set of transfer function matrices. To provide nominal performance, interactions are included in individual design using one selected characteristic locus of the interaction matrix, used to reshape frequency responses of decoupled subsystems; such modified subsystems are termed "equivalent subsystems". Local controllers of equivalent subsystems independently tuned for stability and specified feasible performance constitute the decentralized controller guaranteeing specified performance of the full system. To guarantee robust stability, the M−Δ stability conditions are derived. Unlike standard robust approaches, the proposed technique considers full nominal model, thus reducing conservativeness of resulting robust stability conditions. The developed frequency domain design procedure is graphical, interactive and insightful. A case study providing a step-by-step robust DC design for the Quadruple Tank Process [K.H. Johansson: Interaction bounds in multivariable control systems. Automatica 38 (2002), 1045-1051] is included.
Assessment of ultimate aeroelastic response of slender facades equipped with thin plexiglass sheets. The wave approach is used for modeling of aeroelastic wind forcing. The analysis of structural response is based on the transient dynamics. Some theoretical approaches are specified with experimental verification in the wind canal. The comparison of numerical and experimental approaches is made in order to demonstrate the efficiency of the procedures suggested. and Obsahuje seznam literatury
We describe an instrument that allows the rapid measurement of fluorescence lifetime-resolved images of leaves as well as sub-cellular structures of intact plants or single cells of algae. Lifetime and intensity fluorescence images can be acquired and displayed in real time (up to 55 lifetime-resolved images per s). Our imaging technique therefore allows rapid measurements that are necessary to determine the fluorescence lifetimes at the maximum (P level) fluorescence following initial illumination during the chlorophyll (Chl) a fluorescence transient (induction) in photosynthetic organisms. We demonstrate the application of this new instrument and methodology to measurements of: (1) Arabidopsis thaliana leaves showing the effect of dehydration on the fluorescence lifetime images; (2) Zea mays leaves showing differences in the fluorescence lifetimes due to differences in the bundle sheath cells (having a higher amount of low yield photosystem 1) and the mesophyll cells (having a higher amount of high yield photosystem 2); and (3) single cells of wild type Chlamydomonas reinhardtii and its non-photochemical quenching mutant NPQ2 (where the conversion of zeaxanthin to violaxanthin is blocked), with NPQ2 showing lowered lifetime of Chl a fluorescence. In addition to the lifetime differences referred to in (1) and (2), structural dependent heterogeneities in the fluorescence lifetimes were generally observed when imaging mesophyll cells in leaves. and O. Holub ... [et al.].