Control of a Nonsquare Multivariable System Using Pseudoin-verse Model-Based Static Output Feedback

The purpose of the paper is to answer the question: is there the SOF control based on the pseudoinverse concept to stabilize some first-order multivariable system with nonsquare gain matrix? Results. The pseudoinverse model-based control leading to static output feedback is proposed to reject unmeasured disturbances. The optimality and robustness properties of such controller are established. Numerical examples and simulation results are presented to support theoretical study.Мета роботи — дати відповідь на запитання: чи існує регулятор типу SOF, в основу якого покладено концепцію псевдообернення, аби стабілізувати деяку багатовимірну систему першого порядку з прямокутною матрицею коефіцієнтів підсилення? Результати. Аби придушити невимірювальні збурення, запропоновано керування, яке базується на методі псевдооберненої моделі. Цей метод формально приводить до реалізації статичного зворотного зв'язку. Встановлено умови оптимальності та робастності такого регулятора. Для підтвердження теоретичного дослідження наведено числові приклади та результати моделювання

Tests of Classical and Quantum Electrodynamics with Intense Laser Fields

n this chapter classical and quantum electrodynamics in intense laser fields are discussed. We focus on the interaction of relativistic electrons with strong laser pulses. In particular, by analyzing the dynamics of this interaction, we show how the peak intensity of a strong laser pulse can be related to the spectrum of the radiation emitted by the electron during the interaction itself. The discussed method could be used to accurately measure high peak laser intensities exceeding 1020 W/cm2 up to about 1023 W/cm2 with theoretical envisaged accuracies of the order of 10 %. Furthermore, we investigate non-linear quantum effects originating from the interaction of an electron with its own electromagnetic field in the presence of an intense plane wave. These “radiative corrections” modify the electron wave-function in the plane wave. The self-interaction changes, amongst others, the dynamics of the electron’s spin in comparison with the prediction of the Dirac equation. We show that this effect can be measured, in principle, already at intensities of the order of 1022 W/cm

Phytochrome Signaling Mechanisms

Phytochromes are red (R)/far-red (FR) light photoreceptors that play fundamental roles in photoperception of the light environment and the subsequent adaptation of plant growth and development. There are five distinct phytochromes in Arabidopsis thaliana, designated phytochrome A (phyA) to phyE. phyA is light-labile and is the primary photoreceptor responsible for mediating photomorphogenic responses in FR light, whereas phyB-phyE are light stable, and phyB is the predominant phytochrome regulating de-etiolation responses in R light. Phytochromes are synthesized in the cytosol in their inactive Pr form. Upon light irradiation, phytochromes are converted to the biologically active Pfr form, and translocate into the nucleus. phyB can enter the nucleus by itself in response to R light, whereas phyA nuclear import depends on two small plant-specific proteins FAR-RED ELONGATED HYPOCOTYL 1 (FHY1) and FHY1-LIKE (FHL). Phytochromes may function as light-regulated serine/threonine kinases, and can phosphorylate several substrates, including themselves in vitro. Phytochromes are phosphoproteins, and can be dephosphorylated by a few protein phosphatases. Photoactivated phytochromes rapidly change the expression of light-responsive genes by repressing the activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), an E3 ubiquitin ligase targeting several photomorphogenesis-promoting transcription factors for degradation, and by inducing rapid phosphorylation and degradation of Phytochrome-Interacting Factors (PIFs), a group of bHLH transcription factors repressing photomorphogenesis. Phytochromes are targeted by COP1 for degradation via the ubiquitin/26S proteasome pathway