This paper is concerned with the problem of H∞ event-triggered output feedback control of discrete time piecewise-affine systems. Relying on system outputs, a piecewise-affine triggering condition is constructed to release communication burden. Resorting to piecewise Lyapunov functional and robust control techniques, sufficient conditions are built to ensure the closed-loop systems to be asymptotically stable with the prescribed H∞ performance. By utilizing a separation strategy, the static output feedback controller is solved by means of linear matrix inequalities. The validity of the proposed method are demonstrated by numerical examples.
This paper investigates the distributed event-triggered cooperative output regulation problem for heterogeneous linear continuous-time multi-agent systems (MASs). To eliminate the requirement of continuous communication among interacting following agents, an event-triggered adaptive distributed observer is skillfully devised. Furthermore, a class of closed-loop estimators is constructed and implemented on each agent such that the triggering times on each agent can be significantly reduced while at the same time the desired control performance can be preserved. Compared with the existing open-loop estimators, the proposed estimators can provide more accurate state estimates during each triggering period. It is further shown that the concerned cooperative output regulation problem can be effectively resolved under the proposed control scheme and the undesirable Zeno behavior can be excluded. Finally, the effectiveness of the proposed results is verified by numerical simulations.
Following the study of sharp domination in effect algebras, in particular, in atomic Archimedean MV-effect algebras it is proved that if an atomic MV-effect algebra is {\it uniformly Archimedean} then it is sharply dominating.
In this paper I argue that the acceptance of an absolutely unrestricted quantification implies the existence of an absolutely empty possible world. This result could be relevant because David Lewis both admits an absolutely unrestricted quantification (for example in Parts of Classes) and rejects the existence of an absolutely empty possible world (in On the Plurality of Worlds). In order to vindicate my thesis, I propose two strategies. The first is based on the assumption that the phrase ''nothing'' cannot be always reduced to a quantifier phrase, as Graham Priest and Alex Oliver with Timothy Smiley have argued. This strategy consists in a paraphrase of the notion of everything that constrains us to admit an empty possible world. The second strategy mainly consists in the use of an ''idealistic'' principle (say «every determination is negation») and its consequences., V tomto příspěvku tvrdím, že přijetí absolutně neomezené kvantifikace znamená existenci naprosto prázdného možného světa. Tento výsledek by mohl být relevantní, protože David Lewis připouští absolutně neomezenou kvantifikaci (například v částech tříd ) a odmítá existenci absolutně prázdného možného světa (v On the Plurality of Worlds).). Abych svou diplomovou práci obhájil, navrhuji dvě strategie. První je založen na předpokladu, že výraz ,,nic'' nelze vždy omezit na kvantifikační frázi, jak argumentovali Graham Priest a Alex Oliver s Timothy Smiley. Tato strategie spočívá v parafrázi pojmu všeho, co nás nutí připustit prázdný svět. Druhá strategie spočívá především v použití ,,idealistického'' principu (řekněme ,,každé rozhodnutí je negace'') a jeho důsledků., and Marco Simionato
Recent reports have indicated a considerably inactivated PSII in twig cortices, in spite of the low light transmittance of overlying periderms. Corresponding information for more deeply located and less illuminated tissues like xylem rays and pith are lacking. In this investigation we aimed to characterize the efficiency of PSII and its light sensitivity along twig depth, in conjunction with the prevailing light quantity and quality. To that aim, optical methods (spectral reflectance and transmittance, chlorophyll fluorescence imaging, low temperature fluorescence spectra) and photoinhibitory treatments were applied in cut twig sections of four tree species, while corresponding leaves served as controls. Compared to leaves, twig tissues displayed lower chlorophyll (Chl) levels and dark-adapted PSII efficiency, with strong decreasing gradients towards the twig center. The low PSII efficiencies in the inner stem were not an artifact due to an actinic effect of measuring beam or to an enhanced contribution of PSI fluorescence. In fact, the PSII/PSI ratios in cortices were higher and those in the xylem rays similar to that of leaves. Inner twig tissues were quite resistant to photoinhibitory treatments, tolerating irradiation levels several-fold higher than those encountered in their microenvironment. Moreover, the extent of high light tolerance was similar in naturally exposed and shaded twig sides. The results indicate an increasing, inherent and light-independent inactivation of PSII along twig depth. The findings are discussed on the basis of a recently proposed model for photosynthetic electron flow in twigs, taking into account the specific atmospheric and light microenvironment as well as the possible metabolic needs of such bulky organs. and C. Yiotis, Y. Petropoulou, Y. Manetas.
Because of the shortage of phycoerythrin (PE) gene sequences from rhodophytes, peBA encoding β- and α -subunits of PE from three species of red algae (Ceramium boydenn, Halymenia sinensis, and Plocamium telfariae) were cloned and sequenced. Different selection forces have affected the evolution of PE lineages. 8.9 % of the codons were subject to positive selection within the PE lineages (excluding high-irradiance adapted Prochlorococcus). More than 40 % of the sites may be under positive selection, and nearly 20 % sites are weakly constraint sites in high-irradiance adapted Prochlorococcus. Sites most likely undergoing positive selection were found in the chromophore binding domains, suggesting that these sites have played important roles in environmental adaptation during PE diversification. Moreover, the heterogeneous distribution of positively selected sites along the PE gene was revealed from the comparison of low-irradiance adapted Prochlorococcus and marine Synechococcus, which firmly suggests that evolutionary patterns of PEs in these two lineages are significantly different. and S. Qin, F. Q. Zhao, C. K. Tseng.
The effects of environmental salinity on physiological responses, growth, and survival of the Gulf corvina, C. othonopterus, were evaluated in a 6-week completely randomized design experiment. Corvina (17.2±2.3 g mean initial body weight) were subjected to salinities of 5, 15, 25, and 35 ‰ and fed a commercial feed with protein and lipid contents of 46 and 14 %, respectively. Plasma osmolality increased significantly with salinity, ranging from 335.1±5.3 mOsm/kg in fish maintained at 5 ‰, to 354.8±6.8 mOsm/kg in fish kept in seawater, while a significant inverse relationship was observed between salinity and moisture content of whole fish, ranging from 73.8±0.7 (measured at 5 ‰) to 76.9±1.0 % (measured at 35 ‰). In spite of this, growth indices (final weight, weight gain, specific growth rate, condition factor, survival) were not altered, suggesting that, like other members of the family Sciaenidae, the Gulf corvina is a strong osmoregulator. The isosmotic point for this species was estimated to correspond to a salinity of 9.8 ‰. The present study represents the first set of experimental data on salinity tolerance of C. othonopterus and confirms the euryhalinity of this species., M. Perez-Velazquez, P. Urquidez-Bejarano, M. L. González-Félix, C. Minjarez-Osorio., and Obsahuje bibliografii
Though the evidence of rapid variability in early-type stars is rather old, we have passed through the ignition stages of a more recent information explosion on this subject. This explosion started with introduction of new detectors capable to detect even very subtle variations. But the old evidence based on much important changes remains. Different types of rapid variability in 0, B, UR and CP2 stars and their relation are discussed.