Distributed predictive control with minimization of mutual disturbances

In this paper, a distributed model predictive control scheme is proposed for linear, time-invariant dynamically coupled systems. Uniquely, controllers optimize state and input constraint sets, and exchange information about these—rather than planned state and control trajectories—in order to coordinate actions and reduce the effects of the mutual disturbances induced via dynamic coupling. Mutual disturbance rejection is by means of the tube-based model predictive control approach, with tubes optimized and terminal sets reconfigured on-line in response to the changing disturbance sets. Feasibility and exponential stability are guaranteed under provided sufficient conditions on non-increase of the constraint set parameters

Output feedback receding horizon control of constrained systems

Accepted versio

What is "system": the information-theoretic arguments

The problem of "what is 'system'?" is in the very foundations of modern quantum mechanics. Here, we point out the interest in this topic in the information-theoretic context. E.g., we point out the possibility to manipulate a pair of mutually non-interacting, non-entangled systems to employ entanglement of the newly defined '(sub)systems' consisting the one and the same composite system. Given the different divisions of a composite system into "subsystems", the Hamiltonian of the system may perform in general non-equivalent quantum computations. Redefinition of "subsystems" of a composite system may be regarded as a method for avoiding decoherence in the quantum hardware. In principle, all the notions refer to a composite system as simple as the hydrogen atom.Comment: 13 pages, no figure

Geographic patterns of mtDNA and Z-linked sequence variation in the Common Chiffchaff and the ‘chiffchaff complex’

We are grateful to the University of Washington Burke Museum (UWBM), US National Museum of Natural History (USNM), National History Museum Belgrade (NHMBEO), State Darwin Museum (SDM), Zoological Museum of Moscow State University (MSUZM), Yale Peabody Museum (YPM), University of Minnesota Bell Museum (MMNH), Texas A&M University Biodiversity Research and Teaching Collections (TCWC), Staffan Bensch, Stephen Menzie and Nigel Odin for sample loans. This is publication number 1585 of the Biodiversity Research and Teaching Collections at Texas A&M University. Funding: This work was supported by FEDER funds through the COMPETE programme, POPH/QREN/FSE funds to S.V.D. and NORTE2020/PORTUGAL funds (NORTE-01-0145-FEDER-AGRIGEN) to R.J.L., by the Fundação para a Ciência e a Tecnologia/MEC to S.V.D. (FCOMP-01-0124-FEDER-008941; PTDC/BIA- BEC/103435/2008) and R.J.L (SFRH/BPD/84141/2012), by the National Geographic Society to S.V.D, by Torino University Grant ex 60% 2017 and 2018 to M. P. and by Ministarstvo Kulture I Informisanja Republike Srbije (Project: Ptice zapadnog palearktika) to M.R. The Russian Science Foundation grant No. 14-50-00029 'Scientific basis of the national biobank – depository of living systems' (to E.A.K). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The Russian Science Foundation grant No. 14-50-00029 'Scientific basis of the national biobank – depository of living systems' (to E.A.K).Peer reviewedPublisher PD

Classical approach in quantum physics

The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom recently discovered with the help of Poincar$\acute{\mathrm{e}}$ section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treating as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well. In conclusion, the relation between quantum theory, classical physics and measurement is discussed.Comment: This review paper was rejected from J.Phys.A with referee's comment "The author has made many worthwhile contributions to semiclassical physics, but this article does not meet the standard for a topical review"

Numerical study on hygroscopic material drying in packed bed

The paper addresses numerical simulation for the case of convective drying of hygroscopic material in a packed bed, analyzing agreement between the simulated and the corresponding experimental results. In the simulation model of unsteady simultaneous one-dimensional heat and mass transfer between gas phase and dried material, it is assumed that the gas-solid interface is at thermodynamic equilibrium, while the drying rate of the specific product is calculated by applying the concept of a "drying coefficient". Model validation was clone on the basis of the experimental data obtained with potato cubes. The obtained drying kinetics, both experimental and numerical, show that higher gas (drying agent) velocities (flow-rates), as well as lower equivalent grain diameters, induce faster drying. This effect is more pronounced for deeper beds, because of the larger amount of wet material to be dried using the same drying agent capacity

Wintering grounds, population size and evolutionary history of a cryptic passerine species from isotopic and genetic data

Cryptic species pose a particular challenge to biologists in the context of life history investigations because of the difficulty in their field discrimination. Additionally, there is normally a lag in their widespread acceptance by the scientific community once they are formally recognised. These two factors might constrain our ability to properly assess the conservation status of the different species conforming a cryptic complex. In this study, we analysed isotopic and genetic data to shed light into the still unclear wintering grounds, population size and evolutionary history of the Iberian chiffchaff Phylloscopus ibericus, a species included within the common chiffchaff Phylloscopus collybita until two decades ago due to their phenotypic similarity. We used molecular methods to identify spring-migrating Phylloscopus species captured in northern Iberia, and by comparing the Hydrogen isotopic ratios of their claw tips (δ2Hc; which would reflect the signatures of their wintering grounds), we detected that δ2Hc values of Iberian chiffchaffs were similar to willow warblers (Phylloscopus trochilus; a renowned trans-Saharan migrant), and higher than common chiffchaffs (mostly a pre-Saharan migrant). These results strongly support the idea that Iberian chiffchaffs winter in tropical Africa. We additionally reconstructed the phylogeny and evolutionary history of the Iberian chiffchaff's clade using mitochondrial and nuclear markers. Our results revealed relatively high values of nucleotide diversity (and, hence, high Ne) for the species that were greater than the values of the common/Iberian most recent common ancestor. This suggests that the Iberian chiffchaff did not experience strong bottlenecks after diverging from the common chiffchaff approximately one million years ago. Ultimately, our study provides another illustrative example of how isotopic and genetic analysis tools can help to enhance our understanding of avian ecology and evolution.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

Review on computational methods for Lyapunov functions

Lyapunov functions are an essential tool in the stability analysis of dynamical systems, both in theory and applications. They provide sufficient conditions for the stability of equilibria or more general invariant sets, as well as for their basin of attraction. The necessity, i.e. the existence of Lyapunov functions, has been studied in converse theorems, however, they do not provide a general method to compute them. Because of their importance in stability analysis, numerous computational construction methods have been developed within the Engineering, Informatics, and Mathematics community. They cover different types of systems such as ordinary differential equations, switched systems, non-smooth systems, discrete-time systems etc., and employ di_erent methods such as series expansion, linear programming, linear matrix inequalities, collocation methods, algebraic methods, set-theoretic methods, and many others. This review brings these different methods together. First, the different types of systems, where Lyapunov functions are used, are briefly discussed. In the main part, the computational methods are presented, ordered by the type of method used to construct a Lyapunov function

Instantaneous on-line modification of biped walk composed from reconfigurable adaptive motion primitives

The paper presents development and potentials of a novel methodology for biped walk synthesis based on motion primitives (RAMPs). This approach is convenient for online modification of walk in unstructured and immediate environment of humans. The modification is specified just by changing the overall walking parameters (walking speed, direction, step length, ...) and the system automatically adapts walk realization (legs motion) to comply with new requirements. Modifications may be required anytime, even during motion realization. Simulation results illustrate proposed approach. [Projekat Ministarstva nauke Republike Srbije, br. III44008 and by Provincial secretariat for science and technological development under contract 114-451-660/2015-03

Influence of the Head Wind on Determining Braking Performance of Zacns Tank Wagon

From the aspect of safety, brakes of rail vehicles are an extremely important system on the vehicle. Braking performance affects the normal functioning of vehicles and interoperability of rail vehicles in classic railway train compositions. All trains, classic and different type of motor trains must conform with the available stopping distances, which are predefined by the railway signalling, i.e. control length of a signal and depends on the maximum allowable speed for which the track section is designed. Apart from that, in classic wagons, which are combined and participate in the formation of different train compositions, mutual compatibility must be ensured from the aspect of used braking equipment and connection subassemblies, but even more important, braking performance of all wagons in the train has to be uniform within certain tolerances. This prevents weaker braked wagons from running into stronger braked ones, which can cause longitudinal jerks and may in extremes lead to a train rupture. Stopping distance during brake application depends on train braking performances, longitudinal running resistance and presence of wind and its direction. This paper deals with the influence of wind conditions on the results of slip brake tests and the estimation of a single vehicle's braking performance. Based on experimental measurements, simulations using CFD and comparison with the obtained results, this paper proposes a possibility to extract air drag resistance and wind force from the total resistance force. Presented methodology and obtained results may serve for further simulations of aerodynamic characteristics apart from braking performance, such as vehicle running resistance, energy consumption, etc. and for optimization of the wagon shape and design