FINITE-TIME STABILITY ANALYSIS OF DISCRETE TIME-DELAY SYSTEMS USING DISCRETE CONVOLUTION OF DELAYED STATES

Finite-time stability for the linear discrete-time system with state delay was investigated in this article. Stability of the system was analyzed using both the Lyapunov-like approach and the discrete Jensen’s inequality. A novel Lyapunov-like functional with a discrete convolution of delayed states was proposed and used for the derivation of the sufficient stability conditions of the investigated system. As a result, the novel stability conditions guarantee that the states of the systems do not exceed the predefined boundaries on a finite time interval. The proposed methodology was illustrated with a numerical example. A computer simulation was performed for the analysis of the dynamical behavior of this system

THE WINDER DANCER POSITION CONTROL MODEL USING DIFFERENT PID CONTROL STRUCTURES AND MICROLOGIX PLC

In the cable industry, improper regulation of the winding speed of the conductor cable, i.e. the position of the tensioner (dancer) leads to improper stretching of the conductor, which significantly affects the characteristics of the final product. Winding speed control is directly related to tensioning which is an additional problem. This paper presents a system for control a cable winding device using a linear PID controller with and without control signal limitation. The system parameters were determined using integral time-weighted absolute error (ITAE) criteria and realized using a conventional PLC controller

DIGITAL MODEL PREDICTIVE CONTROL OF THE THREE TANK SYSTEM BASED ON LAGUERRE FUNCTIONS

The application of the model predictive control (MPC) based on discrete-time Laguerre functions is presented in this paper. A nonlinear three-tank hydraulic system is used as an object to which the proposed algorithm is applied. The paper also presents the method of For the verification of the proposed control method, digital simulations are performed using Matlab.linearization of the nonlinear system, as well as the procedure for the controller design

A NEW TYPE OF DISCRETE EULER-LAGRANGE EQUATION WITH APPLICATIONS IN OPTIMAL CONTROL

A new type of discrete Euler-Lagrange equation, suitable for generalization, is presented in this paper. Several forms of this equation can be found in references. They have different differential operators as well as combinations of them. The equation given in this paper uses only one differential operator providing easy generalizations of Euler-Lagrange equation. In the paper, generalizations for the case of more variables and more ordered differences in the functional which is optimized, are derived. The application in determining optimal control of a discrete system is also given

FUZZY LOGIC-BASED CONTROL OF THREE-DIMENSIONAL CRANE SYSTEM

The control of three-dimensional (3D) crane system represents one of the most widely challenging control problems. 3D crane system is used for lifting and moving loads horizontally, as well as lowering and realizing the gripper to the original position. In this paper fuzzy logic-based control of three-dimensional crane (3D) system is presented. Hence the system produces oscillations during moving loads, the main objective of the designed controller is to control the swing angle. As a plant for controller design, the bond graph model of 3D crane system is used. To verify the effectiveness of the proposed control method, several digital simulations with concrete values of parameters are performed using Matlab. The simulations results show that the proposed fuzzy logic control produce better performance in regard to the reduction of undesired oscillations.Key words: bond graph, 3D crane, Dymola, fuzzy control, modeling and simulation, Matlab/Simulin

DATA DENOISING PROCEDURE FOR NEURAL NETWORK PERFORMANCE IMPROVEMENT

This paper will present training data denoising procedure for neural network performance improvement. Performance improvement will be measured by evaluation criterion which is based on a training estimation error and signal strength factor. Strength factor will be obtained by applying denoising method on a default training signal. The method is based on a noise removal procedure performed on the original signal in a manner which is defined by the proposed algorithm. Ten different processed signals are obtained from the performed method on a default noisy signal. Those signals are then used as a training data for the nonlinear autoregressive neural network learning phase. Empirical comparisons are made at the end, and they show that the proposed denoising procedure is an effective way to improve network performances when the training set possesses the significant noise component

Contamination, risk, and source apportionment of potentially toxic microelements in river sediments and soil after extreme flooding in the Kolubara River catchment in Western Serbia

Climate change is contributing to an increase in extreme weather events. This results in a higher river flooding risk, causing a series of environmental disturbances, including potential contamination of agricultural soil. In Serbia, the catastrophic floods of 2014 affected six river basins, including the Kolubara River Basin, as one of the larger sub-catchments of the large regional Sava River Basin, which is characterized by large areas under agricultural cultures, various geological substrates, and different types of industrial pollution. The main aim of this study was to establish the sources of potentially toxic elements in soil and flood sediments and the effect of the flood on their concentrations. Field sampling was performed immediately after water had receded from the flooded area in May 2014. In total, 36 soil samples and 28 flood sediment samples were collected. After acid digestion (HNO3), concentrations of the most frequent potentially toxic elements (PTE) in agricultural production (As, Cd, Cr, Cu, Ni, Pb, Zn) and Co which are closely related to the geological characteristics of river catchments, were analyzed. The origin, source, and interrelations of microelements, as well as BACKGROUND: values of the PTE of the river catchment, the pollution index (Pi), enrichment factor (Ef), and geological index (Igeo), were determined, using statistical methods such as Pearson correlations, principal component analysis (PCA), and multiple linear regression (MLRA). The content of the hot acid-extractable forms of the elements, PCA, and MLRA revealed a heavy geological influence on microelement content, especially on Ni, Cr, and Co, while an anthropogenic influence was observed for Cu, Zn, and Cd content. This mixed impact was primarily related to mines and their impact on As and Pb content. The pseudo-total concentrations of all the analyzed elements did not prove to be a danger in the catchment area, except for Cu in some samples, indicating point-source pollution, and Ni, whose pseudo-total content could be a limiting factor in agricultural production. For the Ef, the Ni content in 59% soil and 68% flood sediment samples is classified into influence classes. The similar pseudo-total contents of the elements studied in soil samples and flood sediment and their origin indicate that the long-term soil formation process is subject to periodic flooding in the Kolubara River Basin without any significant changes taking place. This implies that floods are not an endangering factor in terms of the contamination of soil by potentially toxic elements in the explored area

The millipede genus Leucogeorgia Verhoeff, 1930 in the Caucasus, with descriptions of eleven new species, erection of a new monotypic genus and notes on the tribe Leucogeorgiini (Diplopoda: Julida: Julidae)

The Caucasian leucogeorgiinine genera Archileucogeorgia Lohmander, 1936 and Leucogeorgia Verhoeff, 1930 are revised, with Leucogeorgia being considered as a senior subjective synonym of Archileucogeorgia, syn. nov. The following new combinations are thus warranted: Leucogeorgia abchasica (Lohmander, 1936) and L. satunini (Lohmander, 1936), both comb. nov. ex Archileucogeorgia. All four previously described species, viz., L. longipes Verhoeff, 1930, L. abchasica, L. satunini and L. rediviva Golovatch, 1983, are redescribed based on new material, partly also on the type series, with a lectotype being designated for L. longipes. In addition, eleven new species of Leucogeorgia are described, both with normal (L. borealis sp. nov., L. gioi sp. nov., L. golovatchi sp. nov., L. lobata sp. nov., L. oculata sp. nov. and L. prometheus sp. nov.) and modified mouthparts (L. caudata sp. nov., L. mystax sp. nov., L. profunda sp. nov., L. redivivoides sp. nov. and L. turbanovi sp. nov., all clearly troglobionts). Additionally, a new monotypic genus, Martvilia gen. nov., is erected, with M. parva gen. et sp. nov. as the type species, another presumed troglobiont. An identification key to both genera and all 16 species of Caucasian Leucogeorgiini is presented. Several other members of this tribe are also re-examined, including a syntype male of Telsonius nycteridonis Strasser, 1976, from Greece, herewith designated as the lectotype. Troglomorphisms and mouthpart modifications, as well as the distributions and relationships within both Leucogeorgia and Leucogeorgiini, and a Leucogeorgiini species richness estimate for the western Caucasus are discussed

Fig. 4 in The millipede genus Leucogeorgia Verhoeff, 1930 in the Caucasus, with descriptions of eleven new species, erection of a new monotypic genus and notes on the tribe Leucogeorgiini (Diplopoda: Julida: Julidae)

Fig. 4. Leucogeorgia abchasica (Lohmander, 1936) comb. nov. (A–F: ♂ from Bolshaya Medveditza Cave (ZMUM); G: ♂ from Uatapachy Cave (ZMUM)). A. Head, anterior view. B. Head, ventral view. C. Leg-pair 1, anterior view. D. Left leg 1, lateral view. E. Left leg 1, distolateral view. F. Right gonopods, mesal view. G. Penes, anterior view. Abbreviations: am = accessory membrane; m = mesomere; mc = mesomeral claw; ml = mesomeral lamella; o = opisthomere; p = promere; pl = protective lamella; s = solenomere; v = velum. Scale bars: A–B = 0.2 mm; C, F–G = 0.1 mm; D–E = 0.05 mm.Published as part of Antić, Dragan Ž. & Reip, Hans S., 2020, The millipede genus Leucogeorgia Verhoeff, 1930 in the Caucasus, with descriptions of eleven new species, erection of a new monotypic genus and notes on the tribe Leucogeorgiini (Diplopoda: Julida: Julidae), pp. 1-106 in European Journal of Taxonomy 713 on page 11, DOI: 10.5852/ejt.2020.713, http://zenodo.org/record/402075