Observer-Based Control of LPV Systems with Input Delay and Saturation and Matched Disturbances via a Generalized Sector Condition

This paper examines the control design for parameter-dependent input-delay linear parameter-varying (LPV) systems with saturation constraints and matched input disturbances. A gain-scheduled dynamic output feedback controller, coupled with a disturbance observer to cancel out input disturbance effects, was augmented with an anti-windup compensator to locally stabilize the input-delay LPV system under saturation, model uncertainty, and exogenous disturbances. Sufficient delay-dependent conditions to asymptotically stabilize the closed-loop system were derived using Lyapunov-Krasovskii functionals and a modified generalized sector condition to address the input saturation nonlinearity. The level of disturbance rejection was characterized via the closed-loop induced L2-norm of the closed-loop system in the form of linear matrix inequality (LMI) constraints. The results are examined in the context of the mean arterial pressure (MAP) control in the clinical resuscitation of critical hypotensive patients. The MAP variation response to the injection of vasopressor drugs was modeled as an LPV system with a varying input delay and was susceptible to model uncertainty and input/output disturbances. A Bayesian filtering method known as the cubature Kalman filter (CKF) was used to estimate the instantaneous values of the parameters. The varying delay was estimated via a multiple-model approach. The proposed input-delay LPV control was validated in closed-loop simulations to demonstrate its merits and capabilities in the presence of drug administration constraints.

Covid-19 imprints in Latin America

The article reviews the reaction of selected Latin American countries to the pandemic of Covid-19. The authors examine the situation in which the countries where touched by the pandemic and the initial reactions toward the unusual situation in which the world has been found at the beginning of 2020. The authors analyse the data that are fundamental for the anal-ysis of the situation of selected countries in the period of pandemic. In the article readers can find the analysis of the health sector condition when it was hit by the pandemic. It also goes further to check if the reactions of particular countries brought positivie or negative efects. In the end, the authors analize the politics of vaccination in particular countries of Latin America and are debating if it could be called a vaccine geopolitics.

On the conditions for cycles existence in a second-order discrete-time system with sector-nonlinearity

In this paper, a second-order discrete-time automatic control system is studied. This work is a continuation of the research presented in the author’s papers “On the Aizerman problem: coefficient conditions for the existence of a four-period cycle in a second-order discrete-time system” and “On the Aizerman problem: coefficient conditions for the existence of threeand six-period cycles in a second-order discrete-time system”, where systems with two- and three-periodic nonlinearities lying in the Hurwitz angle were considered. The systems with nonlinearities subjected to stronger constraints are discussed in this paper. It is assumed that the nonlinearity not only lies in the Hurwitz angle, but also satisfies the additional sector-condition. This formulation of the problem is found in many works devoted to theoretical and applied questions of the automatic control theory. In this paper, a system with such nonlinearity is explored for all possible values of the parameters. It is shown that in this case there are parameter values for which a system with a two-periodic nonlinearity has a family of four-period cycles, and a system with a three-periodic nonlinearity has a family of three- or six-period cycles. The conditions on the parameters under which the system can have a family of periodic solutions are written out explicitly. The proofs of the theorems provide a method for constructing nonlinearity in such a way that any solution of the system with initial data lying on some definite ray is periodic.

ANALISIS FREE CASH FLOW, PROFITABILITAS, DEVIDEN DAN UKURAN PERUSAHAAN TERHADAP LEVERAGE PERUSAHAAN DENGAN INVESMENT OPPORTUNITY SET SEBAGAI VARIABEL MODERATING PADA SEKTOR TRADE, SERVICE & INVESMENT YANG TERDAFTAR PADA BEI

ABSTRACK The decline in the purchasing power of the public, as seen from the decline in the growth of Trade, Services and Investment sector in the retail sector subsector Retail sub-sector condition has been 2.5 years underperformance This study aims to test whether the influence of Investment Opportunity Set (IOS) free cash flow and profitability to leverage. Population in this research is Trade Company, Services & Investment, retail subsector, which is listed on BEI. period 2014-2016, ie as many as 23 Companies. Using the technique of porposive sampling, the sample in this study were 15 companies. Data analysis technique that is regersion analysis by using moderating variable. From the test results, showed that the Free cash flow has a significant effect on leverage, which is indicated from the significance value> 0.05 is 0.018. Profitability has a significant effect on firm leverage which is shown from significance value> 0.05 ie 0.000. IOS does not affect the relationship between free cash flow and leverage, as indicated by the significance value of IOS interaction with free cash flow <0.05 is 0.053. And IOS Set affects the relationship between Profitability with leverage shown from the significance value of IOS interaction with Profitability> 0.05 is 0.044 Keywords: free cash flow, profitability, leverage, IOS

Formation of programmes the housing-and-communal utilities complex development

The article is devoted to the problems of housing-and- communal services in the cities of Russia and their development in modern conditions. The research purpose was to give the theoretical justification as well as to develop some methodical recommendations on formation and implementation of the programmes of complex development of housing- and-communal services in the municipal units. The authors systematized the typical properties and specifics of housing-and-communal utilities, the role of the sector in preserving the environment, revealed the factors complicating their development significantly, carried out the analysis of the housing-and-communal sector condition and the sector’s needs for investments. According to the analysis results, the authors prove that modernization and improvement of housing-and-communal sector demands drawing up target programmes of complex development. In article Principles and stages of the development of the programmes of the improvement of the housing-and-communal utilities were offered, the directions, considered to be the most relevant, were pointed out. The authors recognize such consequence of the housing-and-communal utilities modernization as the increase of the utility tariffs and the need of assessment of the availability of housing-and-communal services for consumers. The authors offer the new indicator, namely, the share of the provided subsidies in the total amount of payments for premises and utilities, for the improvement of such assessment. The results of the research can be used by the practicians, forming target municipal development programmes of housing-and-public utilities development within the general strategies of the cities and regions development, aimed at the improvement of the population life quality and at the decrease in the environmental risks.

Uniform Hyperbolicity of a Scattering Map with Lorentzian Potential

We show that a two-dimensional area-preserving map with Lorentzian potential is a topological horseshoe and uniformly hyperbolic in a certain parameter region. In particular, we closely examine the so-called sector condition, which is known to be a sufficient condition leading to the uniformly hyperbolicity of the system. The map will be suitable for testing the fractal Weyl law as it is ideally chaotic yet free from any discontinuities which necessarily invokes a serious effect in quantum mechanics such as diffraction or nonclassical effects. In addition, the map satisfies a reasonable physical boundary condition at infinity, thus it can be a good model describing the ionization process of atoms and molecules.

ANALISIS PENGARUH FREE CASH FLOW DAN PROFITABILITAS TERHADAP LEVERAGE PERUSAHAAN DENGAN INVESMENT OPPORTUNITY SET SEBAGAI VARIABEL MODERATING PADA SEKTOR TRADE, SERVICES &INVESTMENT YANG TERDAFTAR PADA BEI

The decline in the purchasing power of the public, as seen from the decline in the growth of Trade, Services and Investment sector in the retail sector subsector Retail sub-sector condition has been 2.5 years underperformance. This study aims to test whether the influence of Investment Opportunity Set (IOS) free cash flow and profitability to leverage. Population in this research is Trade Company, Services &amp; Investment, retail subsector, which is listed on BEI. period 2014-2016, ie as many as 23 Companies. Using the technique of porposive sampling, the sample in this study were 15 companies. Data analysis technique that is rergesion analysis by using moderating variable. From the test results, showed that the Free cash flow has a significant effect on leverage, which is indicated from the significance value&gt; 0.05 is 0.018. Profitability has a significant effect on firm leverage which is shown from significance value&gt; 0.05 ie 0.000. IOS does not affect the relationship between free cash flow and leverage, as indicated by the significance value of IOS interaction with free cash flow &lt;0.05 is 0.053. And IOS Set affects the relationship between Profitability with leverage shown from the significance value of IOS interaction with Profitability&gt; 0.05 is 0.044