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Number of results: 45
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Abstract

We study an elegant snap system with only one nonlinear term, which is a quadratic nonlinearity. The snap systemdisplays chaotic attractors,which are controlled easily by changing a system parameter. By using analysis, simulations and a real circuit, the dynamics of such a snap system has been investigated. We also investigate backstepping based adaptive control schemes for the new snap system with unknown parameters.

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Abstract

This paper presents the design of digital controller for longitudinal aircraft model based on the Dynamic Contraction Method. The control task is formulated as a tracking problem of velocity and flight path angle, where decoupled output transients are accomplished in spite of incomplete information about varying parameters of the system and external disturbances. The design of digital controller based on the pseudo-continuous approach is presented, where the digital controller is the result of continuous-time controller discretization. A resulting output feedback controller has a simple form of a combination of low-order linear dynamical systems and a matrix whose entries depend nonlinearly on certain known process variables. Simulation results for an aircraft model confirm theoretical expectations.

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Authors and Affiliations

Roman Czyba
Lukasz Stajer
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Abstract

This paper presents a concept of humanoid robot motion generation using the dedicated simplified dynamic model of the robot (Extended Cart-Table model). Humanoid robot gait with equal steps length is considered. Motion pattern is obtained here with use of Preview Control method. Motion trajectories are first obtained in simulations (off-line) and then they are verified on a test-bed. Tests performed using the real robot confirmed the correctness of the method. Robot completed a set of steps without losing its balance.

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Authors and Affiliations

Maksymilian Szumowski
Magdalena Sylwia Żórawska
Teresa Zielińska
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Abstract

This work describes a new study to achieve a combination of modified function projective synchronization between three different chaotic systems through adaptive control. Using the Lyapunov function theory, the asymptotic stability of the error dynamics is obtained and discussed. Further, we set some appropriate initial conditions for the state variables and assigning specific values to the parameters and obtain the graphical results, which shows the efficiencies of the new method. Finally, we summarized our work with conclusion and references.

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Authors and Affiliations

N.A. Almohammadi
E.O. Alzahrani
M.M. El-Dessoky
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Abstract

The LQR (linear quadratic regulator) control problem subject to singular system constitutes a optimization problem in which one must be find an optimal control that satisfy the singular system and simultaneously to optimize the quadratic objective functional. In this paper we establish a sufficient condition to obtain the optimal control of discounted LQR optimization problem subject to disturbanced singular system where the disturbance is time varying. The considered problem is solved by transforming the discounted LQR control problem subject to disturbanced singular system into the normal LQR control problem. Some available results in literatures of the normal LQR control problem be used to find the sufficient conditions for the existence of the optimal control for discounted LQR control problem subject to disturbanced singular system. The final result of this paper is in the form a method to find the optimal control of discounted LQR optimization problem subject to disturbanced singular system. The result shows that the disturbance is vanish with the passage of time.

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Authors and Affiliations

Lyra Yulianti
Admi Nazra
Zulakmal
Arifah Bahar
Muhafzan
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Abstract

This paper presents a robust control technique for small-scale unmanned helicopters to track predefined trajectories (velocities and heading) in the presence of bounded external disturbances. The controller design is based on the linearized state-space model of the helicopter. The multivariable dynamics of the helicopter is divided into two subsystems, longitudinallateral and heading-heave dynamics respectively. There is no strong coupling between these two subsystems and independent controllers are designed for each subsystem. The external disturbances and model mismatch in the longitudinal-lateral subsystem are present in all (matched and mismatched) channels. This model mismatch and external disturbances are estimated as lumped disturbances using extended disturbance observer and an extended disturbance observer based sliding mode controller is designed for it to counter the effect of these disturbances. In the case of heading-heave subsystem, external disturbances and model mismatch only occur in matched channels so a second order sliding mode controller is designed for it as it is insensitive to matched uncertainties. The control performance is successfully tested in Simulink.

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Authors and Affiliations

Ihsan Ullah
Hai-Long Pei
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Abstract

The methane hazard is one of the most dangerous phenomena in hard coal mining. In a certain range of concentrations, methane is flammable and explosive. Therefore, in order to maintain the continuity of the production process and the safety of work for the crew, various measures are taken to prevent these concentration levels from being exceeded. A significant role in this process is played by the forecasting of methane concentrations in mine headings. This very problem has been the focus of the present article. Based on discrete measurements of methane concentration in mine headings and ventilation parameters, the distribution of methane concentration levels in these headings was forecasted. This process was performed on the basis of model-based tests using the Computational Fluid Dynamics (CFD). The methodology adopted was used to develop a structural model of the region under analysis, for which boundary conditions were adopted on the basis of the measurements results in real-world conditions. The analyses conducted helped to specify the distributions of methane concentrations in the region at hand and determine the anticipated future values of these concentrations. The results obtained from model-based tests were compared with the results of the measurements in realworld conditions. The methodology using the CFD and the results of the tests offer extensive possibilities of their application for effective diagnosis and forecasting of the methane hazard in mine headings.

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Authors and Affiliations

Jarosław Brodny
Magdalena Tutak
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Abstract

Given a linear discrete system with initial state x0 and output function yi , we investigate a low dimensional linear systemthat produces, with a tolerance index ǫ, the same output function when the initial state belongs to a specified set, called ǫ-admissible set, that we characterize by a finite number of inequalities. We also give an algorithm which allows us to determine an ǫ-admissible set.

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Authors and Affiliations

A. Abdelhak
M. Rachik
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Abstract

We derive exact and approximate controllability conditions for the linear one-dimensional heat equation in an infinite and a semi-infinite domains. The control is carried out by means of the time-dependent intensity of a point heat source localized at an internal (finite) point of the domain. By the Green’s function approach and the method of heuristic determination of resolving controls, exact controllability analysis is reduced to an infinite system of linear algebraic equations, the regularity of which is sufficient for the existence of exactly resolvable controls. In the case of a semi-infinite domain, as the source approaches the boundary, a lack of L2-null-controllability occurs, which is observed earlier by Micu and Zuazua. On the other hand, in the case of infinite domain, sufficient conditions for the regularity of the reduced infinite system of equations are derived in terms of control time, initial and terminal temperatures. A sufficient condition on the control time, heat source concentration point and initial and terminal temperatures is derived for the existence of approximately resolving controls. In the particular case of a semi-infinite domain when the heat source approaches the boundary, a sufficient condition on the control time and initial temperature providing approximate controllability with required precision is derived.

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Authors and Affiliations

Asatur Zh. Khurshudyan
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Abstract

The paper addresses the problem of constrained pole placement in discrete-time linear systems. The design conditions are outlined in terms of linear matrix inequalities for the Dstable ellipse region in the complex Z plain. In addition, it is demonstrated that the D-stable circle region formulation is the special case of by this way formulated and solved pole placement problem. The proposed principle is enhanced for discrete-lime linear systems with polytopic uncertainties.

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Authors and Affiliations

Dušan Krokavec
Anna Filasová
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Abstract

The adverse effects of synthetic acaricides on humans, animals, non-target organisms and the ecosystem are serious problems. Thus, there is a new trend to use nanotechnology for developing new, natural, bio and safe acaricides for mite control in green-pest management. This is the first work for preparing a nanoformulation of rosemary essential oil (EO) and evaluating its effect against the two-spotted spider mite Tetranychus urticae Koch. GC/MS analysis of rosemary EO showed that 1,8 cineole (31.45%), borneol (11.07%), α-pinene (10.91%), D-limonene (9.19%), L-linalool (8.86%), D-camphor (7.32%), γ-terpinene (3.92%), linalyl acetate (3.37%), α-terpineol (3.32%), and p-cymene (1.82%) were the major components. After 6 min of sonication, a nanoemulsion of rosemary EO was formulated with a droplet size of 139.9 nm. The balance between oil (lyophilic) and surfactant (hydrophilic) was correlated with the droplet size and the stability of the nanoemulsion. Spray application of rosemary nanoemulsion showed high acaricidal activity against immature and adult two-spotted spider mites T. urticae with LC50 723.71 and 865.68 μg · ml−1 and the toxicity increased by 54.15 and 52.69% for immature and adult mites, respectively. There were no toxic effects or mortality of rats treated with rosemary nanoemulsion. High acaricidal activity, stability, and safety of rosemary nanoemulsion make this nanoformulation a possible green and nano-acaricidal product. Further studies under field conditions are necessary to study the acaricidal efficiency of rosemary nanoemulsion against two-spotted spider mites and the toxic effect on predacious mites.

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Authors and Affiliations

Abdel-Tawab H. Mossa
Sahar I. Afia
Samia M.M. Mohafrash
Badawi A. Abou-Awad
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Abstract

The lithostratigraphy, biostratigraphy, sequence stratigraphy, ammonite and inoceramid faunas of the Upper Albian, Cenomanian, and Lower Turonian Karai Formation, the highest unit of the Uttatur Group in the Pondicherry Sub-Basin of the Cauvery Basin in Tamil Nadu, south India, are documented. Detailed logs and descriptions of sections between Karai and Kulakkalnattam, Odiyam and Kunnam, and north-west of Garudamangalam are presented. They provide the evidence for an ammonite zonal scheme that can be correlated in detail with sequences developed in Europe, with successive Upper Albian zones of Pervinquieria (Subschloenbachia) rostrata and P. (S.) perinflata (the latter on slight evidence), Cenomanian zones of Mantelliceras mantelli, Cunningtoniceras cunningtoni, Calycoceras (Newboldiceras) asiaticum, Pseudo calycoceras harpax, Euomphaloceras septemseriatum and Pseudspidoceras footeanum. The Lower Turonian is represented by a Neoptychites cephalotus–Mytiloides borkari fauna. Over 120 ammonite species are described, of which Puzosia (Bhimaites) falx, Protacanthoceras parva, Watinoceras elegans, Euomphaloceras varicostatum, Kamerunoceras multinodosum, and Carthaginites multituberculatus are new. The new genus Kunnamiceras, with Ammonites tropicus Kossmat, 1865 as type species, is interpreted as a paedomorphic dwarf derivative of Pseudocalycoceras harpax (Stoliczka, 1864). Ammonite faunas from shales are dominated by feebly-ornamented taxa: leiostraca; those from sandstones by strongly ornamented taxa: trachyostraca, differences interpreted as reflecting the preferred habits of adults in life. 15 species of inoceramid bivalves, including a newly described species Inoceramus chiplonkari, are recognised, with a mixed East African–Euramerican–North Pacific affinity. On the basis of the stratigraphic framework developed, a sequence stratigraphic interpretation of the Karai Formation is proposed, and correlated with those recognised in Europe, Morocco, and the United States Gulf Coast and Western Interior.

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Authors and Affiliations

Andrew S. Gale
William J. Kennedy
Ireneusz Walaszczyk
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Abstract

The positivity and absolute stability of a class of nonlinear continuous-time and discretetime systems are addressed. Necessary and sufficient conditions for the positivity of this class of nonlinear systems are established. Sufficient conditions for the absolute stability of this class of nonlinear systems are also given.

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Authors and Affiliations

Tadeusz Kaczorek
ORCID: ORCID
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Abstract

The article presents Lublin through the analysis of two literary texts that show the existence of the Jewish population of the city and the destruction and absence of Jews from Lublin. Döblin describes in his travelogue Journey to Poland (1925) the parallel existence of the Jewish and Polish city of Lublin in the 1920’s. Krall documents in her literary reportage Exceptionally long line the extermination of the Jewish community and the suppression of the memory of it in Polish collective memory.

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Authors and Affiliations

Anna Pastuszka
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Abstract

The following analysis investigates selected properties of the language of the tweets used in the interaction with consumers on English and Polish brand profiles. The analysis examines the structure of tweets, word frequency, as well as the frequency of informal and non-standard language items, language mistakes, the use of emoticons and hashtags. The study contrasts the language used by English and Polish representatives and reveals a number of similarities and differences between the corpora. What the corpora share is a high frequency of conventional politeness acts and language structures reflecting a customer-oriented tone of the interaction. Differences are observed in the frequency and use of informal and non-standard structures, emoticons and hashtags, as well as in the structure and complexity of the tweets. The study indicates a lower formulaicity and a greater individualization of the interaction on the Polish profiles.

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Authors and Affiliations

Anna Tereszkiewicz
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Abstract

The purpose of the paper is to examine the discursive strategies of persuasion exploring the rhetorical

argument from community combined with linguistic politeness. Based on eighty reviews of two French

comedies, the author shows how the persuasive strategies reflect some methods used in advertising

discourse, especially with regard to the rhetoric principle of movere and delectare and indirect means

of interpretation, activated in discourse by the use of quantity and quality.

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Authors and Affiliations

Dominika Topa-Bryniarska
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Abstract

The object of the study presented in the paper are Yiddish proverbs. The aim of the paper is a linguistic analysis of selected proverbs and their connections with the Polish-language context. The Yiddish language namely has developed in contact with other languages, and one of the languages highly relevant for the Yiddish language, influencing its development, was the Polish language. The richness of Yiddish proverbs has also left its mark on the Polish language, as is evidenced by the presence of Jewish proverbs in Polish. The focus here lies on lexical and structural phenomena characteristic for both languages. Under examination is the extent to which the structure of Yiddish proverbs corresponds with the structure of the Polish language and what lexemes are the result of an interaction at the language level and the sociocultural level.

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Authors and Affiliations

Anna Pilarski
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Abstract

The aim of the article is to compare three literary pictures of the political transformation presented in The impostor (2014) by Javier Cercas, Spis cudzoloznic (1993) by Jerzy Pilch and Sonka (2014) by Ignacy Karpowicz. These novels emphasize their discursive character, thereby revealing that the history is always a narration, not an uninfected series of events. The transformation is shown in conjunction with the theme of cultural memory and imposture.

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Authors and Affiliations

Agnieszka Kłosińska-Nachin
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Abstract

This article focuses on the original writing strategy of Elfriede Jelinek in the period of her political commitment (around the year 2000) as a form of artistic protest and positioning in the literary field. Particularly important in this context seems to be the question of the aesthetic criteria of committed literature, that is, the way writers use their linguistic capital to create valuable and important literary texts or essayistic discourses.

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Authors and Affiliations

Monika Szczepaniak
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Abstract

The article La Rilettura del romanzo Il fu Mattia Pascal di Luigi Pirandello nell’otica del racconto cinematografico di Mario Monicelli, presents an individual story of Mattia Pascal and his reincarnations in Adriano Meis and the late Mattia Pascal. It concentrates on the journey of the main character, in the original dimension of time and space, in search of a new, happy life and of his identity. In reference to the subject matter included here, various different theories are applied to the cinematic analysis of the ‘new’ work of Pirandello.

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Authors and Affiliations

Cezary Bronowski
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Abstract

This study aims to explore the effects of age across adult groups on selected aspects of language learning. To achieve the aim, a study was conducted at the Open University of University of Warsaw. It focuses on reasons for taking up learning, relative importance of individual skills, major difficulties, individual goals, emotions and self-assessed ability to learn. The assumption that adults represent a single age group is questioned and the results are interpreted in terms of practical implications for course design.

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Authors and Affiliations

Agata Klimczak-Pawlak
Sylwia Kossakowska-Pisarek
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Abstract

How is formed the adjective fettleibig (obese)? It may seem an evident derivate from fett (fat) and Leib

(body); however, the NP fetter Leib is as seldom as the adjective is frequent: this sounds paradoxical.

In this contribution, a new way of explaining the formation of this adjective is explored: fettleibig

appears as a subsistance of a in past times rich -leibig-paradigm. Therefore, in a synchronic view, this

adjective is not explained as a derivate, although it remains mainly transparent.

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Authors and Affiliations

Sylvain Farge

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