Number of results to display per page
Search Results
5602. Controllability of invariant control systems at uniform time
- Creator:
- Ayala, Victor, Ayala-Hoffmann, José, and de Azevedo Tribuzy, Ivan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- uniform-time, compact, semisimple, and revers-system
- Language:
- English
- Description:
- Let G be a compact and connected semisimple Lie group and Σ an invariant control systems on G. Our aim in this work is to give a new proof of Theorem 1 proved by Jurdjevic and Sussmann in \cite{ju-su 2}. Precisely, to find a positive time sΣ such that the system turns out controllable at uniform time sΣ. Our proof is different, elementary and the main argument comes directly from the definition of semisimple Lie group. The uniform time is not arbitrary. Finally, if A=⋂t>0A(t,e) denotes the reachable set from arbitrary uniform time, we conjecture that it is possible to determine A as the intersection of the isotropy groups of orbits of G-representations which contains exp(z), where z is the Lie algebra determined by the control vectors.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5603. Controllability of linear impulsive matrix Lyapunov differential systems with delays in the control function
- Creator:
- Muni, Vijayakumar S. and George, Raju K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- matrix Lyapunov systems, controllability, impulsive differential systems, and delays
- Language:
- English
- Description:
- In this paper, we establish the controllability conditions for a finite-dimensional dynamical control system modelled by a linear impulsive matrix Lyapunov ordinary differential equations having multiple constant time-delays in control for certain classes of admissible control functions. We characterize the controllability property of the system in terms of matrix rank conditions and are easy to verify. The obtained results are applicable for both autonomous (time-invariant) and non-autonomous (time-variant) systems. Two numerical examples are given to illustrate the theoretical results obtained in this paper.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5604. Controllability of linear impulsive systems - an eigenvalue approach
- Creator:
- Muni, Vijayakumar S. and George, Raju K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- controllability, eigenvalues, and impulses
- Language:
- English
- Description:
- This article considers a class of finite-dimensional linear impulsive time-varying systems for which various sufficient and necessary algebraic criteria for complete controllability, including matrix rank conditions are established. The obtained controllability results are further synthesised for the time-invariant case, and under some special conditions on the system parameters, we obtain a Popov-Belevitch-Hautus (PBH)-type rank condition which employs eigenvalues of the system matrix for the investigation of their controllability. Numerical examples are provided that demonstrate--for the linear impulsive systems, null controllability need not imply their complete controllability, unlike for the non-impulsive linear systems.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5605. Controllability of semilinear stochastic integrodifferential systems
- Creator:
- Balachandran, Krishnan, Karthikeyan, Shanmugasundaram, and Kim, Jeong-Hoon
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- controllability, approximate controllability, stochastic integrodifferential system, and Picard iteration
- Language:
- English
- Description:
- In this paper we study the approximate and complete controllability of stochastic integrodifferential system in finite dimensional spaces. Sufficient conditions are established for each of these types of controllability. The results are obtained by using the Picard iteration technique.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5606. Controllable and tolerable generalized eigenvectors of interval max-plus matrices
- Creator:
- Gazda, Matej and Plavka, Ján
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- interval generalized eigenvector and fuzzy matrix
- Language:
- English
- Description:
- By max-plus algebra we mean the set of reals R equipped with the operations a⊕b=max{a,b} and a⊗b=a+b for a,b∈R. A vector x is said to be a generalized eigenvector of max-plus matrices A,B∈R(m,n) if A⊗x=λ⊗B⊗x for some λ∈R. The investigation of properties of generalized eigenvectors is important for the applications. The values of vector or matrix inputs in practice are usually not exact numbers and they can be rather considered as values in some intervals. In this paper the properties of matrices and vectors with inexact (interval) entries are studied and complete solutions of the controllable, the tolerable and the strong generalized eigenproblem in max-plus algebra are presented. As a consequence of the obtained results, efficient algorithms for checking equivalent conditions are introduced.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5607. Controlled convergence theorems for Henstock-Kurzweil-Pettis integral on $m$-dimensional compact intervals
- Creator:
- Kaliaj, Sokol B., Tato, Agron D., and Gumeni, Fatmir D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Henstock-Kurzweil-Pettis integral, controlled convergence theorem, complete locally convex spaces, and $m$-dimensional compact interval
- Language:
- English
- Description:
- In this paper we use a generalized version of absolute continuity defined by J. Kurzweil, J. Jarník, Equiintegrability and controlled convergence of Perron-type integrable functions, Real Anal. Exch. 17 (1992), 110–139. By applying uniformly this generalized version of absolute continuity to the primitives of the Henstock-Kurzweil-Pettis integrable functions, we obtain controlled convergence theorems for the Henstock-Kurzweil-Pettis integral. First, we present a controlled convergence theorem for Henstock-Kurzweil-Pettis integral of functions defined on $m$-dimensional compact intervals of $\mathbb {R}^{m}$ and taking values in a Banach space. Then, we extend this theorem to complete locally convex topological vector spaces.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5608. Controlled environment chambers for investigating tree response to elevated CO2 and temperature under boreal conditions
- Creator:
- Kellomäki, S., Wang, Kai-Yun, and Lemettinen, M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- climate change, pine forest, and Pinus sylvestris L.
- Language:
- Multiple languages
- Description:
- A closed CO2 and temperature-controlled, long-term chamber system has been developed and set up in a typical boreal forest of Scots pine (Pinus sylvestris L.) near the Mekrijärvi Research Station (62°47'N, 30°58'E, 145 m above sea level) belonging to the University of Joensuu, Finland. The main objectives of the experiment were to provide a means of assessing the medium to long-term effects of elevated atmospheric CO2 concentration (EC) and temperature (ET) on photosynthesis, respiration, growth, and biomass at the whole-tree level and to measure instantaneous whole-system CO2 exchange. The system consists of 16 chambers with individual facilities for controlling CO2 concentration, temperature, and the combination of the two. The chambers can provide a wide variety of climatic conditions that are similar to natural regimes. In this experiment the target CO2 concentration in the EC chambers was set at a fixed constant of 700 µmol mol-1 and the target air temperature in the ET chambers to track the ambient temperature but with a specified addition. Chamber performance was assessed on the base of recordings covering three consecutive years. The CO2 and temperature control in these closed chambers was in general accurate and reliable. CO2 concentration in the EC chambers was within 600-725 µmol mol-1 for 90 % of the exposure time during the "growing-season" (15 April - 15 September) and 625-725 µmol mol-1 for 88 % of the time in the "off-season" (16 September - 14 April), while temperatures in the chambers were within ±2.0 °C of the ambient or target temperature in the "growing season" and within ±3.0 °C in the "off season". There were still some significant chamber effects. Solar radiation in the chambers was reduced by 50-60 % for 82 % of the time in the "growing season" and 55-65 % for 78 % of the time in the "off season", and the relative humidity of the air was increased by 5-10 % for 72 % of the time in the "growing season" and 2-12 % for 91 % of the time in the "off season". The crown architecture and main phenophase of the trees were not modified significantly by enclosure in the chambers, but some physiological parameters changed significantly, e.g., the radiant energy-saturated photosynthesis rate, transpiration rate, maximum photochemical efficiency of photosystem 2, and chlorophyll content. and S. Kellomäki, Kai-Yun Wang, M. Lemettinen.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5609. Controlling and measuring starvation severity in EHL contacts
- Creator:
- Košťál, David, Šperka, Petr, and Hartl, Martin
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- elastohydrodynamic lubrication, starvation, and replenishment
- Language:
- English
- Description:
- Starvation is the regime of elastohydrodynamic lubrication which is designated with thinner lubrication films than fully flooded regime. Paper summarizes main aspects of starvation and deals with differences in area of experimental investigation of starved lubrication phenomena in comparison with fully flooded regime. Thinner lubrication film creates obstacles in experiment process and data evaluation. Effect that can be neglected in the fully flooded regime can create obstacles. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5610. Controlling the stochastic sensitivity in thermochemical systems under incomplete information
- Creator:
- Bashkirtseva, Irina
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- stabilization, stochastic sensitivity, flow reactor, and incomplete information
- Language:
- English
- Description:
- Complex dynamic regimes connected with the noise-induced mixed-mode oscillations in the thermochemical model of flow reactor are studied. It is revealed that the underlying reason of such excitability is in the high stochastic sensitivity of the equilibrium. The problem of stabilization of the excitable equilibrium regimes is investigated. We develop the control approach using feedback regulators which reduce the stochastic sensitivity and keep the randomly forced system near the stable equilibrium. We consider also a case when the information about system state is incomplete. Our new mathematical technique is applied to the stabilization of operating modes in the flow chemical reactors forced by random disturbances.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public