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Wyszukujesz frazę "Khan, Awais" wg kryterium: Autor


Wyświetlanie 1-6 z 6
Tytuł:
Statistical Estimation and Mathematical Modelling of Tropospheric Radio Refractivity Based on Meteorological Data
Autorzy:
Alimgeer, K. S.
Awais, M.
Ijaz, B.
Khan, S. A.
Subhan, F.
Ahmad, N.
Powiązania:
https://bibliotekanauki.pl/articles/221069.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
radio refractivity
statistical estimation
ITU
mathematical modelling
Opis:
To obtain optimal performance, estimation of radio refractivity is essential in planning and design of radio links/systems. The dependence of radio refractivity on different climatic parameters such as temperature, pressure, humidity and scale height is studied. The method proposed by International Telecommunication Union (ITU) is used in calculation of tropospheric radio refractivity. The main objective of this work is to formulate a mathematical equation/expression which can be used to predict/estimate the value of radio refractivity for an arbitrary day of any year, with a low error of estimation, in a local environment. Sensitivity of radio refractivity to temperature, pressure and humidity has been evaluated for a period of 5 years from 2008 to 2012, in a particular area under consideration. The results presented for tropospheric radio refractivity take into consideration both the location height and scale height parameters. The results are analysed in terms of statistical measures such as the moving averages, probability density function, monthly mean values, and their corresponding standard deviations. Finally, a mathematical model is formulated to calculate the radio refractivity for any day of a whole year. Reliability of error analysis in respect to accuracy is also shown. It was implemented in the industrial enterprise.
Źródło:
Metrology and Measurement Systems; 2018, 25, 1; 115-128
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust estimation based nonlinear higher order sliding mode control strategies for PMSG-WECS
Autorzy:
Nazir, Awais
Khan, Safdar Abbas
Khan, Malak Adnan
Alam, Zaheer
Khan, Imran
Irfan, Muhammad
Rehman, Saifur
Nowakowski, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/27311430.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
wind energy conversion systems
WECS
robust control
maximum power point tracking
MPPT
sliding mode control
SMC
super-twisting algorithm
STA
high gain observer
artificial neural network
ANN
function fitting
backstepping
śledzenie maksymalnego punktu mocy
obserwator o dużym wzmocnieniu
sztuczna sieć neuronowa
dopasowanie funkcji
system konwersji energii wiatrowej
sterowanie odporne
sterowanie ślizgowe
algorytm super skręcania
Opis:
The wind energy conversion systems (WECS) suffer from an intermittent nature of source (wind) and the resulting disparity between power generation and electricity demand. Thus, WECS are required to be operated at maximum power point (MPP). This research paper addresses a sophisticated MPP tracking (MPPT) strategy to ensure optimum (maximum) power out of the WECS despite environmental (wind) variations. This study considers a WECS (fixed pitch, 3KW, variable speed) coupled with a permanent magnet synchronous generator (PMSG) and proposes three sliding mode control (SMC) based MPPT schemes, a conventional first order SMC (FOSMC), an integral back-stepping-based SMC (IBSMC) and a super-twisting reachability-based SMC, for maximizing the power output. However, the efficacy of MPPT/control schemes rely on availability of system parameters especially, uncertain/nonlinear dynamics and aerodynamic terms, which are not commonly accessible in practice. As a remedy, an off-line artificial function-fitting neural network (ANN) based on Levenberg-Marquardt algorithm is employed to enhance the performance and robustness of MPPT/control scheme by effectively imitating the uncertain/nonlinear drift terms in the control input pathways. Furthermore, the speed and missing derivative of a generator shaft are determined using a high-gain observer (HGO). Finally, a comparison is made among the stated strategies subjected to stochastic and deterministic wind speed profiles. Extensive MATLAB/Simulink simulations assess the effectiveness of the suggested approaches.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 5; art. no. e147063
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance evaluation of a single cylinder compressed air engine: an experimental study
Autorzy:
Hanan, Ahmad
Feroze, Tariq
Arif, Awais
Iftikhar, Hasan
Khan, Afzaal A.
Javaid, Sarmad
Powiązania:
https://bibliotekanauki.pl/articles/2105994.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
internal combustion engines
compressed air engine
engine analysis
single cylinder engine
Opis:
The quest to reduce dangerous environmental emissions has led to the research and use of alternate and renewable energy sources. One of the major contributors to the dangerous environmental emissions is the automotive industry. The world is, therefore, quickly moving towards hybrid and electric vehicles. An alternate pollution-free automotive engine is a compressed-air engine, which is powered by compressed air and is more efficient than the electric engine since it requires less charging time than a traditional battery-operated engine. Furthermore, the tanks used in compressed-air engines have a longer lifespan in comparison to the batteries used in electric vehicles. However, extensive research is required to make this engine viable for commercial use. The current study is a step forward in this direction and shows the performance analysis of a single-cylinder compressed-air engine, developed from a four-stroke, single-cylinder, 70 cc gasoline engine. The results show that compressed-air engines are economic, environmental friendly and efficient.
Źródło:
Acta Mechanica et Automatica; 2022, 16, 2; 119--123
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observer design estimating the propofol concentration in PKPD model with feedback control of anesthesia administration
Autorzy:
Ilyas, Muhammad
Khan, Awais
Khan, Muhammad Abbas
Xie, Wei
Riaz, Raja Ali
Khan, Yousaf
Powiązania:
https://bibliotekanauki.pl/articles/2106507.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pharmacokinetic models
pharmacodynamic model
bispectral index monitor
observer design
sliding mode control
Opis:
Propofol infusion in anesthesia administration requires continual adjustment in the manual infusion system to regulate the hypnosis level. Hypnotic level is based on Bispectral Index Monitor (BIS) showing the cortical activity of the brain scaled between 0 to 100. The new challenging aspect of automation in anaesthesia is to estimate the concentration of hypnotic drugs in different compartments of the body including primary, rapid peripheral (muscle), slow peripheral (bones, fat) and effect site (brain) compartment based on Pharmacokinetics (PK) and Pharmacodynamics (PD) model. This paper aimed to regulate the hypnosis level with estimating the Propofol concentrations using a linear observer in feedback control strategy based on Integral Super-Twisting Sliding Mode Controller (ISTSMC). The drug concentration in plasma of the silico patients accurately estimated in nominal transient. The results show that tracking errors between the actual output in form of BIS level and linearized output nearly approaches to zero in the maintenance phase of anesthesia to ensure the controller response on sliding phase with optimum performances by achieving desired hypnotic level 50 on BIS. The robustness of control strategy is further ensured by adding measurement noise of electromagnetic environment of operation theatre distracting signal quality index of the output BIS level.
Źródło:
Archives of Control Sciences; 2022, 32, 1; 85--103
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interval state estimation for linear time-varying (LTV) discrete-time systems subject to component faults and uncertainties
Autorzy:
Khan, Awais
Xie, Wei
Zhang, Langwen
Ihsanullah, A.
Powiązania:
https://bibliotekanauki.pl/articles/949810.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
component faults
interval state estimator
linear time-varying systems
noncooperative systems
Opis:
This paper deals with the design of an interval state estimator for linear time-varying (LTV) discrete-time systems subject to component faults and uncertainties. These component faults and uncertainties are assumed to be unknown but bounded without giving any other information, whose effect can be approximated using these bounds. In the first part of this work, an interval state estimator for such systems is designed to deal with these component faults and uncertainties. The result is then extended to find an interval state estimator for a noncooperative LTV discrete-time system subject to component faults and uncertainties by similarity transformation of coordinates. The proposed interval state estimator guaranteed bounds on the observed states that are consistent with the system states. The observer convergence is also ensured. The designed method is simple and easy to be implemented. Two numerical examples are given to show the effectiveness of the proposed method.
Źródło:
Archives of Control Sciences; 2019, 29, 2; 289-305
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized perturbed Ostrowski-type inequalities
Autorzy:
Bohner, Martin
Khan, Asif
Khan, Maria
Mehmood, Faraz
Shaikh, Muhammad Awais
Powiązania:
https://bibliotekanauki.pl/articles/2078949.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Ostrowski’s inequality
perturbed inequality
twice differentiable
Opis:
In this paper, we present new perturbed inequalities of Ostrowski-type, for twice differentiable functions with absolutely continuous first derivative and second-order derivative in some \(L^p\)-space for \(1\leq p\leq \infty\).
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2021, 75, 2; 13-29
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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