Wyniki wyszukiwania - BazTech

1

Linear barycentric rational collocation method for solving biharmonic equation

Li Jin

Demonstratio Mathematica

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2022

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Vol. 55, nr 1

587--603

EN

Two-dimensional biharmonic boundary-value problems are considered by the linear barycentric rational collocation method, and the unknown function is approximated by the barycentric rational polynomial. With the help of matrix form, the linear equations of the discrete biharmonic equation are changed into a matrix equation. From the convergence rate of barycentric rational polynomial, we present the convergence rate of linear barycentric rational collocation method for biharmonic equation. Finally, several numerical examples are provided to validate the theoretical analysis.

2

Przegląd metod modelowania przepływu ciepła w przewodach elektrycznych

Perka Bogdan

Przegląd Elektrotechniczny

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2021

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R. 97, nr 7

90--93

PL

W artykule proszone zostały zagadnienia związane z metodami modelowania zjawiska wymiany ciepła pomiędzy otoczeniem, a przewodem elektrycznym podczas warunków termicznych przekraczających wartości dopuszczalne, dla powszechnie stosowanych niepalnych przewodów instalacyjnych o przekroju czynnym żył przewodu 2,5; 4; 6 mm2.

EN

The article presents issues related to the methods of modeling the phenomenon of heat exchange between the environment and an electric conductor during thermal conditions exceeding the permissible values for commonly used non-flammable installation cables with a conductor cross-section of 2.5; 4; 6 mm2.

3

Regularized error function-based extended Kalman filter for estimating the cancer chemotherapy dosage: impact of improved grey wolf optimization

Mohite Utkarsha L., Patel Hirenkumar G.

Bio-Algorithms and Med-Systems

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2021

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Vol. 17, no. 1

41--54

EN

Objectives: The main aim of this work is to introduce a robust controller for controlling the drug dosage. Methods: The presented work establishes a novel robust controller that controls the drug dosage and it also carried out parameters estimation. Along with this, a Regularized Error Function-based EKF (REF-EKF) is introduced for estimating the tumor cells that could be adapted for different conditions. It also assists in solving the overfitting problems, which occur during the drug dosage estimation. Moreover, the performance of the adopted controller is compared over other conventional schemes, and the attained outcomes reveal the appropriate impact of drug dosage injection on immune, normal, and tumor cells. It is also ensured that the presented controller does a robust performance on the parameter uncertainties. Moreover, to enhance the performance of the proposed system and for fast convergence, it is aimed to fine-tune the initial state of EKF optimally using a new Improved Gray Wolf Optimization (GWO) termed as Adaptive GWO (AGWO). Finally, analysis is held to validate the betterment of the presented model. Results: The outcomes, the proposed method has accomplished a minimal value of error with an increase in time, when evaluated over the compared models. Conclusions: Thus, the improvement of the proposed REFEKF-AGWO model is proved from the attained results.

4

Robust controller for cancer chemotherapy dosage using nonlinear kernel-based error function

Mohite Utkarsha L., Patel Hirenkumar G.

Bio-Algorithms and Med-Systems

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2020

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Vol. 16, no. 4

art. no. 20190056

EN

It is well-known that chemotherapy is the most significant method on curing the most death-causing disease like cancer. These days, the use of controller-based approach for finding the optimal rate of drug injection throughout the treatment has increased a lot. Under these circumstances, this paper establishes a novel robust controller that influences the drug dosage along with parameter estimation. A new nonlinear error functionbased extended Kalman filter (EKF) with improved scaling factor (NEF-EKF-ISF) is introduced in this research work. In fact, in the traditional schemes, the error is computed using the conventional difference function and it is deployed for the updating process of EKF. In our previous work, it has been converted to the nonlinear error function. Here, the updating process is based on the prior error function, though scaled to a nonlinear environment. In addition, a scaling factor is introduced here, which considers the historical error improvement, for the updating process. Finally, the performance of the proposed controller is evaluated over other traditional approaches, which implies the appropriate impact of drug dosage injection on normal, immune and tumor cells. Moreover, it is observed that the proposed NEF-EKF-ISF has the ability to evaluate the tumor cells with a better accuracy rate.

5

Zastosowanie splotu funkcji do opisu własności niezawodnościowych układów z rezerwowaniem

Zdziennicki Z., Maciejczyk A.

Problemy Eksploatacji

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2011

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nr 1

205-211

PL

Artykuł przedstawia metodę wyznaczania funkcyjnych charakterystyk niezawodnościowych układów z tzw. "rezerwą zimną" (element rezerwowy pozostaje nieczynny - "zimny" do czasu uszkodzenia elementu zasadniczego) . Wyznaczenie charakterystyk niezawodnościowych dokonano w oparciu o funkcję dwóch zmiennych losowych, za pomocą splotu funkcji - funkcji prawdopodobieństw uszkodzeń elementów układu. Prezentowana metoda pozwala wyznaczyć charakterystyki niezawodnościowe układu z "rezerwą zimną" w analitycznej formie. Metodę zastosowano do wyznaczenia funkcji niezawodności układu z "rezerwą zimną", którego elementy mają swoje funkcje prawdopodobieństwa uszkodzeń opisane funkcją Gaussa. Prezentowana metoda zilustrowana została przykładem liczbowym. Wyniki uzyskane w przykładzie przedstawiono także graficznie.

EN

The paper gives a method that allows one to find reliability characteristics for standby redundancy systems. The method is based on the concept of a function of two random variables, and the solution of the problem is done with a convolution of two functions that are probability density functions of the elements of the system. The method allows one to find reliability characteristics systems in their analytical forms (if reliability characteristics of the elements are in the same forms). The method was used to find a reliability function of a standby redundancy system where elements possessed their probability density functions as Gauss functions. In the analysis, we allowed for the fact that the convolution of two Gauss functions is a Gauss function as well. To solve the expression of the reliability function of systems or elements those probability density functions were Gauss functions, we used an error function. That allowed getting a solution of the problem in an analytical form. There were given examples of mechanical elements possessing their probability density functions like Gauss functions. The method was exemplified numerically, and its results were presented graphically.