Wyniki wyszukiwania - Biblioteka Nauki

1

Lagrange and practical stability criteria for dynamical systems with nonlinear perturbations

100%

Krumov A. V.

Archives of Control Sciences

|

2012

|

tom Vol. 22, no. 1

43-58

EN

In the paper two classes of nonlinear dynamical system with perturbations are considered. The sufficient conditions for robust Lagrange and practical stability are proven with theorems, applying the theory of nonlinear operators of the functional analysis. The presented criteria give also the bounds of the analyzed dynamical processes. Three examples comparing the numerical computer solutions and the analytical investigation of the stability of the systems are given. The method can be applied to analytical and computer modeling of nonlinear dynamical systems, synthesis of computer control and optimization.

2

Przegląd modeli rozwiązania problemu głównego balistyki wewnętrznej

89%

Kagankiewicz F. , Magier M.

|

tom R. 52, z. 163

7--25

PL

Współcześnie większość procesów projektowych odbywa się poprzez wyspecjalizowane narzędzia w postaci zaawansowanego oprogramowania komputerowego, jednak w przypadku balistyki wewnętrznej nie jest ono ogólnodostępne lub jest wręcz utajnione. Z innej strony rzecz ujmując, analityczne rozwiązanie układu nieliniowych równań różniczkowych, opisujących fazy zjawiska strzału w broni lufowej nie istnieje. Dlatego w celu uzyskania dokładniejszych rozwiązań układu równań warto wykorzystać metody numeryczne. W pracy przedstawiono opis teoretyczny zagadnienia na podstawie przeglądu modeli analitycznych i numerycznych rozwiązania problemu głównego balistyki wewnętrznej. Na podstawie tej analizy przyjęto, że możliwym kierunkiem rozwoju jest zaimplementowanie kilku modeli rozwiązania problemu głównego balistyki wewnętrznej w ujęciu numerycznym tak, by użytkownik końcowy (projektant) miał możliwość wyboru różnych modeli i sprawdzenia, który model sprawdza się najlepiej w jego warunkach. Dodatkowo, korzystając z technik optymalizacyjnych, można podjąć próbę implementacji algorytmów, które potrafiłyby poszukiwać np. najmniejszej wartości naważki prochowej przy określonych parametrach prochowych i zadanym ciśnieniu maksymalnym i prędkości wylotowej pocisku. Celem utylitarnym dalszych prac badawczych jest stworzenie nowego narzędzia analitycznego wspomagającego projektowanie broni lufowych.

EN

Nowadays, most design processes are computer-aided, but in the case of internal ballistics they are not generally available or are highly specialized and secret. On the other hand, an analytical solution of the system of nonlinear differential equations describing the phases of the phenomenon of a shot in a gun barrel does not exist. Therefore, in order to obtain more accurate solutions to the system of equations, it is worth to use numerical methods. The paper presents a theoretical description of the problem based on a review of analytical and numerical models solving the main problem of internal ballistics. Based on this analysis, it was assumed that a possible direction of development is to implement several models to solve the main problem of internal ballistics in numerical solution, so that the end user (designer) can choose different models and check which model works best in his conditions. In addition, using optimization techniques, an attempt can be made to implement algorithms that would be able to search for example, the smallest powder weight value at specific powder parameters and at given maximum pressure and projectile muzzle velocity. The utilitarian goal of further research is to create a new analytical tool supporting the design of barrel weapons.

3

Historicko‑cirkevné okolnosti vzniku encykliky Leva XIII. Providentissimus Deus

88%

Hromják Ľ.

Studia theologica

|

2023

|

tom 4

43-60

EN

The author initially describes the general situation within theological thinking prior to the pontificate of Leo XIII, characterized by a skepticism concerning the modern method of Catholic theology, especially Biblical Catholic theology. The approach within Protestant churches, where Biblical studies was much more evolved due to the use of the practice of historical-critical method, was very different. The pioneer in this approach within the Catholic Church was the French Dominican and Biblical theologian Jean-Marie Lagrange. The author of this study explicates how the publication of the encyclical Providentissimus Deus influenced Biblical research in general and opened the Catholic Church up to modernity.

4

Application of Smoothed Particle Hydrodynamics Method in Metal Processing: An Overview

63%

Nguyen T. T. T. , Hojny M.

|

2022

|

tom Vol. 22, iss. 3

67--80

EN

Smoothed Particle Hydrodynamics (SPH) is a Lagrangian formula-based non-grid computational method for simulating fluid flows, solid deformation, and fluid structured systems. SPH is a method widely applied in many fields of science and engineering, especially in the field of materials science. It solves complex physical deformation and flow problems. This paper provides a basic overview of the application of the SPH method in metal processing. This is a very useful simulation method for reconstructing flow patterns, solidification, and predicting defects, limitations, or material destruction that occur during deformation. The main purpose of this review article is to give readers better understanding of the SPH method and show its strengths and weaknesses. Studying and promoting the advantages and overcoming the shortcomings of the SPH method will help making great strides in simulation modeling techniques. It can be effectively applied in training as well as for industrial purposes.

5

Leonardo Pisano called Fibonacci, between advanced mathematics, history of mathematics and mathematics education: three examples drawn from Liber Quadratorum

63%

Bussotti P.

|

tom 7

5-25

EN

In this research, three problems faced by Leonardo Pisano, called Fibonacci,are dealt with. The main purpose is to show that history of mathematics can offerinteresting material for mathematics education. The approach to the use of history ofmathematics in mathematics education cannot be merely historical, but adapted to theneeds of the explanations in a classroom. In the course of this paper, the meaning ofsuch assertion will be clarified. A further purpose is a trying to explore the relationshistory of mathematics-mathematics education-advanced mathematics. Last, but notthe least, a further aim is to offer a specific series of interesting material to the teacherin order to develop stimulating lessons. The material here expounded is conceived forpupils frequenting the third and the fourth years of the high school, but, with minormodifications, it can be adapted to the fifth year of the high school and to the initialyears of the scientific faculties at the university.

6

Leonardo Pisano called Fibonacci, between advanced mathematics, history of mathematics and mathematics education: three examples drawn from Liber Quadratorum

63%

Bussotti P.

|

2015

|

tom 7

5-25

PL

In this research, three problems faced by Leonardo Pisano, called Fibonacci,are dealt with. The main purpose is to show that history of mathematics can offerinteresting material for mathematics education. The approach to the use of history ofmathematics in mathematics education cannot be merely historical, but adapted to theneeds of the explanations in a classroom. In the course of this paper, the meaning ofsuch assertion will be clarified. A further purpose is a trying to explore the relationshistory of mathematics-mathematics education-advanced mathematics. Last, but notthe least, a further aim is to offer a specific series of interesting material to the teacherin order to develop stimulating lessons. The material here expounded is conceived forpupils frequenting the third and the fourth years of the high school, but, with minormodifications, it can be adapted to the fifth year of the high school and to the initialyears of the scientific faculties at the university.