Systems of Linear Differential Equations by Laplace Transform

1992 ◽  
Vol 23 (3) ◽  
pp. 196 ◽  
Author(s):  
H. Guggenheimer
Author(s):  
D. F. Lawden

A transform method for the solution of linear difference equations, analogous to the method of the Laplace transform in the field of linear differential equations, has been described by Stone (1). The transform u(z) of a sequence un is defined by the equation


Author(s):  
Fitriana Minggani

AbstractLaplace transform is one typr of integral transformation that allows to be used to solve homogeneous and non- homogeneous second order linear differential equations. Laplace transform modification is obtained by adding coefficients through the corresponding variables in the Laplace transform equation expressed in term of =   with   that a transformation kernel function and  is a transformation variable for . There are several applications of differential equations, one of which is the electrical circuit model. The prblem that often becomes an obstacle is when encountering a limit value problem. This paper aims to obtain the solution of linear differential equations in a simple electric circuits (RLC) model connected in series, using a modified Laplace transform. The results of this study provide solutions in the form of  second order linear differential equations: Keywords: electrical circuits, Laplace transform modifications, second order linear differential equations   AbstrakTransformasi Laplace merupakan salah satu jenis transformasi integral yang memungkinkan digunakan untuk menyelesaikan persamaan diferensial linear orde dua homogen maupun non homogen. Transformasi Laplace Modifikasi diperoleh dengan melakukan penambahan koefisien melalui variabel yang sesuai pada persamaan Transformasi Laplace yang dinyatakan dalam bentuk =   dengan  dan merupakan fungsi kernel transformasi, serta  merupakan variabel transformasi untuk .  Terdapat beberapa penerapan persamaan diferensial, salah satunya yaitu pada model rangkaian listrik. Permasalahan yang seringkali menjadi kendala yaitu ketika menjumpai masalah nilai batas. Paper ini bertujuan untuk mendapatkan penyelesaian persamaan diferensial linear  pada model rangkaian listrik sederhana (RLC) yang dihubungkan secara seri, dengan menggunakan transformasi Laplace modifikasi. Hasil penelitian ini memberikan solusi persamaan diferensial linear orde dua yang berbentuk:                                                           Kata kunci: persamaan diferensial linear orde dua, rangkaian listrik, transformasi Laplace modifikasi


2019 ◽  
Vol 9 (2) ◽  
pp. 39-50
Author(s):  
Michael Spektor ◽  
Walter W. Buchanan ◽  
Lawrence Wolf

Mechanical engineering, mechanical engineering technology, and related educational programs are not addressing in a sufficient way the principles associated with applying analytical investigations in solving actual engineering problems. Because of this, graduates do not have the adequate skills required to use the methods of applied dynamics in the process of analyzing mechanical systems. These methods allow one to obtain an understanding of the role of the parameters of a system and to carry out a purposeful control of the values of these parameters with the goal to achieve the desired performance. Engineering and engineering technology programs pay very little attention to addressing these steps. It should be stressed that these programs do not offer a universal straightforward methodology of solving linear differential equations of motion that allow revealing all important interrelationships between the aspects of the engineering problem. It is difficult to formulate the reasons why there is such a low interest in applying the analytical approach in order to reveal the interrelationships between decisive aspects of the operational process of an engineering system in order to achieve the desired goal. Actually, there is almost a complete silence with regard to this issue. Hence, we assume that the first reason could be that there is no recognition of the existence of such a problem. In other words, there is no need to apply these analytical methods since these methods are not beneficial. We do not believe that the engineering community supports this reason. It is not a matter of demonstrating factual data that show how many times the theory was helpful. Without the support of the theory we cannot justifiably evaluate the results of our solutions. If we agree that there is problem, then why are there no publications that would stimulate discussions leading toward a solution of the problem? Here is the second reason. Until now, engineering programs do not present the straightforward universal theoretically sound methodologies for solving the second order linear differential equations that are vital for mechanical and electrical engineering. Without any suggestions of how to solve this problem, it did not make much sense to begin a discussion. In our opinion, this is why we have silence with the regard to this problem. However, it is well known that Laplace Transforms allow solving any linear differential equation of motion. It is justifiable to assume that the main reason why the Laplace Transform methodology is not adopted by learning environments consists in the absence of the majority of tables of Laplace Transform Pairs that are needed for solving differential equations of motion as well as differential equations describing electrical circuits. However, the situation is changed. Current publications comprise the adequate tables that are needed for solving linear differential equations of motion associated with all common mechanical engineering problems. Practicing engineers and students need assistance in acquiring the knowledge of composing differential equations of motion. They need certain training in solving these equations using Laplace Transform methodology. Several recommendations are proposed on how to expedite the implementation in academia and in industry of the methods of applied dynamics in solving common mechanical engineering problems.


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