Where & When: JBH359 10am-11am June 28 2007 Advisor: Dr. Schubert Committee: Drs Botting and Gomez Title: A SECURE CLIENT/SERVER JAVA APPLICATION MATWIN:JA JAVA TOOL FOR EXPERIMENTING AND COMPUTING IN DYNAMICAL SYSTEMS ABSTRACT The dynamic of any situation refers to how the situation changes over the course of time. A dynamical system is a physical setting together with rules for how the setting changes or evolves from one moment of time to the next. It is the tool with which scientists make mathematical models to represent the real systems. One basic goal of the mathematical theory of dynamical systems is to determine or characterize the long-term behavior of the system. A basic observation of dynamical systems, largely due to the advent of computers and computer graphics, is how extraordinarily complicated the motions of a system can be, even when the underlying rules are extremely simple. An example for this is the NewtonUs description of the motion of bodies under gravity. The forces are extremely simple: bodies attract to each other by a force proportional to the product of their masses and inversely proportional to the square of the distances separating them. Yet the motions caused by these forces are extremely complex, resulting, for instance, in the braided rings of Saturn. One of the main approaches to dynamical systems is Differential equations. Given any initial state, a differential equation, or a system of didderential quations are used to describe the forces, or directions in which a system is being pushed. Some of these differntial equations are easy to solve using integration methods to get exact solutions, while in some other cases, it is hard or even impossible to find exact solutions to other system of differential equations. In such these cases where exact solutions are hard to find, approximate solutions can be calculated using numerical solution methods such as Euler and Runge Kutta. These numerical methods require a huge amount of calculations that need to be repeated over and over for huge number of times, which is a waste of time plus the fact that these repeatd calculations can lead to huge mistakes in the final values calculated. In the 1940s an entirely new tool of analysis also came on the scene-the digital computer. In addition to its obvious brute-force capabilities of grinding out nummerical solutions of differential equations, it presents a flexible, interactive tool for the purpose of discoveries. This interplay between computations and analysis has proved to be of great importance, and represents one of the major methods of ucovering dynamic properties. Indeed, the area of computer science has rapidly progressed to a state in which it can now make fundamental contributions to our knowledge, rather than acting oly as the servant of other methods of analysis. Here, I prsent MATWIN, a toolkit for Windows computers, consisting of four graphics programs for solving some systems of differential equations. These graphics programs include functions to plot grapghs, tangents, derivatives, calculate the roots, maxima and minima, and definite intgrals. It also includes a number of programs for drawing the soltion to a system of differential equations in a plane along with slope field lines. The initial condition is determined by a mouse click at the desired point. With 3Dview program, it is possible to have a 3D view for a system of three differential equations. The view can be rotated, translated or moved using mouse clicks or via inserting the desired angle values in the program. MatWin supports mathematical computation and experimentation in dynamical systems. This software was developed for a college level courses that teach dynamical systems or differential equations. Also, it can be of great help to high school calculus students too.