Groundwater, the major source of human drinking water, is susceptible to contamination from industrial and agricultural activities. This research develops a web-based simulation system of remote high performance computing model for contaminant transport and retention in soils. A three-dimensional advection-dispersion-reaction MRTM model, based on previous experimental and theoretical studies, is proposed to analyze the transport and retention of chemical contaminants in groundwater flowing through soils. Since three-dimensional experiments are difficult to implement and verify, this simulation system provides scientists an alternative to trace the contaminant movement in soils outside laboratories. The alternating direction implicit (ADI) algorithm is used in this study to reduce the computational complexity. Although the ADI method is very efficient to solve the governing advection-dispersionsorption equations in the three-dimensional MRTM model, achieving higher order accuracy with different boundary conditions remains a difficult research topic. This research develops a new numerical scheme to achieve second-order accuracy with the Neumann-type boundary conditions. Furthermore, parallel computing is used to achieve high performance using powerful multiprocessor computers. A web-based simulation system provides users a friendly interface for remote access to the system through Internet browsers, so as to utilize remote computing resources transparently and efficiently. In the client-side computing one-dimensional MRTM simulation system, the legacy code written in FORTRAN and C are wrapped and reused with Java code, which provides the web-based graphic user interface (GUI). The server-side computing three-dimensional MRTM simulation system integrates the remote high performance computing resources, database management systems, online visualization functionality, and web-based userriendly GUIs. Given access to the Internet, users can execute and manage remote high performance computing jobs anywhere anytime, even through a web browser from a laptop personal computer.

A Web-based circuit design package has been improved and evaluated to provide students with an enhanced and innovative teaching tools package for the electrical circuit design course. The project objectives can be summarized as follows: 1) developing enhanced problem solving skills using a Web-based environment, 2) developing the design skills and sharpening the critical thinking process, 3) developing a generic and comprehensive teaching/learning circuit package as an extention to the Electrical Engineering virtual lab environment, which gives students the capability to practice and experience all the circuit design skills with minimum cost and effort. The project provides the students with an enhanced and powerful graphical computer aided design (CAD) tool by which students can carry out an online simulation of AC and DC designs with the capability to plot simulation results graphically. The proposed prototype is implemented by JAVA, which is used to to implement Web-based applications with different platform support. The project provides students with an enhanced graphical user interface (GUI) by which they can build any electrical circuit using either text or schematic entry format, generate the Netlist, which describes all circuit information (circuit topology, circuit attributes and so on), and simulate the design by parsing the Netlist to CIRML format, which is sent over the network to the remote server. The server will process the CIRML data and run the simulation using PSPICE and eventually send back the simulation results to the client for display.

Web-based simulation (WBS) systems offer tradeoffs between user interactivity and hardware requirements striking to seek a balance between the differing concerns. Server-based systems offer little interactivity or concurrent visualization capabilities, while client-based systems have increased hardware requirements asking the user to provide high-end workstations. Concurrent visualization of simulation output proves execution intensive, or unusable in some situations. Creating an execution efficient and user friendly WBS system greatly improves user experience while gaining all of the benefits inherent in a web-based system such as high accessibility and ease of maintenance. In order to provide a usable concurrent visualization WBS this thesis developed the Web-Based Queuing System Simulation System (WebQS3). WebQS3 splits the responsibilities of simulation execution and simulation visualization into a client-server environment; the client is responsible for the visualization display and server is responsible for simulation execution. The system differs from many previous WBS systems in that the client-side application is developed using web-standard technologies such as HTTP, XML, SVG, and ECMAScript instead relying on Java Applets and associated technologies. Using web-standards as the foundation of the client agent opens the visualization and model construction functionality to any user that accesses the application using a web browser while also making the application more scalable in terms of user load. Implementing the client with web-standards also included the development of an asynchronous client-server communication protocol as opposed to traditional synchronous communication protocols used by Java WBS systems. The asynchronous protocol demonstrates similar or better execution performance than similar synchronous communication protocols in most quality characteristics. By creating a WBS system using web-standards implemented in most modern web browsers any user may visit the WebQS3 site and have simulation tools available for use. Providing simulation services on the web makes eases the creation of simulation models my making the tools to readily available while facilitating information sharing and collaboration over the web. The WebQS3 system serves as a model to drive research in WBS systems away from proprietary Java technologies to web standards for front-end visualization technologies. / Master of Science