The Use of On-Line Graphical Computer Systems for Student Research

The purpose of this paper is to point out the advantages and disadvantages of using an on-line graphical computer for graduate student research. The system itself consists of an IBM 2250 model I graphic console operating through IBM 360/40,/75, and /91 computers. It was hoped that this would provide an interactive graphical system permitting the student to solve his dissertation problems in a novel fashion. The experience gained in this endeavor and the methodology which the student might develop could prove to be even more valuable than the solution of the problem itself and would constitute an integral part of his thesis. The paper reports on the work carried out for a Master's thesis and for a Ph. D. dissertation. The former consisted of an attempt to solve nonlinear programming problems in n dimensions by searching for the optima on a CRT screen exhibiting contour lines and constraints in two variables, the others being varied by on-line control. The other application consisted of developing a simulation language allowing for on-line graphical displays and interaction, and applying this language to the design and analysis of a complex digital computer system consisting, in particular, of a variable number of time shared consoles. The results of this work clearly showed the convenience of an interactive graphic system while underlining the difficulties experienced in operating either with an inherently slow system or a powerful system slowed down by batch background operation.     

Graphic Communication of Data from the Digital Computer

Computer technology has provided a means by which large amounts of data may be accumulated and reduced to graphical form. The advantages of this type of computer output are considered and illustrated by means of two applications of particular interest to engineers. The utilization of computer drawn flow charts is discussed and some of the logical and technical problems involved are examined; characteristics of available programs are compared. The procedures of graphical data plotting and the available routines are then discussed and curricular applications are considered.     

A computer architecture laboratory course using programmable logic

This paper describes the software and hardware developed for the laboratory component of a junior/senior level computer architecture course. The principal feature of this course is that students are required to design and build their own computers using programmable logic devices (PLDs). The students use a simple register transfer language (CURTL) with a simulator and commercial PLD tools for their design activity. A graphical PC based debugging tool provides the I/O and main memory for the student built computers     

A Compiler Level Program for Teaching Digital Systems Design

Instruction in the concepts as well as the design techniques of digital systems, including computers, can be considerably facilitated by demonstration. The hardware equipment required for such demonstration in a comprehensive course covering many systems and techniques may be very expensive. One solution to the cost problem is to simulate the systems to be studied using programs written for a general purpose digital computer, which normally is readily available. The instructional aids described are based on systems whose simulation programs are written in a compiler language as well as a language specifically developed for the simulation of digital systems. In summary, the design of digital systems and computers can be made more meaningful through the aid of such digital simulation programs.     

The art of back-of-the-envelope paraxial raytracing

Paraxial raytracing is a valuable tool for making quick "back-of-the-envelope" calculations in optical system design. Its popularity has been highly diminished as a consequence of the growing sophistication of computer-aided raytracing and the availability of powerful computers. The availability of raytracing computer programs does not harm in itself the usefulness of graphical raytracing, but it makes people forget, or never learn the basics of graphical raytracing. In this paper, some of the basic concepts of graphical raytracing are presented, along with some examples that illustrate how it can be applied to multielement systems. The mastering of the methods presented in this paper constitute some of the fundamentals required in the use of any optical software. Such knowledge is absolutely necessary for the conception of novel optical systems     

Circuit Design Application of the Michigan Terminal System

The student use of batch on-line teletypewriter and graphical display facilities for circuit design at the University of Michigan is discussed. This includes batch use of GCA programs, teletypewriter use at the elementary algorithmic level, and display use for man-machine and automatic iterative design. Focus is placed on the economics of each level of design and on student reactions.     

Using MATHCAD in teaching power engineering

Students typically use small calculators or personal computer applications such as MATLAB or MATHCAD to perform basic electrical engineering calculations. From the experience of teaching several power engineering courses, the author noted that when using computer software to solve problems, students tend to lose the meaning of the equations, concentrating solely on typing variables and numbers. Some programs are especially inviting for making this error. MATLAB, for instance, does not use any built-in units of measurement, leaving the management of such units to the user. The user's attention shifts from the problem to the units. Although not as powerful and fast as MATLAB, MATHCAD, on the other hand, has a great potential to help students better understand introductory courses. There are two most important features. First, the screen appearance of the equations matches as closely as possible to the traditional form of the equations and helps the students to become familiar with the concepts. Although a bit difficult to type, the equations written in their natural form help avoid errors. A second feature, the use of built-in measurement units, is particularly helpful because the students can concentrate on the meaning of what they learn and know the transformation will be done properly. A technique for representing magnetization curves in MATHCAD (and the corresponding calculations) is also presented. The technique allows for a computer simulation of "graphical calculations" traditionally used in electrical machine design. The class-related experience has shown that even the simple examples presented in This work could prove to be difficult for students, especially when choosing a programming language to help with the calculations.     

Teaching in a computer classroom with a hyperlinked, interactivebook

A first course in digital signal processing is being taught with an interactive book in a computer classroom. The interactive book is a set of Mathcad documents bound with navigation, full text search, annotation, and special pasting facilities. The documents consist of editable and active text and graphical and mathematical regions. The computer classroom has 20 student PC workstations, 40 seats, an instructor's podium with PC workstation, and lighting and projection (computer screen, overhead, and video) controls. Discussed are the choices of software, interactive book, computer classroom, teaching methods, student evaluations, and future plans     

Stepstone: An Instructional Computer Program for Solving Transportation Problems

The stepping-stone algorithm is a widely taught procedure for solving transportation problems. However, instructional computer programs for it are scarce compared to those available for the simplex method. This correspondence describes an instructional computer program, Stepstone, that presents the stepping-stone algorithm in an easily followed manner for student use, while still having options which extends its use beyond purely instructional purposes.     

Prolog simulation of computer architecture in laboratory activities

Implementation of a computer architecture simulator prototype written in Turbo Prolog, which is suitable for educational purposes, is described. Besides adapting to teaching needs for conventional use, the simulator design incorporates features for an easy alteration of computer architectural structures appropriate to the trainee's learning level. Thus, this simulator is not limited to a particular architecture but permits the student to vary dynamically the architectural characteristics of the computer under study in order to verify the consequences of his decisions and to experiment with families of computers and alternatives of design     

SPICE applications to an undergraduate electronics program

A plan is presented for integrating SPICE (simulation program with integrated circuit emphasis) into an undergraduate electronics curriculum. Three design projects for students are described: a network theory project, an analog electronics design course, and a senior thesis project. In the first project used in a first course on network theory, the emphasis is on simple programs that can extend basic techniques (such as Thevenin's equivalent circuit) to cases where hand analysis is long and tedious. In the electronics course, the application of the bipolar-junction transistor and field-effect transistor is more clearly understood by the student when he/she constructs an analog amplifier according to a given set of specifications. Creativity is encouraged, since the design of the amplifier is flexible as long as the specifications are met. In the senior thesis project, SPICE, along with other computer design packages, enables the student to analyze and modify a project before it is constructed. This saves valuable construction time and allows for a more thorough theoretical analysis     

A Quantitative Analysis of Grouped Single-Phased Induction Motors

A quantitative evaluation of the effect of single-phasing on three-phase induction motors has eluded engineers with an interest or responsibility in this problem area. Although the classical analysis for such an evaluation based on symmetrical components has been generally known, the complex nature of the problem solution did not become feasible until computer programs were developed. The results of a computer-aided study are presented. Quantitative data related to motor voltage and current as well as stator and rotor heat losses?as influenced by system stiffness and motor mechanical loading?are offered in graphical format. The data included are limited to grouped induction motors whose single-phasing is due to the blowing of a fuse in the primary of a delta-wye-connected supply transformer.     

Development of Courses on Power System Energy Control Centers

This paper presents two graduate courses in the area of real-time control and operation of power systems. The objective of the courses is to study real-time control functions as performed by modern energy control centers. The main topics addressed are: 1) data acquisition and estimation, 2) energy management/automatic generation control, and 3) security monitoring and control. A unique feature of the courses is the use of a number of interactive computer programs. These programs assist students in studying in depth and understanding the concepts underlying the real-time operation of power systems. The paper describes course contents and the utilization of computer programs to enhance student comprehension of the concepts involved. Typical homework assignments are described to illustrate the utilization of the computer programs. The courses are presently offered at Georgia Tech, with excellent student response.     

COINGRAD?Control Oriented Interactive Graphical Analysis and Design

The computer has come to be a vital tool in engineering analysis and design. With the introduction of moderately-priced graphics terminals it will be even more so in the future. The rapid graphic interaction between the engineer and the computer will become more and more important in computer-aided design. To provide a vehicle for introducing students to the power and utility of CAD in the automatic control area, three programs have been written incorporating the basic calculations in this area. These include time response, frequency response, and root locus, with a limited optimization facility included with the time and frequency response programs. The major considerations in the development were the graphic interactive nature of the programs and the ease of operation for the user.     

An Open-Ended Computer Package for Signal Processing Teaching and Design

Tutorial, design, and project work in signal processing courses require substantial computational effort and data handling, and rely on computer support. The requirements on the support software of modularity, friendliness, good documentation, and extensibility are identified. This paper describes the structure and underlying methodology of a package written in Basic to meet these needs. It consists of four clearly defined hierarchical layers and has a virtual graphics facility. The principal properties of the package are completely interactive operation, a modular structure, ease of addition of new facilities, well-defined ground rules, and standardized documentation. The user interface is simple and friendly. The data structure is easily visualized and remembered. Program development has taken place through student involvement within strict ground rules. The package now comprises over 300 subroutines which can be invoked interactively. Experience in the use and management of the package is discussed. Digital filter design via the bilinear z transform is used as an example of a problem solution. The documentation for one of the subroutines illustrates the standards that are enforced. The methods adopted to overcome the well-known difficulties encountered when writing a large package in Basic are discussed.     

Computers and computer graphics in the teaching of field phenomena

The use of computers and computer graphics in the teaching of sophomore/junior level students majoring in electrical engineering and computer engineering is discussed. Any previous study of electromagnetic fields is presumed to have been limited to a brief exposure in freshman physics. The author has been using both instructor-written and student-written programs in teaching various topics in the fields area for many years. The major part of the discussion concerns static field phenomena, since the basic introductory concepts taught to these student begins with static phenomena and since the physical meaning of many field quantities can best be understood in terms of static fields. Some of the ways the author is implementing the use of computers and computer graphics in his electromagnetics classes are described     

The QP Triangle: A Graphical Method for Bias Design

A graphical design procedure is presented based upon a QP triangle for the design of bipolar transistor (BJT) bias circuits. The design technique stresses quiescent point (QP) location on the IC-VCE characteristics and considers the effects of simultaneous variations in the BJT parameters hFE, VBE, and ICO upon QP location. The QP triangle method is developed for the standard one-battery BJT CE stage discussed in many introductory electronic circuits textbooks. The QP triangle method is applied to a specific CE stage which has to meet certain design specifications. One important specification is that the circuit must operate over the temperature range 25-100°C with silicon N-P-N BJT's having values of h 40 and hFE 100°C) < 200. The available tradeoffs between the peak-to-peak voltage Vpp and the current gain AI are stressed and the best available design is selected. The performance of the selected design was simulated on a digital computer and measured in the laboratory. Both the computer simulation and the experiment are in good agreement with the design. The QP triangle method has been used in an introductory electronic circuits course with success for several years. Students understand this graphical design procedure and are able to apply it. It is recommended for beginning electronics students. An interactive computer program AMPDSN to aid students and instructors design the standard one-battery BJT CE stage is also described. An algorithm based upon the QP triangle is used. The program language is Basic.     

Integration of Micromouse project with undergraduate curriculum: alarge-scale student participation approach

This paper describes a successful integration of the Micromouse project with regular undergraduate courses at California State University, Fullerton. A micromouse is a computer controlled autonomous mobile robot which can find a predetermined destination when placed in an unknown maze. The goals of this paper are to report a complete design example suitable for large-scale student participation and to discuss the benefits of the program from an educator's view point. The Intel 8088 microprocessor was chosen to make the mouse compatible with the PC systems which are universally available. Two stepping motors and eight optical sensors are used to complete the system. Software is written in C and Assembly language with over 2000 lines. Seven micromice have been built since 1990 and several of these mice have won several awards in the IEEE Region Six Southern California competition. Integration of the project with the conventional curriculum has been very successful in motivating students and keeping their interest high. Students show greater enthusiasm for classroom activities and many continue to participate in the project after the semester is over     

A new course on computational methods in electromagnetics

The authors summarize their three-year experience with a computer-methods course for electromagnetics, introduced as an elective for senior undergraduates. The main features of the course include: (1) the inclusion of the finite-difference method of solving engineering problems formulated in terms of partial differential equations; (2) the use of the finite-difference method to solve engineering problems such as the design of microstrip transmission lines and eigenvalue problems including the propagation characteristics in waveguides of arbitrary cross sections; and (3) the use of the method of moments to solve dynamic field problems including radiation from linear antennas and scattering from two-dimensional inhomogeneous dielectric objects. Key steps in developing the course are noted and results from the various computer programs written by the students are presented