Graphical Utilities Research Articles

Computer-Aided Analysis of Centrifugal Compressors

This paper describes computer-aided analysis of centrifugal compressors (CAACC), a micro-computer-based, interactive, and menu-driven software package for use as an educational tool by mechanical engineering students studying radial flow compressors. CAACC is written in the Pascal computer language and runs on IBM PC, or compatible, computers. In addition to solving for any unknown variables, the graphical utilities of the package allow the user to display a diagrammatic sketch of the compressor and to draw velocity diagrams at several locations. Furthermore, the program allows the investigation and plotting of the variation of any parameter versus any other parameter. Through this option, the package guides the student in learning the basics of centrifugal compressors by the various performance studies that can be undertaken and graphically displayed. The comprehensive example presented demonstrates the capabilities of the package as a teaching tool.

Computer graphicss in the design and manufacture of composite laminate components

Today's composite materials enable designers to conceive innovative designs with desired response characteristics. However, the process of converting the optimization output obtained from the structural analysis of complex composite components into a reliable manufacturable product has remained a laborious and painstaking task. This has lead to large cycle times resulting in reduced cost effectiveness. For reducing the manual effort and for better visualisation of the process a software system, AUTOLAY, has been developed. The aim of this paper is to demonstrate the effective utilization of computer graphics for different aspects of design and manufacture of aircraft composite components using the AUTOLAY system.

The Utilization of Computer Graphics in Hospitality Financial Management Education

ABSTRACT Once considered an invader, today a personal computer is accepted as a help tool used to enhance the user's work performance. The move from isolated microcomputers to network environments has considerably changed the entire approach to conducting business and education.

MIGS--a simple graphics utility program.

MIGS--a simple graphics utility program.

A STABLE KNOTTED SINGULARITY IN AN EXCITABLE MEDIUM

Numerical studies of an apparently stable knotted singularity are used here to seek out regularities of vortex dynamics in three-dimensional excitable media. Initial conditions were contrived to produce a vortex filament in the form of a trefoil (3:2 torus) knot, using the piecewise linear 'B-kinetics', with excitability parameter 'g' set to 0.9. The simulation was pursued for 3000 time units, or about 125 wave rotations, during which time the knot was observed to rigidly 'precess' about its symmetry axis, completing one turn every 96 wave rotations, and also translate along that same axis, at about 1 percent of wavespeed. These motions, described with respect to the local Frenet frame, were shown to be highly correlated with local geometry and twist, yielding possible 'laws of filament motion', which might prove viable in other contexts. The trefoil knot is the first organizing center to be studied in detail which exhibits nonuniform twist, and its dynamical behavior supports the notion that the arclength derivative of twist is an important determinant of filament motion, first postulated by Keener in 1988. The knot also exhibited changes in twist distribution, and, to a lesser extent, local geometry, within one wave rotation period, adding an unforeseen complication to efforts at understanding vortex dynamics. The knot is compact, only about a wavelength in radius, so filament interactions may play a prominent role in determining the stability and behavior of the object. The locus of wave collisions was determined for the knot; in places this surface apparently adjoins the filament itself. In the course of this study, two different criteria for locating the filament were compared, and many analytic and graphical utilities were developed, which may prove useful in further studies of three-dimensional excitable media.

Correlation and Regression using QUEST

SummaryThis article provides a report on how a commonly availbale chemical database and the graphical utilities of a database management system were used to generate discussion when introducing the topics of correlation and regression to sixth form pupils.

A Graphics Utility for Integration in Water Resource and Hydrological Stimulation Problems

This article outlines the development and application of a decision‐support graphics utility for implementation on an IBM or compatible microcomputer. Prime objectives included an affordable system, capable of running on commonly installed hardware configurations, and with the versatility to integrate with other user‐written packages. The package incorporates interfaces for the input, display, and manipulation of spatial data. Both vector and raster graphical information types are supported. This utility was designed as an open‐ended structure to facilitate integration into a wide range of Water Resource and Hydrological applications. Brief descriptions of three applications of the package are presented.

Space-time software: Computer graphics utilities in special relativity

No one can experience directly the world of the very fast, described by special relativity. Interactive graphics displays have been developed for personal computers that help students visualize this world. They are in the form of interactive graphics utilities that students use to carry out homework exercises and take-home projects. Sequential versions of these programs have been used for 3 years in classes in various institutions. This article describes the programs and reports on the educational outcomes of these computer uses.

Computer aided design of pressure vessels

A computer program is developed for the design of pressure vessels. The design rules of ASME Boiler and Pressure Vessel Code Section VIII Division 1 are applied. The program is written in a graphical utility version of GWBASIC, which has a wide variety of uses in IBM and/or IBM compatible PC user. The program has a wide range of choices for the selection of materials which have been specified by the Design Code.

Logical Input Devices and Interaction

AbstractThe logical input device model, as is adopted in the standardized graphics package GKS, has been an accepted basis for producing device‐independent graphics systems. However, when used in highly interactive graphical applications, the logical input device model does not provide sufficient support for a number of fundamental issues inherent to interaction. This paper reopens a discussion which questions the functionality provided by the logical input device model when brought in conjunction with interaction. In particular, the logical input device model does not support the notion of input/output symmetry.CR Categories: 1.3.4 [Computer graphics]: Graphics utilities‐ graphics packages; 1.3.6 [Computer graphics]: Methodology and techniques‐ device independence, interaction techniques

Signal validation with control-room information-processing computers

One of the ‘lessons learned’ from the Three Mile Island accident focuses upon the need for a validated source of plant-status information in the control room. The utilization of computer-generated graphics to display the readings of the major plant instrumentation has introduced the capability of validating signals prior to their presentation to the reactor operations staff. The current operations philosophies allow the operator a quick look at the gauges to form an impression of the fraction of full scale as the basis for knowledge of the current plant conditions. After the introduction of a computer-based information-display system such as the Safety Parameter Display System (SPDS), operational decisions can be based upon precise knowledge of the parameters that define the operation of the reactor and auxiliary systems. The principal impact of this system on the operator will be to remove the continuing concern for the validity of the instruments which provide the information that governs the operator's decisions.

Rationale for nuclear reactor control room data displays

One of the ‘lessons learned’ from the Three Mile Island accident focuses upon the need for a validated source of plant-status information in the control room. The utilization of computer-generated graphics to display the reduced readings of the plant instrumentation has introduced the need for a set of guidelines that focuses upon the mental image of plant conditions that the operators receive from viewing the computer monitors. The principles that govern the design of displays are similar to those employed in the education process because the objective is the same, namely, to transfer information. The philosophy for the development of displays to portray the status of major plant systems bases the level of detail upon the needs of the user. Graphic displays that relate the plant system parameter to the plant systems are recommended along with bar-chart type representations of the relationship between plant parameters and allowable limits.

Data display techniques for transportation analysis and planning: an investigation of three computer‐produced graphics

Graphics are a powerful but often costly means of communication. Computer-drawn graphics offer a new and relatively inexpensive way to assist the communication of complex technical information to both planners and non-technical people whose full potential is now beginning to be realized. This paper discusses the utility of graphics and introduces three computer-drawn graphic techniques which may be useful, both for analysis and presentation of results, in the transportation planning process. Cenvue(s) produces a three-dimensional, perspective-view map, on which virtually any type of transportation data or performance indicator can be displayed. Vap is designed to display origin-destination travel patterns in any region. Tdn transforms a physical-distance network into a time-distance network so that effects of different speeds in the transportation network can be readily seen. The cost-effectiveness of each technique is briefly discussed and some recommendations for evaluating computer graphics techniques are provided to aid the user in further assessing their utility in the transportation planning process. /Author/TRRL/

Utilization of interactive computer graphics for acoustic source localization

Oceanographic studies as well as Naval objectives frequently require one to localize acoustic emitters (targets) in three dimensions within the ocean medium. This series of display formats depict several ways in which interactive graphics techniques, including the use of color, can be of aid in the accomplishment of this task. In each case, the operator is provided with visual feed-back as to the sensitivity of results obtained from the observed data. The display formats along with the interactive technique chosen for discussion include the following figures: (1) range and depth estimation based on multipath time delays induced by the surface and bottom; (2) depth estimation based on available range inputs and a single boundary-induced time delay; (3) an interactive, bearings-only localization technique augmented with color as a visual coding method. The color of the “bearing difference” curves reflect the solution quality in a probabilistic sense; (4) the technique depicted in (3) modified to provide simultaneous depth estimation; and (5) a color-coded sound wave ray trace diagram which visually differentiates among the direct path region, the boundary-reflected insonified regions, and the shadow zones.