A simulation tool for performance evaluation of the IBM 360/75

In this paper we present some results obtained from using simulation as a tool for evaluating alternative methods of improving system performance in network computers. We begin by describing a GPSS model which was developed to evaluate the current computer center operations at the University of Illinois. While using actual data from the center to verify that the model accurately predicts each job's total time in the system, we evaluate the resource utilization within the center. Then we use the simulator to show that a proposed dynamic priority assignment algorithm yields better throughput than the existing algorithm while maintaining a higher level of CPU and memory utilization. Next, turning our attention to a hypothetical network of three centers, we use a generalization of our model to demonstrate the effects of load leveling between centers on the total system throughput. Here we also explore the merits of pay-for-priority schemes in both a single center and in a network of three centers.     

A case study: productivity and quality gains using an object‐oriented framework

The Neuro‐Oncology Information System (NOIS) supports researchers and other personnel throughout the United States engaged in brain tumor research. Graphical user interfaces that allow data input into the NOIS have been evolving over several years. This paper describes the design and implementation of the NOIS Input Forms as they migrated from a procedural approach to a static object‐oriented approach, and finally to a framework approach in which not only static components were reused, but also the patterns of interaction among the components. The paper documents a significant gain in productivity and quality that was realized when using the framework design paradigm. Copyright © 1999 John Wiley & Sons, Ltd.     

Special Feature: A Taxonomy for Valid Test Workload Generation

Sound workload generation methodologies have been developed for only a few evaluation environments. For the remainder, only ad hoc methods of limited applicability are available.     

The automatic generation of translation software for graphicobjects

The authors discuss their effort to extend their translation architecture for textual, tabular, and mathematical material to include graphic objects. They begin with a brief overview of their testbed, the Chameleon Project. They analyze the feasibility of automatically generating translators in the graphics domain. They use an intermediate-form model for translation and establish criteria for the representation of the intermediate and variant forms if automatic generation is to be possible     

Statistical Methods for Comparing Computer Services

The advent of remote terminal access to computer systems, especially as provided by computer networks, has created a marketplace in which computer services rather than computer systems are being sold. And along with that marketplace has come the need for a way to compare and evaluate computer services. This paper presents a methodology for designing and analyzing computer service comparison experiments with the objective of selecting the best system.     

Chameleon: a system for solving the data-translation problem

A comprehensive data translation system is described with the following characteristics: (1) it is derived from a formal model of the translation task; (2) it supports the building of translation tools; (3) it supports the use of translation tools; and (4) it is accessible to its targeted end users. A software architecture to achieve the translation capability is fully implemented. Translators have been generated using the architecture, both by the original software developers and by industrial associates who have installed the architecture at their own sites     

Automatic form generation

The Acuity project, in support of a collaborative brain‐tumor research effort, provides WWW‐based input forms implemented as Java applets for updating a WWW‐accessible database. The continuing need to develop new, but closely related, input forms motivated the design and implementation of the Acuity Form Generator (AFG), an automatic form‐generation tool. This paper documents the AFG technology. Copyright © 2002 John Wiley & Sons, Ltd.     

The Object‐JavaScript language

Complex graphical user interfaces (GUIs) that support a large amount of user interaction require a fast response time, a rich set of building blocks for an esthetic look‐and‐feel, and a development environment that supports ongoing change. On the World Wide Web, client‐side technologies offer more of these features than do server‐side solutions. Java and JavaScript are the two most popular languages used for client‐side GUI implementations. Java implementations require a user to download a plug‐in that contains a virtual machine to execute the Java byte‐code. The installation and maintenance of this plug‐in is sometimes an unsurmountable barrier to using Java. JavaScript lacks some of the desirable features of Java, such as easy to use object‐oriented features and having a GUI class library, but does not require a plug‐in. We have enhanced JavaScript by implementing a new language Object‐JavaScript (OJS) and by providing an OJS library of GUI components, thus making it a viable alternative to Java. Copyright © 2000 John Wiley & Sons, Ltd.