Engineering topics

Gates, Ann Q.

Publications and source records attributed to Gates, Ann Q..

4 records

NASA NTRS1998

Creating a GIS-Based Decision-Support System

Tilting the Balance: Climate Variability and Water Resource Management in the Southwest, a regional conference hosted by the Pan American Center for Environmental Studies, will be held at The University of Texas at El Paso on March 2-4, 1998. The conference is supported through the US Global Change Research Program (USGCRP) established by the President in 1989, and codified by Congress in the Global Change Research Act of 1990. The NASA Mission to Planet Earth program is one of the workshops sponsors. The purpose of the regional workshops is to improve understanding of the consequences of global change. This workshop will be focused on issues along the border and the Rio Grande River and thus will bring together stakeholders from Mexico, California, Texas, New Mexico, Arizona and Colorado representing federal, state, and local governments; universities and laboratories; industry, agricultural and natural resource managers; and non-governmental organizations. This paper discusses the efforts of the NASA PACES center create a GIS-based decision-support system that can be used to facilitate discussion of the complex issues of resource management within the targeted international region.

Alvarado, Lori↗

NASA NTRS1998

A Discussion of Issues in Integrity Constraint Monitoring

In the development of large-scale software systems, analysts, designers, and programmers identify properties of data objects in the system. The ability to check those assertions during runtime is desirable as a means of verifying the integrity of the program. Typically, programmers ensure the satisfaction of such properties through the use of some form of manually embedded assertion check. The disadvantage to this approach is that these assertions become entangled within the program code. The goal of the research is to develop an integrity constraint monitoring mechanism whereby a repository of software system properties (called integrity constraints) are automatically inserted into the program by the mechanism to check for incorrect program behaviors. Such a mechanism would overcome many of the deficiencies of manually embedded assertion checks. This paper gives an overview of the preliminary work performed toward this goal. The manual instrumentation of constraint checking on a series of test programs is discussed, This review then is used as the basis for a discussion of issues to be considered in developing an automated integrity constraint monitor.

Fernandez, Francisco G.↗

NASA NTRS1997

Monitoring Properties of Programs

Development of complex systems requires interaction between a large group of people at various levels of software development, including the communication of properties of the system and the data to be manipulated. A natural idea is to maintain a centralized database of properties of the system to which all members of the development group have access, and to automate the process of checking for violations against this database. The focus of this paper is to discuss such an automated process, called integrity constraint checking. The paper defines the notion of an integrity constraint and discusses considerations for adding an automated checker to a programming language compiler or interpreter. Current work on the implementation of integrity constraint checking in a very high-level language called SequenceL is discussed, and future work in developing a similar checker in an imperative language is outlined.

Fernandez, Francisco G.↗

NASA NTRS1997

Towards a Methodology for Identifying Program Constraints During Requirements Analysis

Requirements analysis is the activity that involves determining the needs of the customer, identifying the services that the software system should provide and understanding the constraints on the solution. The result of this activity is a natural language document, typically referred to as the requirements definition document. Some of the problems that exist in defining requirements in large scale software projects includes synthesizing knowledge from various domain experts and communicating this information across multiple levels of personnel. One approach that addresses part of this problem is called context monitoring and involves identifying the properties of and relationships between objects that the system will manipulate. This paper examines several software development methodologies, discusses the support that each provide for eliciting such information from experts and specifying the information, and suggests refinements to these methodologies.

Romo, Lilly↗