Developing satellite ground control software through graphical models

This paper discusses a program of investigation into software development as graphical modeling. The goal of this work is a more efficient development and maintenance process for the ground-based software that controls unmanned scientific satellites launched by NASA. The main hypothesis of the program is that modeling of the spacecraft and its subsystems, and reasoning about such models, can--and should--form the key activities of software development; by using such models as inputs, the generation of code to perform various functions (such as simulation and diagnostics of spacecraft components) can be automated. Moreover, we contend that automation can provide significant support for reasoning about the software system at the diagram level

Challenges of Developing New Classes of NASA Self-Managing Mission

NASA is proposing increasingly complex missions that will require a high degree of autonomy and autonomicity. These missions pose hereto unforeseen problems and raise issues that have not been well-addressed by the community. Assuring success of such missions will require new software development techniques and tools. This paper discusses some of the challenges that NASA and the rest of the software development community are facing in developing these ever-increasingly complex systems. We give an overview of a proposed NASA mission as well as techniques and tools that are being developed to address autonomic management and the complexity issues inherent in these missions

Knowledge From Pictures (KFP)

The old maxim goes: 'A picture is worth a thousand words'. The objective of the research reported in this paper is to demonstrate this idea as it relates to the knowledge acquisition process and the automated development of an expert system's rule base. A prototype tool, the Knowledge From Pictures (KFP) tool, has been developed which configures an expert system's rule base by an automated analysis of and reasoning about a 'picture', i.e., a graphical representation of some target system to be supported by the diagnostic capabilities of the expert system under development. This rule base, when refined, could then be used by the expert system for target system monitoring and fault analysis in an operational setting. Most people, when faced with the problem of understanding the behavior of a complicated system, resort to the use of some picture or graphical representation of the system as an aid in thinking about it. This depiction provides a means of helping the individual to visualize the bahavior and dynamics of the system under study. An analysis of the picture augmented with the individual's background information, allows the problem solver to codify knowledge about the system. This knowledge can, in turn, be used to develop computer programs to automatically monitor the system's performance. The approach taken is this research was to mimic this knowledge acquisition paradigm. A prototype tool was developed which provides the user: (1) a mechanism for graphically representing sample system-configurations appropriate for the domain, and (2) a linguistic device for annotating the graphical representation with the behaviors and mutual influences of the components depicted in the graphic. The KFP tool, reasoning from the graphical depiction along with user-supplied annotations of component behaviors and inter-component influences, generates a rule base that could be used in automating the fault detection, isolation, and repair of the system

Augmenting High-Level Petri Nets to Support GALS Distributed Embedded Systems Specification

Part 9: Embedded Systems and Petri NetsInternational audienceHigh-level Petri net classes are suited to specify concurrent processes with emphasis both in control and data processing, making them appropriate to specify distributed embedded systems (DES). Embedded systems components are usually synchronous, which means that DES can be seen as Globally-Asynchronous Locally-Synchronous (GALS) systems. This paper proposes to include in high-level Petri nets a set of concepts already introduced for low-level Petri nets allowing the specification of GALS systems, namely time domains, test arcs and priorities. Additionally, this paper proposes external messages and three types of (high-level) asynchronous communication channels, to specify the interaction between distributed components based on message exchange. With these extensions, GALS-DES can be specified using high-level Petri nets. The resulting models include the specification of each component with well-defined boundaries and interface, and also the explicit specification of the asynchronous interaction between components. These models will be used not only to specify the system behavior, but also to be the input for model-checking tools (supporting its verification) and automatic code generation tools (supporting its implementation in software and hardware platforms), giving a contribution to the model-based development approach and hardware-software co-design of DES based on high-level Petri nets

Las enseñanzas de sistemas en los currículos relacionados con la computación: una experiencia acumulada

Este texto propone la incorporación de las ideas de sistemas como elemento indispensable en los currículos universitarios relacionados con computación. Con este objetivo,se presenta la experiencia acumulada en la Escuela Técnica Superior de Ingenieros de Telecomunicación de Madrid desde 1978. Más concretamente, se muestran los objetivos,metodología y resultados obtenidos dentro de una asignatura denominada Ingeniería de Sistemas, integrada en el último curso de una especialización en Ingeniería Telemática (Informática y Comunicaciones)

Case Tool for Developing Process Control Specifications in Dairy Manufacturing

A computer aided software engineering (CASE) tool designed to assist the task of developing the specification of control software for programmable logic controllers for dairy process manufacturing is described. The CASE tool, called the specification assistant, is a part of a larger development environment that may ultimately include automatic generation of PLC code from the specification. The specification assistant includes a set of rule bases and associated rule-base editors that permit customization of the tool to particular manufacturing sites. It aims to standardize control code specifications, support reuse of specifications, allow inspection of specifications through simulation and reports, and facilitate the long term maintenance of specifications. The specification assistant was developed to support the domain of dairy process manufacturing in New Zealand. A domain analysis was performed to identify a specification language appropriate for the particular domain. Initial experience with the specification assistant indicates that it will improve the productivity of the software engineers who are the recipients of the specifications. Results also suggest that quality of both the specifications and the control software will be improved. Keywords: Computer Aided Software Engineering, CASE, PLC, process control, automated manufacturin

November 19, 1969

The Breeze is the student newspaper of James Madison University in Harrisonburg, Virginia

Investigación en el diseño y desarrollo para el enriquecimiento de un framework colaborativo web sensible al contexto

En este proyecto se pondrá en obra el estudio-aplicación-desarrollo de los aspectos fundamentales para el enriquecimiento de un framework web colaborativo con propiedades de sensibilidad al contexto (FWCsc). Para tal fín se proyectan las siguientes acciones con el propósito de fomentar un aporte en perspectiva con intereses de la industria local y la comunidad científica. Primero, desarrollando tareas de diseño, testing, documentación de estilos arquitectónicos y especificación de una herramienta colaborativa web, teniendo en cuenta técnicas y metodología de desarrollo actuales. Segundo, implementación, instalación, configuración y soporte de una aplicación utilizando frameworks de desarrollo estándares. Tercero, consolidar ambientes y prácticas para el aprendizaje-ense˜nanza-investigación, colaboración y otros usos (compartir experiencia, vinculación con la comunidad de usuarios con intereses similares, K-12, Higher-Ed, Portfolios), en la construcción de sitios colaborativos para las actividades de integraci´on entre las c´atedras afines de la carrera de Ingeniería en Sistemas Informáticos (UAI).Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Lightweight and static verification of UML executable models

Executable models play a key role in many software development methods by facilitating the (semi)automatic implementation/execution of the software system under development. This is possible because executable models promote a complete and fine-grained specification of the system behaviour. In this context, where models are the basis of the whole development process, the quality of the models has a high impact on the final quality of software systems derived from them. Therefore, the existence of methods to verify the correctness of executable models is crucial. Otherwise, the quality of the executable models (and in turn the quality of the final system generated from them) will be compromised. In this paper a lightweight and static verification method to assess the correctness of executable models is proposed. This method allows us to check whether the operations defined as part of the behavioural model are able to be executed without breaking the integrity of the structural model and returns a meaningful feedback that helps repairing the detected inconsistencies.Peer ReviewedPostprint (author's final draft