International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Satellite tracking ground stations are under continuous pressure to automate. Autonomy is generally the desired goal, but if the ground stations are in a Commercial Ground Network(CGN) setup to support many missions simultaneously, remote control of such stations is of much more importance. The proliferation of Low Earth Orbiting (LEO) science, earth resources and eventually global communications satellites either in orbit or planned, requires a much lower cost methodology for ground support. A CGN of TCP/IP remotely controlled ground stations lowers much of the manpower that was historically required to operate such stations. This paper will cover the remote control aspects needed for a satellite ground tracking station and offer a unique remote control topology utilizing TCP/IP.

The aggregation hierarchy is one of the most significant data abstraction mechanisms that emerged as a result to semantic extensions to traditional systems analysis and design methods. The way inheritance works in this hierarchy is studied in this thesis. Special emphasis is placed on the behaviour of objects which are related via an aggregation hierarchy. A framework is introduced for capturing the behaviour of a system from the respective behaviour(s) of its components. This framework is based on a 3-level behaviour modelling hierarchy. One of the most significant contributions of this framework is the ability to apply inter-object interactions when building a behaviour model of a system. These interactions are significant in that they can yield totally distinct models of the systems functionality. Some of the notions that are supported by the behaviour modelling framework include unreachable and transient states, transition chains (cascades) and concurrency. The framework also enables the creation of behaviour model (semantic) hierarchies, wherein certain facets of the systems behaviour or functionality can be hidden (abstracted out) in a gradual fashion that suits the requirements of the problem domain. This creates what is effectively, distinct views of the behaviour or functionality of the system. The notions and concepts that are introduced here are verified and presented in a comprehensive case study that shows what can be achieved using these ideas. Suggestions are also made for future work which can help overcome some of the limitations introduced throughout this research.

Abstract Building an embedded system from an idea to a product is a slow and expensive process requiring a lot of expertise. Depending on the developer’s expertise, the required quantity and price level of the final product, and the time and money available for development, the developer can build a device from different granularity of components, ranging from ready-made platforms, kits, and modules to individual components. Generally, solutions requiring less expertise, time and money produce products with higher production costs. The main contribution of this thesis is the EOC (Embedded Object Concept) and Atomi II Framework. EOC utilizes common object-oriented methods used in software by applying them to small electronic modules, which create complete functional entities. The conceptual idea of the embedded objects is implemented with the Atomi II framework, which contains several techniques for making the EOC a commercially feasible implementation. The EOC and the Atomi II Framework decreases the difficulty level of making embedded systems by enabling a use of ready-made modules to build systems. It enables automatic conversion of a device made from such modules into an integrated PCB, lowering production costs compared to other modular approaches. Furthermore, it also enables an automatic production tester generation due to its modularity. These properties lower the number of skills required for building an embedded system and quicken the path from an idea to a commercially applicable device. A developer can also build custom modules of his own if he possesses the required expertise. The test cases demonstrate the Atomi II Framework techniques in real world applications, and demonstrate the capabilities of Atomi objects. According to our test cases and estimations, an Atomi based device becomes approximately 10% more expensive than a device built from individual components, but saves up to 50% time, making it feasible to manufacture up to 10-50k quantities with this approach.

Industrial-scale software is commonly very large and complex, making it difficult and time-consuming to develop. In order to manage complexity in software, developers break systems into smaller components which can be developed independently. Software contracts were first proposed several decades ago; they are used to explicitly specify the interfaces between software components to ensure that they work together correctly. Software contracts specify both the responsibility of a client using a service and of the component providing the service. The advantage of contracts is that they formalise what constitutes correct interactions between software components. In addition, they serve as documentation, as well as a basis for test cases, and help clarify correct use of inheritance. However, despite their usefulness, software contracts are still not widely used in mainstream software engineering. In this work, we aim to develop a new software contract tool which we hope will help increase the use of software contracts. We start our work by evaluating existing software contract technologies and uncover a range of inconsistencies and shortcomings. We find that there are disagreements surrounding even some of the most basic aspects of software contracts. Using the lessons learned from our analysis of existing tools, we design a new contract tool, PACT. We describe in detail the formal semantics and typing of PACT and develop a first implementation of our tool. Finally, we discuss the advantages of PACT over existing tools, including its rigorous separation of interfaces and implementations, its rich inheritance semantics, and its support for flexible and expressive definition of contracts.

Nowadays, with the development of electronic and communication technologies, more and more low-cost vehicles such as small, light-weight aircraft are widely applied in all kinds of fields. Ground Station is an essential part of low cost vehicles for the operator to control and monitor the vehicles. In this thesis, Ground Station Display and Flight Management System for Low-Cost Vehicles have been developed.The major objective of this project is to design an intuitive and easy operative Human Machine Interface for displaying and monitoring the flight data and traffic information on ground. Meanwhile, a Graphic User Interface for the Flight Management System has been developed for realizing the waypoints input and flight plan for the vehicles. To fulfill this task, a low-cost hardware and software architecture is presented. Moreover, some COTS tools such as VAPS and MATLAB are applied for the software development because of their Object-Oriented and Rapid Prototype design methods. At the end of project, simulation has been done for the display HMI to test the behaviours of objects and the impacts of display. The trajectory simulation of flight management control panel is also implemented to test the waypoints creation, trajectory generation and smoothing.

Aircraft conceptual design, as the first design stage, provides major opportunity to compress design cycle time and is the cheapest place for making design changes. However, traditional aircraft conceptual design programs, which are monolithic programs, cannot provide satisfactory functionality to meet new design requirements due to the lack of domain flexibility and analysis scalability. Therefore, we are in need of the next generation aircraft conceptual design environment (NextADE). To build the NextADE, the framework and the data management problem are two major problems that need to be addressed at the forefront. Solving these two problems, particularly the data management problem, is the focus of this research. In this dissertation, a distributed object-oriented framework is firstly formulated and tested for the NextADE. In order to improve interoperability and simplify the integration of heterogeneous application tools, data management is one of the major problems that need to be tackled. To solve this problem, taking into account the characteristics of aircraft conceptual design data, a robust, extensible object-oriented data model is then proposed according to the distributed object-oriented framework. By overcoming the shortcomings of the traditional approach of modeling aircraft conceptual design data, this data model makes it possible to capture specific detailed information of aircraft conceptual design without sacrificing generality. Based upon this data model, a prototype of the data management system, which is one of the fundamental building blocks of the NextADE, is implemented utilizing the state of the art information technologies. Using a general-purpose integration software package to demonstrate the efficacy of the proposed framework and the data management system, the NextADE is initially implemented by integrating the prototype of the data management system with other building blocks of the design environment. As experiments, two case studies are conducted in the integrated design environments. One is based upon a simplified conceptual design of a notional conventional aircraft; the other is a simplified conceptual design of an unconventional aircraft. As a result of the experiments, the proposed framework and the data management approach are shown to be feasible solutions to the research problems.

Refactoring is the process of transforming the internal structure of existing code while keeping the integrity of the code's functional requirements. Refactoring is proven to increase program maintainability, flexibility, and understandability and is recognized as a best practice in the software development community. However, with the exception of courses or lectures on extreme programming, refactoring is overlooked in the computer science curriculum. This paper helps demystify refactoring by introducing an incremental approach for teaching refactoring on the college level. Through this hands-on approach, refactoring can become an integral component in the computer science curriculum and an innovative means of reinforcing software engineering principles and good development practices. The approach and three introductory lessons are presented in this paper.

Refactoring is the process of transforming the internal structure of existing code while keeping the integrity of the code's functional requirements. Refactoring is proven to increase program maintainability, flexibility, and understandability and is recognized as a best practice in the software development community. However, with the exception of courses or lectures on extreme programming, refactoring is overlooked in the computer science curriculum. This paper presents the fourth lesson of an innovative pedagogical approach to teaching refactoring on the college level. This lesson covers the creation of well formed object-oriented methods including characteristics for evaluating such methods. Through this hands-on approach, building well formed object-oriented methods through refactoring can be better understood and integrated into the computer science curriculum.

No description available.

No description available.