Aspect-Oriented Modeling for Quality of Service of Real-Time System in Cyber Physical Systems
|School||Guangdong University of Technology|
|Course||Computer Software and Theory|
|Keywords||Aspect-Oriented Modeling Quality of Service Real-Time Systems|
Quality of Service(QoS) refers to the performance of service related to users’ satisfaction. In the software design process, performance, availability, reliability, and security aspects determine whether the whole software system is "useful" for users or not. Therefore, QoS is an essential aspect of the system.The Object-Oriented Software Development(OOSD) technology makes it easier to design and implement software systems with good reusability and scalability. However, within an object, performance, availability, reliability, and security codes for crosscutting concerns tangle with codes for core concerns. This not only reduces the intelligibility of the codes, but also severely limits the reusability and scalability of the program. The OOSD technology can do nothing to solve this tangling problem.The Aspect-Oriented Software Development(AOSD) technology has inherited and developed the idea of OOSD. It can completely separate crosscutting concerns from core concerns by extracting them from the internal of an object and then modularizing them. This will help to create loosely coupled, reusable and scalable large-scale software systems. It seems reasonable to model QoS with an aspect-oriented approach.With the development of the sensor technology, embedded computing and wireless communication technology, a new computing revolution called Cyber Physical Systems(CPSs) has begun to rise. Just as the Internet has changed the way we interact with others, CPS will change the way we interact with the physical world. The new field of CPS has brought us a lot of challenges, among which is QoS provision.This dissertation utilizes the aspect-oriented technology to model the QoS aspects of real-time systems in cyber physical network environment. Firstly,this dissertation introduces the QoS framework and taxonomy of distributed systems and the key network QoS metrics, and analyzes QoS provision of CPSs. Benefiting from the idea of separation of concerns, it puts forward a modeling method using the Petri net based on Generic Modeling Environment(GME). Specifically, this dissertation has defined a modeling paradigm (i.e., meta-model of Petri nets) by a set of meta-models and the inheritance mechanism provided in GME. Then it utilizes the defined paradigm to model the behavioral structure of component-based real-time systems. And then, a reachability tree is constructed to determine whether individual components or component combinations can meet the QoS requirements of the system. Meanwhile, the undesirable components or component combinations are removed. Finally, the practical application of this modeling approach is exemplified by a Battlefield Augmented Reality System(BARS) example.