Design of Home Network Architecture using ACE/TAO Real Time Event Service

This paper proposes a home network design based on publisher/subscriber architecture which is developed using ACE/TAO Real-time Event Service (RTES) as the middleware platform. This design addresses a feature to support a real-time implementation for home network application such as home automation. Home network participants have been classified into several components based on consumer and supplier implementation in the ACE/TAO RTES in order to simplify the design. To optimize the network utilization, events are filtered based on their type and source for each publisher and subscriber. To deal with heterogeneous type of home appliances, event header information has been extended to wrap more information. Each of events can be configured with a specific scheduling and priority setting to meet its quality of service (QoS) according to the requirement. Network performance in handling an increasing number of consumer or supplier has been evaluated and show an acceptable result. Keywords: Home Network, ACE/TAO, RTES, QoS

Synergizing domain expertise with self-awareness in software systems:a patternized architecture guideline

To promote engineering self-aware and self-adaptive software systems in a reusable manner, architectural patterns and the related methodology provide an unified solution to handle the recurring problems in the engineering process. However, in existing patterns and methods, domain knowledge and engineers' expertise that is built over time are not explicitly linked to the self-aware processes. This linkage is important, as the knowledge is a valuable asset for the related problems and its absence would cause unnecessary overhead, possibly misleading results and unwise waste of the tremendous benefit that could have been brought by the domain expertise. This paper highlights the importance of synergizing domain expertise and the self-awareness to enable better self-adaptation in software systems, relying on well-defined expertise representation, algorithms and techniques. In particular, we present a holistic framework of notions, enriched patterns and methodology, dubbed DBASES, that offers a principled guideline for the engineers to perform difficulty and benefit analysis on possible synergies, in an attempt to keep "engineers-in-the-loop". Through three tutorial case studies, we demonstrate how DBASES can be applied in different domains, within which a carefully selected set of candidates with different synergies can be used for quantitative investigation, providing more informed decisions of the design choices.Comment: Accepted manuscript to the Proceedings of the IEEE. Please use the following citation: Tao Chen, Rami Bahsoon, and Xin Yao. 2020. Synergizing Domain Expertise with Self-Awareness in Software Systems: A Patternized Architecture Guideline. Proc. IEEE, in pres

Design and Implementation of Multi-core Support for an Embedded Real-time Operating System for Space Applications

Nowadays, multi-core processors are widely used in embedded applications due to the advantages of higher performance and lower power consumption. However, the complexity of multi-core architectures makes it a considerably challenging task to extend a single-core version of a real-time operating system to support multi-core platform. This thesis documents the process of design and implementation of a multi-core version of RODOS - an embedded real-time operating system developed by German Aerospace Center and the University of Würzburg - on a dual-core platform. Two possible models are proposed: Symmetric Multiprocessing and Asymmetric Multi- processing. In order to prevent the collision of the global components initialization, a new multi-core boot loader is created to allow that each core boots up in a proper manner. A working version of multi-core RODOS is implemented that has an ability to run tasks on a multi-core platform. Several test cases are applied and verified that the performance on the multi-core version of RODOS achieves around 180% improved than the same tasks running on the original RODOS. Deadlock free communication and synchronization APIs are provided to let parallel applications share data and messages in a safe manner

Towards a software framework for reconfigurable and adaptive fixturing systems

There is an ongoing trend towards advanced fixturing systems that can be automatically reconfigured for different workpieces and dynamically adapt the clamping forces during the manufacturing process. However, the increased utilisation of computer technology and sensor feedback currently requires a significant amount of programming effort during the development phase and deployment of such fixtures which impairs their successful industrial realisation. This research addresses the issue by developing the core concepts of a novel software framework that facilitates the deployment and operation of reconfigurable and adaptive fixturing systems. This includes a new data model for the representation of the fixturing system, using object-oriented modelling techniques. Secondly, a generic methodology for the automatic reconfiguration of fixturing systems has been developed that can be applied to a plethora of different fixture layouts. Thirdly, a flexible communication infrastructure is proposed which supports the platform-independent communication between the various parts of the fixturing system through the adoption of a publish/subscribe approach. The integration of these core knowledge contributions into a software framework significantly reduces the programming effort by providing a ready-to-use infrastructure that can be configured according a given fixture layout. In order to manage the complexity of the research, a structured research methodology has been followed. Based on an extensive literature review, a number of knowledge gaps have been identified which were the basis for the definition of clear research objectives. A use case analysis has been conducted to identify the requirements of the software framework and several potential middleware technologies have been assessed for the communication infrastructure. This was followed by the development of the three core knowledge contributions. Finally, the research results have been demonstrated and initially verified with a prototype of a reconfigurable fixturing system, indicating that the utilisation of the software framework can eliminate the need for programming, thereby drastically reducing deployment effort and lead time

Towards a software framework for reconfigurable and adaptive fixturing systems

There is an ongoing trend towards advanced fixturing systems that can be automatically reconfigured for different workpieces and dynamically adapt the clamping forces during the manufacturing process. However, the increased utilisation of computer technology and sensor feedback currently requires a significant amount of programming effort during the development phase and deployment of such fixtures which impairs their successful industrial realisation. This research addresses the issue by developing the core concepts of a novel software framework that facilitates the deployment and operation of reconfigurable and adaptive fixturing systems. This includes a new data model for the representation of the fixturing system, using object-oriented modelling techniques. Secondly, a generic methodology for the automatic reconfiguration of fixturing systems has been developed that can be applied to a plethora of different fixture layouts. Thirdly, a flexible communication infrastructure is proposed which supports the platform-independent communication between the various parts of the fixturing system through the adoption of a publish/subscribe approach. The integration of these core knowledge contributions into a software framework significantly reduces the programming effort by providing a ready-to-use infrastructure that can be configured according a given fixture layout. In order to manage the complexity of the research, a structured research methodology has been followed. Based on an extensive literature review, a number of knowledge gaps have been identified which were the basis for the definition of clear research objectives. A use case analysis has been conducted to identify the requirements of the software framework and several potential middleware technologies have been assessed for the communication infrastructure. This was followed by the development of the three core knowledge contributions. Finally, the research results have been demonstrated and initially verified with a prototype of a reconfigurable fixturing system, indicating that the utilisation of the software framework can eliminate the need for programming, thereby drastically reducing deployment effort and lead time