@conference {17730,
	title = {A Low Overhead Self-adaptation Technique for KPN Applications on NoC-based MPSoCs},
	booktitle = {Proceedings of the 3rd International Conference on Pervasive and Embedded Computing and Communication Systems (PECCS) - Special Session on Self-Adaptive Networked Embedded Systems (SANES)},
	year = {2013},
	month = {February 19-21},
	address = {Barcelona, Spain},
	abstract = {Self-adaptive systems are able to adapt themselves to mutating internal/external conditions so as to meet their goals. One of the challenges to be tackled when designing such systems is the overhead introduced in making the system monitorable and adaptable. A large overhead can easily compensate the benefits of adaptation. In this work, we are addressing this challenge within the context of KPN applications on NoC-based MPSoCs. In particular, parametric adaptations at the application level are considered. We present a low overhead technique for the implementation of the monitor-controller-adapter loop, which is present in self-adaptive systems. The technique is fundamentally based on an extended network interface which provides the ability to interrupt remote tiles on a NoC-based multiprocessor platform. Results from the MJPEG case study show that the proposed interrupt-based approach incurs an overhead as low as 0.4\% without compromising the quality of the adaptation control. Our new technique provides an improvement of approximately 6.25\% compared to another state-of-the-art technique that interacts with the application using KPN semantics (i.e., blocking channels). Moreover, the sensitivity of the overhead to the complexity of the adaptation controller is much lower in case of our interrupt-based technique as compared to the blocking channel based scheme.},
	keywords = {event-based control, kahn process networks (KPN), network-on-chip (NoC), self-adaptivity},
	author = {Derin, Onur and Ramankutty, Prasanth Kuncheerat and Meloni, Paolo and Tuveri, Giuseppe}
}
@article {17738,
	title = {Towards Self-adaptive KPN Applications on NoC-based MPSoCs},
	journal = {Advances in Software Engineering},
	volume = {2012},
	year = {2012},
	month = {September},
	pages = {16 pages},
	abstract = {Self-adaptivity is the ability of a system to adapt itself dynamically to internal and external changes. Such a capability helps systems to meet the performance and quality goals, while judiciously using available resources. In this paper, we propose a framework to implement application level self-adaptation capabilities in KPN applications running on NoC-based MPSoCs. The monitor-controller-adapter mechanism is used at the application level. The monitor measures various parameters to check whether the system meets the assigned goals. The controller takes decisions to steer the system towards the goal, which are applied by the adapters. The proposed framework requires minimal modifications to the application code and offers ease of integration. It incorporates a generic adaptation controller based on fuzzy logic. We present the MJPEG encoder as a case study to demonstrate the effectiveness of the approach. Our results show that even if the parameters of the fuzzy controller are not tuned optimally, the adaptation convergence is achieved within reasonable time and error limits. Moreover, the incurred steady-state overhead due to the framework is 4\% for average frame-rate, 3.5\% for average bit-rate, and 0.5\% for additional control data introduced in the network.},
	keywords = {kahn process networks (KPN), network-on-chip (NoC), quality of service (QoS), self-adaptivity},
	doi = {http://dx.doi.org/10.1155/2012/172674},
	author = {Derin, Onur and Ramankutty, Prasanth Kuncheerat and Meloni, Paolo and Cannella, Emanuele}
}
