ACCURATE: Accuracy Maximization for Real-Time Multicore Systems With Energy-Efficient Way-Sharing Caches

Abstract

Improving result-accuracy in approximate computing (AC) based real-time applications without violating deadline has recently become an active research domain. Execution-time of AC real-time tasks can individually be separated into: execution of the mandatory part to obtain a result of acceptable quality, followed by a partial/complete execution of the optional part to improve result-accuracy of the initial result within a given deadline. However, obtaining higher result-accuracy at the cost of enhanced execution time may lead to deadline violation, along with higher energy usage. We present ACCURATE, a novel hybrid offline-online approximate real-time scheduling approach that first schedules AC-based tasks on multi-core with an objective to maximize result-accuracy and determines operational processing speeds for each task constrained by system-wide power limit, deadline, and task-dependency. At runtime, by employing a waysharing technique (WH LLC) at the last level cache, ACCURATE improves performance, which is further leveraged, to enhance result-accuracy by executing more from the optional part, and to improve energy efficiency of the cache by turning off a controlled number of cache-ways. ACCURATE also exploits the slacks either to improve result-accuracy of the tasks, or to enhance energy efficiency of the underlying system, or both. ACCURATE achieves 85% QoS with 36% average reduction in cache leakage consumption with a 24% average gain in energy delay product for a 4-core based chip-multiprocessor with 6.4% average improvement in performance.

Application of IoT and Non-Intrusive Load Monitoring Techniques in Microgrid Energy Management and Monitoring Systems

“…The ideas of smart cities, microgrids, and smart homes are interrelated in the context of promoting sustainable urban development. A smart city is a city that incorporates advanced technology and data-driven solutions to improve the quality of life for its citizens and support sustainable growth in urban areas (30). One potential strategy for a smart city to accomplish this objective is through the integration of microgrids, which are selfsustaining energy systems capable of functioning autonomously from the primary power grid.…”