• Energy Research

This paper addresses the energy conservation problem in computing systems. The focus is on energy-efficient routing protocols. We formulated and solved a network-wide optimization problem for calculating energy-aware routing for the recommended network configuration. Considering the complexity of the mathematical models of data center networks and the limitations of calculating routing by solving large-scale optimization problems, and methods described in the literature, we propose an alternative solution. We designed and developed several efficient heuristics for equal-cost multipath (ECMP) and Valiant routing that reduce the energy consumption in the computer network interconnecting computing servers. Implementing these heuristics enables the selection of routing paths and relay nodes based on current and predicted internal network load. The utility and efficiency of our methods were verified by simulation. The test cases were carried out on several synthetic network topologies, giving encouraging results. Similar results of using our efficient heuristic algorithm and solving the optimization task confirmed the usability and effectiveness of our solution. Thus, we produced well-justified recommendations for energy-aware computing system design to conclude the paper.

This paper proposes a methodology for modeling and simulation the operation of Complex Systems considering the energy perspective which may feature both discrete and continuous as well as linear and nonlinear sub-systems. The methodology integrates in a unified view, subsystems with behavioral or phenomenological models, each of them featuring a set of inputs, outputs and control variables with their associated actions. A proactive optimization process is defined in terms of system level flexibility as well as operation self-adaption, and is leveraging on model simulations to calculate over a time window the system outputs for a set of given inputs and actions. We aim to determine the optimal plan of actions over a set of predicted inputs that will minimize the distance between the system outputs and a given target. To prove its effectiveness, we model and simulate the thermal-electrical processes inside a Data Center, aiming to optimize its operation by exploiting the thermal energy flexibility to re-use the otherwise wasted heat in nearby neighborhoods. 1.

The paper describes the design and performance of a novel technique that can be used to calculate the geographic locations of nodes that form wireless sensor network system (WSN). Location awareness is required for many WSN applications, but it is often too expensive to include GPS adapter in each sensor node. Hence, localization systems are provided to calculate the positions of nodes. We developed multihop algorithms based on trilateration and stochastic optimization, and RSSI measurements.