@article{17657, abstract = {{Inter-datacenter transfers of non-interactive but timely large flows over a private (managed) network is an important problem faced by many cloud service providers. The considered flows are non-interactive because they do not explicitly target the end users. However, most of them must be performed on a timely basis and are associated with a deadline. We propose to schedule these flows by a centralized controller, which determines when to transmit each flow and which path to use. Two scheduling models are presented in this paper. In the first, the controller also determines the rate of each flow, while in the second bandwidth is assigned by the network according to the TCP rules. We develop scheduling algorithms for both models and compare their complexity and performance.}}, author = {{Cohen, R. and Polevoy, Gleb}}, issn = {{2168-7161}}, journal = {{Cloud Computing, IEEE Transactions on}}, keywords = {{Approximation algorithms, Approximation methods, Bandwidth, Cloud computing, Routing, Schedules, Scheduling}}, number = {{99}}, pages = {{1--1}}, title = {{{Inter-Datacenter Scheduling of Large Data Flows}}}, doi = {{10.1109/TCC.2015.2487964}}, volume = {{PP}}, year = {{2015}}, } @article{17663, abstract = {{In this paper, we define and study a new problem, referred to as the Dependent Unsplittable Flow Problem (D-UFP). We present and discuss this problem in the context of large-scale powerful (radar/camera) sensor networks, but we believe it has important applications on the admission of large flows in other networks as well. In order to optimize the selection of flows transmitted to the gateway, D-UFP takes into account possible dependencies between flows. We show that D-UFP is more difficult than NP-hard problems for which no good approximation is known. Then, we address two special cases of this problem: the case where all the sensors have a shared channel and the case where the sensors form a mesh and route to the gateway over a spanning tree.}}, author = {{Cohen, R. and Nudelman, I. and Polevoy, Gleb}}, issn = {{1063-6692}}, journal = {{Networking, IEEE/ACM Transactions on}}, keywords = {{Approximation algorithms, Approximation methods, Bandwidth, Logic gates, Radar, Vectors, Wireless sensor networks, Dependent flow scheduling, sensor networks}}, number = {{5}}, pages = {{1461--1471}}, title = {{{On the Admission of Dependent Flows in Powerful Sensor Networks}}}, doi = {{10.1109/TNET.2012.2227792}}, volume = {{21}}, year = {{2013}}, } @article{9795, abstract = {{Power and bandwidth of piezoelectric harvesters can be increased by using multiple piezoelectric elements in one harvester. In this contribution, a novel energy harvesting cantilever array with magnetic tuning including three piezoelectric bimorphs is investigated theoretically and experimentally, with a good agreement between model and experiment. Other than harvester designs proposed before, this array is easy to manufacture and insensitive to manufacturing tolerances because its optimum operation frequency can be re-adjusted after fabrication. Using the superposition principle, the Butterworth-Van Dyke model and a mechanical lumped parameters model, the generated voltage and current are determined analytically. Formulas for calculating the power generated by array harvesters with an arbitrary number of piezoelectric elements connected in series or in parallel are derived. It is shown that optimum harvester design must take both the connected load and the operating frequency into account. Strategies for connecting multiple bimorphs to increase the maximum generated power and/or enhance the bandwidth compared to a single bimorph harvester are investigated. For bandwidth enhancement it is essential that individual rectifiers are used for the bimorphs. An example with three bimorphs shows that, depending on the chosen tuning strategy, the power is increased by about 340\% or the bandwidth is increased by about 500\%, compared to one single bimorph.}}, author = {{Al-Ashtari, Waleed and Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}}, journal = {{Sensors and Actuators A: Physical}}, keywords = {{Energy harvesting, Cantilever array, Bandwidth, Power increase}}, pages = {{138 -- 146}}, title = {{{Enhanced energy harvesting using multiple piezoelectric elements: Theory and experiments}}}, doi = {{10.1016/j.sna.2013.01.008}}, volume = {{200}}, year = {{2013}}, }