Browsing by Subject "Electronics engineering"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Open Access Parametric nonlinear lumped element model for circular CMUTs in collapsed mode(2014) Aydoǧdu, E.; Ozgurluk, A.; Atalar, Abdullah; Köymen, HayrettinWe present a parametric equivalent circuit model for a circular CMUT in collapsed mode. First, we calculate the collapsed membrane deflection, utilizing the exact electrical force distribution in the analytical formulation of membrane deflection. Then we develop a lumped element model of collapsed membrane operation. The radiation impedance for collapsed mode is also included in the model. The model is merged with the uncollapsed mode model to obtain a simulation tool that handles all CMUT behavior, in transmit or receive. Large- and small-signal operation of a single CMUT can be fully simulated for any excitation regime. The results are in good agreement with FEM simulations. © 2014 IEEE.Item Open Access Polar codes for distributed source coding(The Institution of Engineering and Technology, 2013) Önay, S.A polar coding method to construct a distributed source coding scheme which can achieve any point on the dominant face of the Slepian-Wolf rate region for sources with uniform marginals is proposed. Source encoding and decoding operations are performed using efficient algorithms which makes practical implementation feasible. Simulation results are given to exhibit the performance of the presented method. © The Institution of Engineering and Technology 2013.Item Open Access A scratch-pad memory aware dynamic loop scheduling algorithm(IEEE, 2008-03) Öztürk, Özcan; Kandemir, M.; Narayanan, S. H. K.Executing array based applications on a chip multiprocessor requires effective loop parallelization techniques. One of the critical issues that need to be tackled by an optimizing compiler in this context is loop scheduling, which distributes the iterations of a loop to be executed in parallel across the available processors. Most of the existing work in this area targets cache based execution platforms. In comparison, this paper proposes the first dynamic loop scheduler, to our knowledge, that targets scratch-pad memory (SPM) based chip multiprocessors, and presents an experimental evaluation of it. The main idea behind our approach is to identify the set of loop iterations that access the SPM and those that do not. This information is exploited at runtime to balance the loads of the processors involved in executing the loop nest at hand. Therefore, the proposed dynamic scheduler takes advantage of the SPM in performing the loop iteration-to-processor mapping. Our experimental evaluation with eight array/loop intensive applications reveals that the proposed scheduler is very effective in practice and brings between 13.7% and 41.7% performance savings over a static loop scheduling scheme, which is also tested in our experiments. © 2008 IEEE.Item Open Access Theoretical analysis of doping management(IEEE, 2013) Gürsel, A. T.; Elahi, Parviz; İlday, F. Ömer; Ozyazici, M.S.Two opposing requirements, such as thermal load and nonlinear effects are important limitations in rapid progress of high-power fiber laser technologies. Thermal effects, which limit the average power, can be minimized by using low-doped, longer gain fibers, whereas presence of nonlinear effects requires use of high-doped, shorter fibers to maximize the peak power. Proposed solution of the problem is the use of varying doping levels along the gain fiber to circumvent to mitigate the trade-off between thermal load and nonlinear effects. © 2013 The Chamber of Turkish Electrical Engineers-Bursa.