arXiv subjects

Balaji Srinivasan

Publications and source records attributed to Balaji Srinivasan.

22 records · Page 2Linked to original sources

arXiv2018

Multi-point Dynamic Strain Sensing using External Phase Modulation-based Brillouin Optical Correlation Domain Analysis

We report a novel technique to detect dynamic strain variations simultaneously at multiple locations. Our technique is based on Brillouin optical correlation domain analysis implemented through external phase modulation to generate multiple independently-accessible correlation peaks within the sensing fiber. Simulations are carried out to demonstrate the precise determination of Brillouin frequency shift (BFS) from multiple locations independently, and the corresponding results are validated through controlled experiments. Two correlation peaks are generated within a 1 km long fiber and their independent tunability is verified experimentally by mapping the spatial profile of the two correlations. We demonstrate the detection of dynamic strain variations up to 50 Hz (limited only by our test setup) at two locations, each with a spatial resolution of 6 m over 1.1 km long fiber.

physics.optics↗

arXiv2018

Enhanced Image Classification With Data Augmentation Using Position Coordinates

In this paper we propose the use of image pixel position coordinate system to improve image classification accuracy in various applications. Specifically, we hypothesize that the use of pixel coordinates will lead to (a) Resolution invariant performance. Here, by resolution we mean the spacing between the pixels rather than the size of the image matrix. (b) Overall improvement in classification accuracy in comparison with network models trained without local pixel coordinates. This is due to position coordinates enabling the network to learn relationship between parts of objects, mimicking the human vision system. We demonstrate our hypothesis using empirical results and intuitive explanations of the feature maps learnt by deep neural networks. Specifically, our approach showed improvements in MNIST digit classification and beats state of the results on the SVHN database. We also show that the performance of our networks is unaffected despite training the same using blurred images of the MNIST database and predicting on the high resolution database.

cs.CV↗

arXiv2017

Empirical model for combinatorial data center network switch design

Data centers require high-performance network equipment that consume low power and support high bandwidth requirements. In this context, a combinatorial approach was proposed to design data center network (DCN) equipment from a library of components in \cite{infocom}. This library includes power splitter, wavelength multiplexers, reconfigurable add-drop multiplexers and optical amplifiers. When interconnecting optical components, it must be ensured that the resultant network supports specified target bit-error-rates (typically, at most $10^{-12}$). This paper reports experiment conducted on component interconnections and their computed bit-error-rates. From the experimental analysis, it was observed that the desired objective can be decided by considering a zeroth-order threshold for optical power at the receiver and before the amplifier. This paves way for the theoretical evaluation of several other such designs using this empirically derived model.

cs.NI↗

arXiv2015

Perturbative solution of Vlasov equation for periodically driven systems

Statistical systems with time-periodic spatially non-uniform forces are of immense importance in several areas of physics. In this paper, we provide an analytical expression of the time-periodic probability distribution function of particles in such a system by perturbatively solving the 1D Vlasov equation in the limit of high frequency and slow spatial variation of the time-periodic force. We find that the time-averaged distribution function and density cannot be written simply in terms of an effective potential, also known as the fictitious ponderomotive potential. We also find that the temperature of such systems is spatially non-uniform leading to a non-equilibrium steady state which can further lead to a complex statistical time evolution of the system. Finally, we outline a method by which one can use these analytical solutions of the Vlasov equation to obtain numerical solutions of the self-consistent Vlasov-Poisson equations for such systems.

physics.plasm-ph↗