@article{murali_rajasekar_aravind_kohar_ditto_sinha_2021, title={Construction of logic gates exploiting resonance phenomena in nonlinear systems}, volume={379}, ISSN={["1471-2962"]}, DOI={10.1098/rsta.2020.0238}, abstractNote={A two-state system driven by two inputs has been found to consistently produce a response mirroring a logic function of the two inputs, in an optimal window of moderate noise. This phenomenon is called logical stochastic resonance (LSR). We extend the conventional LSR paradigm to implement higher-level logic architecture or typical digital electronic structures via carefully crafted coupling schemes. Further, we examine the intriguing possibility of obtaining reliable logic outputs from a noise-free bistable system, subject only to periodic forcing, and show that this system also yields a phenomenon analogous to LSR, termed Logical Vibrational Resonance (LVR), in an appropriate window of frequency and amplitude of the periodic forcing. Lastly, this approach is extended to realize morphable logic gates through the Logical Coherence Resonance (LCR) in excitable systems under the influence of noise. The results are verified with suitable circuit experiments, demonstrating the robustness of the LSR, LVR and LCR phenomena.}, number={2192}, journal={PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES}, author={Murali, K. and Rajasekar, S. and Aravind, Manaoj V. and Kohar, Vivek and Ditto, W. L. and Sinha, Sudeshna}, year={2021}, month={Mar} }
 @article{murali_sinha_kohar_ditto_2021, title={Harnessing tipping points for logic operations}, volume={230}, ISSN={["1951-6401"]}, DOI={10.1140/epjs/s11734-021-00014-2}, number={16-17}, journal={EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS}, author={Murali, K. and Sinha, Sudeshna and Kohar, Vivek and Ditto, William L.}, year={2021}, month={Oct}, pages={3403–3409} }
 @article{murali_sinha_kohar_kia_ditto_2018, title={Chaotic attractor hopping yields logic operations}, volume={13}, ISSN={["1932-6203"]}, url={https://doi.org/10.1371/journal.pone.0209037}, DOI={10.1371/journal.pone.0209037}, abstractNote={Certain nonlinear systems can switch between dynamical attractors occupying different regions of phase space, under variation of parameters or initial states. In this work we exploit this feature to obtain reliable logic operations. With logic output 0/1 mapped to dynamical attractors bounded in distinct regions of phase space, and logic inputs encoded by a very small bias parameter, we explicitly demonstrate that the system hops consistently in response to an external input stream, operating effectively as a reliable logic gate. This system offers the advantage that very low-amplitude inputs yield highly amplified outputs. Additionally, different dynamical variables in the system yield complementary logic operations in parallel. Further, we show that in certain parameter regions noise aids the reliability of logic operations, and is actually necessary for obtaining consistent outputs. This leads us to a generalization of the concept of Logical Stochastic Resonance to attractors more complex than fixed point states, such as periodic or chaotic attractors. Lastly, the results are verified in electronic circuit experiments, demonstrating the robustness of the phenomena. So we have combined the research directions of Chaos Computing and Logical Stochastic Resonance here, and this approach has potential to be realized in wide-ranging systems.}, number={12}, journal={PLOS ONE}, author={Murali, K. and Sinha, Sudeshna and Kohar, Vivek and Kia, Behnam and Ditto, William L.}, editor={Adamatzky, AndrewEditor}, year={2018}, month={Dec} }
 @article{kohar_kia_lindner_ditto_2017, title={Implementing Boolean Functions in Hybrid Digital-Analog Systems}, volume={7}, ISSN={["2331-7019"]}, DOI={10.1103/physrevapplied.7.044006}, abstractNote={We propose an architecture to implement multi − input one − output Boolean functions using chaos computing in hybrid digital-analog systems consisting of a digital block of conventional AND gates and a nonlinear circuit. This architecture efficiently utilizes the super-stable initial conditions of a nonlinear circuit and enables us to implement all possible 2 2 m Boolean functions of m data inputs in just m iterations of the nonlinear circuit resulting in better operating speed and noise tolerance. In an ideal nonlinear map, this architecture eliminates the need for a decoder as the outputs are mapped to maxima and minima of the map and can be fed directly to the next stage enabling multilayer concatenation. We demonstrate the utility of this architecture in a 3 − transistor circuit.}, number={4}, journal={PHYSICAL REVIEW APPLIED}, author={Kohar, Vivek and Kia, Behnam and Lindner, John F. and Ditto, William L.}, year={2017}, month={Apr} }
 @inproceedings{kia_kohar_ditto_2017, title={Present and the future of chaos computing}, volume={6}, booktitle={Proceedings of the 4th international conference on applications in nonlinear dynamics (icand 2016)}, author={Kia, B. and Kohar, V. and Ditto, W.}, year={2017}, pages={101–109} }
 @inproceedings{kohar_lindner_kia_ditto_2017, title={Spectral scaling analysis of RR Lyrae stars in OGLE-IV Galactic Bulge Fields}, volume={6}, booktitle={Proceedings of the 4th international conference on applications in nonlinear dynamics (icand 2016)}, author={Kohar, V. and Lindner, J. F. and Kia, B. and Ditto, W. L.}, year={2017}, pages={65–76} }
 @article{kohar_kia_kia_lindner_ditto_2016, title={Role of network topology in noise reduction using coupled dynamics}, volume={84}, ISSN={["1573-269X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84954519290&partnerID=MN8TOARS}, DOI={10.1007/s11071-016-2607-6}, number={3}, journal={NONLINEAR DYNAMICS}, author={Kohar, Vivek and Kia, Sarvenaz and Kia, Behnam and Lindner, John F. and Ditto, William L.}, year={2016}, month={May}, pages={1805–1812} }
 @article{kohar_kia_lindner_ditto_2016, title={Superlinearly scalable noise robustness of redundant coupled dynamical systems}, volume={93}, ISSN={["1550-2376"]}, DOI={10.1103/physreve.93.032213}, abstractNote={We illustrate through theory and numerical simulations that redundant coupled dynamical systems can be extremely robust against local noise in comparison to uncoupled dynamical systems evolving in the same noisy environment. Previous studies have shown that the noise robustness of redundant coupled dynamical systems is linearly scalable and deviations due to noise can be minimized by increasing the number of coupled units. Here, we demonstrate that the noise robustness can actually be scaled superlinearly if some conditions are met and very high noise robustness can be realized with very few coupled units. We discuss these conditions and show that this superlinear scalability depends on the nonlinearity of the individual dynamical units. The phenomenon is demonstrated in discrete as well as continuous dynamical systems. This superlinear scalability not only provides us an opportunity to exploit the nonlinearity of physical systems without being bogged down by noise but may also help us in understanding the functional role of coupled redundancy found in many biological systems. Moreover, engineers can exploit superlinear noise suppression by starting a coupled system near (not necessarily at) the appropriate initial condition.}, number={3}, journal={PHYSICAL REVIEW E}, author={Kohar, Vivek and Kia, Behnam and Lindner, John F. and Ditto, William L.}, year={2016}, month={Mar} }