arXiv subjects

Harneet Kaur

Publications and source records attributed to Harneet Kaur.

8 recordsLinked to original sources

arXiv2024

Neural Moving Horizon Estimation: A Systematic Literature Review

The neural moving horizon estimator (NMHE) is a relatively new and powerful state estimator that combines the strengths of neural networks (NNs) and model-based state estimation techniques. Various approaches exist for constructing NMHEs, each with its unique advantages and limitations. However, a comprehensive literature review that consolidates existing knowledge, outlines design guidelines and highlights future research directions is currently lacking. This systematic literature review synthesizes the existing knowledge on NMHE, addressing the above knowledge gap. The paper (1) explains the fundamental principles of NMHE, (2) explores different NMHE architectures, discussing the pros and cons of each, (3) investigates the NN architectures used in NMHE, providing insights for future designs, (4) examines the real-time implementability of current approaches, offering recommendations for practical applications, and (5) discusses the current limitations of NMHE approaches and outlines directions for future research. These insights can significantly improve the design and application of NMHE, which is critical for enhancing state estimation in complex systems.

cs.RO↗

arXiv2023

Knot Architecture for Biocompatible and Semiconducting Two-Dimensional Electronic Fibre Transistors

In recent years, the rising demand for close interaction with electronic devices has led to a surge in the popularity of wearable gadgets. While wearable gadgets have generally been rigid due to their utilisation of silicon-based technologies, flexible semiconducting fibre-based transistors will be needed for future wearables as active sensing components or within microprocessors to manage and analyse data. Two-dimensional (2D) semiconducting flakes are yet to be investigated in fibre transistors but could offer a route toward high-mobility, biocompatible and flexible fibre-based devices. Here we report the electrochemical exfoliation of semiconducting two-dimensional (2D) flakes of tungsten diselenide (WSe2) and molybdenum disulfide (MoS2). The high aspect ratio (>100) of the flakes achieves aligned and conformal flake-to-flake junctions on polyester fibres enabling transistors with mobilities ~ 1 cm^2 V^-1 s^-1 and a current on/off ratio, Ion/Ioff ~ 10^2 - 10^4. Furthermore, the cytotoxic effects of the MoS2 and WSe2 flakes with human keratinocyte cells are investigated and found to be biocompatible. As an additional step, we create a unique transistor knot architecture by leveraging the fibre diameter to establish the length of the transistor channel, facilitating a route to scale down transistor channel dimensions (100 μm) and utilise it to make MoS2 fibre transistors with a human hair that achieves mobilities as high as μ ~ 15 cm^2 V^-1 s^-1.

cond-mat.mtrl-sci↗

arXiv2021

Phase modulated domain walls and dark solitons for surface gravity waves

We report theoretical prediction of exact localized solutions for dynamics of surface gravity waves, at the critical point kh=1.363, modelled by higher-order nonlinear Schrodinger equation. The model possess domain walls (kink solitons) and dark solitons modulated through different phase profiles. The parametric domains are delineated for the existence of soliton solutions. The effect of wave parameters have been discussed on the amplitude of surface gravity waves. Our work is motivated by Tsitoura et al. [1], on experimental and analytical observation of phase domain walls for deep water surface gravity waves modelled by nonlinear Schrodinger equation.

nlin.PS↗

arXiv2020

Generation and controlling of ultrashort self-similar solitons and rogue waves in inhomogeneous optical waveguide

We present exact bright, dark and rogue soliton solutions of generalized higherorder nonlinear Schrodinger equation, describing the ultrashort beam propagation in tapered waveguide amplifier, via a similarity transformation connected with the constant-coefficient Sasa-Satsuma and Hirota equations. Our exact analysis takes recourse to identify the allowed tapering profile in conjunction with appropriate gain function which corresponds to PT-symmetric waveguide. We extend our analysis to study the effect of tapering profiles and higher-order terms on the evolution of self-similar waves and thus enabling one to control the self-similar wave structure and dynamical behavior.

nlin.PS↗

arXiv2020

Controlled self-similar matter waves in PT-symmetric waveguide

We study the dynamics of Bose-Einstein condensate coupled to a waveguide with parity-time symmetric potential in the presence of quadratic-cubic nonlinearity modelled by Gross-Pitaevskii equation with external source. We employ the self-similar technique to obtain matter wave solutions, such as bright, kinktype, rational dark and Lorentzian-type self-similar waves for this model. The dynamical behavior of self-similar matter waves can be controlled through variation of trapping potential, external source and nature of nonlinearities present in the system.

nlin.PS↗

arXiv2017

High yield synthesis and liquid exfoliation of two-dimensional belt like hafnium disulphide

Producing monolayers and few-layers in high yield with environment-stability is still a challenge in hafnium disulphide (HfS2), which is a layered two-dimensional material of group-IV transition metal dichalcogenides, to reveal its unlocked electronic and optoelectronic applications. For the first time, to the best of our knowledge, we demonstrate a simple and cost-effective method to grow layered belt-like nano-crystals of HfS2 with surprisingly large interlayer spacing followed by its chemical exfoliation. Various microscopic and spectroscopic techniques reveal these as-grown crystals exfoliate into single or few layers in some minutes using solvent assisted ultrasonification method in N-Cyclohexyl-2-pyrrolidone. The exfoliated nanosheets of HfS2 exhibit an indirect bandgap of 1.3 eV with high stability against ambient degradation. Further, we demonstrate that these nanosheets holds potential for electronic applications by fabricating field-effect transistors based on few layered HfS2 exhibiting field-effect mobility of 0.95 cm2/V-s with a high current modulation ratio (Ion/Ioff) of 10^4 in ambient. The method is scalable and has potential significance for both academy and industry.

cond-mat.mtrl-sci↗

arXiv2017

Unique Morphologies of Molybdenum Disulphide: Sheets, Diffusion Limited Cluster Aggregates and Fractals, by Langmuir- Blodgett Assembly for Advanced Electronics

A plethora of different morphologies are fabricated by the self assembly of molybdenum disulphide (MoS2) exfoliated flakes with the help of Langmuir-Blodgett (LB) technique at the liquid/air interface. The MoS2 flakes are chemically exfoliated in various solvents but their stable sheet like assembly on substrate is achieved only in case of the flakes exfoliated in dimethylformamide. The density of the monolayer sheets is finely controlled by the surface pressure while the stabilization of MoS2 LB film onto the water subphase results in its self assembly into diffusion limited cluster aggregates and fractals. We further demonstrate the effect of excitation on the emission of LB assembled MoS2 sheets which reveals the existence of a new exciton corresponding to 2.43 eV apart from the direct bandgap emission at 1.86 eV. Finally, field effect transistors are fabricated on SiO2/Si and a mobility of 7.4 cm2V-1s-1 with a current on-off ratio of 10^5 is obtained. This work provides a new approach for the systematic deposition of the solution processed exfoliated flakes on large scale as well as formation of pattern structures in a natural way.

cond-mat.mtrl-sci↗

arXiv2016

Large Area Fabrication of Semiconducting Phosphorene by Langmuir Blodgett Assembly

Although a considerable number of solvent based methodologies have been developed for exfoliating black phosphorus, so far there are no reports on controlled organization of these exfoliated nanosheets on substrates. Here, for the first time to the best of our knowledge, a mixture of N-Methyl-2-pyrrolidone (NMP) and deoxygenated water is employed as a subphase in Langmuir Blodgett (LB) trough for assembling the nanosheets followed by their deposition on substrates and studied its field effect transistor (FET) characteristics. Electron microscopy reveals the presence of densely aligned, crystalline, ultra-thin sheets of pristine phosphorene having lateral dimensions larger than hundred of microns. Furthermore, these assembled nanosheets retain their electronic properties and show a high current modulation of 10^4 at room temperature in FET devices. The proposed technique provides semiconducting phosphorene thin films that are amenable for large area applications.

cond-mat.mtrl-sci↗