A5007117496- Advanced Battery Technologies Research
- Advancements in Battery Materials
- Ferroelectric and Piezoelectric Materials
- Fault Detection and Control Systems
- Morphological variations and asymmetry
- 2D Materials and Applications
- Magnetic and transport properties of perovskites and related materials
- Multiferroics and related materials
- Electric Vehicles and Infrastructure
- Advanced Battery Materials and Technologies
- Bayesian Methods and Mixture Models
- Security and Verification in Computing
- Physics of Superconductivity and Magnetism
- Microwave Dielectric Ceramics Synthesis
- Advanced Thermoelectric Materials and Devices
- Perovskite Materials and Applications
- Machine Learning in Materials Science
- Parallel Computing and Optimization Techniques
- Advanced Condensed Matter Physics
- Occupational and environmental lung diseases
- IoT-based Smart Home Systems
- Physical Unclonable Functions (PUFs) and Hardware Security
- Energy and Environmental Systems
- Air Quality Monitoring and Forecasting
- Chalcogenide Semiconductor Thin Films
The University of Texas at Austin
2025
Yonsei University
2021-2024
Hanyang University
2021-2024
Pohang University of Science and Technology
2016-2024
Materials Science & Engineering
2023
Institute for Basic Science
2023
Seoul Metropolitan Government
2011-2021
University of Nottingham
2013-2019
University of Göttingen
2012
Korea University
2012
Coulomb attraction between electrons and holes in a narrow-gap semiconductor or semimetal is predicted to lead an elusive phase of matter dubbed excitonic insulator. However, direct observation such electronic instability remains extremely rare. Here, we report the incipient divergence static susceptibility candidate material Ta2NiSe5 using Raman spectroscopy. Critical fluctuations order parameter give rise quasi-elastic scattering B2g symmetry, whose intensity grows inversely with...
State of health (SOH) is a key issue for saving cost and guaranteeing safety while using rechargeable battery. Therefore, numerous studies on SOH estimation have been conducted intensively. However, most the need experimental data whole lifetime battery, adopt standard charge/discharge pattern that does not reflect real world driving pattern. For these reasons, it suitable to apply results into battery management system (BMS) an EV. In this paper, practical classification scheme based...
In order to accurately estimate the state of health (SOH) a Li-ion battery, reference performance test (RPT) needs be conducted between several charging/discharging cycles for obtaining accurate data concerning battery capacity and degradation. However, it is not practical perform RPTs frequently because they are time-consuming expensive; moreover, undergoes unnecessary degradation during operations. Therefore, should performed as infrequently possible. this paper, neural network-based SOH...
Electrochemical models of lithium-ion batteries are derived according to the laws physics; therefore, parameters represent specific physical quantities such as lithium diffusivities, particle volume fractions, and ion intercalation rates. It is important estimate these identify internal states a battery for efficient safe management. Until now, parameter estimation algorithms electrochemical have been developed without considering unequal identifiability among target parameters. Thus, it...
To expand the unchartered materials space of lead-free ferroelectrics for smart digital technologies, tuning their compositional complexity via multicomponent alloying allows access to enhanced polar properties. The role isovalent A-site in binary potassium niobate alloys, (K,A)NbO
Abstract 2D materials possess weak inter‐layer van der Waals bonding, allowing them to exist as different polymorphs depending on the stacking sequence of layers. Herein, thermal conductivities 2H‐NbSe 2 and 2H‐3R‐NbSe by conducting experimental measurements theoretical analysis are comparatively studied. Owing its 1.8 times larger unit cell, has a considerably greater number optical phonon branches than does , suggesting that absorbs energy rather transporting it. In addition, scattering is...
Monitoring the state of health (SOH) for Li-ion batteries is crucial in battery management system (BMS), their efficient and safe use. Due to time-varying parameters insufficient computation capability BMSs, computationally online parameter identification practically required. So, a simple equivalent circuit model (ECM) based recursive least squares (RLS) algorithm has been widely used. However, it long acknowledged that this suffers from wind-up problem when input current doesn't provide...
Abstract Group I niobates (KNbO 3 and NaNbO ) are promising lead-free alternatives for high-performance energy storage applications. Despite their potential, complex phase transitions arising from temperature-dependent phonon softening anharmonic effects on dielectric properties remain poorly explored. In this study, we employ density-functional theory (DFT) self-consistent (SCP) calculations to investigate finite-temperature phonons in cubic niobate perovskites. To include explicit...
A novel state of charge (SOC) estimation method for lithium-ion batteries is proposed. The made by combining a model-based and data-driven method. Model-based methods can show acceptable error without large data. However there limit in reducing the because inaccuracy model still exists. solve this problem learning proposed paper optimizes parameters extended Kalman filter (EKF) with reinforcement (RL) when estimating SOC using EKF. This utilizes both advantage Even if RL slightly trained, an...
By means of a first-principles-based Landau–Devonshire model, we predict and explain why newly discovered intermediates can rationalize the persistent lack double polarization–electric field hysteresis for NaNbO 3 under an applied field.
In this paper we approach the problem of analyzing space-time curves. terms classical geometry, characterization space-curves can be summarized in a differential equation involving functional parameters curvature and torsion whose origins are from Frenet-Serret framework. particular, measures rate change angle which nearby tangents make with tangent at some point. situation straight line, is zero. Torsion twisting curve, vanishing describes curve three dimensional range restricted to...
In this study, we simultaneously measured the PM10 and PM2.5 mass concentrations their heavy metal content for three days at a subway station in Seoul to investigate airborne PM flows. The average were 59 µg m–3, 37 111 369 m–3 43 28 58 132 outdoor air inlet, concourse, on platform, tunnel, respectively. We also found strong correlations between temporal variations adjacent sampling locations both fractions, although they higher PM2.5. Additionally, of trace metals detected inside (the...
Lithium-ion batteries (LIBs) are very promising energy storage devices because of their eco-friendly characteristics and economic efficiency. Because the capacity LIBs decreases with use, predicting pattern fade is important for both manufacturers users. In particular, recent surge in interest battery reuse, a method that can predict 'knee point' phenomenon, which rapid decrease occurring later stage life, becoming more critical. This paper proposes Gradient 1-Knee point (G-K) curve knee...
Molecular dynamics simulations produce huge datasets of temporal sequences molecules. It is interest to summarize the shape evolution molecules in a succinct, low-dimensional representation. However, Euclidean techniques such as principal components analysis (PCA) can be problematic data may lie far from flat manifold. Principal nested spheres gives fundamentally different decomposition usual subspace based PCA [Biometrika 99 (2012) 551–568]. Subspaces successively lower dimension are fitted...
The K-means clustering algorithm is a popular and widely used method for clustering. For covariance matrices, we consider geodesic based on the framework in consideration of symmetric positive definite matrices as Riemannian (non-Euclidean) manifold. This paper considers data consisting (SPD) utilizing geometric structure SPD idea algorithm. A divided into two main steps which need dissimilarity measure between matrix points way computing centroids observations clusters. In order to use...
This paper proposes a method of regulating frequency and bus voltage simultaneously with STATCOM battery in an high transmission system. Comparative analysis stand-alone is carried out to compare the steady state characteristics them. Dynamic model controller are designed accomplish two control objectives, regulation. The results verified MATLAB on modified IEEE 14 test
There has been increasing interest in statistical analysis of data lying manifolds. This paper generalizes a smoothing spline fitting method to Riemannian manifold based on the technique unrolling and unwrapping originally proposed Jupp Kent (1987) for spherical data. In particular we develop such procedure shapes configurations general $m$-dimensional Euclidean space, extending our previous work two dimensional shapes. We show that parallel transport along geodesic Kendall shape space is...