604 results match your criteria: "Korea Institute for Advanced Study[Affiliation]"
Chaos
September 2025
Department of Mathematical Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
Reservoir computing (RC) has traditionally relied on tuning systems toward the edge of chaos to optimize their computational capability. In contrast, we propose a novel method that starts from a fully chaotic system and systematically tames it into a trainable reservoir using homotopy. Our approach constructs adaptive reservoirs whose internal dynamics evolve in real time with the input, yielding a new class of computational models: Homotopy Reservoir Computing (Homotopy RC).
View Article and Find Full Text PDFSci Rep
August 2025
Department of Computer Science, Hanyang University, Seoul, 04763, South Korea.
This study aimed to develop and evaluate deep convolutional neural network (DCNN) models with Grad-CAM visualization for the automated classification with interpretability of tongue conditions-specifically glossitis and oral squamous cell carcinoma (OSCC)-using clinical tongue photographs, with a focus on their potential for early detection and telemedicine-based diagnostics. A total of 652 tongue images were categorized into normal control (n = 294), glossitis (n = 340), and OSCC (n = 17). Four pretrained DCNN architectures (VGG16, VGG19, ResNet50, ResNet152) were fine-tuned using transfer learning.
View Article and Find Full Text PDFChaos
August 2025
Department of Mathematical Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
Removing noise from a signal without knowing the characteristics of the noise is a challenging task. This paper introduces a signal-noise separation method based on time-series prediction. We use Reservoir Computing (RC) to extract the maximum portion of "predictable information" from a given signal.
View Article and Find Full Text PDFPhys Rev E
July 2025
Asia Pacific Center for Theoretical Physics, Pohang 37673, Republic of Korea.
Thermodynamic constraints impose a trade-off between power and efficiency in heat engines, preventing the simultaneous achievement of high power and high efficiency. For classical microscopic engines, explicit inequalities have been discovered, demonstrating the inherent inevitability of this power-efficiency trade-off. However, extensions of these results to quantum engines have so far been limited to cases of slow operation.
View Article and Find Full Text PDFPhys Chem Chem Phys
August 2025
Department of Materials Science and Engineering, Incheon National University, Incheon 22012, Republic of Korea.
Ferroelectric semiconductors offer a unique route to enhance photovoltaic (PV) performance through spontaneous polarization-assisted separation of e-h pairs. In this study, we investigate BaGePn (Pn = P or As) as promising candidates for thin-film solar cells using density functional theory with a hybrid functional. These pnictides exhibit spontaneous polarization, suitable optical band gaps near the Shockley-Queisser limit, and strong visible-light absorption.
View Article and Find Full Text PDFPhys Rev Lett
June 2025
Korea Institute for Advanced Study, Seoul, South Korea.
We present a framework for determining effectively the spectrum and stability of traveling waves on networks with symmetries, such as rings and lattices, by computing master stability curves (MSCs). Unlike traditional methods, MSCs are independent of system size and can be readily used to assess wave destabilization and multistability in small and large networks.
View Article and Find Full Text PDFSci Rep
July 2025
Kyungpook National University, Daegu, 41566, Korea.
We investigate the utility of deep neural networks (DNNs) in estimating the Jaynes-Cummings Hamiltonian's parameters from its energy spectrum alone. We assume that the energy spectrum may or may not be corrupted by noise. In the noiseless case, we use the vanilla DNN (vDNN) model and find that the error tends to decrease as the number of input nodes increases.
View Article and Find Full Text PDFJ Chem Inf Model
August 2025
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea.
Supercritical water oxidation offers promising solutions for waste treatment, but understanding its complex molecular reaction mechanisms remains challenging due to extreme experimental conditions. We compare two computational approaches, a machine learning potential (NequIP) and a reactive force field (ReaxFF), to model acetic acid oxidation in supercritical water, a key industrial process. While ReaxFF predicts the apparent activation barrier closer to experimental measurements, NequIP more accurately reproduces the observed product distributions and reaction pathways.
View Article and Find Full Text PDFNat Commun
July 2025
Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea.
Quantum chaos is central to understanding quantum dynamics and is crucial for generating random quantum states, a key resource for quantum information tasks. In this work, we introduce a new class of quantum many-body dynamics, termed pseudochaotic dynamics. Although distinct from chaotic dynamics, out-of-time-ordered correlators, the key indicators of quantum chaos, fail to distinguish them.
View Article and Find Full Text PDFSci Rep
July 2025
Department of Physics, Texas A & M University at Qatar, 23874, Doha, Qatar.
The study of quantum thermodynamics aims to elucidate the role played by quantum principles in the emergent features of quantum thermodynamic processes. Specifically, it is of fundamental importance to understand how quantum correlation among different parties enables thermodynamic features distinguishable from those arising in classical thermodynamics. In this work, we investigate the relation between extractable work and quantum correlations for two-mode Gaussian states.
View Article and Find Full Text PDFSci Rep
July 2025
Department of Surgery, Uijeongbu Eulji Medical Center, Eulji University School of Medicine, Uijeongbu, Gyeonggi-do, Republic of Korea.
Cancer-associated fibroblasts promote tumor progression through growth facilitation, invasion, and immune evasion. This study investigated the impact of activated cancer-associated fibroblasts (aCAFs) on survival outcomes, immune response, and molecular pathways in distal bile duct (DBD) cancer. We analyzed 469 patients (418 from our cohort and 51 from The Cancer Genome Atlas) with DBD adenocarcinoma.
View Article and Find Full Text PDFPNAS Nexus
June 2025
Department of Physics, POSTECH, 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
Thermodynamic uncertainty relations (TURs) delineate tradeoff relations between the thermodynamic cost and the magnitude of an observable's fluctuation. While TURs have been established for various nonequilibrium systems, their applicability to systems influenced by active noise remains largely unexplored. Here, we present an explicit expression of TUR for systems with active Ornstein-Uhlenbeck particles (AOUPs).
View Article and Find Full Text PDFJ Chem Theory Comput
July 2025
Korea Institute for Advanced Study, Seoul 02455, Republic of Korea.
We present a comprehensive benchmarking study of first-principles calculation methods, based on density functional theory (DFT) and its extensions, to evaluate the fundamental and optical band gaps of nanoporous materials, including metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), and a zeolite. We find that a hybrid approach using the HSE06 functional generally underestimates the fundamental band gaps compared to the nonself-consistent GW (GW) approximation, and a DFT approach incorporating self-consistent extended Hubbard interactions shows varying agreement with GW results depending on the electronic characteristics of materials. Using the Bethe-Salpeter equation (BSE) on top of GW calculations (GW+BSE) and time-dependent DFT (TDDFT) with the PBE functional, we compute optical band gaps and absorption spectra that are in good agreement with experiments.
View Article and Find Full Text PDFLangmuir
July 2025
Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
Polymer grafting density critically influences the self-assembly of polymer-grafted nanoparticles, yet the low grafting density regime remains underexplored. Here, we investigate the thin-film self-assembly of bottlebrush polymer-grafted core/shell nanoparticles (BPGNPs) under quasi-2D confinement at near-zero grafting densities through coarse-grained molecular dynamics (CGMD). The NP core is modeled using a hard-core/soft-shoulder (HCSS) potential, and it is compared against Weeks-Chandler-Andersen (WCA) potential.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2025
Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Korea. Electronic address:
Investigating the two-dimensional (2D) diffusion dynamics of multi-component surfactant systems is challenging due to the difficulty in establishing well-defined initial boundaries both temporally and spatially. To overcome this challenge, we employed two key strategies. First, we utilized a merging droplet technique which provides controlled spatiotemporal initial conditions, enabling in-situ measurement of multi-component surfactant diffusion.
View Article and Find Full Text PDFPhys Rev E
May 2025
Korea University, Department of Physics, Seoul 02841, Korea.
Social dynamics are often driven by both pairwise (i.e., dyadic) relationships and higher-order (i.
View Article and Find Full Text PDFJ Chem Phys
June 2025
Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
We develop a highly parallelizable algorithm to calculate long-range electrostatic interactions named the Gauss-Legendre-Spherical-t (GLST) cubature method. Motivated by our recent spherical grid and treecode method, we utilize the Gauss-Legendre quadrature for integration over a finite range and spherical t-design for integration over a unit sphere. The resulting GLST cubature breaks the long-range interaction term into a sum of terms that can be calculated in parallel with minimal inter-processor communication.
View Article and Find Full Text PDFJ Chem Phys
June 2025
Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Computing electrostatic interactions remains the bottleneck of molecular dynamics (MD) simulations despite more than a century of effort in developing methods to accelerate the calculation. Previously, we have developed the spherical grids and treecode and Gauss-Legendre-spherical-t (GLST) algorithms for electrostatic interactions. Here, we explain the computational details and discuss the performance of GLST.
View Article and Find Full Text PDFJ Chem Theory Comput
June 2025
Korea Institute for Advanced Study, Seoul 02455, Korea.
Depletion forces are relevant in a variety of contexts such as the phase behavior of colloid-polymer or colloid-depletant mixtures and clustering of inclusions in mobile brushes. They arise from the tendency to minimize the volume of the depletion zone formed around colloidal particles or inclusions. In comparison to depletion interactions widely studied for colloidal particles or polymers in a suspension of spherical depletants, depletion interactions between nonspherical inclusions in mobile polymer brushes display complex behaviors.
View Article and Find Full Text PDFSci Adv
May 2025
National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, and Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences and School of Physics, Jiangsu Physical Science Research Center, Nanjing Un
Fluctuation theorems have elevated the second law of thermodynamics to a statistical realm by establishing a connection between time-forward and time-reversal probabilities, providing invaluable insight into nonequilibrium dynamics. While well established in classical systems, their quantum generalization, incorporating coherence and the diversity of quantum noise, remains open. We report the experimental validation of a quantum fluctuation theorem (QFT) in a photonic system, applicable to general quantum processes with nonclassical characteristics, including quasi-probabilistic descriptions of entropy production and multiple time-reversal processes.
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May 2025
Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
The gravity model, inspired by Newton's law of universal gravitation, has been a cornerstone in the analysis of trade flows between countries. In this model, each country is assigned an economic mass, where greater economic masses lead to stronger trade interactions. Traditionally, proxy variables like gross domestic product or other economic indicators have been used to approximate this economic mass.
View Article and Find Full Text PDFPhys Rev E
April 2025
Seoul National University, Department of Physics Education and Center for Theoretical Physics and Artificial Intelligence Institute, Seoul 08826, Korea.
Identifying model parameters from observed configurations poses a fundamental challenge in data science, especially with limited data. Recently, diffusion models have emerged as a novel paradigm in generative machine learning, capable of producing new samples that closely mimic observed data. These models learn the gradient of model probabilities, bypassing the need for cumbersome calculations of partition functions across all possible configurations.
View Article and Find Full Text PDFWhile sexual reproduction is a general feature of animals, fissiparity and budding are relatively uncommon modes of asexual reproduction by which a fragment from a parent becomes an independent organism. Unlike unitary development, tumor cells can be included in the detached fragment destined to become offspring. Although fragmentation facilitates the vertical transmission of parental tumor cells to nascent progeny, this process requires significantly fewer cell replications than development from a zygote.
View Article and Find Full Text PDFNature
May 2025
Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea.
Imposing incommensurable periodicity on the periodic atomic lattice can lead to complex structural phases consisting of locally periodic structure bounded by topological defects. Twisted trilayer graphene (TTG) is an ideal material platform to study the interplay between different atomic periodicities, which can be tuned by twist angles between the layers, leading to moiré-of-moiré lattices. Interlayer and intralayer interactions between two interfaces in TTG transform this moiré-of-moiré lattice into an intricate network of domain structures at small twist angles, which can harbour exotic electronic behaviours.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
May 2025
Department of Mathematics and Computer science, Division of Mathematics, University of Cologne, Köln 50931, Germany.
In 2013, Lee, Li, and Zelevinsky introduced combinatorial objects called compatible pairs to construct the greedy bases for rank-2 cluster algebras, consisting of indecomposable positive elements including the cluster monomials. Subsequently, Rupel extended this construction to the setting of generalized rank-2 cluster algebras by defining compatible gradings. We find a class of combinatorial objects which we call tight gradings.
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