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Geonu Kim

Publications and source records attributed to Geonu Kim.

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Scalable Reactive Atomistic Dynamics with GAIA

Groundbreaking advances in materials and chemical research have been driven by the development of atomistic simulations. However, the broader applicability of atomistic simulations remains limited, as they inherently depend on energy models that are either approximate or computationally prohibitive for large-scale simulations. Machine learning interatomic potentials (MLIPs) have recently emerged as a promising class of energy models, but their deployment also remains challenging due to the scarcity of systematic protocols for generating training data spanning diverse structural regimes. Here we introduce GAIA, an end-to-end automated framework that streamlines dataset construction for the development of general-purpose reactive MLIPs. GAIA combines a metadynamics-based exploration scheme with closed-loop data expansion for the efficient sampling of a broad spectrum of atomic arrangements, thereby addressing the reliance on heuristics in conventional dataset generation. Using GAIA, we constructed Titan25, a benchmark-scale dataset, and trained an MLIP that closely matches both static and dynamic density functional theory results. The resulting model reproduces key experimental observations across distinct modes of reactivity, including detonation, coalescence, and catalytic processes. GAIA thus helps bridge the gap between simulation and experiment, paving the way toward scalable and general MLIPs capable of describing a wide range of materials and chemical processes.

physics.chem-ph

ParamISP: Learned Forward and Inverse ISPs using Camera Parameters

RAW images are rarely shared mainly due to its excessive data size compared to their sRGB counterparts obtained by camera ISPs. Learning the forward and inverse processes of camera ISPs has been recently demonstrated, enabling physically-meaningful RAW-level image processing on input sRGB images. However, existing learning-based ISP methods fail to handle the large variations in the ISP processes with respect to camera parameters such as ISO and exposure time, and have limitations when used for various applications. In this paper, we propose ParamISP, a learning-based method for forward and inverse conversion between sRGB and RAW images, that adopts a novel neural-network module to utilize camera parameters, which is dubbed as ParamNet. Given the camera parameters provided in the EXIF data, ParamNet converts them into a feature vector to control the ISP networks. Extensive experiments demonstrate that ParamISP achieve superior RAW and sRGB reconstruction results compared to previous methods and it can be effectively used for a variety of applications such as deblurring dataset synthesis, raw deblurring, HDR reconstruction, and camera-to-camera transfer.

eess.IV

Human Pose Estimation in Extremely Low-Light Conditions

We study human pose estimation in extremely low-light images. This task is challenging due to the difficulty of collecting real low-light images with accurate labels, and severely corrupted inputs that degrade prediction quality significantly. To address the first issue, we develop a dedicated camera system and build a new dataset of real low-light images with accurate pose labels. Thanks to our camera system, each low-light image in our dataset is coupled with an aligned well-lit image, which enables accurate pose labeling and is used as privileged information during training. We also propose a new model and a new training strategy that fully exploit the privileged information to learn representation insensitive to lighting conditions. Our method demonstrates outstanding performance on real extremely low light images, and extensive analyses validate that both of our model and dataset contribute to the success.

cs.CV

Locally Repairable Codes with Unequal Local Erasure Correction

When a node in a distributed storage system fails, it needs to be promptly repaired to maintain system integrity. While typical erasure codes can provide a significant storage advantage over replication, they suffer from poor repair efficiency. Locally repairable codes (LRCs) tackle this issue by reducing the number of nodes participating in the repair process (locality), at the cost of reduced minimum distance. In this paper, we study the tradeoff between locality and minimum distance of LRCs with local codes that have arbitrary distance requirements. Unlike existing methods where both the locality and the local distance requirements imposed on every node are identical, we allow the requirements to vary arbitrarily from node to node. Such a property can be an advantage for distributed storage systems with non-homogeneous characteristics. We present Singleton-type distance upper bounds and also provide an optimal code construction with respect to these bounds. In addition, the feasible rate region is characterized by dimension upper bounds that do not depend on the distance.

cs.IT