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593 results on '"Kim, Kyungsoo"'

2. Partitioned neural network approximation for partial differential equations enhanced with Lagrange multipliers and localized loss functions

Author

Jang, Deok-Kyu, Kim, Kyungsoo, and Kim, Hyea Hyun

Subjects
Mathematics - Numerical Analysis, Physics - Computational Physics
Abstract

Partitioned neural network functions are used to approximate the solution of partial differential equations. The problem domain is partitioned into non-overlapping subdomains and the partitioned neural network functions are defined on the given non-overlapping subdomains. Each neural network function then approximates the solution in each subdomain. To obtain the convergent neural network solution, certain continuity conditions on the partitioned neural network functions across the subdomain interface need to be included in the loss function, that is used to train the parameters in the neural network functions. In our work, by introducing suitable interface values, the loss function is reformulated into a sum of localized loss functions and each localized loss function is used to train the corresponding local neural network parameters. In addition, to accelerate the neural network solution convergence, the localized loss function is enriched with an augmented Lagrangian term, where the interface condition and the boundary condition are enforced as constraints on the local solutions by using Lagrange multipliers. The local neural network parameters and Lagrange multipliers are then found by optimizing the localized loss function. To take the advantage of the localized loss function for the parallel computation, an iterative algorithm is also proposed. For the proposed algorithms, their training performance and convergence are numerically studied for various test examples.

Published
2023

3. Enhanced physics-informed neural networks with domain scaling and residual correction methods for multi-frequency elliptic problems

Author

Jang, Deok-Kyu, Kim, Hyea Hyun, and Kim, Kyungsoo

Subjects
Mathematics - Numerical Analysis, Computer Science - Machine Learning, Physics - Computational Physics
Abstract

In this paper, neural network approximation methods are developed for elliptic partial differential equations with multi-frequency solutions. Neural network work approximation methods have advantages over classical approaches in that they can be applied without much concerns on the form of the differential equations or the shape or dimension of the problem domain. When applied to problems with multi-frequency solutions, the performance and accuracy of neural network approximation methods are strongly affected by the contrast of the high- and low-frequency parts in the solutions. To address this issue, domain scaling and residual correction methods are proposed. The efficiency and accuracy of the proposed methods are demonstrated for multi-frequency model problems.

Published
2023

4. Emergence of task-related spatiotemporal population dynamics in transplanted neurons.

Author

Ghuman, Harman, Kim, Kyungsoo, Barati, Sapeeda, and Ganguly, Karunesh

Subjects
Male, Mice, Animals, Neurons, Nervous System, Cell Transplantation
Abstract

Loss of nervous system tissue after severe brain injury is a main determinant of poor functional recovery. Cell transplantation is a promising method to restore lost tissue and function, yet it remains unclear if transplanted neurons can demonstrate the population level dynamics important for movement control. Here we present a comprehensive approach for long-term single neuron monitoring and manipulation of transplanted embryonic cortical neurons after cortical injury in adult male mice performing a prehension task. The observed patterns of population activity in the transplanted network strongly resembled that of healthy networks. Specifically, the task-related spatiotemporal activity patterns of transplanted neurons could be represented by latent factors that evolve within a low dimensional manifold. We also demonstrate reliable modulation of the transplanted networks using minimally invasive epidural stimulation. Our approach may allow greater insight into how restoration of cell-type specific network dynamics in vivo can restore motor function.

Published
2023

23. ent-Verticilide B1 Inhibits Type 2 Ryanodine Receptor Channels and is Antiarrhythmic inCasq2−/−Mice

Author

Gochman, Aaron, primary, Do, Tri Q., additional, Kim, Kyungsoo, additional, Schwarz, Jacob A., additional, Thorpe, Madelaine P., additional, Blackwell, Daniel J., additional, Ritschel, Paxton A., additional, Smith, Abigail N., additional, Rebbeck, Robyn T., additional, Akers, Wendell S., additional, Cornea, Razvan L., additional, Laver, Derek R., additional, Johnston, Jeffrey N., additional, and Knollmann, Bjorn C., additional

Published
2024
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27. LNK/SH2B3 loss of function increases susceptibility to murine and human atrial fibrillation.

Author

Murphy, Matthew B, Yang, Zhenjiang, Subati, Tuerdi, Farber-Eger, Eric, Kim, Kyungsoo, Blackwell, Daniel J, Fleming, Matthew R, Stark, Joshua M, Amburg, Joseph C Van, Woodall, Kaylen K, Beusecum, Justin P Van, Agrawal, Vineet, Smart, Charles D, Pitzer, Ashley, Atkinson, James B, Fogo, Agnes B, Bastarache, Julie A, Kirabo, Annet, Wells, Quinn S, and Madhur, Meena S

Subjects
ATRIAL fibrillation, ACTION potentials, ADAPTOR proteins, STROKE, ATRIUMS (Architecture)
Abstract

Aims The lymphocyte adaptor protein (LNK) is a negative regulator of cytokine and growth factor signalling. The rs3184504 variant in SH2B3 reduces LNK function and is linked to cardiovascular, inflammatory, and haematologic disorders, including stroke. In mice, deletion of Lnk causes inflammation and oxidative stress. We hypothesized that Lnk−/− mice are susceptible to atrial fibrillation (AF) and that rs3184504 is associated with AF and AF-related stroke in humans. During inflammation, reactive lipid dicarbonyls are the major components of oxidative injury, and we further hypothesized that these mediators are critical drivers of the AF substrate in Lnk−/− mice. Methods and results Lnk−/− or wild-type (WT) mice were treated with vehicle or 2-hydroxybenzylamine (2-HOBA), a dicarbonyl scavenger, for 3 months. Compared with WT, Lnk−/− mice displayed increased AF duration that was prevented by 2-HOBA. In the Lnk−/− atria, action potentials were prolonged with reduced transient outward K+ current, increased late Na+ current, and reduced peak Na+ current, pro-arrhythmic effects that were inhibited by 2-HOBA. Mitochondrial dysfunction, especially for Complex I, was evident in Lnk−/− atria, while scavenging lipid dicarbonyls prevented this abnormality. Tumour necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) were elevated in Lnk−/− plasma and atrial tissue, respectively, both of which caused electrical and bioenergetic remodelling in vitro. Inhibition of soluble TNF-α prevented electrical remodelling and AF susceptibility, while IL-1β inhibition improved mitochondrial respiration but had no effect on AF susceptibility. In a large database of genotyped patients, rs3184504 was associated with AF, as well as AF-related stroke. Conclusion These findings identify a novel role for LNK in the pathophysiology of AF in both experimental mice and humans. Moreover, reactive lipid dicarbonyls are critical to the inflammatory AF substrate in Lnk−/− mice and mediate the pro-arrhythmic effects of pro-inflammatory cytokines, primarily through electrical remodelling. [ABSTRACT FROM AUTHOR]

Published
2024
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37. Samsung PIM/PNM for Transfmer Based AI : Energy Efficiency on PIM/PNM Cluster

Author

Kim, Jin Hyun, primary, Ro, Yuhwan, additional, So, Jinin, additional, Lee, Sukhan, additional, Kang, Shin-haeng, additional, Cho, YeonGon, additional, Kim, Hyeonsu, additional, Kim, Byeongho, additional, Kim, Kyungsoo, additional, Park, Sangsoo, additional, Kim, Jin-Seong, additional, Cha, Sanghoon, additional, Lee, Won-Jo, additional, Jung, Jin, additional, Lee, Jong-Geon, additional, Lee, Jieun, additional, Song, JoonHo, additional, Lee, Seungwon, additional, Cho, Jeonghyeon, additional, Yu, Jaehoon, additional, and Sohn, Kyomin, additional

Published
2023
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41. ent-Verticilide B1 inhibits type 2 ryanodine receptor channels and is antiarrhythmic in Casq2-/- mice

Author

Gochman, Aaron, primary, Do, Tri Q., additional, Kim, Kyungsoo, additional, Schwarz, Jacob A., additional, Thorpe, Madelaine P., additional, Blackwell, Daniel J., additional, Smith, Abigail N., additional, Akers, Wendell S., additional, Cornea, Razvan L., additional, Laver, Derek R., additional, Johnston, Jeffrey N., additional, and Knollmann, Bjorn C., additional

Published
2023
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48. The Breakthrough Memory Solutions for Improved Performance on LLM Inference

Author

Kim, Byeongho, Cha, Sanghoon, Park, Sangsoo, Lee, Jieun, Lee, Sukhan, Kang, Shin-haeng, So, Jinin, Kim, Kyungsoo, Jung, Jin, Lee, Jong-Geon, Lee, Sunjung, Paik, Yoonah, Kim, Hyeonsu, Kim, Jin-Seong, Lee, Won-Jo, Ro, Yuhwan, Cho, YeonGon, Kim, Jin Hyun, Song, JoonHo, Yu, Jaehoon, Lee, Seungwon, Cho, Jeonghyeon, and Sohn, Kyomin

Abstract

Large language models (LLMs) have changed our lives, but they require unprecedented computing resources—especially large memory capacity and high bandwidth to process weights. However, while the logic process was developing, the speed of development of the memory process could not keep up, causing problems that resulted in the performance of LLMs being hindered by memory. Samsung has introduced breakthrough processing-in-memory/processing-near-memory (PIM/PNM) solutions that enhance the main memory bandwidth. With the high bandwidth memory PIM-based GPU-cluster system and LPDDR5-PIM-based system, the performance of transformer-based LLMs improved by up to 1.9$ \times $× and 2.7$ \times $×, respectively. The Compute eXpress Link (CXL)-based PNM solution serves memory-centric computing systems by implementing logic inside the CXL memory controller. This results in a performance gain of more than 4.4$ \times $× with an energy reduction of about 53% with PNM. Furthermore, we provide PIM/PNM software stacks, including an AI compiler targeting the acceleration of AI models.

Published
2024
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