Kookjin Lee

dblp:122/5103 · DBLP profile ↗
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6ranked-venue papers in the field
0as first author
5since 2021 · last 2024
—ORCID · conflict

Domains — venue-derived; a paper can count in several

Data Mining & Knowledge Discovery · 3Information Retrieval & Web Search · 2Big Data, Cloud & Distributed Data Systems · 1
YearPublicationVenuePosition
2024 Identifying Contemporaneous and Lagged Dependence Structures by Promoting Sparsity in Continuous-time Neural Networks
abstract
Continuous-time dynamics models, e.g., neural ordinary differential equations, enable accurate modeling of underlying dynamics in time-series data. However, employing neural networks for parameterizing dynamics makes it challenging for humans to identify dependence structures, especially in the presence of delayed effects. In consequence, these models are not an attractive option when capturing dependence carries more importance than accurate modeling, e.g., in tsunami forecasting.
Woojin Cho 0001, David Korotky, Sanghyun Hong 0001, Donsub Rim, Noseong Park, Kookjin Lee
CIKM7
2024 Not All Asians are the Same: A Disaggregated Approach to Identifying Anti-Asian Racism in Social Media
abstract
Recent policy initiatives have acknowledged the importance of disaggregating data pertaining to diverse Asian ethnic communities to gain a more comprehensive understanding of their current status and to improve their overall well-being. However, research on anti-Asian racism has thus far fallen short of properly incorporating data disaggregation practices. Our study addresses this gap by collecting 12-month-long data from X (formerly known as Twitter) that contain diverse sub-ethnic group representations within Asian communities. In this dataset, we break down anti-Asian toxic messages based on both temporal and ethnic factors and conduct a series of comparative analyses of toxic messages, targeting different ethnic groups. Using temporal persistence analysis, n-gram-based correspondence analysis, and topic modeling, this study provides compelling evidence that anti-Asian messages comprise various distinctive narratives. Certain messages targeting sub-ethnic Asian groups entail different topics that distinguish them from those targeting Asians in a generic manner or those aimed at major ethnic groups, such as Chinese and Indian. By introducing several techniques that facilitate comparisons of online anti-Asian hate towards diverse ethnic communities, this study highlights the importance of taking a nuanced and disaggregated approach for understanding racial hatred to formulate effective mitigation strategies.
Sanyam Lakhanpal, Kookjin Lee, Doowon Kim, Heewon Chae, K. Hazel Kwon
WWW4
2023 Climate modeling with neural advection-diffusion equation
Hwangyong Choi, Jeongwhan Choi 0002, Jeehyun Hwang, Kookjin Lee, Dongeun Lee 0001, Noseong Park
Knowl. Inf. Syst.4
2021 Climate Modeling with Neural Diffusion Equations
abstract
Owing to the remarkable development of deep learning technology, there have been a series of efforts to build deep learning-based climate models. Whereas most of them utilize recurrent neural networks and/or graph neural networks, we design a novel climate model based on the two concepts, the neural ordinary differential equation (NODE) and the diffusion equation. Many physical processes involving a Brownian motion of particles can be described by the diffusion equation and as a result, it is widely used for modeling climate. On the other hand, neural ordinary differential equations (NODEs) are to learn a latent governing equation of ODE from data. In our presented method, we combine them into a single framework and propose a concept, called neural diffusion equation (NDE). Our NDE, equipped with the diffusion equation and one more additional neural network to model inherent uncertainty, can learn an appropriate latent governing equation that best describes a given climate dataset. In our experiments with two real-world and one synthetic datasets and eleven baselines, our method consistently outperforms existing baselines by non-trivial margins.
Jeehyun Hwang, Jeongwhan Choi 0002, Hwangyong Choi, Kookjin Lee, Dongeun Lee 0001, Noseong Park
ICDM4
2021 Large-Scale Flight Frequency Optimization with Global Convergence in the US Domestic Air Passenger Markets
abstract
The US domestic air passenger transportation is one of the largest markets worldwide.Optimally allocating flights to the US domestic airways (i.e., air routes) is essential in maximizing the revenue of airlines and many research works have been proposed to improve their market shares/profits.Most proposed methods, however, suffer from a lack of scalability; even state-of-the-art methods demonstrate their performance with only tens of routes.To address this shortcoming, we propose a novel unified framework to integrate the market share prediction model and the frequency optimization module, which significantly improves the scalability of the entire framework.By design, our proposed prediction model is concave w.r.t.flight frequency and its gradients are Lipschitz continuous.Exploiting these two properties allows us to use an alternating direction method of multipliers (ADMM)-based optimization technique, which quickly solves a large-scale frequency optimization problem with guaranteed global convergence.Our proposed method is able to solve a problem whose search space size is O(n 700 ) (vs.O(n 30 ) in existing works).
Jinsung Jeon, Dongeun Lee 0001, Seunghyun Hwang, Soyoung Kang, Noseong Park, Duanshun Li, Kookjin Lee, Jing Liu 0024
SDM7
2019 Two Problems in Knowledge Graph Embedding: Non-Exclusive Relation Categories and Zero Gradients
abstract
Knowledge graph embedding (KGE) learns latent vector representations of named entities (i.e., vertices) and relations (i.e., edge labels) of knowledge graphs. Herein, we address two problems in KGE. First, relations may belong to one or multiple categories, such as functional, symmetric, transitive, reflexive, and so forth; thus, relation categories are not exclusive. Some relation categories cause non-trivial challenges for KGE. Second, we found that zero gradients happen frequently in many translation based embedding methods such as TransE and its variations. To solve these problems, we propose i) converting a knowledge graph into a bipartite graph, although we do not physically convert the graph but rather use an equivalent trick; ii) using multiple vector representations for a relation; and iii) using a new hinge loss based on energy ratio(rather than energy gap) that does not cause zero gradients. We show that our method significantly improves the quality of embedding.
Nasheen Nur, Noseong Park, Kookjin Lee, Hyun-joong Kang, Soonhyeon Kwon
IEEE BigData3