Sungchul Kim

Prof. Dr. Sungchul Kim

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
12 April 2024 in ACM Transactions on Knowledge Discovery From Data
Verified
Journal Article
Open access
ACApril Chen
April Chen
RRRyan Rossi
Ryan Rossi
NPNamyong Park
Namyong Park
PTPuja Trivedi
Puja Trivedi
YWYu Wang
Yu Wang
NANesreen K. Ahmed
Nesreen K. Ahmed
Graph Neural Networks (GNNs) have become increasingly important due to their representational power and state-of-the-art predictive performance on many fundamental learning tasks. Despite this success, GNNs suffer from fairness issues that arise as a result of the underlying graph data and the fundamental aggregation mechanism that lies at the heart of the large class of GNN models. In this article, we examine and categorize fairness techniques for improving the fairness of GNNs. We categorize these techniques by whether they focus on improving fairness in the pre-processing, in-processing (during training), or post-processing phases. We discuss how such techniques can be used together whenever appropriate and highlight the advantages and intuition as well. We also introduce an intuitive taxonomy for fairness evaluation metrics, including graph-level fairness, neighborhood-level fairness, embedding-level fairness, and prediction-level fairness metrics. In addition, graph datasets that are useful for benchmarking the fairness of GNN models are summarized succinctly. Finally, we highlight key open problems and challenges that remain to be addressed.

31 March 2016 in Journal of Pharmacopuncture
Verified
Journal Article
Open access
SKSungchul Kim
Sungchul Kim
BSBong-Keun Song
Bong-Keun Song
JWJin-Hee Won
Jin-Hee Won
Oriental medicine, since its origin in China, has had a long history extending over 2000 years. Today, it comprises several types of medicine predominately practiced in East Asia, including traditional Chinese, traditional Korean, and Kampo medicine. The distinctive medical system of traditional Korean medicine was established shortly after the publication of Donguibogam by Dr. Heo Jun in 1613. Donguibogam is highly acclaimed across East Asia; in 2009, in light of its historical medical value, the United Nations Educational, Scientific, and Cultural Organization registered the book on its cultural heritage list. Here, we review the historical medical value of Donguibogam. The findings confirm that Donguibogam developed a unique and independent form of traditional Korean medicine and innovatively reformed the disease classification system. Moreover, Donguibogam emphasized the importance of disease prevention and medical pragmatism. This book also accelerated the development of folk medicine. Owing to its historical medical value, Donguibogam is now considered the 'bible' of Oriental medicine. Its wide acceptance has contributed to the expansion of Korean medicine utilization among the general public. Donguibogam has also played an important role in the establishment of traditional Korean medicine as a universally valid and original form of medicine, independent of traditional Chinese medicine.

30 November 2018 in IEEE Transactions on Knowledge and Data Engineering
Verified
Journal Article
Closed access
JYJinyoung Yeo
Jinyoung Yeo
SHSeung-Won Hwang
Seung-Won Hwang
SKSungchul Kim
Sungchul Kim
EKEunyee Koh
Eunyee Koh
NLNedim Lipka
Nedim Lipka
As 98 percent of shoppers do not make a purchase on the first visit, we study the problem of predicting whether they would come back for a purchase later (i.e., conversion prediction). This problem is important for strategizing “retargeting”, for example, by sending coupons for customers who are likely to convert. For this goal, we study the following two problems, prediction of market and predictability of customer. First, prediction of market aims at identifying a conversion rate for a given product and its customer behavior modeling, which is an important analytics metric for retargeting process. Compared to existing approaches using either of customer or product-level conversion pattern, we propose a joint modeling of both patterns based on the well-studied buying decision process. Second, we can observe customer-specific behaviors after showing retargeting ads, to predict whether this specific customer follows the market model (high predictability) or not (low predictability). For the former, we apply the market model, and for the latter, we propose a new customer-specific prediction based on dynamic ad behavior features. To evaluate the effectiveness of our methods, we perform extensive experiments on the simulated dataset generated based on a set of real-world web logs and retargeting campaign logs. The evaluation results show that conversion predictions and predictability by our approach are consistently more accurate and robust than those by existing baselines in dynamic market environment.

1 January 2023
Verified
Conference Paper
Open access
PDF file
THTing-Yao Hsu
Ting-Yao Hsu
CHChieh-Yang Huang
Chieh-Yang Huang
RRRyan Rossi
Ryan Rossi
SKSungchul Kim
Sungchul Kim
CGC. Giles
C. Giles
THTing-Hao Huang
Ting-Hao Huang
Ting-Yao Hsu, Chieh-Yang Huang, Ryan Rossi, Sungchul Kim, C. Giles, Ting-Hao Huang. Findings of the Association for Computational Linguistics: EMNLP 2023. 2023.

31 August 2022 in ACM Transactions on the Web
Verified
Journal Article
Open access
XQXin Qian
Xin Qian
RRRyan Rossi
Ryan Rossi
FDFan Du
Fan Du
SKSungchul Kim
Sungchul Kim
EKEunyee Koh
Eunyee Koh
NANesreen K. Ahmed
Nesreen K. Ahmed
Visualization recommendation work has focused solely on scoring visualizations based on the underlying dataset, and not the actualuserand their past visualization feedback. These systems recommend the same visualizations for every user, despite that the underlying user interests, intent, and visualization preferences are likely to be fundamentally different, yet vitally important. In this work, we formally introduce the problem ofpersonalized visualization recommendationand present a generic learning framework for solving it. In particular, we focus on recommending visualizations personalized for each individual user based on their past visualization interactions (e.g., viewed, clicked, manually created) along with the data from those visualizations. More importantly, the framework can learn from visualizations relevant to other users, even if the visualizations are generated from completely different datasets. Experiments demonstrate the effectiveness of the approach as it leads to higher quality visualization recommendations tailored to the specific user intent and preferences. To support research on this new problem, we release our user-centric visualization corpus consisting of 17.4k users exploring 94k datasets with 2.3 million attributes and 32k user-generated visualizations.

24 August 2020 in IEEE Transactions on Emerging Topics in Computational Intelligence
Verified
Journal Article
Closed access
JLJohn Boaz Lee
John Boaz Lee
GNGiang Nguyen
Giang Nguyen
RRRyan Rossi
Ryan Rossi
NANesreen K. Ahmed
Nesreen K. Ahmed
EKEunyee Koh
Eunyee Koh
SKSungchul Kim
Sungchul Kim
Networks evolve continuously over time with the addition, deletion, and changing of links and nodes. Such temporal networks (or edge streams) consist of a sequence of timestamped edges and are seemingly ubiquitous. Despite the importance of accurately modeling the temporal information, most embedding methods ignore it entirely or approximate the temporal network using a sequence of static snapshot graphs. In this work, we propose using the notion of temporal walks for learning dynamic embeddings from temporal networks. Temporal walks capture the temporally valid interactions (e.g., flow of information, spread of disease) in the dynamic network in a lossless fashion. Based on the notion of temporal walks, we describe a general class of embeddings called continuous-time dynamic network embeddings (CTDNEs) that completely avoid the issues and problems that arise when approximating the temporal network as a sequence of static snapshot graphs. Unlike previous work, CTDNEs learn dynamic node embeddings directly from the temporal network at the finest temporal granularity and thus use only temporally valid information. As such CTDNEs naturally support online learning of the node embeddings in a streaming real-time fashion. Finally, the experiments demonstrate the effectiveness of this class of embedding methods that leverage temporal walks as it achieves an average gain in AUC of $11.9\%$ across all methods and graphs.