Young-Geun Choi

dblp:83/1365 · DBLP profile ↗
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11ranked-venue papers
5as first author
5since 2021 · last 2025
0000-0003-3733-5421ORCID · reported

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 6 · 1 first-author · 4 since 2021Systems, architecture and hardware · 2 · 2 first-authorApplied, interdisciplinary, general and emerging computing · 2 · 1 first-authorDatabases, data management, data science and information retrieval · 1 · 1 first-author · 1 since 2021

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Theoretical computer science
3 papers
Algorithmic game theory and mechanism design · 67% Mathematical optimization · 21% Approximation and online algorithms · 12%
Artificial intelligence
2 papers
Probabilistic and Bayesian machine learning · 46% Reinforcement learning · 23% Transfer learning and domain adaptation · 23%
Interdisciplinary, comprehensive, and emerging computing
1 paper
Medical and health informatics · 100%
Computer architecture, parallel and distributed computing, and storage systems
1 paper
Memory systems · 67% Hardware reliability and fault tolerance · 33%

Topics — the 16 heaviest of 17, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Algorithmic game theory and mechanism design
dynamic pricing
1.522025
A Bayesian Approach to Contextual Dynamic Pricing using the Proportional Hazards Model with Discrete Price Data · NeurIPS 2025
Semi-Parametric Contextual Pricing Algorithm using Cox Proportional Hazards Model · ICML 2023
Machine learning › Probabilistic and Bayesian machine learning › statistical inference
bayesian inference
0.912025
A Bayesian Approach to Contextual Dynamic Pricing using the Proportional Hazards Model with Discrete Price Data · NeurIPS 2025
Machine learning › Reinforcement learning › bandit
contextual bandit
0.912025
A Bayesian Approach to Contextual Dynamic Pricing using the Proportional Hazards Model with Discrete Price Data · NeurIPS 2025
Machine learning › Probabilistic and Bayesian machine learning
probabilistic inference
0.912025
Backpropagation-Free Test-Time Adaptation via Probabilistic Gaussian Alignment · NeurIPS 2025
Machine learning › Transfer learning and domain adaptation
test-time adaptation
0.912025
Backpropagation-Free Test-Time Adaptation via Probabilistic Gaussian Alignment · NeurIPS 2025
Algorithmic game theory and mechanism design
pricing
0.912025
A Bayesian Approach to Contextual Dynamic Pricing using the Proportional Hazards Model with Discrete Price Data · NeurIPS 2025
Algorithmic game theory and mechanism design › dynamic pricing
contextual dynamic pricing
0.712023
Semi-Parametric Contextual Pricing Algorithm using Cox Proportional Hazards Model · ICML 2023
Approximation and online algorithms
online learning
0.712023
Semi-Parametric Contextual Pricing Algorithm using Cox Proportional Hazards Model · ICML 2023
Algorithmic game theory and mechanism design
regret minimization
0.712023
Semi-Parametric Contextual Pricing Algorithm using Cox Proportional Hazards Model · ICML 2023
Medical and health informatics › precision medicine
dynamic treatment regime
0.612022
Estimation and inference on high-dimensional individualized treatment rule in observational data using split-and-pooled de-correlated score · J. Mach. Learn. Res. 2022
Mathematical optimization › statistical estimation › semiparametric estimation
doubly robust estimation
0.612022
Estimation and inference on high-dimensional individualized treatment rule in observational data using split-and-pooled de-correlated score · J. Mach. Learn. Res. 2022
Mathematical optimization
high-dimensional statistics
0.612022
Estimation and inference on high-dimensional individualized treatment rule in observational data using split-and-pooled de-correlated score · J. Mach. Learn. Res. 2022
Machine learning › Trustworthy machine learning › robustness › distribution shift
robustness to distribution shift
0.312025
Backpropagation-Free Test-Time Adaptation via Probabilistic Gaussian Alignment · NeurIPS 2025
Memory systems
cache
0.112011
Matching cache access behavior and bit error pattern for high performance low Vcc L1 cache · DAC 2011
Memory systems › cache › cache technology
fault-tolerant cache
0.112011
Matching cache access behavior and bit error pattern for high performance low Vcc L1 cache · DAC 2011
Hardware reliability and fault tolerance
soft errors
0.112011
Matching cache access behavior and bit error pattern for high performance low Vcc L1 cache · DAC 2011

Methods — techniques the papers use, named apart from their topics

cox proportional hazards model · 2.4regret analysis · 1.7bayesian approach · 1.7penalized doubly robust · 1.1de-correlated score · 1.1data splitting · 1.1probabilistic inference · 0.9covariance modeling · 0.9CLIP · 0.9semiparametric estimation · 0.7word-level sub-block disable · 0.1remapping · 0.1access behavior history · 0.1
YearPublicationVenuePosition
2025 A Bayesian Approach to Contextual Dynamic Pricing using the Proportional Hazards Model with Discrete Price Data
abstract
Dynamic pricing algorithms typically assume continuous price variables, which may not reflect real-world scenarios where prices are often discrete. This paper demonstrates that leveraging discrete price information within a semi-parametric model can substantially improve performance, depending on the size of the support set of the price variable relative to the time horizon. Specifically, we propose a novel semi-parametric contextual dynamic pricing algorithm, namely BayesCoxCP, based on a Bayesian approach to the Cox proportional hazards model. Our theoretical analysis establishes high-probability regret bounds that adapt to the sparsity level $\gamma$, proving that our algorithm achieves a regret upper bound of $\widetilde{O}(T^{(1+\gamma)/2}+\sqrt{dT})$ for $\gamma < 1/3$ and $\widetilde{O}(T^{2/3}+\sqrt{dT})$ for $\gamma \geq 1/3$, where $\gamma$ represents the sparsity of the price grid relative to the time horizon $T$. Through numerical experiments, we demonstrate that our proposed algorithm significantly outperforms an existing method, particularly in scenarios with sparse discrete price points.
Dongguen Kim, Young-Geun Choi, Minwoo Chae
NeurIPS2
2025 Backpropagation-Free Test-Time Adaptation via Probabilistic Gaussian Alignment
abstract
Test-time adaptation (TTA) enhances the zero-shot robustness under distribution shifts by leveraging unlabeled test data during inference. Despite notable advances, several challenges still limit its broader applicability. First, most methods rely on backpropagation or iterative optimization, which limits scalability and hinders real-time deployment. Second, they lack explicit modeling of class-conditional feature distributions. This modeling is crucial for producing reliable decision boundaries and calibrated predictions, but it remains underexplored due to the lack of both source data and supervision at test time. In this paper, we propose ADAPT, an Advanced Distribution-Aware and backPropagation-free Test-time adaptation method. We reframe TTA as a probabilistic inference task by modeling class-conditional likelihoods using gradually updated class means and a shared covariance matrix. This enables closed-form, training-free inference. To correct potential likelihood bias, we introduce lightweight regularization guided by CLIP priors and a historical knowledge bank. ADAPT requires no source data, no gradient updates, and no full access to target data, supporting both online and transductive settings. Extensive experiments across diverse benchmarks demonstrate that our method achieves state-of-the-art performance under a wide range of distribution shifts with superior scalability and robustness.
Youjia Zhang, Youngeun Kim, Young-Geun Choi, Hongyeob Kim, Huiling Liu 0001, Sungeun Hong
NeurIPS3
2023 Semi-Parametric Contextual Pricing Algorithm using Cox Proportional Hazards Model
abstract
Contextual dynamic pricing is a problem of setting prices based on current contextual information and previous sales history to maximize revenue. A popular approach is to postulate a distribution of customer valuation as a function of contextual information and the baseline valuation. A semi-parametric setting, where the context effect is parametric and the baseline is nonparametric, is of growing interest due to its flexibility. A challenge is that customer valuation is almost never observable in practice and is instead type-I interval censored by the offered price. To address this challenge, we propose a novel semi-parametric contextual pricing algorithm for stochastic contexts, called the epoch-based Cox proportional hazards Contextual Pricing (CoxCP) algorithm. To our best knowledge, our work is the first to employ the Cox model for customer valuation. The CoxCP algorithm has a high-probability regret upper bound of $\tilde{O}( T^{\frac{2}{3}}d )$, where $T$ is the length of horizon and $d$ is the dimension of context. In addition, if the baseline is known, the regret bound can improve to $O( d \log T )$ under certain assumptions. We demonstrate empirically the proposed algorithm performs better than existing semi-parametric contextual pricing algorithms when the model assumptions of all algorithms are correct.
Young-Geun Choi, Gi-Soo Kim, Yunseo Choi, Wooseong Cho, Myunghee Cho Paik, Min-hwan Oh
ICML1
2023 Semi-parametric contextual bandits with graph-Laplacian regularization
Young-Geun Choi, Gi-Soo Kim, Seunghoon Paik, Myunghee Cho Paik
Inf. Sci.1
2022 Estimation and inference on high-dimensional individualized treatment rule in observational data using split-and-pooled de-correlated score
abstract
With the increasing adoption of electronic health records, there is an increasing interest in developing individualized treatment rules, which recommend treatments according to patients' characteristics, from large observational data. However, there is a lack of valid inference procedures for such rules developed from this type of data in the presence of high-dimensional covariates. In this work, we develop a penalized doubly robust method to estimate the optimal individualized treatment rule from high-dimensional data. We propose a split-and-pooled de-correlated score to construct hypothesis tests and confidence intervals. Our proposal adopts the data splitting to conquer the slow convergence rate of nuisance parameter estimations, such as non-parametric methods for outcome regression or propensity models. We establish the limiting distributions of the split-and-pooled de-correlated score test and the corresponding one-step estimator in high-dimensional setting. Simulation and real data analysis are conducted to demonstrate the superiority of the proposed method.
Muxuan Liang, Young-Geun Choi, Yang Ning, Maureen A. Smith, Ying-Qi Zhao
J. Mach. Learn. Res.2
2019 Machine learning models based on the dimensionality reduction of standard automated perimetry data for glaucoma diagnosis
Sudong Lee, Ji-Hyung Lee, Young-Geun Choi, Hee-Cheon You, Ja-Heon Kang, Chi-Hyuck Jun
Artif. Intell. Medicine3
2013 MAEPER: Matching Access and Error Patterns With Error-Free Resource for Low Vcc L1 Cache
abstract
Large SRAMs are the practical bottleneck to achieve a low supply voltage, because they suffer from process variation-induced bit errors at a low supply voltage. In this paper, we present an error-resilient cache architecture that resolves the drawback of previous approaches, i.e., the performance degradation at a low supply voltage which is caused by cache misses in accesses to faulty resources. We utilize cache access locality and error-free resources in a cost-effective manner. First, we classify cache lines into fully and partially accessed groups and apply appropriate methods to each group. For the partially accessed group, we propose a method of matching memory access behavior and error locations with intra-cache line word-level remapping. In order to reduce the area overhead used to store the cache access information history, we present an access pattern-learning line-fill buffer (LFB). For the fully accessed group, we propose the utilization of error-free assist functions in the cache, i.e., a LFB and victim cache with no process variation-induced error at the target minimum supply voltage. We also present an error-aware prefetch method that allows us to utilize the error-free victim cache to achieve a further reduction in cache misses due to faulty resources. Experimental results show that the proposed method gives an average 32.6% reduction in cycles per instruction at an error rate of 0.2% with a small area overhead of 8.2%.
Young-Geun Choi, Sungjoo Yoo, Sunggu Lee, Jung Ho Ahn, Kangmin Lee
IEEE Trans. Very Large Scale Integr. Syst.1
2011 Matching cache access behavior and bit error pattern for high performance low Vcc L1 cache
abstract
Cache is a roadblock towards low supply voltage (Vcc). It is mainly because low Vcc incurs process variation-induced bit errors in large SRAM in cache. Existing approaches for low Vcc cache suffer from low performance due to reduced effective capacity, long latency to correct errors, and increased misses due to accesses to faulty words. In our work, we propose a word-level sub-block disable-based method which increases the utilization of available cache capacity. Our key idea is to minimize accesses to faulty words. To do that, we propose utilizing access behavior history in allocating cache resource with faulty words. In addition, we propose remapping cache words inside of cache line in order to better match both access and error patterns. Experimental results show that the proposed method gives average 21.8% (up to 34.0%) performance improvement with a small area overhead in L1 and L2 caches.
Young-Geun Choi, Sungjoo Yoo, Sunggu Lee, Jung Ho Ahn
DAC1
2010 The problems in digital watermarking into intra-frames of H.264/AVC
Young-Geun Choi, Hwa-Sung Kim, Ji-Sang Yoo, Hyun-Jun Choi, Young-Ho Seo
Image Vis. Comput.2
2007 Proactive Code Verification Protocol in Wireless Sensor Network
Young-Geun Choi, Jeonil Kang, DaeHun Nyang
ICCSA (2)1
2007 Certificate Issuing Using Proxy and Threshold Signatures in Self-initialized Ad Hoc Network
Jeonil Kang, DaeHun Nyang, David Mohaisen, Young-Geun Choi, KoonSoon Kim
ICCSA (3)4