Young Woong Ko

Prof. Young Woong Ko

Hallym University
orcid

Research Focus & Metrics

Academic Career Length

37Years (1990-Present)

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

Representative Publications

View All Publications
12 August 2024 in Artificial Intelligence Review
Verified
Journal Article
Open access
PDF file
TRTaki Hasan Rafi
Taki Hasan Rafi
RMRatul Mahjabin
Ratul Mahjabin
EGEmon Ghosh
Emon Ghosh
YKYoung Woong Ko
Young Woong Ko
Jeong-Gun LeeJeong-Gun Lee
Jeong-Gun Lee
Deep neural networks (DNNs) have proven explicit contributions in making autonomous driving cars and related tasks such as semantic segmentation, motion tracking, object detection, sensor fusion, and planning. However, in challenging situations, DNNs are not generalizable because of the inherent domain shift due to the nature of training under the i.i.d. assumption. The goal of semantic segmentation is to preserve information from a given image into multiple meaningful categories for visual understanding. Particularly for semantic segmentation, pixel-wise annotation is extremely costly and not always feasible. Domain generalization for semantic segmentation aims to learn pixel-level semantic labels from multiple source domains and generalize to predict pixel-level semantic labels on multiple unseen target domains. In this survey, for the first time, we present a comprehensive review of DG for semantic segmentation. we present a comprehensive summary of recent works related to domain generalization in semantic segmentation, which establishes the importance of generalizing to new environments of segmentation models. Although domain adaptation has gained more attention in segmentation tasks than domain generalization, it is still worth unveiling new trends that are adopted from domain generalization methods in semantic segmentation. We cover most of the recent and dominant DG methods in the context of semantic segmentation and also provide some other related applications. We conclude this survey by highlighting the future directions in this area.

2 February 2009 in Expert Systems
Verified
Journal Article
Closed access
PDF file
SUSaangyong Uhmn
Saangyong Uhmn
DKDong‐Hoi Kim
Dong‐Hoi Kim
YKYoung Woong Ko
Young Woong Ko
SCSungwon Cho
Sungwon Cho
JCJaeyoun Cheong
Jaeyoun Cheong
JKJin Kim
Jin Kim

1 September 2020 in Sustainability
Verified
Journal Article
Open access
PDF file
SCSe-Hak Chun
Se-Hak Chun
YKYoung Woong Ko
Young Woong Ko
Case based reasoning is a knowledge discovery technique that uses similar past problems to solve current new problems. It has been applied to many tasks, including the prediction of temporal variables as well as learning techniques such as neural networks, genetic algorithms, decision trees, etc. This paper presents a geometric criterion for selecting similar cases that serve as an exemplar for the target. The proposed technique, called geometric Case Based Reasoning, uses a shape distance method that uses the number of sign changes of features for the target case, especially when extracting nearest neighbors. Thus, this method overcomes the limitation of conventional case-based reasoning in that it uses Euclidean distance and does not consider how nearest neighbors are similar to the target case in terms of changes between previous and current features in a time series. These concepts are investigated against the backdrop of a practical application involving the prediction of a stock market index. The results show that the proposed technique is significantly better than the random walk model at p < 0.01. However, it was not significantly better than the conventional CBR model in the hit rate measure and did not surpass the conventional CBR in the mean absolute percentage error.

24 July 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
TRTaki Hasan Rafi
Taki Hasan Rafi
YKYoung Woong Ko
Young Woong Ko
Electrocardiography (ECG)-based arrhythmia classification intends to have a massive role in cardiovascular disease monitoring and early diagnosis. However, ECG datasets are mostly imbalanced and have regularization to use real-time patient data due to privacy concerns. Traditional models do not generalize on unseen cases and are also unable to preserve data privacy. Which incentivizes performance degradation in existing models with privacy limitations. To tackle generalization and privacy issues together, we introduce the framework SF-ECG, a source-free domain adaptation approach for patient-specific ECG classification. This framework does not require source data during adaptation, which solves the privacy issue during adaptation. We adopt a generative model (GAN) that learns to synthesize patient-specific ECG data in data-inefficient classes to make additional source data for imbalanced classes. Then, we use the local structure clustering method to strongly align target ECG features with similar neighbors. After seizing clustered target features, we use a classifier that is trained on source data with generated source samples, which makes the model generalizable in classifying unseen data. Empirical results under different experimental conditions in various interdomain datasets prove that the proposed framework achieves 0.8% improvements in UDA settings, along with preserving privacy and generalizability.

30 May 2016 in Indian Journal of Science and Technology
Verified
Journal Article
Open access
PDF file
JLJea-Gu Lee
Jea-Gu Lee
BKByung-Kwan Kim
Byung-Kwan Kim
SJSung-Bong Jang
Sung-Bong Jang
SYSeung-Ho Yeon
Seung-Ho Yeon
YKYoung Woong Ko
Young Woong Ko
Accuracy Enhancement of RSSI-based Distance Estimation by Applying Gaussian Filter

22 May 2021 in Electronics
Verified
Journal Article
Open access
PDF file
YWYunhee Woo
Yunhee Woo
DKDong Young Kim
Dong Young Kim
JJJaemin Jeong
Jaemin Jeong
YKYoung Woong Ko
Young Woong Ko
Jeong-Gun LeeJeong-Gun Lee
Jeong-Gun Lee
Recent deep learning models succeed in achieving high accuracy and fast inference time, but they require high-performance computing resources because they have a large number of parameters. However, not all systems have high-performance hardware. Sometimes, a deep learning model needs to be run on edge devices such as IoT devices or smartphones. On edge devices, however, limited computing resources are available and the amount of computation must be reduced to launch the deep learning models. Pruning is one of the well-known approaches for deriving light-weight models by eliminating weights, channels or filters. In this work, we propose “zero-keep filter pruning” for energy-efficient deep neural networks. The proposed method maximizes the number of zero elements in filters by replacing small values with zero and pruning the filter that has the lowest number of zeros. In the conventional approach, the filters that have the highest number of zeros are generally pruned. As a result, through this zero-keep filter pruning, we can have the filters that have many zeros in a model. We compared the results of the proposed method with the random filter pruning and proved that our method shows better performance with many fewer non-zero elements with a marginal drop in accuracy. Finally, we discuss a possible multiplier architecture, zero-skip multiplier circuit, which skips the multiplications with zero to accelerate and reduce energy consumption.