hyuk jin kwon

Dr. hyuk jin kwon


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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29 September 2024 in Electronics
Verified
Journal Article
Open access
PDF file
YSYongjoo Shin
Yongjoo Shin
HKhyuk jin kwon
hyuk jin kwon
JJJeong Jaeyeong
Jeong Jaeyeong
Dongkyoo ShinDongkyoo Shin
Dongkyoo Shin
As cyberattacks become increasingly sophisticated with advancements in information and communication technology, the impact of cyberspace threats is growing in both civilian and defense sectors. The utilization of cyber capabilities in operations is on the rise, prompting major nations to continuously enhance their cyber capabilities. This study aims to establish a systematic approach to cyber operations training and propose a framework for the development of cyber training. A hybrid cyber training system is designed as a plan for temporal and spatial integration to simultaneously combine simulation-based training with real-world target training. To develop this concept, a literature review was conducted, expert consultations were held, and data were collected and analyzed through visits to relevant organizations and units. Additionally, the fundamental components of cyber training were examined from environmental, scenario-based, and operational perspectives, leading to the presentation of a development direction for effective cyber training. This study is anticipated to enhance response capabilities to evolving cyber threats and attacks, improve cyber operational proficiency, and secure cyber power to achieve dominance in cyberspace.

11 October 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
CLChanho Lee
Chanho Lee
HKhyuk jin kwon
hyuk jin kwon
HCHanseon Choi
Hanseon Choi
JCJongGeun Choi
JongGeun Choi
ILIlkyun Lee
Ilkyun Lee
Dongkyoo ShinDongkyoo Shin
Dongkyoo Shin
When implementing outside-the-window (OTW) visuals in aviation tactical simulators, maintaining terrain image color consistency is critical for enhancing pilot immersion and focus. However, due to various environmental factors, inconsistent image colors in terrain can cause visual confusion and diminish realism. To address these issues, a color correction technique based on a Wasserstein Generative Adversarial Network with Gradient Penalty (WGAN-GP) is proposed. The proposed WGAN-GP model utilizes multi-scale feature extraction and Wasserstein distance to effectively measure and adjust the color distribution difference between the input image and the reference image. This approach can preserve the texture and structural characteristics of the image while maintaining color consistency. In particular, by converting Bands 2, 3, and 4 of the BigEarthNet-S2 dataset into RGB images as the reference image and preprocessing the reference image to serve as the input image, it is demonstrated that the proposed WGAN-GP model can handle large-scale remote sensing images containing various lighting conditions and color differences. The experimental results showed that the proposed WGAN-GP model outperformed traditional methods, such as histogram matching and color transfer, and was effective in reflecting the style of the reference image to the target image while maintaining the structural elements of the target image during the training process. Quantitative analysis demonstrated that the mid-stage model achieved a PSNR of 28.93 dB and an SSIM of 0.7116, which significantly outperforms traditional methods. Furthermore, the LPIPS score was reduced to 0.3978, indicating improved perceptual similarity. This approach can contribute to improving the visual elements of the simulator to enhance pilot immersion and has the potential to significantly reduce time and costs compared to the manual methods currently used by the Republic of Korea Air Force.

20 December 2022 in Sustainability
Verified
Journal Article
Open access
PDF file
HKhyuk jin kwon
hyuk jin kwon
YSYongjoo Shin
Yongjoo Shin
JJJeong Jaeyeong
Jeong Jaeyeong
Kookjin KimKookjin Kim
Kookjin Kim
Dongkyoo ShinDongkyoo Shin
Dongkyoo Shin
National defense requires uninterrupted decision-making, even under direct or indirect impacts of non-traditional threats such as infectious diseases. Since all work utilizes information systems, it is very important to ensure the sustainability and availability of information systems. In particular, in terms of security management, defense work is being performed by dividing the network into a national defense network and a commercial Internet network. This study suggests a work execution plan for sustainability that takes into account the efficiency of work performed on the Internet and the effectiveness of security through effective defense information system operation. It is necessary to minimize the network contact points between the national defense network and the commercial Internet and to select high-priority tasks from various tasks and operate them efficiently. For this purpose, actual cases were investigated for an institution, “Organization A”, and characteristics were presented. Through the targeted tasks and operation plans presented in this paper to improve the effectiveness of defense tasks and ensure security, it will be possible to increase the sustainability and availability of task performance even under non-traditional threats such as infectious diseases.

1 July 2025 in Edelweiss Applied Science and Technology
Verified
Journal Article
Open access
PDF file
HJHwi Jeon
Hwi Jeon
CLChan-Ho Lee
Chan-Ho Lee
JCJongGeun Choi
JongGeun Choi
HKhyuk jin kwon
hyuk jin kwon
Collaborative filtering recommender systems primarily focus on short-term prediction accuracy but exhibit limitations concerning long-term user satisfaction and content diversity. In this paper, we reinterpret user-item interaction data as reinforcement learning with verifiable rewards and introduce the Group Relative Policy Optimization (GRPO) reinforcement learning algorithm, originally proposed in the large language model domain, to collaborative filtering model fine-tuning for the first time. GRPO directly updates policies without separate critic networks, balancing exploration and exploitation while optimizing long-term user engagement. In experiments conducted on Amazon review datasets covering baby products, video games, and industrial & scientific categories, the GRPO-optimized model achieved up to 15.16% improvement in Recall@10 compared to baseline models. Additionally, we revealed that user embeddings from graph-based collaborative filtering architectures positively contribute to GRPO algorithm optimization, whereas positional embeddings from sequential collaborative filtering architectures impede optimization performance. These findings empirically validate the effectiveness of the GRPO algorithm as a robust approach for recommender system model optimization.

29 July 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
YNYerin Nam
Yerin Nam
HCHanseon Choi
Hanseon Choi
JCJongGeun Choi
JongGeun Choi
HKhyuk jin kwon
hyuk jin kwon
This study develops a domain-adaptive multimodal RAG (Retrieval-Augmented Generation) system to improve the accuracy and efficiency of technical question answering based on large-scale structured manuals. Using Hyundai Staria maintenance documents as a case study, we extracted text and images from PDF manuals and constructed QA, RAG, and Multi-Turn datasets to reflect realistic troubleshooting scenarios. To overcome limitations of baseline RAG models, we proposed an enhanced architecture that incorporates sentence-level similarity annotations and parameter-efficient fine-tuning via LoRA (Low-Rank Adaptation) using the bLLossom-8B language model and BAAI-bge-m3 embedding model. Experimental results show that the proposed system achieved improvements of 3.0%p in BERTScore, 3.0%p in cosine similarity, and 18.0%p in ROUGE-L compared to existing RAG systems, with notable gains in image-guided response accuracy. A qualitative evaluation by 20 domain experts yielded an average satisfaction score of 4.4 out of 5. This study presents a practical and extensible AI framework for multimodal document understanding, with broad applicability across automotive, industrial, and defense-related technical documentation.