Current Organizations / Institutes

The organizations/institutes from the scholar's latest article

Previous Organizations / Institutes

The organizations / institutes from the scholar's other articles in the past ten years


Ohbyung Kwon has a total of 141 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    From National to Sub-National: Estimating a Proxy Nature Relationship Index from Satellite Imagery and Local Statistics for Regional Policy

    by Heera Kim, Sujin Bae, Ohbyung Kwon

    The Nature Relationship Index (NRI) evaluates human–nature relationships through three dimensions (nature thriving, used with care, and safeguarded), but it exists only at the national level, whereas many policies are implemented regionally. Regional statistics describe resource use and protection, but harmonized information on ecological condition is rarely available for regions. This study examines whether satellite imagery can fill this gap. Transformer-based models were trained to estimate the Thriving (ecological condition) dimension from Sentinel-2 and Landsat-8 imagery of 136 countries, with labels constructed from forest cover and two satellite-derived land-condition indicators, while Care and Safeguarded were computed directly from emission, energy, and protected-area statistics. In repeated country-level cross-validation, imagery was essential for Thriving: a statistics-only model had no predictive skill (R2 = −0.04), whereas the image model reached R2 = 0.36 (p < 0.001), and transformer backbones performed similarly, with no gain from ensembling. The image-based Thriving estimates agreed with regional reference values across 42 Japanese prefectures (Spearman ρ = 0.63) and nine Korean provinces (ρ = 0.85) but not for small metropolitan cities. Combining image-based Thriving with statistics-based Care and Safeguarded yields a sub-national NRI whose profiles show whether a region’s standing is driven by ecological condition, resource use, or protection.

  • Open Access

    Differentiated Effects of Agent Diversity on Collective Decision-Making in LLM-Based Multi-Agent Delphi Systems

    by Namyeon Lee, Ohbyung Kwon

    Large language model (LLM)-based multi-agent systems are increasingly being explored as tools for supporting structured collective decision-making, but it remains unclear how the diversity structure of agent groups affects decision-making performance. This study examined the effects of agent diversity in a Delphi-based multi-agent system by applying Harrison and Klein’s framework of variety, separation, and disparity. An LLM-based Multi-Agent Delphi System (MADS) was implemented, and 11 agent-group conditions were constructed by manipulating personality-based variety, belief-orientation-based separation, and influence asymmetry. Each condition consisted of eight agents and was tested across four open-weight LLMs with repeated experimental runs. Performance was evaluated in terms of idea exploration extent, consensus quality, and consensus efficiency, using a human expert Delphi study as an external benchmark. The results showed that diversity had differentiated effects across performance dimensions. The maximum diversity group achieved the highest idea exploration but showed low consensus quality and efficiency, whereas the homogeneous group achieved stable consensus quality and efficiency but limited exploration. The separation diversity conditions formed Pareto-efficient alternatives, indicating balanced trade-offs between idea exploration and consensus. These findings indicate that agent diversity does not uniformly improve collective decision-making performance; instead, its appropriate structure depends on whether the task prioritizes exploration, consensus quality, or consensus efficiency.


  • Open Access

    Rank-Aware Conditional Synthesis: Feasible Quantum Generative Modeling on Matrix Product State Manifolds

    by Dongkyu Lee, Won-Gyeong Lee, Hyunjun Hong, Ohbyung Kwon

    Matrix Product States (MPSs) have become an indispensable symmetry-based representation for simulating quantum systems on near-term hardware by constraining entanglement entropy through a fixed bond dimension χ. This study identifies a critical “rank explosion” phenomenon that destabilizes this low-rank manifold during conditional quantum diffusion processes. We empirically demonstrate that the introduction of conditional guidance—essential for semantic control—injects global correlations that drive the effective Schmidt rank to increase by 4× (from χ=4 to 16), saturating the simulation limits and necessitating quantum circuits with approximately 1.8×103 Controlled-NOT (CNOT) gates. Such circuit depths fundamentally exceed the operational coherence budgets of Noisy Intermediate-Scale Quantum (NISQ) devices. To mitigate this structural instability, we propose Rank-Aware Conditional Synthesis (RACS), a sampling framework that maintains the latent trajectory within a prescribed MPS manifold through step-wise manifold projection and time-shift error correction. Experimental results on real-world semantic data reveal that RACS reduces reconstruction error, or Mean Squared Error (MSE) by 30.8% and enhances latent trajectory smoothness by 36.8% compared to conventional post hoc truncation. At a fixed hardware-efficient rank of χ=4, RACS achieves a +4.8% fidelity gain and exhibits superior robustness against depolarizing noise. By resolving the tension between conditional expressivity and entanglement constraints, RACS provides a principled, hardware-aware methodology for high-fidelity quantum generative modeling.

  • Impact of Socio-Economic Characteristics on the Use and Effectiveness of Generative AI in the Tourism Sector: The Digital Divide Perspective

    by Jiae Choi, Ohbyung Kwon

    This study examines how socioeconomic factors influence the effectiveness of generative AI education in bridging the digital divide. While AI tools like DALL-E, Midjourney, and Canva enhance self-efficacy, economic expectations, cultural engagement, and entrepreneurial intent, their benefits vary across disadvantaged groups. Generative AI plays a crucial role in tourism by enabling AI-driven content creation and personalized recommendations. However, individuals affected by the digital divide may struggle to leverage these tools for tourism experiences or business opportunities. The study analyzes how gender, education, age, income, digital literacy, and prior AI usage impact AI education effectiveness. Findings offer insights into reducing social costs and addressing digital inequality through targeted policies and training programs. By improving access to generative AI, this study highlights its potential to empower marginalized groups and foster economic and creative opportunities.


  • Open Access

    Enhancing Analytic Hierarchy Process Modelling Under Uncertainty With Fine‐Tuning LLM

    by Haeun Park, Hyunjoo Oh, Feng Gao, Ohbyung Kwon

    Given that decision‐making typically encompasses stages such as problem recognition, the generation of alternatives, and the selection of the optimal choice, Large Language Models (LLMs) are progressively being integrated into tasks requiring the enumeration and comparative evaluation of alternatives, thereby promoting more rational decision‐making frameworks. Analysing the extent to which LLMs exhibit meaningful performance at each stage of the decision‐making process has thus become a critical area of inquiry. In particular, LLMs hold the potential to identify latent relationships within contextual information and data related to the problem domain. This capability enables them to propose novel evaluation criteria or alternatives that may otherwise be overlooked by human designers. This study seeks to advance the modelling and evaluation of the analytical hierarchy process (AHP), a widely utilised multiple criteria decision making (MCDM) method, by leveraging LLMs. To achieve this, a methodology was developed for constructing AHP models using LLMs fine‐tuned with domain‐specific documents. The performance of the proposed methodology was assessed by evaluating the extent to which its outputs aligned with reference hierarchies and criteria created by human experts under predefined AHP frameworks. Additionally, the study examined the model's efficacy in generating complete AHP hierarchies and criteria in scenarios where these were not predefined. For empirical validation, the proposed methodology was applied to assess and improve the management performance of six‐sector agricultural enterprises. Comparative analysis of the LLM‐based AHP results with human expert evaluations was conducted to determine the validity and robustness of the approach. The findings provide insights into the potential of LLMs to contribute to structured decision‐making and enhance the application of MCDM methods.


  • Open Access

    Leveraging Quantum Machine Learning to Address Class Imbalance: A Novel Approach for Enhanced Predictive Accuracy

    by Seongjun Kwon, Jihye Huh, Sang Ji Kwon, Sang-Ho Choi, Ohbyung Kwon

    The class imbalance problem presents a critical challenge in real-world applications, particularly in high-stakes domains such as healthcare, finance, disaster management, and fault diagnosis, where accurate anomaly detection is paramount. Class imbalance often disrupts the inherent symmetry of data distributions, resulting in suboptimal performance of traditional machine learning models. Conventional approaches such as undersampling and oversampling are commonly employed to address this issue; however, these methods can introduce additional asymmetries, including information loss and overfitting, which ultimately compromise model efficacy. This study introduces an innovative approach leveraging quantum machine learning (QML), specifically the Variational Quantum Classifier (VQC), to restore and capitalize on the symmetrical properties of data distributions without relying on resampling techniques. By employing quantum circuits optimized to mitigate the asymmetries inherent in imbalanced datasets, the proposed method demonstrates consistently superior performance across diverse datasets, with notable improvements in Recall for minority classes. These findings underscore the potential of quantum machine learning as a robust alternative to classical methods, offering a symmetry-aware solution to class imbalance and advancing QML-driven technologies in fields where equitable representation and symmetry are of critical importance.


  • An Advanced Prediction Model for Risk Assessment of Imported Food

    by Da Hyun Lee, Eun Seo Lee, Sang Ji Kwon, Kyunghwa Hwang, Ohbyung Kwon


  • AI's Role in Making Space Tourism More Sustainable: Applying Mixed Methods to Compare on-Earth, Sub-orbital, and Orbital Space Tourism

    by Myung Ja Kim, C. Michael Hall, Ohbyung Kwon, Kyunghwa Hwang, Jinok Susanna Kim

    Space tourism is a growing industry sector that faces challenges of cost, risk, environmental impact, and sustainability. However, few studies address space tourism in an Asian culture, particularly in the context of artificial intelligence (AI), which is an increasingly significant topic b oth in the tourism sector and in society overall. To address the research gap, this work establishes an analytical framework which contrasts three varieties of space tourism using partial least squares, multi-group analysis, and fuzzy-set Qualitative Comparative Analysis. It surveyed 1,000 prospective space travelers from South Korean who are eager to take part in space to urism to examine AI's role in enhancing sustainable space tourism. Findings indicate that recognizing AI benefits are crucial for sustainable on-Earth, suborbital, and orbital space tourism, particularly the latter. The study offers both conceptual and applied knowledge to enhance the sustainability of space tourism.0000