## 4 Results II--Review of Research Clusters
### Cluster 3: Stability  
The term \"stability\" refers to the ability of a vessel, including fishing boats, to maintain its restoring force, which prevents capsizing. Unlike the approaches that analyze the causes of safety accidents, stability can be calculated by reflecting the ship's main particulars and loading conditions. Studies related to fishing vessel stability can be categorized into two primary approaches: numerical calculation methods employed during the design phase and real-time stability monitoring assessment techniques used for operational safety. The literature related to stability considered in this study is summarized in Table 6, along with the methods for stability analysis and their pros and cons. A detailed description of each study is as follows:  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
Numerical studies include theoretical formulas and computer simulations such as Computational Fluid Dynamics (CFD), which have continuously evolved from past to present. [PERSON] et al. (2011) [26] conducted a study to evaluate the seakeeping performance of fishing vessels in irregular waves and to identify the main factors that limit the operability of vessels under various sea conditions. The study predicted the short-term responses of the vessels using the transfer functions for heave and sway motions along with the Pierson-Moskowitz spectrum. Additionally, the motion responses of each vessel were analyzed based on [PERSON]'s strip theory, and the results were compared against various criteria to evaluate the operational limits of the vessels. The slender body theory, which allows a 6-DOF (Degrees of Freedom) analysis, enables comprehensive assessment of ship movements and provides quick evaluations under multiple conditions. However, because this theory may not fully account for complex physical factors that can occur in real ocean environments, verification of the results is necessary to ensure accuracy. [PERSON] and [PERSON] (2018) [34] used a 6-DOF nonlinear model and a 1-DOF roll model to predict the roll response of fishing vessels and evaluate their dynamic stability. The 6-DOF model provides high accuracy by precisely simulating wave-ship interactions, but its high computational complexity and cost limit its practical use in the design phase. In contrast, the 1-DOF model, though less reliable due to its simplified approach, allows for quick and cost-effective evaluations, making it suitable for initial design stages. The study found that the prediction differences between the two models were minimal under moderate wave heights, but discrepancies increased as wave heights grew, with the 6-DOF model yielding more precise results. To improve this approach, the study suggests enhancing the nonlinear effects in the 1-DOF model and developing hybrid models that can more accurately capture the dynamic interactions between waves and hull structures. Additionally, integrating real-time weather data to reflect complex operational conditions is recommended to increase the reliability of stability assessments for practical applications. [PERSON] et al. (2019) [43] employed CFD to design and optimize bilge keels for traditional fishing vessels, achieving up to an 11.78% reduction in roll motion. However, installing bilge keels may lead to increased hydrodynamic resistance, highlighting the need for an optimal design that minimizes this drawback. While CFD studies allow for extensive case analyses, validation processes must accompany these results to ensure reliability and accuracy. [PERSON] and [PERSON] (2022) [51] evaluated the dynamic stability of fishing vessels using the Second Generation Intact Stability Criteria (SGISC) and analyzed the vulnerability of vessels to surf-riding and broaching phenomena.