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전남 진도-신안 해역에서의 조류발전 기술개발 현황 및 지자체 개발 계획
No full text전남 진도-신안 해역에서의 조류발전 기술개발 현황 및 지자체 개발 계획을 요약 정리하여 발표하였음2
Underwater Thruster Fault Diagnosis Using Acoustic STFT Spectrograms and Vision Transformer
No full text2
Battery-Integrated AUV SOC Analysis Using Model-Based Nonlinear PID Controller with Disturbance Observer
No full textEffective battery management is critical to ensure the operational longevity and reliability of Autonomous Underwater Vehicles (AUVs), especially in long-duration or deep-sea missions. This paper presents a strategy for monitoring State-of-Charge (SOC) within a model-based nonlinear proportional integral derivative with a disturbance observer (M-BNLPID-DO). The proposed method addresses the SOC analysis in dynamic underwater conditions by embedding a disturbance observer in the control loop to mitigate the effects of disturbances and model uncertainties, which often complicate underwater vehicle control. This approach offers a reliable, energy-aware control solution and advances SOC management in underwater systems. By incorporating system nonlinearities and external disturbances into the control framework, the method improves energy efficiency and operational reliability. The approach offers a reliable, energy-aware control solution, advancing SOC management and contributing to the field of battery-integrated AUV control. Simulation results highlight: in undisturbed conditions, the M-BNLPID-DO controller achieved a battery depletion of 46.51%, compared to 49.55% for the proportional integral derivative (PID) controller, representing a difference of 3.04%. Under disturbed conditions, the M-BNLPID-DO maintained a depletion of 46.52%, while the PID controller reached 50.10%, resulting in a difference of 3.59%. By embedding system nonlinearities and external disturbances into the control framework, the method enhances energy efficiency and operational reliability. These findings validate the controller’s performance, demonstrating improved battery utilization and resilience against model uncertainties and environmental variations. This work establishes a foundation for more efficient and effective AUV missions through integrated SOC monitoring and adaptive control strategies. The result establishes a foundation for more efficient and effective AUV missions through integrated SOC monitoring and adaptive control strategies.11Ysciescopu
Tracking Tidal Creek Boundary Migration in Tidal Flats Using KOMPSAT Imagery and Airborne LiDAR DSMs
No full textTidal creeks within tidal flats are key geomorphic features that regulate hydrological flow, sediment transport, and habitat distribution. Their boundaries and spatial configurations are highly dynamic, responding to both natural processes such as sea-level rise, sediment redistribution, and rainfall, as well as anthropogenic drivers including subsidence and reclamation. Quantitatively assessing these boundary shifts using time-series data is critical for diagnosing coastal stability and understanding ecosystem variability. Previous studies of Korean tidal flats have largely focused on shoreline change, sedimentary environments, or ecological surveys, while relatively few have examined tidal-creek boundary migration in a quantitative and spatially explicit manner. In particular, integrated analyses that combine long-term optical satellite imagery with high-resolution topographic datasets such as airborne LiDAR remain limited, despite their complementary strengths for monitoring geomorphological change. To address this gap, this study investigates tidalcreek boundary migration in the Taean tidal flats, South Korea, by integrating multi-temporal KOMPSAT-3/3A highresolution imagery (2015–2025) with digital surface models (DSMs) derived from airborne LiDAR (2023, 2024). Creek boundaries were delineated through visual interpretation of satellite imagery and validated against slope analysis and elevation differencing from LiDAR DSMs. This integrated approach establishes a consistent and transferable workflow for monitoring tidal-flat dynamics, offering robust insights for long-term habitat assessment and coastal management strategies.1
LC-MS-guided isolation of triterpene glycosides from Holothuria atra: structural features governing TRPA1 inhibition
No full textLC-MS-guided investigation of the sea cucumber Holothuria atra led to the isolation of 16 triterpene glycosides (1–16), including seven previously unreported compounds—three sulfated (1, 3, 5) and four non-sulfated (12, 13, 15, 16). The majority of the compounds were identified as mono-sulfated holothurin derivatives, bearing the typical holostene skeleton, while compounds 15 and 16 featured a new aglycone with an 8(9),11(12)-diene scaffold. As triterpene glycosides have been previously reported to exhibit significant TRPA1 inhibitory effects, a series of chemical modifications was performed on the isolated compounds to elucidate the structural features governing biological activity across this chemical diversity. These modifications included alkaline hydrolysis to produce desulfated analogues (17–19) and acid hydrolysis to yield sapogenins (20–22). The obtained compounds were subsequently evaluated for their efficacy against TRPA1. Among the tested copmounds, sulfated glycoside 6—bearing a 9(11)-holostenediol with a 22-hydroxy side chain—exhibited the most potent TRPA1 inhibition (IC₅₀ = 1.4 µM). These findings provide important insights into the pharmacological potential of sea cucumber glycosides and contribute to the development of marine-derived TRPA1 antagonists for therapeutic applications.1
A Grey-Box Modeling Framework for Unmanned Surface Vehicles Responsive to Environmental and Dynamic Disturbances
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시계열 위성영상을 활용한 한국 갯벌 면적 장기 변화 분석
No full text한국 서해안 갯벌은 지속적인 개발, 침식, 매립, 해수면 상승 등 자연적 및 인위적 요인으로 인해 면적 변화가 뚜렷하게 나타나고 있다. 이러한 갯벌은 생태적, 경제적, 환경적으로 중요한 가치를 지니고 있어 면적 변화 모니터링을 통한 체계적인 관리가 필요하다. 최근 갯벌 조사는 주기적이면서 광역적으로 빠르게 관측이 가능한 위성영상을 활용한 방법이 많이 진행되고 있으며, 이러한 방법을 통해 전통적인 현장조사의 접근성 한계와 선박이나 비행기와 같은 플랫폼들의 높은 조사비용을 효율적으로 보완하였다. 그러나 갯벌지역은 조위 변동으로 인해 최저조위와 최고조위와 같은 특정 시점에서 위성영상을 확보하는 것은 어렵다. 또한 연안 지역에서 자주 발생하는 구름은 갯벌 면적 주제도 작성하기 위한 입력 자료 확보에 있어 큰 제한점이 되고 있다.
본 연구는 갯벌 면적 주제도 제작 과정에서 구름과 조위 변동의 영향을 최소화하기 위해 기계 학습 기반 분류 기법을 적용하였다. 이를 통해 normalized difference water index (NDWI)와 enhanced vegetation index (EVI) 등 시계열 영상에서 추출한 다양한 지수와 영상 밝기 정보를 합성하여 분석에 활용하였다. 본 기법을 이용해 1984년부터 2024년까지 40년간Landsat 위성 시리즈 영상을 이용하여 5년단위로 우리나라 서남해안 지역에 대한 갯벌 면적 주제도를 제작하였으며 기간별로 갯벌 면적 변화에 대한 사례 연구를 수행하였다. 제작된 갯벌 면적 주제도의 정확도는 국립해양조사원(KHOA)에서 제공되는 갯벌 면적 자료를 통해 검증하였다.
사례 연구 결과, 기계 학습 기반의 방법은 구름과 조위 조건에도 불구하고 신뢰성 높은 갯벌 면적 주제도를 제작할 수 있었으며, 갯벌 면적의 장기적인 변화 양상을 효과적으로 모니터링할 수 있었다. 본 연구는 한국 갯벌의 체계적인 관리와 보존을 위한 중요한 과학적 근거를 제공하며, 향후 지속 가능한 갯벌 관리 정책 수립에 기여할 것으로 기대된다.2
Seasonal frontal variability and stratification coupling from 2022 CTD observations in the southern coastal waters of Korea
No full textIntroduction: Using May–November 2022 CTD observations from the central– eastern southern coastal waters of Korea, we quantified the variability of oceanic fronts and their coupling with water-column stability. Methods: We used conventional ∇ Tj j, ∇ Sj j thresholds and a composite Integrated Frontal Index (IFI) of ∇ Tj j, ∇ Sj j, and N²; the stability effect is DIFI = IFI TSN2 - IFI TS. Results: Fronts were coherently organized along the coastal–offshore boundary zones near the 70–100 m isobaths. Their intensity and principal formation depths reflected seasonal stratification and thermocline–halocline alignment (DTHD ): fronts were sharp and continuous when the clines co-occurred in summer, but diffuse and deeper when offset during autumnal cooling and mixing. Quantitatively, in the upper layer (10–30 m) the IFI closely co-locates with salinity fronts (≈99–100%) and also with temperature fronts (~87–93%), whereas agreement declines and becomes more variable below about 40–50 m. DIFI exhibited a depth-dependent pattern (mean −5.7 at 10 m, −1.3 at 60 m, −4.6 at 80 m), consistent with surface weakening, mid-layer mitigation, and renewed deep weakening. Discussion: The framework captures transitions between salinity- and temperature-dominated regimes and quantifies the amplification–weakening mechanism associated with DTHD , providing an observation-based diagnostic for front–stratification coupling.11Ysciescopu
Assessment of Exploited Stock and Management Implications of Kingfish (Scomberomorus commerson) in the Omani Waters
No full textThe high demand and economic value of kingfish (Scomberomorus commerson) have led to intensive fishing of this species in the Omani waters. The increased fishing pressure has made the fishery vulnerable; hence, information on the current stock status is essential for the sustainability of the kingfish stock. Three length-based stock assessment approaches (TropFishR, spawning potential ratio, and Bayesian biomass method) were used to estimate growth, mortality, exploitation, spawning potential capacity, and relative biomass in relation to maximum sustainable yield (MSY). Asymptotic length (L∞) was 186.31 cm, and the growth coefficient (K) was 0.15 yr−1 for S. commerson. Fishing mortality was 0.45 yr−1, which was higher than natural mortality (M = 0.18 yr−1) and optimal fishing mortalities (F40% = 0.15 yr−1). The exploitation rate (E) was found to be 0.71 yr−1, higher than the optimum exploitation (E = 0.50), indicating a total overfishing of 42% of the S. commerson in Oman waters. The current length at first capture (Lc50 = 74.38 cm) was significantly smaller than the length at first maturity (Lm50 = 91.25 cm), indicating growth overfishing. The current spawning potential ratio (SPR) was 10%, which was significantly below the reference point (SPR = 20%), indicating that the stock was severely overfished. Biomass was critically low (B/Bo = 0.17), and lower than the reference point of 0.20. Additionally, the current biomass was 44% of Bmsy (B/Bmsy = 0.44), which is significantly lower than the reference point of 1, indicating that the stock biomass was below the maximum sustainable yield level, suggesting recruitment overfishing. Stock indicators revealed that the fishery was primarily targeting immature/juvenile fish, as well as older and larger fish, which indicated stocks were both growth- and recruitment-overfished. Therefore, carrying out commercial fishing for an optimum size range (118 to 144 cm) and reducing fishing pressure to a sustainable level (F = M, 0.18 yr−1) would sustain a healthy stock biomass of kingfish in Omani waters.11Ysciescopu