Freight-rate forecasting in the VLCC TD3C market remains challenged by abrupt regime shifts, pronounced volatility, and heterogeneity in real-time signals from oil prices, seaborne trade, vessel operations, and macroeconomic factors; these directly impact freight planning and chartering. This study presents a daily multivariate dataset with 4,267 samples covering 2014-02-01 to 2025-10-08, integrating crude benchmarks, fuel spreads, refinery margins, port congestion, inventory levels by region, plus detailed AIS-derived VLCC activity, speed, and operation states, scaled and split 80/10/10 for training, validation, and testing. The proposed framework combines a PyTorch Transformer—optimized using Optuna for d_model=128, 9 layers, 8 heads, a 14-day input window, and 5-day output—with Monte Carlo Dropout for uncertainty quantification. Diagnosis uses differential entropy and coefficient-of-variation to verify convergence with 90 separate runs, while a Kalman filter (Q=0.001, R=0.01) smooths the forecast trajectory and enhances temporal reliability. Experimental results show baseline Transformer achieves average MAE 5,259.4, MAPE 13.10%, and R²=0.74 across 1-5 day horizons, with volatility quality metrics declining at longer leads. Applying the Kalman filter reduces errors to MAE 4,326.1, MAPE 10.6%, and raises R² to 0.83; timing and extremity components of volatility quality scores are strengthened, providing a more robust basis for operational decisions. Monte Carlo backtesting for 82 Korean VLCCs over 598 trades finds the Kalman-smoothed strategy earns $108.5M (88.9% win rate, Sharpe ratio 0.83), substantially outperforming raw Transformer ($32.9M, 60.5%, 0.24) and random selection (near zero, 49.3%, 0.005). These results highlight the clear economic value added by calibrating uncertainty and post-processing forecasts, transforming predictive reliability into real-world freight portfolio improvement in the tanker market.
The age and growth of the Pacific cod, Gadus macrocephalus were investigated using left sagittal otoliths of 682 individuals collected in the West Sea of Korea from January to December 2007. The seasonal changes in the ratio of an opaque zone to interval between annular rings revealed that the narrow translucent parts of the otolith were annual growth rings formed between February and March once a year. The spawning period was December to January and therefore the duration from fertilization to the complete formation of the opaque zone became thirteen months. From the parameters calculated using the average length when the year ring was formed, the estimated von Bertalanffy growth equations were Lt=100.0(1-e-0.1640(t+0.5247)) for females and Lt=64.6(1-e-0.3335 (t+0.3342)) for males when is total length in age t.
Characteristics of age and growth of the black rockfish, Sebastes inermis sampled in the Jeonnam Marine Ranching Area (JMRA) around Geumo Islands south of Yeosu were investigated using 642 otoliths from March 2009 to February 2010. The opaque zone was formed in September once a year and hence it was used as an annulus. The parturient period was December to January, and therefore the duration from fertilization to the complete formation of the opaque zone was nineteen months. From the parameters calculated using the average length when the year ring was formed, growth of S. inermis were expressed by von Bertalanffy growth equation as Lt=23.267 (1-e-0.4406(t+1.1971)) for females and Lt=22.030 (1-e-0.5312(t+0.6834)) for males when is total length in age t. Through the growth equations, the maximum length was determined as 23.27cm for females and 22.03cm for males and the growth factor as 0.4406/yr and 0.5312/yr, respectively. Finally, the growth of female S. inermis is larger than the one of male S. inermis.