Article
Engineering, Electrical & Electronic
Atul Kumar Dwivedi, Himanshuram Ranjan, Advaith Menon, Prakasam Periasamy
Summary: The study introduces a novel method using a combination of SWT with EMD and EEMD to remove noise/artifact from ECG signals. By testing on various datasets from the MIT-BIH Arrhythmia database and comparing with existing methods, it is shown that the combination of SWT with EMD and EEMD leads to better SNR enhancement.
CIRCUITS SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Marine
Shuyi Zhou, Brandon J. Bethel, Wenjin Sun, Yang Zhao, Wenhong Xie, Changming Dong
Summary: This study combines EMD and LSTM networks to significantly improve forecasting accuracy for significant wave height, especially for forecasts exceeding 24 hours. EMD-LSTM responds faster to large waves than LSTM, and it is found that LSTM lacks the ability to adequately predict high-frequency significant wave height intrinsic mode functions, leaving room for further improvements.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Marine
Vamshikrishna Domala, Tae-wan Kim
Summary: This study explores the use of Empirical Model Decomposition (EMD) and Hodrick Prescot (HP) filter in predicting significant wave height. The Long Short-Term Memory (LSTM) technique, commonly used for sequence predictions in Natural Language Processing (NLP), is adapted for time series forecasting. The EMD and HP filter are used to extract components and trends from the original wave data, which are then fed into the LSTM model for prediction.
Article
Computer Science, Information Systems
Pritam Anand, Shantanu Jain, Harsh Savaliya
Summary: In this paper, a series of wave hybrid models for predicting significant wave height have been developed. These models incorporate signal decomposition methods, regression models, and meta-heuristic algorithms. The performance of the developed models is evaluated using different criteria, and it is found that the VMD-PSO-LDMR based model outperforms others in most cases. Furthermore, the hybrid models utilizing the VMD method demonstrate superior prediction abilities compared to other decomposition-based models. However, the LSTM model performs better than other regression models when the significant wave height signals are not decomposed apriori.
Article
Engineering, Marine
Wei Hao, Xiaofang Sun, Chenyu Wang, Hangyu Chen, Limin Huang
Summary: This study proposes an EMD-LSTM method combining the advantages of the LSTM model and EMD for accurate wave forecasting. Experimental results show that this method can effectively reduce prediction errors and increase forecast lead time.
Article
Engineering, Electrical & Electronic
Harsh S. Dhiman, Dipankar Deb
Summary: This study predicts ramp events using a hybrid method based on wavelet transform and learning algorithms for different locations, with SVR model showing the best performance among all models, and CNN performing better on larger training datasets.
INTERNATIONAL TRANSACTIONS ON ELECTRICAL ENERGY SYSTEMS
(2021)
Article
Engineering, Marine
Gang Tang, Jingyu Zhang, Jinman Lei, Haohao Du, Hongxia Luo, Yide Wang, Yuehua Ding
Summary: The research aims to improve the prediction of significant wave height (SWH) using a hybrid algorithm. Nonlinear data is preprocessed using empirical mode decomposition (EMD), and a least squares support vector machine (LSSVM) with nonlinear learning ability is used for prediction. Particle swarm optimization (PSO) is applied for parameter selection in the LSSVM modeling. The proposed EMD-PSO-LSSVM model shows improved prediction performance compared to EMD-LSSVM and LSSVM models, providing a valuable solution for SWH prediction.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Management
Guo-Feng Fan, Xiang-Ru Jin, Wei-Chiang Hong
Summary: This paper forecasts the tourism demand of Sanya City using a combination of empirical mode decomposition, support vector regression, and error factor adjustment, demonstrating that the proposed model is more accurate than other models. The paper also provides insight analyses of economic behaviors through the tourism demand's rectangular-ambulatory matrix, revealing the regulation of tourism industry and the future benefits of Sanya's tourism.
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY
(2022)
Article
Engineering, Marine
Yaser Dehghan, Masoud Sadrinasab, Vahid Chegini
Summary: This study described the water level changes in the Caspian Sea using data from three ports. The results showed that the water level reaches its lowest point in winter, increases in spring, peaks in summer, and decreases in autumn. Fourier Transform and Empirical Mode Decomposition were used to analyze the time series data, revealing the dominant sinusoidal component and the characteristics of each Intrinsic Mode Function.
Article
Chemistry, Analytical
Chun-Hsien Hsu, Ya-Ning Wu
Summary: This paper introduces the application of empirical mode decomposition on MEG data, showing that improved data clarity can capture distinguishing features between conditions and raise interesting questions about hemispheric dominance in the encoding of facial and identity information.
Article
Remote Sensing
Alba Viana-Soto, Mariano Garcia, Inmaculada Aguado, Javier Salas
Summary: Understanding post-fire recovery dynamics is crucial for effective management and enhancing fire resilience in Mediterranean pine forests. In this research, LiDAR and Landsat imagery were combined to analyze forest structure recovery over a 30-year period, revealing different responses in tree cover and height after fire.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2022)
Article
Physics, Multidisciplinary
Shuoxuan Dong, Yang Zhou, Tianyi Chen, Shen Li, Qiantong Gao, Bin Ran
Summary: This paper introduces a novel trajectory reconstruction method using Empirical Mode Decomposition (EMD) and Butterworth low-pass filter framework to reduce noise interference while maintaining physical integrity. Experimental results show that the method effectively removes high-frequency noise and maintains data integrity, producing speed and acceleration information of higher quality compared to existing methods.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Lei Gao, Xiaoke Li, Yanchun Yao, Yucong Wang, Xuzhe Yang, Xinyu Zhao, Duanyang Geng, Yang Li, Li Liu
Summary: A method based on EMD and EEMD for estimating modal frequency was proposed, with EEMD showing closer vibration frequencies to those identified by the SSI algorithm. The study provides valuable insights into modal frequency estimation and vibration control in complex working environments.
APPLIED SCIENCES-BASEL
(2022)
Article
Automation & Control Systems
Wenjian Li, Nian Cai, Zhou Ning, Yongchao Dong, Han Wang
Summary: A nonlinear error compensation method based on empirical mode decomposition and adaptive intrinsic mode function selection is proposed to improve the measurement precision of the optical encoder.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Environmental Sciences
Nawin Raj, Jason Brown
Summary: Utilizing advanced deep learning algorithms to forecast significant wave height of coastal sea waves can provide crucial information for planning and decision-making in events such as search and rescue and wave surges. The study developed a highly accurate hybrid algorithm for forecasting, with the EEMD-BiLSTM model outperforming other models in terms of accuracy. Pearson's correlation and relative mean square error values demonstrated the superior performance of the EEMD-BiLSTM model compared to traditional methods.
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.