Article
Engineering, Marine
Shivakumar B. Patil, D. Karmakar
Summary: This study analyzes the integration of a Wave Energy Converter (WEC) with a Pile-Restrained Rectangular Floating Breakwater (PRFB) in the presence of a partially reflecting vertical seawall. The hydrodynamic performance and WEC efficiency of the integrated device are enhanced using small amplitude wave theory and the Boundary Element Method (BEM). The study investigates the impact of various factors on wave energy conversion and hydrodynamic performance. The results show that the integrated system can enhance wave energy extraction without compromising the defined threshold wave reflection coefficient, but with limitations on the range of wavenumbers. The study also highlights the influence of structural parameters on the capture width ratio and wave reflection coefficient.
Article
Biotechnology & Applied Microbiology
Steven Van Andel, Maurice Mohr, Andreas Schmidt, Inge Werner, Peter Federolf
Summary: An increasing number of studies use Principal Component Analysis (PCA) on whole-body kinematic data to analyze posture changes in human movement. This study found that PCA outcomes have strong internal consistency in the lower order Principal Movements (PMs) but start to deviate in the higher order PMs.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Engineering, Marine
Siya Jin, Siming Zheng, Deborah Greaves
Summary: This paper investigates the scalability of wave energy converters (WECs) and shows that the scalability of WECs varies by type. While the point absorber (PA) WEC lacks scalability, terminator and attenuator WECs demonstrate scalability as their capture width increases with device width and length. Practical performance data analysis indicates that the PA unit may have difficulty reaching MW scale due to lack of scalability, while the terminator shows potential for MW scale with a high characteristic dimension. Additionally, PA may be more efficient than terminator and attenuator in some cases.
Article
Energy & Fuels
Meng Li, Zehua Yang, Rukang Wu, Bijun Wu
Summary: A novel floating oscillating water column (OWC) wave energy converter (WEC) with dual chambers is proposed and its hydrodynamic performance and energy conversion characteristics are investigated. The WEC captures wave power through heave motion and relative motion of the pipe and water column, outputting pneumatic power. Increasing the draft increases the optimal response period. The flat-bottomed model has the best capture performance among three different floater bottom shapes.
FRONTIERS IN ENERGY RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Atefeh Neisi, Hamid Reza Ghafari, Hassan Ghassemi, Torgeir Moan, Guanghua He
Summary: This paper presents a novel hybrid system combining a wind turbine and wave energy converter (WEC) in order to increase the harvested power from marine renewable energy. The study focuses on the WEC concept of semi-submersible yaw-drive flap combination (SYFC) and introduces a yaw control system to improve power absorption. Using the boundary element method (BEM), the hydrodynamics response and flap power of the semi-submersible platform under different sea state conditions are predicted. The results show that the combined system has a significantly higher capture width ratio (CWR) compared to the individual flap WEC.
Article
Multidisciplinary Sciences
Zhijiang Lou, Youqing Wang, Shan Lu, Pei Sun
Summary: A new method called minimalist module analysis (MMA) is proposed in this study to address the issue of redundant correlations between process variables in traditional multivariate statistical-based process monitoring (MSPM) methods. Simulation tests demonstrate that MMA achieves superior performance in fault detection and localization.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Marine
Wenbin Lai, Detang Li, Yonghe Xie
Summary: The paper focuses on the Haiyuan No. 1 OBWEC and proposes an improved scheme with longitudinal swing motion to enhance the hydrodynamic performance of the buoys. A numerical model based on RANS equation is established to compare the performance under different motion forms, showing that longitudinal swing motion is more effective in improving hydrodynamic performance.
Article
Engineering, Marine
Meng Li, Rukang Wu, Bijun Wu, Zehua Yang, Guo Li
Summary: By optimizing the geometry of the spar buoy wave energy converter, the flat-bottomed spar buoy model with the best capture performance was selected, and the influence of total mass on capture performance was studied.
Article
Computer Science, Artificial Intelligence
Shuangyan Yi, Feiping Nie, Yongsheng Liang, Wei Liu, Zhenyu He, Qingmin Liao
Summary: The paper presents an inductive robust principal component analysis method IRPCA_OM, extended to a more general EIRPCA_OM framework. Furthermore, a faster version FEIRPCA_OM is proposed by eliminating zero eigenvalues of the data matrix to improve processing speed.
IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING
(2022)
Article
Engineering, Civil
Bi-jun Wu, Fu-ming Zhang, Zi-zhen Qin, Heng-yu Wu, Xiang Rao
Summary: A dual-mode oscillating water column (OWC) wave energy converter with potential sailing capability is proposed in this paper. The converter can convert wave energy in a vertical duct with low sailing resistance or in a backward bend duct with high sailing resistance by opening and closing a gate. Small and medium models were designed and tested, and the capture width ratio (CWR) in the two modes and the conversion characteristics were analyzed. The results showed that the peak CWR of the small model was 145.2% and 90.1% under regular and random waves in the BBD mode, respectively, and the peak CWR in the VD mode was about 60% of that in the BBD mode. The medium model achieved a peak CWR of 228.96% under regular waves, with a maximum wave-to-battery efficiency of 63.36% and 30.17% under regular and random waves, respectively.
CHINA OCEAN ENGINEERING
(2023)
Article
Engineering, Mechanical
Sanja Martinovic, Ana Alil, Sonja Milicevic, Dragana Zivojinovic, Tatjana Volkov Husovic
Summary: The pattern recognition approach in this study utilized principal component analysis (PCA) to evaluate the initiation and propagation of cracks and defects on the surface of cavitated materials. The experiment involved synthesizing two ceramic materials, subjecting them to cavitation, collecting morphological data using image analysis software, and using PCA as a pattern recognition tool to characterize the defects. The approach proved to be highly efficient and cost-effective, offering a better assessment of induced defects and distinguishing them accurately at different levels.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Computer Science, Information Systems
Subhajit Roy, Jaydeep Howlader, Goutam Sanyal
Summary: With the progress of information technology, it has become possible to quickly transfer multimedia information over the Internet. As video data on the Internet continues to grow, video steganography has become a popular choice for data hiding. This paper introduces a new approach to steganography that is based on video frames. By applying a region selection method and principal component analysis (PCA) for compression and embedding of secret data, the proposed method achieves higher embedding capacity and better visual quality, while also improving robustness against known attacks on the channel.
MULTIMEDIA TOOLS AND APPLICATIONS
(2022)
Article
Green & Sustainable Science & Technology
Alva Bechlenberg, Yanji Wei, Bayu Jayawardhana, Antonis I. Vakis
Summary: The aim of this work is to assess the influence of different degrees of adaptability of the power take-off (PTO) system on the power absorption of dense wave energy converter (WEC) arrays. A numerical model is used to consider hydrodynamic interactions and nonlinearities of the PTO. The results show that including a high degree of adaptability and choosing specific WEC array configurations and PTO designs can increase the extracted power.
Article
Biochemistry & Molecular Biology
Lei Zhan, Guowei Lan, Yuniu Wang, Shumin Xie, Shuqing Cai, Qiantong Liu, Pei Chen, Fengwei Xie
Summary: This study investigates the complex interaction of five common food polysaccharides in composite polysaccharide gels and their impact on the overall quality. The findings reveal the phenomenon of thermoreversible gelation and identify specific polysaccharides that enhance network structure or promote layered structure. Principal component analysis highlights the order of importance of these polysaccharides. These insights can inform the development of food products with tailored textural and sensory attributes.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2024)
Article
Engineering, Chemical
Abdalhamid Rahoma, Syed Imtiaz, Salim Ahmed
Summary: Sparse principal component analysis (SPCA) provides a sparse description of the loading matrix. This article proposes two methods to calculate confidence intervals of the loading values, which outperform traditional PCA and benchmark SPCA methods in fault detection and diagnosis.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Energy & Fuels
Ophelie Choupin, Michael Henriksen, Amir Etemad-Shahidi, Rodger Tomlinson
Summary: Wave energy converters (WECs) are crucial in the transition towards a more renewable-based energy mix, but cost information is often limited and there is a lack of flexible cost breakdown methods. This study compares different costing methods and introduces a more flexible and generic CapEx method, showing that factors identified could represent up to 30% of the cost.
Article
Green & Sustainable Science & Technology
O. Choupin, F. Pinheiro Andutta, A. Etemad-Shahidi, R. Tomlinson
Summary: This research highlights the importance and application of wave energy converters globally, proposing a Decision-Making Process to identify optimal wave energy harvesting locations and analyzing different converters and installation sites. The study shows that selecting devices with high rated power may not always be the best option, and that wave direction can significantly impact energy production estimations.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Thermodynamics
Ophelie Choupin, Michael Henriksen, Rodger Tomlinson
Summary: This study investigates the impact of wave direction on the relationship between site-configurations, WEC-configurations, and power in wave energy converters. By developing the Cost-AEP Threshold Criterion, the best WEC/site-configuration pairs were determined, providing a better alternative for enhanced WEC/site-configuration pairing.
Article
Green & Sustainable Science & Technology
Ophelie Choupin, B. Del Rio-Gamero, Julieta Schallenberg-Rodriguez, Pablo Yanez-Rosales
Summary: This study presents a new integrated model to assess coastal locations and wave resource potential for renewable installations, focusing on wave resource metrics and geographical analyses, with a case study in the Canary archipelago.
Article
Energy & Fuels
O. Choupin, A. Tetu, B. Del Rio-Gamero, F. Ferri, J. P. Kofoed
Summary: This paper summarizes different approaches to wave energy utilization and investigates factors such as wave spectrum, wave direction, generator capacity limitations, and the use of the Froude similarity law. The study reveals that neglecting wave direction can lead to an overestimation of energy production and that different standard wave spectra have minimal differences in estimating energy production. The Reverse Froude Law method is introduced to assess converter configuration scaling, and a threshold for generator capacity decrease is determined to maintain high annual energy production.
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.