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Articles 1 - 23 of 23
Full-Text Articles in Engineering
Dynamic Response Analysis Of The Lifting Load System Of A Crane Ship In Irregular Waves, Xiao-Rong Yang, Qiu-Ming Gan, Yan-Hong Wang, Guang-Dong Wang
Dynamic Response Analysis Of The Lifting Load System Of A Crane Ship In Irregular Waves, Xiao-Rong Yang, Qiu-Ming Gan, Yan-Hong Wang, Guang-Dong Wang
Journal of Marine Science and Technology
In this paper, the indirect time domain method is adopted to analyze the dynamic responses of a mooring crane ship. The motion equations of its lifting load system are derived from Lagrange's equations and the features of the coupling motion between the crane ship and its lifting load system are presented. The hydrodynamic coefficients of the crane ship are calculated on the base of 3D potential flow theory. The lumped-mass model is used to analyze the dynamic features of its mooring lines. The nonlinear features of the motion equations being taken into account, the displacements of the crane ship and …
Reconstruction Of Propeller And Complex Ship Hull Surface Based On Reverse Engineering, Guan Guan, Wen-Wen Gu1
Reconstruction Of Propeller And Complex Ship Hull Surface Based On Reverse Engineering, Guan Guan, Wen-Wen Gu1
Journal of Marine Science and Technology
To quickly obtain the digital model of ship surface for detection and redesign, a reconstruction method for propeller and ship surface is proposed. Three-dimensional point cloud data of ship hull was obtained by laser scanning technology and the cloud data was preprocessed by iterative closest point (ICP) algorithm and chord deviation method. Then the surface was reconstructed with traditional surface modeling method and fast surface modeling method. By comparing the reconstructed surface with the initial point cloud data, the error of the reconstructed model was obtained. The result shows that the reconstructed surface gains good smoothness and small error. With …
Fft Phase Shift Of Water Wave Analysis, Chu-Kuan Lin, Shih-Yu Hsu, Jaw-Guei Lin
Fft Phase Shift Of Water Wave Analysis, Chu-Kuan Lin, Shih-Yu Hsu, Jaw-Guei Lin
Journal of Marine Science and Technology
The fast Fourier transform (FFT) has been accepted as a tool for signal processing. This study conducted a series of numerical experiments using Matlab. By conducting FFT analysis on designated wave trains, the FFT results revealed that an extra phase shift of ��ሺ2�� ��⁄ ሻ , with N representing the number of data points for an i-th wave component, was implicitly added to the analyzed phases during the analysis. When extra phase shifts were subtracted from the analyzed phases of each component, signals could be completely reconstructed in the time domain with an acceptable difference. This study tested component and …
Numerical Analysis Of Deep-Water Pipeline Abandonment And Recovery, Pan Gao, Bo-Wen Jin, Ji Zeng, Yi-Ting Zhan, Hui Zhou
Numerical Analysis Of Deep-Water Pipeline Abandonment And Recovery, Pan Gao, Bo-Wen Jin, Ji Zeng, Yi-Ting Zhan, Hui Zhou
Journal of Marine Science and Technology
Pipeline abandonment and recovery (A&R) is of great importance in offshore pipeline installation. A mathematical model of the A&R process is proposed based on the large deflection beam theory. To solve the model, an iteration process is adopted. The initial guess of the solution is obtained through the two-catenary approach, which significantly accelerates the iteration. A moving boundary technique is used to solve the governing equation of the suspended pipeline. With the proposed approach, the effects of the dominant parameters in the A&R process are studied. The cable length increases, and the maximum bending moment decreases, as the vessel moves …
On Waves Propagating Through An Emergent Poroelastic Medium, Yuan-Jyh Lan
On Waves Propagating Through An Emergent Poroelastic Medium, Yuan-Jyh Lan
Journal of Marine Science and Technology
This paper describes a theoretical study of the problem of linear waves propagating over an emergent poroelastic medium. Lan-Lee’s poro-elastomer theory is extended to derive a new analytical solution for describing this problem, with the free surface boundary condition discussed in the context of a poroelastic medium, a topic that has rarely been covered by previous studies. In the present approach, the problem domain is divided into three subregions and a negligible water-exposed region. Using general solutions for each region and the matching dynamic and kinematic conditions for neighboring regions, a set of simultaneous equations is developed and numerically solved. …
Multi-Objective Optimization Of Transferable Water For Cascade Reservoirs In The Upper Yellow River, Tao Bai, Ming Zhang, Xia Liu, Qiang Huang
Multi-Objective Optimization Of Transferable Water For Cascade Reservoirs In The Upper Yellow River, Tao Bai, Ming Zhang, Xia Liu, Qiang Huang
Journal of Marine Science and Technology
Artificially controlled floods generated by cascade reservoirs upstream have been applied to regulate the suspended river formed in the main stream of Ningxia–Inner Mongolia reach, China. The presence of sufficient transferable water in reservoirs is the most important limiting factor for the successful implementation of water and sediment regulation schemes. In this study, the conception and four modes of transferable water are proposed. Taking Longyangxia (LYX) and Liujiaxia (LJX) upper the Yellow River for example, a multi-objective optimal operation model of cascade reservoirs is established and solved by Feasible Search Space Optimal Particle Swarm Optimization (FSSO-PSO). Based on long-term time …
Nonlinear Dynamic Response Of A Fluid-Conveying Pipe With A Y-Type Manifold Under Different End Conditions, Xu Liang, Ti-Tao Wang, Chen-Wei Chen, Yu Deng, Yong-Du Ruan
Nonlinear Dynamic Response Of A Fluid-Conveying Pipe With A Y-Type Manifold Under Different End Conditions, Xu Liang, Ti-Tao Wang, Chen-Wei Chen, Yu Deng, Yong-Du Ruan
Journal of Marine Science and Technology
This article addressed the discussion on the nonlinear dynamic response of a fluid-conveying pipe with a Y-type manifold under different end conditions. In which, the pipe element was regarded as an Euler-Bernoulli beam and the control volume of the flowing fluid was simplified as a jet. The governing equation of such a nonlinear dynamic problem was derived using Hamilton’s principle and the momentum equation for the steady flow condition. The Galerkin method and the RungeKutta method with fourth-order truncation were used for solving the governing equation. To validate the numerical model, the numerical results were compared with the existing literature …
Case Study For The Ground Motion Analyses And Seabed Soil Liquefaction Potential Of Chang-Bin Offshore Wind Farm, Yu-Shu Kuo, Chi-Sheng Lin, Juin-Fu Chai, Yu-Wen Chang, Yu-Hsiu Tseng
Case Study For The Ground Motion Analyses And Seabed Soil Liquefaction Potential Of Chang-Bin Offshore Wind Farm, Yu-Shu Kuo, Chi-Sheng Lin, Juin-Fu Chai, Yu-Wen Chang, Yu-Hsiu Tseng
Journal of Marine Science and Technology
Evaluating seismic forces and soil liquefaction potential during the development of offshore wind farms in Taiwan is crucial. Wang et al. (2016) conducted a seismic hazard analysis and proposed a design earthquake response spectrum for the bedrock at the Changbin offshore wind farm. In this study, the recommended acceleration response spectrum was used to generate two design earthquakes (BH01_EW and BH01_NS) at the bedrock level that were compatible to the seismic characteristics of the Changbin offshore wind farm. The original soil data of borehole BH01(TORI) at the site were used to conduct a ground motion analysis and obtain design seismic …
Application Of Lithium-Ion Batteries In Energy Storage Systems, Yi-Kuan Ke
Application Of Lithium-Ion Batteries In Energy Storage Systems, Yi-Kuan Ke
Journal of Marine Science and Technology
Energy storage systems (ESSs) have features that can help solve various problems in the power system, such as renewable power shortage because of utility peak load. Energy storage technology and markets are gradually developing in the Taiwan power grid. In contrast to the conventional power grid model, energy storage employs a new technology in the power system. Although energy storage has several advantages in the power system, there are also challenges in its application. In this study, we investigated battery applications in ESSs and set up a simulation model to determine its benefits on power load. We implemented an ESS …
Parameter Identification Using The Nelder?€“Mead Simplex Algorithm For Low Signal-To-Noise Ratio Systems In A Frequency Domain, Chyun-Chau Fuh, Hsun-Heng Tsai
Parameter Identification Using The Nelder?€“Mead Simplex Algorithm For Low Signal-To-Noise Ratio Systems In A Frequency Domain, Chyun-Chau Fuh, Hsun-Heng Tsai
Journal of Marine Science and Technology
Parameter identification algorithms are very fundamental techniques in system engineering practices. For example, estimating the parameters of the AutoRegresive model with an eXternal input or AutoRegresive Moving-Average model with an eXternal input by using the least squares (LS) method has become a standard approach. However, the estimated parameters may generate extremely erroneous results when the signal is disturbed by large noise, which cannot be effectively filtered. If a frequency response method that scatters the power of a broadband noise over different frequencies is adopted, the effect of noise on the estimated parameters would be relatively reduced. Moreover, estimating whether the …
Protective Effect Of An Ice-Breaking Structure On Offshore Structures In Shallow Waters, Ji-Wu Dong, Zhi-Jun Li, Xiang-Peng Kong, Xiao-Dong Liang
Protective Effect Of An Ice-Breaking Structure On Offshore Structures In Shallow Waters, Ji-Wu Dong, Zhi-Jun Li, Xiang-Peng Kong, Xiao-Dong Liang
Journal of Marine Science and Technology
In this study, an ice-breaking structure (IBS) was designed to break large ice floes into small fragments through flexural failure predominantly for protecting offshore structures in shallow waters. The protective effect of the IBS on a vertical isolated cylindrical pile (ICP), which was examined through the model tests of the crushing ice loads and collision forces on the ICP from ice pieces broken with the IBS under identical conditions, was evaluated by obtaining the relative difference between the maximum values of the horizontal crushing forces and collision loads on the ICP. The results indicated a notable protective effect of the …
Optimum Arrangement Of Navy Ship Equipment For Radar Cross Section Reduction, Joon-Tae Hwang, Suk-Yoon Hong, Jee-Hun Song, Hyun-Wung Kwon
Optimum Arrangement Of Navy Ship Equipment For Radar Cross Section Reduction, Joon-Tae Hwang, Suk-Yoon Hong, Jee-Hun Song, Hyun-Wung Kwon
Journal of Marine Science and Technology
Multiple reflections on navy ship equipment cause unexpectedly high radar cross-section (RCS) distributions based on the location of each equipment on the ship. No RCS reduction method has been considered to date because the directions of reradiated electromagnetic waves are difficult to predict. In this study, an equipment arrangement design system for navy ships was developed to minimize RCS to reduce the radar detection range of naval ships by the enemy. To minimize the possibility of operating range interferences among equipment, optimal equipment arrangement areas and operation ranges were determined with reference to real navy ships. Various arrangements were tested …
Approach For 4-D Trajectory Management Based On Hmm And Trajectory Similarity, Yi Lin, Bo Yang, Jianwei Zhang, Hong Liu
Approach For 4-D Trajectory Management Based On Hmm And Trajectory Similarity, Yi Lin, Bo Yang, Jianwei Zhang, Hong Liu
Journal of Marine Science and Technology
To improve the accuracy and stability of flight trajectory prediction, a novel four-dimensional (4-D) trajectory management approach is proposed in this paper, which consists of the estimation and updating procedure. Historical flight trajectories are proved to be safe and feasible based on the real-time traffic situation, and serve as the data foundation of 4-D trajectory management in this paper. To achieve the goal of 4-D trajectory management, we firstly apply probabilistic statistical models and machine learning approach to predict the fly-over time and altitude of waypoints along the planning route before the flight takes off. Hidden Markov Models (HMMs) are …
Numerical And Experimental Prediction Of Hydrodynamic Interaction Effects Acting On Tugs During Ship Manoeuvres, Nirman Jayarathne, Dev Ranmuthugala, Zhi Leong, Jiangang Fei, Shuhong Chai
Numerical And Experimental Prediction Of Hydrodynamic Interaction Effects Acting On Tugs During Ship Manoeuvres, Nirman Jayarathne, Dev Ranmuthugala, Zhi Leong, Jiangang Fei, Shuhong Chai
Journal of Marine Science and Technology
The role of tug boats is significant when assisting ships with limited manoeuvring capabilities. Hence, knowledge of the hydrodynamic interaction effects that act on a tug under these operations is of great practical value for the tug master in order to avoid damage, collision, or capsizing. Computational Fluid Dynamic (CFD) simulations are increasingly being adopted as a tool of analysis for determining the interaction effects in such vessel manoeuvres. However, one of the major challenges faced in CFD, is that the results can vary greatly depending on the numerical model settings. This paper investigates modelling techniques and the accuracy of …
Identifying Nonlinear Oscillators By An Energetic Functional In The Linear Space Of Temporal Boundary Functions, Chein-Shan Liu, Yung-Wei Chen, Jiang-Ren Chang
Identifying Nonlinear Oscillators By An Energetic Functional In The Linear Space Of Temporal Boundary Functions, Chein-Shan Liu, Yung-Wei Chen, Jiang-Ren Chang
Journal of Marine Science and Technology
We resolve the inverse problems of a second-order nonlinear oscillator to recover time-dependent damping function and nonlinear restoring force, with the help of temporal boundary data measured at initial time and final time. By using these data, a sequence of temporal boundary functions of time is derived, which satisfy the measured temporal boundary conditions automatically, and are at least the fourth-order polynomials of time. All the temporal boundary functions and zero element constitute a linear space, and a new concept of energetic functional is introduced in the linear space, of which the energy is preserved for each energetic temporal boundary …
The Effect Of Hydro-Meteorology On Ship Collision Avoidance In Heavy Traffic Areas With A Simplified Simulation Model, Ming-Chung Fang, Kun-Yuan Tsai, Chih-Chung Fang
The Effect Of Hydro-Meteorology On Ship Collision Avoidance In Heavy Traffic Areas With A Simplified Simulation Model, Ming-Chung Fang, Kun-Yuan Tsai, Chih-Chung Fang
Journal of Marine Science and Technology
On the basis of the ship collision avoidance steering system in calm water developed by the authors, this paper upgrades the numerical simulation model by considering various hydrometeorological factors for ships with nonuniform movement. A real-time simulator was used for the numerical simulation of the container ship. To clarify the validity of the maneuvering mathematical model, sea trial results for the container ship were compared with the results for the present simulation system in terms of turn trajectory. In this study, a numerical technique based on Nomoto’s second-order model was employed to investigate the turning characteristics of a container ship. …
Spectral Analysis Of Train-Rail-Bridge Coupling System Considering Frequency-Dependent Stiffness Of Rail Fastening Systems, Linya Liu, Jialiang Qin, Quanmin Liu, Jong-Dar Yau, Rui Song
Spectral Analysis Of Train-Rail-Bridge Coupling System Considering Frequency-Dependent Stiffness Of Rail Fastening Systems, Linya Liu, Jialiang Qin, Quanmin Liu, Jong-Dar Yau, Rui Song
Journal of Marine Science and Technology
A rubber rail-pad is typically inserted between the rail and the sleeper to attenuate wheel/rail vibrations for conventional train-rail-bridge (TRB) system. For mathematical modeling, a rail-fastener with rubber pad is simplified as a spring-dashpot unit, whose spring stiffness is related to the exciting frequency of external loads. To exhibit such characteristics of rail-pads on TRB dynamics, based on dynamic flexibility method, two computational models of constant/frequency-dependent stiffness (FDS) are considered for comparison. Numerical studies reveal that the FDS model provides a strengthening benefit for the wheelrail vibration, from which the shifted dominant frequencies in spectral response are observed.
Equivalent Numerical Algorithm For The Strip-Rolling Process Of A Continuous Variable Crown Mill Using The Coupled Rigid-Plastic Finite Element Method, Tao Wang, Zhong-Kai Ren, Dong-Ping He
Equivalent Numerical Algorithm For The Strip-Rolling Process Of A Continuous Variable Crown Mill Using The Coupled Rigid-Plastic Finite Element Method, Tao Wang, Zhong-Kai Ren, Dong-Ping He
Journal of Marine Science and Technology
For the accurate simulation of the rolling process of a wide strip and plates, highly sophisticated algorithms must be developed to couple material flow behavior with the elastic deformation of rolls. A coupling simulation system based on a three-dimensional rigid-plastic finite element method (RPFEM), elastic-plastic finite element method, and influential function method was developed in this study. Calculation of the continuous variable crown (CVC) mill was more complex than that of the normal 4-high rolling mill. According to the point symmetry of the roll gap profile, the CVC curves of work rolls at various shifting positions were equal to various …
Influence Of Fly Ash Fineness And High Replacement Ratios On Concrete Properties, Shihwen Hsu, Maochieh Chi, Ran Huang
Influence Of Fly Ash Fineness And High Replacement Ratios On Concrete Properties, Shihwen Hsu, Maochieh Chi, Ran Huang
Journal of Marine Science and Technology
The influence of fly ash (FA) fineness and a high cement replacement ratio on concrete properties was investigated. Class F FA with an original fineness of 3,150 cm2 /g (3F) and a high fineness of 5,690 cm2 /g (5F) was used; high cement replacement ratios of 30%, 40%, 50%, and 60% by FA with different levels of fineness (two groups: 3F30, 3F40, 3F50, 3F60, and 5F30, 5F40, 5F50, 5F60 by weight of cement) were selected to produce the blended cement concrete. Tests regarding the heat of hydration, compressive strength, water absorption, rapid chloride penetration, and Mercury intrusion porosimetry were performed. …
Flame And Flow Characteristics Of A Plane-Jet Flame Modulated By A V-Shaped Fluidic Oscillator, Ching Min Hsu, Hsiu Feng Yang, Yuan Xu Zhang
Flame And Flow Characteristics Of A Plane-Jet Flame Modulated By A V-Shaped Fluidic Oscillator, Ching Min Hsu, Hsiu Feng Yang, Yuan Xu Zhang
Journal of Marine Science and Technology
The characteristic flame behaviors and velocity fields of a plane-jet flame modulated by a fluidic oscillator were experimentally studied. The flame behaviors were observed by the traditional photographic technique. The time-averaged velocity fields of the jet flame were measured by a high-speed particle image velocimeter. The temperature distributions of the jet flame were measured by an R-type thermocouple. The pulsating reacting jets issued from the side slots of the fluidic-oscillator burner formed two diffusion flames. By observing the flame behavior at around burner exit, three characteristic flame modes: attached flame, transitional flame, and lifted flame, were identified in the domain …
Experimental Study Of Scour Around Monopile And Jacket-Type Offshore Wind Turbine Foundations, Hsin-Hung Chen
Experimental Study Of Scour Around Monopile And Jacket-Type Offshore Wind Turbine Foundations, Hsin-Hung Chen
Journal of Marine Science and Technology
Wind turbines platforms and pillars on offshore wind farms are negatively affected by wave and current action. In Taiwan, the water depth of most planned wind turbine foundations is more than 15 m. At this water depth, scour around offshore wind turbine foundations is mainly subject to the ocean current, which causes damage or collapse of foundations. Therefore, this study focused on the influence of ocean current on the monopile and jacket-type foundations of offshore wind turbines. Hydraulic model experiments were conducted to investigate the maximum scour depth and range around pillars in these foundations. Under the effects of current, …
Application Of Random Geometric Imperfection Method To Nonlinear Buckling Analysis Of Spherical Shell, Zhixin Xiong, Zhiquan Huang, Xiaochuan Yu
Application Of Random Geometric Imperfection Method To Nonlinear Buckling Analysis Of Spherical Shell, Zhixin Xiong, Zhiquan Huang, Xiaochuan Yu
Journal of Marine Science and Technology
This paper focuses on spherical shells with random geometric imperfections under uniform external pressure. An extensive numerical investigation is performed to calculate the buckling loads of perfect and imperfect spherical shells. To discuss the effects of initial geometric imperfections, a finite element analysis model of the perfect spherical shell is considered to obtain its first 60 modes. Then, the consistent imperfect buckling analysis method is applied to analyze the nonlinear stability of the spherical shells with geometric imperfections. The shapes of the shell in the 1st to 20th eigenmode are considered. A lower buckling load is found corresponding to the …
Design Of An Energy-Aware Enhanced Cooperative Mac Protocol In Mobile Ad Hoc Networks, Jaeshin Jang, Balasubramaniam Natarajan
Design Of An Energy-Aware Enhanced Cooperative Mac Protocol In Mobile Ad Hoc Networks, Jaeshin Jang, Balasubramaniam Natarajan
Journal of Marine Science and Technology
In this paper, we present a new energy-efficient cooperative MAC protocol, called the e2 BT-COMAC protocol for mobile ad hoc networks, and evaluate its performance. In the proposed MAC protocol, which is an enhanced version of our previous eBT-COMAC protocol, a cross-layer energy-aware strategy for cooperative communication is employed using mobile nodes. Considering a random waypoint mobility model for all mobile nodes, we compare the system throughput and network lifetime of the e2 BT-COMAC protocol with previously proposed cooperative MAC protocols. Using a new metric that is a weighted combination of normalized system throughput and lifetime, we determine optimal values …