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Journal of Marine Science and Technology–Taiwan

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Full-Text Articles in Engineering

Fbmc/Ldpc-Based Underwater Transceiver Architecture For Voice And Image Transmission, Chin-Feng Lin, Yi-Tai Hung, Hsun-Wei Lu, Shun-Hsyung Chang, Ivan A Parinov, Sergey Shevtsov Jun 2018

Fbmc/Ldpc-Based Underwater Transceiver Architecture For Voice And Image Transmission, Chin-Feng Lin, Yi-Tai Hung, Hsun-Wei Lu, Shun-Hsyung Chang, Ivan A Parinov, Sergey Shevtsov

Journal of Marine Science and Technology–Taiwan

This paper proposes a filter bank multicarrier (FBMC)-based underwater transmission scheme for voice and image signals. In this scheme, FBMC transmission technology, low-density parity-check (LDPC) channel coding, adaptive binary phase shift keying (BPSK) modulation or offset quadrature amplitude modulation (OQAM), and a power assignment mechanism are integrated into an underwater voice and image transmission system. The bit error rates (BERs) of voice and image signals for underwater transmission are required to be less than 10-3, and 10-4, respectively. The BER performances of the proposed scheme in an underwater acoustic channel were demonstrated through simulations, and the power saving ratios for …

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Fast-Convergence Iterative Algorithms For Solving A Nonlinear Beam Equation With An Integral Term Subjected To Different Boundary Conditions, Chein-Shan Liu, Chih-Wen Chang Jun 2018

Fast-Convergence Iterative Algorithms For Solving A Nonlinear Beam Equation With An Integral Term Subjected To Different Boundary Conditions, Chein-Shan Liu, Chih-Wen Chang

Journal of Marine Science and Technology–Taiwan

In this paper, a nonlinear beam equation containing an integral term of the deformation energy, which is unknown before the solution is found, is investigated under different boundary conditions. First, we set the unknown integral term as a scalar variable and then develop a weak-form integral equation to solve the integral. By using the sinusoidal functions as test functions and bases of the numerical solution, we obtain a fast-convergence iterative scheme. Due to the orthogonality of the sinusoidal functions, the expansion coefficients of the numerical solution are in the closed form. The proposed iterative algorithms converge quickly and provide highly …

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Study On Probabilistic Mean Features Of Lower And Upper Free-Surface Profiles And Velocity Fields Of A Highly Fluctuating Free Jet Over A Chute, Chang Lin, Ming-Jer Kao, James Yang, Peng-Hua Teng, Rajkumar Venkatesh Raikar Jun 2018

Study On Probabilistic Mean Features Of Lower And Upper Free-Surface Profiles And Velocity Fields Of A Highly Fluctuating Free Jet Over A Chute, Chang Lin, Ming-Jer Kao, James Yang, Peng-Hua Teng, Rajkumar Venkatesh Raikar

Journal of Marine Science and Technology–Taiwan

An optic-based method that utilizes the particle-laden images captured during high-speed particle image velocimetry (HSPIV) measurements is presented, aiming to explore the probabilistic mean characteristics of the free surface profiles and velocity fields of a free jet with high-frequency random fluctuations over a chute. The technique based on the gray-level gradients in the smoothed gray level distribution of the contrast-enhanced images is used to determine the probabilistic mean features of the free jet, right beneath and above which the water-air interfaces have I%/(100  I)% intermittent appearance of air/water phase and (100  I)%/I% fitful show-up of water/air phase. Further, …

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The Research Of Added Resistance In Waves Based On Nonlinear Time-Domain Potential Flow Theory, Bao-Ji Zhang, Xu- Ning Jun 2018

The Research Of Added Resistance In Waves Based On Nonlinear Time-Domain Potential Flow Theory, Bao-Ji Zhang, Xu- Ning

Journal of Marine Science and Technology–Taiwan

In order to accurately predict the motion performance of the ship in waves, the numerical calculation of heave, pitch and added resistance of a container ship in a regular wave is studied based on the three-dimensional fully nonlinear time-domain potential flow theory. The boundary element method is used to deal with the quadrilateral elements, and the governing equations are solved by the first-order flat-plate theory and the fourth-order RungeKutta time integration method. The ship hull is divided by the fixed mesh. Considering the non-linear superposition of the forward velocity, the stationary ship wave, diffracted wave, diffraction wave and incident wave …

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Evaluation On The Efficiency Of Stability Remediation For T16-Tower Pier Slope (T16-Slope) Of Taipei Mao-Kong Tramway, Der-Guey Lin, Sheng-Hsiunng Hung, Wen-Tsung Liu, Jui-Ching Chou Jun 2018

Evaluation On The Efficiency Of Stability Remediation For T16-Tower Pier Slope (T16-Slope) Of Taipei Mao-Kong Tramway, Der-Guey Lin, Sheng-Hsiunng Hung, Wen-Tsung Liu, Jui-Ching Chou

Journal of Marine Science and Technology–Taiwan

This study performs a series of rainfall-induced seepage and stability analyses of unsaturated slope using strength reduction method (SRM) of two-dimensional (2-D) finite element technique to inspect the efficiency of compound stabilization work adopted for the remediation of the down slope of T16-tower pier (or T16-Slope) situated at the hillside of Taipei City MaoKong tramway. The validities of numerical procedures and various material model parameters are verified by examining the triggering mechanism and occurrence time of landslide in T16-Slope during Jang-Mi typhoon in 2008. After the landslide in 2008, the potential sliding surfaces of T16-Slope with and without remediation are …

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Topographic Survey Of An Open Channel In A Tidal Flat, Yen-Chang Chen, Sheng-Hsiung Hung, Yi-Jiun Liao, Wei-Po Huang Jun 2018

Topographic Survey Of An Open Channel In A Tidal Flat, Yen-Chang Chen, Sheng-Hsiung Hung, Yi-Jiun Liao, Wei-Po Huang

Journal of Marine Science and Technology–Taiwan

This paper describes the fundamental characteristics of an open channel in a tidal flat. In this study, the open channel was characterized using a topographic survey. Because of the limited resources available and special measurement conditions at the study area, cranes and cables were used to transport a sounding weight to the measurement point, and pressure gauges hanging on the sounding weight were used to measure the water depth. The coordinates and altitude of the surface point above the sound weight were measured using a total station. The kriging interpolation was applied to discrete geographic data to create contour lines …

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Improvement Of Dynamic Characteristics For Power System With Wind Farm Using Compensation Devices, Chia-Yu Jihyeong Hsu, Tzu-Yang Tien, Pei-Hwa Huang Jun 2018

Improvement Of Dynamic Characteristics For Power System With Wind Farm Using Compensation Devices, Chia-Yu Jihyeong Hsu, Tzu-Yang Tien, Pei-Hwa Huang

Journal of Marine Science and Technology–Taiwan

This paper presents the development of a new complex marine unmanned platform composed of an unmanned surface vehicle (USV) and a remotely operated vehicle (ROV), and the results of a sea test. The platform structure, control system, sensor system, and control algorithm were developed and are introduced. The complex platform collects information of the underwater structures, such as the wall, floor, and piers and harbors. Using a tether cable, the ROV is connected to the USV for power supply and to receive a large amount of underwater data obtained using a sonar scanner or a camera in real time. The …

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Automatic Classification Of Moving Objects On An Unknown Speed Production Line With An Eye-In-Hand Robot Manipulator, Jinsiang Shaw, Wen-Lin Chi Jun 2018

Automatic Classification Of Moving Objects On An Unknown Speed Production Line With An Eye-In-Hand Robot Manipulator, Jinsiang Shaw, Wen-Lin Chi

Journal of Marine Science and Technology–Taiwan

In this paper, techniques for tracking and grasping moving objects with an unknown speed on a conveyor using an eyein-hand robot arm are presented, which are useful in a production line for automatic object classification. First of all, the CAMshift (Continuously Adaptive Meanshift) algorithm is employed to continuously track a moving object in the image plane. Then, the minimum area rectangle method is integrated for correctly identifying a rectangle enclosing the target object. Object features for tracking purposes can be extracted from this rectangle. Next, through the application of an image Jacobian matrix, the tracking error in the image plane …

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Non-Premixed Transversely Oscillating Plane Jet Flames In Co-Flowing Air Streams, Reuben Mwanza Kivindu, Rong Fung Huang, Ching Min Hsu Apr 2018

Non-Premixed Transversely Oscillating Plane Jet Flames In Co-Flowing Air Streams, Reuben Mwanza Kivindu, Rong Fung Huang, Ching Min Hsu

Journal of Marine Science and Technology–Taiwan

This study examined the flame behavior and thermal structure of non-premixed transversely oscillating plane jet flames. A V-shaped fluidic oscillator was installed with deflection plates to merge alternately issued pulsating jets, and induce transverse oscillations of the merged jet. Co-flowing air streams were supplied with two planar air jets arranged next to the burner. Isothermal jet frequencies were detected using single hot-wire anemometry. Flame behaviors were studied using photographic techniques. Flame temperatures were measured using a finewire type-R thermocouple, and combustion concentrations of products were measured using a gas analyzer. The Strouhal number for the transversely oscillating jet shows an …

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The Investigation Of The Two-Phase Thermosyphon Performance Limit, Chih-Chung Chang, Zun-Long Huang, Yuan-Ching Chiang, Sih-Li Chen Apr 2018

The Investigation Of The Two-Phase Thermosyphon Performance Limit, Chih-Chung Chang, Zun-Long Huang, Yuan-Ching Chiang, Sih-Li Chen

Journal of Marine Science and Technology–Taiwan

In a steel plant, waste heat recovery systems of hot-blast furnace are characterized by high-temperature exhaust gas from a hot stove that flows through heat pipe heat exchangers. By heating gas in a hot stove and combustion air in a blast furnace, stable and balanced heat exchange efficiency is achieved in this system. The thermosyphon, which is also known as a gravitational heat pipe, uses latent heat to transfer the heat. In this article, heat pipe performance limits, including entrainment and boiling limits, are experimentally and theoretically investigated. Heat pipe tube lengths of 130 mm, 200 mm, and 300 mm …

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Design Of An Intelligent Damping Controller Of Statcom With Hvdc For Large Offshore Wind Farm, Kai-Hung Lu, Hsin-Chuan Chen, Yu Su, Qiangqiang Xu Apr 2018

Design Of An Intelligent Damping Controller Of Statcom With Hvdc For Large Offshore Wind Farm, Kai-Hung Lu, Hsin-Chuan Chen, Yu Su, Qiangqiang Xu

Journal of Marine Science and Technology–Taiwan

This paper proposes the design of an Intelligent Damping Controller (IDC) for a Static Synchronous Compensator (STATCOM), linking to a high voltage direct current (HVDC) transmission line, where a permanent magnet synchronous generator (PMSG)- based offshore wind farm (OWF) is connected. This IDC consists of a critic network with the proposed Functional Link based Recurrent Fuzzy Neural Network (FLRFNN) and Genetic Algorithm Hybrid Time Varying Particle Swarm Optimization (GAHTVPSO) algorithm. A single-machine infinite-bus and a multi-machine hybrid power system were used for test the system stability. GAHTVPSO approach is developed to adjust the learning rates to improve the learning capability. …

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Passive Fuzzy Control For Lift Feedback Fin Stabilizer Systems Of A Ship Via Multiplicative Noise Based On Fuzzy Model, Chih-Ming Chang, Wen-Jer Chang, Cheung-Chieh Ku, Fung-Lin Hsu Apr 2018

Passive Fuzzy Control For Lift Feedback Fin Stabilizer Systems Of A Ship Via Multiplicative Noise Based On Fuzzy Model, Chih-Ming Chang, Wen-Jer Chang, Cheung-Chieh Ku, Fung-Lin Hsu

Journal of Marine Science and Technology–Taiwan

This paper proposes a passive fuzzy controller design methodology for stabilization of the nonlinear lift feedback fin stabilizer system of a ship. The proposed design approach is developed based on multiplicative noised Takagi-Sugeno fuzzy model and parallel distributed compensation control technique. Applying the Itô’s formula and the sense of mean square, the sufficient conditions are developed to analyze the stability and to design the controller for stochastic nonlinear systems. The sufficient conditions derived in this paper belong to the linear matrix inequality forms which can be solved efficiently by convex optimal programming algorithm. Besides, the passivity theory is applied to …

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Nonlinear Hydrostatic Analysis Of The Floating Structure Considering The Large Angle Of Inclination, Kwang-Phil Park, Ju-Hwan Cha, Namkug Ku Apr 2018

Nonlinear Hydrostatic Analysis Of The Floating Structure Considering The Large Angle Of Inclination, Kwang-Phil Park, Ju-Hwan Cha, Namkug Ku

Journal of Marine Science and Technology–Taiwan

When ships are flooded or equipped with a heavy object, the floating structures are excessively inclined, and the immersion, heel, and trim affecting the hydrostatic restoration performance are very large. In those cases, the assumption that the position and orientation are independent of each other is not valid. Therefore, nonlinear governing equations were formulated by sequential linearization to calculate the static equilibrium position of floating structures with excessive inclination. The equations are represented using a plane area, a primary moment, and a moment of inertia of the water plane area, and the immersion, heel, and trim are fully coupled. The …

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Thermal Performance Improvement By Spiky Twisted Tapes For Loop Thermosyphon With Ncg, Shyy Woei Chang, Wei Ling Cai Apr 2018

Thermal Performance Improvement By Spiky Twisted Tapes For Loop Thermosyphon With Ncg, Shyy Woei Chang, Wei Ling Cai

Journal of Marine Science and Technology–Taiwan

Thermal performance improvement for a two-phase loop thermosyphon (TPLT) with non-condensable gas (NCG) was attempted by fitting twin spiky ribbed twisted tapes (SRTTs) in the evaporator. The startup process and the steady-state boiling flow structures, boiling heat transfer rates, thermal resistance networks at various heater powers, and condenser thermal resistances were examined with 40% molar fraction of air in the TPLT. With treated water as the working fluid at an evaporator volumetric filling ratio of 50%, all tests were performed at subatmospheric pressures. The thermal performance improvement achieved by using SRTTs in the evaporator was determined by comparing the test …

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Fpga Implementation Of Improved Ant Colony Optimization Algorithm Based On Pheromone Diffusion Mechanism For Path Planning, Chen-Chien Hsu, Wei-Yen Wang, Yi-Hsing Chien, Ru-Yu Hou Apr 2018

Fpga Implementation Of Improved Ant Colony Optimization Algorithm Based On Pheromone Diffusion Mechanism For Path Planning, Chen-Chien Hsu, Wei-Yen Wang, Yi-Hsing Chien, Ru-Yu Hou

Journal of Marine Science and Technology–Taiwan

An improved ant colony optimization (ACO) algorithm is proposed in this paper for improving the accuracy of path planning. The main idea of this paper is to avoid local minima by continuously tuning a setting parameter and the establishment of novel mechanisms by means of partial pheromone updating and opposite pheromone updating. As a result, the global search of the proposed ACO algorithm can be significantly enhanced to derive an optimal path compared to the conventional ACO algorithm. The simulation results of the proposed approach perform better in terms of the short distance, mean distance, and success rate towards optimal …

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Development Trends In Intelligent Homes, I-Chen Chen, Jia-Shing Sheu, Husan-Wei Huang Feb 2018

Development Trends In Intelligent Homes, I-Chen Chen, Jia-Shing Sheu, Husan-Wei Huang

Journal of Marine Science and Technology–Taiwan

Since the U.S. National Science and Technology Council began implementing its plans for the development of intelligent structures in 2004, the Taiwan Communications Industry Alliance has been committed to applying communication and monitoring technologies in the construction industry to develop a market for intelligent houses. Accordingly, in this paper, relevant studies from January 2000 to December 2016 were collected from the Web of Science database. A key-route main path analysis of the text and data as well as a growth analysis of the research clusters in this field were performed to determine the main research topics and development trajectories. The …

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Classification Of Hydrodynamic Coefficients Of Autonomous Underwater Vehicles Based On Sensitivity Analyses In Standard Maneuvers, Mahnaz Abolvafaie, Hamid Reza Koofigar, Maryam Malekzadeh Feb 2018

Classification Of Hydrodynamic Coefficients Of Autonomous Underwater Vehicles Based On Sensitivity Analyses In Standard Maneuvers, Mahnaz Abolvafaie, Hamid Reza Koofigar, Maryam Malekzadeh

Journal of Marine Science and Technology–Taiwan

Due to the important role of hydrodynamic coefficients in the control and guidance of an autonomous underwater vehicle (AUV), sensitivity analysis is proposed here, as a preliminary step to motion control design. Taking the standard maneuvers, including turning circle and horizontal and vertical zigzag, the sensitivity of various hydrodynamic coefficients with respect to velocities and position is determined. Such analyses are then used to classify the model parameters into three categories, as non-sensitive coefficients, coefficients with low influence on the motion and more sensitive coefficients.

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Comparisons Of Position Control Of Valve-Controlled And Pump-Controlled Folding Machines, Ray-Hwa Wong, Wei-Heng Wong Feb 2018

Comparisons Of Position Control Of Valve-Controlled And Pump-Controlled Folding Machines, Ray-Hwa Wong, Wei-Heng Wong

Journal of Marine Science and Technology–Taiwan

Control units of electro-hydraulic double-axial folding machine can be classified as throttling type (valve-controlled) and volumetric type (pump-controlled). This paper focuses to compare their control performances. Valve-controlled folding machine (VCFM) has higher supply pressure, different circuit resistance between subsystems. Pump-controlled folding machine (PCFM) has variable working pressure and circuit resistance is slightly different. The folding machine is a coupled system and has significant structural interaction. This paper proposes coupled adaptive self-organizing sliding-mode fuzzy controllers to improve folding machine’s level control performance. It found higher supply pressure of VCFM cause faster transient response, larger maximum overshoot via a variety of coupled …

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Free Vibration Analysis Of A Nonlinearly Tapered Beam Carrying Arbitrary Concentrated Elements By Using The Continuous-Mass Transfer Matrix Method, Ching-An Huang, Jong-Shyong Wu, Heiu-Jou Shaw Feb 2018

Free Vibration Analysis Of A Nonlinearly Tapered Beam Carrying Arbitrary Concentrated Elements By Using The Continuous-Mass Transfer Matrix Method, Ching-An Huang, Jong-Shyong Wu, Heiu-Jou Shaw

Journal of Marine Science and Technology–Taiwan

Although the exact solutions for the free vibration problems regarding most of the non-uniform beams are not yet obtainable, this is not true for the special case when the equation of motion of a non-uniform beam can be transformed into that of an equivalent uniform beam. The nonlinearly tapered beam studied in this paper is a single-tapered beam with constant depth h0 and varying width b(x) along its length in the form b x( )  4 0 b xL [1 ( )]  , where b0 is the minimum width,  is the taper constant, x is the axial …

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An Approach To Aligning Regions Of Interest On Infrared Palm-Dorsum Images Captured In Contactless Scenarios, Chih-Lung Lin, Hui-Fen Chiang, Hsu-Yung Cheng, Chih-Wei Kuo, Jun-Wei Hsieh Feb 2018

An Approach To Aligning Regions Of Interest On Infrared Palm-Dorsum Images Captured In Contactless Scenarios, Chih-Lung Lin, Hui-Fen Chiang, Hsu-Yung Cheng, Chih-Wei Kuo, Jun-Wei Hsieh

Journal of Marine Science and Technology–Taiwan

This paper presents an approach for solving a highly challenging problem in the preprocessing of hand-based biometrics, namely restoring IR palm-dorsum images captured in contactless scenarios and aligning regions of interest (ROIs) in the same regions on the various restored infrared (IR) palm-dorsum images captured from the same palm-dorsum. IR palm-dorsum images captured in contactless scenarios substantially increase the user-friendliness, security and sanitation of hand-based biometrics. However, images captured in contactless scenarios typically exhibit rotation, translation, scale and shear geometric transformations. These geometric transformations significantly reduce the accuracy of hand-based biometrics. An approach used to restore and align ROI on …

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Strength Analysis For The Rudders Of Power-Free Underwater Vehicle In Kuroshio Subjected To Typhoon Waves, Chuan-Tsung Lee, Ray-Yeng Yang, Huang Hsing Pan, Li-An Kuo Dec 2017

Strength Analysis For The Rudders Of Power-Free Underwater Vehicle In Kuroshio Subjected To Typhoon Waves, Chuan-Tsung Lee, Ray-Yeng Yang, Huang Hsing Pan, Li-An Kuo

Journal of Marine Science and Technology–Taiwan

In this study, a 1/25 hydraulic model of a power-free vehicle was developed. Typhoon waves and Kuroshio current flow in a wave-current flume (200 x 2 x 2 m3 ) were applied to the model for determining the net flow velocity and mooring forces. Through hydraulic experiments with a wave period of 16 s, wave height of 10 m, and ocean current speed of 1.0 m/s, a net flow velocity of up to 3.81 m/s was measured. The maximum lift and drag forces acting on each rudder were calculated through computational fluid dynamics as -245.6 and 151.6 kN, respectively, when …

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Cascaded Uuv Trajectory Tracking Control Based On Model Predictive And Sliding Mode Control, Bing Sun, Wenyang Gan, Man Mei, Daqi Zhu, Simon X Yang Dec 2017

Cascaded Uuv Trajectory Tracking Control Based On Model Predictive And Sliding Mode Control, Bing Sun, Wenyang Gan, Man Mei, Daqi Zhu, Simon X Yang

Journal of Marine Science and Technology–Taiwan

This paper describes a cascaded dynamic trajectory tracking control approach based on model predictive control (MPC) and sliding mode control for unmanned underwater vehicles (UUVs). The proposed method combines kinematic and dynamic controllers to achieve robust control. First, MPC is employed to realize tracking control kinematically. The MPC algorithm is proposed as a solution to the speed jump problem. Considering the computational burden for nonlinear UUV dynamic models, the MPC method is used in conjunction with sliding mode control to achieve dynamic tracking control, which solves problems of modeling uncertainty and external disturbances. Experimental results showed that the proposed method …

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Investigation Of Effects Of Wave Directions On Hull Wave Loads By Hydroelastic Experimental Method, Zhanyang Chen, Jialong Jiao Dec 2017

Investigation Of Effects Of Wave Directions On Hull Wave Loads By Hydroelastic Experimental Method, Zhanyang Chen, Jialong Jiao

Journal of Marine Science and Technology–Taiwan

This paper focuses on the hydroelastic responses of ultralarge vessels under different wave directions. Segmented ship model experiments provide an invaluable tool in naval applications. However, most model tests are performed on heading waves. Therefore, a segmented model with variable cross-section steel backbones was designed and the oblique wave tests were performed in a comprehensive test tank. The oblique wave test system was introduced in detail. Time histories of bending moments in oblique waves were given. In order to analyze the influence of structural elastic effect on hydroelastic responses, the number of segments of the model was changed, and the …

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Determination Of Vertical Datum Level For Tidal Bench Mark Using Gnss Buoy Observations, Jae Young Roh, Kyung Wan Yoo, Yong Cheol Suh, Moon Seung Shin, Dong Ha Lee Dec 2017

Determination Of Vertical Datum Level For Tidal Bench Mark Using Gnss Buoy Observations, Jae Young Roh, Kyung Wan Yoo, Yong Cheol Suh, Moon Seung Shin, Dong Ha Lee

Journal of Marine Science and Technology–Taiwan

Coastal areas are the most vulnerable areas to sea level fluctuations. Such areas comprise approximately 4% of South Korea's total land; therefore, monitoring these fluctuations is crucial. The present study determined the vertical datum level using a global navigation satellite system (GNSS). Unlike traditional sea level measurements, which are performed using fixed-type gauge observations, a GNSS has an accuracy of a few millimetres and no spatiotemporal constraints. For this purpose, a set of buoys containing GNSS devices was installed in coastal waters, and observations were performed for more than 8 h. The processed GNSS buoy data were compared with tidal …

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Modified Pid Controller Design For Active Transverse Anti-Rolling System For Ships With Low Roll Motion, Hsing-Cheng Yu, Jhih-Jyun You Dec 2017

Modified Pid Controller Design For Active Transverse Anti-Rolling System For Ships With Low Roll Motion, Hsing-Cheng Yu, Jhih-Jyun You

Journal of Marine Science and Technology–Taiwan

Multi-domain physical modeling software with an intuitive simulation methodology using MapleSim was adopted in this study to create a rigid body structure model of an active transverse anti-rolling system (ATARS) of a container ship. At the same time, a ship stability analysis was also conducted to determine the force model, dynamic equilibrium, and motion behavior of the ATARS of the container ship. Once various external transverse force generated by waves impact varied roll angles of the ATARS on the vessel, a modified proportional-integral-derivative (PID) controller designed to improve the capability of the active stabilizer fins used in the ATARS is …

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Experimental Assessment Of Suspended Sediment Concentration Changed By Solitary Wave, Jae-Nam Cho, Chang-Geun Song, Kyu-Nam Hwang, Seung-Oh Lee Dec 2017

Experimental Assessment Of Suspended Sediment Concentration Changed By Solitary Wave, Jae-Nam Cho, Chang-Geun Song, Kyu-Nam Hwang, Seung-Oh Lee

Journal of Marine Science and Technology–Taiwan

A large scale solitary wave causes a lot of sediment transportation and coastal beach erosion, for example tsunami is the one type of solitary waves. During passing such solitary wave over coastal region, higher energy on sediment transportation near bottom would bring to massive geomorphological changes and even worse damages in life and economics. The major objective of this study is to analyze the incipient motion of sediment suspended from bottom by a solitary wave through hydraulic experiments and numerical simulations. First, to estimate the process of sediment transport the experimental study was carried out in the prismatic rectangular channel …

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The Nonlinear Dynamics And Anti-Sway Tracking Control For Offshore Container Crane On A Mobile Harbor, You-Gang Sun, Hai-Yan Qiang, Junqi Xu, Da-Shan Dong Dec 2017

The Nonlinear Dynamics And Anti-Sway Tracking Control For Offshore Container Crane On A Mobile Harbor, You-Gang Sun, Hai-Yan Qiang, Junqi Xu, Da-Shan Dong

Journal of Marine Science and Technology–Taiwan

The offshore container crane (OCC), as a novel maritime container transfer system, can handle container from a large container-ship anchored in open sea to address the congestion and limited water-depth of port. However, for the wave- and wind-induced movements of the ship, the crane's control system should be redesigned to ensure the load transfer on the sea. In this paper, we derive the nonlinear dynamic equations of OCC system subjected to the ship motions based on dynamic analysis. Then a double-layer sliding manifold is constructed to realize the position tracking and sway control simultaneously, irrespective of ship motions and parameters …

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Numerical Computation Of The Transient Salinity Distribution In A Macro-Tidal Estuary, Seung Oh Lee, Chang Geun Song Dec 2017

Numerical Computation Of The Transient Salinity Distribution In A Macro-Tidal Estuary, Seung Oh Lee, Chang Geun Song

Journal of Marine Science and Technology–Taiwan

In this study, the flow reversal and salinity distribution associated with tidal effects were investigated at a macro-tidal estuary located in tidal range of the Yellow Sea in South Korea. A 2-D hydrodynamic model (RMA-2) and a 2D advectiondispersion model (RAM4) were employed to simulate flow behavior and salinity distribution, respectively. The results showed that reverse flow occurred five times over 3-day period and the maximum reverse flow extended over 32.9 km upstream. Salinity distribution was obtained by estimating the salinity input with analytical solution of advection-dispersion equation. The total length of the saline wedge calculated from numerical simulation was …

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Simulation And Motion Analysis Of Deepwater Manifold Lifting, Zhiwei Chen, Tingdi Zhao, Jian Jiao, Dongfeng Mao Dec 2017

Simulation And Motion Analysis Of Deepwater Manifold Lifting, Zhiwei Chen, Tingdi Zhao, Jian Jiao, Dongfeng Mao

Journal of Marine Science and Technology–Taiwan

The development and utilization of oil and gas resources has expanded to deep water. The installation of a subsea manifold is crucial for developing offshore oil-gas fields. In this study, we used the lifting installation method (LIM) to install a subsea manifold. First, the appropriate environmental parameters were selected through the analysis of environmental loads at the Liwan 3-1 Gasfield in the South China Sea. The wind and wave spectra were selected using noise power density and Joint North Sea Wave Project spectra, respectively. The entire lifting and installation system that responds to environmental loads comprised a vessel, cable, and …

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Energy Efficient Trajectory Design For The Underwater Vehicle With Bounded Inputs Using The Global Optimal Sliding-Mode Control, Mai The Vu, Hyeung-Sik Choi, Jin-Il Kang, Dae-Hyung Ji, Hyun Joong Dec 2017

Energy Efficient Trajectory Design For The Underwater Vehicle With Bounded Inputs Using The Global Optimal Sliding-Mode Control, Mai The Vu, Hyeung-Sik Choi, Jin-Il Kang, Dae-Hyung Ji, Hyun Joong

Journal of Marine Science and Technology–Taiwan

In this paper, we propose a novel global sliding mode controller (SMC) for an uncertain linear time-varying second order system. The proposed controller was implemented on the underwater vehicle (UV) with uncertainty of bounded parameters and disturbances within limited control input. By applying the proposed controller to the second-order UV system, the arrival time at the reference position and the maximum allowable acceleration are expressed in a closed-form equation if ranges of parametric uncertainties and reference inputs are specified. The closed-form equation can be utilized in designing the capacity of vehicle systems with the condition of the minimum arrival time …

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