Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Journal of Marine Science and Technology–Taiwan

Discipline
Keyword
Publication Year

Articles 361 - 390 of 1299

Full-Text Articles in Engineering

Modeling Navigator Errors In Collisions Using Hidden Markov Models, Deuk-Jin Park, Jeong-Bin Yim, Chun-Ki Lee Dec 2020

Modeling Navigator Errors In Collisions Using Hidden Markov Models, Deuk-Jin Park, Jeong-Bin Yim, Chun-Ki Lee

Journal of Marine Science and Technology–Taiwan

Understanding navigator errors can be used as a basis for preventing collisions. Here, Hidden Markov Models (HMMs) are applied to navigator errors of fishing and merchant ships in collisions. Information on navigator errors providedin accident investigation reports issued by the Korean Maritime Safety Tribunal is surveyed. The surveyed information is converted into data using the framework of slips, lapses, and mistakes proposed in this study. The results of framework data states are inferred using the unsupervised learning of HMMs, with sequences of navigator errors contained in the error data. The expected errors learned using the navigator error models for fishing …

Go to article

Remote Sensing Analysis Of Cold Water Temporal And Spatial Variability In The East Sea, Suk Yoon, Hyun Yang Dec 2020

Remote Sensing Analysis Of Cold Water Temporal And Spatial Variability In The East Sea, Suk Yoon, Hyun Yang

Journal of Marine Science and Technology–Taiwan

In this study, we monitored temporal and spatial variability in summer cold water events in the East Sea of Korea. We defined cold water as seawater that is ≥ 5°C colder than the surrounding area. When cold water expands or changes in propagation direction, the National Institute of Fisheries Science (NIFS) of Korea issues a cold water upwelling warning to prevent aquafarm damage. To understand cold water effects, we analyzed the causes of continuous and strong cold water events, and propagation thereof, using satellite and in situ data for summer to autumn in the period 2011–2019. To investigate the cold …

Go to article

Reinforcement Learning Based Maximum Power Point Tracking Control Of Partially Shaded Photovoltaic System, Kuan-Yu Chou, Chia-Shiou Yang, Yon-Ping Chen Oct 2020

Reinforcement Learning Based Maximum Power Point Tracking Control Of Partially Shaded Photovoltaic System, Kuan-Yu Chou, Chia-Shiou Yang, Yon-Ping Chen

Journal of Marine Science and Technology–Taiwan

Under the sun insolation in the daytime, the Maximum Power Point Tracking (MPPT) technique is usually used to achieve the maximum power in the photovoltaic (PV) system and often implemented by the Perturbation and Observation (P&O) method. However, due to the use of fixed step size, the P&O method will generate undesired oscillation around the maximum power point (MPP) and thus reduce the tracking efficiency. Besides, the output power of PV modules highly depends on the environment factors such as irradiance and temperature, especially for a PV array, which is formed by PV modules connected in series and parallel. The …

Go to article

A Survey Of Advanced Control Methods For Permanent Magnet Stepper Motors, Yong Woo Jeong, Youngwoo Lee, Chung Choo Chung Oct 2020

A Survey Of Advanced Control Methods For Permanent Magnet Stepper Motors, Yong Woo Jeong, Youngwoo Lee, Chung Choo Chung

Journal of Marine Science and Technology–Taiwan

Permanent Magnet (PM) stepper motors have been widely used in industry due to their low material costs and robustness against the environment. Furthermore, it is relatively easy to implement a control system compared to other type motors. It has been recently reported that advanced control methods show improved tracking performance over the conventional microstepping control. In this paper, we make a survey of advanced control methods for PM stepper motors. First, we introduce basic principles of open-loop control of PM stepper motors, including microstepping. Then we explain various advanced feedback control techniques based on Lyapunov stability. Second, we briefly summarize …

Go to article

Agile Rov For Underwater Surveillance, Ikuo Yamamoto, Akihiro Morinaga, Murray Lawn Oct 2020

Agile Rov For Underwater Surveillance, Ikuo Yamamoto, Akihiro Morinaga, Murray Lawn

Journal of Marine Science and Technology–Taiwan

Surveillance of submerged plant is becoming increasingly critical as ocean based resources become more and more important. A wide varieties of new roles have recently emerged ranging from aquaculture to offshore power generation systems, in addition to the monitoring of the aging submerged sections of bridges, piers and dams etc. Consecutive generations of ROVs have been developed at Nagasaki University to meet the changing needs for surveillance of submerged plant. This paper outlines briefly the ROVs developed to date and the move to increase ROV autonomy using AI (artificial intelligence).

Go to article

Gain-Scheduled Control Of Discretized Ship Autopilot System Subject To Poleassignment And Passivity Constraints, Wen-Jer Chang, Cheung-Chieh Ku, Chih-Yu Yen, Guan-Wei Chen Oct 2020

Gain-Scheduled Control Of Discretized Ship Autopilot System Subject To Poleassignment And Passivity Constraints, Wen-Jer Chang, Cheung-Chieh Ku, Chih-Yu Yen, Guan-Wei Chen

Journal of Marine Science and Technology–Taiwan

This paper addresses a control performance problem for discretized ship autopilot system with uncertainty. To completely express the uncertainty, Linear Parameter Varying (LPV) modelling technology is employed such that the ship autopilot system is described via several linear systems and weighting function. Furthermore, gain-scheduled scheme is applied to design a controller to achieve the passivity and pole-assignment constraints. Moreover, a Parameter-Dependent Lyapunov Function (PDLF) is used to derive some sufficient conditions. Through the proposed design method, the attenuation performance and stability of the system can be guaranteed. Besides, the transient responses are furtherly improved such that the ship autopilot system …

Go to article

Adaptive Pid-Like Control Using Broad Learning System For Nonlinear Dynamic Systems, Ching-Chih Tsai, Chun-Chieh Chan, Chien-Cheng Yu, Hung-Sheng Chen, Guo-Shun Hung Oct 2020

Adaptive Pid-Like Control Using Broad Learning System For Nonlinear Dynamic Systems, Ching-Chih Tsai, Chun-Chieh Chan, Chien-Cheng Yu, Hung-Sheng Chen, Guo-Shun Hung

Journal of Marine Science and Technology–Taiwan

This paper presents a new learning control structure using broad learning system (BLS) for adaptive PID-like control of unknown digital nonlinear dynamic systems with time delays. The proposed control method, abbreviated as BLS-APIDLC, is novel in combining BLS and model predictive control to develop a new PID-like control law for high-performance setpoint tracking control and disturbance rejection. Comparative simulations on two renowned nonlinear digital time-delay systems are well used to show the effectiveness and superiority of the proposed method by comparing to four existing methods. I

Go to article

Control Barrier Function Design Using Revived Transformation, Maki Takai, Motoi Igarashi, Hisakazu Nakamura Oct 2020

Control Barrier Function Design Using Revived Transformation, Maki Takai, Motoi Igarashi, Hisakazu Nakamura

Journal of Marine Science and Technology–Taiwan

The state constraint problem is an essential topic in control theory, wherein control methods using a control barrier function (CBF) and a revived transformation have been recently proposed. However, a way of designing the CBF is yet to be developed in a constrained space. In this study, we propose a CBF design method by using a revived transformation. Our method can design a CBF in a constrained space by utilizing a diffeomorphism from an unconstrained space. We demonstrate the effectiveness of the proposed method by human assist control design and computer simulation.

Go to article

Constraints To Guarantee Gain And Phase Margins For Data-Driven Controller Tuning Methods, Taiga Sakatoku, Kazuhiro Yubai, Daisuke Yashiro, Satoshi Komada Oct 2020

Constraints To Guarantee Gain And Phase Margins For Data-Driven Controller Tuning Methods, Taiga Sakatoku, Kazuhiro Yubai, Daisuke Yashiro, Satoshi Komada

Journal of Marine Science and Technology–Taiwan

The Noniterative Correlation-based Tuning (NCbT) is one of the data-driven controller tuning methods which directly tune controller parameters from input/output data set of a plant . The NCbT is based on the correlation approach to robustly tune controller parameters using a noisy input/output data set. Since the NCbT guarantees closed-loop stability only for the situation where the data is acquired, a plant fluctuation is not taken into consideration, which may lead to degradation of control performance and/or destabilization of the closed-loop system . In this paper, we virtually produce input/output data sets of the plant with various gain and/or phase …

Go to article

The Research Of The Rfid Anchor Assisted Slam On An Autonomous Patrolling System, Chien-Wu Lan, Che-Hung Liu Oct 2020

The Research Of The Rfid Anchor Assisted Slam On An Autonomous Patrolling System, Chien-Wu Lan, Che-Hung Liu

Journal of Marine Science and Technology–Taiwan

To allow service robots to patrol indoors is a difficult challenge of the robot control technology. As long as this purpose can be achieved, it can increase the value of service robots in the commercial applications. In this research, an anchor deployment strategy combined with a stereo vision system for the robot synchronization positioning and mapping is proposed, which is based on an open source Gmapping Simultaneous Localization and Mapping (SLAM) algorithm of Robot Operating System (ROS), and enables a robot to simultaneously positioning and build environment maps autonomously. The anchors are developed based on the radio frequency identification (RFID), …

Go to article

Mouse Type Ballbot Identification And Control Using A Convex-Concave Optimization, Sudchai Boonto, Surapong Puychaisong Oct 2020

Mouse Type Ballbot Identification And Control Using A Convex-Concave Optimization, Sudchai Boonto, Surapong Puychaisong

Journal of Marine Science and Technology–Taiwan

This paper shows how to identify and control a mouse type Ballbot. The Ballbot is an unstable complex system. Using the first principle law to model the robot is not accurate enough. An identification method is proposed. The model is transformed to be MIMO state space model and using a convexconcave optimization to design a robust PI+phase-lead controller. Experiments on a design Ballbot are presented. It turns out that an identification model of Bollbot and a PI+phase-lead controller design framework is suitable for using to control a Ballbot

Go to article

Robotic Suturing In Minimally Invasive Surgery, Jia-Yush Yen, Hao-Xiang Kang, Kuan Shen, Yung-Yaw Chen, Ming-Chih Ho Oct 2020

Robotic Suturing In Minimally Invasive Surgery, Jia-Yush Yen, Hao-Xiang Kang, Kuan Shen, Yung-Yaw Chen, Ming-Chih Ho

Journal of Marine Science and Technology–Taiwan

Minimally invasive surgery (MIS) has the advantages of minimal bleeding and rapid postoperative recovery, which can alleviate patient suffering. Therefore, MIS is widely used in clinical applications. However, MIS is more difficult than traditional surgery; surgeons must be more meticulous when performing MIS than when performing ordinary surgery. Using a robotic arm in an auxiliary role in MIS can reduce the workload of surgeons and increase the precision and efficiency of the surgical procedure. The aim of this article is to design an MIS robot system that can perform automatic surgical suturing. First, we designed the basic control architecture for …

Go to article

Motion And Control Simulation For Underwater Robots, Shyh-Kuang Ueng, Chieh-Shih Chou Oct 2020

Motion And Control Simulation For Underwater Robots, Shyh-Kuang Ueng, Chieh-Shih Chou

Journal of Marine Science and Technology–Taiwan

Remotely Operated Vehicles (ROVs) are widely used in underwater explorations and constructions. When navigating under the sea, the motions and stabilities of ROVs are influenced by various forces. Operating ROVs to capture images, grasp samples, avoid obstacles, and examine man-made facilities is challenging. This paper proposes an innovative simulator to train users to handle ROVs. Conventional simulators only can mimic undeformable ROVs. Their educational capabilities are limited. The proposed simulator is developed based on advance mathematics models and is able to emulate a ROV equipped with movable robot arms. Therefore, it can perform more realistic and meaningful simulations to enhance …

Go to article

Path Planning And Obstacle Avoidance Of Uav For Cage Culture Inspection, Yi-En Cai, Jih-Gau Juang Oct 2020

Path Planning And Obstacle Avoidance Of Uav For Cage Culture Inspection, Yi-En Cai, Jih-Gau Juang

Journal of Marine Science and Technology–Taiwan

This paper presents path planning and obstacle avoidance of an unmanned aerial vehicle (UAV) for cage culture inspection. The proposed system can automatically inspect cage farming environment that can cut manpower and reduce cost. The problem is similar to travelling salesman problem (TSP). Genetic algorithms are useful techniques for TSP and can also be used for cage culture inspection. In addition to path planning, an improved particle swarm optimization (IPSO) is applied to avoid obstacle between different cages. The IPSO is applicable to both stationary and dynamic environments with one or more obstacles. Simulation results show the effectiveness of the …

Go to article

Container Throughput Forecasting For International Ports In Taiwan, Juan Huang, Ching-Wu Chu, Yi-Chen Tsai Oct 2020

Container Throughput Forecasting For International Ports In Taiwan, Juan Huang, Ching-Wu Chu, Yi-Chen Tsai

Journal of Marine Science and Technology–Taiwan

This paper compares different univariate forecasting methods and provides a more accurate short-term forecasting model for container throughput to create a reference for relevant authorities. Six different univariate methods, including the classical decomposition model, the trigonometric regression model, the regression model with seasonal dummy variables, the grey forecasting model, the hybrid grey forecasting model, and the seasonal autoregressive integrated moving average (SARIMA) model, were used. We found that the SARIMA model is a reliable forecasting method for forecasting container throughput with seasonal variations. This study’s findings can help to predict the near-future demand for container throughput at international ports.

Go to article

Ship Routing Determination By Virtual Measurements Of An Integrated System, Tsai-Hsin Chang, Jian-Qun Hou Aug 2020

Ship Routing Determination By Virtual Measurements Of An Integrated System, Tsai-Hsin Chang, Jian-Qun Hou

Journal of Marine Science and Technology–Taiwan

According to the requirements of international maritime organization model course 7.03, electronic navigation systems are essential for project pilots. Global positioning system (GPS) is currently the most widely used electronic navigation equipment. However, because of the frequent blockages of GPS signals in complex environments, obtaining a precise and real-time position is difficult. To satisfy the requirement of effective and stable positioning of ship berthing and unberthing, another independent navigation system, inertial navigation system (INS), was adopted. In this study, we developed a 2-dimension (2D) GPS/INS-integrated system by using the constraint of a ship moving on a plane. If GPS signals …

Go to article

Automatic Polyhedral Mesh Generation For Ship Resistance Based On The Locally Refined Cartesian Cut-Cell Method, Kwang-Leol Jeong, Dae-Won Seo Aug 2020

Automatic Polyhedral Mesh Generation For Ship Resistance Based On The Locally Refined Cartesian Cut-Cell Method, Kwang-Leol Jeong, Dae-Won Seo

Journal of Marine Science and Technology–Taiwan

This paper introduces an automatic grid generation algorithm, based on a locally refined cut-cell method, to calculate ship resistance. Sharp edges and apexes are not accurately expressed in the cut-cell method, and the accuracy of the calculation in the turbulence boundary layer is lower than that of other body-fitted methods. In this study, an automatic mesh generation method is developed to effectively represent edge and apex, and a boundary layer grid generation algorithm is developed to generate meshes that improve the accuracy of ship resistance simulation. To validate the method, the resistances of the KRISO container ship and Japan bulk …

Go to article

Analysis The Keelung Harbor Hydrodynamic Environment For The Safety Of Navigation, Hsing-Yu Wang, Dong-Taur Su, Sung-Shan Hsiao Aug 2020

Analysis The Keelung Harbor Hydrodynamic Environment For The Safety Of Navigation, Hsing-Yu Wang, Dong-Taur Su, Sung-Shan Hsiao

Journal of Marine Science and Technology–Taiwan

In this study, we simulated the hydrodynamics of the waters near the Keelung Harbor entrance and fairway before and after harbor expansion. The simulation results are used to discuss the impact of changes in the current characteristic on the inbound vessels. With reference to the fairway planning of Keelung Harbor, the simulation results before the expansion show that the current velocity with inbound fairway during the flood tide ranges from 0.08 to 1.03 m/s. Current direction was affected by the east breakwater, and a circulation occurs near the harbor entrance. After the expansion, during the flood tide, counterclockwise circulations occur …

Go to article

Design Of An Optimal Adaptive Intelligent Control Scheme For Statcom In A Series Compensated Wind Farm, Fei Wang, Kai-Hung Lu, Qiangqiang Xu, Ziwen Chen Aug 2020

Design Of An Optimal Adaptive Intelligent Control Scheme For Statcom In A Series Compensated Wind Farm, Fei Wang, Kai-Hung Lu, Qiangqiang Xu, Ziwen Chen

Journal of Marine Science and Technology–Taiwan

This paper proposes a static synchronous compensator (STATCOM) for use with a self-excited induction generator (SEIG)-based wind farm. The STATCOM applies a damping controller based on an optimal adaptive intelligent controller (OAIC) comprising the critical network, the functional linkbased Elman neural network (FLENN), and the genetic algorithm hybrid time-varying particle swarm optimization (GAHTVPSO) algorithm. The OAIC improves the damping power oscillations in the SEIG-based series-compensated wind farm system. The node-connecting weights of the proposed FLENN and the critical network are trained online via a backpropagation (BP) algorithm, and the GAHTVPSO adjusts the learning rates of the BP algorithm to improve …

Go to article

Research On Design Method Of Hull Surface Based On Reverse Engineering, Guan Guan, Wenwen Gu, Xiaole Yang Aug 2020

Research On Design Method Of Hull Surface Based On Reverse Engineering, Guan Guan, Wenwen Gu, Xiaole Yang

Journal of Marine Science and Technology–Taiwan

To shorten the development cycle of new ship form and improve the efficiency of ship design, this paper proposes a digital design method of hull surface based on reverse engineering. The point cloud information of the hull surface is obtained by a 3D laser scanner. The point cloud is aligned, denoised, and simplified by the improved ICP algorithm and chord height difference method. The hull surface is reconstructed in CATIA and the error analysis is performed. The smooth surface with considerable accuracy is obtained. The offsets of the reconstructed hull surface are obtained by the secondary development of CATIA. The …

Go to article

Nonlinear Breaking-Wave Characteristics In Lagrangian Coordinates, Wen-Jer Tseng, Chia-Yan Cheng Jun 2020

Nonlinear Breaking-Wave Characteristics In Lagrangian Coordinates, Wen-Jer Tseng, Chia-Yan Cheng

Journal of Marine Science and Technology–Taiwan

This paper presents a theoretical investigation of nonlinear surface-wave propagation over a sloping bottom. For a problem with nonlinear surface-wave propagation over a sloping bottom, a perturbation method is first used to find the analytical solution in order to derive the third order terms for the bottom slope  and the wave steepness  in the Eulerian system. Then, by transforming the flow field solution from the Eulerian system into the Lagrangian system, a more accurate wave profile is identified. By using the kinematic stability parameter, new theoretical breaking-wave characteristics are derived. The theoretical solutions are then compared with those …

Go to article

Assessment Of Dynamic Response Of Offshore Jacket Platforms Subjects To Random Waves, Xiaoshuang Han, Weiliang Qiao, Bo Zhou Jun 2020

Assessment Of Dynamic Response Of Offshore Jacket Platforms Subjects To Random Waves, Xiaoshuang Han, Weiliang Qiao, Bo Zhou

Journal of Marine Science and Technology–Taiwan

This paper presents a simplified approach to analyze the dynamic response of offshore jacket platform based on Timoshenko beam theory. In the study, the jacket platform is simulated as a non-uniform cantilever beam structure subjects to random waves. The assessment of dynamic performance is based on the power spectral densities, variances and spectral moments due to wave spectrum. A combination of Pseudo-excitation and Ritz method is proposed and adopted, such as the dynamic characteristics of the jacket platform can be solved more efficiently without a need to examine the modes of vibration. The proposed analytical method also provides a more …

Go to article

Constraint-Type Fictitious Time Integration Method For Solving Non-Linear Multi-Dimensional Elliptic Partial Differential Equations, Yung-Wei Chen, Chein-Shan Liu, Yen-Shen Chang, Jiang-Ren Chang Jun 2020

Constraint-Type Fictitious Time Integration Method For Solving Non-Linear Multi-Dimensional Elliptic Partial Differential Equations, Yung-Wei Chen, Chein-Shan Liu, Yen-Shen Chang, Jiang-Ren Chang

Journal of Marine Science and Technology–Taiwan

In this paper, we propose a constraint-type fictitious time integration method (FTIM) for solving multi-dimensional non-linear elliptic-type partial differential equations. Based on the variable transformation of FTIM, the original governing equation is transformed into a new parabolic equation of an evolution type by introducing a space-time variable, and a new time integration direction is obtained. However, the space-time variable depends on the governing equation, boundary condition and fictitious time variable, especially due to the nonlinear effect. Previous studies have not discussed the definition of these nonlinear parameter problems, which may result in severe numerical instability and inaccuracy. To completely overcome …

Go to article

Numerical Analyses Of Pile Foundation For Support Structure Of Offshore Wind Turbine At Changhua Coast In Taiwan, Der-Guey Lin, Sheng-Hsien Wang, Jui-Ching Chou, Cheng-Yu Ku, Lien-Kwei Chien Jun 2020

Numerical Analyses Of Pile Foundation For Support Structure Of Offshore Wind Turbine At Changhua Coast In Taiwan, Der-Guey Lin, Sheng-Hsien Wang, Jui-Ching Chou, Cheng-Yu Ku, Lien-Kwei Chien

Journal of Marine Science and Technology–Taiwan

This study investigates the bearing capacities of group pile foundation (jacket foundation) installed on the seabed of offshore wind farm (OWF) at the Changhua coast of Western Taiwan for the jacket support structure of offshore wind turbine (OWT) using three-dimensional (3-D) finite element method (FEM). The jacket foundations are subjected to a combined Vertical-Horizontal-Moment (V-H-M) loading for the operational period. The responses of installed group pile foundations are investigated under the combined loading in marine silty sand-low plasticity silt & clay (SM-ML-CL) layers determined by 19 offshore boring logs. The validity of numerical procedures was verified by a large-scale lateral …

Go to article

Using The Chloride Penetration Depth Obtained From Rcpt To Assess The Permeability Of Concrete, Kang-Shiun Huang, Chung-Chia Yang Apr 2020

Using The Chloride Penetration Depth Obtained From Rcpt To Assess The Permeability Of Concrete, Kang-Shiun Huang, Chung-Chia Yang

Journal of Marine Science and Technology–Taiwan

A review of the literature on the rapid chloride permeability test (RCPT; ASTM C1202) indicates that RCPT has a few shortcomings, namely complex anions in concrete and Joule heating. The charge passed through concrete is affected by chloride ions because of the complex anions in concrete. Moreover, Joule heating influences the experimental temperature and causes an abnormal increase in the charge passed. Engineers have focused on the advance of the critical chloride front toward steel, but the charge passed in RCPT experiments has a poor relationship with the chloride penetration depth in fly ash concrete. Thus, it is risky to …

Go to article

Evaluation Of Migration Characteristics Of Opc And Slag Concrete From The Rapid Chloride Migration Test, Rues-Wen Shiu, Chung-Chia Yang Apr 2020

Evaluation Of Migration Characteristics Of Opc And Slag Concrete From The Rapid Chloride Migration Test, Rues-Wen Shiu, Chung-Chia Yang

Journal of Marine Science and Technology–Taiwan

In this study, the non-steady state chloride migration coefficient in concrete was measured using the rapid chloride migration (RCM) test. After completing the test, we established the specimen’s chloride profile by collecting concrete powder samples at predetermined, controlled depths. In order to investigate whether the RCM (NT BUILD 492) can be applied to slag concrete, we made ordinary Portland cement (OPC) concrete and slag concrete with different water binder (w/b) ratios. The combined results from the concrete chloride profile and regression analysis demonstrated that the NT BUILD 492 RCM method can be successfully applied to slag concrete. In summary, a …

Go to article

Fuzzy-Sliding-Mode-Based Robust Tracking Control Of Autonomous Underwater Vehicles, Qiaomei Sun, Jinguo Chen, Wan Yu, Huashan Su Apr 2020

Fuzzy-Sliding-Mode-Based Robust Tracking Control Of Autonomous Underwater Vehicles, Qiaomei Sun, Jinguo Chen, Wan Yu, Huashan Su

Journal of Marine Science and Technology–Taiwan

Control of an autonomous underwater vehicle (AUV) is difficult due to its nonlinear and coupled characteristics, parameter uncertainties, and unknown disturbances. This paper presents a motion control system based on an adaptive fuzzy sliding mode control (FSMC) method for trajectory tracking of an AUV. The proposed FSMC method is primarily based on a combination of sliding mode control (SMC) strategy with an adaptive fuzzy algorithm to estimate external disturbances and weaken the chattering effect. A waypoint guidance law based on a line-of-sight (LOS) algorithm is applied to the guidance system. Simulation studies confirm a good performance of the proposed controller. …

Go to article

P-Y Curve Of Small-Spaced Row Piles Subjected To Lateral Loads In Marine Clay, Runze Xue, Shean Bie, Linlin Guo Apr 2020

P-Y Curve Of Small-Spaced Row Piles Subjected To Lateral Loads In Marine Clay, Runze Xue, Shean Bie, Linlin Guo

Journal of Marine Science and Technology–Taiwan

Newly proposed pile wall frame structures (PWFSs), notably with small-spaced row piles, have great potential for cofferdams of artificial islands applied for oil recovery in shallow seas. Studies have been called to analyze the bearing performance of small-spaced row piles subjected to lateral loads. A numerical investigation of laterally loaded row piles with small pile spacing was conducted to achieve a fitted algebraic expression of the P-Y curve. Significantly different from the hyperbolic P-Y curves of a single pile reported in other studies, the P-Y curve of small-spaced row piles is similar to an elastic–perfectly plastic curve, which simply depends …

Go to article

Manufacturing And Characterization Of Glass Fiber-Fishnet-Woven Roving And Polyester Composites, S. Sahaya Elsi, F. Michael Raj, Mary S. Prince, A. Amala Mithin Minther Singh, R. S. Jayaram Feb 2020

Manufacturing And Characterization Of Glass Fiber-Fishnet-Woven Roving And Polyester Composites, S. Sahaya Elsi, F. Michael Raj, Mary S. Prince, A. Amala Mithin Minther Singh, R. S. Jayaram

Journal of Marine Science and Technology–Taiwan

Glass fibers are imparted as reinforcement material in polyester matrix and still it act as a preferred material for the marine industry. However, it is non-biodegradable material and involves high risk during processing. In this study, new monofilament fishnets were substituted as an alternative material for glass fiber in the polyester matrix. Mechanical properties of these composite specimens such as tensile strength, flexural strength and impact resistance in accordance with ASTM, were evaluated. SEM images of various composites revealed the relations between the reinforced fishnet/glass fiber and woven roving with polyester matrix. The dynamic mechanical analysis of storage modulus, loss …

Go to article

Multiple Fault Analysis Using A Fuzzy Logic Technique For An Inverter Control Drive, V. Kannan, M. Santhi, D. Sureshkumar Feb 2020

Multiple Fault Analysis Using A Fuzzy Logic Technique For An Inverter Control Drive, V. Kannan, M. Santhi, D. Sureshkumar

Journal of Marine Science and Technology–Taiwan

This study evaluates electrical faults on an inverter control drive using simulations in MATLAB Simulink and recommends a fuzzy logic technique for analyzing electrical faults of such drives. Fault analysis of a drive is based on voltage, speed, current, and torque. This article presents soft computing methods for voltage fluctuations and fault detection in an inverter switch to an inverter control drive with the support of a MATLAB Simulink model. Accordingly, failure analysis techniques based on fuzzy logic are explained. The fuzzy system allows altered voltage and open-switch fault detection. Soft computing techniques offer excellent analysis of a faulty structure, …

Go to article

First Prev Next Last