Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Dynamic characteristics (4)
- Micro-continuum theory (4)
- Bridge (3)
- Deep learning (3)
- Genetic algorithm (3)
-
- Japan (3)
- Sea surface temperature (3)
- Sliding mode control (3)
- Target strength (3)
- Bioavailability (2)
- Cluster analysis (2)
- Couple stress fluids (2)
- Enthalpy method (2)
- Finite difference method (2)
- Fuzzy analytic hierarchy process (2)
- Groundwater (2)
- Marine environment (2)
- Marine management (2)
- Maritime safety (2)
- Mechanical properties (2)
- Model test (2)
- Numerical simulation (2)
- Offshore wind turbine (2)
- Quantitative echo sounder (2)
- RUL (2)
- SVM (2)
- Scientific echo sounder (2)
- Slider bearings (2)
- Sliders (2)
- Squeeze films (2)
Articles 331 - 360 of 445
Full-Text Articles in Mechanical Engineering
Research On Design Method Of Hull Surface Based On Reverse Engineering, Guan Guan, Wenwen Gu, Xiaole Yang
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 …
Using The Chloride Penetration Depth Obtained From Rcpt To Assess The Permeability Of Concrete, Kang-Shiun Huang, Chung-Chia Yang
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 …
Evaluation Of Migration Characteristics Of Opc And Slag Concrete From The Rapid Chloride Migration Test, Rues-Wen Shiu, Chung-Chia Yang
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 …
Fuzzy-Sliding-Mode-Based Robust Tracking Control Of Autonomous Underwater Vehicles, Qiaomei Sun, Jinguo Chen, Wan Yu, Huashan Su
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. …
Numerical Investigation Of Vortex-Induced Vibration Of A Vertical Riser In Uniform Flow At High Reynolds Numbers, Jerónimo Domingo, Luis Pérez-Rojas, H. R. Díaz-Ojeda
Numerical Investigation Of Vortex-Induced Vibration Of A Vertical Riser In Uniform Flow At High Reynolds Numbers, Jerónimo Domingo, Luis Pérez-Rojas, H. R. Díaz-Ojeda
Journal of Marine Science and Technology–Taiwan
This work presents a numerical study on the vortex-induced vibration (VIV) phenomenon of synchronization of a vertical, flexible, circular cylinder with a length-to-diameter ratio of 475, being free to move along the in-line (IL) and cross-flow (CF) directions for Reynolds numbers of 42K, 84K and 126K. It is found that the dominant mode numbers, the maximum root mean square amplitudes, the dominant frequencies and the lift coefficient increase with the Reynolds number, but the drag coefficient decreases. The in-line response shows a main frequency component at twice the cross-flow frequency. At some Reynolds number value and riser span location, a …
Verification And Validation Of A Resistance Model For Tanker 17.500 Dwt, D. Purnamasari, I. K. A. P. Utama, I. K. Suastika
Verification And Validation Of A Resistance Model For Tanker 17.500 Dwt, D. Purnamasari, I. K. A. P. Utama, I. K. Suastika
Journal of Marine Science and Technology–Taiwan
Verification and validation study was performed based on to the methodology and procedures of the International Towing Tank Conference. The verification was based on a mesh dependency study, Richardson extrapolations, and uncertainty analysis with factor of safety methods. The validation was performed by comparing the experimental data of the 17.500 DWT tanker, tested in calm water at the Indonesian Hydrodynamic Laboratory, with computational data. The verification and validation results revealed that it was possible to improve the reliability of the numerical simulation by reducing the errors and uncertainties related to resistance prediction.
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–Taiwan
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 …
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–Taiwan
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 …
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–Taiwan
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. …
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–Taiwan
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 …
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–Taiwan
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, …
Oblique Wave Scattering By A Submerged Porous Breakwater With A Partially Reflecting Sidewall, Yang Zhao, Hua-Jun Li, Yong Liu
Oblique Wave Scattering By A Submerged Porous Breakwater With A Partially Reflecting Sidewall, Yang Zhao, Hua-Jun Li, Yong Liu
Journal of Marine Science and Technology–Taiwan
This study develops an analytical solution for oblique wave scattering by a submerged porous breakwater with a leeside partially reflecting vertical wall. The matched eigenfunction expansion method is used to develop the analytical solution. The whole fluid domain is divided into three regions according to the geometries of the structures. The series solution of the velocity potential in each region is obtained by the separation of the variables, and the unknown expansion coefficients are determined using the pressure and velocity continuous conditions on interfaces of different regions. The newly developed analytical solution is confirmed by an independently developed multi-domain boundary …
Feasibility Assessment Of Substituting Stainless Steel With Aluminum Alloy For Hydraulic Gate, Kuo-Ho Chen, Tien-Kuen Huang
Feasibility Assessment Of Substituting Stainless Steel With Aluminum Alloy For Hydraulic Gate, Kuo-Ho Chen, Tien-Kuen Huang
Journal of Marine Science and Technology–Taiwan
In this paper, the feasibility of using aluminum alloy 5083 as a replacement for currently used stainless steel SUS 304L on hydraulic gate is evaluated. Relevant properties of these two materials are compared for use in hydraulic gates. Forty common types of hydraulic gates were analyzed through the finite element program PLAXIS 3D Foundation. It shows the weight for most types of hydraulic gates with aluminum alloy 5083 is in the range of 37.6-45.9% of that of stainless steel SUS 304L. At the same time, the cost of gate manufacturing is reduced 39.6-50.5% and cost of maintanence/operation can be reduced …
Improved Analysis Of Bolted Shear Connection Under Eccentric Loads, Dung-Myau Lue, Cheng-Yen Liao, Chien-Chien Chang, Wei-Ting Hsu
Improved Analysis Of Bolted Shear Connection Under Eccentric Loads, Dung-Myau Lue, Cheng-Yen Liao, Chien-Chien Chang, Wei-Ting Hsu
Journal of Marine Science and Technology–Taiwan
Almost all bolted connections are eccentrically loaded. The American Institute of Steel Construction (AISC) permits the use of elastic and instantaneous center of rotation (IC) methods to analyze eccentric bolted connections. The elastic method normally yields relatively conservative designs and the IC method, which provides more realistic analyses, is rather complex and tedious. The current AISC manual provides tables for determining coefficient C, which is used to obtain the design strength of bolt group patterns. However, the tables provide values for only six angles of inclination (θ = 0°, 15°, 30°, 45°, 60°, and 75°). For other angles, a direct …
Flame Behavior Of Bifurcated Jets In A V-Shaped Bluff-Body Burner, Hsiu Feng Yang, Ching Min Hsu, Rong Fung Huang
Flame Behavior Of Bifurcated Jets In A V-Shaped Bluff-Body Burner, Hsiu Feng Yang, Ching Min Hsu, Rong Fung Huang
Journal of Marine Science and Technology–Taiwan
A plane fuel jet bifurcated into two streams of jets by a V-shaped bluff-body burner with co-flowing air streams was studied. The flame behavior, length, and temperature distributions of the bifurcated jets were experimentally examined. Flame behavior was characterized by flame visualization and instantaneous photograph. The flame length characteristics was obtained by using the long-exposure flame images. The temperatures distributions were measured by using a finewire thermocouple. Three characteristic flame modes were revealed—attached flame, transitional flame, and lifted flame. The flame length and width of the bifurcated jets increase with the increase of the Rec in fixed Rea. The length …
Assessing Fishing Port Locations For Adaption Into Yacht Marinas In Taiwan, Ching-Min Yang, Chi-Chang Lai1, Long-Jing Wu, Jan-Jung Li
Assessing Fishing Port Locations For Adaption Into Yacht Marinas In Taiwan, Ching-Min Yang, Chi-Chang Lai1, Long-Jing Wu, Jan-Jung Li
Journal of Marine Science and Technology–Taiwan
As fishing resources gradually disappear, the original functions of fishing ports change. Modernizing traditional fishing ports is valuable for the fishing industry, tourism, and waterfront development. To determine suitable locations for such ports, an analytic hierarchy process and an interview survey were used to objectively analyze inputs from fishing port managers and yacht users. To establish additional yacht marinas in fishing ports, both groups attached importance to the “support of government and integration of policies” (rank and additive weight of manager : user = 1[0.185] : 2[0.119]). Therefore, inclusion of a complete and appropriate management mechanism must be emphasized during …
Offshore Structural Dynamic Analysis Considering Soil-Structure Interaction By A Coupled Bem And Meshfree Method, Min-Chou Tsai, Hsien Hua Lee, Tinh Quoc Bui, Chuanzeng Zhang
Offshore Structural Dynamic Analysis Considering Soil-Structure Interaction By A Coupled Bem And Meshfree Method, Min-Chou Tsai, Hsien Hua Lee, Tinh Quoc Bui, Chuanzeng Zhang
Journal of Marine Science and Technology–Taiwan
An investigation of dynamic offshore structure considering soil-structure interaction by a coupled approach based on boundary element and meshfree methods is presented. The moving Kriging interpolation is used for generating the shape functions because of possessing the Kronecker delta property, which makes easier in imposing the essential boundary conditions. The governing elastodynamic equations are transformed into a standard weak formulation. It is then discretized into a meshfree system of time-dependent equations, which are solved by the standard implicit Newmark time integration scheme. Numerical examples illustrating the applicability and effectiveness of the proposed method are presented and discussed in details. A …
Geometric Solution In Progressive Collapse Analysis Of Hull Girder, Ertekin Bayraktarkatal, Gökhan Tansel Tayyar
Geometric Solution In Progressive Collapse Analysis Of Hull Girder, Ertekin Bayraktarkatal, Gökhan Tansel Tayyar
Journal of Marine Science and Technology–Taiwan
This paper presents a calculation model for stiffened plates to determine the ultimate strength of ship hull girders from their curvatures using a geometrical approach. The present study employed Smith’s method, in which the cross-section is divided into smaller elements consisting of a stiffener(s) and attached plating. The strength of beam-columns and stiffened plates was obtained using an iterative numerical approach. The deflection curve was evaluated using the curvature values directly instead of by solving differential equations. The deflection curve was taken as an assembly of chains of circular arcs. The ultimate strength of the hull girder of a 1/3 …
Reproducing Laboratory-Scale Rip Currents On A Barred Beach By A Boussinesq Wave Model, Ke-Zhao Fang, Ji-Wei Yin, Zhi-Li Zou, Zhong-Bo Liu, Ping Dong
Reproducing Laboratory-Scale Rip Currents On A Barred Beach By A Boussinesq Wave Model, Ke-Zhao Fang, Ji-Wei Yin, Zhi-Li Zou, Zhong-Bo Liu, Ping Dong
Journal of Marine Science and Technology–Taiwan
The pioneering work of Haller [8] on physically investigating bathymetry-controlled rip currents in the laboratory is a standard benchmark test for verifying numerical nearshore circulation models. In this paper, a numerical model based on higher-order Boussinesq equations was developed to reproduce the number of experiments involved in such an investigation, with emphasis on the effect of computational domain size on the numerical results. A set of Boussinesq equations with optimum linear properties and second-order full nonlinearity were solved using a higher-order finite difference scheme. Wave breaking, moving shoreline, bottom friction, and mixing were all treated empirically. The developed model was …
A Modelling Study Of Seawater Intrusion In The Liao Dong Bay Coastal Plain, China, Fei Ding, Takao Yamashita, Han Soo Lee, Graduate School For International Development And Cooperation, Hiroshima University, Higashi-Hiroshima, Japan Pan
A Modelling Study Of Seawater Intrusion In The Liao Dong Bay Coastal Plain, China, Fei Ding, Takao Yamashita, Han Soo Lee, Graduate School For International Development And Cooperation, Hiroshima University, Higashi-Hiroshima, Japan Pan
Journal of Marine Science and Technology–Taiwan
To investigate the extent of seawater intrusion in the Liao Dong Bay coastal plain, China, a numerical model for variable-density groundwater flow and miscible salt transport was developed. The SEAWAT code was used to solve the density-dependent groundwater flow and solute transport governing equations. The simulation was conducted for 55 months from October, 2004 to April, 2009. The numerical model was calibrated by the hydraulic heads measured in April, 2009. Using the calibrated model and the same hydrogeological conditions in 2004, the extent of seawater intrusion prediction was conducted for the next 40 years. The results show that the extent …
Experimental Study Of Characteristics Of Motions Of A Large Mooring Ship In Long-Period Waves, Xian-Ying Shi, Ning-Chuan Zhang, Chang-Ping Chen, Heng-Zhi Jiang, Lei Cui
Experimental Study Of Characteristics Of Motions Of A Large Mooring Ship In Long-Period Waves, Xian-Ying Shi, Ning-Chuan Zhang, Chang-Ping Chen, Heng-Zhi Jiang, Lei Cui
Journal of Marine Science and Technology–Taiwan
By using the method of physical model tests, the characteristics of mooring ship’s motion responses in transverse long-period waves have been studied under different conditions, including such elements as loading conditions, wave heights, and specific patterns of mooring, etc. The results indicate that: the mooring ship’s movements of surge, sway and yaw had their own natural periods; the movement of sway was a period motion. The ratio of the natural period of sway and the natural rolling period of the mooring ship was within 1.11~1.23. The peak value of sway grew along with the increase of the wave period; the …
Truncated Model Tests For Mooring Lines Of A Semi-Submersible Platform And Its Equivalent Compensated Method, Dong-Sheng Qiao, Jin-Ping Ou
Truncated Model Tests For Mooring Lines Of A Semi-Submersible Platform And Its Equivalent Compensated Method, Dong-Sheng Qiao, Jin-Ping Ou
Journal of Marine Science and Technology–Taiwan
This study conducted a model test of 1:100 model scale of a semi-submersible platform with a 1500 m full-depth mooring system in the Joint Laboratory of Wind Tunnel & Wave Flume at Harbin Institute of Technology. A truncated mooring system of 400 m water depth was designed based on the static equivalent principle. The semi-submersible platform was tested under regular wave excitation periods that ranged from 10 s to 45 s and one year of irregular wave conditions in the South China Sea. The results validated the feasibility of using numerical simulation in the motions calculation of semisubmersible platform and …
Liquefaction Potential Of Non-Plastic Silty Sand, Chun-Chi Chen, Wei F Lee, Jing-Wen Chen, Kenji Ishihara
Liquefaction Potential Of Non-Plastic Silty Sand, Chun-Chi Chen, Wei F Lee, Jing-Wen Chen, Kenji Ishihara
Journal of Marine Science and Technology–Taiwan
This paper is to introduce research progress on liquefaction potential of undisturbed high fines content non-plastic silty sand. A new sampling technique that was applied to the field allowing sensitive and high fines content silty sand material to be retrieved in sounding condition is described. Laboratory tests on the liquefaction resistance of non-plastic silty sand that emphasized on the influence of fines content percentages were conducted. It concludes that soil liquefaction would occur in non-plastic silty sand deposits even with high nonplastic fines contents. Both fines contents and void ratios have deterministic influences to the cyclic resistance of such silty …
Dynamics And Cutting Stability Of Dynamically Loaded Worktable Subjected To Elastic Supports, Kuo-Chiang Cha, Nenzi Wang, Jen-Yi Liao
Dynamics And Cutting Stability Of Dynamically Loaded Worktable Subjected To Elastic Supports, Kuo-Chiang Cha, Nenzi Wang, Jen-Yi Liao
Journal of Marine Science and Technology–Taiwan
This paper investigated the dynamic characteristics and the cutting stability of a dynamically loaded worktable on elastic supports in a surface grinder. The operation of worktables is usually dynamically loaded in various positions, which results in a complex system of governing equations. In this study, the assumptions of elastic and rigid body modes of a free-free beam were specified in analyzing the worktable. By combining the Lagrange energy method with the technique of assumed mode expansion, the system of equations was developed. The absolute value of the maximum negative real part of the overall dynamic compliance (MNRPODC) and the limiting …
Model Reference Robust Control For Marine Propulsion Systems With Model Uncertainty Caused By Hull Deformation, Zhixiong Li, Xinping Yan, Li Qin, Chengqing Yuan, Zhongxiao Peng
Model Reference Robust Control For Marine Propulsion Systems With Model Uncertainty Caused By Hull Deformation, Zhixiong Li, Xinping Yan, Li Qin, Chengqing Yuan, Zhongxiao Peng
Journal of Marine Science and Technology–Taiwan
A marine propulsion system can be strongly coupled with the hull deformation in a large-scale ship. The interaction of this coupling dynamics increases the nonlinearity and complexity of the control model. Traditional control method based on the empirical PID (proportion-integration-differentiation) parameters has difficulty in dealing with the model uncertainty caused by the hull deflection. However, up to date, limited work has been done to address the model uncertainty problem of the marine propulsion system. It is therefore imperative to develop feasible and effective control systems that take the model uncertainty into account. In this study, a new method based on …
The Experimental Study On Local Scour Around A Circular Pipe Undergoing Vortex-Induced Vibration In Steady Flow, Bing Yang, Tao Yang, Jian-Lin Ma, Jin-Sheng Cui
The Experimental Study On Local Scour Around A Circular Pipe Undergoing Vortex-Induced Vibration In Steady Flow, Bing Yang, Tao Yang, Jian-Lin Ma, Jin-Sheng Cui
Journal of Marine Science and Technology–Taiwan
The local scour around a circular pipe undergoing vortexinduced vibration is investigated experimentally in a water flume. The typical characteristic of local scour is analyzed in detail. The influences of initial gap-to-diameter ratio (e0/D), the mode of pipe vibration and the sand type on the local scour are discussed. Experimental results indicate that there exists strong intensity of scour when the pipe moves close to the surface of the sandy bed. The vibration of the pipe results in the rapid development of sandy bed’s scouring. With the increase of gap-to-diameter ratio the distance between the center of the pipe and …
A Piston-Type Porous Wave Energy Converter Theory, Ching-Yun Yueh, Shih-Hsuan Chuang
A Piston-Type Porous Wave Energy Converter Theory, Ching-Yun Yueh, Shih-Hsuan Chuang
Journal of Marine Science and Technology–Taiwan
This study investigates the performance of a piston-type porous wave energy converter (PTPWEC), which consists of a solid wall, a vertical porous plate, a transmission bar, a rigid block constrained by rollers, a spring, and a damper. The PTPWEC is subjected to dynamic external loading by wave actions. To simulate this dynamic system, a mathematical model is used with a single-degree-of-freedom (SDOF) system. Linear wave theory governs the entire fluid domain, which is divided into two regions by the vertical porous plate. Darcy's law is applied to flow through the porous plate. Finally, this investigation employs an eigenfunction expansion to …
Application Of A Support Vector Machine For Liquefaction Assessment, Ching-Yinn Lee, Shuh-Gi Chern
Application Of A Support Vector Machine For Liquefaction Assessment, Ching-Yinn Lee, Shuh-Gi Chern
Journal of Marine Science and Technology–Taiwan
This study presents a support vector machine (SVM)-based approach for predicting earthquake liquefaction. The SVM model database includes five indexes: earthquake magnitude, total overburden pressure, effective overburden pressure, qc values from cone penetration tests (CPT), and peak ground acceleration. The proposed model was trained and tested on a dataset comprising 466 field liquefaction performance records and CPT measurements. A grid search method with k-fold cross-validation was also used to verify the feasibility. Compared with an artificial neural network (ANN)–based method, the SVM-based method has the advantage of increased accuracy and simpler operation. Experimental results show that the proposed SVM approach …
Numerical Simulations And Wind Tunnel Studies Of Pollutant Dispersion In The Urban Street Canyons With Different Height Arrangements, Cheng-Hsin Chang, Jin-Shian Lin, Chii-Ming Cheng, Yung-Shan Hong
Numerical Simulations And Wind Tunnel Studies Of Pollutant Dispersion In The Urban Street Canyons With Different Height Arrangements, Cheng-Hsin Chang, Jin-Shian Lin, Chii-Ming Cheng, Yung-Shan Hong
Journal of Marine Science and Technology–Taiwan
Air pollution in big city areas resulting from exhaust emissions is a major urban problem. Often traffic pollution excess controls air pollution management decisions. There are a number of elaborate predictive models of pollutant dispersion and diffusion that address the effects of variable shapes of city buildings on pollutant concentrations, but few are fully validated. This study presents ventilation behavior in different street canyon configurations. To evaluate dispersion in a model urban street canyon, a series of tests with various street canyons with different height in upwind and downwind of street canyon are presented. These buildings were arranged in 2-D …
Vibration Suppression Of Train-Induced Multiple Resonant Responses Of Two-Span Continuous Bridges Using Ve Dampers, Ying-Jie Wang, Jong-Dar Yau, Qing-Chao Wei
Vibration Suppression Of Train-Induced Multiple Resonant Responses Of Two-Span Continuous Bridges Using Ve Dampers, Ying-Jie Wang, Jong-Dar Yau, Qing-Chao Wei
Journal of Marine Science and Technology–Taiwan
This paper presents a study of reducing multiple resonant peaks of high-speed trains traveling over a two-span continuous railway bridge using visco-elastic (VE) dampers. The moving train is modeled as a series of two-degree-of-freedom (2 DOF) moving oscillators with identical intervals and the two-span continuous bridge as a Bernoulli-Euler beam with uniform span. Because of closely spaced frequencies of a continuous beam, the first several frequencies of the bridge would be excited to resonance during the passage of moving trains, which may result in multiple resonant peaks appearing on the response of train-bridge system. In order to reduce the multiple …