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Journal of Marine Science and Technology

2005

Articles 1 - 23 of 23

Full-Text Articles in Engineering

A Note On Grashof Theorem, Wen-Tung Chang, Chen-Chou Lin, Long-Iong Wu Dec 2005

A Note On Grashof Theorem, Wen-Tung Chang, Chen-Chou Lin, Long-Iong Wu

Journal of Marine Science and Technology

In this paper, Grashof’s theorem is justified from the perspective of the occurrence of stationary configurations and uncertainty configurations of four-link chains. The link length relations at stationary configurations and uncertainty configurations are examined in detail based on the triangle inequality, and then the conditions for the existence of a crank and a change point are deduced.

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An Adaptive Nonlinear Fuel Injection Control Algorithm For Motorcycle Engine, Tung-Chieh Chen, Chiu-Feng Lin, Chyuan-Yow Tseng, Chung-Ying Chen Dec 2005

An Adaptive Nonlinear Fuel Injection Control Algorithm For Motorcycle Engine, Tung-Chieh Chen, Chiu-Feng Lin, Chyuan-Yow Tseng, Chung-Ying Chen

Journal of Marine Science and Technology

The purpose of this research is to apply an adaptive fuel injection control algorithm on a motorcycle engine and evaluate its performance. A highly nonlinear switching type EGO sensor is used to measure the air fuel ratio of the engine. In the research, the nonlinear control algorithm is developed based on a Lyapunov function. Furthermore, an observer is also applied to estimate the air flow rate into the combustion room. The results show that the air fuel ratio and engine speed are stable under steady manoeuvres and the air-fuel ratio values are satisfactory.

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Application Of Fuzzy Soil Classification In Visualizing 3-D Soil Strata, Jing-Wen Chen Dec 2005

Application Of Fuzzy Soil Classification In Visualizing 3-D Soil Strata, Jing-Wen Chen

Journal of Marine Science and Technology

The distribution of soil classes is an important factor in engineering design. In order to generate the soil class map, fuzzy soil classifications were developed to provide the means to characterize and quantify the soil classes, and then the spatial distribution of soil class can be interpolated by geostatistical method. For establishing continuous class soil maps, this paper present an index of fuzzy soil classification generated from principal component analysis (PCA). The ability of classification of the index is tested with a soil database which including 9,260 soil samples, and the accurate rate of simulation was 91.7%. There are two …

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The Optimization Of The Reliability And Construction Cost Of Rc Bridges, Wen-Hu Tsao, Chi-Way Lin, Ming-Te Liang, Wen-Lung Wen-Lung Tsao Tsao Dec 2005

The Optimization Of The Reliability And Construction Cost Of Rc Bridges, Wen-Hu Tsao, Chi-Way Lin, Ming-Te Liang, Wen-Lung Wen-Lung Tsao Tsao

Journal of Marine Science and Technology

In this paper, the relationship between reliability and engineering system construction cost for obtaining optimum reliability was studied. This proposed approach was applied to the repair alternatives of existing reinforced concrete (RC) bridges for acquiring the result of optimization analysis. According to the D(degree) E(extent) R (relevancy) evaluation method, which is widely used by civil engineers in Taiwan the existing RC bridges with and without stridden rivers can be divided into 21 and 17 substructures, respectively. The use of the weighting value and the cost relation is to attain the relationship between the total engineering system construction cost and the …

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Laminar Film Condensation On A Horizontal Plate In A Porous Medium With Surface Tension Effects, Tong-Bou Chang Dec 2005

Laminar Film Condensation On A Horizontal Plate In A Porous Medium With Surface Tension Effects, Tong-Bou Chang

Journal of Marine Science and Technology

The problem of steady filmwise condensation on a finite-size horizontal plate embedded in a porous medium is studied for the case in which a cold plate faces upwards with a dry saturation vapor. Due to the effects of surface tension forces, there is a two-phase zone lying between the liquid film and the vapor zone. As in classical filmwise condensation problems, it is assumed that; (a) the inertia within the liquid film is negligible, and (b) the properties of porous medium, dry vapor, and condensate are constant. A dimensionless parameter Boc is introduced to characterize liquid flow due to surface …

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Effects Of Closure Models On Supercavitating Bubble Development, Bin-Chen Wu, Jiahn-Horng Chen Sep 2005

Effects Of Closure Models On Supercavitating Bubble Development, Bin-Chen Wu, Jiahn-Horng Chen

Journal of Marine Science and Technology

Effects of different cavity closure models on the development sheet supercavitation of two-dimensional hydrofoils were examined in this report. The study was carried out under the assumption of potential flow for which a cavity closure model was needed. A potential-based boundary element method has been developed for this purpose. The models we employed included the constant velocity model and the short plate termination model. Several different airfoil shapes were tested. Their effects on the cavity shape, lift coefficient, cavity volume and computation efficiency were studied. Careful investigations show that closure models have insignificant influence on physical quantities, but do have …

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A Study Of Non-Linear Vibrational Behavior Of Cracked Structures By The Finite Element Method, Tzuo-Liang Luo, James Shih-Shyn Wu, Jui-Pin Hung Sep 2005

A Study Of Non-Linear Vibrational Behavior Of Cracked Structures By The Finite Element Method, Tzuo-Liang Luo, James Shih-Shyn Wu, Jui-Pin Hung

Journal of Marine Science and Technology

Numerical and experimental investigations provide a link to the location and size of cracks caused by natural vibrations. Cracks may generally result in the variation of structural stiffness and hence enable structures to vibrate nonlinearly. In order to understand the vibrational behavior of crack structures accurately, the study proposes a general and efficient algorithm based on the finite element assumptions and the bilinear vibrational theory. All formulae are derived from the time domain properly and may apply to the overall non-linear motion cycle completely. The contact effect is also considered by introducing the degree of penetration on the cracked surface. …

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A Grid-Based Gis Approach To Regional Flood Damage Assessment, Ming-Daw Su, Jui-Lin Kang, Ling-Fang Chang, Albert S Chen Sep 2005

A Grid-Based Gis Approach To Regional Flood Damage Assessment, Ming-Daw Su, Jui-Lin Kang, Ling-Fang Chang, Albert S Chen

Journal of Marine Science and Technology

Regional flood risk assessment is the base for a sound and comprehensive risk planning or management. The regional flood loss is the sum of the damages in all the flooded parcels. The data involved in this process are multifarious and difficult to establish and maintain especially in the developing countries that suffer most often from the flood hazard. A grid-based GIS approach to regional flood damage assessment is proposed in this paper. Aggregated census data that are relatively available were used instead of the data at parcel level. An algorithm was proposed to disaggregated these aggregated census data into spatially …

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Loss Functions And Framework For Regional Flood Damage Estimation In Residential Area, Jui-Lin Kang, Ming-Daw Su, Ling-Fang Chang Sep 2005

Loss Functions And Framework For Regional Flood Damage Estimation In Residential Area, Jui-Lin Kang, Ming-Daw Su, Ling-Fang Chang

Journal of Marine Science and Technology

The risks of flooding damages for a region increase as the population and economy development increased in that area. Damage assessment and risk analysis are important issues for risk management and hazard mitigation. There are huge amount of data involved in the process of regional damage assessment and most of these data are spatially and temporally distributed. This paper focuses on the use of spatial data for capture of spatial characteristics of damage in natural calamities. Because it affects a large number of persons and families, flood damages in the residential area usually attract major attentions in regional flood hazard …

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Design And Implementation Of A Low-Voltage 2.4-Ghz Cmos Rf Receiver Front-End For Wireless Communication, Wan-Rone Liou, Mei-Ling Yeh, Chun-An Tsai, Shun-Hsyung Chang Sep 2005

Design And Implementation Of A Low-Voltage 2.4-Ghz Cmos Rf Receiver Front-End For Wireless Communication, Wan-Rone Liou, Mei-Ling Yeh, Chun-An Tsai, Shun-Hsyung Chang

Journal of Marine Science and Technology

This paper presents the design of a 1.5 V CMOS RF receiver front-end system which contains a low noise amplifier (LNA) with band pass filter and a down conversion mixer. An inter-stage matching network is added between the common-source and common-gate transistors in the LNA’s first stage to further lower the noise and enhance the overall gain. An inductor is used in this inter-stage matching network because of the extra capacitive of MOSFETs in the LNA. The maximum gain achieved of this LNA is 15 dB. The single square-law structure was implemented for this low power consumption and high linearity …

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Acoustic Point-Source Reflection From A Seabed With A Non-Uniform Fluid-Like Sediment Layer, Jin-Yuan Liu, Chung-Ray Chu, Yung-Hong Wu, Hsin-Hung Chen Sep 2005

Acoustic Point-Source Reflection From A Seabed With A Non-Uniform Fluid-Like Sediment Layer, Jin-Yuan Liu, Chung-Ray Chu, Yung-Hong Wu, Hsin-Hung Chen

Journal of Marine Science and Technology

Acoustic point-source reflection from a non-uniform seabed within which the density and sound speed vary continuously with depth is considered in this paper. This fundamental problem has illuminated many interesting phenomena about the effects of sediment stratification on acoustic wave interactions with the seabed. The analysis employs the analytical solutions for the Helmholtz equation in the sediment layer, in which the density and the sound speed are, respectively, described by three kinds of geological models. The results have demonstrated that the effects of sediment stratification are confined in a region in range, where the reflection field is dominated by the …

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An Investigation Of Contact Path And Kinematic Error Of Face-Gear Drives, Tsang-Dong Chung, Yun-Yuan Chang Jun 2005

An Investigation Of Contact Path And Kinematic Error Of Face-Gear Drives, Tsang-Dong Chung, Yun-Yuan Chang

Journal of Marine Science and Technology

Based on the face-gear generation process, the analytical geometry of face-gear drive with its mathematical model for tooth contact analysis of face-gear and spur pinion meshing was derived. In this paper, contact path and transmission error due to assembly misalignment are analyzed by using the proposed mathematical model and the tooth contact analysis. The effects of assembly error along the axis of face-gear, misalignment of crossed and angular displacement between axes of a spur pinion and a face-gear are all investigated. The results are illustrated by several examples

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Genetic Algorithms For Design Of Pipe Network Systems, Hong-Min Shau, Bi-Liang Lin, Wen-Chih Huang Jun 2005

Genetic Algorithms For Design Of Pipe Network Systems, Hong-Min Shau, Bi-Liang Lin, Wen-Chih Huang

Journal of Marine Science and Technology

In the last three decades, a significant number of methods for optimal design of pipe network systems have been developed using linear programming, non-linear programming, dynamic programming, enumeration techniques, and genetic algorithm (GA). This paper presents a genetic algorithm (GA) approach to the design of a pipe network systems. The objectives considered are minimization of the network cost in the practical requirement. Of all the preceding methods, GA based methods appear to be robust, as they can handle discrete pipes sizes with ease and produce a set of alternatives. By judgmentally selecting the Ruey-Fang district water supply system for the …

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A Study On The Practical Model Of Planned Effective Rainfall For Paddy Fields In Taiwan, Shi-Ming Tsai, Shinne Chen, Hsin-Yi Wang Jun 2005

A Study On The Practical Model Of Planned Effective Rainfall For Paddy Fields In Taiwan, Shi-Ming Tsai, Shinne Chen, Hsin-Yi Wang

Journal of Marine Science and Technology

No abstract provided.

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Motion Behavior Of Impact Oscillator, June-Yule Lee Jun 2005

Motion Behavior Of Impact Oscillator, June-Yule Lee

Journal of Marine Science and Technology

This paper concerns a mass-spring-damper linear oscillator with endstop system. The parameter dependence of the impact oscillator is studied and the techniques of the bifurcation diagram, phase trajectory, impact map and Poincare map are applied. For the driving frequency ranges that no explicit solutions in analytical method, a complete bifurcation diagram is plotted using numerical solutions. Consequently, the phenomena of the complete, incomplete and chaotic chattering are classified as m-impact period-n motion using impact map and Poincare map.

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A Synchronous Primary-Side Dimming Controller For Cold-Cathode Fluorescent Lamp Ballast, Jenn-Jong Shieh Jun 2005

A Synchronous Primary-Side Dimming Controller For Cold-Cathode Fluorescent Lamp Ballast, Jenn-Jong Shieh

Journal of Marine Science and Technology

In this paper, a rectified quasi-sinusoidal pulse width modulation (RQSPWM) controller is first proposed for the cold-cathode fluorescent lamp (CCFL) ballast to achieve a synchronous primary-side dimming control. It is seen that, with the novel controller, not only the lamp flickering problem and the thermometer effect can be eliminated but also the useful photo-coupler in secondary side can be avoided to reduce cost. Then, small signal models of the CCFL ballast and the proposed RQSPWM dimming controller are derived to analyze the performance of the ballast system and help corroborate hardware loop measurements. Finally, a prototype is constructed for verifying …

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A Research Combines Nondestructive Testing And A Neuro-Fuzzy System For Evaluating Rigid Pavement Failure Potential, Shuh-Gi Chern, Yu-Shih Lee, Rong-Feng Hu, Yen-Jen Chang Jun 2005

A Research Combines Nondestructive Testing And A Neuro-Fuzzy System For Evaluating Rigid Pavement Failure Potential, Shuh-Gi Chern, Yu-Shih Lee, Rong-Feng Hu, Yen-Jen Chang

Journal of Marine Science and Technology

In recent years, advances in hardware and software technology had brought to significant improvement of NDT (Non-Destructive Test) equipment. In the field of evaluation and designs for the airfield pavement, NDT has been extensively used. NDT is an efficient methodology for assessing the structural condition of an airfield pavement, in the meantime, engineers need to carry other methods for assessing pavement performance, such as visual condition, roughness, and friction characteristics in completing the overall pavement evaluation. In this research, a model combined neuro-fuzzy system, PCI method (pavement condition index, visual inspection) and NDT (Heavy Falling Weight Deflectometer, HWD, structural condition) …

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Electromechanical Analysis Of Piezoelectric Laminated Composite Beams, Ming-Hung Hsu Jun 2005

Electromechanical Analysis Of Piezoelectric Laminated Composite Beams, Ming-Hung Hsu

Journal of Marine Science and Technology

This work demonstrates the electromechanical behavior of piezoelectric laminated composite beams using the differential quadrature method (DQM). The Chebyshev-Gauss-Lobatto sample point equation is used to select the sample points. The electromechanical responses of piezoelectric laminated composite beams with various boundary conditions are determined. The transient responses of the derived systems are calculated using the Wilson-method. In this approach, only nine sample points are required to obtain convergence. Numerical results indicate that the DQM is valid for a piezoelectric laminated composite beam formulation

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Characteristics Of Drop Impact On Elastic And Compliant Surfaces, Jeng-Horng Chen Jun 2005

Characteristics Of Drop Impact On Elastic And Compliant Surfaces, Jeng-Horng Chen

Journal of Marine Science and Technology

Due to its importance and wide applications, drop impact on solid and liquid surfaces has been well studied. However, with the progress and wider applications of more sophisticated materials, the relatively less studied physical properties and behavior of a drop impact on elastic or compliant surfaces gradually become more important. Three kinds of common liquid drops impact on both elastic and compliant surfaces were studied experimentally using high-speed digital camera with regular light source at three different impact speeds. The impact effects on compliant surface and the expansioncontraction processes of impacted drops were recorded and analyzed. It is found that …

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A Water Station Model With Fuzzy C-Means Algorithm To Promote The Ability Of Water Distribution Systems, Hong-Min Shau, Wen-Chih Huang, Bi-Liang Lin, Jui-Min Hsiao Mar 2005

A Water Station Model With Fuzzy C-Means Algorithm To Promote The Ability Of Water Distribution Systems, Hong-Min Shau, Wen-Chih Huang, Bi-Liang Lin, Jui-Min Hsiao

Journal of Marine Science and Technology

A water station model will simulate the performance of a water distribution system for a given station location and quantity patterns in order to analyze present population distribution in the overall region, establish a reasonable local sample for each district network and obtain the optimal solution of the water supply stations. To establish a local sample, this model uses the Fuzzy C-Means algorithm (FCM algorithm) of the fuzzy clustering method. The sites have been modified with the mobile method so that the group points can be located at places nearest to the roadside in order to achieve the minimum cost. …

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The Estimation Of The Initial Number Of Berths In A Port System Based On Cost Function, Wen-Chih Huang, Sheng-Chieh Wu Mar 2005

The Estimation Of The Initial Number Of Berths In A Port System Based On Cost Function, Wen-Chih Huang, Sheng-Chieh Wu

Journal of Marine Science and Technology

The process of optimizing a port queuing system, from a management perspective, is becoming more and more complicated. If we can find a way to measure the required minimum number and initial number of berths in a port system, and arrive at an optimal solution, we can save time. In this study, we have used many evaluation indexes, including cost functions, to estimate the initial number of berths for a port queuing system. According to our research results, we were able to estimate the initial number of berths (N0) for a port queuing system by using the equation No = …

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Simulation And Assessment Of Air Impingement Cooling On Squared Pin-Fin Heat Sinks Applied In Personal Computers, Hwa-Chong Tien, Wei-Dong Huang Mar 2005

Simulation And Assessment Of Air Impingement Cooling On Squared Pin-Fin Heat Sinks Applied In Personal Computers, Hwa-Chong Tien, Wei-Dong Huang

Journal of Marine Science and Technology

The feasibility and effectiveness of air impingement cooling on pin-fin heat sinks applied in personal computers (PC) were investigated numerically in this study. The effects of fin height, fin width, base plate thickness of the heat sink, and ratio of the vertical spacing between the nozzle and the heat sink to jet diameter (z/D) were discussed in detail. For a PC with a P4, 2.8 GHz, 68.4 W CPU, it was found that the cooling effect by using air impingement on a heat sink with z/D = 4 and fin width 4.13 mm for the jet Reynolds number (Re) between …

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Measurement Of Velocity Distribution For Flow Through A Bileaflet Valve Using Color-Coded Digital Particle Tracking Velocimetry, Tienfuan Kerh, Yen-Ming Chen, I Tsou Mar 2005

Measurement Of Velocity Distribution For Flow Through A Bileaflet Valve Using Color-Coded Digital Particle Tracking Velocimetry, Tienfuan Kerh, Yen-Ming Chen, I Tsou

Journal of Marine Science and Technology

An experimental method, the so-called color-coded Digital Particle Tracking Velocimetry system was set up in this study to investigate viscous flow through an artificial bileaflet valve with three different opening angles, 5°, 30°, and 45°, respectively. An oscilloscope that generated stable wave speed was taken to calibrate measuring result of the equipment. Besides, a fully developed pipe flow case was used to check the reliability of experimental system, and a statistical t-test was performed to further enhance the comparison of analytical solution and measurement. From the details of randomly distributed velocities, interpolated velocity components, and velocity profiles for the studied …

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