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Journal of Marine Science and Technology–Taiwan

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Articles 1201 - 1230 of 1299

Full-Text Articles in Engineering

The Influence Of Energy Grouping And Undulation On Sediment Suspension In The Surf Zone, Po-Ching Lin, Hsien-Ter Chou, Jea-Tzyy Juang Dec 2002

The Influence Of Energy Grouping And Undulation On Sediment Suspension In The Surf Zone, Po-Ching Lin, Hsien-Ter Chou, Jea-Tzyy Juang

Journal of Marine Science and Technology–Taiwan

A field experiment was conducted to investigate the effects of the wave energy grouping and undulating on the sediment suspension in the surf zone at Taichung, Taiwan, in 1995. Instruments were deployed in line with the wave front, including one acoustic current meter, one pressure sensor, and four optical turbidity monitors were arranged in line and perpendicular to the bed. During the experiments the water depth was varied from 0.7 m to 3.6 m due to the tide level variations. The instruments were fixed to the ground to have data collected throughout the surf zone while the relative position of …

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Application Of The Force Control On The Working Path Tacking, Sun-Run Wang, Zhi-Zhong Qiao, Pi-Cheng Tung Dec 2002

Application Of The Force Control On The Working Path Tacking, Sun-Run Wang, Zhi-Zhong Qiao, Pi-Cheng Tung

Journal of Marine Science and Technology–Taiwan

For the application of tracking the path on workpieces, the CCD (Charge Couple Device) identificating system is generally used as one of the popular resolutions. However, the implementation of CCD identificating system is complex and environmental-limited. This study presents a compliant motion controller by using the end-effector installed with a force sensor. This results the smoothly path tracking on a workpiece. By applying the algorithm of Fuzzy into this compliant motion, the compliant control is improved and the path on the workpiece is found more quickly and accurately. A radius compensating method is used to correct the measured data. The …

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Atmospheric Transmittance Of Amsu Channels: A Fast Computation Model, Tsung-Hua Kuo, Gin-Rong Liu, Chen-Gen Huang, Tang-Huang Lin, Chung-Chih Liu Dec 2002

Atmospheric Transmittance Of Amsu Channels: A Fast Computation Model, Tsung-Hua Kuo, Gin-Rong Liu, Chen-Gen Huang, Tang-Huang Lin, Chung-Chih Liu

Journal of Marine Science and Technology–Taiwan

In this study, the atmospheric transmittance of individual NOAA AMSU microwave channels was computed into a 40-layer atmospheric line-by-line FASCODE radiation model. Long-term sounding data from 1956 to 1991 collected over the Taiwan area was used to construct a 40-layer standard atmospheric model for the island. The simulated transmittance was also used to establish a regression-based fast-algorithm model to compute the atmospheric transmittance of Taiwan and its surrounding areas for various purposes. Despite the fact that the lower atmospheric layers of channels 14-18 indicated larger errors, the overall results revealed that the absolute value difference between the AMSU pass band-averaged …

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A Reversible Three-Phase Step Up/Down Switching Mode Rectifier, Jenn-Jong Shieh Dec 2002

A Reversible Three-Phase Step Up/Down Switching Mode Rectifier, Jenn-Jong Shieh

Journal of Marine Science and Technology–Taiwan

In this paper, focus on the null space vector duty cycle control, a reversible three-phase step up/down switching mode rectifier is proposed attain clean sinusoidal input current, unity power factor, bidirectional power flow, step up/down output DC voltage and insensitivity for a voltage input. In addition, a precise simulation model is proposed to simulation by using PC software tools. Finally, some simulation and experimental results are presented for verification.

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Mathematical Modeling And Prediction Method Of Concrete Carbonation And Its Applications, Ming Te Liang, Wenjun Qu, Chih-Hsin Liang Dec 2002

Mathematical Modeling And Prediction Method Of Concrete Carbonation And Its Applications, Ming Te Liang, Wenjun Qu, Chih-Hsin Liang

Journal of Marine Science and Technology–Taiwan

The carbonation process of concrete is principally a diffusion phenomenon. The penetration rate of carbon dioxide depends mainly on the concrete quality and the exposure condition. Based on both Fick’s first and second laws of linear diffusion equations, the threedimensional equation of conservation of mass is expressed. This equation can be reduced to two- and one- dimensional equations of conservation of mass which can predict the carbonation depth beneath corners and the general surface of concrete structures, respectively. The objectives of this investigation are to measure the depth of carbonation from the free surface of a concrete member and to …

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On The Permeability Inside The Granular Media, Chen-Yuan Chen, Chung-Pan Lee, Cheng-Wu Chen Dec 2002

On The Permeability Inside The Granular Media, Chen-Yuan Chen, Chung-Pan Lee, Cheng-Wu Chen

Journal of Marine Science and Technology–Taiwan

The permeability and resistance characteristics in porous structures with different grain size and shape have been studied experimentally in the paper. Two materials used in the study are crushed gravels and spherical glass balls with four sizes of 5.2 mm, 7. 4 mm, 12.2 mm, and 31.7 mm for gravels and 13.0 mm, 16.0 mm, 25. 0 mm, and 35.0 mm for balls, respectively. The permeability determined from linear Darcy Law shows a strong dependence on flow velocity in addition to grain sizes and shapes. This is not consistent to the traditional definition of permeability that is only a function …

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Development Of An Automated Airport Pavement Image Collection System, Chau Lee, C.F. Chen, Shu-Meng Huang, Chun-Jung Hsu, Shu-Wang Sheu Jun 2002

Development Of An Automated Airport Pavement Image Collection System, Chau Lee, C.F. Chen, Shu-Meng Huang, Chun-Jung Hsu, Shu-Wang Sheu

Journal of Marine Science and Technology–Taiwan

Airport pavement maintenance is an extremely important link in any airport pavement management system. How to quickly and effectively perform pavement surveys and data collection at today's very busy airports, while minimizing disruption to the airport's normal operation, is a major issue in airport pavement maintenance management research. This study uses a van to perform photographic surveys, and employs a global positioning system (GPS), geographic information system (GIS), image caption device, and the audio acquisition method to develop an automated airport pavement image collection system. This system currently is able to display a pavement image, slab name, and damage location …

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Effects Of Carbonation On Mechanical Properties And Durability Of Concrete Using Accelerated Testing Method, Jack M. Chi, Ran Huang, C. C. Yang Jun 2002

Effects Of Carbonation On Mechanical Properties And Durability Of Concrete Using Accelerated Testing Method, Jack M. Chi, Ran Huang, C. C. Yang

Journal of Marine Science and Technology–Taiwan

An experimental investigation was carried out to study the effect of carbonation on mechanical properties and durability of concrete. Ordinary portland concretes (OPC) with water/cement ratios of 0.58 and 0.48 and self-compacting concretes (SCC) with water/binder ratios of 0.40 and 0.36 were used in this study. Compressive strength test, splitting strength test, electrical resistivity test, rapid chloride penetration test (RCPT), open circuit potential method and alternative current (AC) impedance method were performed to estimate the properties of concrete. Test results showed that carbonation may compensate some concrete properties such as compressive strength, splitting strength, electrical resistivity and chloride ion penetration. …

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Ground Vibration During Gravel Pile Construction, Jin-Hung Hwang, Tung-Yueh Tu Jun 2002

Ground Vibration During Gravel Pile Construction, Jin-Hung Hwang, Tung-Yueh Tu

Journal of Marine Science and Technology–Taiwan

This investigation performs a field measurement of ground vibration due to gravel pile construction at a hydraulic-filled reclamation land. The ground vibrations were characterized by wave form, Fourier spectrum and response spectrum. The attenuation relation between both peak ground velocity and acceleration with distance was also derived from the measured data. An empirical method for evaluating the safe construction distance to adjacent building structures was presented based on the attenuation relation and a building vibration criterion. Vibration response spectra were also suggested for use with the spectral analysis method to determine more accurately the safe construction distance.

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Effect Of Sand Ration On The Elastic Modulus Of Self-Compacting Concrete, J. K. Su, S. W. Cho, C. C. Yang, R. Huang Jun 2002

Effect Of Sand Ration On The Elastic Modulus Of Self-Compacting Concrete, J. K. Su, S. W. Cho, C. C. Yang, R. Huang

Journal of Marine Science and Technology–Taiwan

In order to study the effect of sand ratio (S/A ratio, fine aggregate volume/total aggregate volume) on the elastic modulus of self-compacting concrete (SCC), concretes with various S/A ratios were cast and tested. Elastic moduli of SCC were compared with those of normal concrete. Slump flow test, slump test, and box test were carried out to evaluate concrete flowability. The flowability of SCC increases with an increase in S/A ratio. However, the elastic modulus of SCC is not significantly affected by S/A ratio when total aggregate volume is kept constant.

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Fuzzy Control Of Dynamic Positioning Systems For Ships, Wen-Jer Chang, Guo-Jang Chen, Yi-Lin Yeh Jun 2002

Fuzzy Control Of Dynamic Positioning Systems For Ships, Wen-Jer Chang, Guo-Jang Chen, Yi-Lin Yeh

Journal of Marine Science and Technology–Taiwan

In this paper we consider the control problem of Dynamic Positioning Systems for Ships (DPSS). It interests as a case which study in nonlinear controller design because the model exhibits nonlinear interaction in three degrees of freedom (surge, sway, and yaw) by means of main propellers aft of the ship. The DPSS system considered in this paper is modeled by a Takagi-Sugeno (T-S) type fuzzy model. By using linear feedback controller design technology, we design a nonlinear fuzzy controller for the T-S type fuzzy-based DPSS. Finally, simulation results show the utility of the present fuzzy control methodology.

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Modeling Ship,S Routing Bounded By The Cycle Time For Marine Liner, Hua-An Lu Jun 2002

Modeling Ship,S Routing Bounded By The Cycle Time For Marine Liner, Hua-An Lu

Journal of Marine Science and Technology–Taiwan

This paper addresses the problem of determining an optimal routing that bounded by the cycle time for marine liner. Through exploring the practical planning procedure of shipping company and analyzing the core of route design, this problem is realized as similar as the traveling salesman problem (TSP), but, with some specially industrial properties. A mixed integer programming model is proposed to optimize ship's routing under satisfying the relationships between the cycle time and deployed vessels with given service frequency in a week. Some constraints, besides, are organized to avoid the routing sequence has separated tours. Intuitively, we also divide the …

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Fuzzy-Art Neural Networks For Predicting Chi-Chi Earthquake Induced Liquefaction In Yuan-Lin Area, S. G. Chern, R. F. Hu, Y. J. Chang, I. F. Tsai Jun 2002

Fuzzy-Art Neural Networks For Predicting Chi-Chi Earthquake Induced Liquefaction In Yuan-Lin Area, S. G. Chern, R. F. Hu, Y. J. Chang, I. F. Tsai

Journal of Marine Science and Technology–Taiwan

In this study, a fuzzy adaptive network “Fuzz-ART”, based on adaptive resonance theory (ART) combined with fuzzy set theory is developed to evaluate liquefaction potentials induced by Chi-Chi earthquake in Yuan-Lin area. The proposed system combines the backpropagation algorithm for parameter learning and the fuzzy ART algorithm for structure learning. With the help of case studies, it is shown that the “Fuzz-ART” network is able to predict liquefaction potentials much more satisfactorily than conventional artificial neural network methods. If more data are collected, it may well evaluate liquefaction potentials induced by Chi-Chi earthquake.

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A Stability Criterion Of Time-Delay Fuzzy Systems, Cheng-Wu Chen, Wei-Ling Chiang, Ken Yeh, Zhen-Yuan Chen, Li-Teh Lu Jun 2002

A Stability Criterion Of Time-Delay Fuzzy Systems, Cheng-Wu Chen, Wei-Ling Chiang, Ken Yeh, Zhen-Yuan Chen, Li-Teh Lu

Journal of Marine Science and Technology–Taiwan

To guarantee the asymptotic stability, a stability criterion in terms of Lyapunov's direct method for multiple time-delay fuzzy interconnected systems is proposed in this paper. Each of these systems consists of a number of subsystems represented by TakagiSugeno fuzzy models with multiple time delays.

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Drbem Analysis Of Combined Wave Refraction And Diffraction In The Oresence Of Current, Sung-Shan Hsiao, Ming-Chung Lin, Nien-Chia Hu Jun 2002

Drbem Analysis Of Combined Wave Refraction And Diffraction In The Oresence Of Current, Sung-Shan Hsiao, Ming-Chung Lin, Nien-Chia Hu

Journal of Marine Science and Technology–Taiwan

A more effective numerical model using the dual reciprocity boundary element method (DRBEM) is presented to study the combined effects of wave refraction- diffraction and currents. The mildslope equation with current effects is reformulated to an inhomogeneous Helmholtz equation. Applying the conventional boundary element method to this inhomogeneous equation, the inhomogeneous part will result in a domain integral which makes the computation complicated and messy. To improve this drawback, the DRBEM is adopted to transform the domain integral to boundary integral. In order to verify the validity of this model, the relative amplitudes around a circular island without current effects …

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An Integrated Computer-Aided System And Parts Component Repository For Shaft Design Automation, Ki-Yin Chang, Gene Eu Jan, Kevin C. M. Fan Jun 2002

An Integrated Computer-Aided System And Parts Component Repository For Shaft Design Automation, Ki-Yin Chang, Gene Eu Jan, Kevin C. M. Fan

Journal of Marine Science and Technology–Taiwan

This research proposes an Object-Oriented Database (OODB) system that integrates computer-aided systems and parts component repository to automate a traditional propulsion shaft design for a shipyard. The software system is based on three concepts: an objectoriented graphic user interface, a parametric design, and a shared component database. Calculations of strength, alignment, vibrations, and sag & gap for the shaft design can therefore be completely integrated. All of the data produced in the CAD processes can be managed, integrated and applied in the OODB system. Furthermore, to easily integrate the systems developed at different periods of time, a Common Object Request …

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An Improved Non-Regression Coefficients Method In Finding Sea Surface Temperature With A Vhrr Data, Gin-Rong Liu, Pao-Cheng Kao, Tsung-Hua Kuo, Tang-Huang Lin, Chung-Chih Liu Dec 2001

An Improved Non-Regression Coefficients Method In Finding Sea Surface Temperature With A Vhrr Data, Gin-Rong Liu, Pao-Cheng Kao, Tsung-Hua Kuo, Tang-Huang Lin, Chung-Chih Liu

Journal of Marine Science and Technology–Taiwan

Yu and Barton proposed a non-regression-coefficient method in improving the accuracy of routine sea surface temperature retrievals through satellite data, which are then applied to sea surface temperature estimation models such as MCSST or CPSST algorithms. Their method involves a parameter called R54(=∆T5/∆T4), which is derived from the ratio of neighborhood temperature variances from two window channels in the thermal IR region. Due to the fact that statistical calculations were used in the derivation for the value of R54, the method is not applicable in various real cases. The aim of this study is to retain the advantage of their …

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Multiple Objective And Span Evaluation Method For Damage Grade Of Existing Reinforced Concrete Bridges, Ming-Te Liang, Heng-Dong Wang, Jai-He Wu Dec 2001

Multiple Objective And Span Evaluation Method For Damage Grade Of Existing Reinforced Concrete Bridges, Ming-Te Liang, Heng-Dong Wang, Jai-He Wu

Journal of Marine Science and Technology–Taiwan

The principal purpose of this paper was to investigate the evaluation method of performance for existing reinforced concrete bridges. The least squares technique in classical mathematics was adopted firmly to establish both the multiple objective weight distribution method and multiple span level weight method. Thus, the multiple objective and span evaluation method were built for estimating the performance of existing reinforced concrete bridges. The evaluation model may be divided into grades I, II, III and IV which are described as non-damage, light damage, severe damage and unfit for service, respectively. Using the proposed model, the Huey-tong bridge, Jzyhchyang bridge, Ay-gow …

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A Fuzzy Autopilot Design Approach That Utilizes Non-Linear Consequent Terms, Robert Sutton, Paul J. Craven Dec 2001

A Fuzzy Autopilot Design Approach That Utilizes Non-Linear Consequent Terms, Robert Sutton, Paul J. Craven

Journal of Marine Science and Technology–Taiwan

This paper describes the development of a fuzzy autopilot for controlling the non-linear yaw dynamics of an autonomous underwater vehicle (AUV) model. The autopilot design is based on a new approach that uses a Gaussian fuzzy inference mechanism. For the design study, the AUV model is hosted in the MATLAB/Simulink environment. Simulation results are presented which illustrate the potential of this novel methodology.

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Natural Doundary Element Method For Elliptic Boundary Value Problems In Domains With Concave Angle, Qi-Kui Du, De-Hao Yu Dec 2001

Natural Doundary Element Method For Elliptic Boundary Value Problems In Domains With Concave Angle, Qi-Kui Du, De-Hao Yu

Journal of Marine Science and Technology–Taiwan

In this paper the natural boundary reduction for some elliptic boundary value problems with concave angle domains and its natural boundary element methods are investigated. Natural integral equations and Poisson integral formulae are given. A finite element methods of natural integral equations are discussed in details. The convergence of approximate solutions and their error estimates are obtained. Some numerical experiments are presented to demonstrate the performance of the method and our estimates. As an application, we present the coupling of FEM and natural boundary element.

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Application And Robust H??Control Of Pdc Fuzzy Controller For Nonlinear Systems With External Disturbance, Wei-Ling Chiang, Treng-Wu Chen, Ming-Yi Liu, Chun-Jung Hsu Dec 2001

Application And Robust H??Control Of Pdc Fuzzy Controller For Nonlinear Systems With External Disturbance, Wei-Ling Chiang, Treng-Wu Chen, Ming-Yi Liu, Chun-Jung Hsu

Journal of Marine Science and Technology–Taiwan

In terms of Lyapunov's direct method, a stability criterion is derived to guarantee the stability of the system especially for the resonant and chaotic systems. The common P matrix of the criterion is obtained by using linear matrix inequality (LMI) optimization algorithms to solve the robust fuzzy control problem. Based on the control scheme and this criterion, a fuzzy controller is then designed via the technique of parallel distributed compensation (PDC) to stabilize the nonlinear system. Finally, the proposed controller design method is demonstrated through numerical simulations on the chaotic and resonant systems.

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On A Computational Algorithm To The Hje In Nnlinear H∞ Control, Shr-Shiung Hu, Pao-Hwa Yang, Jeng-Yih Juang Dec 2001

On A Computational Algorithm To The Hje In Nnlinear H∞ Control, Shr-Shiung Hu, Pao-Hwa Yang, Jeng-Yih Juang

Journal of Marine Science and Technology–Taiwan

The Hamilton-Jacobi equation (HJE) plays an essential role in both classical mechanics and nonlinear H∞ control theory. In this paper, we propose a detailed successive algorithm for finding an approximate solution of the HJE by solving linear equations. A scalar example is given to compare the computational procedures and the accuracy for the proposed approach with some other methods. In addition, the nonlinear H∞ controller design for the inverted pendulum is also included to show the superiority of the nonlinear H∞ controller, as compared with the linear H∞ controller, in the aspect of the robust performance/stability.

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A Sensitivity Function Approach To The Design Of Rudder Roll Stabilization Controller, Ching-Yaw Tzeng, Chung-Yi Wu, Yu-Lung Chu Dec 2001

A Sensitivity Function Approach To The Design Of Rudder Roll Stabilization Controller, Ching-Yaw Tzeng, Chung-Yi Wu, Yu-Lung Chu

Journal of Marine Science and Technology–Taiwan

This paper is concerned with the design of a rudder roll stabilization (RRS) system by the internal model control (IMC) method. The proposed method directly shapes the output sensitivity function which relates the wave disturbance to the ship roll motion, to achieve good disturbance rejection. Under the IMC structure, the sensitivity functions depend linearly on a design transfer function and this makes it easy to satisfy the internal stability condition. A reference conditioning technique is employed in the design that takes the limited actuator authority into the controller design consideration to avoid unknowingly pushing the actuator beyond its saturation and …

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On The Modified Tikhonov's Regularization Method For The Cauchy Problem Of The Laplace Equation, Jiang-Ren Chang, Weichung Yeih, Min-Harng Shieh Dec 2001

On The Modified Tikhonov's Regularization Method For The Cauchy Problem Of The Laplace Equation, Jiang-Ren Chang, Weichung Yeih, Min-Harng Shieh

Journal of Marine Science and Technology–Taiwan

In this paper, an inverse problem of the Laplace equation with Cauchy data is examined. Due to the ill-posed behavior of this inverse problem, the Tikhonov's regularization technique is employed and the L-curve concept is adopted to determine the optimal regularization parameter. Also, the singular value decomposition method is used in conjunction with the L-curve concept for the same problem. Numerical results show that neither the traditional Tikhonov's regularization method nor the singular value decomposition method can yield acceptable results when the influence matrix is highly ill-posed. A modified regularization method, which combines the singular value decomposition method and regularization …

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Coulomb Friction Applied To Analyze The Cutting Vibration Of Tool On Workpiece, Chein-Shan Liu Dec 2001

Coulomb Friction Applied To Analyze The Cutting Vibration Of Tool On Workpiece, Chein-Shan Liu

Journal of Marine Science and Technology–Taiwan

In this paper we study a single-degree-of-freedom model with the parallel presence of a linear spring and a Coulomb's contact friction device, the mass slider of which is mounted on the belt which running forward at a constant speed. We prove that no matter what the parameters are, the mass upon starting to slide never comes to stick on the belt. The oscillating amplitude of the slider is proportional to the belt running speed υ, and is inverse proportional to the natural frequency ω. In order to depress the vibration amplitude we may either decrease the belt running speed, increase …

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Faraday Resonance For Stratified Two-Layer Flow, Wu-Ting Tsai Dec 2001

Faraday Resonance For Stratified Two-Layer Flow, Wu-Ting Tsai

Journal of Marine Science and Technology–Taiwan

The analysis developed in Tsai [1] is extended to consider the parametrically resonant motion of a stratified two-layer fluid in a twodimensional rectangular basin forced to oscillate vertically. The modulation equation governing the slowly-varying amplitude of the interface is derived using method of multiple scales. For steady harmonic response, the present result compares well with available experimental measurements for the low frequency region. The discrepancy increases, however, for high-frequency response.

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The Effects Of Particle Shape On Bond Strength Improvement Of Epoxy-Particle Coating Composites, Jiang-Jhy Chang, Wei-Chung Yeih Dec 2001

The Effects Of Particle Shape On Bond Strength Improvement Of Epoxy-Particle Coating Composites, Jiang-Jhy Chang, Wei-Chung Yeih

Journal of Marine Science and Technology–Taiwan

In this paper the effect of particle shape on the bond improvement of epoxy-particle coating composite is evaluated. In our previous studies, it has been shown that adding foreign particles in the epoxy may enhance the bond characteristics of coating. It has been found that the enhancement of bond for coating by adding foreign particles in epoxy may come from two reasons: one comes from the mechanical improvement by foreign particles and the other comes from the chemical reaction of foreign particles which yields a better binding material. In our previous study, the size of foreign particle influenced the degree …

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Applying Time-Frequency Distribution Function To Doa Of Mobile Active Sensor, Shun-Hsyung Chang, Jun-Cheng Liu, Chih-Wei Chiu Dec 2001

Applying Time-Frequency Distribution Function To Doa Of Mobile Active Sensor, Shun-Hsyung Chang, Jun-Cheng Liu, Chih-Wei Chiu

Journal of Marine Science and Technology–Taiwan

Increasing the accuracy of time-frequency detection in engineering is always the goal that scientists are striving to achieve, because it is widely applied in the fields of Radar, Sonar, the exploration of earthquake epicenter etc. The current high-resolution time-frequency methods are mostly based on the structure of time-frequency distribution function of Cohen Family. Time frequency distribution function can trace the instantaneous frequency of nonstationary signal. This paper combines the process principle of multi-aperture Radar and Array signal and applies time-frequency distribution function in DOA of active sensor devices. By decoding of physical characteristics from the changes of frequency, which can …

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Roll Motion Of A Roro-Ship In Irregular Following Waves, Jianbo Hua, Wei-Hui Wang Jun 2001

Roll Motion Of A Roro-Ship In Irregular Following Waves, Jianbo Hua, Wei-Hui Wang

Journal of Marine Science and Technology–Taiwan

A RoRo-ship usually has a fine hull form with large flare at bow and stern. In order to achieve large cargo space, large ratio of the beam to draught are quite common for this kind ship. Such a hull configuration can be subjected to considerable variation of the metacentre height as she sailing in waves. As a consequence the parametric excitation becomes considerably great so that a large roll motion appears. This is a strongly nonlinear problem. A simplified model is formulated in this paper to take account for the parametrically excited roll motion of a RoRo-ship in irregular following …

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Dual Boundary Integral Equations For Helmholtz Equation At A Corner Using Contour Approach Around Singularity, I-Lin Chen, Ming-Te Liang, Shyh-Rong Kuo, Jeng-Tzong Chen Jun 2001

Dual Boundary Integral Equations For Helmholtz Equation At A Corner Using Contour Approach Around Singularity, I-Lin Chen, Ming-Te Liang, Shyh-Rong Kuo, Jeng-Tzong Chen

Journal of Marine Science and Technology–Taiwan

A dual integral formulation for the Helmholtz equation problem at a corner is derived by means of the contour approach around the singularity. It is discovered that employing the contour approach the jump term comes half and half from the free terms in the L and M kernel integrations, respectively, which differs from the limiting process from an interior point to a boundary point where the jump term is descended from the L kernel only. Thus, the definition of the Hadamard principal value for hypersingular integration at the collocation point of a corner is extended to a generalized sense for …

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