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Full-Text Articles in Engineering
Added Mass Computation For Control Of An Open-Frame Remotely-Operated Vehicle: Application Using Wamit And Matlab, You-Hong Eng, Cheng-Siong Chin, Michael Wai-Shing Lau
Added Mass Computation For Control Of An Open-Frame Remotely-Operated Vehicle: Application Using Wamit And Matlab, You-Hong Eng, Cheng-Siong Chin, Michael Wai-Shing Lau
Journal of Marine Science and Technology
In this paper, numerical modeling and testing of a complexshaped remotely-operated vehicle (ROV) are shown. The paper emphasizes on systematic modeling of hydrodynamic added mass using computational fluid dynamic software WAMITTM on the open frame ROV that is not commonly applied in practice. From initial design and prototype testing, a small-scale test using a free-decaying experiment is used to verify the theoretical models obtained from WAMITTM. Simulation results have shown to coincide with the experimental tests. The proposed method is able to determine the hydrodynamic added mass coefficients of the open frame ROV.
A Synchronous Primary-Side Dimming Controller For Cold-Cathode Fluorescent Lamp Ballast, Jenn-Jong Shieh
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 …