Application of Feature Curves and Shape Blending on Yacht Designing

The global yacht market share and industry might expand continually since increasing people are willing to enjoy the yacht life in lower price nowadays while yacht activities were regards as a luxury acitivity in the past.Additionally,Taiwan Residents yacht manufacturers are well-known worldwide.They show excellent performances on the international annual rankings which implies Taiwan has excellent manufacturing technologies.However,Taiwan Residents manufacturers so far do not have a mature local design team.Therefore,this study goals to developing a systematic and objective design method for hull designing,which facilitates designers to design innovative yachts or create a series product with brand recognition.This study is divided into three parts:the first part is the investigation of the yachts market;the second is establishing a shape blending platform;the third is 3D forming.Finally,it is used the existing ship CAD software to design an innovative yacht based on the blended curves and then calculates its basic hydrostatic performance.This study provides a quantitative method to create a new form and to preserve the features for a brand.The exist yacht combines with other graphics to create a new form and maximizes the features of the original graphics.

Application of Active Contour Model in Tracking Sequential Nearshore Waves

In the present study, a generalized active contour model of gradient vector flow is combined with the video techniques of Argus system to delineate and track sequential nearshore wave crest profiles in the shoaling process, up to their breaking on the shoreline. Previous applications of active contour models to water wave problems are limited to controllable wave tank experiments. By contrast, our application in this study is in a nearshore field environment where oblique images obtained under natural and varying condition of ambient light are employed. Existing Argus techniques produce plane image data or time series data from a selected small subset of discrete pixels. By contrast, the active contour model produces line image data along continuous visible curves such as wave crest profiles. The combination of these two existing techniques, the active contour model and Argus methodologies, facilitates the estimates of the direction wave field and phase speeds within the whole area covered by camera. These estimates are useful for the purpose of inverse calculation of the water depth. Applications of the present techniques to Hsi-tzu bay where a beach restoration program is currently undertaken are illustrated. This extension of Argus video techniques provides new application of optical remote sensing to study the hydrodynamics and morphology of a nearshore environment.

Portable Dynamic Positioning Control System on A Barge in Short-Crested Waves Using the Neural Network Algorithm

This paper develops a nonlinear mathematical model to simulate the dynamic motion behavior of the barge equipped with the portable outboard Dynamic Positioning （DP） system in short-crested waves. The self-tuning Proportional- Derivative （PD） controller based on the neural network algorithm is applied to control the thrusters for optimal adjustment of the barge position in waves. In addition to the wave, the current, the wind and the nonlinear drift force are also considered in the calculations. The time domain simulations for the six-degree-of-freedom motions of the barge with the DP system are solved by the 4th order Runge-Kutta method which can compromise the efficiency and the accuracy of the simulations. The technique of the portable alternative DP system developed here can serve as a practical tool to assist those ships without being equipped with the DP facility while the dynamic positioning missions are needed.