Browsing by Author "Chien, CC"

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A study of bispectra in relation to the adequacy of wave spectral model
(1997-01-01)
Kuo, YY
;
Chien, CC
;
Yim, JY
;
土木工程學系
;
Department of Civil Engineering
In this paper, the characteristics of laboratory wind waves under various wind speeds and water depths are studied. It is found that either the real or the imaginary part of the bispectrum can be related to the asymmetry of the wave profile, and the bicoherence is related to the ratio of nonlinear to linear wave component. Occasionally, these two categories of nonlinear index lead to opposite inferences, because each of them has its own significance and functions. The applicability of linear wave spectral model in ocean waves becomes questionable only when strong nonlinearity is indicated by both of these two indexes, The linear spectral representation of wave fields does not necessarily become inadequate as water depth decreases, and its appropriateness can be examined through the characteristics of the bispectrum.
A study of bispectra in relation to the adequacy of wave spectral model
(1997-01-01)
Kuo, YY
;
Chien, CC
;
Yim, JY
;
土木工程學系
;
Department of Civil Engineering
In this paper, the characteristics of laboratory wind waves under various wind speeds and water depths are studied. It is found that either the real or the imaginary part of the bispectrum can be related to the asymmetry of the wave profile, and the bicoherence is related to the ratio of nonlinear to linear wave component. Occasionally, these two categories of nonlinear index lead to opposite inferences, because each of them has its own significance and functions. The applicability of linear wave spectral model in ocean waves becomes questionable only when strong nonlinearity is indicated by both of these two indexes, The linear spectral representation of wave fields does not necessarily become inadequate as water depth decreases, and its appropriateness can be examined through the characteristics of the bispectrum.
Frequency control in a low voltage, wide tuning VCO design at 2.4 GHz
(2001-07-01)
Kao, YH
;
Chien, CC
;
傳播研究所
;
Institute of Communication Studies
A low voltage and wide tuning rang voltage controlled oscillator (VCO)( at 2.4 GHz is developed for ISM applications. A design procedure wit the parasitics of packaged devices considered is offered A VCO with a 200 MHz tuning range for les than 2 V using a packaged varactor is demonstrated.
Visual tracking of a moving person for a home robot
(2005-06-01)
Song, KT
;
Chien, CC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a visual tracking system for a home robot to pursue a person. The system works by detecting a human face and tracking a person via controlling a two-degree-of-freedom robot head and the robot body. An image processing system has been developed to extract facial features using a complementary metal-oxide semiconductor (CMOS) web camera. An algorithm is proposed to recognize a human face by using skin colour and elliptical edge information of a human face. A digital signal processing (DSP)-based motor control card is designed and implemented for robot motion control. The visual tracking control system has been integrated on a self-constructed prototype home robot. Experimental results show that the robot tracks a person in real-time.