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This thesis investigates the effects of the earth's rotation on internal waves from two perspectives of nonlinear internal wave theory: near-resonant triads and weakly nonlinear models. We apply perturbation theory (multiple scale analysis) to the governing equations of internal waves and develop a near-resonant internal wave triad theory. This theory explains a resonant-like phenomenon in the numerical results obtained from simulating internal waves generated by tide topography interaction. Furthermore, we find that the inclusion of the earth's rotation (nonzero $f$) in the numerical runs leads to a very special type of resonance: parametric subharmonic instability. Through using perturbation expansion to solve separable solutions to the governing equations of internal waves, we derive a new rotation modified KdV equation (RMKdV). Of particular interest, the dispersion relation of the new equation obeys the exact dispersion relation for internal waves for both small and moderate wavenumbers ($k$). Thus this new RMKdV is able to model wea kly nonlinear internal waves with various wavenumbers ($k$), better than the Ostrovsky equation which fails at describing waves of small $k$.

This thesis investigates the effects of the earth's rotation on internal waves from two perspectives of nonlinear internal wave theory: near-resonant triads and weakly nonlinear models. We apply perturbation theory (multiple scale analysis) to the governing equations of internal waves and develop a near-resonant internal wave triad theory. This theory explains a resonant-like phenomenon in the numerical results obtained from simulating internal waves generated by tide topography interaction. Furthermore, we find that the inclusion of the earth's rotation (nonzero $f$) in the numerical runs leads to a very special type of resonance: parametric subharmonic instability. Through using perturbation expansion to solve separable solutions to the governing equations of internal waves, we derive a new rotation modified KdV equation (RMKdV). Of particular interest, the dispersion relation of the new equation obeys the exact dispersion relation for internal waves for both small and moderate wavenumbers ($k$). Thus this new RMKdV is able to model wea kly nonlinear internal waves with various wavenumbers ($k$), better than the Ostrovsky equation which fails at describing waves of small $k$.

Along with rapid development of information technology, all kinds of algorithms have been presented, to achieve significant progress in image tracking. Most methods tend to identify features of moving objects, and filter out background components which do not meet these features. This thesis uses a spatio-temporal planar-resonant filter to accomplish moving object tracking tasks. Under the condition without prior knowledge about features of moving objects, choosing appropriate filter¡¦s parameters is able to enhance the object with a certain moving speed and reduce intensity of objects with different velocities. Nevertheless, this filter cannot solve the problem background filtering. Therefore, a homomorphic filtering with fast optical flow estimation is implemented to identify and separate the background and moving components in dynamic images. This thesis also considers different 3-D bandwidth parameters. To develop a systematic approach to design filter¡¦s parameters for actual implementations.

For applications of wireless communication of the fourth generation (4G LTE), the technique of using a printed parallel-resonant spiral strip for bandwidth enhancement of a small-size planar laptop computer (especially the thin Ultrabook) antenna for the LTE operation is first presented. The antenna is printed on a thin FR4 substrate of small size 45 x 9 mm2 with a simple uniplanar structure which is promising for Ultrabook application. Based on the proposed antenna structure, its application for MIMO operation to achieve enhanced isolation is also analyzed in this thesis. Different from the works for the relatively much smaller ground plane conditions such as in the mobile phones, the effect of different size of the supporting conductive plate of the upper corner of the Ultrabook is discussed for the isolation issue of the MIMO antennas. Finally, the technique of isolation improvement in the LTE700 band for the MIMO operation in the Ultrabook is presented.

In the study, conductive distributed Bragg reflectors (DBRs) fabricated at room temperature based on porous indium tin oxide (ITO) on dense ITO bilayers were proposed for resonant cavity organic light emitting diodes (RCOLEDs). In the fabrication of the ITO DBRs, the low refractive index porous ITO films were obtained by applying supercritical CO2 treatment at different temperature and pressures on the spin-coated sol-gel ITO films. On the other hand, the high refractive index ITO films were grown at room temperature by long-throw reactive ratio-frequency magnetron sputtering. The refractive index of the porous ITO film and ITO films were 1.54 and 2.0, respectively. For the DBR with 4 pairs ITO bilayers, the optical reflectance of more than 70 % was achieved. The stop band and the average resistivity is 140 nm and 2.2¡Ñ10-3 £[-cm, respectively. Finally, electrical and optical characteristics of the RCOLEDs fabricated on the ITO DBR were investigated and compared with those of the conventional OLEDs. The maximum luminous efficiency of 3.79 cd/A was obtained at 347 mA/cm2 for the RCOLED. This luminous efficiency was 26 % higher than that of the conventional OLED.

High efficient optical spot size converter (SSC) is one of the most important building blocks for dense optical interconnection network and high-speed optical fiber communications due to efficient optical power transfer between different optical modules. Using tapered optical direction coupler (TODC) as SSC can reduce the dimension with high efficiency because of resonant condition and tapered structure. However, the strong dependence of operation on wavelength leads to narrow band operation, reducing the usage of wavelength division multiplexer (WDM) technique for upgrading optical data capacity through optical spectrum. In this work, based on multi- resonant points of TODC, a broadband SSC integrated with optical electroabsorption modulator (EAM) is proposed, designed, and fabricated. By tapering quantum well of the top active waveguide (AW), the integration with bottom passive waveguide (PW) can form a TODC. With the tapered structure, the gradually varied effective index forms a resonant point along wave propagation, inducing strong coupling, collecting optical power after resonant point, and thus leading to high efficient coupling. With multi-section of resonant conditions and also tapered structure, broadband operation can be realized. Through 3 section of tapered AW of TODC, the calculated coupling efficiency from bottom PW with larger than 70% is found for the regime of 1530nm~1550nm wavelength. The EAM-integrated SSC is also fabricated. With counter direction of optical coupling, the measured photocurrent in EAM shows a broadband of flap coupling from 1570nm~1585nm is observed, suggesting the multi-section TODC can bring out broadband operation.

Fluorescent lamps are in general driven by ac ballasting currents. The cyclic variation in arc discharging power results in light fluctuation at twice the frequency of the ac current. Light fluctuation may be intolerable when a steady light output is required in some particular applications. To eliminate light fluctuation, an electronic ballast with dc current is proposed to operate the fluorescent lamp at a constant power. The main power conversion of the electronic ballast employs the single-stage high-power-factor inverter, which is originated from a combination of the half-bridge resonant inverter and the buck-boost converter. With such a circuit configuration, the output power can be regulated by asymmetrical pulse-width-modulation. The ac output of the inverter is then rectified and filtered to provide the dc ballasting current. Driven by dc current, however, the fluorescent lamp emits electrons unilaterally from one end leading to wearing out of emission material on the cathode filament. To solve this problem, an inverter is integrated for commutation of the lamp electrodes. Furthermore, a preheating control is included to start the fluorescent lamps with zero glow-current. A prototype is designed and built for the OSRAM T5-80W fluorescent lamp. The dc operating characteristics of starting transient, light fluctuation, lighting spectra, color temperature as well as the light fluctuation are investigated from experiments. Experimental results also show that the electronic ballast is capable of high-power-factor, dimming capability and zero glow-current preheating.

A flash lighting circuit with the fluorescent lamp is designed to produce lighting flicker by means of controlling the operating frequency and the duty-ratio of the lamp voltage and current. The intensity of the flash lighting is adjusted by the DC-link voltage of the electronic ballast circuit. The circuit structure is mainly composed of the class-D series-resonant inverter, the full-bridge rectifier, the LC filter and the commutation circuit. A control circuit with complex programmable logic device (CPLD) is used to accomplish the regulation of the operating frequency and the duty-ratio, which should be carefully controlled to ensure a stable lighting arc. In the meantime, a flash lighting detected circuit is designed to transform the flash lighting into a voltage signal. Experiment tests are conducted to human visual perception to demonstrate the applicability of the flash lighting circuit.

This thesis presents the design and implementation of a millimeter-wave Gunn diode oscillator operating at 35 GHz (Ka (R) 26.5-40 GHz Band). The aim of the study is to produce a high frequency, high power signal from a negative resistance device situated in a waveguide cavity by applying a direct current bias. First the physics of Gunn diodes is studied and the requirements that Gunn diode operates within the negative differential resistance region is obtained. Then the best design configuration is selected. The design of the oscillator includes the design of the waveguide housing, diode mounting and the bias insertion network. Some simulation tools are used to predict, approximately, the behaviour of the oscillator and the bias coupling circuit. For tuning purposes, a sliding backshort and a triplescrew- tuner system is used. For different bias values and different positions of the tuning elements oscillations are observed. A much more stable and higher magnitude oscillations were obtained with the inclusion of &ldquo / resonant disc&rdquo / placed on top of the diode. 15 dBm power was measured at a frequency of 28 GHz. Laboratory measurements have been carried out to determine the oscillator frequency, power output and stability for different bias conditions.