The chaotic dynamic characteristic in Bose-Einstein Condensate (BEC) system of a 1D tilted optical superlattice potential
with attractive interaction is investigated in this paper. The spatial evolution of chaos was shown numerically by resolving
Gross-Pitaevskii (G-P) equation for the system with the fourth Runge-Kutta(RK) algorithm. Numerical analysis reveals
that as the tilt or the amplitude of the optical superlattice potential is increased the chaos in the BEC system increases. These
elements make the chaotic system more unstable and the phase-space orbit becomes more chaotic. The chaotic system
can be effectively controlled to a stable periodic orbit through adjusting the amplitude of the optical superlattice potential
and initial condition. Controlling chaos can also be realized by spatial constant bias in the BEC system of a 1D tilted optical
superlattice potential with attractive interaction. Phase orbits are suppressed gradually then the chaotic states of the BEC
system are converted into period one through quais-period.
We study the evolutions of spatiotemporal chaos for the photorefractive ring oscillator. As the system parameters are
changed, we obtain different patterns such as the frozen random state, the pattern selection state, the defect chaotic
diffusion state and fully developed turbulence state in the one- dimensional map lattice system. We can observe
symmetry breaking from four corners and the boundaries and finally lead to spatiotemporal chaos in the two-dimensional
map lattices system. Then we demonstrate that the global and local constant bias can suppress spatiotemporal chaos in
photorefractive ring oscillator by varying the bias strength. Only if we choose suitable bias strength, spatiotemporal
chaos in photorefractive ring oscillator system can be controlled into stable periodic states.
Proc. SPIE. 5637, Electronic Imaging and Multimedia Technology IV
KEYWORDS: Data hiding, Raster graphics, Digital imaging, Information technology, Human vision and color perception, Computer programming, Digital image processing, Multimedia, Image processing, Eye models
Information hiding is a new technology which integrates with theories and technologies of many academic and technical subjects. For information hiding, digital media are used as the carrier of the information to be hidden. The carrier conceals secret messages by covering the form of their existence. In this paper, we briefly introduce the definition, basic models and basic characters of information hiding. The application and research trends for information hiding system are concerned. The information hiding technology based on digital image processing is closely related to human vision system. When the messages are having been concealed, the human eyes are due to verify the existence of hiding messages. That is, the status of information coverage depends on the human vision system. It is obvious that the characteristics of human vision system is to be taken advantage. The added secrete information in the digital image should have no any effect onto human eyes. In our research work, an implementation of information hiding technology system which is based on digital image encoding is proposed. First by analyzing knowledge of digital image processing and the model of human vision system, we discussed the algorithm of time domain appending method and the algorithm of substitution of lease significant bit. Secondly, we analyzed theory and algorithms of 2-D discrete wavelet transform and frequency domain algorithm based on discrete wavelet transformation. Carefully design software for information hiding based on digital image using Microsoft Visual C++6.0 is implemented. The communication with hiding messages may use any format of images such as BMP. It is proved to be an effective application.