Symbolic dynamics and synchronization of coupled map networks with multiple delays

We use symbolic dynamics to study discrete-time dynamical systems with multiple time delays. We exploit the concept of avoiding sets, which arise from specific non-generating partitions of the phase space and restrict the occurrence of certain symbol sequences related to the characteristics of the dynamics. In particular, we show that the resulting forbidden sequences are closely related to the time delays in the system. We present two applications to coupled map lattices, namely (1) detecting synchronization and (2) determining unknown values of the transmission delays in networks with possibly directed and weighted connections and measurement noise. The method is applicable to multi-dimensional as well as set-valued maps, and to networks with time-varying delays and connection structure.Comment: 13 pages, 4 figure

Expanding the ROK Navy : implications for the U.S.-ROK alliance

Stability on the Korean peninsula is a goal for several countries. The Republic of Korea (ROK) has depended on the United States to maintain stability on the Korean peninsula, but realizes its greater independence from a long time ally may be inevitable, especially after reunification. Measures now required afford the ROK every opportunity to provide for its own security and stability, including the need for modernizing the ROK Navy (ROKN). Present and future South Korean naval commitments to regional and international maritime environments support the transition from a brown water navy to a blue water navy capable of meeting future challenges. The ROK intends to achieve a naval force capable of projecting power, carrying out its strategic objectives, and ultimately guaranteeing vital defense for ROK sea lanes of communications. South Korea borders on the East Sea and the West Sea, dictating the need for a maritime force, to protect the lifeblood of the South Korean economy. Currently, the ROKN cannot compete against large modern navies, capable of conducting sustained naval operations while concurrently maintaining various platforms assigned numerous tasks. The ROKN's opportunity is ripe to expand its existing force into a modern blue water navy.http://archive.org/details/expandingroknavy109451242US Navy (USN) autho

Complete and flexible replacement of chaotic uncertainty with transmitted information

Natural chaos can be described as an information source emitting symbolic sequences with positive entropy. We use two algorithmic techniques from data compression in a nonstandard way along with a control scheme to replace the natural uncertainty in chaotic systems with an arbitrary digital message. Unlike previous targeting-based control, the controlled, deterministic, transmission appears statistically identical to natural chaos, with a message modulated on it at the intrinsic Kolmogorov-Sinai information generation rate of the chaotic oscillator. Thus, chaotic communication by targeting need not consume any additional channel capacity beyond that required by the message itself and the message-bearing signal may appear identical to the uncontrolled oscillator. We also demonstrate control and data transmission at the channel capacity of the oscillator, the maximum possible data rate compatible with the grammar

Quantum-classical Correspondence in Intense Laser Field-atom Interactions

High-field ionization suppression in a classical Kepler ensemble is discussed in terms of optimization with respect to pulse turn-on rate as well as pre-pulse preparation. It is argued that high-field ionization suppression is best understood in terms of reduced probability of ionization for pulsed fields, whereas for a quasi-steady field, high-field ionization suppression implies a reduced ionization rate at higher intensities. The classical ensemble is used to calculate the high-field ionization rate of a one-dimensional atomic model using a Gaussian short-range potential and the results are compared with high-frequency Floquet theory results recently reported by other authors. Better than qualitative agreement is found and the results are compared and discussed in terms of quantum superposition and classical interference. Finally, high-field ionization suppression is discussed in relation to statistical relative stability of classical orbits of the ensemble, and classical interference for both short- and long-range potentials. Correspondence with quantum superposition is interpreted in relation to quantum-classical correspondence