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For their good randomness and long iteration periods, chaotic maps have been widely used in cryptography. Recently, we have revealed the correlation between Lyapunov exponent and sequence randomness of multidimensional chaotic maps based on modular operation. Since the modular operation can realize the boundedness of chaotic state points, it is important to further reveal the deterministic correlation between Lyapunov exponent and modulus. First, we constructed an n -dimensional nondegenerate hyperchaotic map model with the desired Lyapunov exponents. Then, we gave the existence and uniqueness proof of quadrature rectangle decomposition theorem and revealed the correlation between Lyapunov exponent and modulus. The novelty lies in that (1) in order to realize the irreversibility of the iterative processes of chaotic maps, we constructed a chaotic map based on modular exponentiation, and its inverse function is the discrete logarithm problem; and (2) we reveal for the first time the correlation between Lyapunov exponent and modulus, and give the lower bound of the modulus of the nondegenerate chaotic map. In addition, to verify the effectiveness of the scheme, we constructed four-dimensional and five-dimensional chaotic maps, respectively, and analyzed their dynamical behaviors, and the results revealed that there exist linear or nonlinear correlation between Lyapunov exponent and modulus. [ABSTRACT FROM AUTHOR]

Polycrystalline Na 0. 9 Ba 0. 1 Nb 0. 9 ( Sn 0. 5 Ti 0. 5 ) 0. 1 O3 is prepared by the solid-state reaction technique. The formation of single-phase material was confirmed by an X-ray diffraction study and it was found to be a tetragonal phase at room temperature. Nyquist plots ( Z ′ ′ versus Z ′) show that the conductivity behavior is accurately represented by an equivalent circuit model which consists of a parallel combination of bulk resistance and constant phase elements (CPE). The frequency dependence of the conductivity is interpreted in terms of Jonscher's law. The conductivity σ d c follows the Arrhenius relation. The modulus plots can be characterized by the empirical Kohlrausch–Williams–Watts (KWW), φ (t) = exp(− (t / τ) β) function and the value of the stretched exponent (β) is found to be almost independent of temperature. The near value of activation energies obtained from the analyses of modulus and conductivity data confirms that the transport is through an ion hopping mechanism dominated by the motion of the ( O 2 −) ions in the structure of the investigated material. [ABSTRACT FROM AUTHOR]

A Reversible Data Hiding technique by using histogram shifting and modulus operator is proposed in which secret data is embedded into blocks of the cover image. These blocks are modified by using modulus operator to increase the number of peak points in the histogram of the cover image which further increases its embedding capacity. Secret data is embedded in the original cover blocks of the cover image by using peak points of the predicted blocks, which are generated by using modulus operator. Peak Signal to Noise Ratio and PSNR-Human Visual System are used to show the human visual acceptance of the proposed technique. Experimental results show that the embedding capacity is high as compared to the capacity of existing RDH techniques, while distortion in marked images is also less as compared to distortion produced by these existing techniques. [ABSTRACT FROM AUTHOR]

Frequency dividers are used in frequency synthesizers to generate specific frequencies or clock (CK) waveforms. As consequences of their operating principles, frequency dividers often produce output waveforms that exhibit duty cycles other than 50%. However, some circuits and systems, including dynamic memory systems and data converters, which accommodate frequency divider outputs, may need symmetric or 50%-duty-cycle clock waveforms to optimize timing margins or to obtain sufficient timing reliability. In this review paper, design principles and methods are studied to produce symmetric waveforms for the in-phase (I) and quadrature (Q) outputs of high-speed CMOS frequency dividers with design considerations from the logic gate level down to the transistor level in terms of speed, reliability, noise, and latency. A compact and robust multi-gigahertz frequency divider with moduli 12, 14, and 16 to provide I and Q outputs with 50% duty cycle is proposed and designed using a 90-nm digital CMOS process technology with 1.2-V supply. [ABSTRACT FROM AUTHOR]

The micro- and nano-indentation techniques and compression tests were employed to determine the mechanical properties of PZT based composites dispersed with Al2O3 nano-particles for comparison. Compared with the reduced modulus, the nano-hardness, which exhibited indentation size effect (ISE), seemed to be more sensitive to the indentation depth. The true hardness values were deduced, based on the modified proportional specimen resistance (PSR) model, from the depth sensing machine and micro-indenter. Both the micro- and nano-hardness of the nano-composites confirmed that the hardness was best improved by addition of 0.5wt% of Al2O3. [ABSTRACT FROM AUTHOR]