The oxygen diffusion in Y B a X u j O ^ , , was studied between 300 K and 1273 K in flowing oxygen by monitoring the 1 3 Ba(EC) Cs nuclear quadrupole interaction by time differential perturbed angular correlation. The data are analyzed in a model of two different nearest neighbour oxygen configurations and yield hopping rates, the energy barrier and the difference in free enthalpy between both ...

Increasing the energy autonomy of a hopping one-legged robot is studied in this paper. For a particular passive gait, of all those possible, the energy dissipated per unit length of travel is shown to be less than for any other gait. This optimal gait is identified analytically, by exploiting the commonly used SLIP model to simplify real robot dynamics. Both mechanical and electrical losses are...

In this paper, we present a novel audio watermarking scheme that uses attack characterization to obtain high robustness against standard watermark attacks. The watermark embedding and detection are based on the frequency hopping method in the spectral domain. Perceptual transparency of the algorithm, achieved using frequency masking property of the human auditory system, was con5rmed throughout...

G. L. Celardo, 2 R. Kaiser, and F. Borgonovi Dipartimento di Matematica e Fisica and Interdisciplinary Laboratories for Advanced Materials Physics, Università Cattolica, via Musei 41, 25121 Brescia, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, via Bassi 6, I-27100, Pavia, Italy Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon, Korea Univ...

Laughter in speech has been studied mostly relying upon the spectral representation like formants and harmonics derived from the short-time spectrum. Significant changes appear to take place in the characteristics of glottal source of excitation during the production of laughter, but these changes have not been explored much. In this study, we examine the changes in the glottal vibration charac...

In this paper we introduce the PCPH (Pseudo-Chaotic Phase Hopping) telecommunication scheme, which is obtained by combining pseudo-chaotic encoding with N -ary phase shift keying. For this system, we address the problem of finding the optimal constellation labeling in order to minimize the error probability.

We devised a new noise filtering method to reduce the noise in the line spread function (LSF) for presampled modulation transfer function (MTF) analysis with the edge method. A filter was designed to reduce noise effectively using a position-dependent filter controlled by the boundary frequency b for low-pass filtering, which is calculated by 1/2d (d: distance from the LSF center). In this filt...

Research in the design of ultra-wideband (UWB) radio systems suggests di erent kinds of signal design criteria. After an introduction to UWB radio, a variety of sequence design problems, motivated by UWB system constraints, will be presented. Design for time-hopping, for spectral atness, for rapid acquisition, and for multiple access will be discussed, and some sample designs will be presented.

AbsuactFrequency-Hopping (FH) techniques in conjunction with coding have been proposed for indoor radio systems based on the fact that FH behaves as an intrinsic frequency diversity technique. In this paper we assess the performance of a FH-BPSK for other situations not previously considered in the literature. In particular, the effects of having a non-null correlation coeffiiient in function o...

This paper presents a subspace method for bland channel est imation based on a special output correlation matrix. T h e approach relies on the i.i.d. assumption of the data sequence and uses the cyclic prefix redundancy present in OFDM systems or single-carrier systems with frequency domain equalization. This method has an important feature that allows channels to be longer than the cyclic pref...