An LSI is fabricated and measured to demonstrate the feasibility of the VDD-hopping scheme in a system level. In the scheme, supply voltage, VDD, is dynamically controlled through software depending on workload. The VDD-hopping scheme is shown to reduce the power to less than 1/4 compared with the conventional fixed-VDD scheme. The power saving is achieved without degrading the real-time featur...

In the present work ferromagnetic ordering in the Hubbard model generalized by taking into account the inter-atomic exchange interaction and correlated hopping in partially filled narrow band is considered. Expressions for the magnetization and Curie temperature as functions of model parameters and band filling are obtained in the case of weak intra-atomic Coulomb interaction. Condition of ferr...

We calculated the density of states in a Hubbard mortel with nearest and next nearest neighbour hopping. Using an exact diagonalisation technique, we examined this mortel in a wide area of parameters. The density of states was calculated for dilferent fillings and for positive and negative interaction U. The additional hopping to the next nearest neighbour sites has dilferent elfects on the gap...

Wireless communication services may in the future be provided by a larger number of operators than provide the services today. A key enabling factor is the possibility to automatically share the radio spectrum. Bandwidth efficiency is defined as the number of users that can be supported by a basestation in a given spectrum. The bandwidth efficiency in a DS-CDMA and a frequency hopping system is...

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...