Evaluation of Scale-Invariance In Physiological Signals By Means Of Balanced Estimation Of Diffusion Entropy

By means of the concept of balanced estimation of diffusion entropy we evaluate reliable scale-invariance embedded in different sleep stages and stride records. Segments corresponding to Wake, light sleep, REM, and deep sleep stages are extracted from long-term EEG signals. For each stage the scaling value distributes in a considerable wide range, which tell us that the scaling behavior is subject- and sleep cycle- dependent. The average of the scaling exponent values for wake segments is almost the same with that for REM segments ($\sim 0.8$). Wake and REM stages have significant high value of average scaling exponent, compared with that for light sleep stages ($\sim 0.7$). For the stride series, the original diffusion entropy (DE) and balanced estimation of diffusion entropy (BEDE) give almost the same results for de-trended series. Evolutions of local scaling invariance show that the physiological states change abruptly, though in the experiments great efforts have been done to keep conditions unchanged. Global behaviors of a single physiological signal may lose rich information on physiological states. Methodologically, BEDE can evaluate with considerable precision scale-invariance in very short time series ($\sim 10^2$), while the original DE method sometimes may underestimate scale-invariance exponents or even fail in detecting scale-invariant behavior. The BEDE method is sensitive to trends in time series. Existence of trend may leads to a unreasonable high value of scaling exponent, and consequent mistake conclusions.Comment: 7 pages, 8 figure

Dirac Cosmology and the Acceleration of the Contemporary Universe

A model is suggested to unify the Einstein GR and Dirac Cosmology. There is one adjusted parameter $b_2$ in our model. After adjusting the parameter $b_2$ in the model by using the supernova data, we have calculated the gravitational constant $\bar G$ and the physical quantities of $a(t)$, $q(t)$ and $\rho_r(t)/ \rho_b(t)$ by using the present day quantities as the initial conditions and found that the equation of state parameter $w_{\theta}$ equals to -0.83, the ratio of the density of the addition creation $\Omega_{\Lambda}=0.8$ and the ratio of the density of the matter including multiplication creation, radiation and normal matter $\Omega_m =0.2$ at present. The results are self-consistent and in good agreement with present knowledge in cosmology. These results suggest that the addition creation and multiplication creation in Dirac cosmology play the role of the dark energy and dark matter.Comment: 13 pages, 8 figure

A low power supply and high frequency driver design for DC-DC converter applications

This paper presents an improved driver circuit design for boost DC-DC converter applications. The circuit possesses the characteristics of low power supply and high speed and is, thus, suitable for portable equipment and mobile applications. The simulation results demonstrate that the design has achieved a low power voltage of 1.0V, which is ideal for single battery applications. The operational frequency of the circuit can be as high as 1 MHz, which meets the increasing demand for high switch speed. Using Samsung Bipolar Process, this design has been prototyped, and the testing on chips confirms that the prototypes fully meet design specifications and are ready for commercial products applications

Internal and near-surface electromagnetic fields for a chiral cylinder with arbitrary monochromatic illumination

A semi-analytical solution is proposed to the electromagnetic scattering by an infinite chiral circular cylinder with arbitrary monochromatic illumination. The scattered and internal fields are expanded in terms of appropriate cylindrical vector wave functions, and their expansion coefficients are determined by virtue of the boundary conditions and the projection method. As a demonstration of the theoretical procedure, the normalized internal and near-surface field intensity distributions are evaluated for a fundamental Gaussian beam, and the scattering properties are discussed briefly for different chirality parametersKeywords: Scattering; Chiral circular cylinder; Arbitrary monochromatic illumination; Normalized field intensity distribution<br/