DIGITAL SIGNAL PROCESSING FOR RADIO MONITORING

A radio monitoring system based on a receiver, interfaces and FFT analyzer is described. The controller of the system evaluates spectra and the frequencies and levels of sinusoid signals (carriers) are accurately measured by interpolation of spectral values. The interpolation procedure and a new interpolation algorithm is described. The Cramer-Rao Lower Bound is also calculated for real- and complex-valued input data. Real-life measurement results are also presented

HIGH ACCURACY FREQUENCY DETERMINATION FROM DISCRETE SPECTRA

The problem of determining the characteristics of a sine wave from its discrete spectrum is considered. The nontriviality of the problem is caused basicly by a phenomenon called spectral leakage, that is, by the fact that the spectral envelope of a single sinusoid forms a bell-shaped curve, even in the ideal noiseless case. In the paper a simple and self-contained treatment of spectral leakage is presented and a computationally efficient frequency estimation method is derived, taking into consideration different types of time-domain windows

IMPROVEMENT OF THE USE-VALUE OF POLYESTER-BASED FABRICS

The tendency to staining and the ability for stain retentivity of polyester fabrics can be decreased by basic treatment and tenside modification. The inflammability and risk of accidence of these textiles can also be reduced. This characteristic is also reflected in the rate of burning

Candidates for multiple impact craters?: Popigai and Chicxulub as seen by the global high resolution gravitational field model EGM2008

In 2008 the new Earth Gravitational Model (EGM2008) was released. It contains a complete set of spherical harmonic coefficients of the Earth's gravitational potential (Stokes parameters) to degree 2190 and order 2159 and selected orders to degree 2190, that can be used for evaluation of various potential quantities with both the unprecedented accuracy and high spatial resolution. Two such quantities, the gravity anomaly and second-order radial derivative of the disturbing potential, were computed over selected areas with known impact craters. The displays of these derivatives for two such sites clearly show not only the strong circular-like features known to be associated with them but also other symmetrical structures which appear to make them multiple impact sites. At Popigai, Siberia, the series of circular features fall in a line from the "primary crater" in the southeast (SE) direction. At Chicxulub, Yucatán, there appears to be one more crater close to the "primary" in the northeast (NE) direction, as well as possibly others in the vicinity of the main crater (SW). Gravity information alone is not, however, proof of impact craters but it is useful in identifying <i>candidate sites</i> for further study, for examination by geologists and geophysicists. In the case of Chicxulub, a very recent single seismic profile suggests that a more likely explanation for the observed circular like gravity signal from EGM2008 NE of the "primary" is a pre-impact basin

Time scale and dimension analysis of a budding yeast cell cycle model

The progress through the eukaryotic cell division cycle is driven by an underlying molecular regulatory network. Cell cycle progression can be considered as a series of irreversible transitions from one steady state to another in the correct order. Although this view has been put forward some time ago, it has not been quantitatively proven yet. Bifurcation analysis of a model for the budding yeast cell cycle has identified only two different steady states (one for G1 and one for mitosis) using cell mass as a bifurcation parameter. By analyzing the same model, using different methods of dynamical systems theory, we provide evidence for transitions among several different steady states during the budding yeast cell cycle. By calculating the eigenvalues of the Jacobian of kinetic differential equations we have determined the stability of the cell cycle trajectories of the Chen model. Based on the sign of the real part of the eigenvalues, the cell cycle can be divided into excitation and relaxation periods. During an excitation period, the cell cycle control system leaves a formerly stable steady state and, accordingly, excitation periods can be associated with irreversible cell cycle transitions like START, entry into mitosis and exit from mitosis. During relaxation periods, the control system asymptotically approaches the new steady state. We also show that the dynamical dimension of the Chen’s model fluctuates by increasing during excitation periods followed by decrease during relaxation periods. In each relaxation period the dynamical dimension of the model drops to one, indicating a period where kinetic processes are in steady state and all concentration changes are driven by the increase of cytoplasmic growth.We apply two numerical methods, which have not been used to analyze biological control systems. These methods are more sensitive than the bifurcation analysis used before because they identify those transitions between steady states that are not controlled by a bifurcation parameter (e.g. cell mass). Therefore by applying these tools for a cell cycle control model, we provide a deeper understanding of the dynamical transitions in the underlying molecular network

Spin state transition and covalent bonding in LaCoO3

We use the dynamical mean-field theory to study a p-d Hubbard Hamiltonian for LaCoO3 derived from ab initio calculations in local density approximation (LDA+DMFT scheme). We address the origin of local moments observed above 100 K and discuss their attribution to a particular atomic multiplet in the presence of covalent Co-O bonding. We show that in solids such attribution, based on the single ion picture, is in general not possible. We explain when and how the single ion picture can be generalized to provide a useful approximation in solids. Our results demonstrate that the apparent magnitude of the local moment is not necessarily indicative of the underlying atomic multiplet. We conclude that the local moment behavior in LaCoO3 arises from the high-spin state of Co and explain the precise meaning of this statement