Use of time-frequency distributions to estimate the parameters of motion of a tonal signal source

Algorithms for obtaining estimates of the trajectory parameters of a moving signal source for the case of one receiver and two spatially separated receivers are considered. The optimization algorithm is based on the method of coordinate descent using a combination of the golden-section method and subsequent parabolic interpolation. For the interferometric scheme and moderate signal/noise ratios a distance estimation error of ±(5–15%)%, a traverse time error of ±(1–2) sec and a velocity error of ±(2–4)% are attainable. Translated from Izmeritel'naya Tekhnika, No. 3, pp. 48–52, March, 1997.     

Computational Aspects of a Method of Determining the Quantity of Liquids and Gases by Constrictor-Equipped Measurement Systems with the Use of Diagram Scanning

This article examines a method of determining the quantity of a substance in the automatic regime with a computer. The method is based on the results from the scanning and numerical representation of diagrams obtained from instruments that record variable parameters.     

Investigation of the coupling coefficients of stripline resonators in combline filters on a suspended substrate

Expressions for the frequency-dependent coupling coefficients of codirectional resonators used in a miniature design of a stripline filter on a suspended substrate are derived. The obtained expressions fully reflect the specific features of the frequency response of the analyzed structure. It is shown that the numerical analysis of a 1D model of this device performed in the quasi-static approximation provides sufficiently good agreement with experimental results. The influence of the design parameters of the analyzed structure on the frequency-selective properties of band-pass filters designed on the basis of this structure is theoretically investigated, and the capabilities for a substantial improvement of the selectivity of such devices are demonstrated.     

Switching effect in Si-CdS heterojunctions synthesized in highly nonequilibrium conditions

The results of the investigation of electrical properties and processes of the formation of heterojunctions on crystalline Si substrate cooled to negative centigrade temperatures is reported. The data of technology, electron diffraction analysis, and electrical investigations are given. The effect of conductivity switching is revealed in heterojunctions based on two-phase CdS films, and conditions for the formation of amorphous CdS films and amorphous CdS films with crystalline inclusions are determined. It is demonstrated that the results are in agreement with the soliton model.     

Calibration of the LHCb electromagnetic calorimeter using the technique of neutral pion invariant mass reconstruction

Calibration of the electromagnetic calorimeter for the LHCb experiment is aimed at measuring the electron and photon energies with an accuracy of 2% or better. A number of calibration techniques are sequentially used for this purpose. One of these techniques is based on reconstruction of the π⁰ meson invariant mass in a two-photon decay. Using this procedure, it is possible to calibrate the electromagnetic calorimeter in the transverse energy range of 300–1500 MeV. An important advantage of this technique is its independence of the states of the other LHCb spectrometer systems. Statistics sufficient for attaining the declared purpose can be rapidly acquired owing to the large cross section of neutral pion production in deep inelastic events. The algorithm has been implemented as a part of the LHCb software. The calibration procedure using neutral pions takes no more than 2 weeks and helps achieve the required accuracy.     

Examination of the Dynamic Threshold Characteristics of a VO2 Switch in an Oscillatory Circuit

Technical Physics Letters - The dependence of the dynamic threshold characteristics of a VO2 switch on the oscillation frequency of a self-oscillatory circuit has been studied. A transient...     

Calculation of the deformation properties of materials made of chemical fibres

A comparatively simple repeating element whose relative deformation corresponds to the deformation of the entire sample can be distinguished in many materials made of chemical (including rigid-chain) fibres. A simple program based on the MATLAB mathematics package that allows calculating the relative deformation of each element and consequently also the deformation of the sample is described. The result of calculating the deformation of a repeating element consisting of two circles of different radius twisted to opposite sides is reported as an example of running the program.