The period of the quasi-biennial oscillation is examined through the use of a harmonic procedure which allows one to examine periods of interest without omission of any data. On the basis of 8, and 5th years, of mean-monthly zonal-wind and temperature data in the Northern and Southern Hemispheres, respectively, it is found that: (1) A quasi-biennial oscillation in zonal-wind exists in the tropo...

Mars Global Surveyor accelerometer observations of the martian upper atmosphere revealed large variations in density with longitude during northern hemisphere spring at altitudes of 130–160 km, all latitudes, and mid-afternoon local solar times (LSTs). This zonal structure is due to tides from the surface. The zonal structure is stable on timescales of weeks, decays with increasing altitude abo...

In this paper, we investigate synchronization of coupled second-order linear harmonic oscillators with random noises and time delays. The interaction topology is modeled by a weighted directed graph and the weights are perturbed by white noise. On the basis of stability theory of stochastic differential delay equations, algebraic graph theory and matrix theory, we show that the coupled harmonic...

The paper reports main results of a comprehensive study of the vibrational spectrum of ketene computed using second-order perturbation theory treatment based on quartic, cubic and semidiagonal quartic force constants. Two different models--a homogeneous model using the same density functionals and basis functions for the harmonic calculations and anharmonic corrections, and a hybrid model in wh...

Unique information about the dynamo process acting at Jupiter can be inferred by modeling and interpreting its magnetic field. Using fluxgate magnetometer measurements acquired during 4 years of Juno mission, we derive a field model which describes simultaneously main secular variation (SV) up to spherical harmonic degrees 16 8, respectively. Apart from Earth's, this is first time another plane...

We address the problem of determining whether or not a harmonic oscillator has been perturbed by an external force. Quantum detection and estimation theory has been used in devising optimum measurement schemes. Detection probability has been evaluated for different initial state preparations of oscillator. The corresponding lower bounds on minimum detectable perturbation intensity has been eval...

The bound state solutions of Schrodinger’s equation for the anharmonic oscillator potentials V = x2+ AxZk ( k = 2 , 3 , . . .) have been investigated, using elementary techniques of low-order variational perturbation theory. For the quartic oscillator ( k = 2) a scaled harmonic potential provides a remarkably accurate model for all A. Although this model is slightly less satisfactory for higher...

A simultaneous perturbation approach for cascade learning of single hidden layer neural network is presented. A sigmoidal hidden neuron is added to the single layer of hidden neurons after training until the error has stopped decreasing after a certain limit. Then, the cascaded network is again trained using simultaneous perturbation. Perturbation employed on the weights connecting to hidden ne...