Deflection of ice cover caused by an underwater body moving in channel

Deflections and strains in an ice cover of a frozen channel caused by an underwater body moving under the ice with a constant speed along the channel are studied. The channel is of rectangular cross section, the fluid in the channel is inviscid and incompressible. The ice cover is clamped to the channel walls. The ice cover is modeled by a thin viscoelastic plate. The underwater body is modeled by a three-dimensional dipole. The intensity of the dipole is related to the speed and size of the underwater body. The problem is considered within the linear theory of hydroelasticity. For small deflections of the ice cover the velocity potential of the dipole in the channel is obtained by the method of images in leading order without account for the deflection of the ice cover. The problem of moving dipole in the channel with rigid walls provides the hydrodynamic pressure on the upper boundary of the channel, which corresponds to the ice cover. This pressure distribution does not depend on the deflection of the ice cover in the leading approximation. The deflections of the ice and strains in the ice plate are independent of time in the coordinate system moving together with the dipole. The problem is solved numerically using the Fourier transform, method of the normal modes and the truncation method for infinite systems of algebraic equations

Prediction for vascular mild cognitive impairment using the p300 event-related potentials technique

Evoked potentials technique owing to informativeness and diagnostic value is widely used in clinical and experimental studies. Herein, we investigated whether the auditory P300 event-related potentials predict syndrome vascular mild cognitive impairment. 42 patients with I and II stages of discirulatory encephalopathy (50-70 years) included in clinical study. The discriminant analysis method was used to work out an equation with two variables as predictors - the P300 latent period and patient's age. The diagnostic accuracy of the discriminant equation at a cut-off -0,268 was established through receiver operating characteristic (ROC) analysis (sensitivity 80%, specificity 74,1%)