Machine learning with different digital images classification in laparoscopic surgery

The evaluation of the effectiveness of the automatic computer diagnostic (ACD) systems developed based on two classifiers – HAAR features cascade and AdaBoost for the laparoscopic diagnostics of appendicitis and ovarian cysts in women with chronic pelvic pain is presented. The training of HAAR features cascade, and AdaBoost classifiers were performed with images/ frames, which have been extracted from video gained in laparoscopic diagnostics. Both gamma-corrected RGB and RGB converted into HSV frames were used for training. Descriptors were extracted from images with the method of Local Binary Pattern (LBP), which includes both data on color characteristics («modified color LBP» - MCLBP) and textural characteristics, which have been used later on for AdaBoost classifier training. Classification of test video images revealed that the highest recall for appendicitis diagnostics was achieved after training of AdaBoost with MCLBP descriptors extracted from RGB images – 0.708, and in the case of ovarian cysts diagnostics – for MCLBP gained from RGB images – 0.886. Developed AdaBoost-based ACD system achieved a 73.6% correct classification rate (accuracy) for appendicitis and 85.4% for ovarian cysts. The accuracy of the HAAR features classifier was highest in the case of ovarian cysts identification and achieved 0.653 (RGB) – 0.708 (HSV) values. It was concluded that the HAAR feature-based cascade classifier turned to be less effective when compared with the AdaBoost classifier trained with MCLBP descriptors. Ovarian cysts were better diagnosed when compared with appendicitis with the developed ACD

Competitive 0 and {\pi} states in S/F multilayers: multimode approach

We have investigated the critical temperature behavior in periodic superconductor/ ferromagnet (S/F) multilayers as a function of the ferromagnetic layer thickness $d_f$ and the interface transparency. The critical temperature $T_c(d_f)$ exhibits a damped oscillatory behavior in these systems due to an exchange field in the ferromagnetic material. In this work we have performed $T_c$ calculations using the self-consistent multimode approach, which is considered to be exact solving method. Using this approach we have derived the conditions of 0 or $\pi$ state realization in periodic S/F multilayers. Moreover, we have presented the comparison between the single-mode and multimode approaches and established the limits of applicability of the single-mode approximation, frequently used by experimentalists

Electrical Discharge in a Cavitating Liquid under an Ultrasound Field

A theoretical model for an electrical discharge in a cavitating liquid is developed and compared with experiments for the optimization of the water treatment device. The calculations based on solution of the Noltingk─Neppiras equation support the hypothesis that the electric field promotes the formation of vapor microchannels inside a liquid gap between the electrodes, where at a low gas pressure Paschen’s conditions of rupture and abnormal glow discharge maintenance in those microchannels are fulfilled. Theoretical analysis of the cavitation processes and the discharge formation processes is in qualitative agreement with the experimental data obtained in this work in a water treatment device using a hydrodynamic emitter. The following graphic illustrates the experimental setup: (1) feeding tank, (2) hydrodynamic emitter, (3) zone of cavitation inside the plasma reactor, (4) high-frequency generator of electric impulses, and (5) outlet.</p

Luminescence of sapphire single crystals irradiated with high-power ion beams

Optical absorption, photo- and cathodoluminescence of a sapphire single crystal (α-Al 2 O 3 ) exposed to pulsed nanosecond radiation with high-power ion beams C + /H + with an energy of 300 keV and energy density 0.5-1.5 J/cm 2 were first investigated in this work. It was found that under ion irradiation accompanied by heating of sapphire up to melting, the formation of F-type centers and their aggregates associated with oxygen vacancies was observed in the crystals under study. These centers have luminescence bands at 330, 410 and 500 nm which depend on the type and wavelength of the optical excitation. The appearance of a new PL emission at 435 nm, presumably associated with a complex vacancy-impurity defect, was also observed in the photoluminescence spectra. © Published under licence by IOP Publishing Ltd.The work was supported by the initiative scientific project № 16.5186.2017/8.9 of the Ministry of Education and Science of the Russian Federation. Experiments on ion irradiation of sapphire was done at the KIPT as a part of the state task

Anomalous Transient Current in Nonuniform Semiconductors

Nonequilibrium processes in semiconductors are considered with highly nonuniform initial densities of charge carriers. It is shown that there exist such distributions of charge densities under which the electric current through a sample displays quite abnormal behaviour flowing against the applied voltage. The appearance of this negative electric current is a transient phenomenon occurring at the initial stage of the process. After this anomalous negative fluctuation, the electric current becomes normal, i.e. positive as soon as the charge density becomes more uniform. Several possibilities for the practical usage of this effect are suggested.Comment: 1 file, 11 pages, RevTex, no figure

Computer engineering in distance credit -modular training of health workers

У статті висвітлено досвід Одеського національного медичного університету щодо вивчення основ комп'ютерної інженерії в режимі дистанційного кредитно-модульного навчання медичних працівників.The article highlights the experience of Odessa National Medical University for the study of computer engineering in distance mode of credit-modular training of health workers