Journal "Research Bulletin of National Technical University of Ukraine "Kyiv Polytechnic Institute" (Naukovi visti) publishes original research results and practical developments from areas of technical, physical, mathematical, chemical and biological sciences.

Using of Thermal Imaging in the Study of the Temperature Distribution of Myocardial

Qualitative comparative analysis of thermal infarction was conducted using thermograph in the spectral range 8–14 microns. Quantitative assessment of myocardial temperature measurement accuracy is made depending on the ambient temperature. Based on the proposed approach to the analysis of thermal images infarction, researching area of temperature on the surface of the myocardium, which give a clear picture on the distribution of the internal temperature and the level of the microcirculation in the myocardium and vessels, were conducted.

Model of Plane Distribution of Heat Sources for Multi-Channel Matrix Oxygen Sensors

Transcutaneous polarography is one of the most objective noninvasive assessment of the capillary blood flow and microcirculation by controlling the oxygen partial pressure in the subcutaneous tissue. The outcome of research is influenced by such common factors as the oxygen content in the ambient air, the adequacy of the central hemodynamics of the patient, the presence of violations of the transport function of the blood, the pathology of the pulmonary system and local factors (disturbance of the local microcirculation, tissue edema, marked capillary spasm, etc.).

Improvement of Calculating Medical Thermovision Camera Minimum Resolvable Temperature Difference

The paper is devoted to improvement of the equation for calculating the minimum resolvable temperature difference (MRTD) of medical thermovision camera by means of more sophisticated models of thermal images visual perception. An MRTD calculating algorithm, which is based on a more reliable approximation of the visual system modulation transfer function by Schultz, is considered. We obtain new expression for the bandwidth of Schultz’s approximation, which does not depend on the angular size of the Foucault pattern bar. An improved equation for calculating the MRTD was obtained.

Formation of Structure and Phase Composition in Ecviatomic Alloys of Cu–Ni–Al–Fе–Cr System Synthesized by Mechanical Alloying

Nanocrystalline equiatomic high-entropy alloys (HEAs) have been synthesized by mechanical alloying in Cu–Ni–Al–Fе–Cr system from the binary CuNi alloy to the quinary CuNiAlFeCr alloy. By using X-ray diffraction analysis structure and phase evolution during mechanical alloying (MA) in binary to quinary alloys selected from Cu, Ni, Al, Fe и Cr in sequence were investigated. Binary CuNi alloy formed solid solution with face-centered cubic crystal structure in nanocrystalline state.

Diffusion Coatings with the Participation of Titanium, Alumi¬nium and Silicon on Surface of the Steel 12X18H10T

Patterns of forming a multilayered diffusion coatings after complex saturation of titanium, aluminum and silicon to steel to improve heat resistance 12Cr18Ni10Ti were obtained and studied. The possibility of obtaining titanium-aluminum-silicon layers on steel 12Cr18Ni10Ti powder in containers with a gate in unpressurized conditions at temperature 1050 C and with duration 4 hours was studied. As initial components powders of titanium, aluminum, silicon, aluminum oxide, ammonium chloride were used.

Control Oxygen-Converter Process in Closed Loop

The work was done in order to increase the efficiency of BOF smelting by constructing closed-loop control system. The creation of BOF melt models was based on the combined modeling method, which includes deterministic, probabilistic and heuristic approaches, methods of automatic classification and the positive experience of the previous administration. A closed-loop system including a static, dynamic and closed control model BOF steelmaking process was developed.

Effect of Diamond Honing Technological Factors for Parameters of Roughness and Exactness of Composite Sliding Bearings Surfaces for Printing Machines

In a paper the research results concerning an influence of honing process’ technological factors such as abrasive tool composition, cutting parameters, number of hones in honing head on surface roughness and surfaces’ exactness of new composite sliding bearings manufactured of new high-alloy composite alloys from tool steels wastes for high-speed printing machine have been presented.

Adjustment of the Iterative Reclassification Method for Including the Rejected Appli-cations into the Credit Scoring

The objective of the research is the adjustment of the Iterative Reclassification Method for including the rejected applications into the credit scoring. The methodology of implementation uses partially classified data and the logistic regression generalization. The method of the adjustment the Weight Of Evidence and the Information Value indicators using the rejected loan applications is proposed at the first stage.

A 2-Layer Perceptron Performance Improvement in Classifying 26 Turned Monochrome 60-by-80-Images Via Training with Pixel-Distorted Turned Images

There is tried 2-layer perceptron in classifying turn-distorted objects at acceptable classification error percentage. The object model is a letter of English alphabet, which is monochrome 60-by-80-image. Neither training 2-layer perceptron with pixel-distorted images, nor with turn-distorted images makes it classify satisfactorily. Therefore in classifying turn-distorted images a 2-layer perceptron performance might be improved via training under distortion modification.

Optimization of Reinsurance Strategies Using DSS

The basic purpose of the work is a study of existing approaches to reinsurance directed towards modeling of distribution and minimization of risk for an insurance portfolio, and forming a strategy for its optimal reinsurance using developed decision support system. A method for a search of optimal reinsurance strategy is proposed. For this purpose statistical models were selected that correspond to the structure and volume of portfolio losses as well as the number of these losses. The simulation model for the total insurance losses is developed.