Комп’ютерне моделювання процесу поширення вищих гармонік в електричних мережах

В статті запропоновано алгоритм розрахунку спектру наявних гармонік у вузлах і вітках живлячої електричної мережі. Алгоритм дозволяє проаналізувати проникнення гармонік струму від їх джерел в розподільні мережі і оцінити їх вплив на електроустановки живлячої мережі

THE FERMAT-TORRICELLI PROBLEM IN NORMED SPACES

The article studies a generalization of the classical Fermat-Torricelli problem to normed spaces of arbitrary finite dimension. Given integer n, we describe all normed spaces such that the solution of the Fermat-Torricelli problem is unique for any n points in this space. More precise conditions for normed planes and three-dimensional spaces are presented. In addition, we apply the criterion to norms whose unit balls are regular polyhedra

The Fermat-Torricelli problem in the case of three-point sets in normed planes

In the paper the Fermat-Torricelli problem is considered. The problem asks a point minimizing the sum of distances to arbitrarily given points in d-dimensional real normed spaces. Various generalizations of this problem are outlined, current methods of solving and some recent results in this area are presented. The aim of the article is to find an answer to the following question: in what norms on the plane is the solution of the Fermat-Torricelli problem unique for any three points. The uniqueness criterion is formulated and proved in the work, in addition, the application of the criterion on the norms set by regular polygons, the so-called lambda planes, is shown.Comment: 13 pages, 9 figure

Modernized algorithm of neural network initial weighting factors during the diagnosis of diesel engine faults

© Research India Publications. A lot of knowledge and experience is required in order to perform diesel fault diagnosis from an expert. However, one should not rule out the “human factor”, the expert may forget something or miss some important facts during analysis. In order to assist an expert during the analysis of diesel engine faults the task of an expert system development becomes a relevant one. It is advisable to develop this system based on an artificial neural network, which allows to classify diesel faults. The application of an artificial neural network for solving this class of problems makes it possible to reduce the volume of stored data through the creation of a weight factor knowledge base and to carry out a refinement of this base through training if necessary, which allows to improve the accuracy of clustering, as well as to change the network structure easily if new types of faults appear. The modernized method is based on the appointment of an input vector data as the initial weighting coefficient which is encountered first in each cluster group. The effectiveness of the modernized algorithm concerning the selection of initial weighting factors prior to existing ones is in the significant reduction of training cycle number, reducing the load on processing devices. The greatest effect may be achieved at a large number of training samples, and the dimension of an input and an output vector

Flotation extraction of elemental sulfur from gold-bearing cakes

Currently, in the development of the raw materials base of the gold mining industry, there is a tendency to reduce the quality of the initial mineral raw materials due to the depletion of reserves of rich gold-bearing ores. The article discusses the technology of extraction of refractory gold-bearing concentrates based on low-temperature leaching of pyrite concentrate. A decrease in the parameters of the autoclave oxidation of sulfide minerals, such as pyrite and arsenopyrite, leads to the incomplete extraction of gold into the solution and, consequently, its losses during subsequent cyanidation. As a possible option for a more complete extraction of gold using low-temperature oxidation technology, a method of flotation separation of elemental sulfur from leaching cakes is proposed. According to the basic process flow chart, the flotation process designed for gold extraction is carried out after autoclave oxidation, but before cyanidation. A series of experiments were carried out with varying reagent conditions and the dependence of gold losses on the extraction of elemental sulfur in the flotation tailings was established. As determining factors, pH and solid content in the initial pulp were considered. The paper justifies the separation of elemental sulfur from autoclave cake to enriched sulfur concentrate. The cake flotation modes after autoclave oxidative leaching of pyrite concentrate are investigated. The distribution of elemental sulfur and gold by flotation products makes it possible to conduct the tailings cyanidation process with acceptable indicators

Sustainable Development: Effect of Technogenic Factors

Равновесие социума в условиях современных экономических и политических вызовов во многом зависит от техногенных факторов. Риски очень высоки, поэтому правильная их оценка и учет позволяет существенно воздействовать на результативность хозяйственной деятельности и устойчивое развитие экономики на техногенных территориях. Исследованы природные и техногенные факторы территории России за десять лет, сделаны выводы о том, что важным фактором устойчивого развития является не только профилактика чрезвычайных ситуаций, но и изучение и научно обоснованное финансирование развития институтов, обеспечивающих их предотвращение.The balance of society in the conditions of modern economic and political challenges largely depends on man-made factors. The risks are very high, therefore, their correct assessment and accounting can significantly affect the effectiveness of economic activity and the sustainable development of the economy in man-made territories. The natural and man-made factors of the territory of Russia for ten years have been studied, conclusions have been drawn that an important factor of sustainable development is not only the prevention of emergency situations, but also the study and scientifically sound financing of the development of institutions that ensure their prevention