Authors

Approach to enhance the sharpness of the image by separating the contour information of software and hardware

Study of moire formation in the reproduction of information using software methods

Investigation of color differences in the reproduction of memorable colors on visualization devices

This work is devoted to the study of changes in color coordinates on various visualization devices during color reproduction, in particular smartphones, as one of the most commonly used devices in the modern world, which is associated with the hardware dependence of the color reproduction system. The purpose of the work is to select visualization tools, determine their technical characteristics, determine test colors for visualization on various devices, determine the tolerances in reproduction of each color when using various viewing devices. To achieve the goal, such tasks were set as the selection of images containing memorable colors. These colors are fundamental in determining the tolerances in color reproduction, since information about them is inherent in each person on the basis of his life experience and knowledge, and a change in the reproduction of memorable colors, a violation in color rendering, is the most visually noticeable. Memorable colors are converted into samples – test objects, which are used to determine coordinates in a device-independent color space. Determination of tolerances is made when changing color reproduction through the use of selective (color) correction. When solving the problem, it was noted that there are colors in which, with small changes in color coordinates, the visual component changes to a sufficiently strong degree, while other colors, with a numerically identical change, do not visually change. For the selected colors on various visualization tools, the difference in color reproduction is calculated and the calculations of color differences for different models of viewing devices with a visual difference in perception are given. Read more...

Building and analyzing a machine learning model for short-term bitcoin market forecasting based on recurrent neural networks

In this article, the construction and analysis of machine learning models were performed for short-term forecasting in the cryptocurrency market on the example of bitcoin – one of the most popular cryptocurrencies in the world. The initial data for the study leads to the conclusion that over the long period of its existence, bitcoin has shown a high degree of volatility, especially evident in comparison with traditional financial instruments. The article substantiates that this market is influenced by a multitude of factors. No one can say for sure what makes up the value of a particular cryptocurrency, as it involves a range of reasons, which cannot be fully taken into account. To overcome this problem, we have considered the principle of recurrent neural network. It is described why networks with memory are better at making predictions on the time series than conventional autoregressive model and standard forward propagation networks. The initial data processing algorithm and transformation methods are defined. The sample was reduced in order to increase the speed of the network, by reducing the number of recalculations of weights. The algorithm of the family of recurrent neural networks was built and trained to test the hypothesis about their better adaptivity due to short-term and long-term memory. The model is evaluated on the test data representing the bitcoin exchange rate for 2021–2022, since this period is characterized by high volatility. It is concluded that it is reasonable to use a similar type of models for short-term forecasting of cryptocurrency rates. Read more...

Building the mathematical model of the decision support system in the field of pricing for e-commerce

This work is devoted to the study of pricing issues for obtaining maximum profit when selling consumer goods at a constant purchase price. The said goods come in from either manufacturers or warehouses where the retail companies buy the goods in order to sell them directly to the consumers. The dependence of the selling rate per unit of time on the level of the added price in relation to the purchase price of the item is established by the means of sales price variation. The object of the research is the specific case of a linear approximation of said dependence, which is usually actualized in the event of either more elastic or less elastic demand for goods, when they are sold through Internet platforms. The proposed approach to determining prices of all the goods which are being sold for maximizing the total profit from the sales of all consumer goods or maximizing the total revenue throughout the whole period of sales time, based on the search of extremum points of the profit and revenue functions for each item of goods remains valid in the case of more complex approximations by quadratic and cubic functions of demand function. The type of the function of maximum value added revenue and the type of the function of maximum profit can be both found per unit of time depending on the variable level of the added price included into the sales price of the item. The type of maximum revenue function can be found per unit of time depending on the sales price of the item. The extremum points of the found functions are being determined. The theorems have been proved, that the extremum points which are being determined appear to be the maximum points of the researched functions for each item of goods, when the maximum profit or the maximum revenues are reached by selling goods to consumers. All common variables of said functions are found by summing up these functions among the multitude of goods on the interval of the whole sales time. The received data is used for the practical implementation of an effective sales strategy that ensures maximum profits for companies specializing in direct sales to consumers of the purchased goods. An applied methodicalэф approach to the sales of goods which ensures maximum profit from the sales in the field of elastic demand approximated by a linear function and under the condition of a constant purchase price for goods is proposed and theoretically substantiated. Read more...

Improvement of contactless fare payment by ground urban passenger transport based on geolocation

One of the important social tasks is the task of improving the efficiency of transport service systems. The paper proposes approaches to solving the problem of increasing the efficiency of contactless fare payment on passenger road transport, which are based on geolocation technology. Based on the consideration of fare payment schemes for closed and open cycles, scenarios for the implementation of fare payment using a flat fare system, a zonal fare system and electronic tickets with QR codes are presented. Several payment implementation work schemes have been developed based on the application of the geolocation concept and using various technologies to implement this concept, namely 1) Bluetooth Low Energy, 2) obtaining coordinates from GPS/GLONASS navigation systems, 3) data received through Wi-Fi access points and 4) location data provided by basic stations of GSM networks. A comparative analysis was carried out for each proposed option, a basic set of technical and software support tools was determined, and recommendations were given on the conditions that determine the feasibility of its application. For experimental confirmation of the operability of each of the options for obtaining the estimated values of the main characteristics, operating samples were constructed on which the corresponding measurements were carried out. Read more...