Development of Compression Algorithms for Hyperspectral Aerospace Images Based on Discrete Orthogonal Transformations

The work is devoted to the description of the development of compression algorithms for hyperspectral aerospace images based on discrete orthogonal transformations for the purpose of subsequent compression in Earth remote sensing systems. As compression algorithms necessary to reduce the amount of transmitted information, it is proposed to use the developed compression methods based on Walsh-Hadamard transformations and discrete-cosine transformation. The paper considers a methodology for developing lossy and high-quality compression algorithms during recovery of 85 % or more, taking into account which an adaptive algorithm for compressing hyperspectral AI and the generated quantization table have been developed. The existing solutions to the lossless compression problem for hyperspectral aerospace images are analyzed. Based on them, a compression algorithm is proposed taking into account inter-channel correlation and the Walsh-Hadamard transformation, characterized by data transformation with a decrease in the range of the initial values by forming a set of channel groups [10–15] with high intra-group correlation [0.9–1] of the corresponding pairs with the selection of optimal parameters. The results obtained in the course of the research allow us to determine the optimal parameters for compression: the results of the compression ratio indicators were improved by more than 30 % with an increase in the size of the parameter channels. This is due to the fact that the more values to be converted, the fewer bits are required to store them. The best values of the compression ratio [8–12] are achieved by choosing the number of channels in an ordered group with high correlation

Determination of Rational Parameters for Heat Treatment of Concrete Mixture Based on A Hollow Aluminosilicate Microsphere

The research on determining rational parameters of heat treatment of a concrete mixture based on hollow aluminosilicate microspheres has defined the features of the intensifying action on the structural concrete mixture by low-pressure steam with optimum heat and mass transfer. Optimum values of temperature, humidity and speed of the medium have been identified. The obtained heat treatment parameters are subject to general regularities of structures for the formation of hydraulic bindings and are in accordance with production conditions, thus providing possibilities for their adaptation into production. The mechanisms for determining the strength of concrete stone according to the structural and thermal effectiveness of the active medium have been defined. Thanks to the strength-building mechanisms obtained, it is possible to reduce the thermal destruction capacity of the system while reducing the process heat consumption. It is confirmed that the main direction in reducing the destructive capacity is determined by the mass flow of moisture, which has the greatest heat capacity and the least thermal conductivity at the initial stages. The invention relates to periods of temperature rise and isothermal heating without impairing the mechanical properties of concrete. It is shown that the real duration excludes high-temperature destruction processes, thereby increasing the mechanical strength of concrete and reducing the overall energy consumption. Thus, there is a reason to argue that it is possible to produce strong and light concrete products under accelerated structure formation and new technologies for heat treatment of concrete based on lightweight fillers with reduced heat consumption