Satellite and aerial imagery geo-referencing using ground features

The method of geo-referencing satellite- and aerial imagery using reference points, linear and non-linear features, and segments of geodetic tracks as elements of a plan-altitude basis is discussed in this article. The method can be used for any mathematical model of satellite- and aerial imagery. The parametric description of the features, that can be used for the geo-referencing and various mathematical models of the above-mentioned imagery are presented. The mathematical formulation of the matter of satellite and aerial imagery geo-referencing using terrain objects and reference points is presented. A list of linear and non-linear features that can be included in a high-raised basis along with reference points is made. A generalized algorithm for geo-referencing satellite and aerial imagery using reference points and terrain features is given. The algorithm includes making a nonlinear system of equations for reference points and items, linearizing the system and solving by the sequential approximation technique according to the least squares method. An example of clarifying the satellite RPC-model and aerial imagery using reference points, linear and non-linear features is given. The advantages of the proposed method of using features created according to the measurements on satellite and aerial imagery compared with method, when the model of the feature is created according to the measurements on the ground are described.

Dimensional Analysis of Technological Processes for Reconditioning Machine Parts

Reconditioning of worn-out machine components is a significant reserve for improving the efficiency of repair production. Recovery technologies are necessary not only to extend the service life of machine components, they also can improve the efficiency of machine operation. The greatest costs of the repair complex resources are associated with the restoration of the size, spatial deviations, shape and roughness of worn surfaces. With that the operational properties of surfaces corresponding to their functional purpose, are formed simultaneously and first of all, wear resistance and antifrictionality. The key methods of dimensional reconstruction of machine parts are systematized. The required geometric accuracy of the surfaces being restored is obtained by sequential approximation as the operations and stages of the restoration processing are performed. Saving material and labor resources of the repair complex can be ensured by the proper selection and control of the interoperative dimensions obtained at various machining steps. Therefore, along with the study of the physical and technological capabilities of restoration methods, the dimensional analysis of technological processes with a reasonable allowance setting for operating steps of processing the restored surfaces, the thickness of the applied coatings, their final and intermediate values, the size of additional repair parts, etc. becomes relevant. Methods of dimensional restoration of parts by the type of technological impacts are considered. The article describes methods for determining the optimal part dimensions at the stages of preparation for dimensional restoration, intermediate and final dimensions during processing operations, as well as the thickness of the applied coatings, which reduce energy, material and labor costs and improve the quality and operational properties of the restored parts.

Optimization design of rockoons based on improved sequential approximation optimization

In this study, a multidisciplinary design optimization framework and detailed procedure based on improved sequential approximation optimization (SAO) and 3-degree-of-freedom trajectory simulation are proposed for conceptual design and parameters optimization of a rockoon (from rocket and balloon) system. A reliable and efficient strategy, which considers the approximation accuracy of the response surfaces in the sampling process, is proposed to reduce the evaluation times of the original model for finding the global optimal solution. Besides, a modified SAO algorithm based on the multistage adaptive sampling strategy is presented, and the obtained tested results verify the fine robustness, high efficiency, reliability, and validity of the proposed SAO algorithm. The objective is to minimize the liftoff gross mass of the launch vehicle which reflects the cost for satellite launching. Constraints are imposed to ensure the orbit injection accuracy and stability of the launch vehicle. Finally, based on the multidisciplinary design framework with modified SAO, the optimal design results in 12 design cases from various payload mass, objective orbit, and ignition altitude are discussed and compared with the generic launch vehicle.

Stable systems of schedule contracts

The paper studies the systems of paired contracts between agents of two complementary groups (workers and firms, students and universities, depositors and banks). Multiple contracts are allowed, as well as flexible contracts when the contract is concluded with some intensity. Agent preferences are described using choice functions. It is shown that if these choice functions satisfy the condition that we call conservativeness, then there are so-called stable systems of contracts, when it is unprofitable for any pair of counterparties to change the concluded contracts. The existence of a stable system of contracts is established using the transfinite process of sequential approximation, which generalizes the classical Gale−Shapley algorithm. As a result, we relieved of the finiteness conditions of the set of contracts. Such properties of stable systems as polarization and latticeness are also studied.

ON ONE APPROACH TO NUMERICAL MULTIVARIATE SIGNAL DESIGNING

The method of sequential approximation (MSA) [1] allows representation of a reproduced function in an analytical form in the form of a product of functions, each of which depends on one variable. The paper is devoted to application of the representation of a function in the vicinity of a point and is considered for evaluation of numerical filter parameters. The result of this representation is an analytical expression in the form of a product of independent functions of one variable. As the practical experience of technical applications shows, the function of the parameters is quite satisfactorily describes its behavior throughout the definition area. An example of the application of this approach to the solution of an important scientific problem of numerical filter parameters determination is proposed.

DETERMINATION OF THE FREE FLOW DEPTH UNDER UNEVEN CURRENT MODE IN PRISMATIC CHANNELS

The aim of the work is to analyze the existing method of calculating the spillway from the depth of the free flow under uneven mode in prismatic channels with a slowly changing movement and to develop a method of calculations that allows applying it to any flows in a prismatic channel without using any special tables. The existing methods for calculating flow parameters are based on the use of the Chesy formula to determine the flow consumption with a slowly changing water movement. At the same time, there is a V.I. Charnomsky’s method of direct calculation of the flow parameters from the energy equation without limiting the value of the channel slope. The disadvantage of this method is a possibility to solve the energy equation by the method of sequential approximation since the flow energy equation includes two variables, the flow depth and the distance between the sections. To eliminate this difficulty, it is proposed to determine the distance between the depths that make up the geometric progression on the considered part of the channel which allows calculating parameters of the free fl ow surface for any channel slopes and hydraulic flow modes without to special tables.