DOI: 10.25136/2644-5522.2019.1.28720

Abstract: The subject of the research is an optical direction finder for the navigation and guiding a space probe. The usage of the optical correlation computing device is determined by the necessity to reduce the load to a space probe on-board computer system. The paper describes especially the optical correlation computing devices for building the correlation-extremal direction finders. The principle optical schemes of this class of optical devices are described. The method of mathematical modeling is used for building and analyzing the optical scheme of the proposed optical correlation computing devices. Both advantages and disadvantages of the existed optical schemes are noted. The requirements to parameters of the special on-board optical correlation computing device for the direction finding are proposed. It is shown that the optical device potentially can be used for navigation and guiding a space probe in the process of the landing on a small body of the solar system.

DOI: 10.25136/2644-5522.2018.5.26513

Abstract: The object of research is the workload implementation management subsystem in a network database. The subject of research is the management of the formation of the schedule for the implementation of subscriber requests and transactions in a network database. In many cases, existing solutions do not provide the necessary results in terms of access time and accuracy of the found solution. There is a need to develop a method for scheduling the implementation of user and transaction requests. Particular attention is paid to the algorithms of sampling queries in network databases, as well as the conceptual model of the process of managing transactions and queries. We use methods of graph theory. The evaluation of the effectiveness of the task solution was performed using a systems approach, system analysis and the theory of operations research. Processing of experimental data obtained during the work was carried out in accordance with the provisions of mathematical statistics. A method has been developed for finding the shortest Hamiltonian path in an arbitrary graph based on a rank approach, which provides high efficiency and small error in solving the problem of organizing the process of managing multiple transactions and queries when they are implemented in network databases. Using the developed method allows minimizing idle time of computing devices, reducing the volume and time of data transfer from one device to another, increases overall scalability, minimizes data access time, etc. An important advantage of the proposed method is to reduce the number of elementary operations and the number of vectors being processed the queue of the operations of the request, which leads to a significant reduction in time to implement the procedures for the formation of echer di operations in the requests.

DOI: 10.7256/2454-0714.2018.2.26217

Abstract: The basic requirements for the on-board complex of the spacecraft for purposes of guidance and landing on small bodies of the solar system are formulated in the work. The main tasks of the landing and landing vehicles are braking and approaching the surface of the celestial body, landing, working on its surface, possibly taking off from the surface to deliver the returned vehicle to the ground. Providing high requirements to the accuracy and reliability of the on-board guidance and landing system, an actual solution is proposed. Using the traditional approach to the modeling of processes and systems, a functional model of the onboard guidance and landing system in IDEF0 notation was created. In the process of creating a functional model, the main processes performed by the complex during descent from orbit and landing are described. As a result of the work, a description of the procedures performed by the multifunctional on-board guidance and landing system of the spacecraft has been obtained. An applied functional model of the "to-be" level was constructed, based on the use of an integrated approach. The proposed integrated approach is focused on the sharing of data from all on-board devices, both basic and backup information. This approach allows to increase the accuracy and reliability of the landing procedure.