Samara University

Samara, Ethiopia

Samara University

Samara, Ethiopia

Time filter

Source Type

Zagidullin M.V.,RAS Lebedev Physical Institute | Malyshev M.S.,Samara University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

A novel optical pumping scheme considering a two-step irradiation by light at wavelengths near 500 nm and 1315 nm is proposed in this work. Radiation at 500 nm is used to dissociate about 1% of iodine molecules. The radiation at 1315 nm excites atomic iodine to the 2P1/2 state. Singlet oxygen molecules are produced via the energy exchange process I(2P1/2)+O2(X3∑)→ I(2P3/2)+O2(a1Δ), while I(2P1/2)+O2(a1Δ) energy pooling produces b1∑ oxygen. I(2P1/2) and O2(1∑) then accelerate the dissociation of I2. After gas dynamic cooling in supersonic nozzle, active medium may reach ∼100 W cm-2 and small signal gain of ∼0.01 cm-1. © 2017 SPIE.

Kudryavtsev I.,Samara University
ACM International Conference Proceeding Series | Year: 2016

The article is focused on an example of a course of digital electronics and microprocessors in a modern university. Main problems and tendencies are discussed. © 2016 ACM.

Khabibullin R.,Samara University | Starinova O.,Samara University
AIP Conference Proceedings | Year: 2017

This paper outlines the mathematical motion model of the research spacecraft that uses solar sail instead of an engine and a propellant. The mathematical motion model for solar sail spacecraft is formulated and described. The work considers the mathematical motion model within the heliocentric system of coordinates. The best way to assess the reasonableness of the mathematical model is the using model in motion simulation process. On the basis of the formulated mathematical model the special software complex for interplanetary transfer simulation is developed. Especially, the mission of the transfer of the spacecraft from the Earth's orbit to the potentially hazardous asteroid is simulated. The obtained results during simulation demonstrate correctness and feasibility of the considered mathematical motion model. © 2017 Author(s).

Gorbunova I.,Samara University | Starinova O.,Samara University
AIP Conference Proceedings | Year: 2017

This article is devoted to an interplanetary movement of the solar sail spacecraft. Authors propose to use locally-optimal control laws for the solar sail control model. We used previously obtained by the authors locally-optimal control laws for chosen interplanetary missions. The obtained laws can provide rapid change of Keplerian elements or stabilize its values. Authors offer an approach for combination of these laws. To confirm the result correctness authors simulated the heliocentric motion of the solar sail spacecraft to the selected planet. Model of solar sail spacecraft called Helios is designed by students of Samara State Aerospace University. We define heliocentric motion of the solar sail spacecraft via Keplerian elements. Authors used combination technique for locally-optimal control laws to obtained several trajectories for interplanetary missions. The distinctive feature of the proposed method that parameters of osculating elements are used as destination phase coordinates. © 2017 Author(s).

There is a problem to control spacecraft's motion near objects with irregular gravitational fields as asteroids. In this paper we present a mathematical model of spacecraft motion with an electric propulsion engine in an irregular non-spherical gravitational field of the asteroid Eros 433. We propose to use the model of single gravity points for simulation of the motion of a spacecraft in the irregular gravitational field. The equations of spacecraft motion are corresponding equations of the n-body problem. A boundary task of the control spacecraft's transfer between circular orbits from 200 km to 100 km is considered. Authors propose a combination of the Pontryagin's maximum principle and the Newton's step by step approximation as solutions methods for the boundary problem. © 2017 Author(s).

Starinova O.,Samara University
AIP Conference Proceedings | Year: 2017

The developed method of iterative optimization of interplanetary missions with the low thrust, using sequence of movement specified mathematical models and design shape spacecraft, is realized. The new articular analytical decision describing planar movement of spacecraft with solar electric propulsion is described, allowing to construct initial approach in the iterative scheme of optimization. Developed a method of modelling and optimization of interplanetary missions ballistic schemes, based on a combination of Pontryagin's maximum principle formalism conditions of transversality and methods of the mathematical programming, allowing to consider restrictions characteristic for concrete interplanetary missions. Recommendations for choice design-ballistic parameters of the interplanetary missions spacecraft, received taking into account features nuclear and solar power plant for missions on delivery of a payload to orbits of Mars, expeditions the Earth-Mars-Earth are received. © 2017 Author(s).

Flight mechanics with a low-thrust is a new chapter of mechanics of space flight, considered plurality of all problems trajectory optimization and movement control laws and the design parameters of spacecraft. Thus tasks associated with taking into account the additional factors in mathematical models of the motion of spacecraft becomes increasingly important, as well as additional restrictions on the possibilities of the thrust vector control. The complication of the mathematical models of controlled motion leads to difficulties in solving optimization problems. Author proposed methods of finding approximate optimal control and evaluating their optimality based on analytical solutions. These methods are based on the principle of extending the class of admissible states and controls and sufficient conditions for the absolute minimum. Developed procedures of the estimation enabling to determine how close to the optimal founded solution, and indicate ways to improve them. Authors describes procedures of estimate for approximately optimal control laws for space flight mechanics problems, in particular for optimization flight low-thrust between the circular non-coplanar orbits, optimization the control angle and trajectory movement of the spacecraft during interorbital flights, optimization flights with low-thrust between arbitrary elliptical orbits Earth satellites. © 2017 Author(s).

-- There is an urgent need for efficient labour markets, for generating employment, poverty alleviation and wealth creation in different economies of the world, as generating employment and alleviation of poverty are among the most important priorities of any government in the world, said IIF Professor Aman Agarwal, while delivering the Plenary Keynote Speech as a Guest of Honour at State University of Aerospace Instrumentations, (SUAI), St. Petersburg,in the SUAI International Week on Knowledge Economy : Challenges and Opportunities today 22May, 2017. Professor Agarwal is currently Professor of Finance and Dean, Indian Institute of Finance and Executive Editor, Finance India.To create efficient labour markets, there is a need to setup a National Labour Exchange, urged Professor Agarwal. His speech was based upon "Theory of Employment, Wealth and Efficient labour Market through National Labour Exchange" developed at the Indian Institute of Finance by its four senior economists: Professor J.D.Agarwal, Professor Manju Agarwal, Professor Aman Agarwal and Professor Yamini Agarwal.Efficient labour market will help the nation, a firm and the labour in reducing poverty, easy access to information by removing information asymmetry, facilitate nearly perfect mobility of labour and reduce unemployment said Prof. Agarwal while addressing a large audience at State University of Aerospace Instrumentations, Russia.To create efficient labour market, digitization of labour records is requiredfeels Prof. Agarwal.Prof. Agarwal was critical of Keynsian'sGeneralTheory of Employment as it was a result of the great depression of 1931-36. Keynsian theory is irrelevant in today's context.Prof. Agarwal is of the opinion that Labour in itself is wealth of a nation and required to be utilized effectively but suffer from lack of employment opportunities, poverty, poor wage, income variations, immobility and many other problemsAccording to him the labour market today is far from perfect due to lack of necessary information. Prof. Agarwal stated that the payment to labour should be based upon on the basis of value addition rather than wages as currently done. The return to labourshould be directly linked to productivity. An efficient labour market can best be developed through setting up of National Labour Exchange. It would help save employment cost in the market driven economic system with asymmetric information and help solve the problems of laying off in the adverse economic conditions.Thein the international week was delivered by Prof. Dr. Yulia A. Antokhina, Rektor, State University of Aerospace Instrumentations,and Prof. Dr. Ovodenko Anatoly Arkadevich, President and UNESCO Head of Chair, State University of Aerospace Instrumentations,. Other key speakers were Dr. KseniiaBaimakova, State University of Aerospace Instrumentations,; Dr. Arthur Colin, Samara University,; Dr. Nadine Hackmann, Westphalian University of Applied Sciences,; Dr. Harm Hilvers, Christian University of Applied Sciencess, The, Dr. Peter Holicza, Obuda University,; Dr. Mikhail Krichevsky, State University of Aerospace Instrumentations,Dr. Pascal Ricordel, Universite Le Havre Normandie, France and Dr. Anna Sankina, State University of Aerospace Instrumentations,It is an honour for IIF that one of the authors of the theory and its professor is invited as a guest of honour and plenary key note speaker by SUAI, RUSSIA in International Week on Knowledge Economy; Challenges and Opportunities. Professor Agarwal would deliver a series of lectures on different subjects including Financial inclusion, digital economy etc. during the week.

Myasnikov E.,Samara University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

In this paper we consider the possibility of using several multivariate interpolation methods as a supplement to existing dimensionality reduction techniques. Analyzed methods including nearest neighbor interpolation, inverse distance weighting, radial basis functions, and data mapping error minimization are evaluated using well-known datasets. Conducted experiments showed that radial basis functions and interpolation by the data mapping error minimization outperformed other considered methods in terms of the data mapping error yielding slightly worse quality then using stochastic gradient descent method for the whole data sets without interpolation. © Springer International Publishing AG 2016.

Asmamaw D.K.,Samara University
International Journal of River Basin Management | Year: 2015

It is known that river basin is the most appropriate unit for planning, developing and managing water resources and for analysing water availability and water use. However, conflicting views of water resource utilization and ownership as well as sedimentation and flooding have challenged the development of appropriate management of the Nile River basin. The riparian states’, especially Egypt, Sudan and Ethiopia's, livelihood and energy source are solely dependent on the Nile River. Thus, effective and cooperative management of soil erosion/sedimentation in the upper Nile basin is increasingly important from an economic, social and environmental perspective. The Ethiopian government alone has implemented watershed management practices since 1980s which have not proved to be satisfactory. However, there is a lack of updated information concerning the Upper Nile River basin where many questions are raised from downstream and upstream states, communities and scholars. To fill this gap, the study included the following research questions: Is there updated published information about integrated river basin management (IRBM) concerning the Upper Blue Nile basin (BNB)? What effects brought the implementation of IRBM practices in the Upper BNB? What is the role of stakeholder's participation in the river basin management at various levels? How are institutions contributing for successful river basin management? Is there strong linkage between upstream and downstream countries so far? Thus to answer these questions, this review paper intends to provide comprehensive information about the IRBM impact in the upper BNB in Ethiopia. According to the study, the implemented in situ watershed management practices in the upper Blue Nile River had brought positive effects on sediment and flooding reduction as well as on improving water flow. Moreover, the upstream–downstream linkages and cooperation are essential for sustainable water resources management and equitable water share among the Nile riparian states. It was founded that strong institutions and stakeholder participation at all levels as well as appropriate policy could facilitate the river basin management implementation. It is concluded that a better understanding of the sustainable impact of river basin management in the headwaters of the BNB is of paramount importance because of the divergent interest in water resources access, and the ever-growing demand for energy and food in upstream and downstream countries. Thus, it is suggests that the negotiations of riparian states in the Nile basin should continue focusing on ‘benefit sharing’ and the win–win option. © 2015 International Association for Hydro-Environment Engineering and Research.

Loading Samara University collaborators
Loading Samara University collaborators