University of Architecture, Civil Engineering and Geodesy

About: University of Architecture, Civil Engineering and Geodesy is a education organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Finite element method & Beam (structure). The organization has 3808 authors who have published 3822 publications receiving 30736 citations. The organization is also known as: Sofia Polytechnic.

On subgroups in division rings of type 2

Abstract: Let D be a division ring with center F. We say that D is a division ring of type 2 if for every two elements x, y ∈ D, the division subring F(x, y) is a finite dimensional vector space over F. In this paper we investigate multiplicative subgroups in such a ring.

Analysis of mathematical models and a theory of polarization distribution in continuous 3D-porous electrodes

Abstract: Conventional and original mathematical models describing the distribution of an electrochemical process in a continuous 3D volume electrode as in a pseudohomogeneous environment are discussed. Some peculiarities of the operation of such electrodes related to the appearance of anodic zones on a cathodically polarized electrode are considered. Mathematical analysis of the model equations and their solutions is given.

Design of Wireless Sensor Networks for Monitoring at Construction Sites

Abstract: An integrated hardware and software system for a three dimensional wireless sensor networks is designed and developed for construction monitoring system Compared to traditional monitoring system, the construction monitoring system based on wireless sensor networks has many advantages. In this paper, we discuss the design and evaluation of the three dimensional wireless sensor networks for construction monitoring system. We proposed the ensemble structure of the system We proposed the topological structure of the three dimensional wireless sensor networks. The sensor node is designed, developed, and calibrated to meet the requirements for construction monitoring wireless sensor networks. Software components have been implemented within the TinyOS operating system to provide a flexible software platform and scalable performance for construction monitoring applications. We also proposed the deployment of three dimensional wireless sensor networks for construction monitoring system.

Design of optimal control under uncertain initial conditions: A minimax approach

Abstract: The need for a game-theoretical formulation of the problem of linear-quadratic control under nonmeasurable plant state where the functional depends on the uncertain initial state was substantiated. The minimax output control law in terms of linear matrix inequalities that may be regarded as the optimal robust control law for the given set of the plant initial states was established assuming that the measurable components of the initial state were known and the nonmeasurable components take on values within the given ellipsoid. The results obtained were generalized to the plants with uncertain parameters.

Application of the fast expansion method for spacecraft trajectory calculation

Abstract: This paper deals with the problems on the spacecraft motion in the Earth’s atmosphere taking into account the Earth’s atmospheric drag as well as on the extra-atmospheric part of the trajectory, where resistance is absent. An analytical solution of these problems by the method of fast expansions is proposed.