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.

Total $k$-Rainbow domination numbers in graphs

Abstract: Let $kgeq 1$ be an integer, and let $G$ be a graph. A $k$-rainbow dominating function (or a {it $k$-RDF}) of $G$ is a function $f$ from the vertex set $V(G)$ to the family of all subsetsof ${1,2,ldots ,k}$ such that for every $vin V(G)$ with$f(v)=emptyset $, the condition $bigcup_{uin N_{G}(v)}f(u)={1,2,ldots,k}$ is fulfilled, where $N_{G}(v)$ is the open neighborhood of $v$. The weight of a $k$-RDF $f$ of$G$ is the value $omega (f)=sum _{vin V(G)}|f(v)|$. A $k$-rainbowdominating function $f$ in a graph with no isolated vertex is calleda total $k$-rainbow dominating function if the subgraph of $G$induced by the set ${vin V(G) mid f (v) neq emptyset}$ has no isolated vertices. The total $k$-rainbow domination number of $G$, denoted by$gamma_{trk}(G)$, is the minimum weight of a total $k$-rainbowdominating function on $G$. The total $1$-rainbow domination is thesame as the total domination. In this paper we initiate thestudy of total $k$-rainbow domination number and we investigate itsbasic properties. In particular, we present some sharp bounds on thetotal $k$-rainbow domination number and we determine the total$k$-rainbow domination number of some classes of graphs.

Continuous-Wave Green Laser of 9.9 W by Intracavity Frequency Doubling in Laser-Diode Single-End-Pumped Nd:YVO4/LBO

Abstract: A maximum of 9.9?W cw TEM00 output at 532?nm laser has been obtained by intracavity frequency doubling with LBO in laser-diode single-end-pumped Nd:YVO4. The Nd:YVO4/LBO green laser has a simple three-mirror V-fold cavity structure. The optical-optical conversion efficiency was 34.8%. Based on the equation of thermal conduction, a general solution for the laser-crystal interior temperature distribution is obtained by the semi-analytical thermal analysis method. Using the software system, the cavity parameters have been optimized according to the stability condition and the astigmatic compensation principle. The astigmatism in the cavity has been effectively controlled and the resonator was insensitive to the thermal lens in the Nd:YVO4 crystal.

Elastodynamic analysis of anisotropic elastic solid with multiple nanocavities

Abstract: 2D elastodynamic problem for a finite elastic anisotropic solid with nanosized cavities is worked out in this paper. The solid under plane strain conditions is subjected to time-harmonic load. The developed computational tool for the steady-state problem is boundary integral equation method based on frequency-dependent fundamental solutions for elastic anisotropic continuum obtained by Radon transform. Accuracy of the dynamic stress concentration factor and displacement components is proven by comparisons with existing in the literature analytical solution and with the results obtained using commercial finite element package. In addition, a parametric study is performed in order to examine the sensitivity of the dynamic stress concentration field to the geometrical configuration of multiple cavities, to the characteristics of the surface elastic properties, to the type of orthotropy and to the dynamic interaction between cavities.

Infrastructure in the Region: Long-Term Investments of Institutional Investors in Russia

Abstract: The article deals with the possibility of long-term investment in infrastructure development in the region at the expense of internal resources of the pension market of institutional investors (Pension Fund of Russia, private pension funds Vnesheconombank and private management companies). We have analyzed various theoretical and empirical studies that have shown the dependence of the financial sector and its impact on economic growth; analysis of the institutional changes in the pension system in Russia; analysis of the impact of the financial crisis of 2014 – 2015 on the results of the investment of institutional investors in the pension market. We offer for the development of the region to use economic mechanism of redistribution of pension assets and their direction in the development of the regional economy. The methodology of long-term investment of pension assets of State funded part of the pension system in infrastructure projects of regional economy through closed real estate funds will solve the problem of obtaining a stable private pension funds, investment income above the level of inflation and maintain purchasing power of the pension capital of the financial market. In addition to the accepted measures of federal social politics we suggest to use regional state support of institutional investors (investing of infrastructural projects of region due to creation of bank of regional earth and their contributing to the closed funds of the real estate). The original typology of pension assets investment of institutional investors in infrastructure projects under the regional guarantee regional authorities (through standardized contractual pledge of land from the land bank in the region) would solve two pressing problems: the regional authorities will be able to access internal resources to long-term investments in their areas of the spatial development of the region and in infrastructure projects, and institutional investors will be able to ensure the growth of pension assets at the level of inflation in a closed real estate fund. Structural policy of the government on the development of the region, the implementation of infrastructure projects will improve access to markets and services and public goods firms in urban agglomerations and rural settlements, will contribute to the performance of the regional economy and promote economic growth in the region.