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## Lecture Notes in Engineering and Computer Science. Proceedings of The World Congress on Engineering 2013

The present paper is devoted to the research of controlled queueing models at control of CBSMAP-flow, Controlled Batch Semi-Markov Arrival Process (Kashtanov, Kondrashova 2012). The control is based on the theory of controlled semi-markov processes and used for the system optimization. The control is carried out using the choice of the next batch type.

The World Congress on Engineering 2013 has been organized by the International Association of Engineers (IAENG), a non-profit international association for the engineers and the computer scientists. The WCE 2013 takes place in Imperial College London, London, U.K., 3-5 July, 2013. The congress scope covers the frontier topics in the theoretical and applied engineering and computer science subjects. The WCE conferences serve as excellent platforms for our members and the entire engineering community to meet with each other and to exchange ideas. The conferences also strike a balance between theoretical development and applications.

A hybrid of two novel methods - additive fuzzy spectral clustering and lifting method over a taxonomy - is applied to analyse the research activities of a department. To be specific, we concentrate on the Computer Sciences area represented by the ACM Computing Classification System (ACM-CCS), but the approach is applicable also to other taxonomies. Clusters of the taxonomy subjects are extracted using an original additive spectral clustering method involving a number of model-based stopping conditions. The clusters are parsimoniously lifted then to higher ranks of the taxonomy by minimizing the count of “head subjects” along with their “gaps” and “offshoots”. An example is given illustrating the method applied to real-world data.

The article describes the use of a number of alternative blended learning models based on a mixture of traditional face-to-face classes with some elements of e-learning in the course of “English for Academic Purposes” (EAP) and “English for Specific Academic Purposes” (ESAP) taught to junior and senior undergraduate students of computer sciences in the undergraduate program of Business Informatics and Software Engineering over a period of time from 2009 to 2012 at the National Research University Higher School of Economics (NRU HSE), Moscow, Russia

The functional model of the application of mathematical modeling , reflecting the sequence of solving problems in the design of complex electronic systems . Developed a functional model of information technology to ensure the reliability of complex electronic systems. Showing the basic concept of implementing continuous information support program to ensure the reliability of the calculation of the indicators of reliability of complex electronic systems for the purpose of specifying the requirements of software

The three already traditional volumes of the WDS Proceedings you are holding in the hands are composed of the contributions which have been presented during the 21st Annual Conference of Doctoral Students that was held in Prague, at Charles University, Faculty of Mathematics and Physics from May 29 to June 1, 2012. In this year, 100 student manuscripts were submitted to publishing and 88 were accepted after the review process.

In 2013, the InternationalConference on Advance Information Systems Engineering (CAiSE) is turning 25. Started in 1989, in these years, the conference has provided a broad forum for researchers working in the area of Information Systems Engineering. To reflect on the work done so far and to examine perspectives of future work, the CAiSE Steering Committee decided to collect a selection of papers published in the conference proceedings in these years and to ask their authors, well-known researchers in the area, to comment on their work and how it developed during the years. CAiSE Proceedings have been published by Springer in the Lecture Notes in Computer Science Series (LNCS) since 1990.

The book provides an overview on the conference from different points of view: a historical analysis on how it developed and its goals over the years, a social network analysis of the positioning of CAiSE in the research community, and future perspectives for the conference in an evolving world.

Let k be a field of characteristic zero, let G be a connected reductive algebraic group over k and let g be its Lie algebra. Let k(G), respectively, k(g), be the field of k- rational functions on G, respectively, g. The conjugation action of G on itself induces the adjoint action of G on g. We investigate the question whether or not the field extensions k(G)/k(G)^G and k(g)/k(g)^G are purely transcendental. We show that the answer is the same for k(G)/k(G)^G and k(g)/k(g)^G, and reduce the problem to the case where G is simple. For simple groups we show that the answer is positive if G is split of type A_n or C_n, and negative for groups of other types, except possibly G_2. A key ingredient in the proof of the negative result is a recent formula for the unramified Brauer group of a homogeneous space with connected stabilizers. As a byproduct of our investigation we give an affirmative answer to a question of Grothendieck about the existence of a rational section of the categorical quotient morphism for the conjugating action of G on itself.

Let G be a connected semisimple algebraic group over an algebraically closed field k. In 1965 Steinberg proved that if G is simply connected, then in G there exists a closed irreducible cross-section of the set of closures of regular conjugacy classes. We prove that in arbitrary G such a cross-section exists if and only if the universal covering isogeny Ĝ → G is bijective; this answers Grothendieck's question cited in the epigraph. In particular, for char k = 0, the converse to Steinberg's theorem holds. The existence of a cross-section in G implies, at least for char k = 0, that the algebra k[G]G of class functions on G is generated by rk G elements. We describe, for arbitrary G, a minimal generating set of k[G]G and that of the representation ring of G and answer two Grothendieck's questions on constructing generating sets of k[G]G. We prove the existence of a rational (i.e., local) section of the quotient morphism for arbitrary G and the existence of a rational cross-section in G (for char k = 0, this has been proved earlier); this answers the other question cited in the epigraph. We also prove that the existence of a rational section is equivalent to the existence of a rational W-equivariant map T- - - >G/T where T is a maximal torus of G and W the Weyl group.