Actions of certain arithmetic groups on Gromov hyperbolic spaces

We study the variety of actions of a fixed (Chevalley) group on arbitrary geodesic, Gromov hyperbolic spaces. In high rank we obtain a complete classification. In rank one, we obtain some partial results and give a conjectural picture.Comment: v1: 23 pages, 4 figures. v2: 24 pages, 4 figures. Fixed a bad typo in Claim 3.3 and made some other small changes. v3: A few small clarifications. To appear in AG

Программно-техническая реализация узла дистанционного обучения

This paper proposes a structural network scheme of the on-line educational system which is based on the Unibel/NIKS network. In addition to purely educational functions this system can provide the possibility of professional communication and exchange of experience between the system-users. The technical package of the on-line educational system includes a personal computer loaded with the relevant software that ensures realization of the following functions: a server of applications, integrated data transfer from a local network to the on-line educational system organization and external network. The main server components of the on-line educational network and operational station are considered and suggested in the paper.Предложена структурная сетевая схема системы ДО на базе сети Unibel/НИКС, которая функционально, помимо чисто образовательных функций, может обеспечить возможность профессионального общения и обмена опытом для участников системы. Комплекс технических средств системы ДО включает собственно компьютер, на котором функционируют программные средства, обеспечивающие реализацию функций сервера приложений, сетевую среду передачи данных локальной сети организации ДО и внешней сети. Рассмотрены и предложены основные компоненты сервера узла ДО и рабочей станции

On bi-invariant word metrics

We prove that bi-invariant word metrics are bounded on certain Chevalley groups. As an application we provide restrictions on Hamiltonian actions of such groups.Comment: 16 pages; few typos from printed version correcte

Isometry groups of non-positively curved spaces: structure theory

We develop the structure theory of full isometry groups of locally compact non-positively curved metric spaces. Amongst the discussed themes are de Rham decompositions, normal subgroup structure and characterising properties of symmetric spaces and Bruhat--Tits buildings. Applications to discrete groups and further developments on non-positively curved lattices are exposed in a companion paper: "Isometry groups of non-positively curved spaces: discrete subgroups".Comment: The original version (September 2, 2008) has been split into two articles. This is the first part; the second is available as of today on the arxiv under the title: "Isometry groups of non-positively curved spaces: discrete subgroups

Technical and Program Realization of On-Line Educational Network

This paper proposes a structural network scheme of the on-line educational system which is based on the Unibel/NIKS network. In addition to purely educational functions this system can provide the possibility of professional communication and exchange of experience between the system-users. The technical package of the on-line educational system includes a personal computer loaded with the relevant software that ensures realization of the following functions: a server of applications, integrated data transfer from a local network to the on-line educational system organization and external network. The main server components of the on-line educational network and operational station are considered and suggested in the paper

Influence of noise on people working in foundry shop

The results of investigation of noise level at the working places of founders, their influence on the workers are given and mathematical dependencies are received

Complex for monitoring respiratory parameters of the patient

Разработан комплекс «MobiPneg», который позволяет проводить дистанционный мониторинг дыхания у детей и взрослых и обрабатывать полученные данные в режиме реального времени. Данный комплекс предназначен регистрировать частоту дыхания, длительность вдоха и выдоха, ритм и тип дыхания. The developed complex «MobiPneg» allows remote monitoring of respiration in children and adults and process the received data in real time. This complex is designed to record the frequency of breathing, the duration of inhalation and exhalation, the rhythm and type of breathing