
проводят
3е РоссийскоНемецкое Совещание
по перспективным исследованиям в вычислительных науках и высокопроизводительных вычислениях
при поддержке
Deutsche Forschungsgemeinschaft (German Research Foundation)
2327 июля, 2007 г.
Институт вычислительных технологий СО РАН
Академгородок, Новосибирск, Россия
Программный комитет
Сопредседатели:
академик Ю.И. Шокин (ИВТ СО РАН)
проф. M.M. Resch (HLRS)
Члены программного комитета:
проф. М.П. Федорук (ИВТ СО РАН)
чл.корр. РАН В.В. Шайдуров (ИВМ СО РАН)
проф. И.В. Бычков (ИДСТУ СО РАН)
проф. Б.Я. Рябко (СибГУТИ, ИВТ СО РАН)
Организационный комитет
Председатель:
проф. М.П. Федорук (ИВТ СО РАН)
Члены организационного комитета:
В.Б. Барахнин (ИВТ СО РАН)
Д.Л. Чубаров (ИВТ СО РАН)
U. Küster (HLRS)
Н.Н. Кузнецова (ИВТ СО РАН)
Ю.И. Молородов (ИВТ СО РАН)
В.А. Пестунов (ИВТ СО РАН)
Н.Ю. Шокина (HLRS)
А.В. Юрченко (ИВТ СО РАН)
В.Н. Яруткин (ИВТ СО РАН)
В.А. Ясаков (ИВТ СО РАН)
Рабочий язык: английский
Программа совещания
The computational facility of the Institute of Computational Technologies (ICT SB RAS)
Yu. I. Shokin, M.P. Fedoruk, D. Chubarov, A.V. Yurchenko
Institute of computational technologies SB RAS, Novosibirsk, Russia
Institute of Computational Technologies provides expertise in developing mathematical and numerical models in a wide range of disciplines including mechanical engineering, physics and ecology. To cater for the diverse needs of the users within the institute a centralized computational facility is being developed. Several avenues of development are pursued at once. The Institute is introducing new hardware to increase the raw compute power, runs an educational program and works to improve the utility of the existing computational resources for fundamental research and industrial collaborations. We present an overview of the computational resources currently available and describe several case studies that describe the role the computing facility plays in some of the research projects the Institute is currently working on.
HPC and Grids
M. Resch
High Performance Computing Center Stuttgart, University of Stuttgart, Stuttgart, Germany
Grid computing has become a standard technology to connect computers and instruments as well as data and software. This allows creating virtual pools of resources that can easily be used. As part of this so called service oriented architectures (SOA) have evolved that claim to provide the user with a service while hiding the complexity of hardware and software. HPC has to adapt to this new scenario. Supercomputing is in itself a service and the user is mainly interested in this service and not in the details of the hardware. The paper will describe how HPC can be defined as a service in a Grid environment.
Mathematical modelling of threedimensional electromagnetic fields in inhomogeneous domains
S. Haberhauer^{1}, O.V. Nechaev^{2}, N. Shokina^{3,4}, E.P. Shurina^{2,4}
^{1}NEC  High Performance Computing Europe GmbH, Stuttgart, Germany
^{2}Novosibirsk State Technical University, Novosibirsk, Russia
^{3}High Performance Computing Center Stuttgart, University of Stuttgart, Stuttgart, Germany
^{4}Institute of computational technologies SB RAS, Novosibirsk, Russia
The results of the joint project of the Institute of Computational
Technologies of Siberian Branch of Russian Academy of Sciences (ICT
SB RAS, Novosibirsk, Russia) and the High Performance Computing
Center Stuttgart (HLRS, Stuttgart, Germany) are presented. The
project is realized within the framework of the activities of the
GermanRussian Center for Computational Technologies and High
Performance Computing (http://www.grchpc.de).
The parallel realization of the problem on mathematical modelling of threedimensional electromagnetic fields in inhomogeneous domains in frequency domain is presented.
The computational schemes are investigated in domains, which are inhomogeneous with respect to physical (electroconductivity) and geometrical (different scales of individual fragments of a modelling domain) characteristics, in the presence of field sources changing geometrical position with respect to interfragmentary boundaries, which separate individual subdomains.
The threedimensional vector Helmholtz equation is approximated on inhomogeneous tetrahedral grid with local grid refinements using the vector finite element method on the vector basis functions of high order. The basis functions (edgeelements) for calculating the electric field E guarantee continuity of tangential components of the field on interelement and interfragmentary boundaries. For exact calculation of a jump of electric field normal component the special procedure for taking into account a weak divergence on basis functions of high order is realized.
The problem on highfrequency induction logging isoparametric soundings (the VIKIZmethod in Russia) in a domain with complicated geometry is solved. The parallelization is done by formulating of n independent problems, where n is a number of probe positions, and associating each of these problems with a separate processor of computing system. The calculation results are presented, obtained on NEC SX8 cluster.
Numerical solution of some direct and inverse mathematical problems for tidal flows
V.V. Shaidurov, L.P.Kamenschikov
Institute of Computational Modelling SB RAS, Krasnoyarsk, Russia
Siberian Federal University, Krasnoyarsk, Russia
Twodimensional shallow water equations are considered, which describe tidal flows in seas and oceans. The first part is devoted to the solution of the direct problem including three differential equations for two horizontal velocities and waterlevel. The linear finite elements on triangles adapted for coastline are used for discretisation. The computational stability and convergence to exact solution are proved. In the important case of World Ocean the parallel realisation of algorithm with decomposition of solution domain is used. These computations are useful for geophysical research, coastline erosion, and tidal hydro stations. In the second part the inverse problem is studied, where the righthand side of the boundary condition is unknown and has to be reconstructed. The combination of regularization method with optimal control is used for this purpose. As the result the combination of direct problem and ajoint problem with some additional equality is obtained. A stable method for reconstruction of unknown function using other known data is used.
Hardware development and impact on numerical algorithms
U. Küster
High Performance Computing Center Stuttgart, University of Stuttgart, Stuttgart, Germany
After decades of increasing per processor performance with small architectural changes progress is now facing a handicap in the stagnation of the processors frequencies.
The chip densities and sizes are still enlarging and used for increase of the number of cores. What bottlenecks we have to be aware? What are the implications for numerical algorithms? Are there foreseeable rules for implementations?
Parallel numerical modeling of modern fiber optics devices
L.Y. Prokopeva, Yu.I. Shokin, A.S. Lebedev, M.P. Fedoruk
Institute of computational technologies SB RAS, Novosibirsk, Russia
Two and threedimensional complex structures written in modern photonic integrated devices offer so many possible design variations that a direct experimental comparison of different options is almost impractical. So, the realistic numerical modelling seems to be of a leading importance while the designing process.
The paper addresses a numerical modeling for the processing of electric and magnetic fields in the fiber media, generally described by Maxwell equations. Complex microstructures and composite materials that are presented at modern optics devices require special techniques to be modeled. These peculiarities are all considered in FVTD method proposed. The computational complexity typically appeared in multidimensional computations is resolved with parallel computations. For this purpose the decomposition of unstructured triangular grids and MPI programming model are implemented. The resulting efficiency graphics has been obtained on HLRS cluster (NEC Xeon EM64T Cluster(cacau)) show quite good scalability.
In particular case, the simple fiber waveguide can also be described by the simplified mathematical model. Nevertheless the high computational complexity arises when femtosecond laser inscription with close to critical input power are considered. In order to parallelize these computations the parallel Thomas algorithm for solving the tridiagonal linear systems was implemented. The obtained efficiency graphics are discussed.
Parallel and Adaptive Simulation of Fuel Cells in 3d
R. Klöfkorn, D. Kröner, M. Ohlberger, A. Dedner
Institute of Applied Mathematics, University of Freiburg i. Br., Freiburg i. Br., Germany
As a further development of our research on Simulation of Fuel Cells in this paper we present parallel, adaptive computations using a complex fuel cell model. Previously, in [1] we could show that with the software package Dune (see [2]) parallel and adaptive computations of problems in the field of fluid dynamics can be done efficiently. Furthermore, in [3] we derived a general object oriented framework for discretising nonlinear evolution equations arising in this field. Based on this work, in this paper we present a complex fuel cell model including twophase flow, multicomponent transport in porous media. The model is derived from the model we presented in [4] and has been adapted slightly. The considered system of equations is discretised by using the Discontinuous Galerkin Method, e.g. the OdenBaumann method for the pressure equation and the Local Discontinuous Galerkin method for the saturation and transport equations. Numerical results for the simulation of a half cell (cathodic side of the fuel cell) are presented using the above described features. The presented simulations use implicit and explicit solvers and are done in parallel including local grid adaptivity and dynamic load balancing.
 A. Burri, A. Dedner, R. Klöfkorn, and M. Ohlberger. An efficient implementation of an adaptive and parallel grid in DUNE. In: Computational science and high performance computing II. The 2nd RussianGerman advanced research workshop, Stuttgart, Germany, March 1416, 2005. Springer Series: Notes on Numerical Fluid Mechanics and Multidisciplinary Design (NNFM), Springer.
 P. Bastian, M. Droske, C. Engwer, R. Klöfkorn, T. Neubauer, M. Ohlberger, M. Rumpf. Towards a unified framework for scientific computing. In: Proceedings of the 15th international conference on domain decomposition methods, 2004.
 A. Burri, A. Dedner, D. Diehl, R. Klöfkorn, M. Ohlberger. A general object oriented framework for discretizing nonlinear evolution equations. In: Advances in high performance computing and computational science. The 1st KazakhGerman advanced research workshop, Almaty, Kazakhstan, September 24  October 1, 2005. Springer Series: Notes on Numerical Fluid Mechanics and Multidisciplinary Design (NNFM), Springer.
 K. Kühn, M. Ohlberger, J.O. Schumacher, C. Ziegler, R. Klöfkorn. A dynamic twophase flow model of proton exchange membrane fuel cells. Preprint CSCAMM Report 0307, Submitted to the 2nd EUROPEAN PEFC FORUM, Luzern, 2003.
Mathematical modelling in regional tsunami warning systems
L.B. Chubarov
Institute of computational technologies SB RAS, Novosibirsk, Russia
Catastrophic tsunamis that crushed upon the ocean coast in the past had taken many human lives and destroyed the infrastructure of the coastal areas in several countries in Asia and in the Pacific. Recent tragic events motivated governments to develop new and improve the existing tsunami warning systems capable of mitigating the impact of catastrophic events. In future regional tsunami warning systems will be integrated into a network including both the systems currently being developed and the existing warning systems (in the past tsunami warning systems had been deployed to protect the coastal areas in Japan, USA, Australia, Chile and New Zealand).
We present the work conducted by the Institute of Computational Technologies in collaboration with other research institutes in Novosibirsk within the project to design a new generation of the tsunami warning system for the Pacific coast of Kamchatka. The aim of the project is to develop a technology that will allow us to build a database of possible occurrences of disastrous waves along the coast in a series of numerical experiments. In the first stage of the project a collection of basic model sources of tsunamigenic earthquakes will be defined. The model sources will be used to calculated initial elevation fields on the ocean surface. The next stage will employ numerical modelling to model the propagation and transformation of tsunami waves on the way from the source towards the coast. This information will be presented as a decision support system used by persons responsible for initiating disaster mitigation procedures such as evacuation of people and sending ships away from the dangerous areas of the coast.
The project will involve numerical solution of a large number of instances of wave hydrodynamics problems. At the same time interpretation of the results will require non trivial postprocessing and building specialized information systems. Numerical solution of wave hydrodynamics problems for multiple combinations of parameters of the earthquake source with high spatial resolution constitutes the major part of the computational requirements of the project. The amount of computations needed implies the use of high performance computers and may require adaptation of numerical algorithms to specific computing platforms.
In the future this approach may be extended to other areas of the basins of the Pacific and the Indian ocean. In the latter case we plan to consider the problem of finding the zones of the coast that carry a high level of risk of being affected by tsunamis. This would require to perform runup calculations. To achieve the necessary precision we will need to take into account such features of the coastal line as small rivers, lakes and swamps. This will significantly increase the amount of computational power needed both during the development of numerical models and algorithms and in the production runs.
Zonal LargeEddy Simulations and Aeroacoustics of HighLift Airfoil Configurations
M. Meinke, D. König, Q. Zhang, W. Schröder
Institute of Aerodynamics, RWTH Aachen University, Aachen, Germany
For the efficient prediction of aerodynamic noise, zonal LargeEddy Simulations are carried out for highlift airfoil configurations. Subsequently, the aeroacoustic sound field is determined with two different approaches, first by solving acoustic perturbation equations and second by using an acoustic analogy. The zonal LES is based on a hybrid RANSLES solution, in which the LES is only carried out in the part of the domain where the unsteady flow field is required for the acoustic analysis. The flow around the airfoil (slat and main wing) is performed at a Reynolds number of 1.4~million based on the clean chord length. The free stream Mach number is M=0.16 and the angle of attack is 130 degrees. A computational mesh with about 55~million points is used for the full LES to resolve all relevant turbulent scales in the boundary layers and within the slat cove region. A comparison of results with experimental data shows an acceptable agreement. For the determination of the acoustic field two different approaches, acoustic perturbation equations (APE) and the FfowcsWilliams and Hawkings (FWH) equation, are used, which both need the unsteady LES solution. Results from the acoustic field are presented, which allow a detailed analysis of the flow phenomena responsible for the slat noise generation.
Serviceoriented modeling and architecture for control of municipality administrations
I.V. Bychkov
Institute of System Dynamics and Control Theory SB RAS, Irkutsk, Russia
The paper presents the fundamentals of a serviceoriented architecture (SOA), its layers, and the associated types of architectural decisions. The method for serviceoriented modeling and the characteristics of activities from a service consumer and provider perspectives are described. This method guarantees necessary requirements for analysis and design in order to determine three fundamental aspects of a serviceoriented architecture: services, flows, and components that realize the services.
SOA is an architectural style, which has a goal to achieve a loose coupling among interacting software agents. A service is a unit of work done by a service provider to achieve desired final results for a service consumer. Both provider and consumer are roles played by software agents on behalf of their owners.
A template is described, which can be used for architectural decisions in each of the SOA layers. For service identification it is important to combine three approaches of topdown, bottomup, and crosssectional analysis of problem modelling. The main activities of specification and realization of services are considered.
Mathematical and numerical modelling of fluid flow in elastic tubes
E. Bänsch^{1}, O. Goncharova^{2}, A. Koop^{3}, D. Kröner^{4}
^{1}Chair of Applied Mathematics, University of Erlangen
^{2}Altai State University, Barnaul, Russia
^{2}Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, Russia
^{3}Sternenberg 19, 42279 Wuppertal, Germany
^{4}Institute of Applied Mathematics, University of Freiburg i. Br., Freiburg i. Br., Germany
The study of fluid flow inside compliant vessels, which are deformed under an action of the fluid, is important due to many biochemical and biomedical applications, e.g. the flows in blood vessels.
The mathematical problem consists of the 3D NavierStokes equations for incompressible fluids coupled with the differential equations, which describe the displacements of the vessel wall (or elastic structure). We study the fluid flow in a tube with different boundaries: inflow boundary, outflow boundary and elastic wall and prescribe different boundary conditions of Dirichlet and Neumann types on these boundaries. The velocity of the fluid on the elastic wall is given by the deformation velocity of the wall.
In this report we present the mathematical modelling for the elastic structures based on the shell theory, the simplifications for cylindertype shells, the solver for the coupled problem, the numerical results for the benchmark "pressure pulse in a compliant vessel" and further numerical experiments.
Parameter partitioning methods for optimal numerical solution of interval linear systems
S.P. Shary
Institute of computational technologies SB RAS, Novosibirsk, Russia
There exists a variety of problem statements that arise in connection with interval linear systems of the form Ax = b, where A is an interval matrix and b is an interval righthand side vector. The most popular and historically first of these problems is that of finding "outer" componentwise estimates for the solution set constituted by solutions to all the point linear systems Ax = b with the matrices A from A and righthand sides b from b. An exact description of the solution sets proves both impossible (due to its enormous complexity) and unnecessary, while in real life one usually needs approximate estimates, in this or that sense, of the solution sets. Our presentation is a survey of the socalled parameter partitioning methods recently developed for numerical computation of sharp (optimal) enclosures of the solution sets to interval linear systems of equations. We overview their main advantages  capability to adapt the execution to the problem under solution, sequential guarantee and good parallelism  as well as possible extensions for the solution of the interval linear systems with tied (dependent) interval parameters.
Integrated Design of Runners for Francis Turbines
E. Göde
Institute for Fluid Mechanics and Hydraulic Machinery, University of Stuttgart, Stuttgart, Germany
Depending on the hydraulic head there is a variety of different types of turbines used in hydro electric power plants. In the range of 50 to 500 m head normally the Francis turbine is used. In total all over the world roughly 85% of the turbines are of the type Francis. Even the biggest hydroelectric turbines ever built are of this type. Within the two biggest power plants worldwide  Itaipu in Argentina as well as Three Gorges in China  one single turbine generates a power output of more than 700 MW at rated head. As an example the picture shows a runner for Three Gorges before installation in the power house having a diameter of 10 m and a weight of 350 tons.
In modern hydraulic engineering the numerical flow simulation is still a key tool but only one part of the whole design process. It has been found that the integration of all the other parts that are necessary to perform the complete design process is of equal importance:
 to create the runner geometry in terms of blade profiles and flow channel,
 to generate the (appropriate) computational mesh,
 to specify the (correct) boundary condition,
 to perform the flow simulation,
 to visualise the important computational results in detail,
 to summarize the main results in order to decide whether,
 to continue or to stop the design procedure.
This is to be done in accordance with the connected components of the plant and in the whole range of operation given by the hydrology of the power station.
It is obvious that this complex design process has to be integrated and stream lined as much as possible to enable the engineer to optimise a Francis runner. This is not only true in order to achieve the desired power output and hydraulic efficiency. In addition, to minimise the cavitation inception at critical flow regimes and to minimise vibration due to rotor  stator interaction as well as due to draft tube vortex formation at offdesign conditions, a great number of design steps are necessary to be carried out.
Some examples will be given.
Numerical modelling of some free turbulent flows
G.G. Chernykh^{1}, A.G. Demenkov^{2}, A.V. Fomina^{1}, B.B. Ilyushin^{2},
V.A. Kostomakha^{3}, N.P. Moshkin^{1}, O.F. Voropayeva^{1}
^{1}Institute of computational technologies SB RAS, Novosibirsk, Russia
^{2}Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
^{3}Lavrentiev Institute of Hydrodynamics SB RAS, Novosibirsk, Russia
Based on the closed KarmanHowarth equation a numerical model for isotropic turbulence dynamics has been constructed. Comparisons with measurements demonstrate good agreement in the case of developed turbulence dynamics and quite satisfactory agreement for weak turbulence dynamics.
The numerical simulation of plane and axisymmetric wakes with varied values of total excess momentum has been performed. The numerical analysis of dynamics of swirling turbulent wakes with varied values of total excess momentum and angular momentum was carried out . The numerical model of axisymmetric turbulent jet dynamics has been constructed.
The numerical investigation of the propagation of admixture from a local instantaneous source in twodimensional turbulent mixing zone in a continuously stratified fluid was conducted. The results of numerical experiments indicate that the nature of the average admixture concentration distribution depends significantly on the initial data for this quantity.
A numerical analysis of the evolution of momentumless and drag turbulent wakes in continuously stratified fluid has been carried out by using a hierarchy of modern semiempirical turbulence models. The calculation results show that the turbulent wake behind a towed body generates the waves of essentially greater amplitude then behind the selfpropelled body.
The work was supported by the Russian Foundation for the Basic Research (010100783, 040100209, 060100724, 070100363).
On performance and accuracy of lattice Boltzmann approaches
for single phase flow in porous media
A toy became an accepted tool  how to maintain/improve its features
despite/with more and more complex (physical) models
and changing trends in high performance computing?!
T. Zeiser
Regional Computing Centre Erlangen, University of ErlangenNuremberg, Erlangen, Germany
During the last two decades, lattice Boltzmann approaches quickly evolved from a toy of physicists to a well accepted tool of engineers and scientists. An exponentially growing number of groups investigates in the meantime very diverse fields from computational fluid dynamics (CFD) with the help of Lattice Boltzmann methods (LBM), including single or multiphase flow in porous media, basic turbulence research, free surface flow, nanoscale flow, blood flow, car aerodynamics, fluidstructure interaction, or aeroacoustics  in short: almost any type of "complex" flow.
Arguments for the choice of LBM have since the very beginning been:
 ease of implementation,
 good parallel performance,
 acceptable accuracy (2nd order if boundary conditions are handled appropriately),
 solid physical basis.
This presentation will focus on single phase flow in porous media and comment on performance and accuracy issues:
 different types of lattice Boltzmann models (BGK, TRT, MRT, weakly compressible, more incompressible, linear LB scheme for Stokes flow, ...) have been developed. They not only show varying stability and accuracy but also very different computational costs,
 the same is true for the handling of solidwall boundary conditions (e.g. from simple bounce back to 2nd order geometric schemes with quadratic interpolation).
With evolving computer hardware, algorithmic and implementations issues change all the time, i.e. owing to hardware changing
 from specially designed HPC hardware like vectorparallel system
 to commodity  but often massively parallel  clusters with multicore CPUs, and
 perhaps specialpurpose hardware (again) in the future.
Data layout and placement, partitioning strategies, spatial and temporal blocking, or hybrid programming therefore become more and more important. As some specialpurpose hardware available today (e.g. the Cell processor or GPUs) can only handle single precision floating point data, it is also a question how well LBM can do with that. The presentation will touch many of these topics theoretically or with examples and show performance results from bleeding edge hardware.
Distinguishing attacks on RC4 and ZKcrypt stream ciphers using the book stack test
S. Doroshenko^{1}, A. Fionov^{1}, A. Lubkin^{1}, V. Monarev^{1}, B. Ryabko^{1,2}
^{1}Siberian State University of Telecommunications and Computer Science, Novosibirsk, Russia
^{2}Institute of Computational Technologies SB RAS, Novosibirsk, Russia
Cryptanalysis of information protection systems is an important application field of computing facilities and technologies. The paper presents a new technology that offers considerable advances in cryptanalysis of stream ciphers and pseudorandom bit generators (PRBGs) used as the basic tool in many information protection systems. The distinguishing attack on stream ciphers and PRBGs aims to find deviations from randomness in the output sequences produced thereby. A PRBG (and a corresponding stream cipher based on it) is cryptographically secure if it passes all polynomialtime statistical tests, i.e., the bit sequences it produces are indistinguishable from truly random sequences in polynomial time. The recently suggested statistical test named "Book Stack'' is successfully applied to detect deviations from randomness in bit sequences generated by RC4 and ZKCrypt stream ciphers (RC4 is a renown and widely used stream cipher, ZKCrypt is a candidate cipher suggested for ECRYPT Stream Cipher Project (eSTREAM)). The paper briefly describes the essence of the test. An efficient program implementation and experiments data are provided.
A Grid Management System for the solution of complex simulation problems
N. CurrleLinde
High Performance Computing Center Stuttgart, University of Stuttgart, Stuttgart, Germany
Currently, numerical simulation using automated parameter studies is already a key tool in discovering functional optima in complex systems such as biochemical drug design and car crash analysis.
In the future, such studies of complex systems will be extremely important for the purpose of steering simulations. One such example is the optimum design and steering of high power furnaces of power plants. The performance of today's high performance computers and PCclusters enables simulation studies with results that are as reliable as those obtained from physical experimentation. Recently, Grid technology has supported this development by providing uniform and secure access to computing resources over wide area networks (WANs), making it possible for industries to investigate large numbers of parameter sets using sophisticated simulations. However, the large scale of such studies requires organized support for the submission, monitoring, and termination of jobs, as well as mechanisms for the collection of results, and the dynamic generation of new parameter sets in order to intelligently approach an optimum. In this talk, we describe a solution to these problems which we call Science Experimental Grid Laboratory (SEGL). The system defines complex workflows which can be executed in the Grid environment, and supports the dynamic generation of parameter sets. It also allows the execution of sets of independent tasks of interdependent jobs which can run either synchronously or asynchronously on heterogeneous systems.
Tropospheric dynamics response to polar stratospheric vortex perturbations
in general circulation model
V.N. Krupchatnikov
Institute of Computational Mathematics and Mathematical Geophysics SB RAS, Novosibirsk, Russia
Novosibirsk State University, Novosibirsk, Russia
Dynamic interaction between a stratosphere and troposphere, in particular, connected with planetary waves, can render essential influence on variations of tropospheric circulation with time scales from several days about several months. Climatology of extratropical stratospheres it is defined by intensity of a polar vortex, which is connected, with gradients rate of temperature. Recently there is decrease of temperature of the top layers of an atmosphere, contrast between a tropical and polar stratosphere and, accordingly, a temperature gradient decreases. Therefore the question on how changes of a polar vortex influence a condition of the bottom layers of an atmosphere represents essential interest. So, for example, in several works, using daily and monthly average data has been established communication between variations surface pressure, strength of polar vortex and tropopause altitude. Increasing of polar vortex connected with low tropopause over Iceland and high tropopause over Arctic. High tropopause altitude is connected with strength and twisting of column of air and small drop of surface pressure in polar region. However, we have no deep understanding of mechanism of interaction of atmosphere and stratosphere. This report deals with modeling research of the problem using atmosphere general circulation model.
The work was supported by the RFBR grant No. 0505  64989
Trends in high performance computers: How to get scalable applications?
W.E. Nagel
Center for Information Services and High performance Computing, TU Dresden, Dresden, Germany
Since a couple of years, multicore chips get more and more common in high performance computing (HPC), and we expect to see systems with more than 100000 cores even in reasonably sized HPC systems. This will increase the peak performance of such computers to Petaflops and more. The only remaining question is: Are we prepared to efficiently use such machines? Do we already know how to program these computers, how to detect bottlenecks and how to improve efficiency? The talk will address these topics and describe actual trends and perspectives.
Principal tendencies of development of telemedical technologies in Siberian region
A.V. Efremov^{1}, A.V. Karpov^{1,2}
^{1}Novosibirsk State medical University, Novosibirsk, Russia
^{2}Institute of Computational Technologies SB RAS, Novosibirsk, Russia
Telemedicine is the using of achievements of telecommunication technologies in the public health service.
Telemedicine allows improving the efficacy of treatment and diagnosis on a new level. With the aid of such technologies you can render a great qualified help to a remote patient in the best medical institutions of our country as well as of the whole world.
Doctors can make a diagnosis using as the base received through the email or the Internet Xray pictures, computer tomograms, electrocardiograms, brainwaves or other findings of laboratory or instrumental patient's examinations.
In connection with the fact that the essential part of specialists in different fields of medicine work in specialized medical centers of big cities, so it provoked some centralization of attendance. However, the achievements of telemedicine remove the necessity of direct physical presence of a specialist.
Modern telemedical ways allow realizing removed advisories of doctors and their patients locating in far regions.
By the way, for realizing of consultation of any ill person a physician can repose not only his own experience.
Thank to telecommunication technologies physicians and specialists can listen to lectures of famous scientists of the most actual problems of the public health service and medical science, to keep professional contacts with global scientific centers, and also with their colleagues from neighboring district hospitals or from principal specialists of regional center.
The possibility of using of technologies of videoconferences is very attractive which permits the real communication in the regimen of video transmission.
