A Development Environment for Visual Physics Analysis

The Visual Physics Analysis (VISPA) project integrates different aspects of physics analyses into a graphical development environment. It addresses the typical development cycle of (re-)designing, executing and verifying an analysis. The project provides an extendable plug-in mechanism and includes plug-ins for designing the analysis flow, for running the analysis on batch systems, and for browsing the data content. The corresponding plug-ins are based on an object-oriented toolkit for modular data analysis. We introduce the main concepts of the project, describe the technical realization and demonstrate the functionality in example applications

SECURITY OF RUNNING OF COMPETETIVE COURSE IN ALPINE SKIING ACCORDING TO ITS GEOMETRY OF SETTING

In alpine ski disciplines there are plenty of incidents. Sometimes up to 40 % of competitors do not finish the run. The reasons are wrong preparation of skiers and wrong tactics of running. But there are also some errors in setting of gates of a course. The aim of this paper is to present some examples of those errors. One of them is a long intergate distances with small angles of deviation where skier achieves high velocity and just after that a big angle of deviation of a course with small intergate distance. The other is positioning of one gate above a downcast and the other just below a downcast. In Kvitfjel 2007 up to 10 skiers ran off the track in such a configuration

KINEMATICS OF TACTICS IN THE MEN'S 1500 M FREESTYLE SWIMMING FINAL AT THE BEIJING 2008 OLYMPIC GAMES

The purpose of this study was to obtain a knowledge on tactics of long distance swimming at the highest professional level. Eight swimmers - men, finalists of 1500 m distance of freestyle of the Beijing 2008 Olympic Games were investigated. The distribution of velocity of swimming for the entire distance based on 50 m segments was analyzed. Partial, halves and tierces velocities, velocity indexes and linear regression equations were calculated. It was revealed that better swimmers (placed 1 – 4) had their distribution of swimming as ascending line and with very small difference between segmental velocities and that of the entire distance, while the rest of swimmers had descending velocity line and higher dispersion of partial values

Generation of Pure-State Single-Photon Wavepackets by Conditional Preparation Based on Spontaneous Parametric Downconversion

We study the conditional preparation of single photons based on parametric downconversion, where the detection of one photon from a given pair heralds the existence of a single photon in the conjugate mode. We derive conditions on the modal characteristics of the photon pairs, which ensure that the conditionally prepared single photons are quantum-mechanically pure. We propose specific experimental techniques that yield photon pairs ideally suited for single-photon conditional preparation.Comment: 14 pages, 6 figure

Collective motion of active Brownian particles in one dimension

We analyze a model of active Brownian particles with non-linear friction and velocity coupling in one spatial dimension. The model exhibits two modes of motion observed in biological swarms: A disordered phase with vanishing mean velocity and an ordered phase with finite mean velocity. Starting from the microscopic Langevin equations, we derive mean-field equations of the collective dynamics. We identify the fixed points of the mean-field equations corresponding to the two modes and analyze their stability with respect to the model parameters. Finally, we compare our analytical findings with numerical simulations of the microscopic model.Comment: submitted to Eur. Phys J. Special Topic

When it Pays to Rush: Interpreting Morphogen Gradients Prior to Steady-State

During development, morphogen gradients precisely determine the position of gene expression boundaries despite the inevitable presence of fluctuations. Recent experiments suggest that some morphogen gradients may be interpreted prior to reaching steady-state. Theoretical work has predicted that such systems will be more robust to embryo-to-embryo fluctuations. By analysing two experimentally motivated models of morphogen gradient formation, we investigate the positional precision of gene expression boundaries determined by pre-steady-state morphogen gradients in the presence of embryo-to-embryo fluctuations, internal biochemical noise and variations in the timing of morphogen measurement. Morphogens that are direct transcription factors are found to be particularly sensitive to internal noise when interpreted prior to steady-state, disadvantaging early measurement, even in the presence of large embryo-to-embryo fluctuations. Morphogens interpreted by cell-surface receptors can be measured prior to steady-state without significant decrease in positional precision provided fluctuations in the timing of measurement are small. Applying our results to experiment, we predict that Bicoid, a transcription factor morphogen in Drosophila, is unlikely to be interpreted prior to reaching steady-state. We also predict that Activin in Xenopus and Nodal in zebrafish, morphogens interpreted by cell-surface receptors, can be decoded in pre-steady-state.Comment: 18 pages, 3 figure

Qualification Procedures of the CMS Pixel Barrel Modules

The CMS pixel barrel system will consist of three layers built of about 800 modules. One module contains 66560 readout channels and the full pixel barrel system about 48 million channels. It is mandatory to test each channel for functionality, noise level, trimming mechanism, and bump bonding quality. Different methods to determine the bump bonding yield with electrical measurements have been developed. Measurements of several operational parameters are also included in the qualification procedure. Among them are pixel noise, gains and pedestals. Test and qualification procedures of the pixel barrel modules are described and some results are presented.Comment: 7 Pages, 7 Figures. Contribution to Pixel 2005, September 5-8, 2005, Bonn, Germna