368 research outputs found
Measurement criteria in man machine systems simulation
Simulation, models, and games as analogies measurement criteria in man-machine system simulatio
On the inverse optimal control problem in manual control systems
Inverse optimal control in manual control system
Modern control system theory and human control functions
Optimal control system theory applied to manual control systems - adaptive control - mathematical model
Human performance prediction in man-machine systems. Volume 1 - A technical review
Tests and test techniques for human performance prediction in man-machine systems task
Human performance prediction in man-machine systems. Part 2 - The test catalog
Human performance prediction in man machine systems - test catalog table
Stress-Energy Tensor for the Massless Spin 1/2 Field in Static Black Hole Spacetimes
The stress-energy tensor for the massless spin 1/2 field is numerically
computed outside and on the event horizons of both charged and uncharged static
non-rotating black holes, corresponding to the Schwarzschild,
Reissner-Nordstrom and extreme Reissner-Nordstr\"om solutions of Einstein's
equations. The field is assumed to be in a thermal state at the black hole
temperature. Comparison is made between the numerical results and previous
analytic approximations for the stress-energy tensor in these spacetimes. For
the Schwarzschild (charge zero) solution, it is shown that the stress-energy
differs even in sign from the analytic approximation. For the
Reissner-Nordstrom and extreme Reissner-Nordstrom solutions, divergences
predicted by the analytic approximations are shown not to exist.Comment: 5 pages, 4 figures, additional discussio
A freely relaxing polymer remembers how it was straightened
The relaxation of initially straight semiflexible polymers has been discussed
mainly with respect to the longest relaxation time. The biologically relevant
non-equilibrium dynamics on shorter times is comparatively poorly understood,
partly because "initially straight" can be realized in manifold ways. Combining
Brownian dynamics simulations and systematic theory, we demonstrate how
different experimental preparations give rise to specific short-time and
universal long-time dynamics. We also discuss boundary effects and the onset of
the stretch--coil transition.Comment: 14 pages, 5 figures, 3 table
Emergence of robust nucleosome patterns from an interplay of positioning mechanisms
Proper positioning of nucleosomes in eukaryotic cells is determined by a complex interplay of factors, including nucleosome-nucleosome interactions, DNA sequence, and active chromatin remodeling. Yet, characteristic features of nucleosome positioning, such as geneaveraged nucleosome patterns, are surprisingly robust across perturbations, conditions, and species. Here, we explore how this robustness arises despite the underlying complexity. We leverage mathematical models to show that a large class of positioning mechanisms merely affects the quantitative characteristics of qualitatively robust positioning patterns. We demonstrate how statistical positioning emerges as an effective description from the complex interplay of different positioning mechanisms, which ultimately only renormalize the model parameter quantifying the effective softness of nucleosomes. This renormalization can be species-specific, rationalizing a puzzling discrepancy between the effective nucleosome softness of S. pombe and S. cerevisiae. More generally, we establish a quantitative framework for dissecting the interplay of different nucleosome positioning determinants
Pinwheel stabilization by ocular dominance segregation
We present an analytical approach for studying the coupled development of
ocular dominance and orientation preference columns. Using this approach we
demonstrate that ocular dominance segregation can induce the stabilization and
even the production of pinwheels by their crystallization in two types of
periodic lattices. Pinwheel crystallization depends on the overall dominance of
one eye over the other, a condition that is fulfilled during early cortical
development. Increasing the strength of inter-map coupling induces a transition
from pinwheel-free stripe solutions to intermediate and high pinwheel density
states.Comment: 10 pages, 4 figure
Asymptotic Level Density of the Elastic Net Self-Organizing Feature Map
Whileas the Kohonen Self Organizing Map shows an asymptotic level density
following a power law with a magnification exponent 2/3, it would be desired to
have an exponent 1 in order to provide optimal mapping in the sense of
information theory. In this paper, we study analytically and numerically the
magnification behaviour of the Elastic Net algorithm as a model for
self-organizing feature maps. In contrast to the Kohonen map the Elastic Net
shows no power law, but for onedimensional maps nevertheless the density
follows an universal magnification law, i.e. depends on the local stimulus
density only and is independent on position and decouples from the stimulus
density at other positions.Comment: 8 pages, 10 figures. Link to publisher under
http://link.springer.de/link/service/series/0558/bibs/2415/24150939.ht
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