467,562 research outputs found
Making up for the deficit in a marathon run
To predict the final result of an athlete in a marathon run thoroughly is the
eternal desire of each trainer. Usually, the achieved result is weaker than the
predicted one due to the objective (e.g., environmental conditions) as well as
subjective factors (e.g., athlete's malaise). Therefore, making up for the
deficit between predicted and achieved results is the main ingredient of the
analysis performed by trainers after the competition. In the analysis, they
search for parts of a marathon course where the athlete lost time. This paper
proposes an automatic making up for the deficit by using a Differential
Evolution algorithm. In this case study, the results that were obtained by a
wearable sports-watch by an athlete in a real marathon are analyzed. The first
experiments with Differential Evolution show the possibility of using this
method in the future.Comment: ISMSI 201
Cellular decision-making bias: the missing ingredient in cell functional diversity
Cell functional diversity is a significant determinant on how biological
processes unfold. Most accounts of diversity involve a search for sequence or
expression differences. Perhaps there are more subtle mechanisms at work. Using
the metaphor of information processing and decision-making might provide a
clearer view of these subtleties. Understanding adaptive and transformative
processes (such as cellular reprogramming) as a series of simple decisions
allows us to use a technique called cellular signal detection theory (cellular
SDT) to detect potential bias in mechanisms that favor one outcome over
another. We can apply method of detecting cellular reprogramming bias to
cellular reprogramming and other complex molecular processes. To demonstrate
scope of this method, we will critically examine differences between cell
phenotypes reprogrammed to muscle fiber and neuron phenotypes. In cases where
the signature of phenotypic bias is cryptic, signatures of genomic bias
(pre-existing and induced) may provide an alternative. The examination of these
alternates will be explored using data from a series of fibroblast cell lines
before cellular reprogramming (pre-existing) and differences between fractions
of cellular RNA for individual genes after drug treatment (induced). In
conclusion, the usefulness and limitations of this method and associated
analogies will be discussed.Comment: 18 pages; 6 figures, 2 tables, 4 supplemental figure
Relationship Between Quantum Walk and Relativistic Quantum Mechanics
Quantum walk models have been used as an algorithmic tool for quantum
computation and to describe various physical processes. This paper revisits the
relationship between relativistic quantum mechanics and the quantum walks. We
show the similarities of the mathematical structure of the decoupled and
coupled form of the discrete-time quantum walk to that of the Klein-Gordon and
Dirac equations, respectively. In the latter case, the coin emerges as an
analog of the spinor degree of freedom. Discrete-time quantum walk as a coupled
form of the continuous-time quantum walk is also shown by transforming the
decoupled form of the discrete-time quantum walk to the Schrodinger form. By
showing the coin to be a means to make the walk reversible, and that the
Dirac-like structure is a consequence of the coin use, our work suggests that
the relativistic causal structure is a consequence of conservation of
information. However, decoherence (modelled by projective measurements on
position space) generates entropy that increases with time, making the walk
irreversible and thereby producing an arrow of time. Lieb-Robinson bound is
used to highlight the causal structure of the quantum walk to put in
perspective the relativistic structure of quantum walk, maximum speed of the
walk propagation and the earlier findings related to the finite spread of the
walk probability distribution. We also present a two-dimensional quantum walk
model on a two state system to which the study can be extended.Comment: 12 pages and 1 figure, Published versio
On the Complete Integrability of Nonlinear Dynamical Systems on Discrete Manifolds within the Gradient-Holonomic Approach
A gradient-holonomic approach for the Lax type integrability analysis of
differentialdiscrete dynamical systems is devised. The asymptotical solutions
to the related Lax equation are studied, the related gradient identity is
stated. The integrability of a discrete nonlinear Schredinger type dynamical
system is treated in detail.Comment: 20 page
Open Quantum Systems. An Introduction
We revise fundamental concepts in the dynamics of open quantum systems in the
light of modern developments in the field. Our aim is to present a unified
approach to the quantum evolution of open systems that incorporates the
concepts and methods traditionally employed by different communities. We
present in some detail the mathematical structure and the general properties of
the dynamical maps underlying open system dynamics. We also discuss the
microscopic derivation of dynamical equations, including both Markovian and
non-Markovian evolutions.Comment: 100 pages, 3 figures. Updated version with typos corrected. Preprint
version of the published boo
Time-sliced path integrals with stationary states
The path integral approach to the quantization of one degree-of-freedom
Newtonian particles is considered within the discrete time-slicing approach, as
in Feynman's original development. In the time-slicing approximation the
quantum mechanical evolution will generally not have any stationary states. We
look for conditions on the potential energy term such that the quantum
mechanical evolution may possess stationary states without having to perform a
continuum limit. When the stationary states are postulated to be solutions of a
second-order ordinary differential equation (ODE) eigenvalue problem it is
found that the potential is required to be a solution of a particular
first-order ODE. Similarly, when the stationary states are postulated to be
solutions of a second-order ordinary difference equation (OE)
eigenvalue problem the potential is required to be a solution of a particular
first-order OE. The classical limits (which are at times very
nontrivial) are integrable maps.Comment: 7 page
Algorithms Applied to Global Optimisation – Visual Evaluation
Evaluation and assessment of various search and optimisation algorithms is subject of large research efforts. Particular interest of this study is global optimisation and presented approach is based on observation and visual evaluation of Real-Coded Genetic Algorithm, Particle Swarm Optimisation, Differential Evolution and Free Search, which are briefly described and used for experiments. 3D graphical views, generated by visualisation tool VOTASA, illustrate essential aspects of global search process such as divergence, convergence, dependence on initialisation and utilisation of accidental events. Discussion on potential benefits of visual analysis, supported with numerical results, which could be used for comparative assessment of other methods and directions for further research conclude presented study
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