1,032 research outputs found
Optimizing genetic algorithm strategies for evolving networks
This paper explores the use of genetic algorithms for the design of networks,
where the demands on the network fluctuate in time. For varying network
constraints, we find the best network using the standard genetic algorithm
operators such as inversion, mutation and crossover. We also examine how the
choice of genetic algorithm operators affects the quality of the best network
found. Such networks typically contain redundancy in servers, where several
servers perform the same task and pleiotropy, where servers perform multiple
tasks. We explore this trade-off between pleiotropy versus redundancy on the
cost versus reliability as a measure of the quality of the network.Comment: 9 pages, 5 figure
Techniques for noise removal from EEG, EOG and air flow signals in sleep patients
Noise is present in the wide variety of signals obtained from sleep patients.
This noise comes from a number of sources, from presence of extraneous signals
to adjustments in signal amplification and shot noise in the circuits used for
data collection. The noise needs to be removed in order to maximize the
information gained about the patient using both manual and automatic analysis
of the signals. Here we evaluate a number of new techniques for removal of that
noise, and the associated problem of separating the original signal sources.Comment: 9 pages, 3 figure
Fluctuations and noise in cancer development
This paper explores fluctuations and noise in various facets of cancer
development. The three areas of particular focus are the stochastic progression
of cells to cancer, fluctuations of the tumor size during treatment, and noise
in cancer cell signalling. We explore the stochastic dynamics of tumor growth
and response to treatment using a Markov model, and fluctutions in tumor size
in response to treatment using partial differential equations. We also explore
noise within gene networks in cancer cells, and noise in inter-cell signalling.Comment: 11 pages, 6 figure
Gene network analysis and design
Gene networks are composed of many different interacting genes and gene products (RNAs and proteins). They can be thought of as switching regions in n-dimensional space or as mass-balanced signaling networks. Both approaches allow for describing gene networks with the limited quantitative or even qualitative data available. We show how these approaches can be used in modeling the apoptosis gene network that has a vital role in tumor development. The open question is whether engineering changes to this network could be used as a possible cancer treatment
Too good to be true: when overwhelming evidence fails to convince
Is it possible for a large sequence of measurements or observations, which
support a hypothesis, to counterintuitively decrease our confidence? Can
unanimous support be too good to be true? The assumption of independence is
often made in good faith, however rarely is consideration given to whether a
systemic failure has occurred.
Taking this into account can cause certainty in a hypothesis to decrease as
the evidence for it becomes apparently stronger. We perform a probabilistic
Bayesian analysis of this effect with examples based on (i) archaeological
evidence, (ii) weighing of legal evidence, and (iii) cryptographic primality
testing.
We find that even with surprisingly low systemic failure rates high
confidence is very difficult to achieve and in particular we find that certain
analyses of cryptographically-important numerical tests are highly optimistic,
underestimating their false-negative rate by as much as a factor of
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