633 research outputs found
Rejoinder: The 2005 Neyman Lecture: Dynamic Indeterminism in Science
Rejoinder to ``The 2005 Neyman Lecture: Dynamic Indeterminism in Science''
[arXiv:0808.0620]Comment: Published in at http://dx.doi.org/10.1214/08-STS246REJ the
Statistical Science (http://www.imstat.org/sts/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Combining frequency and time domain approaches to systems with multiple spike train input and output
A frequency domain approach and a time domain approach have been combined in an investigation of the behaviour of the primary and secondary endings of an isolated muscle spindle in response to the activity of two static fusimotor axons when the parent muscle is held at a fixed length and when it is subjected to random length changes. The frequency domain analysis has an associated error process which provides a measure of how well the input processes can be used to predict the output processes and is also used to
specify how the interactions between the recorded processes
contribute to this error. Without assuming stationarity of the input, the time domain approach uses a sequence of probability models of increasing complexity in which the number of input processes to the model is progressively increased. This feature of the time domain approach was used to identify a preferred direction of interaction between the processes underlying the generation of the activity of the primary and secondary endings. In the presence of fusimotor activity and dynamic length changes imposed on the muscle, it was shown that the activity of the primary and secondary endings carried different information about the effects of the inputs imposed on the muscle spindle. The results presented in this work emphasise that the analysis of the behaviour of complex
systems benefits from a combination of frequency and time
domain methods
Examining an Irregularly Sampled Time Series for Whiteness
Suppose it is of interest whether the series itself is white noise. The empirical Fourier transform is proposed to address this question
The 2005 Neyman Lecture: Dynamic Indeterminism in Science
Jerzy Neyman's life history and some of his contributions to applied
statistics are reviewed. In a 1960 article he wrote: ``Currently in the period
of dynamic indeterminism in science, there is hardly a serious piece of
research which, if treated realistically, does not involve operations on
stochastic processes. The time has arrived for the theory of stochastic
processes to become an item of usual equipment of every applied statistician.''
The emphasis in this article is on stochastic processes and on stochastic
process data analysis. A number of data sets and corresponding substantive
questions are addressed. The data sets concern sardine depletion, blowfly
dynamics, weather modification, elk movement and seal journeying. Three of the
examples are from Neyman's work and four from the author's joint work with
collaborators.Comment: This paper commented in: [arXiv:0808.0631], [arXiv:0808.0638].
Rejoinder in [arXiv:0808.0639]. Published in at
http://dx.doi.org/10.1214/07-STS246 the Statistical Science
(http://www.imstat.org/sts/) by the Institute of Mathematical Statistics
(http://www.imstat.org
Asymptotic normality of finite Fourier transforms of stationary generalized processes
AbstractThis paper indicates a mixing condition under which a net of Fourier transforms, of a stationary generalized process over an abelian locally compact group, has a limiting normal distribution
Comparative Aspects of the Analysis of Stationary Time Series, Point Processes and Hybrids
This paper brings out comparative aspects of the analysis of time series, point processes and hybrids such as sampled time series and marked point processes. Secondand third-order moments and spectra prove useful tools for addressing certain scientific problems involving such processes. Illustrative analyses are presented for data on tides, neurons and earthquakes
Synthetic plots: some history and examples
Jerzy Neyman and Elizabeth Scott developed the idea of synthetic plots. These plots are a display of the data values of an experiment side by side with a display of simulated data values, with the simulation-based on a considered stochastic model. The Neyman and Scott work concerned the distribution of galaxies on the celestial sphere. A review of their wo is presented here followed by personal examples from hydrology, neuroscience, and animal motion.Jerzy Neyman and Elizabeth Scott developed the idea of synthetic plots. These plots are a display of the data values of an experiment side by side with a display of simulated data values, with the simulation-based on a considered stochastic model. The Neyman and Scott work concerned the distribution of galaxies on the celestial sphere. A review of their wo is presented here followed by personal examples from hydrology, neuroscience, and animal motion
Three months journeying of a Hawaiian monk seal
Hawaiian monk seals (Monachus schauinslandi) are endemic to the Hawaiian
Islands and are the most endangered species of marine mammal that lives
entirely within the jurisdiction of the United States. The species numbers
around 1300 and has been declining owing, among other things, to poor juvenile
survival which is evidently related to poor foraging success. Consequently,
data have been collected recently on the foraging habitats, movements, and
behaviors of monk seals throughout the Northwestern and main Hawaiian Islands.
Our work here is directed to exploring a data set located in a relatively
shallow offshore submerged bank (Penguin Bank) in our search of a model for a
seal's journey. The work ends by fitting a stochastic differential equation
(SDE) that mimics some aspects of the behavior of seals by working with
location data collected for one seal. The SDE is found by developing a time
varying potential function with two points of attraction. The times of location
are irregularly spaced and not close together geographically, leading to some
difficulties of interpretation. Synthetic plots generated using the model are
employed to assess its reasonableness spatially and temporally. One aspect is
that the animal stays mainly southwest of Molokai. The work led to the
estimation of the lengths and locations of the seal's foraging trips.Comment: Published in at http://dx.doi.org/10.1214/193940307000000473 the IMS
Collections (http://www.imstat.org/publications/imscollections.htm) by the
Institute of Mathematical Statistics (http://www.imstat.org
Special Issue Paper
An exploratory data analysis of the temperature fluctuations in a spreading fir
- …