A5009815533- History of Computing Technologies
- Computability, Logic, AI Algorithms
- Control Systems and Identification
- Neural Networks and Applications
- Fault Detection and Control Systems
- Time Series Analysis and Forecasting
- Cybernetics and Technology in Society
- Logic, programming, and type systems
- Complex Systems and Time Series Analysis
- Blind Source Separation Techniques
- Twentieth Century Scientific Developments
- Pancreatic and Hepatic Oncology Research
- Target Tracking and Data Fusion in Sensor Networks
- Gene Regulatory Network Analysis
- Spectroscopy and Chemometric Analyses
- Religious Education and Schools
- Historical Studies on Reproduction, Gender, Health, and Societal Changes
- Statistical and numerical algorithms
- Advanced Statistical Methods and Models
- Simulation Techniques and Applications
- Advanced Control Systems Optimization
- Global Peace and Security Dynamics
- Statistical and Computational Modeling
- Social Policy and Reform Studies
- History and Theory of Mathematics
University Hospitals Plymouth NHS Trust
2023-2024
Leeds Teaching Hospitals NHS Trust
2023-2024
Swansea Bay University Health Board
2023
Hospital Universitario Miguel Servet
2023
University of Plymouth
2023
Westmead Hospital
2022
Film Independent
2018
University College London
2014
University of Westminster
1995-2011
University of Leeds
2010
Summary We develop an approach to the spectral analysis of non-stationary processes which is based on concept “evolutionary spectra”; that is, functions are time dependent, and have a physical interpretation as local energy distributions over frequency. It shown notion evolutionary spectra generalizes usual definition for stationary processes, that, under certain conditions, spectrum at each instant may be estimated from single realization process. By such means it possible study with...
Summary In this note we consider the problem of fitting a general functional relationship between two variables. We require only that function to be fitted is, in some sense, “smooth”, and do not assume it has known mathematical form involving finite number unknown parameters.
Abstract. We construct a general class of non‐linear models, called ‘state‐dependent models’, which have very flexible structure and contain, as special cases, bilinear, threshold autoregressive, exponential autoregressive models. describe sequential type recursive algorithm for identifying state‐dependent show how such models may be used forecasting indicating specific types behaviour.
Summary We consider the problem of testing a given time-series for stationarity. The approach is based on evolutionary spectral analysis, and proposed method consists essentially in “homogeneity” set spectra evaluated at different instants time. Using logarithmic transformation, we show that mechanics test are formally equivalent to two-factor analysis variance procedure when residual known, priori. In addition stationarity, provides also whether observed series fits “uniformly modulated”...
Abstract. One of the key features wavelet analysis is its potential use for effecting time‐frequency decompositions non‐stationary signals. The relationship between and time‐dependent spectral has so far rested mainly on heuristic reasoning:in this paper we examine in a more precise mathematical form. A crucial feature need to define carefully notion “frequency” when applied
Summary Further developments in the theory of evolutionary spectra are discussed, and some asymptotic results derived sampling spectral estimates. Various forms “design” criteria for estimation constructed terms resolvability conditions, it is shown that by introducing concepts “frequency-domain” “time-domain” bandwidths, estimates may be obtained which satisfy required conditions.
Summary In this paper, we propose a general definition of the evolutionary (time-dependent) cross-spectrum between two non-stationary processes and describe its physical interpretation. We also study estimation at each time instant t from single realization bivariate process. Further, (and method estimation) for coherency (spectrum) components process show that notion residual variance bound first introduced in analysis stationary can be extended to processes. As an application...
The existing methods of estimating the spectrum a stationary time series are surveyed from point view user spectral techniques, and role bandwidth in design estimates is emphasised. A discussion on construction "optimum" included, note added effect transients obtained by means filters.
Language is one of the central metaphors around which discipline computer science has been built. The language metaphor entered modern computing as part a cybernetic discourse, but during second half 1950s acquired more abstract meaning, closely related to formal languages logic and linguistics. article argues that this transformation was appearance commercial in mid-1950s. Managers installations specialists on programming academic centers, confronted with an increasing variety machines,...
Summary (i) A review has been made of spectral analysis and its relation with other branches time-series analysis. detailed account given the methods available for estimating density, band spectrum integrated spectrum; suggestions have also confidence intervals latter two estimators. (ii) Emphasis laid throughout upon difficulties which are met in practice gaps theoretical structure indicated. In applications to physical problems, it is suggested that an empirical statistical approach not...
SUMMARY a process with mixed spectrum. The paper also includes some discussion of two different methods estimating the coefficients AR models (the Burg method and Yule-Walker approach), performance various order determination criteria, such as FPE, AIC CAT. 1. I NTRODUCTION problem fitting finite parameter linear to time series has recently aroused renewed interest, particularly in relation use automatic model procedures Akaike's Parzen's CAT criteria. Such can be used provide parametric...
Today, computers fulfil a dazzling array of roles, flexibility resulting from the great range programs that can be run on them.A Science Operations examines history what we now call programming, defined not simply as computer but more broadly definition steps involved in computations and other information-processing activities. This unique perspective highlights how programming is distinct computer, despite close relationship between two 20th century. The book also discusses development...
Summary We consider the problem of linear least-squares prediction for a class non-stationary processes which possess “evolutionary spectral representations”. It is shown that, under certain conditions, such admit moving-average representations in terms time-dependent coefficients. This feature enables us to develop close analogue Wiener–Kolmogorov approach corresponding stationary processes.
Part 1 Time series - theory and methodology: A short history of time series, M.B. Priestley Frequency estimation, E.J. Hannan et al Asymptotic expansion estimators for diffusions with small noises, N. Yoshida Spatial-temporal spectral analysis random sampling, I-Shang Chow, Ken-Shin Lii Detection periodicities, Spectral multivariate probability density estimation continuous stationary processes from randomly sampled data, Elias Masry Minimum distance approach in parametric diffusion...
Abstract. The theory of state‐dependent models was developed by Priestley (1980), and a few simple applications were given in (1981). In this paper, an extensive study the application to wide variety non‐linear time series data is carried out. Both real simulated are used study, problems encountered highlighted. method demonstrated be successful practice many cases, suggestions for further development algorithm also given.