462,192 research outputs found
Forecasting Method for Grouped Time Series with the Use of k-Means Algorithm
The paper is focused on the forecasting method for time series groups with
the use of algorithms for cluster analysis. -means algorithm is suggested to
be a basic one for clustering. The coordinates of the centers of clusters have
been put in correspondence with summarizing time series data the centroids of
the clusters. A description of time series, the centroids of the clusters, is
implemented with the use of forecasting models. They are based on strict binary
trees and a modified clonal selection algorithm. With the help of such
forecasting models, the possibility of forming analytic dependences is shown.
It is suggested to use a common forecasting model, which is constructed for
time series the centroid of the cluster, in forecasting the private
(individual) time series in the cluster. The promising application of the
suggested method for grouped time series forecasting is demonstrated.Comment: 18 page
Forecasting growth with time series models
This paper compares the structure of three models for estimating future growth in a time series. It is shown that a regression model gives minimum weight to the last observed growth and maximum weight to the observed growth in the middle of the sample period. A first order integrated ARIMA model, or I(1) model, gives uniform weights to all observed growths. Finally, a second order integrated ARIMA model gives maximum weights to the last observed gro~1h andı minimum weights to the observed growths at the beginning of the sample period
Forecasting Time Series from Clusters.
Forecasting large numbers of time series is a costly and time-consuming exercise. Before forecasting a large number of series that are logically connected in some way, the authors can first cluster them into groups of similar series. In this paper they investigate forecasting the series in each cluster. Similar series are first grouped together using a clustering procedure that is based on a test of hypothesis. The series in each cluster are then pooled together and forecasts are obtained. Simulated results show that this procedure for forecasting similar series performs reasonably well.Autoregressive models, Clustering technique, Mean square forecast error, Pooled series,
Forecasting with time series imaging
Feature-based time series representations have attracted substantial
attention in a wide range of time series analysis methods. Recently, the use of
time series features for forecast model averaging has been an emerging research
focus in the forecasting community. Nonetheless, most of the existing
approaches depend on the manual choice of an appropriate set of features.
Exploiting machine learning methods to extract features from time series
automatically becomes crucial in state-of-the-art time series analysis. In this
paper, we introduce an automated approach to extract time series features based
on time series imaging. We first transform time series into recurrence plots,
from which local features can be extracted using computer vision algorithms.
The extracted features are used for forecast model averaging. Our experiments
show that forecasting based on automatically extracted features, with less
human intervention and a more comprehensive view of the raw time series data,
yields highly comparable performances with the best methods in the largest
forecasting competition dataset (M4) and outperforms the top methods in the
Tourism forecasting competition dataset
With string model to time series forecasting
Overwhelming majority of econometric models applied on a long term basis in
the financial forex market do not work sufficiently well. The reason is that
transaction costs and arbitrage opportunity are not included, as this does not
simulate the real financial markets. Analyses are not conducted on the non
equidistant date but rather on the aggregate date, which is also not a real
financial case. In this paper, we would like to show a new way how to analyze
and, moreover, forecast financial market. We utilize the projections of the
real exchange rate dynamics onto the string-like topology in the OANDA market.
The latter approach allows us to build the stable prediction models in trading
in the financial forex market. The real application of the multi-string
structures is provided to demonstrate our ideas for the solution of the problem
of the robust portfolio selection. The comparison with the trend following
strategies was performed, the stability of the algorithm on the transaction
costs for long trade periods was confirmed.Comment: 13 figures, 2 tables. arXiv admin note: text overlap with
arXiv:physics/0205053 by other author
Multivariate Bayesian Predictive Synthesis in Macroeconomic Forecasting
We develop the methodology and a detailed case study in use of a class of
Bayesian predictive synthesis (BPS) models for multivariate time series
forecasting. This extends the recently introduced foundational framework of BPS
to the multivariate setting, with detailed application in the topical and
challenging context of multi-step macroeconomic forecasting in a monetary
policy setting. BPS evaluates-- sequentially and adaptively over time-- varying
forecast biases and facets of miscalibration of individual forecast densities,
and-- critically-- of time-varying inter-dependencies among them over multiple
series. We develop new BPS methodology for a specific subclass of the dynamic
multivariate latent factor models implied by BPS theory. Structured dynamic
latent factor BPS is here motivated by the application context-- sequential
forecasting of multiple US macroeconomic time series with forecasts generated
from several traditional econometric time series models. The case study
highlights the potential of BPS to improve of forecasts of multiple series at
multiple forecast horizons, and its use in learning dynamic relationships among
forecasting models or agents
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