Results 51 to 60 of about 7,382 (224)

Modelling Short- and Long-Term Dependencies of Clustered High-Threshold Exceedances in Significant Wave Heights

open access: yesMathematics, 2021
The peaks-over-threshold (POT) method has a long tradition in modelling extremes in environmental variables. However, it has originally been introduced under the assumption of independently and identically distributed (iid) data. Since environmental data
Pushpa Dissanayake   +3 more
doaj   +1 more source

Combining long memory and level shifts in modeling and forecasting the volatility of asset returns [PDF]

open access: yes, 2015
We propose a parametric state space model of asset return volatility with an accompanying estimation and forecasting framework that allows for ARFIMA dynamics, random level shifts and measurement errors.
Perron, Pierre, Varneskov, Rasmus T.
core  

PEMODELAN AUTOREGRESSIVE FRACTIONALLY INTEGRATED MOVING AVERAGE DENGAN EFEK EXPONENTIAL GARCH (ARFIMA-EGARCH) UNTUK PREDIKSI HARGA BERAS DI KOTA SEMARANG

open access: yesJurnal Gaussian, 2021
Time series data is a type of data that is often used to estimate future values. Long memory phenomenon often occurs in time series data. Long memory is a condition that shows a strong correlation between observations even though they are quite far away.
Rezky Dwi Hanifa   +2 more
semanticscholar   +1 more source

A Fuzzy Framework for Realized Volatility Prediction: Empirical Evidence From Equity Markets

open access: yesJournal of Forecasting, Volume 45, Issue 3, Page 1261-1291, April 2026.
ABSTRACT This study introduces a realized volatility fuzzy time series (RV‐FTS) model that applies a fuzzy c‐means clustering algorithm to estimate time‐varying c latent volatility states and their corresponding membership degrees. These memberships are used to construct a fuzzified volatility estimate as a weighted average of cluster centroids.
Shafqat Iqbal, Štefan Lyócsa
wiley   +1 more source

Stock-return volatility persistence over short and long range horizons: Some empirical evidences

open access: yesJurnal Perspektif Pembiayaan dan Pembangunan Daerah, 2020
In this paper, we account for memory failure or otherwise in the daily evolution of stock return and volatility within the purview of short and long ranges based on the arrival of fundamental news.
Kolawole Subair, Ajibola Arewa
doaj   +1 more source

Efficient Bayesian inference for ARFIMA processes [PDF]

open access: yes, 2015
Abstract. Many geophysical quantities, like atmospheric temperature, water levels in rivers, and wind speeds, have shown evidence of long-range dependence (LRD). LRD means that these quantities experience non-trivial temporal memory, which potentially enhances their predictability, but also hampers the detection of externally forced trends. Thus, it is
Graves, T.   +3 more
openaire   +2 more sources

Using Fuzzy-ARFIMA Models to Predict Births in Basra Governorate

open access: yesJournal of Physics: Conference Series, 2021
Today’s time series analysis is one of the most important statistical methods in forecasting, and it has been used in many economic, industrial, commercial and science fields, by representing time series characterized by long-term memory that helps ...
Raissan A. Zalan, Zainab Sami Yaseen
semanticscholar   +1 more source

Early Detection of Cyberattacks in Banking Networks via a Fractional Partial Differential Equation Model

open access: yesJournal of Applied Mathematics, Volume 2026, Issue 1, 2026.
In this paper, we model edge traffic with a conformable fractional partial differential equation that keeps memory in time and space. The solution represents a unit‐free attack pressure, built from a z‐scored edge series, a quiet period baseline, and a partially absorbing boundary that reflects scrubbing and rate limits.
Ahmad Alshanty   +3 more
wiley   +1 more source

Semiparametric stationarity and fractional unit roots tests based on data-driven multidimensional increment ratio statistics

open access: yes, 2016
In this paper, we show that the central limit theorem (CLT) satisfied by the data-driven Multidimensional Increment Ratio (MIR) estimator of the memory parameter d established in Bardet and Dola (2012) for d $\in$ (--0.5, 0.5) can be extended to a ...
Bardet, Jean-Marc, Dola, Béchir
core   +2 more sources

A brief history of long memory: Hurst, Mandelbrot and the road to ARFIMA [PDF]

open access: yes, 2016
Long memory plays an important role in many fields by determining the behaviour and predictability of systems; for instance, climate, hydrology, finance, networks and DNA sequencing.
Franzke, Christian   +3 more
core   +3 more sources

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