Results 41 to 50 of about 23,794,745 (244)

Geometric shrinkage priors for K\"ahlerian signal filters

open access: yes, 2015
We construct geometric shrinkage priors for K\"ahlerian signal filters. Based on the characteristics of K\"ahler manifolds, an efficient and robust algorithm for finding superharmonic priors which outperform the Jeffreys prior is introduced. Several ans\"
Choi, Jaehyung, Mullhaupt, Andrew P.
core   +2 more sources

On the invertibility in periodic ARFIMA models

open access: yes, 2020
The present paper, characterizes the invertibility and causality conditions of a periodic ARFIMA (PARFIMA) models. We first, discuss the conditions in the multivariate case, by considering the corresponding p-variate stationary ARFIMA models. Second, we construct the conditions using the univariate case and we deduce a new infinite autoregressive ...
Amimour, Amine, Belaide, Karima
openaire   +2 more sources

Using Deep Learning Conditional Value‐at‐Risk Based Utility Function in Cryptocurrency Portfolio Optimisation

open access: yesInternational Journal of Finance &Economics, EarlyView.
ABSTRACT One of the critical risks associated with cryptocurrency assets is the so‐called downside risk, or tail risk. Conditional Value‐at‐Risk (CVaR) is a measure of tail risks that is not normally considered in the construction of a cryptocurrency portfolio.
Xinran Huang   +3 more
wiley   +1 more source

Sesgos en estimación, tamaño y potencia de una prueba sobre el parámetro de memoria larga en modelos ARFIMA

open access: yesLecturas de Economía, 2011
Sesgos en estimación, tamaño y potencia de una prueba sobre el parámetro de memoria larga en modelos ARFIMA   Resumen: Castaño et al. (2008) proponen una prueba para investigar la existencia de memoria larga, basada en el parámetro de diferenciación ...
Elkin Castaño Vélez   +2 more
doaj   +1 more source

Error and Model Misspecification in ARFIMA Process

open access: yesBrazilian Review of Econometrics, 2001
In developing the long and short memory estimation, it is usually assumed that the innovations in the ARFIMA model are normally distributed. However, circumstances may occur where this assumption is not true. This paper uses Monte Carlo simulation to evaluate the robustness of different estimators of the fractional parameter in stationary and ...
Valderio A. Reisen   +2 more
openaire   +2 more sources

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

Evaluation of Dual Long Memory Properties with Emphasizing the Skewed and Fat-Tail Distribution: Evidence from Tehran Stock Exchange [PDF]

open access: yesMuṭāli̒āt-i Mudīriyyat-i Ṣan̒atī, 2014
This paper investigates the presence of long memory in the Tehran stock market, using the ARFIMA, GPH, GSP and FIGARCH models. The data set consists of daily returns, and long memory tests are carried out both for the returns and volatilities of TEPIX ...
Mohammad Javad Mohagheghnia   +3 more
doaj  

Statistical inference of one-dimensional persistent nonlinear time series and application to predictions

open access: yesPhysical Review Research, 2022
We introduce a method for reconstructing macroscopic models of one-dimensional stochastic processes with long-range correlations from sparsely sampled time series by combining fractional calculus and discrete-time Langevin equations.
Johannes A. Kassel, Holger Kantz
doaj   +1 more source

Investigating the Dynamic Correlation of the Turkish Stock Market With Conventional Financial Assets and Digital Currencies

open access: yesDiscrete Dynamics in Nature and Society, Volume 2026, Issue 1, 2026.
Today, the astonishing growth of digital currency has attracted many bold investors. This has caused digital currencies to be gradually introduced as a new asset class with its own criteria. However, the relationship between traditional assets and new assets is not yet deeply understood. This study’s objective is to investigate the dynamic relationship
Farzaneh Shams Tarnabi, Fabio Tramontana
wiley   +1 more source

Semiparametric Conditional Quantile Models for Financial Returns and Realized Volatility [PDF]

open access: yes, 2013
This paper investigates how the conditional quantiles of future returns and volatility of financial assets vary with various measures of ex-post variation in asset prices as well as option-implied volatility.
Barunik, Jozef, Zikes, Filip
core   +2 more sources

Home - About - Disclaimer - Privacy