Results 161 to 170 of about 222 (211)
Marchenko–Pastur Laws for Daniell Smoothed Periodograms
ABSTRACT Given a sample X0,…,Xn−1$$ {X}_0,\dots, {X}_{n-1} $$ from a d$$ d $$‐dimensional stationary time series (Xt)t∈ℤ$$ {\left({X}_t\right)}_{t\in \mathbb{Z}} $$, the most commonly used estimator for the spectral density matrix F(θ)$$ F\left(\theta \right) $$ at a given frequency θ∈[0,2π)$$ \theta \in \left[0,2\pi \right) $$ is the Daniell smoothed ...
Ben Deitmar
wiley +1 more source
ABSTRACT Traditional graph representations are insufficient for modelling real‐world phenomena involving multi‐entity interactions, such as collaborative projects or protein complexes, necessitating the use of hypergraphs. While hypergraphs preserve the intrinsic nature of such complex relationships, existing models often overlook temporal evolution in
Xianghe Zhu, Qiwei Yao
wiley +1 more source
Estimation of the Intercept Parameter in Integrated Galton–Watson Processes
ABSTRACT We study the estimation of the intercept parameter in an integrated Galton–Watson process, an important building block for many count‐valued time series models. In this unit root setting, the ordinary least squares estimator is known to be inconsistent, whereas the existing weighted least squares (WLS) estimator is consistent only in the case ...
Yang Lu
wiley +1 more source
Identifiability of Phylogenetic Level-2 Networks under the Jukes-Cantor Model
Englander AK +6 more
europepmc +1 more source
On Testing for Independence Between Generalized Error Models of Several Time Series
ABSTRACT We define generalized innovations associated with generalized error models having arbitrary distributions, that is, distributions that can be mixtures of continuous and discrete distributions. These models include stochastic volatility models and regime‐switching models with possibly zero‐inflated regimes.
Kilani Ghoudi +2 more
wiley +1 more source
Penalized Convex Estimation in Dynamic Location Models
ABSTRACT This paper studies L1$$ {L}^1 $$‐penalized estimation for location models yt=mt+ϵt$$ {y}_t={m}_t+{\epsilon}_t $$, where mt$$ {m}_t $$ is defined by a possibly non‐Markovian recursion and ϵt$$ {\epsilon}_t $$ is a martingale difference sequence with possibly time‐varying conditional variance.
Reda Alami Chentoufi
wiley +1 more source
Moving Aggregate Modified Autoregressive Copula‐Based Time Series Models (MAGMAR‐Copulas)
ABSTRACT Copula‐based time series models can model univariate and stationary time series in a flexible way by decomposing the joint distribution of consecutive observations into a copula and the stationary distribution. Implicitly, this approach assumes a finite Markov order. In reality, a time series may not follow the Markov property.
Sven Pappert
wiley +1 more source
Detecting Periodicity of a General Stationary Time Series via AR(2)‐Model Fitting
ABSTRACT Estimating the periodicity of a stationary time series via fitting a second‐order stationary autoregressive (AR(2)) model has been initiated by the seminal paper of Yule (1927). We investigate properties of this procedure when applied to general stationary processes possessing a spectral density with a dominant peak at some unknown frequency ...
Jens‐Peter Kreiss +2 more
wiley +1 more source
Asymptotics of Time‐Varying Processes in Continuous‐Time Using Locally Stationary Approximations
ABSTRACT We introduce a general theory on stationary approximations for locally stationary continuous‐time processes. Based on the stationary approximation, we use θ$$ \theta $$‐weak dependence to establish laws of large numbers and central limit type results under different observation schemes.
Robert Stelzer, Bennet Ströh
wiley +1 more source
How Institutions Shape the Effects of Agricultural Cooperatives on Their Members
ABSTRACT Agricultural cooperatives represent a promising way of improving the quality of life of half a billion smallholders, who account for the vast majority of the world's food production. Yet, little is known about the institutional factors that explain the potential benefits of being a member of a cooperative.
Simon Cornée +2 more
wiley +1 more source

