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20202024
most citedFused-Lasso Regularized Cholesky Factors of Large Nonstationary Covariance Matrices of Longitudinal Data

2 citations · 2 across the 6 of their papers we have counts for

collaborators

6 papers

stat.ME2024

Generalized Criterion for Identifiability of Additive Noise Models Using Majorization

Aramayis Dallakyan, Yang Ni

The discovery of causal relationships from observational data is very challenging. Many recent approaches rely on complexity or uncertainty concepts to impose constraints on probab…

stat.CO2024

Unifying Sparse Estimation of Precision and Covariance Matrices

Aramayis Dallakyan, Mohsen Pourahmadi

Penalized maximum likelihood is a widely used approach to estimate a sparse precision or a sparse covariance matrix. A zero in the precision matrix encodes a conditional independen…

stat.CO2023

On Learning Time Series Summary DAGs: A Frequency Domain Approach

Aramayis Dallakyan

The fields of time series and graphical models emerged and advanced separately. Previous work on the structure learning of continuous and real-valued time series utilizes the time…

stat.CO2021

Time Series Graphical Lasso and Sparse VAR Estimation

Aramayis Dallakyan, Rakheon Kim, Mohsen Pourahmadi

We improve upon the two-stage sparse vector autoregression (sVAR) method in Davis et al. (2016) by proposing an alternative two-stage modified sVAR method which relies on time seri…

stat.ML2021

Learning Bayesian Networks through Birkhoff Polytope: A Relaxation Method

Aramayis Dallakyan, Mohsen Pourahmadi

We establish a novel framework for learning a directed acyclic graph (DAG) when data are generated from a Gaussian, linear structural equation model. It consists of two parts: (1)…

stat.ML2020★ 2 cited

Fused-Lasso Regularized Cholesky Factors of Large Nonstationary Covariance Matrices of Longitudinal Data

Aramayis Dallakyan, Mohsen Pourahmadi

Smoothness of the subdiagonals of the Cholesky factor of large covariance matrices is closely related to the degrees of nonstationarity of autoregressive models for time series and…