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Graphical Models

description1,663 papers
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lightbulbAbout this topic
Graphical models are probabilistic models that use graphs to represent the conditional dependencies between random variables. They provide a framework for modeling complex multivariate distributions through nodes (representing variables) and edges (representing dependencies), facilitating inference and learning in statistics, machine learning, and artificial intelligence.
lightbulbAbout this topic
Graphical models are probabilistic models that use graphs to represent the conditional dependencies between random variables. They provide a framework for modeling complex multivariate distributions through nodes (representing variables) and edges (representing dependencies), facilitating inference and learning in statistics, machine learning, and artificial intelligence.

Key research themes

1. How can Bayesian methods be employed for joint estimation and adaptive inference in Gaussian graphical models to capture heterogeneous and dynamic network structures?

This theme explores Bayesian frameworks for estimating multiple related Gaussian graphical models (GGMs) simultaneously, particularly in settings with heterogeneous data (e.g., multiple related subpopulations or disease subtypes) and networks that evolve with covariates. It emphasizes the advantages of Bayesian approaches in encouraging sparsity, incorporating prior knowledge, and explicitly quantifying uncertainty in graph structures. Additionally, it covers methods for adaptive inference to efficiently update graphical model estimates under model changes without recomputing from scratch.

Key finding: This review introduces Bayesian techniques tailored for large-scale biological networks under non-standard, heterogeneous settings, such as multiple related subpopulations and networks varying with covariates. It highlights... Read more
Key finding: This work proposes a novel Bayesian framework using Markov random field priors to jointly estimate multiple undirected Gaussian graphical models across related groups. By placing spike-and-slab priors on parameters... Read more
Key finding: Jewel 2.0 advances joint estimation of multiple GGMs by modeling both common (shared) structures and class-specific differences, enhancing the biological relevance of inferred networks. It introduces a weighted penalty... Read more
Key finding: This paper presents algorithms enabling adaptive exact inference on general graphical models subject to arbitrary changes in factors or graph structure, improving efficiency by reusing prior computations. Through hierarchical... Read more
Key finding: Introduces a balanced-tree data structure built from hierarchical clustering and factor elimination approaches that allows the efficient computation of marginals and MAP configurations under arbitrary changes to model... Read more

2. What are efficient computational strategies to handle large-scale Gaussian graphical models, particularly for maximum likelihood estimation and dealing with non-chordal graphs?

This theme focuses on numerical and algorithmic approaches for maximum likelihood estimation (MLE) in Gaussian graphical models, paying special attention to computational challenges arising from large graph sizes and non-chordal (non-decomposable) graph structures. It examines leveraging chordal embeddings, gradient-based optimization techniques, dual formulations, and matrix completion methods to improve scalability and efficiency in estimating sparse inverse covariance matrices consistent with conditional independence constraints.

Key finding: This work proposes efficient gradient-based algorithms (coordinate descent, conjugate gradient, limited-memory BFGS) exploiting chordal embeddings to accelerate maximum likelihood estimation for Gaussian graphical models with... Read more
Key finding: Presents a Bayesian framework for undirected Gaussian graphical model structure learning that exploits graph-theoretic properties of decomposable graphs to enable fast local updates when adding or deleting edges. The method... Read more

3. How do shrinkage methods affect partial correlation estimation in Gaussian graphical models, and how can bias be corrected to improve biological network analysis?

Shrinkage approaches (e.g., Ledoit–Wolf shrinkage) stabilize the estimation of covariance matrices in high-dimensional settings common in bioinformatics, enabling Gaussian graphical model estimation even when sample sizes are limited. However, shrinkage biases partial correlations non-linearly, altering both their magnitudes and ranking, thereby hindering interpretability, comparability across studies, and downstream inference like differential network analysis. This theme examines statistical characterizations of this bias and introduces methods to unshrink partial correlations for accurate hypothesis testing and meaningful biological interpretation.

Key finding: The study quantifies how Ledoit–Wolf shrinkage biases estimated partial correlations in GGMs non-linearly, affecting both magnitude and rank order, which impedes fair comparison across studies with differing shrinkage levels.... Read more
Key finding: This work derives statistical properties of partial correlations computed with Ledoit–Wolf shrinkage and adapts classical parametric tests to account for shrinkage effects, providing confidence intervals and hypothesis tests... Read more

All papers in Graphical Models

This research develops Prisma Project as a governed Tier B structural companion within the Genesis ODE framework. The study focuses on converting a designed geometric source figure into a formal mathematical object through normalized... more
Canonical forms attempt to factor out a non-rigid shape's pose, giving a pose-neutral shape. This opens up the possibility of using methods originally designed for rigid shape retrieval for the task of non-rigid shape retrieval. We extend... more
Deformation transfer is an important research problem in geometry processing and computer animation.A fundamental problem for existing deformation transfer methods is to build reliable correspondences. This is challenging, especially when... more
We propose VoxMorph, a new interactive freeform deformation tool for high resolution voxel grids. Our system exploits cages for high-level deformation control. We tackle the scalability issue by introducing a new 3-scale deformation... more
We present a new curve skeleton model designed for surface modeling and processing. This skeleton is defined as the geometrical integration of a piecewise harmonic parameterization defined over a disk‐cylinder surface decomposition. This... more
We devise a novel inference algorithm to effectively solve the cancer progression model reconstruction problem. Our empirical analysis of the accuracy and convergence rate of our algorithm, CAncer PRogression Inference (CAPRI), shows that... more
In molecular analysis, Spatial Distribution Functions (SDF) are fundamental instruments in answering questions related to spatial occurrences and relations of atomic structures over time. Given a molecular trajectory, SDFs can, for... more
There are various techniques to design complex free-form shapes with general topology. In contrast to the approaches based on trimmed surfaces and control polyhedra, in curve network-based design feature curves can be directly created and... more
Transfinite surface interpolation is a classic topic of computer-aided geometric design (CAGD), and many non-quadrilateral schemes are known. Surfaces defined solely by means of their boundary curves and cross-tangent functions are... more
Palavras-chave: políticos profissionais, comunicação política, plataformas digitais, TikTok, análise de conteúdo. RESUMO Introdução: O artigo explora como políticos brasileiros fazem uso das affordances do TikTok. Investigamos os... more
This paper describes a technology for modelling and rendering heterogeneous objects containing entities of various dimensionalities within a cellular-functional framework based on the implicit complex notion. Implicit complexes make it... more
Digitization of cuneiform documents is important to boost the research activity on ancient Middle East and some projects have been launched in around 2,000. However, the digitization process is laborious due to the huge scale of the... more
The best recovered ordering for the CRC data set. The ordering is plotted against the survival time. The samples in the left part have higher survival times, as expected. The best recovered ordering for the CRC data set. The ordering is... more
This paper formulates a novel probabilistic graphical model for noisy stimulus-evoked MEG and EEG sensor data obtained in the presence of large background brain activity. The model describes the observed data in terms of unobserved evoked... more
Bayesian network structures are usually built using only the data and starting from an empty network or from a naïve Bayes structure. Very often, in some domains, like medicine, a prior structure is already known based on expert... more
Bayesian network structures are usually built using only the data and starting from an empty network or from a naïve Bayes structure. Very often, in some domains, like medicine, a prior structure knowledge is already known. This structure... more
In this paper, we study the behavior of the vertex-edge Wiener polynomials and their related indices under the disjunctive product of graphs. Results are applied to compute the vertex-edge Wiener indices for the disjunctive product of... more
Maximum and minimum indices and polynomials of graphs have been introduced by the present authors, recently. In this paper, we compute these new indices and polynomials for the composition of graphs.
Gaussian graphical models, where it is assumed that the variables of interest jointly follow a multivariate normal distribution with a sparse precision matrix, have been used to study intrinsic dependence among variables, but the... more
Networks represent a useful tool to describe relationships among financial firms and network analysis has been extensively used in recent years to study financial connectedness. An aspect, which is often neglected, is that network... more
With the elapse of time, financial markets have become more and more correlated. The respective literature presents different channels that have caused these interlinkages. Across financial markets, these mutual dependencies could reflect... more
With the elapse of time, financial markets have become more and more correlated. The respective literature presents different channels that have caused these interlinkages. Across financial markets, these mutual dependencies could reflect... more
Belief propagation (BP) is a popular method for performing probabilistic inference on graphical models. In this work, we enhance BP and propose self-guided belief propagation (SBP) that incorporates the pairwise potentials only gradually.... more
Belief propagation (BP) is a popular method for performing probabilistic inference on graphical models. In this work, we enhance BP and propose self-guided belief propagation (SBP) that incorporates the pairwise potentials only gradually.... more
This paper presents new methods for stylising video to produce cartoon motion emphasis cues and modern art. Specifically, we introduce "dynamic cues" as a class of motion emphasis cue, encompassing traditional animation techniques such as... more
Graphical models (e.g., Bayesian and constraint networks, influence diagrams, and Markov decision processes) have become a central paradigm for knowledge representation and reasoning in both artificial intelligence and computer science in... more
In this paper we present a cycle-cutset driven stochastic local search algorithm which approximates the optimum of sums of unary and binary potentials, called Stochastic Tree Local Search or ST LS. We study empirically two pure variants... more
Graphical models (e.g., Bayesian and constraint networks, influence diagrams, and Markov decision processes) have become a central paradigm for knowledge representation and reasoning in both artificial intelligence and computer science in... more
This paper is concerned with a multivariate extension of Gaussian message passing applied to pairwise Markov graphs (MGs). Gaussian message passing applied to pairwise MGs is often labeled Gaussian belief propagation (GaBP) and can be... more
This paper is concerned with a multivariate extension of Gaussian message passing applied to pairwise Markov graphs (MGs). Gaussian message passing applied to pairwise MGs is often labeled Gaussian belief propagation (GaBP) and can be... more
This paper analyses the noise present in range data measured by a Konica Minolta Vivid 910 scanner, in order to better characterise real scanner noise. Methods for denoising 3D mesh data have often assumed the noise to be Gaussian, and... more
We present a segmentation method for live cell images, using graph cuts and learning methods. The images used here are particularly challenging because of the shared grey-level distributions of cells and background, which only differ by... more
Dual graph contraction reduces the number of vertices and of edges of a pair of dual image graphs while, at the same time, the topological relations among the 'surviving' components are preserved. Repeated application produces a stack of... more
An irregular pyramid consists of a stack of successively reduced graphs. Each smaller graph is deduced from the preceding one using contraction or removal kernels. A contraction (resp. removal) kernel defines a forest of the initial... more
This paper presents a new formalism for irregular pyramids based on combinatorial maps. The combinatorial map formalism allows us to encode a planar graph thanks to two permutations encoding the edges and the vertices of the graph.The... more
In this paper, we study the behavior of the vertex-edge Wiener polynomials and their related indices under the disjunctive product of graphs. Results are applied to compute the vertex-edge Wiener indices for the disjunctive product of... more
The computational cost of Gaussian process regression grows cubically with respect to the number of variables due to the inversion of the covariance matrix, which is impractical for data sets with more than a few thousand nodes.... more
In this paper, we present an analytic-iterative Inverse Kinematics (IK) method, called Sequential IK (SIK), that reconstructs 3D human full-body movements in real time. The input data for the reconstruction is the least possible (i.e.,... more
In high-dimensional vector autoregressive (VAR) models, it is natural to have large number of predictors relative to the number of observations, and a lack of efficiency in estimation and forecasting. In this context, model selection is a... more
In high-dimensional vector autoregressive (VAR) models, it is natural to have large number of predictors relative to the number of observations, and a lack of efficiency in estimation and forecasting. In this context, model selection is a... more
1. The concept of model ………………………..................………………………………….. 2 2. Conceptual foundations and conceptual system ……………………………..…. 2 2.1 Theoretical Relevance ……………………………………...................……………………. 2 2.2 Models in Business... more
In this text, we present a Bayesian framework for active multimodal perception of 3D structure and motion. The design of this framework finds its inspiration in the role of the dorsal perceptual pathway of the human brain. Its composing... more
This paper develops a measure for bounding the performance of AND/OR search algorithms for solving a variety of queries over graphical models. We show how drawing a connection to the recent notion of hypertree decompositions allows to... more
The paper investigates the potential of look-ahead in the con-text of AND/OR search in graphical models using the Mini-Bucket heuristic for combinatorial optimization tasks (e.g., MAP/MPE or weighted CSPs). We present and analyze the... more
Given two solids A and B with piecewise smooth boundary we discuss the computation of the boundary Γ of the Minkowski sum A + B. This boundary surface Γ is part of the envelope when B is moved by translations defined by vectors a ∈ A, or... more
Fil: Sili, Marcelo Enrique. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Bahia Blanca; Argentina. Universidad Nacional del Sur. Departamento de Geografia y Turismo; Argentina
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