60 citations · 178 across the 22 of their papers we have counts for
26 papers
Non-Negative Spherical Relaxations for Universe-Free Multi-Matching and Clustering
Johan Thunberg, Florian Bernard
We propose a novel non-negative spherical relaxation for optimization problems over binary matrices with injectivity constraints, which in particular has applications in multi-matc…
Sparse Quadratic Optimisation over the Stiefel Manifold with Application to Permutation Synchronisation
Florian Bernard, Daniel Cremers, Johan Thunberg
We address the non-convex optimisation problem of finding a sparse matrix on the Stiefel manifold (matrices with mutually orthogonal columns of unit length) that maximises (or mini…
Isometric Multi-Shape Matching
Maolin Gao, Zorah Lähner, Johan Thunberg +2
Finding correspondences between shapes is a fundamental problem in computer vision and graphics, which is relevant for many applications, including 3D reconstruction, object tracki…
A state-space approach to sparse dynamic network reconstruction
Zuogong Yue, Johan Thunberg, Lennart Ljung +1
Dynamic network reconstruction has been shown to be challenging due to the requirements on sparse network structures and network identifiability. The direct parametric method (e.g.…
Higher-order Projected Power Iterations for Scalable Multi-Matching
Florian Bernard, Johan Thunberg, Paul Swoboda +1
The matching of multiple objects (e.g. shapes or images) is a fundamental problem in vision and graphics. In order to robustly handle ambiguities, noise and repetitive patterns in…
High-dimensional Kuramoto models on Stiefel manifolds synchronize complex networks almost globally
Johan Markdahl, Johan Thunberg, Jorge Goncalves
The Kuramoto model of coupled phase oscillators is often used to describe synchronization phenomena in nature. Some applications, e.g., quantum synchronization and rigid-body attit…
A Lifting method for analyzing distributed synchronization on the unit sphere
Johan Thunberg, Johan Markdahl, Florian Bernard +1
This paper introduces a new lifting method for analyzing convergence of continuous-time distributed synchronization/consensus systems on the unit sphere. Points on the d-dimensiona…
Synchronisation of Partial Multi-Matchings via Non-negative Factorisations
Florian Bernard, Johan Thunberg, Jorge Goncalves +1
In this work we study permutation synchronisation for the challenging case of partial permutations, which plays an important role for the problem of matching multiple objects (e.g.…
Towards Almost Global Synchronization on the Stiefel Manifold
Johan Markdahl, Johan Thunberg, Jorge Goncalves
A graph is referred to as -synchronizing if, roughly speaking, the Kuramoto-like model whose interaction topology is given by synchronizes…
Experimental design trade-offs for gene regulatory network inference: an in silico study of the yeast Saccharomyces cerevisiae cell cycle
Johan Markdahl, Nicolo Colombo, Johan Thunberg +1
Time-series of high throughput gene sequencing data intended for gene regulatory network (GRN) inference are often short due to the high costs of sampling cell systems. Moreover, e…
Dynamic controllers for column synchronization of rotation matrices: a QR-factorization approach
Johan Thunberg, Johan Markdahl, Jorge Goncalves
In the multi-agent systems setting, this paper addresses continuous-time distributed synchronization of columns of rotation matrices. More precisely, k specific columns shall be sy…
Finite-time attitude synchronization with distributed discontinuous protocols
Jieqiang Wei, Silun Zhang, Antonio Adaldo +3
The finite-time attitude synchronization problem is considered in this paper, where the rotation of each rigid body is expressed using the axis-angle representation. Two discontinu…
Distributed methods for synchronization of orthogonal matrices over graphs
Johan Thunberg, Florian Bernard, Jorge Goncalves
This paper addresses the problem of synchronizing orthogonal matrices over directed graphs. For synchronized transformations (or matrices), composite transformations over loops equ…
Dynamic Network Reconstruction from Heterogeneous Datasets
Zuogong Yue, Johan Thunberg, Wei Pan +2
Performing multiple experiments is common when learning internal mechanisms of complex systems. These experiments can include perturbations to parameters or external disturbances.…
A Combinatorial Solution to Non-Rigid 3D Shape-to-Image Matching
Florian Bernard, Frank R. Schmidt, Johan Thunberg +1
We propose a combinatorial solution for the problem of non-rigidly matching a 3D shape to 3D image data. To this end, we model the shape as a triangular mesh and allow each triangl…
Almost global consensus on the n-sphere
Johan Markdahl, Johan Thunberg, Jorge Goncalves
This paper establishes novel results regarding the global convergence properties of a large class of consensus protocols for multi-agent systems that evolve in continuous time on t…
Inverse Problems for Matrix Exponential in System Identification: System Aliasing
Zuogon Yue, Johan Thunberg, Jorge Goncalves
This note addresses identification of the -matrix in continuous time linear dynamical systems on state-space form. If this matrix is partially known or known to have a sparse st…
Identification of Sparse Continuous-Time Linear Systems with Low Sampling Rate: Optimization Approaches
Zuogong Yue, Johan Thunberg, Lennart Ljung +1
This paper addresses identification of sparse linear and noise-driven continuous-time state-space systems, i.e., the right-hand sides in the dynamical equations depend only on a su…
Systems Aliasing in Dynamic Network Reconstruction: Issues on Low Sampling Frequencies
Zuogon Yue, Johan Thunberg, Lennart Ljung +2
Network reconstruction of dynamical continuous-time (CT) systems is motivated by applications in many fields. Due to experimental limitations, especially in biology, data could be…
Shape-aware Surface Reconstruction from Sparse 3D Point-Clouds
Florian Bernard, Luis Salamanca, Johan Thunberg +7
The reconstruction of an object's shape or surface from a set of 3D points plays an important role in medical image analysis, e.g. in anatomy reconstruction from tomographic measur…
Consensus and Formation Control on SE(3) for Switching Topologies
Johan Thunberg, Xiaoming Hu, Jorge Goncalves
This paper addresses the consensus problem and the formation problem on SE(3) in multi-agent systems with directed and switching interconnection topologies. Several control laws ar…
Optimal output consensus for linear systems: A topology free approach
Johan Thunberg, Xiaoming Hu
In this paper, for any homogeneous system of agents with linear continuous time dynamics, we formulate an optimal control problem. In this problem a convex cost functional of the c…
Linear Shape Deformation Models with Local Support Using Graph-based Structured Matrix Factorisation
Florian Bernard, Peter Gemmar, Frank Hertel +2
Representing 3D shape deformations by linear models in high-dimensional space has many applications in computer vision and medical imaging, such as shape-based interpolation or seg…
On Transitive Consistency for Linear Invertible Transformations between Euclidean Coordinate Systems
Johan Thunberg, Florian Bernard, Jorge Goncalves
Transitive consistency is an intrinsic property for collections of linear invertible transformations between Euclidean coordinate frames. In practice, when the transformations are…