Università della Svizzera italiana

Multilevel minimization in trust-region framework : algorithmic and software developments

Kopaničáková, Alena ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2020 ; 2020INFO021.

The field of scientific computing is associated with the modeling of complex physical phenomena. The resulting numerical models are often described by differential equations, which, in many cases, can be related to non-convex minimization problems. Thus, after discretization, the solution of large-scale non-convex optimization problem is required. Various iterative solution strategies can be...

Università della Svizzera italiana

A hierarchy of graph-based methods to study the behavior of immune cells in vivo

Pizzagalli, Diego Ulisse ; Krause, Rolf (Dir.) ; Gonzalez, Santiago Fernandez (Codir.)

Thèse de doctorat : Università della Svizzera italiana, 2020 ; 2020INFO018.

The immune system has a critical role in diseases of primary importance such as infections and cancer. Hence, it represents a target for novel therapeutic strategies. However, the immune system relies on a complex network of cell-to-cell interactions which remains largely unknown, or difficult to be interpreted. The combination of experimental data with computational methods is of paramount...

Università della Svizzera italiana

Multilevel solution strategies for unfitted finite element methods

Kothari, Hardik ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2020 ; 2020INFO009.

In the unfitted finite element methods, traditionally we can use Nitsche's method or the method of Lagrange multipliers to enforce the boundary/interface conditions. In this work, we present tailored multilevel methods for solving the problems stemming from either of these discretizations. Generally, multigrid methods require a hierarchy of finite element (FE) spaces which can be created...

Università della Svizzera italiana

Parallel space-time multilevel methods with application to electrophysiology : theory and implementation

Benedusi, Pietro ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2020 ; 2020INFO005.

The goal of this thesis is to design and study an efficient strategy to solve possibly non-linear parabolic partial differential equations on massively parallel machines. Traditionally, when solving time-dependent problems, time stepping methods are used to advance the solution in time. These techniques are inherently sequential and therefore they introduce a bottleneck in the overall...

Università della Svizzera italiana

Enhancing multi-scale cardiac simulations by coupling electrophysiology and mechanics : a flexible high performance approach to cardiac electromechanics

Pozzi, Sonia ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2019 ; 2019INFO005.

This work focuses on the development of computational methods for the simulation of the propagation of the electrical potential in the heart and of the resulting mechanical contraction. The interaction of these two physical phenomena is described by an electromechanical model which consists of the monodomain system, which describes the propagation of the action potential in the cardiac tissue,...

Università della Svizzera italiana

Deciphering the complexity of human noncoding promoter-proximal transcriptome : different scales of transcriptional control : from a single gene to the whole epigenome

Mapelli, Sarah Natalia ; Krause, Rolf (Dir.) ; Catapano, Carlo V. (Codir.)

Thèse de doctorat : Università della Svizzera italiana, 2019 ; 2019INFO001.

Long noncoding RNAs (lncRNAs) have gained increasing interest in molecular studies, their active participation in important biological functions has emerged and their direct involvement in genomic reprogramming during development and diseases, including cancer, has been demonstrated. Several studies have shown their active contribution in transcriptional control and they are emerging as...

Università della Svizzera italiana

Modelling protein-protein interactions to elucidate molecular mechanisms behind neurodegenerative diseases

Grasso, Gianvito ; Krause, Rolf (Dir.) ; Danani, Andrea (Codir.)

Thèse de doctorat : Università della Svizzera italiana, 2018 ; 2018INFO017.

The worldwide significant increase in life expectancy has recently drawn the attention of the scientific community to neurodegenerative pathologies of the elderly population. These neurodegenerative disorders arise from the abnormal protein aggregation in the nervous tissue leading to intracellular inclusions or extracellular aggregates in specific brain areas. A feasible strategy to prevent...

Università della Svizzera italiana

Geometry–aware finite element framework for multi–physics simulations : an algorithmic and software-centric perspective

Zulian, Patrick ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2017 ; 2017INFO006.

In finite element simulations, the handling of geometrical objects and their discrete representation is a critical aspect in both serial and parallel scientific software environments. The development of codes targeting such envinronments is subject to great development effort and man-hours invested. In this thesis we approach these issues from three fronts. First, stable and efficient ...

Università della Svizzera italiana

Derivation, simulation and validation of poroelastic models in dental biomechanics

Favino, Marco ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2014 ; 2014INFO015.

Poroelasticity and mechanics of growth are playing an increasingly relevant role in biomechanics. This work is a self- contained and holistic presentation of the modeling and simulation of non-linear poroelasticity with and without growth inhomogeneities. Balance laws of poroelasticity are derived in Cartesian coordinates. These allow to write the governing equations in a form that is general...

Università della Svizzera italiana

The effects of roughness on the area of contact and on the elastostatic friction : FEM simulation of micro-scale rough contact and real world applications

Rigazzi, Alessandro Pietro ; Krause, Rolf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2014 ; 2014INFO014.

Roughness is everywhere. Every object, every surface we touch or look at, is rough. Even when it looks smooth and flat, if analyzed at the proper length scale, it will reveal roughness. Thus, macro-scale, micro-scale, and even nano-scale roughness exist. What is even more fascinating, is that most of the rough structures, which can be observed at a given length scale, repeat themselves at...