PhD Candidates

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Room:  A415 (Exactum)
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: markus.juvonen@helsinki.fi

Research Interests

I am interested in image processing in general and anything that combines mathematics with photography and visualization.
The main focus of my research is the development of a patch-based image restoration approach that will create visually more realistic and natural reconstructions made locally out of real image data. 
Another research topic is the automation of image restoration by learning the model and the optimal parameters from the given image data.

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Room: B323 (Exactum)
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: salla.latva-aijo@helsinki.fi

Research Interests

I am interested in dynamic and spectral X-ray tomography and its applications. I focus on developing and improving iterative reconstruction algorithms, especially algorithms for extremely sparse and time-dependent data, like the modified level set method. Attenuation of materials is dependent of the energy of X-rays. This energy dependency makes it possible to get more information out from the reconstructed tomographic images with using multiple X-ray energies. My aim is to apply the Level Set method to material decomposition and extend the MLS method to work with two or more level set functions, both in terms of computational implementation and theoretical convergence.

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email:  jonatan.lehtonen@helsinki.fi

Research Interests

My primary interest is in applying mathematics to real-world problems, which naturally led me to the field of inverse problems. My PhD thesis focuses on atmospheric tomography, an inverse problem related to next-generation telescopes.

A well-known issue with ground-based telescope imaging is that atmospheric turbulence (fluctuations of the refractive index) perturbs the phase of incoming light waves, resulting in degraded resolution and blurred images. In atmospheric tomography, the basic idea is to reconstruct the turbulence profile in real time based on measurements of aberrations in the phase of incoming light waves from known light sources, e.g. natural stars or artificial laser stars.  The turbulence profile can then be used to correct for the effect of turbulence on images in real time

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Room: A415  (Exactum)
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email:alexander.meaney@helsinki.fi

Research Interests

I am interested in the mathematics and physics of medical imaging. My current research is focused on inverse problems and tomographic reconstruction algorithms in X-ray imaging. The range of my scientific activities varies from working with X-ray imaging hardware to computational mathematics and theoretical research.

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Room: C315  (Exactum)
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: anna.suomenrinne-nordvik@helsinki.fi

Research Interests

My research interests are applications related to biological systems, especially infectious diseases.  This includes mathematical modeling and data analysis to gain insight on issues such as the non-observable properties of diseases and disease prevention measures.

I am currently working on a multi-strain HPV model and inference on cervical cancer screening data. Screening data gives indirect measurements on the prevalence of HPV and on the progression of infections towards cancer within the body. There are only a handful of strains that cause cancer, and my focus is on correctly identifying those and their rate of progression.

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Room:  A329 (Exactum)
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: siiri.rautio@helsinki.fi

Research Interests

My main interest in research is combining deep learning with rigorous analytical mathematical methods, developing algorithms that take advantage of both approaches. By keeping the machine-learned parts of complicated methods fairly limited, the results are more explainable and trustworthy. I am mainly interested in medical imaging applications, such as limited-angle X-ray tomography and electrical impedance tomography.

Contact Information

Department of Mathematics and Statistics, University of Helsinki
Room: A423 (Exactum)
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: ziyao.zhao@helsinki.fi

Research Interests: 

Inverse problems and numerical analysis.

Contact information:

Department of Mathematics and Statistics, University of Helsinki
Room:  Room: B323
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: eetu.halme@helsinki.fi 

Research interests:

Current interests include studying invisibility/cloaking solutions to Calderón's problem using techniques of stochastic analysis.

Contact information:

Department of Mathematics and Statistics, University of Helsinki
Room:  Room: B323
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email: joel.siurua@helsinki.fi

Research interests:

Mathematical modelling of infectious diseases

Contact information:

Department of Mathematics and Statistics, University of Helsinki
Room:  Room: B323
Address: P.O. Box 68 (Pietari Kalmin katu 5)
FI-00014 University of Helsinki
Email:  saara.malila@helsinki.fi

Research interests:

I'm currently researching perception-based imaging methods with an initial focus on photographic imaging. The goal is to find methods of regularization and measuring image quality that are best suited for human visual perception.