While obtaining high quality images of static objects is feasible with many tomography modalities nowadays, imaging fast dynamic processes with both high spatial and temporal resolution remains very challenging but is of high interest in various clinical and scientific applications. Often, a high temporal resolution is achieved by a sub-sampled data acquisition (compressed sensing) and images reconstructed from the noisy, incomplete data by conventional algorithms are heavily impaired by artifacts and noise. Novel reconstruction approaches that incorporate mathematical models of the image dynamics demonstrated great potential to improve upon this in proof-of-concept studies but their formulation and implementation for high resolution 3D applications with complex dynamics pose severe mathematical and computational challenges.
The PhD candidate will start from a recently proposed generic mathematical and computational framework for dynamic inverse problems and tailor it towards a challenging, concrete application with X-ray computed tomography (CT). Depending on the interests and background of the PhD candidate, the focus can be on the mathematical modeling of the specific spatio-temporal image dynamics, improving the numerical optimization algorithms used to compute the image or incorporating machine learning approaches to replace the hand-crafted mathematical image models by learned ones. Furthermore, the developed methods should be evaluated with data measured in our FleX-ray imaging lab (see below). As such, the PhD candidate needs to carry out experimental work, such as designing and building appropriate phantoms and extending FleX-ray’s capabilities to perform dynamic experiments. The research of this PhD position will be performed within the Computational Imaging group at CWI, the national research center for Mathematics and Computer Science in The Netherlands (see below).
Dynamic tomography, compressed sensing, image reconstruction, computational inverse problems, variational modeling, numerical optimization, machine learning.
Candidates are required to have a Master’s degree in Mathematics, Physics, Computer Science or Electrical Engineering. Good programming skills are essential. Experience with tomographic reconstruction, image processing, and volumetric reconstruction is desirable. Preferable qualifications for candidates include proven research talent, an excellent command of English, and good academic writing and presentation skills.
The terms of employment are in accordance with the Dutch Collective Labour Agreement for Research Centres ("CAO-onderzoeksinstellingen"). The initial labour agreement will be for a period of 18 months. After a positive evaluation, the agreement will extended by 30 months. The gross monthly salary, for a PhD student on a full time basis, is €2,246 during the first year and increases to €2,879 over the four year period.
Employees are also entitled to a holiday allowance of 8% of the gross annual salary and a year-end bonus of 8.33%. CWI offers attractive working conditions, including flexible scheduling and help with housing for expat employees.
Please visit our website for more information about our terms of employment: www.cwi.nl/terms-of-employment
Please note that there is no fixed deadline for submitting your application. We will evaluate the applications on a running basis. We therefore advise you to submit your application as soon as possible. We expect that you start between 1 May and 1 December 2018.
Applications can be sent through the 'Apply' button. All applications should include a detailed resume, motivation letter, list of your MSc courses and grades, copy of your Master’s thesis or a description of the Master's thesis project including the current status and results, a list of publications and at least two references that we can contact as part of the application process.
For residents outside the EER-area, a Toefl English language test might be required.
For more information about the vacancy, please contact Felix Lucka, email Felix.Lucka@cwi.nl, telephone +31 (0)20-592 4071.
For more information about CWI, please visit www.cwi.nl or watch our video “A Fundamental Difference” about working at CWI.