What does it takes to create and sustain environments that support the development of high-level research projects?
Doctoral candidate Ines Petra Junge at the Department of Informatics, Faculty of Mathematics and Natural Sciences, is defending the thesis Good design doesn’t cost the Earth: How sustainability in ICT is enabled, encouraged, engaged, and exemplified by means of the mobile phone for the degree of Philosophiae Doctor.
his talk discusses a nonparametric inference framework for occupation time curves derived from wearable device data. Such curves provide the total time a subject maintains activity above a given level as a function of that level. Taking advantage of the monotonicity and smoothness properties of these curves, we develop a likelihood ratio approach to construct confidence bands for mean occupation time curves. An extension to fitting concurrent functional regression models is also developed. Application to wearable device data from an ongoing study of an experimental gene therapy for mitochondrial DNA depletion syndrome will be discussed. Based on joint work with Hsin-Wen Chang (Academia Sinica).
The frictional behavior of surfaces is a problem of great scientific and practical significance. Recent progress in molecular scale modeling allows us to determine the coefficient of friction for nanoscale surfaces from first principles using molecular dynamics modeling. However, inverse design, that is, designing surfaces with specific frictional propeties is still a complex and largely unsolved challenge in part due to the enormous space of possible surface configurations. Here, we demonstrate how we can use physical forward modeling to find the frictional properties of a set of surfaces that can serve as a training set to design machine learning models. In this talk, we demonstrate both discriminative and generative models for frictional surface design and analyze what physical principles the machine learning models have learned in this process.
PhD candidate Renate Marie Alling at the Department of Biosciences, Faculty of Mathematics and Natural Sciences, is defending the thesis 'Environmental and genetic factors affecting endosperm-based post-zygotic hybridization barriers' for the degree of PhD.
Doctoral candidate Anders Brennhagen at the Department of Chemistry, Faculty of Mathematics and Natural Sciences, is defending the thesis "Bi metallates as conversion-alloying anodes for Na-ion batteries" for the degree of Philosophiae Doctor.
Doctoral candidate Jasmina Masovic at the Department of Informatics, Faculty of Mathematics and Natural Sciences, is defending the thesis The relational view of the impact of new technologies on medical work: The case of Transcatheter Aortic Valve Implantation (TAVI) for the degree of Philosophiae Doctor.
Structural equation models are simultaneous equation regression models, whose variables are latent, and measured via a confirmatory factor model (that is, with measurement error and repeated measurements). When the functional form of the simultaneous equation system is unknown, it has previously been observed in simulations that factor scores inputted into non-parametric regression methods approximate the true functional form. Factor scores estimate the latent variables (per person), and several types exist. We provide a theoretical (though population-based) analysis of this procedure, and provide assumptions under which it is theoretically justified in using Bartlett factor scores, which are simple linear transformations of the data. In simulations, we compare this suggestion to an already available though understudied non-linear and computationally heavy procedure, and observe that the simple Bartlett approach appears to work better.
Doctoral candidate Viktor Balch Barth at the Department of Mathematics will be defending the thesis Endomorphisms of ℙ¹ and 𝔸ⁿ. Motivic homotopy classes and open images for the degree of Philosophiae Doctor .
Jane Luu, Adjunct Professor at Centre for Planetary Habitability (PHAB) and Institute of Theoretical Astrophysics, University of Oslo.