Tidlegare arrangement - Side 67
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 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.
Markus Fleten Kreutzer, Jonas Timmann Mjaaland and Halvor Tyseng:
Qualitative analysis is a cornerstone of social science research, used in fields as diverse as education research, sociology, history, and business. Traditional qualitative analysis, however, is time consuming, labor intensive, and difficult to both scale and replicate. To tackle these issues, we have devised a fast, replicable, and scalable technique for deductive, qualitative research on text-data, by utilizing novel advances in machine learning and artificial intelligence.
Natalie Dye is a group leader at the Mildred Scheel Early Career Center (MSNZ) research group leader and core group leader at the TUD Cluster of Excellence, Physics of Life (POL), TU-Dresen.
Hylleraas seminar, hosted in Tromsø
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.
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.
Øystein Håvard Færder, Rosseland Centre for Solar Physics, University of Oslo.
“Combating resistant bacteria and fungi with hybrid drugs”
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).
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.
En viktig del av tverrfaglige emner og program er de administrative ressursene som finner nye veier og løsninger gjennom systemet.
Skriver du en kronikk eller populærvitenskapelig tekst? Dette skriveverkstedet er for deg som vil ha tips om skriving for allmennheten og som vil utvikle teksten din i et felleskap med skrivende kollegaer.
Dag Kristian Dysthe (Njord, UiO): "Active materials shape themselves".
Hylleraas seminar, hosted in Tromsø
During this cold winter in Oslo, we certainly all have experienced the unsteady nature of friction and the sudden loss of stress bearing capacity that initiates catastrophic sliding. A similar kind of frictional rupture arises at the onset of a wide variety of natural disasters that includes earthquakes, landslides, as well as snow avalanches. In this talk, I will focus on the incipient stage of these catastrophic events that is characterized by the local nucleation of failure and its rapid propagation towards intact regions of the material. I will discuss how the analogy to fracture mechanics can be exploited to describe the dynamics of these rupture fronts and develop quantitative models to characterize the onset of failure in geomaterials.
Luis Teodoro, Centre for Space Sensors and Systems, Faculty of Mathematics and Natural Sciences, University of Oslo.
Donaldson-Thomas and Pandharipande-Thomas theory are two approaches to counting curves on projective threefolds in terms of their moduli spaces of sheaves. An important special case in understanding the DT/PT correspondence the equivariant geometry of affine three-space with the natural coordinate action of the rank 3 torus. I will show how one can use new wall-crossing techniques to prove the equivariant K-theoretic DT/PT correspondence in this situation, which was previously known only in the Calabi-Yau limit.
This is part of an ongoing project with Felix Thimm and Henry Liu in which we aim to prove wall-crossing for virtual enumerative invariants associated to equivariant CY3 geometries by extending a vertex algebra formalism for wall-crossing developed by Joyce.
Through INTED lectures, we will create a sharing arena for interdisciplinary education and provide insight into recent research and practice.
Er du usikker på hvilket masterstudium du vil søke på, eller bare har lyst til å høre litt mer om masterprogrammene som tilbys ved Matematisk institutt? Vi inviterer til informasjonsmøte for masterprogrammene i
Stokastisk modellering, statistikk og risikoanalyse
CS:Applied Mathematics and Risk Analysis
På informasjonsmøtet får du et innblikk i masterprogrammene våre, samt muligheten til å stille spørsmål som du sitter inne med direkte til programledererne. For studenter som fremdeles har ett år igjen, vil vi også si noe om hvilke kurs som en bør velge det siste året.
"Functional Characterization of Bardet Biedl associating protein-IFT27"
MN International inviterer til digital gruppeveiledning for MN-studenter med opptak til utveksling høsten 2024.
University of Oslo and University of Gothenburg invite to an informal workshop within machine learning with a focus on statistical aspects related to Machine Learning.
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I forbindelse med fotoutstillingen «Kvinner i eksil», inviterer vi til samtale mellom Begard Reza, Sairan Morafi og Emma Kalo, moderert av Wendy Hamelink.
Jan Martin Nordbotten is a Professor in Department of Mathematics and part of porous media research group at the University of Bergen.