Search

Your search keyword '"Sundberg, Rolf"' showing total 342 results
Start Over Author "Sundberg, Rolf"
342 results on '"Sundberg, Rolf"'

2. Subjectivity (Re)Visited: A Corpus Study of English Forward Causal Connectives in Different Domains of Spoken and Written Language

Author

Andersson, Marta and Sundberg, Rolf

Abstract

Through a structured examination of four English causal discourse connectives, our article tackles a gap in the existing research, which focuses mainly on written language production, and entirely lacks attests on English spoken discourse. Given the alleged general nature of English connectives commonly emphasized in the literature, the underlying question of our investigation is the potential role of the connective phrases in marking the basic conceptual distinction between objective and subjective causal event types. To this end, our study combines a traditional corpus analysis with 'predictive' statistical modeling for subjectivity variables to investigate whether and how the tendencies found in the corpus depend on the systematic preferences of the language user to encode subjectivity via a discourse connective. Our findings suggest that while certain conceptual structures are quite fundamental to the usages of English connectives, the connectives "per se" do not seem to have a steady part in categorization of causal events. Rather, their role pertains to the level of intended explicitness bound to specific rhetorical purposes and contexts of use.

Published
2021
Full Text
View/download PDF

3. Distribution-free factor analysis - Estimation theory and applicability to high-dimensional data

Author

Sundberg, Rolf and Feldmann, Uwe

Subjects
Mathematics - Statistics Theory, Statistics - Methodology
Abstract

We here provide a distribution-free approach to the random factor analysis model. We show that it leads to the same estimating equations as for the classical ML estimates under normality, but more easily derived, and valid also in the case of more variables than observations ($p>n$). For this case we also advocate a simple iteration method. In an illustration with $p=2000$ and $n=22$ it was seen to lead to convergence after just a few iterations. We show that there is no reason to expect Heywood cases to appear, and that the factor scores will typically be precisely estimated/predicted as soon as $p$ is large. We state as a general conjecture that the nice behaviour is not despite $p>n$, but because $p>n$., Comment: 12 pages, 2 figures

Published
2013

18. Evaluation of simulated responses to climate forcings : a flexible statistical framework using confirmatory factor analysis and structural equation modelling – Part 1: Theory

Author

Lashgari, Katarina, Brattström, Gudrun, Moberg, Anders, Sundberg, Rolf, Lashgari, Katarina, Brattström, Gudrun, Moberg, Anders, and Sundberg, Rolf

Abstract

Evaluation of climate model simulations is a crucial task in climate research. Here, a new statistical framework is proposed for evaluation of simulated temperature responses to climate forcings against temperature reconstructions derived from climate proxy data for the last millennium. The framework includes two types of statistical models, each of which is based on the concept of latent (unobservable) variables: confirmatory factor analysis (CFA) models and structural equation modelling (SEM) models. Each statistical model presented is developed for use with data from a single region, which can be of any size. The ideas behind the framework arose partly from a statistical model used in many detection and attribution (D&A) studies. Focusing on climatological characteristics of five specific forcings of natural and anthropogenic origin, the present work theoretically motivates an extension of the statistical model used in D&A studies to CFA and SEM models, which allow, for example, for non-climatic noise in observational data without assuming the additivity of the forcing effects. The application of the ideas of CFA is exemplified in a small numerical study, whose aim was to check the assumptions typically placed on ensembles of climate model simulations when constructing mean sequences. The result of this study indicated that some ensembles for some regions may not satisfy the assumptions in question.

Published
2022
Full Text
View/download PDF

32. Willy Feller vid Stockholms högskola, 1934–1939 : En gigant inom sannolikhetsteorin på svensk mark

Author

Rydén, Jesper and Sundberg, Rolf

Subjects
probabilist, Stockholm, mathematician, Sannolikhetsteori och statistik, Willy Feller, Probability Theory and Statistics
Abstract

Harald Cramér utnämndes 1929 till professor i forsäkringsmatematik och matematisk statistik vid Stockholms högskola. Efter nagra år hade han ett eget institut, Institutet for forsäkringsmatematik och matematisk statistik, med egna lokaler vid Odengatan, och 1-2 anstallda amanuenser. Där bedrevs en livlig verksamhet. Cramér hade ett brett kontakt nät bland stora namn inom sannolikhetsteorin. I hans outgivna memoarer, "Korta minnen fran ett långt liv", kan man läsa om nära kontakter med t.ex. Lévy och Féechet i Paris. I Institutets seminarieserie märks internationella namn som t.ex. Theodore (Ted) W. Anderson, Jerzy Neyman - och från 1934 en begåvad ung matematiker vid namn Willy Feller, som gästade Institutet under nära fem års tid. Det är Feller som är ämnet för var uppsats, en sedermera berömd probabilist, inte minst känd för sina två böcker i ämnet.

Published
2021

46. Minnen och meningar

Author

Sundberg, Rolf

Subjects
Sannolikhetsteori och statistik, Probability Theory and Statistics
Abstract

Rolf Sundberg utsågs av Statistikfrämjandet till årets statistikfrämjare. Här berättar han om hur han blev statistiker och sedan fortsatt att jobba inom detta område. Dessutom synpunkter på kurser, forskning, teori/tillämpningar och bredd/djup i forskningen.

Published
2017

49. Lithic Raw Material Economy in the Mesolithic : Experimental Test of Edged Tool Efficiency and Durability in Bone Tool Production

Author

Gummesson, Sara, Sundberg, Rolf, Knutsson, Helena, Zetterlund, Peter, Molin, Fredrik, Knutsson, Kjel, Gummesson, Sara, Sundberg, Rolf, Knutsson, Helena, Zetterlund, Peter, Molin, Fredrik, and Knutsson, Kjel

Abstract

The foundation of this paper is lithic economy with a focus on the actual use of different lithic raw materials for tasks at hand. Our specific focus is on the production of bone tools during the Mesolithic. The lithic and osseous assemblages from Strandvägen, Motala, in east-central Sweden provide the archaeological background for the study. Based on a series of experiments we evaluate the efficiency and durability of different tool edges of five lithic raw materials: Cambrian flint, Cretaceous flint, mylonitic quartz, quartz, and porphyry, each used to whittle bone. The results show that flint is the most efficient of the raw materials assessed. Thus, a non-local raw material offers complements of functional characteristics for bone working compared to locally available quartz and mylonitic quartz. This finding provides a new insight into lithic raw material distribution in the region, specifically for bone tool production on site.

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results