Browsing by Author "Andersson, Pontus"

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Elever som inte kan bråka bra nog – En kvantitativ studie om gymnasieelevers missuppfattningar av bråk
(2018) Andersson, Pontus; Institutionen för matematiska vetenskaper
This study aims to highlight what kind of misconceptions students show when solving problems and tasks involving fractions amongst Swedish students in upper secondary school. The purpose of the study is to get an idea of the common errors that students exhibit and use that information to give examples on how to plan and execute lessons in a way that these misconceptions can be prevented. The study used was a quantitative based study where the results are compared with the study Algebra students difficulty with fractions - an error analysis by Brown and Quinn from 2006. My study shows that many of the Swedish students have misconceptions when it comes to how they handle fractions. Some types of misconceptions that students show in the study is discussed. The most common misconception found in my study was that the students overgeneralize.
Laser Photodetachment of Negative Ions - Fundamental Research and Applications
(2009-05-07T09:56:52Z) Andersson, Pontus
Photodetachment studies of atomic and molecular negative ions in the gas phase are presented. Negative ions are loosely bound quantum systems whose existence is strongly dependent on the correlations between the electrons. This makes sophisticated calculations of the structure and dynamics for these systems complex and experimental data are needed for verification. Negative ions are also important in applications such as plasma etching and atmospheric studies. One of the most important applications for negative ions is as the state of matter for injection in tandem accelerators used in Accelerator Mass Spectrometry (AMS), the most sensitive method for ultra trace isotope analysis. Using negative ions in the injection stage provides isobar suppression in cases where the contaminating isobar does not form stable negative ions. Several experiments on laser interaction with a beam of mass-selected negative ions are presented. The objective for these studies can be divided into three subgroups: structure studies, dynamic studies, and proof-of-principle experiments for applications of negative ions. In the first group, the value for the electron affinity and the fine structure splitting of phosphorus is refined. The value of the electron affinity of tungsten is improved and the origin of the photodetachment signal below threshold is discussed. Resonant structure in the cross section and the electron affinity of cerium is treated. Finally, a predicted excited state in platinum is observed experimentally for the first time. The second group consists of the lifetime measurements of metastable excited states for tellurium, selenium and silicon. These measurements were made at the magnetic heavy ion storage ring CRYRING at Manne Siegbahn Laboratories in Stockholm. The third and last group are proof-of-principle experiments of isobar and neighboring isotope suppression by laser interaction. Suppression of up to four orders of magnitude is reached and the implementation into mass spectrometric systems are discussed.
MAKTENS IDEOLOGISKA KOSTNAD En studie av filtreringseffekten i en svensk kontext
(2020-03-03) Andersson, Pontus; Göteborgs universitet/Statsvetenskapliga institutionen; University of Gothenburg/Department of Political Science
This essay aims to investigate Heinisch’s filtration effect in a Swedish context. It does so by analysing the policy-related differences between the local Sweden Democrats of Staffanstorp and Sölvesborg and the local Sweden Democrats of the rest of south Sweden, defined as Skåne and Blekinge. This is done through a qualitative content analysis of motions proposed and/or plans of action published by concerned SD-parties from the electoral terms of 2014-2018 and 2018-2022. The results show a significant radicalisation of SD-parties not included in a ruling coalition, while the SD-parties of Staffanstorp and Sölvesborg demonstrate clear moderation.
Räkna med bråk i skolan -- En litteraturstudie om elevers inlärning av bråkräkning i skolan
(2016) Andersson, Pontus; Ingvarsson, Simon; Institutionen för matematiska vetenskaper
Fractions and fraction calculation, is something that students seem to have problems with, even though it is a subject that is following them from the early ages of preschool, all the way up to the upper secondary school, which is something that both PISA and TIMSS studies can agree on. This literature study has its focus in the mathematics of upper secondary school, where problems and misconceptions regarding fractions become apparent, compared with the elementary school. The Swedish curriculum LGY11 does not even mention the word fraction once, even though it is a huge part of the mathematics of the upper secondary school. Almost all series of literature have chapters specifically involving fractions, even though it is not required form the curriculum. Studies made by didactics have proven that calculation with fractions is much more complicated than it seems at first glance and that it requires a solid foundation of mathematical understanding, which is something that not all students or teachers possess. This thesis also includes a fundamental mathematical construction of fractions to prove the concepts of mathematical rules that can be applied in fraction calculations. Our conclusion, is that the problems regarding fraction calculation, has its roots during the elementary school, where the foundation of mathematical understanding is created. We highlight some of the aspects regarding the understanding of the mathematics of fractions, and compare them with teaching materials of the upper secondary school.
Serenity: A Case Study in Developing Sustainable Information Systems
(2008-07-03T05:56:25Z) Andersson, Pontus; Birath, David; Willard, Patrik; IT-universitetet i Göteborg/Tillämpad informationsteknologi; IT University of Gothenburg /Applied Information Technology
The Internet has made a huge impact on the way we, as humans, communicate. During the last decade a series of new communication mediums have emerged and communication protocols have come and gone. This puts new requirements on the development process and architecture of the communication platforms, operated by communities, in order to pro-actively ensure support for future communication protocols. Even further, additional requirements are added when the software itself will be maintained by a community. In this thesis we explore the world of Free/Libre and Open Source Software in a case study of the Serenity Information System. We present our suggestions of usable design-principles and our process in developing a sustainable information system.