The aim of the thesis is to study the role of instruction in the interconnection of instruction-learning-development. The thesis consists of six empirical papers and a summing-up and perspectivizing introductory paper. Five of the empirical studies concern so called heart conferences, clinical diagnostic meetings, which at the time of my study, 1995-1996, were arranged as telemediated conferences between a sub-team of surgeons and radiologists in a university clinic, and a sub-team of cardiologists and radiologists in a regional hospital. The outcome of the coronary diagnostic work in the heart conferences was patient diagnoses and decided-upon treatment (surgery, balloon dilatation, or conservative treatment). The sixth empirical study, conducted in the autumn 2000, investigates the design and redesign of a central artifact used in the heart conference, ?the angio film,? produced in the angio lab. A recurrent theme in the empirical papers is whether artifacts might be instructive and, if so, in what ways. The introductory paper is a hybrid between an ordinary summing-up paper of the findings in the empirical studies, and a perspectivizing presentation of activity-theoretical approaches to instruction, learning and development, elaborating on three basic aspects (learning as a collaborative phenomenon, the instructiveness of artifacts, and the relation between learning and development on an individual level, but primarily on an activity level). In conclusion, my study outlines an approach to learning based on new perspectives on instruction. / Studier av läkares co-coaching av varandra som ett led i deras samarbete rörande kranskärlsdiagnostiskt arbete. Artefaktanvändning, lärande och versamhetsutveckling.

In this essay i present a study on political learning of a minority ethnicity whose political history in the institutional form began in 1993. The ethnicity in question is the Sami’s and in 1993 the Sami Parliament was established. The establishment of the Sami parliament radically changed the preconditions for political work. Sami politics came to be pursued in an organized manner in the form of a public authority and democratically elected units. In these study Sami politician's perceptions of political learning is investigated. Special attention is directed towards individual- as well as organizational and institutional level. The theories used are Vygotsky's sociocultural perspective on learning complemented with a Foucault-inspired discourse analysis. The method used is semi-structured interviews. The results show that learning is essentially perceived to take place on an individual level and that the organizational and institutional level only to some extent supports the individual level of learning

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With the advancement of display technology, consumers expect high quality display of image and video data. Many viewers are used to watching video content on high definition television and large screens. However, certain display technologies, such as several of those used in portable electronic books, are limited on resources such as the availability of number of bits per pixel (i.e. the bit-depth). Display of good or even acceptable perceptual quality video on these devices is a hard technical problem that a display designer must solve. Video halftoning reduces the number of represented colors or gray levels for display on devices that are unable to render the video at full bit-depth. Bit-depth reduction results in visible spatial and temporal artifacts. The designer would want to choose the halftoning algorithm that reduces these artifacts while meeting the target platform constraints. These constraints include available bit-depth, spatial resolution, computational power, and desired frame rate. Perceptual quality assessment techniques are useful in comparing different video halftoning algorithms that satisfy the constraints. This dissertation develops a framework for the evaluation of two key temporal artifacts, flicker and dirty-window-effect, in medium frame rate binary video halftones generated from grayscale continuous-tone videos. The possible causes underlying these temporal artifacts are discussed. The framework is based on perceptual criteria and incorporates properties of the human visual system. The framework allows for independent assessment of each of the temporal artifacts. This dissertation presents design of algorithms that generate medium frame rate binary halftone videos. The design of the presented video halftone generation algorithms benefits from the proposed temporal artifact evaluation framework and is geared towards reducing the visibility of temporal artifacts in the generated medium frame rate binary halftone videos. This dissertation compares the relative power consumption associated with several medium frame rate binary halftone videos generated using different video halftone generation algorithms. The presented power performance analysis is generally applicable to bistable display devices. This dissertation develops algorithms to enhance medium frame rate binary halftone videos by reducing flicker. The designed enhancement algorithms reduce flicker while attempting to constrain any resulting increase in perceptual degradation of the spatial quality of the halftone frames. This dissertation develops algorithms to enhance medium frame rate binary halftone videos by reducing dirty-window-effect. The enhancement algorithms reduce dirty-window-effect while attempting to constrain any resulting increase in perceptual degradation of the spatial quality of the halftone frames. Finally, this dissertation proposes design of medium frame rate binary halftone video enhancement algorithms that attempt to reduce a temporal artifact, flicker or dirty-window-effect, under both spatial and temporal quality constraints. Temporal quality control is incorporated by using the temporal artifact assessment framework developed in this dissertation. The incorporation of temporal quality control, in the process of reducing flicker or dirty-window-effect, helps establish a balance between the two temporal artifacts in the enhanced video. At the same time, the spatial quality control attempts to constrain any increase in perceptual degradation of the spatial quality of the enhanced halftone frames. / text

Technical artifacts, such as smartphones, computers, search engines and computer programs are extensively used by the modern human. It seems like people use these artifacts to remember important information and become better at finding information effectively with them as a constant available aid. This study aims to explore the possibility that human memory sieves away information that is saved in a database and instead focuses on remembering how to get access to the needed information. More precisely this paper aims to examine if people do focus on the content of information or where information is to be found. The motivation of the study was to investigate if smartphones can bring positive outcomes to human cognitive processes and if modern humans are adapting to the technical world. The present study is a replication of Sparrow et al.’s (2011) original study, which presents findings that suggest that humans remember things they know they have access to less than information they do not have access to. Two research questions were investigated in the present study through an experiment, conducted with university students at Linköping University as test participants. The experiment investigated if the participants focused on remembering the content of presented statements, or remembering if the statements were about to be saved or deleted after being exposed to them. The result presented nostatistically significance. Conclusively it is recommended to continue with further studies on the subject and to conduct more replication of Sparrow et al.’s original study, due to the conflicting findings. A speculation is that a cause for the lacking significant result is the relatively small sample size, and future studies are therefore recommended to test a greater number of test participants. Despite the result it is possible that humans use technical artefacts to enhance cognitive processes, and use smartphones as a transactive memory partners, due to the extensive use of technical artifacts and the original study’s findings.

The way in which students perceive their learningsituation is the starting point for a successful learning process in school, aswell as the starting point for individualized teaching. The study´s aim was todescribe the findings from a group of students at a secondary special schoolwho use a tablet as a tool in learning situations. The study is based onqualitative methods with focus group interviews and research underpinning thecollated data. The study connects students´ perceptions with the conceptsmediated artifacts, motivation and availability to clarify students´ experiencesin different situations. The results shows that the tablet is a flexible toolwhere the possibilities for personalization are great if there is knowledgeabout how, when and for what purpose it will be used. Students express bothinterest and a good understanding of the use of the tablet as a tool, but theyalso experience the obstacle of inaccessibility, depending on how much tabletuse the teacher allows during lessons. Research shows that students withintellectual disabilities feel stimulation from the use of the tablet as atool. This is useful in special educational contexts where the focus is onproviding students with the right conditions to acquire and develop skills.

Coronary stent placement is a routine treatment of coronary artery disease, the leading cause of death worldwide. Intravascular Optical Coherence Tomography (IVOCT) is a superior imaging assessment technique in coronary stenting. To characterize IVOCT artifacts, phantom blood vessels were constructed and metallic and bioabsorable coronary stents were deployed with and without phantom neointima. High resolution Micro-CT images of the stent strut were recorded as a gold standard and utilized to create a three-dimensional representation of a strut that was imported into computer optical simulations. Simulated IVOCT images were computed that include the IVOCT catheter, light reflection from stent struts with varying neointimal thickness and scattering in the vessel lumen. The simulation results along with IVOCT images of the phantom vessels were utilized to elucidate the mechanisms underlying the “sunflower effect”, bending of stent struts toward the imaging catheter and “merry-go-round” effect, variable apparent strut size of metallic stents. Atomic force microscopy was used to examine surface properties of metallic and bioabsorbale stents, revealing sources of the distinctive appearance of bioabsorable stents in IVOCT images. The model formed a basis to develop a correction algorithm to remove stent artifacts in clinical IVOCT images. / text

Information politics is a concept widely acknowledged in several disciplines. However, scant empirical evidence exists in the literature that codifies or measures information politics as a construct. This exploratory study developed and tested the Information Politics Assessment Scale (IPAS), a survey instrument that measured individual perceptions of organizational information artifacts as indictors of its information politics. Data collected with the IPAS was examined to investigate the latent structure of the information politics variable, determine information politics models, and explore the relationship between information politics, strategy, and organization effectiveness. A purposive sample of 240 participants from a cross-section of organizations completed the IPAS in an online administration. Exploratory factor analysis generated three factors, labeled Behavioral Flexibility (BF), Environmental Sensitivity (ES), and Structural Autonomy (SA), suggesting three dimensions of the information politics variable. Cluster analysis of aggregate scores on the BF, ES, and SA factors together resulted in determining four distinct information politics models. Crosstab and ANOVA, respectively, enabled explaining the relationship between strategy and information politics, and how it influenced organization effectiveness. This study breaks ground by broadening the theoretical and empirical understanding of information politics in confirming the proposition that an organization’s information artifacts are measureable and reliable indicators of its information politics. Further, it supports the efficacy of the IPAS to identify the information politics model operating in a given organization.

In the present work we study conceptual modeling of business ar- tifacts and their implementation in Active XML. Business artifacts are key con- ceptual entities of business processes that develop in their lifecycle during these processes. There are several possible methods for definition of artifact lifecycles. In this work, we make use of emerging method called Guard-Stage-Milestone meta- model and we study the question on how to appropriately use and extend current framework for conceptual modeling of XML schemas in order to support modeling of business artifacts. We also deal with the issue of design of suitable represen- tation of business artifacts using Active XML. Last but not least, we study the question how to translate defined model into proposed Active XML representation, so that it was possible to immediately use and demonstrate functionality of defined model. Important part of this work is an implementation of proposed extension and a prototype implementation of system for execution of Active XML repre- sentations of translated models. The present work also introduces the reader in individual used concepts and describes similar existing approach for Active XML representation of business artifacts. 1

Over the past decade, there has been an increasing interest in the real-time monitoring of ambulatory vital signs such as heart rate (HR) and arterial blood oxygen saturation (SpO2) using wearable medical sensors during field operations. These measurements can convey valuable information regarding the state of health and allow first responders and front-line medics to better monitor and prioritize medical intervention of military combatants, firefighters, miners and mountaineers in case of medical emergencies. However, the primary challenge encountered when using these sensors in a non-clinical environment has been the presence of persistent motion artifacts (MA) embedded in the acquired physiological signal. These artifacts are caused by the random displacement of the sensor from the skin and lead to erroneous output readings. Several signal processing techniques, such as time and frequency domain segmentation, signal reconstruction techniques and adaptive noise cancellation (ANC), have been previously developed in an offline environment to address MA in photoplethysmography (PPG) with varying degrees of success. However, the performance of these algorithms in a spasmodic noise environment usually associated with basic day to day ambulatory activities has still not been fully investigated. Therefore, the focus of this research has been to develop novel MA algorithms to combat the effects of these artifacts. The specific aim of this thesis was to design two novel motion artifact (MA) algorithms using a combination of higher order statistical tools namely Kurtosis (K) for classifying 10 s PPG data segments, as either ‘clean’ or ‘corrupt’ and then extracting the aforementioned vital parameters. To overcome the effects of MA, the first algorithm (termed ‘MNA’) processes these ‘corrupt’ PPG data segments by identifying abnormal amplitudes changes. The second algorithm (termed ‘MNAC’), filters these ‘corrupt’ data segments using a 16th order normalized least mean square (NLMS) ANC filter and then extracts HR and SpO2.