liu.seSearch for publications in DiVA
Change search
Refine search result
2017201820192020202120222023 100951 - 101000 of 101516
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 100951.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, The Institute of Technology.
    Goldkuhl, Göran
    Linköping University, Department of Management and Engineering, VITS - Development of Informations Systems and Work Context. Linköping University, Faculty of Arts and Sciences.
    Dacke, Peter
    Botkyrka kommun, Sweden.
    Needs for a Semi-Open Source Software Business Model for Local Governments2008In: Collaboration and the Knowledge Economy: Issues, Applications, Case Studies / [ed] Paul Cunningham and Miriam Cunningham, Amsterdam, The Netherlands: IOS Press, 2008Conference paper (Other academic)
    Abstract [en]

    The search for efficient business models for open source software is a hot topic both for software vendors and for customers and users of software. In this paper we investigate possibilities for a network of municipalities in Sweden, Sambruk, to use an open source business model for their procurement of software solutions. More specifically, the procurement of public e-services has been followed in seven case studies, of which one was studied in-depth and is accounted for in detail in this paper. The results are that municipalities- investments in e-services are important both concerning function and long-term cost of ownership. Open source software, OSS, can be an alternative, but in the studied procurement cases it appeared not to be a realistic choice in practise. This paper investigates why, and the conclusions are presented as general results. The authors also suggest an alternative business model referred to as Sambruk Community Licence, ie a semi-open source software business model for local governments. 

  • 100952.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Economics.
    Gullander, Staffan
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Economics, Industrial marketing.
    Produktutveckling för företag i samverkan - Studie av små och medelstora svenska verkstadsföretag2003Report (Other academic)
    Abstract [sv]

       

  • 100953.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Janhager, Jenny
    Royal Institute of Technology, Stockholm.
    Abdullah, M Ailieen
    Royal Institute of Technology, Stockholm.
    Enhancing the prospects for entering emerging markets via business networks2010In: Proceedings of the XXI ISPIM Conference / [ed] Ian Bitran, ISPIM , 2010Conference paper (Other academic)
    Abstract [en]

    Multiple factors affect a company’s ability to enter a foreign market. Despite the challenges faced by SMEs, it is suggested that emerging markets (EM) possess high investment potential, thus should seriously be considered as new markets for Swedish environmental technology companies. Researchers within the field of internationalization activities suggest that psychic distance and experiential learning heavily affect market selection. This paper is based upon a case study of four companies that unite in a joint venture with the purpose of developing and constructing a complete plant in an EM based on a radical technology innovation. Of importance to the network partners is the knowledge shared between them for the purpose of successful commercialization, and also knowledge that enhances the prospects for companies to consider EM for their business.

  • 100954.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Olsson, Claes-Olof
    Sambruk.
    Collaborative Development of Public Information Systems: A Case Study of “Sambruk” e-Services Development2010In: eChallenges e-2010 Conference Proceedings / [ed] Paul Cunningham and Miriam Cunningham, IEEE Press, 2010, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Today, public e-services provide essential and efficient tools for municipalities to serve their citizens. However, the development can be quite complex, and in order to efficiently develop solutions, municipalities need to collaborate with many actors and stakeholders such as IT-vendors and developers, as well as government agencies. In this paper collaboration with various stakeholders in different scenarios, comprising four different information systems development projects are analysed, and the pro’s and con’s in the various approaches are described. Furthermore, there are important lessons learned and identified in the three alternatives of user involvement in the projects covered in the paper. Sambruk, ie the Swedish Association of Municipalities for Joint Development of eServices, has in several projects challenged the existing near monopolistic market and business models in Sweden by carrying out significant development projects, utilising new approaches in user involvement and setting up a new collaborative arena for Swedish municipalities, working together in creating new e-service solutions.

  • 100955.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Risberg, Per
    Saab Combitech.
    Att leda högteknologiska innovationsföretag: Erfarenheter från Combitech 1977-19972009Book (Other (popular science, discussion, etc.))
    Abstract [sv]

    Per Risberg skapade Combitech-gruppen och var dess koncernchef i 20 år. Genom detta hade han en unik erfarenhet av att starta och driva fram tillväxt av teknikbaserade nya företag. Ur SAAB-koncernens huvudsakligen militära verksamhet, med en både bred och djup teknikbas, initierade Per nya kompetensområden och byggde upp en grupp mindre, applikationsfokuserade, självständiga men helägda bolag, som tillsammans bildade Combitech-gruppen. Gruppen utvecklades framgångsrikt under Pers ledarskap, och bidrog till ökat värdeskapande och ökad tillväxt.

    I VINNOVAs arbete är tillväxt i mindre företag ett viktigt fokus. För VINNOVA-anställda som arbetar med teknikbaserade nya företag är det mycket värdefullt att ta del av Pers erfarenheter från Combitech-tiden. Det blev därför mycket uppskattat när Per lovade att berätta om sina erfarenheter inom ramen för en serie om sju heldagsseminarier för VINNOVAs anställda.

    I denna seminarieserie, som löpte under åren 2007-2008, delade Per, på ett öppet, utförligt och

    personligt sätt, med sig av sina kunskaper och erfarenheter. Hans insikter grundar sig på upplevelser av både med- och motgång, och lockade åhörarna till både eftertänksamhet och många goda skratt.

    Pers berättelse är nu dokumenterad i denna sammanfattande skrift, förtjänstfullt nedtecknad av Tekn dr. Anna Öhrwall Rönnbäck. Berättelsen utgår från ett antal konkreta fallbeskrivningar som underbygger hans slutsatser och reflektioner, organiserade under ett antal teman.

    Vi vill hävda att Per hade en unik erfarenhet av att bygga upp ny teknikbaserad affärsverksamhet samt att han utvecklade ett spännande framgångskoncept med Combitech-gruppen. Att på detta sätt få möjlighet att ta del av och dokumentera dessa erfarenheter har stort värde. Vi känner stor och djup tacksamhet till Per för att han på ett engagerat och pedagogiskt sätt delade med sig av sina kunskaper. 

    VINNOVA hoppas och tror att du som läsare kan få inspiration och vägledning kring vilka faktorer som är avgörande för att ett teknikbaserat nytt företag skall lyckas. Det är också vår förhoppning att innehållet ska stimulera till diskussion och bidra till att ge såväl VINNOVAs medarbetare som VINNOVAs bidragsmottagare, samt övriga läsare, en ökad kännedom kring, och förståelse för frågeställningar som är väsentliga i vårt gemensamma arbete med att främja och skapa hållbar tillväxt.

  • 100956.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics . Linköping University, The Institute of Technology.
    Rosén, Thomas
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics . Linköping University, The Institute of Technology.
    Olsson, Claes-Olof
    Föreningen Sambruk.
    Goldkuhl, Göran
    Linköping University, Department of Management and Engineering, VITS - Development of Informations Systems and Work Context. Linköping University, Faculty of Arts and Sciences.
    Innovative Business Models Enhancing Open Source Software in the Public Sector2010Conference paper (Refereed)
    Abstract [en]

    The objective of this paper is to suggest new business models and supporting arrangements for open source software in the public sector, specifically for municipalities. Methodologically, the study was carried out as a practical inquiry. Results from the initial diagnosis of longitudinal case studies 2005-2008 in a Swedish network of 80 collaborating municipalities, and a survey 2008 to all Swedish national and local authorities, indicated that Swedish municipalities do not use OSS to a large extent for several reasons, and that experience sharing and a supporting framework were requested. As a solution, a semi-open business model framework was suggested. This framework was developed and implemented in the form of action research. Evaluation of the implementation indicated two major conclusions presented in this paper. First, it that a semi-open source business model could strengthen the community, in so motto that the user-driven innovative solutions stay under control of the user organization. This prevents that the customer’s own development efforts in collaborative projects unintentionally are transferred to supplier companies, and need to be re-purchased in the form of packaged solutions, a phenomena that was observed in several previously studied cases. Second, it was concluded that the semi-open source business model can work only if both customer-side and supplier-side can take advantage. An open attitude to enhance fulfilment of the supplier’s drivers, such as commercialization opportunities, is needed from the customer side. Otherwise important knowledge contributions from suppliers may be limited.

  • 100957.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Sjöström, Roland
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Uddenberg, Anders
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Brege, Staffan
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Evaluating innovation aspects for rapid growth in SMEs2012In: Proceedings of the XXIII ISPIM Conference: “Action for Innovation: Innovating from Experience” / [ed] Ian Bitran, ISPIM , 2012Conference paper (Other academic)
    Abstract [en]

    The importance of fast-growing companies, so-called gazelles, for

    the creation of jobs and wealth in society is undisputed (e.g. Birch 1981). Less

    is known about how a firm can become – and stay – a gazelle. While

    innovation is often pointed out as a key to successful business development, the

    relationship between investments in innovation and R&D activities and

    profitable long-term growth is still unclear. The aim of this paper is to evaluate

    the importance of innovation aspects for rapid growth in small and mediumsized

    enterprises, SMEs. Empirically, it is based on an initiative to enhance fast

    growth in SMEs in a region in Sweden. Early results from analyzing 39 cases

    indicate that innovation factors distinguish fast-growing companies from lowgrowing

    ones.

  • 100958.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, Department of Management and Engineering, Industrial Marketing and Industrial Economics. Linköping University, The Institute of Technology.
    Zander, Ivo
    Stockholms universitet.
    Ur startblocken: svensk innovationskraft II: baserad på Forum for Innovation Managements seminarier och salongsdebatter under 2004-2007 : bidrag från inbjudna medskribenter och intervjupersoner2008Book (Other (popular science, discussion, etc.))
    Abstract [sv]

    Ur startblocken – Svensk innovationskraft II. I den här boken ger Forum for Innovation Management, FIM, en samlad bild av Sveriges förutsättningar som innovationsland nu och i framtiden. Bokens teman speglar fims seminarier och salongsdebatter under 2004–2007 och baseras på intervjuer och texter av tongivande personer i Innovationssverige, bland andra Ayad Al Saffar, Efva Attling, Leif Johansson, Lars G Josefsson, Margareta Norell Bergendal, Maud Olofsson, Alf Rehn, Lena Treschow Torell, Per Unckel och Thomas Östros. Boken avslutas med ett manifest riktat till Sveriges beslutsfattare i innovationsfrågor. © Forum for Innovation Management (FIM) 2008. isbn: 978-91-633-2409-3.

  • 100959.
    Öhrwall Rönnbäck, Anna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Economics.
    Öhlund Sandström, Gunilla
    Developing Integrated Product and Service Offerings: A Comparison Between Large and Small Manufacturing Firms' Business2007In: 2nd National Workshop on Functional Product Development and Sales 2007,2007, Luleå: Luleå Tekniska Universitet , 2007Conference paper (Refereed)
  • 100960.
    Öijerholm, Mikael
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Department of Electrical Engineering.
    Aspects of the choice of sampling frequency in the control system of a gas turbine2009Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    At Siemens, plcs are used to control the gas turbines, and to execute the code in the plcs cyclic interrupts are used. If the execution time for the interrupt becomes close to the cyclic time of the interrupt the load of the plc increases. High load levels can lead to situations were segments of code are not executed on time or even not executed at all. In this thesis an analysis of the regulators used to govern a gas turbine has been performed. The purpose of the analysis is to study the performance of the regulators for different cycle times with the aim to be able to reduce the load by sampling more slowly.

    To determine the load contribution from each regulator a review of the regulators and their execution times has been made. For the analysis the Matlab program Simulink has been used to make models of the regulators, which have then been sampled at different rates. With this information it is possible to determine for which cycle times each regulator has accepetable performance and how much load each regulator contributes with. A save of load of approximately 2 percent can be obtained without loosing too much performance.

  • 100961.
    Öjerteg, Theo
    Linköping University, Department of Electrical Engineering.
    Design and implementation of test a tool for the GSM traffic channel.2002Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    Todays’ systems for telecommunication are getting more and more complex. Automatic testing is required to guarantee quality of the systems produced. An actual example is the introduction of GPRS traffic in the GSM network nodes. This thesis investigates the need and demands for such an automatic testing of the traffic channels in the GSM system. A solution intended to be a part of the Ericsson TSS is proposed. One problem to be solved is that today’s tools for testing do not support testing of speech channels with the speech transcoder unit installed. As part of the investigation, a speech codec is implemented for execution on current hardware used in the test platform. The selected speech codec is the enhanced full rate codec, generating a bitstream of 12.2 kbit/s, and gives a good trade-off between compression and speech quality. The report covers the design of the test tool and the implementation of speech codec. Particularly performance problems in the implementation of the encoder will be addressed.

  • 100962.
    Öllinger, Karin
    Linköping University, Department of Neuroscience and Locomotion, Pathology. Linköping University, Faculty of Health Sciences.
    Cellular toxicity of quinones: Redox- and addition chemistry1992Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Quinoid compounds are widely occurring in nature. They have cytotoxic properties and they are also used as antineoplastic agents. The cytotoxic properties can be explained by the ability of quinones to generate active oxygen species by redox cycling, by addition to cellular nucleophiles, and by inhibition of DNA transcription.

    This study aims to the characterisation of free radical generating capacity and electrophilicity of 1,4- naphthoquinones as a function of their substitution pattern. Further, the mechanism for adriamycin toxicity to heart myocytes has been investigated.

    The two-electron reducing enzyme DT-diaphorase reduces 1,4-naphthoquinones bearing methyl-, hydroxy-, methoxy-, and glutathionyl substituents to their corresponding 1 ,4-naphthohydroquinone. The 1 ,4-naphthohydroquinones bearing hydroxy- and glutathionyl substituents are readily oxidized by oxygen, generating superoxide anion radicals and subsequently hydrogen peroxide. All quinones studied can be reduced by the one-electron reducing enzyme NADPH cytochrome P-450 reductase yielding semiquinones that efficiently reduces oxygen to superoxide anion radicals.

    The nucleophilic addition of glutathione to un- and benzene-ring hydroxy substituted 1,4- naphthoquinones proceeds with glutathione addition at rates decreasing with the number of hydroxy groups, reflecting the decreased electrophilicity of these quinones.

    The effect of hydroxy-substituent position on 1 ,4-naphthoquinone toxicity in primary rat hepatocyte cultues revealed that substituents in the benzene ring increase the toxicity, compared to 1 Anaphthoquinone, due to an increased efficiency ofredoxcycling. Hydroxy-substituent in the quinoid ring renders a quinone that is much less cytotoxic due to decreased electrophilicity and unfavorable reduction potential.

    The antineoplastic drug Adriamycin has the broadest spectrum of activity of all chemotherapeutic agents. Its clinical use, however, is diminished by an unique cardiamyopathy. The involvment of oxygen free radicals in adriamycin cardiotoxicity was investigated using primary cultured neonatalrat heart myocytes. The toxicity decreased at low oxygen pressure and was further decreased by addition of the antioxidant N,N' -diphenyl-p-phenylenediamine, indicating that generation of free radicals contribute to the myocardial toxicity.

  • 100963.
    Öllinger, Karin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Pathology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Inhibition of cathepsin D prevents free-radical-induced apoptosis in rat cardiomyocytes2000In: Archives of Biochemistry and Biophysics, ISSN 0003-9861, E-ISSN 1096-0384, Vol. 373, no 2, p. 346-351Article in journal (Refereed)
    Abstract [en]

    Apoptosis was inhibited in rat cardiomyocytes pretreated with the aspartic protease inhibitor pepstatin A and subsequently exposed to naphthazarin (5,8-dihydroxy-1,4-naphthoquinone). Cathepsin D was released from lysosomes to the cytosol upon exposure to naphthazarin, and the enzyme activity decreased simultaneously. Later, cathepsin D reappeared in granules of increased size, and enzyme activity was restored. Activation of caspase-3- like proteases was detected, and the number of cells showing apoptotic morphology increased with time. Pepstatin A pretreatment did not prevent release of cathepsin D from lysosomes but did significantly inhibit subsequent naphthazarin-induced caspase activation and apoptotic morphology. This suggests that cathepsin D exerts its apoptosis-stimulating effect upstream of caspase-3-like activation. (C) 2000 Academic Press.

  • 100964.
    Öllinger, Karin
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Pathology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Kågedal, Katarina
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Pathology.
    Induction of apoptosis by redoxcycling quinones2002In: Phospholipid metabolism in apoptosis / [ed] Peter J. Quinn and Valerian E. Kagan, Linköping: Linköpings universitet , 2002, p. 151-170Chapter in book (Other academic)
    Abstract [en]

    The last few years have witnessed an explosion of both interest and knowledge about apoptosis, the process by which a cell actively commits suicide. It is now well recognised that apoptosis is essential in many aspects of normal development and is required for maintaining tissue homeostasis. The molecular mechanisms of apoptosis are presently unknown and the subject of focused research effort. It is clear that cell membrane structure and properties play an early part in the induction process. There is increasing evidence that the arrangement of polar lipids in the membrane lipid matrix is an important factor coupled with the homeostatic mechanisms responsible for preserving membrane lipid composition and asymmetry. Changes in membrane permeability are also likely to be involved, possibly as a direct consequence of disturbances in the lipid bilayer matrix. The purpose of this volume is to examine the involvement of membrane lipids in early events of apoptosis. In particular, the role of phospholipids in mitochondrial permeability, membrane lipid asymmetry, and sphingolipid and phospholipid signalling processes in early apoptotic events are reviewed by current researchers in these fields

  • 100965.
    Ölund, Fredrik
    Linköping University, Department of Mechanical Engineering.
    San Pedro S.A.: Taking the first step to a safer work environment2006Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    As a part of improving the production, the Bolivian door manufacturer San Pedro S.A. needs to develop their level of industrial safety. Today their safety level is considered to be almost non-existing. Together with CADEFOR, San Pedro wishes for a handbook that show them how to work with industrial safety, how to implement it and were to begin.

    Much needs to be done at San Pedro and the task has been to show both them and CADEFOR which parts San Pedro need to focus on to increase the overall safety.

    It is considered important that they chose to start with the most crucial areas but the aim is that they will, during a period of time, attend to all problem areas mentioned.

    The first thing San Pedro needs to do is to form an aim for the safety work. This means setting up a policy and routines for the ongoing work.

    Secondly they should start working with improving the fire security, informing the personal about the risks they are exposed to. Further they should educate attendants in first aid, use the protection on the machines available and create a better luminosity environment.

  • 100966.
    Ölundh Sandström, Gunilla
    et al.
    KTH, Stockholm, Sweden.
    Janhager, Jenny
    KTH, Stockholm, Sweden.
    Öhrwall Rönnbäck, Anna
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, The Institute of Technology.
    Lindahl, Mattias
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Sundin, Erik
    Linköping University, Department of Management and Engineering, Assembly technology. Linköping University, The Institute of Technology.
    Sakao, Tomohiko
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Managing Innovation Processes for a Business-Driven Collaborative Network to Export Total Technical Solutions2008In: ISPIM Innovation Symposium, 2008, Singapore: ISPIM , 2008Conference paper (Other academic)
    Abstract [en]

    There is a large need of environmental solutions at developing countries, where a network of small firms, e.g. in Sweden, have much opportunity for their business. This paper discusses, from both theoretical and from practical aspects, the high degree of complexity that needs to be managed when small firms export environmental-technology innovation to emerging markets. Especially, it deals with how a network of firms should manage its innovation processes. Based on the review of some 50 literature, the paper explains the methodologies adopted in an on-going project to study these issues. Discussions include differences with development of an integration of products/services within a single firm.

  • 100967.
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design.
    Design of Fluid Power Systems Using a Multi-Objective Genetic Algorithm2004In: Applications of Multi-Objective Evolutionary Algorithms / [ed] Carlos A. Coello Coello, Gary B. Lamont, Singapore: World Scientific , 2004, p. -761Chapter in book (Other academic)
    Abstract [en]

    This book presents an extensive variety of multi-objective problems across diverse disciplines, along with statistical solutions using multi-objective evolutionary algorithms (MOEAs). The topics discussed serve to promote a wider understanding as well as the use of MOEAs, the aim being to find good solutions for high-dimensional real-world design applications. The book contains a large collection of MOEA applications from many researchers, and thus provides the practitioner with detailed algorithmic direction to achieve good results in their selected problem domain.

  • 100968.
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design .
    Robustness considerations in multi-objective optimal design2005In: Journal of engineering design (Print), ISSN 0954-4828, E-ISSN 1466-1837, Vol. 16, no 5, p. 511-523Article in journal (Refereed)
    Abstract [en]

    In real-world engineering design problems we have to search for solutions that simultaneously optimize a wide range of different criteria. Furthermore, the optimal solutions also have to be robust. Therefore, this paper presents a method where a multi-objective genetic algorithm is combined with response surface methods in order to assess the robustness of the identified optimal solutions. The design example is two different concepts of hydraulic actuation systems, which have been modelled in a simulation environment to which an optimization algorithm has been coupled. The outcome from the optimization is a set of Pareto optimal solutions that elucidate the trade-off between energy consumption and control error for each system. Based on these Pareto fronts, promising regions could be identified for each concept. In these regions, sensitivity analyses are performed and thus it can be determined how different design parameters affect the system at different optimal solutions.

  • 100969.
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design.
    Sensitivity Analysis in Multi-objective Evolutionary Design, in Recent Advances in Simulated Evolution and Learning2004In: Recent Advances in Simulated Evolution and Learning / [ed] K. C. Tan, Singapore: World Scientific series on Advances in Natural Computation , 2004, 2, p. -832Chapter in book (Other academic)
    Abstract [en]

          Inspired by the Darwinian framework of evolution through natural selection and adaptation, the field of evolutionary computation has been growing very rapidly, and is today involved in many diverse application areas. This book covers the latest advances in the theories, algorithms, and applications of simulated evolution and learning techniques. It provides insights into different evolutionary computation techniques and their applications in domains such as scheduling, control and power, robotics, signal processing, and bioinformatics. The book will be of significant value to all postgraduates, research scientists and practitioners dealing with evolutionary computation or complex real-world problems

  • 100970.
    Ölvander, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Feng, X.
    ABB Corporate Research, Västerås, Sweden.
    Holmgren, B.
    ABB Corporate Research, Västerås, Sweden.
    Optimal kinematics design of an industrial robot family in 2008 Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, DETC 2008, vol 1, issue PART B, pp 777-7872009In: ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference: Volume 1: 34th Design Automation Conference, Parts A and B, The American Society of Mechanical Engineers (ASME) , 2009, Vol. 1, no PART B, p. 777-787Conference paper (Refereed)
    Abstract [en]

    Product family design is a well recognized method to address the demands of mass customization. A potential drawback of product families is that the performance of individual members are reduced due to the constraints added by the common platform, i.e. parts and components need to be shared by other family members. This paper presents a formal mathematical framework where the product family design problem is stated as an optimization problem and where optimization is used to find an optimal product family. The object of study is kinematics design of a family of industrial robots. The robot is a serial manipulator where different robots share arms from a common platform. The objective is to show the trade-off between the size of the common platform and the kinematics performance of the robot.

  • 100971.
    Ölvander, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design .
    Krus, Petter
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    A multi-objective optimization approach to aircraft preliminary design2004In: SAE Transactions Journal of Aerospace, p. 454-460Article in journal (Refereed)
  • 100972.
    Ölvander, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Krus, Petter
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Optimizing the Optimization - A Method for Comparison of Optimization Algorithms2006In: AIAA Multidisciplinary Design Optimization Specialists Conference,2006, Newport, RI; USA: AIAA , 2006Conference paper (Refereed)
  • 100973.
    Ölvander, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Lundén, Björn
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Gavel , Hampus
    Saab Aerosystems.
    A computerized optimization framework for the morphological matrix applied to aircraft conceptual design2009In: Computer-Aided Design, ISSN 0010-4485, E-ISSN 1879-2685, Vol. 41, no 3, p. 187-196Article in journal (Refereed)
    Abstract [en]

    This paper presents a formal mathematical framework for the use of the morphological matrix in a computerized conceptual design framework. Within the presented framework, the matrix is quantified so that each solution principle is associated with a set of characteristics such as weight, cost, performance, etc. Selection of individual solutions is modeled with decision variables and an optimization problem is formulated. The applications are the conceptual design of subsystems for an Unmanned Aerial Vehicle and an aircraft fuel transfer system. Both the system models and the mathematical framework are implemented in MS Excel.

  • 100974.
    Ölvander, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Tarkian, Mehdi
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Feng, Xiaolong
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Multi-objective Optimization of a family of Industrial Robots2011In: Multi-objective Evolutionary Optimisation for Product Design and Manufacturing / [ed] Wang L., Ng A. H.C., Deb K., Springer Verlag , 2011, p. 189-217Chapter in book (Refereed)
    Abstract [en]

    With the increasing complexity and dynamism in today’s product design and manufacturing, more optimal, robust and practical approaches and systems are needed to support product design and manufacturing activities. Multi-objective Evolutionary Optimisation for Product Design and Manufacturing presents a focused collection of quality chapters on state-of-the-art research efforts in multi-objective evolutionary optimisation, as well as their practical applications to integrated product design and manufacturing. Multi-objective Evolutionary Optimisation for Product Design and Manufacturing consists of two major sections. The first presents a broad-based review of the key areas of research in multi-objective evolutionary optimisation. The second gives in-depth treatments of selected methodologies and systems in intelligent design and integrated manufacturing. Recent developments and innovations in multi-objective evolutionary optimisation make Multi-objective Evolutionary Optimisation for Product Design and Manufacturing a useful text for a broad readership, from academic researchers to practicing engineers.

  • 100975.
    Ölvingson, Christina
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    On development of information systems with GIS functionality in public health informatics: a requirements engineering approach2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Public health informatics has in recent years emerged as a field of its own from medical informatics. Since public health informatics is newly established and also new to public health professionals, previous research in the field is relatively scarce. Even if the overlap with medical informatics is large, there are differences between the two fields. Public health is, for example, more theoretical and more multi-professional than most clinical fields and the focus is on populations rather than individuals. These characteristics result in a complex setting for development of information systems. To our knowledge there exist few systems that support the collaborative process that constitutes the foundation of public health programs. Moreover, most applications that do support public health practitioners are small-scale, developed for a specific purpose and have not gained any wider recognition.

    The main objective of this thesis is to explore a novel approach to identifying the requirements for information system support with geographical information system (GIS) functionality in public health informatics. The work is based on four case studies that are used to provide the foundation for the development of an initial system design. In the first study, problems that public health practitioners experience in their daily work were explored. The outcome of the study was in terms of descriptions of critical activities. In the second study, the use case map notation was exploited for modeling the process of public health programs. The study provides a contextual description of the refinement of data to information that could constitute a basis for both political and practical decision in complex inter-organizational public health programs. In the third study, ethical conflicts that arose when sharing geographically referenced data in public health programs were analyzed to find out how these affect the design of information systems. The results pointed out issues that have to be considered when developing public health information systems. In the fourth study, the use of information systems with GIS functionality in WHO Safe Communities in Sweden and the need for improvements were explored. The study resulted in identification of particular needs concerning information system support among public health practitioners.

    From these studies, general knowledge about the issues public health practitioners experience in daily practice was gained and the requirements identified were used as a starting-point for the design of information systems for Motala WHO Safe Community.

    The main contributions of the thesis involve two areas: public health informatics and requirements engineering. First, a novel approach to system development in public health informatics is presented. Second, the application of use case maps as a tool for requirements engineering in complex settings such as public health programs is presented. Third, the introduction of requirements engineering in public health informatics has been exemplified. The contributions of the thesis should enhance the possibility to perform more adequate requirements engineering in the field of public health informatics. As a result, it should be possible to develop information systems that better meet the needs in the field of public health. Hence, it contributes to making the public health programs more effective, which in the long run will improve public health. 

    List of papers
    1. Using the critical incident technique to define a minimal data set for requirements elicitation in public health
    Open this publication in new window or tab >>Using the critical incident technique to define a minimal data set for requirements elicitation in public health
    2002 (English)In: International Journal of Medical Informatics, ISSN 1386-5056, E-ISSN 1872-8243, Vol. 68, no 1-3, p. 165-174Article in journal (Refereed) Published
    Abstract [en]

    The introduction of computer-based information systems (ISs) in public health provides enhanced possibilities for service improvements and hence also for improvement of the population's health. Not least, new communication systems can help in the socialization and integration process needed between the different professions and geographical regions. Therefore, development of ISs that truly support public health practices require that technical, cognitive, and social issues be taken into consideration. A notable problem is to capture ‘voices’ of all potential users, i.e., the viewpoints of different public health practitioners. Failing to capture these voices will result in inefficient or even useless systems. The aim of this study is to develop a minimal data set for capturing users' voices on problems experienced by public health professionals in their daily work and opinions about how these problems can be solved. The issues of concern thus captured can be used both as the basis for formulating the requirements of ISs for public health professionals and to create an understanding of the use context. Further, the data can help in directing the design to the features most important for the users.

    Keywords
    Critical incident technique, Information systems design, Public health, Public health informatics, Requirements engineering
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-46775 (URN)10.1016/S1386-5056(02)00074-6 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
    2. Requirements Engineering for inter-organizational health information systems with functions for spatial analyses: modeling a WHO safe community applying Use Case Maps
    Open this publication in new window or tab >>Requirements Engineering for inter-organizational health information systems with functions for spatial analyses: modeling a WHO safe community applying Use Case Maps
    2002 (English)In: Methods of Information in Medicine, ISSN 0026-1270, Vol. 41, no 4, p. 299-304Article in journal (Refereed) Published
    Abstract [en]

    Objectives: To evaluate Use Case Maps (UCMs) as a technique for Requirements Engineering (RE) in the development of information systems with functions for spatial analyses in inter-organizational public health settings.

    Methods: In this study, Participatory Action Research (PAR) is used to explore the UCM notation for requirements elicitation and to gather the opinions of the users. The Delphi technique is used to reach consensus in the construction of UCMs.

    Results: The results show that UCMs can provide a visualization of the system's functionality and in combination with PAR provide a sound basis for gathering requirements in inter-organizational settings. UCMs were found to represent a suitable level for describing the organization and the dynamic flux of information including spatial resolution to all stakeholders. Moreover, by using PAR, the voices of the users and their tacit knowledge is intercepted. Further, UCMs are found useful in generating intuitive requirements by the creation of use cases.

    Conclusions: With UCMs and PAR it is possible to study the effects of design changes in the general information display and the spatial resolution in the same context. Both requirements on the information system in general and the functions for spatial analyses are possible to elicit when identifying the different responsibilities and the demands on spatial resolution associated to the actions of each administrative unit. However, the development process of UCM is not well documented and needs further investigation and formulation of guidelines.

    Keywords
    health informatics, public health, system development, requirements engineering (RE), case study methods
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-48753 (URN)12425241 (PubMedID)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
    3. Ethical issues in public health informatics: implications for system design when sharing geographic information
    Open this publication in new window or tab >>Ethical issues in public health informatics: implications for system design when sharing geographic information
    2002 (English)In: Journal of Biomedical Informatics, ISSN 1532-0464, E-ISSN 1532-0480, Vol. 35, no 3, p. 178-185Article in journal (Refereed) Published
    Abstract [en]

    Public health programs today constitute a multi-professional inter-organizational environment, where both health service and other organizations are involved. Developing information systems, including the IT security measures needed to suit this complex context, is a challenge. To ensure that all involved organizations work together towards a common goal, i.e., promotion of health, an intuitive strategy would be to share information freely in these programs. However, in practice it is seldom possible to realize this ideal scenario. One reason may be that ethical issues are often ignored in the system development process. This investigation uses case study methods to explore ethical obstacles originating in the shared use of geographic health information in public health programs and how this affects the design of information systems. Concerns involving confidentiality caused by geographically referenced health information and influences of professional and organizational codes are discussed. The experience presented shows that disregard of ethical issues can result in a prolonged development process for public health information systems. Finally, a theoretical model of design issues based on the case study results is presented.

    Keywords
    Confidentiality, Geographical information systems (GIS), Health informatics, IT security, Privacy, Public health, Requirements engineering (RE), Systems development
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-46991 (URN)10.1016/S1532-0464(02)00527-0 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
    4. Prerequisites to use information system as support in Public Health Programs: an initial requirements elicitation and analysis for WHO safe sommunities
    Open this publication in new window or tab >>Prerequisites to use information system as support in Public Health Programs: an initial requirements elicitation and analysis for WHO safe sommunities
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The public health context constitutes a heterogeneous environment and presents a complex task for system developers. In this study, the requirements elicitation and analysis of prerequisites for using information systems (ISs) in public health programs is investigated. Special interest is also paid to geographical information system (GIS) functionality. The specific objective of this study is to explore the need for support of ISs and GISs that exists in WHO Safe Communities in Sweden. To elicit the requirements, a questionnaire based on the critical incident technique (CIT) was used. By using CIT, it is possible to focus the development on the problems experienced by the users. Moreover, it covers both technical and social requirements. Thereafter a voice of the customer table is used to transform the needs to technical requirements. The study results in recommendations for ISs development with GIS functionality for public health practitioners.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-86940 (URN)
    Available from: 2013-01-08 Created: 2013-01-08 Last updated: 2013-09-05
    5. Design of information systems for Public Health Programs: the case of Motala WHO safe community
    Open this publication in new window or tab >>Design of information systems for Public Health Programs: the case of Motala WHO safe community
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Objectives: In public health only a fraction of the potential that information systems (ISs) and geographical information systems (GISs) provides has been used. Public-health programs are executed in complex environments, and are characterized by being multi-professional and inter-organizational. Hence, there is a need for extensive studies of how ISs should be con figured to truly support public health practitioners. The objective of this study is to explore how information technology, including GIS functionality, should be configured to support practitioners in community-based public health programs.

    Measurements: The critical incident technique, interviews, the voice of the customer table, and use case maps were used for data collection.

    Results: Communication and a clearinghouse with contact persons were identified as key features and support for creating both official and unofficial contact networks is provided. The design has a module-based architecture, including an extendable easy-to-use module with GIS functionality.

    Conclusions: To support both individuals and heterogonous teams in complex public health programs, a module-based architecture is proposed. Hence, the system can be tailor-made to support individuals in their specific tasks and at their specific skill level.

    Keywords
    Public health, Requirements engineering, Prototypes, Information systems development, Safe community, GIS
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-86942 (URN)
    Available from: 2013-01-08 Created: 2013-01-08 Last updated: 2013-09-05
  • 100976.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallberg, Jonas
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Lindqvist, Kent
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Ethical issues in public health informatics: implications for system design when sharing geographic information2002In: Journal of Biomedical Informatics, ISSN 1532-0464, E-ISSN 1532-0480, Vol. 35, no 3, p. 178-185Article in journal (Refereed)
    Abstract [en]

    Public health programs today constitute a multi-professional inter-organizational environment, where both health service and other organizations are involved. Developing information systems, including the IT security measures needed to suit this complex context, is a challenge. To ensure that all involved organizations work together towards a common goal, i.e., promotion of health, an intuitive strategy would be to share information freely in these programs. However, in practice it is seldom possible to realize this ideal scenario. One reason may be that ethical issues are often ignored in the system development process. This investigation uses case study methods to explore ethical obstacles originating in the shared use of geographic health information in public health programs and how this affects the design of information systems. Concerns involving confidentiality caused by geographically referenced health information and influences of professional and organizational codes are discussed. The experience presented shows that disregard of ethical issues can result in a prolonged development process for public health information systems. Finally, a theoretical model of design issues based on the case study results is presented.

  • 100977.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallberg, Niklas
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Design of information systems for Public Health Programs: the case of Motala WHO safe communityManuscript (preprint) (Other academic)
    Abstract [en]

    Objectives: In public health only a fraction of the potential that information systems (ISs) and geographical information systems (GISs) provides has been used. Public-health programs are executed in complex environments, and are characterized by being multi-professional and inter-organizational. Hence, there is a need for extensive studies of how ISs should be con figured to truly support public health practitioners. The objective of this study is to explore how information technology, including GIS functionality, should be configured to support practitioners in community-based public health programs.

    Measurements: The critical incident technique, interviews, the voice of the customer table, and use case maps were used for data collection.

    Results: Communication and a clearinghouse with contact persons were identified as key features and support for creating both official and unofficial contact networks is provided. The design has a module-based architecture, including an extendable easy-to-use module with GIS functionality.

    Conclusions: To support both individuals and heterogonous teams in complex public health programs, a module-based architecture is proposed. Hence, the system can be tailor-made to support individuals in their specific tasks and at their specific skill level.

  • 100978.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallberg, Niklas
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Prerequisites to use information system as support in Public Health Programs: an initial requirements elicitation and analysis for WHO safe sommunitiesManuscript (preprint) (Other academic)
    Abstract [en]

    The public health context constitutes a heterogeneous environment and presents a complex task for system developers. In this study, the requirements elicitation and analysis of prerequisites for using information systems (ISs) in public health programs is investigated. Special interest is also paid to geographical information system (GIS) functionality. The specific objective of this study is to explore the need for support of ISs and GISs that exists in WHO Safe Communities in Sweden. To elicit the requirements, a questionnaire based on the critical incident technique (CIT) was used. By using CIT, it is possible to focus the development on the problems experienced by the users. Moreover, it covers both technical and social requirements. Thereafter a voice of the customer table is used to transform the needs to technical requirements. The study results in recommendations for ISs development with GIS functionality for public health practitioners.

  • 100979.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallberg, Niklas
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Department of Health and Society. Linköping University, Faculty of Health Sciences.
    Greenes, RA
    Adaptation of the critical incident technique to requirements engineering in public health2001In: Studies in Health Technology and Informatics, ISSN 0926-9630, E-ISSN 1879-8365, Vol. 84, no 2, p. 1180-1184Article in journal (Refereed)
    Abstract [en]

    The introduction of modern information systems in public health provides new possibilities for improvements in public health services and hence also of population's health. However, development of information systems that truly supports public health practices requires that technical, cognitive, and social issues be taken into consideration. In requirements engineering for public health, a notable problem is that of capturing all aspects of the future user's voices, i.e., the viewpoints of different public health practitioners. Failing to capture these voices will result in inefficient or even useless systems. The aim of this paper is to report a requirements-engineering instrument to describe problems in the daily work of public health professionals. The issues of concern thus captured can be used as the basis for formulating the requirements of information systems for public health professionals.

  • 100980.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallberg, Niklas
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Greenes, Robert A.
    Decision Systems Group, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA.
    Using the critical incident technique to define a minimal data set for requirements elicitation in public health2002In: International Journal of Medical Informatics, ISSN 1386-5056, E-ISSN 1872-8243, Vol. 68, no 1-3, p. 165-174Article in journal (Refereed)
    Abstract [en]

    The introduction of computer-based information systems (ISs) in public health provides enhanced possibilities for service improvements and hence also for improvement of the population's health. Not least, new communication systems can help in the socialization and integration process needed between the different professions and geographical regions. Therefore, development of ISs that truly support public health practices require that technical, cognitive, and social issues be taken into consideration. A notable problem is to capture ‘voices’ of all potential users, i.e., the viewpoints of different public health practitioners. Failing to capture these voices will result in inefficient or even useless systems. The aim of this study is to develop a minimal data set for capturing users' voices on problems experienced by public health professionals in their daily work and opinions about how these problems can be solved. The issues of concern thus captured can be used both as the basis for formulating the requirements of ISs for public health professionals and to create an understanding of the use context. Further, the data can help in directing the design to the features most important for the users.

  • 100981.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science, EISLAB - Economic Information Systems. Linköping University, The Institute of Technology.
    Hallberg, Niklas
    Linköping University, Department of Computer and Information Science, MDALAB - Human Computer Interfaces. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Public Health Sciences.
    Lindqvist, Kent
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ethical issues in public health projects: Implications of geographic information resolution2002In: Alvarez I:, Ward Bynum T., Àlvaro de Assis Lopes J., and Rogerson S. Proceedings of the sixth international conference: The transformation of organisations in the information Age: Social and ethical implications. ETHICOMP 2002, 2002Conference paper (Refereed)
  • 100982.
    Ölvingson, Christina
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallberg, Niklas
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Timpka, Toomas
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Lindqvist, Kent
    Linköping University, Department of Computer and Information Science. Linköping University, Department of Department of Health and Society. Linköping University, The Institute of Technology.
    Requirements Engineering for inter-organizational health information systems with functions for spatial analyses: modeling a WHO safe community applying Use Case Maps2002In: Methods of Information in Medicine, ISSN 0026-1270, Vol. 41, no 4, p. 299-304Article in journal (Refereed)
    Abstract [en]

    Objectives: To evaluate Use Case Maps (UCMs) as a technique for Requirements Engineering (RE) in the development of information systems with functions for spatial analyses in inter-organizational public health settings.

    Methods: In this study, Participatory Action Research (PAR) is used to explore the UCM notation for requirements elicitation and to gather the opinions of the users. The Delphi technique is used to reach consensus in the construction of UCMs.

    Results: The results show that UCMs can provide a visualization of the system's functionality and in combination with PAR provide a sound basis for gathering requirements in inter-organizational settings. UCMs were found to represent a suitable level for describing the organization and the dynamic flux of information including spatial resolution to all stakeholders. Moreover, by using PAR, the voices of the users and their tacit knowledge is intercepted. Further, UCMs are found useful in generating intuitive requirements by the creation of use cases.

    Conclusions: With UCMs and PAR it is possible to study the effects of design changes in the general information display and the spatial resolution in the same context. Both requirements on the information system in general and the functions for spatial analyses are possible to elicit when identifying the different responsibilities and the demands on spatial resolution associated to the actions of each administrative unit. However, the development process of UCM is not well documented and needs further investigation and formulation of guidelines.

  • 100983.
    Öman, Andreas
    Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    CO2-utsläpp och konsumtion: Förutsättningar för att påvisa och minska indirekta CO2-utsläpp i den enskilde individens konsumtion av varor2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [sv]

    IVL Svenska Miljöinstitutet utvecklade år 2001 – 2002 i projektet “Klimat.nu – Den stora miljöutmaningen”, ett webbaserat verktyg för att upplysa och vägleda individen i klimatfrågan. Verktygets syfte är att kvantifiera fossila koldioxidutsläpp som en konsekvens av individens energikonsumtion; hushållsel, drivmedel m.m. Syftet är även att individen ges råd om hur man minskar CO2-utsläpp genom att förändra sitt leverne. IVL Svenska Miljöinstitutet vill utöka beräkningsverktygets innehåll till att även omfatta konsumentvaror. Studien har sökt svar hur enskilda individers olika typer av varukonsumtion sättas i samband med CO2-utsläpp och vilka konsumentråd är rimliga att ge för att uppnå utsläppsminskningar, samt hur dessa minskningar kan kvantifieras.

    I studien har ett systemanalytiskt tillvägagångssätt tillämpats och empirin har bestått av miljöexpanderad input-output-data (MIOA). Data har samlats in från Statistiska Centralbyrån (SCB) på miljöräkenskapernas data- och analyssidor. Insamlad data beskriver utsläpp som sker i varors livscykel till och med distribution till affär (indirekta utsläpp). Det är dock viktigt att ha varuklassers hela livscykel i åtanke så att försök till att minska konsumentens indirekta CO2-utsläpp inte leder till ökade totala utsläpp. Dataosäkerheter har identifierats, vilka visar att insamlad data underskattar varors indirekta CO2-utsläpp. Data grundar sig på antagandet att Sverige skulle ha producerat alla varor som importeras. I genomsnitt är ca 69 % av varors indirekta CO2-utsläpp av utländsk härkomst, dessa länder har vanligtvis högre utsläppsintensitet än Sverige i sina produktionsstrukturer. I Sverige finns data endast tillgänglig med ca tre års fördröjning. I sin nuvarande form representerar data trots osäkerheter en lägsta nivå på olika varuklassers indirekta CO2-utsläpp.

    För att göra insamlad data funktionell i beräkningsverktyget prövades en metodik där utsläppsintensiteter beräknades. Utsläppsintensiteter tillgodoser kravet för att enskilda individers olika typer av varukonsumtion ska kunna kopplas till dess CO2-utsläpp. I beräkningsverktyget innebär det att utsläppsintensiteter integreras, som tillsammans med en viss summa pengar, utgör underlaget för att beräkna individens indirekta CO2-utsläpp. Ur ett individperspektiv är metodiken särskilt tilltalande eftersom pengar används som beräkningsenhet, enheten är något som individen oftast har lätt att relatera till. Användningen av utsläppsintensiteter möjliggör kvantifiering av en utsläppsminskning om individen spenderar en summa pengar på en varuklass med lägre utsläppsintensitet i stället en med högre. Med pengar som enhet kan även ”rebound-effekten” undvikas.

    På grund av osäkerheter i dataunderlaget kan studien inte påvisa att förändrad konsumtion av varor leder till en faktisk utsläppsminskning. Störst sannolikhet att uppnå en faktisk minskning är dock om individen råds att fördela en summa pengar från en varuklass till en annan, i vilka det finns stora kvantitativa skillnader mellan utsläppsintensiteterna.

  • 100984.
    Öman, Michael
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Optimization and Robustness of Structural Product Families2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis concerns structural optimization and robustness evaluations, and new methods are presented that considerably reduce the computational cost of these evaluations.

    Optimization is an effective tool in the design process and the interest from industry of its usage is quickly increasing. However, the usage would probably have grown faster if the required number of computationally costly finite element analyses could be reduced. Especially in the case of product family optimization, the problem size can easily get too large to be solved within a reasonable time. This is sometimes also true for robustness evaluations. To enable the usage of optimization and robustness evaluations also for large scale industrial problems, two new methods are here presented, which require a considerably smaller number of finite element analyses.

    The first method concerns structural optimization of product families subjected to multiple crash load cases. Here, the number of required finite element analyses are considerably reduced by only considering the critical constraint in each iteration step.

    The second method is an approach to approximate the variable sensibility based on the distribution of internal energy in a structure. The method can be used to evaluate the relative robustness of different design proposals or for structural optimization. Since the method is independent of the number of parameters and design variables the computational cost of such evaluations is drastically reduced for computationally large problems.

    List of papers
    1. Finite element based robustness study of a truck cab subjected to impact loading
    Open this publication in new window or tab >>Finite element based robustness study of a truck cab subjected to impact loading
    2009 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 14, no 2, p. 111-124Article in journal (Refereed) Published
    Abstract [en]

    Optimised designs have a tendency of being sensitive to variations. It is therefore of great importance to analyse this sensitivity to assure that a design is robust, i.e. sufficiently insensitive to variations. To analyse robustness, variations are introduced in model parameters and their influences on simulation responses are studied. This is usually achieved using the Monte Carlo method. Though, due to the large number of simulations needed, the Monte Carlo method is very costly for problems requiring a long computing time. Therefore, in this work a meta model-based Monte Carlo method is used to evaluate the robustness of a vehicle structure. That is, the Monte Carlo analysis is performed on a surface approximation of the true response, over the domain of interest. The methodology used is to first identify the variables that influence the response the most, referred to as a screening, using simple linear response surfaces. This is followed by a more detailed sensitivity analysis using only the identified variables and a quadratic response surface, thereby incorporating second order effects. A truck cab model exposed to a pendulum impact load is used as an evaluation of this method, and the important variables and their influence on the response are identified. The effect of including results from forming simulations is also evaluated using the truck cab model. Variations are introduced before forming simulations, thereby taking forming effects into account in the sensitivity analysis. The method was found to be a good tool to identify important dispersion variables and to give an approximate result of the total dispersion, all with a reasonable amount of simulations.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2009
    Keywords
    Monte Carlo, meta model, robust design, response surface method, sensitivity analysis, robustness
    National Category
    Applied Mechanics
    Identifiers
    urn:nbn:se:liu:diva-15474 (URN)10.1080/13588260802412992 (DOI)
    Projects
    ROBDES
    Note
    On the day of the defence date the status of this article was: Accepted.Available from: 2008-11-11 Created: 2008-11-11 Last updated: 2017-12-14Bibliographically approved
    2. Structural optimization of product families subjected to multiple crash load cases
    Open this publication in new window or tab >>Structural optimization of product families subjected to multiple crash load cases
    2010 (English)In: Structural and multidisciplinary optimization (Print), ISSN 1615-147X, E-ISSN 1615-1488, Vol. 41, no 5, p. 797-815Article in journal (Refereed) Published
    Abstract [en]

    This paper discusses the problem of structural optimization of product families subjected to multiple load cases, evaluated by computationally costly finite element analysis. Product families generally have a complex composition of shared components that makes individual product optimization difficult as the relation between the shared variables is not always intuitive. More optimal is to treat the problem as a product family optimization problem. Though, for product families subjected to multiple and computationally costly crash loads, the optimization problem takes too long time to solve with traditional methods. Therefore, a new optimization algorithm is presented that decomposes the family problem into sub-problems and iteratively reduces the number of sub-problems, decouple and solve them. The algorithm is applicable for module based product families with predefined composition of generalized commonality, subjected to multiple load cases that can be analyzed separately. The problem reduction is performed by only considering the constraints that are critical in the optimal solution. Therefore the optimization algorithm is called the Critical Constraint Method, CCM. Finally the CCM algorithm is evaluated by two product family optimization problems.

    Place, publisher, year, edition, pages
    Springer Science Business Media, 2010
    Keywords
    Product family optimization, Multiple crash loads, Nonlinear systems, Response surface methodology, Meta model approximations, Critical constraints
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-54846 (URN)10.1007/s00158-009-0471-4 (DOI)000276075900011 ()
    Available from: 2010-04-16 Created: 2010-04-16 Last updated: 2017-12-12Bibliographically approved
    3. An improved critical constraint method for structural optimization of product families
    Open this publication in new window or tab >>An improved critical constraint method for structural optimization of product families
    2012 (English)In: Structural and multidisciplinary optimization (Print), ISSN 1615-147X, E-ISSN 1615-1488, Vol. 45, no 2, p. 235-246Article in journal (Refereed) Published
    Abstract [en]

    This paper discusses important improvements in the efficient Critical Constraint Method (CCM) for the optimization of structural product families subjected to multiple crash load cases. The method was first presented by Öman and Nilsson (Struct Multidisc Optim 41(5):797–815, 2010). However, the algorithm often converged towards an infeasible solution, which considerably limited the applicability of the method. Therefore, improvements are presented here to make the method more robust regarding feasible solutions, resulting in only a minor decrease in efficiency compared to the original method. The improvements include; a penalty approach to control the feasibility of the method by continuously pushing the solution out of the infeasible region, a dynamic contraction algorithm to increase the accuracy and robustness of the method by considering the optimization progress and variable history in the reduction of the step size, and the implementation of a parallel approach to further increase the efficiency of the method by enabling the full potential of large-scale computer clusters. Finally, the potential of the improved CCM algorithm is demonstrated on a large-scale industrial family optimization problem and it is concluded that the high efficiency of the method enables the usage of large product family optimization in the design process.

    Place, publisher, year, edition, pages
    Springer-Verlag, 2012
    Keywords
    Product family optimization – Multiple crash loads – Nonlinear systems – Response surface methodology – Meta model approximations – Critical constraints
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-70787 (URN)10.1007/s00158-011-0689-9 (DOI)000298500500006 ()
    Available from: 2011-09-19 Created: 2011-09-19 Last updated: 2017-12-08Bibliographically approved
    4. Evaluation of structural robustness basedon internal energy distribution
    Open this publication in new window or tab >>Evaluation of structural robustness basedon internal energy distribution
    2011 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Robustness evaluations give valuable information about the sensitivity of a structure to stochastic variation of design parameters, but are in general expensive to perform due to the extensive number of function evaluations required. Therefore, an Internal Energy Based (IEB) method is presented here, in which the structural sensitivity to variation of each thickness parameter is estimated based on the internal energy distribution obtained from one single function evaluation. In this way, the cost of such structural robustness evaluations is significantly reduced. However, the accuracy of the IEB method depends on the structural behaviour. Here it is tested for two structures with nonlinear displacement responses caused by impact loads. The method is however believed to be applicable to any structure exposed to a single load acting on a limited area of the structure, and for response functions related to the displacement of the loaded area.

    Keywords
    Robustness evaluations, Internal energy based gradients, Internal energy distribution, Internal energy based method, Structural robustness
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-70788 (URN)
    Available from: 2011-09-19 Created: 2011-09-19 Last updated: 2011-09-19Bibliographically approved
    5. Structural optimization based on internal energy distribution
    Open this publication in new window or tab >>Structural optimization based on internal energy distribution
    2011 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Structural optimization is a valuable tool to improve the performance of products, but it is in general expensive to perform due to the required extensive number of function evaluations. Therefore, an approximate method based on the internal energy distribution, which only requires a small number of function evaluations, is presented here. By this method, structural optimization can be enabled already in the initial steps in the design of new products when fast, but not necessarily precise, results are often desired. However, the accuracy of the approximate solution depends on the structural behaviour. The internal energy based optimization method is here validated for three structures, but it is believed to be applicable to any structure subjected to a single load where the functions considered are related to the displacement of the loaded area and/or the material thicknesses of the structural parts.

    Keywords
    Structural Optimization, Internal Energy Gradients, Internal Energy Based Method, Internal Energy Distribution, Product Family Optimization
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-70789 (URN)
    Available from: 2011-09-19 Created: 2011-09-19 Last updated: 2011-09-19Bibliographically approved
  • 100985.
    Öman, Michael
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Optimization and robustness of structural product families2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis concerns structural optimization of product families and robustness. The overall objective is to find a method for performing structural optimization of product families subjected to multiple crash load cases and to ensure a robust behavior.

    A product family is a family of products where every product variant, or family member, shares at least one component with at least one other product in the family. Structural optimization of such a family is complex and for expensive function evaluations, e.g. crash simulations, the computing time to solve the problem with traditional methods gets unrealistically long. Therefore, a new optimization algorithm for product families is presented, called the critical constraint method (CCM), that reduces the number of required evaluations by only considering the active constraints in the optimal solution.

    Traditionally optimized structures have a tendency of being sensitive to small variations in the design or loading conditions. As these kind of variations are inevitable, it is important to account for this sensitivity in the design process to ensure the robustness of the optimized design.

    The thesis is divided in two parts. The first part serves as a theoretical background to the second part, the two appended articles. This first part includes introductions to the concepts of product families, optimization, meta modeling and robust design.

    The first appended paper presents a new optimization algorithm for product families subjected to multiple crash loads. The method is compared to traditional methods and tested on two smaller product family examples.

    The second paper is an application of an existing sensitivity analysis method on a large industrial application example. A sensitivity analysis is performed on a Scania truck cab subjected to an impact load in order to identify the most  influencing variables on the crash responses.

    List of papers
    1. Structural optimization of product families subjected to multiple crash load cases
    Open this publication in new window or tab >>Structural optimization of product families subjected to multiple crash load cases
    2010 (English)In: Structural and multidisciplinary optimization (Print), ISSN 1615-147X, E-ISSN 1615-1488, Vol. 41, no 5, p. 797-815Article in journal (Refereed) Published
    Abstract [en]

    This paper discusses the problem of structural optimization of product families subjected to multiple load cases, evaluated by computationally costly finite element analysis. Product families generally have a complex composition of shared components that makes individual product optimization difficult as the relation between the shared variables is not always intuitive. More optimal is to treat the problem as a product family optimization problem. Though, for product families subjected to multiple and computationally costly crash loads, the optimization problem takes too long time to solve with traditional methods. Therefore, a new optimization algorithm is presented that decomposes the family problem into sub-problems and iteratively reduces the number of sub-problems, decouple and solve them. The algorithm is applicable for module based product families with predefined composition of generalized commonality, subjected to multiple load cases that can be analyzed separately. The problem reduction is performed by only considering the constraints that are critical in the optimal solution. Therefore the optimization algorithm is called the Critical Constraint Method, CCM. Finally the CCM algorithm is evaluated by two product family optimization problems.

    Place, publisher, year, edition, pages
    Springer Science Business Media, 2010
    Keywords
    Product family optimization, Multiple crash loads, Nonlinear systems, Response surface methodology, Meta model approximations, Critical constraints
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-54846 (URN)10.1007/s00158-009-0471-4 (DOI)000276075900011 ()
    Available from: 2010-04-16 Created: 2010-04-16 Last updated: 2017-12-12Bibliographically approved
    2. Finite element based robustness study of a truck cab subjected to impact loading
    Open this publication in new window or tab >>Finite element based robustness study of a truck cab subjected to impact loading
    2009 (English)In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 14, no 2, p. 111-124Article in journal (Refereed) Published
    Abstract [en]

    Optimised designs have a tendency of being sensitive to variations. It is therefore of great importance to analyse this sensitivity to assure that a design is robust, i.e. sufficiently insensitive to variations. To analyse robustness, variations are introduced in model parameters and their influences on simulation responses are studied. This is usually achieved using the Monte Carlo method. Though, due to the large number of simulations needed, the Monte Carlo method is very costly for problems requiring a long computing time. Therefore, in this work a meta model-based Monte Carlo method is used to evaluate the robustness of a vehicle structure. That is, the Monte Carlo analysis is performed on a surface approximation of the true response, over the domain of interest. The methodology used is to first identify the variables that influence the response the most, referred to as a screening, using simple linear response surfaces. This is followed by a more detailed sensitivity analysis using only the identified variables and a quadratic response surface, thereby incorporating second order effects. A truck cab model exposed to a pendulum impact load is used as an evaluation of this method, and the important variables and their influence on the response are identified. The effect of including results from forming simulations is also evaluated using the truck cab model. Variations are introduced before forming simulations, thereby taking forming effects into account in the sensitivity analysis. The method was found to be a good tool to identify important dispersion variables and to give an approximate result of the total dispersion, all with a reasonable amount of simulations.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2009
    Keywords
    Monte Carlo, meta model, robust design, response surface method, sensitivity analysis, robustness
    National Category
    Applied Mechanics
    Identifiers
    urn:nbn:se:liu:diva-15474 (URN)10.1080/13588260802412992 (DOI)
    Projects
    ROBDES
    Note
    On the day of the defence date the status of this article was: Accepted.Available from: 2008-11-11 Created: 2008-11-11 Last updated: 2017-12-14Bibliographically approved
  • 100986.
    Öman, Michael
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Asadi Rad, Nima
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Nilsson, Larsgunnar
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Evaluation of structural robustness basedon internal energy distribution2011Manuscript (preprint) (Other academic)
    Abstract [en]

    Robustness evaluations give valuable information about the sensitivity of a structure to stochastic variation of design parameters, but are in general expensive to perform due to the extensive number of function evaluations required. Therefore, an Internal Energy Based (IEB) method is presented here, in which the structural sensitivity to variation of each thickness parameter is estimated based on the internal energy distribution obtained from one single function evaluation. In this way, the cost of such structural robustness evaluations is significantly reduced. However, the accuracy of the IEB method depends on the structural behaviour. Here it is tested for two structures with nonlinear displacement responses caused by impact loads. The method is however believed to be applicable to any structure exposed to a single load acting on a limited area of the structure, and for response functions related to the displacement of the loaded area.

  • 100987.
    Öman, Michael
    et al.
    Scania CV AB, Södertälje.
    Nilsson, Larsgunnar
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    An improved critical constraint method for structural optimization of product families2012In: Structural and multidisciplinary optimization (Print), ISSN 1615-147X, E-ISSN 1615-1488, Vol. 45, no 2, p. 235-246Article in journal (Refereed)
    Abstract [en]

    This paper discusses important improvements in the efficient Critical Constraint Method (CCM) for the optimization of structural product families subjected to multiple crash load cases. The method was first presented by Öman and Nilsson (Struct Multidisc Optim 41(5):797–815, 2010). However, the algorithm often converged towards an infeasible solution, which considerably limited the applicability of the method. Therefore, improvements are presented here to make the method more robust regarding feasible solutions, resulting in only a minor decrease in efficiency compared to the original method. The improvements include; a penalty approach to control the feasibility of the method by continuously pushing the solution out of the infeasible region, a dynamic contraction algorithm to increase the accuracy and robustness of the method by considering the optimization progress and variable history in the reduction of the step size, and the implementation of a parallel approach to further increase the efficiency of the method by enabling the full potential of large-scale computer clusters. Finally, the potential of the improved CCM algorithm is demonstrated on a large-scale industrial family optimization problem and it is concluded that the high efficiency of the method enables the usage of large product family optimization in the design process.

  • 100988.
    Öman, Michael
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Nilsson, Larsgunnar
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Structural optimization based on internal energy distribution2011Manuscript (preprint) (Other academic)
    Abstract [en]

    Structural optimization is a valuable tool to improve the performance of products, but it is in general expensive to perform due to the required extensive number of function evaluations. Therefore, an approximate method based on the internal energy distribution, which only requires a small number of function evaluations, is presented here. By this method, structural optimization can be enabled already in the initial steps in the design of new products when fast, but not necessarily precise, results are often desired. However, the accuracy of the approximate solution depends on the structural behaviour. The internal energy based optimization method is here validated for three structures, but it is believed to be applicable to any structure subjected to a single load where the functions considered are related to the displacement of the loaded area and/or the material thicknesses of the structural parts.

  • 100989.
    Öman, Michael
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Nilsson, Larsgunnar
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Structural optimization of product families subjected to multiple crash load cases2010In: Structural and multidisciplinary optimization (Print), ISSN 1615-147X, E-ISSN 1615-1488, Vol. 41, no 5, p. 797-815Article in journal (Refereed)
    Abstract [en]

    This paper discusses the problem of structural optimization of product families subjected to multiple load cases, evaluated by computationally costly finite element analysis. Product families generally have a complex composition of shared components that makes individual product optimization difficult as the relation between the shared variables is not always intuitive. More optimal is to treat the problem as a product family optimization problem. Though, for product families subjected to multiple and computationally costly crash loads, the optimization problem takes too long time to solve with traditional methods. Therefore, a new optimization algorithm is presented that decomposes the family problem into sub-problems and iteratively reduces the number of sub-problems, decouple and solve them. The algorithm is applicable for module based product families with predefined composition of generalized commonality, subjected to multiple load cases that can be analyzed separately. The problem reduction is performed by only considering the constraints that are critical in the optimal solution. Therefore the optimization algorithm is called the Critical Constraint Method, CCM. Finally the CCM algorithm is evaluated by two product family optimization problems.

  • 100990.
    Önnegren, Anna
    Linköping University, Department of Electrical Engineering.
    Feldetektering för diagnos med differentialgeometriska metoder -en implementering i Mathematica2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    Diagnosis means detection and isolation of faults. A model based diagnosis system is built on a mathematical model of the system. The difficulty when constructing the diagnosis system depends om how the model is formulated. In this report, a method is described that rewrites the model on such a form that the construction of the diagnosis algoritm is easy. The model is transformed by two state space transformations and the result will be a system on state space form where one part of the system becomes easy to supervise.

    The main part of the report describes the procedure to create these transformations, which can be done in seven steps, based on differential geometric methods.

    The aim of this masters thesis was to create an implementation in Mathematica (a computer tool for symbolic formula manipulation) of the creation of the two transformations and the system transformation. The created functions are described and examples of these are given.

    A further aim was to evaluate if Mathematica could be a good support to rewrit a model. This was done by studying examples, and on the basis of the examples, identify difficult and easy steps.

    The program has shown to be a good aid. Two of the seven steps have been identified as difficult and proposals for improvements have been given.

  • 100991.
    Öquist, Mats
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Northern peatland carbon biogeochemistry: the influence of vascular plants and edaphic factors on carbon dioxide and methane exchange2001Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The interest in carbon dynamics and the interactions between ecosystems and the atmosphere has increased during the last decade due to the postulated threat of anthropgenically induced global and climate change. Northern peatlands, with their large stores of organic carbon and long-term net accumulation of atmospheric carbon dioxide are key ecosystems in these interactions. Furthermore, peatlands transform organic carbon to methane, which also is an important greenhouse gas.

    The findings reported in this thesis and in the accompanying papers are based on both laboratory and field investigations of carbon transformation dynamics on the process scale and at the resolution of individual peatland plant communities. The data from one of the studies also is extrapolated in an attempt to identify environmental controls on regional scales in order to predict the response of northern pcatlands to climate warming.

    The laboratory experiments focus on how climate variations, inducing fluctuations in groundwater level and also soil freeze-thaw cycles, influences organic matter mineralisation to carbon dioxide and methane. The field studies investigate year-to-year variations and interdecadal differences in carbon gas exchange at a subarctic peatland, and also how the physiological activities of vascular plants control methane emission rates.

    The main conclusions presented include:

    Soil freeze-thaw events may be very important for the annual carbon balance in northern peatlands, because they have the potential to increase mineralisation rates and alter biogeochemical degradation pathways.

    Vascular plants exert a strong influence on methane flux dynamics during the growing season, both by mediating methane transport and through substrate-based interactions with the soil microbial community. However, there are important species-related factors that govern the nature and extent of this influence.

    Caution has to be taken when extrapolating field data to estimate regional carbon exchange because the relevance of the specific environmental parameters that control this exchange varies depending on resolution. On broad spatial and temporal scales the best predictor of peatland methane emissions is mean soil temperature, but also microbial substrate availability (expressed as the organic acid concentration in peat water) is of importance. This temperature sensitivity represents a strong potential feedback mechanism on climate change.

    List of papers
    1. Effects of a transient oxic period on mineralization of organic matter to CH4 and CO2 in anoxic peat incubations
    Open this publication in new window or tab >>Effects of a transient oxic period on mineralization of organic matter to CH4 and CO2 in anoxic peat incubations
    1998 (English)In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 15, no 4, p. 325-333Article in journal (Refereed) Published
    Abstract [en]

    Rates of organic matter mineralization in peatlands, and hence production of the greenhouse gases CH4 and CO2, are highly dependent on the distribution of oxygen in the peat. Using laboratory incubations of peat, we investigated the sensitivity of the anoxic production of CH4 and CO2 to a transient oxic period of a few weeks’ duration. Production rates during 3 successive anoxic periods were compared with rates in samples incubated in the presence of oxygen during the second period. In surface peat (5–10‐cm depth), with an initially high level of CH4 production, oxic conditions during period 2 did not result in a lower potential CH4 production rate during period 3, although production was delayed 1 week. In permanently anoxic, deep peat (50–55‐cm depth) with a comparatively low initial production of CH4, oxic conditions during period 2 resulted in zero production of CH4 during period 3. Thus, the methanogens in surface peal—but not in deep peat—remained viable after several weeks of oxic conditions. In contrast to CH4 production, the oxic period had a negligible effect on anoxic CO2 production during period 3, in surface as well as deep peat. In both surface and deep peat, CO2 production was several times higher under oxic than under anoxic conditions. However, for the first 2 weeks of oxic conditions, CO2 production in the deep peat was very low. Still, deep peat obviously contained facultative microorganisms that, after a relatively short period, were able to maintain a considerably higher rate of organic matter mineralization under oxic than under anoxic conditions.

    Keywords
    carbon dioxide production, methane production, mineralization, oxygen tolerance, peatland, Sphagnum peat
    National Category
    Social Sciences Interdisciplinary
    Identifiers
    urn:nbn:se:liu:diva-79154 (URN)10.1080/01490459809378086 (DOI)
    Available from: 2012-06-29 Created: 2012-06-29 Last updated: 2018-01-12Bibliographically approved
    2. Effects of freeze-thaw cycles on low temperature carbon mineralisation in peat
    Open this publication in new window or tab >>Effects of freeze-thaw cycles on low temperature carbon mineralisation in peat
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Recent investigations indicate that winter carbon emission from peatlands and low temperature carbon mineralisation processes conld have the potential to affect annual carbon budgets. Special emphasis has been put on periods of freeze-thaw events during spring and autumn. The aim of this study was to investigate the impact of freeze-thaw cycles on peat carbon mineralisation. This was addressed by following production rates and total amounts of CO,- and CH4-formation in surface (0-5 cm) and deep (45-50 cm) peat samples incubated at 4°C and comparing controls with replicate samples subjected to three consecutive freeze-thaw cyclesprior to incubation. Accumulation of fermentation products (H2, VF A and ethanol) were measured in order to gain further insight to the biogeochemical processes and transformation pathways involved. We conclude that freeze-thaw cycles affect both short and long term formation and exchange of C02 by altering the availability and amount of peat carbon substrates. Freeze-thaw events also resulted in an inhibition of methanogenesis with a concomitant accumulation in H2 and butyrate. We conclude that freezethaw cycling events can be of large importance for the carbon budgets of northern peatland ecosystems, although they are of a limited temporal duration.

    National Category
    Social Sciences Interdisciplinary
    Identifiers
    urn:nbn:se:liu:diva-79155 (URN)
    Available from: 2012-06-29 Created: 2012-06-29 Last updated: 2018-01-12Bibliographically approved
    3. Interdecadal changes in CO2 and CH4 fluxes of subarctic mire: Stordalen revisted after 20 years
    Open this publication in new window or tab >>Interdecadal changes in CO2 and CH4 fluxes of subarctic mire: Stordalen revisted after 20 years
    1999 (English)In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 85, no 1, p. 22-30Article in journal (Refereed) Published
    Abstract [en]

    The first subarctic wetland CO2 and CH4 flux measurements were made at Stordalen in the beginning of the 1970s in connection with the IBP study. A return to this area in 1994-95 offered a unique opportunity to study possible interdecadal changes in northern wetland CO2 and CH4 emissions. Measurements of CO2 and CH4 fluxes were carried out in similar habitats as those investigated in 1974. The mire distribution of wet minerotrophic areas relative to the elevated ombrotrophic areas had changed dramatically over the twenty years. There were no significant differences between the CH4-flux in 1974, 1994, and 1995. However, the CO2 fluxes were significantly higher in 1995 than in 1974. Since differences in climatic conditions gave no cause for such a change it suggests a possible increase in decomposition rate to be due to other factors. We suggest changes in vegetation composition, altered mineralization pathways and disintegration of permafrost as causes for the interdecadal increase in decomposition rates.

    National Category
    Social Sciences Interdisciplinary
    Identifiers
    urn:nbn:se:liu:diva-33657 (URN)10.2307/3546788 (DOI)19692 (Local ID)19692 (Archive number)19692 (OAI)
    Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2018-01-13Bibliographically approved
    4. Vascular plants as regulators of methane emissions from a subarctic mire ecosystem
    Open this publication in new window or tab >>Vascular plants as regulators of methane emissions from a subarctic mire ecosystem
    2002 (English)In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 107, no 21, p. 4580-4590Article in journal (Refereed) Published
    Abstract [en]

    Vascular plant functions as controlling mechanisms of methane emissions were investigated at two contrasting habitat types at a subarctic peatland ecosystem in northern Sweden. One of the habitats was ombrotrophic (vegetation dominated by Eriophorum vaginatum and Carex rotundata), while the other was minerotrophic (vegetation dominated by Eriophorum angustifolium). Through shading manipulations we successfully reduced the gross photosynthetic rates of the vascular plant communities. At the ombrotrophic site a 25% reduction in gross photosynthesis lead to a concomitant 20% reduction in methane emission rates, indicating a strong substrate-based coupling between the vascular plant community and the methanogenic populations. At the minerotrophic site, methane emission rates were unaffected, although plant photosynthesis was reduced by almost 50%. However, the methane emission rates at the minerotrophic site were significantly correlated with the number of vascular plants. We conclude that at the minerotrophic site the vegetation influences methane emission rates by facilitating methane transportation between the soil and the atmosphere, while at the ombrotrophic site the relationship between the vascular plant community and methane emissions is mediated by substrate-based interactions regulated by plant photosynthetic activity. Copyright 2002 by the American Geophysical Union.

    Keywords
    Carbon exchange, Methane emission, Peatland biogeochemistry, Plant-microbe interactions, Vascular plants
    National Category
    Social Sciences
    Identifiers
    urn:nbn:se:liu:diva-46812 (URN)10.1029/2001JD001030 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13Bibliographically approved
    5. Large scale variations in CH4 emissions from wetlands explained by temperature and substrate availability
    Open this publication in new window or tab >>Large scale variations in CH4 emissions from wetlands explained by temperature and substrate availability
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Globally, wetlands are at estimates ranging 115-237 Tg C4/yr1 the largest single source of the greenhouse gas CH4 to the atmosphere. Important feedback mechanisms on climate change arising from changing exchanges of C02 between the terrestrial biosphere and the atmosphere have recently been identified2. A related question is how will possible changes in the CH4 emissions from wetlands affect the further development of the greenhouse effect? Here we show using comparable methods in a wide range of wetlands ranging from Greenland to Siberia that regardless the dependency on soil moisture, plant productivity and other factors, temperature is the strongest control and predictor of CH4 emissions across both temporal and large spatial scales. Furthermore, we show that CH4 flux variations not explained by temperature can beattributed to differences in microbial substrate availability (expressed as the organic acid concentration in peat water). Combined, soil temperature and organic acid concentrations explains 99% of the variation in CH4 fluxes between the different sites. The temperature sensitivity of the CH4 emissions shown suggests a strong feedback mechanism on climatechange that should valid incorporation in developments of global circulation models.

    National Category
    Social Sciences Interdisciplinary
    Identifiers
    urn:nbn:se:liu:diva-79157 (URN)
    Available from: 2012-06-29 Created: 2012-06-29 Last updated: 2018-01-12Bibliographically approved
  • 100992.
    Öquist, Mats
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Berg, Anders
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Effects of freeze-thaw cycles on low temperature carbon mineralisation in peatManuscript (preprint) (Other academic)
    Abstract [en]

    Recent investigations indicate that winter carbon emission from peatlands and low temperature carbon mineralisation processes conld have the potential to affect annual carbon budgets. Special emphasis has been put on periods of freeze-thaw events during spring and autumn. The aim of this study was to investigate the impact of freeze-thaw cycles on peat carbon mineralisation. This was addressed by following production rates and total amounts of CO,- and CH4-formation in surface (0-5 cm) and deep (45-50 cm) peat samples incubated at 4°C and comparing controls with replicate samples subjected to three consecutive freeze-thaw cyclesprior to incubation. Accumulation of fermentation products (H2, VF A and ethanol) were measured in order to gain further insight to the biogeochemical processes and transformation pathways involved. We conclude that freeze-thaw cycles affect both short and long term formation and exchange of C02 by altering the availability and amount of peat carbon substrates. Freeze-thaw events also resulted in an inhibition of methanogenesis with a concomitant accumulation in H2 and butyrate. We conclude that freezethaw cycling events can be of large importance for the carbon budgets of northern peatland ecosystems, although they are of a limited temporal duration.

  • 100993.
    Öquist, Mats
    et al.
    Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Sundh, Ingvar
    Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Effects of a transient oxic period on mineralization of organic matter to CH4 and CO2 in anoxic peat incubations1998In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 15, no 4, p. 325-333Article in journal (Refereed)
    Abstract [en]

    Rates of organic matter mineralization in peatlands, and hence production of the greenhouse gases CH4 and CO2, are highly dependent on the distribution of oxygen in the peat. Using laboratory incubations of peat, we investigated the sensitivity of the anoxic production of CH4 and CO2 to a transient oxic period of a few weeks’ duration. Production rates during 3 successive anoxic periods were compared with rates in samples incubated in the presence of oxygen during the second period. In surface peat (5–10‐cm depth), with an initially high level of CH4 production, oxic conditions during period 2 did not result in a lower potential CH4 production rate during period 3, although production was delayed 1 week. In permanently anoxic, deep peat (50–55‐cm depth) with a comparatively low initial production of CH4, oxic conditions during period 2 resulted in zero production of CH4 during period 3. Thus, the methanogens in surface peal—but not in deep peat—remained viable after several weeks of oxic conditions. In contrast to CH4 production, the oxic period had a negligible effect on anoxic CO2 production during period 3, in surface as well as deep peat. In both surface and deep peat, CO2 production was several times higher under oxic than under anoxic conditions. However, for the first 2 weeks of oxic conditions, CO2 production in the deep peat was very low. Still, deep peat obviously contained facultative microorganisms that, after a relatively short period, were able to maintain a considerably higher rate of organic matter mineralization under oxic than under anoxic conditions.

  • 100994.
    Öquist, Mats
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Vascular plants as regulators of methane emissions from a subarctic mire ecosystem2002In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 107, no 21, p. 4580-4590Article in journal (Refereed)
    Abstract [en]

    Vascular plant functions as controlling mechanisms of methane emissions were investigated at two contrasting habitat types at a subarctic peatland ecosystem in northern Sweden. One of the habitats was ombrotrophic (vegetation dominated by Eriophorum vaginatum and Carex rotundata), while the other was minerotrophic (vegetation dominated by Eriophorum angustifolium). Through shading manipulations we successfully reduced the gross photosynthetic rates of the vascular plant communities. At the ombrotrophic site a 25% reduction in gross photosynthesis lead to a concomitant 20% reduction in methane emission rates, indicating a strong substrate-based coupling between the vascular plant community and the methanogenic populations. At the minerotrophic site, methane emission rates were unaffected, although plant photosynthesis was reduced by almost 50%. However, the methane emission rates at the minerotrophic site were significantly correlated with the number of vascular plants. We conclude that at the minerotrophic site the vegetation influences methane emission rates by facilitating methane transportation between the soil and the atmosphere, while at the ombrotrophic site the relationship between the vascular plant community and methane emissions is mediated by substrate-based interactions regulated by plant photosynthetic activity. Copyright 2002 by the American Geophysical Union.

  • 100995.
    Öqvist, Jenny
    Linköping University, Department of Language and Culture.
    I samhörighetens tjänst. Användningen av pronomen 'han' och 'hon' i initialposition.2005In: Samtal och grammatik. Studier i svenskt samtalsspråk. / [ed] Jan Anward & Bengt Nordberg, Lund: Studentlitteratur , 2005, p. 139-156Chapter in book (Other academic)
    Abstract [sv]

    Samtalsspråkets grammatik, finns den? Frågan kan tyckas överraskande, men för de flesta människor är grammatik förknippat med skriftspråk och med skolans språkundervisning. Den traditionella grammatikforskningen har mesta-dels byggt på skriftspråket. Den här boken vill visa att också det fritt flödande, oreflekterade talet i dialoger och flerpartssamtal följer grammatiska regler, även om dessa delvis är av annan art och framsprungna ur andra praktiker än skriftspråkets.

    Syftet med boken är att beskriva strategiskt valda, återkommande grammatiska strukturer som kan bilda underlag för fortsatta talspråksgrammatiska studier. Alla studierna bygger på audio- och videoinspelningar av autentiska, spontana samtal, såväl institutionella som vardagliga, personliga.

    Detta är den första bok som på svenska presenterar det nya forskningsområdet interaktionell lingvistik för en större läsekrets. Förutom som ett inlägg i den vetenskapliga debatten, är den tänkt att användas på olika nivåer i den akademiska undervisningen i sociolingvistik, samtalsforskning och grammatik.

    Den kan också med fördel nyttiggöras inom andra ämnen, t.ex. sociologi, och ge viktiga insikter till studerande inom utbildningar till olika service- och människovårdande yrken.

  • 100996.
    Öqvist, Jenny
    Linköping University, Department of Culture and Communication. Linköping University, Faculty of Arts and Sciences.
    När man talar om trollen: Personreferens i svenskt samtalsspråk2005Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The thesis investigates reference to non-present, singular persons in Swedish talk-ininteraction. The overall aim of the study is to analyse instances of person reference as parts of their linguistic, sequential and social contexts, and to describe these instances with regard to interactional, formal/structural, and functional aspects. An important point of departure for the study is that instances of person reference must be analysed as choices from different alternatives. This means that instances of person reference should neither be thought of as mere manifestations of the speaker’s own state of knowledge of the referent and her/his assessment of the addressee’s knowledge state, nor as reflections of structural aspects of the discourse. Theoretically and methodologically, the study belongs to the fields of interactional linguistics and conversation analysis (CA). The data for the study are drawn from naturally occurring everyday and institutional interaction and includes two-party and multi-party interaction, and telephone as well as face-to-face interaction.

    The analyses of introductory references to persons highlight issues such as the speaker’s claimed knowledge of/familiarity with the referent as well as the claims being made on behalf of the addressee, the role and importance of the referent in the activity of the talk, and the implications of person reference on the affiliation/disaffiliation of the participants with the referent, as well as with each other. The analyses of references to persons that have already been introduced in the interaction centres on partly different issues. The categorization of these references is based on two factors; the first being the sequential position of the reference and the second being whether the reference contributes to sequential continuity or discontinuity. The analyses emphasize that referential choice is an important resource for the construction of continuity and discontinuity, and that participants make use of these resources in unmarked as well as marked ways. This means that participants choose between different referential expressions, and these choices have different consequences depending on, inter alia, the sequential position of the reference. The study shows that reference to persons is doubly contextual: participants’ referential choices are made in consideration of the foregoing as well as the upcoming activity of the talk. Consequently, in order to adequately describe instances of person reference, the sequential context must be taken into account.

  • 100997.
    Öqvist, Jenny
    Linköping University, Department for Studies of Social Change and Culture. Linköping University, Faculty of Arts and Sciences.
    Personreferens som socialt verktyg - en analys.2003In: Grammatik och samtal: studier till minne av Mats Eriksson / [ed] Bengt Nordberg, Uppsala: Inst. för nordiska språk, Uppsala universitet. , 2003, p. 101-111Chapter in book (Other academic)
  • 100998.
    Öqvist, Johanna
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Bergfelt, Petra
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Nudge; en knuff i rätt riktning?: Ett beteendeekonomiskt experiment om svenskars attityder till nudge2015Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Behavioral interventions – so-called nudge – aim to get individuals to make decisions that are beneficial for the individual as well as for the society by making subtle changes in the decision context. Policymakers worldwide use nudge as an additional policy tool. However, nudging has been criticized for its questionable ethical principles and to date the debate concerning these issues has largely proceeded without much input from the general public. When should nudges be deemed as acceptable and when are they perceived as restrictive of an individual’s freedom of choice? Should all nudges be perceived as equal or do attitudes depend on specific characteristics of the nudge-intervention?The objective of this study is to elicit public views on the use of nudges with regard to i) acceptance and ii) restrictive on an individual’s freedom of choice. In particular, the study examines attitudes towards pro-self nudges (i.e. focusing on private welfare) and pro-social nudges (i.e. focusing on social welfare) as well as nudge of three degrees of intrusiveness (categorization of level of intrusiveness on the individual’s autonomy). In addition, we explore how individual differences in worldview affect attitudes towards nudge. A general population sample in Sweden (n=677) were presented with nudge-scenarios concerning three policy contexts; energy saving, smoking and retirement, in which they responded to questions regarding attitudes. To explore preferences towards pro-self and pro-social nudge, we used a contrastive vignette technique. To test for individual differences, measures on cultural cognition were included.The result show that all nudge-scenarios have majority support (for acceptance). However, a quarter of the nudge-scenarios were perceived as restrictive of an individual’s freedom of choice. Differences regarding attitudes towards pro-self and pro-social nudge cannot be ensured statistically. For degree of intrusiveness we found that a higher degree of intrusiveness reduces the level of acceptance for the nudge-scenarios. As for restrictive on an individual’s freedom of choice, we found the remarkable result that a medium degree of intrusiveness is perceived as less intrusive than a high degree of intrusiveness. Furthermore, we found that individuals with an individualistic worldview tend to be less accepting towards nudge-scenarios.In conclusion, our results indicate that there is no general accepted formula for how a nudge should be designed. Highlighting this is a fundamental aspect both for broadening the theory of nudge as a policy tool as well as to implement efficient nudges in the future.

  • 100999.
    Öresjö, Per
    Linköping University, Department of Electrical Engineering.
    A High Speed Sigma Delta A/D-Converter for a General Purpose RF Front End in 90nm-Technology2007Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    In this report a transistor-level design of a GHz Sigma-Delta analog-to-digital converter for an RF front end is proposed. The design is current driven, where the integration is done directly over two capacitances and it contains no operational amplifiers.

    The clock frequency used for verification was 2.5 GHz and the output band-width was 10 MHz. The system is flexible in that the number of internal bits can be scaled easily and in this report a three-bit system yielding an SNR of 76.5 dB as well as a four-bit system yielding an SNR of 82.5 dB are analyzed.

  • 101000.
    Örjeman, Johanna
    et al.
    Linköping University, Department of Behavioural Sciences and Learning.
    Hjertstedt, Lina
    Linköping University, Department of Behavioural Sciences and Learning.
    Litteratur i undervisningen, en tillgång för elevers lärande?: En litteraturstudie kring litteraturs användning i undervisningen i årskurs F-3.2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
2017201820192020202120222023 100951 - 101000 of 101516
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf