liu.seSearch for publications in DiVA
Change search
Refine search result
1234567 1 - 50 of 1246
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)
  • 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)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Gardström, Karin
    Linköping University, Department of Science and Technology.
    3D Navigation for Real-Time MRI using Six Degree of Freedom Interaction Devices2003Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    Real-time MRI scanning is used to visualize tissue and organs in motion. The real-time approach requires new interaction techniques to facilitate interaction with the scanning plane. The aim of this thesis is to investigate the use of input with six degrees of freedom – 6DOF. An overview over existing 6DOF input devices is given. Three devices are chosen for implementation and evaluation, Flock of Birds, SpaceBall and SpaceMouse.

    A simulator application is developed to test the different input devices. The simulator purpose is to imitate the real-time scanning situation. To be able to evaluate speed andaccuracy of the different interaction techniques, methods for measuring time and error are developed. A statistical survey is done on two different tasks to gather data of the interaction. The data is analyzed and the result is that the test subjects find the SpaceMouse superior to the other devices thanks to its kinesthetic feed-back properties and ergonomic benefits. However, the statistical data shows that Flock of Birds is the fastest device and no great difference is showed in accuracy between Flock of Birds and SpaceMouse. SpaceBall was the device that generated the least satisfying data.

  • 2.
    Johansson, Ted
    et al.
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Bengtsson, Olof
    Lotfi, Sara
    Uppsala University, Sweden.
    Vestling, Lars
    Uppsala University, Sweden.
    Norström, Hans
    Uppsala University, Sweden.
    Olsson, Jörgen
    Uppsala University, Sweden.
    Nyström, Christian
    A +32.8 dBm LDMOS power amplifier for WLAN in 65 nm CMOS technology2013Conference paper (Refereed)
    Abstract [en]

    Postlingually acquired hearing impairment (HI) is associated with changes in the representation of sound in semantic long-term memory. An indication of this is the lower performance on visual rhyme judgment tasks in conditions where phonological and orthographic cues mismatch, requiring high reliance on phonological representations. In this study, event-related potentials (ERPs) were used for the first time to investigate the neural correlates of phonological processing in visual rhyme judgments in participants with acquired HI and normal hearing (NH). Rhyme task word pairs rhymed or not and had matching or mismatching orthography. In addition, the inter-stimulus interval (ISI) was manipulated to be either long (800 ms) or short (50 ms). Long ISIs allow for engagement of explicit, top-down processes, while short ISIs limit the involvement of such mechanisms. We hypothesized lower behavioral performance and N400 and N2 deviations in HI in the mismatching rhyme judgment conditions, particularly in short ISI. However, the results showed a different pattern. As expected, behavioral performance in the mismatch conditions was lower in HI than in NH in short ISI, but ERPs did not differ across groups. In contrast, HI performed on a par with NH in long ISI. Further, HI, but not NH, showed an amplified N2-like response in the non-rhyming, orthographically mismatching condition in long ISI. This was also the rhyme condition in which participants in both groups benefited the most from the possibility to engage top-down processes afforded with the longer ISI. Taken together, these results indicate an early ERP signature of HI in this challenging phonological task, likely reflecting use of a compensatory strategy. This strategy is suggested to involve increased reliance on explicit mechanisms such as articulatory recoding and grapheme-to-phoneme conversion.

  • 3.
    Lindblad, Ulrik
    et al.
    Linköping University, Department of Electrical Engineering.
    Thalin, Patrik
    Linköping University, Department of Electrical Engineering.
    A Behavioral Model of a DSP Processor with Scalable Structure2002Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    In mobile digital devices, low power consumption is an important matter to reduce the need for a heavy and big battery. One way of reducing the power consumption is to construct the hardware so that the performance is optimal for the application. The demand of performance is dependent of the tasks that the device will be performing. This is where scalable structure of the hardware is an idea to solve the problem.

    This master thesis serve as a starting point for developing a digital signal processor with scalable structure. The digital signal processor is a common and important part of digital processing. Scalable struture is in this case adding and removing parts of the memory and/or the instruction set, and to make the data wordlength variable. The development is simplified by modeling it on an existing processor. The result of this master thesis is an instruction simulator written in C language. The simulator will be a model for development of the hardware.

  • 4.
    Saifullah, Mohammad
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A Biologically-Inspired Approach for Object Search2013In: Proceedings of the World Congress on Engineering 2013 WCE 2013, July 3-5, 2013, London, U.K. Vol. III, Newswood and International Association of Engineers , 2013, 792-797 p.Conference paper (Refereed)
    Abstract [en]

    In this paper a biologically-inspired approach for object search is introduced. This approach is based on the visual information processing in the human brain and more specifically along the two visual processing pathways of the visual cortex. According to this approach different processes, with similar representational structure, work in parallel toward their local tasks, while at the same time, their mutual interaction leads to achievement of larger global goals. The model based on this approach provides a platform where bottom-up and top-down cues are computed and integrated in small incremental steps and lead to emergence of attention that selects an appropriate object. The two important principles of visual information processing, i.e., constraint satisfaction and inhibition play the key role in this model. The model is implemented with an interactive neural network. Simulation results demonstrate the practicality as well as the strength of this approach for object search tasks.

  • 5. Macoveanu, Julian
    et al.
    Klingberg, T.
    Tegnér, Jesper
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Computational Biology .
    A biophysical model of multiple-item working memory: A computational and neuroimaging study2006In: Neuroscience, ISSN 0306-4522, Vol. 141, no 3, 1611-1618 p.Article in journal (Refereed)
    Abstract [en]

    Biophysically based computational models have successfully accounted for the persistent neural activity underlying the maintenance of single items of information in working memory. The aim of the present study was to extend previous models in order to retain multiple items, in agreement with the observed human storage capacity. This was done by implementing cellular mechanisms known to occur during the childhood development of working memory, such as an increased synaptic strength and improved contrast and specificity of the neural response. Our computational study shows that these mechanisms are sufficient to create a neural network which can store information about multiple items through sustained neural activity. Furthermore, by using functional magnetic resonance imaging, we found that the information-activity curve predicted by the model corresponds to that in the human posterior parietal cortex during performance of working memory tasks, which is consistent with previous studies of brain activity related to working memory capacity in humans. © 2006 IBRO.

  • 6.
    Rustichini, Aldo
    et al.
    University of Minnesota.
    Dickhaut, John
    University of Minnesota.
    Ghirardato, Paolo
    Università di Torino.
    Smith, Christian Skinner
    Kansas State University.
    Pardo, José V.
    University of Minnesota.
    A Brain Imaging Study of the Choice Procedure2005In: Games and Economic Behavior, ISSN 0899-8256, E-ISSN 1090-2473, Vol. 52, no 2, 257-282 p.Article in journal (Refereed)
    Abstract [en]

    We study the behavior of subjects facing choices between certain, risky, and ambiguous lotteries. Subjects' choices are consistent with the economic theories modeling ambiguity aversion. Our results support the conjecture that subjects face choice tasks as an estimation of the value of the lotteries, and that the difficulty of the choice is an important explanatory variable (in addition to risk and ambiguity aversion).

    The brain imaging data suggest that such estimation is of an approximate nature when the choices involve ambiguous and risky lotteries, as the regions in the brain that are activated are typically located in parietal lobes. Thus such choices require mental faculties that are shared by all mammals, and in particular are independent of language. In contrast, choices involving partial ambiguous lotteries additionally produce an activation of the frontal region, which indicates a different, more sophisticated cognitive process.

  • 7.
    Tsirepli, Ismini
    Linköping University, Department of Electrical Engineering.
    A Cadence layout wrapper for MATLAB2006Independent thesis Basic level (professional degree), 10 points / 15 hpStudent thesis
    Abstract [en]

    In this thesis, the focus is on creating a wrapper between MATLAB and the Cadence Virtuoso design environment. The central idea is to use the wrapper and write the code for an entire analog layout as scripts in MATLAB. Basically, we will implement a set of necessary commands for performing the most fundamental tasks in layout generation from within MATLAB.

  • 8.
    Bernfort, Lars
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Health Care Analysis. Linköping University, Faculty of Health Sciences.
    Eckard, Nathalie
    Linköping University, Department of Medical and Health Sciences, Division of Health Care Analysis. Linköping University, Faculty of Health Sciences.
    Husberg, Magnus
    Linköping University, Department of Medical and Health Sciences, Division of Health Care Analysis. Linköping University, Faculty of Health Sciences.
    Alwin, Jenny
    Linköping University, Department of Medical and Health Sciences, Division of Health Care Analysis. Linköping University, Faculty of Health Sciences.
    A case of community-based fall prevention: Survey of organization and content of minor home help services in Swedish municipalities2014In: Scandinavian Journal of Public Health, ISSN 1403-4948, E-ISSN 1651-1905, Vol. 42, no 7, 643-8 p.Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The aim of this study was to survey minor home help services provided by Swedish municipalities with the main purpose to prevent fall injuries.

    METHODS: If minor home help services were presented on the homepage of a municipality, an initial telephone contact was taken. Thereafter a questionnaire was administered, including questions about target groups, aim with the services, tasks included, costs and restrictions for users, budget, and experienced gains with the services. Municipalities not providing minor home help services were asked about the reason therefore and if the municipality had previously provided the services Results: The questionnaire response rate was 92%. In 191 of Sweden's 290 municipalities services were provided by, or in cooperation with, the municipality. Reasons for not providing the services were mainly financial and lack of demand. Services were more often provided in larger cities and in municipalities located in populous regions. In some municipalities services were performed by persons with functional disabilities or unemployed persons. CONCLUSIONS: BOTH PROVIDERS AND USERS EXPRESSED SATISFACTION WITH THE SERVICES ASPECTS EXPRESSED WERE THAT SERVICES LEAD TO GREATER SENSE OF SAFETY AND SOCIAL GAINS THE EFFECT OF THE SERVICES IN TERMS OF FALL PREVENTION IS YET TO BE PROVED WITH ONLY A SMALL FALL-PREVENTIVE EFFECT SERVICES ARE PROBABLY COST-EFFECTIVE IMPROVED QUALITY OF LIFE, SENSE OF SAFETY, AND BEING ABLE TO OFFER MEANINGFUL WORK TO OTHERWISE UNEMPLOYED PERSONS ARE IMPORTANT ASPECTS THAT MIGHT IN THEMSELVES MOTIVATE THE PROVISION OF MINOR HOME HELP SERVICES.

  • 9.
    Rankin, Amy
    et al.
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, The Institute of Technology.
    Dahlbäck, Nils
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.
    Lundberg, Jonas
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    A case study of factor influencing role improvisation in crisis response teams2013In: Cognition, Technology & Work, ISSN 1435-5558, E-ISSN 1435-5566, Vol. 15, no 1, 79-93 p.Article in journal (Refereed)
    Abstract [en]

    Common characteristics of crisis situations are ambiguous and unplanned for events. The need for improvised roles can therefore be an imperative factor for the success of an operation. The aim of this study is to deepen the understanding of the processes taking place during improvised work ‘‘as it happens’’. A case study of a crisis management team at work is presented and provides an in-depth analysis of the information and communication flow of persons acting in improvised roles, including con- textual factors influencing the task at hand. The analysis suggests that three main factors lay behind decreased per- formance by the team when some of its members were forced to take on roles for which they lacked professional training; lack of language skills, lack of domain knowledge and insufficient organizational structure of the tasks. Based on the observations from this case study, we suggest three ways of improving a team’s performance and hence resil- ience when forced to improvise due to lack of personnel in one or more required competence areas. These are training to take on the responsibility for tasks or roles outside ones professional area of specialization, developing formal routines for changes in roles and tasks and developing and using tools and routines for information sharing.

  • 10.
    Eliasson, Karolina
    Linköping University, Department of Computer and Information Science, CASL - Cognitive Autonomous Systems Laboratory. Linköping University, The Institute of Technology.
    A case-based approach to dialogue systems2010In: Journal of experimental and theoretical artificial intelligence (Print), ISSN 0952-813X, E-ISSN 1362-3079, Vol. 22, no 1, 23-51 p.Article in journal (Refereed)
    Abstract [en]

    We describe an approach to integrate dialogue management, machine-learning and action planning in a system for dialogue between a human and a robot. Case-based techniques are used because they permit life-long learning from experience and demand little prior knowledge and few static hand-written structures. This approach has been developed through the work on an experimental dialogue system, called CEDERIC, that is connected to an unmanned aerial vehicle (UAV). A single case base and case-based reasoning engine is used both for understanding and for planning actions by the UAV. Dialogue experiments both with experienced and novice users, where the users have solved tasks by dialogue with this system, showed very adequate success rates.

  • 11.
    Höst, Gunnar E.
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    Schönborn, Konrad J.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    Lundin Palmerius, Karljohan
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    A Case-Based Study of Students' Visuohaptic Experiences of Electric Fields around Molecules: Shaping the Development of Virtual Nanoscience Learning Environments2013In: Education Research International, ISSN 2090-4002, E-ISSN 2090-4010, Vol. 2013, 194363Article in journal (Refereed)
    Abstract [en]

    Recent educational research has suggested that immersive multisensory virtual environments offer learners unique and exciting knowledge-building opportunities for the construction of scientific knowledge. This paper delivers a case-based study of students’ immersive interaction with electric fields around molecules in a multisensory visuohaptic virtual environment. The virtual architecture presented here also has conceptual connections to the flourishing quest in contemporary literature for the pressing need to communicate nanoscientific ideas to learners. Five upper secondary school students’ prior conceptual understanding of electric fields and their application of this knowledge to molecular contexts, were probed prior to exposure to the virtual model. Subsequently, four students interacted with the visuohaptic model while performing think-aloud tasks. An inductive and heuristic treatment of videotaped verbal and behavioural data revealed distinct interrelationships between students’ interactive strategies implemented when executing tasks in the virtual system and the nature of their conceptual knowledge deployed. The obtained qualitative case study evidence could serve as an empirical basis for informing the rendering and communication of overarching nanoscale ideas. At the time of composing this paper for publication in the current journal, the research findings of this study have been put into motion in informing a broader project goal of developing educational virtual environments for depicting nanophenomena.

  • 12.
    Bergsten, Christer
    Linköping University, Faculty of Educational Sciences. Linköping University, Department of Mathematics, Applied Mathematics.
    A classification of algebraic tasks2003In: New trends in mathematics education research: an European perspective,2003, 2003Conference paper (Other academic)
  • 13.
    Doherty, Patrick
    et al.
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems.
    Kvarnström, Jonas
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems.
    Rudol, Piotr
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    Wzorek, Mariusz
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    Conte, Gianpaolo
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    Berger, Cyrille
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Integrated Computer Systems. Linköping University, Faculty of Science & Engineering.
    Hinzmann, Timo
    Stastny, Thomas
    A Collaborative Framework for 3D Mapping using Unmanned Aerial Vehicles2016In: PRIMA 2016: Principles and Practice of Multi-Agent Systems, Springer Publishing Company, 2016, 110-130 p.Conference paper (Refereed)
    Abstract [en]

    This paper describes an overview of a generic framework for collaboration among humans and multiple heterogeneous robotic systems based on the use of a formal characterization of delegation as a speech act. The system used contains a complex set of integrated software modules that include delegation managers for each platform, a task specification language for characterizing distributed tasks, a task planner, a multi-agent scan trajectory generation and region partitioning module, and a system infrastructure used to distributively instantiate any number of robotic systems and user interfaces in a collaborative team. The application focusses on 3D reconstruction in alpine environments intended to be used by alpine rescue teams. Two complex UAV systems used in the experiments are described. A fully autonomous collaborative mission executed in the Italian Alps using the framework is also described.

  • 14.
    Nyasulu, Jonas
    Linköping University, Department of Computer and Information Science.
    A Comparison of Vistrails and Taverna, and Workflow Interoperability2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In silico experiments in the field of bioinformatics generate large amounts of data since most of the tasks are done in an exploratory fashion. Workflows are one of the many tools used by scientists to model complex tasks.The interoperability of data generated from these tools plays an important role in improving the efficiency of such tools and also in verifying results from other experiments.We aim to compare workflow systems by integrating bioinformatics data in Vistrails and Taverna. We also look at how the two systems use the open provenance model that has been developed to bring provenance interoperability. We developed web services to perform similar functions of some workflows in Vistrails. With the services we were able to perform most of the tasks we planned using both systems. Differences in how lists of items are processed in the two systems results in differences in how workflows are composed in the two systems. In Taverna there is implicit iteration and Vistrails requires the use of additional modules to perform iteration.There are also differences in the execution times of workflows using web services, with workflows in Taverna taking longer than their counterparts in Vistrails. There are some similarities in the execution pattern of workflows if same workflow is invokedmultiple times, with the first invocation taking longer time than the subsequent ones.

  • 15.
    Karlsson, Fredrik
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    A comprehensive investigation of a low-energy building in Sweden2007In: Renewable Energy, ISSN 0960-1481, Vol. 32, no 11, 1830-1841 p.Article in journal (Refereed)
    Abstract [en]

    In Sweden, the building sector alone accounts for almost 40% of the total energy demand and people spend more than 80% of their time indoors. Reducing energy demand in the buildings is essential to the achievement of a sustainable built environment. At the same time, it is important to not deteriorate people's health, well-being and comfort in buildings. Thus, designing healthy and energy efficient buildings are one of the most challenging tasks for building scientists. A low-energy building that uses less than half of the purchased energy of a comparable typical Swedish building has been investigated from different viewpoints in an attempt to represent the building at different system levels. First, the ventilation performance in different rooms using the tracer gas method is reported. Second, results from simulations and in situ measurements are used to analyse the building's power demand and energy performance. The household's behaviour and their impact on energy usage as well as acceptance are reported. Finally, the CO2 emissions with regard to the energy usage are analysed on the basis of different supply energy forms from surrounding energy systems, for example a Swedish and European electricity mix, or district heating as a substitute for electrical heating.

  • 16.
    Blikstad, Mathias
    et al.
    Saab AB, Sweden.
    Karlsson, Emil
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    Lööw, Tomas
    Saab AB, Sweden.
    Rönnberg, Elina
    Linköping University, Department of Mathematics, Optimization . Linköping University, Faculty of Science & Engineering.
    A constraint generation procedure for pre-runtime scheduling of integrated modular avionic systems2017In: Proceedings of the 13th Workshop on Models and Algorithms for Planning and Scheduling Problems / [ed] Susanne Albers, Nicole Megow, Andreas S. Schulz, Leen Stougie, 2017Conference paper (Other academic)
    Abstract [en]

    In modern integrated modular avionic systems, applications share hardware resources on a common avionic platform. Such an architecture necessitates strict requirements on the spatial and temporal partitioning of the system to prevent fault propagation between different aircraft functions. One way to establish a temporal partitioning is through pre-runtime scheduling of the system, which involves creating a schedule for both tasks and a communication network.

    While the avionic systems are growing more and more complex, so is the challenge of scheduling them. Scheduling of the system has an important role in the development of new avionic systems since functionality typically is added to the system over a period of several years and a scheduling tool is used both to detect if the platform can host the new functionality and, in case this is possible, to create a new schedule. For this reason an exact solution strategy for avionics scheduling is preferred over a heuristic one.

    In this paper we present a mathematical model for an industrially relevant avionic system and present a constraint generation  procedure for scheduling of such systems. We apply our optimisation approach to instances provided by our industrial partner. These instances are of relevance for the development of future avionic systems and contain up to 20 000 tasks to be scheduled. The computational results show that our optimisation approach can be used to create schedules for such instances within reasonable time.

  • 17.
    Carvalho Bittencourt, André
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Saarinen, Kari
    ABB Corporate Research Västerås, Sweden.
    Sander-Tavallaey, Shiva
    ABB Corporate Research Västerås, Sweden.
    A Data-driven Method for Monitoring Systems that Operate Repetitively: Applications to Robust Wear Monitoring inan Industrial Robot Joint2011Manuscript (preprint) (Other academic)
    Abstract [en]

    This paper presents a method for condition monitoring of systems that operate in a repetitive manner. A data driven method is proposed that considers changes in the distribution of data samples obtained from multiple executions of one or several tasks. This is made possible with the use of kernel density estimators and the Kullback-Leibler distance measure between distributions. To increase robustness to unknown disturbances and sensitivity to faults, the use of a weighting function is suggested which can considerably improve detection performance. The method is very simple to implement, it does not require knowledge about the monitored system and can be used without process interruption, in a batch manner. The method is illustrated with applications to robust wear monitoring in a robot joint. Interesting properties of the application are presented through a real case study and simulations. The achieved results show that robust wear monitoring in industrial robot joints is made possible with the proposed method.

  • 18.
    Carvalho Bittencourt, André
    et al.
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Saarinen, Kari
    ABB Corporate Research Västerås, Sweden.
    Sander-Tavallaey, Shiva
    ABB Corporate Research Västerås, Sweden.
    A Data-Driven Method for Monitoring Systems that Operate Repetitively: Applications to Robust Wear Monitoring inan Industrial Robot Joint2011Report (Other academic)
    Abstract [en]

    This paper presents a method for condition monitoring of systems that operate in a repetitive manner. A data driven method is proposed that considers changes in the distribution of data samples obtained from multiple executions of one or several tasks. This is made possible with the use of kernel density estimators and the Kullback-Leibler distance measure between distributions. To increase robustness to unknown disturbances and sensitivity to faults, the use of a weighting function is suggested which can considerably improve detection performance. The method is very simple to implement, it does not require knowledge about the monitored system and can be used without process interruption, in a batch manner. The method is illustrated with applications to robust wear monitoring in a robot joint. Interesting properties of the application are presented through a real case study and simulations. The achieved results show that robust wear monitoring in industrial robot joints is made possible with the proposed method.

  • 19.
    Doherty, Patrick
    et al.
    Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab. Linköping University, The Institute of Technology.
    Heintz, Fredrik
    Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab. Linköping University, The Institute of Technology.
    Landén, David
    Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab. Linköping University, The Institute of Technology.
    A Delegation-Based Architecture for Collaborative Robotics2011In: Agent-Oriented Software Engineering XI: 11th International Workshop, AOSE 2010, Toronto, Canada, May 10-11, 2010, Revised Selected Papers / [ed] Danny Weyns and Marie-Pierre Gleizes, Springer Berlin/Heidelberg, 2011, 205-247 p.Chapter in book (Refereed)
    Abstract [en]

    Collaborative robotic systems have much to gain by leveraging results from the area of multi-agent systems and in particular agent-oriented software engineering. Agent-oriented software engineering has much to gain by using collaborative robotic systems as a testbed. In this article, we propose and specify a formally grounded generic collaborative system shell for robotic systems and human operated ground control systems. Collaboration is formalized in terms of the concept of delegation and delegation is instantiated as a speech act. Task Specification Trees are introduced as both a formal and pragmatic characterization of tasks and tasks are recursively delegated through a delegation process implemented in the collaborative system shell. The delegation speech act is formally grounded in the implementation using Task Specification Trees, task allocation via auctions and distributed constraint problem solving. The system is implemented as a prototype on Unmanned Aerial Vehicle systems and a case study targeting emergency service applications is presented.

  • 20.
    Doherty, Patrick
    et al.
    Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab. Linköping University, The Institute of Technology.
    Heintz, Fredrik
    Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab. Linköping University, The Institute of Technology.
    A Delegation-Based Cooperative Robotic Framework2011In: Proceedings of the IEEE International Conference on Robotics and Biomimetic, IEEE conference proceedings, 2011, 2955-2962 p.Conference paper (Refereed)
    Abstract [en]

    Cooperative robotic systems, such as unmanned aircraft systems, are becoming technologically mature enough to be integrated into civil society. To gain practical use and acceptance, a verifiable, principled and well-defined foundation for interactions between human operators and autonomous systems is needed. In this paper, we propose and specify such a formally grounded collaboration framework. Collaboration is formalized in terms of the concept of delegation and delegation is instantiated as a speech act. Task Specification Trees are introduced as both a formal and pragmatic characterization of tasks and tasks are recursively delegated through a delegation process. The delegation speech act is formally grounded in the implementation using Task Specification Trees, task allocation via auctions and distributed constraint solving. The system is implemented as a prototype on unmanned aerial vehicle systems and a case study targeting emergency service applications is presented.

  • 21.
    Rönnberg, Jerker
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences, The Swedish Institute for Disability Research.
    A descriptive scheme for memory and cognitive tasks.1983In: Guest lecture presented at the Ebbinghouse Empire Meeting,1983, 1983Conference paper (Other academic)
  • 22.
    Svensson, Tomas
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Gunnarsson, Svante
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    A Design-Build-Test course in electronics based on the CDIO framework for engineering education2012In: International Journal of Electrical Engineering Education, ISSN 0020-7209, Vol. 49, no 4, 349-364 p.Article in journal (Refereed)
    Abstract [en]

    A Design-Build-Test (DBT) course in electronics is presented. The course is designed based on the CDIO (Conceive-Design-Implement-Operate) framework for engineering education. It is part of the curriculum of two engineering programs at Linköping University, Sweden, where it has been given successfully for a number of years. The cornerstones of the course consist of carefully designed learning outcomes based on the CDIO Syllabus, a structured project management model such that the project tasks are carried out according to professional and industry-like routines, with well-designed organisation of the staff supporting the course, and challenging project tasks.

  • 23.
    Koch, Felix-Sebastian
    Linköping University, Department of Computer and Information Science.
    A direct comparison between mathematical operations in mental arithmetic with regard to working memory’s subsystems2004Independent thesis Advanced level (degree of Magister)Student thesis
    Abstract [en]

    This study examined the idea that each mathematical operation (addition, subtraction, multiplication and division) is mainly linked to one of the components of working memory as proposed by Baddeley. The phonological loop, visual-spatial sketchpad and central executive have been studied using a dual-task methodology with 7 different secondary tasks. 35 undergraduate and graduate students were timed in their response time for mental calculation and error rates were calculated. Results show clear differences of operations and of number pairs. Interaction between conditions and operations was just approaching significance. Results did not give support to the idea that operations can be linked to a certain working memory component. Several factors, such as language, problem size, lack for detail in the working memory model, difficulty of the secondary tasks, and internal validity problems are discussed with regard to the results and mental arithmetic.

  • 24.
    Larsson, Erik
    et al.
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, The Institute of Technology.
    Vermeulen, Bart
    NXP Semiconductors, Netherlands.
    Goossens, Kees
    Eindhoven University of Technology, Netherlands.
    A Distributed Architecture to Check Global Properties for Post-Silicon Debug2010In: IEEE European Test Symposium (ETS'10), Prague, Czech Republic, May 24-28, 2010., IEEE , 2010, 182-187 p.Conference paper (Refereed)
    Abstract [en]

    Post-silicon validation and debug, or ensuring that software executes correctly on the silicon of a multi-processor system-on-chip (MPSOC) is complicated, as it involves checking global properties that are distributed on the chip. In this paper we define an architecture to non-intrusively observe global properties at run time using distributed monitors. The architecture enables to perform actions when a property holds, such as stopping (part of) the system for inspection. We apply this architecture to the problem of software races that result in incorrect communication between concurrent tasks on different processors. In a case study, where we implemented monitors, event distribution, and instruments to stop communication between intellectual property (IP) blocks, we demonstrate that these races can be detected and classified as timing violations or as FIFO protocol violations.

  • 25.
    Gustafsson, Mikael
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    A distributed image-processing system for measurements of intracellular calcium in living cells1991In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 36, no 4, 199-221 p.Article in journal (Refereed)
    Abstract [en]

    During the last decade, image-processing techniques have been introduced as a valuable tool in biologically oriented research. In combination with novel fluorescent probes, these techniques permit assessment of subcellular distributions of several intracellularly important cations, such as free calcium ions and protons. Typically, systems used for image processing are located centrally around the experimental setup. This configuration has drawbacks, mainly because the laborious extraction and processing of data that generally follow an experimental session limits the access to the system for other investigators. We describe here the principles of a distributed image processing system, based on IBM-compatible personal computers (PCs), that without extra hardware can cope with all the necessary image processing involved in imaging of intracellular cations. The potential of the PC as an image processor, however, reaches beyond this specific application and many image processing tasks can be carried out successfully on a standard PC. Thus, the centrally located dedicated image processor is used only for image acquisition in the experimental situation. This in turn optimizes the utilization of expensive resources and increases efficiency. The mouse-operated software is described in detail, so that interested investigators can extract useful parts for integration into their own applications and experimental environment.

  • 26.
    Doherty, Patrick
    et al.
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    Heintz, Fredrik
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    Landén, David
    Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab. Linköping University, The Institute of Technology.
    A Distributed Task Specification Language for Mixed-Initiative Delegation2012In: Principles and Practice of Multi-Agent Systems: 13th International Conference, PRIMA 2010, Kolkata, India, November 12-15, 2010, Revised Selected Papers / [ed] Nirmit Desai, Alan Liu, Michael Winikoff, Springer Berlin/Heidelberg, 2012, Vol. 7057, 42-57 p.Chapter in book (Refereed)
    Abstract [en]

    In the next decades, practically viable robotic/agent systems are going to be mixed-initiative in nature. Humans will request help from such systems and such systems will request help from humans in achieving the complex mission tasks required. Pragmatically, one requires a distributed task specification language to define tasks and a suitable data structure which satisfies the specification and can be used flexibly by collaborative multi-agent/robotic systems. This paper defines such a task specification language and an abstract data structure called Task Specification Trees which has many of the requisite properties required for mixed-initiative problem solving and adjustable autonomy in a distributed context. A prototype system has been implemented for this delegation framework and has been used practically with collaborative unmanned aircraft systems.

  • 27.
    Bednarski, Andrzej
    Linköping University, Department of Computer and Information Science, PELAB - Programming Environment Laboratory. Linköping University, The Institute of Technology.
    A dynamic programming approach to optimal retargetable code generation for irregular architectures2002Licentiate thesis, monograph (Other academic)
    Abstract [en]

    In this thesis we address the problem of optimal code generation for irregular architectures such as Digital Signal Processors (DSPs). Code generation consists mainly of three tasks: instruction selection, instruction scheduling and register allocation. These tasks have been discovered to be NP-difficult for most of the architectures and most situations.

    A common approach to code generation consists in solving each task separately, i.e. in a decoupled manner, which is easier from an engineering point of view. Decoupled phase based compilers produce good code quality for regular architectures, but if applied to DSPs the resulting code is of significantly lower performance due to strong interdependencies between the different tasks.

    We report on a novel method for fully integrated code generation based on dynamic programming. It handles the most important tasks of code generation in a single optimization step and produces optimal code sequence. Our dynamic programming algorithm is applicable to small, yet not trivial problem instances with up to 50 instructions per basic block if data locality is not an issue, and up to 20 instructions if we take data locality on irregular processor architectures into account.

    In order to obtain a retargetable framework we developed a first version of a structured hardware description language, ADML, which is based on XML. We implemented a prototype framework of such a retargetable system for optimal code generation.

    As far as we know from the literature, this is the first time that the main tasks of code generation are solved optimally in a single and fully integrated optimization step that additionally considers data placement in registers. 

  • 28.
    Wideheim, Ann-Kristin
    et al.
    Örebro.
    Edvardsson, Tanja
    Örebro.
    Påhlsson, Anneli
    Örebro.
    Ahlström, Gerd
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    A family's perspective on living with a highly malignant brain tumor2002In: Cancer Nursing, ISSN 0162-220X, Vol. 25, no 3, 236-244 p.Article in journal (Refereed)
    Abstract [en]

    The purpose of the study is to describe what it like to live with a highly malignant brain tumor from a family perspective. It is a qualitative study in which 3 families, 3 patients, and 5 next of kin have described their experiences in 15 interviews. The study is prospective, with interviews occurring 2-3 weeks after surgery and 3 and 6 months after the onset of the illness. Inductive content analysis has been employed. The results indicate that when a highly malignant brain tumor is diagnosed, the effect on the family is devastating and there is a state of crisis. Characteristically, there is distancing and a sense of helplessness. The members of the family live from day to day in a state of constant anxiety and fear of losing the patient. The affliction limits the patient's capacity regarding activities of daily life, which increases the burden of the next of kin. The next of kin attempt to cope with their grief by occupying themselves with practical tasks and activities that they believe are meaningful. The family members have only good words to say about their encounter with healthcare staff and about the information given. Negative information that the family have not asked for can cause a long period of frustration and anxiety, and they believe that their hope has been taken away from them.

  • 29.
    Ghaeini, Bentolhoda
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    A Fault-Aware Resource Manager for Multi-Processor System-on-Chip2013Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    The semiconductor technology development empowers fabrication of extremelycomplex integrated circuits (ICs) that may contain billions of transistors. Suchhigh integration density enables designing an entire system onto a single chip,commonly referred to as a System-on-Chip (SoC). In order to boost performance,it is increasingly common to design SoCs that contain a number of processors, socalled multi-processor system-on-chips (MPSoCs).While on one hand, recent semiconductor technologies enable fabrication ofdevices such as MPSoCs which provide high performance, on the other hand thereis a drawback that these devices are becoming increasingly susceptible to faults.These faults may occur due to escapes from manufacturing test, aging effects orenvironmental impacts. When present in a system, faults may disrupt functionalityand can cause incorrect system operation. Therefore, it is very importantwhen designing systems to consider methods to tolerate potential faults. To copewith faults, there is a need of fault handling which implies automatic detection,identification and recovery from faults which may occur during the system’s operation.This work is about the design and implementation of a fault handling methodsfor an MPSoC. A fault aware Resource Manager (RM) is designed and implementedto obtain correct system operation and maximize the system’s throughputin the presence of faults. The RM has the responsibility of scheduling jobs to availableresources, collecting fault states from resources in the system and performingfault handling tasks, based on fault states. The RM is also employed in multipleexperiments in order to study its behavior in different situations.

  • 30.
    Grill, Tomas
    et al.
    Linköping University, Department of Mathematics.
    Östberg, Håkan
    Linköping University, Department of Mathematics.
    A Financial Optimization Approach to Quantitative Analysis of Long Term Government Debt Management in Sweden2003Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish National Debt Office (SNDO) is the Swedish Government’s financial administration. It has several tasks and the main one is to manage the central government’s debt in a way that minimizes the cost with due regard to risk. The debt management problem is to choose currency composition and maturity profile - a problem made difficult because of the many stochastic factors involved.

    The SNDO has created a simulation model to quantitatively analyze different aspects of this problem by evaluating a set of static strategies in a great number of simulated futures. This approach has a number of drawbacks, which might be handled by using a financial optimization approach based on Stochastic Programming.

    The objective of this master’s thesis is thus to apply financial optimization on the Swedish government’s strategic debt management problem, using the SNDO’s simulation model to generate scenarios, and to evaluate this approach against a set of static strategies in fictitious future macroeconomic developments.

    In this report we describe how the SNDO’s simulation model is used along with a clustering algorithm to form future scenarios, which are then used by an optimization model to find an optimal decision regarding the debt management problem.

    Results of the evaluations show that our optimization approach is expected to have a lower average annual real cost, but with somewhat higher risk, than a set of static comparison strategies in a simulated future. These evaluation results are based on a risk preference set by ourselves, since the government has not expressed its risk preference quantitatively. We also conclude that financial optimization is applicable on the government debt management problem, although some work remains before the method can be incorporated into the strategic work of the SNDO.

  • 31.
    Ellkvist, Tommy
    et al.
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    Strömbäck, Lena
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    Didier Linz, Lauro
    University of Utah.
    Freire, Juliana
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology. University of Utah.
    A First Study on Strategies for Generating Workflow Snippets2009In: The first International Workshop on Keyword Search ob structured data KEYS 2009, Collocated with ACM SIGMOD/PODS, Association for Computing Machinery (ACM), 2009, 15-20 p.Conference paper (Refereed)
    Abstract [en]

    Workflows are increasingly being used to specify computational tasks, from simulations and data analysis to the creation of Web mashups. Recently, a number of public workflow repositories have become available, for example, myExperiment for scientific workflows, and Yahoo! Pipes. Workflow collections are also commonplace in many scientific projects. Having such collections opens up new opportunities for knowledge sharing and re-use. But for this to become a reality, mechanisms are needed that help users explore these collections and locate useful workflows. Although there has been work on querying workflows, not much attention has been given to presenting query results. In this paper, we take a first look at the requirements for workflow snippets and study alternative techniques for deriving concise, yet informative snippets.

  • 32.
    Andersson, Johan
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    A framework for evaluation of iterative learning control2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In many industrial applications robots are used for heavy and repetitive tasks. For these applications iterative learning control (ILC) is a way to capture the repetitive nature and use it to improve some kind of reference tracking.

    In this master thesis a framework has been developed to help a user getting started with ILC. Some hands-on examples are given on how to easily use the framework. The transition from the far more common discrete time domain to the continuous time domain used by the framework is eased by tuning theory. The achievable performance is demonstrated with the help of the built-in plot functions of the framework.

  • 33.
    Yousefi Mojir, Kayvan
    et al.
    Linköping University, Department of Management and Engineering, Information Systems. Linköping University, Faculty of Arts and Sciences.
    Pilemalm, Sofie
    Linköping University, Department of Management and Engineering, Information Systems. Linköping University, Faculty of Arts and Sciences.
    A Framework for “New Actors” in Emergency Response Systems2013In: ISCRAM2013. Conference Proceedings, Book of Papers, 10th International Conference on Information Systems for Crisis Response and Management / [ed] T. Comes, F. Fiedrich , S. Fortier, J. Geldermann and T. Müller, 2013, 741-746 p.Conference paper (Refereed)
    Abstract [en]

    Using actors from different societal sectors can improve the response operation quality in emergency management. The different roles, tasks and responsibilities these actors have in response operations and the legal frameworks they work within influence their needs for proper information system support. There is thus a substantial need to study and systemize the concept of “new actors” before providing them with technical solutions. In this study, a framework is constructed showing 14 dimensions of new actors that need to be considered when new actors are studied in more detail.

  • 34.
    Rönnberg, Jerker
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences, The Swedish Institute for Disability Research.
    A framework for reproductive memory tasks.1983In: Scandinavian Journal of Psychology, ISSN 0036-5564, Vol. 24, 45-56 p.Article in journal (Refereed)
  • 35.
    Madhusudan, Seegapalya Chikkagangaiah
    Linköping University, Department of Management and Engineering, Quality Technology and Management.
    A Literature study on Factors that enables Communication between R&D and Manufacturing2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Communication, coordination and cooperation are critical for a successful organization. This master's thesis work presents a literature study of the factors that influence the interface between Research & development and manufacturing functions. Research & development and manufacturing functions rarely share information among each other and rarely combine their skills and knowledge to produce effective and efficient work within organization. This is due to lack of mutual understanding improper communication and coordination among members in the teams. In the late 1990's, competition, Information Technology proliferation, increasing customer demands for better products at shorter lead times emphasized increased need for effective product development. Each function has its specialization and is effective in their domain. Each department has roles and responsibilities to complete given tasks. But they neglect the organizational and management issues and lack the focus where they are a part of a bigger process (i.e. delivering value to customer and making the company successful at the end of the day). The main focus of the thesis is to give deeper knowledge on communication and coordination between Research and Development and manufacturing. This is achieved by review of the articles, analysis and finally synthesis of literature to develop constructs and analysis models. This will help to understand the factors and its interaction. The factors identified are individual responsibilities, artefacts and system or domain understanding, communication idea, control and role distribution, teams, accessibility and arena for personal meetings and finally overall leadership.

    Each factor has its own and unique contribution to success with in the organization. These factors are interrelated and dependent on one another. Artefacts understanding deals with some actions and steps has to be taken in order to executive the give tasks, individual role plays an important role in what sense he\she will contribute to the team as well as to the organization. Even active responsibilities must understand the system or domain and quickly adjust to the environment and get practice on it. Teams are essential tool in any organization, working together creates creative problem solving,  improves effective of communication, improves development skills and ability of an individual, mutual understanding and cooperation among group members all will constitute to the teams. Finally teams are the critical building blocks of an organization. The model developed needs further testing through empirical evidence to increase its validity.

  • 36.
    Mårdh, Selina
    et al.
    The Swedish National Road and Transport Research Institute, Linköping, Sweden.
    Nägga, Katarina
    Clinical Memory Research, Lund University, Sweden.
    Samuelsson, Stefan
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    A longitudinal study of semantic memory impairment in patients with Alzheimer’s disease2013In: Cortex, ISSN 0010-9452, Vol. 49, no 2, 528-533 p.Article in journal (Refereed)
    Abstract [en]

    Introduction

    The present study explored the nature of the semantic deterioration normally displayed in the course of Alzheimer’s disease (AD). The aim was to disentangle the extent to which semantic memory problems in patients with AD are best characterized as loss of semantic knowledge rather than difficulties in accessing semantic knowledge.

    Method

    A longitudinal approach was applied. The same semantic tests as well as same items were used across three test occasions a year apart. Twelve Alzheimer patients and 20 matched control subjects, out of a total of 25 cases in each group, remained at the final test occasion.

    Results and Conclusions

    Alzheimer patients were impaired in all the semantic tasks as compared to the matched comparison group. A progressing deterioration was evident during the study period. Our findings suggest that semantic impairment is mainly due to loss of information rather than problems in accessing semantic information.

  • 37.
    Danelljan, Martin
    et al.
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, The Institute of Technology.
    Khan, Fahad Shahbaz
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering.
    Felsberg, Michael
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, The Institute of Technology. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Granström, Karl
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Heintz, Fredrik
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    Rudol, Piotr
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    Wzorek, Mariusz
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    Kvarnström, Jonas
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    Doherty, Patrick
    Linköping University, Department of Computer and Information Science, Artificial Intelligence and Intergrated Computer systems. Linköping University, The Institute of Technology.
    A Low-Level Active Vision Framework for Collaborative Unmanned Aircraft Systems2015In: COMPUTER VISION - ECCV 2014 WORKSHOPS, PT I / [ed] Lourdes Agapito, Michael M. Bronstein and Carsten Rother, Springer Publishing Company, 2015, Vol. 8925, 223-237 p.Conference paper (Refereed)
    Abstract [en]

    Micro unmanned aerial vehicles are becoming increasingly interesting for aiding and collaborating with human agents in myriads of applications, but in particular they are useful for monitoring inaccessible or dangerous areas. In order to interact with and monitor humans, these systems need robust and real-time computer vision subsystems that allow to detect and follow persons.

    In this work, we propose a low-level active vision framework to accomplish these challenging tasks. Based on the LinkQuad platform, we present a system study that implements the detection and tracking of people under fully autonomous flight conditions, keeping the vehicle within a certain distance of a person. The framework integrates state-of-the-art methods from visual detection and tracking, Bayesian filtering, and AI-based control. The results from our experiments clearly suggest that the proposed framework performs real-time detection and tracking of persons in complex scenarios

  • 38.
    Buckwalter, Claes
    Linköping University, Department of Science and Technology, Digital Media. Linköping University, The Institute of Technology.
    A Messaging-Based Integration Architecture for Print Production Workflow Systems2006In: Proceedings of Printing Technology SPb’06, 2006, 13-17 p.Conference paper (Refereed)
    Abstract [en]

    A print production workflow consists of a number of systems

    specialized at executing specific tasks. In order to realize an

    efficient workflow it is not enough to simply assemble all the

    required systems, the systems must also communicate with each

    other and exchange information. The printing industry has used

    several approaches for integrating systems. A common

    approach has been to use so-called “hot folders” to exchange

    content files, such as PDF documents, between systems.

    Another approach, which focuses on the exchange of production

    and configuration data, is the XML-based Job Definition

    Format (JDF) and its messaging protocol Job Messaging

    Format (JMF).

     

    The need to integrate heterogeneous systems is nothing unique

    to the printing industry. The experience and knowledge in this

    area has been documented in several pattern languages. By

    applying a combination of several such pattern languages, this

    paper presents a hypothetical integration architecture that

    enables a system to communicate with other systems using JMF

    messaging.

  • 39.
    Jakoniené, Vaida
    et al.
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    Rundqvist, David
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, Database and information techniques.
    Lambrix, Patrick
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    A Method for Similarity-Based Grouping of Biological Data2006In: Data Integration in the Life Sciences: Third International Workshop, DILS 2006, Hinxton, UK, July 20-22, 2006. Proceedings / [ed] Ulf Leser, Felix Naumann, Barbara Eckman, Springer Berlin/Heidelberg, 2006, 136-151 p.Chapter in book (Refereed)
    Abstract [en]

    Similarity-based grouping of data entries in one or more data sources is a task underlying many different data management tasks, such as, structuring search results, removal of redundancy in databases and data integration. Similarity-based grouping of data entries is not a trivial task in the context of life science data sources as the stored data is complex, highly correlated and represented at different levels of granularity. The contribution of this paper is two-fold. 1) We propose a method for similarity-based grouping and 2) we show results from test cases. As the main steps the method contains specification of grouping rules, pairwise grouping between entries, actual grouping of similar entries, and evaluation and analysis of the results. Often, different strategies can be used in the different steps. The method enables exploration of the influence of the choices and supports evaluation of the results with respect to given classifications. The grouping method is illustrated by test cases based on different strategies and classifications. The results show the complexity of the similarity-based grouping tasks and give deeper insights in the selected grouping tasks, the analyzed data source, and the influence of different strategies on the results.

  • 40.
    Hultén, Magnus
    et al.
    Linköping University, Department of Social and Welfare Studies, Learning, Aesthetics, Natural science. Linköping University, Faculty of Educational Sciences.
    Artman, Henrik
    Royal Institute of Technology, Sweden.
    House, David
    Royal Institute of Technology, Sweden.
    A model to analyse students’ cooperative idea generation in conceptual design2016In: International journal of technology and design education, ISSN 0957-7572, E-ISSN 1573-1804Article in journal (Refereed)
    Abstract [en]

    In this article we focus on the co-creation of ideas. Through the use of concepts from collaborative learning and communication theory we suggest a model that will enable the cooperative nature of creative design tasks to emerge. Four objectives of the model are stated and elaborated on in the paper: that the model should be anchored in previous research; that it should allow for collaborative aspects of creative design to be accounted for; that it should address the mechanisms by which new ideas are generated, embraced and cultivated during actual design; and that it should have a firm theoretical grounding. The model is also exemplified by two test sessions where two student pairs perform a time-constrained design task. We hope that the model can play a role both as an educational tool to be used by students and a teacher in design education, but primarily as a model to analyse students’ cooperative idea generation in conceptual design.

  • 41.
    Trnka, Jiri
    et al.
    Linköping University, Department of Computer and Information Science, GIS - Geographical Information Science Group. Linköping University, The Institute of Technology.
    Lundberg, Jonas
    Linköping University, Department of Science and Technology, Digital Media. Linköping University, The Institute of Technology.
    Jungert, Erland
    Linköping University, Department of Computer and Information Science, GIS - Geographical Information Science Group. Linköping University, The Institute of Technology.
    A Model-Based Simulation Approach to Study Role Improvisation of a Command Staff2009In: IEEE transactions on systems, man and cybernetics. Part A. Systems and humans, ISSN 1083-4427, E-ISSN 1558-2426Article in journal (Other academic)
    Abstract [en]

    This research gives attention to role improvisation in command and controlteams designated for crisis and disaster response operations in aninternational context. The paper reports a study, which had the goal todevelop, on the bases of real response operations, a role-playing simulationto explore and study role improvisation in highly realistic situations. Thestudy was based on a single-case, the command staff of the SwedishResponse Team. The objective of the study was achieved by (a) identifyingcritical areas concerning role improvisation of the command staff, (b)proposing a model-based simulation design that incorporates these areas,and (c) preparing and executing a role-playing simulation based on thisdesign. The critical areas were identified from two previous responseoperations. The analysis utilized a phenomenological approach, and wasbased on twenty-two interviews and three workshops. The identified critical areas were integrated in the simulation design by means of the initial set-up,scenario stimuli, and interactions with the simulation staff. This was basedon a synthesis of the models of command and control and responseoperations, scenario and tasks, simulation approach and manipulation of theimprovisation variables. The developed simulation was a scenario-basedreal-time role-playing simulation with a progressively unfolding scenario.The scenario was based on events taking place during the 2007 Californiawildfires. The simulation was evaluated by assessing the subjective realism.The paper reports experience from designing and conducting the roleplayingsimulation. It identifies demands and requirements, which have tobe met in order to simulate highly realistic situations. It also demonstrateshow, on the bases of real response operations, such simulations can bedesigned. Lastly, it also identifies areas that require attention in order o usethe role-playing simulations to explore and study role improvisation.

  • 42.
    Nilsson, Robert
    Linköping University, Department of Computer and Information Science, RTSLAB - Real-Time Systems Laboratory. Linköping University, The Institute of Technology.
    A Mutation-based Framework for Automated Testing of Timeliness2006Doctoral thesis, monograph (Other academic)
    Abstract [en]

    A problem when testing timeliness of event-triggered real-time systems is that response times depend on the execution order of concurrent tasks. Conventional testing methods ignore task interleaving and timing and thus do not help determine which execution orders need to be exercised to gain confidence in temporal correctness. This thesis presents and evaluates a framework for testing of timeliness that is based on mutation testing theory. The framework includes two complementary approaches for mutation-based test case generation, testing criteria for timeliness, and tools for automating the test case generation process. A scheme for automated test case execution is also defined. The testing framework assumes that a structured notation is used to model the real-time applications and their execution environment. This real-time system model is subsequently mutated by operators that mimic potential errors that may lead to timeliness failures. Each mutated model is automatically analyzed to generate test cases that target execution orders that are likely to lead to timeliness failures. The validation of the theory and methods in the proposed testing framework is done iteratively through case-studies, experiments and proof-of-concept implementations. This research indicates that an adapted form of mutation-based testing can be used for effective and automated testing of timeliness and, thus, for increasing the confidence level in real-time systems that are designed according to the event-triggered paradigm.

  • 43.
    Taxén, Lars
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    A Neurobiological Perspective on Socio-Technical Systems2015In: Proceedings of the 1st International Workshop on Socio-Technical Perspective in IS Development (STPIS'15) / [ed] S. Kowalski, P. Bednar, I. Bider, 2015, 56-68 p.Conference paper (Refereed)
    Abstract [en]

    The Socio-Technical Systems approach assumes that an organizational work system can be seen as two independent but tightly correlated systems – a technical one and a social one. Together, these systems determine the performance of the work system. However, in spite of decades of research efforts, it is far from clear how to define these systems. Without a firm basis, analytical and constructive initiatives are bound to become either fragmented or ad-hoc. To this end, the purpose of this paper is to suggest a neurobiological perspective on Socio-Technical Systems. The reason for this seemingly odd point of departure is quite simple: any conceptualization of Socio-Technical Systems must ultimately take stock of the sine qua non of our existence as biological creatures. A fundamental prerequisite for survival is coordination – without coordination, acting in the world is inhibited. Based on many years of coordinating complex system development tasks in industry, I have proposed the construct of activity modalitiesobjectivation, contextualization, spatialization, temporalization, stabilization, and transition – as intrinsic neural predispositions enabling coordination. This position is elaborated into a particular kind of work system, called the activity domain. In the activity domain, individual lines of actions are fit together using means such as IT artifacts and common identifiers to achieve a common goal. Actions are manifested internally as changed brain structures in individuals, and externally as various artifacts reflecting the modalities. In conclusion, I claim that this approach indicates a paradigm shift, which may provide a solid ground for further inquiries into the analysis and construction of Socio-Technical Systems.

  • 44.
    Ertzgaard, Per
    et al.
    Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Rehabilitation Medicine. Linköping University, Department of Medical and Health Sciences, Division of Community Medicine.
    Ohberg, Fredrik
    Umeå University, Sweden.
    Gerdle, Björn
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Pain and Rehabilitation Center.
    Grip, Helena
    Umeå University, Sweden.
    A new way of assessing arm function in activity using kinematic Exposure Variation Analysis and portable inertial sensors - A validity study2016In: Manual Therapy, ISSN 1356-689X, E-ISSN 1532-2769, Vol. 21, 241-249 p.Article in journal (Refereed)
    Abstract [en]

    Portable motion systems based on inertial motion sensors are promising methods, with the advantage compared to optoelectronic cameras of not being confined to a laboratory setting. A challenge is to develop relevant outcome measures for clinical use. The aim of this study was to characterize elbow and shoulder motion during functional tasks, using portable motion sensors and a modified Exposure Variation Analysis (EVA) and evaluate system accuracy with optoelectronic cameras. Ten healthy volunteers and one participant with sequel after stroke performed standardised functional arm tasks. Motion was registered simultaneously with a custom developed motion sensor system, including gyroscopes and accelerometers, and an optoelectronic camera system. The EVA was applied on elbow and shoulder joints, and angular and angular velocity EVA plots was calculated. The EVA showed characteristic patterns for each arm task in the healthy controls and a distinct difference between the affected and unaffected arm in the participant with sequel after stroke. The accuracy of the portable system was high with a systematic error ranging between -1.2 degrees and 2.0 degrees. The error was direction specific due to a drift component along the gravity vector. Portable motion sensor systems have high potential as clinical tools for evaluation of arm function. EVA effectively illustrates joint angle and joint angle velocity patterns that may capture deficiencies in arm function and movement quality. Next step will be to manage system drift by including magnetometers, to further develop clinically relevant outcome variables and apply this for relevant patient groups. (C) 2015 Elsevier Ltd. All rights reserved.

  • 45.
    Jonson, Henrik
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    A Newton Method for Solving Non-Linear Optimal Control Problems with General Constraints1983Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Optimal control of general dynamic systems under realistic constraints on input signals and state variables is an important problem area in control theory. Many practical control problems can be formulated as optimization tasks, and this leads toa significant demand for efficient numerical solution algorithms.

    Several such algorithms have been developed, and they are typically derived from a dynamic programming view point. In this thesis a differentapproach is taken. The discretetime dynamic optimization problem is formulated as a static one, with the inputs as free variables. Newton's approach to solving such a problem with constraints, also known as Wilson's method, is then consistently pursued, anda algorithm is developed that isa true Newton algorithm for the problem, at the same time as the inherent structure is utilized for efficient calculations. An advantage with such an approach is that global and local convergence properties can be studied in a familiar framework.

    The algorithm is tested on several examples and comparisons to other algorithms are carried out. These show that the Newton algorithm performs well and is competitive with other methods. lt handles state variable constraints in a direct and efficient manner, and its practical convergence properties are robust.

    A general algorithm for !arge scale static problems is also developed in the thesis, and it is tested on a problem with load distribution in an electrical power network.

  • 46.
    Reiss, Attila
    et al.
    University of Passau, Passau, Germany.
    Hendeby, Gustaf
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology. Swedish Def Res Agcy FOI, Dept Sensor & EW Syst, Linkoping, Sweden.
    Stricker, Didier
    German Research Center for Artificial Intelligence, Kaiserslautern, Germany.
    A novel confidence-based multiclass boosting algorithm for mobile physical activity monitoring2015In: Personal and Ubiquitous Computing, ISSN 1617-4909, E-ISSN 1617-4917, Vol. 19, no 1, 105-121 p.Article in journal (Refereed)
    Abstract [en]

    This paper addresses one of the main challenges in physical activity monitoring, as indicated by recent benchmark results: The difficulty of the complex classification problems exceeds the potential of existing classifiers. Therefore, this paper proposes the ConfAdaBoost.M1 algorithm. This algorithm is a variant of the AdaBoost.M1 that incorporates well-established ideas for confidence-based boosting. ConfAdaBoost.M1 is compared to the most commonly used boosting methods using benchmark datasets from the UCI machine learning repository.  Moreover, it is evaluated on an activity recognition and an intensity estimation problem, including a large number of physical activities from the recently released PAMAP2 dataset. The presented results indicate that the proposed ConfAdaBoost.M1 algorithm significantly improves the classification performance on most of the evaluated datasets, especially for larger and more complex classification tasks. Finally, two empirical studies are designed and carried out to investigate the feasibility of ConfAdaBoost.M1 for physical activity monitoring applications in mobile systems.

  • 47.
    Duppils, Mattias
    et al.
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Eklund, Jan-Erik
    MERC (Microelectronics Research Center), Ericsson Components, Kista, Sweden.
    Svensson, Christer
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    A novel mixed analog/digital MAC unit implemented with SC technique suitable for fully programmable narrow-band FIR filter applications1999In: Proceedings of ICECS '99. The 6th IEEE International Conference on Electronics, Circuits and Systems, 1999, 1999, 1197-1200 p.Conference paper (Refereed)
    Abstract [en]

    A mixed analog/digital (MAD) multiply-accumulate (MAC) unit, implemented with switched-capacitor (SC) technique is presented. The MAC unit consist of a programmable capacitor array (PCA) for coefficient representation, and an integrator for accumulation. A coefficient compensation technique to neutralize the non-ideal MAC properties due to finite opamp gain is introduced. The MAD-MAC unit is a new concept for effective mapping of signal processing tasks on SC technique; in particular high-order fully programmable narrow-band FIR filter applications. The utilization of the MAD-MAC unit concept is shown with a simulation of a decimated 400-tap narrow-band FIR filter

  • 48.
    Dahlbäck, Nils
    et al.
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.
    Kristiansson (Forsblad), Mattias
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.
    A perspective on all cognition? A study of everyday environments from the perspective of distributed cognition2016In: Proceedings of the 38th Annual Conference of the Cognitive Science Society / [ed] Papafragou, A., Grodner, D., Mirman, D., & Trueswell, J.C. (Eds.), Cognitive Science Society, Inc., 2016, 734-739 p.Conference paper (Refereed)
    Abstract [en]

    Distributed cognition is a perspective that primarily has been applied to complex socio-technical systems such as flight decks of commercial airliners, or operating rooms where professionals perform cognitive tasks in environments specifically designed for this. For some scholars distributed cognition is exactly this kind of specialized cognitive system. On the other hand it has been claimed by some workers in the field that distributed cognition is not a kind of cognition but a perspective on all cognition. We have therefore studied an environment very different from the systems previously studied, namely single people’s homes. We find that there are many similarities between the home and the specialized socio-technical environments. To us this suggests that the specially designed complex environments can be seen as specialized cases of the general principles of distributed cognition which are not reflections of “particular work practices” but of general features of human cognition.

  • 49.
    Johansson, Olof
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, EDSLAB - Laboratory for Engineering Databases Systems.
    A Perspective on Engineering Database Research1989Report (Other academic)
    Abstract [en]

    Engineering tasks have become more and more dependent on supporting software. The amount and complexity of engineering data that CAE systems have to deal with, increases continuously and the management of it has become a tedious task. Traditional database technology is ofthen not suited to handle the complex data types needed for engineering. This has lead to the emerging of a new class of databases called engineering databases (EDBs). They combine techniques developed in research areas, such as traditional database research and object-oriented programming, to support the management of engineering data. This report gives and introduction to EDBs by describing the features that a typicat EDB-system should contain, and presents some existing systems that demonstrate these features. The material has been collected mainly from the latest conferences related to EDBs.

  • 50.
    Cortés, Luis Alejandro
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, The Institute of Technology.
    A Petri Net based Modeling and Verification Technique for Real-Time Embedded Systems2001Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Embedded systems are used in a wide spectrum of applications ranging from home appliances and mobile devices to medical equipment and vehicle controllers. They are typically characterized by their real-time behavior and many of them must fulfill strict requirements on reliability and correctness.

    In this thesis, we concentrate on aspects related to modeling and formal verification of realtime embedded systems.

    First, we define a formal model of computation for real-time embedded systems based on Petri nets. Our model can capture important features of such systems and allows their representations at different levels of granularity. Our modeling formalism has a welldefined semantics so that it supports a precise representation of the system, the use of formal methods to verify its correctness, and the automation of different tasks along the design process.

    Second, we propose an approach to the problem of formal verification of real-time embedded systems represented in our modeling formalism. We make use of model checking to prove whether certain properties, expressed as temporal logic formulas, hold with respect to the system model. We introduce a systematic procedure to translate our model into timed automata so that it is possible to use available model checking ools. Various examples, including a realistic industrial case, demonstrate the feasibility of our approach on practical applications.

1234567 1 - 50 of 1246
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