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  • 9151.
    Öfverstedt, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Lindblad, Joakim
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Sladoje, Natasa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Robust Symmetric Affine Image Registration2019Ingår i: Swedish Symposium on Image Analysis, 2019Konferensbidrag (Övrigt vetenskapligt)
  • 9152.
    Öfverstedt, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Lindblad, Joakim
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Sladoje, Natasa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Stochastic Distance Functions with Applications in Object Detection and Image Segmentation2019Ingår i: Swedish Symposium on Image Analysis, 2019Konferensbidrag (Övrigt vetenskapligt)
  • 9153.
    Öfverstedt, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Lindblad, Joakim
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Sladoje, Natasa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Stochastic Distance Transform2019Ingår i: Discrete Geometry for Computer Imagery, Springer, 2019, s. 75-86Konferensbidrag (Refereegranskat)
    Abstract [en]

    The distance transform (DT) and its many variations are ubiquitous tools for image processing and analysis. In many imaging scenarios, the images of interest are corrupted by noise. This has a strong negative impact on the accuracy of the DT, which is highly sensitive to spurious noise points. In this study, we consider images represented as discrete random sets and observe statistics of DT computed on such representations. We, thus, define a stochastic distance transform (SDT), which has an adjustable robustness to noise. Both a stochastic Monte Carlo method and a deterministic method for computing the SDT are proposed and compared. Through a series of empirical tests, we demonstrate that the SDT is effective not only in improving the accuracy of the computed distances in the presence of noise, but also in improving the performance of template matching and watershed segmentation of partially overlapping objects, which are examples of typical applications where DTs are utilized.

  • 9154.
    Öfverstedt, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Normann, Per
    Deterministic parallel graph coloring with repartitioning by auxiliary graph coloring2015Rapport (Övrigt vetenskapligt)
  • 9155.
    Öfverstedt, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Sladoje, Natasa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Lindblad, Joakim
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Distance between vector-valued fuzzy sets based on intersection decomposition with applications in object detection2017Ingår i: Mathematical Morphology and its Applications to Signal and Image Processing, Springer, 2017, Vol. 10225, s. 395-407Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present a novel approach to measuring distance between multi-channel images, suitably represented by vector-valued fuzzy sets. We first apply the intersection decomposition transformation, based on fuzzy set operations, to vector-valued fuzzy representations to enable preservation of joint multi-channel properties represented in each pixel of the original image. Distance between two vector-valued fuzzy sets is then expressed as a (weighted) sum of distances between scalar-valued fuzzy components of the transformation. Applications to object detection and classification on multi-channel images and heterogeneous object representations are discussed and evaluated subject to several important performance metrics. It is confirmed that the proposed approach outperforms several alternative single-and multi-channel distance measures between information-rich image/ object representations.

  • 9156.
    Öfverstedt, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Sladoje, Natasa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Lindblad, Joakim
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Distance Between Vector-valued Images based on Intersection Decomposition with Applications in Object Detection2018Ingår i: Swedish Symposium on Image Analysis, 2018Konferensbidrag (Övrigt vetenskapligt)
  • 9157.
    Öfverstedt, Linn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion.
    Why go headless – a comperative study between traditional CMS and the emerging headless trend2018Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    There has been an exponential increase in the number of websites, digital channels and consequently digital content in the last years. Not only are the number of websites increasing but they are also becoming more complex, therefore it is no longer feasible to handle content and code with the same tools. Content Management Systems (CMS) are the solution to this problem and offers a way of managing content. The market today offers a broad variety of solutions that each have their own advantages, one of the more common being WYSWYG-functionality which often means that the functionality and the presentation of the content are tightly coupled. "Headless" CMS are a new way of doing things and offers the user a way of managing content without presenting them with a way of displaying the content. The different types of CMS present advantages and disadvantages from a user centred point of view as well as from a technical one. The thesis aims to explore these perspectives and form a hypothesis based on the studied cases. The study presents a set of aspects that based on the context in which the CMS is used and implemented can be perceived as either advantages or disadvantages. "Headless" CMS however shows a tendency to be the preferable choice where the editors have a technical background and the developing part values an agnostic approach when implementing a CMS, whereas a traditional CMS with WYSIWYG functionality tends to be more favourable where stability and editorial freedom are valued.

  • 9158.
    Öhman Persson, Jenny
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för människa-datorinteraktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Människa-datorinteraktion.
    The Obvious & The Essential: Interpreting Software Development & Organizational Change2004Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Examining how our basic values affect development processes is the overall theme of this thesis. In practice, the question is investigated in relation to software development and organizational change and in research, in relation to science and its relationship to common sense, specifically within the area of Human Computer Interaction. The thesis discusses how it might be possible to discover what is essential for development processes and why the essential may be interpreted as something other than the simply obvious. This thesis examines ways of studying and understanding our social environment and development processes, particularly those concerning people, organizations and software. The empirical examples deal with a software development project and a project that scrutinized the strategy for a governmental authority’s business and information technology. Attitudes are discussed in terms of how they view the user, the customer, the software developers, the software, organizational and implementation processes, organizational management, aesthetic values, functionality and use, research, methods, paradigmatic approaches, ethical issues, psychological reactions, sociological prerequisites, categorizations of people and stress-related health consequences. One particular prerequisite for developing superior computer-supported office work has repeatedly presented itself: an open, questioning attitude towards the software development process, towards organizational change and towards the people working in the organizations. A similar attitude towards research and its design can be crucial to the development of new knowledge. This circumstance can be interpreted as an indication of how important it is that we be aware of and question our preconceived notions, in order to develop an autonomous behavior where we take responsibility for our actions. By doing so, we can avoid misinterpretations and not get trapped into making categorizations that are simply obvious. This is essential and must be emphasized in our search for the path to »healthy work«.

  • 9159.
    Öhrn, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion.
    General image classifier for fluorescence microscopy using transfer learning2019Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Modern microscopy and automation technologies enable experiments which can produce millions of images each day. The valuable information is often sparse, and requires clever methods to find useful data. In this thesis a general image classification tool for fluorescence microscopy images was developed usingfeatures extracted from a general Convolutional Neural Network (CNN) trained on natural images. The user selects interesting regions in a microscopy image and then, through an iterative process, using active learning, continually builds a training data set to train a classifier that finds similar regions in other images. The classifier uses conformal prediction to find samples that, if labeled, would most improve the learned model as well as specifying the frequency of errors the classifier commits. The result show that with the appropriate choice of significance one can reach a high confidence in true positive. The active learning approach increased the precision with a downside of finding fewer examples.

  • 9160.
    Öhrn, Håkan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap.
    Lindell, Adam
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap.
    Discretization of the Dirac delta function for application in option pricing2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This paper compares two different approximations of the Dirac deltafunction used in a Fokker-Planck equation. Both methods deal with the singularity problem in the initial condition. The Dirac delta approximation, constructed in MATLAB with a method derived by Tornberg and Engquist, was compared to an already given method Aït-Sahalia. The methods were implemented as the initial condition in the Fokker-Planck equation, e.g approximating a probability density function. In most cases Aït-Sahalia and Tornberg-Engquist were interchangeable. During specific circumstances one method was significantly more accurate than the other. Increasing the amount of time/spatial steps enhanced the differences in error while having less time/spatial steps made the difference in error converge. The Aït-Sahalia method produces slightly more accurate results in more cases.

  • 9161.
    Önell, A
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Reglerteknik. AUTOMATIC CONTROL.
    Söderström, T
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Reglerteknik. AUTOMATIC CONTROL.
    Halvorsen, K
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Reglerteknik. AUTOMATIC CONTROL.
    Lanshammar, H
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Reglerteknik. AUTOMATIC CONTROL.
    Identifiering av människokroppens balanssystem2000Ingår i: Reglermöte 2000 (National Conference on Control), 2000Konferensbidrag (Refereegranskat)
  • 9162.
    Önell, Annica
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för systemteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Reglerteknik.
    Quantifying human balance: Analysis of force plate data1999Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    There is a lack of reliable methods for assessment of balance suited for routine use in clinical settings. The thesis focuses on analysis of force plate data for evaluation of balance during normal, unperturbed standing and sitting. Some commonly used force plate based methods during unperturbed standing are presented.

    Traditional measures, which have been used to quantify the postural sway during standing, were applied to seated children with and without spina bifida. Fundamental differences, that can not be observed visually, were found between the groups. However, the reliability on an individual level was limited since the method could not be used to distinguish between subjects from the two groups.

    It is not only of interest to measure how much the subject sways, but also what movement strategy the subject uses, that is, how he or she sways. A method for analysis of the movement strategy in the sagittal plane during standing is presented and tested. The subject's movements are compared to the movements of an inverted pendulum model. For movement analysis a kinematic measurement system is usually required, while the inverted pendulum method only needs force plate data for the analysis.

    To investigate the relationship between different force plate measures the measures were a) compared to each other and b) compared to a clinical balance test. Results on stroke patients showed that many of the measures quantify different aspects of standing. The standard deviation of the vertical ground reaction force was the only measure that was significantly correlated to the clinical balance test. Measurements on healthy adults and three groups of subjects with reduced or not fully developed balance were analysed to investigate the vertical force further. The healthy adults damped the vertical bodyoscillations caused by the heartbeats more efficiently than the other three groups.

    Finally, it was investigated under what conditions system identification can be used to model the balance system. In contrast to previous studies the model parameters were successfully estimated without any external perturbations and without a kinematic measurement system.

  • 9163. Östberg, Per-Olov
    et al.
    Hellander, Andreas
    Drawert, Brian
    Elmroth, Erik
    Holmgren, Sverker
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Petzold, Linda
    Abstractions for scaling eScience applications to distributed computing environments: A StratUm integration case study in molecular systems biology2012Ingår i: Proc. 3rd International Conference on Bioinformatics Models, Methods and Algorithms, Setúbal, Portugal: SciTePress , 2012, s. 290-294Konferensbidrag (Refereegranskat)
  • 9164. Östberg, Per-Olov
    et al.
    Hellander, Andreas
    Drawert, Brian
    Elmroth, Erik
    Holmgren, Sverker
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Petzold, Linda
    Reducing complexity in management of eScience computations2012Ingår i: Proc. 12th International Symposium on Cluster, Cloud and Grid Computing, Los Alamitos, CA: IEEE Computer Society, 2012, s. 845-852Konferensbidrag (Refereegranskat)
  • 9165.
    Österberg, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Profiling memory accesses on the ODROID-XU42017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Decoupled Access-Execute(DAE) is an innovative approach to optimize energy consumption of computer programs by splitting the program into two tasks; the first task is to access data, this is profoundly memory-bound and can be done with energy efficient cores. The second task is to execute and compute the data, which iscompute-bound and can be done with powerful cores. This thesis work aims todevelop a profiling tool that can measure the efficiency of DAE by investigating thecache misses in the original code and the DAE code (in the access and executephases). This was achieved by measuring the cache loads and memory accesses forthe DAE transformation for the benchmarks done by a previous study that targets DAE on Arm's HMP architecture, big.LITTLE. The data obtained from this study showt hat DAE on big.LITTLE has a potential for energy savings, especially with applications that feature indirection in memory accesses. Arm DynamIQ opens up new possibilities for DAE code transformation. New levels of energy efficiency can be reached with a finer-grained Dynamic Voltage Frequency Scaling(DVFS), a more rapid power, state transition mechanism and a shared cache for 'big' and 'LITTLE' CPUs.

  • 9166.
    Österlind, Fredrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datorteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Improving Low-Power Wireless Protocols with Timing-Accurate Simulation2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Low-power wireless technology enables numerous applications in areas from environmental monitoring and smart cities, to healthcare and recycling. But resource-constraints and the distributed nature of applications make low-power wireless networks difficult to develop and understand, resulting in increased development time, poor performance, software bugs, or even network failures. Network simulators offer full non-intrusive visibility and control, and are indispensible tools during development. But simulators do not always adequately represent the real world, limiting their applicability.

    In this thesis I argue that high simulation timing accuracy is important when developing high-performance low-power wireless protocols. Unlike in generic wireless network simulation, timing becomes important since low-power wireless networks use extremely timing-sensitive software techniques such as radio duty-cycling. I develop the simulation environment Cooja that can simulate low-power wireless networks with high timing accuracy.

    Using timing-accurate simulation, I design and develop a set of new low-power wireless protocols that improve on throughput, latency, and energy-efficiency. The problems that motivate these protocols were revealed by timing-accurate simulation. Timing-accurate software execution exposed performance bottlenecks that I address with a new communication primitive called Conditional Immediate Transmission (CIT). I show that CIT can improve on throughput in bulk transfer scenarios, and lower latency in many-to-one convergecast networks. Timing-accurate communication exposed that the hidden terminal problem is aggravated in duty-cycled networks that experience traffic bursts. I propose the Strawman mechanism that makes a radio duty-cycled network robust against traffic bursts by efficiently coping with hidden terminals.

    The Cooja simulation environment is available for use by others and is the default simulator in the Contiki operating system since 2006.

    Delarbeten
    1. Cross-Level Sensor Network Simulation with COOJA
    Öppna denna publikation i ny flik eller fönster >>Cross-Level Sensor Network Simulation with COOJA
    Visa övriga...
    2006 (Engelska)Ingår i: Proceedings of the First IEEE International Workshop on Practical Issues in Building Sensor Network Applications (SenseApp), 2006Konferensbidrag, Publicerat paper (Refereegranskat)
    Nationell ämneskategori
    Datorteknik
    Identifikatorer
    urn:nbn:se:uu:diva-159822 (URN)
    Konferens
    First IEEE International Workshop on Practical Issues in Building Sensor Network Applications (SenseApp)
    Tillgänglig från: 2011-10-10 Skapad: 2011-10-10 Senast uppdaterad: 2018-01-12
    2. Approaching the maximum 802.15.4 multihop throughput
    Öppna denna publikation i ny flik eller fönster >>Approaching the maximum 802.15.4 multihop throughput
    2008 (Engelska)Ingår i: In Proceedings of the Fifth ACM Workshop on Embedded Networked Sensors (HotEmNets 2008), June 2008, 2008Konferensbidrag, Publicerat paper (Refereegranskat)
    Identifikatorer
    urn:nbn:se:uu:diva-142774 (URN)
    Konferens
    Fifth ACM Workshop on Embedded Networked Sensors (HotEmNets 2008), June 2008
    Projekt
    wisenet
    Tillgänglig från: 2011-01-17 Skapad: 2011-01-17 Senast uppdaterad: 2011-11-10
    3. Rapid Convergecast on Commodity Hardware: Performance Limits and Optimal Policies
    Öppna denna publikation i ny flik eller fönster >>Rapid Convergecast on Commodity Hardware: Performance Limits and Optimal Policies
    Visa övriga...
    2010 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Identifikatorer
    urn:nbn:se:uu:diva-142608 (URN)
    Konferens
    The 7th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks, June 2010, Boston, Massachusetts, USA
    Projekt
    wisenet
    Tillgänglig från: 2011-01-14 Skapad: 2011-01-14 Senast uppdaterad: 2013-12-02
    4. Sensornet checkpointing: “Enabling repeatability in test-beds and realism in simulators.”
    Öppna denna publikation i ny flik eller fönster >>Sensornet checkpointing: “Enabling repeatability in test-beds and realism in simulators.”
    Visa övriga...
    2009 (Engelska)Ingår i: In Proceedings of the 6th European Conference on Wireless Sensor Networks, EWSN 2009, Cork, Ireland, February 2009, 2009Konferensbidrag, Publicerat paper (Refereegranskat)
    Identifikatorer
    urn:nbn:se:uu:diva-142758 (URN)
    Konferens
    6th European Conference on Wireless Sensor Networks, EWSN 2009, Cork, Ireland, February 2009
    Projekt
    wisenet
    Tillgänglig från: 2011-01-17 Skapad: 2011-01-17 Senast uppdaterad: 2013-12-02
    5. StrawMAN: Making Sudden Traffic Surges Graceful in Low-Power Wireless Networks
    Öppna denna publikation i ny flik eller fönster >>StrawMAN: Making Sudden Traffic Surges Graceful in Low-Power Wireless Networks
    Visa övriga...
    2010 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Identifikatorer
    urn:nbn:se:uu:diva-142561 (URN)
    Konferens
    ACM HotEMNETS 2010 Workshop on Hot Topics in Embedded Networked Sensors, June 2010, Killarney, Ireland.
    Projekt
    wisenet
    Tillgänglig från: 2011-01-14 Skapad: 2011-01-14 Senast uppdaterad: 2013-12-02
    6. Strawman: Resolving Collisions Through Collisions
    Öppna denna publikation i ny flik eller fönster >>Strawman: Resolving Collisions Through Collisions
    Visa övriga...
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Datorteknik
    Identifikatorer
    urn:nbn:se:uu:diva-159823 (URN)
    Projekt
    wisenet
    Tillgänglig från: 2011-10-10 Skapad: 2011-10-10 Senast uppdaterad: 2018-01-12
  • 9167.
    Österlund, Ragnar
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Konvertering av CRM-system från ASP till ASP.NET2008Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    S2 CRM is a Customer Relations Management system built in classic ASP that runs on a web server servicing customers with varying needs. The purpose of this thesis work is to convert parts of the system to the web development environment ASP.NET. The purpose is also to gain knowledge of the framework itself. The ASP.NET environment is compared with another framework, JBoss Seam, in order to understand the differences and to evaluate the possibility of using another framework than ASP.NET, when building the new system. The outcome of this comparison is that although JBoss Seam is just as good, and in some aspects better than ASP.NET, the use of ASP.NET simplifies the continuation of development on the S2 CRM product. The conversion that was made includes a way to share information between the new and the old system, an implementation of listing and search modules and an approach to the data model and techniques for achieving good performance. Modularity is also an important aspect of the work, and this was achieved by constructing controls that can be used in different contexts, configurable by configuration objects. The result of the thesis is a basic system for listing and searching that can coexist with the original system and that can be built further upon to create a new version of S2 CRM that fully runs on the ASP.NET platform.

  • 9168.
    Östh, Mattias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Smartphone Application Development: Porting existing PC game for multiple platforms2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    An already created PC game exists and the goal of this project is to find a solution to port the game to the most popular smartphone platforms using mostly one generic code. The game to be ported is a musical game where the player uses an acoustic guitar to interact with the game using with the help of real time audio analysis. This thesis goes through the development process to reach the objective by investigating proper tools and issues around the performance and human-computer interaction from the perspective of the smartphone. The result of the project is an application prepared for the platforms Android and Ios.

  • 9169.
    Östlund, C
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Centrum för bildanalys. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datoriserad bildanalys.
    Flink, P
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Strömbeck, N
    Pierson, D
    Lindell, T
    Mapping of the water quality of Lake Erken, Sweden, from Imaging Spectrometry and Landsat Thematic Mapper2001Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 268, nr 1-3, s. 139-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hyperspectral data have been collected by the Compact Airborne Spectrographic Imager (CASI) and multispectral data by the Landsat Thematic Mapper (TM) instrument for the purpose of mapping lake water quality. Field campaigns have been performed on Lake Erken

  • 9170.
    Östlund, Catherine
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Centrum för bildanalys. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datoriserad bildanalys.
    The Coast of the South-East Mediterrenian - El Alamein to Haifa1997Ingår i: Third International Airborne Remote Sensing Conference and Exhibition, TERIM INternational Inc. , 1997, s. 526-533Konferensbidrag (Refereegranskat)
  • 9171.
    Östlund, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datalogi.
    Language Constructs for Safe Parallel Programming on Multi-Cores2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The last decade has seen the transition from single-core processors to multi-cores and many-cores. This move has by and large shifted the responsibility from chip manufacturers to programmers to keep up with ever-increasing expectations on performance. In the single-core era, improvements in hardware capacity could immediately be leveraged by an application: faster machine - faster program. In the age of the multi-cores, this is no longer the case. Programs must be written in specific ways to utilize available parallel hardware resources.

    Programming language support for concurrent and parallel programming is poor in most popular object-oriented programming languages. Shared memory, threads and locks is the most common concurrency model provided. Threads and locks are hard to understand, error-prone and inflexible; they break encapsulation - the very foundation of the object-oriented approach. This makes it hard to break large complex problems into smaller pieces which can be solved independently and composed to make a whole. Ubiquitous parallelism and object-orientation, seemingly, do not match.

    Actors, or active objects, have been proposed as a concurrency model better fit for object-oriented programming than threads and locks. Asynchronous message passing between actors each with a logical thread of control preserves encapsulation as objects themselves decide when messages are executed. Unfortunately most implementations of active objects do not prevent sharing of mutable objects across actors. Sharing, whether on purpose or by accident, exposes objects to multiple threads of control, destroying object encapsulation.

    In this thesis we show techniques for compiler-enforced isolation of active objects, while allowing sharing and zero-copy communication of mutable data in the cases where it is safe to do so. We also show how the same techniques that enforce isolation can be utilized internal to an active object to allow data race-free parallel message processing and data race-free structured parallel computations. This overcomes the coarse-grained nature of active object parallelism without compromising safety.

    Delarbeten
    1. Ownership, Uniqueness, and Immutability
    Öppna denna publikation i ny flik eller fönster >>Ownership, Uniqueness, and Immutability
    2008 (Engelska)Ingår i: Lecture Notes in Business Information Processing, ISSN 1865-1348, E-ISSN 1865-1356Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Programming in an object-oriented language demands a fine balance between flexibility and control. At one level, objects need to interact freely to achieve our implementation goals. At a higher level, architectural constraints that ensure the system can be understood by new developers and can evolve as requirements change must be met. To resolve this tension, researchers have developed type systems expressing ownership and behavioural restrictions such as immutability. This work reports on our consolidation of the resulting discoveries into a single programming language. Our language, Joe 3 , imposes little additional syntactic overhead, yet can encode powerful patterns such as fractional permissions and the reference modes of Flexible Alias Protection.

    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:uu:diva-266671 (URN)10.1007/978-3-540-69824-1_11 (DOI)
    Konferens
    46th International Conference, TOOLS EUROPE 2008, Zurich, Switzerland, June 30 - July 4, 2008.
    Tillgänglig från: 2015-11-10 Skapad: 2015-11-10 Senast uppdaterad: 2018-01-10
    2. Minimal Ownership for Active Objects
    Öppna denna publikation i ny flik eller fönster >>Minimal Ownership for Active Objects
    2008 (Engelska)Ingår i: Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Active objects offer a structured approach to concurrency, encapsulating both unshared state and a thread of control. For efficient data transfer, data should be passed by reference whenever possible, but this introduces aliasing and undermines the validity of the active objects. This paper proposes a minimal variant of ownership types that preserves the required race freedom invariant yet enables data transfer by reference between active objects (that is, without copying) in many cases, and a cheap clone operation where copying is necessary. Our approach is general and should be adaptable to several existing active object systems.

    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:uu:diva-266793 (URN)10.1007/978-3-540-89330-1_11 (DOI)
    Konferens
    6th Asian Symposium, APLAS 2008, Bangalore, India, December 9-11, 2008
    Projekt
    EU project IST-33826 CREDO
    Tillgänglig från: 2015-11-10 Skapad: 2015-11-10 Senast uppdaterad: 2018-01-10
    3. Welterweight Java
    Öppna denna publikation i ny flik eller fönster >>Welterweight Java
    2010 (Engelska)Ingår i: Objects, Models, Components, Patterns / [ed] Vitek, Jan, Berlin: Springer-Verlag , 2010, s. 97-116Konferensbidrag, Publicerat paper (Refereegranskat)
    Ort, förlag, år, upplaga, sidor
    Berlin: Springer-Verlag, 2010
    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743 ; 6141
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:uu:diva-130897 (URN)10.1007/978-3-642-13953-6_6 (DOI)000286162000006 ()978-3-642-13952-9 (ISBN)
    Konferens
    48th International Conference, TOOLS 2010
    Projekt
    UPMARCFacilitating Concurrent and Parallel Programming in Mainstream Programming Languages
    Tillgänglig från: 2010-09-17 Skapad: 2010-09-17 Senast uppdaterad: 2018-01-12Bibliografiskt granskad
    4. Multiple Aggregate Entry Points for Ownership Types
    Öppna denna publikation i ny flik eller fönster >>Multiple Aggregate Entry Points for Ownership Types
    2012 (Engelska)Ingår i: ECOOP 2012 – Object-Oriented Programming, Springer Berlin/Heidelberg, 2012, s. 156-180Konferensbidrag, Publicerat paper (Refereegranskat)
    Ort, förlag, år, upplaga, sidor
    Springer Berlin/Heidelberg, 2012
    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743 ; 7313
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:uu:diva-176660 (URN)10.1007/978-3-642-31057-7_8 (DOI)978-3-642-31056-0 (ISBN)
    Konferens
    26th European Conference on Object-Oriented Programming
    Projekt
    UPMARCFacilitating Concurrent and Parallel Programming in Mainstream Programming Languages
    Tillgänglig från: 2012-06-28 Skapad: 2012-06-21 Senast uppdaterad: 2018-01-12Bibliografiskt granskad
    5. Refined Ownership: Fine-grained controlled internal sharing
    Öppna denna publikation i ny flik eller fönster >>Refined Ownership: Fine-grained controlled internal sharing
    2015 (Engelska)Ingår i: Formal Methods for Multicore Programming, 2015, Vol. 9104, s. 179-210Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Ownership type systems give a strong notion of separation between aggregates. Objects belonging to different owners cannot be aliased, and thus a mutating operation internal to one object is guaranteed to be invisible to another. This naturally facilitates reasoning about correctness on a local scale, but also proves beneficial for coarse-grained parallelism as noninterference between statements touching different objects is easily established. For fine-grained parallelism, ownership types fall short as owner-based disjointness only allows separation of the innards of different aggregates, which is very coarse-grained. Concretely: ownership types can reason about the disjointness of two different data structures, but cannot reason about the internal structure or disjointness within the data structure, without resorting to static and overly constraining measures. For similar reasons, ownership fails to determine internal disjointness of external pointers to objects that share a common owner. In this paper, we introduce the novel notion of refined ownership which overcomes these limitations by allowing precise local reasoning about a group of objects even though they belong to the same external owner. Using refined ownership, we can statically check determinism of parallel operations on tree-shaped substructures of a data structure, including operations on values external to the structure, without imposing any non-local alias restrictions.

    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743 ; 9104
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:uu:diva-266673 (URN)10.1007/978-3-319-18941-3_5 (DOI)000362511600005 ()978-3-319-18941-3 (ISBN)978-3-319-18940-6 (ISBN)
    Konferens
    15th International School on Formal Methods for the Design of Computer, Communication, and Software Systems; SFM 2015, June 15–19, Bertinoro, Italy
    Projekt
    UPMARCUPSCALE
    Tillgänglig från: 2015-05-07 Skapad: 2015-11-10 Senast uppdaterad: 2019-12-13Bibliografiskt granskad
  • 9172.
    Östlund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Brandauer, Stephan
    Wrigstad, Tobias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    The Joelle Programming Language: Evolving Java Programs Along Two Axes of Parallel Eval2012Konferensbidrag (Övrigt vetenskapligt)
  • 9173.
    Östlund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Wrigstad, Tobias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Multiple Aggregate Entry Points for Ownership Types2012Ingår i: ECOOP 2012 – Object-Oriented Programming, Springer Berlin/Heidelberg, 2012, s. 156-180Konferensbidrag (Refereegranskat)
  • 9174.
    Östlund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Wrigstad, Tobias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Regions as Owners: A Discussion on Ownership-based Effects in Practice2011Konferensbidrag (Refereegranskat)
  • 9175.
    Östlund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Wrigstad, Tobias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Welterweight Java2010Ingår i: Objects, Models, Components, Patterns / [ed] Vitek, Jan, Berlin: Springer-Verlag , 2010, s. 97-116Konferensbidrag (Refereegranskat)
  • 9176.
    Östlund, Mikael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Benchmarking Parallelism and Concurrency in the Encore Programming Language2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Due to the limit in speedup of clock speed, most modern computers now sport multicore chips to provide computing power. Currently, programming language support for such machines often consists of extensions to languages that were originally designed to be sequential. New programming models and languages are needed that are parallel by design. One class of such languages are actor- (and active object) based languages and one such language is Encore, a new actor based language currently under development. When developing a programming language it is often important to compare the performance of the language with other well-known and proven languages in the same paradigm. This thesis compares the concurrency and parallelism performance of Encore with Scala and Erlang over a set of benchmarks. The results show that Encore features a very fair scheduling policy and also performs up to par with the languages Scala and Erlang when measuring wall-clock execution time on a desktop computer. Encore currently lag behind a bit in terms of strong scalability when a lot of communication occur, when communication is kept at a minimum however, Encore showcases a strong scalability just as good as the one of Erlang and Scala in the parallelism benchmark Fannkuch. The memory usage of Encore is higher than the memory consumption of Scala and Erlang in one of the three analysed benchmarks and lower on the other two. Overall the results for Encore look promising for the future.

  • 9177.
    Östlund, Mikael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Implementation and Evaluation of a Sweep-Based Propagator for Diffn in Gecode2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This thesis builds upon Beldiceanu and Carlsson's sweep-based propagator for a non-overlapping-rectangle constraint. I design and implement a sweep-based propagator for the Diffn constraint, which deals with rectangles generalised to any number of dimensions. Such a constraint is useful in modelling scheduling, assignment, and packing problems. The work is carried out in the context of the copying constraint programming solver Gecode. Different algorithm optimisations are explored and evaluated across a range of benchmarks in terms of inference strength and execution time. The best optimisation configuration is compared against the propagator for Gecode's current two-dimensional counterpart to Diffn: NoOverlap. The results show that the sweep-based Diffn propagator yields smaller search trees than the NoOverlap propagator in models where non-overlapping constraints dominate the propagation phase, as the sweep-based propagator yields stronger bounds tightening. As other constraints are introduced into the models, the difference in search-tree size becomes smaller, and in cases where the two propagators yield identical search trees, the NoOverlap propagator performs best. While the sweep-based approach shows great potential in some of the benchmarks, the stronger inference is often dwarfed in models with several different constraints.

  • 9178.
    Özdeğer, Tuğçe
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Development of Models for Rule Based Decision Support for Flight Plans in a Synthetic Environment2012Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Flygruttsplanering är en tidskrävande process vid uppdragsplanering. Den bör göras med stor omsorg för att garantera en säker flygning som når målet på utsatt tid. Ett autonomt beslutstödssystem kan spara tid genom att hitta den säkraste och kortaste rutten mellan avgång och destination. I detta sammanhang används olika externa källor som indata och de ligger till grund för att fatta intelligenta beslut med hjälp av regelbaserat resonerande. Konceptet regelbaserat beslutsstöd är baserat på Drools regelmotor för att minska arbetsbördan för piloter under ruttplanering.

  • 9179.
    Özkan, Emre
    et al.
    Middle East Tech Univ, Dept Elect & Elect Engn, Ankara, Turkey.
    Wahlström, Niklas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Reglerteknik.
    Godsill, Simon J.
    Univ Cambridge, Dept Engn, Cambridge CB2 1TN, England.
    Rao-Blackwellised Particle Filter for Star-ConvexExtended Target Tracking Models2016Ingår i: 2016 19th International Conference on Information Fusion, 2016, s. 1193-1199Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we explore the potential gains in using Sequential Monte Carlo (SMC) methods for extended target tracking (ETT) models based on Gaussian processes (GP). The existing random hypersurface based ETT models use Extended/Unscented Kalman filter for inference, which may lead to poor performance under high uncertainty. Particle filters (PFs) are known to provide robust performance in the cases where the non-linear Kalman filtering solutions fail. We design a Rao-Blackwellised particle filter (RBPF) where we exploit the conditional linear Gaussian structure of the GP parameters. We illustrate the gain in the performance with simulations.

  • 9180.
    Þorgeirsson, Sverrir
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi.
    Bayesian parameter estimation in Ecolego using an adaptive Metropolis-Hastings-within-Gibbs algorithm2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Ecolego is scientific software that can be used to model diverse systems within fields such as radioecology and pharmacokinetics. The purpose of this research is to develop an algorithm for estimating the probability density functions of unknown parameters of Ecolego models. In order to do so, a general-purpose adaptive Metropolis-Hastings-within-Gibbs algorithm is developed and tested on some examples of Ecolego models. The algorithm works adequately on those models, which indicates that the algorithm could be integrated successfully into future versions of Ecolego.

  • 9181.
    Ćurić, Vladimir
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Distance Functions and Their Use in Adaptive Mathematical Morphology2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    One of the main problems in image analysis is a comparison of different shapes in images. It is often desirable to determine the extent to which one shape differs from another. This is usually a difficult task because shapes vary in size, length, contrast, texture, orientation, etc. Shapes can be described using sets of points, crisp of fuzzy. Hence, distance functions between sets have been used for comparing different shapes.

    Mathematical morphology is a non-linear theory related to the shape or morphology of features in the image, and morphological operators are defined by the interaction between an image and a small set called a structuring element. Although morphological operators have been extensively used to differentiate shapes by their size, it is not an easy task to differentiate shapes with respect to other features such as contrast or orientation. One approach for differentiation on these type of features is to use data-dependent structuring elements.

    In this thesis, we investigate the usefulness of various distance functions for: (i) shape registration and recognition; and (ii) construction of adaptive structuring elements and functions.

    We examine existing distance functions between sets, and propose a new one, called the Complement weighted sum of minimal distances, where the contribution of each point to the distance function is determined by the position of the point within the set. The usefulness of the new distance function is shown for different image registration and shape recognition problems. Furthermore, we extend the new distance function to fuzzy sets and show its applicability to classification of fuzzy objects.

    We propose two different types of adaptive structuring elements from the salience map of the edge strength: (i) the shape of a structuring element is predefined, and its size is determined from the salience map; (ii) the shape and size of a structuring element are dependent on the salience map. Using this salience map, we also define adaptive structuring functions. We also present the applicability of adaptive mathematical morphology to image regularization. The connection between adaptive mathematical morphology and Lasry-Lions regularization of non-smooth functions provides an elegant tool for image regularization.

    Delarbeten
    1. On set distances and their application to image registration
    Öppna denna publikation i ny flik eller fönster >>On set distances and their application to image registration
    2009 (Engelska)Ingår i: Proc. 6th International Symposium on Image and Signal Processing and Analysis, Salzburg, Austria: IEEE , 2009, s. 449-454Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    In this paper we study set distances that are used in image processing. We propose a generalization of Sum of minimal distances and show that its special cases include a metric by Symmetric difference. The Hausdorff metric and the Chamfer matching distances are also closely related with the presented framework. In addition, we define the Complement set distance of a given distance. We evaluate the observed distance with respect to applicability to image object registration. We perform comparative evaluations with respect to noise sensitivity, as well as with respect to rigid body transformations. We conclude that the family of Generalized sum of minimal distances has many desirable properties for this application.

    Ort, förlag, år, upplaga, sidor
    Salzburg, Austria: IEEE, 2009
    Nationell ämneskategori
    Datorseende och robotik (autonoma system)
    Forskningsämne
    Datoriserad bildanalys; Datoriserad bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-110684 (URN)10.1109/ISPA.2009.5297672 (DOI)978-953-184-135-1 (ISBN)
    Konferens
    6th International Symposium on Image and Signal Processing and Analysis, Salzburg, Austria, 16-18 September, 2009
    Tillgänglig från: 2009-11-26 Skapad: 2009-11-23 Senast uppdaterad: 2018-12-18
    2. A new set distance and its application to shape registration
    Öppna denna publikation i ny flik eller fönster >>A new set distance and its application to shape registration
    Visa övriga...
    2014 (Engelska)Ingår i: Pattern Analysis and Applications, ISSN 1433-7541, E-ISSN 1433-755X, Vol. 17, nr 1, s. 141-152Artikel i tidskrift (Refereegranskat) Published
    Nationell ämneskategori
    Diskret matematik
    Identifikatorer
    urn:nbn:se:uu:diva-220413 (URN)10.1007/s10044-012-0290-x (DOI)000330839400011 ()
    Tillgänglig från: 2012-08-23 Skapad: 2014-03-13 Senast uppdaterad: 2018-12-18Bibliografiskt granskad
    3. Distance measures between digital fuzzy objects and their applicability in image processing
    Öppna denna publikation i ny flik eller fönster >>Distance measures between digital fuzzy objects and their applicability in image processing
    2011 (Engelska)Ingår i: Combinatorial Image Analysis / [ed] Jake Aggarwal, Reneta Barneva, Valentin Brimkov, Kostadin Koroutchev, Elka Koroutcheva, Springer Berlin/Heidelberg, 2011, s. 385-397Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    We present two different extensions of the Sum of minimal distances and the Complement weighted sum of minimal distances to distances between fuzzy sets. We evaluate to what extent the proposed distances show monotonic behavior with respect to increasing translation and rotation of digital objects, in noise free, as well as in noisy conditions. Tests show that one of the extension approaches leads to distances exhibiting very good performance. Furthermore, we evaluate distance based classification of crisp and fuzzy representations of objects at a range of resolutions. We conclude that the proposed distances are able to utilize the additional information available in a fuzzy representation, thereby leading to improved performance of related image processing tasks.

    Ort, förlag, år, upplaga, sidor
    Springer Berlin/Heidelberg, 2011
    Serie
    Lecture Notes in Computer Science ; 6636
    Nyckelord
    Fuzzy sets, set distance, registration, classification
    Nationell ämneskategori
    Datorseende och robotik (autonoma system) Diskret matematik
    Forskningsämne
    Datoriserad bildanalys; Datoriserad bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-157186 (URN)10.1007/978-3-642-21073-0_34 (DOI)978-3-642-21072-3 (ISBN)
    Konferens
    Internatiional Workshop on Combinatorial Image Analysis, IWCIA 2011
    Tillgänglig från: 2011-08-18 Skapad: 2011-08-18 Senast uppdaterad: 2018-12-18
    4. Salience adaptive structuring elements
    Öppna denna publikation i ny flik eller fönster >>Salience adaptive structuring elements
    2012 (Engelska)Ingår i: IEEE Journal on Selected Topics in Signal Processing, ISSN 1932-4553, E-ISSN 1941-0484, Vol. 6, nr 7, s. 809-819Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Spatially adaptive structuring elements adjust their shape to the local structures in the image, and are often defined by a ball in a geodesic distance or gray-weighted distance metric space. This paper introduces salience adaptive structuring elements as spatially variant structuring elements that modify not only their shape, but also their size according to the salience of the edges in the image. Morphological operators with salience adaptive structuring elements shift edges with high salience to a less extent than those with low salience. Salience adaptive structuring elements are less flexible than morphological amoebas and their shape is less affected by noise in the image. Consequently, morphological operators using salience adaptive structuring elements have better properties.

    Nyckelord
    Adaptive mathematical morphology, anisotropic filtering, morphological amoebas, salience distance transform
    Nationell ämneskategori
    Annan matematik
    Identifikatorer
    urn:nbn:se:uu:diva-181248 (URN)10.1109/JSTSP.2012.2207371 (DOI)000310138400007 ()
    Tillgänglig från: 2012-09-20 Skapad: 2012-09-20 Senast uppdaterad: 2017-12-07Bibliografiskt granskad
    5. Adaptive structuring elements based on salience information
    Öppna denna publikation i ny flik eller fönster >>Adaptive structuring elements based on salience information
    2012 (Engelska)Ingår i: Computer Vision and Graphics / [ed] L. Bolc, K. Wojciechowski, R. Tadeusiewicz, L.J. Chmielewski, Springer, 2012, s. 321-328Konferensbidrag, Publicerat paper (Övrigt vetenskapligt)
    Abstract [en]

    Adaptive structuring elements modify their shape and size according to the image content and may outperform fixed structuring elements. Without any restrictions, they suffer from a high computational complexity, which is often higher than linear with respect to the number of pixels in the image. This paper introduces adaptive structuring elements that have predefined shape, but where the size is adjusted to the local image structures. The size of adaptive structuring elements is determined by the salience map that corresponds to the salience of the edges in the image, which can be computed in linear time. We illustrate the difference between the new adaptive structuring elements and morphological amoebas. As an example of its usefulness, we show how the new adaptive morphological operations can isolate the text in histo