umu.sePublications
Change search
Refine search result
1234567 1 - 50 of 1764
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    KTH Royal Institute of Technology, Department of Media Technology and Interaction Design.
    Liu, Li
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    KTH Royal Institute of Technology, Department of Media Technology and Interaction Design.
    Head operated electric wheelchair2014In: IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI 2014), IEEE , 2014, p. 53-56Conference paper (Refereed)
    Abstract [en]

    Currently, the most common way to control an electric wheelchair is to use joystick. However, there are some individuals unable to operate joystick-driven electric wheelchairs due to sever physical disabilities, like quadriplegia patients. This paper proposes a novel head pose estimation method to assist such patients. Head motion parameters are employed to control and drive an electric wheelchair. We introduce a direct method for estimating user head motion, based on a sequence of range images captured by Kinect. In this work, we derive new version of the optical flow constraint equation for range images. We show how the new equation can be used to estimate head motion directly. Experimental results reveal that the proposed system works with high accuracy in real-time. We also show simulation results for navigating the electric wheelchair by recovering user head motion.

  • 2.
    Abedin, Md Reaz Ashraful
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Bensch, Suna
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Hellström, Thomas
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Self-supervised language grounding by active sensing combined with Internet acquired images and text2017In: Proceedings of the Fourth International Workshop on Recognition and Action for Scene Understanding (REACTS2017) / [ed] Jorge Dias George Azzopardi, Rebeca Marf, Málaga: REACTS , 2017, p. 71-83Conference paper (Refereed)
    Abstract [en]

    For natural and efficient verbal communication between a robot and humans, the robot should be able to learn names and appearances of new objects it encounters. In this paper we present a solution combining active sensing of images with text based and image based search on the Internet. The approach allows the robot to learn both object name and how to recognise similar objects in the future, all self-supervised without human assistance. One part of the solution is a novel iterative method to determine the object name using image classi- fication, acquisition of images from additional viewpoints, and Internet search. In this paper, the algorithmic part of the proposed solution is presented together with evaluations using manually acquired camera images, while Internet data was acquired through direct and reverse image search with Google, Bing, and Yandex. Classification with multi-classSVM and with five different features settings were evaluated. With five object classes, the best performing classifier used a combination of Pyramid of Histogram of Visual Words (PHOW) and Pyramid of Histogram of Oriented Gradient (PHOG) features, and reached a precision of 80% and a recall of 78%.

  • 3.
    Abrahamsson, Johan
    et al.
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Sjöberg, Robin
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    E-tjänstutveckling ur ett medborgarperspektiv: Att skapa beslutsunderlag baserat på medborgarärendens lämplighet för olika kommunikationskanaler2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Citizens’ interaction with governments is an area with unique implications for channel management. Governments need to take the citizens perspective into further consideration in order to be successful in delivering high-quality e-services. This paper aims to determine if a categorization of citizen-initiated contacts from a citizen-centric perspective can be a valuable basis for decisions regarding e-service development. The study consisted of three steps. The first step was an examination of the existing related literature, which resulted in the uncovering of the most important aspects of citizens channel choice. The second step consisted of an elaboration of a classification based on perceived task characteristics and a subsequent matching of the categories to desirable channel characteristics. The third and final step consisted of an application of the proposed categorization on a content management system containing all citizen-initiated contacts in a Swedish municipality. The application indicated that the proposed categorization could possibly be used to guide investments in e-services towards a channel-appropriate direction.

  • 4.
    Adler, Robert
    et al.
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Eriksson, Andreas
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Visuella Effekter Inom Genrespecifik Musikvideoproduktion2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today almost every artist has a music video. With today’s technology it has become a lot easier for smaller companies or amateur filmers to produce and distribute their work. But how important is an artist’s music video and where do people find their music these days? Other questions we wanted to answer were if there is a typical way a music video looks like based on its genre. And is it possible to break these stereotypical ways of producing music videos and thereby create a higher level of enjoyment from the viewer? Our main idea of achieving this was by the use of visual effects in a genre, which in our opinion usually don’t showcase these types of effects. The genre we decided to work with was singer/songwriter, which we think is one genre that doesn’t typically use visual effects. To back up our opinions we studied a lot of music videos from different genres to really see what was typical for each of them. Furthermore we made a survey to find answers for our questions about people’s views on the importance of a well-made music video and where they watch and find them. After we had found some of our answers we produced a music video, one with, and one without visual effects. We then showed these to a number of people and asked them questions about their opinions. Based on our results from studying different music videos and the surveys we came up with a conclusion. And we can say that using visual effects in a genre were they typically aren’t used is possible and it can enhance a viewers enjoyment of the music video. Although we also found out that it should be done with moderation and in good relations with the specific genre.

  • 5.
    Adlerborn, Björn
    Umeå University, Faculty of Science and Technology, Department of Computing Science. Umeå University, Faculty of Science and Technology, High Performance Computing Center North (HPC2N).
    Parallel Algorithms and Library Software for the Generalized Eigenvalue Problem on Distributed Memory Computer Systems2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    We present and discuss algorithms and library software for solving the generalized non-symmetric eigenvalue problem (GNEP) on high performance computing (HPC) platforms with distributed memory. Such problems occur frequently in computational science and engineering, and our contributions make it possible to solve GNEPs fast and accurate in parallel using state-of-the-art HPC systems. A generalized eigenvalue problem corresponds to finding scalars y and vectors x such that Ax = yBx, where A and B are real square matrices. A nonzero x that satisfies the GNEP equation is called an eigenvector of the ordered pair (A,B), and the scalar y is the associated eigenvalue. Our contributions include parallel algorithms for transforming a matrix pair (A,B) to a generalized Schur form (S,T), where S is quasi upper triangular and T is upper triangular. The eigenvalues are revealed from the diagonals of S and T. Moreover, for a specified set of eigenvalues an associated pair of deflating subspaces can be computed, which typically is requested in various applications. In the first stage the matrix pair (A,B) is reduced to a Hessenberg-triangular form (H,T), where H is upper triangular with one nonzero subdiagonal and T is upper triangular, in a finite number of steps. The second stage reduces the matrix pair further to generalized Schur form (S,T) using an iterative QZ-based method. Outgoing from a one-stage method for the reduction from (A,B) to (H,T), a novel parallel algorithm is developed. In brief, a delayed update technique is applied to several partial steps, involving low level operations, before associated accumulated transformations are applied in a blocked fashion which together with a wave-front task scheduler makes the algorithm scale when running in a parallel setting. The potential presence of infinite eigenvalues makes a generalized eigenvalue problem ill-conditioned. Therefore the parallel algorithm for the second stage, reduction to (S,T) form, continuously scan for and robustly deflate infinite eigenvalues. This will reduce the impact so that they do not interfere with other real eigenvalues or are misinterpreted as real eigenvalues. In addition, our parallel iterative QZ-based algorithm makes use of multiple implicit shifts and an aggressive early deflation (AED) technique, which radically speeds up the convergence. The multi-shift strategy is based on independent chains of so called coupled bulges and computational windows which is an important source of making the algorithm scalable. The parallel algorithms have been implemented in state-of-the-art library software. The performance is demonstrated and evaluated using up to 1600 CPU cores for problems with matrices as large as 100000 x 100000. Our library software is described in a User Guide. The software is, optionally, tunable via a set of parameters for various thresholds and buffer sizes etc. These parameters are discussed, and recommended values are specified which should result in reasonable performance on HPC systems similar to the ones we have been running on.

  • 6.
    Adlerborn, Björn
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science. Umeå University, Faculty of Science and Technology, High Performance Computing Center North (HPC2N).
    Kågström, Bo
    Umeå University, Faculty of Science and Technology, Department of Computing Science. Umeå University, Faculty of Science and Technology, High Performance Computing Center North (HPC2N).
    Kressner, Daniel
    A parallel QZ algorithm for distributed memory HPC systems2014In: SIAM Journal on Scientific Computing, ISSN 1064-8275, E-ISSN 1095-7197, Vol. 36, no 5, p. C480-C503Article in journal (Refereed)
    Abstract [en]

    Appearing frequently in applications, generalized eigenvalue problems represent one of the core problems in numerical linear algebra. The QZ algorithm of Moler and Stewart is the most widely used algorithm for addressing such problems. Despite its importance, little attention has been paid to the parallelization of the QZ algorithm. The purpose of this work is to fill this gap. We propose a parallelization of the QZ algorithm that incorporates all modern ingredients of dense eigensolvers, such as multishift and aggressive early deflation techniques. To deal with (possibly many) infinite eigenvalues, a new parallel deflation strategy is developed. Numerical experiments for several random and application examples demonstrate the effectiveness of our algorithm on two different distributed memory HPC systems.

  • 7. Agugiaro, G.
    et al.
    Remondino, F.
    Girardi, G.
    von Schwerin, J.
    Richards-Rissetto, Heather
    Umeå University, Faculty of Arts, Humlab.
    De Amicis, R.
    A web-based interactive tool for multi-resolution 3d models of a maya archaeological site2011In: 4TH ISPRS INTERNATIONAL WORKSHOP 3D-ARCH 2011: 3D VIRTUAL RECONSTRUCTION AND VISUALIZATION OF COMPLEX ARCHITECTURES / [ed] Remondino, F; ElHakim, S, 2011, no W16, p. 23-30Conference paper (Refereed)
    Abstract [en]

    Continuous technological advances in surveying, computing and digital-content delivery are strongly contributing to a change in the way Cultural Heritage is "perceived": new tools and methodologies for documentation, reconstruction and research are being created to assist not only scholars, but also to reach more potential users (e.g. students and tourists) willing to access more detailed information about art history and archaeology. 3D computer-simulated models, sometimes set in virtual landscapes, offer for example the chance to explore possible hypothetical reconstructions, while on-line GIS resources can help interactive analyses of relationships and change over space and time. While for some research purposes a traditional 2D approach may suffice, this is not the case for more complex analyses concerning spatial and temporal features of architecture, like for example the relationship of architecture and landscape, visibility studies etc. The project aims therefore at creating a tool, called "QueryArch3D" tool, which enables the web-based visualisation and queries of an interactive, multi-resolution 3D model in the framework of Cultural Heritage. More specifically, a complete Maya archaeological site, located in Copan (Honduras), has been chosen as case study to test and demonstrate the platform's capabilities. Much of the site has been surveyed and modelled at different levels of detail (LoD) and the geometric model has been semantically segmented and integrated with attribute data gathered from several external data sources. The paper describes the characteristics of the research work, along with its implementation issues and the initial results of the developed prototype. [GRAPHICS] .

  • 8.
    Ahlgren, Per
    et al.
    Department of e-Resources, University Library, Stockholm University.
    Colliander, Cristian
    Högskolan i Jönköping, Högskolebiblioteket.
    Document-document similarity approaches and science mapping: experimental comparison of five approaches2009In: Journal of Informetrics, ISSN 1751-1577, E-ISSN 1875-5879, Vol. 3, no 1, p. 49-63Article in journal (Refereed)
    Abstract [en]

    This paper treats document-document similarity approaches in the context of science mapping. Five approaches, involving nine methods, are compared experimentally. We compare text-based approaches, the citation-based bibliographic coupling approach, and approaches that combine text-based approaches and bibliographic coupling. Forty-three articles, published in the journal Information Retrieval, are used as test documents. We investigate how well the approaches agree with a ground truth subject classification of the test documents, when the complete linkage method is used, and under two types of similarities, first-order and second-order. The results show that it is possible to achieve a very good approximation of the classification by means of automatic grouping of articles. One text-only method and one combination method, under second-order similarities in both cases, give rise to cluster solutions that to a large extent agree with the classification.

  • 9.
    Ahlgren, Per
    et al.
    Department of e-Resources, University Library, Stockholm University.
    Colliander, Cristian
    Umeå University, Faculty of Social Sciences, Department of Sociology.
    Persson, Olle
    Umeå University, Faculty of Social Sciences, Department of Sociology.
    Field normalized citation rates, field normalized journal impact and Norwegian weights for allocation of university research funds2012In: Scientometrics, ISSN 0138-9130, E-ISSN 1588-2861, Vol. 92, no 2, p. 767-780Article in journal (Refereed)
    Abstract [en]

    We compared three different bibliometric evaluation approaches: two citationbased approaches and one based on manual classification of publishing channels into quality levels. Publication data for two universities was used, and we worked with two levels of analysis: article and department. For the article level, we investigated the predictive power of field normalized citation rates and field normalized journal impact with respect to journal level. The results for the article level show that evaluation of journals based on citation impact correlate rather well with manual classification of journals into quality levels. However, the prediction from field normalized citation rates to journal level was only marginally better than random guessing. At the department level, we studied three different indicators in the context of research fund allocation within universities and the extent to which the three indicators produce different distributions of research funds. It turned out that the three distributions of relative indicator values were very similar, which in turn yields that the corresponding distributions of hypothetical research funds would be very similar.

  • 10.
    Ahmad, Farooq
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Lindgren, Helena
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Selection of foundational ontology for collaborative knowledge modeling in healthcare domain2010In: Artificial intelligence: methodology, systems, and applications / [ed] Dicheva, Darina; Dochev, Danail, Springer Berlin/Heidelberg, 2010, p. 261-262Conference paper (Refereed)
    Abstract [en]

    Ontology design is an important process for structuring knowledge to be reused in different projects in the health domain. In this paper, we describe an ontology design for the collaborative knowledge building system ACKTUS to be used for developing personalized knowledge applications for different domains. Different foundational ontologies were compared with respect to selected criteria considered vital for the project, such as modularity and descriptiveness.

  • 11. Aichroth, Patrick
    et al.
    Weigel, Christian
    Kurz, Thomas
    Stadler, Horst
    Drewes, Frank
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Björklund, Johanna
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Schlegel, Kai
    Berndl, Emanuel
    Perez, Antonio
    Bowyer, Alex
    Volpini, Andrea
    MICO - MEDIA IN CONTEXT2015In: 2015 IEEE International Conference on Multimedia & Expo Workshops (ICMEW), 2015Conference paper (Refereed)
    Abstract [en]

    The abundance of digital content requires cost-effective technologies to extract the hidden meaning from media objects. However, current approaches fail to deal with the challenges related to cross-media analysis, metadata publishing, querying and recommendation that are necessary to overcome this challenge. In this paper, we describe the EU project MICO (Media in Context) which aims to provide the necessary technologies based on open-source software (OSS) core components.

  • 12.
    Akoglu, Canan
    Umeå University, Faculty of Science and Technology, Umeå Institute of Design.
    The relationship between industrial design and interaction design in product development activities2012In: Human Factors in Computing Systems (CHI) International Conference, Austin, TX, USA, May 5-10, 2012 (on DVD), Association for Computing Machinery (ACM), 2012Conference paper (Refereed)
  • 13.
    Alaa, Halawani
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Haibo, Li
    School of Computer Science & Communication, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Template-based Search: A Tool for Scene Analysis2016In: 12th IEEE International Colloquium on Signal Processing & its Applications (CSPA): Proceeding, IEEE, 2016, article id 7515772Conference paper (Refereed)
    Abstract [en]

    This paper proposes a simple and yet effective technique for shape-based scene analysis, in which detection and/or tracking of specific objects or structures in the image is desirable. The idea is based on using predefined binary templates of the structures to be located in the image. The template is matched to contours in a given edge image to locate the designated entity. These templates are allowed to deform in order to deal with variations in the structure's shape and size. Deformation is achieved by dividing the template into segments. The dynamic programming search algorithm is used to accomplish the matching process, achieving very robust results in cluttered and noisy scenes in the applications presented.

  • 14.
    Alaqra, Alaa
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Cell-phone Travel Planner GUI for SpaceTime2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Global positioning systems have been having an increasing interest recently and been integrated and used in many applications to service positioning, navigation and travel planning. This project has set to design and test an interface of a travel planner for cell phones. A pre-study was made to investigate other travel planners to help the design of this application that has targeted a user friendly interface that people can use regardless of their background. A special feature, carpooling, has been introduced to ease the environmental, economical, and social aspects of navigation. The test was done as walk-through mockup images case scenarios. The test subjects were pleased with the interface’s friendliness, invoked carpooling issues, presented contradictory opinions regarding the interface's design, and offered future integration with other applications suggestions all of which were discussed. Overall, the test results were positive and few problems with the overall design were identified. A future study with more participants and a deeper analysis of the interface would be one way to further investigate the proposed interface.

  • 15.
    Alatalo, André
    et al.
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Vallgren, Erik
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Anpassningar till standardisering inom Software Configuration Management: En fallstudie om standardisering inom mjukvarukonfigurationshantering2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Change is inevitable when software is built and deployed. It’s not particularly problematic to manage change if there is just one system. But in a large global IT organization, with several systems and people who develop, problems may arise. If organizations don’t control change, change will control the organization. Software Configuration Management (SCM) is a set of activities to manage change by identifying objects that are likely to change, establishing relationships among them, managing different versions of the objects, controlling the changes imposed and reporting on the changes made. A way to support the work of SCM is to follow standards. A standard can be compared to a type of rule, but also a directive. In this study we examined how a multinational organization applies standards within SCM. We examined the challenges with applying standards. We also examined whether there are deviations from standards, and in such cases why did the deviations arise and what are the following consequences? The study is based on a qualitative case study that employed interviews with developers, IT architects, operations manager and solution leader. The result of this study shows that some of the challenges in applying standards within SCM are: legacy systems, globalization, CMDB and ITSM-related tools (and their processes). The study also shows that standardization within maintenance is complex and that it’s easily breach and forgotten. The study shows that the consequence of this is that the developers must constantly compromise with standards. The result of this compromise is that it’s possible to carry out the business, but the solutions may not meet standards. In this study we concluded that the organization need to direct more attention towards maintenance, and less on new development. 

  • 16.
    Alekzandra, Granath
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Filmskapande för nybörjare - steg för steg2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about film making, wich parts that are included in film making and things that is good to think of when doing film for the first time. A short movie has been created and from this, this study has been done to figure out if the theory is like the reality. Also the report is based om the book ”How to get started in film making” by Tom Holden and interviews with people working with film.

  • 17.
    Alexander, Bodén
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kommunikation och marknadsföring inom Sociala medier – Novamedia Svenska PostkodLotteriet AB2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When I worked with the daily communication with the lottery’s customers on social media the Communications Department at Nova Media Swedish Postcode Lottery contacted me to write a document, plan and present an advertising campaign in their social media channels to Christmas 2014. The company had ideas on a campaign that they wanted develop where my job was to develop and present a plan for how to implement the campaign. The purpose is to explain what PostkodTomten is and to highlight its commercial advantages for marketing purposes. To have succeeded with this work, I needed a clear methodology and plan. I deepened my knowledge in marketing with a clear focus on social media, literary studies has been key and theoretical studies have been a good basis to implement my work practically. The conclusion I take with me in the future, the importance of how to dispose of your work, meetings booked weekly and milestones were set up giving the project good order and structure. This report will first and foremost focus and process these documents but also contains a theoretical part of marketing and communications in social media in general. The document and the report were presented to the company as an appendix. The theoretical parts of the report focuses on the marketing and communications in social media, how it is going to and how to do it appropriately. It is also up to what a company can do to strategically "stick out" and promote themselves on social media and its various channels. The terms "Buzz marketing" and "viral marketing" will also be explained.

  • 18.
    Algers, Björn
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Stereo Camera Calibration Accuracy in Real-time Car Angles Estimation for Vision Driver Assistance and Autonomous Driving2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The automotive safety company Veoneer are producers of high end driver visual assistance systems, but the knowledge about the absolute accuracy of their dynamic calibration algorithms that estimate the vehicle’s orientation is limited.

    In this thesis, a novel measurement system is proposed to be used in gathering reference data of a vehicle’s orientation as it is in motion, more specifically the pitch and roll angle of the vehicle. Focus has been to estimate how the uncertainty of the measurement system is affected by errors introduced during its construction, and to evaluate its potential in being a viable tool in gathering reference data for algorithm performance evaluation.

    The system consisted of three laser distance sensors mounted on the body of the vehicle, and a range of data acquisition sequences with different perturbations were performed by driving along a stretch of road in Linköping with weights loaded in the vehicle. The reference data were compared to camera system data where the bias of the calculated angles were estimated, along with the dynamic behaviour of the camera system algorithms. The experimental results showed that the accuracy of the system exceeded 0.1 degrees for both pitch and roll, but no conclusions about the bias of the algorithms could be drawn as there were systematic errors present in the measurements.

  • 19.
    Ali-Eldin, Ahmed
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Kihl, Maria
    Dept. of Electrical and Information Technology, Lund University, Lund, Sweden.
    Tordsson, Johan
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Elmroth, Erik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Efficient provisioning of bursty scientific workloads on the cloud using adaptive elasticity control2012In: Proceedings of the 3rd workshop on Scientific Cloud Computing Date, Association for Computing Machinery (ACM), 2012, p. 31-40Conference paper (Refereed)
    Abstract [en]

    Elasticity is the ability of a cloud infrastructure to dynamically change theamount of resources allocated to a running service as load changes. We build anautonomous elasticity controller that changes the number of virtual machinesallocated to a service based on both monitored load changes and predictions offuture load. The cloud infrastructure is modeled as a G/G/N queue. This modelis used to construct a hybrid reactive-adaptive controller that quickly reactsto sudden load changes, prevents premature release of resources, takes intoaccount the heterogeneity of the workload, and avoids oscillations. Using simulations with Web and cluster workload traces, we show that our proposed controller lowers the number of delayed requests by a factor of 70 for the Web traces and 3 for the cluster traces when compared to a reactive controller. Ourcontroller also decreases the average number of queued requests by a factor of 3 for both traces, and reduces oscillations by a factor of 7 for the Web traces and 3 for the cluster traces. This comes at the expense of between 20% and 30% over-provisioning, as compared to a few percent for the reactive controller.

  • 20.
    Ali-Eldin, Ahmed
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Tordsson, Johan
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Elmroth, Erik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    An adaptive hybrid elasticity controller for cloud infrastructures2012In: 2012 IEEE Network operations and managent symposium (NOMS), IEEE Communications Society, 2012, p. 204-212Conference paper (Refereed)
    Abstract [en]

    Cloud elasticity is the ability of the cloud infrastructure to rapidly change the amount of resources allocated to a service in order to meet the actual varying demands on the service while enforcing SLAs. In this paper, we focus on horizontal elasticity, the ability of the infrastructure to add or remove virtual machines allocated to a service deployed in the cloud. We model a cloud service using queuing theory. Using that model we build two adaptive proactive controllers that estimate the future load on a service. We explore the different possible scenarios for deploying a proactive elasticity controller coupled with a reactive elasticity controller in the cloud. Using simulation with workload traces from the FIFA world-cup web servers, we show that a hybrid controller that incorporates a reactive controller for scale up coupled with our proactive controllers for scale down decisions reduces SLA violations by a factor of 2 to 10 compared to a regression based controller or a completely reactive controller.

  • 21.
    Alin, Lars
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Object Tracking withIphone 3Gs2010Independent thesis Advanced level (degree of Master (One Year)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    In June of 2007 Apple Inc. released the smartphone Iphone. It was a groundbreaking success that set a new standard for what a smartphone should be able to do. Apple has improved the Iphone every year since then and the 3Gs is the newest Iphone model. As the phones have improved, both when looking at hardware and software, the applications have improved as well. The Iphone 3Gs provides the possibility to use the camera as an application background and with that the possibility to analyze the surroundings, making it possible to track objects that the phone is pointed towards.This thesis examines how object tracking can be implemented in applications for Iphone 3Gs as well as providing a survey of four different areas of use that have been implemented in Xcode: an augmented reality car game, a letter tracking application, a face recognition application and an object recognition application.

  • 22.
    AliNazari, Mirian
    Umeå University, Faculty of Teacher Education, Department of Creative Studies.
    Kreativ Uppväxtmiljö: en studie av stadieteorier2007Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I examensarbetet studerades bildutveckling som även jämförts med författarens egen uppväxtmiljö. Metoden har varit en litteraturstudie som behandlar ämnet estetiska uttrycksformer och kreativ uppväxt. Därtill har en granskning av författarens uppväxtmiljö gällande möjlighet till övande av kreativ förmåga tagits upp i relation till personlig utveckling. Jämförelse har gjorts med stadieteorier om utvecklande av barns bildanvändning. Genom dokumenterade av författarens egna bilder under tidiga år visades bildutveckling i de olika teckningsutvecklingsstadierna. Slutsatsen är att kreativ förmåga påverkas sannolikt av uppfostran fylld med möjligheten att få måla och teckna, något som bildlärare kan utveckla i arbetet med barn. Behov att som blivande lärare integrera bilden i de teoretiska ämnena kan utveckla dessa möjligheter ytterligare.

  • 23.
    Almgren, Anton
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Winbäck, Hannes
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Användbarhet inom människa-datorinteraktion i praktiken: En kartläggning av utvärderingsmetoder2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studiens syfte är att kartlägga yrkesverksammas preferenser och användning av utvärderingsmetoder för användbarhet inom människa-datorinteraktion. En webbenkät distribuerades via epost till företag med minst en anställd som arbetar med användbarhet samt via sociala medier genom intresseorganisationen STIMDI och företaget Inuse. Totalt erhölls 104 svarande varav en räknades som bortfall då den ansågs vara en dubblett. Resultaten visar att ingen enskild eller kombination av metoder används oftast och rankas ge högst effekt på användbarhet. Angående vilka utvärderingsmetoder som används är intervju och tänka högt med användare de två metoder som nämns av flest deltagare. Resultaten visar även att nästan 80 % skattar användning av utvärderingsmetoder och involvering av användare i deras arbete som mycket viktigt. En tydlig preferens för att involvera användare och arbeta med kombinationer av metoder framgår i denna kartläggning. Forskning bör möjligtvis fokusera mer på hur användandet av utvärderingsmetoder sker i kombination. 

  • 24.
    Al-Naser, Mohammad
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Söderström, Ulrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Reconstruction of occluded facial images using asymmetrical Principal Component Analysis2012In: Integrated Computer-Aided Engineering, ISSN 1069-2509, E-ISSN 1875-8835, Vol. 19, no 3, p. 273-283Article in journal (Refereed)
    Abstract [en]

    When only non-occluded image parts are available for facial images it is difficult or impossible to correctly recognize the person in the image. The problem addressed in this work is reconstruction of the occluded parts in facial images; e. g. eyes covered with sunglasses. Asymmetrical Principal Component Analysis (aPCA) allows estimation of occluded facial parts based on the content of the facial parts which are visible. aPCA is used to estimate full non-occluded faces from 3 kinds of occlusion with 2 different reconstruction methods in this work and we present the results with both objective and subjective evaluation. The subjective evaluation shows that clear and sharp image regions are preferred even if this results in visible edges in the images. The method also performs well when a different facial expression than the one in the database is used to calculate the reconstruction parameters.

  • 25.
    Alpay, Aylin
    Umeå University, Faculty of Science and Technology, Umeå Institute of Design.
    Untangling Road Trip Experiences with Conected Car: Planning and bringing it to the car2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With developing technologies and growing infrastructures, connected experiences are expanding their realms towards various devices and scenarios in our lives. One of the areas, which is going under a big change due to this connectivity is the car related experiences. As connectivity is intrinsically enabler of different experiences and services, it is foreseen that it will bring a different dimension to car and driving related experiences as well.By investigating the future trends and possibilities that connectivity can provide to car and driving related experiences, this thesis aims for imagining the near future scenarios with an explorative approach, focusing on one and addressing to the rising issues with a design proposal that is meaningful to both users and the industry.The result, Tripcloud, contributes to the future scenario of having a road trip with the car, with a new digital platform that aims for supporting the users throughout the planning and bringing the plans into the car experience seamlessly and safely. It aims for reducing today’s existing complexity in terms of interaction and cognition to provide a better experience and avoid driver distraction. With providing organised information pieces, information exchange between people and automated links with mobile devices and car, Tripcloud offers easier an more convenient alternative for road trip planing and bringing the plans into car experiences for the near future.

  • 26.
    Amcoff Nyström, Christina
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Design rules for intranets according to the viable system model2006In: Systemic Practice and Action Research, ISSN 1094-429X, E-ISSN 1573-9295, Vol. 19, no 6, p. 523-535Article in journal (Refereed)
    Abstract [en]

    The Viable System Model, VSM, by Stafford Beer is a model used for diagnosing and designing organizational structure and communication to facilitate necessary and sufficient conditions for viability. The model has been used for diagnosing different kinds of organizations at different levels where its use highlights existing or missing communication patterns and information flows in different communication channels and relates findings to a viable system. In a previous article, VSM and Intranet have been discussed and examples of advantages of combining the two concepts when designing organizations, has been given. In this article, VSM is combined with Intranet and possible functions in an intranet that support information exchange between different systems are identified and described. The suggested functions identified in this article are finally related to Intranet use modes, and the concepts of Empowerment vs. control.

  • 27.
    Anani, Adi
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    M-learning in review: Technology, standard and evaluation2008In: Journal of Communication and Computer, ISSN 1548-7709, Vol. 5, no 11, p. 1-6Article in journal (Refereed)
    Abstract [en]

    Nowadays E-learning as a form of learning depending on networks and computer devices has been expanding by leaps and bounds. As a special kind of E-learning, M-learning (mobile learning) aims at the use of mobile devices anywhere at anytime by anybody. In this paper, the technologies to develop a M-learning system is deeply analyzed according to the layer model at first. Secondly, from the view of application, the standardization in M-learning is researched in order to accelerate the development and popularization of M-learning. Finally, quality estimation of M-learning system is discussed from the view of QoE (quality of experiences). The experience form end-user is the sole effective norm to judge the result of M-learning technology. It is no doubt that technologies, standardization and evaluation will play very important parts in the course of M-learning development.

  • 28.
    Andersson, Axel
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Real-Time Feedback for Agility Training: Tracking of reflective markers using a time-of-flight camera2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 29. Andersson, Magnus
    et al.
    Vincent, Jonathan
    Uppsala Univ, Dept Photochem & Mol Sci.
    van der Spoel, David
    Davidsson, Jan
    Neutze, Richard
    A Proposed Time-Resolved X-Ray Scattering Approach to Track Localand Global Conformational Changes in Membrane Transport Proteins2008In: Structure, ISSN 0969-2126, E-ISSN 1878-4186, Vol. 16, p. 21-28Article in journal (Refereed)
    Abstract [en]

    Time-resolved X-ray scattering has emerged as a powerful technique for studying the rapid structural dynamics of small molecules in solution. Membrane-protein-catalyzed transport processes frequently couple large-scale conformational changes of the transporter with local structural changes perturbing the uptake and release of the transported substrate. Using light-driven halide ion transport catalyzed by halorhodopsin as a model system, we combine molecular dynamics simulations with X-ray scattering calculations to demonstrate how small-molecule time-resolved X-ray scattering can be extended to the study of membrane transport processes. In particular, by introducing strongly scattering atoms to label specific positions within the protein and substrate, the technique of time-resolved wide-angle X-ray scattering can reveal both local and global conformational changes. This approach simultaneously enables the direct visualization of global rearrangements and substrate movement, crucial concepts that underpin the alternating access paradigm for membrane transport proteins.

  • 30.
    Andersson, Maja
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Enhancing content discovery in Video on Demand services for children2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The media landscape is changing and Internet-based streaming services for children are becoming increasingly popular. The concept of online streaming extends freedom and control over content selection but discovering new content is often experienced as troublesome. The objective of this thesis is to identify parameters to make it easier for users of streaming services for children to discover and watch unfamiliar programs. Guidelines are formed based on literature studies, interviews, observations, a survey, a benchmark, data analysis with Adobe Analytics, a workshop and finally user tests with prototypes. These guidelines conclude that content should be categorized, dynamicized, highlighted and socially engaging. Categorization based on age is primarily important but interests and genres can also be used to make children more interested in a title. Content should be dynamic, customizable and personal to each user to give more accurate recommendations based on age and interests. Making one alternative more visually prominent will make this alternative more interesting especially for younger children and social features with information about other users opinions can motivate a decision to discover new content among older children. 

  • 31.
    Andersson, Marcus
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Complexity and problem solving: A tale of two systems2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate if increasing complexity for a problem makes a difference for a learning system with dual parts. The dual parts of the learning system are modelled after the Actor and Critic parts from the Actor-Critic algorithm, using the reinforcement learning framework. The results conclude that not any difference can be found in the relative performance in the Actor and Critic parts when increasing the complexity of a problem. These results could depend on technical difficulties in comparing the environments and the algorithms. The difference in complexity would then be non-uniform in an unknowable way and uncertain to use as comparison. If on the other hand the change of complexity is uniform, this could point to the fact that there is an actual difference in how each of the actor and critic handles different types of complexity. Further studies with a controlled increase in complexity are needed to establish which of the scenarios is most likely to be true. In the discussion an idea is presented of using the Actor-Critic framework as a model to understand the success rate of psychological treatments better.

  • 32.
    Andersson, Ola
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Threat, risk, and vulnerabilityanalyses during the developmentof IT systems in the SwedishArmed Forces2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master’s thesis describes how two models from the Swedish Armed Forces; the risk management model and the IT lifecycle model can be combined. An example is then presented for how the risk management model can be extended for threats, risks, and vulnerabilities related to information technology. The combination and extension of the models are based on a literature study that lists and compares models and methods for threat, risk, andvulnerability analyses, as well as an analysis of threats related to information technology. From the combined and extended model, a design proposal for how to implement the identified functionality was identified. Based on an evaluation that showed that the program NTE and the plugin EASTER were suitable as the foundation for this implementation, the program NTE and the plugin EASTER were extended with further functionality and resulted in the implementation of the plugin ASCENSION. This was evaluated and resulted in ideas for a possible re-design and examples of the future potential of ASCENSION.

  • 33.
    Andersson, Pehr
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Hedman, Leif
    Umeå University, Faculty of Social Sciences, Department of Psychology. Center for Surgical Sciences, Karolinska Institutet at Huddinge University Hospital.
    Enochsson, Lars
    Ström, Pär
    Kjellin, Ann
    Westman, Bo
    Felländer-Tsai, Li
    Working memory and virtual endoscopy simulation2004In: Proceedings of the twenty-sixth annual conference of the cognitive science society / [ed] Forbus, K; Gentner, D; Regier, T, Mahwah: Lawrence Erlbaum Associates, 2004, p. 1519-1519Conference paper (Refereed)
  • 34.
    Andersson, Peter
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Model based object finding in occluded cluttered environments2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of the thesis is object finding in occluded and cluttered environment using computer vision techniques and robot motion. Difficulties of the object finding are 1. finding objects at hidden area and 2. finding unrecognized objects. For solving the difficulties, two methods were developed, one is for finding objects in occluded cluttered environments using model based object finding and the other to increase the robustness in object finding by identifying known objects that are unidentified. The goal was to search occluded areas with the bumblebee2 stereo camera to be able to identify all known objects in the environment by removing all visible known objects To identify known objects SURF [9] was used and to be able to remove the identified objects their location first needed to be localized. To localize the object‘s x and y coordinate the information from SURF [9] was used, and the distance coordinate z is calculated using the depth image from the stereo camera. The method to identify objects the SURF [9] algorithm had missed to identify uses a method to find unknown segments in the environment. By using a push motion on the segments to change their angle it can remove possible light reflections and the object can be identified. The results of this research show that the method can find objects in occluded cluttered areas and it can also identified missed known objects.

  • 35.
    Andersson, Pär
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Digital Fabrication and Open Concepts: An emergent paradigm of consumer electronics production2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Open Source och relaterade mjukvarukoncept och utvecklingsmodeller är vid det här laget allmänt bekanta och har varit föremål för många studier. Open Source Hardware är mindre spritt och studerat, och så även emergent teknologi som för in traditionellt industriella tekniker som 3D-printing, laserskärare, och CAD-baserade produktionsverktyg i mindre skala i hem- och hobbymiljöer. Dessa ämnen har främst studerats ur mer renodlat tekniska perspektiv, snarare än att sättas i samband i en vidare kontext. Denna kombinerar internet som infrastruktur och socialt medium för kunskaps- och resursdelning; open source-koncept; de möjligheter som tillgängligheten av mer och mer kapabel och överkomlig hårdvara byggd på öppen design bereder; och andra relaterade socio-tekniska fenomen vilka börjat framträda de senaste 5-10 åren.

    I denna uppsats undersöker jag denna större kontext. Uppsatsen har utförts i form av en litteraturstudie av existerande forskning inom ovanstående diskreta områden, och i den mån de finns även dess inbördes relationer. Denna kontext framträder som ett emergent paradigm kring produktion av hemelektronik, och även som exemplifierande trenden av teknologins fortsatta intåg som allestädes närvarande i våra liv och vår omgivning. Resultaten indikerar en gryende förändring i hur vi interagerar med teknik, vilka som gör det och varför, i vilka kontexter, och ett framträdande av en ny ekonomi. Jag visar på att ytterligare forskning behövs, och att perspektivet bör flyttas från att analyseras enbart i diskreta termer som teknik, open source-principer, DIY et cetera, utan även till vad som framstår som resultatet där dessa konvergerar, den naturliga konsekvensen av ett folkligt anammande av denna teknik och open source-koncept.

  • 36.
    Andersson, Rickard
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Pseudo-optimal strategies in no-limit poker2006In: ICGA Journal, ISSN 1389-6911, Vol. 29, no 3, p. 143-149Article in journal (Refereed)
    Abstract [en]

    Games have always been a strong driving force in Artificial Intelligence. In the last ten years huge improvements has been made in perfect information games like chess and Othello. The strongest computer agents can nowadays beat the strongest human players. This is not the case for imperfect information games such as poker and bridge where creating an expert computer player has shown to be much harder. Previous research in poker has either addressed limit poker or simplified variations of poker games. This paper tries to extend known techniques successfully used in limit poker to no-limit. No-limit poker increases the size of the game tree drastically. To reduce the complexity an abstracted model of the game is created. Finding an optimal strategy for the new model is now a minimization problem using linear programming techniques. The result is a set of pseudo-optimal strategies for no-limit Texas Hold'em. A bot named AGGROBOT was built from these strategies which perform well as long as the players' stack sizes are fairly small.

  • 37.
    André, Caroline
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Design aspects in a mobile biofeedback system - developmentof a new interface concept usingdesign qualities2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It has been established that long term stress can lead to chronic illness of cardiac disease and vascular disorder. In the way people live their lives today they are surrounded by stress and they contribute to the stressful society when they constantly chase the time. The Mobile Life Centre explores how the system Aective Health can get people to reect up on their stress levels and connect that to their everyday activities by using bio sensors and a mobile phone. The bio sensor data visualization in the interface of the system is today tied to time. Since time is perceived dierently from person to person that is something that has caused problems for the design team of Aective Health. This thesis examines how dierent representations of time in user interfaces can be used to mediate the design qualities of subjective time, aliveness and uency in the Aective Health system. As a result from investigating the time aspect and how time can be visualized in a subjective way a suggestion for a design solution was developed.

  • 38.
    Anjum, Chaudhary
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Learner’s Interaction With Information and Communication Technologies2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This Master’s thesis aims to explore how children and teen-agers (i.e. learners) interact and create a use for information and communication technology in the classroom during their lectures. The study is based on distributed cognition theory in order to describe a cognitive  system which involves interactions among humans (i.e. learners), artifacts which they use (i.e. information and communication technology active boards) and the environment in which they interact (i.e. a classroom).

    User’s (such as the children, teen-agers and teachers) interaction with information and communication technology can lead towards new and important ways of invention in the classroom. No doubt the ideas, thoughts and vision of these users (such as children and teenagers) are very important which can change an environment that supports learning. The Distributed Cognition Approach is a widely acknowledged approach, but it is less commonly applied in order to observe learner’s (such as children and teen-agers) interaction with information and communication technologies in their learning setting. Therefore this study aims to explore the children and teen-agers interaction with the information and communication technology active boards by using distributed cognition theory which can be expressed as important and interesting for the researchers, designers and developers in evaluating, designing and developing effective interactive technologies that supports better education.

    Through an empirical case study, qualitative data have been collected using interviews and observations. Based on related research, related theory, qualitative results and analysis, a conclusion is presented which shows that (with the help of the analysis of distributed cognition theory) the information and communication technology active boards seems to engage the children and teen-ager’s to collaborative learning activities which supports collaboration and shared knowledge. It helps to capture their concentration towards learning which can increase the opportunities and possibilities of better learning results related to their education.

    The distributed cognition approach provides an analytic and investigative methodology in order to examine the learner’s interactions with artifacts which are difficult with other traditional methodologies to the analysis of cognitive-tasks. This approach highlights the complicated interdependencies among learners and artifacts in collaborative learning activities.

  • 39.
    Anttila, L.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Eklund, Patrik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Kallin, Lena
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Koskinen, P.
    Penttilä, T.-A.
    The Generalised Preprocessing Perceptron for Medical Data Analysis: A Case Study for the Polycystic Ovary Syndrome1996In: Cybernetics and Systems '96: Proceedings of the 13th European Meeting on Cybernetics and Systems Research / [ed] Robert Trappl, 1996, p. 597-602Conference paper (Other academic)
  • 40.
    Anttila, Lars
    et al.
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Ögren, Martin
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    A design process from a collaborative point of view: Exploring the importance of collaboration between designers and clients2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This essay studies the design process from a collaborative point of view. A literature study has been carried out with focus on design processes and collaborative design, where important concepts and notions are presented. A practical design process was carried out where the project was to create a station identification for Swedish Channel 9. The process was than retrospectively analyzed and broken down into a time-line describing the whole process from amongst other a collaborative point of view. Collaboration between designers and client is found to be very important for the final design. Constraints are considered important to force creativity and the ability to convey abstract thoughts over long distance channels such as e-mail is found to be important in order to overcome the spatial barrier that exists in many design processes today.

  • 41.
    Appelgren, Ester
    et al.
    Södertörns högskola.
    Leckner, Sara
    Malmö högskola.
    Mejtoft, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    The media consumers' conscious and unconscious choices: a key to understanding the news media consumption of tomorrow2014In: Communication électronique, cultures et identités: actes du colloque international organisé au Havre les 11, 12 et 13 juin 2014, Editions Klog , 2014, p. 521-528Conference paper (Refereed)
    Abstract [en]

    The digital society of today is dramatically different than that of a decade ago. During the past decades computers have gone from being clearly visible and at the center of attention to becoming an integrated and omnipresent part of our everyday lives. Today, individuals are catching up on a reality where homes, workplaces and society to a large extent consist of microprocessors that collect, analyze and present information. With regards to news and information sharing, it may seem that the users, thanks to greater ability to choose content, hold the upper hand in this process. However, since these data are constantly collected and analyzed for various purposes by companies, for example in the media industry, the users’ choices may not be as unconditional as they may think they are.Using the Swedish media market as an example, this exploratory paper discusses the interdependency between people’s choices and the market-driven choices made by the media industry in relation to news, and the impact these choices may have on media consumption and the media market.

  • 42.
    Appelgren, Ester
    et al.
    Södertörns högskola.
    Sara, Leckner
    Malmö högskola.
    Mejtoft, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Mediekonsumentens medvetna och omedvetna val: en nyckel till morgondagens mediekonsumtion2014In: Medie-Sverige: statistik och analys. 2014 / [ed] Ulla Carlsson & Ulrika Facht, Göteborg: Nordicom, 2014, p. 29-37Chapter in book (Other (popular science, discussion, etc.))
  • 43. Arafat, Yeasin
    et al.
    Hellström, Thomas
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Rashid, Jayedur
    Parameterized sensor model and an approach for measuring goodness of robotic maps2010In: Proceedings of the 15th IASTED International Conference on Robotics and Applications (RA 2010), 2010Conference paper (Refereed)
  • 44.
    Armstrong, Django
    et al.
    School of Computing, University of Leeds.
    Djemame, Karin
    School of Computing, University of Leeds.
    Nair, Srijith
    British Telecom.
    Tordsson, Johan
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Ziegler, Wolfgang
    Fraunhofer SCAI.
    Towards a Contextualization Solution for Cloud Platform Services2011In: 2011 IEEE Third International Conference on Cloud Computing Technology and Science, IEEE Computer Society, 2011, p. 328-331Conference paper (Refereed)
    Abstract [en]

    We propose a cloud contextualization mechanism which operates in two stages, contextualization of VM images prior to service deployment (PaaS level) and self-contextualization of VM instances created from the image (IaaS level). The contextualization tools are implemented as part of the OPTIMIS Toolkit, a set of software components for simplified management of cloud services and infrastructures. We present the architecture of our contextualization tools and the feasibility of our contextualization mechanism is demonstrated in a three-tier web application scenario. Preliminary performance results suggest acceptable performance and scalability.

  • 45.
    Armstrong, Django
    et al.
    University of Leeds.
    Espling, Daniel
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Tordsson, Johan
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Djemame, Karim
    University of Leeds.
    Elmroth, Erik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Contextualization: dynamic configuration of virtual machines2015In: Journal of Cloud Computing - Advances, Systems and Applications, ISSN 2192-113X, Vol. 4, no 17Article in journal (Refereed)
    Abstract [en]

    New VM instances are created from static templates that contain the basic configuration of the VM to achieve elasticity with regards to capacity. Instance specific settings can be injected into the VM during the deployment phase through means of contextualization. So far this is limited to a single data source and data remains static throughout the lifecycle of the VM.

    We present a layered approach to contextualization that supports different classes of contextualization data available from several sources. The settings are made available to the VM through virtual devices. Inside each VM data from different classes are layered on top of each other to create a unified file hierarchy.

    Context data can be modified during runtime by updating the contents of the virtual devices, making our approach the first contextualization approach to natively support recontextualization. Recontextualization enables runtime reconfiguration of an executing service and can act as a trigger and key enabler of self-* techniques. This trigger provides a service with a mechanism to adapt or optimize itself in response to a changing environment. The runtime reconfiguration using recontextualization and its potential gains are illustrated in an example with a distributed file system, demonstrating the feasibility of our approach.

  • 46.
    Armstrong, Django
    et al.
    University of Leeds.
    Espling, Daniel
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Tordsson, Johan
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Djemame, Karim
    University of Leeds.
    Elmroth, Erik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Runtime virtual machine recontextualization for clouds2013In: Euro-Par 2012: Parallel Processing Workshops / [ed] Ioannis Caragiannis et al., Springer Berlin/Heidelberg, 2013, Vol. 7640, p. 567-576Conference paper (Refereed)
    Abstract [en]

    We introduce and define the concept of recontextualization for cloud applications by extending contextualization, i.e. the dynamic configuration of virtual machines (VM) upon initialization, with autonomous updates during runtime. Recontextualization allows VM images and instances to be dynamically re-configured without restarts or downtime, and the concept is applicable to all aspects of configuring a VM from virtual hardware to multi-tier software stacks. Moreover, we propose a runtime cloud recontextualization mechanism based on virtual device management that enables recontextualization without the need to customize the guest VM. We illustrate our concept and validate our mechanism via a use case demonstration: the reconfiguration of a cross-cloud migratable monitoring service in a dynamic cloud environment. We discuss the details of the interoperable recontextualization mechanism, its architecture and demonstrate a proof of concept implementation. A performance evaluation illustrates the feasibility of the approach and shows that the recontextualization mechanism performs adequately with an overhead of 18% of the total migration time.

  • 47.
    Arvidsson, Viktor
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    A model for strategic e-service implementation in the public sector: challenges for local governments in identifying potential candidates for e-service delivery2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As more and more local governments begin to understand that the great promises of e-service delivery are harder than expected to realize, efficient use of ICT-resources have become increasingly important. Since simply providing more e-services is not the solution, the need to understand what constitutes a suitable e-service has arisen. Public services reach beyond the market domain; therefore, the complexities of public value must be dealt with when services are appraised. Furthermore, due to the heterogeneous nature of local government services it is impossible to evaluate all the options in depth; thus, there is a clear need for early-stage appraisal. However, existing methods of appraisal are burdened by intricacy, and associated with high costs. In response, this paper presents a model capable of reducing this intricacy. The model was developed through a participatory design process involving members on both operational and strategic level in the municipality of Skellefteå. The model implements state of the art into the workspace context while taking measures to reduce intricacy such as: incremental filtering, moving high intricacy elements to the end of the process, and exploitation of available data. As a result the organization is enabled to capture not only the low hanging fruit, but also the long tail of services. Furthermore, the improved understanding of e-service delivery has the potential to open up opportunities for new ways of business development and private-public partnerships. Finally, whereas the model presented is highly context-dependent, the implications outlined in this paper are not limited to this narrow scope.

  • 48.
    Arvidsson, Viktor
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Coordination from an Awareness perspective: Mechanisms and techniques for Awareness based Coordination support.2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When a task becomes shared the need for coordination arises. One fundamental factor for coordination is awareness. This study aimed to answer the question of how awareness-based coordination support systems could increase the efficiency in the processing of tasks generated by the Customer Support Unit in Skellefteå municipality, ultimately creating a better work situation for the officers responsible for the handling of tasks and increasing the service level for the customers of their services. This question was answered by conducting interviews, observing system usage and through analysis of pre-existing interviews from earlier studies of the municipality’s CSU project. This study shows that there are aspects in the task management that are in need of coordination support and presents a task classification system based on the logistic nature of the task. Furthermore this paper identifies the main problems related to the current task management and from an awareness perspective discusses and outlines various mechanisms and techniques to address these problems. Alongside these problems the general lack of coordination support in the current Document and Workflow System (FlexiteBPMS) is approached. Furthermore all outlined proposals share the common aspiration of lessening the burden for the officers without simply shifting the workload onto other units in the workflow chain.

  • 49.
    Arvidsson, Viktor
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Evaluating E-Service Candidates: Participatory design of an e-service valuation model2011Conference paper (Refereed)
  • 50.
    Arvidsson, Viktor
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    The revolution that wasn’t: Investigating barriers to platform-based e-service delivery partnerships2012In: Proceedings of the 45th Annual Hawaii International Conference on System Sciences, Wailea, January 4-7, 2012, 2012Conference paper (Refereed)
    Abstract [en]

    In response to the increasing political and popular demand on e-government to deliver, governments have begun to seek out new, alternative forms of operation. One such development in the domain of e-government is the emergence of private-public partnerships (PPP). However, research on PPPs in the service layer of e- government is virtually silent. In this paper we argue that one possible approach to help close this gap is by investigating key partnership issues from a platform perspective. Building on a case study, and using this novel perspective, we identify three key barriers for developing platform-based partnerships for e-service delivery in local government: the bureaucratic barrier, the interface barrier and the business barrier. Based on experiences from this study, we also conclude that the platform approach have proven useful as a means to close the highlighted gap in research. 

1234567 1 - 50 of 1764
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • 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