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  • 1. Aaghabali, M.
    et al.
    Akbari, S.
    Friedland, S.
    Markström, Klas
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Tajfirouz, Z.
    Upper bounds on the number of perfect matchings and directed 2-factors in graphs with given number of vertices and edges2015In: European journal of combinatorics (Print), ISSN 0195-6698, E-ISSN 1095-9971, Vol. 45, p. 132-144Article in journal (Refereed)
    Abstract [en]

    We give an upper bound on the number of perfect matchings in simple graphs with a given number of vertices and edges. We apply this result to give an upper bound on the number of 2-factors in a directed complete bipartite balanced graph on 2n vertices. The upper bound is sharp for even n. For odd n we state a conjecture on a sharp upper bound.

  • 2.
    Aalto, Anders
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Biodiversity and habitat conditions in reaches with high flow velocity along gradients in hydrological and geomorphological alteration: A study of six rivers in Sweden2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The vast majority of rivers in the developed world are affected by human alteration, which in turn negatively affects the species that rely on these highly diverse and species rich areas to survive. Homogenization of previously heterogenic areas due to a change in water discharge and the substrate availability in the rivers is often regarded as the main reason for the loss of species richness in rivers and the riparian zone. Because of this, there are a lot of restoration projects which main goal is to increase heterogeneity. The goal of this thesis is to compare hydrology and geomorphology variables between four types of reaches with high flow velocity (rapids in free-flowing reaches, rapids with regulated flow, impounded reaches and reaches in outlet channels below hydropower plants). In this thesis I wanted to find out how changes in geomorphology and hydrology affect fish species richness, riparian vegetation richness and aquatic vascular plants species richness. The result show that both fish species richness and riparian vegetation species richness are negatively affected by the changes in geomorphology and hydrology. There was no significant difference for aquatic vascular plants when comparing the regulation types. The most altered reach type, outlet channels, had significantly fewer fish species compared to the less altered reach type, impounded reaches. Outlet channels also had less riparian vegetation cover compared to all other regulation types, and fewer riparian vegetation species compared to both free-flowing reaches and impounded reaches. In conclusion, hydropower plants and timber floating have both negatively impacted the riverine ecosystem, and in turn caused a decrease in species richness for fish and riparian plants. The reaches studied in this thesis will continue to be altered and the species richness and species composition will change from an ecosystem that relied on the natural flow regime to an ecosystem more used to the flow regime created by the hydropower plants. 

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  • 3.
    Aalto, Anders
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Kanalisering och restaurering av vattendrag påverkar mossamhällen i strandzonen: -En studie av Vindelälvens biflöden2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study compared three different types of reaches at streams and how bryophyte species richness, diversity and abundance in the riparian zone differ between them. The different types of reaches are those that have been treated by two types of restoration techniques (best practise and advanced) and streams that have still not been restored (channelized). The bryophytes were gathered from 15 tributaries to Vindelälven, which is in northern Sweden. Bryophyte species richness and diversity was highest at the streams that were still not restored, and I found numerous factors that could explain why this was the case. Fourteen environmental variables were tested against the three bryophyte factors to try to explain the variation found in the study. Time since restoration and the amount of tree biomass in the area could explain the species richness found at the different river types. The study shows that short-term effects of restoration on the riparian zone is a decrease in bryophyte species richness and diversity. However, given enough time the bryophytes are expected to recover in regards to species richness and diversity.

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  • 4.
    Aaro, Fredrik
    Umeå University, Faculty of Science and Technology, Umeå Institute of Design.
    En intuitiv & lättillgänglig flyktmask för gruvmiljö2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    I have always lived around mines and around people work­ing with mines. They are a natural part of my life and, inev­itably, a great interest of mine. When time came to make a decision for a degree project, focusing on the mine context felt as natural as breathing.

    In LKABs underground mines, safety in fire accidents is a great priority. Of outmost importance for the escape is to have a personal gas filter for filtration of smoke and/or gas. My design project resulted in a concept which is aimed at shortening the user journey from the start of the accident until the user has applied the personal safety solution and is ready to escape.

    Throughout the project I’ve been working with a context which is heavily regulated, and all problems are serious, important ones. I have been striving towards keeping a high level of innovation during the process, whatever the result in the end might be. I’ve been heavily relying on scenarios/workflows, product testing, observation, and I’ve had the great joy to be able to take part of LKABs accident reports.

    The concept can be divided into three parts, but it is the way these collaborate that makes out the main part of the concept.

    1: An escape station, providing a standardized placement of escape hoods.

    2: A container for the vacuum sealed escape hood.

    3: An escape hood which enables a personalized fit for the user.

    Interactive surfaces are color coded with the goal to provide an intuitive workflow. When the container is opened, the vacuum seal is immediately broken and the user gains access to two handles, one white and one red. The handles are used to lift and apply the escape hood, and the red handle is then used, by pulling, to tighten the throat fit.

    Combined, these solutions help the user applying her escape hood in shorter time, and a large head size, glasses, beard and a thick neck are no longer problematic for the applica­tion

     

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  • 5.
    Aasa, Sofia
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Designing a User Interface for a Planning Tool Powered by Artificial Intelligence2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis aimed to improve the user interface of the LAIsa planning tool for the Post Anaesthesia Care Unit (PACU) at University Hospital of Umeå, with the goal of increasing usability and intuitiveness. The tool is still under development, and the team at University Hospital of Umeå wished for a more user-friendly design, leading to this thesis collaboration. 

    Using the iterative design framework Design Thinking, a new design was developed and suggested for LAIsa. Firstly, to empathize with the users a heuristic evaluation (based on Nielsen's 10 heuristics) and interviews were conducted for the current tool. Then from the results two versions of a MidFi prototype were produced. The given feedback from the evaluation of the MidFi prototypes was used to shape the final HiFi prototype that was a proof of concept for a future interface design for LAIsa.

    The user feedback from the evaluation of the HiFi prototype highlighted a need for visual and functional refinements, including clearer color coding, consistency in naming, as well as readability of the icon sizes and symbols. However, a System Usability Scale (SUS) score averaging 83.75, indicated an overall excellent rating, though individual scores varied. In conclusion, the evaluation of the HiFi prototype showed an overall high usability, but highlighted aspects of it that could be improved.

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  • 6.
    Aavik, Ida
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Onboarding New Users for Initial Creation of Photo Book in Mobile Application2024Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Photography holds great significance by capturing memories and sharing stories. Today, the average user has around 2,000 photos on their smartphone, many of which go unnoticed. Once Upon is a mobile application launched in 2017, where users can create photo books to collect their memories in a physical book. Observations and previous data from Once Upon show that new users encounter certain challenges when creating their first photo book with the application. This has sparked interest in exploring how onboarding can be used to help new users. Onboarding is a broad term that includes introducing users to a new product or service.

    This study followed the Design Thinking process to create a prototype of an onboarding process that facilitates understanding for new users how to get started with creating their first photo book using the Once Upon mobile application. In the first phase, Empathize, research methods were conducted to identify how users interact with the Once Upon mobile application. The data was further analyzed in order to narrow down the topic and define the problems in the Define phase, employing methods such as personas, user flow diagrams and mind mapping. Subsequently, ideas began to be generated in the next phase, Ideate, where How Might We statements were formulated. These were utilized in two workshops for brainstorming, and then contributed to the initial sketching of different design proposals. The last two phases, Prototype and Test, were performed iteratively to produce prototypes and test them with usability testing.

    It was observed that new users experienced some challenges when creating a photo book for the first time in the application. Among other things, they lacked inspiration, looked in the wrong place for certain functions or did not know how to start from scratch. With this, the focus was placed on the onboarding flow being about introducing users to creating their first photo book with the Once Upon mobile application. Different strategies and types of onboarding had been analyzed, and then some that were deemed suitable for the application were chosen to proceed with. During the tests of the prototypes, a flow was finally chosen that the participants appreciated the most. The result contributed to helping new users get started and get inspired to create their first photo book with the Once Upon mobile application, through the creation of a design proposal of an onboarding process.

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  • 7. Abafe, Ovokeroye A.
    et al.
    Späth, Jana
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Buckley, Chris
    Stark, Annegret
    Pietruschka, Bjoern
    Martincigh, Bice S.
    LC-MS/MS determination of antiretroviral drugs in influents and effluents from wastewater treatment plants in KwaZulu-Natal, South Africa2018In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 200, p. 660-670Article in journal (Refereed)
    Abstract [en]

    South Africa has the largest occurrence of the human immune deficiency virus (HIV) in the world but has also implemented the largest antiretroviral (ARV) treatment programme. It was therefore of interest to determine the presence and concentrations of commonly used antiretroviral drugs (ARVDs) and, also, to determine the capabilities of wastewater treatment plants (WWTPs) for removing ARVDs. To this end, a surrogate standard based LC-MS/MS method was optimized and applied for the detection of thirteen ARVDs used in the treatment and management of HIV/acquired immune deficiency syndrome (HIV/AIDS) in two major and one modular WWTP in the eThekwini Municipality in KwaZulu-Natal, South Africa. The method was validated and the detection limits fell within the range of 2–20 ng L−1. The analytical recoveries for the ARVDs were mainly greater than 50% with acceptable relative standard deviations. The concentration values ranged from <LOD – 53000 ng L−1 (influent), <LOD – 34000 ng L−1 (effluent) in a decentralized wastewater treatment facility (DEWATS); <LOD – 24000 ng L−1 (influent), <LOD – 33000 ng L−1 (effluent) in Northern WWTP and 61–34000 ng L−1 (influent), <LOD – 20000 ng L−1 (effluent) in Phoenix WWTP. Whilst abacavir, lamivudine and zidovudine were almost completely removed from the effluents, atazanavir, efavirenz, lopinavir and nevirapine persisted in the effluents from all three WWTPs. To estimate the ecotoxicological risks associated with the discharge of ARVDs, a countrywide survey focussing on the occurrence of ARVDs in WWTPs, surface and fresh water bodies, and aquatic organisms, is necessary.

  • 8.
    Abbasi, Ahtisham Fazeel
    et al.
    German Research Center for Artificial Intelligence (DFKI), Kaiserslautern, Germany; University of Kaiserslautern-Landau, Kaiserslautern (RPTU), Germany.
    Asim, Muhammad Nabeel
    German Research Center for Artificial Intelligence (DFKI), Kaiserslautern, Germany.
    Trygg, Johan
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Sartorius Corporate Research, Sartorius Stedim Data Analytics, Umeå, Sweden.
    Dengel, Andreas
    German Research Center for Artificial Intelligence (DFKI), Kaiserslautern, Germany; University of Kaiserslautern-Landau, Kaiserslautern (RPTU), Germany.
    Ahmed, Sheraz
    German Research Center for Artificial Intelligence (DFKI), Kaiserslautern, Germany.
    Deep learning architectures for the prediction of YY1-mediated chromatin loops2023In: Bioinformatics research and applications: 19th international symposium, ISBRA 2023, Wrocław, Poland, October 9–12, 2023, proceedings / [ed] Xuan Guo; Serghei Mangul; Murray Patterson; Alexander Zelikovsky, Springer, 2023, p. 72-84Conference paper (Refereed)
    Abstract [en]

    YY1-mediated chromatin loops play substantial roles in basic biological processes like gene regulation, cell differentiation, and DNA replication. YY1-mediated chromatin loop prediction is important to understand diverse types of biological processes which may lead to the development of new therapeutics for neurological disorders and cancers. Existing deep learning predictors are capable to predict YY1-mediated chromatin loops in two different cell lines however, they showed limited performance for the prediction of YY1-mediated loops in the same cell lines and suffer significant performance deterioration in cross cell line setting. To provide computational predictors capable of performing large-scale analyses of YY1-mediated loop prediction across multiple cell lines, this paper presents two novel deep learning predictors. The two proposed predictors make use of Word2vec, one hot encoding for sequence representation and long short-term memory, and a convolution neural network along with a gradient flow strategy similar to DenseNet architectures. Both of the predictors are evaluated on two different benchmark datasets of two cell lines HCT116 and K562. Overall the proposed predictors outperform existing DEEPYY1 predictor with an average maximum margin of 4.65%, 7.45% in terms of AUROC, and accuracy, across both of the datases over the independent test sets and 5.1%, 3.2% over 5-fold validation. In terms of cross-cell evaluation, the proposed predictors boast maximum performance enhancements of up to 9.5% and 27.1% in terms of AUROC over HCT116 and K562 datasets.

  • 9. Abbasi, Arshad Mehmood
    et al.
    Khan, Mir Ajab
    Khan, Nadeem
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Shah, Munir H
    Ethnobotanical survey of medicinally important wild edible fruits species used by tribal communities of Lesser Himalayas-Pakistan2013In: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 148, no 2, p. 528-536Article in journal (Refereed)
    Abstract [en]

    Ethnopharmacological relevance: Present survey was conducted to explore ethnomedicinal uses and cultural importance of wild edible fruits species by the inhabitants of Lesser Himalayas-Pakistan. Materials and methods: Information was obtained through informed consent semi-structured interviews, questionnaires, market survey, focus group conversation, unceremonious dialogue and village walks with key informants. Cultural significance of each species was calculated based on use report by participants at each study site. Results: A total of 35 wild edible fruits belonging to 21 genera and 17 families were used for the treatment of various ailments and consumed. Rosaceae was found dominating family with (8 spp.), followed by Moraceae (6 spp.), Rhamnaceae (5 spp.), Palmae and Vitaceae (2 spp. each) and remaining families were represented by one species each. Fruits (48%) were found highly utilized plant parts, followed by leaves (34%), bark, flowers and seeds (4% each), branches, latex and roots (2% each). Water was used as a medium for preparation while milk, ghee, oil, egg and butter are used for application. Modes of preparation were fall into seven categories like fresh parts eaten raw (38%), powder (24%), decoction (20%), extract (12 %), paste (4%), juice and latex (2% each). Based on cultural important index (CI) Morus nigra was found most significant species within top ten fruit plants followed by Morus alba, Olea ferruginea, Berberis lycium, Pyrus pashia, Ficus carica, Ficus palmata, Ziziphus mauritiana, Diospyros lotus and Ziziphus nummularia. Conclusions: Traditional uses of wild edible plant depend mainly on socio-economic factors rather than climatic conditions or wealth of flora. Use reports and citation demonstrated that there is a common cultural heritage regarding the gathered food plants. Further investigation is required for Antioxidant study, essential and toxic components, pharmacological applications; dietary requirements and biotechnological techniques to improve yields.

    (C) 2013 Elsevier Ireland Ltd. All rights reserved.

  • 10.
    Abbasi, Farid
    Umeå University, Faculty of Science and Technology, Umeå School of Architecture.
    The High Garden: An architectural exploration on how to integrate vertical farming and modular architecture inside city centres2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The state of the world is changing. By 2050, The earth’s population will increase by 3 billion and building sector is asked to construct 3 billion new housing units inside urban centres. Since one of the fundamental needs is food, agriculture sector also needs to adjust itself to this growing number of people. Nevertheless, in 2019, Agriculture used 50 per cent of all earth’s habitable land and experts estimate that we need 109 hectares more land to cultivate however this amount of habitable land is approximately the land which is represented by the country of Brazil and 20 per cent more. Moreover, the Food and Agriculture Organization of the United Nations states that water use grew twice as much as population increase and agriculture already is using approximately 70 per cent of the global freshwater. At this point, experts like Professor Dickinson Despommier suggests that the only way humanity can tackle its future food safety issues is to find ways to introduce vertical farming inside Urban centres. The High Garden project is resulted by the world state today and is trying to find an architectural solution to the mentioned issues. It starts firstly by studying the issues more thoroughly and then tries to form a framework which includes and transcends them. It studies how the construction sector is acting now and how it can reorient itself to the situation whilst limiting its negative environmental impact. Then the thesis tries to understand the basics of vertical farming methods compared to the conventional geoponics farming as it is practised today and how it can integrate the better cultivation solution inside city centres. The last step of the theoretical studies of the project is to look at the history of integrated farming and EcoArchitecture. After understanding the theories of the issue, then the thesis starts to form itself as an architectural intervention using the architectural tools and methods and combining the studied disciplines. The result of the thesis is a modular configuration which can accommodate various activities such as aeroponic farming, local markets, zen areas, and drone subscription deliveries etc. Because of the modular construction of the project, it can adapt and adjust itself to different situations and it uses an algorithmic tool to analyse and study existing cities to find proper intervention points. Then it is attached to the existing buildings as a sustainable green extension solving some issues and revitalizing the dead city edges. Keywords: State of the World, rapid urbanization, population growth, geoponic agriculture, Co2 emission, greenhouse gas emission, aeroponic farming, modular architecture, sustainable architecture, EcoArchitecture

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    The High Garden: An architectural exploration on how to integrate vertical farming and modular architecture inside city centres
    Download (pdf)
    The High Garden Design Portfolio
  • 11.
    Abbasi, Jasim Aftab
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Test of Rapid Control System Development using TargetLink2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis is to employ and evaluate an evaluation board with the standard microprocessor freescale MPC5554EVB board for implementation of control algorithms which are created in Matlab/Simulink instead of using dSPACE prototyping hardware. The Simulink real-time model shall be compiled to the MPC5554EVB board. TargetLink is a powerful software tool which allows an automatic generation of efficient C code from Simulink and facilitates model-based control design. The goal of this thesis is to learn how to use TargetLink in a control design workflow from model to real code and what are the limitations of a microprocessor platform and to evaluate the capabilities of TargetLink to generate a working code for a generic microprocessor.

  • 12.
    Abbasi, Mahdi
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science. LIS UMR CNRS 7020, Aix-Marseille University, Marseille, France.
    Haghighi, Hassan
    LIS UMR CNRS 7020, Aix-Marseille University, Marseille, France.
    Benelghali, Seifeddine
    LIS UMR CNRS 7020, Aix-Marseille University, Marseille, France.
    Pour-Hosseini, Mohammad Reza
    Department of Computer Engineering, Bu-Ali Sina University, Hamedan, Iran.
    Mohammadi-Pasand, Ehsan
    Department of Computer Engineering, Bu-Ali Sina University, Hamedan, Iran.
    Javadi, Bahman
    School of Computer, Data and Mathematical Sciences, Western Sydney University, Sydney, Australia.
    Moradi, Parham
    School of Engineering, RMIT University, Melbourne, Australia.
    Efficient edge computing: harnessing compact machine learning models for workload optimization2024In: GECCO '24 Companion: proceedings of the 2024 Genetic and Evolutionary Computation Conference Companion, Association for Computing Machinery (ACM), 2024, p. 239-242Conference paper (Refereed)
    Abstract [en]

    This paper proposes an innovative lightweight workload distribution model, TinyXCS, specifically designed for traditional edge devices, emphasizing efficiency and compactness. TinyXCS, an online model based on XCS learning classifier systems, demonstrates high levels of performance in reducing delays and energy consumption. Engineered to operate efficiently on conventional edge devices, The model offers a promising solution for optimizing workload distribution while considering memory constraints. Experimental results validate effectiveness of this model, representing a significant advancement in the quest for streamlined edge computing solutions.

  • 13.
    Abbevik, Julia
    Umeå University, Faculty of Science and Technology, Umeå School of Architecture.
    A city for youths: An urban strategy to encourage and enhance existing activities and activate social space to strengthen youths leisure time in Lycksele2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    On a national scale, statistics relating to moving patterns shows that youths and young adults are the ones who tend to move the most. The case in Västerbotten is similar as in the rest of Sweden and many municipalities are experiencing a population decline. This thesis aims to look into the motives behind moving from the perspective of youths and young adults and through that propose a strategy to strengthen the place attachment youths and young adults feel to their home municipality. The research is centered around Lycksele in Västerbotten.

    The research questions that the thesis aims to seek answers for are; What could an architectural strategy that aims to support youths in their leisure time and also strengthen their connection to the area look like? and What programmatic aspects are important to consider in such a strategy?

    The thesis investigates spatial needs from the perspective of youths and young adults which have been investigated through literature studies and action based research focused on interviews and a workshop. Four themes were common in both interviews and the workshop, these were; closeness to nature, possibility of work, valuable leisure time and a sense of home. To understand how an urban strategy can respond to the themes, strategies applied in other municipalities have been analysed. A finding was that in order for strategies to attract more inhabitants, they need to have a holistic approach and offer a complete lifestyle. Creativity is a theme which came up during interviews and literature studies as a possible platform around which an area can become considered as more attractive.

    The proposal is an urban strategy which aims to respond to the common themes from interviews and the workshop by enhancing and encouraging activities taking place and activating social space. This proposal suggests a strategy which aims to strengthen the notion of sense of place to enhance place attachment and through that possibly invite more young adults to move back in the future.

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    Thesis text
  • 14.
    Abbevik, Julia
    Umeå University, Faculty of Science and Technology, Umeå School of Architecture.
    Open Music2017Independent thesis Basic level (degree of Bachelor of Fine Arts), 10 credits / 15 HE creditsStudent thesis
  • 15. Abbott, Benjamin W.
    et al.
    Jones, Jeremy B.
    Schuur, Edward A. G.
    Chapin, F. Stuart, III
    Bowden, William B.
    Bret-Harte, M. Syndonia
    Epstein, Howard E.
    Flannigan, Michael D.
    Harms, Tamara K.
    Hollingsworth, Teresa N.
    Mack, Michelle C.
    McGuire, A. David
    Natali, Susan M.
    Rocha, Adrian V.
    Tank, Suzanne E.
    Turetsky, Merritt R.
    Vonk, Jorien E.
    Wickland, Kimberly P.
    Aiken, George R.
    Alexander, Heather D.
    Amon, Rainer M. W.
    Benscoter, Brian W.
    Bergeron, Yves
    Bishop, Kevin
    Blarquez, Olivier
    Bond-Lamberty, Ben
    Breen, Amy L.
    Buffam, Ishi
    Cai, Yihua
    Carcaillet, Christopher
    Carey, Sean K.
    Chen, Jing M.
    Chen, Han Y. H.
    Christensen, Torben R.
    Cooper, Lee W.
    Cornelissen, J. Hans C.
    de Groot, William J.
    DeLuca, Thomas H.
    Dorrepaal, Ellen
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Fetcher, Ned
    Finlay, Jacques C.
    Forbes, Bruce C.
    French, Nancy H. F.
    Gauthier, Sylvie
    Girardin, Martin P.
    Goetz, Scott J.
    Goldammer, Johann G.
    Gough, Laura
    Grogan, Paul
    Guo, Laodong
    Higuera, Philip E.
    Hinzman, Larry
    Hu, Feng Sheng
    Hugelius, Gustaf
    Jafarov, Elchin E.
    Jandt, Randi
    Johnstone, Jill F.
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Kasischke, Eric S.
    Kattner, Gerhard
    Kelly, Ryan
    Keuper, Frida
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Kling, George W.
    Kortelainen, Pirkko
    Kouki, Jari
    Kuhry, Peter
    Laudon, Hjalmar
    Laurion, Isabelle
    Macdonald, Robie W.
    Mann, Paul J.
    Martikainen, Pertti J.
    McClelland, James W.
    Molau, Ulf
    Oberbauer, Steven F.
    Olefeldt, David
    Pare, David
    Parisien, Marc-Andre
    Payette, Serge
    Peng, Changhui
    Pokrovsky, Oleg S.
    Rastetter, Edward B.
    Raymond, Peter A.
    Raynolds, Martha K.
    Rein, Guillermo
    Reynolds, James F.
    Robards, Martin
    Rogers, Brendan M.
    Schaedel, Christina
    Schaefer, Kevin
    Schmidt, Inger K.
    Shvidenko, Anatoly
    Sky, Jasper
    Spencer, Robert G. M.
    Starr, Gregory
    Striegl, Robert G.
    Teisserenc, Roman
    Tranvik, Lars J.
    Virtanen, Tarmo
    Welker, Jeffrey M.
    Zimov, Sergei
    Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment2016In: Environmental Research Letters, E-ISSN 1748-9326, Vol. 11, no 3, article id 034014Article in journal (Refereed)
    Abstract [en]

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

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  • 16.
    Abd Alrahman, Chadi
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Qu, Zhechao
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Cavity-enhanced optical frequency comb spectroscopy of high-temperature H2O in a flame2014In: Optics Express, E-ISSN 1094-4087, Vol. 22, no 11, p. 13889-13895Article in journal (Refereed)
    Abstract [en]

    We demonstrate near-infrared cavity-enhanced optical frequency comb spectroscopy of water in a premixed methane/air flat flame. The detection system is based on an Er:fiber femtosecond laser, a high finesse optical cavity containing the flame, and a fast-scanning Fourier transform spectrometer (FTS). High absorption sensitivity is obtained by the combination of a high-bandwidth two-point comb-cavity lock and auto-balanced detection in the FTS. The system allows recording high-temperature water absorption spectra with a resolution of 1 GHz and a bandwidth of 50 nm in an acquisition time of 0.4 s, with absorption sensitivity of 4.2 x 10 (9) cm(-1) Hz(-1/2) per spectral element.

  • 17.
    Abdel-Fattah, Wael R.
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Carlsson, Mattias
    Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, Uppsala, Sweden.
    Hu, Guo-Zhen
    Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, Uppsala, Sweden.
    Singh, Ajeet
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Vergara, Alexander
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Aslam, Rameen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Ronne, Hans
    Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, Uppsala, Sweden.
    Björklund, Stefan
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Growth-regulated co-occupancy of Mediator and Lsm3 at intronic ribosomal protein genes2024In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 52, no 11, p. 6220-6233Article in journal (Refereed)
    Abstract [en]

    Mediator is a well-known transcriptional co-regulator and serves as an adaptor between gene-specific regulatory proteins and RNA polymerase II. Studies on the chromatin-bound form of Mediator revealed interactions with additional protein complexes involved in various transcription-related processes, such as the Lsm2–8 complex that is part of the spliceosomal U6 small nuclear ribonucleoprotein complex. Here, we employ Chromatin Immunoprecipitation sequencing (ChIP-seq) of chromatin associated with the Lsm3 protein and the Med1 or Med15 Mediator subunits. We identify 86 genes co-occupied by both Lsm3 and Mediator, of which 73 were intron-containing ribosomal protein genes. In logarithmically growing cells, Mediator primarily binds to their promoter regions but also shows a second, less pronounced occupancy at their 3́-exons. During the late exponential phase, we observe a near-complete transition of Mediator from these promoters to a position in their 3́-ends, overlapping the Lsm3 binding sites ∼250 bp downstream of their last intron–exon boundaries. Using an unbiased RNA sequencing approach, we show that transition of Mediator from promoters to the last exon of these genes correlates to reduction of both their messenger RNA levels and splicing ratios, indicating that the Mediator and Lsm complexes cooperate to control growth-regulated expression of intron-containing ribosomal protein genes at the levels of transcription and splicing.

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  • 18.
    Abdelraouf, Hussein
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    LARGE LANGUAGE MODELS ADAPTED TO SWEDISH OF THE 1920S2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Large Language Models typically perform best when there is a lot of data to train on. An interesting question is how such models perform in less dominant languages (e.g., Swedish) and over domains of historical interest where less modern words and phrasings are used. Specifically, how can existing language models for current usage be adapted to get the best question-answering results when applied over such historical domains? In this Master's thesis, we will use domain adaption on three different pre-trained Swedish NLP language models: BERT base Swedish Cased SQuAD Experimental, GPT-SW3, and IBM Watson. We will fine-tune these models on the specific domain of Vasaloppet's 100-year-old articles to evaluate if the models will have difficulties predicting results from a Swedish source that is a century old. We will evaluate how well these models perform on question answering and report results and lessons learned. 

  • 19. Abdelsalam, UM
    et al.
    Moslem, WM
    Shukla, Padma Kant
    Umeå University, Faculty of Science and Technology, Department of Physics. Institut für Theoretische Physik IV, Fakultät für Physik und Astronomie, Ruhr-Universität Bochum, D-44780 Bochum, Germany; Nonlinear Physics Centre & Center for Plasma Science and Astrophysics, Ruhr-Universität Bochum, D-44780 Bochum, Germany; Max-Planck-Institut für extraterrestrische Physik, D-85741 Garching, Germany; GoLP/Instituto Superior Técnico, 1049-001 Lisbon, Portugal; CCLRC Centre for Fundamental Physics, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon 0X11 0QX, UK; SUPA Department of Physics, University of Strathclyde, Glasgow G 40NG, UK; School of Physics, Faculty of Science & Agriculture, University of Kwazulu-Natal, Durban 4000, South Africa; Department of Physics, CITT, Islamabad, Pakistan.
    Ion-acoustic solitary waves in a dense pair-ion plasma containing degenerate electrons and positrons2008In: Physics Letters A, ISSN 0375-9601, E-ISSN 1873-2429, Vol. 372, no 22, p. 4057-4061Article in journal (Refereed)
    Abstract [en]

    Fully nonlinear propagation of ion-acoustic solitary waves in a collisionless dense/quantum electron-positron-ion plasma is investigated. The electrons and positrons are assumed to follow the Thomas-Fermi density distribution and the ions are described by the hydrodynamic equations. An energy balance-like equation involving a Sagdeev-type pseudo-potential is derived. Finite amplitude solutions are obtained numerically and their characteristics are discussed. The small-but finite-amplitude limit is also considered and an exact analytical solution is obtained. The present studies might be helpful to understand the excitation of nonlinear ion-acoustic solitary waves in a degenerate plasma such as in superdense white dwarfs.

  • 20. Abdelsalam, UM
    et al.
    Moslem, WM
    Shukla, Padma Kant
    Umeå University, Faculty of Science and Technology, Department of Physics. Institut für Theoretische Physik IV, Fakultät für Physik und Astronomie, Ruhr-Universität Bochum, D-44780 Bochum, Germany; Nonlinear Physics Centre & Center for Plasma Science and Astrophysics, Ruhr-Universität Bochum, D-44780 Bochum, Germany; Max-Planck-Institut für Extraterrestrische Physik, D-85741 Garching, Germany; GoLP/Instituto Superior Técnico, 1049-001 Lisbon, Portugal; CCLRC Centre for Fundamental Physics, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon 0X11 0QX, UK; SUPA Department of Physics, University of Strathclyde, Glasgow G 40NG, UK; School of Physics, Faculty of Science & Agriculture, University of Kwazulu-Natal, Durban 4000, South Africa; Department of Physics, CITT, Islamabad, Pakistan.
    Localized electrostatic excitations in a Thomas-Fermi plasma containing degenerate electrons2008In: Physics of Plasmas, ISSN 1070-664X, E-ISSN 1089-7674, Vol. 15, no 5, article id 052303Article in journal (Refereed)
    Abstract [en]

    By using the Thomas-Fermi electron density distribution for quantum degenerate electrons, the hydrodynamic equations for ions, and the Poisson equation, planar and nonplanar ion-acoustic solitary waves in an unmagnetized collisionless plasma are investigated. The reductive perturbation method is used to derive cylindrical and spherical Korteweg-de Vries equations. Numerical solutions of the latter are presented. The present results can be useful in understanding the features of small but finite amplitude localized ion-acoustic solitary pulses in a degenerate plasma.

  • 21.
    Abderhalden, Bigna Lu
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Seasonal Reindeer Grazing Effects on Mountain Birch Forests: A 3D Perspective using Drones2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Reindeer are important drivers of ecosystem processes in arctic and subarctic ecosystems, changing nutrient conditions and influencing vegetation by grazing and trampling. Mountain birch forests are one of the ecosystems impacted by reindeer grazing, but the effect on the 3D structure of these forests is not well understood. Drones are revolutionising ecological studies, allowing to create high-resolution 3D point clouds at low costs. I investigated the effect of year-round and autumn reindeer grazing on mountain birch forest vegetation in historically separated grazing areas at the Finnish-Norwegian border, using a combination of field data and drone data. The two sampling techniques were further compared to evaluate the possibility to use photogrammetric point clouds to characterise mountain birch forests. I found lower productivity in the year-round grazing regime, coinciding with generally higher vegetation density. Vertically, higher densities were found above browsing height, while the understory showed lower densities compared to autumn grazed areas. These results suggest that mountain birches allocate more biomass to the canopy area, which can be direct or indirect grazing effects. Nevertheless, overall productivity is lowered by grazing indicating changes in vegetation biomass and composition. The point clouds generally matched field data, but the understory vegetation tended to be underrepresented, arising the question if found effects are ecological or technical. As this could not be disentangled, cautious interpretation of my results is required. I conclude that using photogrammetric point clouds is a promising technique for ecological studies, but needs further development to improve accuracy and reliability of results.

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  • 22.
    Abdipour, Morteza
    Umeå University, Faculty of Science and Technology, Umeå Institute of Design.
    Arrangement Design Studies: the introduction of the digital wall in domestic environments2021Licentiate thesis, monograph (Other academic)
    Abstract [en]

    This research focuses on the emergence of 'digital walls' that can project images onto almost all or even the entirety of interior (and perhaps exterior) walls, and what implications this might have for how we arrange our rooms. It demonstrates the arrangement, i.e., the way that domestic products are arranged physically, of rooms changes in the domestic environment in a complex scenario when using large screens. Due to the fast-growing demand for large screens, this product could potentially be available to be used by people in their home environments; however, it does not yet exist in reality at this scale. Constructing large screens can be carried out using different production methods. Here, this concept is called the digital wall, a very thin wall-sized interactive screen. The characteristics of the digital wall will vary to be able to create different scenarios. One such scenario is a space in the home where the surface of the wall is covered with screens, which allows multiple possibilities to experience and interact with digital content. 

    In this research, the social gathering space of homes, nowadays called the living room, is considered as a highly relevant space for installing the digital wall. In this space, the conceptual framework outlines the basic elements of the research and demonstrates the relationships between people’s interactions with the digital wall and domestic products in the domestic environment. I show two examples from design history to understand how arrangement changes impact the home environment: the transformation of the parlor to the living room, and entry of the television into the living room. These two examples are focused on the place in the home where people gather for socializing. The discussion of these examples led to the elaboration of the relationships between the elements in the conceptual framework.

    I explored relevant design research methodologies to bring this future scenario into the present to understand the relationships between people and the digital wall. I applied research through design and the constructive design research approaches to frame the design research methodology. In this thesis, I set up seven series of design studies in two cluster groups: Supportive studies and Main studies. All of the design studies were conducted in the Design Research Lab, the actual space for carrying out the design experiments, prototyping the digital wall, and the setting of the experiments for user participation. The Lab was fully equipped with relevant technology and allowed me to use multiple methods to collect data while people were experiencing the design study sessions. The Lab was useful as a platform to understand user experiences, barriers for interactions as well as people's experiences in a simulated space of a domestic environment. 

    The main contribution of this research is to understand the forms of arrangement changes when people use the digital wall in homes. The research demonstrates two significant implications that are seen in two forms of arrangements: tangible arrangement and imperceptible arrangement. These findings are useful for both designers and users of the elements of domestic contexts and the relations that can be shaped by the presence of a digital wall in home environments. This understanding may provide design guidelines in future scenarios in which the digital wall is used in homes. The findings are also beneficial for designing the domestic environment, improving the arrangement of space, and raising the requirements for designing domestic products.

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  • 23.
    Abdollahi, Elham
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Development of breath sampling system for detection of exhaled nitric oxide by Faraday modulation spectroscopy2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Technological developments over the years have resulted in many different techniques for detection of nitric oxide (NO) in both the atmosphere and from biological sources. One such technique is Faraday Modulation Spectroscopy (FAMOS), which is a laser-based spectroscopic technique for detection of paramagnetic molecules in gas phase. The technique uses a modulated magnetic field that introduce rotation of the polarization plane of linearly polarized laser light, which can be related to the concentration of the molecules. This enables sensitive and selective detection of paramagnetic gaseous compounds and the technique is thus well suited for detection of NO for biomedical applications in low concentrations which is essential for breath analysis.

    In this thesis, a system for breath analysis is developed and coupled to a Faraday modulation spectrometer for sensitive detection of NO at 5.33 μm based on a room temperature continuous wave distributed feedback (DFB) QCL. It also provides a theoretical model of FAMOS utilizing the most sensitive Q3/2 (3/2 ) transition in NO. The results from this study indicate that the mid-infrared FAMOS system, which was built around a continuous wave (cw) quantum cascade laser (QCL) emitting light with an output power of approximately 70 mW, is fully capable of detection of ppb levels of NO in exhaled human breath.

  • 24.
    Abdollahi, Elham
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Realization of an instrumentation for detection of acetylene in breath by the NICE-OHMS technique2014Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Measurement is an important activity in nearly all branches of science and technology. A measurement technique provides an observer with a numerical value corresponding to the variable being measured. Researchers envision that laser spectroscopy will serve as a functional tool for measurement to detect molecules in gas phase. One such a laser spectroscopic technique for measurement is noise-immune cavity enhanced optical heterodyne molecular spectroscopy (NICE-OHMS), which is a highly sensitive laser-based spectroscopic technique for detection of molecules in gas phase. The technique was developed in the mid-1990s at the Joint Institute for Laboratory Astrophysics (JILA).

    In this thesis, a realization of instrumentation for detection of acetylene in breath by a fiber laser-based NICE-OHMS instrumentation working in the near-infrared wavelength region is obtained. The results of this study show that the NICE-OHMS system is fully capable of detection of parts-per-billion (ppb) levels of acetylene in exhaled human breath.

  • 25.
    Abdollahian, Josef
    et al.
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Kanwar, Anna
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Optimering av kortaste vägen vid hantering och avledning av skadligt dagvatten: Lösning med A-stjärna algoritm samt en guide med ekonomiska styrmedel för beslutsfattande aktörer2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The earth's population is growing and increasingly more people move into urban areas. This means that as cities grow, new buildings are being built and infrastructures are expanding. This rapid growth is directly related to increased floods as a result of man-made changes in nature.

    The already overloaded storm water systems for rain-, melt-, rinsing and other surplus water cannot often handle the existing demand. Therefore, floods arise at greater rain intensity and pose significant costs to society. Due to an unclear division of responsibility within the municipality's organizations there is a failure to handle the existing storm water problem. In order to be able to plan for sustainable cities in the future, it is important to find a viable solution regarding the responsibility issue and how to best handle the storm water to achieve cost advantage.

    This study presents a guide for municipalities on how to allocate the responsibility between the municipality and the exploiter. The guide is based on simulations and theories in optimization to propose effective solutions for harmful surplus storm water. Through simulations of the storm water system, the amount of surplus water that does not fit the storm water system capacity has been quantified. In addition, to find a reasonable alternative run-off path for the surplus water, different methods of the shortest path problem have been investigated.

    The results show that a classical shortest path algorithm with a heuristic function is not the most appropriate alternative. This because the heuristic function in the algorithm prevents the selection of a more natural pathway upstream even though it could be a more optimal solution.

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    Optimering av kortaste vägen vid hantering och avledning av skadligt dagvatten
  • 26. Abdoullaye, Doukary
    et al.
    Acevedo, I
    Adebayo, Abisola A
    Behrmann-Godel, Jasminca
    Benjamin, RC
    Bock, Dan G
    Born, Celine
    Brouat, Carine
    Caccone, Adalgisa
    Cao, Ling-Zhen
    Casadoamezua, P
    Cataneo, J
    Correa-Ramirez, MM
    Cristescu, Melania E
    Dobigny, Gauthier
    Egbosimba, Emmanuel E
    Etchberger, Lianna K
    Fan, Bin
    Fields, Peter D
    Forcioli, D
    Furla, P
    de Leon, FJ Garcia
    Garcia-Jimenez, R
    Gauthier, Philippe
    Gergs, Rene
    Gonzalez, Clementina
    Granjon, Laurent
    Gutierrez-Rodriguez, Carla
    Havill, Nathan P
    Helsen, P
    Hether, Tyler D
    Hoffman, Eric A
    Hu, Xiangyang
    Ingvarsson, Pär K
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Ishizaki, S
    Ji, Heyi
    Ji, XS
    Jimenez, ML
    Kapil, R
    Karban, R
    Keller, Stephen R
    Kubota, S
    Li, Shuzhen
    Li, Wansha
    Lim, Douglas D
    Lin, Haoran
    Liu, Xiaochun
    Luo, Yayan
    Machordom, A
    Martin, Andrew P
    Matthysen, E
    Mazzella, Maxwell N
    McGeoch, Melodie A
    Meng, Zining
    Nishizawa, M
    O'Brien, Patricia
    Ohara, M
    Ornelas, Juan Francisco
    Ortu, MF
    Pedersen, Amy B
    Preston, L
    Ren, Qin
    Rothhaupt, Karl-Otto
    Sackett, Loren C
    Sang, Qing
    Sawyer, GM
    Shiojiri, K
    Taylor, Douglas R
    van Dongen, S
    van Vuuren, Bettine Jansen
    Vandewoestijne, S
    Wang, H
    Wang, JT
    Wang, Le
    Xu, Xiang-Li
    Yang, Guang
    Yang, Yongping
    Zeng, YQ
    Zhang, Qing-Wen
    Zhang, Yongping
    Zhao, Y
    Zhou, Yan
    Permanent genetic resources added to molecular ecology resources database 1 August 2009 - 30 September 20092010In: Molecular Ecology Resources, ISSN 1755-098X, E-ISSN 1755-0998, Vol. 10, no 1, p. 232-236Article in journal (Refereed)
    Abstract [en]

    This article documents the addition of 238 microsatellite marker loci and 72 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Adelges tsugae, Artemisia tridentata, Astroides calycularis, Azorella selago, Botryllus schlosseri, Botrylloides violaceus, Cardiocrinum cordatum var. glehnii, Campylopterus curvipennis, Colocasia esculenta, Cynomys ludovicianus, Cynomys leucurus, Cynomys gunnisoni, Epinephelus coioides, Eunicella singularis, Gammarus pulex, Homoeosoma nebulella, Hyla squirella, Lateolabrax japonicus, Mastomys erythroleucus, Pararge aegeria, Pardosa sierra, Phoenicopterus ruber ruber and Silene latifolia. These loci were cross-tested on the following species: Adelges abietis, Adelges cooleyi, Adelges piceae, Pineus pini, Pineus strobi, Tubastrea micrantha, three other Tubastrea species, Botrylloides fuscus, Botrylloides simodensis, Campylopterus hemileucurus, Campylopterus rufus, Campylopterus largipennis, Campylopterus villaviscensio, Phaethornis longuemareus, Florisuga mellivora, Lampornis amethystinus, Amazilia cyanocephala, Archilochus colubris, Epinephelus lanceolatus, Epinephelus fuscoguttatus, Symbiodinium temperate-A clade, Gammarus fossarum, Gammarus roeselii, Dikerogammarus villosus and Limnomysis benedeni. This article also documents the addition of 72 sequencing primer pairs and 52 allele specific primers for Neophocaena phocaenoides.

  • 27.
    Abdulhussein, Saba
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education.
    Cell- och molekylärbiologi i läromedlen - En läromedelsanalys av två läromedel i biologiämnet2020Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna studie innefattar en läromedelsanalys av två läromedel i biologiämnet. Syftet med studien är att undersöka huruvida läromedlen följer det centrala innehållet i kunskapsområdet cell- och molekylärbiologi. Därutöver ämnar studien undersöka om läromedlen bidrar till att utveckla elevers kunskaper och förmågor som återfinns ämnesplanen. Studien omfattar en innehållsanalys enligt Blooms reviderade taxonomi och diskuterar frågeställningarna I vilken utsträckning följer läromedlen det centrala innehållet i kunskapsområdet cell- och molekylärbiologi? samt I vilken utsträckning bidrar läromedlen till att utveckla? diskuteras. Resultaten visar att de två läromedlen följer det centrala innehållet och bidrar till att utveckla kunskaper och förmågor i varierande grad. Ett läromedel är kopplat till det centrala innehållet i hög grad då det fokuserar på att förmedla cell- och molekylärbiologi samt bidrar till att eleverna utvecklar relevanta kunskaper och förmågor. Det andra läromedlet är endast delvis kopplat till ämnesplanen. Studien påvisar att läromedel som påstår att de uppfyller läroplanen inte alltid gör det. Således diskuterar studien vikten av att läromedel kvalitetsgranskas.

  • 28.
    Abduljalel, Viyan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Improving post-productionfeedback process2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The process of producing entertaining video and films is complicated and time consuming. One of the complicated parts of post-production of entertaining content is getting feedback and reviewing the draft edit. After the filming process of a series or a film completed, the editors start working on the cut materials. This is a stage in the process where the editor will get their cut reviewed and receive feedback from different teams on the rough-cut or editor cuts. Today the review and the feedback between the editor and reviewer is done online directly through email.

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  • 29.
    Abdulkader, Ammar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förseningar i byggprojektering och hur de kan förebyggas2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Idag är förseningar inom byggbranschen vanliga och orsakar problem och konsekvenser i byggprojekt. När ett projekt blir försenat uppstår extra kostnader för projektägaren, entreprenören eller båda parter. Med andra ord innebär förseningar ekonomiska förluster och skapar en stressig arbetsmiljö för alla inblandade aktörer och projektmedlemmar. I detta examensarbete identifieras betydande risker som kan orsaka förseningar i projekteringsfasen av byggprocessen, samt presenteras lösningar för att förebygga dem.

    Byggprocessen består av fyra faser: förstudie, projektering, produktion och överlämning. Projekteringsfasen är ett av de viktigaste stegen i byggprocessen och har stor betydelse för att förebygga förseningar. I denna fas utformas och ritas byggnader, och bygghandlingar tas fram med konstruktionsritningar, tekniska lösningar och beskrivningar upprättas för att styra hela byggprocessen.

    Detta arbete fokuserar på förseningar i själva projekteringsfasen och dess påverkan på hela projektet, samt hur de kan förebyggas. Arbetet består av en teoretisk och en praktisk del. Syftet med arbetet är att undersöka orsakerna till förseningar inom projekteringsfasen och att hantera dem på bästa sätt genom att utveckla riskhanteringen. Orsakerna kan vara ofullständig information, förändringar i projektspecifikationer och tekniska problem. Teorin bygger på litteratur om projektering i byggprocessen för att ge en bred kunskapsbas om projektering innan den praktiska delen genomförs. Den praktiska delen baseras på intervjuer med erfarna projektledare inom projektering som har varit involverade i olika försenade projekteringsprocesser. Resultatet presenterar projektledarens svar angående orsakerna till förseningarna i de två projekten. I diskussionen jämförs och analyseras resultaten med teorin, vilket visar att sjukdomar och bristande kommunikation, tillsammans med andra risker, kan vara orsaker till förseningar i projekteringsfasen. Förbättringsförslag inkluderar att skapa en trygg och hälsosam arbetsmiljö som en viktig faktor för projektets framgång, genom att anlita ytterligare konsulter från andra företag vid arbetsbelastning och erbjuda avkopplande aktiviteter som exempelvis spa-besök när det behövs. Andra förslag innefattar att lägga extra tid på riskanalys för att identifiera potentiella problem samt att etablera en kommunikationsmetod för grupper, såsom en grupp på Messenger eller en annan applikation, där all information om projektet regelbundet delas.

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  • 30. Abdulla, Parosh Aziz
    et al.
    Högberg, Johanna
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Kaati, Lisa
    Bisimulation minimization of tree automata2007In: International Journal of Foundations of Computer Science, ISSN 0129-0541, Vol. 18, no 4, p. 699-713Article in journal (Refereed)
    Abstract [en]

    We extend an algorithm by Paige and Tarjan that solves the coarsest stable refinement problem to the domain of trees. The algorithm is used to minimize nondeterministic tree automata (NTA) with respect to bisimulation. We show that our algorithm has an overall complexity of $O(\hat{r} m \log n)$, where $\hat{r}$ is the maximum rank of any symbol in the input alphabet, m is the total size of the transition table, and n is the number of states.

  • 31. Abdulla, Parosh Aziz
    et al.
    Katti, Lisa
    Högberg, Johanna
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Bisimulation minimization of tree automata2006In: Implementation and Application of Automata : 11th International Conference, CIAA 2006, 2006, p. 699-713Conference paper (Refereed)
    Abstract [en]

    We extend an algorithm by Paige and Tarjan that solves the coarsest stable refinement problem to the domain of trees. The algorithm is used to minimize nondeterministic tree automata (NTA) with respect to bisimulation. We show that our algorithm has an overall complexity of O ((r) over cap log n), where (r) over cap is the maximum rank of any symbol in the input alphabet, m is the total size of the transition table, and n is the number of states.

  • 32. Abdullah, Muhammad Imran
    et al.
    Janjua, Muhammad Ramzan Saeed Ashraf
    Mahmood, Asif
    Ali, Sajid
    Ali, Muhammad
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Quantum Chemical Designing of Efficient Sensitizers for Dye Sensitized Solar Cells2013In: Bulletin of the Korean Chemical Society (Print), ISSN 0253-2964, E-ISSN 1229-5949, Vol. 34, no 7, p. 2093-2098Article in journal (Refereed)
    Abstract [en]

    Density functional theory (DFT) was used to determine the ground state geometries of indigo and new design dyes (IM-Dye-1 IM-Dye-2 and IM-Dye-3). The time dependant density functional theory (TDDFT) was used to calculate the excitation energies. All the calculations were performed in both gas and solvent phase. The LUMO energies of all the dyes were above the conduction band of TiO2, while the HOMOs were below the redox couple (except IM-Dye-3). The HOMO-LUMO energy gaps of new design dyes were smaller as compared to indigo. All new design dyes were strongly red shifted as compared to indigo. The improved light harvesting efficiency (LHE) and free energy change of electron injection Delta G(inject) of new designed sensitizers revealed that these materials would be excellent sensitizers. The broken coplanarity between the benzene near anchoring group having LUMO and the last benzene attached to TPA unit in all new design dyes consequently would hamper the recombination reaction. This theoretical designing will the pave way for experimentalists to synthesize the efficient sensitizers for solar cells.

  • 33.
    Abdullah, Sarwin
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Low-energy radar for handheld IR-cameras: Using mmWave radar as a complement for Multi Spectral Dynamic Imaging in handheld cameras2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this project is to assess whether a low energy radar, more specifically the mmWave radar from Acconer could be used as a complement to the handheld cameras from FLIR, in order to improve its performance, in particular the alignment of visual and infra-red image. The specific camera used for this project is a FLIR C5 IR-camera. It was found that if the distance is known, then one could align the images more easily and by the help of the radar this could occur automatically instead of doing it manually as it is implemented today. 

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  • 34.
    Abdullatif, Zina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjuksköterskors bidrag till farmakovigilans arbete i Sverige En retrospektiv analys av alla sjuksköterskors biverkningsrapporter år 2015: En retrospektiv analys av alla sjuksköterskors biverkningsrapporter år 20152016Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
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  • 35.
    Abed, Ahmed Ghafel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering vid renovering av Lamellhus på Mariehemsvägen2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden more houses than ever before are being built, and the house production is moving forward. At the same time, awareness of the energy use of buildings and its accompanying impacts on climate and sustainability are increasing. Therefore, Boverket constantly raises the demands for the energy performance of newly built and refurbished buildings.

    According to current requirements from Boverket (BBR, 2017), the primary energy value for apartment buildings may not be more than 85 kWh per square meter of tempered floor space and year. This also applies according to future requirements in 2021, but with the difference that the average U-value will decrease from 0.4 to 0.35 W/m2 K which means that apartment buildings must be built in an efficient way to reduce energy use. A large part of new construction and newly refurbished apartment buildings must then implement energy efficiency measures on their buildings to meet future requirements.

    This degree project has been carried out in collaboration with Rikshem AB who wants to investigate the impact of various energy efficiency measures on their apartment building ”Lamellhus”. The aim is to theoretically reduce apartment buildings ”Lamellhusets” specific energy use from 187,4 to 70 kWh/m2 Atemp, year and thus reduce the primary energy enough to meet future requirements according to BBR near-zero energy building.

    To theoretically reduce specific energy use and thus primary energy value, the project through manual calculations and with the help of computer tools examined various energy efficiency measures on the building's construction and installation system.

    The results show that the measures on the property climate shell are sufficient to meet the requirements. If all the measures according to package 1 or 2 on the design are combined, specific energy use according to BBR 16 (2010) will be at 83-94 kWh/m2 Atemp, year and the primary energy value according to BBR 25 (2017) will be at 68-77 kWh/m2 Atemp, year.

    The results also show how much of a building's energy use is ventilated. Replacing the ventilation system from F-systems to FTX-systems on the reference house in the base case, is the measure that gives one of the greatest impacts with a heat saving of (25.5-26.7%). In combination FTX-system with district heating, specific energy consumption can be reduced as low as possible. If the operation with the FTX-system is applied together with the existing district heating and all measures on the construction according to package 1 or 2, this gives a reduction of approximately (70-75 %) compared to the base case corresponding to 42-51 kWh/m2 Atemp, year according to BBR 16 and according to BBR 25, the figures are even lower. If the calculation considers thermal bridges and air leakage in the house, the result will increase.

    The results also show that the investment repays itself after 15-16 years with a simplified payback. With a calculation rate of 5 %, it is profitable over 30-31 years or more, but with a calculation rate of 8 % it is not profitable.

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    Energieffektivisering vid renovering av Lamellhus på Mariehemsvägen
  • 36.
    Abed, Shahla
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Läkemedel mot Bcl-2 överuttryckande resistenta Prostatatumörer: Läkemedel mot Bcl-2 överuttryckande resistenta Prostatatumörer2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 37.
    Abedan Kondori, Farid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Bring Your Body into Action: Body Gesture Detection, Tracking, and Analysis for Natural Interaction2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Due to the large influx of computers in our daily lives, human-computer interaction has become crucially important. For a long time, focusing on what users need has been critical for designing interaction methods. However, new perspective tends to extend this attitude to encompass how human desires, interests, and ambitions can be met and supported. This implies that the way we interact with computers should be revisited. Centralizing human values rather than user needs is of the utmost importance for providing new interaction techniques. These values drive our decisions and actions, and are essential to what makes us human. This motivated us to introduce new interaction methods that will support human values, particularly human well-being.

    The aim of this thesis is to design new interaction methods that will empower human to have a healthy, intuitive, and pleasurable interaction with tomorrow’s digital world. In order to achieve this aim, this research is concerned with developing theories and techniques for exploring interaction methods beyond keyboard and mouse, utilizing human body. Therefore, this thesis addresses a very fundamental problem, human motion analysis.

    Technical contributions of this thesis introduce computer vision-based, marker-less systems to estimate and analyze body motion. The main focus of this research work is on head and hand motion analysis due to the fact that they are the most frequently used body parts for interacting with computers. This thesis gives an insight into the technical challenges and provides new perspectives and robust techniques for solving the problem.

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  • 38.
    Abedan Kondori, Farid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Human Motion Analysis for Creating Immersive Experiences2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    From an early age, people display the ability to quickly and effortlessly interpret the orientation and movement of human body parts, thereby allowing one to infer the intentions of others who are nearby and to comprehend an important nonverbal form of communication. The ease with which one accomplishes this task belies the difficulty of a problem that has challenged computational systems for decades, human motion analysis.

    Technological developments over years have resulted into many systems for measuring body segment positions and angles between segments. In these systems human body is typically considered as a system of rigid links connected by joints. The motion is estimated by the use of measurements from mechanical, optical, magnetic, or inertial trackers. Among all kinds of sensors, optical sensing encompasses a large and varying collection of technologies.

    In a computer vision context, human motion analysis is a topic that studies methods and applications in which two or more consecutive images from an image sequences, e.g. captured by a video camera, are processed to produce information based on the apparent human body motion in the images.

    Many different disciplines employ motion analysis systems to capture movement and posture of human body for applications such as medical diagnostics, virtual reality, human-computer interaction etc.

    This thesis gives an insight into the state of the art human motion analysissystems, and provides new methods for capturing human motion.

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  • 39.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Liu, Li
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    3D Active Human Motion Estimation for Biomedical Applications2012In: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer Berlin/Heidelberg, 2012, , p. 4p. 1014-1017Conference paper (Refereed)
    Abstract [en]

    Movement disorders forbid many people from enjoying their daily lives. As with other diseases, diagnosis and analysis are key issues in treating such disorders. Computer vision-based motion capture systems are helpful tools for accomplishing this task. However Classical motion tracking systems suffer from several limitations. First they are not cost effective. Second these systems cannot detect minute motions accurately. Finally they are spatially limited to the lab environment where the system is installed. In this project, we propose an innovative solution to solve the above-mentioned issues. Mounting the camera on human body, we build a convenient, low cost motion capture system that can be used by the patient while practicing daily-life activities. We refer to this system as active motion capture, which is not confined to the lab environment. Real-time experiments in our lab revealed the robustness and accuracy of the system.

  • 40.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Smart Baggage in Aviation2011In: 2011 IEEE International Conferences on Internet of Things, and Cyber, Physical and Social Computing / [ed] Feng Xia, Zhikui Chen, Gang Pan, Laurence T. Yang, and Jianhua Ma, Los Alamitos: IEEE Computer Society, 2011, p. 620-623Conference paper (Refereed)
    Abstract [en]

    Nowadays, the Internet has dramatically changed the way people take the normal course of actions. By the recent growth of the Internet, connecting different objects to users through mobile phones and computers is no longer a dream. Aviation industry is one of the areas which have a strong potential to benefit from the Internet of Things. Among many problems related to air travel, delayed and lost luggage are the most common and irritating. Therefore, this paper suggests anew baggage control system, where users can simply track their baggage at the airport to avoid losing them. Attaching a particular pattern on the bag, which can be detected and localized from long distance by an ordinary camera, users are able to track their baggage. The proposed system is much cheaper than previous implementations and does not require sophisticated equipment.

  • 41.
    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.
    Kouma, Jean-Paul
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    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.
    Direct hand pose estimation for immersive gestural interaction2015In: Pattern Recognition Letters, ISSN 0167-8655, E-ISSN 1872-7344, Vol. 66, p. 91-99Article in journal (Refereed)
    Abstract [en]

    This paper presents a novel approach for performing intuitive gesture based interaction using depth data acquired by Kinect. The main challenge to enable immersive gestural interaction is dynamic gesture recognition. This problem can be formulated as a combination of two tasks; gesture recognition and gesture pose estimation. Incorporation of fast and robust pose estimation method would lessen the burden to a great extent. In this paper we propose a direct method for real-time hand pose estimation. Based on the range images, a new version of optical flow constraint equation is derived, which can be utilized to directly estimate 3D hand motion without any need of imposing other constraints. Extensive experiments illustrate that the proposed approach performs properly in real-time with high accuracy. As a proof of concept, we demonstrate the system performance in 3D object manipulation On two different setups; desktop computing, and mobile platform. This reveals the system capability to accommodate different interaction procedures. In addition, a user study is conducted to evaluate learnability, user experience and interaction quality in 3D gestural interaction in comparison to 2D touchscreen interaction.

  • 42.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Direct three-dimensional head pose estimation from Kinect-type sensors2014In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 50, no 4, p. 268-270Article in journal (Refereed)
    Abstract [en]

    A direct method for recovering three-dimensional (3D) head motion parameters from a sequence of range images acquired by Kinect sensors is presented. Based on the range images, a new version of the optical flow constraint equation is derived, which can be used to directly estimate 3D motion parameters without any need of imposing other constraints. Since all calculations with the new constraint equation are based on the range images, Z(xyt), the existing techniques and experiences developed and accumulated on the topic of motion from optical flow can be directly applied simply by treating the range images as normal intensity images I(xyt). In this reported work, it is demonstrated how to employ the new optical flow constraint equation to recover the 3D motion of a moving head from the sequences of range images, and furthermore, how to use an old trick to handle the case when the optical flow is large. It is shown, in the end, that the performance of the proposed approach is comparable with that of some of the state-of-the-art approaches that use range data to recover 3D motion parameters.

  • 43.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Gesture Tracking for 3D Interaction in Augmented Environments2011Conference paper (Other academic)
  • 44.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Real 3D Interaction Behind Mobile Phones for Augmented Environments2011In: 2011 IEEE International Conference on Multimedia and Expo (ICME), IEEE conference proceedings, 2011, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Number of mobile devices such as mobile phones or PDAs has been dramatically increased over the recent years. New mobile devices are equipped with integrated cameras and large displays which make the interaction with device easier and more efficient. Although most of the previous works on interaction between humans and mobile devices are based on 2D touch-screen displays, camera-based interaction opens a new way to manipulate in 3D space behind the device in the camera's field of view. This paper suggests the use of particular patterns from local orientation of the image called Rotational Symmetries to detect and localize human gesture. Relative rotation and translation of human gesture between consecutive frames are estimated by means of extracting stable features. Consequently, this information can be used to facilitate the 3D manipulation of virtual objects in various applications in mobile devices.

  • 45.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sonning, Samuel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sonning, Sabina
    3D Head Pose Estimation Using the Kinect2011Conference paper (Refereed)
    Abstract [en]

    Head pose estimation plays an essential role for bridging the information gap between humans and computers. Conventional head pose estimation methods are mostly done in images captured by cameras. However accurate and robust pose estimation is often problematic. In this paper we present an algorithm for recovering the six degrees of freedom (DOF) of motion of a head from a sequence of range images taken by the Microsoft Kinectfor Xbox 360. The proposed algorithm utilizes a least-squares minimization of the difference between themeasured rate of change of depth at a point and the rate predicted by the depth rate constraint equation. We segment the human head from its surroundings and background, and then we estimate the head motion. Our system has the capability to recover the six DOF of the head motion of multiple people in one image. Theproposed system is evaluated in our lab and presents superior results.

  • 46.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Liu, Li
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Active human gesture capture for diagnosing and treating movement disorders2013Conference paper (Other academic)
    Abstract [en]

    Movement disorders prevent many people fromenjoying their daily lives. As with other diseases, diagnosisand analysis are key issues in treating such disorders.Computer vision-based motion capture systems are helpfultools for accomplishing this task. However Classical motiontracking systems suffer from several limitations. First theyare not cost effective. Second these systems cannot detectminute motions accurately. Finally they are spatially limitedto the lab environment where the system is installed. In thisproject, we propose an innovative solution to solve the abovementionedissues. Mounting the camera on human body, webuild a convenient, low cost motion capture system that canbe used by the patient in daily-life activities. We refer tothis system as active motion capture, which is not confinedto the lab environment. Real-time experiments in our labrevealed the robustness and accuracy of the system.

    Download full text (pdf)
    Active Human Gesture Capture for Diagnosing and Treating Movement Disorders
  • 47.
    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.

  • 48.
    Abedan Kondori, Farid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Yousefi, Shahrouz
    Ostovar, Ahmad
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Liu, Li
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    A Direct Method for 3D Hand Pose Recovery2014In: 22nd International Conference on Pattern Recognition, 2014, p. 345-350Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel approach for performing intuitive 3D gesture-based interaction using depth data acquired by Kinect. Unlike current depth-based systems that focus only on classical gesture recognition problem, we also consider 3D gesture pose estimation for creating immersive gestural interaction. In this paper, we formulate gesture-based interaction system as a combination of two separate problems, gesture recognition and gesture pose estimation. We focus on the second problem and propose a direct method for recovering hand motion parameters. Based on the range images, a new version of optical flow constraint equation is derived, which can be utilized to directly estimate 3D hand motion without any need of imposing other constraints. Our experiments illustrate that the proposed approach performs properly in real-time with high accuracy. As a proof of concept, we demonstrate the system performance in 3D object manipulation. This application is intended to explore the system capabilities in real-time biomedical applications. Eventually, system usability test is conducted to evaluate the learnability, user experience and interaction quality in 3D interaction in comparison to 2D touch-screen interaction.

  • 49.
    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%.

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  • 50.
    Abedin, Reaz Ashraful
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Autonomous Object Category Learning for Service Robots Using Internet Resources2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the developments in the field of Artificial Intelligence (AI), robots are becoming smarter, more efficient and capable of doing more dififcult tasks than before. Recent progress in Machine Learning has revolutionized the field of AI. Rather than performing pre-programmed tasks, nowadays robots are learning things, and becoming more autonomous along the way. However, in most of the cases, robots need a certain level of human assistance to learn something. To recognize or classify daily objects is a very important skill that a service robot should possess. In this research work, we have implemented a fully autonomous object category learning system for service robots, where the robot uses internet resources to learn object categories. It gets the name of an unknown object by performing reverse image search in the internet search engines, and applying a verification strategy afterwards. Then the robot retrieves a number of images of that object from internet and use those to generate training data for learning classifiers. The implemented system is tested in actual domestic environment. The classification performance is examined against some object categories from a benchmark dataset. The system performed decently with 78:40% average accuracy on ve object categories taken from the benchmark dataset and showed promising results in real domestic scenarios. There are existing research works that deal with object category learning for robots using internet images. But those works use Human-in-the-loop models, where humans assist the robot to get the object name for using it as a search cue to retrieve training images from internet. Our implemented system eliminates the necessity of human assistance by making the task of object name determination automatic. This facilitates the whole process of learning object categories with full autonomy, which is the main contribution of this research.

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