| 1. |
- Aasmundtveit, K.E., et al.
(author)
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Structural anisotropy of poly(alkylthiophene) films
- 2000
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In: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 33:8, s. 3120-3127
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Journal article (peer-reviewed)abstract
- The structural anisotropy of various poly(alkylthiophene) films have been studied by X-ray diffraction, using both conventional methods and synchrotron radiation at grazing incidence. Solution-cast films orient with the side chains preferably normal to the film surface, whereas spin-cast films of nonstereoregular material orient with both the main and the side chains in the film plane. For thick (10-50 µm) solution-cast films, the degree of orientation depends strongly on the solvent used for casting, and on the stereoregularity of the polymer, films of stereoregular materials being more oriented than those of nonregular materials. The most oriented nonregular films are those cast from mixtures of chloroform and tetrahydrofuran. Thin (50-500 nm) solution-cast films are more oriented than the thicker ones, and the effects of different stereoregularity or different casting solvents are small. For spin-cast films, the degree of orientation is independent of substrate and solvent. Spin-cast films of stereoregular material have two different phases: One with the side chains normal to the substrate, and another where they are parallel to the substrate. The diffraction peaks of spin-cast poly(octylthiophene) narrow considerably upon heating.
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| 2. |
- Aljumaili, Mustafa, et al.
(author)
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Quality of Streaming Data in Condition Monitoring Using ISO 8000
- 2016
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In: Current Trends in Reliability, Availability, Maintainability and Safety. - Cham : Encyclopedia of Global Archaeology/Springer Verlag. - 9783319235967 - 9783319235974 ; , s. 703-715
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Conference paper (peer-reviewed)abstract
- The purpose of this paper is to propose a Data Quality Measurement Model based on ISO 8000 standard. This paper deals about the concepts implied in the measurement process, not about the measures themselves. Poor quality information causes customer dissatisfaction, lost revenue and higher costs associated with additional time to reconcile information. An understanding of the characteristics of the data that determine its quality, and an ability to measure, manage and report on data quality is required. Measurement is a major activity in data quality management. In literature, there are many proposals contributing somehow to the measurement of data quality. However, these measurement methods lack the unification. ISO 8000 provides a framework for improving data quality that can be used independently or in conjunction with quality management systems. ISO 8000 defines characteristics that can be tested by any organization in the data supply chain to objectively determine conformance of the data to ISO 8000.
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| 4. |
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| 5. |
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| 6. |
- Andersson, Mats, 1957
(author)
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Pseudomeromorphic currents on subvarieties
- 2016
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In: Complex Variables and Elliptic Equations. - : Informa UK Limited. - 1747-6933 .- 1747-6941. ; 61:11, s. 1533-1540
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Journal article (peer-reviewed)abstract
- Let i : X --> Y be pure-dimensional reduced subvariety of a smooth manifold Y. We prove that direct images of pseudomeromorphic currents on X are pseudomeromorphic on Y. We also prove a partial converse: if i(*)tau is pseudomeromorphic and has the standard extension property, then tau is pseudomermorphic on X.
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| 7. |
- Berggren, Martin, et al.
(author)
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A discontinuous Galerkin extension of the vertex-centered edge-based finite volume method
- 2009
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In: Communications in Computational Physics. - 1815-2406. ; 5:2-4, s. 456-468
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Journal article (peer-reviewed)abstract
- The finite volume (FV) method is the dominating discretization technique for computational fluid dynamics (CFD), particularly in the case of compressible fluids. The discontinuous Galerkin (DG) method has emerged as a promising high-accuracy alternative. The standard DG method reduces to a cell-centered FV method at lowest order. However, many of today's CFD codes use a vertex-centered FV method in which the data structures are edge based. We develop a new DG method that reduces to the vertex-centered FV method at lowest order, and examine here the new scheme for scalar hyperbolic problems. Numerically, the method shows optimal-order accuracy for a smooth linear problem. By applying a basic hp-adaption strategy, the method successfully handles shocks. We also discuss how to extend the FV edge-based data structure to support the new scheme. In this way, it will in principle be possible to extend an existing code employing the vertex-centered and edge-based FV discretization to encompass higher accuracy through the new DG method.
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| 8. |
- Berggren, Martin, et al.
(author)
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Decreasing organic carbon bioreactivity in European rivers
- 2020
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In: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 65:6, s. 1128-1138
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Journal article (peer-reviewed)abstract
- European rivers experience increased loading of total organic carbon (TOC) from terrestrial sources due to factors involving changes in land use, climate and soil acidity. However, little is known about how increased TOC is linked to changes in the bioreactivity of organic matter in these rivers on a continental scale. We compiled paired measurements of TOC and biological oxygen demand in 5‐day 20°C dark incubations from 3,486 EU monitoring rivers. Assuming first‐order decay and a fixed respiratory quotient, annual average TOC and biological oxygen demand values were used to calculate 11,060 values of the decay coefficient k . The k decreased by two orders of magnitude as a power function of increasing TOC. This relationship could partly be explained by carbon quality, as the C:N ratio of the organic matter was the lowest in high‐reactivity low‐TOC rivers, and vice versa. A trend analysis showed that TOC increased by 18% from 1996 to 2012, while k decreased by as much as 50%. As a consequence, the biological oxygen demand in the water decreased over time in spite of the water browning trend (increased TOC). Together, these results suggest that reactivity is low near terrestrial hot spots for TOC export, and low during years with high terrestrial TOC loading, but increases in rivers with low TOC concentrations where internal processes in the water have high relative influence on bulk TOC quality. Thus, browning of European freshwaters is linked to strong decreases in TOC reactivity on a continental scale, suggesting that the impacts of browning on microbial water deoxygenation and greenhouse gas production are less severe than previously thought.
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| 10. |
- Bjornsson, Jonas, et al.
(author)
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Gauged non-compact WZNW models, revisited
- 2010
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In: Nuclear Physics B. - : Elsevier. - 0550-3213 .- 1873-1562. ; 832:1-2, s. 52-88
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Journal article (peer-reviewed)abstract
- The purpose of the present paper is to investigate the necessary conditions for unitarity of the spectrum of non-compact gauged WZNW models to some depth. In particular, we would like to investigate the necessity of integer weights and level. We will learn that the problem is very complex and we have not found any simple and general way to formulate the necessary conditions. Instead one must resort to studying the problem almost case by case. The only nearly complete conditions that we will find, is for the case g = su(n, 1). Furthermore, the horizontal part of the case g = su(p, g) is nearly completed as well. In other cases, we will find conditions associated with certain subalgebras and nodes in the Dynkin diagram close to the one corresponding to the non-compact root. In these examples we can give conditions for the horizontal part of the algebra. As a by-product of our investigation we will prove some nice formulae of character identities and explicit branching functions for these representations. (C) 2010 Elsevier B.V. All rights reserved.
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| 11. |
- Granström, Kjell
(author)
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Psychological observations and their credibility
- 2004
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In: Nordisk Psykologi. - 0029-1463. ; 56:4, s. 289-303
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Journal article (peer-reviewed)abstract
- In this presentation observation as research method and clinical method is scrutinised and discussed. The aim of the article is to define and separate different types of observations, mainly with reference to the degree of awareness among the subjects of being observed. This implies that ethics of research and clinical interventions, constituted by observations, will be discussed and related to different approaches. Further, I will comment on the influence that researchers or psychologists may have on the situation and on the subjects observed. It is argued that even open observations can be valid if the observer considers in what way the situation, the arrangements and the participants are influenced by the data collection.
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| 12. |
- Granström, Karl, 1981-, et al.
(author)
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Random Set Methods : Estimation of Multiple Extended Objects
- 2014
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In: IEEE robotics & automation magazine. - : IEEE Robotics and Automation Society. - 1070-9932 .- 1558-223X. ; 21:2, s. 73-82
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Journal article (peer-reviewed)abstract
- Random set based methods have provided a rigorous Bayesian framework and have been used extensively in the last decade for point object estimation. In this paper, we emphasize that the same methodology offers an equally powerful approach to estimation of so called extended objects, i.e., objects that result in multiple detections on the sensor side. Building upon the analogy between Bayesian state estimation of a single object and random finite set estimation for multiple objects, we give a tutorial on random set methods with an emphasis on multiple extended object estimation. The capabilities are illustrated on a simple yet insightful real life example with laser range data containing several occlusions.
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| 13. |
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Information and computation : Essays on scientific and philosophical understanding of foundations of information and computation
- 2011
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Editorial collection (other academic/artistic)abstract
- Information is a basic structure of the world, while computation is a process of the dynamic change of information. This book provides a cutting-edge view of world's leading authorities in fields where information and computation play a central role. It sketches the contours of the future landscape for the development of our understanding of information and computation, their mutual relationship and the role in cognition, informatics, biology, artificial intelligence, and information technology. This book is an utterly enjoyable and engaging read which gives readers an opportunity to understand and relate phenomena seemingly unrelated in a completely new light - especially the connections between information, computation, cognition and life.
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| 14. |
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| 15. |
- Jeschke, Peter, et al.
(author)
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Protection of workers exposed to radiofrequency electromagnetic fields : a perspective on open questions in the context of the new ICNIRP 2020 guidelines
- 2022
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In: Frontiers In Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 10
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Research review (peer-reviewed)abstract
- Workers in occupational settings are usually exposed to numerous sources of electromagnetic fields (EMF) and to different physical agents. Risk assessment for industrial workplaces concerning EMF is not only relevant to operators of devices or machinery emitting EMF, but also to support-workers, bystanders, service and maintenance personnel, and even visitors. Radiofrequency EMF guidelines published in 2020 by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) may also be indirectly applied to assess risks emerging from EMF sources at workplaces by technical standards or legislation. To review the applicability and adequacy to assess exposure to EMF in occupational settings in the European Union, the most current ICNIRP guidelines on radiofrequency EMF are reviewed. Relevant ICNIRP fundamentals and principles are introduced, followed by practical aspects of exposure assessment. To conclude, open questions are formulated pointing out gaps between the guidelines' principles and occupational practice, such as the impact of hot and humid environments and physical activity or controversies around ICNIRPS's reduction factors in view of assessment uncertainty in general. Thus, the article aims to provide scientific policy advisors, labor inspectors, or experts developing standards with a profound understanding about ICNIRP guidelines' applicability to assess hazards related to radiofrequency EMF in occupational settings.
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| 16. |
- Müller, Anne H, et al.
(author)
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Proteomic Expression Changes in Large Cerebral Arteries After Experimental Subarachnoid Hemorrhage in Rat Are Regulated by the MEK-ERK1/2 Pathway
- 2017
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In: Journal of Molecular Neuroscience. - : Springer Science and Business Media LLC. - 0895-8696 .- 1559-1166. ; 62:3-4, s. 380-394
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Journal article (peer-reviewed)abstract
- Subarachnoid hemorrhage (SAH) is a serious clinical condition where leakage of blood into the subarachnoid space causes an acute rise in intracranial pressure and reduces cerebral blood flow, which may lead to delayed cerebral ischemia and poor outcome. In experimental SAH, we have previously shown that the outcome can be significantly improved by early inhibition of the MAPK/ERK kinase/extracellular signal-regulated kinase (MEK/ERK1/2) pathway. The aim of this study was to apply mass spectrometry to investigate the overall late effects of experimental SAH on cerebrovascular protein expression. SAH was induced in rats that were treated with the MEK1/2 inhibitor U0126 or vehicle. Neurological outcome was assessed using a battery of behavioral tests. Specific protein expression of large cerebral arteries was analyzed quantitatively with high-throughput tandem mass spectrometry. SAH resulted in a marked reduction of neurological scores, which was counteracted by U0126 treatment. Mass spectrometry analysis demonstrated regulation of 184 proteins after SAH, regulations that were in part prevented by U0126 treatment. Network analysis identified several protein networks including a strong structural network centered around 14-3-3. Additionally, protein networks with functions in mRNA metabolism and protein folding were identified. Treatment with U0126 inhibited cerebral vessel wall pERK1/2 expression and significantly improved outcome of the rats. In conclusion, we show that SAH induces a broad array of specific changes in the overall protein networks in cerebral artery smooth muscle cells and suggest that this is essential for understanding the vascular pathophysiology after SAH.
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| 17. |
- Nørregaard, Kamilla, et al.
(author)
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DNA Supercoiling Enhances Cooperativity and Efficiency of an Epigenetic Switch
- 2015
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In: Biophysical Journal. - : Elsevier BV. - 0006-3495 .- 1542-0086. ; 108:2, s. 188A-188A
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Journal article (other academic/artistic)abstract
- Upon infection by bacteriophage λ the λ repressor protein, CI, interacts with the λ operator DNA, thereby regulating protein expression and deciding between the lysogenic and lytic state. This λ switch is a model on the basis of which epigenetic switch regulation is understood. In order to study the interaction between naturally supercoiled DNA and the DNA associating protein CI, we invented a novel assay where supercoiled circular DNA plasmids were individually tethered by peptide nucleic acid (PNA) handles [1]. We used this tethered plasmid assay for a single molecule investigation of the dynamics of supercoiled DNA and studied both the dynamics of the molecule itself and its interactions with the regulatory CI protein. The dynamics of the construct was analyzed by tracking the tethered bead. This revealed that compared with relaxed DNA, the presence of supercoils greatly enhances juxtaposition probability [2]. When CI was added to the supercoiled assay, the protein would attach to the operator sites thereby looping DNA. Our studies reveal that the efficiency and cooperativity of the epigenetic λ switch are significantly increased in the supercoiled system compared with a linear assay, thus increasing the Hill coefficient [2,3]. In contrast to other single molecule assays, the current methodology allows for studying DNA dynamics and DNA-protein interactions of DNA in its naturally supercoiled state.
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| 18. |
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| 19. |
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| 20. |
- Teig, Nani, et al.
(author)
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Theoretical Framework of Teacher Practice.
- 2024
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In: Teig, N., Nilsen, T., Yang Hansen, K. (eds) Effective and Equitable Teacher Practice in Mathematics and Science Education. IEA Research for Education, vol 14. Springer, Cham. https://doi.org/10.1007/978-3-031-49580-9_2. - : Springer Cham.
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Book chapter (other academic/artistic)
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| 21. |
- Vanags, Peteris, 1962-
(author)
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The Latvian Vocabulary
- 2011
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In: Wörter-Büchlein. A German-Swedish-Polish-Latvian Dictionary Published in Riga in 1705. - Stockholm : Kungl. Vitterhets Historie och Antikvitets Akademien. - 9789174024005 ; , s. 74-82
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Book chapter (other academic/artistic)
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| 22. |
- Zhang, Dai, et al.
(author)
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Power Consumption Bounds for SAR ADCs
- 2011
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In: European Conference on Circuit Theory and Design (ECCTD). - Linköping, Sweden : IEEE conference proceedings. - 9781457706172 - 9781457706165 ; , s. 556-559
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Conference paper (peer-reviewed)abstract
- Power consumption is an important limitation to analog-to-digital converters. The objective of this paper is to estimate a lower bound to the power consumption of successive approximation analog-to-digital converters. This is an extension of our previous work which was limited to pipelined and flash architectures. We find that the power consumption in our case is bounded by capacitor mismatch or thermal noise at high resolution and by digital switching power at low resolution. We also evaluate our methods and the estimated lower bound is compatible with experimental data.
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