| 1. |
- Dima, Elijs, et al.
(författare)
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LIFE: A Flexible Testbed For Light Field Evaluation
- 2018
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Konferensbidrag (refereegranskat)abstract
- Recording and imaging the 3D world has led to the use of light fields. Capturing, distributing and presenting light field data is challenging, and requires an evaluation platform. We define a framework for real-time processing, and present the design and implementation of a light field evaluation system. In order to serve as a testbed, the system is designed to be flexible, scalable, and able to model various end-to-end light field systems. This flexibility is achieved by encapsulating processes and devices in discrete framework systems. The modular capture system supports multiple camera types, general-purpose data processing, and streaming to network interfaces. The cloud system allows for parallel transcoding and distribution of streams. The presentation system encapsulates rendering and display specifics. The real-time ability was tested in a latency measurement; the capture and presentation systems process and stream frames within a 40 ms limit.
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| 2. |
- Eklundh, Lars, et al.
(författare)
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Analysing vegetation changes in the Sahel using sensor data from Landsat and NOAA
- 2005
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Konferensbidrag (refereegranskat)abstract
- The semi-arid Sahel zone of Africa has suffered several periods of severe drought since about 1950. We have analyzed AVHRR Normalized Difference Vegetation Index (NDVI) over the Sahel for the period 1982-2002, and found extensive areas of increasing NDVI. To verify these changes we have analyzed Landsat TM and ETM+ scenes from 1984-1986 and 1999-2001 for areas in the Sudan, Central African Republic, Niger, Mali and Mauritania. Changes in the Landsat data were analysed by visual interpretation and change vector analysis. In areas of positive AVHRR NDVI change the analysis of Landsat data generally showed a transition from barren or sparse vegetation to a denser vegetation cover. Rainfall had increased over the course of time in several of these areas. In some areas visual interpretation indicated an expansion of agricultural land.
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| 3. |
- Eklundh, Lars, et al.
(författare)
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High resolution mapping of vegetation dynamics from Sentinel-2
- 2012
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Ingår i: Proceedings of 1st Sentinel-2 Preparatory Symposium. - 0379-6566. - 9789290922711 ; 707 SP
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Konferensbidrag (refereegranskat)abstract
- The aim of this work is to develop and test a method for generation of information on vegetation dynamics from high-spatial resolution data, such as Sentinel-2. In order to accomplish this, Sentinel-2 data were simulated from existing SPOT HRG and HRVIR scenes over Sweden. We used TIMESAT, a well-tested computer package for generating smooth seasonal profiles and generation of seasonality parameters, like start and end, length, amplitude, integrated values, seasonal maximum, derivatives, etc. The processing works on a pixel-by-pixel basis and is resistant to clouds and noise. Data gaps are handled, and quality information can be included to increase the fidelity of the fits. The pilot study demonstrated that TIMESAT was successful in fitting smooth model functions to the data, and generating seasonality parameters for the test area at 10 × 10 m resolution. We conclude that TIMESAT will be useful for generating vegetation dynamics data from high-spatial resolution data such as Sentinel-2. The smooth seasonal profiles will be extremely useful for driving high-resolution biophysical vegetation models, and the seasonality parameters will be excellent for change detection, and for studying trends in vegetation productivity and seasonality.
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| 4. |
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| 5. |
- Eriksson, Mikael, et al.
(författare)
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The MAX IV Facility
- 2013
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Ingår i: 11th International Conference on Synchrotron Radiation Instrumentation (SRI 2012). - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 425
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Konferensbidrag (refereegranskat)abstract
- The MAX IV synchrotron radiation facility is currently being constructed in Lund, Sweden. The accelerator park consists of a 3 GeV linac injector and 2 storage rings operated at 1.5 and 3 GeV respectively. The linac injector will also be used for the generation of short Xray pulses. Close to 30 straight sections will be available for IDs at the rings. The three machines mentioned above are described below with some emphasis on the effort to create a very small emittance in the 3 GeV ring. Some unconventional technical solutions imposed by the emittance minimisation are discussed.
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| 6. |
- Eriksson, Mikael, et al.
(författare)
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The MAX IV Synchrotron Light Source
- 2011
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Ingår i: [Host publication title missing]. - 9789290833666 ; , s. 3026-3028
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Konferensbidrag (refereegranskat)abstract
- The MAX IV synchrotron radiation facility is currently being constructed in Lund, Sweden. It consists of a 3 GeV linac injector and 2 storage rings operated at 1.5 and 3 GeV respectively. The linac injector will also be used for the generation of short X-ray pulses. The three machines mentioned above are described with some emphasis on the effort to create a very small emittance in the 3 GeV ring. Some unconventional technical solutions will also be presented.
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| 7. |
- Johansson, Martin, et al.
(författare)
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MAX IV 3 GeV storage ring magnet block production series measurement results
- 2015
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Ingår i: 6th International Particle Accelerator Conference, IPAC 2015. - 9783954501687 ; , s. 3069-3071
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Konferensbidrag (refereegranskat)abstract
- The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation synchrotron radiation light sources with a compact (Ø25 mm aperture) integrated design having several consecutive magnet elements precision-machined out of a common solid iron block. The production series of 140 integrated magnet block units, which was totally outsourced to industry, was completed mid-2014. This article presents mechanical and magnetic field measurement results of the full production series.
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| 8. |
- Johansson, Martin, et al.
(författare)
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MAX IV 3 GeV storage ring magnet block production series measurement results
- 2016
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Ingår i: IPAC 2016 - Proceedings of the 7th International Particle Accelerator Conference. - 9783954501472 ; , s. 1157-1159
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Konferensbidrag (refereegranskat)abstract
- The MAX IV 3 GeV storage ring magnets are integrated "magnet block" units consisting of several consecutive magnet elements precision-machined out of a common solid iron block. In the 3 GeV ring, there are 140 magnet blocks containing a total of 1320 magnet elements. During the manufacturing phase of the project, a field measurement was performed for each magnet element, by Hall probe and/or by rotating coil. This article presents an overview of the magnetic field measurement results that were obtained for the full production series.
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| 9. |
- Leemann, Simon, et al.
(författare)
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Status of the MAX IV Storage Rings
- 2010
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Ingår i: Proceedings of IPAC’10. - 9789290833529 ; , s. 2618-2620
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Konferensbidrag (refereegranskat)abstract
- In 2009 the MAX IV facility was granted funding by Swedish authorities. Construction of the facility will begin this summer and user operation is expected by 2015. MAX IV will consist of a 3.4 GeV linac as a driver for a short-pulse radiation facility (with planned upgrade to a seeded/cascaded FEL) as well as an injector for two storage rings at different energies serving user communities in separate spectral ranges. Thanks to a novel compact multibend-achromat design, the 3 GeV ring will deliver a 500 mA electron beam with a horizontal emittance below 0.3 nmrad to x-ray insertion devices located in 19 dispersion-free 5 m straight sections. When the 3 GeV ring goes into operation in 2015 it is expected to become the highest electron-brightness storage ring light source world-wide. The 1.5 GeV ring will serve as a replacement for both present-day MAX II and MAX III storage rings. Its below 6 nm rad horizontal emittance electron beam will be delivered to IR and UV insertion devices in twelve 3.5 m straight sections. We report on design progress for the two new storage rings of the MAX IV facility.
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| 10. |
- Lewis, Jeffrey, et al.
(författare)
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PFAS – A threat for groundwater and drinking water supply in Sweden?
- 2015
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Ingår i: EGU General Assembly 2015. ; 17
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Perfluoroalkyl substances (PFAS) are a group of anthropogenic environmental pollutants that are widely distributed in the global environment. They have multiple industrial uses, including water repellents in clothing, paper coatings and firefighting foam. According to a study released by the Environmental Directorate of the OECD, they are persistent, bioaccumulative and toxic to mammalian species (OECD, 2002). In some municipal drinking water wells in Sweden, measured concentrations of PFAS found to be several hundred times higher than the allowed threshold values. This has created a huge public concern and has recently attracted much media attention in Sweden (e.g. Afzelius et al., 2014; Bergman et al., 2014; Lewis et al., 2014). PFAS findings raised questions such as “What can we do to solve the problem?” When it comes to drinking water, there are a number of techniques that can ensure that PFAS levels are reduced to acceptable levels. This may be a costly challenge, but from a technical point of view it is possible. To ensure the safety of drinking water from a public health perspective is obviously a top priority. However, international experience shows that the cost of cleaning up PFAS in groundwater may be significantly higher than continuously treat drinking water in water works. Approximately fifty percent of Sweden’s drinking water comes from groundwater. As a result, there are several ongoing and planned PFAS-related environmental and drinking-water investigations in Sweden. Many aquifers that supply municipal water plants are located in areas of sand and gravel deposits. Such soils have relatively high permeabilities, which permits extraction of large volumes of water. However, the downside to high permeabilities is that they also allow dissolved contaminants as PFAS to spread over large areas. If one disregards the health risks linked to its presence in drinking water, PFAS have an impact on three of Sweden’s national environmental quality objectives, namely, A Non-Toxic Environment, Flourishing Lakes and Streams and Good-Quality Groundwater. Although the survey of PFAS in our groundwater supplies will take time, it is feasible. Much research in the field of hydrogeology and geochemistry remains before a viable and cost-effective groundwater remediation method can be operational. Until then, it is essential that measures are taken to identify the present distribution and magnitude of PFAS in groundwater and prevents its further spread in our most important aquifers. Afzelius, H. et al., 2014. Vågar vi dricka kranvattnet? (Do we dare drinking tap water?), Svenska Dagbladet. Bergman, Å., Hansson, S.O., Hellsten, E., 2014. En miljöskandal av historiska mått (An environmental scandal of historic proportions), Svenska Dagbladet. Lewis, J. et al., 2014. Kartlägg det förorenade dricksvattnet (Survey the contaminated drinking water), Svenska Dagbladet. OECD, 2002. Hazard Assessment of Perfluorooctane Sulfonate (PFOS) and its Salt.
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