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- Bulakei, Omer, et al.
(författare)
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Agile Resource Management for 5G A METIS-II Perspective
- 2015
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Ingår i: 2015 IEEE CONFERENCE ON STANDARDS FOR COMMUNICATIONS AND NETWORKING (CSCN). - 9781479989287 ; , s. 30-35
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Konferensbidrag (refereegranskat)abstract
- An explosive growth in the demand for higher data rates and capacity along with diverse requirements set by massive and ultra-reliable machine-type communications are the main drivers behind the development on new access technologies as part of the fifth generation (5G) networks. Currently, different air interface (AIF) and/or AIF variants, optimized based on the frequency band of operation and use case, are envisioned for such a network. Developing an agile resource management framework for 5G networks is one of the main goals of the METIS-II project. The METIS-II project builds strongly upon the EU flagship project METIS, which has laid the foundation of 5G. This framework will take into account the multi-link and multi-layer constraints currently envisioned for 5G. In this paper, we provide our first insights into agile resource management and the associated synchronous control functions. We will discuss the essential building blocks in terms of technology enablers and their mapping to 5G services and deployments. The introduced agile resource management framework for 5G is expected to enable enhanced interference management, dynamic traffic steering, fast radio access network (RAN) moderation, efficient context management, and optimized integration with legacy networks.
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| 2. |
- Gareis, Daniel, et al.
(författare)
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Mouse MRI using phased-array coils
- 2007
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Ingår i: NMR in Biomedicine. ; 20:3, s. 326-334
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Tidskriftsartikel (refereegranskat)abstract
- The advantages of array coil imaging in human whole-body MR systems are well known and have gained relevance in many applications and MR techniques. In the field of small-animal studies, this concept has become increasingly important. In this work, three different phased-array coils for performing MRI on mice are presented. For imaging at 300 MHz, a four-channel receive-only phased-array coil is introduced. One two-channel and a four-channel transmit/receive setup operating at 750 MHz show the feasibility of array coil imaging at 17.6 T. All of these coils show excellent performance and deliver high-quality MR images of mice.
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| 6. |
- Kaeufl, Hans Ulrich, et al.
(författare)
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NEAR : New Earths in the Alpha Cen Region (bringing VISIR as a "visiting instrument" to ESO-VLT-UT4)
- 2018
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Ingår i: Ground-Based And Airborne Instrumentation For Astronomy VII. - : SPIE. - 9781510619586
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Konferensbidrag (refereegranskat)abstract
- ESO in collaboration with the Breakthrough Initiatives, is adding a dedicated coronagraph to the Very Large Telescope mid-IR imager (VISIR) to further boost the high dynamic range imaging capability of this instrument. After the VISIR upgrade in 2012, where coronagraphic masks were first added to VISIR, it became evident that coronagraphy at a ground-based 8m-class telescope, even at wavelengths as long as 10 mu m, critically needs adaptive optics. For VISIR, a work-horse observatory facility instrument in normal operations, this is "easiest" achieved by bringing VISIR as a visiting instrument to the ESO-VLT-UT4 having an adaptive M2. This "visit" enables a meaningful search for Earth-like planets in the habitable zone around both alpha-Cen(1) and alpha-Cen(2). Meaningful here means, achieving a contrast of approximate to 10(-6) within approximate to 0.8 arcsec from the star. Various measures to improve the sensitivity of VISIR will be applied, especially a dedicated filter, faster chopping and a Strehl-ratio close to 100% thanks to extreme adaptive optics. This should allow to detect a planet twice the diameter of Earth in 50 h on source integration time. Key components will be a diffractive coronagraphic mask, the annular groove phase mask (AGPM), optimized for the most sensitive spectral band-pass in the N-band, complemented by a sophisticated apodizer at the level of the Lyot stop. For VISIR noise filtering based on fast chopping is required. A novel internal chopper system will be integrated into the cryostat. This chopper is based on the standard technique from early radio astronomy, conceived by the microwave pioneer Robert Dicke in 1946, which was instrumental for the discovery of the 3K microwave background. For risk mitigation all components are being tested and quali fi ed under realistic conditions in the lab at ESO headquarters before integration into the instrument. The performance or suppression of the coronagraph is so good, that a non-thermal source (vulgo a laser) is needed on the test-bench. We will give an overview of the optical changes to VISIR, the implementation of wave front sensing, the Dicke switch design and laboratory testing, the AGPM design and laboratory testing, non common path error control with a ZELDA mask, sensitivity and contrast estimates, data flow and analysis, the overall project status, plan and outlook Needless to say that this project is of critical interest for future infrared instrumentation at the next generation of extremely large telescopes aiming at surveying the solar neighborhood for terrestrial planets by detecting and characterizing them based on their mid-IR fluxes.
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| 7. |
- Sigsgaard, Torben, et al.
(författare)
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Health impacts of anthropogenic biomass burning in the developed world.
- 2015
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Ingår i: The European respiratory journal. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 46:6, s. 1577-1588
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Tidskriftsartikel (refereegranskat)abstract
- Climate change policies have stimulated a shift towards renewable energy sources such as biomass. The economic crisis of 2008 has also increased the practice of household biomass burning as it is often cheaper than using oil, gas or electricity for heating. As a result, household biomass combustion is becoming an important source of air pollutants in the European Union.This position paper discusses the contribution of biomass combustion to pollution levels in Europe, and the emerging evidence on the adverse health effects of biomass combustion products.Epidemiological studies in the developed world have documented associations between indoor and outdoor exposure to biomass combustion products and a range of adverse health effects. A conservative estimate of the current contribution of biomass smoke to premature mortality in Europe amounts to at least 40000 deaths per year.We conclude that emissions from current biomass combustion products negatively affect respiratory and, possibly, cardiovascular health in Europe. Biomass combustion emissions, in contrast to emissions from most other sources of air pollution, are increasing. More needs to be done to further document the health effects of biomass combustion in Europe, and to reduce emissions of harmful biomass combustion products to protect public health.
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| 8. |
- Wagner, Kevin, et al.
(författare)
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Imaging low-mass planets within the habitable zone of α Centauri
- 2021
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Giant exoplanets on wide orbits have been directly imaged around young stars. If the thermal background in the mid-infrared can be mitigated, then exoplanets with lower masses can also be imaged. Here we present a ground-based mid-infrared observing approach that enables imaging low-mass temperate exoplanets around nearby stars, and in particular within the closest stellar system, alpha Centauri. Based on 75-80% of the best quality images from 100h of cumulative observations, we demonstrate sensitivity to warm sub-Neptune-sized planets throughout much of the habitable zone of alpha Centauri A. This is an order of magnitude more sensitive than state-of-the-art exoplanet imaging mass detection limits. We also discuss a possible exoplanet or exozodiacal disk detection around alpha Centauri A. However, an instrumental artifact of unknown origin cannot be ruled out. These results demonstrate the feasibility of imaging rocky habitable-zone exoplanets with current and upcoming telescopes. Imaging of low-mass exoplanets can be achieved once the thermal background in the mid-infrared (MIR) wavelengths can be mitigated. Here, the authors present a ground-based MIR observing approach enabling imaging low-mass temperate exoplanets around nearby stars.
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