| 1. |
- Aad, G, et al.
(author)
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- 2015
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swepub:Mat__t
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| 2. |
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| 3. |
- Farnocchia, Davide, et al.
(author)
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The Second International Asteroid Warning Network Timing Campaign: 2005 LW3
- 2023
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In: The Planetary Science Journal. - : Institute of Physics (IOP). - 2632-3338. ; 4:11
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Journal article (peer-reviewed)abstract
- The Earth close approach of near-Earth asteroid 2005 LW3 on 2022 November 23 represented a good opportunity for a second observing campaign to test the timing accuracy of astrometric observation. With 82 participating stations, the International Asteroid Warning Network collected 1046 observations of 2005 LW3 around the time of the close approach. Compared to the previous timing campaign targeting 2019 XS, some individual observers were able to significantly improve the accuracy of their reported observation times. In particular, U.S. surveys achieved good timing performance. However, no broad, systematic improvement was achieved compared to the previous campaign, with an overall negative bias persisting among the different observers. The calibration of observing times and the mitigation of timing errors should be important future considerations for observers and orbit computers, respectively.
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| 4. |
- Ankel, Martin, et al.
(author)
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Experimental Evaluation of Moving Target Compensation in High Time-Bandwidth Noise Radar
- 2023
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In: Proceedings 20th European Radar Conference (EuRAD). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 213-216
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Conference paper (peer-reviewed)abstract
- In this article, the effect a moving target has on the signal-to-interference-plus-noise-ratio (SINR) for high time-bandwidth noise radars is investigated. To compensate for cell migration we apply a computationally efficient stretch processing algorithm that is tailored for batched processing and suitable for implementation onto a real-time radar processor. The performance of the algorithm is studied using experimental data. In the experiment, pseudorandom noise, with a bandwidth of 100 MHz, is generated and transmitted in real-time. An unmanned aerial vehicle (UAV), flown at a speed of 11.5 m/s, is acting as a target. For an integration time of 1 s, the algorithm is shown to yield an increase in SINR of roughly 13 dB, compared to no compensation. It is also shown that coherent integration times of 2.5 s can be achieved.
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| 5. |
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| 6. |
- Farnocchia, Davide, et al.
(author)
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International Asteroid Warning Network Timing Campaign: 2019 XS
- 2022
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In: The Planetary Science Journal. - : Institute of Physics Publishing (IOPP). - 2632-3338. ; 3:7
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Journal article (peer-reviewed)abstract
- As part of the International Asteroid Warning Network's observational exercises, we conducted a campaign to observe near-Earth asteroid 2019 XS around its close approach to Earth on 2021 November 9. The goal of the campaign was to characterize errors in the observation times reported to the Minor Planet Center, which become an increasingly important consideration as astrometric accuracy improves and more fast-moving asteroids are observed. As part of the exercise, a total of 957 astrometric observations of 2019 XS during the encounter were reported and subsequently were analyzed to obtain the corresponding residuals. While the timing errors are typically smaller than 1 s, the reported times appear to be negatively biased, i.e., they are generally earlier than they should be. We also compared the observer-provided position uncertainty with the cross-track residuals, which are independent of timing errors. A large fraction of the estimated uncertainties appear to be optimistic, especially when <0 2. We compiled individual reports for each observer to help identify and remove the root cause of any possible timing error and improve the uncertainty quantification process. We suggest possible sources of timing errors and describe a simple procedure to derive reliable, conservative position uncertainties.
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| 7. |
- Hellberg, C., et al.
(author)
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Evidence and evidence gaps in assessments and interventions in areas related to social work research and practice - an overview of four evidence maps
- 2023
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In: European Journal of Social Work. - : Informa UK Limited. - 1369-1457 .- 1468-2664. ; 26:5
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Journal article (peer-reviewed)abstract
- This overview of four evidence maps is based on systematic reviews of assessment and interventions in social work practice. The aim was to investigate the evidence and evidence gaps within four important areas for social work research and practice. Descriptive data on search strategies and domains were collected from four evidence maps, on Social Assistance, Substance Dependence, Care for older adults respectively for persons with disabilities. The scientific quality and scientific evidence were assessed. Key findings were summarised by analyzing and discussing common and specific elements in the evidence maps. The overview was undertaken in close collaboration between researchers with expertise in the field and a government agency. The overview identified both evidence and evidence gaps with respect to effects and experiences of interventions and assessment methods in four evidence maps. Evidence maps provide a comprehensive picture of the state of social services research and can thereby be of use to both researchers and practitioners, and in the production of evidence based social work.
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| 8. |
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| 9. |
- Sanandaji, Nima, et al.
(author)
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Inkjet printing as a possible route to study confined crystal structures
- 2012
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In: European Polymer Journal. - : Elsevier BV. - 0014-3057 .- 1873-1945. ; 49:1, s. 203-208
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Journal article (peer-reviewed)abstract
- Inkjet printing is a technique for the precise deposition of liquid droplets in the pL-volume range in well-defined patterns. Previous studies have shown that inkjet printing is attractive in polymer technology since it permits the controlled deposition of functional polymer surfaces. We suggest that the technique might also be useful for studying crystallization, in particular confined crystallization. Inkjet printing is a non-contact deposition method with minimal risk of contamination, which allows the exact deposition of both polymer solutions and polymer melts. This paper demonstrates the possibility of utilizing the technique to create surfaces where polymer chains form isolated small structures. These structures were confined by both the low polymer content in each droplet and the time constraint on crystal formation that arose as the result of the rapid solvent evaporation from the pL-sized droplets. In theory, inkjet printing enables the exact deposition of systems with as few as a single polymer chain in the average droplet. With appropriate instrumentation, the versatile inkjet technology can be utilized to create whole surfaces covered with polymer structures formed by the crystallization of small, dilute and rapidly evaporating droplets. 110 pL droplets of a 10 -6 g L -1 poly(ε-caprolactone) solution in 1-butanol have been deposited and studied by atomic force microscopy. Small structures of ca. 10 nm thickness and ca. 50 nm diameter also seemed to exhibit crystalline features. Some of the small structures had unusual rectangular forms whilst others were interpreted to be early precursors to six-sided single crystals previously observed for poly(ε-caprolactone). The unusual forms observed may have resulted from the entrapment of crystal structures into metastable phases, due to the limited amount of polymer material present and the rapid evaporation of the droplets.
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