| 1. |
- Vu, Viet Thuy, 1977-, et al.
(författare)
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Image extra-coregistration based on GIP for radar applications
- 2022
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Ingår i: Proceedings - 2022 RIVF International Conference on Computing and Communication Technologies, RIVF 2022. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665461665 ; , s. 274-278
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Konferensbidrag (refereegranskat)abstract
- Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.
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| 2. |
- Vu, Viet Thuy, 1977-, et al.
(författare)
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Implementing Backprojection at Base Station for Precise Localization in Indoor Environment
- 2023
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Ingår i: Proceedings - 2023 RIVF International Conference on Computing and Communication Technologies, RIVF 2023. - : Institute of Electrical and Electronics Engineers (IEEE). - 9798350315844 ; , s. 212-217
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Konferensbidrag (refereegranskat)abstract
- Mobile equipment with an integrated radar system allows active localization by realizing monostatic, bistatic, multistatic and passive SAR. For mobile user localization, it is also possible by implementing backprojection at base station. In the paper, an approach for precise mobile user localization by implementing backprojection at base station is proposed. The simulation shows the feasibility of the proposal. Some technical issues such as accuracy and backprojection ambiguity, are also addressed. The practicality of the proposal is also demonstrated with a practical frequency-modulated continuous wave (FMCW) radar system and a monostatic radar measurement based on the system. © 2023 IEEE.
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| 3. |
- Adielsson, Anna, et al.
(författare)
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Outcome prediction for patients assessed by the medical emergency team : a retrospective cohort study
- 2022
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Ingår i: BMC Emergency Medicine. - : Springer Science and Business Media LLC. - 1471-227X .- 1471-227X. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Medical emergency teams (METs) have been implemented to reduce hospital mortality by the early recognition and treatment of potentially life-threatening conditions. The objective of this study was to establish a clinically useful association between clinical variables and mortality risk, among patients assessed by the MET, and further to design an easy-to-use risk score for the prediction of death within 30 days.Methods: Observational retrospective register study in a tertiary university hospital in Sweden, comprising 2,601 patients, assessed by the MET from 2010 to 2015. Patient registry data at the time of MET assessment was analysed from an epidemiological perspective, using univariable and multivariable analyses with death within 30 days as the outcome variable. Predictors of outcome were defined from age, gender, type of ward for admittance, previous medical history, acute medical condition, vital parameters and laboratory biomarkers. Identified factors independently associated with mortality were then used to develop a prognostic risk score for mortality.Results: The overall 30-day mortality was high (29.0%). We identified thirteen factors independently associated with 30-day mortality concerning; age, type of ward for admittance, vital parameters, laboratory biomarkers, previous medical history and acute medical condition. A MET risk score for mortality based on the impact of these individual thirteen factors in the model yielded a median (range) AUC of 0.780 (0.774-0.785) with good calibration. When corrected for optimism by internal validation, the score yielded a median (range) AUC of 0.768 (0.762-0.773).Conclusions: Among clinical variables available at the time of MET assessment, thirteen factors were found to be independently associated with 30-day mortality. By applying a simple risk scoring system based on these individual factors, patients at higher risk of dying within 30 days after the MET assessment may be identified and treated earlier in the process.
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| 4. |
- Arya, Mina, et al.
(författare)
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Enhancing Sustainability: Jute Fiber-Reinforced Bio-Based Sandwich Composites for Use in Battery Boxes
- 2023
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Ingår i: Polymers. - : Multidisciplinary Digital Publishing Institute (MDPI). - 2073-4360. ; 15:18
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Tidskriftsartikel (refereegranskat)abstract
- The rising industrial demand for environmentally friendly and sustainable materials has shifted the attention from synthetic to natural fibers. Natural fibers provide advantages like affordability, lightweight nature, and renewability. Jute fibers’ substantial production potential and cost-efficiency have propelled current research in this field. In this study, the mechanical behavior (tensile, flexural, and interlaminar shear properties) of plasma-treated jute composite laminates and the flexural behavior of jute fabric-reinforced sandwich composites were investigated. Non-woven mat fiber (MFC), jute fiber (JFC), dried jute fiber (DJFC), and plasma-treated jute fiber (TJFC) composite laminates, as well as sandwich composites consisting of jute fabric bio-based unsaturated polyester (UPE) composite as facing material and polyethylene terephthalate (PET70 and PET100) and polyvinyl chloride (PVC) as core materials were fabricated to compare their functional properties. Plasma treatment of jute composite laminate had a positive effect on some of the mechanical properties, which led to an improvement in Young’s modulus (7.17 GPa) and tensile strength (53.61 MPa) of 14% and 8.5%, respectively, as well as, in flexural strength (93.71 MPa) and flexural modulus (5.20 GPa) of 24% and 35%, respectively, compared to those of JFC. In addition, the results demonstrated that the flexural properties of jute sandwich composites can be significantly enhanced by incorporating PET100 foams as core materials.
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| 5. |
- Askman, Sandra, et al.
(författare)
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Decreased neutrophil function in newly diagnosed multiple myeloma patients is restored with lenalidomide therapy
- 2024
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Ingår i: EUROPEAN JOURNAL OF HAEMATOLOGY. - 0902-4441 .- 1600-0609.
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesBacterial infections are common and a major cause of morbidity and mortality in multiple myeloma (MM). We have investigated the function of polymorphonuclear leukocyte (PMN), the immune system's first line of defense against bacteria, in peripheral blood (PB) and bone marrow (BM) samples from patients with newly diagnosed MM (NDMM), smoldering MM (SMM), monoclonal gammopathy of undetermined significance (MGUS) and healthy controls.MethodsPhagocytosis and oxidative burst in PMN cells from patients and healthy donors were investigated using PhagoTest and PhagoBurst assay.ResultsPMN from NDMM, SMM, and MGUS patients had reduced phagocytosis and oxidative burst ability compared with healthy controls. The dysfunction was most prominent in BM samples from MM, SMM, and MGUS patients. Importantly the reduced phagocytosis in MM patients was restored in patients on lenalidomide therapy. Consistently the ability of Escherichia coli stimulated oxidative burst in BM was reduced for the MM, SMM, and MGUS cohort in contrast to the healthy controls and the patients on lenalidomide treatment.ConclusionOur results show that MM patients have neutrophil dysfunction that could contribute to susceptibility for bacterial infections and that lenalidomide therapy was associated with restored PMN function.
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| 6. |
- Batra, Aman, et al.
(författare)
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Experimental analysis of high resolution indoor THz SAR imaging
- 2020
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Ingår i: WSA 2020 - 24th International ITG Workshop on Smart Antennas. - : VDE Verlag GmbH. - 9783800752003
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Konferensbidrag (refereegranskat)abstract
- Synthetic Aperture Radar (SAR) technology is most commonly used in the frequency span of sub-30 GHz which provides the spatial resolution in the range of sub-cm. This technology is being extended to higher frequencies such as millimeter wave and THz region to achieve higher resolution in the range of sub-mm. This expands the SAR applications for material characterization, classification and sub-mm localization. However, the region is suitable for short propagation distance such as an indoor environment. Therefore, to investigate the achieved resolution and quality of the SAR images at THz, an indoor SAR testbed based on vector network analyzer has been setup for the measurements. This paper explains the indoor SAR geometry and describes the associated testbed along with the system parameters. The measurements are performed at a centre frequency of 275 GHz with a bandwidth of 110 GHz. The measurement results are analyzed for the theoretical resolution with the Backprojection Algorithm and the findings are presented in this paper. The sub-mm spatial resolution imaging of two small size metallic objects are performed. © WSA 2020.
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| 7. |
- Batra, Aman, et al.
(författare)
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Sub-mm Resolution Indoor THz Range and SAR Imaging of Concealed Object
- 2020
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Ingår i: 2020 IEEE MTT-S International Conference on Microwaves for Intelligent Mobility, ICMIM 2020. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728167558
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Konferensbidrag (refereegranskat)abstract
- In radar systems, the frequency range is being extended to high frequencies such as THz for sub-mm resolution. The spectrum offers high resolution but on the contrary, propagation distance and penetration depth are limited because of smaller wavelength. It suffers from higher atmospheric absorption in comparison to sub-GHz systems. In comparison to optical technology, the radar technique majorly benefits with respect to the penetration property such as cloud/smoke cover penetration and detection of concealed objects. However, the THz range and synthetic aperture radar (SAR) imaging of concealed objects are not very well established. Therefore, this paper examines this property at THz. A testbed has been set up with a bandwidth of 110 GHz at a carrier frequency of 275 GHz. The imaging is performed of a very small metal object. Firstly, the sub-mm resolution is validated with the experiment after that the range and SAR imaging are performed in which this object is covered with different types of materials. The backscattered data is processed with the image reconstruction algorithms and the results are presented in this paper with respect to sub-mm resolution and detection. © 2020 IEEE.
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| 8. |
- Chuquimia, Olga D., et al.
(författare)
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Molecular analyses of fecal bacteria and hydrodynamic modeling for microbial risk assessment of a drinking water source
- 2020
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Ingår i: Water (Switzerland). - : MDPI AG. - 2073-4441 .- 2073-4441. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Safe water is a global concern, and methods to accurately monitor quality of water are vital. To assess the risks related to bacterial pathogen load in Lake Vomb that provides drinking water to the southern part of Sweden, this study combined molecular analyses of enterobacteria and bacterial pathogens in water using quantitiative real-time PCR with hydrodynamic modeling and quantitative microbial risk assessment (QMRA). A real-time PCR assay to detect enterobacteria was set up by primers targeting ssrA. Between February 2015 and May 2016, presence of ssrA gene copies as well as Campylobacter spp., Salmonella spp., and EHEC O157 DNA was analyzed by real-time PCR at several locations in the catchment of Lake Vomb and its tributaries Bjorkaan, Borstbacken, and Torpsbacken. Bjorkaan had the highest detected concentrations of the ssrA gene and, according to the results of hydrodynamic modeling, contributed most to the contamination of the water intake in the lake. None of the water samples were positive for genes encoding EHEC O157 and Campylobacter spp., while invA (Salmonella spp.) was present in 11 samples. The QMRA showed that the suggested acceptable risk level (daily probability of infection <2.7 x 10-7) is achieved with a 95% probability, if the Salmonella concentrations in the water intake are below 101 bacteria/100 mL. If a UV-disinfection step is installed, the Salmonella concentration at the water intake should not exceed 106 bacteria/100 mL.
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| 9. |
- Coder Gylling, Kira, 1988-
(författare)
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Cut-off and coordinated survey sampling
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The problem of estimation from a sample is well known and its solutions are the foundation for the sample surveys conducted at e.g. national statistical institutes. This dissertation looks at the estimation problem from the perspective of business survey methodology. The focus is on two types of survey sampling: Cut-off sampling and coordinated sampling. We introduce and evaluate new method for estimation in cut-off sampling as well as a tool for drawing coordinated samples in the R programming language.
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| 10. |
- Drakman, Annelie, et al.
(författare)
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Inledning
- 2021
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Ingår i: Vetenskapens förtrollning och avförtrollning. - Göteborg : Daidalos. - 9789171736413
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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