1. |
- Aanæs, Henrik, et al.
(författare)
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Factorization with erroneous data
- 2002
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Konferensbidrag (refereegranskat)abstract
- Factorization algorithms for recovering structure and motion from an image stream have many advantages, but traditionally requires a set of well tracked feature points. This limits the usability since, correctly tracked feature points are not available in general. There is thus a need to make factorization algorithms deal successfully with incorrectly tracked feature points. We propose a new computationally efficient algorithm for applying an arbitrary error function in the factorization scheme, and thereby enable the use of robust statistical techniques and arbitrary noise models for individual feature points. These techniques and models effectively deal with feature point noise as well as feature mismatch and missing features. Furthermore, the algorithm includes a new method for Euclidean reconstruction that experimentally shows a significant improvement in convergence of the factorization algorithms. The proposed algorithm has been implemented in the Christy–Horaud factorization scheme and the results clearly illustrate a considerable increase in error tolerance.
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- Adde, Magdalena, 1960-, et al.
(författare)
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Little usefullness of mid-treatment FDG-PET and biopsy for treatment intensification in patients with aggressive lymphoma
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: To evaluate the experiences of introducing mid-treatment FDG-PET in patients with aggressive lymphoma, in a population based program with decentralized examinations, with emphasis on finding patients who would benefit from dose-escalation. Patients and Methods: Twenty-five patients with aggressive lymphoma were included. Twenty-four (95%) of these having an aggressive B-cell lymphoma (84% diffuse large B-cell lymphoma) were treated with CHOP-like treatment given at two week intervals + rituximab. One patient having an anaplastic T-cell lymphoma was treated with CHOEP-14. Mid-treatment FDG-PET was performed and assessed as positive, uncertain or negative for remaining lymphoma. The intention was to perform a biopsy in those with a positive FDG-PET, and, to change to a platina-containing therapy and consolidate with high-dose therapy if viable lymphoma was found. Retrospective review of the PET investigations was done. Living patients were followed for a median of 22 months. Results: At primary analysis five patients (20%) had positive uptake on FDG-PET. Two of them had biopsy-proven viable tumor but did not complete the planned salvage treatment, one due to chemotherapy toxicity and one due to progressive disease during salvage therapy. Two patients had a negative biopsy and one patient had no biopsy due to technical difficulties at diagnosis. These three patients remain in remission after standard treatment. Out of seven patients (28%) having “uncertain” uptake two relapsed. Thirteen patients (52%) were negative,two of whom relapsed giving a negative predictive value of 85%. Conclusion: Mid-treatment FDG PET-CT in order to find patients with biopsy-proven aggressive lymphoma, who can be salvaged with dose escalation, was not feasible in clinical routine.
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3. |
- Berg, Axel, et al.
(författare)
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THE LU SYSTEM FOR DCASE 2024 SOUND EVENT LOCALIZATION AND DETECTION CHALLENGE
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This technical report gives an overview of our submission to task 3 of the DCASE 2024 challenge. We present a sound event localization and detection (SELD) system using input features based on trainable neural generalized cross-correlations with phase transform (NGCC-PHAT). With these features together with spectrograms as input to a Transformer-based network, we achieve significant improvements over the baseline method. In addition, we also present an audio-visual version of our system, where distance predictions are updated using depth maps from the panorama video frames.
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4. |
- Gulin, Jens, et al.
(författare)
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GCC-PHAT Re-Imagined - A U-Net Filter for Audio TDOA Peak-Selection
- 2024
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Ingår i: ICASSP 2024 - 2024 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). - 9798350344868 - 9798350344851 ; , s. 8806-8810
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Konferensbidrag (refereegranskat)abstract
- Time-difference-of-arrival (TDOA) estimation from GCC-PHAT is not always as straight forward as finding the maximum peak. This work views the GCC output as an image, with time on the vertical axis and TDOA horizontally, to explore if image-to-image machine learning methods can make a more robust filter. The Structure from Sound Database provides audio recorded with a distributed microphone setup and a moving sound source. The audio was fed to GCC-PHAT without pre-processing, and images were produced for batch processing. The ground truth, the direct-path TDOA, shows a continuous curve through time. The GCC output image has a similar curve, but obscured by noise and not at all times texturally different from the multi-path components. The main approach tested is binary semantic segmentation with a U-Net. A challenge is the extreme class imbalance within the image. Preliminary results indicate that the method is valid to detect curves, yet more work is needed to single out the direct path TDOA with confidence.
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6. |
- Kuklane, Kalev, et al.
(författare)
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Evaluation of BARRIER® EasyWarm on Healthy Volunteers in Three Different Climates and Verification of the Degree of Correlation Between Tests Performed on Healthy Volunteers and in a standardized bench test
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION Anaesthesia induced hypothermia is a common serious but preventable condition associated with increased bleeding and blood transfusion, increased risk for surgical site infections and increased risk for morbid cardiac events. Active warming is effective in preventing hypothermia but there is a need for more easy to use cost-effective products making active warming available to more patients. Establishing how the environment affects skin temperature and total body heat content (TBHC) as well as the correlation between standardized bench tests and healthy volunteer skin temperature is an important aspect in developing new, more effective warming products to prevent or treat hypothermia as this means fewer healthy volunteers are needed as changes to skin temperature could be estimated based on data from bench tests. OBJECTIVES This investigation was undertaken in order to investigate the safety and efficacy of Active warming with BARRIER® EasyWarm when used in three different climate settings and using different test methods; standardized bench test T-1127 measuring temperatures on a wooden board and measuring skin and core temperature on healthy volunteers. An additional objective in this investigation was to determine the degree of correlation between these test methods. OUTCOME A statistically significant increase in TBHC is seen when comparing TBHC over time in all three climates, respectively. With this investigation design we cannot show that there is a difference in TBHC between the different climates though, i.e. the heat generated from the blanket to the subject is not significantly different in the different climates. Based on this investigation the active warming blanket managed to maintain or increase the temperature of the subjects without any adverse thermal effects. Thermal comfort and the mean thermal sensation were maintained between slightly cold and warm throughout the whole exposure length. The active self-warming blanket was well tolerated in healthy male volunteers. None of the six Adverse Events (AE) reported were serious and none of them were related to the investigational device but rather to the immobilisation or the tension of participating in the investigation. All AEs were resolved at end of test. Skin temperature reached maximally 42.2°C, and thus, it never reached the lowest pain threshold of 43°C under any conditions. Increase of core temperature over time in climate 18°C and 24°C was in average 0.1°C to 0.2°C leading to mean final core temperatures of 36.9 (SD 0.2) and 37.1 (SD 0.4) °C for 18°C and 24°C exposures, respectively.
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7. |
- Lyu, Yezhe, 1987-, et al.
(författare)
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Recycling of worn out brake pads impact on tribology and environment
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Disc brake systems are widely used on commercial vehicles for braking. The brake pads are usually replaced by new ones before being totally worn out. Current methods to deal with the replaced brake pads include landfill and combustion, resulting in a huge waste of resources and increase of CO2 footprint. From a sustainable point of view, this study aims to evaluate the feasibility of recycling replaced brake pads by addressing a protocol recycling procedure. The results show that the recycled brake pads yield similar friction, wear and airborne particle emission to virgin brake pads. A streamlined life cycle assessment is conducted to compare the environmental impacts between producing virgin brake pads and recycling replaced brake pads. Energy consumption and CO2 footprint of the recycled brake pads are 36% and 34% less than virgin brake pads, indicating that recycling could be a promising method of handling replaced brake pads.
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8. |
- Ma, Jijie, et al.
(författare)
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A Comparison of Airborne Particles Generated from Disk Brake Contacts : Induction Versus Frictional Heating
- 2020
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Ingår i: Tribology letters. - : SPRINGER/PLENUM PUBLISHERS. - 1023-8883 .- 1573-2711. ; 68:1
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Tidskriftsartikel (refereegranskat)abstract
- Volatile emissions of vehicle brakes relate to the high temperature of the brake friction pair. However, as a passive parameter of braking applications, temperature is usually studied together with other parameters such as sliding speed and load. Heating tests that increase the friction pair temperature with an induction heater instead of friction are proposed in this study to imitate the rise in temperature in friction tests. Non-friction airborne particles produced solely by the high temperature in heating tests were studied in comparison with friction tests. The results confirmed the existence of non-friction airborne particles and they can represent about 4.5% of the total airborne particles in friction tests. The high-temperature behaviour as well as the composition of the non-friction airborne particles is also presented.
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10. |
- Olofsson, Ulf, 1962-, et al.
(författare)
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Laser Cladding Treatment for Refurbishing Disc Brake Rotors : Environmental and Tribological Analysis
- 2021
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Ingår i: Tribology letters. - New York : Springer Nature. - 1023-8883 .- 1573-2711. ; 69:2
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Tidskriftsartikel (refereegranskat)abstract
- In this study, grey cast iron disc brake rotors are refurbished by adding a surface layer through laser cladding. Current methods to deal with replaced rotors mainly include remelting, with a minority fraction disposed in landfill. Both approaches result in a huge waste of resources and an increase in CO2 footprint. From a sustainable point of view, this study aims to evaluate the feasibility of refurbishing brake rotors by a combined environmental and tribological performance approach. A streamlined life cycle assessment is conducted to compare the environmental impacts between producing virgin grey cast iron brake rotors and refurbishing replaced brake rotors by laser cladding. It turns out that the energy consumption and CO2 footprint of the laser cladding refurbished brake rotors are 80% and 90% less than the virgin brake rotors. The results show that the refurbished brake rotor yields higher friction compared to the original cast iron utilizing the same pad material. The wear and particle emissions of the disc brake contact are in this study higher for the laser-cladded one compared to the original cast iron one.
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