| 1. |
- Collin, David, et al.
(författare)
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Added value of interpreter experience in occult and suspect hip fractures: a retrospective analysis of 254 patients.
- 2016
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Ingår i: Emergency Radiology. - : Springer Science and Business Media LLC. - 1438-1435 .- 1070-3004. ; 23:3, s. 229-234
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Tidskriftsartikel (refereegranskat)abstract
- The influence of experience in categorizing suspect and occult fractures on radiography compared to MRI and clinical outcome has not been studied. The aim of this study is to evaluate the importance of experience in diagnosing normal or suspect hip radiographs compared to MRI. Primarily reported normal or suspect radiography in 254 patients with low-energy hip trauma and subsequent MRI was re-evaluated by two experienced reviewers. Primary readings and review were compared. The prevalence of fractures among normal and suspect radiographic studies was assessed. Clinical outcome was used as reference. At review of radiography, 44 fractures (17 %) were found. Significantly more fractures were found among suspect cases than among normal cases. At MRI, all 44 fractures were confirmed, and further 64 fractures were detected (25 %). MRI detected all fractures with no missed fractures revealed at follow-up. There were a significantly higher proportion of fractures at MRI among the suspect radiographic diagnoses for both the primary report and at review than among occult cases. The more experienced reviewers classified radiography examinations with higher accuracy than primary reporting general radiologists. There was almost complete agreement on MRI diagnoses.
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| 2. |
- Cyron, Wojciech, et al.
(författare)
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Bonded Concrete Overlays: A Brief Discussion on Restrained Shrinkage Deformations and Their Prediction Models
- 2019
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Ingår i: Nordic Concrete Research. - : Walter de Gruyter. - 0800-6377 .- 2545-2819. ; 61:2, s. 107-129
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Tidskriftsartikel (refereegranskat)abstract
- Bonded concrete overlays (BCO) on bridge decks are beneficial solutions due to their superior properties as compared to the typical asphalt pavement. A significant number of overlays suffer however, from occurrence of cracks and delamination due to poor bond, and restrained shrinkage and thermal dilation. Over the past years different appraisals for estimation of the restrained deformations have been developed, from micro-scale models, based on poromechanics, to empirical equations as given in B3 or B4 models suggested by Baiant. This paper provides a short overview of calculation models along with a brief theoretical explanation of shrinkage mechanism.
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| 3. |
- Ekelin, Svante, et al.
(författare)
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Real-Time Measurement of End-to-End Available Bandwidth using Kalman Filtering
- 2006
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Ingår i: 10th IEEE/IFIP Network Operations and Management Symposium, 2006. NOMS 2006.. - Piscataway, New Jersey, USA : IEEE Computer Society. - 1424401429 - 9781424401420 ; , s. 73-84
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Konferensbidrag (refereegranskat)abstract
- This paper presents a new method, BART (bandwidth available in real-time), for estimating the end-to-end available bandwidth over a network path. It estimates bandwidth quasi-continuously, in real-time. The method has also been implemented as a tool. It relies on self-induced congestion, and repeatedly samples the available bandwidth of the network path with sequences of probe packet pairs, sent at randomized rates. BART requires little computation in each iteration, is lightweight with respect to memory requirements, and adds only a small amount of probe traffic. The BART method uses Kalman filtering, which enables real-time estimation (a.k.a. tracking). It maintains a current estimate, which is incrementally improved with each new measurement of the inter-packet time separations in a sequence of probe packet pairs. The measurement model has a strong non-linearity, and would not at first sight be considered suitable for Kalman filtering, but we show how this non-linearity can be handled. BART may be tuned according to the specific needs of the measurement application, such as agility vs. stability of the estimate. We have tested an implementation of BART in a physical test network with carefully controlled cross traffic, with good accuracy and agreement. Test measurements have also been performed over the Internet. We compare the performance of BART with that of pathChirp, a state-of-the-art tool for measuring end-to-end available bandwidth in real-time
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| 4. |
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| 5. |
- Ekelin, Svante, et al.
(författare)
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Real-time measurement of end-to-end available bandwidth using Kalman filtering
- 2006. - 1
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Konferensbidrag (refereegranskat)abstract
- This paper presents a new method, BART (Bandwidth Available in Real-Time), for estimating the end-to-end available bandwidth over a network path. It estimates bandwidth quasi-continuously, in real-time. The method has also been implemented as a tool. It relies on self-induced congestion, and probes the network path with trains of probe packets, sent at randomized rates. BART requires little computation in each iteration, is light-weight with respect to memory requirements, and adds only a small amount of probe traffic. The BART method is based on Kalman filtering, which enables real-time estimation (a.k.a. tracking) with optimum performance under general conditions. It maintains a current estimate, which is incrementally improved with each new measurement of the inter-packet time separations in a probe packet train. The measurement model has a strong non-linearity, and would not at first sight be considered suitable for Kalman filtering, but we show how this non-linearity can be handled. BART may be tuned according to the specific needs of the measurement application, such as agility vs. stability of the estimate, and the desired time-scale on which to track traffic fluctuations. We have tested BART in a physical test network with carefully controlled cross traffic, with good accuracy and agreement. Test measurements have also been performed over the Internet. We compare the performance of BART with that of pathChirp, a state-of-the-art tool for measuring end-to-end available bandwidth in real-time.
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| 6. |
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| 7. |
- Emborg, Mats, et al.
(författare)
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Designing robust SCC for industrial construction with cast in place concrete
- 2005
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Ingår i: Second North American Conference on the Design and Use of Self-Consolidating Concrete [and] Fourth International RILEM Symposium on Self-Compacting Concrete; [October 30 - November 2, 2005];Second North American Conference on the Design and Use of Self-Consolidating Concrete [and] Fourth International RILEM Symposium on Self-Compacting Concrete; [October 30 - November 2, 2005. - Hanley Wood. ; , s. 1251-1257
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Konferensbidrag (refereegranskat)
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| 8. |
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| 9. |
- Fischer, Martin, et al.
(författare)
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SPASS : Strengthen Performance Active Safety Simulator
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the SPASS project was to evaluate early development/rapid prototyping of new driver assistance systems by utilizing an advanced driving simulator in combination with a vehicle electrical architecture (including sensors, actuators and HMI). As a case study, the project demonstrated a novel active safety function which was rather well penetrated at Volvo Car Corporation (VCC), i.e. VCC had reference vehicles up and running. The project used VTI’s advanced driving simulator (Sim IV) in Gothenburg to establish a simulator platform for evaluation of driver-system interaction. The objective was to understand the capability of Sim IV when studying active safety functions requiring interaction between road infrastructure, sensors, electrical architecture, actuators and Human-Machine Interaction, and to understand how useful Sim IV is during the ordinary concept development phase at vehicle manufacturers. Warning systems that act when the driver is on the way to unintentionally leave the lane are already available today. The next generation of systems will not only warn the driver but will actively contribute to the steering task. One such system is VCC’s eLKA (emergency lane keeping assistance). As part of the SPASS project a scenario which lead to triggering of the eLKA function was developed and tested. The scenario consisted of rural road driving where drivers were distracted by means of a visual distraction task (reading numbers from a screen, placed at a relative large down angle relative to the view of the forward roadway) and then poured across the median towards an oncoming vehicle by introducing an additional steering angle in the simulated vehicle. An integrated test environment for active safety functions has been developed and evaluated. VCC’s emergency lane keeping assistance system (eLKA) has been used as test case in the evaluation, and the functioning of the eLKA has been validated and approved by experts at VCC.
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| 10. |
- Ghasemi, Yahya, 1982-
(författare)
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Aggregates in Concrete Mix Design
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The importance of studying the behaviour and properties of concrete can be highlighted by considering the fact that concrete is the most used man-made material in the world. The very first step in making concrete is its mix design and deciding the type and amount of constitutes used in the production of concrete which should fulfil the requirements of the final product. Mix design models are commonly used for the purpose of proportioning concrete ingredients while anticipating the properties of the final product. The current document deals with the commonly used principals in mix design models namely particle packing theory and excess water/paste layer theories. The conducted studies includes an investigation on accuracy of particle packing models (Toufar, 4C, CPM) and also tries to address the issue with measurement of specific surface area of particles as an essential input to water/paste layer theories. It has been observed that the particle packing models can predict the packing density with acceptable margin. However, it should be mentioned that the particle packing models by themselves are not mix design models but should be rather used as a part of a mix design. In addition, it was found that the accuracy of calculating the specific surface area of particles based on their size distribution curve can be further improved by assuming angular platonic solids as uniform shape of aggregate instead of traditional approach of assuming spheres for aggregates’ shape.
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