| 1. |
- Aderklou, Christina, et al.
(författare)
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Pedatronics : Robotic toys as a source to evoke young girls’ technological interest
- 2002
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Ingår i: 32nd Annual Frontiers in Education. Leading a Revolution in Engineering and Computer Science Education. - San Diego : Institute of Electrical and Electronics Engineers (IEEE). - 0780374444 ; , s. F1C-19-F1C-24
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Konferensbidrag (refereegranskat)abstract
- This paper presents some results within Pedatronics; a fusion between pedagogics and mechatronics. Our research interest is to study what emerges in the play with robotic toys. Field-experimental studies of 67 year old children’s purposeless play with robotic toys created a self-developmental sphere, as well as evoked young girl’s technological interest. Both girls and boys prolonged and intensified their interest according to the amount of gadgets involved. The results disclose a learning potential, indicating the importance to develop strategies at an early stage in order to encourage girls to choose technological and engineering educations. The study recommend engineers and toy designers, in cooperation with children, to move towards ’Integrated Play Systems’. Due to an ethological method, the results differ from other studies of children’s play with technological advanced artefacts. © 2002 IEEE
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| 2. |
- Arvidson, Nicklas, 1967, et al.
(författare)
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Cerebrospinal fluid viral load, virus isolation, and intrathecal immunoactivation in HIV type 2 infection.
- 2004
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Ingår i: AIDS research and human retroviruses. - : Mary Ann Liebert Inc. - 0889-2229 .- 1931-8405. ; 20:7, s. 711-5
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Tidskriftsartikel (refereegranskat)abstract
- Four patients with HIV-2 infection were followed longitudinally with cerebrospinal fluid (CSF) analyses. Two patients had positive CSF HIV-2 isolations. These two patients had CD4 cell count below 200 x 10(6)/liter and maximum CSF HIV-2 RNA viral loads above 4000 copies/ml. Intrathecal immune activation was demonstrated by elevated CSF neopterin concentrations (14-18 nmol/liter). No opportunistic infections were diagnosed. After antiretroviral treatment CSF viral counts decreased to below 125 copies/ml and CSF neopterin concentrations decreased. In two other patients who had CD4 counts within the normal range CSF virus isolations were repeatedly negative and viral CSF loads were below 125 copies/ml. However, a slightly elevated CSF neopterin concentration in one sample and pleocytosis in another might also be caused by HIV-2 in these patients. Before antiretroviral treatment HIV-2 isolations from blood were positive in all four patients. Maximum HIV-2 RNA viral loads were higher in blood than in CSF. Treatment failure in one patient with increasing viral loads in blood did not result in viral rebound in CSF.
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| 3. |
- Baerveldt, Albert-Jan
(författare)
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A vision system for object verification and localization based on local features
- 2001
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Ingår i: Robotics and Autonomous Systems. - Amsterdam : Elsevier. - 0921-8890 .- 1872-793X. ; 34:2-3, s. 83-92
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Tidskriftsartikel (refereegranskat)abstract
- An object verification and localization system should answer the question whether an expected object is present in an image or not, i.e. verification, and if present where it is located. Such a system would be very useful for mobile robots, e.g. for landmark recognition or for the fulfilment of certain tasks. In this paper, we present an object verification and localization system specially adapted to the needs of mobile robots. The object model is based on a collection of local features derived from a small neighbourhood around automatically detected interest points. The learned representation of the object is then matched with the image under consideration. The tests, based on 81 images, showed a very satisfying tolerance to scale changes of up to 50%, to viewpoint variations of 20, to occlusion of up to 80% and to major background changes as well as to local and global illumination changes. The tests also showed that the verification capabilities are very good and that similar objects did not trigger any false verification.
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| 4. |
- Baerveldt, Albert-Jan, et al.
(författare)
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Editorial
- 2003
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Ingår i: Robotics and Autonomous Systems. - Amsterdam : Elsevier. - 0921-8890 .- 1872-793X. ; 44:1, s. 1-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 5. |
- Baerveldt, Albert-Jan
(författare)
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Guest editorial : Agricultural robotics
- 2002
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Ingår i: Autonomous Robots. - Berlin : Springer. - 0929-5593 .- 1573-7527. ; 13:1, s. 5-7
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Baerveldt, Albert-Jan, et al.
(författare)
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Vision-guided mobile robots for design competitions
- 2003
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Ingår i: IEEE robotics & automation magazine. - : IEEE, The Institute of Electrical and Electronics Engineers. - 1070-9932 .- 1558-223X. ; 10:2, s. 38-44
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Tidskriftsartikel (refereegranskat)abstract
- The use of popular and effective robot-design competitions in teaching system integration in engineering curricula was discussed. Such robot competitions give students open-ended problem spaces, teaches them to work in groups and stimulates creativity. The technical and pedagogical aspects of robot competitions along with their experiences and shortcomings were also discussed.
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| 7. |
- Bengtsson, Ola, et al.
(författare)
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Localization in changing environments - Estimation of a covariance matrix for the IDC algorithm
- 2001
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Ingår i: Proceedings 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems. Expanding the Societal Role of Robotics in the the Next Millennium (Cat. No.01CH37180). - Piscataway, N.J. : IEEE. - 0780366123 ; , s. 1931-1937
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Konferensbidrag (refereegranskat)abstract
- Previously we have presented a new scan-matching algorithm, based on the IDC - Iterative Dual Correspondence- algorithm, which showed a good localization performance even in the case of severe changes in the environment. The Problem of the IDC-algorithm is that there is no good way to estimate the covariance matrix of the position estimate, which prohibits an effective fusion with other position estimates from other sensors, e.g by means of the Kalman filter. In this paper we present a new way to estimate the covariance matrix, by estimating the Hessian matrix of the error function that is minimized by the IDC scan-matching algorithm. Simulation results show that the estimated covariance matrix correspond well to the real one.
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| 8. |
- Bengtsson, Ola, et al.
(författare)
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Robot localization based on scan-matching - estimating the covariance matrix for the IDC algorithm
- 2003
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Ingår i: Robotics and Autonomous Systems. - Amsterdam : Elsevier. - 0921-8890 .- 1872-793X. ; 44:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- We have previously presented a new scan-matching algorithm based on the IDC (iterative dual correspondence) algorithm, which showed a good localization performance even in environments with severe changes. The problem of the IDC algorithm is that there is no good way to estimate a covariance matrix of the position estimate, which prohibits an effective fusion with other position estimates of other sensors. This paper presents two new ways to estimate the covariance matrix. The first estimates the covariance matrix from the Hessian matrix of the error function minimized by the scan-matching algorithm. The second one, which is an off-line method, estimates the covariance matrix of a specific scan, from a specific position by simulating and matching scans around the position. Simulation results show that the covariance matrix provided by the off-line method fully corresponds with the real one. Some preliminary tests on real data indicate that the off-line method gives a good quality value of a specific scan position, which is of great value in map building.
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| 9. |
- Brandin, Eleonor, et al.
(författare)
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pol gene sequence variation in Swedish HIV-2 patients failing antiretroviral therapy
- 2003
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Ingår i: AIDS Res Hum Retroviruses. ; 19:7, s. 543-50
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Tidskriftsartikel (refereegranskat)abstract
- There is limited knowledge about how to treat and interpret results from genotypic resistance assays in HIV-2 infection. Here, genetic variation in HIV-2 pol gene was studied in 20 of 23 known HIV-2 cases in Sweden. Five patients with signs of virological treatment failure were longitudinally studied. Clinical, virological and immunological data were collected and the protease (PR) and first half of the reverse transcriptase (RT) was amplified and directly sequenced from plasma samples. Moderate to extensive genetic evolution was observed in four of the five patients who failed treatment. Some mutations occurred at positions known to confer resistance in HIV-1, but many occurred at other positions in PR and RT. All patients had been treated with zidovudine alone or in combination with other antiretroviral drugs, but none displayed a mutation at position 215, which is the primary zidovudine resistance site in HIV-1. Instead, a E219D mutation evolved in virus from two patients and a Q151M mutation evolved in two other patients. A M184V mutation indicative of lamivudine resistance was detected in three patients. The virus of one patient who had been treated with ritonavir, nelfinavir, and lopinavir successively acquired nine unusual mutations in the protease gene, most of which are not considered primary or secondary resistance mutations in HIV-1. Our data indicate that the evolutionary pathways that lead to antiretroviral resistance in HIV-2 and HIV-1 exhibit both similarities and differences. Genotypic HIV-2 resistance assays cannot be interpreted using algorithms developed for HIV-1, instead new algorithms specific for HIV-2 have to be developed.
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| 10. |
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