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- Bergvall, Nils, et al.
(författare)
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Emission line flux limits in four QSO metal line absorbers
- 1997
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Ingår i: ASTRONOMY AND ASTROPHYSICS. - : SPRINGER VERLAG. - 0004-6361. ; 321:3, s. 771-775
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Tidskriftsartikel (refereegranskat)abstract
- In an effort to detect the early phases of star formation in massive galaxies, we have searched for Ly alpha and [O II]lambda 3727 emission from four QSO metal absorption line systems and possible associated galaxies, using narrow-band filters. None of th
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| 2. |
- Båvall, Lennart, et al.
(författare)
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Capacitive detection of humans for safety in industry : a numerical and experimental investigation
- 1998
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Ingår i: Measurement science and technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 9:3, s. 505-509
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Tidskriftsartikel (refereegranskat)abstract
- The detection of humans for their own safety in an industrial environment is vital, especially with increases in the flexibility and velocity of automated working machines. A capacitive detector for the detection of humans in guarded zones has been designed. An electromagnetic model accounting for bodies of different permittivity in the vicinity of the sensor is described. Numerical calculations based on the electromagnetic model have been made and experimental measurements have been taken. An example shows how the electromagnetic model can be used to model the output of the person detector.
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| 6. |
- Karlsson, Nils
(författare)
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A Measurement Approach to some Robot Related Issues : Robot Safety, Robot Control Tool and Robot Object Recognition
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The research of the measurement group at Linköping university has for some time been focused on the role of measurements in robotics. The main objective of the group's research work has been to provide the robot with sensor information in order to increase its autonomy.In this work I have studied problematic aspects of robot use that are related to robot safety as seen from the measurement technology point of view. The work can be divided into three subparts:• a sensor for person presence detection• a tool for robot control with built in emergency stop• object recognition, a requirement for increased autonomy that can decrease human presence close to the robot.In robot safety the aim was to develop a man-detecting sensor that could be used for safety purposes. The efforts were concentrated upon a capacitive sensor for the following reasons:• man's electrical characteristics differ strongly from those of the air forced out of its place by the human body• man can not change its electrical characteristics.Both model calculations and practical tests have been made. Persons are detected as intended.Industrial robots are equipped with a teach pendant, a hand held control device. It is connected to the control system of the robot and is used for work in close interaction with the robot. Work close to the robot might for instance be necessary during program verification or adjustments. It is important for a person, physically close to the robot, to be able to change command or initiate an emergency stop rapidly and easily. To that aim a user-friendly control tool with a built-in emergency stop is proposed. The tool is based on a glove that measures the finger flexions. The finger flexions form patterns that correspond to different commands. The commands are recognised by methods based on fuzzy principles. The glove is tested on gestures inspired by the manual alphabet used by deaf people. All gestures/commands were correctly recognised.In the sensor system used by the measurement group a 2-D vision system is used for the localisation and recognition of different work pieces. This system does not in all cases provide the 3-D information needed, e. g. whether an object is a cylinder or a cube. A two-camera system or special illumination techniques can provide the information. A very simple laser scanner provides however enough information for the detection, i. e. gives unique signatures for differently shaped objects. We have investigated this simple and relatively cheap solution. Fourier transformation is used to recognise the differences in the detected laser scanner signal. The result shows that it is possible to recognise objects by this method.
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| 7. |
- Karlsson, S., et al.
(författare)
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Epitaxial growth of SiC in a new multi-wafer VPE reactor
- 1999
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Ingår i: Materials Science & Engineering. - 0921-5107 .- 1873-4944. ; 61-62, s. 143-146
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Tidskriftsartikel (refereegranskat)abstract
- SiC epitaxial layers have been grown in a commercial multi-wafer reactor. Results from the initial growth runs are presented. The reactor is vertical and has a high speed rotating susceptor that can support up to six 50 mm diameter wafers. The surface morphology of the grown layers are specular and show no indication of step-bunching. The unintentional background doping is p-type in the low 10(15) cm(-3) range, consisting mainly of Al. Both N and Al have been used for doped layers showing wide doping range capability and sharp transients. The best uniformity in thickness and doping achieved so far on the same 35 mm wafer are +/- 7% and +/- 10%, respectively. (C) 1999 Elsevier Science S.A. All rights reserved.
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| 9. |
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Konsten som kunskap
- 1995
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Ingår i: Framtider. - 0281-0492. ; 14:1
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Special issue av Framtider
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| 10. |
- Lohmander, L. Stefan, et al.
(författare)
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Intra-articular hyaluronan injections in the treatment of osteoarthritis of the knee : A randomised, double blind, placebo controlled multicentre trial
- 1996
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967. ; 55:7, s. 424-431
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Tidskriftsartikel (refereegranskat)abstract
- Objective - To assess the effects of intraarticular injections of hyaluronan on symptoms of knee osteoarthritis (OA). Methods - Two hundred and forty patients with symptomatic, radiological knee OA were randomly assigned to treatment with weekly injections for five weeks with either 25 mg of high molecular weight hyaluronan or vehicle. Results were evaluated at weeks 1, 2, 3, 4, 5, 13, and 20 by visual analogue scales (pain, function, motion, activity), algofunctional index, and global evaluation by patient and investigator. Analysis was by 'intention to treat', 'per protocol), and area under the curve principles on unstratified patient groups and for patients stratified into four groups of equal size by age and baseline algofunctional index. Results - No serious side effects were reported. At 20 weeks both treatment groups were improved compared with baseline, with no difference between unstratified groups treated with placebo or hyaluronan. Comparison of treatment-groups stratified by age and baseline algofunctional index revealed a significant-difference in favour of hyaluronan over placebo (pain, activity, algofunctional index, global evaluations by patient-and investigator) for patients older than 60 years and with a baseline algofunctional index greater than 10. There was no clinically relevant difference between the two treatments for the other three stratified subgroups of younger age or fewer symptoms. Similar results were obtained by area under the curve, intention to treat, and per protocol analysis. Conclusions-Patients older than 60 years with knee osteoarthritis and with significant symptoms corresponding to an index of severity of knee disease of 10 or more, comprise the group most likely to benefit from treatment with intra-articular hyaluronan injections.
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