| 161. |
- Olsson-Strömberg, Ulla, et al.
(författare)
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Imatinib activity in vitro in tumor cells from patients with chronic myeloid leukemia in chronic phase and blast crisis
- 2006
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Ingår i: Anti-Cancer Drugs. - : Ovid Technologies (Wolters Kluwer Health). - 0959-4973 .- 1473-5741. ; 17:6, s. 631-639
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were to evaluate the feasibility of using the non-clonogenic fluorometric microculture cytotoxicity assay in drug sensitivity testing of tumor cells from patients with chronic myeloid leukemia. In nine samples (six chronic phase, three blast crisis), the drug sensitivities in tumor cells from blood versus from bone marrow and fresh tumor cells versus cryopreserved were compared. In 26 samples obtained in chronic phase (pretreatment), in six samples from patients in blast crisis and in the K 562 cell line, the activity of imatinib alone and in combination with cytarabine, vincristine, daunorubicin, interferon, arsenic trioxide and homoharringtonine was evaluated. All chronic myeloid leukemia chronic phase samples were sensitive to imatinib, with a mean IC50 at 10.3 mumol/l. The chronic myeloid leukemia samples from blast crisis (n=6) were significantly more sensitive to imatinib than the samples from chronic phase (n=26) (P<0.05), with an IC50 mean at 0.4 mumol/l. In blast crisis samples, significant positive interaction effects were observed between imatinib and all other tested drugs except for interferon. In chronic phase samples, interferon, daunorubicin and arsenic trioxide were the drugs with the highest frequency of positive interactions with imatinib (P<0.05). We conclude that the fluorometric microculture cytotoxicity assay may be a useful method for drug sensitivity testing in chronic myeloid leukemia patient samples from both chronic phase and blast crisis, and that testing primary tumor cells may have advantages over cell line studies. Imatinib shows a higher in vitro activity and more positive drug interactions in cells from blast crisis than chronic phase chronic myeloid leukemia patients. Combinations between imatinib and interferon, daunorubicin and arsenic trioxide may be interesting for future clinical trials in patients with chronic myeloid leukemia chronic phase.
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| 162. |
- Olsson, Tomas, et al.
(författare)
-
Cost-efficient drilling using industrial robots with high-bandwidth force feedback
- 2010
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Ingår i: Robotics and Computer-Integrated Manufacturing. - : Elsevier. - 0736-5845 .- 1879-2537. ; 26:1, s. 24-38
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Tidskriftsartikel (refereegranskat)abstract
- Here we present a method for high-precision drilling using an industrial robot with high-bandwidth force feedback which is used for building up pressure to clamp-up an end-effector to the work-piece surface prior to drilling, The focus is to eliminate the sliding movement (skating) of the end-effector during the clamp-up of the end-effector to the work-piece surface, an undesired effect that is due to the comparatively low mechanical stiffness of typical serial industrial robots. This compliance also makes the robot deflect due to the cutting forces, resulting in poor hole position accuracy and to some extent in poor hole quality. Recently, functionality for high-bandwidth force control has found its way into industrial robot control systems. This could potentially open up the possibility for robotic drilling systems with improved performance, using only standard systems without excessive extra hardware and calibration techniques. Instead of automation with expensive fixtures and precise machinery, our approach was to make use of standard low-cost robot equipment in combination with sensor feedback. The resulting sliding suppression control results in greatly improved hole positioning and quality. The conceptual idea behind the force control is useful also in many other robotic applications requiring external sensor feedback control.
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| 163. |
- Olsson, Thomas, et al.
(författare)
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Flexible Force Control for Accurate Low-Cost Robot Drilling
- 2007
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Ingår i: 2007 IEEE International Conference on Robotics and Automation (IEEE Cat No. 07CH37836D). ; , s. 4770-4775
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Konferensbidrag (refereegranskat)abstract
- The problem of robot drilling presents a significant challenge, due to the comparatively low mechanical stiffness of typical serial industrial robots. This compliance makes the robot deflect due to the cutting forces, resulting in poor hole quality. Recently, functionality for high-bandwidth force control has found its way into industrial robot control systems. This could potentially open up the possibility of robotic drilling systems with improved performance, using only standard systems without costly extra hardware and calibration techniques. In this paper, we present methods and systems for force-controlled robot drilling, based on active suppression of drill sliding through a model-based force control scheme. The methods are validated in a number of drilling experiments using an industrial robot.
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| 164. |
- Olsson, Tomas, et al.
(författare)
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Flexible Force-Vision Control for Surface Following using Multiple Cameras
- 2004
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Ingår i: Proceedings. 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2004. (IROS 2004).. - 0780384636 ; 1, s. 789-803
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Konferensbidrag (refereegranskat)abstract
- A flexible method for six-degree-of-freedom combined vision/force control for interaction with a stiff uncalibrated environment is presented. An edge-based rigidbody tracker is used in an observer-based controller, and combined with a six-degree-of-freedom force- or impedance controller. The effect of error sources such as image space measurement noise and calibration errors are considered. Finally, the method is validated in simulations and a surface following experiment using an industrial robot.
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| 165. |
- Olsson, Tomas, et al.
(författare)
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Force Control and Visual Servoing Using Planar Surface Identification
- 2002
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Ingår i: Proceedings. ICRA '02.. - 0780372727 ; 4, s. 4211-4216
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Konferensbidrag (refereegranskat)abstract
- When designing flexible multi-sensor based robot systems, one important problem is how to combine the measurements fromdisparate sensors such as cameras and force sensors. In this paper,we present a method for combining direct force control and visualservoing in the presence of unknown planar surfaces. The controlalgorithm involves a force feedback control loop and a vision basedreference trajectory as a feed-forward signal. The vision system isbased on a constrained image-based visual servoing algorithm designedfor surface following, wherethe location and orientation of the planar constraint surface is estimated online using position-, force- and visual data.We show how data from a simple and efficient camera calibration method can be used in combination withforce and position data to improve the estimation and referencetrajectories.The method is validated through experiments involving force controlleddrawing on an unknown surface. The robot will grasp a pen and use itto draw lines between a number of markers drawn ona white-board, while the contact force is kept constant. Despite its simplicity, the performance of the method is satisfactory.
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| 166. |
- Olsson, Tomas, et al.
(författare)
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Force/Vision Based Active Damping Control of Contact Transition in Dynamic Environments
- 2007
-
Ingår i: Dynamical Vision. - 9783540709312 ; 4358, s. 299-313
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- When a manipulator interacts with objects with poorly damped oscillatory modes, undesired oscillations and bouncing may result. In this paper, we present a method for observer-based control of a rigid manipulator interacting with an environment with linear dynamics.The controller injects a desired damping into the environment dynamics, using both visual-and force sensing for stable control of the contact transition.Stability of the system is shown using an observer-based backstepping design method, and simulations are performed in order to validate the chosen approach.
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| 167. |
- Olsson, Tomas, et al.
(författare)
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Force/Vision Based Active Damping Control of Contact Transition in Dynamic Environments
- 2005
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Ingår i: In Proc. 10th IEEE Int. Conf. Computer Vision, Workshop on Dynamical Vision, Beijing.
-
Konferensbidrag (refereegranskat)abstract
- When a manipulator interacts with objects with poorly damped oscillatory modes, undesired oscillations and bouncing may result. In this paper, we present a method for observer-based control of a rigid manipulator interacting with an environment with linear dynamics.The controller injects a desired damping into the environment dynamics, using both visual-and force sensing for stable control of the contact transition.Stability of the system is shown using an observer-based backstepping design method, and simulations are performed in order to validate the chosen approach.
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| 168. |
- Olsson, Tomas, et al.
(författare)
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High-Speed Visual Robot Control Using an Optimal Linearizing Intensity-Based Filtering Approach
- 2006
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Ingår i: 2006 IEEE/RSJ International Conference on Intelligent Robots and Systems (IEEE Cat. No. 06CH37780D). - 1424402581 ; , s. 1212-1217
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Konferensbidrag (refereegranskat)abstract
- Many contact operations in robotics require accurate positioning, which is made difficult by the presence of rapidly varying interaction forces and compliances in gear boxes and links. In order to compensate for such effects, rapid feedback from the measured tool position in several degrees of freedom is needed. This paper presents a dynamic visual tracking technique based directly on intensity measurements in the image, which can be used to obtain state estimates at a very high rate, and with very short input-output latency. Methods for analysis of the stability and sensitivity to disturbances are presented, and an improved version for better disturbance suppression of illumination variations and noise is developed. Positioning experiments using an industrial robot with camera feedback at 250 Hz are used to validate the approach
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| 169. |
- Olsson, Tomas, et al.
(författare)
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Visual Position Tracking using Dual Quaternions with Hand-Eye Motion Constraints
- 2003
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Ingår i: Proceedings. ICRA '03.. - 2152-4092 .- 1050-4729. - 0780377362 ; 3, s. 3491-3496
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Konferensbidrag (refereegranskat)abstract
- In this paper a method for contour-based rigid body tracking with simultaneouscamera calibration is developed. The method works for a singleeye-in-hand camera with unknown hand-eye transformation,viewing a stationary object with unknown position. The method usesdual quaternions to express the relationship between the camera- andend-effector screws. It is shown how using the measured motion of therobot end-effector can improve the accuracy of theestimation, even if the relative position and orientation between sensorand actuator is completely unknown.The method is evaluated in simulations on images from a real-time 3D renderingsystem. The system is shown to be able to track the pose of rigid objects and changes in intrinsic camera parameters, using only rough initial values for the parameters. The method is finally validated in anexperiment using real images from a camera mounted on an industrial robot.
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| 170. |
- Pavlović, Tomislav, et al.
(författare)
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Predicting attitudinal and behavioral responses to COVID-19 pandemic using machine learning
- 2022
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Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542 .- 2752-6542. ; 1:3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- At the beginning of 2020, COVID-19 became a global problem. Despite all the efforts to emphasize the relevance of preventive measures, not everyone adhered to them. Thus, learning more about the characteristics determining attitudinal and behavioral responses to the pandemic is crucial to improving future interventions. In this study, we applied machine learning on the multinational data collected by the International Collaboration on the Social and Moral Psychology of COVID-19 ( = 51,404) to test the predictive efficacy of constructs from social, moral, cognitive, and personality psychology, as well as socio-demographic factors, in the attitudinal and behavioral responses to the pandemic. The results point to several valuable insights. Internalized moral identity provided the most consistent predictive contribution-individuals perceiving moral traits as central to their self-concept reported higher adherence to preventive measures. Similar results were found for morality as cooperation, symbolized moral identity, self-control, open-mindedness, and collective narcissism, while the inverse relationship was evident for the endorsement of conspiracy theories. However, we also found a non-neglible variability in the explained variance and predictive contributions with respect to macro-level factors such as the pandemic stage or cultural region. Overall, the results underscore the importance of morality-related and contextual factors in understanding adherence to public health recommendations during the pandemic.
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