| 1. |
- Berbyuk, Viktor, 1953
(författare)
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Multibody dynamics and optimization problems of an above-knee prostheses
- 1996
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- New prosthetic materials and designs have resulted in many prostheses of lower limbs which are presently available for the amputee to use. As a result, it is becoming more difficult for the prosthetists and the physicians to choose which prosthesis is the best for the individual amputee. Presently, there is limited information about how the prosthesis performs dynamically in achieving optimal symmetrical gait for amputee. To provide insight into the interaction between dynamics and control in biotechnical systems and for optimizing the prosthesis's structure the energy-optimal control problem of the human locomotor system (HLS) wearing an above-knee prosthesis has been considered. The algorithm based on multibody dynamics approach and special conversion of the optimal control problem for nonlinear dynamic system model of the HLS into a standard nonlinear programming problem has been proposed. A number of the energy-optimal control problems of human locomotion with an artificial leg and the optimization problems of the constructive parameters of an above-knee prostheses under different boundary conditions and constraints have been solved.
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| 2. |
- Angelopoulos, A., et al.
(författare)
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K 0–KÌ„0 mass and decay-width differences : CPLEAR evaluation
- 1999
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 471:2, s. 332-338
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Tidskriftsartikel (refereegranskat)abstract
- The CPT-violation parameters Re(δ) and Im(δ) determined recently by CPLEAR are used to evaluate the K0– mass and decay-width differences, as given by the difference between the diagonal elements of the neutral-kaon mixing matrix (M−iΓ/2). The results – GeV and GeV – are consistent with CPT invariance. The CPT invariance is also shown to hold within a few times 10−3–10−4 for many of the amplitudes describing neutral-kaon decays to different final states.
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| 3. |
- van der Wijngaart, Wouter, et al.
(författare)
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Valve-less diffuser fluid micropump
- 1999
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Ingår i: Gordon Research Conference 1999, Analytical Chemistry, New Hampshire, USA.
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Konferensbidrag (refereegranskat)
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| 4. |
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| 5. |
- Munthe, Christian, 1962
(författare)
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Pure Selection. The Ethics of Preimplantation Genetic Diagnosis and Choosing Children without Abortion
- 1999
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Preimplantation ge¬netic diagnosis (PGD) is taken to mark the starting-point of a new phase in human reproduction, where the possibility of choosing children on genetic grounds without having to resort to ethi¬cally controversial procedures (such as abortion) will grad¬ually increase. Ethical and political issues actu¬alised by this develop¬ment are addressed. The discussion touches upon issues regarding the moral status of em¬bryos and gametes, the moral import of respecting individual auton¬omy and its implications for the requirement of informed consent in health-care, the connec¬tion between sickness, dis¬ability and the value of life, the moral status of possible future people, and the connection between choosing children and eugenic policies of the past. Practical policy issues are adressed on the basis of this, as well as an empirical case-study of the intro¬duction of PGD in Sweden. The book ends up in a set of recommendations regarding the management of re¬search on, introduction and routine use of procedures for pure se¬lection, both within health care and from the point of view of society as a whole. It is argued that research on such procedures should be allowed and supported by society. However, tight restrictions regarding the clinical introduction of new procedures in this area is highly desirable. A rough model for implementing such re¬strictions is also pre¬sented. It is further asserted that, although reasons of economy and safety should limit the access to pure se¬lection, society should not apply any explicit restrictions based on ideasregarding how different traits affect a person’s quality of life. It is stressed that, in order to to avoid a re¬sur¬rection of eugenic policies of the past, the development in this field un¬der¬lines the need for continued and strengthen public support to the sick, dis¬abled and mentally retarded.
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| 6. |
- Berbyuk, Viktor, 1953
(författare)
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Dynamics and optimal control of biotechnical systems "Man-Prosthesis"
- 1997
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Ingår i: IUTAM Symposium on Interaction Between Dynamics and Control in Advanced Mechanical Systems, Ed. D. van Campen, Kluwer Academic Publishers, 1997. - Dordrecht : Springer Netherlands. ; , s. 35-42
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Konferensbidrag (refereegranskat)abstract
- In the paper, a mathematical model is proposed for investigating the controlled motion of human locomotion system (HLS) with an above-knee prosthesis. To provide insight into the interaction between dynamics and control in biotechnical system Man-Prosthesis the energy optimal control problem of the HLS wearing a lower limb prosthesis has been considered. The algorithm is based on special conversion of the optimal control problem for a nonlinear dynamical system which models HLS into a standard nonlinear programming problem. A number of energy-optimal control problems of human locomotion with an artificial leg, and optimization problems for the constructive parameters of the prostheses under different boundary conditions and constraints have been solved. The numerical results obtained were compared with experimental data for normal human locomotion. The energy-optimal elastic and viscoelastic characteristics of the ankle and knee joints of the prostheses have been determined.
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| 7. |
- Berbyuk, Viktor, 1953
(författare)
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Multibody systems modeling and optimization problems of lower limb prostheses
- 1996
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Ingår i: 1996 IUTAM Symposium on Optimization of Mechanical Systems. - Dordrecht : Springer Netherlands. ; , s. 25-32
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Konferensbidrag (refereegranskat)abstract
- To study the effect of prosthesis design on the kinematic, dynamic, energetic and other characteristics of an amputee's locomotion and to improve and create new efficient lower limb prostheses it is expendient to use mathematical modeling of a human walk process and dynamic optimization techniques. In this paper a mathematical model is proposed for investigating the dynamics of a man's skeletal system (MSS) with a below-knee prosthesis. A MSS is simulated by a plane controlled dynamic system of rigid masses. The controlled motions of the system are described by Lagrange's equations of the second kind, and for the expressions for kineto-static balance of the prosthesis under the action of ankle and metatarsal moments and the forces of reactions are derived. An algorithm is construced for solving the problem of human gait dynamics with a below-knee prosthesis. The series of dynamics problems for multibody biothechnical system "Man-Prosthesis" and optimization of structural parameters of the artificial lower extremity of a man has been solved.
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| 8. |
- Apostolakis, A, et al.
(författare)
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A determination of the CP violation parameter η+- from the decay of strangeness-tagged neutral kaons
- 1999
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 458:4, s. 545-552
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Tidskriftsartikel (refereegranskat)abstract
- LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of CP, T and CPT symmetries in the neutral-kaon system. A variety of measurements allowed us to determine with high precision the parameters which describe the time evolution of the neutral kaons and their antiparticles, including decay amplitudes, and the related symmetry properties. Limits concerning quantum-mechanical predictions (EPR, coherence of the wave function) or the equivalence principle of general relativity have been obtained. An account of the main features of the experiment and its performances is given here, together with the results achieved.
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| 9. |
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| 10. |
- Borga, Magnus, et al.
(författare)
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An Adaptive Stereo Algorithm Based on Canonial Correlation Analysis
- 1998
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Ingår i: Proceedings of the Second IEEE International Conference on Intelligent Processing Systems. ; , s. 177-182
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Konferensbidrag (refereegranskat)abstract
- This paper presents a novel algorithm that uses CCA and phase analysis to detect the disparity in stereo images. The algorithm adapts filters in each local neighbourhood of the image in a way which maximizes the correlation between the filtered images. The adapted filters are then analysed to find the disparity. This is done by a simple phase analysis of the scalar product of the filters. The algorithm can even handle cases where the images have different scales. The algorithm can also handle depth discontinuities and give multiple depth estimates for semitransparent images.
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