1. |
|
|
2. |
- Berbyuk, Viktor, 1953
(författare)
-
Dynamics and optimal control of biotechnical systems "Man-Prosthesis"
- 1997
-
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
-
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.
|
|
3. |
- Berbyuk, Viktor, 1953
(författare)
-
On complete controllability of linear nonstationary systems
- 1993
-
Ingår i: Journal of Soviet Mathematics. - 0090-4104. ; 67:2, s. 2973-2975
-
Tidskriftsartikel (refereegranskat)abstract
- The concept of controllability is connected with the transfer of a dynamic system from one state to another by means of a control. An important problem in the theory of control systems is the search for necessary and sufficient conditions for complete controllability of dynamic systems. By using of the first integrals of the equations of unperturbed motion the necessary and sufficient conditions for complete controllability of linear nonstationary dynamic systems have been proposed.
|
|
4. |
- Berbyuk, Viktor, 1953
(författare)
-
The use of first integrals to synthesize the energetically optimal control of a nonlinear system
- 1997
-
Ingår i: Journal of Mathematical Sciences. - 1573-8795 .- 1072-3374. ; 86:2, s. 2642-2645
-
Tidskriftsartikel (refereegranskat)abstract
- In the paper a method of solving problems of optimal control of the motion of nonlinear dynamical systemswith respect to energy expenditure given a fixed time and fixed ends of the phase trajectory has been proposed. The method is based on the use of first integrals of the equations of free motion. The application of the method isillustrated by examples.
|
|
5. |
- Eriksson, T., et al.
(författare)
-
Successive Encoding of Correlated Sources
- 1982
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The encoding of a discrete memoryless multiple source for reconstruction of a sequence with is considered. We require that the encoding should be such that is encoded first without any consideration of , while in a seeond part of the encoding this latter sequence is encoded based on knowledge of the outcome of the first encoding. The resulting scheme is called successive encoding. We find general outer and inner bounds for the corresponding set of achievable rates along with a complete single letter characterization for the special case . Comparisons with the Slepian-Wolf problem [3] and the Ahlswede-Körner-Wyner side information problem [2 ], [9) are carried out.
|
|
6. |
- Svanström, Mattias
(författare)
-
Ternary Codes with Weight Constraints
- 1999
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- We study the problem of maximizing the size of a ternary block code with given length and minimum Hamming distance. The problem is further restricted in two different ways. Either we require all codewords to have constant Hamming weight, or we require all codewords to have constant composition. We let the alphabet consist of the symbols zero, one and two. In a constant-composition code the number of zeros, the number of ones and the number of twos in each codeword are fixed, while in a constant-weight code only the total number of ones and twos in each codeword is fixed.For both code classes several upper bounds are presented. We give a number of constructions of codes that meet the upper bounds. A construction of perfect ternary constant-weight codes with minimum distance three is presented. We have also compiled tables of the best possible upper and lower bounds on the code size.
|
|
7. |
|
|
8. |
- Diehl, Stefan, et al.
(författare)
-
Analytical and numerical description of the settling process in the activated sludge operation
- 1990
-
Ingår i: Instrumentation, control, and automation of water and wastewater treatment and transport systems : proceedings of the 5th IAWPRC Workshop held in Yokohama and Kyoto, Japan, 26 July-3 August 1990. - 0080407765 ; , s. 471-478
-
Konferensbidrag (refereegranskat)abstract
- The secondary clarifier or settler is crucial for the whole activated sludge operation. Consequently, it is important to obtain a reliable analytical model as well as a useful numerical method, which can be used in the automatic control of the settling process. Discontinuities (shocks) appear physically, and an analytical description as well as a stable numerical algorithm must be able to handle these discontinuities. A model based on the Kynch theory of sedimentation is used, where the settling flux is a function only of the local concentration and is assumed to have one inflexion point. For such non-convex flux functions, the settling process is qualitatively the same, independent of further assumptions on the shapes of the settling functions. Using the theory of nonlinear conservation laws, the main results obtained are: how to calculate transient and asymptotic behavior; how to control the concentration profile of the settler, in particular the depth of the sludge blanket, for a given load; and, a numerical algorithm which automatically preserves shocks and gives the physically correct solution according to the analytical treatment. The algorithm can be applied on any flux function (with more than one inflexion point).
|
|
9. |
|
|
10. |
|
|