| 1. |
- Ekman, Stefan, et al.
(författare)
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Skånes lavar
- 2003
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Ingår i: Floran i Skåne. Vegetation och utflyktsmål.. - 9197102148 ; , s. 125-132
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Bokkapitel (populärvet., debatt m.m.)
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| 2. |
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| 3. |
- Gustafsson, Mats
(författare)
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On the non-uniqueness of the electromagnetic instantaneous response
- 2003
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Ingår i: Journal of Physics A: Mathematical and General. - : IOP Publishing. - 0305-4470. ; 36:6, s. 1743-1758
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Tidskriftsartikel (refereegranskat)abstract
- The instantaneous response models the rapid part of the interaction between electromagnetic fields and materials. From a physical point of view the instantaneous response is non-observable and from a mathematical point of view it constitutes the principal part of the Maxwell equations. In this paper, it is shown that the instantaneous response is not uniquely determined from a given set of values of the constitutive map. The given values only give an upper bound on the size of the instantaneous response. A numerical example illustrates the non-uniqueness of the instantaneous response.
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| 4. |
- Gustafsson, Mats, et al.
(författare)
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Refractometry of microscopic objects using digital holography
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Digital holography has some desirable properties for refractometry of microscopic objects since it gives phase and amplitude information of an object in all depths of focus from one set of exposures. The refractive index of the object can be determined by observation of the movements of the Becke lines between different focus depths. It is also shown that one single phase image provides an independent technique to determine sign of the relief between an object and the surrounding medium.
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| 5. |
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| 6. |
- Jonsson, B Lars G, et al.
(författare)
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Retrofocusing of Acoustic Wave Fields by Iterated Time Reversal
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the present paper an iterative time-reversal algorithm, that retrofocuses an acoustic wave field to its controllable part is established. For a fixed temporal support, i.e., transducer excitation time, the algorithm generates an optimal retrofocusing in the least-squares sense. Thus the iterative time-reversal algorithm reduces the temporal support of the excitation from the requirement of negligible remaining energy to the requirement of controllability. The timereversal retrofocusing is analyzed from a boundary control perspective where time reversal is used to steer the acoustic wave field towards a desired state. The wave field is controlled by transducers located at subsets of the boundary, i.e., the controllable part of the boundary. The time-reversal cavity and time-reversal mirror cases are analyzed. In the cavity case, the transducers generate a locally plane wave in the fundamental mode through a set of ducts. Numerical examples are given to illustrate the convergence of the iterative time-reversal algorithm. In the mirror case, a homogeneous half space is considered. For this case the analytic expression for the retrofocused wave field is given for finite temporal support. It is shown that the mirror case does not have the same degree of steering as the cavity case. It is also shown that the pressure can be perfectly retrofocused for infinite temporal support. Two examples are given that indicate that the influence of the evanescent part of the wave field is small.
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| 7. |
- Lenart, Thomas, et al.
(författare)
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Accelerating signal processing algorithms in digital holography using an FPGA platform
- 2003
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Ingår i: Proceedings. 2003 IEEE International Conference on Field-Programmable Technology (FPT). - 0780383206 ; , s. 387-390
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Konferensbidrag (refereegranskat)abstract
- This paper describes the implementation of a custom DSP system to accelerate image processing algorithms used in the field of digital holography. The system, implemented on an FPGA platform, is intended for real-time reconstruction of images captured on a large image sensor. Due to the large amount of processing information, it is not possible to perform a HDL simulation of a complete image reconstruction in reasonable time. Instead, a reconfigurable solution is being used for full scale image reconstruction, exhaustive testing of the functionality and for connecting the accelerator to external components, i.e. the image sensor, monitor output device and high-speed memory banks
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| 8. |
- Snogerup, Sven, et al.
(författare)
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Skånska vegetationstyper
- 2003
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Ingår i: Floran i Skåne. Vegetation och utflyktsmål. - 9197102148 ; , s. 53-76
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Bokkapitel (populärvet., debatt m.m.)
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| 9. |
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| 10. |
- Tyler, Torbjörn, et al.
(författare)
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Skånes mossor.
- 2003
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Ingår i: Floran i Skåne. Vegetation och utflyktsmål.. - 9197102148 ; , s. 117-124
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Bokkapitel (populärvet., debatt m.m.)
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