125 research outputs found
Kiri Fr. von Matthisson'ile
Lichtenberg, Georg Christoph, 1742-1799, saksa filosoof ja loodusteadlane, Peterburi TA liigeMatthisson, Friedrich von, 1761-1831, saksa kirjanikSelgitab eksitust, mis tekkis adressaadiga kohtumise
An Approach to State Signal Shaping by Limit Cycle Model Predictive Control
A novel nonlinear model predictive control approach for state signal shaping
is proposed. The control strategy introduces a residual shape cost kernel based
on the dynamics of circular limit cycles from a supercritical Neimark-Sacker
bifurcation normal form. This allows the controller to impose a fundamental
harmonic state signal shape with a specific frequency and amplitude. An
application example for harmonic compensation in distribution grids integrated
with renewable energies is presented. The controller is tasked with the
calculation of the reference current for an active power filter used for load
compensation. The results achieved are successful, reducing the harmonic
distortion to satisfactory levels while ensuring the correct frequency and
amplitude.Comment: \copyright 2020 Carlos Cateriano Y\'a\~nez, Gerwald Lichtenberg,
Georg Pangalos and Javier Sanchis S\'aez. This work has been accepted to IFAC
for publication under a Creative Commons Licence CC-BY-NC-N
Classical and quantum dynamics of the n-dimensional kicked rotator
The classical and quantum dynamics for an n-dimensional generalization of the
kicked planar (n=1) rotator in an additional effective centrifugal potential.
Therefore, typical phenomena like the diffusion in classical phase space are
similar to that of the one-dimensional model. For the quantum dynamics such a
result is not expected as in this case the evolution does depend in a very
complicated way on the number n of degrees of freedom. In the limit n -->
infinity we find the free undistrubed quantum motion. For finite values of n
(1<=n<=26) we study numerically the quantum dynamics. Here, we always find
localization independent of the actual number of degrees of freedom.Comment: uuencoded gzipped postscript file, Problem in postscript file
resolved. For uncompressed postscript file see
http://faupt101.physik.uni-erlangen.de/junker/papers95.ht
Active Power Filter Shape Class Model Predictive Controller tuning by Multiobjective Optimization
[EN] In order to compensate the power quality issues that arise in distribution
grids with high penetration of renewable energy sources, an active power
filter device controlled by a novel model-based predictive controller, i.e. the
linear state signal shaping model predictive controller, is implemented. This
paper proposes the use of a Multiobjective Optimization evolutionary
algorithm, i.e. the Multiobjective Differential Evolution with Spherical
Pruning X, for the tuning of this novel controller. An application example for
power quality compensation of a grid modeled as a switched system with four
modes is given. The model includes nonlinear loads that introduce harmonic
distortion and multiple consumer loads that enable the existence of
conflicting objectives, typical of multiobjective optimization problems. A
decision making strategy is developed in order to find the best controller
parameters in a reasonable amount of time that enable the provision of
optimal power quality services by balancing multiple objectives that can
conflict with each other.This contribution was partly developed within the project NEW 4.0 (North German Energy
Transition 4.0) which is funded by the German Federal Ministry for Economic Affairs and
Energy (BMWI). This paper was also partly funded by the Free and Hanseatic City of
Hamburg (Hamburg City Parliament publication 20/11568).Cateriano Yáñez, C.; Richter, J.; Pangalos, G.; Lichtenberg, G.; Sanchís Saez, J. (2019). Active Power Filter Shape Class Model Predictive Controller tuning by Multiobjective Optimization. En Proceedings 5th CARPE Conference: Horizon Europe and beyond. Editorial Universitat Politècnica de València. 79-86. https://doi.org/10.4995/CARPE2019.2019.10166OCS798
Improving comparability between microarray probe signals by thermodynamic intensity correction
Signals from different oligonucleotide probes against the same target show great variation in intensities. However, detection of differences along a sequence e.g. to reveal intron/exon architecture, transcription boundary as well as simple absent/present calls depends on comparisons between different probes. It is therefore of great interest to correct for the variation between probes. Much of this variation is sequence dependent. We demonstrate that a thermodynamic model for hybridization of either DNA or RNA to a DNA microarray, which takes the sequence-dependent probe affinities into account significantly reduces the signal fluctuation between probes targeting the same gene transcript. For a test set of tightly tiled yeast genes, the model reduces the variance by up to a factor ∼1/3. As a consequence of this reduction, the model is shown to yield a more accurate determination of transcription start sites for a subset of yeast genes. In another application, we identify present/absent calls for probes hybridized to the sequenced Escherichia coli strain O157:H7 EDL933. The model improves the correct calls from 85 to 95% relative to raw intensity measures. The model thus makes applications which depend on comparisons between probes aimed at different sections of the same target more reliable
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