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21 results on '"Rainer, Manuel"'

1. Refined Telluric Absorption Correction for Low-Resolution Ground-Based Spectroscopy: Resolution and Radial Velocity Effects in the O2 A-Band for Exoplanets and K I Emission Lines

Author

Kimeswenger, Stefan, Rainer, Manuel, Przybilla, Norbert, and Kausch, Wolfgang

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Telluric correction of spectroscopic observations is either performed via standard stars that are observed close in time and airmass along with the science target, or recently growing in importance, by theoretical telluric absorption modeling. Both approaches work fine when the telluric lines are resolved, i.e. at spectral resolving power larger than about 10000, and it is sufficient to facilitate the detection of spectral features at lower resolution. However, a meaningful quantitative analysis requires also a reliable recovery of line strengths. Here, we show for the Fraunhofer A-band of molecular O2 that the standard telluric correction approach fails in this at lower spectral resolutions, as an example for the general problem. Doppler-shift dependent errors of the restored flux may arise, which can amount to more than 50% in extreme cases, depending on the line shapes of the target spectral features. Two applications are discussed: the recovery of the O2-band in the reflected light of an Earth analog atmosphere, as facilitated potentially in the future using an orbiting starshade and a ground-based extremely large telescope; and the recovery of the intrinsic ratio of the K I lines in the post-nova V4332 Sgr tracing the optical depth of the emitting region, to exemplify the relevance using present-day instrumentation. We show how one should derive correction functions for the compensation of the error in dependence of radial velocity shift, spectral resolution and target line-profile function by use of high resolution atmospheric transmission modeling, which has to be solved for the individual case., Comment: 11 pages, 9 figures, accepted for publication in Astronomical Journal (AJ)

Published
2020
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2. Robust model predictive control

Author

Schaich, Rainer Manuel and Cannon, Mark

Subjects
629.8, Robust Control, Polytope Operation, Parametric Convexity, Set-Valued Map
Abstract

This thesis deals with the topic of min-max formulations of robust model predictive control problems. The sets involved in guaranteeing robust feasibility of the min-max program in the presence of state constraints are of particular interest, and expanding the applicability of well understood solvers of linearly constrained quadratic min-max programs is the main focus. To this end, a generalisation for the set of uncertainty is considered: instead of fixed bounds on the uncertainty, state- and input-dependent bounds are used. To deal with state- and input dependent constraint sets a framework for a particular class of set-valued maps is utilised, namely parametrically convex set-valued maps. Relevant properties and operations are developed to accommodate parametrically convex set-valued maps in the context of robust model predictive control. A quintessential part of this work is the study of fundamental properties of piecewise polyhedral set-valued maps which are parametrically convex, we show that one particular property is that their combinatorial structure is constant. The study of polytopic maps with a rigid combinatorial structure allows the use of an optimisation based approach of robustifying constrained control problems with probabilistic constraints. Auxiliary polytopic constraint sets, used to replace probabilistic constraints by deterministic ones, can be optimised to minimise the conservatism introduced while guaranteeing constraint satisfaction of the original probabilistic constraint. We furthermore study the behaviour of the maximal robust positive invariant set for the case of scaled uncertainty and show that this set is continuously polytopic up to a critical scaling factor, which we can approximate a-priori with an arbitrary degree of accuracy. Relevant theoretical statements are developed, discussed and illustrated with examples.

Published
2017

3. How scaling of the disturbance set affects robust positively invariant sets for linear systems

Author

Darup, Moritz Schulze, Schaich, Rainer Manuel, and Cannon, Mark

Subjects
Mathematics - Optimization and Control
Abstract

This paper presents new results on robust positively invariant (RPI) sets for linear discrete-time systems with additive disturbances. In particular, we study how RPI sets change with scaling of the disturbance set. More precisely, we show that many properties of RPI sets crucially depend on a unique scaling factor which determines the transition from nonempty to empty RPI sets. We characterize this critical scaling factor, present an efficient algorithm for its computation, and analyze it for a number of examples from the literature.

Published
2016

5. A laboratory-based multifunctional near ambient pressure X-ray photoelectron spectroscopy system for electrochemical, catalytic, and cryogenic studies.

Author

Haug, Leander, Griesser, Christoph, Thurner, Christoph W., Winkler, Daniel, Moser, Toni, Thaler, Marco, Bartl, Pit, Rainer, Manuel, Portenkirchner, Engelbert, Schumacher, David, Dierschke, Karsten, Köpfle, Norbert, Penner, Simon, Beyer, Martin K., Loerting, Thomas, Kunze-Liebhäuser, Julia, and Klötzer, Bernhard

Subjects
HETEROGENEOUS catalysis, CRYOCHEMISTRY, HETEROGENEOUS catalysts, AQUEOUS electrolytes, SURFACES (Technology), X-ray photoelectron spectroscopy, ELECTROLYTIC oxidation, ELECTROLYTIC cells
Abstract

A versatile multifunctional laboratory-based near ambient pressure x-ray photoelectron spectroscopy (XPS) instrument is presented. The entire device is highly customized regarding geometry, exchangeable manipulators and sample stages for liquid- and solid-state electrochemistry, cryochemistry, and heterogeneous catalysis. It therefore delivers novel and unique access to a variety of experimental approaches toward a broad choice of functional materials and their specific surface processes. The high-temperature (electro)catalysis manipulator is designed for probing solid state/gas phase interactions for heterogeneous catalysts including solid electrolyzer/fuel cell electrocatalysts at pressures up to 15 mbar and temperatures from room temperature to 1000 °C. The liquid electrochemistry manipulator is specifically designed for in situ spectroscopic investigations of polarized solid/liquid interfaces using aqueous electrolytes and the third one for experiments for ice and ice-like materials at cryogenic temperatures to approximately −190 °C. The flexible and modular combination of these setups provides the opportunity to address a broad spectrum of in situ and operando XPS experiments on a laboratory-based system, circumventing the limited accessibility of experiments at synchrotron facilities. [ABSTRACT FROM AUTHOR]

Published
2023
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6. Single molecule force spectroscopy with acid chloride anchors using polyethylene glycol

Author

Rainer, Manuel and Rainer, Manuel

Abstract

In force spectroscopy of chemical bonds, single molecule chains are being stretched using an atomic force microscope (AFM). Strong surface anchors are required to provide sufficient mechanochemical stability to address covalent bonds. This thesis discusses experiments with acid chloride anchors, featuring a very reactive functional group, tested by stretching polyethylene glycol (PEG). An extensive, experimental description of the anchoring was worked out, including rupture force, rupture length and loading rates. The slope of the force curves is used to derive the elasticity of the molecule, which in turn yields the length and thus the molecular weight distribution for the stretched molecules, proving successful attachment $via$ comparison with the molecular weight distribution provided by the manufacturer. Force clamp spectroscopy was performed to measure the lifetimes of the stretched PEG and extract activation energies via Arrhenius diagrams., Manuel Rainer, Masterarbeit Universität Innsbruck 2022

Published
2022

8. How scaling of the disturbance set affects robust positively invariant sets for linear systems

Author

Moritz Schulze Darup, Mark Cannon, and Rainer Manuel Schaich

Subjects
0209 industrial biotechnology, Efficient algorithm, Mechanical Engineering, General Chemical Engineering, Computation, 020208 electrical & electronic engineering, Linear system, Biomedical Engineering, Aerospace Engineering, 02 engineering and technology, Invariant (physics), Industrial and Manufacturing Engineering, 020901 industrial engineering & automation, Critical scaling, Control and Systems Engineering, 0202 electrical engineering, electronic engineering, information engineering, Applied mathematics, Electrical and Electronic Engineering, Scaling, Mathematics
Abstract

Summary This paper presents new results on robust positively invariant (RPI) sets for linear discrete-time systems with additive disturbances. In particular, we study how RPI sets change with scaling of the disturbance set. More precisely, we show that many properties of RPI sets crucially depend on a unique scaling factor, which determines the transition from nonempty to empty RPI sets. We characterize this critical scaling factor, present an efficient algorithm for its computation, and analyze it for a number of examples from the literature. Copyright © 2017 John Wiley & Sons, Ltd.

Published
2017

9. Maximising the guaranteed feasible set for stochastic MPC with chance constraints

Author

Rainer Manuel Schaich and Mark Cannon

Subjects
0209 industrial biotechnology, Mathematical optimization, Computer science, Feasible region, Linear system, Probabilistic logic, Sampling (statistics), 02 engineering and technology, Invariant (physics), 020901 industrial engineering & automation, Control and Systems Engineering, Control theory, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Invariant (mathematics), Probability measure
Abstract

This paper proposes a method of approximating positively invariant sets and n-step controllable sets of uncertain linear systems that are subject to chance constraints. The computed sets are robustly invariant and are guaranteed to satisfy the probabilistic constraints of the control problem. In contrast, existing methods based on random sampling are only able to satisfy such constraints with a fixed level of confidence. The proposed approach uses explicitly parametrised auxiliary disturbance sets, which are optimised subject to a constraint on their probability measure so as to maximise the relevant positively invariant or n-step controllable set. The results are illustrated by numerical examples.

Published
2017

10. Robust receding horizon control for linear systems with state and input dependent disturbances

Author

Rainer Manuel Schaich and Mark Cannon

Subjects
Mathematical optimization, Online optimization, Control and Systems Engineering, Control theory, Horizon, Control (management), Linear system, State (functional analysis), Piecewise affine, Constraint satisfaction, Robust control, Mathematics
Abstract

A robust model predictive controller is proposed for constrained linear systems with unknown disturbances that are subject to state and input dependent piecewise affine bounds. The formulation encompasses problems involving model uncertainty arising from unknown system parameters and linearisation errors. We propose a computationally efficient method for the online optimization of a receding horizon min-max cost over the class of feedback strategies subject robust constraint satisfaction and provide an illustrative numerical example.

Published
2015

12. The adsorption of helium atoms on small cationic gold clusters

Author

Goulart, Marcelo, Gatchell, Michael, Kranabetter, Lorenz, Kuhn, Martin, Martini, Paul, Gitzl, Norbert, Rainer, Manuel, Postler, Johannes, Scheier, Paul, Ellis, Andrew M., Goulart, Marcelo, Gatchell, Michael, Kranabetter, Lorenz, Kuhn, Martin, Martini, Paul, Gitzl, Norbert, Rainer, Manuel, Postler, Johannes, Scheier, Paul, and Ellis, Andrew M.

Abstract

Adducts formed between small gold cluster cations and helium atoms are reported for the first time. These binary ions, Aun+Hem, were produced by electron ionization of helium nanodroplets doped with neutral gold clusters and were detected using mass spectrometry. For a given value of n, the distribution of ions as a function of the number of added helium atoms, m, has been recorded. Peaks with anomalously high intensities, corresponding to so-called magic number ions, are identified and interpreted in terms of the geometric structures of the underlying Au-n(+) ions. These features can be accounted for by planar structures for Au-n(+) ions with n <= 7, with the addition of helium having no significant effect on the structures of the underlying gold cluster ions. According to ion mobility studies and some theoretical predictions, a 3-D structure is expected for Au-8(+). However, the findings for Au-8(+) in this work are more consistent with a planar structure.

Published
2018
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13. Robust positively invariant sets for state dependent and scaled disturbances

Author

Mark Cannon and Rainer Manuel Schaich

Subjects
Discrete time and continuous time, Control theory, Robustness (computer science), Linear system, Parametric model, Sensitivity analysis, Additive model, Uncertainty analysis, Parametric statistics, Mathematics
Abstract

This paper introduces methods of deriving and computing maximal robust positively invariant sets for linear discrete time systems with additive model uncertainty. Two types of uncertainty are considered: state dependent uncertainty, which can handle multiplicative parametric model uncertainty as well as linearisation errors for nonlinear systems, and scaled sets of uncertainty. We provide a framework for analysing both types of uncertainty with illustrative examples.

Published
2017

14. How scaling of the disturbance set affects robust positively invariant sets for linear systems

Author

Darup, Moritz Schulze, Schaich, Rainer Manuel, and Cannon, Mark

Subjects
Optimization and Control (math.OC), FOS: Mathematics, Mathematics - Optimization and Control
Abstract

This paper presents new results on robust positively invariant (RPI) sets for linear discrete-time systems with additive disturbances. In particular, we study how RPI sets change with scaling of the disturbance set. More precisely, we show that many properties of RPI sets crucially depend on a unique scaling factor, which determines the transition from nonempty to empty RPI sets. We characterize this critical scaling factor, present an efficient algorithm for its computation, and analyze it for a number of examples from the literature.

Published
2017

15. A distributed model predictive control scheme for networks with communication failure

Author

Rainer Manuel Schaich, Frank Allgöwer, and Matthias A. Müller

Subjects
Scheme (programming language), Nonlinear system, Distributed model predictive control, Exponential stability, Coupling (computer programming), Computer science, Control theory, computer, computer.programming_language
Abstract

A method to ensure recursive feasibility and asymptotic stability for a distributed model predictive control scheme in case of temporary communication failure is presented. The considered networks are made up of dynamically uncoupled nonlinear systems, coupled through constraints and objectives. The proposed method substitutes affected coupling constraints in such a way that the scheme can not become infeasible, while a decrease in the cost is guaranteed.

Published
2014

16. Parametric robust positively invariant sets for linear systems with scaled disturbances

Author

Mark Cannon, Rainer Manuel Schaich, and Moritz Schulze Darup

Subjects
0209 industrial biotechnology, 020901 industrial engineering & automation, Control theory, 020208 electrical & electronic engineering, Linear system, 0202 electrical engineering, electronic engineering, information engineering, 02 engineering and technology, Invariant (physics), Scaling, Mathematics, Parametric statistics
Abstract

This paper presents novel results on robust positively invariant (RPI) sets for linear discrete-time systems with additive disturbances. In particular, we determine how RPI sets change with scaling of the disturbance set. In this context, we analyze families of RPI sets for a given interval of scaling factors. Such parametric RPI sets are useful to study the sensitivity of the system to changes in the disturbance strength.

Published
2016

17. The adsorption of helium atoms on small cationic gold clusters

Author

Goulart, Marcelo, primary, Gatchell, Michael, additional, Kranabetter, Lorenz, additional, Kuhn, Martin, additional, Martini, Paul, additional, Gitzl, Norbert, additional, Rainer, Manuel, additional, Postler, Johannes, additional, Scheier, Paul, additional, and Ellis, Andrew M., additional

Published
2018
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19. Passives Portfoliomanagement

Author

Rainer, Manuel

Subjects
Portfoliomanagement
Abstract

Manuel Rainer Graz, Univ., Masterarb., 2009

Published
2009

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