# Kolloquiumsvortrag (MAWI), Nian. X Sun W.M. Keck Laboratory for Integrated Ferroics, & ECE Department, Northeastern University, Boston, / am 18.06.2018

18.06.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: RF NEMS Magnetoelectric Sensors

Abstract: The coexistence of electric polarization and magnetization in multiferroic materials provides great opportunities for realizing magnetoelectric coupling, including electric field control of magnetism, or vice versa, through a strain mediated magnetoelectric coupling in layered magnetic/ferroelectric multiferroic heterostructures [1-9]. Strong magnetoelectric coupling has been the enabling factor for different multiferroic devices, which however has been elusive, particularly at RF/microwave frequencies. In this presentation, I will cover the most recent progress on new integrated magnetoelectric materials, magnetoelectric NEMS (nanoelectromechanical system) based sensors and antennas. Specifically, we will introduce magnetoelectric multiferroic materials, and their applications in different devices, including: (1) novel ultra-compact RF NEMS acoustic magnetoelectric antennas immune from ground plane effect with < l0/100 in size, self-biased operation and potentially 1~2% voltage tunable operation frequency; and (2) ultra-sensitive RF NEMS magnetoelectric magnetometers with ultra-low noise of ~1pT/Hz1/2 at 10 Hz for DC and AC magnetic fields sensing. These novel magnetoelectric devices show great promise for applications in compact, lightweight and power efficient sensors and sensing systems, ultra-compact antennas and for radars, communication systems, biomedical devices, IoT, etc.

Reference: 1. N.X. Sun and G. Srinivasan, SPIN, 02, 1240004 (2012); 2. J. Lou, et al., Advanced Materials, 21, 4711 (2009); 3. J. Lou, et al. Appl. Phys. Lett. 94, 112508 (2009); 4. M. Liu, et al. Advanced Functional Materials, 21, 2593 (2011); 5. T. Nan, et al. Scientific Reports, 3, 1985 (2013); 6. M. Liu, et al. Advanced Materials, 25, 1435 (2013); 7. M. Liu, et al. Advanced Functional Materials, 19, 1826 (2009); 8. Ziyao Zhou, et al. Nature Communications, 6, 6082 (2015). 9. T. Nan, et al. Nature Comm. 8, 296 (2017).

Short Bio: Nian Sun is professor at the Electrical and Computer Engineering Department, Director of the W.M. Keck Laboratory for Integrated Ferroics, Northeastern University, and Thrust Leader of 2-D Multiferroics in the NSF ERC Transitional Applications of Nanoscale Multiferroic Systems (TANMS). He received his Ph.D. degree from Stanford University. Prior to joining Northeastern University, he was a Scientist at IBM and Hitachi Global Storage Technologies. Dr. Sun was the recipient of the NSF CAREER Award, ONR Young Investigator Award, the Søren Buus Outstanding Research Award, etc. His research interests include novel magnetic, ferroelectric and multiferroic materials, devices and subsystems. He has over 240 publications and over 20 patents and patent applications. One of his papers was selected as the “ten most outstanding full papers in the past decade (2001~2010) in Advanced Functional Materials”. Dr. Sun has given over 100 plenary or invited presentations and seminars in national and international conferences and universities. He is an editor of Sensors, and IEEE Transactions on Magnetics, and a fellow of the Institute of Physics, and of the Institution of Engineering and Technology.

# Kolloquiumsvortrag (MAWI), Nian. X Sun W.M. Keck Laboratory for Integrated Ferroics, & ECE Department, Northeastern University, Boston, / am 18.06.2018

18.06.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: RF NEMS Magnetoelectric Sensors

Abstract: The coexistence of electric polarization and magnetization in multiferroic materials provides great opportunities for realizing magnetoelectric coupling, including electric field control of magnetism, or vice versa, through a strain mediated magnetoelectric coupling in layered magnetic/ferroelectric multiferroic heterostructures [1-9]. Strong magnetoelectric coupling has been the enabling factor for different multiferroic devices, which however has been elusive, particularly at RF/microwave frequencies. In this presentation, I will cover the most recent progress on new integrated magnetoelectric materials, magnetoelectric NEMS (nanoelectromechanical system) based sensors and antennas. Specifically, we will introduce magnetoelectric multiferroic materials, and their applications in different devices, including: (1) novel ultra-compact RF NEMS acoustic magnetoelectric antennas immune from ground plane effect with < l0/100 in size, self-biased operation and potentially 1~2% voltage tunable operation frequency; and (2) ultra-sensitive RF NEMS magnetoelectric magnetometers with ultra-low noise of ~1pT/Hz1/2 at 10 Hz for DC and AC magnetic fields sensing. These novel magnetoelectric devices show great promise for applications in compact, lightweight and power efficient sensors and sensing systems, ultra-compact antennas and for radars, communication systems, biomedical devices, IoT, etc.

Reference: 1. N.X. Sun and G. Srinivasan, SPIN, 02, 1240004 (2012); 2. J. Lou, et al., Advanced Materials, 21, 4711 (2009); 3. J. Lou, et al. Appl. Phys. Lett. 94, 112508 (2009); 4. M. Liu, et al. Advanced Functional Materials, 21, 2593 (2011); 5. T. Nan, et al. Scientific Reports, 3, 1985 (2013); 6. M. Liu, et al. Advanced Materials, 25, 1435 (2013); 7. M. Liu, et al. Advanced Functional Materials, 19, 1826 (2009); 8. Ziyao Zhou, et al. Nature Communications, 6, 6082 (2015). 9. T. Nan, et al. Nature Comm. 8, 296 (2017).

Short Bio: Nian Sun is professor at the Electrical and Computer Engineering Department, Director of the W.M. Keck Laboratory for Integrated Ferroics, Northeastern University, and Thrust Leader of 2-D Multiferroics in the NSF ERC Transitional Applications of Nanoscale Multiferroic Systems (TANMS). He received his Ph.D. degree from Stanford University. Prior to joining Northeastern University, he was a Scientist at IBM and Hitachi Global Storage Technologies. Dr. Sun was the recipient of the NSF CAREER Award, ONR Young Investigator Award, the Søren Buus Outstanding Research Award, etc. His research interests include novel magnetic, ferroelectric and multiferroic materials, devices and subsystems. He has over 240 publications and over 20 patents and patent applications. One of his papers was selected as the “ten most outstanding full papers in the past decade (2001~2010) in Advanced Functional Materials”. Dr. Sun has given over 100 plenary or invited presentations and seminars in national and international conferences and universities. He is an editor of Sensors, and IEEE Transactions on Magnetics, and a fellow of the Institute of Physics, and of the Institution of Engineering and Technology.

# Kolloquiumsvortrag (INF), NN, / am 15.06.2018

15.06.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (MAWI), Jan Lammerding, Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology Cornell University/ am 11.06.2018

11.06.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Squish and squeeze – Nuclear mechanics and mechanotransduction in physiology and disease

Abstract: The nucleus is the characteristic feature of eukaryotic cells and houses the genomic information of the cell. The Lammerding laboratory is combining cell and molecular biology approaches with microfabricated devices that mimic physiological environments, live-cell microscopy, and in vivo models to investigate how physical forces acting on the nucleus, for example, in contracting muscle cells or during migration of cells through tight interstitial spaces, can challenge the integrity of the nucleus, alter its structure, and cause genomic and transcriptional changes. These processes play important roles in cellular mechanotransduction, i.e., the ability of cells to convert mechanical stimuli into biochemical signals, but can also contribute to various diseases when the nuclear structure is perturbed by mutations or altered protein expression. In particular, mutations in the nuclear envelope proteins lamin A/C are responsible for a broad spectrum of diseases (laminopathies), including Emery-Dreifuss muscular dystrophy (EDMD) and dilated cardiomyopathy. The fact that most mutations result in highly tissue-specific disease phenotypes primarily affecting skeletal and cardiac muscles, in spite of the near ubiquitous expression of lamins A/C, suggest that lamin mutations may render cells more sensitive to mechanical stress, which then causes progressive cell failure in mechanically stressed tissues. I will discuss our recent findings that highlight the importance of lamins A/C in mediating nuclear stability and mechanotransduction in mechanically stressed cells and tissues. At the same time, increased nuclear deformability, caused for example by reduced levels of lamins A/C, can promote cell migration through tight spaces with cross-sections smaller than the nuclear diameter, where the large size and rigidity of the nucleus can constitute a rate-limiting factor. I will present recent findings that demonstrate the importance of nuclear mechanics during cell migration in confined environments in vitro and in vivo, as well as the functional consequences of cells having to squeeze their large nuclei through tight interstitial spaces and small pores in the extracellular matrix network, with a particular focus on breast cancer.

# Kolloquiumsvortrag (MAWI), Jan Lammerding, Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology Cornell University/ am 11.06.2018

11.06.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Squish and squeeze – Nuclear mechanics and mechanotransduction in physiology and disease

Abstract: The nucleus is the characteristic feature of eukaryotic cells and houses the genomic information of the cell. The Lammerding laboratory is combining cell and molecular biology approaches with microfabricated devices that mimic physiological environments, live-cell microscopy, and in vivo models to investigate how physical forces acting on the nucleus, for example, in contracting muscle cells or during migration of cells through tight interstitial spaces, can challenge the integrity of the nucleus, alter its structure, and cause genomic and transcriptional changes. These processes play important roles in cellular mechanotransduction, i.e., the ability of cells to convert mechanical stimuli into biochemical signals, but can also contribute to various diseases when the nuclear structure is perturbed by mutations or altered protein expression. In particular, mutations in the nuclear envelope proteins lamin A/C are responsible for a broad spectrum of diseases (laminopathies), including Emery-Dreifuss muscular dystrophy (EDMD) and dilated cardiomyopathy. The fact that most mutations result in highly tissue-specific disease phenotypes primarily affecting skeletal and cardiac muscles, in spite of the near ubiquitous expression of lamins A/C, suggest that lamin mutations may render cells more sensitive to mechanical stress, which then causes progressive cell failure in mechanically stressed tissues. I will discuss our recent findings that highlight the importance of lamins A/C in mediating nuclear stability and mechanotransduction in mechanically stressed cells and tissues. At the same time, increased nuclear deformability, caused for example by reduced levels of lamins A/C, can promote cell migration through tight spaces with cross-sections smaller than the nuclear diameter, where the large size and rigidity of the nucleus can constitute a rate-limiting factor. I will present recent findings that demonstrate the importance of nuclear mechanics during cell migration in confined environments in vitro and in vivo, as well as the functional consequences of cells having to squeeze their large nuclei through tight interstitial spaces and small pores in the extracellular matrix network, with a particular focus on breast cancer.

Prof. Selhuber

# Kolloquiumsvortrag (INF), NN, / am 08.06.2018

08.06.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (MAWI), Prof. Dr. Ulrich Schwarz,Heidelberg University, Institute for Theoretical Physics am 04.06.2018

04.06.2018 von 16:00 bis 16:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Cells and tissue as active materials

Abstract:

Biological systems such as cells and tissue use non-equilibrium processes to actively generate mechanical stress, movement and growth. Some of these processes can actually be reconstituted in biomimetic experiments with active soft matter. In this talk, we first discuss why and how contractile forces are generated by biological systems and how they can be measured, for example on soft elastic substrates. We then discuss how these contractile systems can be mathematically described by classical continuum mechanics extended by active elements. We finally explain how the local contractility of cells and tissue can be controled with optogenetics, and how the resulting forces and flows can be used to estimate their material properties.

# Kolloquiumsvortrag (INF), Dr. Matthias Mnich, Uni Bonn / am 01.06.2018

01.06.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: Multivariate Algorithms for Machine Scheduling Problems

Abstract: Machine scheduling problems are a long-time key domain of algorithms and complexity research.  In those problems, we are generally given a finite set J of jobs with certain characteristics, and we must find a schedule for processing the jobs on one or more machines, which also may have their individual specifications. Typical characteristics of a job are its processing time, its release date, its due date, or its importance reflected by an integer weight. A significant amount of research has been devoted in the past 60 years towards designing polynomial-time algorithms which approximate the value of optimal schedules (for various objective functions). A novel approach to machine scheduling problems are multivariate algorithms, which aim to find a provably optimal schedule at the expense of an increased run time, which is permitted to depend moderately exponentially on the job characteristics or other structural parameters. We survey some recent algorithms in this paradigm, present some novel results, and discuss several challenging open problems in this exciting research area.

# Kolloquiumsvortrag (INF), Dr. Matthias Mnich, Uni Bonn / am 01.06.2018

01.06.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: Multivariate Algorithms for Machine Scheduling Problems

Abstract: Machine scheduling problems are a long-time key domain of algorithms and complexity research.  In those problems, we are generally given a finite set J of jobs with certain characteristics, and we must find a schedule for processing the jobs on one or more machines, which also may have their individual specifications. Typical characteristics of a job are its processing time, its release date, its due date, or its importance reflected by an integer weight. A significant amount of research has been devoted in the past 60 years towards designing polynomial-time algorithms which approximate the value of optimal schedules (for various objective functions). A novel approach to machine scheduling problems are multivariate algorithms, which aim to find a provably optimal schedule at the expense of an increased run time, which is permitted to depend moderately exponentially on the job characteristics or other structural parameters. We survey some recent algorithms in this paradigm, present some novel results, and discuss several challenging open problems in this exciting research area.

Prof. Jansen

# Kolloquiumsvortrag (MaWi), Prof. Richard Fu, Faculty of Engineering and Environment, Northumbria University, Newcastle / am 28.05.2018

28.05.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Acoustic wave lab-on-chip is now flexible, bendable and potentially wearable!

Abstract: Thin film acoustic wave devices especially surface acoustic waves (SAW) have been used for sample preparation (sorting, separating, mixing, nebulization and dispensing) as well as bio-sensing. This talk will focus on our recent work of flexible and wearable thin film acoustic wave lab-on-chip (mainly using ZnO and AlN films on flexible substrates) for acoustic wave based microfluidic applications. We report theoretical and experimental studies of the evolution, hybridization and decoupling of wave modes in the flexible acoustic wave devices, as well as their vibration patterns. thus providing a guide for different microfluidic applications. Thin film based flexible SAW devices have the potential to be integrated with other microfluidic and sensing technology on flexible substrates including CMOS integrated circuits to make novel lab-on-chip for bio-detection for wearable and flexible applications. SAW devices on commercial polymer and aluminum foils have been fabricated and various microfluidic functions, such as mixing, pumping, jetting have been demonstrated with bent and deformed acoustic wave devices.

About Prof. Richard Fu. He has extensive experience in smart thin film/materials, biomedical microdevices, lab-on-chip, micromechanics, MEMS, nanotechnology, sensors and microfluidics. He has established a good reputation from his pioneer research work on shape memory films, piezoelectric thin films, nanostructured composite/films for applications in MEMS, sensing and energy applications. He published over 330 science citation index (SCI) journal papers (including Progress in Materials Science and Nature Communications), 2 books, 20 book chapters, and over 120 conference papers. His current SCI H-index is 39 with over 6500 citations. He is associate editor/editorial board members for seven international journals including Scientific Report. He is regular journal paper reviewers for more than 30 journals, and has co-organized 12 international conferences worldwide, and co-edited six special issues for journals.

# Kolloquiumsvortrag (MaWi), Prof. Richard Fu, Faculty of Engineering and Environment, Northumbria University, Newcastle / am 28.05.2018

28.05.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Acoustic wave lab-on-chip is now flexible, bendable and potentially wearable!

Abstract: Thin film acoustic wave devices especially surface acoustic waves (SAW) have been used for sample preparation (sorting, separating, mixing, nebulization and dispensing) as well as bio-sensing. This talk will focus on our recent work of flexible and wearable thin film acoustic wave lab-on-chip (mainly using ZnO and AlN films on flexible substrates) for acoustic wave based microfluidic applications. We report theoretical and experimental studies of the evolution, hybridization and decoupling of wave modes in the flexible acoustic wave devices, as well as their vibration patterns. thus providing a guide for different microfluidic applications. Thin film based flexible SAW devices have the potential to be integrated with other microfluidic and sensing technology on flexible substrates including CMOS integrated circuits to make novel lab-on-chip for bio-detection for wearable and flexible applications. SAW devices on commercial polymer and aluminum foils have been fabricated and various microfluidic functions, such as mixing, pumping, jetting have been demonstrated with bent and deformed acoustic wave devices.

About Prof. Richard Fu. He has extensive experience in smart thin film/materials, biomedical microdevices, lab-on-chip, micromechanics, MEMS, nanotechnology, sensors and microfluidics. He has established a good reputation from his pioneer research work on shape memory films, piezoelectric thin films, nanostructured composite/films for applications in MEMS, sensing and energy applications. He published over 330 science citation index (SCI) journal papers (including Progress in Materials Science and Nature Communications), 2 books, 20 book chapters, and over 120 conference papers. His current SCI H-index is 39 with over 6500 citations. He is associate editor/editorial board members for seven international journals including Scientific Report. He is regular journal paper reviewers for more than 30 journals, and has co-organized 12 international conferences worldwide, and co-edited six special issues for journals.

# Kolloquiumsvortrag (INF), Dr. Hermann Lindhorst, Fachanwalt für IT-Recht / am 25.05.2018

25.05.2018 von 14:15 bis 15:45

Christian-Albrechts-Platz 2, 24118 Kiel, Raum: Hörsaal A

Titel:  „Datenschutz: Anbruch eines neuen Zeitalters? – Zur Geltung der EU-Datenschutzgrundverordnung ab dem 25. Mai"

Abstract: Ab dem 25.5.2018 haben alle Bürger, Behörden und Unternehmen neue Vorschriften zum Datenschutz zu beachten, denn dann gelten europaweit die Regelungen der „EU-Datenschutzgrundverordnung“ sowie in Deutschland ein Bundesdatenschutzgesetz, bei dem nicht ein einziger Paragraph so wie vorher geblieben ist. Darauf weisen seit Monaten nicht nur Datenschützer, sondern auch viele andere hin, wie z.B. Unternehmensberater, Rechtsanwälte und Zertifizierungsunternehmen wie der TÜV. Doch was wird sich ab Ende Mail tatsächlich ändern? Hat vor dem Hintergrund z.B. der drastisch erhöhten Sanktionen ein echtes Umdenken stattgefunden oder bleibt der Datenschutz eine ungeliebte bürokratische Bürde?

Prof. Hasselbring

# Kolloquiumsvortrag (INF), Dr. Hermann Lindhorst, Fachanwalt für IT-Recht / am 25.05.2018

25.05.2018 von 14:15 bis 15:45

Christian-Albrechts-Platz 2, 24118 Kiel, Raum: Hörsaal A

Titel:  „Datenschutz: Anbruch eines neuen Zeitalters? – Zur Geltung der EU-Datenschutzgrundverordnung ab dem 25. Mai"

Abstract: Ab dem 25.5.2018 haben alle Bürger, Behörden und Unternehmen neue Vorschriften zum Datenschutz zu beachten, denn dann gelten europaweit die Regelungen der „EU-Datenschutzgrundverordnung“ sowie in Deutschland ein Bundesdatenschutzgesetz, bei dem nicht ein einziger Paragraph so wie vorher geblieben ist. Darauf weisen seit Monaten nicht nur Datenschützer, sondern auch viele andere hin, wie z.B. Unternehmensberater, Rechtsanwälte und Zertifizierungsunternehmen wie der TÜV. Doch was wird sich ab Ende Mail tatsächlich ändern? Hat vor dem Hintergrund z.B. der drastisch erhöhten Sanktionen ein echtes Umdenken stattgefunden oder bleibt der Datenschutz eine ungeliebte bürokratische Bürde?

# -- Pfingstmontag--

21.05.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag (INF), NN, / am 18.05.2018

18.05.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (MAWI), Prof. Xian (Sherry) Chen, Hong Kong University of Science and Technology, / am 14.05.2018

14.05.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel:  Enhanced fatigue properties of phase-transforming materials by satisfying the cofactor conditions

Abstract:

Materials undergoing reversible solid-solid phase transformations provide emerging applications such as biomedical implants and stents, microelectronic actuators and sensors. The essential functionality of these materials is the ability to recover large deformation (i.e. 5~8%) before and after the structural transformation driven by temperature/stress/electromagnetic fields. The change of the lattice parameters and the breaking of symmetries, in turn, will cause the formation of microstructures, which lead to the accumulation of intrinsic defects at the stressed transition layer between phases.  It has been theorized that the macroscopic behaviors strongly depend on the kinematic properties of the transition layer between phases. If the lattice parameters satisfy some special mathematical conditions (the cofactor conditions), we observe that the functional fatigue properties of the phase-transforming materials have been tremendously improved. In this talk, we will briefly review the mathematical framework of the cofactor conditions and introduce an algorithmic way to evaluate these conditions directly from the X-ray measurements. We will also show some experimental results how the functional fatigue properties are enhanced at various length scales.

## Brief Biography of Prof. Xian(Sherry) Chen (HKUST)

Education:

Ph.D. and M.S., Aerospace Engineering and Mechanics, University of Minnesota, US

B.S., Materials Science and Engineering, Huazhong University of Science and Technology, China

2015 – present, Assistant Professor, Mechanical and Aerospace Engineering, Hong Kong Univ. of Science and Technology, HK

2015 – 2016, Visiting Professor, Mechanical and Civil Engineering, California Institute of Technology, US

2014 – 2015, Postdoctoral Fellowship, Lawrence Berkeley National Lab, US

Research interests:

The research of our group integrates the theories of mechanics of crystalline solids with advanced structural characterization methods and algorithms to develop new phase-transforming materials. These materials have emerging applications in medical devices, microelectronics and energy conversion devices.

GRF grant (2016 – 2019): Investigation of microstructure-reversibility relationship for phase-transforming materials (Early Career Award)

GRF grant (2017 - 2020): Algorithmic approaches for high-throughput screen and discovery of new shape memory alloys

UGC grant (2017-2019): Measure 3D strain of phase transforming materials by Differential Interference Contrast optical system

# Kolloquiumsvortrag (INF), NN, / am 11.05.2018

11.05.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, NN / am 07.05.2018

07.05.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag (INF), NN, / am 04.05.2018

04.05.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, NN, / am 30.04.2018

30.04.2018 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag (INF), NN, / am 27.04.2018

27.04.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Sonderkolloquium (ET/IT), Antrittsvorleseung, Prof. Dr. Andreas Bahr, Technische Fakultät der CAU am 26.04.2018

26.04.2018 von 17:00 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Brain Signal Acquisition with Miniaturized Electronic Systems for the Investigation of Local Neural Networks

Abstract:  In this talk, I will exemplify how advancements in the design of integrated sensor electronics enable new kinds of biomedical signal analysis:

In neuroscience research the development of the brain and the treatment of diseases like certain forms of epilepsy are analyzed with genetic mouse disease models. For the special case of the recording from neonatal mice (2-3 cm, 3-5 g) an implantable system has been developed, that enables chronic recordings. To achieve this, an application specific integrated circuit (ASIC) has been developed in an advanced 130 nm CMOS technology. Moreover, an implant and a recording system for live view of neural data have been presented. The functionality of the integrated circuit and the suitability of the implant system have been confirmed with in-vivo experiments with adult and 12 days old mice.

Andreas Bahr, Institute of Electrical Engineering and Information Technology, University of Kiel, Kiel, Germany, andreas.bahr@tf.uni-kiel.de

# Kolloquiumsvortrag, Dr. Sander-Thömmes, Physikalisch-Technische Bundesanstalt (PTB) in Berlin / am 23.04.2018

23.04.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Biomagnetic Sensing and Processing – Progress Using a Modular Approach

Abstract: In the field of biomagnetism the application of mathematical algorithms has been as important as the hardware itself. Traditionally, the hardware (the sensor Array) was based on superconducting quantum interference devices (SQUIDs) and operated for decades without large modifications. In contrast to that the range of relevant mathematical algorithms increased at a steady pace. This was driven by factors such as an ever increasing PC based computing power, new physiological insights motivating the application of existing algorithms, and the development of new algorithms to test biophysical models among others.

After around three decades of SQUID based Hardware, now new magnetic field sensors with the potential to replace or complement SQUIDs are available or under development. The opportunity for new sensors is the consequence of clinical challenges unsolved by state-of-the art SQUID based systems and due to new technology allowing alternative quantum physics based sensors in a small sized housing. These new sensors often have extra capabilities compared with SQUIDs and naturally some disadvantages. I will illustrate the modular approach using the example of optically pumped magnetometers and the signal processing toolbox FieldTrip.

Short biography

Tilmann Sander-Thömmes studied Physics at University of Freiburg and ETH Zürich and graduated there in 1992. He continued to obtain a PhD in solid-state physics at Imperial College in London. Following two post-docs in Berlin he has been working at Physikalisch-Technische Bundesanstalt since 2000 in the laboratory for Biosignals. Since 1998 he is involved with measuring and analysing magnetic brain signals. He is an expert in magnetoencephalography using both SQUIDs and more recently optically pumped magnetometers.

gus@tf.uni-kiel.de

# Kolloquiumsvortrag (INF), NN, / am 20.04.2018

20.04.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, (ET/IT), Dr. Jan Abshagen, Wehrtechnische Dienststelle für Schiffe und Marinewaffen, Maritime Technologie und Forschung - WTD 71. / am 16.04.2018

16.04.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Flow-induced Noise in Hydroacoustic Sensor Systems

Abstract: Sound can propagate over a large distance in the sea without significant attenuation and is therefore of unique importance in underwater communication, navigation, and detection. Underwater sound is received in these applications with hydroacoustic sensor systems that are often attached to or towed behind a vessel. The turbulent flow that forms around the hull of the moving sensor system induces hydroacoustic noise in the interior that dominates the noise level (and therefore limits the performance) at larger speeds due to the strong speed dependence of flow acoustic sources (e.g. Lighthill’s v8-law). In a series of research cruises in recent years the statistical properties and underlying physical mechanisms of interior hydroacoustic noise induced from outer turbulent flows have been investigated under sea conditions with towed measurement systems. The talk will focus on the spatio-temporal correlation of the turbulent noise sources as well as the filter properties of the mechanical hull structure and the embedded hydrophones. The analysis is predominantly performed in wavenumber-frequency space. New developments in piezoelectric thin-film sensor technology allow in principle the design of specific wavenumber filters for flow noise reduction. The potential of such sensors for future underwater applications is discussed.

# Kolloquiumsvortrag (INF), Prof. Dr. Vijay Ganesh, University of Waterloo, Canada, am 13.04.2018

13.04.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Thema: Modern SAT Solving in Practice

Abstract:

Dr. Vijay Ganesh is an assistant professor at the University of Waterloo since 2012. Prior to that he was a research scientist at MIT, and completed his PhD in computer science from Stanford University in 2007. Vijay's primary area of research is the theory and practice of automated reasoning aimed at software engineering, formal methods, security, and mathematics. In this context he has led the development of many SAT/SMT solvers, most notably, STP, The Z3 string solver, MapleSAT, andMathCheck. He has also proved several decidability and complexity results relating to the SATisfiability problem for various mathematical theories. For his research, he has won over 20 awards including an ACM Test of Time Award at CCS 2016, two Google Faculty Research Awards in 2011 and 2013, and a Ten-Year Most Influential Paper Award at DATE 2008.

# Sonderkolloquiumsvortrag (ET&IT) Prof. Frank Vollmer, University of Exeter / am 12.04.2018

12.04.2018 von 14:00 bis 14:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Sensing the Nanoscale with Optoplasmonics

Abstract: Nanophotonic device building blocks, such as optical nano/microcavities and plasmonic nanostructures, lie at the forefront of sensing and spectrometry of trace biological and chemical substances. My laboratory is developing a new class of nanophotonic architectures by combining optically resonant dielectric nano/microcavities with plasmonically resonant metal nanostructures to enable detection at the nanoscale with extraordinary sensitivity. Initial demonstrations include single-molecule detection and even single-ion sensing. The coupled photonic-plasmonic resonator system promises a leap forward in the nanoscale analysis of physical, chemical, and biological entities. I will review our work in this burgeoning field of optoplasmonic biosensors. I will also talk about our most recent advances in localising light at the nanoscale in disordered 2D photonic crystals.

1Department of Physics and Astronomy, Living Systems Institute, University of Exeter, EX44QD, Exeter, UK

E-mail: f.vollmer@exeter.ac.uk

CV: Frank Vollmer is a Professor of Biophysics at the Living Systems Institute at the University of Exeter. Prof Vollmer pioneers optical technology to study processes at the nanoscale. He held several appointments at leading US institutions including Instructor in Medicine at Harvard Medical School. Before moving to the LSI in 2016, he held the position of Research Group Leader at the Max Planck Institute for the Science of Light (DE). In 2017 Prof Vollmer was awarded the Royal Society Wolfson Research Merit Award.

References

# Kolloquiumsvortrag (ETI/IT), Prof. Claus Hilgetag, UK Eppendorf, / am 09.04.2018

09.04.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel:  A simple excitable model reveals how brain network topology shapes neural activity patterns

Abstract: Brain networks are characterized by a number of distinctive topological features, such as a
heterogenous degree distribution with hubs, hierarchically organized modules, as well as a
characteristic spectrum of motifs and cycles. These features have consequences for various aspects
of brain dynamics, such as self‐sustained network activity, the wave‐like propagation of activations as
well as correlations and anti‐correlations of activity patterns. In a series of recent studies we have
demonstrated that the relation between neural network topology and dynamics can be
systematically investigated with the help of a simple, but powerful excitable (cellular automaton)
model which facilitates a mechanistic understanding of the contributions of different topological
features of brain networks to brain dynamics.

# Kolloquiumsvortrag (ET&IT), Dr. Timm Faulwasser, Karlsruhe Institute of Technology / am 12.02.2018

12.02.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Recent Progress on Distributed and Stochastic Optimization for Power Systems

Abstract: The increasing need for the de-carbonization of energy supply calls for new operational methods for power systems. In this context, tailored system and control approaches are pivotal- The specific challenges include the consideration of volatile renewable generation, uncertain forecasts thereof, and highly nonlinear system behavior.

In this talk, we focus on the so-called Optimal Power Flow (OPF) problem, which refers to a class of large-scale non-convex steady-state optimization problems frequently arising in power systems. For example, OPF problems provide optimal set points for power dispatch that satisfy the power flow equations and technical limitations such as generation and/or transmission limits. However, OPF problems are highly non-convex and subject to considerable uncertainties, which includes forecasts of renewable generation and household consumption, line parameters and grid topology.

After a concise problem statement, we provide an overview of the state of the art techniques to considering uncertainties in OPF problems and their bottlenecks. Moreover, we will discuss the concept of Polynomial Chaos Expansions (PCE) which allows to consider non-Gaussian uncertainties in OPF problems. PCE builds upon a series expansion of random-variables. We will present recent results on PCE for convex DC-OPF problems and non-convex AC-OPF problems [1, 2]. Moreover, we will comment on the quantification of PCE truncation errors [3].

Due to their large-scale nature, the distributed solution of OPF problems is subject to considerable research efforts. Thus, we will also comment on our recent results on the distributed solution of OPF problems [4].

References

[1] Mühlpfordt, T.; Faulwasser, T.; Roald, L. & Hagenmeyer, V. Solving optimal power flow with non-Gaussian uncertainties via polynomial chaos expansion. 56th IEEE Conference on Decision and Control, 2017. To appear.

[2] Mühlpfordt, T.; Faulwasser, T. & Hagenmeyer, V. Solving stochastic AC power flow via polynomial chaos expansion. IEEE International Conference on Control Applications, 2016, 70-76.

[3] Mühlpfordt, T.; Findeisen, R.; Hagenmeyer, V. & Faulwasser, T. Comments on Quantifying Truncation Errors for Polynomial Chaos Expansions. arXiv:1708.07655.

[4] Engelmann, A.; Mühlpfordt, T.; Jiang, Y.; Houska, B. & Faulwasser, T. Distributed AC optimal power flow using ALADIN. 20th IFAC World Congress, 2017.

Bio Sketch

Timm Faulwasser has studied Engineering Cybernetics at the University Stuttgart, with majors in systems and control and philosophy, where he graduated 2006. In 2007 he joined the group of Rolf Findeisen at the Institute of Automation Engineering at the Otto-von-Guericke University Magdeburg, Germany. From 2008-2012 he was a member of the International Max Planck Research School for Analysis, Design and Optimization in Chemical and Biochemical Process Engineering Magdeburg. In 2012 he obtained his PhD (with distinction) from Faculty of Electrical Engineering and Information Engineering, Otto-von-Guericke University Magdeburg, Germany. 2013-2016 he was with the Laboratoire d’Automatique, Ecole Polytechnique Fédérale de Lausanne, Switzerland. Since April 2015, he is with the Institute for Applied Informatics at the Karlsruhe Institute for Technology, where he leads the Optimization and Control Group.

His main research interests are optimization-based and predictive control of nonlinear systems with applications in energy systems, mechatronics/robotics, physics, process systems engineering and climate economics.

# Kolloquiumsvortrag, nn / am 09.02.2018

09.02.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (MaWi), Frau Dr. Berit Zeller-Plumdorf, Helmholtz Zentrum Geesthacht / am 05.02.2018

05.02.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Imaging and image-based modelling of biological and material systems

Abstract: Synchrotron radiation-based computed tomography (SRμCT) is a powerful tool for high-resolution imaging of materials. Whilst it traditionally depends on the X-ray attenuation by material components with high Z-numbers, it can be enhanced to enable imaging of biological soft tissues and other low-attenuation materials through propagation-based phase contrast. Due to the available high photon flux it is also possible to perform in situ testing, e.g. of material corrosion or mechanical loading experiments. In combination with image-based mathematical modelling, SRμCT enables the correlation between morphological and/or structural material measures and their function. In this presentation, showcases will be presented where SRμCT and image-based modelling have successfully been used to this end. These showcases include the assessment of osseointegration and in vitro degradation of biodegradable implants, the computational analysis of oxygenation in mouse muscle and the corrosion of steel embedded in concrete in aqueous solutions.

# Kolloquiumsvortrag (INF) Arindam Khan, TU München / am 02.02.2018

02.02.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: Approximating Geometric Knapsack via L-packings

Abstract: We study the two-dimensional geometric knapsack problem (2DK), a
geometric variant of the classical knapsack problem. In this problem, we
are given a set of axis-aligned rectangular items, each one with an
associated profit, and an axis-aligned square knapsack. The goal is to
find a (non-overlapping) packing of a maximum profit subset of items
inside the knapsack without rotating items. This is a very well-studied
optimization problem and finds applications in scheduling, memory
approximation factor for this problem (even just in the cardinality
case) is $2+\epsilon$ [Jansen and Zhang, SODA 2004].

After more than a decade, in this paper we break the 2-approximation
barrier, achieving a polynomial-time $17/9+\epsilon<1.89$ approximation,
which improves to $558/325+\epsilon<1.72$ in the cardinality case. We
also consider the variant of the problem with rotations (2DKR), where
the items can be rotated by $90$ degrees. Also, in this case, the
best-known polynomial-time approximation factor (even for the
cardinality case) is $2+\epsilon$ [Jansen and Zhang, SODA 2004].
Exploiting part of the machinery developed for 2DK plus a few additional
ideas, we obtain a polynomial-time $3/2+\epsilon$-approximation for
2DKR, which improves to $4/3+\epsilon$ in the cardinality case (joint
work with Waldo Galvez, Fabrizio Grandoni, Sandy Heydrich, Salvatore
Ingala and Andreas Wiese.).

Bio: Arindam Khan is a postdoc in Lehrstuhl für Theoretische Informatik
at Technische Universität München. His research areas include
approximation algorithms, online algorithms and computational geometry.
He has obtained his PhD in Algorithms, Combinatorics and Optimization
(ACO) from Georgia Institute of Technology, Atlanta, USA under Prof.
Prasad Tetali. Previously he has been a research intern in Theory group,
Microsoft Research Redmond and Microsoft Research Silicon Valley USA, a
visiting researcher at Simons Institute, Berkeley, USA; a blue scholar
in IBM Research India and a researcher at IDSIA, Lugano, Switzerland.

# Kolloquiumsvortrag (MaWi), Prof. Kläui, Uni Mainz / am 29.01.2018

29.01.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Topological Spin Dynamics for GreenIT

Abstract: In our information-everywhere society IT is a major player for energy consumption. Novel spintronic
devices can play a role in the quest for GreenIT if they are stable and can transport and manipulate
spin with low power. Devices have been proposed, where switching by energy-efficient approaches,
such as spin-polarized currents is used [1], for which we develop new highly spin-polarized materials
and characterize the spin transport using THz spectroscopy [2]. Firstly to obtain ultimate stability, topological spin structures that emerge due to the
Dzyaloshinskii-Moriya interaction (DMI) at structurally asymmetric interfaces, such as chiral domain
walls and skyrmions with enhanced topological protection can be used [3-5]. We have investigated in
detail their dynamics and find that it is governed by the topology of their spin structures [3]. By
designing the materials, we can even obtain a skyrmion lattice phase as the ground state of the thin
films [4]. Secondly, for ultimately efficient spin manipulation, we use spin-orbit torques, that can transfer
more than 1ħ per electron by transferring not only spin but also orbital angular momentum. We
combine ultimately stable skyrmions with spin orbit torques into a skyrmion racetrack device [4],
where the real time imaging of the trajectories allows us to quantify the novel skyrmion Hall effect
[5]. Finally to obtain efficient spin transport, we study graphene and low damping ferro- and
antiferromagnetic insulators as spin conduits for long distance spin transport [6] and explore the
superfluid spin current regime in antiferromagnets [7]. We find that we can control magnonic spin
currents by a newly developed magnon spin valve device [8].

[1] Reviews: O. Boulle et al., Mater. Sci. Eng. R 72, 159
(2011); G. Finocchio et al., J. Phys. D: Appl. Phys. 49,
423001 (2016); A. Bisig et al., PRL 117, 277203 (2016)
[2] M. Jourdan et al., Nature Commun. 5, 3974 (2014);
Z. Jin et al., Nature Phys. 11, 761 (2015).
[3] F. Büttner et al., Nature Phys. 11, 225 (2015).
[4] S. Woo et al, Nature Mater. 15, 501 (2016).
[5] K. Litzius et al., Nature Phys. 13, 170 (2017).
[6] A. Kehlberger et al., Phys. Rev. Lett. 115, 096602 (2015);
S. Geprägs et al., Nature Commun. 7, 10452 (2016).
[7] Y. Tserkovnyak and M. Kläui, arxiv:1707.01082
[8] J. Cramer et al., arxiv:1706.07592

# Kolloquiumsvortrag, nn / am 26.01.2018

26.01.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (ET&IT), Prof. Martjin van den Heuvel, Brain Center Rudolf Magnu Utrecht / am 22.01.2018

22.01.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Exploring the human connectome

Abstract: Using network science as a general framework to study the network architecture of nervous system connectivity, more and more studies have highlighted the human and animal brain to display features of an efficient communication network. In my talk I will discuss potential general principles of wiring of connectome organization, principles conserved across species, and which may play an important role in general nervous system functioning. I will highlight findings that show connectomes to display cost-effective wiring, pronounced community structure, short communication relays, and the existence of richly connected 'hub regions'. I will discuss theories on how these themes of wiring may play a role in brain disorders, as well as establish a putative link between the micro- and macroscale organization of the human brain in health and disease.

# Kolloquiumsvortrag, nn / am 19.01.2018

19.01.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (MaWi), Prof. Weller, Uni Hamburg / am 15.01.2018

15.01.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Nanocrystals in Materials and Life Science Applications

Abstract:

Horst Weller,
Institut für Physikalische Chemie, Universität Hamburg, Fraunhofer-Zentrum für Angewandte Nanotechnologie (CAN), The Hamburg Centre for Ultrafast Imaging (CUI)

Nanocrystals are already used for many applications in technical products for every day life. The talk will describe actual developments such as quantum dots in display and lighting technology and ultra-hard nanocomposite materials. Modern aspects of particle synthesis will be discussed.
The key idea for using nanocrystals for biomedical diagnostics is to benefit from their outstanding physical properties in the visualization of biological events or malignant cells or tissues. This requires a special design of the ligand shell, which preserves the fluorescent, magnetic and plasmonic properties of the particles in the biological environment on one side and allows a specific targeting on the other. The lecture reports on different chemical approaches and describes factors determining the biological response on fully synthetic nanocrystals. We will highlight concepts based on PEGylation and show how small deviations in the ligand shell alter the behavior in biological environment substantially. Moreover, we will present combinatorial approaches for the functionalization of the nanocrystals with biological affinity molecules to improve targeting specificity and concepts to optimize the physical properties of the inorganic core to increase the sensitivity for the respective imaging techniques.

# Kolloquiumsvortrag, nn / am 12.01.2018

12.01.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (ET&IT) - muss leider entfallen - Prof. Frank Vollmer, University of Exeter / am 08.01.2018

08.01.2018 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Sensing the Nanoscale with Optoplasmonics

Abstract: Nanophotonic device building blocks, such as optical nano/microcavities and plasmonic nanostructures, lie at the forefront of sensing and spectrometry of trace biological and chemical substances. My laboratory is developing a new class of nanophotonic architectures by combining optically resonant dielectric nano/microcavities with plasmonically resonant metal nanostructures to enable detection at the nanoscale with extraordinary sensitivity. Initial demonstrations include single-molecule detection and even single-ion sensing. The coupled photonic-plasmonic resonator system promises a leap forward in the nanoscale analysis of physical, chemical, and biological entities. I will review our work in this burgeoning field of optoplasmonic biosensors. I will also talk about our most recent advances in localising light at the nanoscale in disordered 2D photonic crystals.

1Department of Physics and Astronomy, Living Systems Institute, University of Exeter, EX44QD, Exeter, UK

E-mail: f.vollmer@exeter.ac.uk

CV: Frank Vollmer is a Professor of Biophysics at the Living Systems Institute at the University of Exeter. Prof Vollmer pioneers optical technology to study processes at the nanoscale. He held several appointments at leading US institutions including Instructor in Medicine at Harvard Medical School. Before moving to the LSI in 2016, he held the position of Research Group Leader at the Max Planck Institute for the Science of Light (DE). In 2017 Prof Vollmer was awarded the Royal Society Wolfson Research Merit Award.

References

# Kolloquiumsvortrag, nn / am 05.01.2018

05.01.2018 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, nn / am 22.12.2017

22.12.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (MaWi), PD Dr. Pavel Levkin, Karlsruhe Institute of Technology / am 18.12.2017

18.12.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Abstract: Patterns of different surface properties are ubiquitous in nature and serve various important purposes. Desert beetles exploit superhydrophilic spots on their superhydrophobic back to collect water from the morning mist in the desert. Hydrophilic spots on a superhydrophobic surface of lichen plants allow them to uptake water, but also prevent the formation of water layers on the surface that could interfere with the discharge of lichen spores into the air. Superhydrophobic and omniphobic surfaces possess various unique properties including self-cleaning, liquid repellent and cell repellent properties. We are interested in creating precise two-dimensional micropatterns of apparently incompatible and opposite properties such as superhydrophobicity and superhydrophilicity or slippery and adhesive properties. To create such patterns we develop surface coatings with special wettabilities and photochemical surface functionalization strategies. Combining seemingly opposite properties in micropatterns leads to functionalities non-existent on the original homogeneous interfaces. For example, we showed that superhydrophobic-superhydrophilic patterned surfaces could be used to create patterns of cells, arrays of microdroplets suitable for high-throughput cell screenings, formation of arrays of hydrogel micropads or free-standing hydrogel particles with defined shapes for 3D cell culture. Patterned liquid-infused interfaces could be also used to form cell microarrays or arrays of isolated biofilm colonies for biofilm screenings.

# Kolloquiumsvortrag, Dr. Patrick Totzke / Laboratory for Foundations of Computer Science at Edinburgh/ am 15.12.2017

15.12.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: Combined Objectives in Simple Stochastic Games

Abstract: SSG are turn-based, perfect information games where states are controlled by Adam, Eve or a randomized environment. The two opposing players compete to maximize/minimize the probability of a given winning condition (the objective of the game). I will outline a line of research that considers combinations of objectives classically studied for the verification of reactive systems, such as Parity, Mean-Payoff or limit-reward criteria. The aim is to determine under which conditions, to what extend, and with how much extra effort a player can achieve multiple objectives simultaneously. Time permitting, I will outline a recent result that exposes a subtle bug in the literature and shows how to fix it.

# Kolloquiumsvortrag (MaWi), Prof. Friedrich Frischknecht, Universität Heidelberg / am 11.12.2017

11.12.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Malaria transmission: new insights from in vivo imaging and materials science

Abstract: Malaria parasites are transmitted by mosquitoes and multiply to large numbers in red blood cells to cause disease. When taken up by mosquitoes the parasite develop in large cysts in their guts from where they emerge to colonize the salivary glands of the insect. From there the parasites are injected into the skin where they have to migrate to find a blood vessel. After entering the blood vessel the parasites first enter liver cells where they multiply without causing disease symptoms. In this seminar I will illuminate some of this curious biology using a set of different microscopy techniques, molecular genetics and biophysical approaches. We will see how parasites form within the cysts, how they leave the cysts, move within salivary glands and in the skin. Using laser tweezers we have measured the force they can produce and using micro-pillar arrays we have asked whether they adapted their shape in order to find the small blood capillaries into which they enter. For more info see: www.sporozoite.org

# Kolloquiumsvortrag, nn / am 08.12.2017

08.12.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (ET&IT), Dr. Andreas Bisplinghoff, Cisco / am 04.12.2017

04.12.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: From Long-Haul to Data-Center-Interconnect - Effiziente Signalverarbeitungsalgorithmen für Flexible Optische Netze

Abstract: First coherent optical communication systems, operating at 40Gbps, have been deployed in 2005. Since then, coherent optical technology has undergone remarkable development in the most recent years. Nowadays, state of the art products support line rates up to 400Gbps per wavelength. Next generation systems will primarily target for higher integration density but will presumably also reach line rates of 600Gbps and beyond.

With progress both in CMOS technology and of optical components, coherent optical transmission continuously pushes forward to highest reach for ultra-long haul applications as well as to highest capacity for shorter reach data-center interconnects. Both directions involve very specific requirements both on the capabilities of applied DSP algorithms and integration density of electrical and optical components.

Each new CMOS technology node facilitates the implementation of more sophisticated DSP algorithms. Many DSP components have undergone tremendous development during the most recent years, enabling coherent systems operating at highest transmission rates. Very efficient equalizer algorithms compensate for linear (CD, PMD) and non-linear (SPM, XPM) signal distortions, enhanced soft-decoded forward error correction schemes improve the noise tolerance, and with probabilistic constellation shaping performance will ultimately approach the Shannon limit.

This talk gives a high-level overview about state of the art DSP algorithms and most recent developments in coherent optical communication. It then discusses the balancing act to address the specific requirements of highest reach as well as highest capacity transmission within a single ASIC. Finally, some selected tradeoffs in algorithm and architecture optimization are shown by means of soft-decoded forward error correction as an example.

Bio: Andreas Bisplinghoff was born in Forchheim in 1984. He received the Dipl.-Ing. and Dr.-Ing. degrees both in electrical and electronic engineering from the Friedrich-Alexander University of Erlangen in 2009 and 2015, respectively.

From 2010 to 2013, he was a Research Assistant with the Institute of Microwaves and Photonics at the University of Erlangen. Since 2013 he has been a Hardware Engineer in Advanced Development with the Cisco Optical GmbH. His research interests include the development of slip-reduced carrier phase recovery techniques and of power-efficient forward error correction schemes for coherent optical communication. Andreas Bisplinghoff has broad experience in complexity-aware algorithm design, FPGA-based prototyping, and power-optimized ASIC implementation.

# Kolloquiumsvortrag, nn / am 01.12.2017

01.12.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (ET&IT), Dr.-Ing. Vasudev Kanade Rajan / am 27.11.2017

27.11.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Digital Road Noise Cancellation System Through Active Noise Control

Abstract: The application of active noise cancellation in real-world has not been fully realized yet. From reducing environment noise through the usage of headphones, to engine noise on commercial jets there are a number of use cases. Each of these use case brings its own set of challenges which can be understood only through multi-disciplinary work. One such use case the the reduction of road noise in vehicles. Structure-borne road noise dominates the cabin of modern vehicles. Several road noise cancellation (RNC) prototype systems have been implemented and demonstrated. These systems are based mainly on analog sensors. The placement of these sensors has been so far been based on random optimization methods. In this talk I will talk about the challenges in developing a generic digital RNC system which includes problem analysis, sensor placement, and performance. An adaptive algorithm process the acceleration signals with high convergence and reaction time for various speed and surface ranges, in order to maintain high audible effects for the passengers. Several modern vehicle platforms are integrated with the digital RNC system with ANC microphone at the headliners and the standard audio loudspeaker setup in order to integrate the technology with the existing audio layout of the vehicle.

#### Short biography

Vasudev Kandade Rajan received Bachelors degree in Electronics and Communication from Visvesvaraya Technological University, Bangalore, India. He joined as Project Research Assistant in July 2008 in the Electrical Communication Engineering Dept, Indian Institute of Science, Bangalore. There he worked on performance management of IEEE 802.11 WLANs until Sept 2009. He then went to obtain his Masters degree (MSc.) in Digital Communications, 2011 and PhD degree in Signal Processing, 2017 from Universtiy of Kiel, Germany. Currently he is working in the R&D department of Harman Becker Automotive Systems GmbH, Straubing, Germany.

# Kolloquiumsvortrag, nn / am 24.11.2017

24.11.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (ET&IT), M.Sc. Jonas Sauter, Nuance Communications / am 20.11.2017

20.11.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Artificial Bandwidth Extension for Speech Signals Using Deep Neural Networks

Abstract: In mobile communication, the bandwidth of transferred speech signals is either narrow-band (300Hz – 3.4kHz) or wide-band (50Hz – 7kHz or higher). As the limitation to 3.4kHz degrades the speech quality and intelligibility, it is of great interest to artificially extend narrow-band speech signals to wide-band speech.

This talk presents a deep neural network (DNN) approach to artificial bandwidth extension with a focus on robustness in practical applications.

It is based on the source-filter model which decomposes the signal into two parts: an excitation signal and a spectral envelope. The excitation (source part) describes the fine spectral structure which consists of white noise for unvoiced speech and an impulse train for voiced speech. The spectral envelope (filter part) describes the coarse spectral structure, i.e. the formants or resonance frequencies that make up different phonemes.

While the extension of the excitation signal can be done with simple mathematical methods that do not introduce strong artifacts, the envelope is much more relevant for the quality of the reconstructed wide-band signal. That is why the wide-band envelope is estimated with DNNs in this approach, which are trained on a large speech corpus.

Short biography

Jonas Sautter studied Electrical Engineering, Information Technology and Computer Engineering at RWTH Aachen University, Germany. He received his Master of Science degree in 2016. The Master’s thesis with the title “Digital Robust Control for Active Noise Cancellation in Headphones and Hearing Aids” was composed at the Institute of Communication Systems at RWTH Aachen. Since November 2016, he is a PhD student at Nuance Communications in Ulm, supervised by Professor Gerhard Schmidt, Head of the Digital Signal Processing and System Theory group at Christian-Albrechts-Universität, Kiel.

# Kolloquiumsvortrag, nn / am 17.11.2017

17.11.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag (ET&IT), Prof. Elisabetta Chicca, Uni Bielefeld / am 13.11.2017

13.11.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Learning in silico beyond STDP

Abstract: Synaptic plasticity empowers biological nervous systems with the ability to learn from experience and adjust to environmental changes. Such abilities are a must for artificial autonomous systems and therefore researchers have been devoting significant efforts to the understanding and modelling of plasticity mechanisms. In particular, the field of neuromorphic engineering focuses on the development of full-custom hybrid analog/digital electronic systems for the implementation of models of biological computation and learning in hardware. I will give a short historical overview of the most important plasticity circuits developed following the approach originally proposed by Carver Mead in the late eighties. Afterwards, I will present recent advancements in this field.

# Kolloquiumsvortrag, nn / am 10.11.2017

10.11.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, nn / am 06.11.2017

06.11.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 03.11.2017

03.11.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, nn / am 30.10.2017

30.10.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 27.10.2017

27.10.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, nn / am 23.10.2017

23.10.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 20.10.2017

20.10.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Sonderkolloquium (INF), Vijay Ganesh, University of Waterloo, Kanada / am 17.10.2017

17.10.2017 von 14:00 bis 15:00

Institut für Informatik, Christian-Albrechts-Platz 4, 24118 Kiel

Titel: On The Unreasonable Effectiveness of Boolean SAT Solvers

Abstract: Modern conflict-driven clause-learning (CDCL) Boolean SAT solvers routinely solve very large industrial SAT instances in relatively short periods of time. This phenomenon has stumped both theoreticians and practitioners since Boolean satisfiability is an NP-complete problem widely believed to be intractable. It is clear that these solvers somehow exploit the structure of real-world instances. However, to-date there have been few results that precisely characterize this structure or shed any light on why these SAT solvers are so efficient.

In this talk, I will present results that provide a deeper empirical understanding of why CDCL SAT solvers are so efficient, which may eventually lead to a complexity-theoretic result. Our results can be divided into two parts. First, I will talk about structural parameters that can characterize industrial instances and shed light on why they are easier to solve even though they may contain millions of variables compared to small crafted instances with hundreds of variables. Second, I will talk about internals of CDCL SAT solvers, and describe why they are particularly suited to solve industrial instances.

Brief Bio: Dr. Vijay Ganesh is an assistant professor at the University of Waterloo since 2012. Prior to that he was a research scientist at MIT, and completed his PhD in computer science from Stanford University in 2007. Vijay's primary area of research is the theory and practice of automated reasoning aimed at software engineering, formal methods, security, and mathematics. In this context he has led the development of many SAT/SMT solvers, most notably, STP, The Z3 string solver, MapleSAT, and MathCheck. He has also proved several decidability and complexity results relating to the SATisfiability problem for various mathematical theories. For his research, he has won over 20 awards including an ACM Test of Time Award at CCS 2016, two Google Faculty Research Awards in 2011 and 2013, and a Ten-Year Most Influential Paper Award at DATE 2008.

# Kolloquiumsvortrag, nn / am 16.10.2017

16.10.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 13.10.2017

13.10.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, nn / am 09.10.2017

09.10.2017 von 17:15 bis 18:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 06.10.2017

06.10.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, Prof. Dr. Stefan Sauter, Uni Zürich / am 21.07.2017

21.07.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: A Family of Crouzeix-Raviart Non-Conforming Finite Elements in Two- and Three Spatial Dimensions

Abstract: In this talk we will present a family of non-conforming "Crouzeix-Raviart" type finite elements in two and three dimensions. They consist of local polynomials of maximal degree p on simplicial finite element meshes while certain jump conditions are imposed across adjacent simplices.

We will prove optimal a priori estimates for these finite elements. The characterization of this space via jump conditions goes back to the seminal paper of Crouzeix and Raviart in 1973. However, the definition is implicit and the derivation of an explicit representation of the local basis functions for general p in 3D was an open problem.

We present explicit representations for these functions by developing some theoretical tools for fully symmetric and reflection symmetric orthogonal polynomials on triangles and their representation.

Finally we will analyze the linear independence of these sets of functions and discuss the question whether they span the whole non-conforming space. This talk comprises joint work with P. Ciarlet Jr., ENSTA, Paris and Charles F. Dunkl, Virginia Tech.

# Sonderkolloquium, Prof. Dr. María López Fernández, Universität Zürich / am 18.07.2017

18.07.2017 von 11:00 bis 13:00

Ludewig-Meyn-Str. 2. Raum Ü2/K (LMS2, R. Ü2/K), 24118 Kiel

established method for the time discretization of retarded potentials
associated to wave equations. It has been very much developed in the
last decade, both from the theoretical and the algorithmic point of
view. However, despite its nice properties, the Convolution Quadrature
is strictly restricted to the use of fixed time steps. In this talk I
will present the "generalized Convolution Quadrature", a new family of
methods designed to overcome the strong restriction to uniform
temporal grids. I will show stability and convergence estimates and
numerical results illustrating the good behaviour of the new method. I
will also outline the current limitations in the implementation of the
generalized Convolution Quadrature and future possibilities of
development.

# Kolloquiumsvortrag, nn / am 17.07.2017

17.07.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 14.07.2017

14.07.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Sonderkolloquium, Tomislav Dragicevic, University Aalborg / 12.07.2017

12.07.2017 von 15:00 bis 16:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Coordination Strategies for DC Microgrids

Abstract: DC distribution systems have higher efficiency, better current carrying capacity and faster response when compared to conventional AC systems. They also provide more natural interface with many types of RES and ESSs and better compliance with consumer electronics. Furthermore, when components are coupled around a DC bus, there are no issues with reactive power flow, power quality and frequency regulation, resulting in a notably less complex control system when compared to the AC coupled systems. All these facts lead to more and more applications of DC systems in modern power systems, including data/telecom centers, maritime industry, high voltage transmission systems, electric vehicle charging infrastructure, and DC microgrids. Still, design and operation of general DC systems imposes a number of specific challenges. The aim of this lecture is in particular to present functionalities of different coordinated control strategies for DC microgrids. In this context, centralized, decentralized and distributed controls are assessed. Decentralized control can be regarded as an extension of local control since it is also based exclusively on local measurements. In contrast, centralized and distributed control strategies rely on digital communication technologies. A number of approaches of using these three coordinated control strategies to achieve various control objectives are reviewed in the paper. Moreover, properties of DC MG dynamics and stability are discussed.

# Kolloquiumsvortrag, nn / am 10.07.2017

10.07.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, Prof. Grandoni, IDSIA USI-SUPSI in Lugano / am 07.07.2017

07.07.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Raum Ü2/K (LMS2, R. Ü2/K), 24114 Kiel

Titel: Approximating Geometric Knapsack via L-packings

Abstract: Joint work with: Waldo Galvez, Sandy Heydrich, Salvatore Ingala,
Arindam Khan, Andreas Wiese

In the 2-dimensional geometric knapsack problem (2DK) we are given a
set of n axis-aligned rectangular items, each one with an associated
profit, and an axis-aligned square knapsack. The goal is to find a
(non-overlapping) packing of a maximum profit subset of items inside
the knapsack (without rotating items). The best-known polynomial-time
approximation factor for this problem (even just in the cardinality
case) is 2 + ε [Jansen and Zhang, SODA 2004]. In this work we break
the 2 approximation barrier, achieving a polynomial-time 17/9 + ε <
1.89 approximation, which improves to 558/325+ ε < 1.72 in the
cardinality case.

Essentially all prior work on 2DK approximation packs items inside a
constant number of rectangular containers, where items inside each
container are packed using a simple greedy strategy. We deviate for
the first time from this setting: we show that there exists a large
profit solution where items are packed inside a constant number of
containers plus one L-shaped region at the boundary of the knapsack
which contains items that are high and narrow and items that are wide
and thin. The items of these two types possibly interact in a complex
manner at the corner of the L.

The above structural result is not enough however: the best-known
approximation ratio for the sub-problem in the L-shaped region is 2 +
ε (obtained via a trivial reduction to 1-dimensional knapsack by
considering tall or wide items only). Indeed this is one of the
simplest special settings of the problem for which this is the best
known approximation factor. As a second major, and the main
algorithmic contribution of this work, we present a PTAS for this
case. We believe that this will turn out to be useful in future work
in geometric packing problems.

We also consider the variant of the problem with rotations (2DKR),
where items can be rotated by 90 degrees. Also in this case the
best-known polynomial-time approximation factor (even for the
cardinality case) is 2 + ε [Jansen and Zhang, SODA 2004]. Exploiting
part of the machinery developed for 2DK plus a few additional ideas,
we obtain a polynomial-time 3/2 + ε-approximation for 2DKR, which
improves to 4/3 + ε in the cardinality case.

# Sonderkolloquium, Jun.-Prof. Dr. Mattias Heinrich, Uni Lübeck / am 07.07.2017

07.07.2017 von 14:15 bis 15:45

Institut für Informatik,Christian-Albrechts-Platz 4, R.715, 24114 Kiel

Titel: Learning Sparse Binary Features for Medical Image Segmentation of the Abdomen

Abstract: In this talk, we explore the capabilities of sparse binary features for medical image segmentation. Due to insufficient contrast and anatomical shape variations local image patches rarely provide sufficient information for accurate segmentation of abdominal structures. Based on our two recent MICCAI papers, we propose to use long-range binary features to robustly capture the image context. Two different classification strategies are subsequently developed.

First, a very fast approximate nearest neighbour search based on vantage point forests and Hamming distances between feature strings is presented. The classifier can be learned and applied to new data in few seconds. The approach reaches state-of-the-art performance for larger organs on the VISCERAL3 benchmark.

Second, we develop a deep neural network architecture that combines a local CNN path with a new contextual path that encodes the sparse binary features. Following the ideas from Network-in-Network, 1x1 convolutions are employed to learn the best combination of different binary offset locations. We demonstrate experimentally that this restricted feature extraction in the first layer enables to regularise the network with a huge receptive field and leads to short training times of less than 10 minutes. Using only 1 million trainable parameters, the model achieves a accuracy of 64.5% Dice, which is comparable to the best performing, much more complex deep CNN approach for pancreas segmentation.

Finally, the potential use of learned binary features for other tasks in medical image analysis, such as image registration and disease classification will be discussed.

# Kolloquiumsvortrag, Carsten Grashoff / am 03.07.2017

03.07.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Piconewton-sensitive biosensors to investigate molecular forces in cells

Abstract: The ability of cells to adhere and simultaneously sense differences in tissue stiffness is crucial for organ development and function. Yet, the molecular mechanisms by which cells sense extracellular matrix rigidity have remained unknown because suitable techniques to measure mechanical forces across intracellular proteins in living cells were missing.

We therefore develop novel, single-molecule‒calibrated tension sensor modules that allow the analysis of a physiologically highly relevant force regime in cells. Our new probes are sensitive to forces of 3–5 piconewton (pN), 6–8 pN and 9–11 pN, respectively; they are characterized by fast folding/unfolding transitions, reversibility and a sharp force-response threshold (1, 2, 3). By applying these new probes to the cell adhesion proteins talin-1 and talin-2, we demonstrate that these central integrin activators establish intracellular, mechanical linkages that bear mechanical forces of about 7–10 pN upon cell adhesion and are regulated by f-actin and vinculin association. We find that the integrin–talin–actin linkage is indispensable for extracellular rigidity sensing and, surprisingly, talin isoform-specific (1). Furthermore, multiplexing distinct tension sensor constructs by dual-color FLIM reveals an unexpected intramolecular tension gradient across talin that is modulated by intracellular signals and extracellular rigidity (3).

References:

1. Austen KA et al., and Grashoff C. 2015. Nat Cell Biol.

2. Freikamp A, Cost AL, and Grashoff C. 2016. Trends Cell Biol.

3. Ringer et al., and Grashoff C. 2017. under review

# Sommerfest am 30.06.2017

30.06.2017 von 15:00 bis 15:00

Technische Fakultät, Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, Antrittsvorlesung Prof. Kapels / am 26.06.2017

26.06.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Von der Siliziumtechnologie zu Wide-Bandgap Leistungshalbleitern

Abstract: Kontinuierliche Innovationen im Bereich der siliziumbasierten Leistungshalbleiterbauelemente ermöglichten grundlegende Fortschritte für eine effiziente dezentrale Energieversorgung, die Weiterentwicklung der Elektromobilität und energieeffiziente Stromrichter für Industrie- und Consumer-Anwendungen. Aktuelle Trends in Leistungsdichte und Gewicht werden jedoch zunehmend nicht mehr mit Halbleiterbauelementen auf Siliziumbasis erfüllt werden können. Leistungstransistoren auf Basis von SiC und GaN ermöglichen hier Zukunftspotentiale zu heben. Die Vorlesung zeigt die wesentlichen Bauelementekonzepte, aktuelle Herausforderungen und Lösungen auf.

# Kolloquiumsvortrag, nn / am 23.06.2017

23.06.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Sonderkolloquium, Prof. R.D. Lorenz, University of Wisconsin-Madison / 23.06.2017

23.06.2017 von 13:00 bis 15:00

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Disruptive Paradigm Changes for Electrical Machines and Electrical Drives

Abstract: Electric machine design paradigms have been dramatically changed by the need to meet the demands for minimizing losses and smooth torque control during driving cycles with widely vary loads and speeds.  Simultaneously, new drive control paradigms systematically out-perform industry standard field oriented control (FOC) and simultaneously solve several classical problems with FOC. In addition, the internet of things is opening expansive opportunities for motor drives.  This presentation with focus on these disruptive changes in the paradigms for electric machines and electrical drives and explore the opportunities for innovation that these technologies provide.

Affiliation:

Chaired Professor and Co-Director of WEMPEC at the University of Wisconsin-Madison, in Madison, Wisconsin, USA

Short Bio:

Prof. Robert D. (Bob) Lorenz is a Life Fellow of IEEE, Past President of IEEE IAS, and Past Member of the IEEE Board of Directors. He is a Chaired Professor at the University of Wisconsin-Madison and Co-Director of the Wisconsin Electric Machines and Power Electronics Consortium (WEMPEC) which just celebrated its 36th Anniversary with over 85 international sponsor firms.    He has pioneered core technologies for physics-based control design, self-sensing, flux observers, current regulators, deadbeat-direct torque and flux control, variable flux and variable magnetization state PM machines and power semiconductor temperature and strain control and has won 33 prize paper awards from the IEEE.

# Sonderkolloquium Prof. Tamulevicius, Technische Universität Kaunas / am 20.06.2017

20.06.2017 von 17:15 bis 18:45

Technische Fakultät, Institut für Materialwissenschaft, Kaiserstr. 2, Kiel, Raum: "Aquarium", Geb. D

Titel: Nanoparticles, nanocomposites - from optics to medicine

Abstract: Principles of deposition and applications of diamond-like carbon thin films, diamond-like carbon-based nanocomposites including metallic nanoparticles as well as capillary assisted deposition of nanoparticles will be presented, thereby concentrating on the optical, electrical  properties and the use of the assembly of particles as building blocks for optical sensors and antimicrobial surfaces. Features of localized surface plasmon effects, surface enhanced Raman scattering, detection of ultrafast energy transfer processes will be discussed.

# Kolloquiumsvortrag, Prof. Dr.-Ing. Mücklich, Functional Materials, Dept. Mat. Science & Engineering, Saarland University / am 19.06.2017

19.06.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Optimized functionality by 3D microstructure research and efficient surface patterning

Abstract: In the introduction a short overview will be given concerning the three units of the institute, such as the chair for functions materials which is dedicated to fundamental research and teaching, the European School of Materials, which is focused on the international study programs on all academic levels and the Material Engineering Center Saarland, which is promoted by applied research and transfer activities. Then some of the research activities will be discussed based on three main questions:

-          How does 3D microstructure research on the micro, nano and atomic scale help to understand the quantitative relations between microstructure formation and properties

-          How does the initial 3D morphology control the processing and formation of microstructures and

-          How can Direct Laser Interference Patterning be exploited to design optimized surface functionalities

# Kolloquiumsvortrag, nn / am 16.06.2017

16.06.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, Prof. Herbert Jäger, Jacobs University Bremen / am 12.06.2017

12.06.2017 von 17:15 bis 18:45

Institut für Elektrotechnik und Informationstechnik, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Thema: An introduction to Reservoir Computing

Abstract: Recurrent neural networks (RNNs) are general approximators for nonlinear dynamical systems and have recently become widely used in the "deep learning" field of machine learning, especially for speech and language processing tasks. For instance, Google's speech recognition and language translation services are based on RNNs.

However, the deep learning set-ups for RNN training are computationally very expensive, require very large volumes of training data, and need high-precision numerical processing. For such reasons, deep-learning variants of RNNs are problematic in fields where training data are scarce, where fast and cheap algorithms are desired, or where noisy or low-precision hardware is to be used. This is often the case in domains of nonlinear signal processing, control, brain-machine interfacing, or biomedical signal processing.

Reservoir Computing (RC) is an alternative machine learning approach for RNNs which is in many aspects complementary to the ways of deep learning. In RC, a large, random, possibly low-precision and noisy RNN is used as a nonlinear excitable medium - called the "reservoir" - which is driven by an input signal. The reservoir itself is not adapted or trained. Instead, only a "readout" mechanism is trained, which assembles the desired output signal from the large variety of random, excited signals within the reservoir. This readout training is cheap - typically just a linear regression. RC has become a popular approach in research that aims at useful computations on the basis on unconventional hardware (non-digital, noisy, low-precision).

The talk gives an introduction to the basic principles and variants of RC. Numerous examples will be presented according to wishes from the audience.

# Sonderkolloquium, Prof. Remus Teodorescu, Universität Aalborg / 12.06.2017

12.06.2017 von 15:15 bis 16:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Modular Multilevel Converter Research at Aalborg University

Abstract:This presentation is aiming on summarizing the main features of the recently published book: Design, Control, and Application of Modular Multilevel Converters for HVDC Transmission Systems, ISBN: 978-1-118-85156-2, Wiley 2016http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1118851560.html#. Special focus will be on Control under unbalanced conditions of MMC.

# Kolloquiumsvortrag, PhD Tammy Riklin Raviv, Ben-Gurion-University of the Negev, Beer Sheva, Israel / am 09.06.2017

09.06.2017 von 13:30 bis 15:00

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel:

Ensemble of Expert Deep Neural Networks for Spatio-Temporal Denoising of Contrast-Enhanced MRI Sequences

Abstract:

Abstract: Dynamic contrast-enhanced MRI (DCE-MRI) is an imaging protocol where MRI scans are acquired repetitively throughout the injection of a contrast agent. The analysis of dynamic scans is widely used for the detection and quantification of blood-brain barrier (BBB) permeability. Extraction of the pharmacokinetic (PK) parameters from the DCE-MRI concentration curves allows quantitative assessment of the integrity of the BBB functionality. However, curve fitting required for the analysis of DCE-MRI data is error-prone as the dynamic scans are subject to non-white, spatially dependent and anisotropic noise.

We present a novel spatio-temporal framework based on Deep Convolution Neural Networks (DCNNs) to address the DCE-MRI denoising challenges. This is accomplished by an ensemble of expert DCNNs constructed as deep autoencoders, where each is trained on a specific subset of the input space to accommodate different noise characteristics and curve prototypes. The most likely reconstructed curves are then chosen using a classifier DCNN followed by a quadratic programming optimization. As clean signals (ground-truth)

for training are not available, a fully automatic model for generating realistic training sets with complex nonlinear dynamics is introduced. The proposed approach has been applied to full and even temporally down-sampled DCE-MRI datasets acquired by MRI machines in different locations and of different manufacturers and is shown to favorably compare to state-of-the-art denoising methods.

# Sonderkolloquium, Prof. Dr. Raj, Universität Agra, Indien / am 08.06.2017

08.06.2017 von 11:30 bis 13:00

Institut für Informatik, Christian-Albrechts-Platz 4, Raum: 910 (CAP 4), 24118 Kiel

Titel: Finite Element Modelling and Simulation of Selected Bulk Nano-material Processing Techniques

Abstract: A brief review of the material modeling such as visco-plastic, coupled thermo visco-plastic along with mathematical formulation is presented with application to forming of Bulk Nano-structured Materials using Severe Plastic Deformation(SPD). The material is assumed to be homogeneous, isotropic, incompressible. Elasticity is neglected and the material behavior chosen is given by the Norton-Hoff law. A power law is used to simulate the friction between the die and the work-piece. The flow problem with a given temperature distribution is solved simultaneously with the heat diffusion equation. Using the Penalty approach to enforce approximate incompressibility, the Variational principle is applied. This finds the velocity field solution of the problem by minimizing the functional. The coupling between the mechanical and the thermal problems is obtained through the dependency of the consistency of the material with temperature. Being a non-steady state process, SPD is analyzed by using small steady-like deformation steps. The usual finite element method is used to discretize the two problems at a given state Ω(t), and in the axi-symmetrical case the interpolation of the variables is performed in the (r2, z) space. The SPD processes that are modeled are Equal Channel Angular Pressing (ECAP), Twist Extrusion (TE), Accumulative Roll Bonding(ARB), Repetitive Corrugation and Straightening (RCS) and High Pressure Torsion (HPT). Finite Element Modeling and experimentation of these SPD processes is presented in this paper.

# Kolloquiumsvortrag, Prof. Dr. Helmut Harbrecht, Uni Basel / am 02.06.2017

02.06.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: On multilevel quadrature for elliptic partial differential equations with random input

Abstract: This talk is dedicated to multilevel quadrature methods for the rapid solution of partial differential equations with a random input parameter. The key idea of such approaches is a sparse-grid approximation of the occurring product space between the stochastic and the spatial variable. We develop the mathematical theory and present error estimates for the computation of the solution’s moments with focus on the mean and the variance in case of second order elliptic boundary value problems with random diffusion. In particular, the present framework covers the multilevel Monte Carlo method and the multilevel quasi-Monte Carlo method as special cases. The theoretical findings are supplemented by numerical experiments.

# Kolloquiumsvortrag, nn / am 29.05.2017

29.05.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

# Kolloquiumsvortrag, nn / am 26.05.2017

26.05.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, Dr. Barth / am 22.05.2017

22.05.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Hochfrequenz-Filterdesign unter Berücksichtigung hoher Transmissionsleistung

Abstract: Das Design von Hohlleiterfiltern mit Hilfe der Softwareprogramme HFSS, MATHCAD und AWR wird beschrieben. Das Design berücksichtigt die hohe Transmissionsleistung (hier 40KW gepulst), die bei Radargeräten auftritt und den Entwickler vor besondere Herausforderung stellt. Die Designmethode ist äußerst präzise, so dass die Anforderungen an das Filter schon im ersten Designschritt erreicht werden. Eine Abstimmung, die Feldkonzentrationen und damit Überschläge in den Filterresonatoren hervorrufen könnten, ist damit nicht nötig. Trotzdem wird eine Abstimmmethode bei hohen Feldstärken diskutiert.

Ein Filter, das für die Luftraumüberwachung eines Flughafens konstruiert wurde und dort auch seit Jahren in Betrieb ist, wird als Beispiel vorgestellt.

# Kolloquiumsvortrag, nn / am 19.05.2017

19.05.2017 von 14:45 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, Prof. Knut Graichen, Institut für Mess-, Regel- und Mikrotechnik, Universität Ulm / am 15.05.2017

15.05.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Eingebettete nichtlineare Optimierung und MPC im (Sub-)Millisekundenbereich

Abstract: Nichtlineare Optimierungsverfahren und deren Anwendung im Zusammenhang mit der nichtlinearen modellprädiktiven Regelung (NMPC) sind in der Regelungstechnik insbesondere für dynamische Systeme mit mehreren Stellgrößen und zur Berücksichtigung von Systembeschränkungen von zunehmender Bedeutung. Eine Herausforderung bei der Umsetzung dieser Verfahren in der Praxis ist jedoch der hohe numerische Aufwand und die algorithmische Komplexität, insbesondere bei hochdynamischen Systemen mit Abtastzeiten im (Sub-)Millisekundenbereich. Die Problematik der Umsetzbarkeit wird durch die Tatsache weiter verschärft, dass Hardware-Lösungen in der industriellen Praxis häufig sehr limitierte Ressourcen besitzen. Als Beispiele seien Speicherprogrammierbare Steuerungen (SPS) oder Steuergeräte (Electronic Control Unit – ECU) genannt. Diesen Herausforderungen kann im Sinne eines eingebetteten Entwurfs durch die Verwendung von zugeschnittenen Optimierungsalgorithmen in Kombination mit einer echtzeitfähigen Auswertung begegnet werden.
Im Hinblick auf die oben genannten Herausforderungen präsentiert der Vortrag einen Ansatz zur nichtlinearen dynamischen Optimierung und modellprädiktiven Regelung, der eine echtzeitfähige Umsetzung selbst auf leistungsschwacher Hardware ermöglicht. Neben der methodischen und algorithmischen Vorstellung wird das Verfahren anhand von ausgewählten mechatronischen Beispielen erläutert.

# Kolloquiumsvortrag, Prof. Armin Iske, Universität Hamburg / am 12.05.2017

12.05.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

Titel: Error Estimates and Convergence Rates for Filtered Back Projection.

Abstract: We consider the approximation of target functions from fractional Sobolev spaces by the method of filtered back projection (FBP), which gives an inversion of the Radon transform. To this end, we analyze the intrinsic FBP approximation error which is incurred by the use of a low-pass filter with finite bandwidth, before we prove $L^2$-error estimates on Sobolev spaces of fractional order. The obtained error bounds are affine-linear with respect to the distance between the filter's window function and the constant function $1$ in the $L^\infty$-norm. With assuming more regularity for the window function, we refine the error estimates to prove convergence for the FBP approximation in the $L^2$-norm as the filter's bandwidth goes to infinity. We finally give asymptotic convergence rates in terms of the bandwidth of the low-pass filter and the smoothness of the target function.

# Sonderkolloquium, Prof. Dr. Mayr, Universität Klagenfurt / 10.05.2017

10.05.2017 von 17:00 bis 18:30

Hermann-Rodewald-Str. 3, 408a, 24118 Kiel

Titel: Konzeptuelle Modellierung – eine Disziplin mit Potenzial

Abstract: Die Welt ist voll von Menschen, die konzeptuell modellieren, sich dessen aber nicht bewusst sind und daher pragmatisch agieren. Dies ist nicht weiter schlimm. Es sei denn, es handelt sich um ExpertInnen der Informatik und angrenzender Gebiete, die es besser wissen sollen. Denn viele und vor allem sehr teure Probleme im Umfeld der Erstellung und des Betriebs von Softwaresystemen – zu denen ich natürlich auch datenintensive Informationssysteme zähle – entstehen durch unzureichende oder unsachgemäße Modellierung: selbst wenn man glaubt, hierauf großes Augenmerk zu legen bzw. gelegt zu haben.

Die Schuld hieran liegt nur zu einem kleineren Teil an den in der Praxis Handelnden selbst. Denn als Konsumenten von Lehrbüchern, Kursen usw. können sie es kaum besser wissen. Verantwortlich sind  vor allem diejenigen, die im Bereich der Modellierungsforschung arbeiten und lehren, mich eingeschlossen. Denn es ist uns offenbar nicht gelungen, (konzeptuelle) Modellierungsmethoden so zu gestalten und zu vermitteln, dass an ihrer systematischen und erfolgsbringenden Verwendung kein Weg vorbeiführt. Also muss man die Ursachen analysieren und daraus Konsequenzen für die Zukunft ziehen. Hierzu soll dieser Vortrag beitragen.

Zunächst werde ich versuchen, einen Eindruck davon zu vermitteln, was falsch läuft: vom Fehlen einer scharfen Definition des Begriffes „Konzeptuelle Modellierung“ selbst, über die anschwellende Ontologieflut, die offenbar den Mangel an Standards und Konstruktionsregeln ausgleichen soll, bis zum damit verbundenen Begriffs- und Methodenchaos.

Hiervon ausgehend werde ich aufzeigen, wohin, und mit welchen meist einfachen Mitteln, die Reise gehen könnte, ohne dass wieder (vermeintlich) Neues zu erfinden, zu predigen und zu verkraften wäre: über vieles wurde nämlich bereits nachgedacht und geschrieben, teils unbeachtet, teils wieder vergessen.

Heinrich C. Mayr ist emeritierter Ordentlicher Universitätsprofessor an der Alpen-Adria-Universität Klagenfurt (AAU), an der er seit 1990 tätig ist und die Forschungsgruppe Application Engineering leitet. Zuvor war er Assistent und Hochschulassistent an der Universität Karlsruhe (heute KIT), Gastprofessor an verschiedenen Universitäten im In- und Ausland und geschäftsführender Gesellschafter eines Softwareunternehmens. Seine Forschungsergebnisse sind in über 200 meist begutachteten (peer review) Veröffentlichungen dokumentiert. Sie betreffen im Wesentlichen Entwurfs- und Entwicklungsmethoden für Informationssysteme, die Modellierung im Kontext von Anforderungsanalyse, Systementwurf und Wissensmanagement, sowie die Entwicklung domänenspezifischer Modellierungssprachen. Unter anderem war er Sprecher des Fachbereichs Softwaretechnik und Informationssysteme, Vizepräsident und Präsident der Gesellschaft für Informatik (GI), Aufsichtsratsvorsitzender der Stadtwerke Klagenfurt AG, Aufsichtsratsmitglied der FH Kärnten, Hochschulrat der Pädagogischen Hochschule Kärnten, acht Jahre Dekan der seinerzeitigen Fakultät für Wirtschaftswissenschaften und Informatik und sechs Jahre Rektor der AAU. Derzeit ist er Hauptherausgeber der Lecture Notes in Informatics (LNI), Chairman des ER Steering Committee, Vorsitzender des Beirats des Software Internet Cluster SIC und Mitglied des Fachausschusses “Wirtschaftsinformatik” der  ASIIN.

# Kolloquiumsvortrag, Prof. Jacquelien Scherpen von der Universität Groningen (NL) / am 08.05.2017

08.05.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Passivity based control techniques for (micro-)grid control

Abstract: In this presentation I will discuss some physical modeling consideration for grid models, and the various devices in the grid, such as synchronous generators and inverter models for the embedding of renewables. Furthermore, the (passivity based) control possibilities and difficulties of networks with such generating devices will be discussed, as well as control considerations for inverters. Finally, a more simple OPF control model for microgrids is considered in the analysis.

# Kolloquiumsvortrag, nn / am 05.05.2017

05.05.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Sonderkolloquium, Prof. Thomas Plagemann / Prof. Vera Goebel, Universität Oslo / am 04.05.2017

04.05.2017 von 16:30 bis 18:00

ZBW, Düsternbrooker Weg 120, 24105 Kiel, Raum B024

Titel: A Platform for fine-granular migration of multimedia applications

Abstract: As a step towards mobile and ubiquitous computing, the TRAMP Real-time Application Mobility Platform (TRAMP) enables secure and user-friendly migration of multimedia application components. The motivating factors are device and user mobiliy, i.e., to let the user determine where application components should execute at all times. In order to organize and locate roaming devices, a decentralized peer-to-peer overlay is developed. To provide location transparency for application developers and enable efficient data sharing among application components, an API is provided that hides whether shared memory or latency optimized network distribution is used to share data. The problem of open TCP connections to third-party applications is solved with a proxy-based approach. Multimedia applications are especially sensitive to service interruptions that can be caused by migration, and a new approach for check-pointing, state transfer and resuming an application with minimal freeze time is therefore introduced. The evaluation of TRAMP shows that this optimization for low freeze time has significant effect. For example, migrating the Skype video-conferencing application with TRAMP reduces the average freeze time from 41.1 seconds with legacy approaches to 213 milliseconds. Further results from the empirical evaluation of TRAMP demonstrate that it has no negative impact on the Quality of Experience.

# Kolloquiumsvortrag, nn / am 28.04.2017

28.04.2017 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Straße 2, 24118 Kiel, Raum: Übungsraum 2/K

# Kolloquiumsvortrag, Prof. Massimo Guarnieri, University Padua (Italien) / am 24.04.2017

24.04.2017 von 17:15 bis 18:45

Institute Ostufer, Geb. D, "Aquarium", Kaiserstr. 2, 24143 Kiel

Titel: Vanadium Redox Flow Batteries: Potentials and Challenges of an Emerging Storage Technology.

# Kolloquiumsvortrag: PD Dr. Frank Gurski - Universität Düsseldorf/ 17.07.2015

17.07.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: Knapsack Problems: A Parameterized point of view

Abstract:

The knapsack problem is a very famous NP-hard problem in combinatorial optimization. In the 0-1 knapsack problem (0-1 KP) we are given a set A of n items. Every item j has a profit p(j) and a size s(j). Further there is a capacity c of the knapsack. The task is to choose a subset A' of A, such that the total profit of A' is maximized and the total size of A' is at most c.

Within the d-dimensional 0-1 knapsack problem (d-KP) a set A of n items and a number d of dimensions is given. Every item j has a profit p(j) and for dimension i the size s(i,j). Further for every dimension i there is a capacity c(i). The goal is to find a subset A' of A, such that the total profit of A' is maximized and for every dimension i the total size of A' is at most the capacity c(i).

Further we consider the multiple 0-1 knapsack problem (MKP) where beside n items a number m of knapsacks is given. Every item j has a profit p(j) and a size s(j) and each knapsack i has a capacity c(i). The task is to choose m disjoint subsets of A such that the total profit of the selected items is maximized and each subset can be assigned to a different knapsack i without exceeding its capacity c(i) by the sizes of the selected items.

Since d-KP and MKP are defined on inputs of various informations, we study the fixed-parameter tractability of these problems. The idea behind fixed-parameter tractability is to split the complexity into two parts - one part that depends purely on the size of the input, and one part that depends on some parameter of the problem that tends to be small in practice. We discuss the following parameters: the number of items, the threshold value for the profit, the sizes, the profits, the number d of dimensions, and the number m of knapsacks.

We also consider the connection of parameterized knapsack problems to linear programming, approximation, and pseudopolynomial algorithms.

# Kolloquiumsvortrag: Dr. Stephan Warnat/ Dalhousie University, Halifax, Canada / 13.07.2015

13.07.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: Multi User MEMS environment to test microorganisms in aqueous media

Abstract:

90 % of international traded products are transported using marine transportation.  Transport and delivery of microorganisms through ballast water from departure to arrival location is an unwanted consequence. Some organisms are invaders or alien species and change the marine ecosystem irreversibly. These irreversible changes cause annual damage in ecosystems, farming and tourism of several million dollars.

I will present our current work on a cell monitoring system using Micro-Electrochemical Systems (MEMS) in a microfluidic camera environment: 1) Devices have to work reliable in seawater. Several MEMS materials show immediate corrosion during operation in seawater. An encapsulation strategy of active structures using Al2O3, TiO2 multilayers deposited by Atomic Layer Deposition (ALD) will be presented which allowed a constant operation in seawater for 30 days; 2) A novel Gecko inspired adhesive technology is currently evaluated to form sealed fluidic chamber systems on top of the MEMS. This technology allows fluidic sealing without bonding processes; 3) The mechanical stiffness of single cells allow an assessment of cell viability. An approach was developed to measure the mechanical cell stiffness based on differential displacement measurements on a two stage spring system. Displacements were measured optically within a ±10 nm accuracy during MEMS operation in aqueous media. This technique allowed differentiation of viable and non-viable Saccharomyces cerevisiae (baker’s yeast). I will conclude the talk with our plans to integrate the developed MEMS platform into a mobile camera platform.

# Kolloquiumsvortrag: N.N. / 10.07.2015

10.07.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: Dr. Davide Barater, Department of Information Engineering, University of Parma, Italy/ 06.07.2015

06.07.2015 von 17:15 bis 18:45

Institut für (Ost), Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: “Accelerated Life tests for Electric drives in Aircrafts”

Abstract:

The concept behind the More Electric Aircraft (MEA) is the progressive electrification of on-board actuators and services. It is a way to reduce or eliminate the dependence on hydraulic, mechanical and the bleed air/pneumatic systems and pursue efficiency, reliability and maintainability. At the moment, the lifetime problems of electromechanical actuators, adopted in MEA, have been addressed by analyzing separately the causes of failures, and accelerated tests were proposed for the single components. This project aims at realizing a test bed able to apply multiple age accelerating stresses and to realize the on-line test of the electric machine and drive, under different operating conditions.

The main failure in electric drives is due to electric faults resulting from the damage in the motor winding insulation system. In this work the main stress factors affecting the lifespan of insulation materials in aerospace applications will be analyzed. A special test bed will be also proposed, to assess insulation lifespan modelling under various stress conditions, especially investigating the interaction between ageing factors. The test bed will allow to characterize insulation degradation under variable ambient and power supply parameters for simple models, such as twisted pairs, up to coil form and complete machine operated at rated load. The proposed approach is based on the design of experiments (DOE). The results of the work that will be carried out will allow to identify the most influential factors affecting insulation lifetime and the interactions between them.

The test setup comprises a Thermal vacuum chamber, an embedded dynamometer/brake system and a custom inverter based on SiC devices capable to apply PWM commutation of different dv/dt ratio.

The test rig would allow an all-in-one approach for multi-parameter measurement, thus minimizing the required test runs.

The test set-up will thus provide a means to confirm, experimentally validate, and also fine-tune insulation degradation lifetime models. In particular a lifetime model, based on the physic Of Failure (PoF) method, that considers the impact of the different stress factors on the system, is expected to be developed during the project.

The ultimate goal is to foster the development and adoption of electric drives for aerospace applications, resulting from more reliable procedures that allow accurate estimation of a system lifetime from the design stage (design reliability work flow)

Presentation:

Title: “Impact of wide-bandgap devices on the insulation system of magnetics”

In the last few years wide-bandgap power devices, such as SiC and GaN switches, have been started to market. They provide superior performances respect to their Silicon counterparts, reaching faster commutation and maintaining their efficiency even in case of high temperature operation. Nevertheless, their impact on real system has not been completely investigated. The high dv/dt ratio, enabled by the fast commutation transients of SiC or GaN devices, introduces very high frequency harmonics that can trigger partial discharge phenomena in the windings of magnetics present in the circuit, leading to deterioration of the insulation systems.

For this reasons a trade-off between performance and reliability must be reached to enable the widespread utilization of wide-bandgap devices.

Davide Barater was born in Italy on August 13, 1983. He received Master’s degree in Electronic Engineering in 2009 and the Ph.D. degree in Information Technologies in 2014 from the University of Parma, Italy. He was an honorary scholar at the University of Nottingham, U.K, during 2012. He is now working as a postdoctoral research associate at the Department of Information Engineering, University of Parma, Italy. His research area is focused on power electronics for renewable energy systems, static energy conversion and motor drives. He is a reviewer of IEEE transaction on Power Electronics, on Industry application, on Industrial Informatics. He is author or coauthor of more than 20 international papers,  He holds one international patents.

# Kolloquiumsvortrag: N.N. / 03.07.2015

03.07.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: Prof. Alexandr Dmitriev, Chalmers University, Göteborg/ 29.06.2015

29.06.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel:

Magnetoplasmonics and active control of light at the bottom-up playground (for nano-, meta-, micro- and beyond)

Abstract:

The combination of magnetism and plasmonics developed into a new burgeoning

field - magnetoplasmonics, where the control of non-reciprocity in light’s interaction with a magnetized media is targeted for various applications. I will discuss the two aspects of magnetoplasmonics: optical polarization-rotator metasurfaces actively tunable with magnetic field; and the label-free optical biochemosensing, where magnetoplasmonics delivers two orders of magnitude higher sensitivity than the current nanoplasmonic sensors.

All discussed magnetoplasmonic platforms are produced on a large (cm2) scale with the affordable and simple bottom-up nanofabrication we develop. I will also highlight our latest ‘any pattern on any surface’ versatile conformal nanofab protocol.

# Sonderkolloquium: Prof. Dr. Thanassis Tiropanis (University of Southampton)/ 25.06.2015

25.06.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel:  "Web Observatories: Infrastructures for Engaging with Data and Analytics on a Global Scale"

Abstract:

Web Observatories are global distributed resources that can engage communities with data and analytic resources to make the most of existing and emergent datasets including those of the linked data cloud, social media, online archives and media archives. This undertaking is promising in terms of fostering data literacy and innovation on a large scale but comes with infrastructural challenges. Those challenges include resource description and discovery, interoperability, privacy and performance for queries and analytics on a distributed scale. This talk presents how those challenges are addressed in the architecture of the Southampton University Web Observatory and discusses a research roadmap on Web Observatory development.

# Kolloquiumsvortrag: Prof. Dr.-Ing. Dr.-Ing. habil. Robert Weigel / TU Erlangen

22.06.2015 von 17:15 bis 18:45

Institut für Materialwissenschaf UND Institut für Elektrotechnik und Informationstechnik, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: Highly Integrated Wideband Microwave Sensors for Emerging Biomedical Applications

Abstract: One of the most important challenges of modern and aging societies that need to be addressed is the improvement of health and lifetime of individuals. In the last decade, immense progress has been made in electronics based on nanoelectronics technologies in conjunction with complex smart and embedded system realizations. The current development trends in these key technologies are going to enable crucial innovations and the proliferation of solutions for medical applications such as biomedical sensing and spectroscopy. This talk presents miniaturized microwave and millimeter-wave silicon-germanium circuits and sensor systems for the above mentioned challenges. The present work explains the basic measurement principles and introduces the integrated vector network analyzer as a fundamental component for the design of compact powerful biomedical sensors. Several single-chip sensors as well as hybrid solutions will be presented and discussed. Furthermore, a special ultra-wideband sensor concept for spectroscopy coming with solutions for the injection of electromagnetic waves into biological samples will be demonstrated. Finally, future development trends will be discussed.

# Kolloquiumsvortrag: N.N. / 19.06.2015

19.06.2015 von 14:15 bis 18:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: Prof. Andreas Hütten - Universität Bielefeld / 15.06.2015

15.06.2015 von 17:15 bis 18:45

Institut für (Ost), Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: Heusler alloys: fundamentals and applications

Abstract:
The triumphant advance of Heusler compounds can mainly be attributed to their unique band structure
enabling the realization of different physical properties such as ferromagnetism, semi- and superconductivity in one material class. As a consequence of the theoretically predictions of 100% spin polarized half- and full-Heusler compounds over the past decade, Heusler alloys are among the most promising materials class for future applications in magneto electronics. The resulting electronic structures as well as their magnetic properties will be used to identify potential areas of applications. Among these areas are magnetic logic, biosensors and granular GMR-sensors. Thin films made of Heusler compounds are not only relevant for spintronic applications. There is also great interest in the class of shape-memory compounds like X-Mn-Y (X=Ni, Co,Y= Ga, Sn, In) in thin films. For applications such as actuators, magnetic cooling and hybrid systems, thin films are often advantageous or mandatory. For magnetic cooling devices, thin films offer the advantage of a high surface to volume ratio. This allows a fast heat transfer. A general knowledge of the thin film influence on the martensitic transition (MT) is required for all these applications and will be discussed.

# Sonderkolloquiumsvortrag: Prof. Dr. Mario Bebendorf (Universität Bayreuth) / 09.06.2015

09.06.2015 von 10:15 bis 11:45

Institut für Informatik, CAP 4, Raum 715

Titel: Niedrigrang-Approximation von elliptischen Randwertproblemen bei stark variablen Koeffizienten

Abstract:

Hierarchische Matrizen erlauben es unter Anderem, die Inverse und die Faktoren der LU-Zerlegung von Finite-Element-Diskretisierungen elliptischer Randwertprobleme nachweislich mit logarithmisch-linearer Komplexität zu approximieren. Der entsprechende Beweis weist allerdings eine starke Abhängigkeit des lokalen Ranges vom Verhältnis des größten und kleinsten Koeffizienten des Differentialoperators bzgl. der "L²"-Norm aus, was in numerischen Experimenten allerdings nie beobachtet werden konnte. Im Vortrag zeigen wir, dass diese Abhängigkeit bei Wahl geeigneter Normen nicht besteht. Hieraus kann eine logarithmische Abhängigkeit bzgl. der "L²"-Norm abgeleitet werden.

# Kolloquiumsvortrag: Prof.Tamas Kerekes Aalborg Universität / DK / 08.06.2015

08.06.2015 von 17:15 bis 18:45

Institut für (Ost), Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel:  "Problem Based Learning – the Aalborg way"

Abstract:

Problem Based Learning (PBL) has been successfully applied at Aalborg University (AAU) since it was established in 1974. PBL is not only about rote learning. Every semester students work in a group with fellow students having different academic strengths and weaknesses, combining their common knowledge to solve a problem. The work should end in the submission of a semester report, describing the main problem, the objectives and the methodology how the problem was solved and how successful they were in achieving the objectives, detailing the results, including simulation, modelling and laboratory experiments.

Group members will need to collaborate with each other, define and divide the tasks for achieving the goals that they set in the beginning of the project. This way the group work will have an academic and social dimension at the same time, by which the students will learn how to work together with other people, a quality which is very important on the labor market/in industry.

PBL gives the opportunity to put theoretical knowledge into practice. By working with “real-life” problems, the students will not only gain professional experience, but they will also make good contacts, that can be used in the future in case of job applications. Furthermore, these “real-life” problems come from industrial partners/companies, therefore students will work with problems related to leading edge research, and their results/findings might be included in tomorrow’s commercial products.

# Kolloquiumsvortrag: N.N. / 05.06.2015

06.06.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: Prof. Lene Oddershede, Niels Bohr Institut, Universität Kopenhagen / 01.06.2015

01.06.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: Optical control and biomedical applications of HOT nanoparticles

Abstract:

Precise optical control over individual metallic nanoparticles has huge potential for nano-architectural purposes. The talk will commence by explaining how a focused laser beam can control not only the position, but also the orientation of a single nanoparticle [1]. While optically manipulating metallic nanostructures, it is worth noting that absorption and heating associated with resonant irradiation of metallic nanoparticles can be extreme [2]. Moreover, the heating of a nanoparticle cannot be theoretically predicted as the precise focal intensity distribution on the nanoscale is unknown and typically highly aberrated [3]. Utilizing a novel membrane-based assay we directly quantify the heating of an individual irradiated gold nanoparticle and show how this depends on laser power and particle size, shape, orientation and composition [4,5]. Also, our novel results show how the photo-thermal effect of metallic nanoparticles can be used to create localized heat gradients inside living cells, which is highly useful for targeted drug delivery and for photothermal treatment of cancers.

[1] Selhuber-Unkel et al., Quantitative optical trapping of single gold nanorods. Nano Letters, vol. 8, p. 2998-3003 (2008).

[2] Bendix et al., Direct measurements of heating by electromagnetically trapped gold nanoparticles on supported lipid bilayers, ACS Nano, vol. 4 p.2256-2262 (2010).

[3] Kyrsting et al., Mapping 3D focal intensity exposes the stable trapping positions of single nanoparticles. Nano Letters vol.13 p.31-35 (2013).

[4] Ma et al., Large-Scale Orientation Dependent Heating from a Single Irradiated Gold Nanorod. Nano Letters vol.12 p.3954-3960 (2012).

[5] Ma et al., Heat generation by irradiated complex composite nanostructures. Nano Letters, vol. 14 p.612-619 (2014).

# Kolloquiumsvortrag: N.N. / 22.05.2015

29.05.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: PD Dr. Oleg Petracic, Forschungszentrum Juelich GmbH / 18.05.2015

18.05.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: Functional nanomaterials from self-assembled magnetic nanoparticles

Abstract:

Nanoparticles (NPs) can be considered as multi-functional 'building blocks' for novel materials with tunable physical and chemical properties. Magnetic NPs can be used e.g. for novel energy efficient data storage systems, spintronic devices or permanent magnets with improved properties. I will report on (1.) magnetic monomer NPs from FePt, MnO and iron oxide and (2.) heterodimer ('Janus') NPs consisting of a ferromagnetic (FM) FePt particle attached to an antiferromagnetic (AF) MnO particle. The monomer iron oxide NPs have a diameter of 15 or 20 nm. By applying them onto various substrates and also using various techniques, they form self-organized sub-monolayers, monolayers, multilayers or 3d supercrystals. The structure and magnetism of these assemblies has been investigated using grazing incidence small angle x-ray and neutron scattering, electron microscopy and magnetometry. In FePt@MnO heterodimer particle systems the close contact of the two subunits yields an exchange bias effect. The spin structure has been studied using neutron scattering.

Our results yield the perspective on how to tune the magnetic behavior of the individual building blocks on the one hand and the collective properties of the entire NP assembly on the other hand.

References:

[1]       S. A. Claridge, A. W. Castleman, S. N. Khanna, C. B. Murray, A. Sen, and P. S. Weiss, ACS Nano 3, 244 (2009).

[2]       O. Petracic, Superlatt. Microstr. 47, 569 (2010).

[3]       S. Bedanta, A. Barman, W. Kleemann, O. Petracic, and T. Seki, Magnetic nanoparticles-
a subject for both fundamental research and applications,
J. Nanomater. 2013, 952540 (2013)

[4]       D. Mishra, D. Greving, G. A. Badini Confalonieri, J. Perlich, B.P. Toperverg, H. Zabel, and
O. Petracic, Growth modes of nanoparticle superlattice thin films, Nanotechnology 25, 205602 (2014)

[5]       S. Bedanta, O. Petracic, and W. Kleemann , Supermagnetism, Handbook of Magnetic Materials, Vol. 23, Ed. K.J.H. Buschow, Elsevier (2015)

# Kolloquiumsvortrag: N.N. / 15.05.2015

15.05.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: N.N. / 11.05.2015

11.05.2015 von 17:15 bis 18:45

Institut für (Ost), Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: N.N.

Abstract: N.N.

# Kolloquiumsvortrag: N.N. / 08.05.2015

08.05.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt

# Kolloquiumsvortrag: Prof. Harald Giessen, Physikalisches Institut, Uni Stuttgart / 04.05.2015

04.05.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel: Complex functional plasmonics: from fundamentals to applications

Abatract: folgt

# Kolloquiumsvortrag: Prof. Dr. Nan Ma, Biomaterialforschung HZG / FU Berlin/ 27.04.2015

27.04.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiserstr. 2, Geb.C , Raum "Aquarium"

Titel: Stem cell and cardiac repair

Abstract:

Stem cell mediated therapies offer great regenerative potential to improve cardiac function and neovascularization in patients with cardiovascular disorder. Recently, numerous clinical and preclinical studies using different type of stem (progenitor) cells have demonstrated their promising therapeutic effect. However, the low rate of cell engraftment and survival in the ischemic tissue greatly limits their therapeutic efficacy. To achieve the maximal clinical benefits, Dr. Nan Ma and her team attempted to explore cell pre-selection, genetic enhancement, tissue engineering and protein and/or small molecule treatment approaches to further augment cell homing, engraftment and cell survival. In this presentation, Dr. Nan Ma will introduce you how to employ the novel cell-enhancement strategies to aid the stem cell treatment of ischemic heart disease. The presentation will also highlight the potential of applying genetic and chemical modulation to enhance stem cell therapeutic and latest progress on gaining mechanistic insights of stem cell-extracellular matrix interactions. Further, using Laser-Induced-Forward-Transfer (LIFT) cell printing techniques, we are able to produce functional cardiac patch. LIFT-based stem cell cardiac patches for the treatment of myocardial infarction might improve wound healing and functional preservation.

# Kolloquiumsvortrag: N.N. / 24.04.2015

24.04.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: N.N.

Abstract: N.N.

# Kolloquimsvortrag: Dr. Karsten Wegner, ETH Zurich / 20.04.2015

20.04.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium

Titel: Flame Manufacture of ZnO and other Metal Oxide Nanoparticles

Abstract:

Flame spray pyrolysis has evolved into an extremely versatile process for production of single and multicomponent oxide nanoparticles of almost all periodic table elements. Material development has been carried out mostly with laboratory reactors at g/h scale, now requiring transfer into an industrial production environment. Successful process scale-up to kg/h output has been achieved for instance for zirconia or iron phosphate whereas the transfer remained challenging for zinc oxide nanoparticles.
This prompted us to investigate flame synthesis of ZnO in more detail. Formation and growth of spherical and rod-like structures was tracked by sampling nanoparticles thermophoretically in-situ the reactor and analyzing their morphology by electron microscopy. Along with temperature measurements and process simulations, conditions for production of sphere-like particles and nanorods could be developed. Characterization of the surface chemistry revealed shape-dependent differences that could affect the performance of the powders in catalytic hydrogen production, one envisioned application.

# Kolloquiumsvortrag: Prof. Dr. James Currie / 17.04.2015

17.04.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: Growth rate of binary words avoiding xxxR

Abstract:

Consider the set of those binary words with no non-empty factors of the form xxxR. Du, Mousavi, Schaeffer, and Shallit asked whether this set of words grows polynomially or exponentially with length. In this talk, we demonstrate the existence of upper and lower bounds on the number of such words of length n, where each of these bounds is asymptotically equivalent to a (different) function of the form Cnlg n+c, where C, c are constants.

# Kolloquiumsvortrag: Professor Arno Ehresmann, Universität Kassel (CINSaT) / 13.04.2015

13.04.2015 von 17:15 bis 18:45

Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium"

Titel:  Light-ion bombardment induced tailored domains in magnetic thin film systems

Abstract:

Artificial magnetic domain patterns can be fabricated in magnetic thin film systems by light-ion bombardment induced magnetic patterning. This technique enables a local modification of anisotropies, e.g., the unidirectional anisotropy in exchange bias layer systems or the perpendicular anisotropy in Co/ Au multilayers. Remanently stable magnetic patterns (tailored domains) may be created, where the geometry and the local anisotropy may be set independently without large changes in surface topography. These patterns allow also a tailoring of the associated magnetic strayfield landscapes over the surface of the magnetic layer system. The talk will discuss the fundamentals for fabricating such artificial domain patterns, their use in a variety of sensor concepts and the use of the associated stray field landscapes for positioning and controlled movement of small particles.

# Kolloquiumsvortrag: N.N. / 10.04.2015

10.04.2015 von 14:15 bis 15:45

Institut für Informatik, Ludewig-Meyn-Str. 2, Übungsraum 2

Titel: folgt

Abstract: folgt