A5003046370- Semiconductor Quantum Structures and Devices
- Robot Manipulation and Learning
- Spectroscopy and Quantum Chemical Studies
- Magneto-Optical Properties and Applications
- Quantum and electron transport phenomena
- AI-based Problem Solving and Planning
- Reinforcement Learning in Robotics
- Photorefractive and Nonlinear Optics
- Modular Robots and Swarm Intelligence
- Quantum optics and atomic interactions
- Semantic Web and Ontologies
- Terahertz technology and applications
- Laser-Matter Interactions and Applications
- Robotic Path Planning Algorithms
- Laser and Thermal Forming Techniques
- Metallurgy and Material Forming
- Magnetic properties of thin films
- Manufacturing Process and Optimization
- Optical Polarization and Ellipsometry
- EEG and Brain-Computer Interfaces
- Quantum Information and Cryptography
- Metal Forming Simulation Techniques
- Logic, Reasoning, and Knowledge
- Robotics and Automated Systems
- Quantum Dots Synthesis And Properties
University of Bremen
2012-2022
Robotics Research (United States)
2022
University of Birmingham
2018
German Research Centre for Artificial Intelligence
2013-2014
University of Rhode Island
2013
Otto-von-Guericke University Magdeburg
2009
University Hospital Magdeburg
2009
University of California, Riverside
2008
RWTH Aachen University
1995-2000
Philips (Germany)
1972-1981
In this paper we present KnowRob2, a second generation knowledge representation and reasoning framework for robotic agents. KnowRob2 is an extension partial redesign of KnowRob, currently one the most advanced processing systems robots that has enabled them to successfully perform complex manipulation tasks such as making pizza, conducting chemical experiments, setting tables. The base appears be conventional first-order time interval logic base, but it exists large part only virtually: many...
Many future application scenarios of robotics envision robotic agents to be in close physical interaction with humans: On the factory floor, shall support their human co-workers dull and health threatening parts jobs. In homes, enable people stay independent, even if they have disabilities that require help daily life - a pressing need for our aging societies. A key requirement such is are safety-aware, is, know when actions may hurt or threaten humans actively refrain from performing them....
The validity of the semiconductor Bloch equations (SBE) depends on approximate decomposition an intraband correlation function into a product interband transition densities. We analyze consequences this approximation dynamics optically excited semiconductor. As special example where SBE treatment becomes questionable we consider THz emission narrow band superlattice in static bias field. A comparison second order solution with rigorous system helps one identify weak points approach and...
Four-wave-mixing signals from excitons under linear-circular polarized excitation exhibit an elliptical polarization, depending on both the pulse delay and spectral position. Besides resonances corresponding to exciton-biexciton transitions, a breakup of exciton line is found reflecting influence correlations four-point level. An analysis accounting for density, bound biexciton, exciton-exciton scattering continuum reveals that these features are not due antibound two-exciton state. Instead,...
Transient pump-probe signals of a GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As quantum well are investigated both theoretically and experimentally for different excitation conditions. The calculations based on microscopic density-matrix approach taking higher-order correlations into account. We present spectrally resolved transients which provide insights the nature differential transmission change. Especially complex phase signature...
For robotic agents to perform manipulation tasks in human environments at a level or higher, they need be able relate the physical effects of their actions how are executing them; small variations execution can have very different consequences. This paper proposes framework for acquiring and applying action knowledge from naive user demonstrations an interactive simulation environment under varying conditions. The combines flexible constraint-based motion control approach with...
Robots that are to master everyday manipulation tasks need both: The ability reason about actions, objects and action effects, the perform sophisticated movement control. To bridge gap between these two worlds, we consider problem of connecting symbolic representation with strategies from motion control engineering. We present a system using task function approach [1] define common description language which defines motions as sets constraints. constraints geometric features, like points,...
We analyze coherent beats with a period corresponding to the biexciton binding energy in time-integrated four-wave-mixing experiments GaAs/${\mathrm{Al}}_{0.3}$${\mathrm{Ga}}_{0.7}$As superlattice at high excitation densities. Theoretical and experimental evidence is presented that beating decay fifth-order process electric field, therefore ${\mathrm{\ensuremath{\chi}}}^{(5)}$ contributions signal 2${\mathit{k}}_{2}$-${\mathit{k}}_{1}$ direction have be considered for qualitative...
In this paper we discuss how the combination of modern technologies in "big data" storage and management, knowledge representation processing, cloud-based computation, web technology can help robotics community to establish strengthen an open research discipline. We describe made demonstrator a EU project review openly available community. Specifically, recorded episodic memories with rich semantic annotations during pizza preparation experiment autonomous robot manipulation. Afterwards,...
Thermomagnetic flux reversal has been studied in single-crystal layers of Y3Ga1.1Fe3.9O12 with 5-μm thickness, prepared by liquid-phase epitaxy (LPE) on a (111) Gd3Ga5O12 wafer. By structuring the checkerboard pattern squares 10-μm periodicity and 2-μm width depth surface grooves, arbitrary stable domain patterns have obtained. Individual switched magnetically using heat pulses from laser beam 20-mW intensity at 5145-Å wavelength fields as low 13 Oe case nearly demagnetized distribution. The...
Service robots in the future need to execute abstract instructions such as "fetch milk from fridge". To translate into actionable plans, require in-depth background knowledge. With regards interactions with doors and drawers, articulation models that they can use for state estimation motion planning. Existing frameworks model articulated connections concepts prismatic, or revolute, but do not provide a parameterized of these computation. In this paper, we introduce novel framework uses...
The polarization state of the diffracted beam in degenerate four-wave mixing is experimentally and theoretically investigated, resolved time as well frequency domain. use thin ZnSe quantum wells having large (bi)exciton binding energies makes it possible to restrict optical excitation by broadband 110 fs pulses quasi-two-dimensional heavy-hole excitons biexcitons only. Despite these most simple experimental conditions, an extremely complex dynamics observed when one circularly linearly...
We address the problem of executing tool-using manipulation skills in scenarios where objects to be used may vary. assume that point clouds tool and target object can obtained, but no interpretation or further knowledge about these is provided. The system must interpret decide how use complete a task with object; this means it adjust motion trajectories appropriately task. tackle three everyday manipulations: scraping material from into container, cutting, scooping container. Our solution...
Suitable simulation approaches for the preliminary investigation of electromagnetic metal forming process are presented.For this purpose an uncoupled (loose-coupled) model is compared to a more rigorous sequential-coupled approach.As shown by examples, connection between field and spatiotemporal evolution deformation workpiece cannot always be neglected describe with adequate accuracy.