University of Paderborn

About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Control reconfiguration & Software. The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

Story Diagrams: A New Graph Rewrite Language Based on the Unified Modeling Language and Java

Abstract: Graph grammars and graph rewrite systems improved a lot towards practical usability during the last years. Nevertheless, there are still major problems to overcome in order to attract a broad number of software designers and developers to the usage of graph grammars and graph rewrite systems. Two of the main problems are, (1) that current graph grammar notations are too proprietary and (2) that there exists no seamless integration of graph rewrite systems with common (OO) design and implementation languages like UML and C++ or Java.

Beam switching and bifocal zoom lensing using active plasmonic metasurfaces

Abstract: Compact nanophotonic elements exhibiting adaptable properties are essential components for the miniaturization of powerful optical technologies such as adaptive optics and spatial light modulators. While the larger counterparts typically rely on mechanical actuation, this can be undesirable in some cases on a microscopic scale due to inherent space restrictions. Here, we present a novel design concept for highly integrated active optical components that employs a combination of resonant plasmonic metasurfaces and the phase-change material Ge3Sb2Te6. In particular, we demonstrate beam switching and bifocal lensing, thus, paving the way for a plethora of active optical elements employing plasmonic metasurfaces, which follow the same design principles.

Stabilization in a two-dimensional chemotaxis-Navier–Stokes system

Abstract: This paper deals with an initial-boundary value problem for the system $$\left\{ \begin{array}{llll} n_t + u\cdot abla n &=& \Delta n - abla \cdot (n\chi(c) abla c), \quad\quad & x\in\Omega, \, t > 0,\\ c_t + u\cdot abla c &=& \Delta c-nf(c), \quad\quad & x\in\Omega, \, t > 0,\\ u_t + \kappa (u\cdot abla) u &=& \Delta u + abla P + n abla\phi, \qquad & x\in\Omega, \, t > 0,\\ abla \cdot u &=& 0, \qquad & x\in\Omega, \, t > 0,\end{array} \right.$$ which has been proposed as a model for the spatio-temporal evolution of populations of swimming aerobic bacteria. It is known that in bounded convex domains $${\Omega \subset \mathbb{R}^2}$$ and under appropriate assumptions on the parameter functions χ, f and ϕ, for each $${\kappa\in\mathbb{R}}$$ and all sufficiently smooth initial data this problem possesses a unique global-in-time classical solution. The present work asserts that this solution stabilizes to the spatially uniform equilibrium $${(\overline{n_0},0,0)}$$ , where $${\overline{n_0}:=\frac{1}{|\Omega|} \int_\Omega n(x,0)\,{\rm d}x}$$ , in the sense that as t→∞, $$n(\cdot,t) \to \overline{n_0}, \qquad c(\cdot,t) \to 0 \qquad \text{and}\qquad u(\cdot,t) \to 0$$ hold with respect to the norm in $${L^\infty(\Omega)}$$ .

Gaussian Boson Sampling.

Abstract: Boson sampling has emerged as a tool to explore the advantages of quantum over classical computers as it does not require universal control over the quantum system, which favors current photonic experimental platforms. Here, we introduce Gaussian Boson sampling, a classically hard-to-solve problem that uses squeezed states as a nonclassical resource. We relate the probability to measure specific photon patterns from a general Gaussian state in the Fock basis to a matrix function called the Hafnian, which answers the last remaining question of sampling from Gaussian states. Based on this result, we design Gaussian Boson sampling, a #P hard problem, using squeezed states. This demonstrates that Boson sampling from Gaussian states is possible, with significant advantages in the photon generation probability, compared to existing protocols.