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.

Ti:Er:LiNbO/sub 3/ waveguide laser of optimized efficiency

Abstract: The development of a Fabry-Perot-type Ti,Er:LiNbO/sub 3/ waveguide laser of optimized CW output power up to 63 mW (/spl lambda//sub s/=1561 nm) at a pump power level of 210 mW (/spl lambda//sub p/=1480 nm) and a slope efficiency of up to 37% is reported. The theoretical model for the waveguide laser is presented and applied to determine the optimum resonator configuration using waveguide parameters obtained from a detailed characterization of the laser sample. With pulsed pumping, waveguide laser pulses of up to 6.2 W peak power were observed. Apart from residual relaxation oscillations, the laser emission proved to be shot-noise limited.

Stabilizing Consensus with the Power of Two Choices

Abstract: Consensus problems occur in many contexts and have therefore been intensively studied in the past. In the standard consensus problem there are n processes with possibly different input values and the goal is to eventually reach a point at which all processes commit to exactly one of these values. We are studying a slight variant of the consensus problem called the stabilizing consensus problem. In this problem, we do not require that each process commits to a final value at some point, but that eventually they arrive at a common value without necessarily being aware of that. This should work irrespective of the states in which the processes are starting. Coming up with a self-stabilizing rule is easy without adversarial involvement, but we allow some T-bounded adversary to manipulate any T processes at any time. In this situation, a perfect consensus is impossible to reach, so we only require that there is a time point t and value v so that at any point after t, all but up to O(T) processes agree on v, which we call an almost stable consensus. As we will demonstrate, there is a surprisingly simple rule for the standard message passing model that just needs O(log n loglog n) time for any sqrt{n}-bounded adversary and just O(log n) time without adversarial involvement, with high probability, to reach an (almost) stable consensus from any initial state. A stable consensus is reached, with high probability, in the absence of adversarial involvement.

Synthesis, characterization and antimicrobial activities of transition metal complexes of N,N -dialkyl- N′ -(2-chlorobenzoyl)thiourea derivatives

Abstract: N,N-di-n-propyl-N′-(2-chlorobenzoyl)thiourea (HL1) (1), N,N-diphenyl-N′-(2-chlorobenzoyl)thiourea (HL2) (2), and their NiII, CoII, CuII, ZnII, PtII, CdII and PdII complexes have been synthesized and characterized. HL1 and its copper complex were characterized by single-crystal X-ray diffraction methods. The ligands coordinate as bidentates yielding essentially neutral complexes of the type [ML2]. The complexes were screened for their in vitro antibacterial, antifungal activities and toxicity. All compounds showed antimicrobial activity, but antibacterial efficacy is greater than antifungal activity.

Innovative joining technologies for multi-material structures

Abstract: The affordable implementation of lightweight constructions in automotive engineering depends not only on the availability of suitable processing technologies for new lightweight materials but also on suitable, cost-efficient joining methods for multi-material combinations with high process reliability. Therefore, joining technology plays a key role in realizing energy-efficient vehicles. The systematic development of joining methods is necessary to overcome the metallurgical and thermal incompatibility of steel/aluminium or steel/fibre-reinforced plastic combinations. This paper presents two innovative and highly productive joining technologies and characterizes these processes based on their technological properties for one specific steel/aluminium material combination.