Now showing items 1-10 of 139
Optimal control theory for a unitary operation under dissipative evolution
We show that optimizing a quantum gate for an open quantum system requires the time evolution of only three states irrespective of the dimension of Hilbert space. This represents a significant reduction in computational resources compared to the complete basis of Liouville space that is commonly believed necessary for this task. The reduction is based on two observations: the target is not a general dynamical map but a unitary operation; and the time evolution of two properly chosen states is sufficient to ...
Crack Paths at Multiple-crack Systems in Anisotropic Simulation and Experiment
This paper is targeted on numerical methods for accurate crack tip loading analysis and crack path prediction. Those are based on finite element calculations of the boundary value problem. Applying path-independent integrals to curved cracks in order to accurately calculate the J-integral, energy release rate (ERR) or stress intensity factors (SIF) is still not state of the art. Contours which are not confined to the crack tip require special analytical preparation and numerical treatment to supply results which are ...
Happy growers! Relationship quality in the German organic apple chain
Relational factors between supply chain actors have been acknowledged to contribute significantly to competitiveness. With the example of the German market for organic apples the suitability of the concept of the Relational View for explaining competitiveness was investigated. Structured interviews were conducted with selected actors of the supply chain. Actors at all levels of the supply chain proved to be highly committed and described their business relations as satisfying and trustful. Strong vertical and horizontal ...
Effect of Auger recombination and leakage on the droop in InGaN/GaN quantum well LEDs
(Optical Society of America, 2014)
We investigate the effect of the epitaxial structure and the acceptor doping profile on the efficiency droop in InGaN/GaN LEDs by the physics based simulation of experimental internal quantum efficiency (IQE) characteristics. The device geometry is an integral part of our simulation approach. We demonstrate that even for single quantum well LEDs the droop depends critically on the acceptor doping profile. The Auger recombination was found to increase stronger than with the third power of the carrier density and has ...
Left preference for sport tasks does not necessarily indicate left-handedness
In the elite domain of interactive sports, athletes who demonstrate a left preference (e.g., holding a weapon with the left hand in fencing or boxing in a ‘southpaw’ stance) seem overrepresented. Such excess indicates a performance advantage and was also interpreted as evidence in favour of frequency-dependent selection mechanisms to explain the maintenance of left-handedness in humans. To test for an overrepresentation, the incidence of athletes’ lateral preferences is typically compared with an expected ratio ...
Electronic origin of bond softening and hardening in femtosecond-laser-excited magnesium
Many ultrafast structural phenomena in solids at high fluences are related to the hardening or softening of particular lattice vibrations at lower fluences. In this paper we relate femtosecond-laser-induced phonon frequency changes to changes in the electronic density of states, which need to be evaluated only in the electronic ground state, following phonon displacement patterns. We illustrate this relationship for a particular lattice vibration of magnesium, for which we—surprisingly—find that there is both softening ...
„Sehe ich nun gnädig aus?“
(Wissenschaftlicher Verlag Trier, 2014)
Zusammenfassend lässt sich Eindruckssteuerung als evolutionär gewachsenes und definitiv überindividuelles Phänomen/Programm begreifen, das auch in die Literatur als eigenständiges Darstellungsmittel eingegangen ist und häufig einen genre- wie epochenübergreifenden Ansatzpunkt für Figurencharakteristik und Textanalyse liefern kann. Anhand von Grimmelshausens „Der abenteuerliche Simplicissimus Teutsch“ (1668), Tiecks „Der blonde Eckbert“ (1797) und Schnitzlers „Fräulein Else“ (1924) veranschaulicht der Artikel dieses ...
Controlling the transport of an ion: classical and quantum mechanical solutions
The accurate transport of an ion over macroscopic distances represents a challenging control problem due to the different length and time scales that enter and the experimental limitations on the controls that need to be accounted for. Here, we investigate the performance of different control techniques for ion transport in state-of-the-art segmented miniaturized ion traps. We employ numerical optimization of classical trajectories and quantum wavepacket propagation as well as analytical solutions derived from invariant ...
Symbolic versus non-symbolic magnitude estimations among children and adults
The ability of children and adults to generate symbolic and non-symbolic magnitude estimations was examined in the light of their familiarity with numbers. Children (6-year-old kindergartners, 7-year-old first graders, and 9-year-old third graders) and adults made symbolic estimations either by saying number words that matched numbers of dots (i.e., perception task) or by generating numbers of dots that matched given number words (i.e., production task). In the non-symbolic estimation task, participants generated the ...
Gefühlvoll oder voller Gefühl?
(Peter Lang, 2014)
Die „erzählerische Funktionsweise“ und die „Machart“ der mystischen Offenbarungsschrift das „Fließende Licht der Gottheit“ (Mechthild von Magdeburg; 13. Jahrhundert) und des Romans „Die Liebesblödigkeit“ (Wilhelm Genazino; 2005) zu analysieren und diese Ergebnisse mit den im Text angelegten Emotionalisierungsstrategien ins Gespräch zu bringen, ist gemeinsam mit der Liebessujet-Untersuchung, also dem analytischen Blick auf den entfalteten Liebesentwurf in der fiktionalen Welt, das Kernanliegen dieses Beitrags.