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: Computer science & Context (language use). The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

Transform-limited single photons from a single quantum dot.

Abstract: Developing a quantum photonics network requires a source of very-high-fidelity single photons. An outstanding challenge is to produce a transform-limited single-photon emitter to guarantee that single photons emitted far apart in the time domain are truly indistinguishable. This is particularly difficult in the solid-state as the complex environment is the source of noise over a wide bandwidth. A quantum dot is a robust, fast, bright and narrow-linewidth emitter of single photons; layer-by-layer growth and subsequent nano-fabrication allow the electronic and photonic states to be engineered. This represents a set of features not shared by any other emitter but transform-limited linewidths have been elusive. Here, we report transform-limited linewidths measured on second timescales, primarily on the neutral exciton but also on the charged exciton close to saturation. The key feature is control of the nuclear spins, which dominate the exciton dephasing via the Overhauser field.

Dissemination of Information in Interconnection Networks (Broadcasting & Gossiping)

Abstract: Considerable attention in recent theoretical computer science is devoted to parallel computing. Here, we would like to present a special part of this large topic, namely, the part devoted to an abstract study of the dissemination of information in interconnection networks. The importance of this research area lies in the fact that the ability of a network to effectively disseminate information is an important qualitative measure for the suitabilty of the network for parallel computing. This follows simply from the observation that the communication among processes working in parallel is one of the main parts of the whole parallel computation. So, the effectivity of information exchange among processors essentially influences the effectivity of the whole computation process.

The football players' labor market: empirical evidence from the major european leagues

Abstract: The growing economic importance of professional football and the recent fundamental changes in the regulatory regime governing the football players' labor market together with the availability of detailed information on player salaries, transfer fees and contract lengths have convinced an increasing number of economists from all over Europe to devote their attention to the operation of that particular market. The following paper reviews the available evidence on the various dimensions of that market (remuneration, transfers, contracts and mobility) and points out some promising directions for further research.

Academic Procrastination: Psychological Antecedents Revisited

Abstract: Taking Beswick, Rothblum, and Mann's seminal paper on academic procrastination as a starting point, we provide an updated review of academic procrastination and consolidate this knowledge with a pr...

The FUJABA environment

Abstract: However, a single collaboration diagram is usually not expressive enough to model complex operations performing several modifications at different parts of the overall object structure. Such series of modifications need several collaboration diagrams to be modeled. In addition, there may be different situations where certain collaboration diagrams should be executed and others not. Thus, we need additional control structures to control the execution of collaboration diagrams. In our approach we combine collaboration diagrams with statecharts and activity diagrams for this purpose. This means, instead of just pseudo code, any state or activity may contain a collaboration diagram modeling the do-action of this step.Figure 1 illustrates the main concepts of Fujaba. Fujaba uses a combination of statecharts and collaboration diagrams to model the behavior of active classes. A combination of activity diagrams and collaboration diagrams models the bodies of complex methods. This integration of class diagrams and UML behavior diagrams enables Fujaba to perform a lot of static analysis work facilitating the creation of a consistent overall specification. In addition, it turns these UML diagrams into a powerful visual programming language and allows to cover the generation of complete application code. During testing and maintenance the code of an application may be changed on the fly, e.g. to fix small problems. Some application parts like the graphical user interface or complex mathematical computations may be developed with other tools. In cooperative (distributed) software development projects some developers may want to use Fujaba, others may not. Code of different developers may be merged by a version management tool. There might already exist a large application and one wants to use Fujaba only for new parts. One may want to do a global search-and-replace to change some text phrases. One may temporarily violate syntactic code structures while she or he restructures some code. For all these reasons, Fujaba aims to provide not just code generation but also the recovery of UML diagrams from Java code. One may analyse (parts of) the application code, recover the corresponding UML diagram (parts), modify these diagram (parts), and generate new code (into the remaining application code). So far, this works reasonable for class diagrams and to some extend for the combination of activity and collaboration diagrams. For statecharts this is under development.The next chapters outline the (forward engineering) capabilities of Fujaba with the help of an example session.