184 research outputs found
Nonlinear Spin Dynamics in Ferromagnets with Electron-Nuclear Coupling
Nonlinear spin motion in ferromagnets is considered with nonlinearity due to
three factors: (i) the sample is prepared in a strongly nonequilibrium state,
so that evolution equations cannot be linearized as would be admissible for
spin motion not too far from equilibrium, (ii) the system considered consists
of interacting electron and nuclear spins coupled with each other via hyperfine
forces, and (iii) the sample is inserted into a coil of a resonant electric
circuit producing a resonator feedback field. Due to these nonlinearities,
coherent motion of spins can develop, resulting in their ultrafast relaxation.
A complete analysis of mechanisms triggering such a coherent motion is
presented. This type of ultrafast coherent relaxation can be used for studying
intrinsic properties of magnetic materials.Comment: 1 file, LaTex, 23 page
Origin of Pure Spin Superradiance
The question addressed in this paper is: What originates pure spin
superradiance in a polarized spin system placed inside a resonator? The term
"pure" means that no initial coherence is imposed on spins, and its appearance
manifests a purely self-organized collective effect. The consideration is based
on a microscopic model with dipole spin interactions. An accurate solution of
evolution equations is given. The results show that the resonator Nyquist noise
does not play, contrary to the common belief, any role in starting spin
superradiance, but the emergence of the latter is initiated by local spin
fluctuations. The decisive role of nonsecular dipole interactions is stressed.Comment: 1 file, 13 pages, RevTe
On being a good Bayesian
Bayesianism is fast becoming the dominant paradigm in archaeological chronology construction. This paradigm shift has been brought about in large part by widespread access to tailored computer software which provides users with powerful tools for complex statistical inference with little need to learn about statistical modelling or computer programming. As a result, we run the risk that such software will be reduced to the status of black boxes. This would be a dangerous position for our community since good, principled use of Bayesian methods requires mindfulness when selecting the initial model, defining prior information, checking the reliability and sensitivity of the software runs and interpreting the results obtained. In this article, we provide users with a brief review of the nature of the care required and offer some comments and suggestions to help ensure that our community continues to be respected for its philosophically rigorous scientific approach
Der Mediensport Olympia - ein globales Integrationsritual?
Die Olympischen Spiele wirken als ein Integrationsritus in einer sich globalisierenden Welt. Der Sport überwindet die Länder-, Kultur- und Rassengrenzen und vereint die Öffentlichkeit mithilfe der Medien. Diese inszenieren die Sportarten gemäß ihrer Wirkungslogik, und verändern somit den Sport selbst. Trotz Skandalen nimmt die Bedeutung der Spiele stetig zu, sie erreichen mit der Eröffnungsfeier das weltweit größte (Fernseh-)Publikum. Diese Feier ist ein globaler sakraler Ritus. Besonders das Fernsehen lässt alle um Ritus teilhaben. Der Sport als soziales Handeln vermittelt einen Glauben an Fortschritt durch Leistung, und die Zuschauer können mithilfe der Medien auch teilnehmen. In Zeiten des Wandels wird der Ritus wichtig für die Gemeinschaft.The Olympic Games appear to be a rite of integration in a world of increasing globalization. Sport overcomes national, cultural und racial boundaries, und unites the public with the help of the media. The media (re)produce the different sports according to the functional logic of their medial presentation und therefore change the sports itself: Economy has replaced morality as the highest precept. Despite certain scandals, the Games become more und more significant. The opening ceremony reaches the largest (TV-)audience worldwide. This ceremony is a global religious rite which could have never been accomplished without the media. It is especially television that enables everyone to be a part of the rite. Sport as social action educates a belief in Progress through achievement, and the audience can participate with the help of the media. In times of constant changes, this rite becomes highly important to the community
Towards the Development of an Empirical Model for Islamic Corporate Social Responsibility: Evidence from the Middle East
Biomedical informatics and translational medicine
Biomedical informatics involves a core set of methodologies that can provide a foundation for crossing the "translational barriers" associated with translational medicine. To this end, the fundamental aspects of biomedical informatics (e.g., bioinformatics, imaging informatics, clinical informatics, and public health informatics) may be essential in helping improve the ability to bring basic research findings to the bedside, evaluate the efficacy of interventions across communities, and enable the assessment of the eventual impact of translational medicine innovations on health policies. Here, a brief description is provided for a selection of key biomedical informatics topics (Decision Support, Natural Language Processing, Standards, Information Retrieval, and Electronic Health Records) and their relevance to translational medicine. Based on contributions and advancements in each of these topic areas, the article proposes that biomedical informatics practitioners ("biomedical informaticians") can be essential members of translational medicine teams
Biografieforschung: theoretische Perspektiven und methodologische Konzepte fĂĽr eine re-konstruktive Geschlechterforschung
Die Biografieforschung bezeichnet einen komplexen Forschungsansatz, der auf eine lange Geschichte des wissenschaftlichen Interesses an "persönlichen Dokumenten" verweisen kann. Sie ist eine voraussetzungsvolle Forschungsperspektive, die sich in zentralen Aspekten ihres Vorgehens auf Biografien als theoretisches Konzept, als historisch-empirischen Gegenstand und als komplexe methodologische Strategie bezieht. Andere Begriffe, welche oftmals synonym gebraucht, in der Biografieforschung aber systematisch unterschieden werden, sind "Lebensgeschichte" und "Lebenslauf". Die Autorin skizziert die Perspektiven einer rekonstruktiven Geschlechterforschung innerhalb der Biografieforschung, wozu sie auf die Differenzierungen empirischer Forschung, die methodologischen Prinzipien sowie auf Datenerhebung und Datenanalyse eingeht. Sie hebt insbesondere drei Kontextrelationen bei der Interpretation eines biografischen Textes hervor: Biografie, Interaktion, kulturelle Muster und soziale Regeln. Das skizzierte Konzept von Biografieforschung begreift sie als ein offenes Programm, das vielfältige Anknüpfungspunkte zu aktuellen theoretischen Diskussionen in der Geschlechterforschung aufweist. (ICI2
Allgemeine Überlegungen zum Konzept des Studienganges Medizinische Informatik an der Universität Heidelberg und der Fachhochschule Heilbronn
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