5,723 research outputs found
Risiken im Lebenszyklus: Theorie und Evidenz
Der einzelne Mensch ist im Lebensverlauf erheblichen biometrischen, ökonomischen, familiĂ€ren und politischen Risiken ausgesetzt. Viele meinen, diese wĂ€ren in den letzten Jahren gröĂer geworden. Haben wir die richtigen Institutionen, um diese Risiken effizient abzudecken? Unter Institutionen verstehen wir individuelles Sparen, familiĂ€re Hilfe, private Versicherungen und schlieĂlich den Staat mit seinen Sozialversicherungen. Wo und wann funktionieren diese Institutionen? Wo und wann nicht? Was muss man tun, um sie zu verbessern? Wie sieht modernes "Social Risk Management" aus? Der erste Teil dieses Ăbersichtsbeitrags skizziert die wirtschaftstheoretischen Grundlagen des Sparverhaltens, der Portefeuillewahl und der Versicherungsnachfrage. Im Hauptteil werden die empirischen Befunde gesammelt, um im dritten Teil wirtschaftspolitische Schlussfolgerungen zu ziehen
Relativistic and Radiative Energy Shifts for Rydberg States
We investigate relativistic and quantum electrodynamic effects for
highly-excited bound states in hydrogenlike systems (Rydberg states). In
particular, hydrogenic one-loop Bethe logarithms are calculated for all
circular states (l = n-1) in the range 20 <= n <= 60 and successfully compared
to an existing asymptotic expansion for large principal quantum number n. We
provide accurate expansions of the Bethe logarithm for large values of n, for
S, P and circular Rydberg states. These three expansions are expected to give
any Bethe logarithms for principal quantum number n > 20 to an accuracy of five
to seven decimal digits, within the specified manifolds of atomic states.
Within the numerical accuracy, the results constitute unified, general formulas
for quantum electrodynamic corrections whose validity is not restricted to a
single atomic state. The results are relevant for accurate predictions of
radiative shifts of Rydberg states and for the description of the recently
investigated laser-dressed Lamb shift, which is observable in a strong
coherent-wave light field.Comment: 8 pages; RevTeX
Target Zones in History and Theory: Lessons from an Austro-Hungarian Experiment (1896-1914)
The first known experiment with an exchange rate band took place in Austria-
Hungary between 1896 and 1914. The rationale for introducing this policy rested
on precisely those intuitions that the modern literature has emphasized: the band
was designed to secure both exchange rate stability and monetary policy
autonomy. However, unlike more recent experiences, such as the ERM, this
policy was not undermined by credibility problems. The episode provides an ideal
testing ground for some important ideas in modern macroeconomics: specifically,
can formal rules, when faithfully adhered to, provide policy makers with some
advantages such as short term autonomy? First, we find that a credible band has a
"microeconomic" influence on exchange rate stability. By reducing uncertainty, a
credible fluctuation band improves the quality of expectations, a channel that has been neglected in the modern literature. Second, we show that the standard test of the basic target zone model is flawed and develop an alternative methodology. We believe that these findings shed a new light on the economics of exchange rate bands
Simplicial quantum dynamics
Present-day quantum field theory can be regularized by a decomposition into
quantum simplices. This replaces the infinite-dimensional Hilbert space by a
high-dimensional spinor space and singular canonical Lie groups by regular spin
groups. It radically changes the uncertainty principle for small distances.
Gaugeons, including the gravitational, are represented as bound fermion-pairs,
and space-time curvature as a singular organized limit of quantum
non-commutativity.
Keywords: Quantum logic, quantum set theory, quantum gravity, quantum
topology, simplicial quantization.Comment: 25 pages. 1 table. Conference of the International Association for
Relativistic Dynamics, Taiwan, 201
Cluster Performance reconsidered: Structure, Linkages and Paths in the German Biotechnology Industry, 1996-2003
This paper addresses the evolution of biotechnology clusters in Germany between 1996 and 2003, paying particular attention to their respective composition in terms of venture capital, basic science institutions and biotechnology firms. Drawing upon the significance of co-location of "money and ideas", the literature stressing the importance of a cluster's openness and external linkages, and the path dependency debate, the paper aims to analyse how certain cluster characteristics correspond with its overall performance. After identifying different cluster types, we investigate their internal and external interconnectivity in comparative manner and draw on changes in cluster composition. Our results indicate that the structure, i.e. to which group the cluster belongs, and the openness towards external knowledge flows deliver merely unsystematic indications with regard to a cluster's overall success. Its ability to change composition towards a more balanced ratio of science and capital over time, on the other hand, turns out as a key explanatory factor. Hence, the dynamic perspective proves effective illuminating cluster growth and performance, where our explorative findings provide a promising avenue for further evolutionary research
Nanotechnologien im âDialogâ - Partizipative Technikgestaltung oder Sicherung gesellschaftlicher Akzeptanz?
Learning through exchange about organic agriculture - case of Europe and Australia
LEAFSE is the catch word for an innovative program of exchange study for young Australians and Europeans, with organic agriculture as the focal point of their Masters level studies. Two years ago, the European Commission and the Australian Department of Education, Science and Technology (DEST) came up with the call for applications for a pilot project to support international mobility of tertiary students between the two continents. The grand aims set for the exchange included providing students with an international outlook and a range of perspectives, preparing them for the global marketplace, enable their understanding and empathy for different cultures and traditions and foster exchange of information. A number of us with an interest and an already existing academic network in organic agriculture proposed LEAFSE - Learning through Exchange - Agriculture, Food Systems and Environment, a winning project, which was chosen as the single pilot project from a field of well over a dozen contenders. Within the broader theme of Agriculture, Food Systems and Environment, we named organic farming as the focal point of the exchange, and we were aware of the immense possibilities for learning through exchange inter-continentally in this field.
Under this project, Master's level students from EU study for a semester at a partner university in Australia, and students from Australia study for a semester at a partner university in EU. The partners in the programme are,
from Europe:
âą The Royal Veterinary and Agricultural University, Denmark
âą University of Wales, Aberystwyth, United Kingdom
âą Wageningen University and Research Centre, The Netherlands
âą University of Kassel, Witzenhausen, Germany, and
from Australia:
âą University of Western Sydney, New South Wales
âą University of New England, New South Wales
âą University of Western Australia, Western Australia
âą University of Queensland, Queensland
The project has an innovative but manageable framework for mobility of the students, a joint programme of study which incorporates many novel elements including holistic thinking, experiential and integrated learning and use of newer tools of communication technologies, and above all, a structure that fosters a high degree of inter-cultural understanding and network building. When completed, the pilot phase of the project would have enabled exchange of 36 students from each continent, nine from each participating institution. The respective government agencies provide the students with an adequate stipend to cover travel and living expenses for six months of study.
The project has been running on target and the results of the first year of exchange have been more than impressive. This presentation will be a joint effort by the faculty and a number of participating students to demonstrate the cultural, agricultural, pedagogic, and practical lessons that have been learnt from this exchange in the field of organic farming. It will also highlight some of the challenges which need to be overcome in our efforts towards shaping sustainable agricultural and food systems which are cognizant of our respective environments
- âŠ