An exactly solvable model of the Calogero type for the icosahedral group

We construct a quantum mechanical model of the Calogero type for the icosahedral group as the structural group. Exact solvability is proved and the spectrum is derived explicitly.Comment: 13 pages, no figures, latex 2epsilo

Exactly solvable dynamical systems in the neighborhood of the Calogero model

The Hamiltonian of the $N$-particle Calogero model can be expressed in terms of generators of a Lie algebra for a definite class of representations. Maintaining this Lie algebra, its representations, and the flatness of the Riemannian metric belonging to the second order differential operator, the set of all possible quadratic Lie algebra forms is investigated. For N=3 and N=4 such forms are constructed explicitly and shown to correspond to exactly solvable Sutherland models. The results can be carried over easily to all $N$.Comment: 23 pages, 2 figures, replaced and enlarged versio

Development of an intelligent object for grasp and manipulation research

Kõiva R, Haschke R, Ritter H. Development of an intelligent object for grasp and manipulation research. Presented at the ICAR 2011, Tallinn, Estonia.In this paper we introduce a novel device, called iObject, which is equipped with tactile and motion tracking sensors that allow for the evaluation of human and robot grasping and manipulation actions. Contact location and contact force, object acceleration in space (6D) and orientation relative to the earth (3D magnetometer) are measured and transmitted wirelessly over a Bluetooth connection. By allowing human-human, human-robot and robot-robot comparisons to be made, iObject is a versatile tool for studying manual interaction. To demonstrate the efficiency and flexibility of iObject for the study of bimanual interactions, we report on a physiological experiment and evaluate the main parameters of the considered dual-handed manipulation task

Construction of exactly solvable quantum models of Calogero and Sutherland type with translation invariant four-particle interactions

We construct exactly solvable models for four particles moving on a real line or on a circle with translation invariant two- and four-particle interactions.Comment: 14 pages, no figures, 1 table, replaced and enlarged version, a note adde

The construction of trigonometric invariants for Weyl groups and the derivation of corresponding exactly solvable Sutherland models

Trigonometric invariants are defined for each Weyl group orbit on the root lattice. They are real and periodic on the coroot lattice. Their polynomial algebra is spanned by a basis which is calculated by means of an algorithm. The invariants of the basis can be used as coordinates in any cell of the coroot space and lead to an exactly solvable model of Sutherland type. We apply this construction to the $F_4$ caseComment: 13 pages, no figures, latex 2epsilon, corrected versio

Three dimensional maps of the Magellanic Clouds using RR Lyrae Stars and Cepheids II. The Small Magellanic Cloud

We use data on variable stars from the Optical Gravitational Lensing Experiment (OGLE III) survey to determine the three-dimensional structure of the Small Magellanic Cloud (SMC). Deriving individual distances to RR Lyrae stars and Cepheids we investigate the distribution of these tracers of the old and young population in the SMC. Photometrically estimated metallicities are used to determine the distances to 1494 RR Lyrae stars, which have typical ages greater than 9 Gyr. For 2522 Cepheids, with ages of a few tens to a few hundred Myr, distances are calculated using their period-luminosity relation. Individual reddening estimates from the intrinsic color of each star are used to obtain high precision three-dimensional maps. The distances of RR Lyrae stars and Cepheids are in very good agreement with each other. The median distance of the RR Lyrae stars is found to be 61.5 +/- 3.4 kpc. For the Cepheids a median distance of 63.1 +/- 3.0 kpc is obtained. Both populations show an extended scale height, with 2.0 +/- 0.4 kpc for the RR Lyrae stars and 2.7 +/- 0.3 kpc for the Cepheids. This confirms the large depth of the SMC suggested by a number of earlier studies. The young population is very differently oriented than the old stars. While we find an inclination angle of 7{\deg} +/- 15{\deg} and a position angle of 83{\deg} +/- 21{\deg} for the RR Lyrae stars, for the Cepheids an inclination of 74{\deg} +/- 9{\deg} and a position angle of 66{\deg} +/- 15{\deg} is obtained. The RR Lyrae stars show a fairly homogeneous distribution, while the Cepheids follow roughly the distribution of the bar with their northeastern part being closer to us than the southwestern part of the bar. Interactions between the SMC, LMC, and Milky Way are presumably responsible for the tilted, elongated structure of the young population of the SMC.Comment: 13 pages, 6 figures, 4 tables, published in A

Is it possible to construct exactly solvable models?

We develop a constructive method to derive exactly solvable quantum mechanical models of rational (Calogero) and trigonometric (Sutherland) type. This method starts from a linear algebra problem: finding eigenvectors of triangular finite matrices. These eigenvectors are transcribed into eigenfunctions of a selfadjoint Schr\"odinger operator. We prove the feasibility of our method by constructing a new "$AG_3$ model" of trigonometric type (the rational case was known before from Wolfes 1975). Applying a Coxeter group analysis we prove its equivalence with the $B_3$ model. In order to better understand features of our construction we exhibit the $F_4$ rational model with our method.Comment: 22 pages, 2 eps figures, latex 2epsilon, usepackage epsfi

Nachfrageeinbrüche in Krisenregionen dämpfen ostdeutsche Exportentwicklung

Die durch Währungs- und Finanzkrisen ausgelöste Eintrübung des weltwirtschaftlichen Umfelds hinterließ ihre Spuren auch in der ostdeutschen Wirtschaft. Die Warenlieferungen in die besonders von Krisen betroffenen Regionen wie Südostasien und Russland gingen drastisch zurück. Die Ausfuhrentwicklung in die westeuropäischen Industrieländer verlangsamte sich ebenfalls aufgrund der nachlassenden Auslandsnachfrage. Für eine Fortsetzung der konjunkturellen Aufwärtsentwicklung in den Neuen Bundesländern wurden Gefahren vor allem im Zusammenhang mit dem Einbruch der Russlandexporte gesehen, weil dieser Markt einen ähnlichen Stellenwert wie der gesamte NAFTA-Raum beispielsweise hat.

Ostdeutsche Exporte noch mit hoher Dynamik im 1. Halbjahr 2001

Since last year, growth has weakened sharply in most regions of the world, accompanied by a marked decline in world trade growth. There was a significant impact on demand and activity in the industrial countries. In contrast to that the data indicate increasing east German exports of goods. In the first half of 2001 the exports of the new states rose sharply by around 25% compared with the period of the previous year and the share of exports in GDP rose. The export structure by regions has changed over time. At the beginning of the nineties the main customers of east German exports were still central and eastern Europe. Now almost half of the goods are delivered to EU-countries. Cars and electrical engineering products are the main export goods with a share of around 30%.

Hohe Exportdynamik im Verarbeitenden Gewerbe: Bessere Aussichten für die ostdeutschen Unternehmen

Der Beitrag gibt einen Überblick über die Exportentwicklung in Ostdeutschland, die nach 1996 besonders dynamisch verlief. Es wird auf die zwar immer noch geringe, jedoch zunehmende Einbindung der ostdeutschen Wirtschaft in die internationalen Wirtschaftsbeziehungen eingegangen. Die Analyse der Warenausfuhr nach güterbezogenen und regionalen Gesichtspunkten ergab, dass mit ansteigender Tendenz vor allem Fertigwaren exportiert werden und sich als Hauptabsatzmarkt für ostdeutsche Produkte immer mehr die Länder der Europäischen Union herausbilden