2,915 research outputs found
The IMF and the countries of the Council for Mutual Economic Assistance
In November 1981 Hungary and, one week later, Poland applied for membership of the International Monetary Fund (IMF) and the International Bank for Reconstruction and Development (World Bank). These applications have highlighted a subject which had been neglected for quite some time. This analysis deals with the problems and consequences which arise from the membership of countries of the Council for Mutual Economic Assistance (Comecon)—the economies of which largely conform to principles of central economic planning—in IMF, an institution organized according to market principles
Banking reforms in East Central Europe
The first step towards the establishment of a banking sector geared to the market economy, the introduction of a two-tier banking system, has long since been taken by the countries of East Central Europe. A large number of shortcomings are still to be found in their banking systems, however, and the speed of reforms, after a lightning start, has slowed down to a snail’s pace
Why Panel Surveys (Version 2.0)
This contribution provides an overview of the advantages and disadvantages of panel surveys and of fundamental considerations when deciding for or against a panel design
Shortcomings of the Bond Orientational Order Parameters for the Analysis of Disordered Particulate Matter
Local structure characterization with the bond-orientational order parameters
q4, q6, ... introduced by Steinhardt et al. has become a standard tool in
condensed matter physics, with applications including glass, jamming, melting
or crystallization transitions and cluster formation. Here we discuss two
fundamental flaws in the definition of these parameters that significantly
affect their interpretation for studies of disordered systems, and offer a
remedy. First, the definition of the bond-orientational order parameters
considers the geometrical arrangement of a set of neighboring spheres NN(p)
around a given central particle p; we show that procedure to select the spheres
constituting the neighborhood NN(p) can have greater influence on both the
numerical values and qualitative trend of ql than a change of the physical
parameters, such as packing fraction. Second, the discrete nature of
neighborhood implies that NN(p) is not a continuous function of the particle
coordinates; this discontinuity, inherited by ql, leads to a lack of robustness
of the ql as structure metrics. Both issues can be avoided by a morphometric
approach leading to the robust Minkowski structure metrics ql'. These ql' are
of a similar mathematical form as the conventional bond-orientational order
parameters and are mathematically equivalent to the recently introduced
Minkowski tensors [Europhys. Lett. 90, 34001 (2010); Phys. Rev. E. 85, 030301
(2012)]
Regionale Verschuldungssituation und Armutsgefährdung
Die Überschuldung von Personen und die Armutsgefährdung stehen in einem engen räumlichen Zusammenhang, wie der Vergleich der einkommensbezogenen Armutsgefährdung und der Überschuldungsquote für die deutschen Kreise zeigt
Regionale Armut in Deutschland: Risikogruppen erkennen, Politik neu ausrichten
Nicht alle Regionen sind in Deutschland gleichermaßen von Einkommensarmut betroffen. Um die besonders armutsgefährdeten Gebiete zu identifizieren, ist es wichtig, regionale Preisunterschiede zu berücksichtigen. Mit dem Maßstab der so ermittelten Kaufkraftarmut bewertet, treten die größeren Städte als regionale Brennpunkte besonders deutlich hervor. Dagegen schwächt sich das Ost-West-Gefälle gegenüber einer Betrachtung, welche die Preisniveaus außer Acht lässt, erheblich ab. Bestimmte Gruppen wie Arbeitslose, Alleinerziehende und Migranten besitzen ein stark erhöhtes Armutsrisiko. Maßnahmen zur Armutsbekämpfung sollten daher die Situation dieser Menschen und die Verbesserung ihrer Potenziale zur Einkommenserzielung besonders in den Blick nehmen. Die unterschiedliche regionale Verteilung dieser drei Gruppen determiniert maßgeblich die regionale Armutsbetroffenheit. Hier bestehen Anknüpfungspunkte für die Regionalpolitik, um regionale Strukturprobleme und Armutsbetroffenheit gemeinsam zu bekämpfen. Eine bessere Koordinierung von Programmen kann dabei Synergieeffekte heben.Not all regions in Germany are affected by income poverty to the same extent and when attempting to identify areas which are particularly prone to poverty, it is important to take regional price differentials into account. Applying the yardstick of this purchasing power poverty reveals the larger cities to be particularly deprived areas. By contrast, the east-west divide appears much less pronounced than it is presented in studies which disregard price levels. Certain groups, such as the unemployed, single parents and immigrants, have a considerably increased poverty risk and measures aimed at alleviating poverty should therefore pay special attention to their situation and means of improving their earning potential. The degree to which individual regions are affected by poverty is substantially determined by the variation in the regional distribution of these three groups. This provides points of reference from which regional policy can tackle both structural problems and the effects of poverty. Improved coordination of such programmes could enhance the synergy effects
Regionale Armut: Welche Regionen sind in Deutschland besonders von Armut betroffen?
Nicht alle Regionen sind in Deutschland gleichermaßen von Einkommensarmut betroffen. Um die besonders armutsgefährdeten Gebiete zu identifizieren, ist es wichtig, regionale Preisunterschiede zu berücksichtigen. Die größeren Städte treten dann als regionale Brennpunkte besonders deutlich hervor, während sich das Ost-West-Gefälle gegenüber einer Betrachtung, welche die Preisniveaus außer Acht lässt, deutlich abschwächt
Group Theory of Chiral Photonic Crystals with 4-fold Symmetry: Band Structure and S-Parameters of Eight-Fold Intergrown Gyroid Nets
The Single Gyroid, or srs, nanostructure has attracted interest as a
circular-polarisation sensitive photonic material. We develop a group
theoretical and scattering matrix method, applicable to any photonic crystal
with symmetry I432, to demonstrate the remarkable chiral-optical properties of
a generalised structure called 8-srs, obtained by intergrowth of eight
equal-handed srs nets. Exploiting the presence of four-fold rotations, Bloch
modes corresponding to the irreducible representations E- and E+ are identified
as the sole and non-interacting transmission channels for right- and
left-circularly polarised light, respectively. For plane waves incident on a
finite slab of the 8-srs, the reflection rates for both circular polarisations
are identical for all frequencies and transmission rates are identical up to a
critical frequency below which scattering in the far field is restricted to
zero grating order. Simulations show the optical activity of the lossless
dielectric 8-srs to be large, comparable to metallic metamaterials,
demonstrating its potential as a nanofabricated photonic material
Does Telemedical Support of First Responders Improve Guideline Adherence in an Offshore Emergency Scenario? A Simulator-Based Prospective Study
OBJECTIVE:
To investigate, in a simulator-based prospective study, whether telemedical support improves quality of emergency first response (performance) by medical non-professionals to being non-inferior to medical professionals.
SETTING:
In a simulated offshore wind power plant, duos (teams) of offshore engineers and teams of paramedics conducted the primary survey of a simulated patient.
PARTICIPANTS:
38 offshore engineers and 34 paramedics were recruited by the general email invitation.
INTERVENTION:
Teams (randomised by lot) were supported by transmission technology and a remote emergency physician in Berlin.
OUTCOME MEASURES:
From video recordings, performance (17 item checklist) and required time (up to 15 min) were quantified by expert rating for analysis. Differences were analysed using two-sided exact Mann-Whitney U tests for independent measures, non-inferiority was analysed using Schuirmann one-sided test. The significance level of 5 % was Holm-Bonferroni adjusted in each family of pairwise comparisons.
RESULTS:
Nine teams of engineers with, nine without, nine teams of paramedics with and eight without support completed the task. Two experts quantified endpoints, insights into rater dependence were gained. Supported engineers outperformed unsupported engineers (p<0.01), insufficient evidence was found for paramedics (p=0.11). Without support, paramedics outperformed engineers (p<0.01). Supported engineers' performance was non-inferior (at one item margin) to that by unsupported paramedics (p=0.03). Supported groups were slower than unsupported groups (p<0.01).
CONCLUSIONS:
First response to medical emergencies in offshore wind farms with substantially delayed professional care may be improved by telemedical support. Future work should test our result during additional scenarios and explore interdisciplinary and ecosystem aspects of this support.
TRIAL REGISTRATION NUMBER:
DRKS0001437
Group Theory of Circular-Polarization Effects in Chiral Photonic Crystals with Four-Fold Rotation Axes, Applied to the Eight-Fold Intergrowth of Gyroid Nets
We use group or representation theory and scattering matrix calculations to
derive analytical results for the band structure topology and the scattering
parameters, applicable to any chiral photonic crystal with body-centered cubic
symmetry I432 for circularly-polarised incident light. We demonstrate in
particular that all bands along the cubic [100] direction can be identified
with the irreducible representations E+/-,A and B of the C4 point group. E+ and
E- modes represent the only transmission channels for plane waves with wave
vector along the ? line, and can be identified as non-interacting transmission
channels for right- (E-) and left-circularly polarised light (E+),
respectively. Scattering matrix calculations provide explicit relationships for
the transmission and reflectance amplitudes through a finite slab which
guarantee equal transmission rates for both polarisations and vanishing
ellipticity below a critical frequency, yet allowing for finite rotation of the
polarisation plane. All results are verified numerically for the so-called
8-srs geometry, consisting of eight interwoven equal-handed dielectric Gyroid
networks embedded in air. The combination of vanishing losses, vanishing
ellipticity, near-perfect transmission and optical activity comparable to that
of metallic meta-materials makes this geometry an attractive design for
nanofabricated photonic materials
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