9,484 research outputs found
Explaining the Policy Constraints of Anti-democratic Regimes by Means of Sequential OLS-Regressions
One of the key problems of many sociological regression models is their modest explanatory power. This has not only to do with the insufficient development of the underlying theories but also with the free will of the concerned social actors, which manifests itself in irrational, spontaneous, and sometimes even arbitrary decisions. The foreign and economic policy of the US government under Donald Trump is an excellent example of this source of indeterminacy.
An alternative and more promising approach is an explanation of the constraints of social behaviour by the unequal distribution of power resources and the competing interests of the actors concerned. This approach requires, on the one hand, enough observational data which include cases that reached the analysed constraints. On the other hand, there is a need for statistical procedures which estimate and explain these constraints. Assuming that sufficient amounts of data are available, this paper proposes the use of sequential OLS regressions, which eliminate step by step non-critical observations in order to identify the cases that reached the mentioned constraints.
For illustrative purposes, the author analyses the policy space of anti-democratic regimes with regard to their possibilities of curbing democracy. On the basis of the democracy scores of Freedom House, the author explores the governmental constraints set by (i) national civil societies and (ii) international NGOs for the promotion of political/civil rights. The related sequential regressions allow for an assessment of how effective the different constraints are and how far democracy may deteriorate in the worst case under given structural conditions
A New Test for Chaos
We describe a new test for determining whether a given deterministic
dynamical system is chaotic or nonchaotic. (This is an alternative to the usual
approach of computing the largest Lyapunov exponent.) Our method is a 0-1 test
for chaos (the output is a 0 signifying nonchaotic or a 1 signifying chaotic)
and is independent of the dimension of the dynamical system. Moreover, the
underlying equations need not be known. The test works equally well for
continuous and discrete time. We give examples for an ordinary differential
equation, a partial differential equation and for a map.Comment: 10 pages, 5 figure
Twist-bend nematic phase in cyanobiphenyls and difluoroterphenyls bimesogens
The paper reviews assignment of the low-temperature nematic phase observed in simple bimesogenic or dimeric systems based on cyanobiphenyls and difluoroterphenyls to the twist-bend nematic phase, NTB, using a range of experimental techniques. These include DSC, X-rays, Polarising Microscopy, electro-optics, birefringence and measurements of the electroclinic effect arising from flexoelectricity. An emphasis is laid on the observations of the chiral domains of opposite handedness at zero field in an otherwise achiral liquid crystalline system in this phase. These observations are a direct consequence of the structure of the twist-bend phase predicted by Ivan Dozov for achiral bent core molecules. The paper reviews the electro-optic phenomena and the observed electroclinic effect and how these observations assign it as the NTB phase. Results of the nanoscale helical pitch measurements using freeze-fracture microscopy are reviewed and discussed briefly. Results of the measurements of elastic constants especially close to the N–NTB transition are also reviewed
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