6,905 research outputs found
Federalism: a tool for conflict resolution?
Federalism has become increasingly used as a tool of conflict resolution in the post-Cold War era. This contribution discusses the rationale in using federalism as a tool of peace-building, conflict resolution and democratisation in deeply divided,ethnically heterogeneous and post-conflict societies. In doing so, it is highlighted how federalism can serve as an acceptable and viable solution for different ethnic groups because of its emphasis on autonomy and territorial integrity. The contribution also demonstrates that federalism is not able to solve all problems in ethnically heterogeneous societies and that further research is needed in order to understand the conditions in which federalism can be used to end conflict and bring peace and democracy to divided countries
Scotland, the UK and Brexit - at a constitutional crossroads: what next for Scotland?
The purpose of this paper is to provide an overview
of the constitutional debate in the UK vis-à-vis Scotland and the future of the UK union. We take stock of
this debate in the post-referendum period, and look
at what next for Scotland in the light of the Scottish
government’s push for a second independence
referendum
Spanning Properties of Theta-Theta Graphs
We study the spanning properties of Theta-Theta graphs. Similar in spirit
with the Yao-Yao graphs, Theta-Theta graphs partition the space around each
vertex into a set of k cones, for some fixed integer k > 1, and select at most
one edge per cone. The difference is in the way edges are selected. Yao-Yao
graphs select an edge of minimum length, whereas Theta-Theta graphs select an
edge of minimum orthogonal projection onto the cone bisector. It has been
established that the Yao-Yao graphs with parameter k = 6k' have spanning ratio
11.67, for k' >= 6. In this paper we establish a first spanning ratio of
for Theta-Theta graphs, for the same values of . We also extend the class of
Theta-Theta spanners with parameter 6k', and establish a spanning ratio of
for k' >= 5. We surmise that these stronger results are mainly due to a
tighter analysis in this paper, rather than Theta-Theta being superior to
Yao-Yao as a spanner. We also show that the spanning ratio of Theta-Theta
graphs decreases to 4.64 as k' increases to 8. These are the first results on
the spanning properties of Theta-Theta graphs.Comment: 20 pages, 6 figures, 3 table
On the appearance of hyperons in neutron stars
By employing a recently constructed hyperon-nucleon potential the equation of
state of \beta-equilibrated and charge neutral nucleonic matter is calculated.
The hyperon-nucleon potential is a low-momentum potential which is obtained
within a renormalization group framework. Based on the Hartree-Fock
approximation at zero temperature the densities at which hyperons appear in
neutron stars are estimated. For several different bare hyperon-nucleon
potentials and a wide range of nuclear matter parameters it is found that
hyperons in neutron stars are always present. These findings have profound
consequences for the mass and radius of neutron stars.Comment: 12 pages, 12 figures, RevTeX4; summary and conclusions are
strengthened, to appear in PR
Robust Forecasting for Robotic Control: A Game-Theoretic Approach
Modern robots require accurate forecasts to make optimal decisions in the
real world. For example, self-driving cars need an accurate forecast of other
agents' future actions to plan safe trajectories. Current methods rely heavily
on historical time series to accurately predict the future. However, relying
entirely on the observed history is problematic since it could be corrupted by
noise, have outliers, or not completely represent all possible outcomes. To
solve this problem, we propose a novel framework for generating robust
forecasts for robotic control. In order to model real-world factors affecting
future forecasts, we introduce the notion of an adversary, which perturbs
observed historical time series to increase a robot's ultimate control cost.
Specifically, we model this interaction as a zero-sum two-player game between a
robot's forecaster and this hypothetical adversary. We show that our proposed
game may be solved to a local Nash equilibrium using gradient-based
optimization techniques. Furthermore, we show that a forecaster trained with
our method performs 30.14% better on out-of-distribution real-world lane change
data than baselines
Variations of tropical lapse rates in climate models and their implications for upper tropospheric warming
The vertical temperature structure in the tropics is primarily set by convection and therefore follows a moist adiabat to first order. However, tropical upper tropospheric temperatures differ among climate models and observations, as atmospheric convection remains poorly understood. Here, we quantify the variations in tropical lapse rates in CMIP6 models and explore reasons for these variations. We find that differences in surface temperatures weighted by the regions of strongest convection cannot explain these variations and therefore we hypothesise that the representation of convection itself and associated small scale processes are responsible. We reproduce these variations in perturbed physics experiments with the global atmospheric model ICON-A, in which we vary autoconversion and entrainment parameters. For smaller autoconversion values, additional freezing enthalpy from the cloud water that is not precipitated warms the upper troposphere. Smaller entrainment rates also lead to a warmer upper troposphere, as convection and thus latent heating reaches higher. Furthermore, we show that according to most radiosonde datasets all CMIP6 AMIP simulations overestimate recent upper tropospheric warming. Additionally, all radiosonde datasets agree that climate models on average overestimate the amount of upper tropospheric warming for a given lower tropospheric warming. We demonstrate that increased entrainment rates reduce this overestimation, likely because of the reduction of latent heat release in the upper troposphere. Our results suggest that imperfect convection parameterisations are responsible for a considerable part of the variations in tropical lapse rates and also part of the overestimation of warming compared to the observation
Apollo 15 rake sample microbreccias and non-mare rocks: Bulk rock, mineral and glass electron microprobe analyses
Quantitative electron microprobe data of Apollo 15 nonmare rake samples are presented. Bulk analyses of lithic fragments in the nomare rocks (expressed in oxide weight-percent) and the corresponding CIPW molecular norms are given. The mineralogy of the rocks and lithic fragments are also given; structural formulae for complete analyses and molecular end-members for all mineral analyses are included. The mineral analyses include pyroxene, olivine, plagioclase, barian K-feldspar, spinel and ilmenite, cobaltian metallic nickel-iron as well as SiO2-K2O-rich residual glass. Electron micropobe analyses (oxide weight percent) of glasses in loose fines and microbreccia samples and their CIPW molecular norms are presented along with electron microprobe data on bulk, mineral, and matrix glass from chondrules
Two-Stream Instability Model With Electrons Trapped in Quadrupoles
We formulate the theory of the two-stream instability (e-cloud instability)
with electrons trapped in quadrupole magnets. We show that a linear instability
theory can be sensibly formulated and analyzed. The growth rates are
considerably smaller than the linear growth rates for the two-stream
instability in drift spaces and are close to those actually observed
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