1,921 research outputs found
Juduicial Power & Illusion: The Republic of China\u27s Council of Grand Justices and Constitutional Interpretation
The Republic of China underwent a rapid political transformation from an authoritarian nation to a democratic state which required change at every level of the government. The ROC\u27s Council of Grand Justices has contributed to this period of reform through a number of constitutional interpretations which have resulted in greater individual liberties and further restrictions on government actions. This has been accomplished even though the Council operates against substantive and procedural limitations on its powers. A review of these Council interpretations from the past decade reveals that the Council has made steady inroads towards fulfilling its role as the supreme judicial body of the ROC. The Council, however, is not sufficiently protected from the influence of other government branches and still issues decisions carefully. The ROC government must ensure the Council is isolated from political influences before the Council will be able to impartially exercise the full range of its constitutionally mandated authority
Stellar mass functions of galaxies, disks and spheroids at z~0.1
We present the stellar mass functions (SMF) and mass densities of galaxies,
and their spheroid and disk components in the local (z~0.1) universe over the
range 8.9 <= log(M/M_solar) <= 12 from spheroid+disk decompositions and
corresponding stellar masses of a sample of over 600,000 galaxies in the
SDSS-DR7 spectroscopic sample. The galaxy SMF is well represented by a single
Schechter function (M* = 11.116+/-0.011, alpha = -1.145+/-0.008), though with a
hint of a steeper faint end slope. The corresponding stellar mass densities are
(2.670+/-0.110), (1.687+/-0.063) and (0.910+/-0.029)x10^8 M_solar Mpc^-3 for
galaxies, spheroids and disks respectively. We identify a crossover stellar
mass of log(M/M_solar) = 10.3+/-0.030 at which the spheroid and disk SMFs are
equal. Relative contributions of four distinct spheroid/disk dominated
sub-populations to the overall galaxy SMF are also presented. The mean
disk-to-spheroid stellar mass ratio shows a five fold disk dominance at the low
mass end, decreasing monotonically with a corresponding increase in the
spheroidal fraction till the two are equal at a galaxy stellar mass,
log(M/M_solar)=10.479+/-0.013, the dominance of spheroids then grows with
increasing stellar mass. The relative numbers of composite disk and spheroid
dominated galaxies show peaks in their distributions, perhaps indicative of a
preferred galaxy mass. Our characterization of the low redshift galaxy
population provides stringent constraints for numerical simulations to
reproduce.Comment: 30 pages, 18 figures, 5 tables (2 online), Accepted for publication
in MNRA
Parallel Metric Tree Embedding based on an Algebraic View on Moore-Bellman-Ford
A \emph{metric tree embedding} of expected \emph{stretch~}
maps a weighted -node graph to a weighted tree with such that, for all ,
and
. Such embeddings are highly useful for designing
fast approximation algorithms, as many hard problems are easy to solve on tree
instances. However, to date the best parallel -depth algorithm that achieves an asymptotically optimal expected stretch of
requires
work and a metric as input.
In this paper, we show how to achieve the same guarantees using
depth and
work, where and is an arbitrarily small constant.
Moreover, one may further reduce the work to at the expense of increasing the expected stretch to
.
Our main tool in deriving these parallel algorithms is an algebraic
characterization of a generalization of the classic Moore-Bellman-Ford
algorithm. We consider this framework, which subsumes a variety of previous
"Moore-Bellman-Ford-like" algorithms, to be of independent interest and discuss
it in depth. In our tree embedding algorithm, we leverage it for providing
efficient query access to an approximate metric that allows sampling the tree
using depth and work.
We illustrate the generality and versatility of our techniques by various
examples and a number of additional results
Comments on: Interval Type-2 Fuzzy Sets are generalization of Interval-Valued Fuzzy Sets: Towards a Wider view on their relationship
This Letter makes some observations about [2] that further support the distinction between an interval type-2 fuzzy set (IT2 FS) and an interval-valued fuzzy set (IV FS), points out that all operations, methods and systems that have been developed and published about IT2 FSs are, so far, only valid in the special case when IT2 FS = IVFS, and suggests some research opportunities
Bulge mass is king: The dominant role of the bulge in determining the fraction of passive galaxies in the Sloan Digital Sky Survey
We investigate the origin of galaxy bimodality by quantifying the relative
role of intrinsic and environmental drivers to the cessation (or `quenching')
of star formation in over half a million local Sloan Digital Sky Survey (SDSS)
galaxies. Our sample contains a wide variety of galaxies at z=0.02-0.2, with
stellar masses of 8 < log(M*/M_sun) < 12, spanning the entire morphological
range from pure disks to spheroids, and over four orders of magnitude in local
galaxy density and halo mass. We utilise published star formation rates and add
to this recent GIM2D photometric and stellar mass bulge + disk decompositions
from our group. We find that the passive fraction of galaxies increases steeply
with stellar mass, halo mass, and bulge mass, with a less steep dependence on
local galaxy density and bulge-to-total stellar mass ratio (B/T). At fixed
internal properties, we find that central and satellite galaxies have different
passive fraction relationships. For centrals, we conclude that there is less
variation in the passive fraction at a fixed bulge mass, than for any other
variable, including total stellar mass, halo mass, and B/T. This implies that
the quenching mechanism must be most tightly coupled to the bulge. We argue
that radio-mode AGN feedback offers the most plausible explanation of the
observed trends.Comment: Accepted to MNRAS. 32 pages, 27 figures. [This version is virtually
identical to v1
Coarse and uniform embeddings between Orlicz sequence spaces
We give an almost complete description of the coarse and uniform
embeddability between Orlicz sequence spaces. We show that the embeddability
between two Orlicz sequence spaces is in most cases determined only by the
values of their upper Matuszewska-Orlicz indices. On the other hand, we present
examples which show that sometimes the embeddability is not determined by the
values of these indices.Comment: 12 pages. This is the final version. To appear in Mediterr. J. Mat
Practical free-start collision attacks on 76-step SHA-1
In this paper we analyze the security of the compression function
of SHA-1 against collision attacks, or equivalently free-start collisions
on the hash function. While a lot of work has been dedicated to the analysis
of SHA-1 in the past decade, this is the first time that free-start collisions
have been considered for this function. We exploit the additional
freedom provided by this model by using a new start-from-the-middle
approach in combination with improvements on the cryptanalysis tools
that have been developed for SHA-1 in the recent years. This results in
particular in better differential paths than the ones used for hash function
collisions so far. Overall, our attack requires about evaluations
of the compression function in order to compute a one-block free-start
collision for a 76-step reduced version, which is so far the highest number
of steps reached for a collision on the SHA-1 compression function.
We have developed an efficient GPU framework for the highly branching
code typical of a cryptanalytic collision attack and used it in an optimized
implementation of our attack on recent GTX 970 GPUs. We report
that a single cheap US\$ 350 GTX 970 is sufficient to find the collision in
less than 5 days. This showcases how recent mainstream GPUs seem to
be a good platform for expensive and even highly-branching cryptanalysis
computations. Finally, our work should be taken as a reminder that
cryptanalysis on SHA-1 continues to improve. This is yet another proof
that the industry should quickly move away from using this function
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