52,897 research outputs found
Alternative industrial development paths for Indonesia: SAM and CGE analyses
In this article, we examine the economy-wide effects of three alternative growth paths for Indonesia's industrial sector using SAM (social accounting matrix) multiplier analysis and CGE (computable general equilibrium) modeling. The context of the analysis is the immediate post-crisis period — most likely to be in the next millennium — represented in our study by a modified benchmark data set for 1995. Special attention is given to the overall income and equity effects, considering that egalitarian growth has become a particularly important development objective in Indonesia. The results of SAM multiplier analysis indicate relatively strong macro-linkages from agricultural demand-led (ADL) industrialization, yielding a significantly larger increase in real GDP compared to that arising from industrial development oriented to either food processing or light manufacturing. The simulation results based on CGE modeling, which take account of nonlinearities and supply constraints that are ignored in SAM analysis, bear out the dominant influence of demand linkages in showing that ADL industrialization is associated with a larger GDP increase than the two industrial-led development paths.Social accounting., Indonesia., Industrialization.,
On the "Medieval Climate Anomaly" and climate instability around the end of 9th century
In this study, reconstruction of MCA (Medieval Climate Anomaly) through proxy data was tried to clarify its nature. At first, "prayers for rain" records were collected from "Rikkokushi", six national histories of the ancient Japan, and the climate variation was clarified by their appearance changes. Next, the climate variation of Japan was compared with those from MCAreconstruction studies on many areas in the world. Furthermore, MCA was examined by comparison with its simulation by global circulation model. The main results are as follows: 1) There remain many records on prayers for rain from the end of the first millennium to the beginning of the second millennium, which may show that it was time of warm and dry climate condition. 2) During MCA, there might have been a period of cool and moist condition around 900, specifically from 880 to 910. 3) A prevailing circulation like La Nina on the Pacific Ocean played an important role in MCA. 4) Around the Atlantic Ocean, the North Atlantic Oscillation was usually at its positive mode, and played an important role for the climate there
Genus statistics using the Delaunay tessellation field estimation method: (I) tests with the Millennium Simulation and the SDSS DR7
We study the topology of cosmic large-scale structure through the genus
statistics, using galaxy catalogues generated from the Millennium Simulation
and observational data from the latest Sloan Digital Sky Survey Data Release
(SDSS DR7). We introduce a new method for constructing galaxy density fields
and for measuring the genus statistics of its isodensity surfaces. It is based
on a Delaunay tessellation field estimation (DTFE) technique that allows the
definition of a piece-wise continuous density field and the exact computation
of the topology of its polygonal isodensity contours, without introducing any
free numerical parameter. Besides this new approach, we also employ the
traditional approaches of smoothing the galaxy distribution with a Gaussian of
fixed width, or by adaptively smoothing with a kernel that encloses a constant
number of neighboring galaxies. Our results show that the Delaunay-based method
extracts the largest amount of topological information. Unlike the traditional
approach for genus statistics, it is able to discriminate between the different
theoretical galaxy catalogues analyzed here, both in real space and in redshift
space, even though they are based on the same underlying simulation model. In
particular, the DTFE approach detects with high confidence a discrepancy of one
of the semi-analytic models studied here compared with the SDSS data, while the
other models are found to be consistent.Comment: 14 pages, 9 figures, accepted by Ap
Structure in the 3D Galaxy Distribution: I. Methods and Example Results
Three methods for detecting and characterizing structure in point data, such
as that generated by redshift surveys, are described: classification using
self-organizing maps, segmentation using Bayesian blocks, and density
estimation using adaptive kernels. The first two methods are new, and allow
detection and characterization of structures of arbitrary shape and at a wide
range of spatial scales. These methods should elucidate not only clusters, but
also the more distributed, wide-ranging filaments and sheets, and further allow
the possibility of detecting and characterizing an even broader class of
shapes. The methods are demonstrated and compared in application to three data
sets: a carefully selected volume-limited sample from the Sloan Digital Sky
Survey redshift data, a similarly selected sample from the Millennium
Simulation, and a set of points independently drawn from a uniform probability
distribution -- a so-called Poisson distribution. We demonstrate a few of the
many ways in which these methods elucidate large scale structure in the
distribution of galaxies in the nearby Universe.Comment: Re-posted after referee corrections along with partially re-written
introduction. 80 pages, 31 figures, ApJ in Press. For full sized figures
please download from: http://astrophysics.arc.nasa.gov/~mway/lss1.pd
Hubble flow variations as a test for inhomogeneous cosmology
Context. Backreactions from large-scale inhomogeneities may provide an
elegant explanation for the observed accelerated expansion of the universe
without the need to introduce dark energy. Aims. We propose a cosmological test
for a specific model of inhomogeneous cosmology, called timescape cosmology.
Using large-scale galaxy surveys such as SDSS and 2MRS, we test the variation
of expansion expected in the -CDM model versus a more generic
differential expansion using our own calibrations of bounds suggested by
timescape cosmology. Method. Our test measures the systematic variations of the
Hubble flow towards distant galaxies groups as a function of the matter
distribution in the lines of sight to those galaxy groups. We compare the
observed systematic variation of the Hubble flow to mock catalogues from the
Millennium Simulation in the case of the -CDM model, and a deformed
version of the same simulation that exhibits more pronounced differential
expansion. Results. We perform a series of statistical tests, ranging from
linear regressions to Kolmogorov-Smirnov tests, on the obtained data. They
consistently yield results preferring -CDM cosmology over our
approximated model of timescape cosmology. Conclusions. Our analysis of
observational data shows no evidence that the variation of expansion differs
from that of the standard -CDM model.Comment: 20 pages, 21 figures, accepted for publication in A&
Assembly Bias and Splashback in Galaxy Clusters
We use publicly available data for the Millennium Simulation to explore the
implications of the recent detection of assembly bias and splashback signatures
in a large sample of galaxy clusters. These were identified in the SDSS/DR8
photometric data by the redMaPPer algorithm and split into high- and
low-concentration subsamples based on the projected positions of cluster
members. We use simplified versions of these procedures to build cluster
samples of similar size from the simulation data. These match the observed
samples quite well and show similar assembly bias and splashback signals.
Previous theoretical work has found the logarithmic slope of halo density
profiles to have a well-defined minimum whose depth decreases and whose radius
increases with halo concentration. Projected profiles for the observed and
simulated cluster samples show trends with concentration which are opposite to
these predictions. In addition, for high-concentration clusters the minimum
slope occurs at significantly smaller radius than predicted. We show that these
discrepancies all reflect confusion between splashback features and features
imposed on the profiles by the cluster identification and concentration
estimation procedures. The strong apparent assembly bias is not reflected in
the three-dimensional distribution of matter around clusters. Rather it is a
consequence of the preferential contamination of low-concentration clusters by
foreground or background groups.Comment: 17 pages, 16 figures, 3 tables, accepted versio
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