4,896 research outputs found
Elements of Design for Containers and Solutions in the LinBox Library
We describe in this paper new design techniques used in the \cpp exact linear
algebra library \linbox, intended to make the library safer and easier to use,
while keeping it generic and efficient. First, we review the new simplified
structure for containers, based on our \emph{founding scope allocation} model.
We explain design choices and their impact on coding: unification of our matrix
classes, clearer model for matrices and submatrices, \etc Then we present a
variation of the \emph{strategy} design pattern that is comprised of a
controller--plugin system: the controller (solution) chooses among plug-ins
(algorithms) that always call back the controllers for subtasks. We give
examples using the solution \mul. Finally we present a benchmark architecture
that serves two purposes: Providing the user with easier ways to produce
graphs; Creating a framework for automatically tuning the library and
supporting regression testing.Comment: 8 pages, 4th International Congress on Mathematical Software, Seoul :
Korea, Republic Of (2014
Do we need a zero pure time preference or the risk of climate catastrophes to justify a 2C global warming target ?
This paper confronts the wide political support for the 2C objective of global increase in temperature, reaffirmed in Copenhagen, with the consistent set of hypotheses on which it relies. It explains why neither an almost zero pure time preference nor concerns about catastrophic damages in case of uncontrolled global warming are prerequisites for policy decisions preserving the possibility of meeting a 2C target. It rests on an optimal stochastic control model balancing the costs and benefits of climate policies resolved sequentially in order to account for the arrival of new information (the RESPONSE model). This model describes the optimal abatement pathways for 2,304 worldviews, combining hypotheses about growth rates, baseline emissions, abatement costs, pure time preference, damages, and climate sensitivity. It shows that 26 percent of the worldviews selecting the 2C target are not characterized by one of the extreme assumptions about pure time preference or climate change damages.Climate Change Mitigation and Green House Gases,Climate Change Economics,Science of Climate Change,Global Environment Facility,Environment and Energy Efficiency
Social studies in West German schools
Includes bibliographical references and index.The authors describe the process and results of the implementation of a social sciences curriculum in German schools after World War II, and compares this curriculum with that of American schools.Authority and the unpolitical German : The cultural context of German "politische Bildung" -- The contemporary political-educational context -- The school system -- The new "politische Bildung" : The curriculum plans of the Social Democratic Party -- The curriculum -- Instructional goals -- Methods, materials, and classroom tone -- Education of teachers -- Questions for social-studies educators -- Glossary of German terms.Digitized at the University of Missouri--Columbia MU Libraries Digitization Lab in 2013. Digitized at 600 dpi with Zeutschel, OS 15000 scanner. Access copy, available in MOspace, is 400 dpi, grayscale
Translating standard process models to BPEL
Standardisation of languages in the field of business process management has long been an elusive goal. Recently though, consensus has built around one process implementation language, namely BPEL, and two fundamentally similar process modelling notations, namely UML Activity Diagram (UML AD) and BPMN. This paper presents a technique for generating BPEL code from process models expressed in a core subset of BPMN and UML AD. This model-to-code translation is a necessary ingredient to the emergence of model-driven business process development environments based on these standards. The proposed translation has been implemented as an open source tool
Near-infrared spatially resolved spectroscopy of (136108) Haumea's multiple system
The transneptunian region of the solar system is populated by a wide variety
of icy bodies showing great diversity. The dwarf planet (136108) Haumea is
among the largest TNOs and displays a highly elongated shape and hosts two
moons, covered with crystalline water ice like Hamuea. Haumea is also the
largest member of the sole TNO family known to date. A catastrophic collision
is likely responsible for its unique characteristics. We report here on the
analysis of a new set of observations of Haumea obtained with SINFONI at the
ESO VLT. Combined with previous data, and using light-curve measurements in the
optical and far infrared, we carry out a rotationally resolved spectroscopic
study of the surface of Haumea. We describe the physical characteristics of the
crystalline water ice present on the surface of Haumea for both regions, in and
out of the Dark Red Spot (DRS), and analyze the differences obtained for each
individual spectrum. The presence of crystalline water ice is confirmed over
more than half of the surface of Haumea. Our measurements of the average
spectral slope confirm the redder characteristic of the spot region. Detailed
analysis of the crystalline water-ice absorption bands do not show significant
differences between the DRS and the remaining part of the surface. We also
present the results of applying Hapke modeling to our data set. The best
spectral fit is obtained with a mixture of crystalline water ice (grain sizes
smaller than 60 micron) with a few percent of amorphous carbon. Improvements to
the fit are obtained by adding ~10% of amorphous water ice. Additionally, we
used the IFU-reconstructed images to measure the relative astrometric position
of the largest satellite Hi`iaka and determine its orbital elements. An orbital
solution was computed with our genetic-based algorithm GENOID and our results
are in full agreement with recent results.Comment: Accepted for publication in A&
Extreme AO Observations of Two Triple Asteroid Systems with SPHERE
We present the discovery of a new satellite of asteroid (130) Elektra -
S/2014 (130) 1 - in differential imaging and in integral field spectroscopy
data over multiple epochs obtained with SPHERE/VLT. This new (second) moonlet
of Elektra is about 2 km across, on an eccentric orbit and about 500 km away
from the primary. For a comparative study, we also observed another triple
asteroid system (93) Minerva. For both systems, component-resolved reflectance
spectra of the satellites and primary were obtained simultaneously. No
significant spectral difference was observed between the satellites and the
primary for either triple system. We find that the moonlets in both systems are
more likely to have been created by sub-disruptive impacts as opposed to having
been captured.Comment: 8 pages, 4 figures, 1 table, accepted to be published in the
Astrophysical Journal Letter
Estimating Peak Demand for Beach Parking Spaces
The United States Army Corps of Engineers planning guidance stipulates that in order for local beach communities to qualify for Federal cost share funds for Hurricane and Storm Damage Reduction beach renourishment projects, the community must provide public beach access and parking to satisfy peak demand. This study presents a method for estimating peak demand for beach parking spaces in the presence of parking constraints. A Tobit regression model is developed to estimate the number of parking spaces that would be necessary to meet unconstrained demand on a given percentage of peak demand days. For example, the model can be used to estimate the number of parking spaces that would be adequate to meet peak demand on 90% of peak parking days. The Tobit model provides a promising framework for estimating peak parking demand under constrained parking conditions, a situation that characterizes most beach communities.
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