349 research outputs found
Did Spending Cuts During the Great Recession Really Cause Student Outcomes to Decline?
Jackson, Wigger, and Xiong (2020a, JWX) provide evidence that education spending reductions following the Great Recession had widespread negative impacts on student achievement and attainment. This paper describes our process of duplicating JWX and highlights a variety of tests we employ to investigate the nature and robustness of the relationship between school spending reductions and student outcomes. Though per-pupil expenditures undoubtedly shifted downward due to the Great Recession, contrary to JWX, our findings indicate there is not a clear and compelling story about the impact of those reductions on student achievement. Moreover, we find that the relationship between K-12 spending and college-going rates is likely confounded with contemporaneous higher education funding trends. While we believe that K-12 spending reductions may have negative impacts on student outcomes, our results suggest that estimating generalizable causal effects remains a significant challenge
The Effect of School District Consolidation on Student Achievement: Evidence from Arkansas
School district consolidation is one of the most widespread education reforms of the last century, but surprisingly little research has directly investigated its effectiveness. To examine the impact of consolidation on student achievement, this study takes advantage of a policy that requires the consolidation of all Arkansas school districts with enrollment of fewer than 350 students for two consecutive school years. Using a regression discontinuity model, we find that consolidation has either null or small positive impacts on student achievement in math and English Language Arts (ELA). We do not find evidence that consolidation in Arkansas results in positive economies of scale, either by reducing overall cost or allowing for a greater share of resources to be spent in the classroom
Advanced Placement Course-Taking and ACT Test Outcomes in Arkansas
Since 2008, Arkansas has sought to dramatically increase the number of students participating in Advanced Placement (AP) classes. This program, which allows students to access college -level content while still enrolled in high school, has been linked to higher student achievement and attainment. This brief shares recent research from the Office for Education Policy investigating whether students who take AP courses demonstrate better college readiness and examines how these trends vary for different demographic and socioeconomic groups in the state
Does the Timing of Money Matter? A Case Study of the Arkansas Academic Challenge Scholarship
In 2008, legislation passed to dramatically increase a small merit-aid program—the Arkansas Academic Challenge Scholarship (ACS) using newly created funds from the Arkansas Lottery. The expansion of this program created three unique groups of students eligible for funding: Prior Recipients, Traditional Recipients, and Current Achievers. Recent research from the Department of Education Reform at the University of Arkansas investigates how the scholarship influenced student outcomes for Current Achievers, who were already enrolled in college at the time the money was distributed. The study also investigates whether GPA, credit accumulation, and graduation rates vary depending on which year of college students were in when they received funding
Dipole-Deformed Bound States and Heterotic Kodaira Surfaces
We study a particular N = 1 confining gauge theory with fundamental flavors
realised as seven branes in the background of wrapped five branes on a rigid
two-cycle of a non-trivial global geometry. In parts of the moduli space, the
five branes form bound states with the seven branes. We show that in this
regime the local supergravity solution is surprisingly tractable, even though
the background topology is non-trivial. New effects such as dipole deformations
may be studied in detail, including the full backreactions. Performing the
dipole deformations in other ways leads to different warped local geometries.
In the dual heterotic picture, which is locally given by a C* fibration over a
Kodaira surface, we study details of the geometry and the construction of
bundles. We also point out the existence of certain exotic bundles in our
framework.Comment: 40 pages, 3 .eps figures, Harvma
The Arecibo Legacy Fast ALFA Survey: III. HI Source Catalog of the Northern Virgo Cluster Region
We present the first installment of HI sources extracted from the Arecibo
Legacy Fast ALFA (ALFALFA) extragalactic survey, initiated in 2005. Sources
have been extracted from 3-D spectral data cubes and then examined
interactively to yield global HI parameters. A total of 730 HI detections are
catalogued within the solid angle 11h44m < R.A.(J2000) < 14h00m and +12deg <
Dec.(J2000) < +16deg, and redshift range -1600 \kms < cz < 18000 \kms. In
comparison, the HI Parkes All-Sky Survey (HIPASS) detected 40 HI signals in the
same region. Optical counterparts are assigned via examination of digital
optical imaging databases. ALFALFA HI detections are reported for three
distinct classes of signals: (a) detections, typically with S/N > 6.5; (b) high
velocity clouds in the Milky Way or its periphery; and (c) signals of lower S/N
(to ~ 4.5) which coincide spatially with an optical object of known similar
redshift. Although this region of the sky has been heavily surveyed by previous
targeted observations based on optical flux-- or size-- limited samples, 69% of
the extracted sources are newly reported HI detections. The resultant
positional accuracy of HI sources is 20" (median). The median redshift of the
sample is ~7000 \kms and its distribution reflects the known local large scale
structure including the Virgo cluster. Several extended HI features are found
in the vicinity of the Virgo cluster. A small percentage (6%) of HI detections
have no identifiable optical counterpart, more than half of which are high
velocity clouds in the Milky Way vicinity; the remaining 17 objects do not
appear connected to or associated with any known galaxy.Comment: Astronomical Journal, in pres
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
The LSST Dark Energy Science Collaboration (DESC) Science Requirements Document
The Large Synoptic Survey Telescope (LSST) Dark Energy Science Collaboration
(DESC) will use five cosmological probes: galaxy clusters, large scale
structure, supernovae, strong lensing, and weak lensing. This Science
Requirements Document (SRD) quantifies the expected dark energy constraining
power of these probes individually and together, with conservative assumptions
about analysis methodology and follow-up observational resources based on our
current understanding and the expected evolution within the field in the coming
years. We then define requirements on analysis pipelines that will enable us to
achieve our goal of carrying out a dark energy analysis consistent with the
Dark Energy Task Force definition of a Stage IV dark energy experiment. This is
achieved through a forecasting process that incorporates the flowdown to
detailed requirements on multiple sources of systematic uncertainty. Future
versions of this document will include evolution in our software capabilities
and analysis plans along with updates to the LSST survey strategy.Comment: 32 pages + 60 pages of appendices. This is v1 of the DESC SRD, an
internal collaboration document that is being made public and is not planned
for submission to a journal. Data products for reproducing key plots are
available at the LSST DESC Zenodo community,
https://zenodo.org/communities/lsst-desc; see "Executive Summary and User
Guide" for instructions on how to use and cite those product
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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