21,426 research outputs found
Analysis and Conservation of Native Forests at Kessler Mountain Fayetteville, Arkansas
Kessler Mountain in Fayetteville Arkansas has long been recognized for its beauty and natural resources. Parts of Kessler Mountain have been homesteaded and developed in the past, but most of the mountain has remained relatively undisturbed. The planned development of over 4,000 housing units to cover Kessler Mountain stimulated controversy and consideration of other management alternatives. A twist of fate involving an economic recession, a dedicated group of outdoor recreation enthusiasts, and environmental conservationists led to the permanent protection of 384 acres in the Kessler Mountain Regional Park. To help evaluate the natural resources at Kessler Mountain, forest composition, structure, and tree age were measured at two old growth forest parcels on Kessler Mountain. Forest understory and overstory were surveyed and increment cores were collected from select overstory trees. The overstory of the post oak (Quercus stellata) site (Site A) was dominated by post oak and northern red oak (Quercus rubra). The understory was dominated by northern red oak and black locust (Robnia pseudoacacia). The oldest post oak trees at the post oak site were in the 250 to 300-year-old age class based on dendrochronological analysis of core samples. The overstory of the chinkapin oak (Quercus muehlenbergii) site (Site B) was dominated by sugar maple (Acer saccharum var. saccharum) and chinkapin oak. The understory was dominated by eastern red cedar (Juniperous virginiana) and northern red oak. The oldest chinkapin oak trees at Site B were in the 200 to 250-year-old age class. The data suggest that chinkapin oak and post oak are currently not regenerating at rates necessary to maintain long term dominance in the canopy at these particular study sites on Kessler Mountain. As more land is conserved in the region significant planning and funding need to be dedicated to proper management of these lands to maintain biodiversity and healthy forests
A boost for the EW SUSY hunt: monojet-like search for compressed sleptons at LHC14 with 100 fb^-1
Current Large Hadron Collider (LHC) analyses are blind to compressed
supersymmetry (SUSY) models with sleptons near the lightest super partner (LSP)
in mass:
GeV. We present a search sensitive to the very compressed range using the channel with soft same-flavor leptons and one hard jet from initial state
radiation ( GeV). The sleptons recoil against the jet
boosting them and their decay products, making the leptons detectable and
providing substantial missing transverse momentum. We use the kinematic
variable along with a different-flavor control region to reduce
the large standard model backgrounds and control systematic uncertainty. We
find the analysis should allow LHC14 with to search for
degenerate left-handed selectrons and smuons in the compressed region up to
GeV. In addition, it should be sensitive to
GeV for the very challenging case of
auto-concealed SUSY, in which left-handed sleptons decay to the Kaluza-Klein
tower of a modulino LSP which lives in extra dimensions. In both the
compressed spectrum and auto-concealed SUSY scenarios this analysis will need
more data to improve on LEP2 limits for right-handed sleptons due to their
smaller cross sections.Comment: 15 pages, 3 figures, updated citations in v
On Thin Air Reads: Towards an Event Structures Model of Relaxed Memory
To model relaxed memory, we propose confusion-free event structures over an
alphabet with a justification relation. Executions are modeled by justified
configurations, where every read event has a justifying write event.
Justification alone is too weak a criterion, since it allows cycles of the kind
that result in so-called thin-air reads. Acyclic justification forbids such
cycles, but also invalidates event reorderings that result from compiler
optimizations and dynamic instruction scheduling. We propose the notion of
well-justification, based on a game-like model, which strikes a middle ground.
We show that well-justified configurations satisfy the DRF theorem: in any
data-race free program, all well-justified configurations are sequentially
consistent. We also show that rely-guarantee reasoning is sound for
well-justified configurations, but not for justified configurations. For
example, well-justified configurations are type-safe.
Well-justification allows many, but not all reorderings performed by relaxed
memory. In particular, it fails to validate the commutation of independent
reads. We discuss variations that may address these shortcomings
SIGIR: scholar vs. scholars' interpretation
Google Scholar allows researchers to search through a free and extensive source of information on scientific publications. In this paper we show that within the limited context of SIGIR proceedings, the rankings created by Google Scholar are both significantly different and very negatively correlated with those of domain experts
Query independent measures of annotation and annotator impact
The modern-day web-user plays a far more active role in the creation of content for the web as a whole. In this paper we present Annoby, a free-text annotation system built to give users a more interactive experience of the events of the Rugby World Cup 2007. Annotations can be used for query-independent ranking of both the annotations and the original recorded video footage (or documents) which has been annotated, based on the social interactions of a community of users. We present two algorithms, AuthorRank and MessageRank, designed to take advantage of these interactions so as to provide a means of ranking documents by their social impact
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