4,443 research outputs found
Quality and Seasonal Fluctuation of Headwater Streams in Western Montana
Paper published as Bulletin 38 in the UM Bulletin Forestry Series.https://scholarworks.umt.edu/umforestrybulletin/1022/thumbnail.jp
Effects of Mowing Frequency on the Yield and Protein Content of Several Grasses Grown in Pure Stands
This paper presents results of a five-year experiment conducted at the Agricultural Experiment Station, Lincoln, Nebraska, on the adaptation, yield, and quality of several grasses subjected to different frequencies of harvest as a means of determining their forage value
Introduced Forage Grasses for Nebraska
This circular presents illustrations, descriptions and recommended usage of fourteen introduced cultivated grasses that are worthy of practical consideration in Nebraska. Most of them can easily be identified by comparing plant specimens with the illustrations and descriptions. This circular has been prepared for use by farmers, county agricultural agents, teachers and others who are interested in our most important grasses. Station Circular 59 contains information and illustrations of the more common native perennial grasses of Nebraska
Generalized survival in equilibrium step fluctuations
We investigate the dynamics of a generalized survival probability
defined with respect to an arbitrary reference level (rather than the
average) in equilibrium step fluctuations. The exponential decay at large time
scales of the generalized survival probability is numerically analyzed.
is shown to exhibit simple scaling behavior as a function of
system-size , sampling time , and the reference level . The
generalized survival time scale, , associated with is shown
to decay exponentially as a function of .Comment: 4 pages, 2 figure
Bostonia. Volume 16
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
First measurements of the flux integral with the NIST-4 watt balance
In early 2014, construction of a new watt balance, named NIST-4, has started
at the National Institute of Standards and Technology (NIST). In a watt
balance, the gravitational force of an unknown mass is compensated by an
electromagnetic force produced by a coil in a magnet system. The
electromagnetic force depends on the current in the coil and the magnetic flux
integral. Most watt balances feature an additional calibration mode, referred
to as velocity mode, which allows one to measure the magnetic flux integral to
high precision. In this article we describe first measurements of the flux
integral in the new watt balance. We introduce measurement and data analysis
techniques to assess the quality of the measurements and the adverse effects of
vibrations on the instrument.Comment: 7 pages, 8 figures, accepted for publication in IEEE Trans. Instrum.
Meas. This Journal can be found online at
http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=1
Diagnosing students' difficulties in learning mathematics
This study considers the results of a diagnostic test of student difficulty and contrasts the difference in performance between the lower attaining quartile and the higher quartile. It illustrates a difference in qualitative thinking between those who succeed and those who fail in mathematics, illustrating a theory that those who fail are performing a more difficult type of mathematics (coordinating procedures) than those who succeed (manipulating concepts). Students who have to coordinate or reverse processes in time will encounter far greater difficulty than those who can manipulate symbols in a flexible way. The consequences of such a dichotomy and implications for remediation are then considered
First-Order Logic Theorem Proving and Model Building via Approximation and Instantiation
In this paper we consider first-order logic theorem proving and model
building via approximation and instantiation. Given a clause set we propose its
approximation into a simplified clause set where satisfiability is decidable.
The approximation extends the signature and preserves unsatisfiability: if the
simplified clause set is satisfiable in some model, so is the original clause
set in the same model interpreted in the original signature. A refutation
generated by a decision procedure on the simplified clause set can then either
be lifted to a refutation in the original clause set, or it guides a refinement
excluding the previously found unliftable refutation. This way the approach is
refutationally complete. We do not step-wise lift refutations but conflicting
cores, finite unsatisfiable clause sets representing at least one refutation.
The approach is dual to many existing approaches in the literature because our
approximation preserves unsatisfiability
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