30,344 research outputs found
FROM DATA TO INFORMATION: THE VALUE OF SAMPLING VS. SENSING SOIL DATA
A conceptual model is developed to measure the value of information from in-field soil sensing technologies as compared with grid and other soil sampling methods. Soil sensing offers greater spatial accuracy and the potential to apply inputs such as nitrogen fertilizer immediately, avoiding changes in nutrient status that occur with delays between soil sampling and fertilizer application. By contrast, soil sampling offers greater measurement accuracy, because it does not rely on proxy variables such as electrical conductivity to infer nutrient status. The average profitability and relative riskiness of soil sensing versus sampling depend upon 1) the trade-off between, on the one hand, the spatial and temporal accuracy of sensing and, on the other hand, the measurement accuracy of sampling, 2) the cost of data collection, and 3) input and product prices. Similar trade-offs govern the relative riskiness of sensing versus sampling.Farm Management,
TRADING POULTRY LITTER AT THE WATERSHED LEVEL : A GOAL FOCUSING APPLICATION
We explore the transfer of poultry litter among watersheds incorporating both economic characteristics (litter demand and supply) and environmental characteristics (vulnerability to phosphorus runoff, a major pollutant). A combination of techniques was employed: the Lemunyon-Gilbert P-Index model to determine watershed environmental vulnerability, GIS for land use coverages, and a goal focusing model (incorporating Saaty's eigen-value approach for penalty weight estimation) to identify optimal litter shipments among watersheds. Both primary and secondary data were used. The results should be useful to producers and policy makers in the study area and in other areas where poultry production is linked to water quality, and contribute to a more sustainable poultry sector.Livestock Production/Industries,
Smart Content Recognition from Images Using a Mixture of Convolutional Neural Networks
With rapid development of the Internet, web contents become huge. Most of the
websites are publicly available, and anyone can access the contents from
anywhere such as workplace, home and even schools. Nevertheless, not all the
web contents are appropriate for all users, especially children. An example of
these contents is pornography images which should be restricted to certain age
group. Besides, these images are not safe for work (NSFW) in which employees
should not be seen accessing such contents during work. Recently, convolutional
neural networks have been successfully applied to many computer vision
problems. Inspired by these successes, we propose a mixture of convolutional
neural networks for adult content recognition. Unlike other works, our method
is formulated on a weighted sum of multiple deep neural network models. The
weights of each CNN models are expressed as a linear regression problem learned
using Ordinary Least Squares (OLS). Experimental results demonstrate that the
proposed model outperforms both single CNN model and the average sum of CNN
models in adult content recognition.Comment: To be published in LNEE, Code: github.com/mundher/NSF
Applications of magnetic nanoparticles in biomedicine: the story so far
This Viewpoint relates to an article by Q A Pankhurst et al (2003 J. Phys. D: Appl. Phys. 36 R167) and was published as part of a series of Viewpoints celebrating 50 of the most influential papers published in the Journal of Physics series, which is celebrating its 50th anniversary
Successful Pathways to Undergraduate Completion
This article explores the critical factors that led to successful college completion for Black men. By focusing on success factors from Black male college graduates\u27 lived experiences, a roadmap to college success for this group may be shared with others to encourage increased degree attainment for this population. The lens for this study drew from Harper’s (2012) antideficit theory, which highlights students’ successes rather than problematic issues. A non-random approach of purposeful sampling from eight Black men from LinkedIn who had completed an undergraduate degree from a private, predominately White college in the southeast United States defined the sample size. Using one-on-one interviews, participants\u27 internal and external experiences leading up to and through college were revealed. The study will address their academic success in achieving undergraduate degree attainment. The first two categories, pre-college socialization and readiness and college achievement are the focus of this study
SITE-SPECIFIC VERSUS WHOLE-FIELD FERTILITY AND LIME MANAGEMENT IN MICHIGAN SOYBEANS AND CORN
Prior research into variable-rate application (VRA) of fertilizer nutrients has found profitability to be lacking in single nutrient applications to U.S. cereal crops. This study examines the yield and cost effects of VRA phosphorus, potassium and lime application on Michigan corn and soybean farm fields in 1998-2001. After four years, we found no yield gain from site-specific management, but statistically significant added costs, resulting in no gain in profitability. Contrary to results elsewhere, there was no evidence of enhanced spatial yield stability due to site-specific fertility management. Likewise, there was no evidence of decreased variability of phosphorus, potassium or lime after VRA treatment. Site-specific response functions and yield goals might also enhance the likelihood of profitable VRA in the future.Crop Production/Industries,
Thermomechanical properties of graphene: valence force field model approach
Using the valence force field model of Perebeinos and Tersoff [Phys. Rev. B
{\bf79}, 241409(R) (2009)], different energy modes of suspended graphene
subjected to tensile or compressive strain are studied. By carrying out Monte
Carlo simulations it is found that: i) only for small strains () the total energy is symmetrical in the strain, while it
behaves completely different beyond this threshold; ii) the important energy
contributions in stretching experiments are stretching, angle bending,
out-of-plane term and a term that provides repulsion against
misalignment; iii) in compressing experiments the two latter terms increase
rapidly and beyond the buckling transition stretching and bending energies are
found to be constant; iv) from stretching-compressing simulations we calculated
the Young modulus at room temperature 350\,N/m, which is in good
agreement with experimental results (340\,N/m) and with ab-initio
results [322-353]\,N/m; v) molar heat capacity is estimated to be
24.64\,J/molK which is comparable with the Dulong-Petit value,
i.e. 24.94\,J/molK and is almost independent of the strain; vi)
non-linear scaling properties are obtained from height-height correlations at
finite temperature; vii) the used valence force field model results in a
temperature independent bending modulus for graphene, and viii) the Gruneisen
parameter is estimated to be 0.64.Comment: 8 pages, 5 figures. To appear in J. Phys.: Condens. Matte
Infinite Charge Algebra of Gravitational Instantons
Using a formalism of minitwistors, we derive infinitely many conserved
charges for the -Toda equation which accounts for gravitational
instantons with a rotational Killing symmetry. These charges are shown to form
an infinite dimensional algebra through the Poisson bracket which is isomorphic
to two dimensional area preserving diffeomorphism with central extentions.Comment: 7 page
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