4,111 research outputs found
Energy in the Home: Energy Usage in Agricultural Production
Agriculture, even in its most primitive state, includes activities related to the collection and storage of solar energy in a form that can be used to sustain life. Energy must be expended in terms of human labor, animal labor, and fossil energy used for products and machinery utilized by agriculture. Because fossil energy is in short supply, many people are concerned, and rightfully so, about the effect that restricted energy availability will have upon agriculture production
Investigating Perceptual Congruence Between Data and Display Dimensions in Sonification
The relationships between sounds and their perceived meaning and connotations are complex, making auditory perception an important factor to consider when designing sonification systems. Listeners often have a mental model of how a data variable should sound during sonification and this model is not considered in most data:sound mappings. This can lead to mappings that are difficult to use and can cause confusion. To investigate this issue, we conducted a magnitude estimation experiment to map how roughness, noise and pitch relate to the perceived magnitude of stress, error and danger. These parameters were chosen due to previous findings which suggest perceptual congruency between these auditory sensations and conceptual variables. Results from this experiment show that polarity and scaling preference are dependent on the data:sound mapping. This work provides polarity and scaling values that may be directly utilised by sonification designers to improve auditory displays in areas such as accessible and mobile computing, process-monitoring and biofeedback
Development of Prediction Relationships for Water Requirements with Irrigation Cooling
A model for predicting leaf temperatures during an off-on mist cycle is presented. The model uses a combination of energy budget and aerodynamic techniques. The model was tested for dry leaf temperature and evapotranspiration predictions using average hourly data from Arizona. The accuracy was good. It was also tested for dry leaf temperature predictions using two to three minute data with a widely varying net radiation. When reasonable values of stomatal resistance were used, the agreement was again good.
The model was tested for prediction of wet leaf temperature prediction with a ten minute on, fifty minute off mist irrigation cycle. The agreement was fair when using reasonable input parameters. The poorest predictions were during the mist on cycle
Energy in Agriculture: Energy for Greenhouses Part 1: Energy Conservation
The increased cost and scarcity of all fuels have affected the greenhouse owner as badly as any segment of industry. For some, crops have been damaged or lost. For others, it has reduced the margin of profit. Growers, manufacturers, suppliers, horticulturists, engineers and many others have studied the situation thoroughly in order to come up with viable solutions and alternatives for conserving fuel
Inexact Newton Dogleg Methods
The dogleg method is a classical trust-region technique for globalizing Newton\u27s method. While it is widely used in optimization, including large-scale optimization via truncated-Newton approaches, its implementation in general inexact Newton methods for systems of nonlinear equations can be problematic. In this paper, we first outline a very general dogleg method suitable for the general inexact Newton context and provide a global convergence analysis for it. We then discuss certain issues that may arise with the standard dogleg implementational strategy and propose modified strategies that address them. Newton-Krylov methods have provided important motivation for this work, and we conclude with a report on numerical experiments involving a Newton-GMRES dogleg method applied to benchmark CFD problems
Some Like It Hot: Linking Diffuse X-ray Luminosity, Baryonic Mass, and Star Formation Rate in Compact Groups of Galaxies
We present an analysis of the diffuse X-ray emission in 19 compact groups of
galaxies (CGs) observed with Chandra. The hottest, most X-ray luminous CGs
agree well with the galaxy cluster X-ray scaling relations in and
, even in CGs where the hot gas is associated with only the
brightest galaxy. Using Spitzer photometry, we compute stellar masses and
classify HCGs 19, 22, 40, and 42 and RSCGs 32, 44, and 86 as fossil groups
using a new definition for fossil systems that includes a broader range of
masses. We find that CGs with total stellar and HI masses
M are often X-ray luminous, while lower-mass CGs only sometimes exhibit
faint, localized X-ray emission. Additionally, we compare the diffuse X-ray
luminosity against both the total UV and 24 m star formation rates of each
CG and optical colors of the most massive galaxy in each of the CGs. The most
X-ray luminous CGs have the lowest star formation rates, likely because there
is no cold gas available for star formation, either because the majority of the
baryons in these CGs are in stars or the X-ray halo, or due to gas stripping
from the galaxies in CGs with hot halos. Finally, the optical colors that trace
recent star formation histories of the most massive group galaxies do not
correlate with the X-ray luminosities of the CGs, indicating that perhaps the
current state of the X-ray halos is independent of the recent history of
stellar mass assembly in the most massive galaxies.Comment: 20 pages, 7 figures, accepted for publication in Ap
Economic Comparison of Alternative Burley Tobacco Harvesting Practices by Computer
The computer model CATCH (Computer Analysis of Tobacco Cutting and Housing) was developed to provide the individual tobacco producer with management information concerning alternative methods of harvesting burley tobacco. CATCH utilizes specific producer in-puts to analyze 24 alternative burley production systems and presents up to four economic rankings containing costs, equipment and labor for each system. The economic rankings aid the producer in decision making with regard to his own operation
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