5,070 research outputs found

    LANDSAT 4 investigations of thematic mapper and multispectral scanner applications

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    Digital data analyses suggest the potential for TM data to provide improved land cover information with the mid-IR band being especially useful. Coefficients of variations for major land categories were greater for MSS data channels than for TM channels. Interpretation of black and white images of the six reflective TM bands indicates a strong interpreter preference for bands 5 and 7 for making distinctions in most of the classification categories that were addressed; however, a strong case can be made for a color composite containing visible, near-IR, and mid-IR spectral regions when distinguishing vegetation. A transformation from each red, green, blue color space into hue, intensity, and saturation space has potential for enhanced interpretability of TM color composite images. A perspective view transformation was demonstrated that could be useful for presently registered layers of spatial data in an oblique view format

    LANDSAT 4 investigation of thematic mapper and multispectral scanner applications

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    Six different band combinations of TM data were selected for evaluation by four experienced photointerpreters who were asked to rank the band combinations according to the ease with which the category of image feature designated for each set of combinations could be distinguished. There were four sets of combinations selected for each category of image feature. Scenes of Oklahoma City, Oklahoma and of the Sacramento Valley, California area were enlarged to 1:250,000 and 2 cm circular chips were cut from each print. A nonparametric rank order test was carried out on the data to determine if the interpreters found no difference among the band combinations in ranking for the designated categories. Kendall's coefficient of concordance (W) was calculated and the significance of the W value was determined by a chi-square test. A table summarizes the results of the evaluation and shows the rank order of band combinations indicated as valid by rejection of the null hypothesis

    Testing Multiband and Multidate Photography for Crop Identification

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    Procedures used and results derived in a series of prerequisite interpretation tests that were performed on multiband and multidate photography are described. The results of these quantitative tests led to the selection of what was considered to be the best combination of multiband and multidate photographs for use in the Maricopa County Survey

    Testing the usefulness of ERTS-1 imagery for inventorying wildland resources in northern California

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    The usefulness of ERTS-1 imagery for inventorying wildland resources in northern California is discussed. Studies are being conducted in two large wildland areas, namely, the Feather River Watershed and the Northern Coastal Zone. The 2.5 million-acre Feather River headwaters area in northern California is the keystone watershed for the California Water Project, one of the most extensive and ambitious water resource developments ever attempted. Consequently, accurate and timely information on the quantity, quality and distribution of timber, forage, water and recreational resources is of immediate importance to each public agency and private group managing this vast, but inaccessible, wildland area. The Northern Coastal Zone (consisting of the counties of Marin, Sonoma, Mendicino, Humbolt and Del Norte) is relatively rural, with an economy based on agriculture, timber, commercial fishing and tourism. However, it is expected that intensive resource use resulting from increasing population will soon become a serious problem unless wise land use planning is undertaken. Thus, this coastal region is particularly well suited to investigations of the ways in which ERTS-1 imagery and other supporting data may be used in conducting land use evaluations

    LANDSAT 4 investigations of Thematic Mapper and Multispectral Scanner applications

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    Interband detector noise was suppressed in the TIPS TM North Dakota data by median filtering. Procedures were developed to optimize the visual information content of thematic mapper data and evaluate the resulting photographic products by visual interpretation. A digital to analog TM transfer function was developed which properly placed the digital values on the most useable portion of film response curve. Utilizing the calculated minimum, mean, and maximum and the respective standard deviations of the bands from 50 sample scenes of TM data, look up tables were designed which resulted in acceptable photographic products. These products were evaluated by generation of color composites of selected band combinations using standard photo production procedures, and visual interpretation of scene features

    Effect of Prices, Traits and Market Structure on Corn Seeding Density

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    Recent agronomic research finds that economically optimal seeding densities have likely increased for many Midwestern corn farmers as a result of genetic improvements including new GM traits such as Bt corn and herbicide tolerance. We derive a per acre demand model for hybrid seed corn to examine the determinants of corn seeding densities and estimate the model using a large data set of individual farmer seed corn purchases. Current results identify factors other than prices affecting farmer corn seeding densities. Among these factors are the GM trait of the seed corn, measures of the local seed corn market structure, seed purchase source and intended end use. We interpret these effects in terms of information effects—farmers with more/better access to the latest agronomic research indicating that recommended seeding densities should be increased tend to plant corn at higher densities.hybrid seed corn, Bt corn, herbicide tolerance, Herfindahl index, corn borer, rootworm, hyperbolic yield model, Agribusiness, Crop Production/Industries, Farm Management, Industrial Organization, Production Economics, D2, D21, Q1, Q12,

    Effect of Imperceptible Vibratory Noise Applied to Wrist Skin On Fingertip Touch Evoked Potentials – An EEG Study

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    Random vibration applied to skin can change the sense of touch. Specifically, low amplitude white-noise vibration can improve fingertip touch perception. In fact, fingertip touch sensation can improve even when imperceptible random vibration is applied to other remote upper extremity areas such as wrist, dorsum of the hand, or forearm. As such, vibration can be used to manipulate sensory feedback and improve dexterity, particularly during neurological rehabilitation. Nonetheless, the neurological bases for remote vibration enhanced sensory feedback are yet poorly understood. This study examined how imperceptible random vibration applied to the wrist changes cortical activity for fingertip sensation. We measured somatosensory evoked potentials to assess peak-to-peak response to light touch of the index fingertip with applied wrist vibration versus without. We observed increased peak-to-peak somatosensory evoked potentials with wrist vibration, especially with increased amplitude of the later component for the somatosensory, motor, and premotor cortex with wrist vibration. These findings corroborate an enhanced cortical-level sensory response motivated by vibration. It is possible that the cortical modulation observed here is the result of the establishment of transient networks for improved perception

    Quantitative evaluation of multiband photographic techniques Final report

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    Quantitative evaluation of multiband photographic techniques using combination of black and white and color photo

    Bremsstrahlung in alpha-Decay Reexamined

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    A high-statistics measurement of bremsstrahlung emitted in the alpha decay of 210Po has been performed, which allows to follow the photon spectra up to energies of ~ 500 keV. The measured differential emission probability is in good agreement with our theoretical results obtained within the quasi classical approximation as well as with the exact quantum mechanical calculation. It is shown that due to the small effective electric dipole charge of the radiating system a significant interference between the electric dipole and quadrupole contributions occurs, which is altering substantially the angular correlation between the alpha particle and the emitted photon.Comment: 10 pages, 5 figures, v2: fix of small typo

    The novel properties of SF6_6 for directional dark matter experiments

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    SF6_{6} is an inert and electronegative gas that has a long history of use in high voltage insulation and numerous other industrial applications. Although SF6_{6} is used as a trace component to introduce stability in tracking chambers, its highly electronegative properties have limited its use in tracking detectors. In this work we present a series of measurements with SF6_{6} as the primary gas in a low pressure Time Projection Chamber (TPC), with a thick GEM used as the avalanche and readout device. The first results of an 55^{55}Fe energy spectrum in SF6_{6} are presented. Measurements of the mobility and longitudinal diffusion confirm the negative ion drift of SF6_{6}. However, the observed waveforms have a peculiar but interesting structure that indicates multiple drift species and a dependence on the reduced field (E/pE/p), as well as on the level of water vapor contamination. The discovery of a distinct secondary peak in the waveform, together with its identification and use for fiducializing events in the TPC, are also presented. Our measurements demonstrate that SF6_{6} is an ideal gas for directional dark matter detection. In particular, the high fluorine content is desirable for spin-dependent sensitivity, negative ion drift ensures low diffusion over large drift distances, and the multiple species of charge carriers allow for full detector fiducialization
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