1,854 research outputs found
A study of atmospheric effects on pattern recognition devices
The author has identified the following significant results. ERTS-1 imagery can be applied in the broadscale assessment of forest resources as a supplement to aerial photography and field survey. There was no application to inventory of crop and pasture diseases mainly because of poor quality and low resolution, and unreliability of image acquisition. Inventory of soil erosion was satisfactory in humid eastern New South Wales, but not in semi-arid areas. Patterns of snow cover, areas of water in natural and artificial water bodies, extent of bushfires, and location of coastal mobile sand bodies were readily apparent. ERTS-1 imagery was judged to be a valuable addition to conventional techniques of regional small scale geological mapping. ERTS data was successfully used to map flooding and flood progression. The imagery was found suitable for mapping at 1:1,000,000 scale both on the mainland and in Antarctica, but did not meet accuracy specifications for 1:250,000 mapping
Investigation of Techniques for Inventorying Forested Regions. Volume 1: Reflectance Modeling and Empirical Multispectral Analysis of Forest Canopy Components
The author has identified the following significant results. Effects of vegetation density on overall canopy reflectance differed dramatically, depending on spectral band, base material, and vegetation type. For example, reflectance changes caused by variations in vegetation density were hardly apparant for a simulated burned surface in LANDSAT band 5, while large changes occurred in band 7. When increasing densities of tree overstory were placed over understories, intermediate to dense overstories effectively masked the understories and dominated the spectral signatures. Dramatic changes in reflectance occurred for canopies placed on a number of varying topographic positions. Such changes were seen to result in the spectral overlap of some nonforested with densely forested situations
Efficiency Mapping and Determination of Reliability, Resiliency and Vulnerability of Atmospheric Water Generators in the United States
Atmospheric Water Generators (AWG) extract water from the air using one of three available technologies: refrigeration, sorption, and fog harvesting. A refrigeration device works like a dehumidifier and works best in conditions above 60% relative humidity. A sorption device utilizes a desiccant to extract the water vapor from the air and works in very low humidity levels. A fog harvesting device utilizes a mesh to capture the water vapor from the air and requires 100% relative humidity. In this research, I analyze two refrigeration-based devices and one sorption-based device and their efficacy in providing supplemental water supply. Due to climatological and technological constraints, not all regions in the world would see the same water production from an AWG as production is driven by high relative humidity and temperature. This climatological reliance also subjects them to dramatic changes in performance depending on the season. By using previously established hydrologic performance indicators and weather data for the United States, I determine the year-round efficiency metrics of the typical residential sized refrigeration AWG. Using these efficiency metrics, I also determined the reliability, resiliency, and vulnerability of the AWG to produce potable water seasonally across the United States. By evaluating several different devices and mapping the efficiency on the country-scale, this research determines the regional efficacy in adopting AWG technology to supplement potable water supply. This study was the first to look at the performance of atmospheric water generators with such granularity, as well as comparing specific devices predicted water production output to each other and over the years and calculating their Hashimoto’s hydrological indicators
The influence of multispectral scanner spatial resolution on forest feature classification
Inappropriate spatial resolution and corresponding data processing techniques may be major causes for non-optimal forest classification results frequently achieved from multispectral scanner (MSS) data. Procedures and results of empirical investigations are studied to determine the influence of MSS spatial resolution on the classification of forest features into levels of detail or hierarchies of information that might be appropriate for nationwide forest surveys and detailed in-place inventories. Two somewhat different, but related studies are presented. The first consisted of establishing classification accuracies for several hierarchies of features as spatial resolution was progressively coarsened from (2 meters) squared to (64 meters) squared. The second investigated the capabilities for specialized processing techniques to improve upon the results of conventional processing procedures for both coarse and fine resolution data
Radio light curves during the passage of cloud G2 near Sgr A*
We calculate radio light curves produced by the bow shock that is likely to
form in front of the G2 cloud when it penetrates the accretion disk of Sgr A*.
The shock acceleration of the radio-emitting electrons is captured
self-consistently by means of first-principles particle-in-cell simulations. We
show that the radio luminosity is expected to reach maximum in early 2013,
roughly a month after the bow shock crosses the orbit pericenter. We estimate
the peak radio flux at 1.4 GHz to be 1.4 - 22 Jy depending on the assumed orbit
orientation and parameters. We show that the most promising frequencies for
radio observations are in the 0.1<nu<1 GHz range, for which the bow shock
emission will be much stronger than the intrinsic radio flux for all the models
considered.Comment: 15 pages, 10 figures, accepted for publication in MNRA
Analysis of recreational land using Skylab data
The author has identified the following significant results. S192 data collected on 5 August 1973 were processed by computer to produce a classification map of a part of the Gratiot-Saginaw State Game Area in south central Michigan. A 10-category map was prepared of an area consisting of diverse terrain types, including forests, wetlands, brush, and herbaceous vegetation. An accuracy check indicated that 54% of the pixels were correctly recognized. When these ten scene classes were consolidated to a 5-category map, the accuracy increased to 72%. S190 A, S190 B, and S192 data can be used for regional surveys of existing and potential recreation sites, for delineation of open space, and for preliminary evaluation of geographically extensive sites
Biblijne i koraniczne argumenty na rzecz zrównoważonych zachowań wobec natury
We observe an ever-increasing role of religions in fighting the environmental crisis. Religious argumentation has enormous potential to shape the attitudes of the followers of religions. Applying this argumentation can signifi-cantly change attitudes towards the environment in the majority of the human population. Christianity and Islam together have over 4 billion followers. Here, we present seven common Biblical and Quranic issues that are key to human attitudes to nature. The conducted analysis leads to a surprising conclusion. The Bible and Quran similarly encourage their followers to build harmonious relations with the natural world.Obserwujemy coraz większą rolę religii w walce z kryzysem ekologicznym. Argumentacja religijna ma ogromny potencjał kształtowania postaw wyznawców religii. Zastosowanie tej argumentacji może znacząco zmienić postawy wobec środowiska u większości populacji ludzkiej. Chrześcijaństwo i islam razem mają ponad 4 miliardy wyznawców. W tej pracy przedstawiamy siedem powszechnych zagadnień biblijnych i koranicznych, które są kluczowe dla stosunku człowieka do natury. Przeprowadzona analiza prowadzi do zaskakującego wniosku. Biblia i Koran w podobny sposób zachęcają swoich wyznawców do budowania harmonijnych relacji ze światem przyrody
Magnetic properties of GaMnAs single layers and GaInMnAs superlattices investigated at low temperature and high magnetic field
Magnetotransport properties of GaMnAs single layers and InGaMnAs/InGaAs
superlattice structures were investigated at temperatures from 4 K to 300 K and
magnetic fields up to 23 T to study the influence of carriers confinement
through different structures. Both single layers and superlattice structures
show paramagnetic-to-ferromagnetic phase transition. In GaMnAs/InGaAs
superlattice beside the Curie temperature (Tc ~ 40 K), a new phase transition
is observed close to 13 K.Comment: 8 pages, 5 figures, Proceedings of the XXXII International School on
the Physics of Semiconducting Compounds, Jaszowiec 2003, Polan
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