147 research outputs found

    Crop identification technology assessment for remote sensing (CITARS). Volume 10: Interpretation of results

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    The CITARS was an experiment designed to quantitatively evaluate crop identification performance for corn and soybeans in various environments using a well-defined set of automatic data processing (ADP) techniques. Each technique was applied to data acquired to recognize and estimate proportions of corn and soybeans. The CITARS documentation summarizes, interprets, and discusses the crop identification performances obtained using (1) different ADP procedures; (2) a linear versus a quadratic classifier; (3) prior probability information derived from historic data; (4) local versus nonlocal recognition training statistics and the associated use of preprocessing; (5) multitemporal data; (6) classification bias and mixed pixels in proportion estimation; and (7) data with differnt site characteristics, including crop, soil, atmospheric effects, and stages of crop maturity

    Results from the Crop Identification Technology Assessment for Remote Sensing (CITARS) project

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    The author has identified the following significant results. It was found that several factors had a significant effect on crop identification performance: (1) crop maturity and site characteristics, (2) which of several different single date automatic data processing procedures was used for local recognition, (3) nonlocal recognition, both with and without preprocessing for the extension of recognition signatures, and (4) use of multidate data. It also was found that classification accuracy for field center pixels was not a reliable indicator of proportion estimation performance for whole areas, that bias was present in proportion estimates, and that training data and procedures strongly influenced crop identification performance

    Results from the Crop Identification Technology Assessment for Remote Sensing

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    CITARS was an experiment designed to quantitatively evaluate crop identification performance for corn and soybeans in various environments using a well-defined set of automatic data techniques. These techniques differed mainly by the procedure used to obtain signatures from training data (e.g., clustering) and by the method of classification employed (e.g., linear or quadratic decision boundaries and equal or unequal class weights). Each technique was applied to LANDSAT-1 data acquired over six Indiana and Illinois test sites throughout the growing season in an attempt to recognize and estimate proportions of corn and soybeans using both local and non-local (i.e. extended) training statistics. As a result of these analyses the significance of factors which contribute to classification performance was determined. In this paper the results of (1) the differences indifferent ADP procedures; (2) the linear vs. quadratic classifier; (3) the use in classification Of prior probability information derived from historic data: (4) differences in local and non-local recognition and the associated use of preprocessing: (5) the use of multitemporal data: (6) the effects Of classification bias and mixed pixels in proportion estimation: (7) the effects of site characteristics including crop, soil, and atmospheric effects: and (8) the effects of crop maturity are presented and discussed

    The ATLAS SCT grounding and shielding concept and implementation

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    This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the specifications for the construction of the detector, a detailed description of all its different elements is given. These include civil engineering infrastructures, a huge ultra-high vacuum (UHV) chamber (about 6000 cubic metres), all of the optical components, including high quality mirrors and their seismic isolating suspensions, all of the electronics required to control the interferometer and for signal detection. The expected performances of these different elements are given, leading to an overall sensitivity curve as a function of the incoming gravitational wave frequency. This description represents the detector as built and used in the first data-taking runs. Improvements in different parts have been and continue to be performed, leading to better sensitivities. These will be detailed in a forthcoming paper

    ATLAS silicon module assembly and qualification tests at IFIC Valencia

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    ATLAS experiment, designed to probe the interactions of particles emerging out of proton proton collisions at energies of up to 14 TeV, will assume operation at the Large Hadron Collider (LHC) at CERN in 2007. This paper discusses the assembly and the quality control tests of forward detector modules for the ATLAS silicon microstrip detector assembled at the Instituto de Fisica Corpuscular (IFIC) in Valencia. The construction and testing procedures are outlined and the laboratory equipment is briefly described. Emphasis is given on the module quality achieved in terms of mechanical and electrical stability.Comment: 23 pages, 38 EPS figures, uses JINST LaTeX clas

    Forward and reverse genetics of rapid-cycling Brassica oleracea

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    Abstract Seeds of rapid-cycling Brassica oleracea were mutagenized with the chemical mutagen, ethylmethane sulfonate. The reverse genetics technique, TILLING, was used on a sample population of 1,000 plants, to determine the mutation proWle. The spectrum and frequency of mutations induced by ethylmethane sulfonate was similar to that seen in other diploid species such as Arabidopsis thaliana. These data indicate that the mutagenesis was eVective and demonstrate that TILLING represents an eYcient reverse genetic technique in B. oleracea that will become more valuable as increasing genomic sequence data become available for this species. The extensive duplication in the B. oleracea genome is believed to result in the genetic redundancy that has been important for the evolution of morphological diversity seen in today's B. oleracea crops (broccoli, Brussels sprouts, cauliXower, cabbage, kale and kohlrabi). However, our forward genetic screens identiWed 120 mutants in which some aspect of development was aVected. Some of these lines have been characterized genetically and in the majority of these, the mutant trait segregates as a recessive allele aVecting a single locus. One dominant mutation (curly leaves) and one semi-dominant mutation (dwarf-like) were also identiWed. Allelism tests of two groups of mutants (glossy and dwarf) revealed that for some loci, multiple independent alleles have been identiWed. These data indicate that, despite genetic redundancy, mutation of many individual loci in B. oleracea results in distinct phenotypes

    The new ALEPH Silicon Vertex Detector

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    The ALEPH collaboration, in view of the importance of effective vertex detection for the Higgs boson search at LEP 2, decided to upgrade the previous vertex detector. Main changes were an increased length (±20 cm), a higher granularity for rφ view (50 ”m), a new preamplifier (MX7 rad hard chip), a polymide (upilex) fan-out on z side to carry the signals from the strips to the front-end electronics outside the fiducial region reducing consequently the passive material in the central region by a factor of two. The detector, the running experience and its performance will be described

    The new ALEPH Silicon Vertex Detector

    No full text
    The ALEPH collaboration, in view of the importance of effective vertex detection for the Higgs boson search at LEP 2, decided to upgrade the previous vertex detector. Main changes were an increased length (±20 cm), a higher granularity for rφ view (50 ”m), a new preamplifier (MX7 rad hard chip), a polymide (upilex) fan-out on z side to carry the signals from the strips to the front-end electronics outside the fiducial region reducing consequently the passive material in the central region by a factor of two. The detector, the running experience and its performance will be described

    The ATLAS SCT Optoelectronics and the Associated Electrical Services

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    The requirements for the optical links of the ATLAS SCT are described. From the individual detector modules to the first patch panel, the electrical services are integrated with the optical links to aid in mechanical design, construction and integration. The system architecture and critical elements of the system are described. The optical links for the ATLAS SCT have been assembled and mounted onto the carbon fibre support structures. The performance of the system as measured during QA is summarised and compared to the final performance obtained after mounting modules onto the support structures
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