6,736 research outputs found

    Adaptive processing for LANDSAT data

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    Analytical and test results on the use of adaptive processing on LANDSAT data are presented. The Kalman filter was used as a framework to contain different adapting techniques. When LANDSAT MSS data were used all of the modifications made to the Kalman filter performed the functions for which they were designed. It was found that adaptive processing could provide compensation for incorrect signature means, within limits. However, if the data were such that poor classification accuracy would be obtained when the correct means were used, then adaptive processing would not improve the accuracy and might well lower it even further

    Information extraction techniques for multispectral scanner data

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    The applicability of recognition-processing procedures for multispectral scanner data from areas and conditions used for programming the recognition computers to other data from different areas viewed under different measurement conditions was studied. The reflective spectral region approximately 0.3 to 3.0 micrometers is considered. A potential application of such techniques is in conducting area surveys. Work in three general areas is reported: (1) Nature of sources of systematic variation in multispectral scanner radiation signals, (2) An investigation of various techniques for overcoming systematic variations in scanner data; (3) The use of decision rules based upon empirical distributions of scanner signals rather than upon the usually assumed multivariate normal (Gaussian) signal distributions

    Discrimination techniques employing both reflective and thermal multispectral signals

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    Recent improvements in remote sensor technology carry implications for data processing. Multispectral line scanners now exist that can collect data simultaneously and in registration in multiple channels at both reflective and thermal (emissive) wavelengths. Progress in dealing with two resultant recognition processing problems is discussed: (1) More channels mean higher processing costs; to combat these costs, a new and faster procedure for selecting subsets of channels has been developed. (2) Differences between thermal and reflective characteristics influence recognition processing; to illustrate the magnitude of these differences, some explanatory calculations are presented. Also introduced, is a different way to process multispectral scanner data, namely, radiation balance mapping and related procedures. Techniques and potentials are discussed and examples presented

    Flight investigation of the VFR and IFR landing approach characteristics and terminal area airspace requirements for a light STOL airplane

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    A flight research program was conducted to determine the terminal area instrument flight capabilities of a light STOL airplane. Simulated (hooded) instrument landing approaches were made using steep single-segment and two-segment glide slopes. A brief investigation was also made of the visual flight terminal area capabilities of the aircraft. The results indicated that the airplane could be flown on a 7 deg glide-slope ILS-type approach in still air with an adequate 3 deg margin for downward correction

    Four dimensional topological quantum field theory, Hopf categories, and the canonical bases

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    We propose a new mwthod of constructing 4D-TQFTs. The method uses a new type of algebraic structure called a Hopf Category. We also outline the construction of a family of Hopf categories related to the quantum groups, using the canonical bases.Comment: 38 page

    A study of physico-chemical interactions between Haemophilus influenzae type b and meningococcus group C conjugate vaccines.

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    Background: Haemophilus influenzae type b (Hib) and Meningococcal group C (MenC) conjugate vaccines, which protect against otitis media, bacteremia and invasive diseases, including pneumonia and meningitis, are attractive candidates for combination, since they are both administered to infants and children. A Hib-MenC combination booster at 12 mo has recently been introduced in the U.K. Objectives: To rule out the possibility for the individual vaccine components in a Hib-MenC combination to interact, rendering one or both of them less effective, this work assessed whether these two saccharide-protein conjugates, namely, Hib oligosaccharide-CRM197 (Cross-Reacting Material 197) and MenC-CRM197, interact in solution. Furthermore an evaluation of the size and integrity of the vaccines was also performed. Methods: HPLC Size-exclusion chromatography (SEC) with UV-adsorption and refractive index detection was performed with a phosphate and non-phosphate saline buffer to characterize the size of Hib and MenC conjugates as individual components or when combined. Results: Hib-CRM197 eluted significantly earlier than MenC-CRM197 in both phosphate-saline and MOPS-saline buffers on a TSK5000 PWXL column. When combined, there was no significant change in their elution. Refractive index monitoring showed no evidence of significant free saccharide or free protein. Conclusions: By size-exclusion chromatography and refractive index detection methods, there was no indication of degradation, and no evidence of significant associative interactions between Hib-CRM197 and MenC-CRM197 in saline-based buffers, pH 7.2. African Health Sciences Vol. 7 (4) 2007: pp.190-19

    Feature Extraction of Multispectral Data

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    A method is presented for feature extraction of multispectral scanner data. Non-training data is used to demonstrate the reduction in processing time that can be obtained by using feature extraction rather than feature selection

    PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos.

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    Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n=120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase) and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P≤0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P≤0.05) and PON1 192 (P≤0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal

    4-Dimensional BF Theory as a Topological Quantum Field Theory

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    Starting from a Lie group G whose Lie algebra is equipped with an invariant nondegenerate symmetric bilinear form, we show that 4-dimensional BF theory with cosmological term gives rise to a TQFT satisfying a generalization of Atiyah's axioms to manifolds equipped with principal G-bundle. The case G = GL(4,R) is especially interesting because every 4-manifold is then naturally equipped with a principal G-bundle, namely its frame bundle. In this case, the partition function of a compact oriented 4-manifold is the exponential of its signature, and the resulting TQFT is isomorphic to that constructed by Crane and Yetter using a state sum model, or by Broda using a surgery presentation of 4-manifolds.Comment: 15 pages in LaTe
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