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11.
Gini F. Greco M. Farina F. 《IEEE transactions on aerospace and electronic systems》2004,40(3):1046-1059
This work presents a single-scan-processing approach to the problem of detecting and preclassifying a radar target that may belong to different target classes. The proposed method is based on a hybrid of the maximum a posteriori (MAP) and Neyman-Pearson (NP) criteria and guarantees the desired constant false alarm rate (CFAR) behavior. The targets are modeled as subspace random signals having zero mean and given covariance matrix. Different target classes are discriminated based on their different signal subspaces, which are specified by their corresponding projection matrices. Performance is investigated by means of numerical analysis and Monte Carlo simulation in terms of probability of false alarm, detection and classification; the extra signal-to-noise power ratio (SNR) necessary to classify once target detection has occurred is also derived. 相似文献
12.
Biological dosimetry in Russian and Italian astronauts. 总被引:1,自引:0,他引:1
O Greco M Durante G Gialanella G Grossi M Pugliese P Scampoli G Snigiryova G Obe 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,31(6):1495-1503
Large uncertainties are associated with estimates of equivalent dose and cancer risk for crews of long-term space missions. Biological dosimetry in astronauts is emerging as a useful technique to compare predictions based on quality factors and risk coefficients with actual measurements of biological damage in-flight. In the present study, chromosomal aberrations were analyzed in one Italian and eight Russian cosmonauts following missions of different duration on the MIR and the international space station (ISS). We used the technique of fluorescence in situ hybridization (FISH) to visualize translocations in chromosomes 1 and 2. In some cases, an increase in chromosome damage was observed after flight, but no correlation could be found between chromosome damage and flight history, in terms of number of flights at the time of sampling, duration in space and extra-vehicular activity. Blood samples from one of the cosmonauts were exposed in vitro to 6 MeV X-rays both before and after the flight. An enhancement in radiosensitivity induced by the spaceflight was observed. 相似文献