Graphical Electromagnetic Computing (GRECO) is recognized as one of the most valuable methods of the RCS (Radar Cross Section) computation for the high frequency region. The method of GRECO and Monostatic bistatic Equ...Graphical Electromagnetic Computing (GRECO) is recognized as one of the most valuable methods of the RCS (Radar Cross Section) computation for the high frequency region. The method of GRECO and Monostatic bistatic Equivalence Theorem was used to calculate the bistatic RCS for moving targets in the high frequency region. Some computing examples are given to verify the validity of the method. Excellent agreement with the measured data indicates that the method has practical engineering value.展开更多
Graphical Electromagnetic Computing (GRECO) is one of the valuable methods for computing the radar cross section (RCS) of complex radar target in high frequency region. But there are some shortages of wedge detecting ...Graphical Electromagnetic Computing (GRECO) is one of the valuable methods for computing the radar cross section (RCS) of complex radar target in high frequency region. But there are some shortages of wedge detecting method in the original GRECO literature. A new method for collecting the edge pixels and wedge parameters is presented in this paper. An expression of edge diffraction field in the original GRECO literature is in error, the error-corrected formulas are derived by using method of equivalent edge currents (MEC) and physical theory of diffraction (PTD). Finally, the total RCS expression is given by physical optics (PO) and PTD method. The computing results are in close agreement with the measured data.展开更多
Objectives.- The GRECO study has collected data on pregnancies, regardless of their outcome, that occurred in women taking an oral contraceptive. Patients and methods.-The analysis concerned 551 women prospectively re...Objectives.- The GRECO study has collected data on pregnancies, regardless of their outcome, that occurred in women taking an oral contraceptive. Patients and methods.-The analysis concerned 551 women prospectively recruited in services of gynaecology or obstetrics, termination of pregnancy centres, family planning centres or consultations of gynaecology in France throughout 2002 and who were 12 weeks pregnant or less. Results.-Contraception used during the cycle of conception was an estroprogestative combination in 88% of cases, a microprogestative in 8.7% , a macroprogestative in 0.9% or another type of pill in 2.4% . Progestatives were levonorgestrel 59.0% , gestoden 17.2% , desogestrel 4.7% , norethisterone acetate 2.9% , norgestimate 1.8% , cyproterone acetate 2.0% , norgestrel 1.6% . When asked about the potential cause of the oral contraceptive failure, 76.9% of women reported events such as missed pills which were the most frequent cause of failure (60.8% of failures and 80.1% of events, 2.7 ± 2.7 missed pills), followed by vomiting and diarrhoea. 81.5% of women chose to terminate their pregnancy. Discussion and conclusion.-The GRECO study, despite its limitations (retrospective collection of missed pills data, declaratory data)-showed that missed pills, even once, were the most common reason for oral contraceptive failure. The most frequent decision was the termination of pregnancy.展开更多
Exploring Greco-Roman and Chinese classics reveals timeless insights for navigating modern crises.THE enduring wisdom of ancient Greece and China–often found in their classics–holds profound potential to address to...Exploring Greco-Roman and Chinese classics reveals timeless insights for navigating modern crises.THE enduring wisdom of ancient Greece and China–often found in their classics–holds profound potential to address today’s pressing global challenges.This vital connection was powerfully underscored at the Second Global Forum on Mutual Learning among Civilizations.展开更多
基金F oundation of National Key Laboratory of Electrom agnetic Environmental Research(0 0 js67.1.1.hk0 10 1)
文摘Graphical Electromagnetic Computing (GRECO) is recognized as one of the most valuable methods of the RCS (Radar Cross Section) computation for the high frequency region. The method of GRECO and Monostatic bistatic Equivalence Theorem was used to calculate the bistatic RCS for moving targets in the high frequency region. Some computing examples are given to verify the validity of the method. Excellent agreement with the measured data indicates that the method has practical engineering value.
文摘Graphical Electromagnetic Computing (GRECO) is one of the valuable methods for computing the radar cross section (RCS) of complex radar target in high frequency region. But there are some shortages of wedge detecting method in the original GRECO literature. A new method for collecting the edge pixels and wedge parameters is presented in this paper. An expression of edge diffraction field in the original GRECO literature is in error, the error-corrected formulas are derived by using method of equivalent edge currents (MEC) and physical theory of diffraction (PTD). Finally, the total RCS expression is given by physical optics (PO) and PTD method. The computing results are in close agreement with the measured data.
文摘Objectives.- The GRECO study has collected data on pregnancies, regardless of their outcome, that occurred in women taking an oral contraceptive. Patients and methods.-The analysis concerned 551 women prospectively recruited in services of gynaecology or obstetrics, termination of pregnancy centres, family planning centres or consultations of gynaecology in France throughout 2002 and who were 12 weeks pregnant or less. Results.-Contraception used during the cycle of conception was an estroprogestative combination in 88% of cases, a microprogestative in 8.7% , a macroprogestative in 0.9% or another type of pill in 2.4% . Progestatives were levonorgestrel 59.0% , gestoden 17.2% , desogestrel 4.7% , norethisterone acetate 2.9% , norgestimate 1.8% , cyproterone acetate 2.0% , norgestrel 1.6% . When asked about the potential cause of the oral contraceptive failure, 76.9% of women reported events such as missed pills which were the most frequent cause of failure (60.8% of failures and 80.1% of events, 2.7 ± 2.7 missed pills), followed by vomiting and diarrhoea. 81.5% of women chose to terminate their pregnancy. Discussion and conclusion.-The GRECO study, despite its limitations (retrospective collection of missed pills data, declaratory data)-showed that missed pills, even once, were the most common reason for oral contraceptive failure. The most frequent decision was the termination of pregnancy.
文摘Exploring Greco-Roman and Chinese classics reveals timeless insights for navigating modern crises.THE enduring wisdom of ancient Greece and China–often found in their classics–holds profound potential to address today’s pressing global challenges.This vital connection was powerfully underscored at the Second Global Forum on Mutual Learning among Civilizations.
