The objective of this study is to improve the performance of semi-empirical radar backscatter models, which are mainly used in microwave remote sensing (Oh 1992, Oh 2004 and Dubois). The study is based on satellite an...The objective of this study is to improve the performance of semi-empirical radar backscatter models, which are mainly used in microwave remote sensing (Oh 1992, Oh 2004 and Dubois). The study is based on satellite and ground data collected on bare soil surfaces during the Multispectral Crop Monitoring experimental campaign of the CESBIO laboratory in 2010 over an agricultural region in southwestern France. The dataset covers a wide range of soil (viewing top soil moisture, surface roughness and texture) and satellite (at different frequencies: X-, C- and L-bands, and different incidence angles: 24.3° to 53.3°) configurations. The proposed methodology consists in identifying and correcting the residues of the models, depending on the surface properties (roughness, moisture, texture) and/or sensor characteristics (frequency, incidence angle). Finally, one model has been retained for each frequency domain. Results show that the enhancements of the models significantly increase the simulation performances. The coefficient of correlation increases of 23% in mean and the simulation errors (RMSE) are reduced to below 2 dB (at the X and C-bands) and to 1 dB at the L-band, compared to the initial models. At the X- and C-bands, the best performances of the modified models are provided by Dubois, whereas Oh 2004 is more suitable for the L-band (r is equal to 0.69, 0.65 and 0.85). Moreover, the modified models of Oh 1992 and 2004 and Dubois, developed in this study, offer a wider domain of validity than the initial formalism and increase the capabilities of retrieving the backscattering signal in view of applications of such approaches to stronglycontrasted agricultural surface states.展开更多
Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） w...Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing （control）, unplowed soil with dead vegetation cover （DVC）, unplowed soil with live vegetation cover （LVC） and unplowed soil with mixed vegetation cover （MVC）. DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive （2.16–3.05 t/hm2） compared with NERICA 8 （0.71–1.21 t/hm2）. Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.展开更多
A Streetcar Named Desire is regarded as one of the most successful masterpieces of Tennessee Williams. An outstanding feature of the play is the wide use of symbolism. Symbols can be seen everywhere and even all the s...A Streetcar Named Desire is regarded as one of the most successful masterpieces of Tennessee Williams. An outstanding feature of the play is the wide use of symbolism. Symbols can be seen everywhere and even all the symbols in the play are con nected with the protagonist Blanche DuBois. Williams applies symbolism throughout the play to make Blanche's tragic fate more vivid to the readers. Her tragic fate lies in her clinging to illusion, thus she is bound to be abandoned by the harsh reality. There fore, the thesis attempts to give a comprehensive analysis of some specific symbols: symbols of illusion represented by the Chinese paper lantern and a paper moon, and symbol of reality represented by the light to further illustrate Blanche's tragically symbolic fate.展开更多
在当代英语里,随时可见模糊词,imprecise expressions 或称 hedges,在许多背景中,出现一定数量的模糊词是必要的,甚至是必不可少的。因为,语言是人类交际的工具,而语言不是尽善尽美的,它不可能绝对精确地表达思想,而人们也不需要在交流...在当代英语里,随时可见模糊词,imprecise expressions 或称 hedges,在许多背景中,出现一定数量的模糊词是必要的,甚至是必不可少的。因为,语言是人类交际的工具,而语言不是尽善尽美的,它不可能绝对精确地表达思想,而人们也不需要在交流中绝对精确,英国语言学家 Lou Dubois 对一次国际生物医学会议发言稿作了一次有趣的统计,发现出现频率最高的模糊词是about,例如:about 10 per cent of the animals developed the virus,展开更多
Conjunction of two probability laws can give rise to a possibility law. Using two probability densities over two disjoint ranges, we can define the fuzzy mean of a fuzzy variable with the help of means two random vari...Conjunction of two probability laws can give rise to a possibility law. Using two probability densities over two disjoint ranges, we can define the fuzzy mean of a fuzzy variable with the help of means two random variables in two disjoint spaces.展开更多
文摘The objective of this study is to improve the performance of semi-empirical radar backscatter models, which are mainly used in microwave remote sensing (Oh 1992, Oh 2004 and Dubois). The study is based on satellite and ground data collected on bare soil surfaces during the Multispectral Crop Monitoring experimental campaign of the CESBIO laboratory in 2010 over an agricultural region in southwestern France. The dataset covers a wide range of soil (viewing top soil moisture, surface roughness and texture) and satellite (at different frequencies: X-, C- and L-bands, and different incidence angles: 24.3° to 53.3°) configurations. The proposed methodology consists in identifying and correcting the residues of the models, depending on the surface properties (roughness, moisture, texture) and/or sensor characteristics (frequency, incidence angle). Finally, one model has been retained for each frequency domain. Results show that the enhancements of the models significantly increase the simulation performances. The coefficient of correlation increases of 23% in mean and the simulation errors (RMSE) are reduced to below 2 dB (at the X and C-bands) and to 1 dB at the L-band, compared to the initial models. At the X- and C-bands, the best performances of the modified models are provided by Dubois, whereas Oh 2004 is more suitable for the L-band (r is equal to 0.69, 0.65 and 0.85). Moreover, the modified models of Oh 1992 and 2004 and Dubois, developed in this study, offer a wider domain of validity than the initial formalism and increase the capabilities of retrieving the backscattering signal in view of applications of such approaches to stronglycontrasted agricultural surface states.
基金the Laboratory of Biotechnology and Environment as well as the Food and Nutrition Research Center(CRAN)of Institute for Medical Research and Study of Medicinal Plants in Cameroon for their support
文摘Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing （control）, unplowed soil with dead vegetation cover （DVC）, unplowed soil with live vegetation cover （LVC） and unplowed soil with mixed vegetation cover （MVC）. DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive （2.16–3.05 t/hm2） compared with NERICA 8 （0.71–1.21 t/hm2）. Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.
文摘A Streetcar Named Desire is regarded as one of the most successful masterpieces of Tennessee Williams. An outstanding feature of the play is the wide use of symbolism. Symbols can be seen everywhere and even all the symbols in the play are con nected with the protagonist Blanche DuBois. Williams applies symbolism throughout the play to make Blanche's tragic fate more vivid to the readers. Her tragic fate lies in her clinging to illusion, thus she is bound to be abandoned by the harsh reality. There fore, the thesis attempts to give a comprehensive analysis of some specific symbols: symbols of illusion represented by the Chinese paper lantern and a paper moon, and symbol of reality represented by the light to further illustrate Blanche's tragically symbolic fate.
文摘在当代英语里,随时可见模糊词,imprecise expressions 或称 hedges,在许多背景中,出现一定数量的模糊词是必要的,甚至是必不可少的。因为,语言是人类交际的工具,而语言不是尽善尽美的,它不可能绝对精确地表达思想,而人们也不需要在交流中绝对精确,英国语言学家 Lou Dubois 对一次国际生物医学会议发言稿作了一次有趣的统计,发现出现频率最高的模糊词是about,例如:about 10 per cent of the animals developed the virus,
文摘Conjunction of two probability laws can give rise to a possibility law. Using two probability densities over two disjoint ranges, we can define the fuzzy mean of a fuzzy variable with the help of means two random variables in two disjoint spaces.
