In Côte d’Ivoire, the recurring and unregulated use of bushfires, which cause ecological damage, presents a pressing concern for the custodians of protected areas. This study aims to enhance our comprehension of...In Côte d’Ivoire, the recurring and unregulated use of bushfires, which cause ecological damage, presents a pressing concern for the custodians of protected areas. This study aims to enhance our comprehension of the dynamics of burnt areas within the Abokouamékro Wildlife Reserve (AWR) by employing the analysis of spectral indices derived from satellite imagery. The research methodology began with the calculation of mean indices and their corresponding spectral sub-indices, including NDVI, SAVI, NDWI, NDMI, BAI, NBR, TCW, TCG, and TCB, utilizing data from the Sentinel-2A satellite image dated January 17, 2022. Subsequently, a fuzzy classification model was applied to these various indices and sub-indices, guided by the degree of membership α, with the goal of effectively distinguishing between burned and unburned areas. Following the classification, the accuracies of the classified indices and sub-indices were validated using the coordinates of 100 data points collected within the AWR through GPS technology. The results revealed that the overall accuracy of all indices and sub-indices declines as the degree of membership α decreases from 1 to 0. Among the mean spectral indices, NDVI-mean, SAVI-mean, NDMI-mean exhibited the highest overall accuracies, achieving 97%, 95%, and 90%, respectively. These results closely mirrored those obtained by sub-indices using band 8 (NDVI-B8, SAVI-B8, and NDMI-B8), which yield respective overall accuracies of 93%, 92%, and 89%. At a degree of membership α = 1, the estimated burned areas for the most effective indices encompassed 2144.38 hectares for NDVI-mean, 1932.14 hectares for mean SAVI-mean, and 4947.13 hectares for mean NDMI-mean. A prospective approach involving the amalgamation of these three indices could have the potential to yield improved outcomes. This study could be a substantial contribution to the discrimination of bushfires in Côte d’Ivoire.展开更多
In the light of the mapping between[0,1]matrixes of fab-ric weaves,we establish in this paper a mathematical modelfor fabric weave design- One type of non- associative al-gebra composed of 7 basic transformations in a...In the light of the mapping between[0,1]matrixes of fab-ric weaves,we establish in this paper a mathematical modelfor fabric weave design- One type of non- associative al-gebra composed of 7 basic transformations in a 2- elementfield.In view of practice,we expand the generative set ofmapping of this matematical model to cover the generaltransformation methods in traditional weave design.Takingthe algorethm of" Kronecker product" as an example,wefurthermore illustrate applied potentialities of the generativeset of mapping in the CAD of fabic weaves.展开更多
A whole lot of Westerners living in Beijing should thank their lucky stars for the day Kro stopped going to class. Kro, whose real name is Olav Kristoffer Bauer （he acquired his nick name in second grade during a les...A whole lot of Westerners living in Beijing should thank their lucky stars for the day Kro stopped going to class. Kro, whose real name is Olav Kristoffer Bauer （he acquired his nick name in second grade during a lesson about Cro-Magnon man）, runs one of the best American-style pizzerias in town （and that＇s an official CIB editorial stance）.展开更多
文摘In Côte d’Ivoire, the recurring and unregulated use of bushfires, which cause ecological damage, presents a pressing concern for the custodians of protected areas. This study aims to enhance our comprehension of the dynamics of burnt areas within the Abokouamékro Wildlife Reserve (AWR) by employing the analysis of spectral indices derived from satellite imagery. The research methodology began with the calculation of mean indices and their corresponding spectral sub-indices, including NDVI, SAVI, NDWI, NDMI, BAI, NBR, TCW, TCG, and TCB, utilizing data from the Sentinel-2A satellite image dated January 17, 2022. Subsequently, a fuzzy classification model was applied to these various indices and sub-indices, guided by the degree of membership α, with the goal of effectively distinguishing between burned and unburned areas. Following the classification, the accuracies of the classified indices and sub-indices were validated using the coordinates of 100 data points collected within the AWR through GPS technology. The results revealed that the overall accuracy of all indices and sub-indices declines as the degree of membership α decreases from 1 to 0. Among the mean spectral indices, NDVI-mean, SAVI-mean, NDMI-mean exhibited the highest overall accuracies, achieving 97%, 95%, and 90%, respectively. These results closely mirrored those obtained by sub-indices using band 8 (NDVI-B8, SAVI-B8, and NDMI-B8), which yield respective overall accuracies of 93%, 92%, and 89%. At a degree of membership α = 1, the estimated burned areas for the most effective indices encompassed 2144.38 hectares for NDVI-mean, 1932.14 hectares for mean SAVI-mean, and 4947.13 hectares for mean NDMI-mean. A prospective approach involving the amalgamation of these three indices could have the potential to yield improved outcomes. This study could be a substantial contribution to the discrimination of bushfires in Côte d’Ivoire.
文摘In the light of the mapping between[0,1]matrixes of fab-ric weaves,we establish in this paper a mathematical modelfor fabric weave design- One type of non- associative al-gebra composed of 7 basic transformations in a 2- elementfield.In view of practice,we expand the generative set ofmapping of this matematical model to cover the generaltransformation methods in traditional weave design.Takingthe algorethm of" Kronecker product" as an example,wefurthermore illustrate applied potentialities of the generativeset of mapping in the CAD of fabic weaves.
文摘A whole lot of Westerners living in Beijing should thank their lucky stars for the day Kro stopped going to class. Kro, whose real name is Olav Kristoffer Bauer （he acquired his nick name in second grade during a lesson about Cro-Magnon man）, runs one of the best American-style pizzerias in town （and that＇s an official CIB editorial stance）.
