We introduce a general iterative scheme for angle-limited image reconstruction based on Landwebet＇s method. We derive a representation formula for this scheme and consequently establish its convergence conditions. Ou...We introduce a general iterative scheme for angle-limited image reconstruction based on Landwebet＇s method. We derive a representation formula for this scheme and consequently establish its convergence conditions. Our results suggest certain relaxation strategies for an accelerated convergence for angle-limited image reconstruction in L^2-norm comparing with alternative projection methods. The convolution-backprojection algorithm is given for this iterative process.展开更多
We study the existence of competitive equilibria when the excess demand function fails to satisfy the standard boundary behavior. We introduce alternative boundary conditions and we examine their role in proving the e...We study the existence of competitive equilibria when the excess demand function fails to satisfy the standard boundary behavior. We introduce alternative boundary conditions and we examine their role in proving the existence of strictly positive solutions to a system of non-linear equations (competitive equilibium prices). In addition, we slightly generalize a well-known theorem on the existence of maximal elements, and we unveil the link between the hypothesis of our theorem and one of the boundary conditions introduced in this work.展开更多
The two English versions of Lu Xun's stories, translated by Julia Lovell and the Rangs, are to be studied from the ecotranslatological perspective. A comparative study of the two English versions is made to figure...The two English versions of Lu Xun's stories, translated by Julia Lovell and the Rangs, are to be studied from the ecotranslatological perspective. A comparative study of the two English versions is made to figure out how the two translators linguistically and culturally make adaptive selections in the process of translation of Lu Xun's stories—In other words, how the eco-environment has greatly influenced the two translators' decisions to make adaptations and choices in linguistic and cultural aspects.The thesis discovers that the eco-environment has greatly influenced the process of translating Lu Xun's stories into English and eco-translatology is feasible to analyze the two translations, that both the Yangs and Lovell have offered successful translations by making adaptive selections and selective transformations. Therefore, neither of the two translations is superior or inferior to one another in different translational eco- environments. Hopefully, the thesis may enrich current researches on the Yang's and Lovell's translations and may be useful for the further study of applying eco-translatology to studies on other translators and their works.展开更多
基金Supported by the National Natural Science Foundation of China(No.60772041,60325101,60272018,60628102)the National Key Basic Research Special Foundation(2003CB716101),Ministry of Education(306017)Engineering Research Institute of Peking University,and Microsoft Research Asia.
文摘We introduce a general iterative scheme for angle-limited image reconstruction based on Landwebet＇s method. We derive a representation formula for this scheme and consequently establish its convergence conditions. Our results suggest certain relaxation strategies for an accelerated convergence for angle-limited image reconstruction in L^2-norm comparing with alternative projection methods. The convolution-backprojection algorithm is given for this iterative process.
文摘We study the existence of competitive equilibria when the excess demand function fails to satisfy the standard boundary behavior. We introduce alternative boundary conditions and we examine their role in proving the existence of strictly positive solutions to a system of non-linear equations (competitive equilibium prices). In addition, we slightly generalize a well-known theorem on the existence of maximal elements, and we unveil the link between the hypothesis of our theorem and one of the boundary conditions introduced in this work.
文摘The two English versions of Lu Xun's stories, translated by Julia Lovell and the Rangs, are to be studied from the ecotranslatological perspective. A comparative study of the two English versions is made to figure out how the two translators linguistically and culturally make adaptive selections in the process of translation of Lu Xun's stories—In other words, how the eco-environment has greatly influenced the two translators' decisions to make adaptations and choices in linguistic and cultural aspects.The thesis discovers that the eco-environment has greatly influenced the process of translating Lu Xun's stories into English and eco-translatology is feasible to analyze the two translations, that both the Yangs and Lovell have offered successful translations by making adaptive selections and selective transformations. Therefore, neither of the two translations is superior or inferior to one another in different translational eco- environments. Hopefully, the thesis may enrich current researches on the Yang's and Lovell's translations and may be useful for the further study of applying eco-translatology to studies on other translators and their works.
